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Sample records for three-axis thrust-vectoring system

  1. Thrust-vector control of a three-axis stabilized upper-stage rocket with fuel slosh dynamics

    NASA Astrophysics Data System (ADS)

    Rubio Hervas, Jaime; Reyhanoglu, Mahmut

    2014-05-01

    This paper studies the thrust vector control problem for an upper-stage rocket with fuel slosh dynamics. The dynamics of a three-axis stabilized spacecraft with a single partially-filled fuel tank are formulated and the sloshing propellant is modeled as a multi-mass-spring system, where the oscillation frequencies of the mass-spring elements represent the prominent sloshing modes. The equations of motion are expressed in terms of the three-dimensional spacecraft translational velocity vector, the attitude, the angular velocity, and the internal coordinates representing the slosh modes. A Lyapunov-based nonlinear feedback control law is proposed to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes characterizing the internal dynamics. A simulation example is included to illustrate the effectiveness of the control law.

  2. Experimental investigations of thrust vectoring systems for VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Rolls, L. S.; Aoyagi, K.

    1977-01-01

    This paper presents a summary of two technology programs sponsored by NASA to investigate the characteristics of two thrust vectoring schemes for V/STOL aircraft. The operational capability of the VTOL aircraft is dependent on maximum utilization of the installed thrust in both the cruise and powered lift modes of flight. An effective thrust vectoring system on the cruise propulsion unit is therefore essential to provide maximum payload in hover and STOL plus minimum specific fuel consumption in loiter and cruise. Introducing a high by-pass ratio fan system, augmenting the gas generator thrust, as the propulsion system for VTOL aircraft places increased significance on the performance of the relatively short coupled thrust vectoring systems. The two programs discussed herein include both large-scale and small-scale tests of a vectoring hood system with a vented, internal-lip and swivel nozzle systems. These tests indicated that a satisfactory thrust vectoring system can be developed.

  3. Design of an ion thruster movable grid thrust vectoring system

    NASA Astrophysics Data System (ADS)

    Kural, Aleksander; Leveque, Nicolas; Welch, Chris; Wolanski, Piotr

    2004-08-01

    Several reasons justify the development of an ion propulsion system thrust vectoring system. Spacecraft launched to date have used ion thrusters mounted on gimbals to control the thrust vector within a range of about 5. Such devices have large mass and dimensions, hence the need exists for a more compact system, preferably mounted within the thruster itself. Since the 1970s several thrust vectoring systems have been developed, with the translatable accelerator grid electrode being considered the most promising. Laboratory models of this system have already been built and successfully tested, but there is still room for improvement in their mechanical design. This work aims to investigate possibilities of refining the design of such movable grid thrust vectoring systems. Two grid suspension designs and three types of actuators were evaluated. The actuators examined were a micro electromechanical system, a NanoMuscle shape memory alloy actuator and a piezoelectric driver. Criteria used for choosing the best system included mechanical simplicity (use of the fewest mechanical parts), accuracy, power consumption and behaviour in space conditions. Designs of systems using these actuators are proposed. In addition, a mission to Mercury using the system with piezoelectric drivers has been modelled and its performance presented.

  4. Space transportation system solid rocket booster thrust vector control system

    NASA Technical Reports Server (NTRS)

    Verble, A. J., Jr.; Mccool, A. A.; Potter, J. H.

    1979-01-01

    The Solid Rocket Booster, Thrust Vector Control (TVC) system was designed in accordance with the following requirements: self-contained power supply, fail-safe operation, 20 flight uses after exposure to seawater landings, optimized cost, and component interchangeability. Trade studies were performed which led to the selection of a recirculating hydraulic system powered by Auxiliary Power Units (APU) which drive the hydraulic actuators and gimbal the solid rocket motor nozzle. Other approaches for the system design were studied in arriving at the recirculating hydraulic system powered by an APU. These systems must withstand the imposed environment and be usable for a minimum of 20 Space Transportation System flights with a minimum of refurbishment. The TVC system has completed the major portion of qualification and verification tests and is prepared to be cleared for the first Shuttle flight (STS-1). Substantiation data will include analytical and test data.

  5. Space Transportation System solid rocket booster thrust vector control system

    NASA Technical Reports Server (NTRS)

    Verble, A. J., Jr.; Mccool, A. A.; Potter, J. H.

    1980-01-01

    The Solid Rocket Booster, Thrust Vector Control (TVC) system was designed in accordance with the following requirements: self-contained power supply, failsafe operation, 20 flight uses after exposure to seawater landings, optimized cost, and component interchangeability. Trade studies were performed which led to the selection of a recirculating hydraulic system powered by Auxiliary Power Units (APU) which drive the hydraulic actuators and gimbal the solid rocket motor nozzle. Other approaches for the system design were studied in arriving at the recirculating hydraulic system powered by an APU. These systems must withstand the imposed environment and be usable for a minimum of 20 Space Transportation System flights with a minimum of refurbishment. The TVC system completed the required qualification and verification tests and is certified for the intended application. Substantiation data include analytical and test data.

  6. Three axis velocity probe system

    DOEpatents

    Fasching, George E. (Morgantown, WV); Smith, Jr., Nelson S. (Morgantown, WV); Utt, Carroll E. (Morgantown, WV)

    1992-01-01

    A three-axis velocity probe system for determining three-axis positional velocities of small particles in fluidized bed systems and similar applications. This system has a sensor head containing four closely-spaced sensing electrodes of small wires that have flat ends to establish a two axis plane, e.g. a X-Y plane. Two of the sensing electrodes are positioned along one of the axes and the other two are along the second axis. These four sensing electrodes are surrounded by a guard electrode, and the outer surface is a ground electrode and support member for the sensing head. The electrodes are excited by, for example, sinusoidal voltage having a peak-to-peak voltage of up to 500 volts at a frequency of 2 MHz. Capacitive currents flowing between the four sensing electrodes and the ground electrode are influenced by the presence and position of a particle passing the sensing head. Any changes in these currents due to the particle are amplified and synchronously detected to produce positional signal values that are converted to digital form. Using these digital forms and two values of time permit generation of values of the three components of the particle vector and thus the total velocity vector.

  7. Three axis attitude control system

    NASA Technical Reports Server (NTRS)

    Studer, Philip A. (Inventor)

    1988-01-01

    A three-axis attitude control system for an orbiting body comprised of a motor driven flywheel supported by a torque producing active magnetic bearing is described. Free rotation of the flywheel is provided about its central axis and together with limited angular torsional deflections of the flywheel about two orthogonal axes which are perpendicular to the central axis. The motor comprises an electronically commutated DC motor, while the magnetic bearing comprises a radially servoed permanent magnet biased magnetic bearing capable of producing cross-axis torques on the flywheel. Three body attitude sensors for pitch, yaw and roll generate respective command signals along three mutually orthogonal axes (x, y, z) which are coupled to circuit means for energizing a set of control coils for producing torques about two of the axes (x and y) and speed control of the flywheel about the third (z) axis. An energy recovery system, which is operative during motor deceleration, is also included which permits the use of a high-speed motor to perform effectively as a reactive wheel suspended in the magnetic bearing.

  8. Developmental Testing of Electric Thrust Vector Control Systems for Manned Launch Vehicle Applications

    NASA Technical Reports Server (NTRS)

    Bates, Lisa B.; Young, David T.

    2012-01-01

    This paper describes recent developmental testing to verify the integration of a developmental electromechanical actuator (EMA) with high rate lithium ion batteries and a cross platform extensible controller. Testing was performed at the Thrust Vector Control Research, Development and Qualification Laboratory at the NASA George C. Marshall Space Flight Center. Electric Thrust Vector Control (ETVC) systems like the EMA may significantly reduce recurring launch costs and complexity compared to heritage systems. Electric actuator mechanisms and control requirements across dissimilar platforms are also discussed with a focus on the similarities leveraged and differences overcome by the cross platform extensible common controller architecture.

  9. Three-axis asymmetric radiation detector system

    DOEpatents

    Martini, Mario Pierangelo (Oak Ridge, TN); Gedcke, Dale A. (Oak Ridge, TN); Raudorf, Thomas W. (Oak Ridge, TN); Sangsingkeow, Pat (Knoxville, TN)

    2000-01-01

    A three-axis radiation detection system whose inner and outer electrodes are shaped and positioned so that the shortest path between any point on the inner electrode and the outer electrode is a different length whereby the rise time of a pulse derived from a detected radiation event can uniquely define the azimuthal and radial position of that event, and the outer electrode is divided into a plurality of segments in the longitudinal axial direction for locating the axial location of a radiation detection event occurring in the diode.

  10. The digital autopilot for thrust vector control of the Shuttle Orbital maneuvering system

    NASA Technical Reports Server (NTRS)

    Penchuk, A.; Croopnick, S.

    1982-01-01

    This paper describes the requirements for and the design, development and performance of the digital autopilots (DAPs) for thrust vector control, utilizing the orbital maneuvering system (OMS) of the Space Shuttle Orbiter. The hardware and software requirements which caused the design to assume its current form are described. Also, the design synthesis, which considered rigid body stability margins, bending and slosh stabilization, guidance loop compensation, off-nominal performance and hardware and software limitations is presented. The performance of the OMS control system is summarized utilizing flight data from the first three Space Transportation System (STS) flights.

  11. Preliminary design study of a lateral-directional control system using thrust vectoring

    NASA Technical Reports Server (NTRS)

    Lallman, F. J.

    1985-01-01

    A preliminary design of a lateral-directional control system for a fighter airplane capable of controlled operation at extreme angles of attack is developed. The subject airplane is representative of a modern twin-engine high-performance jet fighter, is equipped with ailerons, rudder, and independent horizontal-tail surfaces. Idealized bidirectional thrust-vectoring engine nozzles are appended to the mathematic model of the airplane to provide additional control moments. Optimal schedules for lateral and directional pseudo control variables are calculated. Use of pseudo controls results in coordinated operation of the aerodynamic and thrust-vectoring controls with minimum coupling between the lateral and directional airplane dynamics. Linear quadratic regulator designs are used to specify a preliminary flight control system to improve the stability and response characteristics of the airplane. Simulated responses to step pilot control inputs are stable and well behaved. For lateral stick deflections, peak stability axis roll rates are between 1.25 and 1.60 rad/sec over an angle-of-attack range of 10 deg to 70 deg. For rudder pedal deflections, the roll rates accompanying the sideslip responses can be arrested by small lateral stick motions.

  12. Solid rocket thrust vector control

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Thrust vector control systems that superimpose a side force on the motor thrust, steering being achieved by the side force causing a moment about the vehicle center of gravity are described. A brief review of thrust vector control systems is presented, and two systems, flexible joint and liquid injection, are treated in detail. Treatment of the flexible-joint thrust vector control system is limited to the design of the flexible joint and its insulation against hot motor gases. Treatment of the liquid injection thrust vector control system is limited to discussion of the injectant, valves, piping, storage tanks, and pressurization system; no evaluation is presented of the nozzle except for (1) the effect of the injectant and erosion at the injection port and (2) the effect of injection on pressure distribution within the nozzle.

  13. Implementation of the Orbital Maneuvering Systems Engine and Thrust Vector Control for the European Service Module

    NASA Technical Reports Server (NTRS)

    Millard, Jon

    2014-01-01

    The European Space Agency (ESA) has entered into a partnership with the National Aeronautics and Space Administration (NASA) to develop and provide the Service Module (SM) for the Orion Multipurpose Crew Vehicle (MPCV) Program. The European Service Module (ESM) will provide main engine thrust by utilizing the Space Shuttle Program Orbital Maneuvering System Engine (OMS-E). Thrust Vector Control (TVC) of the OMS-E will be provided by the Orbital Maneuvering System (OMS) TVC, also used during the Space Shuttle Program. NASA will be providing the OMS-E and OMS TVC to ESA as Government Furnished Equipment (GFE) to integrate into the ESM. This presentation will describe the OMS-E and OMS TVC and discuss the implementation of the hardware for the ESM.

  14. Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

  15. Investigation of advanced thrust vectoring exhaust systems for high speed propulsive lift

    NASA Technical Reports Server (NTRS)

    Hutchison, R. A.; Petit, J. E.; Capone, F. J.; Whittaker, R. W.

    1980-01-01

    The paper presents the results of a wind tunnel investigation conducted at the NASA-Langley research center to determine thrust vectoring/induced lift characteristics of advanced exhaust nozzle concepts installed on a supersonic tactical airplane model. Specific test objectives include: (1) basic aerodynamics of a wing body configuration, (2) investigation of induced lift effects, (3) evaluation of static and forward speed performance, and (4) the effectiveness of a canard surface to trim thrust vectoring/induced lift forces and moments.

  16. A static investigation of the thrust vectoring system of the F/A-18 high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Mason, Mary L.; Capone, Francis J.; Asbury, Scott C.

    1992-01-01

    A static (wind-off) test was conducted in the static test facility of the Langley 16-foot Transonic Tunnel to evaluate the vectoring capability and isolated nozzle performance of the proposed thrust vectoring system of the F/A-18 high alpha research vehicle (HARV). The thrust vectoring system consisted of three asymmetrically spaced vanes installed externally on a single test nozzle. Two nozzle configurations were tested: A maximum afterburner-power nozzle and a military-power nozzle. Vane size and vane actuation geometry were investigated, and an extensive matrix of vane deflection angles was tested. The nozzle pressure ratios ranged from two to six. The results indicate that the three vane system can successfully generate multiaxis (pitch and yaw) thrust vectoring. However, large resultant vector angles incurred large thrust losses. Resultant vector angles were always lower than the vane deflection angles. The maximum thrust vectoring angles achieved for the military-power nozzle were larger than the angles achieved for the maximum afterburner-power nozzle.

  17. Results of solar electric thrust vector control system design, development and tests

    NASA Technical Reports Server (NTRS)

    Fleischer, G. E.

    1973-01-01

    Efforts to develop and test a thrust vector control system TVCS for a solar-energy-powered ion engine array are described. The results of solar electric propulsion system technology (SEPST) III real-time tests of present versions of TVCS hardware in combination with computer-simulated attitude dynamics of a solar electric multi-mission spacecraft (SEMMS) Phase A-type spacecraft configuration are summarized. Work on an improved solar electric TVCS, based on the use of a state estimator, is described. SEPST III tests of TVCS hardware have generally proved successful and dynamic response of the system is close to predictions. It appears that, if TVCS electronic hardware can be effectively replaced by control computer software, a significant advantage in control capability and flexibility can be gained in future developmental testing, with practical implications for flight systems as well. Finally, it is concluded from computer simulations that TVCS stabilization using rate estimation promises a substantial performance improvement over the present design.

  18. Application of Diagnostic Analysis Tools to the Ares I Thrust Vector Control System

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Melcher, Kevin J.; Chicatelli, Amy K.; Johnson, Stephen B.

    2010-01-01

    The NASA Ares I Crew Launch Vehicle is being designed to support missions to the International Space Station (ISS), to the Moon, and beyond. The Ares I is undergoing design and development utilizing commercial-off-the-shelf tools and hardware when applicable, along with cutting edge launch technologies and state-of-the-art design and development. In support of the vehicle s design and development, the Ares Functional Fault Analysis group was tasked to develop an Ares Vehicle Diagnostic Model (AVDM) and to demonstrate the capability of that model to support failure-related analyses and design integration. One important component of the AVDM is the Upper Stage (US) Thrust Vector Control (TVC) diagnostic model-a representation of the failure space of the US TVC subsystem. This paper first presents an overview of the AVDM, its development approach, and the software used to implement the model and conduct diagnostic analysis. It then uses the US TVC diagnostic model to illustrate details of the development, implementation, analysis, and verification processes. Finally, the paper describes how the AVDM model can impact both design and ground operations, and how some of these impacts are being realized during discussions of US TVC diagnostic analyses with US TVC designers.

  19. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Astrophysics Data System (ADS)

    Huff, Ronald G.

    1989-02-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  20. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.

    1989-01-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  1. Aerodynamics of thrust vectoring

    NASA Technical Reports Server (NTRS)

    Tseng, J. B.; Lan, C. Edward

    1989-01-01

    Thrust vectoring as a means to enhance maneuverability and aerodynamic performane of a tactical aircraft is discussed. This concept usually involves the installation of a multifunction nozzle. With the nozzle, the engine thrust can be changed in direction without changing the attitude of the aircraft. Change in the direction of thrust induces a significant change in the aerodynamic forces on the aircraft. Therefore, this device can be used for lift-augmenting as well as stability and control purposes. When the thrust is deflected in the longitudinal direction, the lift force and the pitching stability can be manipulated, while the yawing stability can be controlled by directing the thrust in the lateral direction.

  2. Miniature image guided three-axis scanning and positioning system

    NASA Astrophysics Data System (ADS)

    Avirovik, Dragan; Dave, Digant; Priya, Shashank

    2012-04-01

    We have developed a high precision three axes scanning and positioning system for integration with Multifunctional Image Guided Surgical (MIGS) Platform. The stage integrates three main components: an optical coherence tomography (OCT) probe, laser scalpel and suction cup. The requirements for this stage were to provide scanning area of 400mm2, resolution of less than 10 microns and scanning velocity in the range of 10 - 40 mm/s. The stage was modeled using computer aided design software NX Unigraphics. In addition to the parameters mentioned above, additional boundary conditions for the stage were set as low volume and modularity. Optimized stage model was fabricated by using rapid prototyping technique that integrates low cost stepper motors, threaded rod drive train and a stepper motor controller. The EZ4axis stepper motor controller was able to provide 1/8th microstep resolution control over the motors, which met the criterion desired for the MIGS platform. Integration of computer controlled three-axis stage with MIGS platform provides the opportunity for conducting intricate surgical procedures using remote control or joystick. The device is image guided using the OCT probe and it is able to pin point any location requiring a laser scalpel incision. Due to the scanning capabilities, a high quality threedimensional image of the tissue topography is obtained which allows the surgeon to make a confident decision of where to apply the laser scalpel and make an incision.

  3. Haptic controlled three-axis MEMS gripper system

    NASA Astrophysics Data System (ADS)

    Vijayasai, Ashwin P.; Sivakumar, Ganapathy; Mulsow, Matthew; Lacouture, Shelby; Holness, Alex; Dallas, Tim E.

    2010-10-01

    In this work, we describe the development and testing of a three degree of freedom meso/micromanipulation system for handling micro-objects, including biological cells and microbeads. Three-axis control is obtained using stepper motors coupled to micromanipulators. The test specimen is placed on a linear X-stage, which is coupled to one stepper motor. The remaining two stepper motors are coupled to the Y and Z axes of a micromanipulator. The stepper motor-micromanipulator arrangement in the Y and Z axes has a minimum step resolution of 0.4 ?m with a total travel of 12 mm and the stepper motor-X stage arrangement has a minimum resolution of 0.3 ?m with a total travel of 10 mm. Mechanical backlash error is 0.8 ?m for 750 ?m of travel. A MEMS microgripper from Femtotools acts as an end-effector in the shaft end of the micromanipulator. The gripping ranges of the grippers used are 0-100 ?m (for FT-G100) and 0-60 ?m (for FT-G60). As the gripping action is performed, the force sense circuit of FT-G100 measures the handling force. This force feedback is integrated to a commercially available three degree of freedom haptic device (Novint Falcon) allowing the user to receive tactile feedback during the microscale handling. Both mesoscale and microscale controls are important, as mesoscale control is required for the travel motion of the test object whereas microscale control is required for the gripping action. The haptic device is used to control the position of the microgripper, control the actuation of the microgripper, and provide force feedback. A LABVIEW program was developed to interlink communication and control among hardware used in the system. Micro-objects such as SF-9 cells and polystyrene beads (45 ?m) are handled and handling forces of 50 ?N were experienced.

  4. Haptic controlled three-axis MEMS gripper system.

    PubMed

    Vijayasai, Ashwin P; Sivakumar, Ganapathy; Mulsow, Matthew; Lacouture, Shelby; Holness, Alex; Dallas, Tim E

    2010-10-01

    In this work, we describe the development and testing of a three degree of freedom meso/micromanipulation system for handling micro-objects, including biological cells and microbeads. Three-axis control is obtained using stepper motors coupled to micromanipulators. The test specimen is placed on a linear X-stage, which is coupled to one stepper motor. The remaining two stepper motors are coupled to the Y and Z axes of a micromanipulator. The stepper motor-micromanipulator arrangement in the Y and Z axes has a minimum step resolution of ?0.4??m with a total travel of 12 mm and the stepper motor-X stage arrangement has a minimum resolution of ?0.3??m with a total travel of 10 mm. Mechanical backlash error is ?0.8??m for ?750??m of travel. A MEMS microgripper from Femtotools acts as an end-effector in the shaft end of the micromanipulator. The gripping ranges of the grippers used are 0-100??m (for FT-G100) and 0-60??m (for FT-G60). As the gripping action is performed, the force sense circuit of FT-G100 measures the handling force. This force feedback is integrated to a commercially available three degree of freedom haptic device (Novint Falcon) allowing the user to receive tactile feedback during the microscale handling. Both mesoscale and microscale controls are important, as mesoscale control is required for the travel motion of the test object whereas microscale control is required for the gripping action. The haptic device is used to control the position of the microgripper, control the actuation of the microgripper, and provide force feedback. A LABVIEW program was developed to interlink communication and control among hardware used in the system. Micro-objects such as SF-9 cells and polystyrene beads (?45??m) are handled and handling forces of ?50??N were experienced. PMID:21034126

  5. A Change of Inertia-Supporting the Thrust Vector Control of the Space Launch System

    NASA Technical Reports Server (NTRS)

    Dziubanek, Adam J.

    2012-01-01

    The Space Launch System (SLS) is America's next launch vehicle. To utilize the vehicle more economically, heritage hardware from the Space Transportation System (STS) will be used when possible. The Solid Rocket Booster (SRB) actuators could possibly be used in the core stage of the SLS. The dynamic characteristics of the SRB actuator will need to be tested on an Inertia Load Stand (ILS) that has been converted to Space Shuttle Main Engine (SSME). The inertia on the pendulum of the ILS will need to be changed to match the SSME inertia. In this testing environment an SRB actuator can be tested with the equivalent resistence of an SSME.

  6. Preliminary performance of a vertical-attitude takeoff and landing, supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system

    NASA Technical Reports Server (NTRS)

    Robins, A. W.; Beissner, F. L., Jr.; Domack, C. S.; Swanson, E. E.

    1985-01-01

    A performance study was made of a vertical attitude takeoff and landing (VATOL), supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system. Those characteristics considered were aerodynamics, weight, balance, and performance. Preliminary results indicate that high levels of supersonic aerodynamic performance can be achieved. Further, with the assumption of an advanced (1985 technology readiness) low bypass ratio turbofan engine and advanced structures, excellent mission performance capability is indicated.

  7. New Highly Dynamic Approach for Thrust Vector Control

    NASA Astrophysics Data System (ADS)

    Hecht, M.; Ettl, J.; Grothe, D.; Hrbud, I.

    2015-09-01

    For a new launcher system a thrust vector control system is needed. This launch vehicle system consists of two rockets which are namely the VS-50 (two-stage suborbital vehicle) and the VLM-1 (three-stage microsatellite launch vehicle). VLM-1 and VS-50 are developed in a cooperation between the German Aerospace Center (DLR) and the Brazilian Aeronautics and Space Institute (IAE). To keep these two rockets on its trajectory during flight a highly dynamic thrust vector control system is required. For the purpose of developing such a highly dynamic thrust vector control system a master thesis was written by the author. The development includes all mechanical constructions as well as control algorithms and electronics design. Moreover an optimization of control algorithms was made to increase the dynamic capabilities of the thrust vector control system. The composition of the right components plus the sophisticated control algorithm make the thrust vector control system highly dynamic.

  8. Thrust vector control using electric actuation

    NASA Astrophysics Data System (ADS)

    Bechtel, Robert T.; Hall, David K.

    1995-01-01

    Presently, gimbaling of launch vehicle engines for thrust vector control is generally accomplished using a hydraulic system. In the case of the space shuttle solid rocket boosters and main engines, these systems are powered by hydrazine auxiliary power units. Use of electromechanical actuators would provide significant advantages in cost and maintenance. However, present energy source technologies such as batteries are heavy to the point of causing significant weight penalties. Utilizing capacitor technology developed by the Auburn University Space Power Institute in collaboration with the Auburn CCDS, Marshall Space Flight Center (MSFC) and Auburn are developing EMA system components with emphasis on high discharge rate energy sources compatible with space shuttle type thrust vector control requirements. Testing has been done at MSFC as part of EMA system tests with loads up to 66000 newtons for pulse times of several seconds. Results show such an approach to be feasible providing a potential for reduced weight and operations costs for new launch vehicles.

  9. Thrust vectoring for lateral-directional stability

    NASA Technical Reports Server (NTRS)

    Peron, Lee R.; Carpenter, Thomas

    1992-01-01

    The advantages and disadvantages of using thrust vectoring for lateral-directional control and the effects of reducing the tail size of a single-engine aircraft were investigated. The aerodynamic characteristics of the F-16 aircraft were generated by using the Aerodynamic Preliminary Analysis System II panel code. The resulting lateral-directional linear perturbation analysis of a modified F-16 aircraft with various tail sizes and yaw vectoring was performed at several speeds and altitudes to determine the stability and control trends for the aircraft compared to these trends for a baseline aircraft. A study of the paddle-type turning vane thrust vectoring control system as used on the National Aeronautics and Space Administration F/A-18 High Alpha Research Vehicle is also presented.

  10. The Magsat three axis arc second precision attitude transfer system

    NASA Technical Reports Server (NTRS)

    Schenkel, F. W.; Heins, R. J.

    1981-01-01

    The Magsat Attitude Transfer System (ATS), which provides attitude alteration in pitch, yaw, and roll is described. A remote vector magnetometer extends from Magsat on a 20 ft boom, requiring vector orientation by reference to coordinate axes determined by a set of star mapping cameras. The ATS was designed to perform in a solar illuminated environment by using an optically narrow bandwidth with synchronous demodulation at 9300 A. The pitch/yaw optical design, the electrooptics, and signal and switching diagrams are provided. Simple mirrors with no moving parts are placed on the magnetometer to reflect a collimated beam from the ATS for attitude indication, which is accurate to one part in 96. Alignment was completed within 24 hr after launch.

  11. Thrust vector control using electric actuation

    SciTech Connect

    Bechtel, R.T.; Hall, D.K.

    1995-01-25

    Presently, gimbaling of launch vehicle engines for thrust vector control is generally accomplished using a hydraulic system. In the case of the space shuttle solid rocket boosters and main engines, these systems are powered by hydrazine auxiliary power units. Use of electromechanical actuators would provide significant advantages in cost and maintenance. However, present energy source technologies such as batteries are heavy to the point of causing significant weight penalties. Utilizing capacitor technology developed by the Auburn University Space Power Institute in collaboration with the Auburn CCDS, Marshall Space Flight Center (MSFC) and Auburn are developing EMA system components with emphasis on high discharge rate energy sources compatible with space shuttle type thrust vector control requirements. Testing has been done at MSFC as part of EMA system tests with loads up to 66000 newtons for pulse times of several seconds. Results show such an approach to be feasible providing a potential for reduced weight and operations costs for new launch vehicles. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

  12. Three-axis attitude control for solar-powered electric propulsion spacecraft

    NASA Technical Reports Server (NTRS)

    Bouvier, H. K.

    1974-01-01

    Spacecraft utilizing solar electric propulsion (SEP) for certain long-term interplanetary missions will depend on large, flexible solar arrays. The resulting spacecraft configurations present some complex flight control problems. Questions regarding a general design approach are discussed along with options for three-axis control forces, tradeoffs for three-axis control forces, controllers for SEP attitude control, sensors for SEP attitude control, aspects of nonrigid vehicle interaction with attitude control, thrust vector control SEP dynamics, and mass expulsion control SEP dynamics. It is found that the state-of-the-art of control system design is mature enough to support an SEP project.

  13. Computational Investigation of Fluidic Counterflow Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Hunter, Craig A.; Deere, Karen A.

    1999-01-01

    A computational study of fluidic counterflow thrust vectoring has been conducted. Two-dimensional numerical simulations were run using the computational fluid dynamics code PAB3D with two-equation turbulence closure and linear Reynolds stress modeling. For validation, computational results were compared to experimental data obtained at the NASA Langley Jet Exit Test Facility. In general, computational results were in good agreement with experimental performance data, indicating that efficient thrust vectoring can be obtained with low secondary flow requirements (less than 1% of the primary flow). An examination of the computational flowfield has revealed new details about the generation of a countercurrent shear layer, its relation to secondary suction, and its role in thrust vectoring. In addition to providing new information about the physics of counterflow thrust vectoring, this work appears to be the first documented attempt to simulate the counterflow thrust vectoring problem using computational fluid dynamics.

  14. Three axis electronic flight motion simulator real time control system design and implementation

    SciTech Connect

    Gao, Zhiyuan; Miao, Zhonghua Wang, Xiaohua; Wang, Xuyong

    2014-12-15

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  15. Three axis electronic flight motion simulator real time control system design and implementation.

    PubMed

    Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

    2014-12-01

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system. PMID:25554333

  16. Three axis electronic flight motion simulator real time control system design and implementation

    NASA Astrophysics Data System (ADS)

    Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

    2014-12-01

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  17. A review of thrust-vectoring in support of a V/STOL non-moving mechanical propulsion system

    NASA Astrophysics Data System (ADS)

    Pscoa, Jos; Dumas, Antonio; Trancossi, Michele; Stewart, Paul; Vucinic, Dean

    2013-09-01

    The advantages associated to Vertical Short-Take-Off and Landing (V/STOL) have been demonstrated since the early days of aviation, with the initial technolology being based on airships and later on helicopters and planes. Its operational advantages are enormous, being it in the field of military, humanitarian and rescue operations, or even in general aviation. Helicopters have limits in their maximum horizontal speed and classic V/STOL airplanes have problems associated with their large weight, due to the implementation of moving elements, when based on tilting rotors or turbojet vector mechanical oriented nozzles. A new alternative is proposed within the European Union Project ACHEON (Aerial Coanda High Efficiency Orienting-jet Nozzle). The project introduces a novel scheme to orient the jet that is free of moving elements. This is based on a Coanda effect nozzle supported in two fluid streams, also incorporating boundary layer plasma actuators to achieve larger deflection angles. Herein we introduce a state-of-the-art review of the concepts that have been proposed in the framework of jet orienting propulsion systems. This review allows to demonstrate the advantages of the new concept in comparison to competing technologies in use at present day, or of competing technologies under development worldwide.

  18. Solid rocket booster thrust vector control subsystem description

    NASA Technical Reports Server (NTRS)

    Redmon, J., Jr. (compiler)

    1983-01-01

    Major Solid Rocket Booster-Thrust Vector Control (SRB-TVC) subsystem components and subcomponents used in the Space Transportation System (STS) are identified. Simplified schematics, detailed schematics, figures, photographs, and data are included to acquaint the reader with the operation, performance, and physical layout as well as the materials and instrumentation used.

  19. A vector autopilot system. [aircraft attitude determination with three-axis magnetometer

    NASA Technical Reports Server (NTRS)

    Pietila, R.; Dunn, W. R., Jr.

    1976-01-01

    Current technology has evolved low cost, highly reliable solid state vector magnetometers with excellent angular resolution. This paper discusses the role of a three-axis magnetometer as a new instrument for aircraft attitude determination. Using flight data acquired by an instrumented aircraft, attitude is calculated using the earth's magnetic field vector and compared to measured attitudes. The magnetic field alone is not adequate to resolve all attitude variations and the need for a second reference angle or vector is discussed. A system combining the functions of heading determination and attitude measurement is presented to show that both functions can be implemented with essentially the same component count required to measure heading alone. It is concluded that with the correlation achieved in calculated and measured attitude there is a potential application of vector magnetometry in attitude measurement systems.

  20. Thrust Vector Control for Nuclear Thermal Rockets

    NASA Technical Reports Server (NTRS)

    Ensworth, Clinton B. F.

    2013-01-01

    Future space missions may use Nuclear Thermal Rocket (NTR) stages for human and cargo missions to Mars and other destinations. The vehicles are likely to require engine thrust vector control (TVC) to maintain desired flight trajectories. This paper explores requirements and concepts for TVC systems for representative NTR missions. Requirements for TVC systems were derived using 6 degree-of-freedom models of NTR vehicles. Various flight scenarios were evaluated to determine vehicle attitude control needs and to determine the applicability of TVC. Outputs from the models yielded key characteristics including engine gimbal angles, gimbal rates and gimbal actuator power. Additional factors such as engine thrust variability and engine thrust alignment errors were examined for impacts to gimbal requirements. Various technologies are surveyed for TVC systems for the NTR applications. A key factor in technology selection is the unique radiation environment present in NTR stages. Other considerations including mission duration and thermal environments influence the selection of optimal TVC technologies. Candidate technologies are compared to see which technologies, or combinations of technologies best fit the requirements for selected NTR missions. Representative TVC systems are proposed and key properties such as mass and power requirements are defined. The outputs from this effort can be used to refine NTR system sizing models, providing higher fidelity definition for TVC systems for future studies.

  1. A multimission three-axis stabilized spacecraft flight dynamics ground support system

    NASA Technical Reports Server (NTRS)

    Langston, J.; Krack, K.; Reupke, W.

    1993-01-01

    The Multimission Three-Axis Stabilized Spacecraft (MTASS) Flight Dynamics Support System (FDSS) has been developed in an effort to minimize the costs of ground support systems. Unlike single-purpose ground support systems, which attempt to reduce costs by reusing software specifically developed for previous missions, the multimission support system is an intermediate step in the progression to a fully generalized mission support system in which numerous missions may be served by one general system. The benefits of multimission attitude ground support systems extend not only to the software design and coding process, but to the entire system environment, from specification through testing, simulation, operations, and maintenance. This paper reports the application of an MTASS FDSS to multiple scientific satellite missions. The satellites are the Upper Atmosphere Research Satellite (UARS), the Extreme Ultraviolet Explorer (EUVE), and the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX). Both UARS and EUVE use the multimission modular spacecraft (MMS) concept. SAMPEX is part of the Small Explorer (SMEX) series and uses a much simpler set of attitude sensors. This paper centers on algorithm and design concepts for a multimission system and discusses flight experience from UARS.

  2. Application of thrust vectoring for STOL

    NASA Technical Reports Server (NTRS)

    Whitten, P. D.; Woodrey, R. W.; Hames, J. E.

    1981-01-01

    Studies of generic aircraft configurations to determine the payoff of thrust vectoring for direct lift during STOL landings and takeoff and for control power augmentation during weapons-delivery maneuvers are described. Results show that for a nominal 1000-foot landing distance, direct-lift benefits are small, but significant improvements in control power augmentation contribute to payoffs in takeoff distance and recovery from roll-pitch-coupling-induced departures at high angles of attack.

  3. Electromechanical actuation for thrust vector control applications

    NASA Technical Reports Server (NTRS)

    Roth, Mary Ellen

    1990-01-01

    At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of this initiative, an electromechanical actuation system is being developed as an attractive alternative to the hydraulic systems used today. NASA-Lewis is developing and demonstrating an Induction Motor Controller Actuation System with a 40 hp peak rating. The controller will integrate 20 kHz resonant link Power Management and Distribution (PMAD) technology and Pulse Population Modulation (PPM) techniques to implement Field Oriented Vector Control (FOVC) of a new advanced induction motor. Through PPM, multiphase variable frequency, variable voltage waveforms can be synthesized from the 20 kHz source. FOVC shows that varying both the voltage and frequency and their ratio (V/F), permits independent control of both torque and speed while operating at maximum efficiency at any point on the torque-speed curve. The driver and the FOVC will be microprocessor controlled. For increased system reliability, a Built-in Test (BITE) capability will be included. This involves introducing testability into the design of a system such that testing is calibrated and exercised during the design, manufacturing, maintenance and prelaunch activities. An actuator will be integrated with the motor controller for performance testing of the EMA TVC system. The design and fabrication of the motor controller is being done by General Dynamics Space Systems Division. The University of Wisconsin-Madison will assist in the design of the advanced induction motor and in the implementation of the FOVC theory. A 75 hp electronically controlled dynamometer will be used to test the motor controller in all four quadrants of operation using flight type control algorithms. Integrated testing of the controller and actuator will be conducted at a facility yet to be named. The EMA system described above is discussed in detail.

  4. Thrust vector control for the Space Shuttle Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    Counter, D. N.; Brinton, B. C.

    1975-01-01

    Thrust vector control (TVC) for the Space Shuttle Solid Rocket Motor (SRM) is obtained by omniaxis vectoring of the nozzle. The development and integration of the system are under the cognizance of Marshall Space Flight Center (MSFC). The nozzle and flexible bearing have been designed and will be built by Thiokol Corporation/Wasatch Division. The vector requirements of the system, the impact of multiple reuse on the components, and the unique problems associated with a large flexible bearing are discussed. The design details of each of the major TVC subcomponents are delineated. The subscale bearing development program and the overall development schedule also are presented.

  5. Experimental Study of an Axisymmetric Dual Throat Fluidic Thrust Vectoring Nozzle for Supersonic Aircraft Application

    NASA Technical Reports Server (NTRS)

    Flamm, Jeffrey D.; Deere, Karen A.; Mason, Mary L.; Berrier, Bobby L.; Johnson, Stuart K.

    2007-01-01

    An axisymmetric version of the Dual Throat Nozzle concept with a variable expansion ratio has been studied to determine the impacts on thrust vectoring and nozzle performance. The nozzle design, applicable to a supersonic aircraft, was guided using the unsteady Reynolds-averaged Navier-Stokes computational fluid dynamics code, PAB3D. The axisymmetric Dual Throat Nozzle concept was tested statically in the Jet Exit Test Facility at the NASA Langley Research Center. The nozzle geometric design variables included circumferential span of injection, cavity length, cavity convergence angle, and nozzle expansion ratio for conditions corresponding to take-off and landing, mid climb and cruise. Internal nozzle performance and thrust vectoring performance was determined for nozzle pressure ratios up to 10 with secondary injection rates up to 10 percent of the primary flow rate. The 60 degree span of injection generally performed better than the 90 degree span of injection using an equivalent injection area and number of holes, in agreement with computational results. For injection rates less than 7 percent, thrust vector angle for the 60 degree span of injection was 1.5 to 2 degrees higher than the 90 degree span of injection. Decreasing cavity length improved thrust ratio and discharge coefficient, but decreased thrust vector angle and thrust vectoring efficiency. Increasing cavity convergence angle from 20 to 30 degrees increased thrust vector angle by 1 degree over the range of injection rates tested, but adversely affected system thrust ratio and discharge coefficient. The dual throat nozzle concept generated the best thrust vectoring performance with an expansion ratio of 1.0 (a cavity in between two equal minimum areas). The variable expansion ratio geometry did not provide the expected improvements in discharge coefficient and system thrust ratio throughout the flight envelope of typical a supersonic aircraft. At mid-climb and cruise conditions, the variable geometry design compromised thrust vector angle achieved, but some thrust vector control would be available, potentially for aircraft trim. The fixed area, expansion ratio of 1.0, Dual Throat Nozzle provided the best overall compromise for thrust vectoring and nozzle internal performance over the range of NPR tested compared to the variable geometry Dual Throat Nozzle.

  6. Design and test of electromechanical actuators for thrust vector control

    NASA Astrophysics Data System (ADS)

    Cowan, J. R.; Weir, Rae Ann

    1993-05-01

    New control mechanisms technologies are currently being explored to provide alternatives to hydraulic thrust vector control (TVC) actuation systems. For many years engineers have been encouraging the investigation of electromechanical actuators (EMA) to take the place of hydraulics for spacecraft control/gimballing systems. The rationale is to deliver a lighter, cleaner, safer, more easily maintained, as well as energy efficient space vehicle. In light of this continued concern to improve the TVC system, the Propulsion Laboratory at the NASA George C. Marshall Space Flight Center (MSFC) is involved in a program to develop electromechanical actuators for the purpose of testing and TVC system implementation. Through this effort, an electromechanical thrust vector control actuator has been designed and assembled. The design consists of the following major components: Two three-phase brushless dc motors, a two pass gear reduction system, and a roller screw, which converts rotational input into linear output. System control is provided by a solid-state electronic controller and power supply. A pair of resolvers and associated electronics deliver position feedback to the controller such that precise positioning is achieved. Testing and evaluation is currently in progress. Goals focus on performance comparisons between EMA's and similar hydraulic systems.

  7. Design and test of electromechanical actuators for thrust vector control

    NASA Technical Reports Server (NTRS)

    Cowan, J. R.; Weir, Rae Ann

    1993-01-01

    New control mechanisms technologies are currently being explored to provide alternatives to hydraulic thrust vector control (TVC) actuation systems. For many years engineers have been encouraging the investigation of electromechanical actuators (EMA) to take the place of hydraulics for spacecraft control/gimballing systems. The rationale is to deliver a lighter, cleaner, safer, more easily maintained, as well as energy efficient space vehicle. In light of this continued concern to improve the TVC system, the Propulsion Laboratory at the NASA George C. Marshall Space Flight Center (MSFC) is involved in a program to develop electromechanical actuators for the purpose of testing and TVC system implementation. Through this effort, an electromechanical thrust vector control actuator has been designed and assembled. The design consists of the following major components: Two three-phase brushless dc motors, a two pass gear reduction system, and a roller screw, which converts rotational input into linear output. System control is provided by a solid-state electronic controller and power supply. A pair of resolvers and associated electronics deliver position feedback to the controller such that precise positioning is achieved. Testing and evaluation is currently in progress. Goals focus on performance comparisons between EMA's and similar hydraulic systems.

  8. Design and evaluation of thrust vectored nozzles using a multicomponent thrust stand

    NASA Technical Reports Server (NTRS)

    Carpenter, Thomas W.; Blattner, Ernest W.; Stagner, Robert E.; Contreras, Juanita; Lencioni, Dennis; Mcintosh, Greg

    1990-01-01

    Future aircraft with the capability of short takeoff and landing, and improved maneuverability especially in the post-stall flight regime will incorporate exhaust nozzles which can be thrust vectored. In order to conduct thrust vector research in the Mechanical Engineering Department at Cal Poly, a program was planned with two objectives; design and construct a multicomponent thrust stand for the specific purpose of measuring nozzle thrust vectors; and to provide quality low moisture air to the thrust stand for cold flow nozzle tests. The design and fabrication of the six-component thrust stand was completed. Detailed evaluation tests of the thrust stand will continue upon the receipt of one signal conditioning option (-702) for the Fluke Data Acquisition System. Preliminary design of thrust nozzles with air supply plenums were completed. The air supply was analyzed with regard to head loss. Initial flow visualization tests were conducted using dual water jets.

  9. Thrust Vectoring of a Continuous Rotating Detonation Engine by Changing the Local Injection Pressure

    NASA Astrophysics Data System (ADS)

    Liu, Shi-Jie; Lin, Zhi-Yong; Sun, Ming-Bo; Liu, Wei-Dong

    2011-09-01

    The thrust vectoring ability of a continuous rotating detonation engine is numerically investigated, which is realized via increasing local injection stagnation pressure of half of the simulation domain compared to the other half. Under the homogeneous injection condition, both the flow-field structure and the detonation wave propagation process are analyzed. Due to the same injection condition along the inlet boundary, the outlines of fresh gas zones at different moments are similar to each other. The main flow-field features under thrust vectoring cases are similar to that under the baseline condition. However, due to the heterogeneous injection system, both the height of the fresh gas zone and the pressure value of the fresh gas in the high injection pressure zone are larger than that in the low injection pressure zone. Thus the average pressure in half of the engine is larger than that in the other half and the thrust vectoring adjustment is realized.

  10. Extreme Ultraviolet Explorer attitude determination support with a multimission three-axis stabilized spacecraft flight dynamics support system

    NASA Technical Reports Server (NTRS)

    Harman, Richard; Lee, Michael

    1993-01-01

    The Extreme Ultraviolet Explorer (EUVE) was launched June 7, 1992 by an expendable Delta 2 launch vehicle. The Flight Dynamics Facility (FDF) at NASA Goddard Space Flight Center used a multimission three-axis stabilized spacecraft (MTASS) Flight Dynamics Support System (FDSS) to support the EUVE launch and mission operations. For EUVE, MTASS has been used to monitor attitude sensor performance, study OBC attitude determination performance, and study attitude perturbations. The current status of these efforts are summarized. After its successful implementation for EUVE, the Upper Atmosphere Research Satellite (UARS), and the Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), MTASS has demonstrated multimission flight dynamics support systems can effectively bridge the gap between single-mission support systems of the past and future generic systems.

  11. A three-axis high-resolution capacitive tactile imager system based on floating comb electrodes

    NASA Astrophysics Data System (ADS)

    Surapaneni, R.; Guo, Q.; Xie, Y.; Young, D. J.; Mastrangelo, C. H.

    2013-07-01

    We present the design, fabrication and testing of a high-resolution 169-sensing cell capacitive flexible tactile imager (FTI) for normal and shear stress measurement as an auxiliary sensor for robotic grippers and gait analysis. The FTI consists of a flexible high-density array of normal stress and two-dimensional shear stress sensors fabricated using microelectromechanical systems (MEMS) and flexible printed circuit board (FPCB) techniques. The drive/sense lines of the FTI are realized using FPCB whereas the floating electrodes (Au) are patterned on a compressible PDMS layer spin coated on the FPCB layer. The use of unconnected floating electrodes significantly improves the reliability of traditional quad-electrode contact sensing devices by eliminating the need for patterning electrical wiring on PDMS. When placed at the heel of a boot, this FTI senses the position and motion of the line of contact with the ground. Normal stress readouts are obtained from the net capacitance of the cell and the shear-sense direction is determined by the amount of asymmetric overlap of the floating combs with respect to the bottom electrodes. The FTI is characterized using a high-speed switched-capacitor circuit with a 12-bit resolution at full frame rates of 100 Hz (0.8 Mb s-1) capable of resolving a displacement as low as 60 m. The FTI and the readout circuitry contribute to a noise/interference level of 5 mV and the sensitivity of normal and shear stress for the FTI is 0.38 MPa-1 and 79.5 GPa-1 respectively.

  12. Aerodynamics of thrust vectoring by Navier-Stokes solutions

    NASA Technical Reports Server (NTRS)

    Tseng, Jing-Biau; Lan, C. Edward

    1991-01-01

    Induced aerodynamics from thrust vectoring are investigated by a computational fluid dynamic method. A thin-layer Reynolds-averaged Navier-Stokes code with multiblock capability is used. Jet properties are specified on the nozzle exit plane to simulate the jet momentum. Results for a rectangular jet in a cross flow are compared with data to verify the code. Further verification of the calculation is made by comparing the numerical results with transonic data for a wing-body combination. Additional calculations were performed to elucidate the following thrust vectoring effects: the thrust vectoring effect on shock and expansion waves, induced effects on nearby surfaces, and the thrust vectoring effect on the leading edge vortex.

  13. Feedback control for counterflow thrust vectoring with a turbine engine: Experiment design and robust control design and implementation

    NASA Astrophysics Data System (ADS)

    Dores, Delfim Zambujo Das

    2005-11-01

    Engineering research over the last few years has successfully demonstrated the potential of thrust vector control using counterflow at conditions up to Mach 2. Flow configurations that include the pitch vectoring of rectangular jets and multi-axis vector control in diamond and axisymmetric nozzle geometries have been studied. Although bistable (on-off) fluid-based control has been around for some time, the present counterflow thrust vector control is unique because proportional and continuous jet response can be achieved in the absence of moving parts, while avoiding jet attachment, which renders most fluidic approaches unacceptable for aircraft and missile control applications. However, before this study, research had been limited to open-loop studies of counterflow thrust vectoring. For practical implementation it was vital that the counterflow scheme be used in conjunction with feedback control. Hence, the focus of this research was to develop and experimentally demonstrate a feedback control design methodology for counterflow thrust vectoring. This research focused on 2-D (pitch) thrust vectoring and addresses four key modeling issues. The first issue is to determine the measured variable to be commanded since the thrust vector angle is not measurable in real time. The second related issue is to determine the static mapping from the thrust vector angle to this measured variable. The third issue is to determine the dynamic relationship between the measured variable and the thrust vector angle. The fourth issue is to develop dynamic models with uncertainty characterizations. The final and main goal was the design and implementation of robust controllers that yield closed-loop systems with fast response times, and avoid overshoot in order to aid in the avoidance of attachment. These controllers should be simple and easy to implement in real applications. Hence, PID design has been chosen. Robust control design is accomplished by using ?1 control theory in conjunction with the Popov-Tsypkin multiplier. The resulting optimization problem was solved using a real coded genetic-algorithm.

  14. Numerical and Experimental Investigations of Fluidic Thrust Vectoring with Oblique Shock Waves

    NASA Astrophysics Data System (ADS)

    Ouchi, K.; Yamada, K.; Hirota, M.; Hatanaka, Kazuaki; Saito, Tsutomu; Li, L.

    Mechanical thrust vectoring (MTV) has already been put to practical use. It controls the thrust direction of jet propulsion system by mechanically moving structural components such as exhaust nozzles and paddles. MTV has several advantages such as high mobility during supersonic flight in the high-altitude where effective turning is difficult to perform due to low atmospheric density.

  15. Thrust Vectoring on the NASA F-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Pahle, Joseph W.

    1996-01-01

    Investigations into a multiaxis thrust-vectoring system have been conducted on an F-18 configuration. These investigations include ground-based scale-model tests, ground-based full-scale testing, and flight testing. This thrust-vectoring system has been tested on the NASA F-18 High Alpha Research Vehicle (HARV). The system provides thrust vectoring in pitch and yaw axes. Ground-based subscale test data have been gathered as background to the flight phase of the program. Tests investigated aerodynamic interaction and vane control effectiveness. The ground-based full-scale data were gathered from static engine runs with image analysis to determine relative thrust-vectoring effectiveness. Flight tests have been conducted at the NASA Dryden Flight Research Center. Parameter identification input techniques have been developed. Individual vanes were not directly controlled because of a mixer-predictor function built into the flight control laws. Combined effects of the vanes have been measured in flight and compared to combined effects of the vanes as predicted by the cold-jet test data. Very good agreement has been found in the linearized effectiveness derivatives.

  16. Design of thrust vectoring exhaust nozzles for real-time applications using neural networks

    NASA Technical Reports Server (NTRS)

    Prasanth, Ravi K.; Markin, Robert E.; Whitaker, Kevin W.

    1991-01-01

    Thrust vectoring continues to be an important issue in military aircraft system designs. A recently developed concept of vectoring aircraft thrust makes use of flexible exhaust nozzles. Subtle modifications in the nozzle wall contours produce a non-uniform flow field containing a complex pattern of shock and expansion waves. The end result, due to the asymmetric velocity and pressure distributions, is vectored thrust. Specification of the nozzle contours required for a desired thrust vector angle (an inverse design problem) has been achieved with genetic algorithms. This approach is computationally intensive and prevents the nozzles from being designed in real-time, which is necessary for an operational aircraft system. An investigation was conducted into using genetic algorithms to train a neural network in an attempt to obtain, in real-time, two-dimensional nozzle contours. Results show that genetic algorithm trained neural networks provide a viable, real-time alternative for designing thrust vectoring nozzles contours. Thrust vector angles up to 20 deg were obtained within an average error of 0.0914 deg. The error surfaces encountered were highly degenerate and thus the robustness of genetic algorithms was well suited for minimizing global errors.

  17. Design of a three-axis magnetic field measurement system for the magnetic shield of the ring laser gyroscope

    NASA Astrophysics Data System (ADS)

    Rong, Chuiyu; Yao, Xu

    2015-10-01

    The magnetic field is one of the main causes of zero drift in a Ring Laser Gyroscope (RLG), which should be avoided by adopting a magnetic shielding system. The Gauss Meter is usually used to measure the magnetic shielding effectiveness. Generally, the traditional Gauss Meter has advantages of high measure range and high reliability, however, its drawbacks such as complex structure, high price and the PC client software cannot be customized at will, are also obvious. In this paper, aiming at a type of experimental magnetic shielding box of RLG, we design a new portable three-axis magnetic field measurement system. This system has both high modularity degree and reliability, with measuring range at ±48Gs, max resolution at 1.5mGs and can measure the magnetic field in x, y and z direction simultaneously. Besides, its PC client software can be easily customized to achieve the automatic DAQ, analysis, plotting and storage functions. The experiment shows that, this system can meet the measuring requirements of certain type of experimental magnetic shielding box for RLG, meanwhile, for the measurement of some other magnetic shielding effectiveness, this system is also applicable.

  18. Development of a Low-Cost Attitude and Heading Reference System Using a Three-Axis Rotating Platform

    PubMed Central

    Lai, Ying-Chih; Jan, Shau-Shiun; Hsiao, Fei-Bin

    2010-01-01

    A development procedure for a low-cost attitude and heading reference system (AHRS) with a self-developed three-axis rotating platform has been proposed. The AHRS consists of one 3-axis accelerometer, three single-axis gyroscopes, and one 3-axis digital compass. Both the accelerometer and gyroscope triads are based on micro electro-mechanical system (MEMS) technology, and the digital compass is based on anisotropic-magnetoresistive (AMR) technology. The calibrations for each sensor triad are readily accomplished by using the scalar calibration and the least squares methods. The platform is suitable for the calibration and validation of the low-cost AHRS and it is affordable for most laboratories. With the calibrated parameters and data fusion algorithm for the orientation estimation, the self-developed AHRS demonstrates the capabilities of compensating for the sensor errors and outputting the estimated orientation in real-time. The validation results show that the estimated orientations of the developed AHRS are within the acceptable region. This verifies the practicability of the proposed development procedure. PMID:22319258

  19. Thrust vector control by liquid injection for solid propellant rockets

    NASA Technical Reports Server (NTRS)

    Zeamer, R. J.

    1975-01-01

    In liquid injection thrust vector control, a rocket jet is deflected for steering purposed by injecting a liquid into the nozzle exit cone. The liquid is preferably both dense and reactive so that it adds mass and energy and generates shocks in the supersonic exhaust. This behavior increases thrust in the affected part of the jet producing not only a side force for steering but an addition to axial thrust. This paper presents a summary of current liquid injection thrust vector control technology, including procedures for design, development, analysis, testing and evaluation, together with supporting data and references.

  20. Internal performance characteristics of thrust-vectored axisymmetric ejector nozzles

    NASA Technical Reports Server (NTRS)

    Lamb, Milton

    1995-01-01

    A series of thrust-vectored axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at the Langley research center. This study indicated that discontinuities in the performance occurred at low primary nozzle pressure ratios and that these discontinuities were mitigated by decreasing expansion area ratio. The addition of secondary flow increased the performance of the nozzles. The mid-to-high range of secondary flow provided the most overall improvements, and the greatest improvements were seen for the largest ejector area ratio. Thrust vectoring the ejector nozzles caused a reduction in performance and discharge coefficient. With or without secondary flow, the vectored ejector nozzles produced thrust vector angles that were equivalent to or greater than the geometric turning angle. With or without secondary flow, spacing ratio (ejector passage symmetry) had little effect on performance (gross thrust ratio), discharge coefficient, or thrust vector angle. For the unvectored ejectors, a small amount of secondary flow was sufficient to reduce the pressure levels on the shroud to provide cooling, but for the vectored ejector nozzles, a larger amount of secondary air was required to reduce the pressure levels to provide cooling.

  1. Aeroservoelastic Modeling and Validation of a Thrust-Vectoring F/A-18 Aircraft

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.

    1996-01-01

    An F/A-18 aircraft was modified to perform flight research at high angles of attack (AOA) using thrust vectoring and advanced control law concepts for agility and performance enhancement and to provide a testbed for the computational fluid dynamics community. Aeroservoelastic (ASE) characteristics had changed considerably from the baseline F/A-18 aircraft because of structural and flight control system amendments, so analyses and flight tests were performed to verify structural stability at high AOA. Detailed actuator models that consider the physical, electrical, and mechanical elements of actuation and its installation on the airframe were employed in the analysis to accurately model the coupled dynamics of the airframe, actuators, and control surfaces. This report describes the ASE modeling procedure, ground test validation, flight test clearance, and test data analysis for the reconfigured F/A-18 aircraft. Multivariable ASE stability margins are calculated from flight data and compared to analytical margins. Because this thrust-vectoring configuration uses exhaust vanes to vector the thrust, the modeling issues are nearly identical for modem multi-axis nozzle configurations. This report correlates analysis results with flight test data and makes observations concerning the application of the linear predictions to thrust-vectoring and high-AOA flight.

  2. Design and Analysis of a Thrust Vector Mechanism Applied in a Flying Wing

    NASA Astrophysics Data System (ADS)

    Zhu, Yanhe; Gao, Liang; Wang, Hongwei; Zhao, Jie

    This paper presents the design and analysis of a thrust vector mechanism applied in a flying wing. A thrust vector mechanism driven by two servos is developed. An analysis of the dynamic differences in minimum hovering radius between conventional flying wing and one with thrust vector mechanism is given and validated with simulation. It is shown that thrust vector has obvious advantages over the usual flying wing including decreasing the hovering radius and decreasing roll angle. The benefits should improve maneuverability and agility.

  3. Multiaxis Thrust-Vectoring Characteristics of a Model Representative of the F-18 High-Alpha Research Vehicle at Angles of Attack From 0 deg to 70 deg

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Capone, Francis J.

    1995-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the multiaxis thrust-vectoring characteristics of the F-18 High-Alpha Research Vehicle (HARV). A wingtip supported, partially metric, 0.10-scale jet-effects model of an F-18 prototype aircraft was modified with hardware to simulate the thrust-vectoring control system of the HARV. Testing was conducted at free-stream Mach numbers ranging from 0.30 to 0.70, at angles of attack from O' to 70', and at nozzle pressure ratios from 1.0 to approximately 5.0. Results indicate that the thrust-vectoring control system of the HARV can successfully generate multiaxis thrust-vectoring forces and moments. During vectoring, resultant thrust vector angles were always less than the corresponding geometric vane deflection angle and were accompanied by large thrust losses. Significant external flow effects that were dependent on Mach number and angle of attack were noted during vectoring operation. Comparisons of the aerodynamic and propulsive control capabilities of the HARV configuration indicate that substantial gains in controllability are provided by the multiaxis thrust-vectoring control system.

  4. Solid rocket booster thrust vector control V-2 off-nominal testing

    NASA Technical Reports Server (NTRS)

    Pagan, B.

    1981-01-01

    The results of the V-2 off nominal test sequence performed on the space shuttle solid rocket booster thrust vector control (SRB TVC) system are reported. The TVC subsystem was subjected to 19 off nominal test conditions. The test sequence consisted of: 8 burp starts, 30 hot firings, 14 GN2 spin tests, and 3 servicing passive system tests. It is concluded that the TVC subsystem operated nominally in response to the given commands and test conditions. Test objectives, detail results, and data are included.

  5. Numerical simulation of STOL operations using thrust-vectoring

    NASA Technical Reports Server (NTRS)

    Chawla, Kalpana; Van Dalsem, W. R.

    1992-01-01

    The flow field about a delta wing equipped with thrust reverser jets in slow speed flight near the ground has been computed. Results include the prediction of the flow about the delta wing at four fixed heights above the ground, and a simulated landing, in which the delta wing descends towards the ground. Comparison of computed and experimental lift coefficients indicates that the simulations can capture at least the qualitative trends in lift-loss encountered by thrust-vectoring aircraft operating in ground effect.

  6. Thrust vector control algorithm design for the Cassini spacecraft

    NASA Technical Reports Server (NTRS)

    Enright, Paul J.

    1993-01-01

    This paper describes a preliminary design of the thrust vector control algorithm for the interplanetary spacecraft, Cassini. Topics of discussion include flight software architecture, modeling of sensors, actuators, and vehicle dynamics, and controller design and analysis via classical methods. Special attention is paid to potential interactions with structural flexibilities and propellant dynamics. Controller performance is evaluated in a simulation environment built around a multi-body dynamics model, which contains nonlinear models of the relevant hardware and preliminary versions of supporting attitude determination and control functions.

  7. Performance and human factors results from thrust vectoring investigations in simulated air combat

    NASA Technical Reports Server (NTRS)

    Pennington, J. E.; Meintel, A. J., Jr.

    1980-01-01

    In support of research related to advanced fighter technology, the Langley Differential Maneuvering Simulator (DMS) has been used to investigate the effects of advanced aerodynamic concepts, parametric changes in performance parameters, and advanced flight control systems on the combat capability of fighter airplanes. At least five studies were related to thrust vectoring and/or inflight thrust reversing. The aircraft simulated ranged from F-4 class to F-15 class, and included the AV-8 Harrier. This paper presents an overview of these studies including the assumptions involved, trends of results, and human factors considerations that were found.

  8. Attitude control of a spinning rocket via thrust vectoring

    SciTech Connect

    White, J.E.

    1990-12-19

    Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is tested for the ability to track step commands, and for the amount of coupling impurity. Both controllers are developed via a linear-quadratic-regulator synthesis procedure, which is motivated by the multi-input/multi-output nature of second controller. Time responses and a singular value analysis are used to evaluate controller performance. This paper describes the development and comparison of two controllers that are designed to provide attitude control of a spinning rocket that is equipped with thrust vector control. 12 refs., 13 figs., 2 tabs.

  9. Computational Investigation of the Aerodynamic Effects on Fluidic Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Deere, K. A.

    2000-01-01

    A computational investigation of the aerodynamic effects on fluidic thrust vectoring has been conducted. Three-dimensional simulations of a two-dimensional, convergent-divergent (2DCD) nozzle with fluidic injection for pitch vector control were run with the computational fluid dynamics code PAB using turbulence closure and linear Reynolds stress modeling. Simulations were computed with static freestream conditions (M=0.05) and at Mach numbers from M=0.3 to 1.2, with scheduled nozzle pressure ratios (from 3.6 to 7.2) and secondary to primary total pressure ratios of p(sub t,s)/p(sub t,p)=0.6 and 1.0. Results indicate that the freestream flow decreases vectoring performance and thrust efficiency compared with static (wind-off) conditions. The aerodynamic penalty to thrust vector angle ranged from 1.5 degrees at a nozzle pressure ratio of 6 with M=0.9 freestream conditions to 2.9 degrees at a nozzle pressure ratio of 5.2 with M=0.7 freestream conditions, compared to the same nozzle pressure ratios with static freestream conditions. The aerodynamic penalty to thrust ratio decreased from 4 percent to 0.8 percent as nozzle pressure ratio increased from 3.6 to 7.2. As expected, the freestream flow had little influence on discharge coefficient.

  10. Linear Test Bed. Volume 2: Test Bed No. 2. [linear aerospike test bed for thrust vector control

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Test bed No. 2 consists of 10 combustors welded in banks of 5 to 2 symmetrical tubular nozzle assemblies, an upper stationary thrust frame, a lower thrust frame which can be hinged, a power package, a triaxial combustion wave ignition system, a pneumatic control system, pneumatically actuated propellant valves, a purge and drain system, and an electrical control system. The power package consists of the Mark 29-F fuel turbopump, the Mark 29-0 oxidizer turbopump, a gas generator assembly, and propellant ducting. The system, designated as a linear aerospike system, was designed to demonstrate the feasibility of the concept and to explore technology related to thrust vector control, thrust vector optimization, improved sequencing and control, and advanced ignition systems. The propellants are liquid oxygen/liquid hydrogen. The system was designed to operate at 1200-psia chamber pressure at an engine mixture ratio of 5.5. With 10 combustors, the sea level thrust is 95,000 pounds.

  11. Test stand for precise measurement of impulse and thrust vector of small attitude control jets

    NASA Technical Reports Server (NTRS)

    Woodruff, J. R.; Chisel, D. M.

    1973-01-01

    A test stand which accurately measures the impulse bit and thrust vector of reaction jet thrusters used in the attitude control system of space vehicles has been developed. It can be used to measure, in a vacuum or ambient environment, both impulse and thrust vector of reaction jet thrusters using hydrazine or inert gas propellants. The ballistic pendulum configuration was selected because of its accuracy, simplicity, and versatility. The pendulum is mounted on flexure pivots rotating about a vertical axis at the center of its mass. The test stand has the following measurement capabilities: impulse of 0.00004 to 4.4 N-sec (0.00001 to 1.0 lb-sec) with a pulse duration of 0.5 msec to 1 sec; static thrust of 0.22 to 22 N (0.05 to 5 lb) with a 5 percent resolution; and thrust angle alinement of 0.22 to 22 N (0.05 to 5 lb) thrusters with 0.01 deg accuracy.

  12. An MRI-compatible three-axis focused ultrasound system for performing drug delivery studies in small animal models

    NASA Astrophysics Data System (ADS)

    Waspe, Adam C.; Chau, Anthony; Kukic, Aleksandra; Chopra, Rajiv; Hynynen, Kullervo

    2010-03-01

    The objective of this work was to develop an MRI-compatible focused-ultrasound system for preclinical research in small animal models capable of delivering exposures with high spatial precision in a closed-bore clinical imager. A computer-controlled, non-magnetic, 3-axis positioning system was developed using ceramic actuators and linear encoders to position a focused-ultrasound transducer within a clinical MR scanner. Registration between ultrasound and MRI coordinates involves sonicating a tissue-mimicking ultrasound phantom and measuring the centroid of the thermal focal zone with MR thermometry. Linear distances of 5 cm with a positioning resolution of 0.1 mm were achieved for each axis. The system was operated successfully in MR imagers from different vendors at both 1.5 and 3.0 T, and simultaneous motion and imaging was possible without any mutual interference or imaging artifacts. Initial experiments involving opening of the blood-brain barrier at specific targets within the brain suggest a targeting accuracy of 0.4 mm.

  13. Preliminary Investigation on Battery Sizing Investigation for Thrust Vector Control on Ares I and Ares V Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Miller, Thomas B.

    2011-01-01

    An investigation into the merits of battery powered Electro Hydrostatic Actuation (EHA) for Thrust Vector Control (TVC) of the Ares I and Ares V launch vehicles is described. A top level trade study was conducted to ascertain the technical merits of lithium-ion (Li-ion) and thermal battery performance to determine the preferred choice of an energy storage system chemistry that provides high power discharge capability for a relatively short duration.

  14. Static calibration of a two-dimensional wedge nozzle with thrust vectoring and spanwise blowing

    NASA Technical Reports Server (NTRS)

    Harris, M. J.; Falarski, M. D.

    1980-01-01

    The results of a static calibration of the two dimensional wedge nozzles on a STOL configuration of a large-scale fighter model are reported. These nozzles internally turn the efflux produced by two turbojets down 25 degrees and exhaust it over the deflected trailing edge of the wing. This arrangement provides direct thrust lift, enhances wing lift by producting supercirculation, and provides thrust vectoring by varying the deflection of the wing's trailing edge. The thrust is vectored from 10 deg to 38 deg. This system was calibrated with spanwise blowing for augmentation of the leading-edge vortex. When 16% of the turbojet efflux is blown spanwise, the thrust recovered is 92% of the thrust produced when the total efflux is exhausted longitudinally.

  15. Static performance of an axisymmetric nozzle with post-exit vanes for multiaxis thrust vectoring

    NASA Technical Reports Server (NTRS)

    Berrier, Bobby L.; Mason, Mary L.

    1988-01-01

    An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to determine the flow-turning capability and the nozzle internal performance of an axisymmetric convergent-divergent nozzle with post-exit vanes installed for multiaxis thrust vectoring. The effects of vane curvature, vane location relative to the nozzle exit, number of vanes, and vane deflection angle were determined. A comparison of the post-exit-vane thrust-vectoring concept with other thrust-vectoring concepts is provided. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 1.6 to 6.0.

  16. Computational Study of Fluidic Thrust Vectoring using Separation Control in a Nozzle

    NASA Technical Reports Server (NTRS)

    Deere, Karen; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2003-01-01

    A computational investigation of a two- dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. The structured-grid, computational fluid dynamics code PAB3D was used to guide the design and analyze over 60 configurations. Nozzle design variables included cavity convergence angle, cavity length, fluidic injection angle, upstream minimum height, aft deck angle, and aft deck shape. All simulations were computed with a static freestream Mach number of 0.05. a nozzle pressure ratio of 3.858, and a fluidic injection flow rate equal to 6 percent of the primary flow rate. Results indicate that the recessed cavity enhances the throat shifting method of fluidic thrust vectoring and allows for greater thrust-vector angles without compromising thrust efficiency.

  17. Static performance investigation of a skewed-throat multiaxis thrust-vectoring nozzle concept

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1994-01-01

    The static performance of a jet exhaust nozzle which achieves multiaxis thrust vectoring by physically skewing the geometric throat has been characterized in the static test facility of the 16-Foot Transonic Tunnel at NASA Langley Research Center. The nozzle has an asymmetric internal geometry defined by four surfaces: a convergent-divergent upper surface with its ridge perpendicular to the nozzle centerline, a convergent-divergent lower surface with its ridge skewed relative to the nozzle centerline, an outwardly deflected sidewall, and a straight sidewall. The primary goal of the concept is to provide efficient yaw thrust vectoring by forcing the sonic plane (nozzle throat) to form at a yaw angle defined by the skewed ridge of the lower surface contour. A secondary goal is to provide multiaxis thrust vectoring by combining the skewed-throat yaw-vectoring concept with upper and lower pitch flap deflections. The geometric parameters varied in this investigation included lower surface ridge skew angle, nozzle expansion ratio (divergence angle), aspect ratio, pitch flap deflection angle, and sidewall deflection angle. Nozzle pressure ratio was varied from 2 to a high of 11.5 for some configurations. The results of the investigation indicate that efficient, substantial multiaxis thrust vectoring was achieved by the skewed-throat nozzle concept. However, certain control surface deflections destabilized the internal flow field, which resulted in substantial shifts in the position and orientation of the sonic plane and had an adverse effect on thrust-vectoring and weight flow characteristics. By increasing the expansion ratio, the location of the sonic plane was stabilized. The asymmetric design resulted in interdependent pitch and yaw thrust vectoring as well as nonzero thrust-vector angles with undeflected control surfaces. By skewing the ridges of both the upper and lower surface contours, the interdependency between pitch and yaw thrust vectoring may be eliminated and the location of the sonic plane may be further stabilized.

  18. Solid rocket booster thrust vector control subsystem test report (D-1)

    NASA Technical Reports Server (NTRS)

    Pagan, B.

    1978-01-01

    The results of the sequence of tests performed on the space shuttle solid rocket booster thrust vector control subsystem are presented. The operational characteristics of the thrust vector control subsystem components, as determined from the tests, are discussed. Special analyses of fuel consumption, basic steady state characteristics, GN2 spin, and actuator displacement were reviewed which will aid in understanding the performance of the auxiliary power unit. The possibility of components malfunction is also discussed.

  19. Computational Study of an Axisymmetric Dual Throat Fluidic Thrust Vectoring Nozzle for a Supersonic Aircraft Application

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Flamm, Jeffrey D.; Berrier, Bobby L.; Johnson, Stuart K.

    2007-01-01

    A computational investigation of an axisymmetric Dual Throat Nozzle concept has been conducted. This fluidic thrust-vectoring nozzle was designed with a recessed cavity to enhance the throat shifting technique for improved thrust vectoring. The structured-grid, unsteady Reynolds- Averaged Navier-Stokes flow solver PAB3D was used to guide the nozzle design and analyze performance. Nozzle design variables included extent of circumferential injection, cavity divergence angle, cavity length, and cavity convergence angle. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 1.89 to 10, with the fluidic injection flow rate equal to zero and up to 4 percent of the primary flow rate. The effect of a variable expansion ratio on nozzle performance over a range of freestream Mach numbers up to 2 was investigated. Results indicated that a 60 circumferential injection was a good compromise between large thrust vector angles and efficient internal nozzle performance. A cavity divergence angle greater than 10 was detrimental to thrust vector angle. Shortening the cavity length improved internal nozzle performance with a small penalty to thrust vector angle. Contrary to expectations, a variable expansion ratio did not improve thrust efficiency at the flight conditions investigated.

  20. Flight-Determined Subsonic Longitudinal Stability and Control Derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) with Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1997-01-01

    The subsonic longitudinal stability and control derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) are extracted from dynamic flight data using a maximum likelihood parameter identification technique. The technique uses the linearized aircraft equations of motion in their continuous/discrete form and accounts for state and measurement noise as well as thrust-vectoring effects. State noise is used to model the uncommanded forcing function caused by unsteady aerodynamics over the aircraft, particularly at high angles of attack. Thrust vectoring was implemented using electrohydraulically-actuated nozzle postexit vanes and a specialized research flight control system. During maneuvers, a control system feature provided independent aerodynamic control surface inputs and independent thrust-vectoring vane inputs, thereby eliminating correlations between the aircraft states and controls. Substantial variations in control excitation and dynamic response were exhibited for maneuvers conducted at different angles of attack. Opposing vane interactions caused most thrust-vectoring inputs to experience some exhaust plume interference and thus reduced effectiveness. The estimated stability and control derivatives are plotted, and a discussion relates them to predicted values and maneuver quality.

  1. A Computational Study of a New Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2005-01-01

    A computational investigation of a two-dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. Several design cycles with the structured-grid, computational fluid dynamics code PAB3D and with experiments in the NASA Langley Research Center Jet Exit Test Facility have been completed to guide the nozzle design and analyze performance. This paper presents computational results on potential design improvements for best experimental configuration tested to date. Nozzle design variables included cavity divergence angle, cavity convergence angle and upstream throat height. Pulsed fluidic injection was also investigated for its ability to decrease mass flow requirements. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 2 to 7, with the fluidic injection flow rate equal to 3 percent of the primary flow rate. Computational results indicate that increasing cavity divergence angle beyond 10 is detrimental to thrust vectoring efficiency, while increasing cavity convergence angle from 20 to 30 improves thrust vectoring efficiency at nozzle pressure ratios greater than 2, albeit at the expense of discharge coefficient. Pulsed injection was no more efficient than steady injection for the Dual Throat Nozzle concept.

  2. Pneumatic motor powered Thrust Vector Control (TVC) for liquid propelled launch vehicles

    NASA Astrophysics Data System (ADS)

    Malone, Mark C.; Evans, P. S.

    1992-02-01

    Recent studies performed for the Titan 4 launch vehicle indicate significant potential advantages in replacing the current stage 1 and 2 recirculating hydraulic TVC (thrust vector control) system with a PMA (pneumatic mechanical actuation) system. Some of the advantages of a PMA system over the recirculating hydraulic system include reduced part count and weight, reduced maintenance and life-cycle cost, and improved mission reliability. PMA technology, used in aircraft applications since the 1960s, is well suited in launch vehicle TVC applications where an existing pneumatic pressure source is available. A typical pneumatic motor TVC consists of a pneumatic power source, a dual rotor pneumatic motor, a gear box, a ball screw actuator, and the associated closed-loop servo-control elements. One key issue with implementing this mechanical approach is designing a TVC system to withstand large load transient disturbances during liquid engine starting. Hydraulic actuator transient loads have exceeded 60,000 lb(sub f) for a 30,000 lb(sub f) stall design actuator during ground starts of the Titan 3B, Stage 1 engine. A PMA TVC system must also withstand these start transients without imparting excessive reaction loads to the engine nozzle and thrust structure. Work completed to date with Martin Marietta to examine pneumatic motor powered TVC options and technology benefits is presented. The load transient issue is discussed along with potential solutions and the associated trades. General background on PMA technology and experience base is also presented.

  3. Static Investigation of a Multiaxis Thrust-Vectoring Nozzle With Variable Internal Contouring Ability

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Mills, Charles T. L.; Mason, Mary L.

    1997-01-01

    The thrust efficiency and vectoring performance of a convergent-divergent nozzle were investigated at static conditions in the model preparation area of the Langley 16-Foot Transonic Tunnel. The diamond-shaped nozzle was capable of varying the internal contour of each quadrant individually by using cam mechanisms and retractable drawers to produce pitch and yaw thrust vectoring. Pitch thrust vectoring was achieved by either retracting the lower drawers to incline the throat or varying the internal flow-path contours to incline the throat. Yaw thrust vectoring was achieved by reducing flow area left of the nozzle centerline and increasing flow area right of the nozzle centerline; a skewed throat deflected the flow in the lateral direction.

  4. Internal performance of two nozzles utilizing gimbal concepts for thrust vectoring

    NASA Technical Reports Server (NTRS)

    Berrier, Bobby L.; Taylor, John G.

    1990-01-01

    The internal performance of an axisymmetric convergent-divergent nozzle and a nonaxisymmetric convergent-divergent nozzle, both of which utilized a gimbal type mechanism for thrust vectoring was evaluated in the Static Test Facility of the Langley 16-Foot Transonic Tunnel. The nonaxisymmetric nozzle used the gimbal concept for yaw thrust vectoring only; pitch thrust vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps. The model geometric parameters investigated were pitch vector angle for the axisymmetric nozzle and pitch vector angle, yaw vector angle, nozzle throat aspect ratio, and nozzle expansion ratio for the nonaxisymmetric nozzle. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 12.0.

  5. An Experimental/Modeling Study of Jet Attachment during Counterflow Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Strykowski, Paul J.

    1997-01-01

    Recent studies have shown the applicability of vectoring rectangular jets using asymmetrically applied counterflow in the presence of a short collar. This novel concept has applications in the aerospace industry where counterflow can be used to vector the thrust of a jet's exhaust, shortening take-off and landing distances and enhancing in-flight maneuverability of the aircraft. Counterflow thrust vectoring, 'CFTV' is desirable due to its fast time response, low thrust loss, and absence of moving parts. However, implementation of a CFTV system is only possible if bistable jet attachment can be prevented. This can be achieved by properly designing the geometry of the collar. An analytical model is developed herein to predict the conditions under which a two-dimensional jet will attach to an offset curved wall. Results from this model are then compared with experiment; for various jet exit Mach numbers, collar offset distances, and radii of curvature. Their excellent correlation permits use of the model as a tool for designing a CFTV system.

  6. Solid rocket booster thrust vector control subsystem verification test (V-2) report

    NASA Technical Reports Server (NTRS)

    Pagan, B.

    1979-01-01

    The results of the verification testing sequence V-2 performed on the space shuttle solid rocket booster thrust vector control subsystem are presented. A detailed history of the hot firings plus additional discussion of the auxiliary power unit and the hydraulic component performance is presented. The test objectives, data, and conclusions are included.

  7. Design Specification for a Thrust-Vectoring, Actuated-Nose-Strake Flight Control Law for the High-Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bacon, Barton J.; Carzoo, Susan W.; Davidson, John B.; Hoffler, Keith D.; Lallman, Frederick J.; Messina, Michael D.; Murphy, Patrick C.; Ostroff, Aaron J.; Proffitt, Melissa S.; Yeager, Jessie C.; Foster, John V.; Bundick, W. Thomas; Connelly, Patrick J.; Kelly, John W.; Pahle, Joseph W.; Thomas, Michael; Wichman, Keith D.; Wilson, R. Joseph

    1996-01-01

    Specifications for a flight control law are delineated in sufficient detail to support coding the control law in flight software. This control law was designed for implementation and flight test on the High-Alpha Research Vehicle (HARV), which is an F/A-18 aircraft modified to include an experimental multi-axis thrust-vectoring system and actuated nose strakes for enhanced rolling (ANSER). The control law, known as the HARV ANSER Control Law, was designed to utilize a blend of conventional aerodynamic control effectors, thrust vectoring, and actuated nose strakes to provide increased agility and good handling qualities throughout the HARV flight envelope, including angles of attack up to 70 degrees.

  8. Design Enhancements of the Two-Dimensional, Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    NASA Technical Reports Server (NTRS)

    Flamm, Jeffrey D.; Deere, Karen A.; Mason, Mary L.; Berrier, Bobby L.; Johnson, Stuart K.

    2006-01-01

    A Dual Throat Nozzle fluidic thrust vectoring technique that achieves higher thrust-vectoring efficiencies than other fluidic techniques, without sacrificing thrust efficiency has been developed at NASA Langley Research Center. The nozzle concept was designed with the aid of the structured-grid, Reynolds-averaged Navier-Stokes computational fluidic dynamics code PAB3D. This new concept combines the thrust efficiency of sonic-plane skewing with increased thrust-vectoring efficiencies obtained by maximizing pressure differentials in a separated cavity located downstream of the nozzle throat. By injecting secondary flow asymmetrically at the upstream minimum area, a new aerodynamic minimum area is formed downstream of the geometric minimum and the sonic line is skewed, thus vectoring the exhaust flow. The nozzle was tested in the NASA Langley Research Center Jet Exit Test Facility. Internal nozzle performance characteristics were defined for nozzle pressure ratios up to 10, with a range of secondary injection flow rates up to 10 percent of the primary flow rate. Most of the data included in this paper shows the effect of secondary injection rate at a nozzle pressure ratio of 4. The effects of modifying cavity divergence angle, convergence angle and cavity shape on internal nozzle performance were investigated, as were effects of injection geometry, hole or slot. In agreement with computationally predicted data, experimental data verified that decreasing cavity divergence angle had a negative impact and increasing cavity convergence angle had a positive impact on thrust vector angle and thrust efficiency. A curved cavity apex provided improved thrust ratios at some injection rates. However, overall nozzle performance suffered with no secondary injection. Injection holes were more efficient than the injection slot over the range of injection rates, but the slot generated larger thrust vector angles for injection rates less than 4 percent of the primary flow rate.

  9. A Method for Integrating Thrust-Vectoring and Actuated Forebody Strakes with Conventional Aerodynamic Controls on a High-Performance Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Lallman, Frederick J.; Davidson, John B.; Murphy, Patrick C.

    1998-01-01

    A method, called pseudo controls, of integrating several airplane controls to achieve cooperative operation is presented. The method eliminates conflicting control motions, minimizes the number of feedback control gains, and reduces the complication of feedback gain schedules. The method is applied to the lateral/directional controls of a modified high-performance airplane. The airplane has a conventional set of aerodynamic controls, an experimental set of thrust-vectoring controls, and an experimental set of actuated forebody strakes. The experimental controls give the airplane additional control power for enhanced stability and maneuvering capabilities while flying over an expanded envelope, especially at high angles of attack. The flight controls are scheduled to generate independent body-axis control moments. These control moments are coordinated to produce stability-axis angular accelerations. Inertial coupling moments are compensated. Thrust-vectoring controls are engaged according to their effectiveness relative to that of the aerodynamic controls. Vane-relief logic removes steady and slowly varying commands from the thrust-vectoring controls to alleviate heating of the thrust turning devices. The actuated forebody strakes are engaged at high angles of attack. This report presents the forward-loop elements of a flight control system that positions the flight controls according to the desired stability-axis accelerations. This report does not include the generation of the required angular acceleration commands by means of pilot controls or the feedback of sensed airplane motions.

  10. Thrust vectoring for single-stage-to-orbit, horizontal takeoff, horizontal landing, space vehicles

    NASA Technical Reports Server (NTRS)

    Cunningham, M. J.; Freeman, D. C., Jr.; Wilhite, A. W.; Powell, R. W.

    1986-01-01

    The preliminary design of a horizontal takeoff, horizontal landing, single-stage-to-orbit, rocket-powered space vehicle was performed. The purpose was to examine technology requirements for future small payload launch vehicles. The distinguishing aspect of the design was the utilization of thrust vectoring to provide half of the lift at takeoff. The inclusion of a canard was necessary to provide additional lift at takeoff and to balance the moments produced with thrust vectoring. A weights estimation, an aerodynamic assessment, a trajectory analysis, and a gear weight analysis were performed. The takeoff weight of the resulting vehicle was approximately 1.26 million pounds, based on advanced technology structures and subsystems. The vehicle was designed to deliver a 5000-pound payload to a polar orbit.

  11. Optimal Pitch Thrust-Vector Angle and Benefits for all Flight Regimes

    NASA Technical Reports Server (NTRS)

    Gilyard, Glenn B.; Bolonkin, Alexander

    2000-01-01

    The NASA Dryden Flight Research Center is exploring the optimum thrust-vector angle on aircraft. Simple aerodynamic performance models for various phases of aircraft flight are developed and optimization equations and algorithms are presented in this report. Results of optimal angles of thrust vectors and associated benefits for various flight regimes of aircraft (takeoff, climb, cruise, descent, final approach, and landing) are given. Results for a typical wide-body transport aircraft are also given. The benefits accruable for this class of aircraft are small, but the technique can be applied to other conventionally configured aircraft. The lower L/D aerodynamic characteristics of fighters generally would produce larger benefits than those produced for transport aircraft.

  12. Electromechanical three-axis development for remote handling in the Hot Experimental Facility

    SciTech Connect

    Garin, J.; Bolfing, B.J.; Satterlee, P.E.; Babcock, S.M.

    1981-01-01

    A three-axis closed-loop position control system has been designed and installed on an overhead bridge, carriage, tube hoist for automotive positioning of manipulation at a remotely maintained work site. The system provides accurate (within 3 min) and repeatable three-axis positioning of the manipulator. The position control system has been interfaced to a supervisory minicomputer system that provides teach-playback capability of manipulator positioning and color graphic display of the three-axis system position.

  13. Translation Optics for 30 cm Ion Engine Thrust Vector Control

    NASA Technical Reports Server (NTRS)

    Haag, Thomas

    2002-01-01

    Data were obtained from a 30 cm xenon ion thruster in which the accelerator grid was translated in the radial plane. The thruster was operated at three different throttle power levels, and the accelerator grid was incrementally translated in the X, Y, and azimuthal directions. Plume data was obtained downstream from the thruster using a Faraday probe mounted to a positioning system. Successive probe sweeps revealed variations in the plume direction. Thruster perveance, electron backstreaming limit, accelerator current, and plume deflection angle were taken at each power level, and for each accelerator grid position. Results showed that the thruster plume could easily be deflected up to six degrees without a prohibitive increase in accelerator impingement current. Results were similar in both X and Y direction.

  14. Hybrid electrical power source for thrust vector control electromechanical actuation

    SciTech Connect

    Hall, D.K.; Merryman, S.A.

    1995-12-31

    The next generation of launch vehicles propose to use electromechanical actuators (EMA`s) for engine gimbaling and aerosurface control to eliminate hydraulics and its associated systems and problems. The new actuation systems are not without their own challenges. An EMA`s duty cycle has two components: a high power pulse to initiate and perform the actuation, and a nominal load to maintain position. Conventional batteries must be sized to meet the pulse power requirement while maintaining a bus voltage in range to satisfy the needs of the EMA control electronics, and therein lies the problem. Restricting the voltage sag limits the discharge rate of the battery and therefore requires an increase in the Amp-hour rating, which relates directly to an increase in weight. An option to lower power source weight is a hybrid source consisting of a conventional battery and a capacitor bank. A hybrid source of this type would utilize the power density strengths of a capacitor bank to meet the high power pulse demands, and the energy density strengths of a battery to provide average power and capacitor recharging. Testing has been performed at NASA`s Marshall Space Flight Center (MSFC) with support from Auburn University`s Space Power Institute to investigate the validity of the hybrid power source concept. This proof-of-concept testing used chemical double layer (CDL) capacitor technology in the form of a {approx}5 farad-270 volt capacitor bank, standard deep cycle marine lead-acid batteries, and a 25 horse power EMA developed at MSFC. The test data was used to size a flight type Ag-Zn battery to perform the same task in a battery-only configuration, and also size a battery for a hybrid configuration. Test results and analysis show that a >50% weight savings can be realized with this type of hybrid power source with no negative effect on performance. These results support the need for further development in the area of CDL capacitors and hybrid configurations.

  15. Vista/F-16 Multi-Axis Thrust Vectoring (MATV) control law design and evaluation

    NASA Technical Reports Server (NTRS)

    Zwerneman, W. D.; Eller, B. G.

    1994-01-01

    For the Multi-Axis Thrust Vectoring (MATV) program, a new control law was developed using multi-axis thrust vectoring to augment the aircraft's aerodynamic control power to provide maneuverability above the normal F-16 angle of attack limit. The control law architecture was developed using Lockheed Fort Worth's offline and piloted simulation capabilities. The final flight control laws were used in flight test to demonstrate tactical benefits gained by using thrust vectoring in air-to-air combat. Differences between the simulator aerodynamics data base and the actual aircraft aerodynamics led to significantly different lateral-directional flying qualities during the flight test program than those identified during piloted simulation. A 'dial-a-gain' flight test control law update was performed in the middle of the flight test program. This approach allowed for inflight optimization of the aircraft's flying qualities. While this approach is not preferred over updating the simulator aerodynamic data base and then updating the control laws, the final selected gain set did provide adequate lateral-directional flying qualities over the MATV flight envelope. The resulting handling qualities and the departure resistance of the aircraft allowed the 422nd_squadron pilots to focus entirely on evaluating the aircraft's tactical utility.

  16. Effect of thrust vectoring and wing maneuver devices on transonic aeropropulsive characteristics of a supersonic fighter

    NASA Technical Reports Server (NTRS)

    Capone, F. J.; Reubush, D. E.

    1983-01-01

    The aeropropulsive characteristics of an advanced fighter designed for supersonic cruise were determined in the Langley 16-Foot Transonic Tunnel. The objectives of this investigation were to evaluate the interactive effects of thrust vectoring and wing maneuver devices on lift and drag and to determine trim characteristics. The wing maneuver devices consisted of a drooped leading edge and a trailing-edge flap. Thrust vectoring was accomplished with two dimensional (nonaxisymmetric) convergent-divergent nozzles located below the wing in two single-engine podded nacelles. A canard was utilized for trim. Thrust vector angles of 0 deg, 15 deg, and 30 deg were tested in combination with a drooped wing leading edge and with wing trailing-edge flap deflections up to 30 deg. This investigation was conducted at Mach numbers from 0.60 to 1.20, at angles of attack from 0 deg to 20 deg, and at nozzle pressure ratios from about 1 (jet off) to 10. Reynolds number based on mean aerodynamic chord varied from 9.24 x 10 to the 6th to 10.56 x 10 to the 6th.

  17. Static performance of nonaxisymmetric nozzles with yaw thrust-vectoring vanes

    NASA Technical Reports Server (NTRS)

    Mason, Mary L.; Berrier, Bobby L.

    1988-01-01

    A static test was conducted in the static test facility of the Langley 16 ft Transonic Tunnel to evaluate the effects of post exit vane vectoring on nonaxisymmetric nozzles. Three baseline nozzles were tested: an unvectored two dimensional convergent nozzle, an unvectored two dimensional convergent-divergent nozzle, and a pitch vectored two dimensional convergent-divergent nozzle. Each nozzle geometry was tested with 3 exit aspect ratios (exit width divided by exit height) of 1.5, 2.5 and 4.0. Two post exit yaw vanes were externally mounted on the nozzle sidewalls at the nozzle exit to generate yaw thrust vectoring. Vane deflection angle (0, -20 and -30 deg), vane planform and vane curvature were varied during the test. Results indicate that the post exit vane concept produced resultant yaw vector angles which were always smaller than the geometric yaw vector angle. Losses in resultant thrust ratio increased with the magnitude of resultant yaw vector angle. The widest post exit vane produced the largest degree of flow turning, but vane curvature had little effect on thrust vectoring. Pitch vectoring was independent of yaw vectoring, indicating that multiaxis thrust vectoring is feasible for the nozzle concepts tested.

  18. Three-Axis Superconducting Gravity Gradiometer

    NASA Technical Reports Server (NTRS)

    Paik, Ho Jung

    1987-01-01

    Gravity gradients measured even on accelerating platforms. Three-axis superconducting gravity gradiometer based on flux quantization and Meissner effect in superconductors and employs superconducting quantum interference device as amplifier. Incorporates several magnetically levitated proof masses. Gradiometer design integrates accelerometers for operation in differential mode. Principal use in commercial instruments for measurement of Earth-gravity gradients in geo-physical surveying and exploration for oil.

  19. Fabrication and characterization of polymeric three-axis thermal accelerometers

    NASA Astrophysics Data System (ADS)

    Silva, Ctia; Noh, Jong; Fonseca, Helder; Pontes, Antnio; Gaspar, Joo; Alexandre Rocha, Luis

    2015-08-01

    The concept, fabrication process, and characterization of a three-axis thermal accelerometer are presented in this paper. A combination of microelectromechanical systems (MEMS) technology with microinjection molding enables the realization of functional, highly complex 3D geometries at the microscale, used here for the fabrication of a fully integrated three-axis accelerometer. While conventional thermal accelerometers are silicon based, using MEMS technologies only, the integration of polymeric materials and technologies into the fabrication process can greatly improve the realization of three-axis devices while diminishing the typical thermal losses. Three-axis thermal accelerometers were successfully fabricated by combining the proposed technologies proving the viability of the concept. Fabricated accelerometers show xy-axis sensitivity around 8?mV?g-1, a z-axis sensitivity of 2.2?mV?g-1 for a power of 45?mW and a 4?Hz bandwidth (bandwidth is based on simulations). Thermal tests performed showed that the heater can sustain up to 280?C without overheating the remaining structures and damaging the device.

  20. Static investigation of two fluidic thrust-vectoring concepts on a two-dimensional convergent-divergent nozzle

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1994-01-01

    A static investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel of two thrust-vectoring concepts which utilize fluidic mechanisms for deflecting the jet of a two-dimensional convergent-divergent nozzle. One concept involved using the Coanda effect to turn a sheet of injected secondary air along a curved sidewall flap and, through entrainment, draw the primary jet in the same direction to produce yaw thrust vectoring. The other concept involved deflecting the primary jet to produce pitch thrust vectoring by injecting secondary air through a transverse slot in the divergent flap, creating an oblique shock in the divergent channel. Utilizing the Coanda effect to produce yaw thrust vectoring was largely unsuccessful. Small vector angles were produced at low primary nozzle pressure ratios, probably because the momentum of the primary jet was low. Significant pitch thrust vector angles were produced by injecting secondary flow through a slot in the divergent flap. Thrust vector angle decreased with increasing nozzle pressure ratio but moderate levels were maintained at the highest nozzle pressure ratio tested. Thrust performance generally increased at low nozzle pressure ratios and decreased near the design pressure ratio with the addition of secondary flow.

  1. GRADIO three-axis electrostatic accelerometers

    NASA Technical Reports Server (NTRS)

    Bernard, A.

    1987-01-01

    Dedicated accelerometers for satellite gravity gradiometry (GRADIO project) are described. The design profits from experience acquired with the CACTUS accelerometer payload of the satellite CASTOR-D5B and studies of highly accurate accelerometers for inertial navigation. The principle of operation, based on a three-axis electrostatic suspension of a cubic proof mass, is well suited for the measurements of accelerations less than 0.0001 m/sec/sec. A resolution better than 10 to the minus 11th power m/sec/sec/sq root Hz is expected.

  2. Evaluation of dual flow thrust vector nozzles with exhaust stream impingement

    NASA Technical Reports Server (NTRS)

    Carpenter, Thomas W.; Dobbins, Sean; Vaccarezza, Steven

    1992-01-01

    To supplement previous work performed by NASA, a cold-jet facility was established at the California Polytechnic State University, San Luis Obispo campus. The purpose of this facility is to continue the studies of cold flow multiaxis thrust vectoring conducted at the NASA Langley Research Center. A single nozzle test apparatus was completed and is presently operational. Included are the results of the single flow test envelope that was requested by NASA personnel. Details about the test apparatus are included in the Cal Poly Semi-Annual Progress report.

  3. Independent Orbiter Assessment (IOA): Analysis of the ascent thrust vector control actuator subsystem

    NASA Technical Reports Server (NTRS)

    Wilson, R. E.; Riccio, J. R.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Ascent Thrust Vector Control (ATVC) Actuator hardware are documented. The function of the Ascent Thrust Vector Control Actuators (ATVC) is to gimbal the main engines to provide for attitude and flight path control during ascent. During first stage flight, the SRB nozzles provide nearly all the steering. After SRB separation, the Orbiter is steered by gimbaling of its main engines. There are six electrohydraulic servoactuators, one pitch and one yaw for each of the three main engines. Each servoactuator is composed of four electrohydraulic servovalve assemblies, one second stage power spool valve assembly, one primary piston assembly and a switching valve. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Critical failures resulting in loss of ATVC were mainly due to loss of hydraulic fluid, fluid contamination and mechanical failures.

  4. Experimental Study of a Nozzle Using Fluidic Counterflow for Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Flamm, Jeffrey D.

    1998-01-01

    A static experimental investigation of a counterflow thrust vectoring nozzle concept was performed. The study was conducted in the NASA Langley Research Center Jet Exit Test Facility. Internal performance characteristics were defined over a nozzle pressure ratio (jet total to ambient) range of 3.5 to 10.0. The effects of suction collar geometry and suction slot height on nozzle performance were examined. In the counterflow concept, thrust vectoring is achieved by applying a vacuum to a slot adjacent to a primary jet that is shrouded by a suction collar. Two flow phenomena work to vector the primary jet depending upon the test conditions and configuration. In one case, the vacuum source creates a secondary reverse flowing stream near the primary jet. The shear layers between the two counterflowing streams mix and entrain mass from the surrounding fluid. The presence of the collar inhibits mass entrainment and the flow near the collar accelerates, causing a drop in pressure on the collar. The second case works similarly except that the vacuum is not powerful enough to create a counterflowing stream and instead a coflowing stream is present. The primary jet is vectored if suction is applied asymmetrically on the top or bottom of the jet.

  5. Static investigation of a two-dimensional convergent-divergent exhaust nozzle with multiaxis thrust-vectoring capability

    NASA Technical Reports Server (NTRS)

    Taylor, John G.

    1990-01-01

    An investigation was conducted in the Static Test Facility of the NASA Langley 16-Foot Transonic Tunnel to determine the internal performance of two-dimensional convergent-divergent nozzles designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap rotation of thrust vectoring in the pitch plane and deflection of flat yaw flaps hinged at the end of the sidewalls for yaw thrust vectoring. The hinge location of the yaw flaps was varied at four positions from the nozzle exit plane to the throat plane. The yaw flaps were designed to contain the flow laterally independent of power setting. In order to eliminate any physical interference between the yaw flap deflected into the exhaust stream and the divergent flaps, the downstream corners of both upper and lower divergent flaps were cut off to allow for up to 30 deg of yaw flap deflection. The impact of varying the nozzle pitch vector angle, throat area, yaw flap hinge location, yaw flap length, and yaw flap deflection angle on nozzle internal performance characteristics, was studied. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 7.0. Static results indicate that configurations with the yaw flap hinge located upstream of the exit plane provide relatively high levels of thrust vectoring efficiency without causing large losses in resultant thrust ratio. Therefore, these configurations represent a viable concept for providing simultaneous pitch and yaw thrust vectoring.

  6. Preliminary Characterization of the Altair Lunar Lander Slosh Dynamics and Some Implications for the Thrust Vector Control Design

    NASA Technical Reports Server (NTRS)

    Lee, Allan Y.; Strahan, Alan; Tanimoto, Rebekah; Casillas, Arturo

    2010-01-01

    This paper describes a conceptual design of the Thrust Vector Control (TVC) system and preliminary modeling of propellant slosh, for the Altair Lunar Lander. Altair is a vehicle element of the NASA Constellation Program aimed at returning humans to the moon. Guidance, Navigation, and Control (GN&C) is the measurement and control of spacecraft position, velocity, and attitude in support of mission objectives. One key GN&C function is the commanding of effectors that control attitude and impart delta V on the vehicle, utilizing both reaction control system (RCS) thrusters and throttling and TVC gimbaling of the vehicle main engine. Both the Altair descent and ascent modules carry fuel tanks. During thrusting maneuvers, the sloshing of liquid fuels in partially filled tanks can interact with the controlled system in such a way as to cause the overall system to be unstable. These fuel tanks must be properly placed, relative to the spacecraft's c.m., to avoid any unstable interactions. Following this will be a discussion of propellant slosh modeling work performed for the present vehicle configuration, including slosh frequency and participatory fluid mass predictions. Knowing the range of slosh mode frequencies over mission phases, the TVC bandwidth must be carefully selected so as not to excite the slosh modes at those frequencies. The likely need to increase the damping factor of slosh modes via baffles will also be discussed. To conclude, a discussion of operations procedures aimed at minimizing TVC-slosh interactions will be given.

  7. Three-axis particle impact probe

    DOEpatents

    Fasching, George E.; Smith, Jr., Nelson S.; Utt, Carroll E.

    1992-01-01

    Three-axis particle impact probes detect particle impact vectors along x-, y-, and z-axes by spherical probe head mounted on the outer end of a shaft that is flexibly mounted in silicone rubber at the top of a housing so as to enable motion imparted to the head upon impact to be transmitted to a grounded electrode secured to the shaft within the housing. Excitable electrodes are mounted in the housing in a fixed position, spaced apart from the ground electrode and forming, with the ground electrode, capacitor pairs. Movement of the ground electrode results in changes in capacitance, and these difference in capacitance are used for measurement or derivation of momentum vectors along each of the three axes. In one embodiment, the ground electrode is mounted at the base of the shaft and is secured to a silicone rubber layer at the top of the housing, providing for cantilevered movement. In another embodiment, the shaft is mounted at its mid point in a flexible bushing so that it undergoes pivotal movement around that point.

  8. Three-axis particle impact probe

    SciTech Connect

    Fasching, G.E.; Smith, N.S. Jr.; Utt, C.E.

    1992-09-01

    Three-axis particle impact probes detect particle impact vectors along x-, y-, and z-axes by spherical probe head mounted on the outer end of a shaft that is flexibly mounted in silicone rubber at the top of a housing so as to enable motion imparted to the head upon impact to be transmitted to a grounded electrode secured to the shaft within the housing. Excitable electrodes are mounted in the housing in a fixed position, spaced apart from the ground electrode and forming, with the ground electrode, capacitor pairs. Movement of the ground electrode results in changes in capacitance, and these difference in capacitance are used for measurement or derivation of momentum vectors along each of the three axes. In one embodiment, the ground electrode is mounted at the base of the shaft and is secured to a silicone rubber layer at the top of the housing, providing for cantilevered movement. In another embodiment, the shaft is mounted at its mid point in a flexible bushing so that it undergoes pivotal movement around that point. 9 figs.

  9. Three-axis particle impact probe

    SciTech Connect

    Fasching, G.E.; Smith, N.S. Jr.; Utt, C.E.

    1991-04-02

    Three-axis particle impact probes detect particle impact vectors along x-, y-, and z-axes by means of a head mounted on the outer end of a shaft that is flexibly mounted in silicone rubber at the top of a housing so as to enable motion imparted to the head upon impact to be transmitted to a grounded electrode secured to the shaft within the housing. Excitable electrodes are mounted in the housing in a fixed position, spaced apart from the ground electrode and forming, with the ground electrode, capacitor pairs. Movement of the ground electrode results in changes in capacitance, and these differences in capacitance are used for measurement or derivation of momentum vectors along each of the three axes. In one embodiment, the ground electrode is mounted at the base of the shaft and is secured to a silicone rubber layer at the top of the housing, providing for cantilevered movement. In another embodiment, the shaft is mounted at its mid point in a flexible bushing so that it undergoes pivotal movement around that point.

  10. Static internal performance of single-expansion-ramp nozzles with thrust-vectoring capability up to 60 deg

    NASA Technical Reports Server (NTRS)

    Berrier, B. L.; Leavitt, L. D.

    1984-01-01

    An investigation has been conducted at static conditions (wind off) in the static-test facility of the Langley 16-Foot Transonic Tunnel. The effects of geometric thrust-vector angle, sidewall containment, ramp curvature, lower-flap lip angle, and ramp length on the internal performance of nonaxisymmetric single-expansion-ramp nozzles were investigated. Geometric thrust-vector angle was varied from -20 deg. to 60 deg., and nozzle pressure ratio was varied from 1.0 (jet off) to approximately 10.0.

  11. Static internal performance of a single expansion ramp nozzle with multiaxis thrust vectoring capability

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Schirmer, Alberto W.

    1993-01-01

    An investigation was conducted at static conditions in order to determine the internal performance characteristics of a multiaxis thrust vectoring single expansion ramp nozzle. Yaw vectoring was achieved by deflecting yaw flaps in the nozzle sidewall into the nozzle exhaust flow. In order to eliminate any physical interference between the variable angle yaw flap deflected into the exhaust flow and the nozzle upper ramp and lower flap which were deflected for pitch vectoring, the downstream corners of both the nozzle ramp and lower flap were cut off to allow for up to 30 deg of yaw vectoring. The effects of nozzle upper ramp and lower flap cutout, yaw flap hinge line location and hinge inclination angle, sidewall containment, geometric pitch vector angle, and geometric yaw vector angle were studied. This investigation was conducted in the static-test facility of the Langley 16-Foot Transonic Tunnel at nozzle pressure ratios up to 8.0.

  12. F-15B ACTIVE with thrust vectoring nozzles on test stand view from rear

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This November 13, 1995, photograph of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the aircraft's two new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. These nozzles give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. Ground testing of a new thrust-vectoring concept employing the nozzles took place during the first two weeks of November 1995 and went well, and flight tests began in March 1996. These tests could result in significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace.

  13. PAB3D Simulations of a Nozzle with Fluidic Injection for Yaw Thrust-Vector Control

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.

    1998-01-01

    An experimental and computational study was conducted on an exhaust nozzle with fluidic injection for yaw thrust-vector control. The nozzle concept was tested experimentally in the NASA Langley Jet Exit Test Facility (JETF) at nozzle pressure ratios up to 4 and secondary fluidic injection flow rates up to 15 percent of the primary flow rate. Although many injection-port geometries and two nozzle planforms (symmetric and asymmetric) were tested experimentally, this paper focuses on the computational results of the more successful asymmetric planform with a slot injection port. This nozzle concept was simulated with the Navier-Stokes flow solver, PAB3D, invoking the Shih, Zhu, and Lumley algebraic Reynolds stress turbulence model (ASM) at nozzle pressure ratios (NPRs) of 2,3, and 4 with secondary to primary injection flow rates (w(sub s)/w(sub p)) of 0, 2, 7 and 10 percent.

  14. Selected Performance Measurements of the F-15 Active Axisymmetric Thrust-vectoring Nozzle

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Sims, Robert L.

    1998-01-01

    Flight tests recently completed at the NASA Dryden Flight Research Center evaluated performance of a hydromechanically vectored axisymmetric nozzle onboard the F-15 ACTIVE. A flight-test technique whereby strain gages installed onto engine mounts provided for the direct measurement of thrust and vector forces has proven to be extremely valuable. Flow turning and thrust efficiency, as well as nozzle static pressure distributions were measured and analyzed. This report presents results from testing at an altitude of 30,000 ft and a speed of Mach 0.9. Flow turning and thrust efficiency were found to be significantly different than predicted, and moreover, varied substantially with power setting and pitch vector angle. Results of an in-flight comparison of the direct thrust measurement technique and an engine simulation fell within the expected uncertainty bands. Overall nozzle performance at this flight condition demonstrated the F100-PW-229 thrust-vectoring nozzles to be highly capable and efficient.

  15. Selected Performance Measurements of the F-15 ACTIVE Axisymmetric Thrust-Vectoring Nozzle

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Sims, Robert L.

    1999-01-01

    Flight tests recently completed at the NASA Dryden Flight Research Center evaluated performance of a hydromechanically vectored axisymmetric nozzle onboard the F-15 ACTIVE. A flight-test technique whereby strain gages installed onto engine mounts provided for the direct measurement of thrust and vector forces has proven to be extremely valuable. Flow turning and thrust efficiency, as well as nozzle static pressure distributions were measured and analyzed. This report presents results from testing at an altitude of 30,000 ft and a speed of Mach 0.9. Flow turning and thrust efficiency were found to be significantly different than predicted, and moreover, varied substantially with power setting and pitch vector angle. Results of an in-flight comparison of the direct thrust measurement technique and an engine simulation fell within the expected uncertainty bands. Overall nozzle performance at this flight condition demonstrated the F100-PW-229 thrust-vectoring nozzles to be highly capable and efficient.

  16. Closed-Loop Simulation Study of the Ares I Upper Stage Thrust Vector Control Subsystem for Nominal and Failure Scenarios

    NASA Technical Reports Server (NTRS)

    Chicatelli, Amy; Fulton, Chris; Connolly, Joe; Hunker, Keith

    2010-01-01

    As a replacement to the current Shuttle, the Ares I rocket and Orion crew module are currently under development by the National Aeronautics and Space Administration (NASA). This new launch vehicle is segmented into major elements, one of which is the Upper Stage (US). The US is further broken down into subsystems, one of which is the Thrust Vector Control (TVC) subsystem which gimbals the US rocket nozzle. Nominal and off-nominal simulations for the US TVC subsystem are needed in order to support the development of software used for control systems and diagnostics. In addition, a clear and complete understanding of the effect of off-nominal conditions on the vehicle flight dynamics is desired. To achieve these goals, a simulation of the US TVC subsystem combined with the Ares I vehicle as developed. This closed-loop dynamic model was created using Matlab s Simulink and a modified version of a vehicle simulation, MAVERIC, which is currently used in the Ares I project and was developed by the Marshall Space Flight Center (MSFC). For this report, the effects on the flight trajectory of the Ares I vehicle are investigated after failures are injected into the US TVC subsystem. The comparisons of the off-nominal conditions observed in the US TVC subsystem with those of the Ares I vehicle flight dynamics are of particular interest.

  17. Parametric study of a simultaneous pitch/yaw thrust vectoring single expansion ramp nozzle

    NASA Technical Reports Server (NTRS)

    Schirmer, Alberto W.; Capone, Francis J.

    1989-01-01

    In the course of the last eleven years, the concept of thrust vectoring has emerged as a promising method of enhancing aircraft control capabilities in post-stall flight incursions during combat. In order to study the application of simultaneous pitch and yaw vectoring to single expansion ramp nozzles, a static test was conducted in the NASA-Langley 16 foot transonic tunnel. This investigation was based on internal performance data provided by force, mass flow and internal pressure measurements at nozzle pressure ratios up to 8. The internal performance characteristics of the nozzle were studied for several combinations of six different parameters: yaw vectoring angle, pitch vectoring angle, upper ramp cutout, sidewall hinge location, hinge inclination angle and sidewall containment. Results indicated a 2-to- 3-percent decrease in resultant thrust ratio with vectoring in either pitch or yaw. Losses were mostly associated with the turning of supersonic flow. Resultant thrust ratios were also decreased by sideways expansion of the jet. The effects of cutback corners in the upper ramp and lower flap on performance were small. Maximum resultant yaw vector angles, about half of the flap angle, were achieved for the configuration with the most forward hinge location.

  18. Computational Issues Associated with Temporally Deforming Geometries Such as Thrust Vectoring Nozzles

    NASA Technical Reports Server (NTRS)

    Boyalakuntla, Kishore; Soni, Bharat K.; Thornburg, Hugh J.; Yu, Robert

    1996-01-01

    During the past decade, computational simulation of fluid flow around complex configurations has progressed significantly and many notable successes have been reported, however, unsteady time-dependent solutions are not easily obtainable. The present effort involves unsteady time dependent simulation of temporally deforming geometries. Grid generation for a complex configuration can be a time consuming process and temporally varying geometries necessitate the regeneration of such grids for every time step. Traditional grid generation techniques have been tried and demonstrated to be inadequate to such simulations. Non-Uniform Rational B-splines (NURBS) based techniques provide a compact and accurate representation of the geometry. This definition can be coupled with a distribution mesh for a user defined spacing. The present method greatly reduces cpu requirements for time dependent remeshing, facilitating the simulation of more complex unsteady problems. A thrust vectoring nozzle has been chosen to demonstrate the capability as it is of current interest in the aerospace industry for better maneuverability of fighter aircraft in close combat and in post stall regimes. This current effort is the first step towards multidisciplinary design optimization which involves coupling the aerodynamic heat transfer and structural analysis techniques. Applications include simulation of temporally deforming bodies and aeroelastic problems.

  19. Independent Orbiter Assessment (IOA): Assessment of the ascent thrust vector control actuator subsystem FMEA/CIL

    NASA Technical Reports Server (NTRS)

    Wilson, R. E.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Ascent Thrust Vector Control Actuator (ATVD) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter ATVC hardware. The IOA product for the ATVC actuator analysis consisted of 25 failure mode worksheets that resulted in 16 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 21 FMEAs and 13 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

  20. Fiber-optic three axis magnetometer prototype development

    NASA Technical Reports Server (NTRS)

    Wang, Thomas D.; Mccomb, David G.; Kingston, Bradley R.; Dube, C. Michael; Poehls, Kenneth A.; Wanser, Keith

    1989-01-01

    The goal of this research program was to develop a high sensitivity, fiber optic, interferometric, three-axis magnetometer for interplanetary spacecraft applications. Dynamics Technology, Inc. (DTI) has successfully integrated a low noise, high bandwidth interferometer with high sensitivity metallic glass transducers. Also, DTI has developed sophisticated signal processing electronics and complete data acquisition, filtering, and display software. The sensor was packaged in a compact, low power and weight unit which facilitates deployment. The magnetic field sensor had subgamma sensitivity and a dynamic range of 10(exp 5) gamma in a 10 Hz bandwidth. Furthermore, the vector instrument exhibited the lowest noise level when only one axis was in operation. A system noise level of 1 gamma rms was observed in a 1 Hz bandwidth. However, with the other two channels operating, the noise level increased by about one order of magnitude. Higher system noise was attributed to cross-channel interference among the dither fields.

  1. A unique three-axis gimbal mechanism

    NASA Astrophysics Data System (ADS)

    Hilkert, J. M.; Jonas, Matthew

    2008-04-01

    Future space based deployable telescopes will be subject to non-atmospheric disturbances. Jitter and optical misalignment on a spacecraft can be caused by mechanical noise of the spacecraft, and settling after maneuvers. The introduction of optical misalignment and jitter can reduce the performance of an optical system resulting in pointing error and contributing to higher order aberrations. Adaptive optics can be used to control jitter and higher order aberrations in an optical system. In this paper, wavefront control methods for the Naval Postgraduate School adaptive optics testbed are developed. The focus is on removing structural noise from the flexible optical surface using discrete time proportional integral control with second order filters. Experiments using the adaptive optics testbed successfully demonstrate wavefront control methods, including a combined iterative feedback and gradient control technique. This control technique results in a three time improvement in RMS wavefront error over the individual controllers correcting from a biased mirror position. Second order discrete time notch filters are also used to remove induced low frequency actuator and sensor noise at 2Hz. Additionally a 2 Hz structural disturbance is simulated on a Micromachined Membrane Deformable Mirror and removed using discrete time notch filters combined with an iterative closed loop feedback controller, showing a 36 time improvement in RMS wavefront error over the iterative closed loop feedback alone.

  2. Improved Controller for a Three-Axis Piezoelectric Stage

    NASA Technical Reports Server (NTRS)

    Rao, Shanti; Palmer, Dean

    2009-01-01

    An improved closed-loop controller has been built for a three-axis piezoelectric positioning stage. The stage can be any of a number of commercially available or custom-made units that are used for precise three-axis positioning of optics in astronomical instruments and could be used for precise positioning in diverse fields of endeavor that include adaptive optics, fabrication of semiconductors, and nanotechnology.

  3. Experimental and Computational Investigation of Multiple Injection Ports in a Convergent-Divergent Nozzle for Fluidic Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Waithe, Kenrick A.; Deere, Karen A.

    2003-01-01

    A computational and experimental study was conducted to investigate the effects of multiple injection ports in a two-dimensional, convergent-divergent nozzle, for fluidic thrust vectoring. The concept of multiple injection ports was conceived to enhance the thrust vectoring capability of a convergent-divergent nozzle over that of a single injection port without increasing the secondary mass flow rate requirements. The experimental study was conducted at static conditions in the Jet Exit Test Facility of the 16-Foot Transonic Tunnel Complex at NASA Langley Research Center. Internal nozzle performance was obtained at nozzle pressure ratios up to 10 with secondary nozzle pressure ratios up to 1 for five configurations. The computational study was conducted using the Reynolds Averaged Navier-Stokes computational fluid dynamics code PAB3D with two-equation turbulence closure and linear Reynolds stress modeling. Internal nozzle performance was predicted for nozzle pressure ratios up to 10 with a secondary nozzle pressure ratio of 0.7 for two configurations. Results from the experimental study indicate a benefit to multiple injection ports in a convergent-divergent nozzle. In general, increasing the number of injection ports from one to two increased the pitch thrust vectoring capability without any thrust performance penalties at nozzle pressure ratios less than 4 with high secondary pressure ratios. Results from the computational study are in excellent agreement with experimental results and validates PAB3D as a tool for predicting internal nozzle performance of a two dimensional, convergent-divergent nozzle with multiple injection ports.

  4. A three-axis ultrasensitive accelerometer for space

    NASA Astrophysics Data System (ADS)

    Bernard, A.

    A three-axis ultrasensitive accelerometer ASTRE (Accelerometre Spatial Triaxial Electrostatique) is a simplified version of the GRADIO accelerometer designed for the ARISTOTELES mission, which operates by measuring the force provided by a three-axis electrostatic suspension of the proof-mass. It covers the g-spectrum from 10 exp -8 to 10 exp -4 in the frequency range dc to 5 Hz. A dedicated test bench was developed in order to preserve the accelerometer from the seismic noise. The paper presents the performance parameters of the ASTRE accelerometer and some of the design schemes.

  5. Calibration of three-axis magnetometers with differential evolution algorithm

    NASA Astrophysics Data System (ADS)

    Pang, Hongfeng; Zhang, Qi; Wang, Wei; Wang, Junya; Li, Ji; Luo, Shitu; Wan, Chengbiao; Chen, Dixiang; Pan, Mengchun; Luo, Feilu

    2013-11-01

    The accuracy of three-axis magnetometers is influenced by different scale and bias of each axis and nonorthogonality between axes. One limitation of traditional iteration methods is that initial parameters influence the calibration, thus leading to the local optimal or wrong results. In this paper, a new method is proposed to calibrate three-axis magnetometers. To employ this method, a nonmagnetic rotation platform, a proton magnetometer, a DM-050 three-axis magnetometer and the differential evolution (DE) algorithm are used. The performance of this calibration method is analyzed with simulation and experiment. In simulation, the calibration results of DE, unscented Kalman filter (UKF), recursive least squares (RLS) and genetic algorithm (GA) are compared. RMS error using DE is least, which is reduced from 81.233 nT to 1.567 nT. Experimental results show that comparing with UKF, RLS and GA, the DE algorithm has not only the least calibration error but also the best robustness. After calibration, RMS error is reduced from 68.914 nT to 2.919 nT. In addition, the DE algorithm is not sensitive to initial parameters, which is an important advantage compared with traditional iteration algorithms. The proposed algorithm can avoid the troublesome procedure to select suitable initial parameters, thus it can improve the calibration performance of three-axis magnetometers.

  6. An experimental investigation of thrust vectoring two-dimensional convergent-divergent nozzles installed in a twin-engine fighter model at high angles of attack

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Mason, Mary L.; Leavitt, Laurence D.

    1990-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine thrust vectoring capability of subscale 2-D convergent-divergent exhaust nozzles installed on a twin engine general research fighter model. Pitch thrust vectoring was accomplished by downward rotation of nozzle upper and lower flaps. The effects of nozzle sidewall cutback were studied for both unvectored and pitch vectored nozzles. A single cutback sidewall was employed for yaw thrust vectoring. This investigation was conducted at Mach numbers ranging from 0 to 1.20 and at angles of attack from -2 to 35 deg. High pressure air was used to simulate jet exhaust and provide values of nozzle pressure ratio up to 9.

  7. Three-axis attitude determination via Kalman filtering of magnetometer data

    NASA Technical Reports Server (NTRS)

    Martel, Francois; Pal, Parimal K.; Psiaki, Mark L.

    1988-01-01

    A three-axis Magnetometer/Kalman Filter attitude determination system for a spacecraft in low-altitude Earth orbit is developed, analyzed, and simulation tested. The motivation for developing this system is to achieve light weight and low cost for an attitude determination system. The extended Kalman filter estimates the attitude, attitude rates, and constant disturbance torques. Accuracy near that of the International Geomagnetic Reference Field model is achieved. Covariance computation and simulation testing demonstrate the filter's accuracy. One test case, a gravity-gradient stabilized spacecraft with a pitch momentum wheel and a magnetically-anchored damper, is a real satellite on which this attitude determination system will be used. The application to a nadir pointing satellite and the estimation of disturbance torques represent the significant extensions contributed by this paper. Beyond its usefulness purely for attitude determination, this system could be used as part of a low-cost three-axis attitude stabilization system.

  8. Design and Modeling of a Three-axis Piezoresistive Microelectronic Accelerometer

    NASA Astrophysics Data System (ADS)

    Benmoussa, N.; Benichou, A.; Ghaffour, K.; Benyoucef, B.

    Micro-electro-mechanical systems (MEMS) for automotive industry and biomedical applications (BioMEMS) have the fastest growth rate within the MEMS market. The Microsystems job market imposes to research laboratories and universities to respond by increasing the quality of MEMS engineering and informatics interdisciplinary training programs. In this fact, our work consists to study and develop a three-axis piezoresistive accelerometer having uniform sensitivities along to three axes. This sensor which is made of a heavy proof mass and four long beams, allow us to obtain high sensitivities, by reducing the resonant frequencies. Uniform axial sensitivities, with a transverse sensitivity, could be obtained using a three-axis sensor. The stress analysis of this sensor was performed in order to determine the positions of the piezoresistances, in the four flexure beams.

  9. Method for spinning up a three-axis controlled spacecraft

    NASA Technical Reports Server (NTRS)

    Vorlicek, Preston L. (Inventor)

    1988-01-01

    A three-axis controlled spacecraft (1), typically a satellite, is spun up about its roll axis (20) prior to firing a motor (2), i.e., a perigee kick motor, to achieve the requisite degree of angular momentum stiffness. Thrusters (21) for imparting rotation about the roll axis (20) are activated in open-loop fashion, typically at less than full duty cycle. Cross-axis torques induced by this rotational motion are compensated for by means of closed control loops for each of the pitch and yaw axes (30, 40, respectively). Each closed control loop combines a prebias torque (72) with torques (75, 74) representative of position and rate feedback information, respectively. A deadband (52) within each closed control loop can be widened during the spinup, to conserve fuel. Position feedback information (75) in each of the control loops is disabled upon saturation of the gyroscope associated with the roll axis (20).

  10. A three-axis SQUID-based absolute vector magnetometer.

    PubMed

    Schnau, T; Zakosarenko, V; Schmelz, M; Stolz, R; Anders, S; Linzen, S; Meyer, M; Meyer, H-G

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz(1/2). The width of superconducting strip lines is restricted to less than 6 ?m in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 ?T amplitude without the need for recalibration. PMID:26520976

  11. A three-axis SQUID-based absolute vector magnetometer

    NASA Astrophysics Data System (ADS)

    Schönau, T.; Zakosarenko, V.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, M.; Meyer, H.-G.

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz1/2. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  12. Static internal performance of a thrust vectoring and reversing two-dimensional convergent-divergent nozzle with an aft flap

    NASA Technical Reports Server (NTRS)

    Re, R. J.; Leavitt, L. D.

    1986-01-01

    The static internal performance of a multifunction nozzle having some of the geometric characteristics of both two-dimensional convergent-divergent and single expansion ramp nozzles has been investigated in the static-test facility of the Langley 16-Foot Transonic Tunnel. The internal expansion portion of the nozzle consisted of two symmetrical flat surfaces of equal length, and the external expansion portion of the nozzle consisted of a single aft flap. The aft flap could be varied in angle independently of the upper internal expansion surface to which it was attached. The effects of internal expansion ratio, nozzle thrust-vector angle (-30 deg. to 30 deg., aft flap shape, aft flap angle, and sidewall containment were determined for dry and afterburning power settings. In addition, a partial afterburning power setting nozzle, a fully deployed thrust reverser, and four vertical takeoff or landing nozzle, configurations were investigated. Nozzle pressure ratio was varied up to 10 for the dry power nozzles and 7 for the afterburning power nozzles.

  13. Miniature multifunctional high-performance three-axis positioning and scanning platform

    NASA Astrophysics Data System (ADS)

    Avirovik, Dragan; Dave, Digant; Priya, Shashank

    2013-03-01

    This study proposes a novel concept for a three-axis positioning and scanning platform that overcomes the existing gap in technology towards meeting the requirements for displacements, resolution, weight carrying capacity and velocity at smaller dimensions. The novelty of this work stems from the fact that our three-axis stage design utilizes only two actuators. This system was developed to meet the specific requirements needed for implementation of Multifunctional Image Guided Surgical (MIGS) platform. Mathematical model accounting for the open and closed loop operation of the stage was developed. The stage can provide displacements between 10-20mm in each axis, resolution of less than 10?m and scanning velocity in the range of 10-40mm/s. It can carry weights up to 10grams while meeting the desired requirements. Additionally, the stage has small footprint (50mm 50mm 34mm), modular design and extremely cost-effective fabrication. Integration of computer controlled three-axis stage with MIGS platform will provide the opportunity for conducting intricate surgical procedures using remote control or joystick. We demonstrate novel applications that became possible due to the development of this stage.

  14. Real-Time Attitude Independent Three Axis Magnetometer Calibration

    NASA Technical Reports Server (NTRS)

    Crassidis, John L.; Lai, Kok-Lam; Harman, Richard R.

    2003-01-01

    In this paper new real-time approaches for three-axis magnetometer sensor calibration are derived. These approaches rely on a conversion of the magnetometer-body and geomagnetic-reference vectors into an attitude independent observation by using scalar checking. The goal of the full calibration problem involves the determination of the magnetometer bias vector, scale factors and non-orthogonality corrections. Although the actual solution to this full calibration problem involves the minimization of a quartic loss function, the problem can be converted into a quadratic loss function by a centering approximation. This leads to a simple batch linear least squares solution. In this paper we develop alternative real-time algorithms based on both the extended Kalman filter and Unscented filter. With these real-time algorithms, a full magnetometer calibration can now be performed on-orbit during typical spacecraft mission-mode operations. Simulation results indicate that both algorithms provide accurate integer resolution in real time, but the Unscented filter is more robust to large initial condition errors than the extended Kalman filter. The algorithms are also tested using actual data from the Transition Region and Coronal Explorer (TRACE).

  15. Three-axis superconducting gravity gradiometer for sensitive gravity experiments

    NASA Astrophysics Data System (ADS)

    Moody, M. Vol; Paik, Ho Jung; Canavan, Edgar R.

    2002-11-01

    Superconducting differential accelerometers have been used to test Newton's inverse square law and have been proposed for other sensitive experiments. These include searches for spin-mass coupling, detecting Earth's gravitomagnetic field, and testing the Equivalence Principle. This article discusses the principle and performance of a sensitive three-axis gravity gradiometer. This device utilizes quantized flux and the Meissner effect to provide stable test mass levitation and signal coupling, and superconducting quantum interference devices to provide very low-noise amplification of the signals. The instrument comprises a total of nine superconducting accelerometers, six linear and three angular. This configuration permits simultaneous measurement of the diagonal components of the gravity gradient tensor as well as platform acceleration in all six degrees of freedom. An analysis of this instrument is presented along with experimental results. Methods to correct for various motion-induced errors are demonstrated. Other error sources are also discussed. The resulting performance of the superconducting gravity gradiometer is 2 x10-11 s-2 Hz-1/2.

  16. Multiaxis control power from thrust vectoring for a supersonic fighter aircraft model at Mach 0.20 to 2.47

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Bare, E. Ann

    1987-01-01

    The aeropropulsive characteristics of an advanced twin-engine fighter aircraft designed for supersonic cruise have been studied in the Langley 16-Foot Tansonic Tunnel and the Lewis 10- by 10-Foot Supersonic Tunnel. The objective was to determine multiaxis control-power characteristics from thrust vectoring. A two-dimensional convergent-divergent nozzle was designed to provide yaw vector angles of 0, -10, and -20 deg combined with geometric pitch vector angles of 0 and 15 deg. Yaw thrust vectoring was provided by yaw flaps located in the nozzle sidewalls. Roll control was obtained from differential pitch vectoring. This investigation was conducted at Mach numbers from 0.20 to 2.47. Angle of attack was varied from 0 to about 19 deg, and nozzle pressure ratio was varied from about 1 (jet off) to 28, depending on Mach number. Increments in force or moment coefficient that result from pitch or yaw thrust vectoring remain essentially constant over the entire angle-of-attack range of all Mach numbers tested. There was no effect of pitch vectoring on the lateral aerodynamic forces and moments and only very small effects of yaw vectoring on the longitudinal aerodynamic forces and moments. This result indicates little cross-coupling of control forces and moments for combined pitch-yaw vectoring.

  17. Three-axis force actuator for a magnetic bearing

    NASA Technical Reports Server (NTRS)

    Gondhalekar, Vijay (Inventor)

    1998-01-01

    This invention features a three-axis force actuator that axially, radially and rotatably supports a bearing member for frictionless rotation about an axis of rotation generally coincident with a Z-axis. Also featured is a magnetic bearing having such an actuator. The actuator includes an inner member, a magnetic member and a pole assembly having a ring member and four pole extending therefrom. The poles are equi-angular spaced from each other and radially spaced about the Z-axis. The inner member extends along the Z-axis and is a highly magnetic permeable material. The magnetic member is formed about the inner member outer surface, extends along the Z-axis and is configured so one magnetic pole polarity is located at its outer surface and the other polarity pole is located at its inner surface. Preferably, the magnetic member is a radially magnetized permanent magnet. The inner surface of the ring member is magnetically coupled to the magnetic member and a face of each pole is coupled to the bearing member. The magnetic member, the pole assembly, the inner member and the bearing member cooperate to generate a magnetic field that radially and rotatably supports a rotating member secured to the bearing member. The actuator further includes a plurality of electromagnetic coils. Preferably, a coil is formed about each pole and at least 2 coils are formed about the inner member. When energized, the electromagnetic coils generate a modulated magnetic field that stabilizes the rotating member in the desired operational position.

  18. Novel Calibration Algorithm for a Three-Axis Strapdown Magnetometer

    PubMed Central

    Liu, Yan Xia; Li, Xi Sheng; Zhang, Xiao Juan; Feng, Yi Bo

    2014-01-01

    A complete error calibration model with 12 independent parameters is established by analyzing the three-axis magnetometer error mechanism. The said model conforms to an ellipsoid restriction, the parameters of the ellipsoid equation are estimated, and the ellipsoid coefficient matrix is derived. However, the calibration matrix cannot be determined completely, as there are fewer ellipsoid parameters than calibration model parameters. Mathematically, the calibration matrix derived from the ellipsoid coefficient matrix by a different matrix decomposition method is not unique, and there exists an unknown rotation matrix R between them. This paper puts forward a constant intersection angle method (angles between the geomagnetic field and gravitational field are fixed) to estimate R. The Tikhonov method is adopted to solve the problem that rounding errors or other errors may seriously affect the calculation results of R when the condition number of the matrix is very large. The geomagnetic field vector and heading error are further corrected by R. The constant intersection angle method is convenient and practical, as it is free from any additional calibration procedure or coordinate transformation. In addition, the simulation experiment indicates that the heading error declines from ±1° calibrated by classical ellipsoid fitting to ±0.2° calibrated by a constant intersection angle method, and the signal-to-noise ratio is 50 dB. The actual experiment exhibits that the heading error is further corrected from ±0.8° calibrated by the classical ellipsoid fitting to ±0.3° calibrated by a constant intersection angle method. PMID:24831110

  19. Control theory analysis of a three-axis VTOL flight director. M.S. Thesis - Pennsylvania State Univ.

    NASA Technical Reports Server (NTRS)

    Niessen, F. R.

    1971-01-01

    A control theory analysis of a VTOL flight director and the results of a fixed-based simulator evaluation of the flight-director commands are discussed. The VTOL configuration selected for this study is a helicopter-type VTOL which controls the direction of the thrust vector by means of vehicle-attitude changes and, furthermore, employs high-gain attitude stabilization. This configuration is the same as one which was simulated in actual instrument flight tests with a variable stability helicopter. Stability analyses are made for each of the flight-director commands, assuming a single input-output, multi-loop system model for each control axis. The analyses proceed from the inner-loops to the outer-loops, using an analytical pilot model selected on the basis of the innermost-loop dynamics. The time response of the analytical model of the system is primarily used to adjust system gains, while root locus plots are used to identify dominant modes and mode interactions.

  20. Three axis vector magnet set-up for cryogenic scanning probe microscopy.

    PubMed

    Galvis, J A; Herrera, E; Guillamn, I; Azpeitia, J; Luccas, R F; Munuera, C; Cuenca, M; Higuera, J A; Daz, N; Pazos, M; Garca-Hernandez, M; Buenda, A; Vieira, S; Suderow, H

    2015-01-01

    We describe a three axis vector magnet system for cryogenic scanning probe microscopy measurements. We discuss the magnet support system and the power supply, consisting of a compact three way 100 A current source. We obtain tilted magnetic fields in all directions with maximum value of 5T along z-axis and of 1.2T for XY-plane magnetic fields. We describe a scanning tunneling microscopy-spectroscopy (STM-STS) set-up, operating in a dilution refrigerator, which includes a new high voltage ultralow noise piezodrive electronics and discuss the noise level due to vibrations. STM images and STS maps show atomic resolution and the tilted vortex lattice at 150 mK in the superconductor ?-Bi2Pd. We observe a strongly elongated hexagonal lattice, which corresponds to the projection of the tilted hexagonal vortex lattice on the surface. We also discuss Magnetic Force Microscopy images in a variable temperature insert. PMID:25638089

  1. Three axis vector magnet set-up for cryogenic scanning probe microscopy

    SciTech Connect

    Galvis, J. A.; Herrera, E.; Buendía, A.; Guillamón, I.; Vieira, S.; Suderow, H.; Azpeitia, J.; Luccas, R. F.; Munuera, C.; García-Hernandez, M.; and others

    2015-01-15

    We describe a three axis vector magnet system for cryogenic scanning probe microscopy measurements. We discuss the magnet support system and the power supply, consisting of a compact three way 100 A current source. We obtain tilted magnetic fields in all directions with maximum value of 5T along z-axis and of 1.2T for XY-plane magnetic fields. We describe a scanning tunneling microscopy-spectroscopy (STM-STS) set-up, operating in a dilution refrigerator, which includes a new high voltage ultralow noise piezodrive electronics and discuss the noise level due to vibrations. STM images and STS maps show atomic resolution and the tilted vortex lattice at 150 mK in the superconductor β-Bi{sub 2}Pd. We observe a strongly elongated hexagonal lattice, which corresponds to the projection of the tilted hexagonal vortex lattice on the surface. We also discuss Magnetic Force Microscopy images in a variable temperature insert.

  2. Microfabrication of Three-Axis Tactile Feedback Actuator for Robot-Assisted Surgery

    NASA Astrophysics Data System (ADS)

    Doh, Eunhyup; Yoo, Jihyung; Lee, Hyungkew; Park, Joonah; Yun, Kwang-Seok

    2013-01-01

    In this paper, we propose and demonstrate a three-axis tactile feedback actuator using pneumatic balloons for human perception applications such as robot-assisted surgery systems. A tactile actuator is composed of a center structure having four balloons, sidewalls with one lateral balloon on each sidewall, and a bottom structure supporting the center structure. We fabricated the proposed device using flexible poly(dimethylsiloxane) and hard polyurethane with final dimensions of 18 ×18 ×18 mm3. The four balloons on the center structure produce normal tactile display during pneumatic-pressure-assisted inflation. The lateral movement of the center structure driven by sidewall balloons generates a shear tactile display on fingertips. The center deflections of the circular and rectangular balloons were calculated and measured experimentally.

  3. Note: A compact three-axis optical force/torque sensor using photo-interrupters

    NASA Astrophysics Data System (ADS)

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot.

  4. Note: A compact three-axis optical force/torque sensor using photo-interrupters.

    PubMed

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot. PMID:24387485

  5. Three-axis MEMS Accelerometer for Structural Inspection

    NASA Astrophysics Data System (ADS)

    Barbin, E.; Koleda, A.; Nesterenko, T.; Vtorushin, S.

    2016-01-01

    Microelectromechanical system accelerometers are widely used for metrological measurements of acceleration, tilt, vibration, and shock in moving objects. The paper presents the analysis of MEMS accelerometer that can be used for the structural inspection. ANSYS Multiphysics platform is used to simulate the behavior of MEMS accelerometer by employing a finite element model and MATLAB/Simulink tools for modeling nonlinear dynamic systems.

  6. Three-axis active magnetic attitude control asymptotical study

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, M. Yu.; Roldugin, D. S.; Penkov, V. I.

    2015-05-01

    Active magnetic attitude control system providing given inertial attitude is considered. Control algorithm is constructed on the basis of a planar motion model. It decreases attitude discrepancy. Alternative approach is based on the PD-controller design. System behavior is analyzed for specific motion cases and sometimes for specific inertia tensor (axisymmetrical satellite) using averaging technique. Overall satellite angular motion is covered. Necessary attitude is found to be accessible for some control parameters. Stability is proven and optimal algorithm parameters are obtained. Floquet-based analysis is performed to verify and broaden analytical results.

  7. Development of an ultraprecision three axis micromilling machine

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Wang, Bo; Liang, Yingchun

    2009-05-01

    To meet the requirement for high efficiency machining of the ultra-precision, ultra-smooth micro structured optical surface, an ultra-precision three axes micro milling machine was developed. The overall size of the machine is 600mm500mm700mm and all the strokes of three axes are 75mm. To overcome nonlinearity that always exists in conventional servo mechanism driven by ball screw, permanent-magnet linear motor is used to directly drive the aerostatic bearing slide. Linear encoder with 1.2 nm resolution was used as the feedback of position to buildup closed loop control system. The open architected CNC system is composed of the high performance embedded PMAC motion control card and standard industrial PC, and the control algorithm is based on "PID + velocity/acceleration feed forward + notch filter" strategy. Test results indicate that the positioning accuracy of all the three axes is less than +/-0.25?m, and the repetitive positioning accuracy is less than +/-0.2?m. The machine is proved to achieve nanometer scale through step response and sinusoidal signal track. The preparatory milling experiments with micro cemented carbide milling cutter further proves the processing capacity.

  8. Performance of twin two-dimensional wedge nozzles including thrust vectoring and reversing effects at speeds up to Mach 2.20

    NASA Technical Reports Server (NTRS)

    Capone, F. J.; Maiden, D. L.

    1977-01-01

    Transonic tunnel and supersonic pressure tunnel tests were reformed to determine the performance characteristics of twin nonaxisymmetric or two-dimensional nozzles with fixed shrouds and variable-geometry wedges. The effects of thrust vectoring, reversing, and installation of various tails were also studied. The investigation was conducted statically and at flight speeds up to a Mach number of 2.20. The total pressure ratio of the simulated jet exhaust was varied up to approximately 26 depending on Mach number. The Reynolds number per meter varied up to 13.20 x 1 million. An analytical study was made to determine the effect on calculated wave drag by varying the mathematical model used to simulate nozzle jet-exhaust plume.

  9. Three-Axis Attitude Estimation With a High-Bandwidth Angular Rate Sensor

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Green, Joseph J.

    2013-01-01

    A continuing challenge for modern instrument pointing control systems is to meet the increasingly stringent pointing performance requirements imposed by emerging advanced scientific, defense, and civilian payloads. Instruments such as adaptive optics telescopes, space interferometers, and optical communications make unprecedented demands on precision pointing capabilities. A cost-effective method was developed for increasing the pointing performance for this class of NASA applications. The solution was to develop an attitude estimator that fuses star tracker and gyro measurements with a high-bandwidth angular rotation sensor (ARS). An ARS is a rate sensor whose bandwidth extends well beyond that of the gyro, typically up to 1,000 Hz or higher. The most promising ARS sensor technology is based on a magnetohydrodynamic concept, and has recently become available commercially. The key idea is that the sensor fusion of the star tracker, gyro, and ARS provides a high-bandwidth attitude estimate suitable for supporting pointing control with a fast-steering mirror or other type of tip/tilt correction for increased performance. The ARS is relatively inexpensive and can be bolted directly next to the gyro and star tracker on the spacecraft bus. The high-bandwidth attitude estimator fuses an ARS sensor with a standard three-axis suite comprised of a gyro and star tracker. The estimation architecture is based on a dual-complementary filter (DCF) structure. The DCF takes a frequency- weighted combination of the sensors such that each sensor is most heavily weighted in a frequency region where it has the lowest noise. An important property of the DCF is that it avoids the need to model disturbance torques in the filter mechanization. This is important because the disturbance torques are generally not known in applications. This property represents an advantage over the prior art because it overcomes a weakness of the Kalman filter that arises when fusing more than one rate measurement. An additional advantage over prior art is that, computationally, the DCF requires significantly fewer real-time calculations than a Kalman filter formulation. There are essentially two reasons for this: the DCF state is not augmented with angular rate, and measurement updates occur at the slower gyro rate instead of the faster ARS sampling rate. Finally, the DCF has a simple and compelling architecture. The DCF is exactly equivalent to flying two identical attitude observers, one at low rate and one at high rate. These attitude observers are exactly of the form currently flown on typical three-axis spacecraft.

  10. Static thrust-vectoring performance of nonaxisymmetric convergent-divergent nozzles with post-exit yaw vanes. M.S. Thesis - George Washington Univ., Aug. 1988

    NASA Technical Reports Server (NTRS)

    Foley, Robert J.; Pendergraft, Odis C., Jr.

    1991-01-01

    A static (wind-off) test was conducted in the Static Test Facility of the 16-ft transonic tunnel to determine the performance and turning effectiveness of post-exit yaw vanes installed on two-dimensional convergent-divergent nozzles. One nozzle design that was previously tested was used as a baseline, simulating dry power and afterburning power nozzles at both 0 and 20 degree pitch vectoring conditions. Vanes were installed on these four nozzle configurations to study the effects of vane deflection angle, longitudinal and lateral location, size, and camber. All vanes were hinged at the nozzle sidewall exit, and in addition, some were also hinged at the vane quarter chord (double-hinged). The vane concepts tested generally produced yaw thrust vectoring angles much less than the geometric vane angles, for (up to 8 percent) resultant thrust losses. When the nozzles were pitch vectored, yawing effectiveness decreased as the vanes were moved downstream. Thrust penalties and yawing effectiveness both decreased rapidly as the vanes were moved outboard (laterally). Vane length and height changes increased yawing effectiveness and thrust ratio losses, while using vane camber, and double-hinged vanes increased resultant yaw angles by 50 to 100 percent.

  11. Dual-waveband MWIR/visible three-axis stabilized sensor suite for submarine optronics masts

    NASA Astrophysics Data System (ADS)

    Armstrong, George R.

    1998-10-01

    A dual-band MWIR/Visible Electro-Optic sensor suite has been developed for use in the CM010 family of Optronics Masts, currently being evolved by Pilkington Optronics for the Royal Navy's new Astute Class submarines. The sensor suite features a medium wave IR thermal imaging camera and a broadcast standard color TV camera, both of which view the scene through a common sapphire pressure window. Three-axis stabilization is provided for both sensors, in which pitch and yaw are controlled by a common line-of-sight prism behind the sensor window, while control of roll about the line of sight is achieved by individual optical derotators within the TI and visible band optics. Precision stabilized control is provided in both the MWIR and visible optical chains. The MWIR sensor consists of a diagonally-microscanned 320 X 240 focal plane, the microscan beam deflection being carried out by the TI piezo mirror. The visible sensor, designed for daylight use, consists of three 1024 X 1024 pixel frame transfer CCD focal planes, which in conjunction with variable neutral density filters yield excellent performance over a 103 dynamic range of daylight scene illuminance. Both optical systems provide Fields of View of 3, 6 and 24 degrees, and a Field of Regard covering from -15 degrees in depression to +60 degrees in elevation. Field of view switching is carried out by dual-band afocal optics situated in the common optical path. A 'Quick Look Round' mode allows both sensors to capture imagery through a full 360 degree azimuth sweep for subsequent analysis, with minimal mast exposure time.

  12. Optimal Three-Axis Attitude Control Design, Simulation and Experimental Verification for Small Satellites Using Magnetic Actuators

    NASA Astrophysics Data System (ADS)

    Yoon, Z.; Terzibaschian, T.; Raschke, C.

    2008-08-01

    Based on experience with the small satellite BIRD BIRD (Bispectral Infra-Red Detection) of German Aerospace Center (DLR), this paper proposes a mathematical and numerical approach to compute the most effective dipole moment while taking into account the spatial dipole characteristic of the magnetic actuator system. The control torque is obtained via quaternion feedback control. The control algorithm is tested and verified by orbit simulation. A three-axis pointing accuracy of better than 5 deg and a more efficient utilization of the actuator are achieved. The proposed control algorithm will also be implemented in the upcoming TET-1 on-orbit verification (OOV) mission and the DLR "Compactsat". The algorithm as well as the full attitude control system will be verified via the introduced state-of-art air attitude control test bed.

  13. Development of an ion energy mass spectrometer for application on board three-axis stabilized spacecraft

    SciTech Connect

    Yokota, Shoichiro; Saito, Yoshifumi; Asamura, Kazushi; Mukai, Toshifumi

    2005-01-01

    We have developed an ion energy mass spectrometer for use aboard three-axis stabilized spacecraft. This spectrometer measures the three-dimensional distribution function of mass-discriminated ions with a high sampling rate using electrostatic energy analysis and time-of-flight mass analysis. Three-axis stabilized spacecraft make it difficult to obtain complete coverage of all possible plasma arrival directions. We have added angular scanning deflectors to a cylindrically symmetric analyzer to provide a hemispherical (2{pi} str) field of view. Ion analyzers need suitable sensitivity with respect to surrounding space plasma fluxes, whose intensities vary greatly depending especially on plasma regions such as the solar wind and the planetary magnetospheres. To obtain a wide range of sensitivity, we equipped the analyzer with sensitivity control electrodes. Ions originating from planetary atmosphere and surface include various ion species such as Na{sup +}, Mg{sup +}, Al{sup +}, and Fe{sup +}. The time-of-flight device of our spectrometer applies a peculiar electric field, called a linear electric field, which increases linearly with the penetration length of incident ions to enable mass resolution higher than that of conventional time-of-flight techniques. In this electric field, ions bounce in simple harmonic motion, where the energy and flight path no longer affect the flight time and thus the mass resolution. We have designed and fabricated the ion energy mass spectrometer, and have evaluated its performance through laboratory experiments.

  14. A Three-Axis Force Sensor for Dual Finger Haptic Interfaces

    PubMed Central

    Fontana, Marco; Marcheschi, Simone; Salsedo, Fabio; Bergamasco, Massimo

    2012-01-01

    In this work we present the design process, the characterization and testing of a novel three-axis mechanical force sensor. This sensor is optimized for use in closed-loop force control of haptic devices with three degrees of freedom. In particular the sensor has been conceived for integration with a dual finger haptic interface that aims at simulating forces that occur during grasping and surface exploration. The sensing spring structure has been purposely designed in order to match force and layout specifications for the application. In this paper the design of the sensor is presented, starting from an analytic model that describes the characteristic matrix of the sensor. A procedure for designing an optimal overload protection mechanism is proposed. In the last part of the paper the authors describe the experimental characterization and the integrated test on a haptic hand exoskeleton showing the improvements in the controller performances provided by the inclusion of the force sensor. PMID:23202012

  15. Micromachined three-axis thermal accelerometer with a single composite heater

    NASA Astrophysics Data System (ADS)

    Bahari, Jamal; Leung, Albert M.

    2011-07-01

    A novel three-axis thermal accelerometer is designed, fabricated, and characterized in this paper. The device includes two half sensor plates attached to buckled cantilevers to form out-of-plane structures. Cantilevers are assembled by a single push of a microprobe and preserve their shapes when they latch into stoppers anchored to the substrate. The fabrication process is based on surface micromachining on silicon substrates using polyimide as the structural layer and amorphous silicon as the sacrificial layer. The fabricated devices are individually packaged and characterized. Using a total heater power of 2.5 mW, the X, Y, and Z axes, respectively, showed sensitivities of 66, 64, and 25 V g-1. Compared to the earlier versions of the same class accelerometers, the fabricated single heater accelerometer demonstrates more than fourfold sensitivity improvement.

  16. Study on grinding of free-form optics surface in three-axis CNC machine

    NASA Astrophysics Data System (ADS)

    Yang, Haicheng; Zhang, Yun-long; Zhang, Feng; Wang, Zhibin; Bao, Long-xiang; Su, Ying; Guo, Rui; Liu, Xuan-min

    2014-08-01

    Due to the glass is a type of brittle material, so the high-precision free-form optics of glass material is usually machined by the technical of grinding. In this paper, for the characteristics of the diamond grinding wheel, analyzing the grinding path of free-form optics and mathematical model of the path is established based on the three-axis CNC grinding device. Moreover, the cause of the interference in the process of grinding is analyzed and the methods of avoiding. Finally, based on the above analysis results, through the experiment, the free-form optics surface accuracy was reached to 3.6um, realize the machining of the free-form optics.

  17. Quantitative evaluation of perspective and stereoscopic displays in three-axis manual tracking tasks

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Tyler, Mitchelle E.; Hannaford, Blake; Stark, Lawrence W.; Kim, Won S.

    1987-01-01

    Optimal presentation of three-dimensional information on a two-dimensional display screen requires careful design of the projection to the display surface. Monoscopic perspective projection alone is usually not sufficient to represent three-dimensional spatial information. It can, however, be improved by the adjustment of perspective parameters and by geometric visual enhancements such as reference lines and a background grid. Stereoscopic display is another method of providing three-dimensional information to the human operator. Two experiments are performed with three-axis manual tracking tasks. The first experiment investigates the effects of perspective parameters on tracking performance. The second experiment investigates the effects of visual enhancements for both monoscopic and stereoscopic displays. Results indicate that, although stereoscopic displays do generally permit superior tracking performance, monoscopic displays can allow equivalent performance when they are defined with optimal perspective parameters and provided with adequate visual enhancements.

  18. Algorithms for Automated Characterization of Three-Axis Stabilized GEOs using Non-Resolved Optical Observations

    NASA Astrophysics Data System (ADS)

    Murray-Krezan, J.; Inbody, W.; Dentamaro, A.; Gregory, S.; Dao, P.; Fulcoly, D.

    2012-09-01

    Non-resolved optical observations of satellites have been known to supply researchers with valuable information about satellite status. Until recently most non-resolved analysis techniques have required an expert human in the loop in order to attribute observed information to satellite features. We are designing algorithms that automate the process of rapidly characterizing satellites from non-resolved optical data of three-axis stabilized geostationary satellites. We will present background information on corrections for lighting conditions that vary as a function of the Earth's season, and permit automated satellite characterization algorithms. Much of this information is empirical, based on a GEO-Sat Color Photometry Catalog, for which collection began in 2004 and continues into the present.

  19. Thermomechanical Actuator-Based Three-Axis Optical Scanner for High-Speed Two-Photon Endomicroscope Imaging

    PubMed Central

    Chen, Shih-Chi; Choi, Heejin; So, Peter T. C.; Culpepper, Martin L.

    2015-01-01

    This paper presents the design and characterization of a three-axis thermomechanical actuator-based endoscopic scanner for obtaining ex vivo two-photon images. The scanner consisted of two sub-systems: 1) an optical system (prism, gradient index lens, and optical fiber) that was used to deliver and collect light during imaging and 2) a small-scale silicon electromechanical scanner that could raster scan the focal point of the optics through a specimen. The scanner can be housed within a 7 mm endoscope port and can scan at the speed of 3 kHz 100 Hz 30 Hz along three axes throughout a 125 125 100 ?m3 volume. The high-speed thermomechanical actuation was achieved through the use of geometric contouring, pulsing technique, and mechanical frequency multiplication (MFM), where MFM is a new method for increasing the device cycling speed by pairing actuators of unequal forward and returning stroke speeds. Sample cross-sectional images of 15-?m fluorescent beads are presented to demonstrate the resolution and optical cross-sectioning capability of the two-photon imaging system. PMID:25673965

  20. A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control

    NASA Astrophysics Data System (ADS)

    Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi; Yasui, Hisako

    The Integrated Flight and Propulsion Control (IFPC) for a highly maneuverable aircraft and a fighter-class engine with pitch/yaw thrust vectoring is described. Of the two IFPC functions the aircraft maneuver control utilizes the thrust vectoring based on aerodynamic control surfaces/thrust vectoring control allocation specified by the Integrated Control Unit (ICU) of a FADEC (Full Authority Digital Electronic Control) system. On the other hand in the Performance Seeking Control (PSC) the ICU identifies engine's various characteristic changes, optimizes manipulated variables and finally adjusts engine control parameters in cooperation with the Engine Control Unit (ECU). It is shown by hardware-in-the-loop simulation that the thrust vectoring can enhance aircraft maneuverability/agility and that the PSC can improve engine performance parameters such as SFC (specific fuel consumption), thrust and gas temperature.

  1. A uniplanar three-axis gradient set for in vivo magnetic resonance microscopy.

    PubMed

    Demyanenko, Andrey V; Zhao, Lin; Kee, Yun; Nie, Shuyi; Fraser, Scott E; Tyszka, J Michael

    2009-09-01

    We present an optimized uniplanar magnetic resonance gradient design specifically tailored for MR imaging applications in developmental biology and histology. Uniplanar gradient designs sacrifice gradient uniformity for high gradient efficiency and slew rate, and are attractive for surface imaging applications where open access from one side of the sample is required. However, decreasing the size of the uniplanar gradient set presents several unique engineering challenges, particularly for heat dissipation and thermal insulation of the sample from gradient heating. We demonstrate a new three-axis, target-field optimized uniplanar gradient coil design that combines efficient cooling and insulation to significantly reduce sample heating at sample-gradient distances of less than 5mm. The instrument is designed for microscopy in horizontal bore magnets. Empirical gradient current efficiencies in the prototype coils lie between 3.75G/cm/A and 4.5G/cm/A with current and heating-limited maximum gradient strengths between 235G/cm and 450G/cm at a 2% duty cycle. The uniplanar gradient prototype is demonstrated with non-linearity corrections for both high-resolution structural imaging of tissue slices and for long time-course imaging of live, developing amphibian embryos in a horizontal bore 7T magnet. PMID:19539503

  2. Three-axis optical force plate for studies in small animal locomotor mechanics

    SciTech Connect

    Hsieh, S. Tonia

    2006-05-15

    The use of force plates to measure whole-body locomotor mechanics is a well-established technique. However, commercially available force plates are not sensitive enough for use on small-bodied vertebrates or invertebrates. The standard design for single- and multiple-axis, high-sensitivity force plates built by individual research groups uses semiconductor foil strain gauges to measure deflections; yet foil strain gauges are highly temperature and position sensitive, resulting in a drifting base line and nonlinear responses. I present here a design for a three-axis optical force plate that was successfully calibrated to measure forces as small as 1.5 mN and is capable of determining the position of center of pressure with a mean error of 0.07 cm along the X axis and 0.13 cm along the Y axis. Using optical sensors instead of foil strain gauges to measure deflection, this force plate is not subject to temperature-related drift and is more robust against slight positioning inaccuracies. This force plate was used to measure forces produced by amphibious fishes weighing less than 2 g as they jumped off the force platform.

  3. An accurate calibration method for accelerometer nonlinear scale factor on a low-cost three-axis turntable

    NASA Astrophysics Data System (ADS)

    Pan, Jianye; Zhang, Chunxi; Cai, Qingzhong

    2014-02-01

    Strapdown inertial navigation system (SINS) requirements are very demanding on gyroscopes and accelerometers as well as on calibration. To improve the accuracy of SINS, high-accuracy calibration is needed. Adding the accelerometer nonlinear scale factor into the model and reducing estimation errors is essential for improving calibration methods. In this paper, the inertial navigation error model is simplified, including only velocity and tilt errors. Based on the simplified error model, the relationship between the navigation errors (the rates of change of velocity errors) and the inertial measurement unit (IMU) calibration parameters is presented. A tracking model is designed to estimate the rates of change of velocity errors. With a special calibration procedure consisting of six rotation sequences, the accelerometer nonlinear scale factor errors can be computed by the estimates of the rates of change of velocity errors. Simulation and laboratory test results show that the accelerometer nonlinear scale factor can be calibrated with satisfactory accuracy on a low-cost three-axis turntable in several minutes. The comparison with the traditional calibration method highlights the superior performance of the proposed calibration method without precise orientation control. In addition, the proposed calibration method saves a lot of time in comparison with the multi-position calibration method.

  4. Three Axis Control of the Hubble Space Telescope Using Two Reaction Wheels and Magnetic Torquer Bars for Science Observations

    NASA Technical Reports Server (NTRS)

    Hur-Diaz, Sun; Wirzburger, John; Smith, Dan

    2008-01-01

    The Hubble Space Telescope (HST) is renowned for its superb pointing accuracy of less than 10 milli-arcseconds absolute pointing error. To accomplish this, the HST relies on its complement of four reaction wheel assemblies (RWAs) for attitude control and four magnetic torquer bars (MTBs) for momentum management. As with most satellites with reaction wheel control, the fourth RWA provides for fault tolerance to maintain three-axis pointing capability should a failure occur and a wheel is lost from operations. If an additional failure is encountered, the ability to maintain three-axis pointing is jeopardized. In order to prepare for this potential situation, HST Pointing Control Subsystem (PCS) Team developed a Two Reaction Wheel Science (TRS) control mode. This mode utilizes two RWAs and four magnetic torquer bars to achieve three-axis stabilization and pointing accuracy necessary for a continued science observing program. This paper presents the design of the TRS mode and operational considerations necessary to protect the spacecraft while allowing for a substantial science program.

  5. Flight-Determined, Subsonic, Lateral-Directional Stability and Control Derivatives of the Thrust-Vectoring F-18 High Angle of Attack Research Vehicle (HARV), and Comparisons to the Basic F-18 and Predicted Derivatives

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1999-01-01

    The subsonic, lateral-directional, stability and control derivatives of the thrust-vectoring F-1 8 High Angle of Attack Research Vehicle (HARV) are extracted from flight data using a maximum likelihood parameter identification technique. State noise is accounted for in the identification formulation and is used to model the uncommanded forcing functions caused by unsteady aerodynamics. Preprogrammed maneuvers provided independent control surface inputs, eliminating problems of identifiability related to correlations between the aircraft controls and states. The HARV derivatives are plotted as functions of angles of attack between 10deg and 70deg and compared to flight estimates from the basic F-18 aircraft and to predictions from ground and wind tunnel tests. Unlike maneuvers of the basic F-18 aircraft, the HARV maneuvers were very precise and repeatable, resulting in tightly clustered estimates with small uncertainty levels. Significant differences were found between flight and prediction; however, some of these differences may be attributed to differences in the range of sideslip or input amplitude over which a given derivative was evaluated, and to differences between the HARV external configuration and that of the basic F-18 aircraft, upon which most of the prediction was based. Some HARV derivative fairings have been adjusted using basic F-18 derivatives (with low uncertainties) to help account for differences in variable ranges and the lack of HARV maneuvers at certain angles of attack.

  6. Verification test results of Apollo stabilization and control systems during undocked operations

    NASA Technical Reports Server (NTRS)

    Copeland, E. L.; Haken, R. L.

    1974-01-01

    The results are presented of analysis and simulation testing of both the Skylark 1 reaction control system digital autopilot (RCS DAP) and the thrust vector control (TVC) autopilot for use during the undocked portions of the Apollo/Soyuz Test Project Mission. The RCS DAP testing was performed using the Skylab Functional Simulator (SLFS), a digital computer program capable of simulating the Apollo and Skylab autopilots along with vehicle dynamics including bending and sloshing. The model is used to simulate three-axis automatic maneuvers along with pilot controlled manual maneuvers using the RCS DAP. The TVC autopilot was tested in two parts. A classical stability analysis was performed on the vehicle considering the effects of structural bending and sloshing when under control of the TVC autopilot. The time response of the TVC autopilot was tested using the SLFS. Results indicate that adequate performance stability margins can be expected for the CSM/DM configuration when under the control of the Apollo control systems tested.

  7. Characterization of the non axial thrust generated by large solid propellant rocket motors in three axis stabilized ascent

    NASA Technical Reports Server (NTRS)

    Kosmann, W. J.; Dionne, E. R.; Klemetson, R. W.

    1978-01-01

    Nonaxial thrusts produced by solid rocket motors during three-axis stabilized attitude control have been determined from ascent experience on twenty three Burner II, Burner IIA and Block 5D-1 upper stage vehicles. A data base representing four different rocket motor designs (three spherical and one extended spherical) totaling twenty five three-axis stabilized firings is generated. Solid rocket motor time-varying resultant and lateral side force vector magnitudes, directions and total impulses, and roll torque couple magnitudes, directions, and total impulses are tabulated in the appendix. Population means and three sigma deviations are plotted. Existing applicable ground test side force and roll torque magnitudes and total impulses are evaluated and compared to the above experience data base. Within the spherical motor population, the selected AEDC ground test data consistently underestimated experienced motor side forces, roll torques and total impulses. Within the extended spherical motor population, the selected AEDC test data predicted experienced motor side forces, roll torques, and total impulses, with surprising accuracy considering the very small size of the test and experience populations.

  8. Fully printed flexible fingerprint-like three-axis tactile and slip force and temperature sensors for artificial skin.

    PubMed

    Harada, Shingo; Kanao, Kenichiro; Yamamoto, Yuki; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

    2014-12-23

    A three-axis tactile force sensor that determines the touch and slip/friction force may advance artificial skin and robotic applications by fully imitating human skin. The ability to detect slip/friction and tactile forces simultaneously allows unknown objects to be held in robotic applications. However, the functionalities of flexible devices have been limited to a tactile force in one direction due to difficulties fabricating devices on flexible substrates. Here we demonstrate a fully printed fingerprint-like three-axis tactile force and temperature sensor for artificial skin applications. To achieve economic macroscale devices, these sensors are fabricated and integrated using only printing methods. Strain engineering enables the strain distribution to be detected upon applying a slip/friction force. By reading the strain difference at four integrated force sensors for a pixel, both the tactile and slip/friction forces can be analyzed simultaneously. As a proof of concept, the high sensitivity and selectivity for both force and temperature are demonstrated using a 33 array artificial skin that senses tactile, slip/friction, and temperature. Multifunctional sensing components for a flexible device are important advances for both practical applications and basic research in flexible electronics. PMID:25437513

  9. Three-axis attitude and direction reference instrument has only one moving part

    NASA Technical Reports Server (NTRS)

    Bossler, F. B.

    1966-01-01

    Lunar vehicle instrument combines the functions of attitude reference, direction reference, and display in a unit having only one moving part. The device, using bubble levels and a calibrated dial, is used as a sextant prior to takeoff, and as a backup navigation system during flight.

  10. Three-axis stabilization of spacecraft using parameter-independent nonlinear quaternion feedback

    NASA Technical Reports Server (NTRS)

    Joshi, Suresh M.; Kelkar, Atul G.

    1994-01-01

    This paper considers the problem of rigid spacecraft. A nonlinear control law which uses the feedback of the unit quaternion and the measured angular velocities is proposed and is shown to provide global asymptotic stability. The control law does not require the knowledge of the system parameters, and is therefore robust to modeling errors. The significance of the control law is that it can be used for large-angle maneuvers with guaranteed stability.

  11. Attitude determination with three-axis accelerometer for emergency atmospheric entry

    NASA Technical Reports Server (NTRS)

    Garcia-Llama, Eduardo (Inventor)

    2012-01-01

    Two algorithms are disclosed that, with the use of a 3-axis accelerometer, will be able to determine the angles of attack, sideslip and roll of a capsule-type spacecraft prior to entry (at very high altitudes, where the atmospheric density is still very low) and during entry. The invention relates to emergency situations in which no reliable attitude and attitude rate are available. Provided that the spacecraft would not attempt a guided entry without reliable attitude information, the objective of the entry system in such case would be to attempt a safe ballistic entry. A ballistic entry requires three controlled phases to be executed in sequence: First, cancel initial rates in case the spacecraft is tumbling; second, maneuver the capsule to a heat-shield-forward attitude, preferably to the trim attitude, to counteract the heat rate and heat load build up; and third, impart a ballistic bank or roll rate to null the average lift vector in order to prevent prolonged lift down situations. Being able to know the attitude, hence the attitude rate, will allow the control system (nominal or backup, automatic or manual) to cancel any initial angular rates. Also, since a heat-shield forward attitude and the trim attitude can be specified in terms of the angles of attack and sideslip, being able to determine the current attitude in terms of these angles will allow the control system to maneuver the vehicle to the desired attitude. Finally, being able to determine the roll angle will allow for the control of the roll ballistic rate during entry.

  12. Three axis pulsed plasma thruster with angled cathode and anode strip lines

    NASA Technical Reports Server (NTRS)

    Cassady, R. Joseph (Inventor); Myers, Roger M. (Inventor); Osborne, Robert D. (Inventor)

    2001-01-01

    A spacecraft attitude and altitude control system utilizes sets of three pulsed plasma thrusters connected to a single controller. The single controller controls the operation of each thruster in the set. The control of a set of three thrusters in the set makes it possible to provide a component of thrust along any one of three desired axes. This configuration reduces the total weight of a spacecraft since only one controller and its associated electronics is required for each set of thrusters rather than a controller for each thruster. The thrusters are positioned about the spacecraft such that the effect of the thrusters is balanced.

  13. OPMILL - MICRO COMPUTER PROGRAMMING ENVIRONMENT FOR CNC MILLING MACHINES THREE AXIS EQUATION PLOTTING CAPABILITIES

    NASA Technical Reports Server (NTRS)

    Ray, R. B.

    1994-01-01

    OPMILL is a computer operating system for a Kearney and Trecker milling machine that provides a fast and easy way to program machine part manufacture with an IBM compatible PC. The program gives the machinist an "equation plotter" feature which plots any set of equations that define axis moves (up to three axes simultaneously) and converts those equations to a machine milling program that will move a cutter along a defined path. Other supported functions include: drill with peck, bolt circle, tap, mill arc, quarter circle, circle, circle 2 pass, frame, frame 2 pass, rotary frame, pocket, loop and repeat, and copy blocks. The system includes a tool manager that can handle up to 25 tools and automatically adjusts tool length for each tool. It will display all tool information and stop the milling machine at the appropriate time. Information for the program is entered via a series of menus and compiled to the Kearney and Trecker format. The program can then be loaded into the milling machine, the tool path graphically displayed, and tool change information or the program in Kearney and Trecker format viewed. The program has a complete file handling utility that allows the user to load the program into memory from the hard disk, save the program to the disk with comments, view directories, merge a program on the disk with one in memory, save a portion of a program in memory, and change directories. OPMILL was developed on an IBM PS/2 running DOS 3.3 with 1 MB of RAM. OPMILL was written for an IBM PC or compatible 8088 or 80286 machine connected via an RS-232 port to a Kearney and Trecker Data Mill 700/C Control milling machine. It requires a "D:" drive (fixed-disk or virtual), a browse or text display utility, and an EGA or better display. Users wishing to modify and recompile the source code will also need Turbo BASIC, Turbo C, and Crescent Software's QuickPak for Turbo BASIC. IBM PC and IBM PS/2 are registered trademarks of International Business Machines. Turbo BASIC and Turbo C are trademarks of Borland International.

  14. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    NASA Technical Reports Server (NTRS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  15. Attitude control study for a large flexible spacecraft using a Solar Electric Propulsion System (SEPS)

    NASA Technical Reports Server (NTRS)

    Tolivar, A. F.; Key, R. W.

    1980-01-01

    The attitude control performance of the solar electric propulsion system (SEPS) was evaluated. A thrust vector control system for powered flight control was examined along with a gas jet reaction control system, and a reaction wheel system, both of which have been proposed for nonpowered flight control. Comprehensive computer simulations of each control system were made and evaluated using a 30 mode spacecraft model. Results obtained indicate that thrust vector control and reaction wheel systems offer acceptable smooth proportional control. The gas jet control system is shown to be risky for a flexible structure such as SEPS, and is therefore, not recommended as a primary control method.

  16. Research flight-control system development for the F-18 high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Powers, Bruce; Regenie, Victoria; Chacon, Vince; Degroote, Steve; Murnyak, Steven

    1991-01-01

    The F-18 high alpha research vehicle was recently modified by adding a thrust vectoring control system. A key element in the modification was the development of a research flight control system integrated with the basic F-18 flight control system. Discussed here are design requirements, system development, and research utility of the resulting configuration as an embedded system for flight research in the high angle of attack regime. Particular emphasis is given to control system modifications and control law features required for high angle of attack flight. Simulation results are used to illustrate some of the thrust vectoring control system capabilities and predicted maneuvering improvements.

  17. Intelligent tires for identifying coefficient of friction of tire/road contact surfaces using three-axis accelerometer

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Ryosuke; Kamai, Kazuto; Seki, Ryosuke

    2015-02-01

    Intelligent tires equipped with sensors as well as the monitoring of the tire/road contact conditions are in demand for improving vehicle control and safety. With the aim of identifying the coefficient of friction of tire/road contact surfaces during driving, including during cornering, we develop an identification scheme for the coefficient of friction that involves estimation of the slip angle and applied force by using a single lightweight three-axis accelerometer attached on the inner surface of the tire. To validate the developed scheme, we conduct tire-rolling tests using an accelerometer-equipped tire with various slip angles on various types of road surfaces, including dry and wet surfaces. The results of these tests confirm that the estimated slip angle and applied force are reasonable. Furthermore, the identified coefficient of friction by the developed scheme agreed with that measured by standardized tests.

  18. Three Three-Axis IEPE Accelerometers on the Inner Liner of a Tire for Finding the Tire-Road Friction Potential Indicators †

    PubMed Central

    Niskanen, Arto; Tuononen, Ari J.

    2015-01-01

    Direct tire-road contact friction estimation is essential for future autonomous cars and active safety systems. Friction estimation methods have been proposed earlier for driving conditions in the presence of a slip angle or slip ratio. However, the estimation of the friction from a freely-rolling tire is still an unsolved topic. Knowing the existing friction potential would be beneficial since vehicle control systems could be adjusted before any remarkable tire force has been produced. Since accelerometers are well-known and robust, and thus a promising sensor type for intelligent tires, this study uses three three-axis IEPE accelerometers on the inner liner of a tire to detect friction potential indicators on two equally smooth surfaces with different friction levels. The equal roughness was chosen for both surfaces in order to study the friction phenomena by neglecting the effect of surface texture on vibrations. The acceleration data before the contact is used to differentiate the two friction levels between the tire and the road. In addition, the contact lengths from the three accelerometers are used to validate the acceleration data. A method to differentiate the friction levels on the basis of the acceleration signal is also introduced. PMID:26251914

  19. Three Three-Axis IEPE Accelerometers on the Inner Liner of a Tire for Finding the Tire-Road Friction Potential Indicators.

    PubMed

    Niskanen, Arto; Tuononen, Ari J

    2015-01-01

    Direct tire-road contact friction estimation is essential for future autonomous cars and active safety systems. Friction estimation methods have been proposed earlier for driving conditions in the presence of a slip angle or slip ratio. However, the estimation of the friction from a freely-rolling tire is still an unsolved topic. Knowing the existing friction potential would be beneficial since vehicle control systems could be adjusted before any remarkable tire force has been produced. Since accelerometers are well-known and robust, and thus a promising sensor type for intelligent tires, this study uses three three-axis IEPE accelerometers on the inner liner of a tire to detect friction potential indicators on two equally smooth surfaces with different friction levels. The equal roughness was chosen for both surfaces in order to study the friction phenomena by neglecting the effect of surface texture on vibrations. The acceleration data before the contact is used to differentiate the two friction levels between the tire and the road. In addition, the contact lengths from the three accelerometers are used to validate the acceleration data. A method to differentiate the friction levels on the basis of the acceleration signal is also introduced. PMID:26251914

  20. Development of a flexible three-axis tactile sensor based on screen-printed carbon nanotube-polymer composite

    NASA Astrophysics Data System (ADS)

    Pyo, Soonjae; Lee, Jae-Ik; Kim, Min-Ook; Chung, Taeyoung; Oh, Yongkeun; Lim, Soo-Chul; Park, Joonah; Kim, Jongbaeg

    2014-07-01

    A flexible, three-axis carbon nanotube (CNT)-polymer composite-based tactile sensor is presented. The proposed sensor consists of a flexible substrate, four sensing cells, and a bump structure. A CNT-polydimethylsiloxane (PDMS) composite is produced by a solvent evaporation method, and thus, the CNTs are well-dispersed within the PDMS matrix. The composite is directly patterned onto a flexible substrate using a screen printing technique to fabricate a sensor with four sensing cells. When a force is applied on the bump, the magnitude and direction of force could be detected by comparing the changes in electrical resistance of each sensing cell caused by the piezoresistive effect of the composite. The experimentally verified sensing characteristics of the fabricated sensor exhibit a linear relationship between the resistance change and the applied force, and the measured sensitivities of the sensor for the normal and shear forces are 6.67 and 86.7%/N for forces up to 2.0 and 0.5?N, respectively. Experiments to verify the load-sensing repeatability show a maximum 2.00% deviation of the resistance change within the tested force range.

  1. Parameter estimation of a three-axis spacecraft simulator using recursive least-squares approach with tracking differentiator and Extended Kalman Filter

    NASA Astrophysics Data System (ADS)

    Xu, Zheyao; Qi, Naiming; Chen, Yukun

    2015-12-01

    Spacecraft simulators are widely used to study the dynamics, guidance, navigation, and control of a spacecraft on the ground. A spacecraft simulator can have three rotational degrees of freedom by using a spherical air-bearing to simulate a frictionless and micro-gravity space environment. The moment of inertia and center of mass are essential for control system design of ground-based three-axis spacecraft simulators. Unfortunately, they cannot be known precisely. This paper presents two approaches, i.e. a recursive least-squares (RLS) approach with tracking differentiator (TD) and Extended Kalman Filter (EKF) method, to estimate inertia parameters. The tracking differentiator (TD) filter the noise coupled with the measured signals and generate derivate of the measured signals. Combination of two TD filters in series obtains the angular accelerations that are required in RLS (TD-TD-RLS). Another method that does not need to estimate the angular accelerations is using the integrated form of dynamics equation. An extended TD (ETD) filter which can also generate the integration of the function of signals is presented for RLS (denoted as ETD-RLS). States and inertia parameters are estimated simultaneously using EKF. The observability is analyzed. All proposed methods are illustrated by simulations and experiments.

  2. Development of CMOS-MEMS in-plane magnetic coils for application as a three-axis resonant magnetic sensor

    NASA Astrophysics Data System (ADS)

    Chang, Chun-I.; Tsai, Ming-Han; Sun, Chih-Ming; Fang, Weileun

    2014-03-01

    This study designs and implements a single unit three-axis magnetic sensor using the standard TSMC 0.35 m 2P4M CMOS process. The magnetic sensor consists of springs, a proof-mass with embedded magnetic coils, and sensing electrodes. Two sets of in-plane magnetic coils respectively arranged in two orthogonal axes are realized using the stacking of metal and tungsten layers in the CMOS process. The number of turns for the proposed in-plane magnetic-coil is not restricted by the space and thin film layers of the CMOS process. The magnetic coils could respectively generate Lorentz and electromagnetic forces by out-of-plane and in-plane magnetic fields to excite the spring-mass structure. Capacitance sensing electrodes could detect the dynamic response of the spring-mass structure to determine the magnetic fields. Measurements indicate the typical sensitivities of the sensor are 0.21 V T-1 (x-axis), 0.20 V T-1 (y-axis), and 0.90 V T-1 (z-axis) at 1 atm. Moreover, the resolutions of the sensor are respectively 384 nT rtHz-1 for the x-axis, 403 nT rtHz-1 for the y-axis, and 62 nT rtHz-1 for the z-axis at 1 atm. The presented magnetic sensor could monolithically integrate with other CMOS-MEMS devices for various applications.

  3. Liquid Rocket Booster (LRB) for the Space Transportion System (STS) systems study. Appendix D: Trade study summary for the liquid rocket booster

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Trade studies plans for a number of elements in the Liquid Rocket Booster (LRB) component of the Space Transportation System (STS) are given in viewgraph form. Some of the elements covered include: avionics/flight control; avionics architecture; thrust vector control studies; engine control electronics; liquid rocket propellants; propellant pressurization systems; recoverable spacecraft; cryogenic tanks; and spacecraft construction materials.

  4. Apollo guidance, navigation and control: Guidance system operations plan for manned CM earth orbital and lunar missions using Program COLOSSUS 3. Section 3: Digital autopilots (revision 14)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Digital autopilots for the manned command module earth orbital and lunar missions using program COLOSSUS 3 are discussed. Subjects presented are: (1) reaction control system digital autopilot, (2) thrust vector control autopilot, (3) entry autopilot and mission control programs, (4) takeover of Saturn steering, and (5) coasting flight attitude maneuver routine.

  5. Experience with a three-axis side-located controller during a static and centrifuge simulation of the piloted launch of a manned multistage vehicle

    NASA Technical Reports Server (NTRS)

    Andrews, William H.; Holleman, Euclid C.

    1960-01-01

    An investigation was conducted to determine a human pilot's ability to control a multistage vehicle through the launch trajectory. The simulation was performed statically and dynamically by utilizing a human centrifuge. An interesting byproduct of the program was the three-axis side-located controller incorporated for pilot control inputs. This method of control proved to be acceptable for the successful completion of the tracking task during the simulation. There was no apparent effect of acceleration on the mechanical operation of the controller, but the pilot's control feel deteriorated as his dexterity decreased at high levels of acceleration. The application of control in a specific control mode was not difficult. However, coordination of more than one mode was difficult, and, in many instances, resulted in inadvertent control inputs. The acceptable control harmony at an acceleration level of 1 g became unacceptable at higher acceleration levels. Proper control-force harmony for a particular control task appears to be more critical for a three-axis controller than for conventional controllers. During simulations in which the pilot wore a pressure suit, the nature of the suit gloves further aggravated this condition.

  6. Design and fabrication of three-axis accelerometer sensor microsystem for wide temperature range applications using semi-custom process

    NASA Astrophysics Data System (ADS)

    Merdassi, A.; Wang, Y.; Xereas, G.; Chodavarapu, V. P.

    2014-03-01

    This paper describes an integrated CMOS-MEMS inertial sensor microsystem, consisting of a 3-axis accelerometer sensor device and its complementary readout circuit, which is designed to operate over a wide temperature range from - 55C to 175C. The accelerometer device is based on capacitive transduction and is fabricated using PolyMUMPS, which is a commercial process available from MEMSCAP. The fabricated accelerometer device is then post-processed by depositing a layer of amorphous silicon carbide to form a composite sensor structure to improve its performance over an extended wide temperature range. We designed and fabricated a CMOS readout circuit in IBM 0.13?m process that interfaces with the accelerometer device to serve as a capacitance to voltage converter. The accelerometer device is designed to operate over a measurement range of +/-20g. The described sensor system allows low power, low cost and mass-producible implementation well suited for a variety of applications with harsh or wide temperature operating conditions.

  7. Two-photon three-axis digital scanned light-sheet microscopy (2P3A-DSLM)

    NASA Astrophysics Data System (ADS)

    Zong, Weijian; Zhao, Jia; Chen, Xuanyang; Lin, Yuan; Ren, Huixia; Zhang, Yunfeng; Fan, Ming; Zhou, Zhuan; Cheng, Heping; Sun, Yujie; Chen, Liangyi

    2014-09-01

    In this presentation we report a new 3D scanned DSLM. The system combined 1) two-photon excitation, 2) scanning along the illumination axis (x-axis) using tunable acoustic gradient lens (TAG) to stretch the Rayleigh range [5], 3) scanning vertically to the illumination axis (y-axis) by one galvo mirror to create light sheet. 4) scanning along Z-axis to do fast 3D imaging by another galvo mirror. The image plane was kept aligned with the fast z-axis scanned light sheet plane by an electric tunable lens (ETL) as described in ref. 6. The light sheet can be tailored to any shape between 5050 ?m2 and more than 500500 ?m2 with constant thickness limited by diffraction and fast imaging rates limited by the detector. The tailorable illumination area allows multi-scale field of view (FOV), and is consequently capable of imaging cells, tissue and live animals in one setup.

  8. A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: Applications to paleo- and archeointensity determinations

    NASA Astrophysics Data System (ADS)

    Gallet, Y.; Le Goff, M.

    2004-12-01

    We have developed a new three-axis vibrating sample magnetometer (Triaxe) which allows continuous high-temperature magnetization measurements of individual cylindrical 0.75 cm3 samples up to 650C, and the acquisition of thermoremanent magnetization (TRM) in any direction with a field of up to 200 microT. This equipment offers many possibilities for investigating rock magnetic properties at high temperature. As a first application, we propose a fast (2 hours) automated experimental procedure based on a modified version of the Thellier and Thellier (1959) method revised by Coe (1967) which provides continuous intensity determinations over a large (typically 300C) temperature interval for each sample. This procedure takes into account both the cooling rate dependence of the TRM acquisition and the anisotropy of TRM. Analyses of numerous pottery and baked brick fragments from Mesopotamia demonstrate the quality and the reliability of the data, and illustrate the potential of this new instrument for paleo- and archeomagnetism.

  9. Taking low-temperature measurements of remanence beyond the state-of-the-art: new three-axis data from Umkondo Province sills

    NASA Astrophysics Data System (ADS)

    Swanson-Hysell, N.; Solheid, P.; Feinberg, J. M.

    2013-12-01

    Low-temperature cycling of paleomagnetic specimens across the Verwey transition is a common technique used to preferentially remove remanence associated with multi-domain magnetite grains. This low-temperature demagnetization (LTD) step is gaining increasing use in both paleodirectional and paleointensity protocols making it imperative to understand the mechanism, efficiency and possible limitations of LTD. A recently developed cryogenic probe used in conjunction with a superconducting rock magnetometer at the Institute for Rock Magnetism allows for three-axis measurements to be made during cycling to and from low-temperatures in a low-field environment. In this study, we targeted a suite of well-characterized samples from the Umkondo Large Igneous Province of Botswana that displayed large (~50%) demagnetization of the natural remanence after cooling to 77 K including some samples that underwent large directional changes. Three-axis data were continuously collected during low-temperature cycling experiments on both natural remanence and lab-induced anhysteretic remanent magnetization (pARM). Experiments were designed with orthogonal pARMs to observe the behavior and efficiency of demagnetization of remanence carried by low coercivity (multi-domain grains). These experiments revealed high efficiency of demagnetization (>95%) of a pARM imparted to low coercivity grains (AF fields of 0 to 5 mT) with a return to the direction of a pARM imparted to higher coercivity grains (AF fields of 5 to 200 mT). The data also demonstrate that low-temperature demagnetization of such a pARM upon cooling is dominated by changes prior to the Verwey transition or the isotropic point. These results suggests that it is changes in magnetocrystalline anisotropy (K1) at temperatures above the isotropic point that are responsible for the majority of low-temperature demagnetization of multidomain magnetite grains. The low-temperature probe is available for community use at the Institute for Rock Magnetism and we encourage fellowship applications to use it for experiments that continue to take low-temperature measurements of remanence beyond the state-of-the-art.

  10. Optimal design and experiment of a three-axis out-of-plane nano positioning stage using a new compact bridge-type displacement amplifier.

    PubMed

    Lee, Hak-Jun; Kim, Hyun-Chang; Kim, Hyo-Young; Gweon, Dae-Gab

    2013-11-01

    This paper presents the development of a new compact three-axis compliant stage employing piezoelectric actuators and a new flexure structure. A proposed stage works out-of-plane (Z, ?x, ?y) direction. The stage consists of 4 amplification flexures mounted piezoelectric actuators. New structure of flexure reduces height and enhances dynamic performance of stage. To certify excellent performance of the stage, comparison accomplished between conventional amplification flexure and new compact bridge type flexure. Modeling and optimal design of new type nano positioning stage performed. The optimal design is executed on the geometric parameters of the proposed flexure structure using Sequential Quadratic Programming. Experiments are carried out to verify the static and dynamic performance of the stage. The proposed out-of-plane nano-positioning stage has a Z-directional motion range 190 ?m and a ?x, ?y-directional motion range 2 mrad. The resolution of the stage is 4 nm, 40 nrad, and 40 nrad in the Z-, ?x-, and ?y-directional motions, respectively. The size of stage is 150 150 30 mm(3). PMID:24289433

  11. Design and Integration of an Actuated Nose Strake Control System

    NASA Technical Reports Server (NTRS)

    Flick, Bradley C.; Thomson, Michael P.; Regenie, Victoria A.; Wichman, Keith D.; Pahle, Joseph W.; Earls, Michael R.

    1996-01-01

    Aircraft flight characteristics at high angles of attack can be improved by controlling vortices shed from the nose. These characteristics have been investigated with the integration of the actuated nose strakes for enhanced rolling (ANSER) control system into the NASA F-18 High Alpha Research Vehicle. Several hardware and software systems were developed to enable performance of the research goals. A strake interface box was developed to perform actuator control and failure detection outside the flight control computer. A three-mode ANSER control law was developed and installed in the Research Flight Control System. The thrust-vectoring mode does not command the strakes. The strakes and thrust-vectoring mode uses a combination of thrust vectoring and strakes for lateral- directional control, and strake mode uses strakes only for lateral-directional control. The system was integrated and tested in the Dryden Flight Research Center (DFRC) simulation for testing before installation in the aircraft. Performance of the ANSER system was monitored in real time during the 89-flight ANSER flight test program in the DFRC Mission Control Center. One discrepancy resulted in a set of research data not being obtained. The experiment was otherwise considered a success with the majority of the research objectives being met.

  12. Control of Ducted Fan Flying Object Using Thrust Vectoring

    NASA Astrophysics Data System (ADS)

    Miwa, Masafumi; Shigematsu, Yuki; Yamashita, Takashi

    Recently, R/C helicopter is used in fields of aerial photography and aerial investigation. But helicopter rotor blades are not covered, and the thrust is generated by high rotational speed. Thus R/C helicopter has a high risk of damage. In this study, we developed a new flying object using ducted fans instead of rotor blades. At first, PD control was employed for pitch and roll attitude control, but it caused steady state error. Moreover, PI-D control was used instead of PD control, and it reduced the steady state error. We succeeded to achieve stable hovering by 3-axes (roll, pitch and yaw axis) attitude control.

  13. Forebody vortex control as a complement to thrust vectoring

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.; Ng, T. T.

    1990-01-01

    The desire to enhance the controllability of fighter aircraft at high angles of attack, particularly yaw control, has fostered an interest in both vectored thrust and active control of forebody vortices. This paper reviews several methods of forebody vortex control that have been investigated with water and wind tunnel tests of both generic and actual fighter configurations. The methods investigated include pneumatic or blowing techniques using surface-mounted jets and slots, surface suction, variable-height deployable strakes, and rotatable tip strakes. Flow visualization, and force and moment measurements have shown that all of the methods are effective in manipulating the forebody vortices over a wide range of angles of attack and sideslip, primarily through control over flow separation on the surface of the forebody. All are most effective when applied near the forebody tip. The advantages and limitations of the various methods are reviewed.

  14. Strategic avionics technology definition studies. Subtask 3-1A3: Electrical Actuation (ELA) Systems Test Facility

    NASA Technical Reports Server (NTRS)

    Rogers, J. P.; Cureton, K. L.; Olsen, J. R.

    1994-01-01

    Future aerospace vehicles will require use of the Electrical Actuator systems for flight control elements. This report presents a proposed ELA Test Facility for dynamic evaluation of high power linear Electrical Actuators with primary emphasis on Thrust Vector Control actuators. Details of the mechanical design, power and control systems, and data acquisition capability of the test facility are presented. A test procedure for evaluating the performance of the ELA Test Facility is also included.

  15. Titan 3E/Centaur D-1T Systems Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A systems and operational summary of the Titan 3E/Centaur D-1T program is presented which describes vehicle assembly facilities, launch facilities, and management responsibilities, and also provides detailed information on the following separate systems: (1) mechanical systems, including structural components, insulation, propulsion units, reaction control, thrust vector control, hydraulic systems, and pneumatic equipment; (2) astrionics systems, such as instrumentation and telemetry, navigation and guidance, C-Band tracking system, and range safety command system; (3) digital computer unit software; (4) flight control systems; (5) electrical/electronic systems; and (6) ground support equipment, including checkout equipment.

  16. A 3D error measurement system for CNC machining tools

    NASA Astrophysics Data System (ADS)

    Jywe, Wenyuh; Jeng, Y. R.; Li, Yitsung; Liu, Chienhung; Hsu, Tunghui; Jwo, Hsinhung; Lin, Borjeng; Lee, Mengtse; Kuo, Hsing-Chia; Lin, Chorng-Tyan; Chiu, Cheng-Chang

    2008-10-01

    A new system for measuring the errors of three-axis machines is presented in this paper. It is composed of a planar encoder system and a magnetic telescoping ball bar. The individual signals of three-axis displacement can be simultaneous obtained. The errors of the three-axis machines, geometric error, kinematic error, wobble error and volumetric error, can be effectively measured. The system is characterized by short set up time, low capital requirement, high measuring speed and high accuracy.

  17. Three-axis superconducting gravity gradiometer

    SciTech Connect

    Paik, H.J.

    1989-06-27

    This patent describes a gradiometer having a sensitive axis for detecting a gravity gradient along the sensitive axis, comprising: a pair of accelerometers having respective sensitive axes; each accelerometer including a proof mass having a pair of hollowed out annular portions; each proof mass having at least one sensing coil arranged adjacent a bottom-side surface of the respective proof mass in one of the hollowed out portions and a levitation coil arranged adjacent a second bottom-side surface of the respective proof mass in the other hollowed out portion, at least one sensing coil and the levitation coil thus being located on the same side of the respective proof mass in relation to the direction of an external force exerted on the gradiometer thereby to compensate for temperature induced changes in magnetic field penetration into the respective proof mass; at least one first superconducting circuit in which the sensing coils of the accelerometers are interconnected and in which a first persistent current flows, the first circuit having an output indicative of a gravity gradient along the sensitive axis of the gradiometer.

  18. The Control System for the X-33 Linear Aerospike Engine

    NASA Technical Reports Server (NTRS)

    Jackson, Jerry E.; Espenschied, Erich; Klop, Jeffrey

    1998-01-01

    The linear aerospike engine is being developed for single-stage -to-orbit (SSTO) applications. The primary advantages of a linear aerospike engine over a conventional bell nozzle engine include altitude compensation, which provides enhanced performance, and lower vehicle weight resulting from the integration of the engine into the vehicle structure. A feature of this integration is the ability to provide thrust vector control (TVC) by differential throttling of the engine combustion elements, rather than the more conventional approach of gimballing the entire engine. An analysis of the X-33 flight trajectories has shown that it is necessary to provide +/- 15% roll, pitch and yaw TVC authority with an optional capability of +/- 30% pitch at select times during the mission. The TVC performance requirements for X-33 engine became a major driver in the design of the engine control system. The thrust level of the X-33 engine as well as the amount of TVC are managed by a control system which consists of electronic, instrumentation, propellant valves, electro-mechanical actuators, spark igniters, and harnesses. The engine control system is responsible for the thrust control, mixture ratio control, thrust vector control, engine health monitoring, and communication to the vehicle during all operational modes of the engine (checkout, pre-start, start, main-stage, shutdown and post shutdown). The methodology for thrust vector control, the health monitoring approach which includes failure detection, isolation, and response, and the basic control system design are the topic of this paper. As an additional point of interest a brief description of the X-33 engine system will be included in this paper.

  19. System for imposing directional stability on a rocket-propelled vehicle

    NASA Technical Reports Server (NTRS)

    Perkins, H. (Inventor)

    1976-01-01

    An improved system for use in imposing directional stability on a rocket-propelled vehicle is described. The system includes a pivotally supported engine-mounting platform, a gimbal ring mounted on the platform and adapted to pivotally support a rocket engine and an hydraulic actuator connected to the platform for imparting selected pivotal motion. An accelerometer and a signal comparator circuit for providing error intelligence indicative of aberration in vehicle acceleration is included along with an actuator control circuit connected with the actuator and responsive to error intelligence for imparting pivotal motion to the platform. Relocation of the engine's thrust vector is thus achieved for imparting directional stability to the vehicle.

  20. Development of a unified guidance system for geocentric transfer. [for solar electric propulsion spacecraft

    NASA Technical Reports Server (NTRS)

    Cake, J. E.; Regetz, J. D., Jr.

    1975-01-01

    A method is presented for open loop guidance of a solar electric propulsion spacecraft to geosynchronous orbit. The method consists of determining the thrust vector profiles on the ground with an optimization computer program, and performing updates based on the difference between the actual trajectory and that predicted with a precision simulation computer program. The motivation for performing the guidance analysis during the mission planning phase is discussed, and a spacecraft design option that employs attitude orientation constraints is presented. The improvements required in both the optimization program and simulation program are set forth, together with the efforts to integrate the programs into the ground support software for the guidance system.

  1. Development of a unified guidance system for geocentric transfer. [solar electric propulsion spacecraft

    NASA Technical Reports Server (NTRS)

    Cake, J. E.; Regetz, J. D., Jr.

    1975-01-01

    A method is presented for open loop guidance of a solar electric propulsion spacecraft to geosynchronsus orbit. The method consists of determining the thrust vector profiles on the ground with an optimization computer program, and performing updates based on the difference between the actual trajectory and that predicted with a precision simulation computer program. The motivation for performing the guidance analysis during the mission planning phase is discussed, and a spacecraft design option that employs attitude orientation constraints is presented. The improvements required in both the optimization program and simulation program are set forth, together with the efforts to integrate the programs into the ground support software for the guidance system.

  2. X-31 high angle of attack control system performance

    NASA Technical Reports Server (NTRS)

    Huber, Peter; Seamount, Patricia

    1994-01-01

    The design goals for the X-31 flight control system were: (1) level 1 handling qualities during post-stall maneuvering (30 to 70 degrees angle-of-attack); (2) thrust vectoring to enhance performance across the flight envelope; and (3) adequate pitch-down authority at high angle-of-attack. Additional performance goals are discussed. A description of the flight control system is presented, highlighting flight control system features in the pitch and roll axes and X-31 thrust vectoring characteristics. The high angle-of-attack envelope clearance approach will be described, including a brief explanation of analysis techniques and tools. Also, problems encountered during envelope expansion will be discussed. This presentation emphasizes control system solutions to problems encountered in envelope expansion. An essentially 'care free' envelope was cleared for the close-in-combat demonstrator phase. High angle-of-attack flying qualities maneuvers are currently being flown and evaluated. These results are compared with pilot opinions expressed during the close-in-combat program and with results obtained from the F-18 HARV for identical maneuvers. The status and preliminary results of these tests are discussed.

  3. Lift/cruise fan V/STOL technology aircraft design definition study. Volume 2: Propulsion transmission system design

    NASA Technical Reports Server (NTRS)

    Obrien, W. J.

    1976-01-01

    Two types of lift/cruise fan technology aircraft were conceptually designed. One aircraft used turbotip fans pneumatically interconnected to three gas generators, and the other aircraft used variable pitch fans mechanically interconnected to three turboshaft engines. The components of each propulsion transmission system were analyzed and designed to the depth necessary to determine areas of risk, development methods, performance, weights and costs. The types of materials and manufacturing processes were identified to show that the designs followed a low cost approach. The lift/cruise fan thrust vectoring hoods, which are applicable to either aircraft configuration, were also evaluated to assure a low cost/low risk approach.

  4. SIT-5 system development.

    NASA Technical Reports Server (NTRS)

    Hyman, J., Jr.

    1972-01-01

    A 5-cm structurally integrated ion thruster (SIT-5) has been developed for attitude control and stationkeeping of synchronous satellites. With two-dimension thrust-vectoring grids, a first generation unit has demonstrated a thrust of 0.56 mlb at a beam voltage of 1200 V, total mass efficiency of 64%, and electrical efficiency of 46.8%. Structural integrity is demonstrated with a dielectric-coated grid for shock (30 G), sinusoidal (9 G), and random (19.9 G rms) accelerations. System envelope is 31.8 cm long by 13.9 cm flange bolt circle, with a mass of 8.5 kg, including 6.2 kg mercury propellant. Characteristics of a second-generation unit indicate significant performance gains.

  5. F-15B ACTIVE with thrust vectoring nozzles on test stand at sunrise

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This November 13, 1995, photograph of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the aircraft on a test stand at sunrise. Not shown in this photograph are the aircraft's two new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. These nozzles give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. These tests could result in significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace. The aircraft was originally built as an F-15B (Serial #71-0290).

  6. Advanced Launch System (ALS): Electrical actuation and power systems improve operability and cost picture

    NASA Technical Reports Server (NTRS)

    Sundberg, Gale R.

    1990-01-01

    To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications.

  7. Advanced Launch System (ALS) actuation and power systems impact operability and cost

    NASA Technical Reports Server (NTRS)

    Sundberg, Gale R.

    1990-01-01

    To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications.

  8. Advanced launch system (ALS) - Electrical actuation and power systems improve operability and cost picture

    NASA Technical Reports Server (NTRS)

    Sundberg, Gale R.

    1990-01-01

    To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrrical power system and controls for all aviation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a sdpecific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military ans civilian aircraft, lunar/Martian vehicles, and a multitude of comercial applications.

  9. Performance optimized, small structurally integrated ion thruster system

    NASA Technical Reports Server (NTRS)

    Hyman, J., Jr.

    1973-01-01

    A 5-cm structurally integrated ion thruster has been developed for attitude control and stationkeeping of synchronous satellites. As optimized with a conventional ion extraction system, the system demonstrates a thrust T = 0.47 mlb at a beam voltage of 1600 V, total mass efficiency of 76%, and electrical efficiency of 56%. Under the subject contract effort, no significant performance change was noted for operation with two dimensional electrostatic thrust-vectoring grids. Structural integrity with the vectoring grids was demonstrated for shock (+ or - 30 G), sinusoidal (9 G), and random (19.9 G rms) accelerations. System envelope is 31.2 cm long by 13.4 cm flange bolt circle, with a mass of 9.0 Kg, including 6.8 Kg mercury propellant.

  10. Flight-determined benefits of integrated flight-propulsion control systems

    NASA Technical Reports Server (NTRS)

    Stewart, James F.; Burcham, Frank W., Jr.; Gatlin, Donald H.

    1992-01-01

    Over the last two decades, NASA has conducted several experiments in integrated flight-propulsion control. Benefits have included improved maneuverability; increased thrust, range, and survivability; reduced fuel consumption; and reduced maintenance. This paper presents the basic concepts for control integration, examples of implementation, and benefits. The F-111E experiment integrated the engine and inlet control systems. The YF-12C incorporated an integral control system involving the inlet, autopilot, autothrottle, airdata, navigation, and stability augmentation systems. The F-15 research involved integration of the engine, flight, and inlet control systems. Further extension of the integration included real-time, onboard optimization of engine, inlet, and flight control variables; a self-repairing flight control system; and an engines-only control concept for emergency control. The F-18A aircraft incorporated thrust vectoring integrated with the flight control system to provide enhanced maneuvering at high angles of attack. The flight research programs and the resulting benefits of each program are described.

  11. Analysis of a Linear System for Variable-Thrust Control in the Terminal Phase of Rendezvous

    NASA Technical Reports Server (NTRS)

    Hord, Richard A.; Durling, Barbara J.

    1961-01-01

    A linear system for applying thrust to a ferry vehicle in the 3 terminal phase of rendezvous with a satellite is analyzed. This system requires that the ferry thrust vector per unit mass be variable and equal to a suitable linear combination of the measured position and velocity vectors of the ferry relative to the satellite. The variations of the ferry position, speed, acceleration, and mass ratio are examined for several combinations of the initial conditions and two basic control parameters analogous to the undamped natural frequency and the fraction of critical damping. Upon making a desirable selection of one control parameter and requiring minimum fuel expenditure for given terminal-phase initial conditions, a simplified analysis in one dimension practically fixes the choice of the remaining control parameter. The system can be implemented by an automatic controller or by a pilot.

  12. Three-axis attitude control for a geostationary satellite

    NASA Technical Reports Server (NTRS)

    Freeman, H. R.

    1976-01-01

    The Applications Technology Satellite-6 was successfully launched into a geostationary orbit in May, 1974. Since that time, its attitude control subsystem has routinely demonstrated its ability to perform precision pointing and precision closed loop maneuvers. This paper describes the ATS-6 attitude control subsystem. The requirements imposed by the spacecraft mission objectives are outlined, and functional descriptions of the principal attitude control subsystem components and control laws are presented. The paper concludes with a summary comparison of in-orbit performance relative to its specified performance requirements.

  13. Three-axis fiber-optic vector magnetometer

    SciTech Connect

    Koo, K.P.; Sigel, G.H.; Bucholtz, F.

    1991-01-01

    This patent application discloses an optical fiber for magnetostrictive responsive detection of magnetic fields. The strength of the protective magnetic field is determined by standard interferometry techniques by comparing the phase or mode properties of the light from a light source exiting the fiber having a magnetostrictive jacket against the phase or mode properties of light from a light source exiting a reference fiber having pre-determined or identical light transmission properties. The sensitivity of magnetic effect upon the magnetostrictively affected fiber is enhanced by subjecting the magnetostrictive material to a quantitative low-level magnetic field.

  14. Performance characteristics of a three-axis superconducting rock magnetometer

    NASA Technical Reports Server (NTRS)

    Lienert, B. R.

    1977-01-01

    A series of measurements are carried out with the purpose of quantitatively determining the characteristics of a commercial 6.8 cm access superconducting rock magnetometer located in the magnetic properties laboratory at the Goddard Space Flight Center. The measurements show that although a considerable improvement in measurement speed and signal to noise ratios can be obtained using such an instrument, a number of precautions are necessary to obtain accuracies comparable with more conventional magnetometers. These include careful calibration of the sensor outputs, optimum positioning of the sample within the detection region and quantitatively establishing the degree of cross-coupling between the detector coils. In order to examine the uniformity of response for each detector, the responses are mapped as a function of position, using a small dipole.

  15. Three-axis electron-beam test facility

    NASA Technical Reports Server (NTRS)

    Dayton, J. A., Jr.; Ebihara, B. T.

    1981-01-01

    An electron beam test facility, which consists of a precision multidimensional manipulator built into an ultra-high-vacuum bell jar, was designed, fabricated, and operated at Lewis Research Center. The position within the bell jar of a Faraday cup which samples current in the electron beam under test, is controlled by the manipulator. Three orthogonal axes of motion are controlled by stepping motors driven by digital indexers, and the positions are displayed on electronic totalizers. In the transverse directions, the limits of travel are approximately + or - 2.5 cm from the center with a precision of 2.54 micron (0.0001 in.); in the axial direction, approximately 15.0 cm of travel are permitted with an accuracy of 12.7 micron (0.0005 in.). In addition, two manually operated motions are provided, the pitch and yaw of the Faraday cup with respect to the electron beam can be adjusted to within a few degrees. The current is sensed by pulse transformers and the data are processed by a dual channel box car averager with a digital output. The beam tester can be operated manually or it can be programmed for automated operation. In the automated mode, the beam tester is controlled by a microcomputer (installed at the test site) which communicates with a minicomputer at the central computing facility. The data are recorded and later processed by computer to obtain the desired graphical presentations.

  16. Three-axis electron-beam test facility

    NASA Astrophysics Data System (ADS)

    Dayton, J. A., Jr.; Ebihara, B. T.

    1981-03-01

    An electron beam test facility, which consists of a precision multidimensional manipulator built into an ultra-high-vacuum bell jar, was designed, fabricated, and operated at Lewis Research Center. The position within the bell jar of a Faraday cup which samples current in the electron beam under test, is controlled by the manipulator. Three orthogonal axes of motion are controlled by stepping motors driven by digital indexers, and the positions are displayed on electronic totalizers. In the transverse directions, the limits of travel are approximately + or - 2.5 cm from the center with a precision of 2.54 micron (0.0001 in.); in the axial direction, approximately 15.0 cm of travel are permitted with an accuracy of 12.7 micron (0.0005 in.). In addition, two manually operated motions are provided, the pitch and yaw of the Faraday cup with respect to the electron beam can be adjusted to within a few degrees. The current is sensed by pulse transformers and the data are processed by a dual channel box car averager with a digital output. The beam tester can be operated manually or it can be programmed for automated operation. In the automated mode, the beam tester is controlled by a microcomputer (installed at the test site) which communicates with a minicomputer at the central computing facility. The data are recorded and later processed by computer to obtain the desired graphical presentations.

  17. Linearized transfer between inclined circular orbits using low-thrust blow down propulsion system

    NASA Technical Reports Server (NTRS)

    Kechichian, J. A.; White, L. K.

    1983-01-01

    Noncoplanar transfers between neighboring circular orbits are presented for spacecraft using their own low-thrust blow down propulsion system. It is assumed that the out-of-plane angle between the decaying thrust vector and the current orbit plane remains constant for each extended burn. Switching conditions are derived for the cutoff and relight of the propulsion system in order to carry out a given transfer with inclination change. Furthermore the location where the thrust acceleration is initially applied with respect to the line of nodes of the two orbits is uniquely determined. Finally an analytic derivation of the linearized coplanar motion for stationkeeping and terminal rendezvous studies is also presented and a scheme for deriving the second order correction shown.

  18. NASA Marshall Space Flight Center Controls Systems Design and Analysis Branch

    NASA Technical Reports Server (NTRS)

    Gilligan, Eric

    2014-01-01

    Marshall Space Flight Center maintains a critical national capability in the analysis of launch vehicle flight dynamics and flight certification of GN&C algorithms. MSFC analysts are domain experts in the areas of flexible-body dynamics and control-structure interaction, thrust vector control, sloshing propellant dynamics, and advanced statistical methods. Marshall's modeling and simulation expertise has supported manned spaceflight for over 50 years. Marshall's unparalleled capability in launch vehicle guidance, navigation, and control technology stems from its rich heritage in developing, integrating, and testing launch vehicle GN&C systems dating to the early Mercury-Redstone and Saturn vehicles. The Marshall team is continuously developing novel methods for design, including advanced techniques for large-scale optimization and analysis.

  19. Solar electric propulsion thrust subsystem development

    NASA Technical Reports Server (NTRS)

    Masek, T. D.

    1973-01-01

    The Solar Electric Propulsion System developed under this program was designed to demonstrate all the thrust subsystem functions needed on an unmanned planetary vehicle. The demonstration included operation of the basic elements, power matching input and output voltage regulation, three-axis thrust vector control, subsystem automatic control including failure detection and correction capability (using a PDP-11 computer), operation of critical elements in thermal-vacuum-, zero-gravity-type propellant storage, and data outputs from all subsystem elements. The subsystem elements, functions, unique features, and test setup are described. General features and capabilities of the test-support data system are also presented. The test program culminated in a 1500-h computer-controlled, system-functional demonstration. This included simultaneous operation of two thruster/power conditioner sets. The results of this testing phase satisfied all the program goals.

  20. Study of vortex valve for medium temperature solid propellants

    NASA Technical Reports Server (NTRS)

    Holt, W. D.; Rivard, J. G.

    1966-01-01

    Fluid state vortex valve secondary injection control system shows considerable promise for future application to solid propellant rocket engine thrust vector control. The single axis injection system tested would be capable of providing secondary injection thrust vector control using 2000 deg F gas.

  1. Aircraft ground test and subscale model results of axial thrust loss caused by thrust vectoring using turning vanes

    NASA Technical Reports Server (NTRS)

    Johnson, Steven A.

    1992-01-01

    The NASA-Dryden F/A-18 high alpha research vehicle was modified to incorporate three independently controlled turning vanes located aft of the primary nozzle of each engine to vector thrust for pitch and yaw control. Ground measured axial thrust losses were compared with the results from a 14.25 pct. cold jet model for single and dual vanes inserted up to 25 degs into the engine exhaust. Data are presented for nozzle pressure ratios of 2.0 and 3.0 and nozzle exit areas of 253 and 348 sq in. The results indicate that subscale nozzle test results properly predict trends but underpredict the full scale results by approx. 1 to 4.5 pct. in thrust loss.

  2. Evaluation of dual flow thrust vectored nozzles with exhaust stream impingement. MS Thesis Final Technical Report, Oct. 1990 - Jul. 1991

    NASA Technical Reports Server (NTRS)

    Carpenter, Thomas W.

    1991-01-01

    The main objective of this project was to predict the expansion wave/oblique shock wave structure in an under-expanded jet expanding from a convergent nozzle. The shock structure was predicted by combining the calculated curvature of the free pressure boundary with principles and governing equations relating to oblique shock wave and expansion wave interaction. The procedure was then continued until the shock pattern repeated itself. A mathematical model was then formulated and written in FORTRAN to calculate the oblique shock/expansion wave structure within the jet. In order to study shock waves in expanding jets, Schlieren photography, a form of flow visualization, was employed. Thirty-six Schlieren photographs of jets from both a straight and 15 degree nozzle were taken. An iterative procedure was developed to calculate the shock structure within the jet and predict the non-dimensional values of Prandtl primary wavelength (w/rn), distance to Mach Disc (Ld) and Mach Disc radius (rd). These values were then compared to measurements taken from Schlieren photographs and experimental results. The results agreed closely to measurements from Schlieren photographs and previously obtained data. This method provides excellent results for pressure ratios below that at which a Mach Disc first forms. Calculated values of non-dimensional distance to the Mach Disc (Ld) agreed closely to values measured from Schlieren photographs and published data. The calculated values of non-dimensional Mach Disc radius (rd), however, deviated from published data by as much as 25 percent at certain pressure ratios.

  3. Flywheel energy storage for electromechanical actuation systems

    NASA Technical Reports Server (NTRS)

    Hockney, Richard L.; Goldie, James H.; Kirtley, James L.

    1991-01-01

    The authors describe a flywheel energy storage system designed specifically to provide load-leveling for a thrust vector control (TVC) system using electromechanical actuators (EMAs). One of the major advantages of an EMA system over a hydraulic system is the significant reduction in total energy consumed during the launch profile. Realization of this energy reduction will, however, require localized energy storage capable of delivering the peak power required by the EMAs. A combined flywheel-motor/generator unit which interfaces directly to the 20-kHz power bus represents an ideal candidate for this load leveling. The overall objective is the definition of a flywheel energy storage system for this application. The authors discuss progress on four technical objectives: (1) definition of the specifications for the flywheel-motor/generator system, including system-level trade-off analysis; (2) design of the flywheel rotor; (3) design of the motor/generator; and (4) determination of the configuration for the power management system.

  4. Solid Rocket Booster (SRB) Flight System Integration at Its Best

    NASA Technical Reports Server (NTRS)

    Wood, T. David; Kanner, Howard S.; Freeland, Donna M.; Olson, Derek T.

    2011-01-01

    The Solid Rocket Booster (SRB) element integrates all the subsystems needed for ascent flight, entry, and recovery of the combined Booster and Motor system. These include the structures, avionics, thrust vector control, pyrotechnic, range safety, deceleration, thermal protection, and retrieval systems. This represents the only human-rated, recoverable and refurbishable solid rocket ever developed and flown. Challenges included subsystem integration, thermal environments and severe loads (including water impact), sometimes resulting in hardware attrition. Several of the subsystems evolved during the program through design changes. These included the thermal protection system, range safety system, parachute/recovery system, and others. Because the system was recovered, the SRB was ideal for data and imagery acquisition, which proved essential for understanding loads, environments and system response. The three main parachutes that lower the SRBs to the ocean are the largest parachutes ever designed, and the SRBs are the largest structures ever to be lowered by parachutes. SRB recovery from the ocean was a unique process and represented a significant operational challenge; requiring personnel, facilities, transportation, and ground support equipment. The SRB element achieved reliability via extensive system testing and checkout, redundancy management, and a thorough postflight assessment process. However, the in-flight data and postflight assessment process revealed the hardware was affected much more strongly than originally anticipated. Assembly and integration of the booster subsystems required acceptance testing of reused hardware components for each build. Extensive testing was done to assure hardware functionality at each level of stage integration. Because the booster element is recoverable, subsystems were available for inspection and testing postflight, unique to the Shuttle launch vehicle. Problems were noted and corrective actions were implemented as needed. The postflight assessment process was quite detailed and a significant portion of flight operations. The SRBs provided fully redundant critical systems including thrust vector control, mission critical pyrotechnics, avionics, and parachute recovery system. The design intent was to lift off with full redundancy. On occasion, the redundancy management scheme was needed during flight operations. This paper describes some of the design challenges and technical issues, how the design evolved with time, and key areas where hardware reusability contributed to improved system level understanding.

  5. Dynamic interactions between hypersonic vehicle aerodynamics and propulsion system performance

    NASA Technical Reports Server (NTRS)

    Flandro, G. A.; Roach, R. L.; Buschek, H.

    1992-01-01

    Described here is the development of a flexible simulation model for scramjet hypersonic propulsion systems. The primary goal is determination of sensitivity of the thrust vector and other system parameters to angle of attack changes of the vehicle. Such information is crucial in design and analysis of control system performance for hypersonic vehicles. The code is also intended to be a key element in carrying out dynamic interaction studies involving the influence of vehicle vibrations on propulsion system/control system coupling and flight stability. Simple models are employed to represent the various processes comprising the propulsion system. A method of characteristics (MOC) approach is used to solve the forebody and external nozzle flow fields. This results in a very fast computational algorithm capable of carrying out the vast number of simulation computations needed in guidance, stability, and control studies. The three-dimensional fore- and aft body (nozzle) geometry is characterized by the centerline profiles as represented by a series of coordinate points and body cross-section curvature. The engine module geometry is represented by an adjustable vertical grid to accommodate variations of the field parameters throughout the inlet and combustor. The scramjet inlet is modeled as a two-dimensional supersonic flow containing adjustable sidewall wedges and multiple fuel injection struts. The inlet geometry including the sidewall wedge angles, the number of injection struts, their sweepback relative to the vehicle reference line, and strut cross-section are user selectable. Combustion is currently represented by a Rayleigh line calculation including corrections for variable gas properties; improved models are being developed for this important element of the propulsion flow field. The program generates (1) variation of thrust magnitude and direction with angle of attack, (2) pitching moment and line of action of the thrust vector, (3) pressure and temperature distributions throughout the system, and (4) performance parameters such as thrust coefficient, specific impulse, mass flow rates, and equivalence ratio. Preliminary results are in good agreement with available performance data for systems resembling the NASP vehicle configuration.

  6. The 3-axis Dynamic Motion Simulator (DMS) system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A three-axis dynamic motion simulator (DMS) consisting of a test table with three degrees of freedom and an electronics control system was designed, constructed, delivered, and tested. Documentation, as required in the Data Requirements List (DRL), was also provided.

  7. Advanced communications satellite systems

    NASA Technical Reports Server (NTRS)

    Sivo, J. N.

    1983-01-01

    There is a rapidly growing demand for satellite circuits, particularly for domestic service within the U.S. NASA's current program is aimed at developing the high risk, advanced satellite communications technologies required to significantly increase the capacity of future satellite communications systems. Attention is given to aspects of traffic distribution and service scenario, problems related to effects of rain attenuation, details regarding system configuration, a 30/20 GHz technology development approach, an experimental flight system, the communications payload for the experimental flight system, a typical experiment flight system coverage, and a typical three axis stabilized flight spacecraft.

  8. Design of power electronics for TVC EMA systems

    NASA Technical Reports Server (NTRS)

    Nelms, R. Mark

    1993-01-01

    The Composite Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 volts. MSFC has selected the brushless dc motor for implementation in EMA's. This report presents the results of an investigation into the applicability of two new technologies, MOS-controlled thyristors (MCT's) and pulse density modulation (PDM), to the control of brushless dc motors in EMA systems. MCT's are new power semiconductor devices, which combine the high voltage and current capabilities of conventional thyristors and the low gate drive requirements of metal oxide semiconductor field effect transistors (MOSFET's). The commanded signals in a PDM system are synthesized using a series of sinusoidal pulses instead of a series of square pulses as in a pulse width modulation (PWM) system. A resonant dc link inverter is employed to generate the sinusoidal pulses in the PDM system. This inverter permits zero-voltage switching of all semiconductors which reduces switching losses and switching stresses. The objectives of this project are to develop and validate an analytical model of the MCT device when used in high power motor control applications and to design, fabricate, and test a prototype electronic circuit employing both MCT and PDM technology for controlling a brushless dc motor.

  9. Design of power electronics for TVC EMA systems

    NASA Astrophysics Data System (ADS)

    Nelms, R. Mark

    1993-08-01

    The Composite Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 volts. MSFC has selected the brushless dc motor for implementation in EMA's. This report presents the results of an investigation into the applicability of two new technologies, MOS-controlled thyristors (MCT's) and pulse density modulation (PDM), to the control of brushless dc motors in EMA systems. MCT's are new power semiconductor devices, which combine the high voltage and current capabilities of conventional thyristors and the low gate drive requirements of metal oxide semiconductor field effect transistors (MOSFET's). The commanded signals in a PDM system are synthesized using a series of sinusoidal pulses instead of a series of square pulses as in a pulse width modulation (PWM) system. A resonant dc link inverter is employed to generate the sinusoidal pulses in the PDM system. This inverter permits zero-voltage switching of all semiconductors which reduces switching losses and switching stresses. The objectives of this project are to develop and validate an analytical model of the MCT device when used in high power motor control applications and to design, fabricate, and test a prototype electronic circuit employing both MCT and PDM technology for controlling a brushless dc motor.

  10. General equilibrium characteristics of a dual-lift helicopter system

    NASA Technical Reports Server (NTRS)

    Cicolani, L. S.; Kanning, G.

    1986-01-01

    The equilibrium characteristics of a dual-lift helicopter system are examined. The system consists of the cargo attached by cables to the endpoints of a spreader bar which is suspended by cables below two helicopters. Results are given for the orientation angles of the suspension system and its internal forces, and for the helicopter thrust vector requirements under general circumstances, including nonidentical helicopters, any accelerating or static equilibrium reference flight condition, any system heading relative to the flight direction, and any distribution of the load to the two helicopters. Optimum tether angles which minimize the sum of the required thrust magnitudes are also determined. The analysis does not consider the attitude degrees of freedom of the load and helicopters in detail, but assumes that these bodies are stable, and that their aerodynamic forces in equilibrium flight can be determined independently as functions of the reference trajectory. The ranges of these forces for sample helicopters and loads are examined and their effects on the equilibrium characteristics are given parametrically in the results.

  11. Critical engine system design characteristics for SSTO vehicles

    NASA Astrophysics Data System (ADS)

    Fanciullo, Thomas J.; Judd, D. C.; Obrien, C. J.

    1992-02-01

    Engine system design characteristics are summarized for typical vertical take-off and landing (VTOL) and vertical take-off and horizontal landing (VTHL) Strategic Defense Initiative Organization (SDIO) single stage to orbit (SSTO) vehicles utilizing plug nozzle configurations. Power cycle selection trades involved the unique modular platelet engine (MPE) with the use of (1) LO2 and LH2 at fixed and variable mixture ratios, (2) LO2 and propane or RP-1, and (3) dual fuels (LO2 with LH2 and C3H8). The number of thrust cells and modules were optimized. Dual chamber bell and a cluster of conventional bell nozzle configurations were examined for comparison with the plug configuration. Thrust modulation (throttling) was selected for thrust vector control. Installed thrust ratings were established to provide an additional 20 percent overthrust capability for engine out operation. Turbopumps were designed to operate at subcritical speeds to facilitate a wide range of throttling and long life. A unique dual spool arrangement with hydrostatic bearings was selected for the LH2 turbopump. Controls and health monitoring with expert systems for diagnostics are critical subsystems to ensure minimum maintenance and supportability for a less than seven day turnaround. The use of an idle mode start, in conjunction with automated health condition monitoring, allows the rocket propulsion system to operate reliably in the manner of present day aircraft propulsion.

  12. Transition of a technology base for advanced aircraft gas turbine control systems

    SciTech Connect

    McGlone, M.E.

    1998-07-01

    Technology assessments during the 1980s projected the development of advanced military fighter aircraft that would require propulsion systems that could accommodate multimission capability with super maneuverability. These propulsion systems would be required to provide significantly improved thrust to weight, reduced thrust specific fuel consumption, and up and away thrust vectoring capabilities. Digital electronic control systems with significantly expanded capabilities would be required to handle these multifunction control actuation systems, to integrate them with flight control systems, and to provide fail-operational capability. This paper will discuss the challenges that were presented to propulsion system control designers, the innovation of technology to address these challenges, and the transition of that technology to production readiness. Technology advancements will be discussed in the area of digital electronic control capability and packaging, advanced fuel management systems, high pressure fuel hydraulic actuation systems for multifunction nozzles, integrated flight propulsion controls, and higher-order language software development tools. Each of these areas provided unique opportunities where technology development programs and flight prototyping carried concepts to reality.

  13. Lift/cruise fan V/STOL technology aircraft design definition study. Volume 3: Development program and budgetary estimates

    NASA Technical Reports Server (NTRS)

    Obrien, W. J.

    1976-01-01

    The aircraft development program, budgetary estimates in CY 1976 dollars, and cost reduction program variants are presented. Detailed cost matrices are also provided for the mechanical transmission system, turbotip transmission system, and the thrust vector hoods and yaw doors.

  14. Auxiliary lift propulsion system with oversized front fan

    SciTech Connect

    Castells, O.T.; Johnson, J.E.; Rundell, D.J.

    1980-09-16

    A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting. Additional lift is generated by the high energy products of combustion of the variable cycle engine which are further energized in an afterburner and exhausted through a thrust vectorable nozzle at the rear of the engine.

  15. Attitude Determination Error Analysis System (ADEAS) mathematical specifications document

    NASA Technical Reports Server (NTRS)

    Nicholson, Mark; Markley, F.; Seidewitz, E.

    1988-01-01

    The mathematical specifications of Release 4.0 of the Attitude Determination Error Analysis System (ADEAS), which provides a general-purpose linear error analysis capability for various spacecraft attitude geometries and determination processes, are presented. The analytical basis of the system is presented. The analytical basis of the system is presented, and detailed equations are provided for both three-axis-stabilized and spin-stabilized attitude sensor models.

  16. Aristoteles magnetometer system

    NASA Astrophysics Data System (ADS)

    Smith, Edward J.; Marquedant, Roy J.; Langel, Robert; Acuna, Mario

    1991-12-01

    A magnetometer system capable of meeting the stringent requirements of the Aristoteles mission is described. The system will comprise a three axis or Vector Flux gas Magnetometer (VFM) and a highly accurate resonance magnetometer, the Scalar Helium Magnetometer (SHM). Basic operational features of these instruments are described and their performance is related to the scientific objectives of the mission appropriate to the geomagnetic field measurements. The major requirements imposed on the spacecraft are summarized. Photographs and diagrams of both instruments are presented along with graphs of the sensitivity of the SHM to magnetic field orientation.

  17. X-31 Post Stall Maneuver - Duration: 51 seconds.

    NASA Video Gallery

    The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at ...

  18. X-31 Herbst Turn - Duration: 29 seconds.

    NASA Video Gallery

    The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at ...

  19. Navy and the HARV: High angle of attack tactical utility issues

    NASA Technical Reports Server (NTRS)

    Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.

    1994-01-01

    This presentation will highlight results from the latest Navy evaluation of the HARV (March 1994) and focus primarily on the impressions from a piloting standpoint of the tactical utility of thrust vectoring. Issue to be addressed will be mission suitability of high AOA flight, visual and motion feedback cues associated with operating at high AOA, and the adaptability of a pilot to effectively use the increased control power provided by the thrust vectoring system.

  20. Design and on-orbit performance of the attitude determination and control system for the ZDPS-1A pico-satellite

    NASA Astrophysics Data System (ADS)

    Xiang, Tian; Meng, Tao; Wang, Hao; Han, Ke; Jin, Zhong-He

    2012-08-01

    The ZDPS-1A pico-satellite, developed by the Zhejiang University, is featured with a three-axis stabilizing capability. It is 151515 cm3 cube-shaped satellite with a total mass of 3.5 kg. ZDPS-1A is the first pico-satellite that has been launched successfully in China. The mission of ZDPS-1A is on-orbit system verification of student-build pico-satellite and wide range earth observation with a micro panoramic camera. A miniature momentum wheel is employed to offer gyro stiffness stability in the pitch (orbit normal) axis. Magnetic coils are employed to generate control torques to achieve the three-axis stabilization of nadir-pointing. The attitude sensors employed in the design include two three-axis magnetometers (TAMs), a three-axis gyro, and two sun sensors. Both ground simulations and on-orbit testing are conducted to verify the feasibility of the given attitude determination and control system (ADCS).

  1. Neutron resonance spin-echo upgrade at the three-axis spectrometer FLEXX

    SciTech Connect

    Groitl, F. Quintero-Castro, D. L.; Habicht, K.; Keller, T.

    2015-02-15

    We describe the upgrade of the neutron resonance spin-echo setup at the cold neutron triple-axis spectrometer FLEXX at the BER II neutron source at the Helmholtz-Zentrum Berlin. The parameters of redesigned key components are discussed, including the radio frequency (RF) spin-flip coils, the magnetic shield, and the zero field coupling coils. The RF-flippers with larger beam windows allow for an improved neutron flux transfer from the source to the sample and further to the analyzer. The larger beam cross sections permit higher coil inclination angles and enable measurements on dispersive excitations with a larger slope of the dispersion. Due to the compact design of the spin-echo units in combination with the increased coil tilt angles, the accessible momentum-range in the Larmor diffraction mode is substantially enlarged. In combination with the redesigned components of the FLEXX spectrometer, including the guide, the S-bender polarizer, the double focusing monochromator, and a Heusler crystal analyzer, the count rate increased by a factor of 15.5, and the neutron beam polarization is enhanced. The improved performance extends the range of feasible experiments, both for inelastic scattering on excitation lifetimes in single crystals, and for high-resolution Larmor diffraction. The experimental characterization of the instrument components demonstrates the reliable performance of the new neutron resonance spin-echo option, now available for the scientific community at FLEXX.

  2. The vTAS suite: A simulator for classical and multiplexed three-axis neutron spectrometers

    NASA Astrophysics Data System (ADS)

    Boehm, M.; Filhol, A.; Raoul, Y.; Kulda, J.; Schmidt, W.; Schmalzl, K.; Farhi, E.

    2013-01-01

    The vTAS suite provides graphical assistance to prepare and perform inelastic neutron scattering experiments on a TAS instrument, including latest multiplexed instrumental configurations, such as FlatCone, IMPS and UFO. The interactive display allows for flexible translation between instrument positions in real space and neutron scattering conditions represented in reciprocal space. It is a platform independent public domain software tool, available for download from the website of the Institut Laue Langevin (ILL).

  3. Neutron resonance spin-echo upgrade at the three-axis spectrometer FLEXX

    NASA Astrophysics Data System (ADS)

    Groitl, F.; Keller, T.; Quintero-Castro, D. L.; Habicht, K.

    2015-02-01

    We describe the upgrade of the neutron resonance spin-echo setup at the cold neutron triple-axis spectrometer FLEXX at the BER II neutron source at the Helmholtz-Zentrum Berlin. The parameters of redesigned key components are discussed, including the radio frequency (RF) spin-flip coils, the magnetic shield, and the zero field coupling coils. The RF-flippers with larger beam windows allow for an improved neutron flux transfer from the source to the sample and further to the analyzer. The larger beam cross sections permit higher coil inclination angles and enable measurements on dispersive excitations with a larger slope of the dispersion. Due to the compact design of the spin-echo units in combination with the increased coil tilt angles, the accessible momentum-range in the Larmor diffraction mode is substantially enlarged. In combination with the redesigned components of the FLEXX spectrometer, including the guide, the S-bender polarizer, the double focusing monochromator, and a Heusler crystal analyzer, the count rate increased by a factor of 15.5, and the neutron beam polarization is enhanced. The improved performance extends the range of feasible experiments, both for inelastic scattering on excitation lifetimes in single crystals, and for high-resolution Larmor diffraction. The experimental characterization of the instrument components demonstrates the reliable performance of the new neutron resonance spin-echo option, now available for the scientific community at FLEXX.

  4. A three-axis flight simulator. [for testing and evaluating inertial measuring units, and flight platforms

    NASA Technical Reports Server (NTRS)

    Mason, M. G.

    1975-01-01

    A simulator is described, which was designed for testing and evaluating inertial measuring units, and flight platforms. Mechanical and electrical specifications for the outer, middle, and inner axis are presented. Test results are included.

  5. Three-axis digital holographic microscopy for high speed volumetric imaging.

    PubMed

    Saglimbeni, F; Bianchi, S; Lepore, A; Di Leonardo, R

    2014-06-01

    Digital Holographic Microscopy allows to numerically retrieve three dimensional information encoded in a single 2D snapshot of the coherent superposition of a reference and a scattered beam. Since no mechanical scans are involved, holographic techniques have a superior performance in terms of achievable frame rates. Unfortunately, numerical reconstructions of scattered field by back-propagation leads to a poor axial resolution. Here we show that overlapping the three numerical reconstructions obtained by tilted red, green and blue beams results in a great improvement over the axial resolution and sectioning capabilities of holographic microscopy. A strong reduction in the coherent background noise is also observed when combining the volumetric reconstructions of the light fields at the three different wavelengths. We discuss the performance of our technique with two test objects: an array of four glass beads that are stacked along the optical axis and a freely diffusing rod shaped E.coli bacterium. PMID:24921564

  6. Three-axis accelerometer package for slimhole and microhole seismic monitoring and surveys

    SciTech Connect

    Hunter, S.L.; Harben, P.E.

    1997-01-07

    The development of microdrilling technology, nominally defined as drilling technology for 1-in.-diameter boreholes, shows potential for reducing the cost of drilling monitoring wells. A major question that arises in drilling microholes is if downhole logging and monitoring in general--and downhole seismic surveying in particular--can be conducted in such small holes since the inner working diameter of such a seismic tool could be as small as 0.31 in. A downhole three-component accelerometer package that fits within a 031-in. inner diameter tube has been designed, built, and tested. The package consists of three orthogonally mounted Entran EGA-125-5g piezoresistive silicon micromachined accelerometers with temperature compensation circuitry, downhole amplification, and line drivers mounted in a thin-walled aluminum tube. Accelerometers are commercially available in much smaller package sizes than conventional geophones, but the noise floor is significantly higher than that for the geophones. Cross-well tests using small explosives showed good signal-to-noise ratio in the recorded waveform at various receiver depths with a 1,50-ft source-receiver well separation. For some active downhole surveys, the accelerometer unit would clearly be adequate. It can be reasonably assumed, however, that for less energetic sources and for greater well separations, the high accelerometer noise floor is not acceptable. By expanding the inner working diameter of a microhole seismic tool to 0.5 in., other commercial accelerometers can be used with substantially lower noise floors.

  7. Space Launch System Implementation of Adaptive Augmenting Control

    NASA Technical Reports Server (NTRS)

    Wall, John H.; Orr, Jeb S.; VanZwieten, Tannen S.

    2014-01-01

    Given the complex structural dynamics, challenging ascent performance requirements, and rigorous flight certification constraints owing to its manned capability, the NASA Space Launch System (SLS) launch vehicle requires a proven thrust vector control algorithm design with highly optimized parameters to provide stable and high-performance flight. On its development path to Preliminary Design Review (PDR), the SLS flight control system has been challenged by significant vehicle flexibility, aerodynamics, and sloshing propellant. While the design has been able to meet all robust stability criteria, it has done so with little excess margin. Through significant development work, an Adaptive Augmenting Control (AAC) algorithm has been shown to extend the envelope of failures and flight anomalies the SLS control system can accommodate while maintaining a direct link to flight control stability criteria such as classical gain and phase margin. In this paper, the work performed to mature the AAC algorithm as a baseline component of the SLS flight control system is presented. The progress to date has brought the algorithm design to the PDR level of maturity. The algorithm has been extended to augment the full SLS digital 3-axis autopilot, including existing load-relief elements, and the necessary steps for integration with the production flight software prototype have been implemented. Several updates which have been made to the adaptive algorithm to increase its performance, decrease its sensitivity to expected external commands, and safeguard against limitations in the digital implementation are discussed with illustrating results. Monte Carlo simulations and selected stressing case results are also shown to demonstrate the algorithm's ability to increase the robustness of the integrated SLS flight control system.

  8. Space Launch System Implementation of Adaptive Augmenting Control

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Wall, John H.; Orr, Jeb S.

    2014-01-01

    Given the complex structural dynamics, challenging ascent performance requirements, and rigorous flight certification constraints owing to its manned capability, the NASA Space Launch System (SLS) launch vehicle requires a proven thrust vector control algorithm design with highly optimized parameters to robustly demonstrate stable and high performance flight. On its development path to preliminary design review (PDR), the stability of the SLS flight control system has been challenged by significant vehicle flexibility, aerodynamics, and sloshing propellant dynamics. While the design has been able to meet all robust stability criteria, it has done so with little excess margin. Through significant development work, an adaptive augmenting control (AAC) algorithm previously presented by Orr and VanZwieten, has been shown to extend the envelope of failures and flight anomalies for which the SLS control system can accommodate while maintaining a direct link to flight control stability criteria (e.g. gain & phase margin). In this paper, the work performed to mature the AAC algorithm as a baseline component of the SLS flight control system is presented. The progress to date has brought the algorithm design to the PDR level of maturity. The algorithm has been extended to augment the SLS digital 3-axis autopilot, including existing load-relief elements, and necessary steps for integration with the production flight software prototype have been implemented. Several updates to the adaptive algorithm to increase its performance, decrease its sensitivity to expected external commands, and safeguard against limitations in the digital implementation are discussed with illustrating results. Monte Carlo simulations and selected stressing case results are shown to demonstrate the algorithm's ability to increase the robustness of the integrated SLS flight control system.

  9. Space construction base control system

    NASA Technical Reports Server (NTRS)

    Kaczynski, R. F.

    1979-01-01

    Several approaches for an attitude control system are studied and developed for a large space construction base that is structurally flexible. Digital simulations were obtained using the following techniques: (1) the multivariable Nyquist array method combined with closed loop pole allocation, (2) the linear quadratic regulator method. Equations for the three-axis simulation using the multilevel control method were generated and are presented. Several alternate control approaches are also described. A technique is demonstrated for obtaining the dynamic structural properties of a vehicle which is constructed of two or more submodules of known dynamic characteristics.

  10. A PC-based magnetometer-only attitude and rate determination system for gyroless spacecraft

    NASA Technical Reports Server (NTRS)

    Challa, M.; Natanson, G.; Deutschmann, J.; Galal, K.

    1995-01-01

    This paper describes a prototype PC-based system that uses measurements from a three-axis magnetometer (TAM) to estimate the state (three-axis attitude and rates) of a spacecraft given no a priori information other than the mass properties. The system uses two algorithms that estimate the spacecraft's state - a deterministic magnetic-field only algorithm and a Kalman filter for gyroless spacecraft. The algorithms are combined by invoking the deterministic algorithm to generate the spacecraft state at epoch using a small batch of data and then using this deterministic epoch solution as the initial condition for the Kalman filter during the production run. System input comprises processed data that includes TAM and reference magnetic field data. Additional information, such as control system data and measurements from line-of-sight sensors, can be input to the system if available. Test results are presented using in-flight data from two three-axis stabilized spacecraft: Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) (gyroless, Sun-pointing) and Earth Radiation Budget Satellite (ERBS) (gyro-based, Earth-pointing). The results show that, using as little as 700 s of data, the system is capable of accuracies of 1.5 deg in attitude and 0.01 deg/s in rates; i.e., within SAMPEX mission requirements.

  11. V/STOL systems research aircraft: A tool for cockpit integration

    NASA Technical Reports Server (NTRS)

    Stortz, Michael W.; ODonoghue, Dennis P.

    1995-01-01

    The next generation ASTOVL aircraft will have a complicated propulsion system. The configuration choices include Direct Lift, Lift-Fan and Lift + Lift/Cruise but the aircraft must also have supersonic performance and low-observable characteristics. The propulsion system may have features such as flow blockers, vectoring nozzles and flow transfer schemes. The flight control system will necessarily fully integrate the aerodynamic surfaces and the propulsive elements. With a fully integrated, fly-by-wire flight/propulsion control system, the options for cockpit integration are interesting and varied. It is possible to de-couple longitudinal and vertical responses allowing the pilot to close the loop on flightpath and flightpath acceleration directly. In the hover, the pilot can control the translational rate directly without having to stabilize the inner rate and attitude loops. The benefit of this approach, reduced workload and increased precision, has previously been demonstrated through several motion-based simulations. In order to prove the results in flight, the V/STOL System Research Aircraft (VSRA) was developed at the NASA Ames Research Center. The VSRA is the YAV-8B Prototype modified with a research flight control system using a series-parallel servo configuration in all the longitudinal degrees of freedom (including thrust and thrust vector angle) to provide an integrated flight and propulsion control system in a limited envelope. Development of the system has been completed and flight evaluations of the response types have been performed. In this paper we will discuss the development of the VSRA, the evolution of the flightpath command and translational rate command response types and the Guest Pilot evaluations of the system. Pilot evaluation results are used to draw conclusions regarding the suitability of the system to satisfy V/STOL requirements.

  12. V/STOL Systems Research Aircraft: A Tool for Cockpit Integration

    NASA Technical Reports Server (NTRS)

    Stortz, Michael W.; ODonoghue, Dennis P.; Tiffany, Geary (Technical Monitor)

    1995-01-01

    The next generation ASTOVL aircraft will have a complicated propulsion System. The configuration choices include Direct Lift, Lift-Fan and Lift+Lift /Cruise but the aircraft must also have supersonic performance and low-observable characteristics. The propulsion system may have features such as flow blockers, vectoring nozzles and flow transfer schemes. The flight control system will necessarily fully integrate the aerodynamic surfaces and the propulsive elements. With a fully integrated, fly-by-wire flight/propulsion control system, the options for cockpit integration are interesting and varied. It is possible to decouple longitudinal and vertical responses allowing the pilot to close the loop on flight path and flight path acceleration directly. In the hover, the pilot can control the translational rate directly without having to stabilize the inner rate and attitude loops. The benefit of this approach, reduced workload and increased precision. has previously been demonstrated through several motion-based simulations. In order to prove the results in flight, the V/STOL System Research Aircraft (VSRA) was developed at the NASA Ames Research Center. The VSRA is the YAV-8B Prototype modified with a research flight control system using a series-parallel servo configuration in all the longitudinal degrees of freedom (including thrust and thrust vector angle) to provide an integrated flight and propulsion control system in a limited envelope. Development of the system has been completed and flight evaluations of the response types have been performed. In this paper we will discuss the development of the VSRA, the evolution of the flight path command and translational rate command response types and the Guest Pilot evaluations of the system. Pilot evaluation results will be used to draw conclusions regarding the suitability of the system to satisfy V/STOL requirements.

  13. Design of power electronics for TVC and EMA systems

    NASA Technical Reports Server (NTRS)

    Nelms, R. Mark; Bell, J. Brett; Shepherd, Michael T.

    1994-01-01

    The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 volts. MSFC has selected the brushless dc motor for implementation in EMA's. A previous project performed by Auburn University examined the use of the resonant dc link (RDCL) inverter, pulse density modulation (PDM), and mos-controlled thyristors (MCT's) for speed control of a brushless dc motor. The speed of the brushless dc motor is proportional to the applied stator voltage. In a PDM system, the control system determines the number of resonant voltage pulses which must be applied to the stator to achieve a desired speed. The addition of a waveshaping circuit to the front end of a standard three-phase inverter yields a RDCL inverter; the resonant voltage pulses are produced through the action of this wave shaping circuit and the inverter. This project has focused on the implementation of a system which permits zero-voltage switching with the bus voltage clamped at the input voltage level. In the same manner as the RDCL inverter, the inverter selected for this implementation is a combination of waveshaping circuit and a standard three-phase inverter. In addition, this inverter allows a pulse-width modulated (PWM)-like control scheme instead of a PDM scheme. The operation of waveshaping circuit will be described through analysis and waveforms. Design relationships will also be presented.

  14. Design of power electronics for TVC and EMA systems

    NASA Astrophysics Data System (ADS)

    Nelms, R. Mark; Bell, J. Brett; Shepherd, Michael T.

    1994-11-01

    The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 volts. MSFC has selected the brushless dc motor for implementation in EMA's. A previous project performed by Auburn University examined the use of the resonant dc link (RDCL) inverter, pulse density modulation (PDM), and mos-controlled thyristors (MCT's) for speed control of a brushless dc motor. The speed of the brushless dc motor is proportional to the applied stator voltage. In a PDM system, the control system determines the number of resonant voltage pulses which must be applied to the stator to achieve a desired speed. The addition of a waveshaping circuit to the front end of a standard three-phase inverter yields a RDCL inverter; the resonant voltage pulses are produced through the action of this wave shaping circuit and the inverter. This project has focused on the implementation of a system which permits zero-voltage switching with the bus voltage clamped at the input voltage level. In the same manner as the RDCL inverter, the inverter selected for this implementation is a combination of waveshaping circuit and a standard three-phase inverter. In addition, this inverter allows a pulse-width modulated (PWM)-like control scheme instead of a PDM scheme. The operation of waveshaping circuit will be described through analysis and waveforms. Design relationships will also be presented.

  15. A wireless swing angle measurement scheme using attitude heading reference system sensing units based on microelectromechanical devices.

    PubMed

    Gao, Bingtuan; Zhu, Zhenyu; Zhao, Jianguo; Huang, Boran

    2014-01-01

    Feasible real-time swing angle measurement is significant to improve the efficiency and safety of industrial crane systems. This paper presents a wireless microelectromechanical system (MEMS)-based swing angle measurement system. The system consists of two attitude heading reference system (AHRS) sensing units with a wireless communication function, which are mounted on the hook (or payload) and the jib (or base) of the crane, respectively. With a combination of a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, the standard extended Kalman filter (EKF) is used to estimate the desired orientation of the payload and the base. Wireless ZigBee communication is employed to transmit the orientation of the payload to the sensing unit mounted on the base, which measures the orientation of the base. Because several physical parameters from the payload to the base can be acquired from the original crane control system, the swing angles of the payload can be calculated based on the two measured orientation parameters together with the known physical parameters. Experiments were performed to show the feasibility and effectiveness of the proposed swing angle measurement system. PMID:25436657

  16. A Wireless Swing Angle Measurement Scheme Using Attitude Heading Reference System Sensing Units Based on Microelectromechanical Devices

    PubMed Central

    Gao, Bingtuan; Zhu, Zhenyu; Zhao, Jianguo; Huang, Boran

    2014-01-01

    Feasible real-time swing angle measurement is significant to improve the efficiency and safety of industrial crane systems. This paper presents a wireless microelectromechanical system (MEMS)-based swing angle measurement system. The system consists of two attitude heading reference system (AHRS) sensing units with a wireless communication function, which are mounted on the hook (or payload) and the jib (or base) of the crane, respectively. With a combination of a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, the standard extended Kalman filter (EKF) is used to estimate the desired orientation of the payload and the base. Wireless ZigBee communication is employed to transmit the orientation of the payload to the sensing unit mounted on the base, which measures the orientation of the base. Because several physical parameters from the payload to the base can be acquired from the original crane control system, the swing angles of the payload can be calculated based on the two measured orientation parameters together with the known physical parameters. Experiments were performed to show the feasibility and effectiveness of the proposed swing angle measurement system. PMID:25436657

  17. The Submillimeter Wave Astronomy Satellite (SWAS) solar array system

    NASA Technical Reports Server (NTRS)

    Sneiderman, Gary

    1993-01-01

    The SWAS (Submillimeter Wave Astronomy Satellite) solar array system is described. It is an innovative approach to meet the missions requirements. The SWAS satellite provides a three axis stabilized platform to survey a variety of galactic cloud structures. This system includes highly reliable, lightweight launch latch, deployment, and lock mechanisms, and solar array panels that provide the maximum solar cell area. The design of the solar arrays are the result of system trades that included instrument and spacecraft thermal constraints, attitude control system maneuvering rates and pointing accuracies, the power system, and the spacecraft structure.

  18. System Error Compensation Methodology Based on a Neural Network for a Micromachined Inertial Measurement Unit

    PubMed Central

    Liu, Shi Qiang; Zhu, Rong

    2016-01-01

    Errors compensation of micromachined-inertial-measurement-units (MIMU) is essential in practical applications. This paper presents a new compensation method using a neural-network-based identification for MIMU, which capably solves the universal problems of cross-coupling, misalignment, eccentricity, and other deterministic errors existing in a three-dimensional integrated system. Using a neural network to model a complex multivariate and nonlinear coupling system, the errors could be readily compensated through a comprehensive calibration. In this paper, we also present a thermal-gas MIMU based on thermal expansion, which measures three-axis angular rates and three-axis accelerations using only three thermal-gas inertial sensors, each of which capably measures one-axis angular rate and one-axis acceleration simultaneously in one chip. The developed MIMU (100 × 100 × 100 mm3) possesses the advantages of simple structure, high shock resistance, and large measuring ranges (three-axes angular rates of ±4000°/s and three-axes accelerations of ±10 g) compared with conventional MIMU, due to using gas medium instead of mechanical proof mass as the key moving and sensing elements. However, the gas MIMU suffers from cross-coupling effects, which corrupt the system accuracy. The proposed compensation method is, therefore, applied to compensate the system errors of the MIMU. Experiments validate the effectiveness of the compensation, and the measurement errors of three-axis angular rates and three-axis accelerations are reduced to less than 1% and 3% of uncompensated errors in the rotation range of ±600°/s and the acceleration range of ±1 g, respectively. PMID:26840314

  19. System Error Compensation Methodology Based on a Neural Network for a Micromachined Inertial Measurement Unit.

    PubMed

    Liu, Shi Qiang; Zhu, Rong

    2016-01-01

    Errors compensation of micromachined-inertial-measurement-units (MIMU) is essential in practical applications. This paper presents a new compensation method using a neural-network-based identification for MIMU, which capably solves the universal problems of cross-coupling, misalignment, eccentricity, and other deterministic errors existing in a three-dimensional integrated system. Using a neural network to model a complex multivariate and nonlinear coupling system, the errors could be readily compensated through a comprehensive calibration. In this paper, we also present a thermal-gas MIMU based on thermal expansion, which measures three-axis angular rates and three-axis accelerations using only three thermal-gas inertial sensors, each of which capably measures one-axis angular rate and one-axis acceleration simultaneously in one chip. The developed MIMU (100 100 100 mm) possesses the advantages of simple structure, high shock resistance, and large measuring ranges (three-axes angular rates of 4000/s and three-axes accelerations of 10 g) compared with conventional MIMU, due to using gas medium instead of mechanical proof mass as the key moving and sensing elements. However, the gas MIMU suffers from cross-coupling effects, which corrupt the system accuracy. The proposed compensation method is, therefore, applied to compensate the system errors of the MIMU. Experiments validate the effectiveness of the compensation, and the measurement errors of three-axis angular rates and three-axis accelerations are reduced to less than 1% and 3% of uncompensated errors in the rotation range of 600/s and the acceleration range of 1 g, respectively. PMID:26840314

  20. Development of a GPS-aided motion measurement, pointing, and stabilization system for a Synthetic Aperture Radar. [Global Positioning System (GPS)

    SciTech Connect

    Fellerhoff, J.R.; Kohler, S.M.

    1991-01-01

    An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.

  1. A Measuring System for Well Logging Attitude and a Method of Sensor Calibration

    PubMed Central

    Ren, Yong; Wang, Yangdong; Wang, Mijian; Wu, Sheng; Wei, Biao

    2014-01-01

    This paper proposes an approach for measuring the azimuth angle and tilt angle of underground drilling tools with a MEMS three-axis accelerometer and a three-axis fluxgate sensor. A mathematical model of well logging attitude angle is deduced based on combining space coordinate transformations and algebraic equations. In addition, a system implementation plan of the inclinometer is given in this paper, which features low cost, small volume and integration. Aiming at the sensor and assembly errors, this paper analyses the sources of errors, and establishes two mathematical models of errors and calculates related parameters to achieve sensor calibration. The results show that this scheme can obtain a stable and high precision azimuth angle and tilt angle of drilling tools, with the deviation of the former less than 1.4 and the deviation of the latter less than 0.1. PMID:24859028

  2. Space Launch System Development Status

    NASA Technical Reports Server (NTRS)

    Lyles, Garry

    2014-01-01

    Development of NASA's Space Launch System (SLS) heavy lift rocket is shifting from the formulation phase into the implementation phase in 2014, a little more than three years after formal program approval. Current development is focused on delivering a vehicle capable of launching 70 metric tons (t) into low Earth orbit. This "Block 1" configuration will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017, followed by its first crewed flight in 2021. SLS can evolve to a130-t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Benefits associated with its unprecedented mass and volume include reduced trip times and simplified payload design. Every SLS element achieved significant, tangible progress over the past year. Among the Program's many accomplishments are: manufacture of Core Stage test panels; testing of Solid Rocket Booster development hardware including thrust vector controls and avionics; planning for testing the RS-25 Core Stage engine; and more than 4,000 wind tunnel runs to refine vehicle configuration, trajectory, and guidance. The Program shipped its first flight hardware - the Multi-Purpose Crew Vehicle Stage Adapter (MSA) - to the United Launch Alliance for integration with the Delta IV heavy rocket that will launch an Orion test article in 2014 from NASA's Kennedy Space Center. Objectives of this Earth-orbit flight include validating the performance of Orion's heat shield and the MSA design, which will be manufactured again for SLS missions to deep space. The Program successfully completed Preliminary Design Review in 2013 and Key Decision Point C in early 2014. NASA has authorized the Program to move forward to Critical Design Review, scheduled for 2015 and a December 2017 first launch. The Program's success to date is due to prudent use of proven technology, infrastructure, and workforce from the Saturn and Space Shuttle programs, a streamlined management approach, and judicious use of new technologies. The result is a safe, affordable, sustainable, and evolutionary path to development of an unprecedented capability for future missions across the solar system. In an environment of economic challenges, the nationwide SLS team continues to meet ambitious budget and schedule targets. This paper will discuss SLS program and technical accomplishments over the past year and provide a look at the milestones and challenges ahead.

  3. America's Next Great Ship: Space Launch System Core Stage Transitioning from Design to Manufacturing

    NASA Technical Reports Server (NTRS)

    Birkenstock, Benjamin; Kauer, Roy

    2014-01-01

    The Space Launch System (SLS) Program is essential to achieving the Nation's and NASA's goal of human exploration and scientific investigation of the solar system. As a multi-element program with emphasis on safety, affordability, and sustainability, SLS is becoming America's next great ship of exploration. The SLS Core Stage includes avionics, main propulsion system, pressure vessels, thrust vector control, and structures. Boeing manufactures and assembles the SLS core stage at the Michoud Assembly Facility (MAF) in New Orleans, LA, a historical production center for Saturn V and Space Shuttle programs. As the transition from design to manufacturing progresses, the importance of a well-executed manufacturing, assembly, and operation (MA&O) plan is crucial to meeting performance objectives. Boeing employs classic techniques such as critical path analysis and facility requirements definition as well as innovative approaches such as Constraint Based Scheduling (CBS) and Cirtical Chain Project Management (CCPM) theory to provide a comprehensive suite of project management tools to manage the health of the baseline plan on both a macro (overall project) and micro level (factory areas). These tools coordinate data from multiple business systems and provide a robust network to support Material & Capacity Requirements Planning (MRP/CRP) and priorities. Coupled with these tools and a highly skilled workforce, Boeing is orchestrating the parallel buildup of five major sub assemblies throughout the factory. Boeing and NASA are transforming MAF to host state of the art processes, equipment and tooling, the most prominent of which is the Vertical Assembly Center (VAC), the largest weld tool in the world. In concert, a global supply chain is delivering a range of structural elements and component parts necessary to enable an on-time delivery of the integrated Core Stage. SLS is on plan to launch humanity into the next phase of space exploration.

  4. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1996-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA-High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high order characteristics of the system. In this paper, only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles at attack : 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  5. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1999-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high-order characteristics of the system. In this paper only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles of attack: 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of the identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the estimated closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  6. Characterization of in-flight performance of ion propulsion systems

    NASA Technical Reports Server (NTRS)

    Sovey, James S.; Rawlin, Vincent K.

    1993-01-01

    In-flight measurements of ion propulsion performance, ground test calibrations, and diagnostic performance measurements were reviewed. It was found that accelerometers provided the most accurate in-flight thrust measurements compared with four other methods that were surveyed. An experiment has also demonstrated that pre-flight alignment of the thrust vector was sufficiently accurate so that gimbal adjustments and use of attitude control thrusters were not required to counter disturbance torques caused by thrust vector misalignment. The effects of facility background pressure, facility enhanced charge-exchange reactions, and contamination on ground-based performance measurements are also discussed. Vacuum facility pressures for inert-gas ion thruster life tests and flight qualification tests will have to be less than 2 mPa to ensure accurate performance measurements.

  7. Characterization of in-flight performance of ion propulsion systems

    NASA Astrophysics Data System (ADS)

    Sovey, James S.; Rawlin, Vincent K.

    1993-06-01

    In-flight measurements of ion propulsion performance, ground test calibrations, and diagnostic performance measurements were reviewed. It was found that accelerometers provided the most accurate in-flight thrust measurements compared with four other methods that were surveyed. An experiment has also demonstrated that pre-flight alignment of the thrust vector was sufficiently accurate so that gimbal adjustments and use of attitude control thrusters were not required to counter disturbance torques caused by thrust vector misalignment. The effects of facility background pressure, facility enhanced charge-exchange reactions, and contamination on ground-based performance measurements are also discussed. Vacuum facility pressures for inert-gas ion thruster life tests and flight qualification tests will have to be less than 2 mPa to ensure accurate performance measurements.

  8. A baseline maritime satellite communication system

    NASA Technical Reports Server (NTRS)

    Durrani, S. H.; Mcgregor, D. N.

    1974-01-01

    This paper describes a baseline system for maritime communications via satellite during the 1980s. The system model employs three geostationary satellites with global coverage antennas. Access to the system is controlled by a master station; user access is based on time-ordered polling or random access. Each Thor-Delta launched satellite has an RF power of 100 W (spinner) or 250 W (three-axis stabilized), and provides 10 equivalent duplex voice channels for up to 1500 ships with average waiting times of approximately 2.5 minutes. The satellite capacity is bounded by the available bandwidth to 50 such channels, which can serve up to 10,000 ships with an average waiting time of 5 minutes. The ships must have peak antenna gains of approximately 15.5 dB or 22.5 dB for the two cases (10 or 50 voice channels) when a spinner satellite is used; the required gains are 4 dB lower if a three-axis stabilized satellite is used. The ship antenna requirements can be reduced by 8 to 10 dB by employing a high-gain multi-beam phased array antenna on the satellite.

  9. NASA's Space Launch System Development Status

    NASA Technical Reports Server (NTRS)

    Lyles, Garry

    2014-01-01

    Development of the National Aeronautics and Space Administration's (NASA's) Space Launch System (SLS) heavy lift rocket is shifting from the formulation phase into the implementation phase in 2014, a little more than 3 years after formal program establishment. Current development is focused on delivering a vehicle capable of launching 70 metric tons (t) into low Earth orbit. This "Block 1" configuration will launch the Orion Multi-Purpose Crew Vehicle (MPCV) on its first autonomous flight beyond the Moon and back in December 2017, followed by its first crewed flight in 2021. SLS can evolve to a130t lift capability and serve as a baseline for numerous robotic and human missions ranging from a Mars sample return to delivering the first astronauts to explore another planet. Benefits associated with its unprecedented mass and volume include reduced trip times and simplified payload design. Every SLS element achieved significant, tangible progress over the past year. Among the Program's many accomplishments are: manufacture of core stage test barrels and domes; testing of Solid Rocket Booster development hardware including thrust vector controls and avionics; planning for RS- 25 core stage engine testing; and more than 4,000 wind tunnel runs to refine vehicle configuration, trajectory, and guidance. The Program shipped its first flight hardware - the Multi-Purpose Crew Vehicle Stage Adapter (MSA) - to the United Launch Alliance for integration with the Delta IV heavy rocket that will launch an Orion test article in 2014 from NASA's Kennedy Space Center. The Program successfully completed Preliminary Design Review in 2013 and will complete Key Decision Point C in 2014. NASA has authorized the Program to move forward to Critical Design Review, scheduled for 2015 and a December 2017 first launch. The Program's success to date is due to prudent use of proven technology, infrastructure, and workforce from the Saturn and Space Shuttle programs, a streamlined management approach, and judicious use of new technologies. The result is a safe, affordable, sustainable, and evolutionary path to development of an unprecedented capability for future missions across the solar system. In an environment of economic challenges, the nationwide SLS team continues to meet ambitious budget and schedule targets. This paper will discuss SLS Program and technical accomplishments over the past year and provide a look at the milestones and challenges ahead.

  10. An electromechanical actuation system for an expendable launch vehicle

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Roth, Mary Ellen

    1992-01-01

    A major effort at the NASA Lewis Research Center in recent years has been to develop electro-mechanical actuators (EMA's) to replace the hydraulic systems used for thrust vector control (TVC) on launch vehicles. This is an attempt ot overcome the inherent inefficiencies and costs associated with the existing hydraulic structures. General Dynamics Space Systems Division, under contract to NASA Lewis, is developing 18.6 kW (25 hp), 29.8 kW (40 hp), and 52.2 kW (70 hp) peak EMA systems to meet the power demands for TVC on a family of vehicles developed for the National Launch System. These systems utilize a pulse population modulated converter and field-oriented control scheme to obtain independent control of both the voltage and frequency. These techniques allow an induction motor to be operated at its maximum torque at all times. At NASA Lewis, we are building on this technology to develop our own in-house system capable of meeting the peak power requirements for an expendable launch vehicle (ELV) such as the Atlas. Our EMA will be capable of delivering 22.4 kW (30 hp) peak power with a nominal of 6.0 kW (8 hp). This system differs from the previous ones in two areas: (1) the use of advanced control methods, and (2) the incorporation of built-in-test. The advanced controls are essential for minimizing the controller size, while the built-in-test is necessary to enhance the system reliability and vehicle health monitoring. The ultimate goal of this program is to demonstrate an EMA which will be capable of self-test and easy integration into other projects. This paper will describe the effort underway at NASA Lewis to develop an EMA for an Atlas class ELV. An explanation will be given for each major technology block, and the status of each major technology block and the status of the overall program will be reported.

  11. CMG-Augmented Control of a Hovering VTOL Platform

    NASA Technical Reports Server (NTRS)

    Lim, K. B.; Moerder, D. D.

    2007-01-01

    This paper describes how Control Moment Gyroscopes (CMGs) can be used for stability augmentation to a thrust vectoring system for a generic Vertical Take-Off and Landing platform. The response characteristics of the platform which uses only thrust vectoring and a second configuration which includes a single-gimbal CMG array are simulated and compared for hovering flight while subject to severe air turbulence. Simulation results demonstrate the effectiveness of a CMG array in its ability to significantly reduce the agility requirement on the thrust vectoring system. Albeit simplifying physical assumptions on a generic CMG configuration, the numerical results also suggest that reasonably sized CMGs will likely be sufficient for a small hovering vehicle.

  12. Field Mapping System for Solenoid Magnet

    NASA Astrophysics Data System (ADS)

    Park, K. H.; Jung, Y. K.; Kim, D. E.; Lee, H. G.; Park, S. J.; Chung, C. W.; Kang, B. K.

    2007-01-01

    A three-dimensional Hall probe mapping system for measuring the solenoid magnet of PLS photo-cathode RF e-gun has been developed. It can map the solenoid field either in Cartesian or in cylindrical coordinate system with a measurement reproducibility better than 5 10-5 T. The system has three axis motors: one for the azimuthal direction and the other two for the x and z direction. This architecture makes the measuring system simple in fabrication. The magnetic center was calculated using the measured axial component of magnetic field Bz in Cartesian coordinate system because the accuracy of magnetic axis measurement could be improved significantly by using Bz, instead of the radial component of magnetic field Br. This paper describes the measurement system and summarizes the measurement results for the solenoid magnetic of PLS photo-cathode RF e-gun.

  13. Flight experience with a fail-operational digital fly-by-wire control system

    NASA Technical Reports Server (NTRS)

    Brown, S. R.; Szalai, K. J.

    1977-01-01

    The NASA Dryden Flight Research Center is flight testing a triply redundant digital fly-by-wire (DFBW) control system installed in an F-8 aircraft. The full-time, full-authority system performs three-axis flight control computations, including stability and command augmentation, autopilot functions, failure detection and isolation, and self-test functions. Advanced control law experiments include an active flap mode for ride smoothing and maneuver drag reduction. This paper discusses research being conducted on computer synchronization, fault detection, fault isolation, and recovery from transient faults. The F-8 DFBW system has demonstrated immunity from nuisance fault declarations while quickly identifying truly faulty components.

  14. New image-stabilizing system

    NASA Astrophysics Data System (ADS)

    Zhao, Yuejin

    1996-06-01

    In this paper, a new method for image stabilization with a three-axis image- stabilizing reflecting prism assembly is presented, and the principle of image stabilization in this prism assembly, formulae for image stabilization and working formulae with an approximation up to the third power are given in detail. In this image-stabilizing system, a single chip microcomputer is used to calculate value of compensating angles and thus to control the prism assembly. Two gyroscopes act as sensors from which information of angular perturbation is obtained, three stepping motors drive the prism assembly to compensate for the movement of image produced by angular perturbation. The image-stabilizing device so established is a multifold system which involves optics, mechanics, electronics and computer.

  15. SCI Hazard Report Methodology

    NASA Technical Reports Server (NTRS)

    Mitchell, Michael S.

    2010-01-01

    This slide presentation reviews the methodology in creating a Source Control Item (SCI) Hazard Report (HR). The SCI HR provides a system safety risk assessment for the following Ares I Upper Stage Production Contract (USPC) components (1) Pyro Separation Systems (2) Main Propulsion System (3) Reaction and Roll Control Systems (4) Thrust Vector Control System and (5) Ullage Settling Motor System components.

  16. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transpot project-demonstration act system definition

    NASA Technical Reports Server (NTRS)

    Hanks, G. W.; Shomber, H. A.; Crumb, C. B.; Flora, C. C.; Macdonald, K. A. B.; Smith, R. D.; Sassi, A. P.; Dorwart, R. J.

    1982-01-01

    The 1985 ACT airplane is the Final Active Controls Technology (ACT) Airplane with the addition of three-axis fly by wire. Thus it retains all the efficiency features of the full ACT system plus the weight and cost savings accruing from deletion of the mechanical control system. The control system implements the full IAAC spectrum of active controls except flutter-mode control, judged essentially nonbeneficial, and incorporates new control surfaces called flaperons to make the most of wing-load alleviation. This redundant electronic system is conservatively designed to preserve the extreme reliability required of crucial short-period pitch augmentation, which provides more than half of the fuel savings.

  17. Measure of absolute speed through the Bradley aberration of light beams on a three-axis frame

    NASA Astrophysics Data System (ADS)

    Sardin, G.

    2001-02-01

    An electromagnetic speed-meter made of a three-dimensional frame is proposed, which allows measuring speeds independently of any external reference. The device is constituted by three orthogonal light beams and uses the motion-induced aberration of light or Bradley aberration. The frame is formed by three orthogonal beams which stand for the three axes. On the top of each axis arm of the frame a diode laser is fixed whose divergent beam impinges on a convergent lens which focalizes the light on an optoelectronic position detector of high resolution, placed on the base of each arm. The shift of each beam spot due to aberration of light is recorded, from which the motion of the frame is derived. Furthermore, if it is settled on a spacecraft its motion can be controlled in a way to record no aberration shift on any axis, indicating that the spacecraft is then at rest in the cosmic space. Since the referential frame does not use any external reference, it can be taken as a universal frame from which absolute speeds can be defined.

  18. Testing the three axis magnetometer and gradiometer MOURA and data comparison on San Pablo de los Montes Observatory.

    NASA Astrophysics Data System (ADS)

    Belen Fernandez, Ana; Sanz, Ruy; Covisa, Pablo; Tordesillas, Jose Manuel; Diaz-Michelena, Marina

    2013-04-01

    A magnetometer and gradiometer named MOURA has been developed with the objective to measure the magnetic field on Mars in the frame of Mars MetNet Precursor Mission (MMPM) [1]. MOURA is a compact, miniaturized, intelligent and low cost instrument, based on two sets of triaxial magnetometers separated one centimeter from each other to do gradiometry studies. It has a resolution of 2.2 nT, and a field range of + 65μT, which can be extended to +130 μT when sensors are saturated. [2] These sensor heads are Anisotropic MagnetoResistances (AMR) Commercial-Off-The-Shelf (COTS) by Honeywell, specifically HMC1043, which has been selected due to their relative low consumption, weight and size, factors very important for the mission with very limited mass and power budget (shared 150 g for three full payloads). Also, this technology has been previously successfully employed on board Unmanned Aerial Vehicles (UAV) to perform geomagnetic surveys in extreme conditions areas [3], and in several space missions for different applications. [4] After the development of the MOURA Engineering Qualification Model (EQM) in November 2011, an exhaustive set of tests have been performed to validate and fully characterize the instrument. Compensation equations have been derived for the temperature corrections in the operation range (between -135 °C and 30 °C) in controlled environments. These compensation equations have been applied to field data, which have shown to follow the daily Earth's magnetic field variations as registered by San Pablo Geomagnetic Observatory (IAGA code: SPT) (available at www.ign.es and www.intermagnet.org) with deviations lower than 40 nT. These deviations were attributed to several error factors as the different locations between MOURA and SPT and other possible different geomagnetic conditions. Due to the above, a measurement campaign on SPT installations are been done. The main objective is to compare MOURA measurements on a relevant environment, with data obtained by SPT magnetometers. This is considered the last step prior to Mars in situ measurements. SPT employs for geomagnetic observations a fluxgate magnetometer FGE-Danish Meteorological Institute and a fluxgate vector magnetometer Geomag M390, both equipped with Overhauser effect magnetometers GSM90. The conditions into the rooms that contain these instruments are controlled. The equipments are situated on several pillars fixed strategically at Earth surface avoiding vibrations and other Earth movement that could affect measurement due to changes on the sensor position, the region is magnetically clean and the temperature variation is very low. Magnetic measurements are performed by MOURA for several days located on one of these pillars. These measurements are compared with SPT reference instrumentation with the aim to obtain a direct and very accurate evaluation of MOURA facing reference instrumentation. http://metnet.fmi.fi/index.php Development of miniaturized instrumentation for Planetary Exploration and its application to the Mars MetNet Precursor Mission. H. Guerrero et al. EGU General Assembly 2010, held 2-7 May, 2010 in Vienna, Austria, p.13330 Funaki, M.; Hirasawa, N.; and the Ant-Plane Group. Outline of a small unmanned aerial vehicle (Ant-Plane) designed for Antartic research. Polar Science 2008, 2, 129-142. M. Diaz-Michelena Sensors 2009, 9(4), 2271-2288

  19. Fingerprinting of Non-resolved Three-axis Stabilized Space Objects Using a Two-Facet Analytical Model

    NASA Astrophysics Data System (ADS)

    Chaudhary, A.; Payne, T.; Gregory, S.; Dao, P.

    2011-09-01

    This approach to resident space object (RSO) fingerprinting is motivated by the established framework of biometric fingerprinting which comprises a basic differentiator, followed by three levels of matching. Level 0 (L0) features would be the size and type of the fingerprint. Level 1 (L1) features are the macro characteristics of the fingerprint. Level 2 (L2) features are locations where a single ridge in the fingerprint splits into two branches or where two branches converge into one. Level 3 (L3) features describe the periodic pattern in the fingerprint. Match at each level provides progressively higher confidence. Correspondingly, the RSO fingerprinting can be considered to comprise matching at a base level, followed by three levels of features. L0 consist of sentinel features such as the gross brightness, and contrast, shape and position of principal specular glints. L1 features comprise the geometric shape of the signature brightness and its color indices. This is analytically represented using a polynomial in the cosine of the subsolar angle, which captures the effect of the seasons. The Level 2 captures the intrinsic character of the sloping regions or bifurcations in the signature brightness and color. It is used to separate the contribution of the solar panel and body. Level 3 consists of the temporal evolution of the fractional abundance of the solar panel and the body. This allows inference on the mechanical stability and basic information about the attitude of the RSO. A collection of L0 to L3 features for an RSO is thus defines its fingerprint.

  20. Beam-centroid tracking instrument for ion thrusters

    NASA Astrophysics Data System (ADS)

    Pollard, J. E.

    1995-03-01

    Thrust vector stability for an electrostatic ion engine can be measured with improved sensitivity and time resolution by the method described here. Four double-wire Langmuir probes, aligned in the form of a cross, are placed in the exhaust plume and are translated by a motorized positioning system to balance the currents collected along two orthogonal axes. The thrust vector position is thereby measured with an angular resolution of less than 0.01 deg and a response time of less than 5 sec.

  1. A marine direction finding system based on global positioning system

    NASA Astrophysics Data System (ADS)

    D?ni?or, Alin; Izet-nsalan, Kunsel-zel; nsalan, Deniz; Tama?, Razvan; D?ni?or, Cosmin

    2015-02-01

    Direction finding and attitude determination is of utmost importance for marine, aerial, spatial and land-based navigation [1], as well as control of vehicles, in surveying and in target acquisition of tracking radars. These problems can be solved using dedicated sensors commonly named as compasses and rate gyros. Unfortunately, the classical means of attitude determination both by magnetic and gyrocompasses become unusable at extreme latitudes. Furthermore, gyrocompasses inherently yield erroneous results on high speed craft. Three-axis attitude of a vehicle can be determined using a GPS receiver with multiple antennas, by measuring carrier phases [2], signal strength [3], or integrated INS/GPS systems [4]. This paper proposes a new method of attitude determination using two low-cost GPS receivers.

  2. Motion capture of a pad measured with accelerometers during squeal noise in a real brake system

    NASA Astrophysics Data System (ADS)

    Renaud, Franck; Chevallier, Gaël; Dion, Jean-Luc; Taudière, Guillaume

    2012-11-01

    The operating deflection shape of a pad during squeal noise is measured on a real brake system with three-axis accelerometers. A time-frequency analysis is performed that highlights the dependency of squeal on the hydraulic pressure of the system and shows that squeal occurs simultaneously with harmonic components. The operating deflection shape of this pad before and during squeal is then visualized using interpolation, showing the predominance of bending motion. Finally, the pad motions observed are compared to the real modal basis of a detailed Finite Element model.

  3. Space Shuttle 1976 into mainstream development - Program commitments on schedule to insure careful progress

    NASA Technical Reports Server (NTRS)

    Malkin, M. S.

    1976-01-01

    A progress report is given on various systems, noting conformity to schedule or changes in design. The Orbiter thermal protection system, the Space Shuttle main engine, the intertank for the structural test article (STA), thrust vector control systems, the Kennedy Space Center launch processing system, and Orbiters No. 1 and No. 2 are discussed.

  4. Reusable Reentry Satellite (RRS) system design study. Phase B, appendix E: Attitude control system study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A study which consisted of a series of design analyses for an Attitude Control System (ACS) to be incorporated into the Re-usable Re-entry Satellite (RRS) was performed. The main thrust of the study was associated with defining the control laws and estimating the mass and power requirements of the ACS needed to meet the specified performance goals. The analyses concentrated on the different on-orbit control modes which start immediately after the separation of the RRS from the launch vehicle. The three distinct on-orbit modes considered for these analyses are as follows: (1) Mode 1 - A Gravity Gradient (GG) three-axis stabilized spacecraft with active magnetic control; (2) Mode 2 - A GG stabilized mode with a controlled yaw rotation rate ('rotisserie') using three-axis magnetic control and also incorporating a 10 N-m-s momentum wheel along the (Z) yaw axis; and (3) Mode 3 - A spin stabilized mode of operation with the spin about the pitch (Y) axis, incorporating a 20 N-m-s momentum wheel along the pitch (Y) axis and attitude control via thrusters. To investigate the capabilities of the different controllers in these various operational modes, a series of computer simulations and trade-off analyses have been made to evaluate the achievable performance levels, and the necessary mass and power requirements.

  5. Near real-time stereo vision system

    NASA Technical Reports Server (NTRS)

    Anderson, Charles H. (Inventor); Matthies, Larry H. (Inventor)

    1993-01-01

    The apparatus for a near real-time stereo vision system for use with a robotic vehicle is described. The system is comprised of two cameras mounted on three-axis rotation platforms, image-processing boards, a CPU, and specialized stereo vision algorithms. Bandpass-filtered image pyramids are computed, stereo matching is performed by least-squares correlation, and confidence ranges are estimated by means of Bayes' theorem. In particular, Laplacian image pyramids are built and disparity maps are produced from the 60 x 64 level of the pyramids at rates of up to 2 seconds per image pair. The first autonomous cross-country robotic traverses (of up to 100 meters) have been achieved using the stereo vision system of the present invention with all computing done onboard the vehicle. The overall approach disclosed herein provides a unifying paradigm for practical domain-independent stereo ranging.

  6. Near real-time stereo vision system

    NASA Astrophysics Data System (ADS)

    Matthies, Larry H.; Anderson, Charles H.

    1991-12-01

    The apparatus for a near real-time stereo vision system for use with a robotic vehicle is described. The system is comprised of two cameras mounted on three-axis rotation platforms, image-processing boards, a CPU, and specialized stereo vision algorithms. Bandpass-filtered image pyramids are computed, stereo matching is performed by least-squares correlation, and confidence ranges are estimated by means of Bayes' theorem. In particular, Laplacian image pyramids are built and disparity maps are produced from the 60 x 64 level of the pyramids at rates of up to 2 seconds per image pair. The first autonomous cross-country robotic traverses (of up to 100 meters) have been achieved using the stereo vision system of the present invention with all computing done onboard the vehicle. The overall approach disclosed herein provides a unifying paradigm for practical domain-independent stereo ranging.

  7. Precision Pointing Control System (PPCS) system design and analysis. [for gimbaled experiment platforms

    NASA Technical Reports Server (NTRS)

    Frew, A. M.; Eisenhut, D. F.; Farrenkopf, R. L.; Gates, R. F.; Iwens, R. P.; Kirby, D. K.; Mann, R. J.; Spencer, D. J.; Tsou, H. S.; Zaremba, J. G.

    1972-01-01

    The precision pointing control system (PPCS) is an integrated system for precision attitude determination and orientation of gimbaled experiment platforms. The PPCS concept configures the system to perform orientation of up to six independent gimbaled experiment platforms to design goal accuracy of 0.001 degrees, and to operate in conjunction with a three-axis stabilized earth-oriented spacecraft in orbits ranging from low altitude (200-2500 n.m., sun synchronous) to 24 hour geosynchronous, with a design goal life of 3 to 5 years. The system comprises two complementary functions: (1) attitude determination where the attitude of a defined set of body-fixed reference axes is determined relative to a known set of reference axes fixed in inertial space; and (2) pointing control where gimbal orientation is controlled, open-loop (without use of payload error/feedback) with respect to a defined set of body-fixed reference axes to produce pointing to a desired target.

  8. Implantable cardiac pacemaker electromagnetic compatibility testing in a novel security system simulator.

    PubMed

    Kainz, Wolfgang; Casamento, Jon P; Ruggera, Paul S; Chan, Dulciana D; Witters, Donald M

    2005-03-01

    This paper describes a novel simulator to perform electromagnetic compatibility (EMC) tests for active implantable medical devices (AIMDs) with electromagnetic fields emitted by security systems. The security system simulator was developed in response to over 100 incident reports over 17 years related to the interference of AIMD's with security systems and the lack of a standardized test method. The simulator was evaluated regarding field homogeneity, signal distortion, and maximum magnetic field strength levels. Small three-axis probes and a three-axis scanning system were designed to determine the spatial and temporal characteristics of the fields emitted by 12 different types of walk through metal detectors (WTMDs). Tests were performed on four implanted pacemakers with a saline phantom and correlated to a newly developed test method performed "in air" (without the phantom). Comparison of the simulator thresholds with tests performed in real WTMDs showed that the simulator is able to mimic the pacemaker interference. The interference thresholds found in the simulator indicate that pulsed magnetic fields are more likely to cause interference in pacemakers than sinusoidal fields. The security system simulator will help biomedical engineers, manufacturers of medical devices, and manufacturers of security systems to identify incompatible combinations of WTMDs and AIMDs early in the development stage. PMID:15759582

  9. Tracking and data relay satellite system configuration and tradeoff study. Volume 1: Study summary

    NASA Technical Reports Server (NTRS)

    Hill, T. E.

    1973-01-01

    A study was conducted to determine the configuration and tradeoffs of a tracking and data relay satellite. The study emphasized the design of a three axis stabilized satellite and a telecommunications system optimized for support of low and medium data rate user spacecraft. Telecommunications support to low and high, or low medium, and high data rate users, considering launches with the Delta 2914, the Atlas/Centaur, and the space shuttle was also considered. The following subjects are presented: (1) launch and deployment profile, (2) spacecraft mechanical and structural design, (3) attitude stabilization and control subsystem, and (4) reliability analysis.

  10. Thermal design of the IUE hydrazine auxiliary propulsion system. [International Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Skladany, J. T.; Kelly, W. H.

    1977-01-01

    The International Ultraviolet Explorer is a large astronomical observatory scheduled to be placed in a three-axis stabilized synchronous orbit in the fourth quarter of 1977. The Hydrazine Auxiliary Propulsion System (HAPS) must perform a number of spacecraft maneuvers to achieve a successful mission. This paper describes the thermal design which accomplishes temperature control between 5 and 65 C for all orbital conditions by utilizing multilayer insulation and commandable component heaters. A primary design criteria was the minimization of spacecraft power by the selective use of the solar environment. The thermal design was carefully assessed and verified in both spacecraft thermal balance and subsystem solar simulation testing.

  11. A computer-aided telescope pointing system utilizing a video star tracker

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.; Lorell, K. R.; Swift, C. D.

    1975-01-01

    The Video Inertial Pointing (VIP) System developed to satisfy the acquisition and pointing requirements of astronomical telescopes is described. A unique feature of the system is the use of a single sensor to provide information for the generation of three axis pointing error signals and for a cathode ray tube (CRT) display of the star field. The pointing error signals are used to update the telescope's gyro stabilization and the CRT display is used by an operator to facilitate target acquisition and to aid in manual positioning of the telescope optical axis. A model of the system using a low light level vidicon built and flown on a balloon-borne infrared telescope is briefly described from a state of the art charge coupled device (CCD) sensor. The advanced system hardware is described and an analysis of the multi-star tracking and three axis error signal generation, along with an analysis and design of the gyro update filter, are presented. Results of a hybrid simulation are described in which the advanced VIP system hardware is driven by a digital simulation of the star field/CCD sensor and an analog simulation of the telescope and gyro stabilization dynamics.

  12. Performance tests of two precision attitude determination systems

    NASA Technical Reports Server (NTRS)

    Mcaloon, K. J.; Farrenkopf, R. L.; Belsky, F. J.; Mann, R. J.

    1977-01-01

    Results of laboratory performance tests of two satellite attitude determination systems are given. One system employed a strapdown star tracker and gyro assembly, the other a single axis, gimballed star tracker and a gyro assembly. The laboratory tests simulated those orbit conditions which would be experienced on a three axis stabilized, earth pointed satellite in geosynchronous orbit. A ground-fixed laboratory test was performed in which system axes remained stationary in the laboratory coordinates while revolving star beams stimulated the star trackers. The laboratory instrumentation techniques used to meet the stringent accuracy requirements are described. Results are presented which show both systems met the performance goal of 3.6 arc seconds. Comparative analyses of both systems are also discussed.

  13. Head-aimed vision system improves tele-operated mobility

    NASA Astrophysics Data System (ADS)

    Massey, Kent

    2004-12-01

    A head-aimed vision system greatly improves the situational awareness and decision speed for tele-operations of mobile robots. With head-aimed vision, the tele-operator wears a head-mounted display and a small three axis head-position measuring device. Wherever the operator looks, the remote sensing system "looks". When the system is properly designed, the operator's occipital lobes are "fooled" into believing that the operator is actually on the remote robot. The result is at least a doubling of: situational awareness, threat identification speed, and target tracking ability. Proper system design must take into account: precisely matching fields of view; optical gain; and latency below 100 milliseconds. When properly designed, a head-aimed system does not cause nausea, even with prolonged use.

  14. Model-reference attitude control and reaction control jet engine placement for space shuttle

    NASA Technical Reports Server (NTRS)

    Boland, J. S., III

    1973-01-01

    Analytical studies on the theoretical aspects of thrust vector control of large space vehicles were conducted. A system for attitude control of the space shuttle vehicle was developed. Major accomplishments of the project are: (1) investigation of a model-reference adaptive control scheme for controlling the space shuttle attitude and (2) determination of optimum placement of reaction control jet engines on space shuttles.

  15. Flight simulation for flight control computer S/N 0104-1 (ASTP)

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Flight control computer (FCC) 0104-I has been designated the prime unit for the SA-210 launch vehicle. The results of the final flight simulation for FCC S/N 0104-I are documented. These results verify satisfactory implementation of the design release and proper interfacing of the FCC with flight-type control sensor elements and simulated thrust vector control system.

  16. Measurement-while-drilling surveying of highly inclined and horizontal well sections utilizing single-axis gyro sensing system

    NASA Astrophysics Data System (ADS)

    Noureldin, Aboelmagd; Irvine-Halliday, Dave; Mintchev, Martin P.

    2004-12-01

    In the oil industry, when developing a plan for drilling horizontal wells, measurement-while-drilling (MWD) surveying becomes one of the important prerequisites for the successful completion of the drilling process. MWD surveying of horizontal wells determines the position and the orientation of the bottom hole assembly (BHA) in real-time during the drilling operation. The BHA orientation is determined by its inclination from the vertical direction as well as its azimuth. The present MWD surveying system incorporates three-axis accelerometers and three-axis magnetometers mounted in three mutually orthogonal directions. This magnetic surveying system suffers from the deviation of the magnetic field measurements due to the massive amount of steel around the drilling rig. A new method utilizing the fibre optic gyroscopes (FOG) technology was suggested to replace the magnetic surveying system. It was reported that a single FOG mounted inside the bearing assembly with its sensitive axis along the tool spin axis could be incorporated with three-axis accelerometers to continuously survey the near-vertical well section. This study aims at suggesting a surveying methodology for highly inclined and horizontal well sections utilizing FOG sensors. At each surveying station, the intrinsic uncertainties of the surveying sensors and the other vibration-induced noise are reduced using a transversal finite impulse response filter. The inclination is then computed by processing the accelerometer measurements, while the gyro measurement is utilized to determine the azimuth. In addition, optimal estimation techniques based on Kalman filtering are used to improve the azimuth accuracy and to limit the effect of the drift of the surveying sensors over time. This study indicates that gyroscopic surveying utilizing the FOG technology can be a reliable solution for MWD surveying of horizontal wells.

  17. Communications satellite systems operations with the space station, volume 2

    NASA Technical Reports Server (NTRS)

    Price, K.; Dixon, J.; Weyandt, C.

    1987-01-01

    A financial model was developed which described quantitatively the economics of the space segment of communication satellite systems. The model describes the economics of the space system throughout the lifetime of the satellite. The expected state-of-the-art status of communications satellite systems and operations beginning service in 1995 were assessed and described. New or enhanced space-based activities and associated satellite system designs that have the potential to achieve future communications satellite operations in geostationary orbit with improved economic performance were postulated and defined. Three scenarios using combinations of space-based activities were analyzed: a spin stabilized satellite, a three axis satellite, and assembly at the Space Station and GEO servicing. Functional and technical requirements placed on the Space Station by the scenarios were detailed. Requirements on the satellite were also listed.

  18. Strapdown system performance optimization test evaluations (SPOT), volume 1

    NASA Technical Reports Server (NTRS)

    Blaha, R. J.; Gilmore, J. P.

    1973-01-01

    A three axis inertial system was packaged in an Apollo gimbal fixture for fine grain evaluation of strapdown system performance in dynamic environments. These evaluations have provided information to assess the effectiveness of real-time compensation techniques and to study system performance tradeoffs to factors such as quantization and iteration rate. The strapdown performance and tradeoff studies conducted include: (1) Compensation models and techniques for the inertial instrument first-order error terms were developed and compensation effectivity was demonstrated in four basic environments; single and multi-axis slew, and single and multi-axis oscillatory. (2) The theoretical coning bandwidth for the first-order quaternion algorithm expansion was verified. (3) Gyro loop quantization was identified to affect proportionally the system attitude uncertainty. (4) Land navigation evaluations identified the requirement for accurate initialization alignment in order to pursue fine grain navigation evaluations.

  19. Restoring Redundancy to the MAP Propulsion System

    NASA Technical Reports Server (NTRS)

    O'Donnell, James R., Jr.; Davis, Gary T.; Ward, David K.; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE). Due to the MAP project's limited mass, power, and financial resources, a traditional reliability concept including fully redundant components was not feasible. The MAP design employs selective hardware redundancy, along with backup software modes and algorithms, to improve the odds of mission success. In particular, MAP's propulsion system, which is used for orbit maneuvers and momentum management, uses eight thrusters positioned and oriented in such a way that its thruster-based attitude control modes can maintain three-axis attitude control in the event of the failure of any one thruster.

  20. Quaternion-based unscented Kalman filter for accurate indoor heading estimation using wearable multi-sensor system.

    PubMed

    Yuan, Xuebing; Yu, Shuai; Zhang, Shengzhi; Wang, Guoping; Liu, Sheng

    2015-01-01

    Inertial navigation based on micro-electromechanical system (MEMS) inertial measurement units (IMUs) has attracted numerous researchers due to its high reliability and independence. The heading estimation, as one of the most important parts of inertial navigation, has been a research focus in this field. Heading estimation using magnetometers is perturbed by magnetic disturbances, such as indoor concrete structures and electronic equipment. The MEMS gyroscope is also used for heading estimation. However, the accuracy of gyroscope is unreliable with time. In this paper, a wearable multi-sensor system has been designed to obtain the high-accuracy indoor heading estimation, according to a quaternion-based unscented Kalman filter (UKF) algorithm. The proposed multi-sensor system including one three-axis accelerometer, three single-axis gyroscopes, one three-axis magnetometer and one microprocessor minimizes the size and cost. The wearable multi-sensor system was fixed on waist of pedestrian and the quadrotor unmanned aerial vehicle (UAV) for heading estimation experiments in our college building. The results show that the mean heading estimation errors are less 10° and 5° to multi-sensor system fixed on waist of pedestrian and the quadrotor UAV, respectively, compared to the reference path. PMID:25961384

  1. Quaternion-Based Unscented Kalman Filter for Accurate Indoor Heading Estimation Using Wearable Multi-Sensor System

    PubMed Central

    Yuan, Xuebing; Yu, Shuai; Zhang, Shengzhi; Wang, Guoping; Liu, Sheng

    2015-01-01

    Inertial navigation based on micro-electromechanical system (MEMS) inertial measurement units (IMUs) has attracted numerous researchers due to its high reliability and independence. The heading estimation, as one of the most important parts of inertial navigation, has been a research focus in this field. Heading estimation using magnetometers is perturbed by magnetic disturbances, such as indoor concrete structures and electronic equipment. The MEMS gyroscope is also used for heading estimation. However, the accuracy of gyroscope is unreliable with time. In this paper, a wearable multi-sensor system has been designed to obtain the high-accuracy indoor heading estimation, according to a quaternion-based unscented Kalman filter (UKF) algorithm. The proposed multi-sensor system including one three-axis accelerometer, three single-axis gyroscopes, one three-axis magnetometer and one microprocessor minimizes the size and cost. The wearable multi-sensor system was fixed on waist of pedestrian and the quadrotor unmanned aerial vehicle (UAV) for heading estimation experiments in our college building. The results show that the mean heading estimation errors are less 10° and 5° to multi-sensor system fixed on waist of pedestrian and the quadrotor UAV, respectively, compared to the reference path. PMID:25961384

  2. A New Approach to Attitude Stability and Control for Low Airspeed Vehicles

    NASA Technical Reports Server (NTRS)

    Lim, K. B.; Shin, Y-Y.; Moerder, D. D.; Cooper, E. G.

    2004-01-01

    This paper describes an approach for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The large thrust vector that characterizes such vehicles can be modulated to provide control forces and moments to the airframe, but such modulation is accompanied by significant unsteady flow effects. These effects are difficult to model, and can compromise the practical value of thrust vectoring in closed-loop attitude stability, even if the thrust vectoring machinery has sufficient bandwidth for stabilization. The stabilization approach described in this paper is based on using internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other "outer loop" control functions. The three main components of this approach are: (1) a z-body axis angular momentum bias enhances static attitude stability, reducing the amount of control activity needed for stabilization, (2) optionally, gimbaled reaction wheels provide high-bandwidth control torques for additional stabilization, or agility, and (3) the resulting strongly coupled system dynamics are controlled by a multivariable controller. A flight test vehicle is described, and nonlinear simulation results are provided that demonstrate the efficiency of the approach.

  3. Image change detection using a SWIR active imaging system

    NASA Astrophysics Data System (ADS)

    Schneider, Armin L.; Monnin, David; Laurenzis, Martin; Christnacher, Frank

    2013-10-01

    We are currently developing a system consisting of a GPS receiver, a three-axis magnetic compass as well as a digital video camera in order to visualize changes occuring along a regularily used itinerary. This is done by comparing actual images with images from the same scene, which have been acquired during a previous measurement. The luminosity of images from two different passages however can be quite different (due to different meteorological conditions). Whereas the global luminosity can be adjusted using non-linear luminosity correction, the treatment of shadows is more di cult. Since meteorological conditions cannot be controlled, we are investigating the possibility of using a Laser Gated Viewing system in the SWIR domain to illuminate the scene. Using appropriate filters for the camera, we are completely independent of natural illumination and in addition, the system can also be used at night.

  4. A study of variable thrust, variable specific impulse trajectories for solar system exploration

    NASA Astrophysics Data System (ADS)

    Sakai, Tadashi

    A study has been performed to determine the advantages and disadvantages of variable thrust and variable Isp (specific impulse) trajectories for solar system exploration. There have been several numerical research efforts for variable thrust, variable Isp, power-limited trajectory optimization problems. All of these results conclude that variable thrust, variable Isp (variable specific impulse, or VSI) engines are superior to constant thrust, constant Isp (constant specific impulse; or CSI) engines. However, most of these research efforts assume a mission from Earth to Mars, and some of them further assume that these planets are circular and coplanar. Hence they still lack the generality. This research has been conducted to answer the following questions: (1) Is a VSI engine always better than a CSI engine or a high thrust engine for any mission to any planet with any time of flight considering lower propellant mass as the sole criterion? (2) If a planetary swing-by is used for a VSI trajectory, is the fuel savings of a VSI swing-by trajectory better than that of a CSI swing-by or high thrust swing-by trajectory? To support this research, an unique, new computer-based interplanetary trajectory calculation program has been created. This program utilizes a calculus of variations algorithm to perform overall optimization of thrust, Isp, and thrust vector direction along a trajectory that minimizes fuel consumption for interplanetary travel. It is assumed that the propulsion system is power-limited, and thus the compromise between thrust and Isp is a variable to be optimized along the flight path. This program is capable of optimizing not only variable thrust trajectories but also constant thrust trajectories in 3-D space using a planetary ephemeris database. It is also capable of conducting planetary swing-bys. Using this program, various Earth-originating trajectories have been investigated and the optimized results have been compared to traditional CSI and high thrust trajectory solutions. Results show that VSI rocket engines reduce fuel requirements for any mission compared to CSI rocket engines. Fuel can be saved by applying swing-by maneuvers for VSI engines; but the effects of swing-bys due to VSI engines are smaller than that of CSI or high thrust engines.

  5. Cosmic non-TEM radiation and synthetic feed array sensor system in ASIC mixed signal technology

    NASA Astrophysics Data System (ADS)

    Centureli, F.; Scotti, G.; Tommasino, P.; Trifiletti, A.; Romano, F.; Cimmino, R.; Saitto, A.

    2014-08-01

    The paper deals with the opportunity to introduce "Not strictly TEM waves" Synthetic detection Method (NTSM), consisting in a Three Axis Digital Beam Processing (3ADBP), to enhance the performances of radio telescope and sensor systems. Current Radio Telescopes generally use the classic 3D "TEM waves" approximation Detection Method, which consists in a linear tomography process (Single or Dual axis beam forming processing) neglecting the small z component. The Synthetic FEED ARRAY three axis Sensor SYSTEM is an innovative technique using a synthetic detection of the generic "NOT strictly TEM Waves radiation coming from the Cosmo, which processes longitudinal component of Angular Momentum too. Than the simultaneous extraction from radiation of both the linear and quadratic information component, may reduce the complexity to reconstruct the Early Universe in the different requested scales. This next order approximation detection of the observed cosmologic processes, may improve the efficacy of the statistical numerical model used to elaborate the same information acquired. The present work focuses on detection of such waves at carrier frequencies in the bands ranging from LF to MMW. The work shows in further detail the new generation of on line programmable and reconfigurable Mixed Signal ASIC technology that made possible the innovative Synthetic Sensor. Furthermore the paper shows the ability of such technique to increase the Radio Telescope Array Antenna performances.

  6. Design and flight experience with a digital fly-by-wire control system in an F-8 airplane

    NASA Technical Reports Server (NTRS)

    Deets, D. A.; Szalai, K. J.

    1974-01-01

    A digital fly-by-wire flight control system was designed, built, and for the first time flown in an airplane. The system, which uses components from the Apollo guidance system, is installed in an F-8 airplane as the primary control system. A lunar module guidance computer is the central element in the three-axis, single-channel, multimode, digital control system. A triplex electrical analog system which provides unaugmented control of the airplane is the only backup to the digital system. Flight results showed highly successful system operation, although the trim update rate was inadequate for precise trim changes, causing minor concern. The use of a digital system to implement conventional control laws proved to be practical for flight. Logic functions coded as an integral part of the control laws were found to be advantageous. Although software verification required extensive effort, confidence in the software was achieved.

  7. Wellborne inertial navigation system

    SciTech Connect

    Kelsey, J.R.

    1983-01-01

    A phototype wireline tool which includes a downhole inertial platform and a surface computer to spatially map a well is described. The hardware consists of a single-gimbaled inertial platform with accelerometers and gyros to obtain three-axis motion information. The gyroscope and accelerometer outputs are transmitted to a computer at the surface which calculates probe attitude relative to north, east, and vertical. Double integration of the accelerometer data provides the position information. A conventional 7-conductor wireline is used for the system data transmission. System accuracy is enhanced by advances made in the computer software which processes the data received from the tool. The software uses statistical sampling estimation to obtain optimal estimates of the system errors. Measurement errors are determined by periodically stopping the tool during the logging procedure and observing the indicated velocity measurements. This procedure, known as Kalman filtering, results in increased accuracy of the data. Present mapping systems have an X-Y-Z location accuracy of +- 100 to +- 200 feet for a typical well depth of 10,000 feet. Test results show that the new system is accurate to about +- 1 foot per 1000 feet of well depth. Unlike conventional systems, the inertial navigator does not require any sort of projection of the cable length (which may not be accurately known). Also this system provides continuous data throughout the wellbore and logging speeds on the order of 10 ft/sec appear possible. The hardware and software associated with this mapping system are described and the recent field test results are reported.

  8. Computer program for prediction of fuel consumption statistical data for an upper stage three-axes stabilized on-off control system

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A FORTRAN coded computer program and method to predict the reaction control fuel consumption statistics for a three axis stabilized rocket vehicle upper stage is described. A Monte Carlo approach is used which is more efficient by using closed form estimates of impulses. The effects of rocket motor thrust misalignment, static unbalance, aerodynamic disturbances, and deviations in trajectory, mass properties and control system characteristics are included. This routine can be applied to many types of on-off reaction controlled vehicles. The pseudorandom number generation and statistical analyses subroutines including the output histograms can be used for other Monte Carlo analyses problems.

  9. Attitude Dynamics and Control of Solar Sails

    NASA Astrophysics Data System (ADS)

    Sperber, Evan

    Solar sails are space vehicles that rely on solar radiation pressure in order to generate forces for thrust and attitude control torques. They exhibit characteristics such as large moments of inertia, fragility of various system components, and long mission durations that make attitude control a particularly difficult engineering problem. Thrust vector control (TVC) is a family of sailcraft attitude control techniques that is on a short list of strategies thought to be suitable for the primary attitude control of solar sails. Every sailcraft TVC device functions by manipulating the relative locations of the composite mass center (cm) of the sailcraft and the center of pressure (cp) of at least one of its reflectors. Relative displacement of these two points results in body torques that can be used to steer the sailcraft. This dissertation presents a strategy for the large-angle reorientation of a sailcraft using TVC. Two forms of TVC, namely the panel and ballast mass translation methods are well represented in the literature, while rigorous studies regarding a third form, gimballed mass rotation, are conspicuously absent. The gimballed mass method is physically realized by placing a ballast mass, commonly the sailcraft's scientific payload, at the tip of a gimballed boom that has its base fixed at some point on the sailcraft. A TVC algorithm will then strategically manipulate the payload boom's gimbal angles, thereby changing the projection of the sailcraft cm in the plane of the sail. This research demonstrates effective three-axis attitude control of a model sailcraft using numerical simulation of its nonlinear equations of motion. The particular TVC algorithm developed herein involves two phases---the first phase selects appropriate gimbal rates with the objective that the sailcraft be placed in the neighborhood of its target orientation. It was discovered, however that concomitantly minimizing attitude error as well as residual body rate was not possible using soley this method. By solving the one-dimensional Euler's equation, a single gimbal angle can be found that will cause simultaneous convergence of both these quantities to their respective target values. The second phase of control consists of calculating such an angle, and then setting and maintaining this configuration until the maneuver is completed. iiOnce the validity of the approach is confirmed via simulation for a model sailcraft, it is demonstrated that three-axis attitude control can be performed using this approach by executing a sequence of maneuvers about principal axes. The algorithm is implemented directly inline with the nonlinear equations of motion and simulations are conducted for sailcraft of various sizes that are representative of the dimensions proposed in the literature for future missions.

  10. An orientable solar panel system for nanospacecraft

    NASA Astrophysics Data System (ADS)

    Santoni, Fabio; Piergentili, Fabrizio; Candini, Gian Paolo; Perelli, Massimo; Negri, Andrea; Marino, Michele

    2014-08-01

    An orientable deployed solar array system for 1-5 kg weight nanospacecraft is described, enhancing the achievable performance of these typically power-limited systems. The system is based on a deployable solar panel system, previously developed with cooperation between Laboratorio di Sistemi Aerospaziali of University of Roma “la Sapienza” and the company IMT (Ingegneria Marketing Tecnologia). The system proposed is a modular one, and suitable in principle for the 1U, 2U and 3U standard Cubesat bus, even if the need for three axis attitude stabilization makes it typically preferred for 3U Cubesats. The size of each solar panel is the size of a lateral Cubesat surface. A single degree of freedom maneuvering capability is given to the deployed solar array, in order to follow the apparent motion of the sun as close as possible, given the mission requirements on the spacecraft attitude. Considerable effort has been devoted to design the system compatible with the Cubesat standard, being mounted outside on the external spacecraft structure, without requiring modifications on the standard prescriptions. The small available volume is the major constraint, which forces to use miniaturized electric motor technology. The system design trade-off is discussed, leading to the selection of an architecture based on two independently steerable solar array wings.

  11. Spacecraft flight control system design selection process for a geostationary communication satellite

    NASA Technical Reports Server (NTRS)

    Barret, C.

    1992-01-01

    The Earth's first artificial satellite, Sputnik 1, slowly tumbled in orbit. The first U.S. satellite, Explorer 1, also tumbled out of control. Now, as we launch the Mars observer and the Cassini spacecraft, stability and control have become higher priorities. The flight control system design selection process is reviewed using as an example a geostationary communication satellite which is to have a life expectancy of 10 to 14 years. Disturbance torques including aerodynamic, magnetic, gravity gradient, solar, micrometeorite, debris, collision, and internal torques are assessed to quantify the disturbance environment so that the required compensating torque can be determined. Then control torque options, including passive versus active, momentum control, bias momentum, spin stabilization, dual spin, gravity gradient, magnetic, reaction wheels, control moment gyros, nutation dampers, inertia augmentation techniques, three-axis control, reactions control system (RCS), and RCS sizing, are considered. A flight control system design is then selected and preliminary stability criteria are met by the control gains selection.

  12. Instrumentation and control system for an F-15 stall/spin

    NASA Technical Reports Server (NTRS)

    Pitts, F. L.; Holmes, D. C. E.; Zaepfel, K. P.

    1974-01-01

    An instrumentation and control system is described that was used for radio-controlled F-15 airplane model stall/spin research at the NASA-Langley Research Center. This stall/spin research technique, using scale model aircraft, provides information on the post-stall and spin-entry characteristics of full-scale aircraft. The instrumentation described provides measurements of flight parameters such as angle of attack and sideslip, airspeed, control-surface position, and three-axis rotation rates; these data are recorded on an onboard magnetic tape recorder. The proportional radio control system, which utilizes analog potentiometric signals generated from ground-based pilot inputs, and the ground-based system used in the flight operation are also described.

  13. Controlling Attitude of a Solar-Sail Spacecraft Using Vanes

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Acikmese, Ahmet; Ploen, Scott

    2006-01-01

    A paper discusses a concept for controlling the attitude and thrust vector of a three-axis stabilized Solar Sail spacecraft using only four single degree-of-freedom articulated spar-tip vanes. The vanes, at the corners of the sail, would be turned to commanded angles about the diagonals of the square sail. Commands would be generated by an adaptive controller that would track a given trajectory while rejecting effects of such disturbance torques as those attributable to offsets between the center of pressure on the sail and the center of mass. The controller would include a standard proportional + derivative part, a feedforward part, and a dynamic component that would act like a generalized integrator. The controller would globally track reference signals, and in the presence of such control-actuator constraints as saturation and delay, the controller would utilize strategies to cancel or reduce their effects. The control scheme would be embodied in a robust, nonlinear algorithm that would allocate torques among the vanes, always finding a stable solution arbitrarily close to the global optimum solution of the control effort allocation problem. The solution would include an acceptably small angle, slow limit-cycle oscillation of the vanes, while providing overall thrust vector pointing stability and performance.

  14. Computer simulation of aircraft motions and propulsion system dynamics for the YF-12 aircraft at supersonic cruise conditions

    NASA Technical Reports Server (NTRS)

    Brown, S. C.

    1973-01-01

    A computer simulation of the YF-12 aircraft motions and propulsion system dynamics is presented. The propulsion system was represented in sufficient detail so that interactions between aircraft motions and the propulsion system dynamics could be investigated. Six degree-of-freedom aircraft motions together with the three-axis stability augmentation system were represented. The mixed compression inlets and their controls were represented in the started mode for a range of flow conditions up to the inlet unstart boundary. Effects of inlet moving geometry on aircraft forces and movements as well as effects of aircraft motions on the inlet behavior were simulated. The engines, which are straight subjects, were represented in the afterburning mode, with effects of changes in aircraft flight conditions included. The simulation was capable of operating in real time.

  15. High Speed, High Temperature, Fault Tolerant Operation of a Combination Magnetic-Hydrostatic Bearing Rotor Support System for Turbomachinery

    NASA Technical Reports Server (NTRS)

    Jansen, Mark; Montague, Gerald; Provenza, Andrew; Palazzolo, Alan

    2004-01-01

    Closed loop operation of a single, high temperature magnetic radial bearing to 30,000 RPM (2.25 million DN) and 540 C (1000 F) is discussed. Also, high temperature, fault tolerant operation for the three axis system is examined. A novel, hydrostatic backup bearing system was employed to attain high speed, high temperature, lubrication free support of the entire rotor system. The hydrostatic bearings were made of a high lubricity material and acted as journal-type backup bearings. New, high temperature displacement sensors were successfully employed to monitor shaft position throughout the entire temperature range and are described in this paper. Control of the system was accomplished through a stand alone, high speed computer controller and it was used to run both the fault-tolerant PID and active vibration control algorithms.

  16. A superconducting quantum interference device magnetometer system for quantitative analysis and imaging of hidden corrosion activity in aircraft aluminum structures

    NASA Astrophysics Data System (ADS)

    Abedi, A.; Fellenstein, J. J.; Lucas, A. J.; Wikswo, J. P.

    1999-12-01

    We have designed and built a magnetic imaging system for quantitative analysis of the rate of ongoing hidden corrosion of aircraft aluminum alloys in planar structures such as intact aircraft lap joints. The system utilizes a superconducting quantum interference device (SQUID) magnetometer that measures the magnetic field associated with corrosion currents. It consists of a three-axis (vector) SQUID differential magnetometer, magnetic, and rf shielding, a computer controlled x-y stage, sample registration, and positioning mechanisms, and data acquisition and analysis software. The system is capable of scanning planar samples with dimensions of up to 28 cm square, with a spatial resolution of 2 mm, and a sensitivity of 0.3 pT/Hz1/2 (at 10 Hz). In this article we report the design and technical issues related to this system, outline important data acquisition techniques and criteria for accurate measurements of the rate of corrosion, especially for weakly corroding samples, and present preliminary measurements.

  17. Development of a reaction wheel attitude control system for sounding rocket experiments and small Shuttle-based free flyers

    NASA Technical Reports Server (NTRS)

    Ward, P. R.

    1986-01-01

    A three-axis reaction wheel control system is currently under development. Initial emphasis is on a magnetic field reference, although the system is easily adaptable to other positional references, e.g., the gyroscopic. The system is housed in a skin section 17.25 inches in diameter and approximately 10 inches long. Current weight estimate is 75 pounds. An orthogonal triad of dc motors forms the basis of the system. Power is provided by silver-zinc cells and controlled by an 8-bit microprocessor. The control law is presented and the dynamical equations derived. Simulation results show that a payload with a roll MOI of 4.1 sl/sq ft and a transverse MOI of 20.3 sl/sq ft can typically be reoriented 90 degrees in 20-35 seconds, depending upon the initial body rates.

  18. A wellbore inertial navigation system

    SciTech Connect

    Kelsey, J.R.

    1983-02-01

    A prototype wireline tool which includes a downhole inertial platform and a surface computer to spatially map a well is described. The hardware consists of a single-gimballed inertial platform with accelerometers and gyros to obtain three-axis motion information. The gyroscope and accelerometer outputs are transmitted to a computer at the surface which calculates probe attitude relative to north, east, and vertical. Double integration of the accelerometer data provides the position information. A conventional 7-conductor wireline is used for the system data transmission. System accuracy is enhanced by advances made in the computer software which processes the data received from the tool. The software uses statistical sampling estimation to obtain optimal estimates of the system errors. Measurement errors are determined by periodically stopping the tool during the logging procedure and observing the indicated velocity measurements. This procedure, known as Kalman filtering, results in increased accuracy of the data. Present mapping systems have an X-Y-Z location accuracy of 100 to 200 feet for a typical well depth of 10,000 feet. Test results show that the new system is accurate to about 1 foot per 1000 feet of well depth. Unlike conventional systems, the inertial navigator does not require any sort of projection of the cable length (which may not be accurately known). Also, this system provides continuous data throughout the wellbore and logging speeds on the order of 10 ft/sec appear possible. The hardware and software associated with this mapping system are described and the recent field test results are reported.

  19. Attitude control system conceptual design for the GOES-N spacecraft series

    NASA Technical Reports Server (NTRS)

    Markley, F. L.; Bauer, F. H.; Deily, J. J.; Femiano, M. D.

    1991-01-01

    The attitude determination sensing and processing of the system are considered, and inertial reference units, star trackers, and beacons and landmarks are discussed as well as an extended Kalman filter and expected attitude-determination performance. The baseline controller is overviewed, and a spacecraft motion compensation (SMC) algorithm, disturbance environment, and SMC performance expectations are covered. Detailed simulation results are presented, and emphasis is placed on dynamic models, attitude estimation and control, and SMC disturbance accommmodation. It is shown that the attitude control system employing gyro/star tracker sensing and active three-axis control with reaction wheels is capable of maintaining attitude errors of 1.7 microrad or less on all axes in the absence of attitude disturbances, and that the sensor line-of-sight pointing errors can be reduced to 0.1 microrad by SMC.

  20. Finite element based electric motor design optimization

    NASA Technical Reports Server (NTRS)

    Campbell, C. Warren

    1993-01-01

    The purpose of this effort was to develop a finite element code for the analysis and design of permanent magnet electric motors. These motors would drive electromechanical actuators in advanced rocket engines. The actuators would control fuel valves and thrust vector control systems. Refurbishing the hydraulic systems of the Space Shuttle after each flight is costly and time consuming. Electromechanical actuators could replace hydraulics, improve system reliability, and reduce down time.

  1. Integrated calibration of magnetic gradient tensor system

    NASA Astrophysics Data System (ADS)

    Gang, Yin; Yingtang, Zhang; Hongbo, Fan; GuoQuan, Ren; Zhining, Li

    2015-01-01

    Measurement precision of a magnetic gradient tensor system is not only connected with the imperfect performance of magnetometers such as bias, scale factor, non-orthogonality and misalignment errors, but also connected with the external soft-iron and hard-iron magnetic distortion fields when the system is used as a strapdown device. So an integrated scalar calibration method is proposed in this paper. In the first step, a mathematical model for scalar calibration of a single three-axis magnetometer is established, and a least squares ellipsoid fitting algorithm is proposed to estimate the detailed error parameters. For the misalignment errors existing at different magnetometers caused by the installation process and misalignment errors aroused by ellipsoid fitting estimation, a calibration method for combined misalignment errors is proposed in the second step to switch outputs of different magnetometers into the ideal reference orthogonal coordinate system. In order to verify effectiveness of the proposed method, simulation and experiment with a cross-magnetic gradient tensor system are performed, and the results show that the proposed method estimates error parameters and improves the measurement accuracy of magnetic gradient tensor greatly.

  2. Analytic investigation of the AEM-A/HCMM attitude control system performance. [Application Explorer Missions/Heat Capacity Mapping Mission

    NASA Technical Reports Server (NTRS)

    Lerner, G. M.; Huang, W.; Shuster, M. D.

    1977-01-01

    The Heat Capacity Mapping Mission (HCMM), scheduled for launch in 1978, will be three-axis stabilized relative to the earth in a 600-kilometer altitude, polar orbit. The autonomous attitude control system consists of three torquing coils and a momentum wheel driven in response to error signals computed from data received from an infrared horizon sensor and a magnetometer. This paper presents a simple model of the attitude dynamics and derives the equations that determine the stability of the system during both attitude acquisition (acquisition-mode) and mission operations (mission-mode). Modifications to the proposed mission-mode control laws which speed the system's response to transient attitude errors and reduce the steady-state attitude errors are suggested. Numerical simulations are performed to validate the results obtained with the simple model.

  3. Linear-Parameter-Varying Antiwindup Compensation for Enhanced Flight Control Performance

    NASA Technical Reports Server (NTRS)

    Lu, Bei; Wu, Fen; Kim, Sung Wan

    2005-01-01

    Actuator saturation is one of the major issues of flight control in the high angle-of-attack region. This paper presents a saturation control scheme for linear parameter varyjing (LPV) systems from an antiwindup control perspective. The proposed control approach is advantageous from the implementation standpoint because it can be thought of as an augmented control algorithm to the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. We have applied te LPV antiwindup controller to an F-16 longitudinal autopilot control system design and compared it with the thrust vectoring control scheme. The nonlinear simulations show that an LPV antiwindup controller improves flight quality and offers advantages over thrust vectoring in a high angle-of-attack region.

  4. Lift/cruise fan VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Quigley, H. C.; Franklin, J. A.

    1977-01-01

    The paper gives an overview of the technology related to lift/cruise fan VTOL aircraft, covering propulsion systems, thrust deflection, flight dynamics, controls, displays, aerodynamics, and configurations. Piloting problems are discussed, and the need for integration of power management and thrust-vector controls is pointed out. Major components for a high-bypass-ratio lift/cruise fan propulsion system for VTOL aircraft have been tested.

  5. Closeup view of an Aft Skirt being prepared for mating ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of an Aft Skirt being prepared for mating with sub assemblies in the Solid Rocket Booster Assembly and Refurbishment Facility at Kennedy Space Center. The most prominent feature in this view are the six Thrust Vector Control System access ports, three per hydraulic actuator. - Space Transportation System, Solid Rocket Boosters, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. Preliminary Design of the Guidance, Navigation, and Control System of the Altair Lunar Lander

    NASA Technical Reports Server (NTRS)

    Lee, Allan Y.; Ely, Todd; Sostaric, Ronald; Strahan, Alan; Riedel, Joseph E.; Ingham, Mitch; Wincentsen, James; Sarani, Siamak

    2010-01-01

    Guidance, Navigation, and Control (GN&C) is the measurement and control of spacecraft position, velocity, and attitude in support of mission objectives. This paper provides an overview of a preliminary design of the GN&C system of the Lunar Lander Altair. Key functions performed by the GN&C system in various mission phases will first be described. A set of placeholder GN&C sensors that is needed to support these functions is next described. To meet Crew safety requirements, there must be high degrees of redundancy in the selected sensor configuration. Two sets of thrusters, one on the Ascent Module (AM) and the other on the Descent Module (DM), will be used by the GN&C system. The DM thrusters will be used, among other purposes, to perform course correction burns during the Trans-lunar Coast. The AM thrusters will be used, among other purposes, to perform precise angular and translational controls of the ascent module in order to dock the ascent module with Orion. Navigation is the process of measurement and control of the spacecraft's "state" (both the position and velocity vectors of the spacecraft). Tracking data from the Earth-Based Ground System (tracking antennas) as well as data from onboard optical sensors will be used to estimate the vehicle state. A driving navigation requirement is to land Altair on the Moon with a landing accuracy that is better than 1 km (radial 95%). Preliminary performance of the Altair GN&C design, relative to this and other navigation requirements, will be given. Guidance is the onboard process that uses the estimated state vector, crew inputs, and pre-computed reference trajectories to guide both the rotational and the translational motions of the spacecraft during powered flight phases. Design objectives of reference trajectories for various mission phases vary. For example, the reference trajectory for the descent "approach" phase (the last 3-4 minutes before touchdown) will sacrifice fuel utilization efficiency in order to provide landing site visibility for both the crew and the terrain hazard detection sensor system. One output of Guidance is the steering angle commands sent to the 2 degree-of-freedom (dof) gimbal actuation system of the descent engine. The engine gimbal actuation system is controlled by a Thrust Vector Control algorithm that is designed taking into account the large quantities of sloshing liquids in tanks mounted on Altair. In this early design phase of Altair, the GN&C system is described only briefly in this paper and the emphasis is on the GN&C architecture (that is still evolving). Multiple companion papers will provide details that are related to navigation, optical navigation, guidance, fuel sloshing, rendezvous and docking, machine-pilot interactions, and others. The similarities and differences of GN&C designs for Lunar and Mars landers are briefly compared.

  7. A multilevel control system for the large space telescope. [numerical analysis/optimal control

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.; Sundareshan, S. K.; Vukcevic, M. B.

    1975-01-01

    A multilevel scheme was proposed for control of Large Space Telescope (LST) modeled by a three-axis-six-order nonlinear equation. Local controllers were used on the subsystem level to stabilize motions corresponding to the three axes. Global controllers were applied to reduce (and sometimes nullify) the interactions among the subsystems. A multilevel optimization method was developed whereby local quadratic optimizations were performed on the subsystem level, and global control was again used to reduce (nullify) the effect of interactions. The multilevel stabilization and optimization methods are presented as general tools for design and then used in the design of the LST Control System. The methods are entirely computerized, so that they can accommodate higher order LST models with both conceptual and numerical advantages over standard straightforward design techniques.

  8. An analysis of cross-coupling of a multicomponent jet engine test stand using finite element modeling techniques

    NASA Technical Reports Server (NTRS)

    Schweikhard, W. G.; Singnoi, W. N.

    1985-01-01

    A two axis thrust measuring system was analyzed by using a finite a element computer program to determine the sensitivities of the thrust vectoring nozzle system to misalignment of the load cells and applied loads, and the stiffness of the structural members. Three models were evaluated: (1) the basic measuring element and its internal calibration load cells; (2) the basic measuring element and its external load calibration equipment; and (3) the basic measuring element, external calibration load frame and the altitude facility support structure. Alignment of calibration loads was the greatest source of error for multiaxis thrust measuring systems. Uniform increases or decreases in stiffness of the members, which might be caused by the selection of the materials, have little effect on the accuracy of the measurements. It is found that the POLO-FINITE program is a viable tool for designing and analyzing multiaxis thrust measurement systems. The response of the test stand to step inputs that might be encountered with thrust vectoring tests was determined. The dynamic analysis show a potential problem for measuring the dynamic response characteristics of thrust vectoring systems because of the inherently light damping of the test stand.

  9. Rocket propulsion elements - An introduction to the engineering of rockets (6th revised and enlarged edition)

    NASA Astrophysics Data System (ADS)

    Sutton, George P.

    The subject of rocket propulsion is treated with emphasis on the basic technology, performance, and design rationale. Attention is given to definitions and fundamentals, nozzle theory and thermodynamic relations, heat transfer, flight performance, chemical rocket propellant performance analysis, and liquid propellant rocket engine fundamentals. The discussion also covers solid propellant rocket fundamentals, hybrid propellant rockets, thrust vector control, selection of rocket propulsion systems, electric propulsion, and rocket testing.

  10. Explicit Finite Element Techniques Used to Characterize Splashdown of the Space Shuttle Solid Rocket Booster Aft Skirt

    NASA Technical Reports Server (NTRS)

    Melis, Matthew E.

    2003-01-01

    NASA Glenn Research Center s Structural Mechanics Branch has years of expertise in using explicit finite element methods to predict the outcome of ballistic impact events. Shuttle engineers from the NASA Marshall Space Flight Center and NASA Kennedy Space Flight Center required assistance in assessing the structural loads that a newly proposed thrust vector control system for the space shuttle solid rocket booster (SRB) aft skirt would expect to see during its recovery splashdown.

  11. Low-speed wind-tunnel test of a STOL supersonic-cruise fighter concept

    NASA Technical Reports Server (NTRS)

    Coe, Paul L., Jr.; Riley, Donald R.

    1988-01-01

    A wind-tunnel investigation was conducted to examine the low-speed static stability and control characteristics of a 0.10 scale model of a STOL supersonic cruise fighter concept. The concept, referred to as a twin boom fighter, was designed as a STOL aircraft capable of efficient long range supersonic cruise. The configuration name is derived from the long twin booms extending aft of the engine to the twin vertical tails which support a high center horizontal tail. The propulsion system features a two dimensional thrust vectoring exhaust nozzle which is located so that the nozzle hinge line is near the aircraft center of gravity. This arrangement is intended to allow large thrust vector angles to be used to obtain significant values of powered lift, while minimizing pitching moment trim changes. Low speed stability and control information was obtained over an angle of attack range including the stall. A study of jet induced power effects was included.

  12. Mathematical modeling and nonlinear attitude and trajectory tracking control of a one stage rocket with varying mass

    NASA Astrophysics Data System (ADS)

    Fenili, Andr

    2014-12-01

    The thrust vector control (TVC) for a one-stage rocket with variable mass is considered. TVC control is used here to correct the rocket deviations from an intended parabolic trajectory and desired attitude angle during powered flight. A rigid body mathematical model with varying mass in the plane is presented. A nonlinear feedback controller together with a SDRE controller is designed. The effectiveness of the proposed mathematical model and control is illustrated through numerical simulations. By controlling the direction of the thrust vectors it is possible to control the angle of attack of the rocket. In this work only the pitch angle is considered. Only one liquid propellant thruster is used. It is also considered here only the flight period when the rocket propulsion system is firing and therefore the TVC is operative.

  13. Hovering Dual-Spin Vehicle Groundwork for Bias Momentum Sizing Validation Experiment

    NASA Technical Reports Server (NTRS)

    Rothhaar, Paul M.; Moerder, Daniel D.; Lim, Kyong B.

    2008-01-01

    Angular bias momentum offers significant stability augmentation for hovering flight vehicles. The reliance of the vehicle on thrust vectoring for agility and disturbance rejection is greatly reduced with significant levels of stored angular momentum in the system. A methodical procedure for bias momentum sizing has been developed in previous studies. This current study provides groundwork for experimental validation of that method using an experimental vehicle called the Dual-Spin Test Device, a thrust-levitated platform. Using measured data the vehicle's thrust vectoring units are modeled and a gust environment is designed and characterized. Control design is discussed. Preliminary experimental results of the vehicle constrained to three rotational degrees of freedom are compared to simulation for a case containing no bias momentum to validate the simulation. A simulation of a bias momentum dominant case is presented.

  14. Piloted simulator assessments of agility

    NASA Technical Reports Server (NTRS)

    Schneider, Edward T.

    1990-01-01

    NASA has utilized piloted simulators for nearly two decades to study high-angle-of-attack flying qualities, agility, and air-to-air combat. These studies have included assessments of an F-16XL aircraft equipped with thrust vectoring, an assessment of the F-18 HARV maneuvering requirements to assist in thrust vectoring control system design, and an agility assessment of the F-18. The F-18 agility assessment was compared with in-flight testing. Open-loop maneuvers such as 180-deg rolls to measure roll rate showed favorable simulator/in-flight comparison. Closed-loop maneuvers such as rolls to 90 deg with precision stops or certain maximum longitudinal pitching maneuvers showed poorer performance due to reduced aggressiveness of pilot inputs in flight to remain within flight envelope limits.

  15. Beam Position and Phase Monitor - Wire Mapping System

    SciTech Connect

    Watkins, Heath A; Shurter, Robert B.; Gilpatrick, John D.; Kutac, Vincent G.; Martinez, Derwin

    2012-04-10

    The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

  16. Static, noise, and transition tests of a combined-surface-blowing V/STOL lift/propulsion system

    NASA Technical Reports Server (NTRS)

    Schoen, A. H.; Kolesar, C. E.; Schaeffer, E. G.

    1977-01-01

    Efficient thrust vectoring and high levels of circulatory lift were obtained in tests of a half model V/STOL airplane by using a type of externally blown jet flap in which the jet exhaust from wing-mounted cruise fans is directed over both upper and lower surfaces of a flapped wing. Approximately 90% thrust recovery with 87 deg of thrust vectoring was achieved under static conditions using 89 deg of trailing edge flap deflection. The approximately 10% loss appears to be associated primarily with pressure losses due to the flap brackets or slot entries. The jet induced lift was shown to be 55% of the theoretical value for a fullspan jet-flapped wing, even though only 27.5% of the wingspan was immersed in the jet. Steady rate of descent capability in excess of 1,000 feet per minute is predicted. The possibility of significant aerodynamic-noise cancelling when blowing over both surfaces at high velocities is indicated.

  17. Simulation model of the F/A-18 high angle-of-attack research vehicle utilized for the design of advanced control laws

    NASA Technical Reports Server (NTRS)

    Strickland, Mark E.; Bundick, W. Thomas; Messina, Michael D.; Hoffler, Keith D.; Carzoo, Susan W.; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    The 'f18harv' six degree-of-freedom nonlinear batch simulation used to support research in advanced control laws and flight dynamics issues as part of NASA's High Alpha Technology Program is described in this report. This simulation models an F/A-18 airplane modified to incorporate a multi-axis thrust-vectoring system for augmented pitch and yaw control power and actuated forebody strakes for enhanced aerodynamic yaw control power. The modified configuration is known as the High Alpha Research Vehicle (HARV). The 'f18harv' simulation was an outgrowth of the 'f18bas' simulation which modeled the basic F/A-18 with a preliminary version of a thrust-vectoring system designed for the HARV. The preliminary version consisted of two thrust-vectoring vanes per engine nozzle compared with the three vanes per engine actually employed on the F/A-18 HARV. The modeled flight envelope is extensive in that the aerodynamic database covers an angle-of-attack range of -10 degrees to +90 degrees, sideslip range of -20 degrees to +20 degrees, a Mach Number range between 0.0 and 2.0, and an altitude range between 0 and 60,000 feet.

  18. X-31A Tactical Utility Flight Testing

    NASA Technical Reports Server (NTRS)

    Friehmelt, Holger; Guetter, Richard; Kim, Quirin

    1997-01-01

    The two X-31A were jointly built by Daimler-Benz Aerospace AG and Rockwell International. These German-American experimental aircraft were designed to explore the new realm of flight far beyond stall by employing advanced technologies like thrust vectoring and sophisticated flight control systems. The X-31A aircraft is equipped with a thrust vectoring system consisting of three aft mounted paddles to deflect the thrust vector in both pitch and yaw axes, thus providing the X-31A in this 'Enhanced Fighter Maneuverability program with an agility and maneuverability never seen before. The tactical utility of the X-31A using post stall technologies has been revealed in an extensive flight test campaign against various current state-of-the-art fighter aircraft in a close-in combat arena. The test philosophy included both simulation and flight test. The tremendous tactical advantage of the X-31A during the tactical utility evaluation flight test phase was accompanied by a deepened insight into post stall tactics its typical maneuvers, impacts on pilot-aircraft interfaces and requirements for future weapons to both engineers and the military community. Some selected aspects of the tactical utility of the X-31A using post stall technologies unveiled by the International Test Organization are presented here.

  19. Comparison of X-31 flight, wind-tunnel, and water-tunnel yawing moment asymmetries at high angles of attack

    NASA Technical Reports Server (NTRS)

    Cobleigh, Brent R.; Croom, Mark A.; Tamrat, B. F.

    1994-01-01

    The X-31 aircraft are being used in the enhanced fighter maneuverability (EFM) research program, which is jointly funded by the (U.S.) Advanced Research Projects Agency (ARPA) and Germany's Federal Ministry of Defense (FMOD). The flight test portion of the program, which involves two aircraft, is being conducted by an International Test Organization (ITO) comprising the National Aeronautics and Space Administration (NASA), the U.S. Navy, the U.S. Air Force, Rockwell International, and Deutsche Aerospace (DASA). The goals of the flight program are to demonstrate EFM technologies, investigate close-in-combat exchange ratios, develop design requirements, build a database for application to future fighter aircraft, and develop and validate low-cost prototype concepts. For longitudinal control the X-31 uses canards, symmetrical movement of the trailing-edge flaps, and pitch deflection of the thrust vectoring system. The trim, inertial coupling, and engine gyroscopic coupling compensation tasks are performed primarily by the trailing-edge flaps. For lateral-directional control the aircraft uses differential deflection of the trailing-edge flaps for roll coordination and a conventional rudder combined with the thrust vectoring system to provide yaw control. The rudder is only effective up to about 40 deg angle of attack (alpha), after which the thrust vectoring becomes the primary yaw control effector. Both the leading-edge flaps and the inlet lip are scheduled with the angle of attack to provide best performance.

  20. Hybrid fault diagnosis of nonlinear systems using neural parameter estimators.

    PubMed

    Sobhani-Tehrani, E; Talebi, H A; Khorasani, K

    2014-02-01

    This paper presents a novel integrated hybrid approach for fault diagnosis (FD) of nonlinear systems taking advantage of both the system's mathematical model and the adaptive nonlinear approximation capability of computational intelligence techniques. Unlike most FD techniques, the proposed solution simultaneously accomplishes fault detection, isolation, and identification (FDII) within a unified diagnostic module. At the core of this solution is a bank of adaptive neural parameter estimators (NPEs) associated with a set of single-parameter fault models. The NPEs continuously estimate unknown fault parameters (FPs) that are indicators of faults in the system. Two NPE structures, series-parallel and parallel, are developed with their exclusive set of desirable attributes. The parallel scheme is extremely robust to measurement noise and possesses a simpler, yet more solid, fault isolation logic. In contrast, the series-parallel scheme displays short FD delays and is robust to closed-loop system transients due to changes in control commands. Finally, a fault tolerant observer (FTO) is designed to extend the capability of the two NPEs that originally assumes full state measurements for systems that have only partial state measurements. The proposed FTO is a neural state estimator that can estimate unmeasured states even in the presence of faults. The estimated and the measured states then comprise the inputs to the two proposed FDII schemes. Simulation results for FDII of reaction wheels of a three-axis stabilized satellite in the presence of disturbances and noise demonstrate the effectiveness of the proposed FDII solutions under partial state measurements. PMID:24239987

  1. Space Launch System Ascent Flight Control Design

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.; Wall, John H.; VanZwieten, Tannen S.; Hall, Charles E.

    2014-01-01

    A robust and flexible autopilot architecture for NASA's Space Launch System (SLS) family of launch vehicles is presented. The SLS configurations represent a potentially significant increase in complexity and performance capability when compared with other manned launch vehicles. It was recognized early in the program that a new, generalized autopilot design should be formulated to fulfill the needs of this new space launch architecture. The present design concept is intended to leverage existing NASA and industry launch vehicle design experience and maintain the extensibility and modularity necessary to accommodate multiple vehicle configurations while relying on proven and flight-tested control design principles for large boost vehicles. The SLS flight control architecture combines a digital three-axis autopilot with traditional bending filters to support robust active or passive stabilization of the vehicle's bending and sloshing dynamics using optimally blended measurements from multiple rate gyros on the vehicle structure. The algorithm also relies on a pseudo-optimal control allocation scheme to maximize the performance capability of multiple vectored engines while accommodating throttling and engine failure contingencies in real time with negligible impact to stability characteristics. The architecture supports active in-flight disturbance compensation through the use of nonlinear observers driven by acceleration measurements. Envelope expansion and robustness enhancement is obtained through the use of a multiplicative forward gain modulation law based upon a simple model reference adaptive control scheme.

  2. Space Launch System Ascent Flight Control Design

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Orr, Jeb S.; Wall, John H.; Hall, Charles E.

    2014-01-01

    A robust and flexible autopilot architecture for NASA's Space Launch System (SLS) family of launch vehicles is presented. As the SLS configurations represent a potentially significant increase in complexity and performance capability of the integrated flight vehicle, it was recognized early in the program that a new, generalized autopilot design should be formulated to fulfill the needs of this new space launch architecture. The present design concept is intended to leverage existing NASA and industry launch vehicle design experience and maintain the extensibility and modularity necessary to accommodate multiple vehicle configurations while relying on proven and flight-tested control design principles for large boost vehicles. The SLS flight control architecture combines a digital three-axis autopilot with traditional bending filters to support robust active or passive stabilization of the vehicle's bending and sloshing dynamics using optimally blended measurements from multiple rate gyros on the vehicle structure. The algorithm also relies on a pseudo-optimal control allocation scheme to maximize the performance capability of multiple vectored engines while accommodating throttling and engine failure contingencies in real time with negligible impact to stability characteristics. The architecture supports active in-flight load relief through the use of a nonlinear observer driven by acceleration measurements, and envelope expansion and robustness enhancement is obtained through the use of a multiplicative forward gain modulation law based upon a simple model reference adaptive control scheme.

  3. TRMM On Orbit Attitude Control System Performance

    NASA Technical Reports Server (NTRS)

    Robertson, Brent; Placanica, Sam; Morgenstern, Wendy

    1999-01-01

    This paper presents an overview of the Tropical Rainfall Measuring Mission (TRMM) Attitude Control System (ACS) along with detailed in-flight performance results for each operational mode. The TRMM spacecraft is an Earth-pointed, zero momentum bias satellite launched on November 27, 1997 from Tanegashima Space Center, Japan. TRMM is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan designed to monitor and study tropical rainfall and the associated release of energy. Launched to provide a validation for poorly known rainfall data sets generated by global climate models, TRMM has demonstrated its utility by reducing uncertainties in global rainfall measurements by a factor of two. The ACS is comprised of Attitude Control Electronics (ACE), an Earth Sensor Assembly (ESA), Digital Sun Sensors (DSS), Inertial Reference Units (IRU), Three Axis Magnetometers (TAM), Coarse Sun Sensors (CSS), Magnetic Torquer Bars (MTB), Reaction Wheel Assemblies (RWA), Engine Valve Drivers (EVD) and thrusters. While in Mission Mode, the ESA provides roll and pitch axis attitude error measurements and the DSS provide yaw updates twice per orbit. In addition, the TAM in combination with the IRU and DSS can be used to provide pointing in a contingency attitude determination mode which does not rely on the ESA. Although the ACS performance to date has been highly successful, lessons were learned during checkout and initial on-orbit operation. This paper describes the design, on-orbit checkout, performance and lessons learned for the TRMM ACS.

  4. Feedback control laws for highly maneuverable aircraft

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Balas, Gary J.

    1995-01-01

    During this year, we concentrated our efforts on the design of controllers for lateral/directional control using mu synthesis. This proved to be a more difficult task than we anticipated and we are still working on the designs. In the lateral-directional control problem, the inputs are pilot lateral stick and pedal commands and the outputs are roll rate about the velocity vector and side slip angle. The control effectors are ailerons, rudder deflection, and directional thrust vectoring vane deflection which produces a yawing moment about the body axis. Our math model does not contain any provision for thrust vectoring of rolling moment. This has resulted in limitations of performance at high angles of attack. During 1994-95, the following tasks for the lateral-directional controllers were accomplished: (1) Designed both inner and outer loop dynamic inversion controllers. These controllers are implemented using accelerometer outputs rather than an a priori model of the vehicle aerodynamics; (2) Used classical techniques to design controllers for the system linearized by dynamics inversion. These controllers acted to control roll rate and Dutch roll response; (3) Implemented the inner loop dynamic inversion and classical controllers on the six DOF simulation; (4) Developed a lateral-directional control allocation scheme based on minimizing required control effort among the ailerons, rudder, and directional thrust vectoring; and (5) Developed mu outer loop controllers combined with classical inner loop controllers.

  5. Linear parameter-varying control of an F-16 aircraft at high angle of attack

    NASA Astrophysics Data System (ADS)

    Lu, Bei

    To improve the aircraft capability at high angle of attack and expand the flight envelope, advanced linear parameter-varying (LPV) control methodologies are studied in this thesis with particular applications of actuator saturation control and switching control. A standard two-step LPV antiwindup control scheme and a systematic switching LPV control approach are derived, and the advantages of LPV control techniques are demonstrated through nonlinear simulations of an F-16 longitudinal autopilot control system. The aerodynamic surface saturation is one of the major issues of flight control in the high angle of attack region. The incorporated unconventional actuators such as thrust vectoring can provide additional control power, but may have a potentially significant pay-off. The proposed LPV antiwindup control scheme is advantageous from the implementation standpoint because it can be thought of as an augmented control algorithm to the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. By treating the input saturation as a sector bounded nonlinearity with a tight sector bound, the synthesized antiwindup compensator can stabilize the open-loop exponentially unstable systems. The LPV antiwindup control scheme is applied to the nonlinear F-16 longitudinal model, and compared with the thrust vectoring control approach. The simulation results show that the LPV antiwindup compensator improves the flight quality, and offers advantages over thrust vectoring in a high angle of attack region. For a thrust vectoring augmented aircraft, the actuator sets may be different at low and high angles of attack. Also due to different control objectives, a single controller may not exist over a wide angle of attack region. The proposed switching LPV control approach based on multiple parameter-dependent Lyapunov functions provides a flexible design method with improved performance. A family of LPV controllers are designed, each suitable for a specific angle of attack region. They are switched according to the trajectory of angle of attack so that the closed-loop system remains stable and its performance is optimized. Two switching logics, hysteresis switching and switching with average dwell time, are examined. The control synthesis conditions for both switching logics are formulated as generally non-convex matrix optimization problems. To make the switching LPV control approach more applicable, two convexified methods are given according to the state of the controller is reset or not at switching time. The thrust vectoring augmented F-16 longitudinal model with different control objectives at low and high angles of attack is used to validate the results of the switching control scheme.

  6. A six-circle diffractometer system for synchrotron X-ray studies of surfaces and thin film growth by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Hong, Hawoong; Chiang, T.-C.

    2007-03-01

    A new ultrahigh vacuum (UHV) surface diffractometer system equipped with molecular beam epitaxy (MBE) capabilities has been developed. It has a versatile 6-circle configuration for defining the diffraction geometry, and a three-axis translation stage for controlling the sample position. Rugged mechanical components are employed in the design to allow accurate diffraction measurements. Sample cooling is facilitated by passing liquid nitrogen into a reservoir in the base of a sample mount. The sample can be heated to very high temperatures by either direct current heating or electron beam bombardment. During film growth and processing, the sample temperature, monitored by thermocouples, can be continuously and rapidly varied between 110 K to above room temperature. A charge coupled device (CCD) camera, attached to the ? circle, allows rapid reciprocal space mapping for real time studies of sample growth and evolution during deposition and annealing. A beam stop and a baffle are implemented to minimize stray scattered radiation.

  7. Testing a satellite automatic nutation control system. [on synchronous meteorological satellite

    NASA Technical Reports Server (NTRS)

    Hrasiar, J. A.

    1974-01-01

    Testing of a particular nutation control system for the synchronous meteorological satellite (SMS) is described. The test method and principles are applicable to nutation angle control for other satellites with similar requirements. During its ascent to synchronous orbit, a spacecraft like the SMS spins about its minimum-moment-of-inertia axis. An uncontrolled spacecraft in this state is unstable because torques due to fuel motion increase the nutation angle. However, the SMS is equipped with an automatic nutation control (ANC) system which will keep the nutation angle close to zero. Because correct operation of this system is critical to mission success, it was tested on an air-bearing table. The ANC system was mounted on the three-axis air-bearing table which was scaled to the SMS and equipped with appropriate sensors and thrusters. The table was spun up in an altitude chamber and nutation induced so that table motion simulated spacecraft motion. The ANC system was used to reduce the nutation angle. This dynamic test of the ANC system met all its objectives and provided confidence that the ANC system will control the SMS nutation angle.

  8. Individual Global Navigation Satellite Systems in the Space Service Volume

    NASA Technical Reports Server (NTRS)

    Force, Dale A.

    2015-01-01

    Besides providing position, navigation, and timing (PNT) to terrestrial users, GPS is currently used to provide for precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis control of Earth orbiting satellites. With additional Global Navigation Satellite Systems (GNSS) coming into service (GLONASS, Beidou, and Galileo), it will be possible to provide these services by using other GNSS constellations. The paper, "GPS in the Space Service Volume," presented at the ION GNSS 19th International Technical Meeting in 2006 (Ref. 1), defined the Space Service Volume, and analyzed the performance of GPS out to 70,000 km. This paper will report a similar analysis of the performance of each of the additional GNSS and compare them with GPS alone. The Space Service Volume, defined as the volume between 3,000 km altitude and geosynchronous altitude, as compared with the Terrestrial Service Volume between the surface and 3,000 km. In the Terrestrial Service Volume, GNSS performance will be similar to performance on the Earth's surface. The GPS system has established signal requirements for the Space Service Volume. A separate paper presented at the conference covers the use of multiple GNSS in the Space Service Volume.

  9. Direct femtosecond laser writing system for sub-micron and micron scale patterning

    NASA Astrophysics Data System (ADS)

    Vanagas, Egidijus; Tuzhilin, Dmitry; Zinkou, Michail; Sedunov, Alexander; Vasiliev, Nikolai; Kudryashov, Igor; Kononov, Vladimir; Suruga, Shozi

    2003-11-01

    Commercial femtosecond micromachining system (FMS) has been developed that capable to process the material in sub-micron (< 200 nm) and micron scale. Core of the system are: optical unit, controller unit and software. The other parts: fs-laser system; focusing unit; stage unit can be varied (exchangeable). Two different fs-laser systems already are compatible with core of FMS: Mira/RegA (Coherent) and Hurricane (Spectra-Physics). FMS controller unit allows to control every single fs-pulse delivery on the target. Three possible types of focusing unit are available: microscope type unit, long focal distance lens unit, and axicon lens based unit. Standard stage unit options are: three-axis piezostage, and two-axis air bearing stage combined with Z-axis piezostage. Repeatability for all dimensions is within +/-5 nm. Also, step motor stages are available. The system allows 3D scan with confocal laser-microscope (resolution ?r=200nm, ?z=540nm) build in optical unit. Software controls all basic functions of the system performance and writing any pattern (including 3D) on or into specimen. The results obtained by direct fs-laser writing method are presented and discussed: bits in the range of 100 - 200 nm sizes, 6 TB/cm3 density optical storage matrix, waveguides fabrication inside transparent materials, high aspect ratio (1:125) patterning of dielectric materials with Gauss-Bessel beam.

  10. Waterhammer Modeling for the Ares I Upper Stage Reaction Control System Cold Flow Development Test Article

    NASA Technical Reports Server (NTRS)

    Williams, Jonathan H.

    2010-01-01

    The Upper Stage Reaction Control System provides three-axis attitude control for the Ares I launch vehicle during active Upper Stage flight. The system design must accommodate rapid thruster firing to maintain the proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted in the fall of 2009 at Marshall Space Flight Center were performed using a water-flow test article to better understand fluid performance characteristics of the Upper Stage Reaction Control System. A subset of the tests examined waterhammer along with the subsequent pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  11. Analytical design and simulation evaluation of an approach flight director system for a jet STOL aircraft

    NASA Technical Reports Server (NTRS)

    Klein, R. H.; Hofmann, L. G.; Mcruer, D. T.

    1974-01-01

    A program was undertaken to develop design criteria and operational procedures for STOL transport aircraft. As part of that program, a series of flight tests shall be performed in an Augmentor Wing Jet STOL Aircraft. In preparation for the flight test programs, an analytical study was conducted to gain an understanding of the characteristics of the vehicle for manual control, to assess the relative merits of the variety of manual control techniques available with attitude and thrust vector controllers, and to determine what improvements can be made over manual control of the bare airframe by providing the pilot with suitable command guidance information and by augmentation of the bare airframe dynamics. The objective of the study is to apply closed-loop pilot/vehicle analysis techniques to the analysis of manual flight control of powered-lift STOL aircraft in the landing approach and to the design and experimental verification of an advanced flight director display.

  12. Space Infrared Telescope Facility/Multimission Modular Spacecraft Attitude Control System conceptual design

    NASA Technical Reports Server (NTRS)

    Class, Brian F.; Welch, Raymond V.; Bauer, Frank H.; Strohbehn, Kim

    1986-01-01

    A control system utilizing the Multi-mission Modular Spacecraft (MMS) Attitude Control System (ACS) was developed and analyzed for the Space Infrared Telescope Facility (SIRTF) spacecraft. Alternative torquer augmentation schemes were studied to determine viable ACS approaches. A control law was developed to use a dual set of single-axis Control Moment Gyros (CMGs) for two-axis control. Flexible structural models were developed using a high fidelity, flight tested NASTRAN model of the MMS, coupled with a NASTRAN model of the SIRTF telescope. Modal significance criteria were employed to reduce the structural model. Multivariable interactive techniques were used to synthesize the control system (including the structural filters). Control system performance for the SIRTF operational modes (quiescent inertial hold, slewing, nodding, and rastering) was then determined using both single-axis and three-axis simulations). The control system described met performance requirements for all modes but the raster with the use of CMGs. The raster performance was limited by the structural flexibility.

  13. Variable Acceleration Force Calibration System (VACS)

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.; Parker, Peter A.; Johnson, Thomas H.; Landman, Drew

    2014-01-01

    Conventionally, force balances have been calibrated manually, using a complex system of free hanging precision weights, bell cranks, and/or other mechanical components. Conventional methods may provide sufficient accuracy in some instances, but are often quite complex and labor-intensive, requiring three to four man-weeks to complete each full calibration. To ensure accuracy, gravity-based loading is typically utilized. However, this often causes difficulty when applying loads in three simultaneous, orthogonal axes. A complex system of levers, cranks, and cables must be used, introducing increased sources of systematic error, and significantly increasing the time and labor intensity required to complete the calibration. One aspect of the VACS is a method wherein the mass utilized for calibration is held constant, and the acceleration is changed to thereby generate relatively large forces with relatively small test masses. Multiple forces can be applied to a force balance without changing the test mass, and dynamic forces can be applied by rotation or oscillating acceleration. If rotational motion is utilized, a mass is rigidly attached to a force balance, and the mass is exposed to a rotational field. A large force can be applied by utilizing a large rotational velocity. A centrifuge or rotating table can be used to create the rotational field, and fixtures can be utilized to position the force balance. The acceleration may also be linear. For example, a table that moves linearly and accelerates in a sinusoidal manner may also be utilized. The test mass does not have to move in a path that is parallel to the ground, and no re-leveling is therefore required. Balance deflection corrections may be applied passively by monitoring the orientation of the force balance with a three-axis accelerometer package. Deflections are measured during each test run, and adjustments with respect to the true applied load can be made during the post-processing stage. This paper will present the development and testing of the VASC concept.

  14. A vector fetal magnetocardiogram system with high sensitivity

    NASA Astrophysics Data System (ADS)

    Kandori, Akihiko; Miyashita, Tsuyoshi; Tsukada, Keiji; Horigome, Hitoshi; Asaka, Mitsuhiro; Shigemitsu, Sadahiko; Takahashi, Miho; Terada, Yasushi; Mitsui, Toshio; Chiba, Yoshihide

    1999-12-01

    The vector fetal magnetocardiogram (V-FMCG) system that measures the three orthogonal components of the magnetic field from a fetal heart has been developed to clearly observe fetal cardiac activity during pregnancy by using the superconducting quantum interference device. To detect a clear V-FMCG signal, the bottom of the cryostat was made of thin glass-fiber-reinforced plastic and the total length between the pickup coil to the outer surface is 12 mm. Because the cryostat bottom was made thinner, the area of the cryostat's top and bottom could be made smaller, thus a low evaporation loss (<1.2 l per day) and a long refilling interval (>10 days) were obtained. The gantry was able to tilt the cryostat and the bed could move in three axis directions, which made it possible to easily locate the vector pickup coil at an optimum position to obtain the maximum magnetic field from a fetal heart. We obtained V-FMCGs from 21 normal fetuses with gestation periods of 27-38 weeks. Using these vector signals, the dipoles were estimated and the relationship between the strength of the dipole moments and the number of gestation weeks could be obtained. Thus, V-FMCG seems to represent a new noninvasive tool for clearly detecting the electrophysiological activity of a fetal heart.

  15. Adaptive control system for large annular momentum control device

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.; Johnson, C. R., Jr.

    1981-01-01

    A dual momentum vector control concept, consisting of two counterrotating rings (each designated as an annular momentum control device), was studied for pointing and slewing control of large spacecraft. In a disturbance free space environment, the concept provides for three axis pointing and slewing capabilities while requiring no expendables. The approach utilizes two large diameter counterrotating rings or wheels suspended magnetically in many race supports distributed around the antenna structure. When the magnets are energized, attracting the two wheels, the resulting gyroscopic torque produces a rate along the appropriate axis. Roll control is provided by alternating the radiative rotational velocity of the two wheels. Wheels with diameters of 500 to 800 m and with sufficient momentum storage capability require rims only a few centimeters thick. The wheels are extremely flexible; therefore, it is necessary to account for the distributed nature of the rings in the design of the bearing controllers. Also, ring behavior is unpredictably sensitive to ring temperature, spin rate, manufacturing imperfections, and other variables. An adaptive control system designed to handle these problems is described.

  16. Attitude control system design using a flywheel suspended by two gimbals

    NASA Astrophysics Data System (ADS)

    Peres, R. W.; Ricci, M. C.

    2015-10-01

    This work presents the attitude control system design procedures for a three axis stabilized satellite in geostationary orbit, which contains a flywheel suspended by two gimbals. The use of a flywheel with two DOFs is an interesting option because with only one device it's possible to control the torques about vehicle's three axes; through the wheel speed control and gyrotorquing phenomenon with two DOFs. If the wheel size and speed are determined properly it's possible to cancel cyclic torques using gas jets only periodically to cancel secular disturbance torques. The system, based on a flywheel, takes only one pitch/roll (earth) sensor to maintain precise attitude, unlike mass expulsion based control systems, which uses propellants continuously, beyond roll, pitch and yaw sensors. It is considered the satellite is in nominal orbit and, therefore, that the attitude's acquisition phase has already elapsed. Control laws and system parameters are determined in order to cancel the solar pressure radiation disturbance torque and the torque due to misalignment of the thrusters. Stability is analyzed and step and cyclic responses are obtained.

  17. Altitude testing of the 2D V/STOL ADEN demonstrator on an F404 engine

    NASA Technical Reports Server (NTRS)

    Blozy, J. T.

    1985-01-01

    The Augmented Deflector Exhaust Nozzle (ADEN) exhaust system was tested in the PSL-3 altitude chamber at the NASA Lewis Research Center in order to evaluate aerodynamic performance, cooling-system effectiveness, and mechanical operation at flight-type conditions. The ADEN, a flight-weight, two-dimensional, thrust-vectoring nozzle, was successfully tested on the F404 engine using a remote engine control system for automatic or manual setting of the throat-area control and available fan air for the nozzle internal cooling system. Throughout the test, the ADEN performed with no adverse effects on the engine or augmentor operation.

  18. Real-time in-flight engine performance and health monitoring techniques for flight research application

    NASA Technical Reports Server (NTRS)

    Ray, Ronald J.; Hicks, John W.; Wichman, Keith D.

    1991-01-01

    Procedures for real time evaluation of the inflight health and performance of gas turbine engines and related systems were developed to enhance flight test safety and productivity. These techniques include the monitoring of the engine, the engine control system, thrust vectoring control system health, and the detection of engine stalls. Real time performance techniques were developed for the determination and display of inflight thrust and for aeroperformance drag polars. These new methods were successfully shown on various research aircraft at NASA-Dryden. The capability of NASA's Western Aeronautical Test Range and the advanced data acquisition systems were key factors for implementation and real time display of these methods.

  19. IRECIN Nano-satellite communication system and ground segment

    NASA Astrophysics Data System (ADS)

    Ferrante, M.; Povia, M.; Di Ciolo, L.; Ortenzi, A.; Petrozzi, M.

    2005-01-01

    On board resources necessary to perform the mission tasks are very limited in nano-satellites. This paper proposes a real-time multi-processing system for the communication system between ground segment and IRECIN nano-satellite. The first microprocessor is devoted to interface to the rice-transceiver subsystem decoding packet information and the second one is in charge to communicate with the other subsystems through I 2C bus. It uses UHF band and less than 1 W in RF. All electronic components are SMD technology in order to reduce weight and size. The realized electronic boards are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Develop Group. This multi-processor system even allows managing the tasks of the microprocessor eventually damaged, the microprocessor still working takes the functionalities of the first one using simpler algorithms. This choice assures an increasing nano-satellite life time. Moreover, the depicted method allows to free the on-board main microprocessor from the control functions of the communication data, increasing its communication capabilities with the other subsystems. The proposed system is implemented on the IRECIN, a modular nano-satellite weighing less than 1.5 kg, constituted by 16 external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Lithium-ion batteries are added for eclipse operations. Attitude is determined by two three-axis magnetometers and the solar panel data. Control is provided by an active magnetic control system. The spacecraft will be spin-stabilized with the spin-axis normal to the orbit.

  20. A smartphone-based driver safety monitoring system using data fusion.

    PubMed

    Lee, Boon-Giin; Chung, Wan-Young

    2012-01-01

    This paper proposes a method for monitoring driver safety levels using a data fusion approach based on several discrete data types: eye features, bio-signal variation, in-vehicle temperature, and vehicle speed. The driver safety monitoring system was developed in practice in the form of an application for an Android-based smartphone device, where measuring safety-related data requires no extra monetary expenditure or equipment. Moreover, the system provides high resolution and flexibility. The safety monitoring process involves the fusion of attributes gathered from different sensors, including video, electrocardiography, photoplethysmography, temperature, and a three-axis accelerometer, that are assigned as input variables to an inference analysis framework. A Fuzzy Bayesian framework is designed to indicate the driver's capability level and is updated continuously in real-time. The sensory data are transmitted via Bluetooth communication to the smartphone device. A fake incoming call warning service alerts the driver if his or her safety level is suspiciously compromised. Realistic testing of the system demonstrates the practical benefits of multiple features and their fusion in providing a more authentic and effective driver safety monitoring. PMID:23247416

  1. System cost/performance analysis (study 2.3). Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Kazangey, T.

    1973-01-01

    The relationships between performance, safety, cost, and schedule parameters were identified and quantified in support of an overall effort to generate program models and methodology that provide insight into a total space vehicle program. A specific space vehicle system, the attitude control system (ACS), was used, and a modeling methodology was selected that develops a consistent set of quantitative relationships among performance, safety, cost, and schedule, based on the characteristics of the components utilized in candidate mechanisms. These descriptive equations were developed for a three-axis, earth-pointing, mass expulsion ACS. A data base describing typical candidate ACS components was implemented, along with a computer program to perform sample calculations. This approach, implemented on a computer, is capable of determining the effect of a change in functional requirements to the ACS mechanization and the resulting cost and schedule. By a simple extension of this modeling methodology to the other systems in a space vehicle, a complete space vehicle model can be developed. Study results and recommendations are presented.

  2. Multi-star processing and gyro filtering for the video inertial pointing system

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.

    1976-01-01

    The video inertial pointing (VIP) system is being developed to satisfy the acquisition and pointing requirements of astronomical telescopes. The VIP system uses a single video sensor to provide star position information that can be used to generate three-axis pointing error signals (multi-star processing) and for input to a cathode ray tube (CRT) display of the star field. The pointing error signals are used to update the telescope's gyro stabilization system (gyro filtering). The CRT display facilitates target acquisition and positioning of the telescope by a remote operator. Linearized small angle equations are used for the multistar processing and a consideration of error performance and singularities lead to star pair location restrictions and equation selection criteria. A discrete steady-state Kalman filter which uses the integration of the gyros is developed and analyzed. The filter includes unit time delays representing asynchronous operations of the VIP microprocessor and video sensor. A digital simulation of a typical gyro stabilized gimbal is developed and used to validate the approach to the gyro filtering.

  3. A Smartphone-Based Driver Safety Monitoring System Using Data Fusion

    PubMed Central

    Lee, Boon-Giin; Chung, Wan-Young

    2012-01-01

    This paper proposes a method for monitoring driver safety levels using a data fusion approach based on several discrete data types: eye features, bio-signal variation, in-vehicle temperature, and vehicle speed. The driver safety monitoring system was developed in practice in the form of an application for an Android-based smartphone device, where measuring safety-related data requires no extra monetary expenditure or equipment. Moreover, the system provides high resolution and flexibility. The safety monitoring process involves the fusion of attributes gathered from different sensors, including video, electrocardiography, photoplethysmography, temperature, and a three-axis accelerometer, that are assigned as input variables to an inference analysis framework. A Fuzzy Bayesian framework is designed to indicate the drivers capability level and is updated continuously in real-time. The sensory data are transmitted via Bluetooth communication to the smartphone device. A fake incoming call warning service alerts the driver if his or her safety level is suspiciously compromised. Realistic testing of the system demonstrates the practical benefits of multiple features and their fusion in providing a more authentic and effective driver safety monitoring. PMID:23247416

  4. Damping Control by One Axis Magnetic Torquer and Gravity Gradient Attitude Stabilization System for Small Satellite

    NASA Astrophysics Data System (ADS)

    Hosokawa, Shigeru; Masumoto, Yoshinari; Takezawa, Susumu; Haneji, Kazuhiko

    A Whale Ecology Observation Satellite (WEOS) was successfully launched on 14th December 2002. We adopted gravity gradient attitude control technique for the attitude stabilization of the WEOS as the first trial in Japan for pointing the communications antennas toward the earth, and the GPS antenna toward the zenith. The attitude control system of the WEOS consists of a three axis magnetometer, a magnetic torquer coil, and a deployable mast with a mass fixed at the tip, and attitude control software. This system carries out rate damping control of the principal axis of maximum moment of inertia and earth pointing attitude control. Immediately after the separation from the H2A-4 rocket, WEOS tumbled due to the imbalance force of three separation springs. The tumbling was reduced by the closed loop damping control and then the mast was extended. After one week, we confirmed the establishment of the gravity gradient attitude stabilization. This paper describes the attitude control system, operation procedure, and control results.

  5. An MRI-compatible system for focused ultrasound experiments in small animal models

    PubMed Central

    Chopra, Rajiv; Curiel, Laura; Staruch, Robert; Morrison, Laetitia; Hynynen, Kullervo

    2009-01-01

    The development of novel MRI-guided therapeutic ultrasound methods including potentiated drug delivery and targeted thermal ablation requires extensive testing in small animals such as rats and mice due to the widespread use of these species as models of disease. An MRI-compatible, computer-controlled three-axis positioning system was constructed to deliver focused ultrasound exposures precisely to a target anatomy in small animals for high-throughput preclinical drug delivery studies. Each axis was constructed from custom-made nonmagnetic linear ball stages driven by piezoelectric actuators and optical encoders. A range of motion of 552.5 cm3 was achieved, and initial bench top characterization demonstrated the ability to deliver ultrasound to the brain with a spatial accuracy of 0.3 mm. Operation of the positioning system within the bore of a clinical 3 T MR imager was feasible, and simultaneous motion and MR imaging did not result in any mutual interference. The system was evaluated in its ability to deliver precise sonications within the mouse brain, linear scanned exposures in a rat brain for blood barrier disruption, and circular scans for controlled heating under MR temperature feedback. Initial results suggest that this is a robust and precise apparatus for use in the investigation of novel ultrasound-based therapeutic strategies in small animal preclinical models. PMID:19544806

  6. Helicopters and VTOL. I

    NASA Technical Reports Server (NTRS)

    Burks, John S.

    1989-01-01

    Performance projections into the next half-century of VTOL aircraft design are presently made on the basis of recent design trends. Attention is given to the technology-development and commercial prospects for tilt-rotor, thrust-vectoring hover, lighter-than-air, and speculative electromagnetic-propulsion, remotely-beamed power systems. Highly automated air traffic control systems are envisioned which will incorporate AI, satellite positioning, synthetic vision, obstacle detection/avoidance and fiber-optic transmission to safely manage giant airborne mass-transit commuter systems. It is expected that tilt-rotor aircraft will become the dominant VTOL configuration as time passes.

  7. Combined Global Navigation Satellite Systems in the Space Service Volume

    NASA Technical Reports Server (NTRS)

    Force, Dale A.; Miller, James J.

    2015-01-01

    Besides providing position, navigation, and timing (PNT) services to traditional terrestrial and airborne users, GPS is also being increasingly used as a tool to enable precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis attitude control of Earth orbiting satellites. With additional Global Navigation Satellite System (GNSS) constellations being replenished and coming into service (GLONASS, Beidou, and Galileo), it will become possible to benefit from greater signal availability and robustness by using evolving multi-constellation receivers. The paper, "GPS in the Space Service Volume," presented at the ION GNSS 19th International Technical Meeting in 2006 (Ref. 1), defined the Space Service Volume, and analyzed the performance of GPS out to seventy thousand kilometers. This paper will report a similar analysis of the signal coverage of GPS in the space domain; however, the analyses will also consider signal coverage from each of the additional GNSS constellations noted earlier to specifically demonstrate the expected benefits to be derived from using GPS in conjunction with other foreign systems. The Space Service Volume is formally defined as the volume of space between three thousand kilometers altitude and geosynchronous altitude circa 36,000 km, as compared with the Terrestrial Service Volume between 3,000 km and the surface of the Earth. In the Terrestrial Service Volume, GNSS performance is the same as on or near the Earth's surface due to satellite vehicle availability and geometry similarities. The core GPS system has thereby established signal requirements for the Space Service Volume as part of technical Capability Development Documentation (CDD) that specifies system performance. Besides the technical discussion, we also present diplomatic efforts to extend the GPS Space Service Volume concept to other PNT service providers in an effort to assure that all space users will benefit from the enhanced interoperability of GNSS services in the space domain. A separate paper presented at the conference covers the individual GNSS performance parameters for respective Space Service Volumes.

  8. Earth Observing System (EOS) Aqua Launch and Early Mission Attitude Support Experiences

    NASA Technical Reports Server (NTRS)

    Tracewell, D.; Glickman, J.; Hashmall, J.; Natanson, G.; Sedlak, J.

    2003-01-01

    The Earth Observing System (EOS) Aqua satellite was successfully launched on May 4,2002. Aqua is the second in the series of EOS satellites. EOS is part of NASA s Earth Science Enterprise Program, whose goals are to advance the scientific understanding of the Earth system. Aqua is a three-axis stabilized, Earth-pointing spacecraft in a nearly circular, sun-synchronous orbit at an altitude of 705 km. The Goddard Space Flight Center (GSFC) Flight Dynamics attitude team supported all phases of the launch and early mission. This paper presents the main results and lessons learned during this period, including: real-time attitude mode transition support, sensor calibration, onboard computer attitude validation, response to spacecraft emergencies, postlaunch attitude analyses, and anomaly resolution. In particular, Flight Dynamics support proved to be invaluable for successful Earth acquisition, fine-point mode transition, and recognition and correction of several anomalies, including support for the resolution of problems observed with the MODIS instrument.

  9. Mass comparisons of electric propulsion systems for NSSK of geosynchronous spacecraft

    NASA Technical Reports Server (NTRS)

    Rawlin, Vincent K.; Majcher, Gregory A.

    1991-01-01

    A model was developed and exercised to allow wet mass comparisons of three axis stabilized communication satellites delivered to geosynchronous transfer orbit. The mass benefits of using advanced chemical propulsion for apogee injection and north-south stationkeeping (NSSK) functions or electric propulsion (hydrazine arcjets and xenon ion thrusters) for NSSK functions are documented. A large derated ion thrusters is proposed which minimizes thruster lifetime concerns and qualification test times when compared to those of smaller ion thrusters planned for NSSK applications. The mass benefits, which depend on the spacecraft mass and mission duration, increase dramatically with arcjet specific impulse in the 500 to 600 s range, but are nearly constant for the derated ion thruster operated in the 2300 to 3000 s range. For a given mission, the mass benefits with an ion system are typically double those of the arcjet system; however, the total thrusting time with arcjets is less than 1/3 that with ion thrusters for the same thruster power. The mass benefits may permit increases in revenue producing payload or reduce launch costs by allowing a move to a smaller launch vehicle.

  10. Mass comparisons of electric propulsion systems for NSSK of geosynchronous spacecraft. [North-South Station Keeping

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Majcher, G. A.

    1991-01-01

    A model was developed and exercised to allow wet mass comparisons of three-axis stabilized communications satellites delivered to geosynchronous transfer orbit. The mass benefits of using advanced chemical propulsion for apogee injection and north-south stationkeeping (NSSK) functions or electric propulsion (hydrazine arcjets and xenon ion thrusters) for NSSK functions are documented. A large derated ion thruster is proposed which minimizes thruster lifetime concerns and qualification test times when compared to those of smaller ion thrusters planned for NSSK applications. The mass benefits, which depend on the spacecraft mass and mission duration, increase dramatically with arcjet specific impulse in the 500-600 s range, but are nearly constant for the derated ion thruster operated in the 2300-3000 s range. For a given mission, the mass benefits with an ion system are typically double those of the arcjet system; however, the total thrusting time with arcjets is less than one-third that with ion thrusters for the same thruster power.

  11. The Implementation of Satellite Attitude Control System Software Using Object Oriented Design

    NASA Technical Reports Server (NTRS)

    Reid, W. Mark; Hansell, William; Phillips, Tom; Anderson, Mark O.; Drury, Derek

    1998-01-01

    NASA established the Small Explorer (SNMX) program in 1988 to provide frequent opportunities for highly focused and relatively inexpensive space science missions. The SMEX program has produced five satellites, three of which have been successfully launched. The remaining two spacecraft are scheduled for launch within the coming year. NASA has recently developed a prototype for the next generation Small Explorer spacecraft (SMEX-Lite). This paper describes the object-oriented design (OOD) of the SMEX-Lite Attitude Control System (ACS) software. The SMEX-Lite ACS is three-axis controlled and is capable of performing sub-arc-minute pointing. This paper first describes high level requirements governing the SMEX-Lite ACS software architecture. Next, the context in which the software resides is explained. The paper describes the principles of encapsulation, inheritance, and polymorphism with respect to the implementation of an ACS software system. This paper will also discuss the design of several ACS software components. Specifically, object-oriented designs are presented for sensor data processing, attitude determination, attitude control, and failure detection. Finally, this paper will address the establishment of the ACS Foundation Class (AFC) Library. The AFC is a large software repository, requiring a minimal amount of code modifications to produce ACS software for future projects.

  12. Thrust-induced effects on low-speed aerodynamics of fighter aircraft

    NASA Technical Reports Server (NTRS)

    Banks, D. W.; Quinto, P. F.; Paulson, J. W., Jr.

    1981-01-01

    The design and technology requirements for STOL fighter aircraft as defined in NASA studies are reviewed. The research has concentrated on advanced high-lift systems using mechanical flaps, methods of obtaining longitudinal trim during the use of thrust vectoring, and thrust reversal to shorten ground roll distances. Several early configurations are described, and investigations of the effect of thrust reversal on the low-speed aerodynamics of the F-15 are detailed. Although the NASA design was a wing-canard configuration, similarities in a Grumman baseline STOL aircraft allowed incorporation of the Grumman nacelle, primary nozzles, spanwise blowing nozzles, and trailing-edge flap systems.

  13. Satellite control mercury ion thruster. [attitude control and stationkeeping in synchronous orbits

    NASA Technical Reports Server (NTRS)

    Hyman, J., Jr.; Poeschel, R. L.

    1973-01-01

    Program status is reviewed for development of an 8-cm structurally integrated ion thruster for application to attitude control and stationkeeping of synchronous satellites. The system is designed to achieve a thrust level of 1 and 2 mlb at a beam voltage of 1200 V, a propellant-utilization efficiency of 85%, and electrical efficiency of 75%. Thrust vectoring will be implemented by a dished-gird roll misalignment system. Design features are incorporated which ensure thruster life of 20,000 hours, with 10,000 thruster-start cycles and 100,000 beam-deflection cycles.

  14. General view of a Solid Rocket Motor Nozzle in the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of a Solid Rocket Motor Nozzle in the Solid Rocket Booster (SRB) Assembly and Refurbishment Facility at Kennedy Space Center, being prepared to be mated with the Aft Skirt. In this view you can see the attach brackets where the Thrust Vector Control System actuators connect to the nozzle which can swivel the nozzle up to 3.5 degrees to redirect the thrust to steer and maintain the Shuttle's programmed trajectory. - Space Transportation System, Solid Rocket Boosters, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  15. Structure and properties of nano-hydroxypatite scaffolds for bone tissue engineering with a selective laser sintering system.

    PubMed

    Shuai, Cijun; Gao, Chengde; Nie, Yi; Hu, Huanlong; Zhou, Ying; Peng, Shuping

    2011-07-15

    In this study, nano-hydroxypatite (n-HAP) bone scaffolds are prepared by a homemade selective laser sintering (SLS) system based on rapid prototyping (RP) technology. The SLS system consists of a precise three-axis motion platform and a laser with its optical focusing device. The implementation of arbitrary complex movements based on the non-uniform rational B-Spline (NURBS) theory is realized in this system. The effects of the sintering processing parameters on the microstructure of n-HAP are tested with x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The particles of n-HAP grow gradually and tend to become spherical-like from the initial needle-like shape, but still maintain a nanoscale structure at scanning speeds between 200 and 300 mm min(-1) when the laser power is 50 W, the light spot diameter 4 mm, and the layer thickness 0.3 mm. In addition, these changes do not result in decomposition of the n-HAP during the sintering process. The results suggest that the newly developed n-HAP scaffolds have the potential to serve as an excellent substrate in bone tissue engineering. PMID:21642759

  16. The SushiBar: An automated system for paleomagnetic investigations

    NASA Astrophysics Data System (ADS)

    Wack, Michael R.; Gilder, Stuart A.

    2012-03-01

    We present a new, automated system based on a three-axis superconducting magnetometer and a custom-made coil designed to experiment on cylindrical specimens used in typical paleomagnetic investigations. The system, which resembles a sushi bar, facilitates stepwise alternating field demagnetization of up to 99 samples per loaded track. It also enables researchers to explore magnetic properties using an anhysteretic remanent magnetization (ARM) in any coercivity window up to peak alternating fields of 95 mT with direct current bias fields up to 0.17 mT. For example, partial ARM (pARM) spectra characterize magnetic grain size distributions in rocks, yet rarely are pARM spectra measured because the complete curve for one sample takes at least two hours to acquire manually. The SushiBar achieves 99 such curves in slightly less than 100 hours. Using the SushiBar, we measured the pARM sprectra, as well as the viscosity and anisotropy of ARM in three discrete switching field windows, of continental sediments from the Xishuigou section (western China). The average grain size remains constant along the 2200 m-thick section, yet magnetic viscosity varies systematically from bottom to top of the section; samples with high magnetic viscosities also have higher proportions of non-viscous material on average. Principal anisotropy axis directions from the lowest switching fields correlate well with principal axis directions from anisotropy of magnetic susceptibility. Principal axis directions defined at higher switching fields systematically deviate from those at lower switching fields, perhaps defining the fabric of the remanence-carrying grains.

  17. The SushiBar: An automated system for paleomagnetic investigations

    NASA Astrophysics Data System (ADS)

    Wack, M.; Gilder, S.

    2012-04-01

    We present a new, automated system based on a three-axis superconducting magnetometer and a custom-made coil designed to experiment on cylindrical specimens used in typical paleomagnetic investigations. The system, which resembles a sushi bar, facilitates stepwise alternating field demagnetization of up to 99 samples per loaded track. It also enables researchers to explore magnetic properties using an anhysteretic remanent magnetization (ARM) in any coercivity window up to peak alternating fields of 95 mT with direct current bias fields up to 0.17 mT. For example, partial ARM (pARM) spectra characterize magnetic grain size distributions in rocks, yet rarely are pARM spectra measured because the complete curve for one sample takes at least two hours to acquire manually. The SushiBar achieves 99 such curves in slightly less than 100 hours. Using the SushiBar, we measured the pARM sprectra, as well as the viscosity and anisotropy of ARM in three discrete switching field windows, of continental sediments from the Xishuigou section (western China). The average grain size remains constant along the 2200 m-thick section, yet magnetic viscosity varies systematically from bottom to top of the section; samples with high magnetic viscosities also have higher proportions of non-viscous material on average. Principal anisotropy axis directions from the lowest switching fields correlate well with principal axis directions from anisotropy of magnetic susceptibility. Principal axis directions defined at higher switching fields systematically deviate from those at lower switching fields, perhaps defining the fabric of the remanence carrying grains.

  18. Navigation accuracy analysis for the Halley flyby phase of a dual comet mission using ion drive

    NASA Technical Reports Server (NTRS)

    Wood, L. J.; Hast, S. L.

    1980-01-01

    A dual comet (Halley Flyby/Tempel 2 Rendezvous) mission, making use of the solar electric propulsion system, is under consideration for a 1985 launch. This paper presents navigation accuracy analysis results for the Halley flyby phase of this mission. Orbit determination and guidance accuracies are presented for the baseline navigation strategy, along with the results of a number of sensitivity studies involving parameters such as data frequencies, data accuracies, ion drive thrust vector errors, comet ephemeris uncertainties, time lags associated with data processing and command sequence generation, probe release time, and navigation coast arc duration.

  19. Nonaxisymmetric nozzle technology program - An overview. [for fighter aircraft engines

    NASA Technical Reports Server (NTRS)

    Berrier, B. L.; Palcza, J. L.; Richey, G. K.

    1977-01-01

    Nonaxisymmetric nozzles, with in-flight thrust vectoring and/or reversing capabilities, provide the potential for substantial gains in fighter aircraft performance, maneuvering, survivability and ground handling. This paper presents an overview of some of the current programs to develop nonaxisymmetric nozzle technology for future aircraft applications. The initial phase of this program, which consists of a series of subscale model tests, engine/nozzle studies, system integration studies and simulation studies, has been initiated. Successful completion of this program will allow designers of future aircraft to consider, with high confidence, the integration of nonaxisymmetric nozzle concepts to improve aircraft mission performance effectiveness, survivability and cost.

  20. Propulsion-induced interference effects on jet-lift VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Winston, M. M.; Weston, R. P.; Mineck, R. E.

    1975-01-01

    Recent investigations of propulsion-induced aerodynamics are reviewed. Experimental and analytical studies of the fundamental properties of lifting jet wakes and wind-tunnel investigations of VTOL configuration variables are discussed. The jet-wake flow studies will provide the data base for evaluating theoretical performance prediction methods; while the configuration studies will provide guidance for optimizing airframe/propulsion system integration. The influence of results to date on high-performance VTOL designs emphasizing minimum jet-induced losses and improved thrust vectoring in forward flight (VIFF) capability is illustrated.

  1. Piloting considerations for terminal area operations of civil tiltwing and tiltrotor aircraft

    NASA Technical Reports Server (NTRS)

    Hindson, William S.; Hardy, Gordon H.; Tucker, George E.; Decker, William A.

    1993-01-01

    The existing body of research to investigate airworthiness, performance, handling, and operational requirements for STOL and V/STOL aircraft was reviewed for its applicability to the tiltrotor and tiltwing design concepts. The objective of this study was to help determine the needs for developing civil certification criteria for these aircraft concepts. Piloting tasks that were considered included configuration and thrust vector management, glidepath control, deceleration to hover, and engine failure procedures. Flight control and cockpit display systems that have been found necessary to exploit the low-speed operating characteristics of these aircraft are described, and beneficial future developments are proposed.

  2. A multiple thruster array for 30-cm thrusters

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Mantenieks, M. A.

    1975-01-01

    The 3.0-m diameter chamber of the 7.6-m diameter by 21.4-m long vacuum tank at NASA LeRC was modified to permit testing of an array of up to six 30-cm thrusters with a variety of laboratory and thermal vacuum bread-board power systems. A primary objective of the Multiple Thruster Array (MTA) program is to assess the impact of multiple thruster operation on individual thruster and power processor requirements. The areas of thruster startup, steady-state operation, throttling, high voltage recycle, thrust vectoring, and shutdown are of special concern. The results of initial tests are reported.

  3. A Miniature Mars Ascent Vehicle

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.

    2000-01-01

    Launch of payloads from the surface of the Mars is a central element in any Sample Return program, and represents one of the most important objectives of NASA planetary science and Human Exploration and Development of Space (HEDS) programs. Analysis of these samples in the sophisticated laboratories of Earth will give vastly more scientific as well as HEDS-relevant engineering and space-medicine knowledge of those bodies than can be performed from any feasible near-term miniaturized instruments. What is proposed here is a launch system with no moving parts of any kind: no gyroscope, no accelerometers, no control surfaces, and no thrust vector control.

  4. Modular design attitude control system

    NASA Technical Reports Server (NTRS)

    Chichester, F. D.

    1982-01-01

    A hybrid multilevel linear quadratic regulator (ML-LQR) approach was developed and applied to the attitude control of models of the rotational dynamics of a prototype flexible spacecraft and of a typical space platform. Three axis rigid body flexible suspension models were developed for both the spacecraft and the space platform utilizing augmented body methods. Models of the spacecraft with hybrid ML-LQR attitude control and with LQR attitude control were simulated and their response with the two different types of control were compared.

  5. An Overview of the NASA F-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Pahle, Joseph W.; Wilson, R. Joseph; Flick, Bradley C.; Rood, Richard L.

    1996-01-01

    This paper gives an overview of the NASA F-18 High Alpha Research Vehicle. The three flight phases of the program are introduced, along with the specific goals and data examples taken during each phase. The aircraft configuration and systems needed to perform the disciplinary and inter-disciplinary research are discussed. The specific disciplines involved with the flight research are introduced, including aerodynamics, controls, propulsion, systems, and structures. Decisions that were made early in the planning of the aircraft project and the results of those decisions are briefly discussed. Each of the three flight phases corresponds to a particular aircraft configuration, and the research dictated the configuration to be flown. The first phase gathered data with the baseline F-18 configuration. The second phase was the thrust-vectoring phase. The third phase used a modified forebody with deployable nose strakes. Aircraft systems supporting these flights included extensive instrumentation systems, integrated research flight controls using flight control hardware and corresponding software, analog interface boxes to control forebody strakes, a thrust-vectoring system using external post-exit vanes around axisymmetric nozzles, a forebody vortex control system with strakes, and backup systems using battery-powered emergency systems and a spin recovery parachute.

  6. A simple 5-DoF MR-compatible motion signal measurement system.

    PubMed

    Chung, Soon-Cheol; Kim, Hyung-Sik; Yang, Jae-Woong; Lee, Su-Jeong; Choi, Mi-Hyun; Kim, Ji-Hye; Yeon, Hong-Won; Park, Jang-Yeon; Yi, Jeong-Han; Tack, Gye-Rae

    2011-09-01

    The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist. To minimize the interference between the MR imaging system and the motion measurement system, nonmagnetic materials were used for all electric circuit components in an MR shield room. To remove the effect of RF pulse, an amplifier, modulation circuit, and power supply were located in a shielded case, which was made of copper and aluminum. The motion signal was modulated to an optic signal using pulse width modulation, and the modulated optic signal was transmitted outside the MR shield room using a high-intensity light-emitting diode and an optic cable. The motion signal was recorded on a PC by demodulating the transmitted optic signal into an electric signal. Various kinematic variables, such as angle, acceleration, velocity, and jerk, can be measured or calculated by using the motion measurement system developed here. This system also enables motion tracking by extracting the position information from the motion signals. It was verified that MR images and motion signals could reliably be measured simultaneously. PMID:21487903

  7. Trial by Fire

    NASA Technical Reports Server (NTRS)

    Covault, Craig

    2005-01-01

    The NASa/ATK Thiokol space shuttle solid rocket motor program has doubled ground test firings and enhanced manufacturing quality and process control to increase safety for Discovery's return to flight. There are a number of places where we've strengthened our engineering and our processes, says Mike Kahn, ATK Thiokol vice president of space launch systems. Protecting the booster against corrosion in the humid Florida environment is one area that has been addressed. Since the loss of Columbia, ATK Thiokol and the Marshall Space Flight Center have completely reevaluated the shuttle solid rocket motor's design certification and found no major problems, Kahn said. The Thiokol solid motors did not play a role in the 2003 Columbia accident, but the motor's older field joint design (since replaced) was the primary cause of the 1986 Challenger accident that killed seven astronauts. The 129 X 12-ft. ATK Thiokol reusable solid rocket motor forms the core of the shuttle's two solid rocket boosters (SRBs). United Space Alliance (USA) has overall responsibility for the booster's nose-mounted systems such as recovery parachutes and aft-mounted thrust vector control systems that increase the length to 149 ft. USA and its subcontractors have also reaffirmed quality control on systems such as the booster's Hamilton Sundstrand hydraulic power units for critical thrust vector control. And to ensure greater safeguards against booster debris jeopardizing the orbiter, a bolt-catcher system to restrain the large bolts, severed at booster separation, was also redesigned.

  8. Assessment of Knee Cartilage Stress Distribution and Deformation Using Motion Capture System and Wearable Sensors for Force Ratio Detection

    PubMed Central

    Mijailovic, N.; Vulovic, R.; Milankovic, I.; Radakovic, R.; Filipovic, N.; Peulic, A.

    2015-01-01

    Knowledge about the knee cartilage deformation ratio as well as the knee cartilage stress distribution is of particular importance in clinical studies due to the fact that these represent some of the basic indicators of cartilage state and that they also provide information about joint cartilage wear so medical doctors can predict when it is necessary to perform surgery on a patient. In this research, we apply various kinds of sensors such as a system of infrared cameras and reflective markers, three-axis accelerometer, and force plate. The fluorescent marker and accelerometers are placed on the patient's hip, knee, and ankle, respectively. During a normal walk we are recording the space position of markers, acceleration, and ground reaction force by force plate. Measured data are included in the biomechanical model of the knee joint. Geometry for this model is defined from CT images. This model includes the impact of ground reaction forces, contact force between femur and tibia, patient body weight, ligaments, and muscle forces. The boundary conditions are created for the finite element method in order to noninvasively determine the cartilage stress distribution. PMID:26417382

  9. Accuracy Studies of a Magnetometer-Only Attitude-and-Rate-Determination System

    NASA Technical Reports Server (NTRS)

    Challa, M. (Editor); Wheeler, C. (Editor)

    1996-01-01

    A personal computer based system was recently prototyped that uses measurements from a three axis magnetometer (TAM) to estimate the attitude and rates of a spacecraft using no a priori knowledge of the spacecraft's state. Past studies using in-flight data from the Solar, Anomalous, and Magnetospheric Particles Explorer focused on the robustness of the system and demonstrated that attitude and rate estimates could be obtained accurately to 1.5 degrees (deg) and 0.01 deg per second (deg/sec), respectively, despite limitations in the data and in the accuracies of te truth models. This paper studies the accuracy of the Kalman filter in the system using several orbits of in-flight Earth Radiation Budget Satellite (ERBS) data and attitude and rate truth models obtained from high precision sensors to demonstrate the practical capabilities. This paper shows the following: Using telemetered TAM data, attitude accuracies of 0.2 to 0.4 deg and rate accuracies of 0.002 to 0.005 deg/sec (within ERBS attitude control requirements of 1 deg and 0.0005 deg/sec) can be obtained with minimal tuning of the filter; Replacing the TAM data in the telemetry with simulated TAM data yields corresponding accuracies of 0.1 to 0.2 deg and 0.002 to 0.005 deg/sec, thus demonstrating that the filter's accuracy can be significantly enhanced by further calibrating the TAM. Factors affecting the fillter's accuracy and techniques for tuning the system's Kalman filter are also presented.

  10. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    NASA Technical Reports Server (NTRS)

    Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

    2013-01-01

    CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode, the software aligns the precision navigation sensors and initializes the communications interfaces with the sensor and the remote computing system. It also monitors the navigation data state for quality and ensures that the system maintains the required fidelity for attitude and positional information. In the operational mode, the software runs at 12.5 Hz and gathers the required navigation/attitude data, computes the required sensor correction values, and then commands the sensor to the required roll correction. In this manner, the sensor will stay very near to vertical at all times, greatly improving the resulting collected data and imagery. CANS greatly improves quality of resulting imagery and data collected. In addition, the software component of the system outputs a concisely formatted, high-speed data stream that can be used for further science data processing. This precision, time-stamped data also can benefit other instruments on the same aircraft platform by providing extra information from the mission flight.

  11. Cape Canaveral Air Force Station, Launch Complex 39, Solid Rocket ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cape Canaveral Air Force Station, Launch Complex 39, Solid Rocket Booster Disassembly & Refurbishment Complex, Thrust Vector Control Deservicing Facility, Hangar Road, Cape Canaveral, Brevard County, FL

  12. Maintaining Aura's Orbit Requirements Under New Maneuver Operations

    NASA Technical Reports Server (NTRS)

    Johnson, Megan; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Auras Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Auras frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under no-slew operations

  13. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    NASA Technical Reports Server (NTRS)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  14. Real-time visual sensing system achieving high-speed 3D particle tracking with nanometer resolution.

    PubMed

    Cheng, Peng; Jhiang, Sissy M; Menq, Chia-Hsiang

    2013-11-01

    This paper presents a real-time visual sensing system, which is created to achieve high-speed three-dimensional (3D) motion tracking of microscopic spherical particles in aqueous solutions with nanometer resolution. The system comprises a complementary metal-oxide-semiconductor (CMOS) camera, a field programmable gate array (FPGA), and real-time image processing programs. The CMOS camera has high photosensitivity and superior SNR. It acquires images of 128120 pixels at a frame rate of up to 10,000 frames per second (fps) under the white light illumination from a standard 100 W halogen lamp. The real-time image stream is downloaded from the camera directly to the FPGA, wherein a 3D particle-tracking algorithm is implemented to calculate the 3D positions of the target particle in real time. Two important objectives, i.e., real-time estimation of the 3D position matches the maximum frame rate of the camera and the timing of the output data stream of the system is precisely controlled, are achieved. Two sets of experiments were conducted to demonstrate the performance of the system. First, the visual sensing system was used to track the motion of a 2 ?m polystyrene bead, whose motion was controlled by a three-axis piezo motion stage. The ability to track long-range motion with nanometer resolution in all three axes is demonstrated. Second, it was used to measure the Brownian motion of the 2 ?m polystyrene bead, which was stabilized in aqueous solution by a laser trapping system. PMID:24216655

  15. A new stand-alone QEXAFS data acquisition system for in situ studies.

    PubMed

    Sttzel, Jan; Ltzenkirchen-Hecht, Dirk; Frahm, Ronald

    2011-03-01

    To meet the demands of the QEXAFS (quick-scanning extended X-ray absorption fine structure) technique for a fast, user-friendly and flexible data acquisition a new stand-alone system with new software exploiting a multi-functional USB board was designed. The chosen approach allows the scanning of several analogue and digital data sources with up to 500000 samples each second over hours storable in binary or ASCII format without any dead-time. At the same time it is possible to visualize the acquired data instantaneously which provides a maximum of interactivity during the running experiment and also optimal conditions to select the best suited beamline and detector settings prior to each measurement. Furthermore, the QEXAFS monochromator and typically three current amplifiers are entirely controlled by the new software so that all monochromator settings can be synchronized with the data acquisition enabling programmed scans with alternating parameter sets. This versatile concept also enables the user to react immediately to changes in the sample during in situ studies. An interface to a three-axis stepper motor control unit is additionally included to control a sample stage which can again be synchronized with the data acquisition. Thus, spatially resolved scans and the usage of scan tools for sample alignment are feasible with the new system. Typical examples to demonstrate the features of the new data acquisition system are presented, the designed graphical user interface is described in detail and, furthermore, the crucial design parameters of a typical QEXAFS set-up are discussed. PMID:21335902

  16. A Vehicle Management End-to-End Testing and Analysis Platform for Validation of Mission and Fault Management Algorithms to Reduce Risk for NASAs Space Launch System

    NASA Technical Reports Server (NTRS)

    Trevino, Luis; Johnson, Stephen B.; Patterson, Jonathan; Teare, David

    2015-01-01

    The engineering development of the National Aeronautics and Space Administration's (NASA) new Space Launch System (SLS) requires cross discipline teams with extensive knowledge of launch vehicle subsystems, information theory, and autonomous algorithms dealing with all operations from pre-launch through on orbit operations. The nominal and off-nominal characteristics of SLS's elements and subsystems must be understood and matched with the autonomous algorithm monitoring and mitigation capabilities for accurate control and response to abnormal conditions throughout all vehicle mission flight phases, including precipitating safing actions and crew aborts. This presents a large and complex systems engineering challenge, which is being addressed in part by focusing on the specific subsystems involved in the handling of off-nominal mission and fault tolerance with response management. Using traditional model-based system and software engineering design principles from the Unified Modeling Language (UML) and Systems Modeling Language (SysML), the Mission and Fault Management (M&FM) algorithms for the vehicle are crafted and vetted in Integrated Development Teams (IDTs) composed of multiple development disciplines such as Systems Engineering (SE), Flight Software (FSW), Safety and Mission Assurance (S&MA) and the major subsystems and vehicle elements such as Main Propulsion Systems (MPS), boosters, avionics, Guidance, Navigation, and Control (GNC), Thrust Vector Control (TVC), and liquid engines. These model-based algorithms and their development lifecycle from inception through FSW certification are an important focus of SLS's development effort to further ensure reliable detection and response to off-nominal vehicle states during all phases of vehicle operation from pre-launch through end of flight. To test and validate these M&FM algorithms a dedicated test-bed was developed for full Vehicle Management End-to-End Testing (VMET). For addressing fault management (FM) early in the development lifecycle for the SLS program, NASA formed the M&FM team as part of the Integrated Systems Health Management and Automation Branch under the Spacecraft Vehicle Systems Department at the Marshall Space Flight Center (MSFC). To support the development of the FM algorithms, the VMET developed by the M&FM team provides the ability to integrate the algorithms, perform test cases, and integrate vendor-supplied physics-based launch vehicle (LV) subsystem models. Additionally, the team has developed processes for implementing and validating the M&FM algorithms for concept validation and risk reduction. The flexibility of the VMET capabilities enables thorough testing of the M&FM algorithms by providing configurable suites of both nominal and off-nominal test cases to validate the developed algorithms utilizing actual subsystem models such as MPS, GNC, and others. One of the principal functions of VMET is to validate the M&FM algorithms and substantiate them with performance baselines for each of the target vehicle subsystems in an independent platform exterior to the flight software test and validation processes. In any software development process there is inherent risk in the interpretation and implementation of concepts from requirements and test cases into flight software compounded with potential human errors throughout the development and regression testing lifecycle. Risk reduction is addressed by the M&FM group but in particular by the Analysis Team working with other organizations such as S&MA, Structures and Environments, GNC, Orion, Crew Office, Flight Operations, and Ground Operations by assessing performance of the M&FM algorithms in terms of their ability to reduce Loss of Mission (LOM) and Loss of Crew (LOC) probabilities. In addition, through state machine and diagnostic modeling, analysis efforts investigate a broader suite of failure effects and associated detection and responses to be tested in VMET to ensure reliable failure detection, and confirm responses do not create additional risks or cause undesired states through interactive dynamic effects with other algorithms and systems. VMET further contributes to risk reduction by prototyping and exercising the M&FM algorithms early in their implementation and without any inherent hindrances such as meeting FSW processor scheduling constraints due to their target platform - the ARINC 6535-partitioned Operating System, resource limitations, and other factors related to integration with other subsystems not directly involved with M&FM such as telemetry packing and processing. The baseline plan for use of VMET encompasses testing the original M&FM algorithms coded in the same C++ language and state machine architectural concepts as that used by FSW. This enables the development of performance standards and test cases to characterize the M&FM algorithms and sets a benchmark from which to measure their effectiveness and performance in the exterior FSW development and test processes. This paper is outlined in a systematic fashion analogous to a lifecycle process flow for engineering development of algorithms into software and testing. Section I describes the NASA SLS M&FM context, presenting the current infrastructure, leading principles, methods, and participants. Section II defines the testing philosophy of the M&FM algorithms as related to VMET followed by section III, which presents the modeling methods of the algorithms to be tested and validated in VMET. Its details are then further presented in section IV followed by Section V presenting integration, test status, and state analysis. Finally, section VI addresses the summary and forward directions followed by the appendices presenting relevant information on terminology and documentation.

  17. Magnetic and electric field testing of the Amtrak Northeast Corridor and New Jersey transit/North Jersey coast line rail systems. Volume 2. Appendices. Final report, May 1993-March 1993

    SciTech Connect

    Dietrich, F.M.; Robertson, D.C.; Steiner, G.A.

    1993-04-01

    The safety of magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is the responsibility of the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) produced by both steady (dc) and alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and above, in the Extreme Low Frequency (ELF) range (3-3000 Hz), is of interest with respect to any potential health effects these fields may have on the public and on transportation workers. An EMF survey of National Rail Passengers Corporation trains operating on the Northeast Corridor (NEC) was performed, as part of a comprehensive comparative safety assessment of the German Transrapid (TR-07) maglev system and of existing (NEC and transit trains) and advanced rail systems (the French TGV). The report is Volume 2 of two volumes. A portable magnetic field monitoring system (augmented to include an electric fields probe) was used to sample, record and store three-axis static and ac magnetic fields waveforms simultaneously, at multiple locations. A real time Digital Audio Tape (DAT) recorder able to capture EMF transients, and two personal power-frequency magnetic field monitors were used to collect complementary data.

  18. Magnetic and electric field testing of the Amtrak Northeast Corridor and New Jersey Transit/North Jersey coast line rail systems. Volume 1. Analysis. Final report, May 1992-March 1992

    SciTech Connect

    Dietrich, F.M.; Feero, W.E.; Papas, P.N.; Steiner, G.A.

    1993-04-01

    The safety of magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is the responsibility of the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) produced by both steady (dc) and alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and above, in the Extreme Low Frequency (ELF) range (3-3000 Hz), is of interest with respect to any potential health effects these fields may have on the public and on transportation workers. An EMF survey of National Rail Passengers Corporation trains operating on the Northeast Corridor (NEC) was performed, as part of a comprehensive comparative safety assessment of the German Transrapid (TR-07) maglev system, and of existing (NEC and transit trains) and advanced rail systems (the French TGV). The report is Volume 1 of two volumes. A portable magnetic field monitoring system (augmented to include an electric fields probe) was used to sample, record and store three-axis static and ac magnetic fields waveforms simultaneously, at multiple locations. A real time Digital Audio Tape (DAT) recorder able to capture EMF transients, and two personal power-frequency magnetic field monitors were used to collect complementary data.

  19. A Vehicle Management End-to-End Testing and Analysis Platform for Validation of Mission and Fault Management Algorithms to Reduce Risk for NASA's Space Launch System

    NASA Technical Reports Server (NTRS)

    Trevino, Luis; Patterson, Jonathan; Teare, David; Johnson, Stephen

    2015-01-01

    The engineering development of the new Space Launch System (SLS) launch vehicle requires cross discipline teams with extensive knowledge of launch vehicle subsystems, information theory, and autonomous algorithms dealing with all operations from pre-launch through on orbit operations. The characteristics of these spacecraft systems must be matched with the autonomous algorithm monitoring and mitigation capabilities for accurate control and response to abnormal conditions throughout all vehicle mission flight phases, including precipitating safing actions and crew aborts. This presents a large and complex system engineering challenge, which is being addressed in part by focusing on the specific subsystems involved in the handling of off-nominal mission and fault tolerance with response management. Using traditional model based system and software engineering design principles from the Unified Modeling Language (UML) and Systems Modeling Language (SysML), the Mission and Fault Management (M&FM) algorithms for the vehicle are crafted and vetted in specialized Integrated Development Teams (IDTs) composed of multiple development disciplines such as Systems Engineering (SE), Flight Software (FSW), Safety and Mission Assurance (S&MA) and the major subsystems and vehicle elements such as Main Propulsion Systems (MPS), boosters, avionics, Guidance, Navigation, and Control (GNC), Thrust Vector Control (TVC), and liquid engines. These model based algorithms and their development lifecycle from inception through Flight Software certification are an important focus of this development effort to further insure reliable detection and response to off-nominal vehicle states during all phases of vehicle operation from pre-launch through end of flight. NASA formed a dedicated M&FM team for addressing fault management early in the development lifecycle for the SLS initiative. As part of the development of the M&FM capabilities, this team has developed a dedicated testbed that integrates specific M&FM algorithms, specialized nominal and off-nominal test cases, and vendor-supplied physics-based launch vehicle subsystem models. Additionally, the team has developed processes for implementing and validating these algorithms for concept validation and risk reduction for the SLS program. The flexibility of the Vehicle Management End-to-end Testbed (VMET) enables thorough testing of the M&FM algorithms by providing configurable suites of both nominal and off-nominal test cases to validate the developed algorithms utilizing actual subsystem models such as MPS. The intent of VMET is to validate the M&FM algorithms and substantiate them with performance baselines for each of the target vehicle subsystems in an independent platform exterior to the flight software development infrastructure and its related testing entities. In any software development process there is inherent risk in the interpretation and implementation of concepts into software through requirements and test cases into flight software compounded with potential human errors throughout the development lifecycle. Risk reduction is addressed by the M&FM analysis group working with other organizations such as S&MA, Structures and Environments, GNC, Orion, the Crew Office, Flight Operations, and Ground Operations by assessing performance of the M&FM algorithms in terms of their ability to reduce Loss of Mission and Loss of Crew probabilities. In addition, through state machine and diagnostic modeling, analysis efforts investigate a broader suite of failure effects and associated detection and responses that can be tested in VMET to ensure that failures can be detected, and confirm that responses do not create additional risks or cause undesired states through interactive dynamic effects with other algorithms and systems. VMET further contributes to risk reduction by prototyping and exercising the M&FM algorithms early in their implementation and without any inherent hindrances such as meeting FSW processor scheduling constraints due to their target platform - ARINC 653 partitioned OS, resource limitations, and other factors related to integration with other subsystems not directly involved with M&FM such as telemetry packing and processing. The baseline plan for use of VMET encompasses testing the original M&FM algorithms coded in the same C++ language and state machine architectural concepts as that used by Flight Software. This enables the development of performance standards and test cases to characterize the M&FM algorithms and sets a benchmark from which to measure the effectiveness of M&FM algorithms performance in the FSW development and test processes.

  20. Acoustic containerless experiment system: A non-contact surface tension measurement

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Wang, T. G.; Barmatz, M.

    1988-01-01

    The Acoustic Containerless Experiment System (ACES) was flown on STS 41-B in February 1984 and was scheduled to be reflown in 1986. The primary experiment that was to be conducted with the ACES module was the containerless melting and processing of a fluoride glass sample. A second experiment that was to be conducted was the verification of a non-contact surface tension measurement technique using the molten glass sample. The ACES module consisted of a three-axis acoustic positioning module that was inside an electric furnace capable of heating the system above the melting temperature of the sample. The acoustic module is able to hold the sample with acoustic forces in the center of the chamber and, in addition, has the capability of applying a modulating force on the sample along one axis of the chamber so that the molten sample or liquid drop could be driven into one of its normal oscillation modes. The acoustic module could also be adjusted so that it could place a torque on the molten drop and cause the drop to rotate. In the ACES, a modulating frequency was applied to the drop and swept through a range of frequencies that would include the n = 2 mode. A maximum amplitude of the drop oscillation would indicate when resonance was reached and from that data the surface tension could be calculated. For large viscosity samples, a second technique for measuring surface tension was developed. The results of the ACES experiment and some of the problems encountered during the actual flight of the experiment will be discussed.

  1. Warm gas TVC design study

    NASA Technical Reports Server (NTRS)

    Moorhead, S. B., Jr.

    1973-01-01

    A warm gas thrust vector control system was studied to optimize the injection geometry for a specific engine configuration, and an injection valve was designed capable of meeting the base line requirements. To optimize injection geometry, studies were made to determine the performance effects of varying injection location, angle, port size, and port configuration. Having minimized the injection flow rate required, a warm gas valve was designed to handle the required flow. A direct drive hydraulic servovalve capable of operating with highly contaminated hydraulic fluid was designed. The valve is sized to flow 15 gpm at 3000 psia and the direct drive feature is capable of applying a spool force of 200 pounds. The baseline requirements are the development of 6 deg of thrust vector control utilizing 2000 F (total temperature) gas for 180 seconds on a 1.37 million pound thrust engine burning LOX and RP-1 at a chamber pressure of 250 psia with a 155 inch long conical nozzle having a 68 inch diameter throat and a 153 inch diameter exit.

  2. Experiments on Ion Beam Deflection Using Ion Optics with Slit Apertures

    NASA Astrophysics Data System (ADS)

    Okawa, Yasushi; Hayakawa, Yukio; Kitamura, Shoji

    2004-03-01

    An experimental investigation on ion beam deflection by grid translation was performed. The ion beam deflection in ion optics is a desired technology for ion thrusters because thrust vector control utilizing this technique can eliminate the need for conventional gimbaling devices and thus reduce propulsion system mass. A grid translation mechanism consisting of a piezoelectric motor, a ceramic lever, and carbon-based grids with slit apertures was fabricated and high repeatability in beam deflection characteristics was obtained using this mechanism. Results showed that the beam deflection angle was proportional to the grid translation distance and independent of slit width and grid voltage. A numerical simulation successfully reproduced the beam deflection characteristics in a qualitative and quantitative sense. A maximum beam deflection angle of approximately plus or minus 6 degrees, which was comparable to that of the ordinary gimbaling devices used in space, was obtained without a severe drain current. Therefore, the beam deflection by grid translation is promising as a thrust vectoring method in ion thrusters.

  3. Development of a two-dimensional dual pendulum thrust stand for Hall thrusters

    SciTech Connect

    Nagao, N.; Yokota, S.; Komurasaki, K.; Arakawa, Y.

    2007-11-15

    A two-dimensional dual pendulum thrust stand was developed to measure thrust vectors (axial and horizontal (transverse) direction thrusts) of a Hall thruster. A thruster with a steering mechanism is mounted on the inner pendulum, and thrust is measured from the displacement between inner and outer pendulums, by which a thermal drift effect is canceled out. Two crossover knife-edges support each pendulum arm: one is set on the other at a right angle. They enable the pendulums to swing in two directions. Thrust calibration using a pulley and weight system showed that the measurement errors were less than 0.25 mN (1.4%) in the main thrust direction and 0.09 mN (1.4%) in its transverse direction. The thrust angle of the thrust vector was measured with the stand using the thruster. Consequently, a vector deviation from the main thrust direction of {+-}2.3 deg. was measured with the error of {+-}0.2 deg. under the typical operating conditions for the thruster.

  4. Bias Momentum Sizing for Hovering Dual-Spin Platforms

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Shin, Jong-Yeob; Moerder, Daniel D.

    2006-01-01

    An atmospheric flight vehicle in hover is typically controlled by varying its thrust vector. Achieving both levitation and attitude control with the propulsion system places considerable demands on it for agility and precision, particularly if the vehicle is statically unstable, or nearly so. These demands can be relaxed by introducing an appropriately sized angular momentum bias aligned with the vehicle's yaw axis, thus providing an additional margin of attitude stability about the roll and pitch axes. This paper describes a methodical approach for trading off angular momentum bias level needed with desired levels of vehicle response due to the design disturbance environment given a vehicle's physical parameters. It also describes several simplifications that provide a more physical and intuitive understanding of dual-spin dynamics for hovering atmospheric vehicles. This approach also mitigates the need for control torques and inadvertent actuator saturation difficulties in trying to stabilize a vehicle via control torques produced by unsteady aerodynamics, thrust vectoring, and unsteady throttling. Simulation results, based on a subscale laboratory test flying platform, demonstrate significant improvements in the attitude control robustness of the vehicle with respect to both wind disturbances and off-center of gravity payload changes during flight.

  5. Wind tunnel and ground static investigation of a large scale model of a lift/cruise fan V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An investigation was conducted in a 40 foot by 80 foot wind tunnel to determine the aerodynamic/propulsion characteristics of a large scale powered model of a lift/cruise fan V/STOL aircraft. The model was equipped with three 36 inch diameter turbotip X376B fans powered by three T58 gas generators. The lift fan was located forward of the cockpit area and the two lift/cruise fans were located on top of the wing adjacent to the fuselage. The three fans with associated thrust vectoring systems were used to provide vertical, and short, takeoff and landing capability. For conventional cruise mode operation, only the lift/cruise fans were utilized. The data that were obtained include lift, drag, longitudinal and lateral-directional stability characteristics, and control effectiveness. Data were obtained up to speeds of 120 knots at one model height of 20 feet for the conventional aerodynamic lift configuration and at several thrust vector angles for the powered lift configuration.

  6. Estimating Thruster Impulses From IMU and Doppler Data

    NASA Technical Reports Server (NTRS)

    Lisano, Michael E.; Kruizinga, Gerhard L.

    2009-01-01

    A computer program implements a thrust impulse measurement (TIM) filter, which processes data on changes in velocity and attitude of a spacecraft to estimate the small impulsive forces and torques exerted by the thrusters of the spacecraft reaction control system (RCS). The velocity-change data are obtained from line-of-sight-velocity data from Doppler measurements made from the Earth. The attitude-change data are the telemetered from an inertial measurement unit (IMU) aboard the spacecraft. The TIM filter estimates the threeaxis thrust vector for each RCS thruster, thereby enabling reduction of cumulative navigation error attributable to inaccurate prediction of thrust vectors. The filter has been augmented with a simple mathematical model to compensate for large temperature fluctuations in the spacecraft thruster catalyst bed in order to estimate thrust more accurately at deadbanding cold-firing levels. Also, rigorous consider-covariance estimation is applied in the TIM to account for the expected uncertainty in the moment of inertia and the location of the center of gravity of the spacecraft. The TIM filter was built with, and depends upon, a sigma-point consider-filter algorithm implemented in a Python-language computer program.

  7. Propulsion Flight Research at NASA Dryden From 1967 to 1997

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Ray, Ronald J.; Conners, Timothy R.; Walsh, Kevin R.

    1997-01-01

    From 1967 to 1997, pioneering propulsion flight research activities have been conceived and conducted at the NASA Dryden Flight Research Center. Many of these programs have been flown jointly with the United States Department of Defense, industry, or the Federal Aviation Administration. Propulsion research has been conducted on the XB-70, F-111 A, F-111E, YF-12, JetStar, B-720, MD-11, F-15, F- 104, Highly Maneuverable Aircraft Technology, F-14, F/A-18, SR-71, and the hypersonic X-15 airplanes. Research studies have included inlet dynamics and control, in-flight thrust computation, integrated propulsion controls, inlet and boattail drag, wind tunnel-to-flight comparisons, digital engine controls, advanced engine control optimization algorithms, acoustics, antimisting kerosene, in-flight lift and drag, throttle response criteria, and thrust-vectoring vanes. A computer-controlled thrust system has been developed to land the F-15 and MD-11 airplanes without using any of the normal flight controls. An F-15 airplane has flown tests of axisymmetric thrust-vectoring nozzles. A linear aerospike rocket experiment has been developed and tested on the SR-71 airplane. This paper discusses some of the more unique flight programs, the results, lessons learned, and their impact on current technology.

  8. Optical system for the calibration and verification of correct axis positioning in medium-big sized milling boring machines

    NASA Astrophysics Data System (ADS)

    Mocellin, M.; Fedel, M.; Cocola, L.; Casarin, R.; Poletto, L.

    2015-05-01

    An optical system for the automatic recalibration of large machine tools during the machining process has been developed. The system provides an error signal during operation in order to compensate for structural deformations of axis and sliding parts. Those signals are used to reach a global positioning error below 50 microns on 3-axis translation stages, having range of several meters. One collimated diode laser beam has been mounted to the machining table reference system. Three resistive-type 2D-position-sensing devices are used to locate the beam on each axis. Before the first two sensors in the optical path, the beam is split by a wedge pentaprism in two secondary beams. The first one propagates linearly along the sensor for the displacement measurement. The second one is deflected with a fixed 90 angle and defines the sampling direction of the next axis. By duplicating the system using a second pentaprism on the latter deflected beam, three axis are monitored. In order to avoid any active electronic devises on the milling head, a passive corner cube is placed on the side of the head. Laser beam is then back reflected on a final position-sensitive sensor mounted in proximity of the second pentaprism. Additional channels consisting in laser beams back-reflected by mirrors on similar position sensing devices were used to acquire angular measurements as well. The tests performed on the prototype demonstrate the capability of mapping the actual deviations from the ideal linear translation with an error of 25 um along the full axis travel.

  9. Waterhammer Testing and Modeling of the Ares I Upper Stage Reaction Control System

    NASA Technical Reports Server (NTRS)

    Williams, J. Hunter; Holt, Kimberly A.

    2010-01-01

    NASA's Ares I rocket is the agency's first step in completing the goals of the Constellation Program, which plans to deliver a new generation of space explorers into low earth orbit for future missions to the International Space Station, the moon, and other destinations within the solar system. Ares I is a two-stage rocket topped by the Orion crew capsule and its service module. The launch vehicle's First Stage is a single, five-segment reusable solid rocket booster (RSRB), derived from the Space Shuttle Program's four segment RSRB. The vehicle's Upper Stage, being designed at Marshall Space Flight Center (MSFC), is propelled by a single J-2X Main Engine fueled with liquid oxygen and liquid hydrogen. During active Upper Stage flight of the Ares I launch vehicle, the Upper Stage Reaction Control System (US ReCS) will perform attitude control operations for the vehicle. The US ReCS will provide three-axis attitude control capability (roll, pitch, and yaw) for the Upper Stage while the J-2X is not firing and roll control capability while the engine is firing. Because of the requirements imposed upon the system, the design must accommodate rapid pulsing of multiple thrusters simultaneously to maintain attitude control. In support of these design activities and in preparation for Critical Design Review, analytical models of the US ReCS propellant feed system have been developed using the Thermal Hydraulic Library of MSC.EASY5 v.2008, herein referred to as EASY5. EASY5 is a commercially available fluid system modeling package with significant history of modeling space propulsion systems. In Fall 2009, a series of development tests were conducted at MSFC on a cold-flow test article for the US ReCS, herein referred to as System Development Test Article (SDTA). A subset of those tests performed were aimed at examining the effects of waterhammer on a flight-representative system and to ensure that those effects could be quantified with analytical models and incorporated into the design of the flight system. This paper presents an overview of the test article and the test approach, along with a discussion of the analytical modeling methodology. In addition, the results of that subset of development tests, along with analytical model pre-test predictions and post-test model correlations, will also be discussed in detail.

  10. Design Challenges of Power Systems for Instrumented Spacecraft with Very Low Perigees in the Earth's Ionosphere

    NASA Technical Reports Server (NTRS)

    Moran, Vickie Eakin; Manzer, Dominic D.; Pfaff, Robert E.; Grebowsky, Joseph M.; Gervin, Jan C.

    1999-01-01

    Designing a solar array to power a spacecraft bus supporting a set of instruments making in situ plasma and neutral atmosphere measurements in the ionosphere at altitudes of 120km or lower poses several challenges. The driving scientific requirements are the field-of-view constraints of the instruments resulting in a three-axis stabilized spacecraft, the need for an electromagnetically unperturbed environment accomplished by designing an electrostatically conducting solar array surface to avoid large potentials, making the spacecraft body as small and as symmetric as possible, and body-mounting the solar array. Furthermore, the life and thermal constraints, in the midst of the effects of the dense atmosphere at low altitude, drive the cross-sectional area of the spacecraft to be small particularly normal to the ram direction. Widely varying sun angles and eclipse durations add further complications, as does the growing desire for multiple spacecraft to resolve spatial and temporal variations packaged into a single launch vehicle. Novel approaches to insure adequate orbit-averaged power levels of approximately 250W include an oval-shaped cross section to increase the solar array collecting area during noon-midnight orbits and the use of a flywheel energy storage system. The flywheel could also be used to help maintain the spacecraft's attitude, particularly during excursions to the lowest perigee altitudes. This paper discusses the approaches used in conceptual power designs for both the proposed Dipper and the Global Electrodynamics Connections (GEC) Mission currently being studied at the NASA/Goddard Space Flight Center.

  11. Clustered engine study

    NASA Technical Reports Server (NTRS)

    Shepard, Kyle; Sager, Paul; Kusunoki, Sid; Porter, John; Campion, AL; Mouritzan, Gunnar; Glunt, George; Vegter, George; Koontz, Rob

    1993-01-01

    Several topics are presented in viewgraph form which together encompass the preliminary assessment of nuclear thermal rocket engine clustering. The study objectives, schedule, flow, and groundrules are covered. This is followed by the NASA groundrules mission and our interpretation of the associated operational scenario. The NASA reference vehicle is illustrated, then the four propulsion system options are examined. Each propulsion system's preliminary design, fluid systems, operating characteristics, thrust structure, dimensions, and mass properties are detailed as well as the associated key propulsion system/vehicle interfaces. A brief series of systems analysis is also covered including: thrust vector control requirements, engine out possibilities, propulsion system failure modes, surviving system requirements, and technology requirements. An assessment of vehicle/propulsion system impacts due to the lessons learned are presented.

  12. Autonomous Operation of the Nanosatellite URSA MAIOR Micropropulsion System

    NASA Astrophysics Data System (ADS)

    Santoni, F.

    Università degli Studi di Roma "La Sapienza", Scuola di Ingegneria Aerospaziale, Via Eudossiana 16, 00184 At Università di Roma "La Sapienza" a nanosatellite bus is under development, with one liter target volume and one kilogram target weight. This nanosatellite, called URSA MAIOR (Università di Roma "la SApienza" Micro Autonomous Imager in ORbit) has a micro camera on board to take pictures of the Earth. The nanosatellite is three axis stabilized, using a micro momentum wheel, with magnetic coils for active nutation damping and pointing control. An experimental micropropulsion system is present on-board, together with the magnetic attitude control system. The design, construction and testing of the satellite is carried on by academic personnel and by students, which are directly involved in the whole process, as it is in the spirit of in the microsatellite program at Università di Roma "La Sapienza". Few technological payloads are present on-board: an Earth imaging experiment, using a few grams commercial-off-the-shelf microcamera; commercial Li-Ion batteries are the only energy storage device; a microwheel developed at our University laboratories provides for attitude stabilization. In addition, a micropropulsion experiment is planned on-board. The Austrian Company Mechatronic, and INFM, an Italian Research Institute at Trieste are developing a microthruster for nanosatelite applications. In the frame of a cooperation established between these two Institutions and Università di Roma "La Sapienza", this newly developed hardware will be tested in orbit. The thruster is made basically of an integrated microvalve, built on a silicon chip, and a micronozzle, etched on the same silicon chip, to get supersonic expansion of the gas flow. The nominal thrust of the system is about 100microN. The throat section is about 100 micron diameter. The first phase in the construction of the microthruster has been the construction of the micronozzle on a silicon chip. A micropropulsion system realized with this micronozzle and with commercial valves, not integrated on a silicon chip, will be tested on board the microsatelite UNISAT-2, to be launched within 2002. A step further with respect to the system configuration to be flown on UNISAT-2 is the miniaturized microvalve, allowing to reduce the system volume and weight. As a matter of fact, the complete micropropulsion system fits in the one liter nanosatellite URSA MAIOR attitude control needs. The microvalve and nozzle occupy few squared millimiters of the external satellite surface, while the gas tank is about one tenth of the nanosatellite volume. One of the goals of the experiment is testing the micropropulsion hardware in space and assessing the microthruster performance in orbit. Another part of the experiment is devoted to the use of the micropropulsion system for autonomous spacecraft attitude maneuvers. One of these is the momentum wheel desaturation. When using the magnetic desaturation, some commands are sent to the satellite in order to perform the maneuver in the most efficient part of the orbit, depending on the magnetic field direction. When the micropropulsion system is active, the maneuver is performed autonomously, without any intervention from the ground. The on-board system monitors the maneuver evolution and stops when the maneuver is complete, sending a message to the ground station. To evaluate the autonomous system performance, attitude telemetry is stored during the maneuver and downloaded to the ground station. In the paper the nanosatellite URSA MAIOR is briefly described. The micropropulsion system is shown in detail and the ground test results discussed. The attitude control hardware is described and the numerical simulation results of the micropropulsion maneuvers described. Particular attention is given to the telemetry analysis performed autonomously on-board to make decision about the maneuver success.

  13. F-18 HARV in flight refueling with KC-135 tanker

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A thrust vectoring system can be seen mounted on the aft end of this NASA F-18 research aircraft at the Dryden Flight Research Center, Edwards, California, during an inflight refueling stop with a KC-135A (Serial #55-3135) tanker. The system was used to enhance its maneuverability and control at high angles of attack (high alpha) when conventional aerodynamic controls - ailerons, rudders, and elevators - are ineffective. The system features three spoon-shaped paddles mounted around the exhaust nozzles of each engine. The system, linked to the aircraft's flight control system, moves the paddles into the exhaust flow to redirect thrust for directional control and increased maneuverability at angles of attack near 70 degrees. First research flights with the system operating began during the spring of 1991. Data from the F-18 High Alpha Research Vehicle (HARV) program produced information to validate computer codes and wind tunnel results and led to design methods providing better performance in future aircraft.

  14. Kinematics of Hooke universal joint robot wrists

    NASA Technical Reports Server (NTRS)

    Mckinney, William S., Jr.

    1988-01-01

    The singularity problem associated with wrist mechanisms commonly found on industrial manipulators can be alleviated by redesigning the wrist so that it functions as a three-axis gimbal system. This paper discussess the kinematics of gimbal robot wrists made of one and two Hooke universal joints. Derivations of the resolved rate motion control equations for the single and double Hooke universal joint wrists are presented using the three-axis gimbal system as a theoretical wrist model.

  15. Accommodating electric propulsion on SMART-1

    NASA Astrophysics Data System (ADS)

    Kugelberg, Joakim; Bodin, Per; Persson, Staffan; Rathsman, Peter

    2004-07-01

    This paper focuses on the technical challenges that arise when electric propulsion is used on a small spacecraft such as SMART-1. The choice of electric propulsion influences not only the attitude control system and the power system, but also the thermal control as well as the spacecraft structure. A description is given on how the design of the attitude control system uses the possibility to control the alignment of the thrust vector in order to reduce the momentum build-up. An outline is made of the philosophy of power generation and distribution and shows how the thermal interfaces to highly dissipating units have been solved. Areas unique for electric propulsion are the added value of a thrust vector orientation mechanism and the special consideration given to the electromagnetic compatibility. SMART-1 is equipped with a thruster gimbal mechanism providing a 10 cone in which the thrust vector can be pointed. Concerning the electromagnetic compatibility, a discussion on how to evaluate the available test results is given keeping in mind that one of the main objectives of the SMART-1 mission is to assess the impact of electric propulsion on the scientific instruments and on other spacecraft systems. Finally, the assembly, integration and test of the spacecraft is described. Compared to traditional propulsion systems, electric propulsion puts different requirements on the integration sequence and limits the possibilities to verify the correct function of the thruster since it needs high quality vacuum in order to operate. Prime contractor for SMART-1 is the Swedish Space Corporation (SSC). The electric propulsion subsystem is procured directly by ESA from SNECMA, France and is delivered to SSC as a customer furnished item. The conclusion of this paper is that electric propulsion is possible on a small spacecraft, which opens up possibilities for a new range of missions for which a large velocity increment is needed. The paper will also present SMART-1 and show how the problems related to the accommodation of electric propulsion have been solved during design and planning of the project.

  16. Development of the command data system and ground software for the SEDSAT-1 microsatellite

    NASA Technical Reports Server (NTRS)

    Wells, B. Earl

    1996-01-01

    SEDSAT-1 is designed to be a low cost scientific satellite which is to be used to perform a minimum of five tasks which include: (1) the acquisition of a number of important parameters associated with the tethering processes from the payloads perspective (such as accelerations incurred and imaging data of the tether during deployment), (2) to act as a remote sensing platform for making measurements of the Earth's Atmosphere (allowing research to be performed in such areas as vertical lightning observation, visible light spectrography, and cloud cover studies, (3) to act as a general purpose amateur radio communication satellite relaying information back to earth, (4) to demonstrate the feasibility of the deployment in low earth orbit of advanced technology such as the Gallium Arsenide Solar Cells, Nickel Metal Hydride batteries, and multi-chip module technology and, (5) to support student's active participation in applying the disciplines of engineering and science to space-based hardware platforms. The project includes the Three-axis Accelerometer System, TAS, Experiment which is designed to report the accelerations that the satellite undergoes during the tethering operations and during the second phase of the mission when the free floating satellite comes in contact with orbit debris. The SEASIS (SEDS Earth, Atmosphere, and Space Imaging System) is another SEDSAT experiment designed to provide images of the tether during its deployment and the earth during the second phase of the mission. To control these experiments and virtually all other satellite operations the Command Data System, CDS is employed. This system utilizes a moderate complexity micro-controller controlled by tasks operating under a real-time operating system to dynamically monitor and control the satellite. The scope of this researchers efforts has been in the general area of coordinating and assisting the student researchers with the development of the CDS and ground station interfaces. This included the low level CDS hardware design and the formulization of a general software plan and schedule for both the CDS and ground station portions of the project.

  17. Solar system positioning system

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I.; Chui, Talso

    2006-01-01

    Power-rich spacecraft envisioned in Prometheus initiative open up possibilities for long-range high-rate communication. A constellation of spacecraft on orbits several A.U. from the Sun, equipped with laser transponders and precise clocks can be configured to measure their mutual distances to within few cm. High on-board power can create substantial non-inertial contribution to the spacecraft trajectory. We propose to alleviate this contribution by employing secondary ranging to a passive daughter spacecraft. Such constellation can form the basis of it navigation system capable of providing position information anywhere in the soIar system with similar accuracy. Apart from obvious Solar System exploration implications, this system can provide robust reference for GPS and its successors.

  18. Endocrine System

    MedlinePLUS

    ... How Can I Help a Friend Who Cuts? Endocrine System KidsHealth > For Teens > Endocrine System Print A A ... is called the endocrine system . What Is the Endocrine System? Although we rarely think about the endocrine system, ...

  19. Closeup view of the interior of an Aft Skirt being ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of the interior of an Aft Skirt being tested and prepared for mating with sub assemblies in the Solid Rocket Booster (SRB) Assembly and Refurbishment Facility at Kennedy Space Center. This view is showing the SRB Thrust Vector Control (TVC) System which includes independent auxiliary power units for each actuator to pressurize their respective hydraulic systems. When the Nozzle is mated with the Aft Skirt the two actuators, located on the left and right side of the TVC System in this view, can swivel it up to 3.5 degrees to redirect the thrust to steer and maintain the Shuttle's programmed trajectory. - Space Transportation System, Solid Rocket Boosters, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  20. International Symposium on Air Breathing Engines, 8th, Cincinnati, OH, June 14-19, 1987, Proceedings

    SciTech Connect

    Billig, F.S.

    1987-01-01

    The present conference on air-breathing aircraft engine technology considers topics in inlet design, radial-flow turbomachinery, fuel injection and combustion systems, axial flow compressor design and performance, ramjet configurations, turbine flow phenomena, engine control and service life, fluid flow-related problems, engine diagnostic methods, propfan design, combustor performance and pollutant chemistry, combustion dynamics, and engine system analysis. Attention is given to thrust-vectoring systems, supersonic missile air intakes, three-dimensional centrifugal compressors, airblast atomizers, secondary flows in axial flow compressors, axial compressor blade tip clearance flows, hydrogen scramjets with sidewall injection, the performance of a variable-geometry turbine, advanced tip clearance control systems, rotary jet mixing, fan blade aeroelastic behavior, flow dynamics in combustion processes, and the technology of low cost turbomachinery.

  1. HermesB: a continuous neural recording system for freely behaving primates.

    PubMed

    Santhanam, Gopal; Linderman, Michael D; Gilja, Vikash; Afshar, Afsheen; Ryu, Stephen I; Meng, Teresa H; Shenoy, Krishna V

    2007-11-01

    Chronically implanted electrode arrays have enabled a broad range of advances in basic electrophysiology and neural prosthetics. Those successes motivate new experiments, particularly, the development of prototype implantable prosthetic processors for continuous use in freely behaving subjects, both monkeys and humans. However, traditional experimental techniques require the subject to be restrained, limiting both the types and duration of experiments. In this paper, we present a dual-channel, battery-powered neural recording system with an integrated three-axis accelerometer for use with chronically implanted electrode arrays in freely behaving primates. The recording system called HermesB, is self-contained, autonomous, programmable, and capable of recording broadband neural (sampled at 30 kS/s) and acceleration data to a removable compact flash card for up to 48 h. We have collected long-duration data sets with HermesB from an adult macaque monkey which provide insight into time scales and free behaviors inaccessible under traditional experiments. Variations in action potential shape and root-mean square (RMS) noise are observed across a range of time scales. The peak-to-peak voltage of action potentials varied by up to 30% over a 24-h period including step changes in waveform amplitude (up to 25%) coincident with high acceleration movements of the head. These initial results suggest that spike-sorting algorithms can no longer assume stable neural signals and will need to transition to adaptive signal processing methodologies to maximize performance. During physically active periods (defined by head-mounted accelerometer), significantly reduced 5-25-Hz local field potential (LFP) power and increased firing rate variability were observed. Using a threshold fit to LFP power, 93% of 403 5-min recording blocks were correctly classified as active or inactive, potentially providing an efficient tool for identifying different behavioral contexts in prosthetic applications. These results demonstrate the utility of the HermesB system and motivate using this type of system to advance neural prosthetics and electrophysiological experiments. PMID:18018699

  2. Systems autonomy

    NASA Technical Reports Server (NTRS)

    Lum, Henry, Jr.

    1988-01-01

    Information on systems autonomy is given in viewgraph form. Information is given on space systems integration, intelligent autonomous systems, automated systems for in-flight mission operations, the Systems Autonomy Demonstration Project on the Space Station Thermal Control System, the architecture of an autonomous intelligent system, artificial intelligence research issues, machine learning, and real-time image processing.

  3. Robust control of hypersonic vehicles considering propulsive and aeroelastic effects

    NASA Technical Reports Server (NTRS)

    Buschek, Harald; Calise, Anthony J.

    1993-01-01

    The influence of propulsion system variations and elastic fuselage behavior on the flight control system of an airbreathing hypersonic vehicle is investigated. Thrust vector magnitude and direction changes due to angle of attack variations affect the pitching moment. Low structural vibration frequencies may occur close to the rigid body modes influencing the angle of attack and lead to possible cross coupling. These effects are modeled as uncertainties in the context of a robust control study of a hypersonic vehicle model accelerating through Mach 8 using H-infinity and mu synthesis techniques. Various levels of uncertainty are introduced into the system. Both individual and simultaneous appearance of uncertainty are considered. The results indicate that the chosen design technique is suitable for this kind of problem provided that a fairly good knowledge of the effects mentioned above is available. The order of the designed controller is reduced but robust performance is lost which shows the need for fixed order design techniques.

  4. Electrical Actuation Technology Bridging

    NASA Technical Reports Server (NTRS)

    Hammond, Monica (Compiler); Sharkey, John (Compiler)

    1993-01-01

    This document contains the proceedings of the NASA Electrical Actuation Technology Bridging (ELA-TB) Workshop held in Huntsville, Alabama, September 29-October 1, 1992. The workshop was sponsored by the NASA Office of Space Systems Development and Marshall Space Flight Center (MSFC). The workshop addressed key technologies bridging the entire field of electrical actuation including systems methodology, control electronics, power source systems, reliability, maintainability, and vehicle health management with special emphasis on thrust vector control (TVC) applications on NASA launch vehicles. Speakers were drawn primarily from industry with participation from universities and government. In addition, prototype hardware demonstrations were held at the MSFC Propulsion Laboratory each afternoon. Splinter sessions held on the final day afforded the opportunity to discuss key issues and to provide overall recommendations. Presentations are included in this document.

  5. Evaluation of aperture cover tank vent nozzles for the IRAS spacecraft

    NASA Technical Reports Server (NTRS)

    Richter, R.

    1983-01-01

    The influence of coefficients for the three axes of the Infrared Astronomical Satellite (IRAS) were established to determine the maximum allowable thrust difference between the two vent nozzles of the aperture cover tank low thrust vent system and their maximum misalignment. Test data generated by flow and torque measurements permitted the selection of two nozzles whose thrust differential was within the limit of the attitude control capability. Based on thrust stand data, a thrust vector misalignment was indicated that was slightly higher than permissible for the worst case, i.e., considerable degradation of the torque capacity of the attitude control system combined with venting of helium at its upper limit. The probability of destabilizing the IRAS spacecraft by activating the venting system appeared to be very low. The selection and mounting of the nozzles have satisfied all the requirements for the safe venting of helium.

  6. Technical Progress on the Ares I-X Flight Test

    NASA Technical Reports Server (NTRS)

    Davis, S.R.; Robinson, K.F.; Flynn, K.C.

    2008-01-01

    Ares I-X will be NASA's first test flight for a new human-rated launch vehicle since 1981, and the team is well on its way toward completing the vehicle's design and hardware fabrication for an April 2009 launch. This uncrewed suborbital development test flight gives NASA its first opportunities to: gather critical data about the flight dynamics of the integrated launch vehicle; understand how to control its roll during flight; better characterize the stage separation environments during future flight; and demonstrate the first stage recovery system. The Ares I-X Flight Test Vehicle (FTV) incorporates a mix of flight and mockup hardware. It is powered by a four-segment solid rocket booster, and will be modified to include a fifth, spacer segment; the upper stage, Orion crew exploration vehicle, and launch abort system are simulator hardware to make the FTV aerodynamically similar to the same size, shape, and weight of Ares I. The Ares IX first stage includes an existing Shuttle solid rocket motor and thrust vector control system controlled by an Ascent Thrust Vector Controller (ATVC) designed and built by Honeywell International. The avionics system will be tested in a dedicated System Integration Laboratory located at Lockheed Martin Space Systems (LMSS) in Denver, Colorado. The Upper Stage Simulator (USS) is made up of cylindrical segments that will be stacked and integrated at Kennedy Space Center (KSC) for launch. Glenn Research Center is already building these segments, along with their internal access structures. The active Roll Control System (RoCS) includes two thruster units harvested from Peacekeeper missiles. Duty cycle testing for RoCS was conducted, and fuel tanking and detanking tests will occur at KSC in early 2008. This important flight will provide valuable experience for the ground operations team in integrating, stacking, and launching Ares I. Data from Ares I-X will ensure the safety and reliability of America's newest launch vehicle.

  7. Immune System

    MedlinePLUS

    ... How Can I Help a Friend Who Cuts? Immune System KidsHealth > For Teens > Immune System Print A A ... could put us out of commission. What the Immune System Does The immune (pronounced: ih-MYOON) system, which ...

  8. The Software Design for the Wide-Field Infrared Explorer Attitude Control System

    NASA Technical Reports Server (NTRS)

    Anderson, Mark O.; Barnes, Kenneth C.; Melhorn, Charles M.; Phillips, Tom

    1998-01-01

    The Wide-Field Infrared Explorer (WIRE), currently scheduled for launch in September 1998, is the fifth of five spacecraft in the NASA/Goddard Small Explorer (SMEX) series. This paper presents the design of WIRE's Attitude Control System flight software (ACS FSW). WIRE is a momentum-biased, three-axis stabilized stellar pointer which provides high-accuracy pointing and autonomous acquisition for eight to ten stellar targets per orbit. WIRE's short mission life and limited cryogen supply motivate requirements for Sun and Earth avoidance constraints which are designed to prevent catastrophic instrument damage and to minimize the heat load on the cryostat. The FSW implements autonomous fault detection and handling (FDH) to enforce these instrument constraints and to perform several other checks which insure the safety of the spacecraft. The ACS FSW implements modules for sensor data processing, attitude determination, attitude control, guide star acquisition, actuator command generation, command/telemetry processing, and FDH. These software components are integrated with a hierarchical control mode managing module that dictates which software components are currently active. The lowest mode in the hierarchy is the 'safest' one, in the sense that it utilizes a minimal complement of sensors and actuators to keep the spacecraft in a stable configuration (power and pointing constraints are maintained). As higher modes in the hierarchy are achieved, the various software functions are activated by the mode manager, and an increasing level of attitude control accuracy is provided. If FDH detects a constraint violation or other anomaly, it triggers a safing transition to a lower control mode. The WIRE ACS FSW satisfies all target acquisition and pointing accuracy requirements, enforces all pointing constraints, provides the ground with a simple means for reconfiguring the system via table load, and meets all the demands of its real-time embedded environment (16 MHz Intel 80386 processor with 80387 coprocessor running under the VRTX operating system). The mode manager organizes and controls all the software modules used to accomplish these goals, and in particular, the FDH module is tightly coupled with the mode manager.

  9. A high-fidelity batch simulation environment for integrated batch and piloted air combat simulation analysis

    NASA Technical Reports Server (NTRS)

    Goodrich, Kenneth H.; Mcmanus, John W.; Chappell, Alan R.

    1992-01-01

    A batch air combat simulation environment known as the Tactical Maneuvering Simulator (TMS) is presented. The TMS serves as a tool for developing and evaluating tactical maneuvering logics and to evaluate the tactical implications of perturbations to aircraft performance or supporting systems. The TMS is capable of simulating air combat between any number of engagement participants, with practical limits imposed by computer memory and processing power. Aircraft are modeled using equations of motion, control laws, aerodynamics and propulsive characteristics, and databases representative of a modern high-performance aircraft with and without thrust-vectoring capability are included. A Tactical Autopilot is implemented in the aircraft simulation model to convert guidance commands issued by computerized maneuvering logics in the form of desired angle-of-attack and wind axis-bank angle into inputs to the inner-loop control augmentation system of the aircraft.

  10. Xenon ion propulsion for orbit transfer

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Patterson, M. J.; Gruber, R. P.

    1990-01-01

    The status of critical ion propulsion system elements is reviewed. Electron bombardment ion thrusters for primary propulsion have evolved to operate on xenon in the 5-10 kW power range. Thruster efficiencies of 0.7 and specific impulse values of 4000 s have been documented. The baseline thruster currently under development by NASA LeRC includes ring-cusp magnetic field plasma containment and dished two-grid ion optics. Based on past experience and demonstrated simplifications, power processors for these thrusters should have approximately 500 parts, a mass of 40 kg, and an efficiency near 0.94. Thrust vector control, via individual thruster gimbals, is a mature technology. High pressure, gaseous xenon propellant storage and control schemes, using flight qualified hardware, result in propellant tankage fractions between 0.1 and 0.2. In-space and ground integration testing has demonstrated that ion propulsion systems can be successfully integrated with their host spacecraft.

  11. Advanced electric motor technology: Flux mapping

    NASA Technical Reports Server (NTRS)

    Doane, George B., III; Campbell, Warren; Brantley, Larry W.; Dean, Garvin

    1992-01-01

    This report contains the assumptions, mathematical models, design methodology, and design points involved with the design of an electromechanical actuator (EMA) suitable for directing the thrust vector of a large MSFC/NASA launch vehicle. Specifically the design of such an actuator for use on the upcoming liquid fueled National Launch System (NLS) is considered culminating in a point design of both the servo system and the electric motor needed. A major thrust of the work is in selecting spur gear and roller screw reduction ratios to achieve simultaneously wide bandwidth, maximum power transfer, and disturbance rejection while meeting specified horsepower requirements at a given stroking speed as well as a specified maximum stall force. An innovative feedback signal is utilized in meeting these diverse objectives.

  12. F-18 high alpha research vehicle: Lessons learned

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Regenie, Victoria A.; Flick, Bradley C.

    1994-01-01

    The F-18 High Alpha Research Vehicle has proven to be a useful research tool with many unique capabilities. Many of these capabilities are to assist in characterizing flight at high angles of attack, while some provide significant research in their own right. Of these, the thrust vectoring system, the unique ability to rapidly reprogram flight controls, the reprogrammable mission computer, and a reprogrammable onboard excitation system have allowed an increased utility and versatility of the research being conducted. Because of this multifaceted approach to research in the high angle of attack regime, the capabilities of the F-18 High Alpha Research Vehicle were designed to cover as many high alpha technology bases as the program would allow. These areas include aerodynamics, controls, handling qualities, and propulsion.

  13. Inertial upper stage - Upgrading a stopgap proves difficult

    NASA Astrophysics Data System (ADS)

    Geddes, J. P.

    The technological and project management difficulties associated with the Inertial Upper Stage's (IUS) development and performance to date are assessed, with a view to future prospects for this system. The IUS was designed for use both on the interim Titan 34D booster and the Space Shuttle Orbiter. The IUS malfunctions and cost overruns reported are substantially due to the system's reliance on novel propulsion and avionics technology. Its two solid rocket motors, which were selected on the basis of their inherent safety for use on the Space Shuttle, have the longest burn time extant. A three-dimensional carbon/carbon nozzle throat had to be developed to sustain this long burn, as were lightweight composite wound cases and shirts, insulation, igniters, and electromechanical thrust vector control.

  14. Effects of internal yaw-vectoring devices on the static performance of a pitch-vectoring nonaxisymmetric convergent-divergent nozzle

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.

    1993-01-01

    An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to evaluate the internal performance of a nonaxisymmetric convergent divergent nozzle designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap deflection for thrust vectoring in the pitch plane and flow-turning deflectors installed within the divergent flaps for yaw thrust vectoring. Modifications consisting of reducing the sidewall length and deflecting the sidewall outboard were investigated as means to increase yaw-vectoring performance. This investigation studied the effects of multiaxis (pitch and yaw) thrust vectoring on nozzle internal performance characteristics. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 13.0. The results indicate that this nozzle concept can successfully generate multiaxis thrust vectoring. Deflection of the divergent flaps produced resultant pitch vector angles that, although dependent on nozzle pressure ratio, were nearly equal to the geometric pitch vector angle. Losses in resultant thrust due to pitch vectoring were small or negligible. The yaw deflectors produced resultant yaw vector angles up to 21 degrees that were controllable by varying yaw deflector rotation. However, yaw deflector rotation resulted in significant losses in thrust ratios and, in some cases, nozzle discharge coefficient. Either of the sidewall modifications generally reduced these losses and increased maximum resultant yaw vector angle. During multiaxis (simultaneous pitch and yaw) thrust vectoring, little or no cross coupling between the thrust vectoring processes was observed.

  15. Evaluation of the Performance Characteristics of the CGLSS and NLDN Systems Based on Two Years of Ground-Truth Data from Launch Complex 39B, Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    Mata, Carlos T.; Hill, Jonathan D.; Mata, Angel G.; Cummins, Kenneth L.

    2014-01-01

    From May 2011 through July 2013, the lightning instrumentation at Launch Complex 39B (LC39B) at the Kennedy Space Center, Florida, has obtained high-speed video records and field change waveforms (dE/dt and three-axis dH/dt) for 54 negative polarity return strokes whose strike termination locations and times are known with accuracy of the order of 10 m or less and 1 µs, respectively. A total of 18 strokes terminated directly to the LC39B lighting protection system (LPS), which contains three 181 m towers in a triangular configuration, an overhead catenary wire system on insulating masts, and nine down conductors. An additional 9 strokes terminated on the 106 m lightning protection mast of Launch Complex 39A (LC39A), which is located about 2.7 km southeast of LC39B. The remaining 27 return strokes struck either on the ground or attached to low-elevation grounded objects within about 500 m of the LC39B LPS. Leader/return stroke sequences were imaged at 3200 frames/sec by a network of six Phantom V310 high-speed video cameras. Each of the three towers on LC39B had two high-speed cameras installed at the 147 m level with overlapping fields of view of the center of the pad. The locations of the strike points of 54 return strokes have been compared to time-correlated reports of the Cloud-to-Ground Lightning Surveillance System (CGLSS) and the National Lightning Detection Network (NLDN), and the results of this comparison will be presented and discussed.

  16. Operating Systems.

    ERIC Educational Resources Information Center

    Denning, Peter J.; Brown, Robert L.

    1984-01-01

    A computer operating system spans multiple layers of complexity, from commands entered at a keyboard to the details of electronic switching. In addition, the system is organized as a hierarchy of abstractions. Various parts of such a system and system dynamics (using the Unix operating system as an example) are described. (JN)

  17. Attitude Ground System (AGS) For The Magnetospheric Multi-Scale (MMS) Mission

    NASA Technical Reports Server (NTRS)

    Raymond, Juan C.; Sedlak, Joseph E.; Vint, Babak

    2015-01-01

    The Magnetospheric Multiscale (MMS) mission is a Solar-Terrestrial Probe mission consisting of four identically instrumented spin-stabilized spacecraft flying in an adjustable pyramid-like formation around the Earth. The formation of the MMS spacecraft allows for three-dimensional study of the phenomenon of magnetic reconnection, which is the primary objective of the mission. The MMS spacecraft were launched early on March 13, 2015 GMT. Due to the challenging and very constricted attitude and orbit requirements for performing the science, as well as the need to maintain the spacecraft formation, multiple ground functionalities were designed to support the mission. These functionalities were incorporated into a ground system known as the Attitude Ground System (AGS). Various AGS configurations have been used widely to support a variety of three-axis-stabilized and spin-stabilized spacecraft missions within the NASA Goddard Space Flight Center (GSFC). The original MMS operational concept required the AGS to perform highly accurate predictions of the effects of environmental disturbances on the spacecraft orientation and to plan the attitude maneuvers necessary to stay within the science attitude tolerance. The orbit adjustment requirements for formation control drove the need also to perform calibrations that have never been done before in support of NASA GSFC missions. The MMS mission required support analysts to provide fast and accurately calibrated values of the inertia tensor, center of mass, and accelerometer bias for each MMS spacecraft. During early design of the AGS functionalities, a Kalman filter for estimating the attitude, body rates, center of mass, and accelerometer bias, using only star tracker and accelerometer measurements, was heavily analyzed. A set of six distinct filters was evaluated and considered for estimating the spacecraft attitude and body rates using star tracker data only. Four of the six filters are closely related and were compared during support of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) and Space Technology-5 (ST-5) missions. These analyses exposed high dependency and sensitivity on the knowledge of the spacecraft inertia tensor for both body rates and accelerometer bias estimation. The conclusion of the analysis led to the design of an inertia tensor calibration technique using only star tracker data. The second most important result of the analysis was the design of two separate Kalman filters to estimate the spacecraft attitude and body rates and the accelerometer bias instead of a single combined filter. In this paper, the calibration results of the mass properties, as well as the performance of the spacecraft attitude and body rates filters using flight data are presented and compared against the mission requirements.

  18. The Implementation of Satellite Control System Software Using Object Oriented Design

    NASA Technical Reports Server (NTRS)

    Anderson, Mark O.; Reid, Mark; Drury, Derek; Hansell, William; Phillips, Tom

    1998-01-01

    NASA established the Small Explorer (SMEX) program in 1988 to provide frequent opportunities for highly focused and relatively inexpensive space science missions that can be launched into low earth orbit by small expendable vehicles. The development schedule for each SMEX spacecraft was three years from start to launch. The SMEX program has produced five satellites; Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), Fast Auroral Snapshot Explorer (FAST), Submillimeter Wave Astronomy Satellite (SWAS), Transition Region and Coronal Explorer (TRACE) and Wide-Field Infrared Explorer (WIRE). SAMPEX and FAST are on-orbit, TRACE is scheduled to be launched in April of 1998, WIRE is scheduled to be launched in September of 1998, and SWAS is scheduled to be launched in January of 1999. In each of these missions, the Attitude Control System (ACS) software was written using a modular procedural design. Current program goals require complete spacecraft development within 18 months. This requirement has increased pressure to write reusable flight software. Object-Oriented Design (OOD) offers the constructs for developing an application that only needs modification for mission unique requirements. This paper describes the OOD that was used to develop the SMEX-Lite ACS software. The SMEX-Lite ACS is three-axis controlled, momentum stabilized, and is capable of performing sub-arc-minute pointing. The paper first describes the high level requirements which governed the architecture of the SMEX-Lite ACS software. Next, the context in which the software resides is explained. The paper describes the benefits of encapsulation, inheritance and polymorphism with respect to the implementation of an ACS software system. This paper will discuss the design of several software components that comprise the ACS software. Specifically, Object-Oriented designs are presented for sensor data processing, attitude control, attitude determination and failure detection. The paper addresses the benefits of the OOD versus a conventional procedural design. The final discussion in this paper will address the establishment of the ACS Foundation Class (AFC) Library. The AFC is a large software repository, requiring a minimal amount of code modifications to produce ACS software for future projects, saving production time and costs.

  19. Optomechanical design of near-null subaperture test system based on counter-rotating CGH plates

    NASA Astrophysics Data System (ADS)

    Li, Yepeng; Chen, Shanyong; Song, Bing; Li, Shengyi

    2014-09-01

    In off-axis subapertures of most convex aspheres, astigmatism and coma dominate the aberrations with approximately quadratic and linear increase as the off-axis distance increases. A pair of counter-rotating computer generated hologram (CGH) plates is proposed to generate variable amount of Zernike terms Z4 and Z6, correcting most of the astigmatism and coma for subapertures located at different positions on surfaces of various aspheric shapes. The residual subaperture aberrations are then reduced within the vertical range of measurement of the interferometer, which enables near-null test of aspheres flexibly. The alignment tolerances for the near-null optics are given with optomechanical analysis. Accordingly a novel design for mounting and aligning the CGH plates is proposed which employs three concentric rigid rings. The CGH plate is mounted in the inner ring which is supported by two couples of ball-end screws in connection with the middle ring. The CGH plate along with the inner ring is hence able to be translated in X-axis and tipped by adjusting the screws. Similarly the middle ring is able to be translated in Y-axis and tilted by another two couples of screws orthogonally arranged and connected to the outer ring. This design is featured by the large center-through hole, compact size and capability of four degrees-of-freedom alignment (lateral shift and tip-tilt). It reduces the height measured in the direction of optical axis as much as possible, which is particularly advantageous for near-null test of convex aspheres. The CGH mounts are then mounted on a pair of center-through tables realizing counter-rotation. Alignment of the interferometer, the CGHs, the tables and the test surface is also discussed with a reasonable layout of the whole test system. The interferometer and the near-null optics are translated by a three-axis stage while the test mirror is rotated and tilted by two rotary tables. Experimental results are finally given to show the near-null subaperture test capability of the system for a convex even asphere.

  20. F-18 HARV on ramp close-up of actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Outlined with gold stripes are the hinged nose strakes, modifications made to NASA's F-18 HARV (High Alpha Research Vehicle) at the Dryden Flight Research Center, Edwards, California. Actuated Nose Strakes for Enhanced Rolling (ANSER) were installed to fly the third and final phase in the HARV flight test project. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Early wind tunnel tests indicated that the strakes would be as effective in yaw control at high angles of attack as rudders are at lower angles. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  1. Optimal three-dimensional flight of a spacecraft between the lunar surface and an artificial satellite orbit.

    NASA Astrophysics Data System (ADS)

    Grigor'ev, K. G.; Zapletina, E. V.; Zapletin, M. P.

    1994-03-01

    The authors analyze and numerically solve the problem of optimal three-dimensional flight between a circular artificial satellite orbit around the Moon and the lunar surface. The spacecraft is equipped with a high limited thrust jet engine. They study the optimal soft landing on the lunar surface from an orbit and the optimal ejection from the lunar surface into orbit. Transfers are accomplished by controlling the thrust vector. The gravitational field of the Moon is assumed to be central Newtonian. The authors determine the trajectories that minimize time, mass expenditure, and compromise functional between the time and mass expenditures. These problems are solved using the maximum principle, which reduces them to boundary problems for a system of nonlinear ordinary 13th and 14th order differential equations. The exact numerical solutions of these boundary problems are obtained using the shooting method, which involves selecting four to five unknown boundary conditions. The optimal trajectories are computed for wide ranges of parameter values.

  2. Finite Element Simulation of a Space Shuttle Solid Rocket Booster Aft Skirt Splashdown Using an Arbitrary Lagrangian-Eulerian Approach

    NASA Astrophysics Data System (ADS)

    Melis, Matthew E.

    2003-01-01

    Explicit finite element techniques employing an Arbitrary Lagrangian-Eulerian (ALE) methodology, within the transient dynamic code LS-DYNA, are used to predict splashdown loads on a proposed replacement/upgrade of the hydrazine tanks on the thrust vector control system housed within the aft skirt of a Space Shuttle Solid Rocket Booster. Two preliminary studies are performed prior to the full aft skirt analysis: An analysis of the proposed tank impacting water without supporting aft skirt structure, and an analysis of space capsule water drop tests conducted at NASA's Langley Research Center. Results from the preliminary studies provide confidence that useful predictions can be made by applying the ALE methodology to a detailed analysis of a 26-degree section of the skirt with proposed tank attached. Results for all three studies are presented and compared to limited experimental data. The challenges of using the LS-DYNA ALE capability for this type of analysis are discussed.

  3. Finite Element Simulation of a Space Shuttle Solid Rocket Booster Aft Skirt Splashdown Using an Arbitrary Lagrangian-eulerian Approach

    NASA Technical Reports Server (NTRS)

    Melis, Matthew E.

    2003-01-01

    Explicit finite element techniques employing an Arbitrary Lagrangian-Eulerian (ALE) methodology, within the transient dynamic code LS-DYNA, are used to predict splashdown loads on a proposed replacement/upgrade of the hydrazine tanks on the thrust vector control system housed within the aft skirt of a Space Shuttle Solid Rocket Booster. Two preliminary studies are performed prior to the full aft skirt analysis: An analysis of the proposed tank impacting water without supporting aft skirt structure, and an analysis of space capsule water drop tests conducted at NASA's Langley Research Center. Results from the preliminary studies provide confidence that useful predictions can be made by applying the ALE methodology to a detailed analysis of a 26-degree section of the skirt with proposed tank attached. Results for all three studies are presented and compared to limited experimental data. The challenges of using the LS-DYNA ALE capability for this type of analysis are discussed.

  4. Bias Momentum Sizing for Hovering Dual-Spin Platforms

    NASA Technical Reports Server (NTRS)

    Lim, K. B.; Shin, J-Y.; Moerder, D. D.

    2005-01-01

    An atmospheric flight vehicle in hover is typically controlled by varying its thrust vector. Achieving both levitation and control with the propulsion system places considerable demands on it for agility and precision, particularly if the vehicle is statically unstable, or nearly so. These demands can be relaxed by introducing an appropriately sized angular momentum bias about the vehicle's yaw axis, thus providing an additional margin of attitude stability about the roll and pitch axes. This paper describes an approach for specifying the appropriate size of such angular momentum bias, based on the vehicle s physical parameters and its disturbance environment. It also describes several simplifications that provide a more physical and intuitive understanding of the dynamics. This will enhance the possibility of practically applying this technology to a flying vehicle.

  5. An 8-cm electron bombardment thruster for auxiliary propulsion

    NASA Technical Reports Server (NTRS)

    Hudson, W. R.; Banks, B. A.

    1973-01-01

    Thruster size, beam current level, and specific impulse trade-offs are considered for mercury electron bombardment ion thrusters to be used for north-south station keeping of geosynchronous spacecraft. An 8-cm diameter thruster operating at 2750 seconds specific impulse at thrust levels of 4.4 mN (1 m1b) to 8.9 mN (2 m6b) with a design life of 20,000 hours and 10,000 cycles is being developed. The thruster will have a dished two-grid system capable of thrust vectoring of + or - 10 degrees in two orthogonal directions. A preliminary thruster has been fabricated and tested; thruster performance characteristics have been determined at 4.45, 6.68, and 8.90 millinewtons.

  6. Solar electric propulsion for the orbital transfer of large spacecraft to geosynchronous orbit

    NASA Technical Reports Server (NTRS)

    Garrison, James L.

    1992-01-01

    Low thrust trajectories utilizing electric propulsion and photovoltaic power sources are derived for the transfer of a large spacecraft from assembly in low earth orbit to operation at geosynchronous orbit. Conventional silicon photovoltaic devices are assumed. A 1 MeV equivalent electron flux model is used. The solar panel mass and size are taken from Advanced Photovoltaic Solar Array design concepts with 3-mil shielding. Shadowing of the vehicle and low earth orbit atmospheric drag are also modeled. The power system is sized so that end of life output is 30 percent of initial output. Steering of the thrust vector is defined by a three term series in which the coefficients are varied as controls to minimize the total power loss with cumulative exposure in the Van Allen region.

  7. Solar Sail Control Actuator Concepts

    NASA Technical Reports Server (NTRS)

    Mangus, David; Heaton, Andy

    2004-01-01

    The thrust produced by a solar sail is a direct function of its attitude. Thus, solar sail thrust vector control is a key technology that must be developed for sailcraft to become a viable form of deep-space transportation. The solar sail community has been studying various sail Attitude Control System (ACS) actuator designs for near Earth orbit as well as deep space missions. These actuators include vanes, spreader bars, two-axis gimbals, floating/locking gimbals with wheels, and translating masses. This paper documents the various concepts and performs an assessment at the highest level. This paper will only compare the various ACS actuator concepts as they stand at the publication time. This is not an endorsement of any particular concept. As concepts mature, the assessments will change.

  8. The cesium bombardment engine north-south stationkeeping experiment on ATS-6

    NASA Technical Reports Server (NTRS)

    Worlock, R. M.; James, E. L.; Hunter, R. E.; Bartlett, R. O.

    1975-01-01

    Two one millipound-thrust cesium bombardment ion thrusters have been developed and integrated on the ATS-F spacecraft for the purpose of demonstrating compatible north-south stationkeeping of a synchronous communication satellite. Preliminary operation of the two thrusters on ATS-6 was completely successful on the first run of each. In addition to verifying operation, the principal accomplishments were the demonstration of a total absence of interference with the communications systems, verification of the predicted spacecraft operating potential, demonstration of compatibility with the star tracker, and demonstration of spacecraft attitude by thrust vectoring. Subsequent attempts to operate the thrusters have not been successful. Analysis indicates that the problem is associated with operation of the propellant reservoirs in zero-g.

  9. Pulsed Plasma Thruster Plume Study: Symmetry and Impact on Spacecraft Surfaces

    NASA Technical Reports Server (NTRS)

    Arrington, Lynn A.; Marrese, Colleen M.; Blandino, John J.

    2000-01-01

    Twenty-four witness plates were positioned on perpendicular arrays near a breadboard Pulsed Plasma Thruster (PPT) to collect plume constituents for analysis. Over one million shots were fired during the experiment at 43 J using fluorocarbon polymer propellant. The asymmetry of the film deposition on the witness plates was investigated with mass and thickness measurements and correlated with off-axis thrust vector measurements. The composition of the films was determined. The transmittance and reflectance of the films were measured and the absorption coefficients were calculated in the wavelength range from 350 to 1200 mn. These data were applied to calculate the loss in signal intensity through the films, which will impact the visibility of spaceborne interferometer systems positioned by these thrusters.

  10. Nozzle Side Load Testing and Analysis at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Ruf, Joseph H.; McDaniels, David M.; Brown, Andrew M.

    2009-01-01

    Realistic estimates of nozzle side loads, the off-axis forces that develop during engine start and shutdown, are important in the design cycle of a rocket engine. The estimated magnitude of the nozzle side loads has a large impact on the design of the nozzle shell and the engine s thrust vector control system. In 2004 Marshall Space Flight Center (MSFC) began developing a capability to quantify the relative magnitude of side loads caused by different types of nozzle contours. The MSFC Nozzle Test Facility was modified to measure nozzle side loads during simulated nozzle start. Side load results from cold flow tests on two nozzle test articles, one with a truncated ideal contour and one with a parabolic contour are provided. The experimental approach, nozzle contour designs and wall static pressures are also discussed

  11. A Boiling-Potassium Fluoride Reactor for an Artificial-Gravity NEP Vehicle

    NASA Technical Reports Server (NTRS)

    Sorensen, Kirk; Juhasz, Albert

    2007-01-01

    Several years ago a rotating manned spacecraft employing nuclear-electric propulsion was examined for Mars exploration. The reactor and its power conversion system essentially served as the counter-mass to an inflatable manned module. A solid-core boiling potassium reactor based on the MPRE concept of the 1960s was baselined in that study. This paper proposes the use of a liquid-fluoride reactor, employing direct boiling of potassium in the core, as a means to overcome some of the residual issues with the MPRE reactor concept. Several other improvements to the rotating Mars vehicle are proposed as well, such as Canfield joints to enable the electric engines to track the inertial thrust vector during rotation, and innovative "cold-ion" engine technologies to improve engine performance.

  12. Development of the Multiple Use Plug Hybrid for Nanosats (MUPHyN) miniature thruster

    NASA Astrophysics Data System (ADS)

    Eilers, Shannon

    The Multiple Use Plug Hybrid for Nanosats (MUPHyN) prototype thruster incorporates solutions to several major challenges that have traditionally limited the deployment of chemical propulsion systems on small spacecraft. The MUPHyN thruster offers several features that are uniquely suited for small satellite applications. These features include 1) a non-explosive ignition system, 2) non-mechanical thrust vectoring using secondary fluid injection on an aerospike nozzle cooled with the oxidizer flow, 3) a non-toxic, chemically-stable combination of liquid and inert solid propellants, 4) a compact form factor enabled by the direct digital manufacture of the inert solid fuel grain. Hybrid rocket motors provide significant safety and reliability advantages over both solid composite and liquid propulsion systems; however, hybrid motors have found only limited use on operational vehicles due to 1) difficulty in modeling the fuel flow rate 2) poor volumetric efficiency and/or form factor 3) significantly lower fuel flow rates than solid rocket motors 4) difficulty in obtaining high combustion efficiencies. The features of the MUPHyN thruster are designed to offset and/or overcome these shortcomings. The MUPHyN motor design represents a convergence of technologies, including hybrid rocket regression rate modeling, aerospike secondary injection thrust vectoring, multiphase injector modeling, non-pyrotechnic ignition, and nitrous oxide regenerative cooling that address the traditional challenges that limit the use of hybrid rocket motors and aerospike nozzles. This synthesis of technologies is unique to the MUPHyN thruster design and no comparable work has been published in the open literature.

  13. Systems Thinking (and Systems Doing).

    ERIC Educational Resources Information Center

    Brethower, Dale M.; Dams, Peter-Cornelius

    1999-01-01

    Introduces human performance technology (HPT) by answering the following questions related to: what systems does; practical issues and questions to which systems thinking is relevant; research questions and answers with respect to systems thinking; how HPT practitioners can do systems thinking; systems thinking tools; what is and is not known

  14. X-31 Unloading Returning from Paris Air Show

    NASA Technical Reports Server (NTRS)

    1995-01-01

    After being flown in the Paris Air Show in June 1995, the X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is off-loaded from an Air Force Reserve C-5 transport after the ferry flight back to Edwards. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the 'Herbst Maneuver' after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a 'J Turn' when flown to an arbitrary heading change. The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation. The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations. The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.

  15. X-31 Loaded in C-5 Cargo Bay

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is secured inside the fuselage of an Air Force Reserve C-5 transport. The C-5 was used to ferry the X-31 from Europe back to Edwards, after being flown in the Paris Air Show in June 1995. The X-31's right wing, removed so the aircraft could fit inside the C-5, is in the shipping container in the foreground. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the 'Herbst Maneuver' after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a 'J Turn' when flown to an arbitrary heading change. The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation. The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations. The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.

  16. X-31 Being Loaded into C-5 Cargo Plane

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards, California, begins rolling aboard an Air Force Reserve C-5 transport which ferried it on May 22, 1995 to Europe where it was flown in the Paris Air Show in June 1995. To fit in the C-5 the right wing of the X-31 had to be removed. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the 'Herbst Maneuver' after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a 'J Turn' when flown to an arbitrary heading change. The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation. The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations. The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.

  17. X-31 in flight - Post Stall Maneuver

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an aircraft with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that can provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This movie clip runs 1 minute, 6 seconds in length and shows the X-31 rotating at takeoff and climbing into a stall maneuver. The aircraft then slides backwards thrust vectoring the tail over the top, turning the stall into a loop in which the aircraft then reverses its heading and resumes level flight.

  18. X-31 in flight - Herbst Turn

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an airplane with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident January 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 32-second clip shows the aircraft at the top of a stall and then thrust vectoring itself around to attain a new heading, thereby allowing the aircraft to gain the advantage over a putative opponent in air-to-air combat. This maneuver is also known as a 'J turn.'

  19. X-31 in flight - Double Reversal

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at the Rockwell International facility, Palmdale, California, and the NASA Dryden Flight Research Center, Edwards, California, to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on October 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is an airplane with a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while he aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust-vectoring paddles made of graphite epoxy mounted on the exhaust nozzle of the X-31 aircraft directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31 aircraft were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This understanding is expected to lead to design methods that provide better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at NASA Dryden. The ARPA had requested flight research for the X-31 aircraft be moved there in February 1992. In addition to ARPA and NASA, the international test organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident Jan. 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 39-second clip begins as the X-31 performs a short loop at the top of a stall maneuver, then quickly reverses its course first left, then right by means of thrust vectoring -- thereby gaining a tactical advantage over a putative opponent in air-to-air combat.

  20. X-31 in flight - Post Stall Maneuver

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Two X-31 Enhanced Fighter Maneuverability (EFM) demonstrators were flown at Rockwell International's Palmdale, Calif., facility and the NASA Dryden Flight Research Center, Edwards, Calif., to obtain data that may apply to the design of highly-maneuverable next-generation fighters. The program had its first flight on Oct. 11, 1990, in Palmdale; it ended in June 1995. The X-31 program demonstrated the value of thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight during close-in air combat at very high angles of attack. The result of this increased maneuverability is a significant advantage over conventional fighters. 'Angle-of-attack' (alpha) is an engineering term to describe the angle of an aircraft's body and wings relative to its actual flight path. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to loss of control and result in the loss of the aircraft, pilot or both. Three thrust vectoring paddles made of graphite epoxy mounted on the X-31's exhaust nozzle directed the exhaust flow to provide control in pitch (up and down) and yaw (right and left) to improve control. The paddles can sustain heat of up to 1,500 degrees centigrade for extended periods of time. In addition the X-31s were configured with movable forward canards and fixed aft strakes. The canards were small wing-like structures set on the wing line between the nose and the leading edge of the wing. The strakes were set on the same line between the trailing edge of the wing and the engine exhaust. Both supplyied additional control in tight maneuvering situations. The X-31 research program produced technical data at high angles of attack. This information is giving engineers and aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This is expected to lead to design methods providing better maneuverability in future high performance aircraft and make them safer to fly. An international test organization of about 110 people, managed by the Advanced Research Projects Agency (ARPA), conducted the flight operations at Dryden, to which flight research was moved in February 1992 at the request of the Advanced Research Projects Agency (ARPA). In addition to ARPA and NASA, the International Test Organization (ITO) included the U.S. Navy, the U.S. Air Force, Rockwell International, the Federal Republic of Germany, and Daimler-Benz Aerospace (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace). NASA was responsible for flight research operations, aircraft maintenance, and research engineering once the program moved to Dryden. The No. 1 X-31 aircraft was lost in an accident Jan. 19, 1995. The pilot, Karl Heinz-Lang, of the Federal Republic of Germany, ejected safely before the aircraft crashed in an unpopulated desert area just north of Edwards. The X-31 program logged an X-plane record of 580 flights during the program, including 555 research missions and 21 in Europe for the 1995 Paris Air Show. A total of 14 pilots representing all agencies of the ITO flew the aircraft. This 34-second movie clip shows the aircraft as it slides backwards, thrust vectoring the tail over the top, turning the stall into a loop in which the aircraft then reverses it's heading and resumes level flight.

  1. Discovery Systems

    NASA Technical Reports Server (NTRS)

    Pell, Barney

    2003-01-01

    A viewgraph presentation on NASA's Discovery Systems Project is given. The topics of discussion include: 1) NASA's Computing Information and Communications Technology Program; 2) Discovery Systems Program; and 3) Ideas for Information Integration Using the Web.

  2. Immune System

    MedlinePLUS

    ... do: B lymphocytes are like the body's military intelligence system, seeking out their targets and sending defenses ... like the soldiers, destroying the invaders that the intelligence system has identified. Here's how it works. A ...

  3. Concentrator Systems

    NASA Astrophysics Data System (ADS)

    Luque-Heredia, Ignacio; Luque, Antonio

    2015-10-01

    The following sections are included: * Introduction * The early development of CPV * Concentrator solar cells * Optics for photovoltaic concentrators * Photovoltaic concentration modules * Tracking systems for photovoltaic concentration * High-concentration systems * Rating and performance * Cost considerations * Conclusions * References

  4. Stimulator system

    SciTech Connect

    Hakansson, B.H.; Saario, R.A.

    1984-02-14

    An electrical stimulator system is described incorporating rechargeable batteries and a charging circuit. A charging set and electrode support are alternatively connected to the stimulator system via a single common two-pole terminal. The system is designed to prevent current from flowing directly from the battery to the electrode support along the charging circuit while allowing charge current to flow in the opposite direction along the charging circuit if the charging set is connected to the system instead of the electrode support.

  5. Systems Engineering

    NASA Technical Reports Server (NTRS)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  6. System Effectiveness

    SciTech Connect

    Powell, Danny H; Elwood Jr, Robert H

    2011-01-01

    An effective risk assessment system is needed to address the threat posed by an active or passive insider who, acting alone or in collusion, could attempt diversion or theft of nuclear material. It is critical that a nuclear facility conduct a thorough self-assessment of the material protection, control, and accountability (MPC&A) system to evaluate system effectiveness. Self-assessment involves vulnerability analysis and performance testing of the MPC&A system. The process should lead to confirmation that mitigating features of the system effectively minimize the threat, or it could lead to the conclusion that system improvements or upgrades are necessary to achieve acceptable protection against the threat. Analysis of the MPC&A system is necessary to understand the limits and vulnerabilities of the system to internal threats. Self-assessment helps the facility be prepared to respond to internal threats and reduce the risk of theft or diversion of nuclear material. MSET is a self-assessment or inspection tool utilizing probabilistic risk assessment (PRA) methodology to calculate the system effectiveness of a nuclear facility's MPC&A system. MSET analyzes the effectiveness of an MPC&A system based on defined performance metrics for MPC&A functions based on U.S. and international best practices and regulations. A facility's MC&A system can be evaluated at a point in time and reevaluated after upgrades are implemented or after other system changes occur. The total system or specific subareas within the system can be evaluated. Areas of potential performance improvement or system upgrade can be assessed to determine where the most beneficial and cost-effective improvements should be made. Analyses of risk importance factors show that sustainability is essential for optimal performance. The analyses reveal where performance degradation has the greatest detrimental impact on total system risk and where performance improvements have the greatest reduction in system risk. The risk importance factors show the amount of risk reduction achievable with potential upgrades and the amount of risk reduction actually achieved after upgrades are completed. Applying the risk assessment tool gives support to budget prioritization by showing where budget support levels must be sustained for MC&A functions most important to risk. Results of the risk assessment are also useful in supporting funding justifications for system improvements that significantly reduce system risk.

  7. Cryogenic Systems

    NASA Astrophysics Data System (ADS)

    Hosoyama, Kenji

    2002-02-01

    In this lecture we discuss the principle of method of cooling to a very low temperature, i.e. cryogenic. The "gas molecular model" will be introduced to explain the mechanism cooling by the expansion engine and the Joule-Thomson expansion valve. These two expansion processes are normally used in helium refrigeration systems to cool the process gas to cryogenic temperature. The reverse Carnot cycle will be discussed in detail as an ideal refrigeration cycle. First the fundamental process of liquefaction and refrigeration cycles will be discussed, and then the practical helium refrigeration system. The process flow of the system and the key components; -compressor, expander, and heat exchanger- will be discussed. As an example of an actual refrigeration system, we will use the cryogenic system for the KEKB superconducting RF cavity. We will also discuss the liquid helium distribution system, which is very important, especially for the cryogenic systems used in accelerator applications. 1 Principles of Cooling and Fundamental Cooling Cycle 2 Expansion engine, Joule-Thomson expansion, kinetic molecular theory, and enthalpy 3 Liquefaction Systems 4 Refrigeration Systems 5 Practical helium liquefier/refrigeration system 6 Cryogenic System for TRISTAN Superconducting RF Cavity

  8. Planetary Systems

    NASA Astrophysics Data System (ADS)

    Artymowicz, P.

    The past decade brought direct evidence of the previously surmised existence of exoplanetary systems. Including into the definition of a such systems disks, where there is manifold and compelling evidence of a large number of planetesimals but not yet of full-fledged planets, we now know both young planetary systems (e.g., Beta Pictoris) and the more mature ones (a dozen of them discovered after 1995 in radial velocity surveys), as well as the somewhat more exotic pulsar planetary systems. The newly imaged disk of HR 4796A appears to be a young system in transition between a protoplanetary disk (primordial solar nebula) and a Beta Pic-type dusty remnant disk. It is a welcome addition to the catalog of types of planetary systems in nature. I will review some of the current theories of the planetary system formation, aimed at predicting or (more often) interpreting the remarkable diversity of exoplanets, including the hot Jupiters and eccentric giants (superplanets).

  9. Reference Systems

    NASA Astrophysics Data System (ADS)

    Fukushima, Toshio

    1996-03-01

    A reference system is a relation connecting observables and their mathematical represententions. The principle of general relativity assures that any sort of coordinate system can be used to describe physical phenomena. Thus, any reference system is only a convention, There is no absolutely true reference system. Instead, people seek for a best reference system, whose meaning may differ thus need to clarify, Taking an example from Earth rotation, we discuss how to find such a best reference system. The definition of the best system will change as scientific understandings deepen and computational environments develop. Therefore, we can not stop improving reference systems. However, when replacing an existing widely-spread system, one must take great care to minimize the inconvenience caused by its transition, especially the inconvenience which users might endure. The Standards Of Fundamental Astronomy (SOFA) project being conducted by the IAU WG on Astronomical Standards has the opportunity to ease this troublesome task. The World Wide Web (WWW) will be a main device to realize the project, namely to provide working standards including reference systems to the world.

  10. Magnetospheric Multiscale (MMS) Mission Attitude Ground System Design

    NASA Technical Reports Server (NTRS)

    Sedlak, Joseph E.; Superfin, Emil; Raymond, Juan C.

    2010-01-01

    This paper describes the attitude ground system (AGS) design to be used for support of the Magnetospheric MultiScale (MMS) mission. The AGS exists as one component of the mission operations control center. It has responsibility for validating the onboard attitude and accelerometer bias estimates, calibrating the attitude sensors and the spacecraft inertia tensor, and generating a definitive attitude history for use by the science teams. NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland is responsible for developing the MMS spacecraft, for the overall management of the MMS mission, and for mission operations. MMS is scheduled for launch in 2014 for a planned two-year mission. The MMS mission consists of four identical spacecraft flying in a tetrahedral formation in an eccentric Earth orbit. The relatively tight formation, ranging from 10 to 400 km, will provide coordinated observations giving insight into small-scale magnetic field reconnection processes. By varying the size of the tetrahedron and the orbital semi-major axis and eccentricity, and making use of the changing solar phase, this geometry allows for the study of both bow shock and magnetotail plasma physics, including acceleration, reconnection, and turbulence. The mission divides into two phases for science; these phases will have orbit dimensions of 1.2 x 12 Earth radii in the first phase and 1.2x25 Earth radii in the second in order to study the dayside magnetopause and the nightside magnetotail, respectively. The orbital periods are roughly one day and three days for the two mission phases. Each of the four MMS spacecraft will be spin stabilized at 3 revolutions per minute (rpm), with the spin axis oriented near the ecliptic north pole but tipped approximately 2.5 deg towards the Sun line. The main body of each spacecraft will be an eight-sided platform with diameter of 3.4 m and height of 1.2 m. Several booms are attached to this central core: two axial booms of 14.9 m length, two radial magnetometer booms of 5 m length, and four radial wire booms of 60 m length. Attitude and orbit control will use a set of axial and radial thrusters. A four-head star tracker and a slit-type digital Sun sensor (DSS) provide input for attitude determination. In addition, an accelerometer will be used for closed-loop orbit maneuver control. The primary AGS product will be a daily definitive attitude history. Due to power limitations, the star tracker and accelerometer data will not be available at all times. However, tracker data from at least 10 percent of each orbit and continuous DSS data will be provided. An extended Kalman filter (EKF) will be used to estimate the three-axis attitude (i.e., spin axis orientation and spin phase) and rotation rate for all times when the tracker data is valid. For other times, the attitude is generated by assuming a constant angular momentum vector in the inertial frame. The DSS sun pulse will provide a timing signal to maintain an accurate spin phase. There will be times when the Sun is occulted and DSS data is not available. If this occurs at the start or end of a definitive attitude product, then the spin phase will be extrapolated using the mean rate determined by the EKF.

  11. Micropower system

    SciTech Connect

    Krupka, Y.; Bachar, A.; Yerushalmi, S.

    1983-11-01

    A micropower DC/DC conversion system is disclosed providing a stabilized voltage output at a predetermined voltage higher than that of the energy source. The system is powered by one or more primary cells in parallel or by a suitable battery, and the system is of special use with systems requiring low power at stabilized voltage which is substantially independent of the energy source impedance and load variations. According to the preferred embodiment of the system the output voltage stabilization is controlled by voltage detection circuit based on C-MOS inverters which allows extremely low power drain. The system is of special value for use with electronic implantable devices such as cardiac pacemakers.

  12. Geothermal systems

    NASA Technical Reports Server (NTRS)

    Mohl, C.

    1978-01-01

    Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

  13. [Information systems].

    PubMed

    Rodrguez Maniega, Jos Antonio; Tro Maseda, Reyes

    2005-03-01

    The arrival of victims of the terrorist attacks of 11 March at the hospital put the efficiency of its information systems to the test. To be most efficient, these systems should be simple and directed, above all, to the follow-up of victims and to providing the necessary information to patients and families. A specific and easy to use system is advisable. PMID:15771852

  14. X-31 post-stall envelope expansion and tactical utility testing

    NASA Technical Reports Server (NTRS)

    Canter, Dave

    1994-01-01

    Technical and nontechnical lessons learned from the X-31 aircraft program are described in this viewgraph presentation. The tactical utility of high angle of attack flight and thrust vector control is discussed.

  15. Systemic darwinism.

    PubMed

    Winther, Rasmus Grnfeldt

    2008-08-19

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a "compositional paradigm" according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality. PMID:18697926

  16. Carbon Systems

    SciTech Connect

    Alisultanov, Z. Z.

    2013-06-15

    The electronic states of a 'quantum dot-graphene monolayer-SiO{sub 2} + n{sup +}-Si substrate' system in an external magnetic field are studied. An analytical expression for charge transfer in this system is obtained. The electronic states of a 'quantum dot-graphene bilayer-SiO{sub 2} + n{sup +}-Si substrate' system are considered. The systems under study are interesting from the viewpoint of controlling the optical properties of a quantum dot by means of an applied electric field.

  17. Anticipatory systems as linguistic systems

    NASA Astrophysics Data System (ADS)

    Ekdahl, Bertil

    2000-05-01

    The idea of system is well established although not well defined. What makes up a system depends on the observer. Thinking in terms of systems is only a convenient way to conceptualize organizations, natural or artificial, that show coherent properties. Among all properties, which can be ascribed to systems, one property seems to be more outstanding than others, namely that of being anticipatory. In nature, anticipatory properties are found only in living organizations. In this way it can be said to separate non-living systems from living because there is no indication that any natural phenomenon occurring in systems where there is no indication of life is anticipatory. The characteristic of living systems is that they are exposed to the evolution contrary to causal systems that do not undergo changes due to the influence of the environment. Causal systems are related to the past in such a way that subsequent situations can be calculated from knowledge of past situations. In causal systems the past is the cause of the present and there is no reference to the future as a determining agent, contrary to anticipatory systems where expectations are the cause of the present action. Since anticipatory properties are characteristic of living systems, this property, as all other properties in living systems, is a result of the evolution and can be found in plants as well as in animals. Thus, it is not only tied to consciousness but is found at a more basic level, i.e., in the interplay between genotype and phenotype. Anticipation is part of the genetic language in such a way that appropriate actions, for events in the anticipatory systems environment, are inscribed in the genes. Anticipatory behavior, as a result of the interpretation of the genetic language, has been selected by the evolution. In this paper anticipatory systems are regarded as linguistic systems and I argue that as such anticipation cannot be fragmented but must be holistically studied. This has the implication that anticipatory behavior can only partially be described in a computer language and, furthermore, it shows that only a restricted class of anticipatory systems can be transferred to computers.

  18. Reference systems

    NASA Astrophysics Data System (ADS)

    Boucher, C.

    Terrestrial and inertial reference systems based on Newtonian physics are introduced. Techniques for determining the coordinates of points in terrestrial reference systems are reviewed. Classical geodesy; satellite laser and Doppler methods; laser-Moon measurements; and very long base interferometry are described.

  19. Power system

    SciTech Connect

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  20. Electronic system

    DOEpatents

    Robison, G H; Dickson, J F

    1960-11-15

    An electronic system is designed for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. The system comprises separate input means electrically associated with the events under observation an electronic channel associated with each input means, including control means and indicating means; timing means adapted to apply a signal from the input means after a predetermined time to the control means to deactivate each of the channels; and means for resetting the system to its initial condition after the observation of each group of events. (D.L.C.)

  1. Saturn Systems.

    PubMed

    U Rehman, Habib; McKee, Nida A; McKee, Michael L

    2016-01-15

    Several ring systems (Saturn systems) have been studied using DFT methods that include dispersion effects. Comparison with X-ray structures are made with three systems, and the agreement is quite good. Binding enthalpies and binding free energies in dichloromethane and toluene have been computed. The effect of an encapsulated lithium cation is accessed by comparing C60 @(C6 H4 )10 and [Li@C60 @(C6 H4 )10 ](+) . The [Li@C60 ](+) cation is a much better acceptor than C60 which leads to greater donor-acceptor interactions and larger charge transfer from the ring to [Li@C60 ](+) . 2015 Wiley Periodicals, Inc. PMID:26096724

  2. Recommender systems

    NASA Astrophysics Data System (ADS)

    L, Linyuan; Medo, Mat; Yeung, Chi Ho; Zhang, Yi-Cheng; Zhang, Zi-Ke; Zhou, Tao

    2012-10-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article, we review recent developments in recommender systems and discuss the major challenges. We compare and evaluate available algorithms and examine their roles in the future developments. In addition to algorithms, physical aspects are described to illustrate macroscopic behavior of recommender systems. Potential impacts and future directions are discussed. We emphasize that recommendation has great scientific depth and combines diverse research fields which makes it interesting for physicists as well as interdisciplinary researchers.

  3. [Systemic mastocytosis].

    PubMed

    Fain, Olivier; Stirnemann, Jerôme; Lortholary, Olivier

    2005-10-15

    Systemic mastocytosis is characterized by mast cell proliferation in different organs. Classification delineates 4 categories: indolent systemic mastocytosis, systemic mastocytosis with an associated clonal hematologic non-mast cell lineage disease, aggressive systemic mastocytosis and mast cell leukaemia. Clinical manifestations are due to organ infiltration (skin, bone, gut, liver, spleen, lymph nodes) and release of mast-cell mediators. Diagnosis of mastocytosis is based on appropriate stains (Giemsa, Toluidine) and immunophenotype features (tryptase, CD117). Serum level of tryptase reflects the total burden of mast cells. Treatment must prevent mast cell mediators release (histamine antagonists, cromolyn sodium, corticosteroids, leukotriene-receptor inhibitors) and have a cytoreductive effect (interferon, cladribine, tyrosine kinase inhibitors). PMID:16334197

  4. Respiratory system

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.

    1973-01-01

    The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

  5. Systems Vaccinology

    PubMed Central

    Pulendran, Bali; Li, Shuzhao; Nakaya, Helder I

    2010-01-01

    Vaccination is one of the greatest triumphs of modern medicine, yet we remain largely ignorant of the mechanisms by which successful vaccines stimulate protective immunity. Two recent advances are beginning to illuminate such mechanisms: realization of the pivotal role of the innate immune system in sensing microbes and stimulating adaptive immunity, and advances in systems biology. Recent studies have used systems biology approaches to obtain a global picture of the immune responses to vaccination in humans. This has enabled the identification of early innate signatures that predict the immunogenicity of vaccines, and identification of potentially novel mechanisms of immune regulation. Here we review these advances, and critically examine the potential opportunities and challenges posed by systems biology in vaccine development. PMID:21029962

  6. Microelectromechanical Systems

    NASA Technical Reports Server (NTRS)

    Gabriel, Kaigham J.

    1995-01-01

    Micro-electromechanical systems (MEMS) is an enabling technology that merges computation and communication with sensing and actuation to change the way people and machines interact with the physical world. MEMS is a manufacturing technology that will impact widespread applications including: miniature inertial measurement measurement units for competent munitions and personal navigation; distributed unattended sensors; mass data storage devices; miniature analytical instruments; embedded pressure sensors; non-invasive biomedical sensors; fiber-optics components and networks; distributed aerodynamic control; and on-demand structural strength. The long term goal of ARPA's MEMS program is to merge information processing with sensing and actuation to realize new systems and strategies for both perceiving and controlling systems, processes, and the environment. The MEMS program has three major thrusts: advanced devices and processes, system design, and infrastructure.

  7. Attitude control system of the Delfi-n3Xt satellite

    NASA Astrophysics Data System (ADS)

    Reijneveld, J.; Choukroun, D.

    2013-12-01

    This work is concerned with the development of the attitude control algorithms that will be implemented on board of the Delfi-n3xt nanosatellite, which is to be launched in 2013. One of the mission objectives is to demonstrate Sun pointing and three axis stabilization. The attitude control modes and the associated algorithms are described. The control authority is shared between three body-mounted magnetorquers (MTQ) and three orthogonal reaction wheels. The attitude information is retrieved from Sun vector measurements, Earth magnetic field measurements, and gyro measurements. The design of the control is achieved as a trade between simplicity and performance. Stabilization and Sun pointing are achieved via the successive application of the classical Bdot control law and a quaternion feedback control. For the purpose of Sun pointing, a simple quaternion estimation scheme is implemented based on geometric arguments, where the need for a costly optimal filtering algorithm is alleviated, and a single line of sight (LoS) measurement is required - here the Sun vector. Beyond the three-axis Sun pointing mode, spinning Sun pointing modes are also described and used as demonstration modes. The three-axis Sun pointing mode requires reaction wheels and magnetic control while the spinning control modes are implemented with magnetic control only. In addition, a simple scheme for angular rates estimation using Sun vector and Earth magnetic measurements is tested in the case of gyro failures. The various control modes performances are illustrated via extensive simulations over several orbits time spans. The simulated models of the dynamical space environment, of the attitude hardware, and the onboard controller logic are using realistic assumptions. All control modes satisfy the minimal Sun pointing requirements allowed for power generation.

  8. Systems and Components Fuel Delivery System, Water Delivery System, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

  9. Systems Studies

    SciTech Connect

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  10. A study of redundancy management strategy for tetrad strap-down inertial systems. [error detection codes

    NASA Technical Reports Server (NTRS)

    Hruby, R. J.; Bjorkman, W. S.; Schmidt, S. F.; Carestia, R. A.

    1979-01-01

    Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction.

  11. ActimedARM - design of a wearable system to monitor daily actimetry.

    PubMed

    Noury, Norbert; Perriot, Bruno; Collet, Julien; Grenier, Etienne; Cerny, Martin; Massot, Bertrand; McAdams, Eric

    2013-01-01

    We developed a low power kinematic sensor, ActimedARM, incorporating three-axis accelerometer and magnetometer, a microcontroller ARM3, a ZigBee wireless communication and μSD memory storage. With embedded algorithms it can detect in real time the postures of the subject. A preliminary assessment conducted on 12 subjects reached a 97% correct classification rate. The device exhibits 32 days of autonomy on a 3600 mAh capacity battery, which makes it convenient for field experiments in true daily life. PMID:24110071

  12. Systemic trauma.

    PubMed

    Goldsmith, Rachel E; Martin, Christina Gamache; Smith, Carly Parnitzke

    2014-01-01

    Substantial theoretical, empirical, and clinical work examines trauma as it relates to individual victims and perpetrators. As trauma professionals, it is necessary to acknowledge facets of institutions, cultures, and communities that contribute to trauma and subsequent outcomes. Systemic trauma-contextual features of environments and institutions that give rise to trauma, maintain it, and impact posttraumatic responses-provides a framework for considering the full range of traumatic phenomena. The current issue of the Journal of Trauma & Dissociation is composed of articles that incorporate systemic approaches to trauma. This perspective extends conceptualizations of trauma to consider the influence of environments such as schools and universities, churches and other religious institutions, the military, workplace settings, hospitals, jails, and prisons; agencies and systems such as police, foster care, immigration, federal assistance, disaster management, and the media; conflicts involving war, torture, terrorism, and refugees; dynamics of racism, sexism, discrimination, bullying, and homophobia; and issues pertaining to conceptualizations, measurement, methodology, teaching, and intervention. Although it may be challenging to expand psychological and psychiatric paradigms of trauma, a systemic trauma perspective is necessary on both scientific and ethical grounds. Furthermore, a systemic trauma perspective reflects current approaches in the fields of global health, nursing, social work, and human rights. Empirical investigations and intervention science informed by this paradigm have the potential to advance scientific inquiry, lower the incidence of a broader range of traumatic experiences, and help to alleviate personal and societal suffering. PMID:24617751

  13. Robotic System

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A complicated design project, successfully carried out by New York manufacturing consultant with help from NERAC, Inc., resulted in new type robotic system being marketed for industrial use. Consultant Robert Price, operating at E.S.I, Inc. in Albany, NY, sought help from NERAC to develop an automated tool for deburring the inside of 8 inch breech ring assemblies for howitzers produced by Watervliet Arsenal. NERAC conducted a search of the NASA data base and six others. From information supplied, Price designed a system consisting of a standard industrial robot arm, with a specially engineered six-axis deburring tool fitted to it. A microcomputer and computer program direct the tool on its path through the breech ring. E.S.I. markets the system to aerospace and metal cutting industries for deburring, drilling, routing and refining machined parts.

  14. Systemic mastocytosis.

    PubMed

    Akin, Cem; Metcalfe, Dean D

    2004-01-01

    Systemic mastocytosis is a clonal disorder of the mast cell and its progenitor. The symptoms of systemic mastocytosis are due to the pathologic accumulation and activation of mast cells in various tissues such as bone marrow, skin, gastrointestinal tract, liver, and spleen. Recent studies revealed striking differences between the molecular and cellular biology of mast cells in patients with mastocytosis and those of healthy individuals. These findings are being used in formulating diagnostic criteria as well as designing novel treatment approaches to the disease. PMID:14746529

  15. Neuromodulatory systems

    PubMed Central

    Werner, Gerhard; Mitterauer, Bernhard J.

    2013-01-01

    We examine the interactions and interdependencies between Neuroglia, the Brain-Cell Microenvironment, and the processes commonly subsumed under Neuromodulation. The interactions of the component processes covering a wide spectrum of frequencies are designated as Neuromodulatory Systems (NMS). This implies NMS's scale-invariance as the capacity of linking actions across many time scales, and self-similarity at any scale. These features endow NMS with the ability to respond adaptively to neural impulse traffic of an unpredictably wide frequency spectrum. In this preliminary perspective, the components of NMS are only outlined based on concepts of Complex Systems Dynamics. However, their interactions must be formally elaborated in further investigations. PMID:23532509

  16. Microbiology System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Technology originating in a NASA-sponsored study of the measurement of microbial growth in zero gravity led to the development of Biomerieux Vitek, Inc.'s VITEK system. VITEK provides a physician with accurate diagnostic information and identifies the most effective medication. Test cards are employed to identify organisms and determine susceptibility to antibiotics. A photo-optical scanner scans the card and monitors changes in the growth of cells contained within the card. There are two configurations - VITEK and VITEK JR as well as VIDAS, a companion system that detects bacteria, viruses, etc. from patient specimens. The company was originally created by McDonnell Douglas, the NASA contractor.

  17. Lubrication system

    SciTech Connect

    Wadding, C.; Lagasse, N.L.; Milo, G.T.; Vankamerik, J.G.

    1986-02-11

    This patent describes a lubrication system for controlling the flow of lubricant as a function of the altitude at which a gas turbine engine is operating. This lubrication system is comprised of: 1.) A source of lubricant under pressure; 2.) A unit requiring lubrication; 3.) A movable valve in fluid communication with the source and with the unit for regulating the flow of lubricant from the source to the unit; and 4.) An altitude sensor associated with the movable valve for positioning the movable valve to control the flow of lubricant from the source to the unit, as a function of the altitude at which the engine is operating.

  18. ELECTRONIC SYSTEM

    DOEpatents

    Robison, G.H. et al.

    1960-11-15

    An electronic system is described for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. It is comprised of separate input means electrically associated with the events under observation: an electronic channel associated with each input means including control means and indicating means; timing means associated with each of the input means and the control means and adapted to derive a signal from the input means and apply it after a predetermined time to the control means to effect deactivation of each of the channels; and means for resetting the system to its initial condition after observation of each group of events.

  19. Computer systems

    NASA Technical Reports Server (NTRS)

    Olsen, Lola

    1992-01-01

    In addition to the discussions, Ocean Climate Data Workshop hosts gave participants an opportunity to hear about, see, and test for themselves some of the latest computer tools now available for those studying climate change and the oceans. Six speakers described computer systems and their functions. The introductory talks were followed by demonstrations to small groups of participants and some opportunities for participants to get hands-on experience. After this familiarization period, attendees were invited to return during the course of the Workshop and have one-on-one discussions and further hands-on experience with these systems. Brief summaries or abstracts of introductory presentations are addressed.

  20. Burner system

    SciTech Connect

    Thorpe, M.L.; Hanson, K.P.

    1987-04-14

    An internal combustion burner system is described comprising: structure defining a combustion chamber including spaced, opposed, plate type, planar, uncooled sidewalls and peripheral structure secured between the sidewalls and extending around the perimeter of the combustion chamber. The sidewalls are of thin flexible high temperature sheet material and are free to flex outwardly to accommodate thermal stresses during operation of the combustion system; and the peripheral structure including means defining housing inlet port structure, means defining chamber inlet port structure, and, means defining perimeter flow paths that extend around the perimeter of the combustion chamber.