Science.gov

Sample records for adaptive maneuvering logic

  1. Improvements to the adaptive maneuvering logic program

    NASA Technical Reports Server (NTRS)

    Burgin, George H.

    1986-01-01

    The Adaptive Maneuvering Logic (AML) computer program simulates close-in, one-on-one air-to-air combat between two fighter aircraft. Three important improvements are described. First, the previously available versions of AML were examined for their suitability as a baseline program. The selected program was then revised to eliminate some programming bugs which were uncovered over the years. A listing of this baseline program is included. Second, the equations governing the motion of the aircraft were completely revised. This resulted in a model with substantially higher fidelity than the original equations of motion provided. It also completely eliminated the over-the-top problem, which occurred in the older versions when the AML-driven aircraft attempted a vertical or near vertical loop. Third, the requirements for a versatile generic, yet realistic, aircraft model were studied and implemented in the program. The report contains detailed tables which make the generic aircraft to be either a modern, high performance aircraft, an older high performance aircraft, or a previous generation jet fighter.

  2. An adaptive maneuvering logic computer program for the simulation of one-on-one air-to-air combat. Volume 1: General description

    NASA Technical Reports Server (NTRS)

    Burgin, G. H.; Fogel, L. J.; Phelps, J. P.

    1975-01-01

    A technique for computer simulation of air combat is described. Volume 1 decribes the computer program and its development in general terms. Two versions of the program exist. Both incorporate a logic for selecting and executing air combat maneuvers with performance models of specific fighter aircraft. In the batch processing version the flight paths of two aircraft engaged in interactive aerial combat and controlled by the same logic are computed. The realtime version permits human pilots to fly air-to-air combat against the adaptive maneuvering logic (AML) in Langley Differential Maneuvering Simulator (DMS). Volume 2 consists of a detailed description of the computer programs.

  3. An adaptive maneuvering logic computer program for the simulation of one-to-one air-to-air combat. Volume 2: Program description

    NASA Technical Reports Server (NTRS)

    Burgin, G. H.; Owens, A. J.

    1975-01-01

    A detailed description is presented of the computer programs in order to provide an understanding of the mathematical and geometrical relationships as implemented in the programs. The individual sbbroutines and their underlying mathematical relationships are described, and the required input data and the output provided by the program are explained. The relationship of the adaptive maneuvering logic program with the program to drive the differential maneuvering simulator is discussed.

  4. Coordination Logic for Repulsive Resolution Maneuvers

    NASA Technical Reports Server (NTRS)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Dutle, Aaron M.

    2016-01-01

    This paper presents an algorithm for determining the direction an aircraft should maneuver in the event of a potential conflict with another aircraft. The algorithm is implicitly coordinated, meaning that with perfectly reliable computations and information, it will in- dependently provide directional information that is guaranteed to be coordinated without any additional information exchange or direct communication. The logic is inspired by the logic of TCAS II, the airborne system designed to reduce the risk of mid-air collisions between aircraft. TCAS II provides pilots with only vertical resolution advice, while the proposed algorithm, using a similar logic, provides implicitly coordinated vertical and horizontal directional advice.

  5. Automated maneuver planning using a fuzzy logic algorithm

    NASA Technical Reports Server (NTRS)

    Conway, D.; Sperling, R.; Folta, D.; Richon, K.; Defazio, R.

    1994-01-01

    Spacecraft orbital control requires intensive interaction between the analyst and the system used to model the spacecraft trajectory. For orbits with right mission constraints and a large number of maneuvers, this interaction is difficult or expensive to accomplish in a timely manner. Some automation of maneuver planning can reduce these difficulties for maneuver-intensive missions. One approach to this automation is to use fuzzy logic in the control mechanism. Such a prototype system currently under development is discussed. The Tropical Rainfall Measurement Mission (TRMM) is one of several missions that could benefit from automated maneuver planning. TRMM is scheduled for launch in August 1997. The spacecraft is to be maintained in a 350-km circular orbit throughout the 3-year lifetime of the mission, with very small variations in this orbit allowed. Since solar maximum will occur as early as 1999, the solar activity during the TRMM mission will be increasing. The increasing solar activity will result in orbital maneuvers being performed as often as every other day. The results of automated maneuver planning for the TRMM mission will be presented to demonstrate the prototype of the fuzzy logic tool.

  6. Adaptive parallel logic networks

    NASA Technical Reports Server (NTRS)

    Martinez, Tony R.; Vidal, Jacques J.

    1988-01-01

    Adaptive, self-organizing concurrent systems (ASOCS) that combine self-organization with massive parallelism for such applications as adaptive logic devices, robotics, process control, and system malfunction management, are presently discussed. In ASOCS, an adaptive network composed of many simple computing elements operating in combinational and asynchronous fashion is used and problems are specified by presenting if-then rules to the system in the form of Boolean conjunctions. During data processing, which is a different operational phase from adaptation, the network acts as a parallel hardware circuit.

  7. Maneuver tracking using an adaptive Gaussian sum technique

    NASA Astrophysics Data System (ADS)

    Stubberud, Stephen C.; Kramer, Kathleen A.

    2005-03-01

    The best method to track through a maneuver is to know the motion model of the maneuvering target. Unfortunately, a priori knowledge of the maneuver is not usually known. If the motion model of the maneuver can be estimated quickly from the measurements then the resulting track estimate will be better than the a priori static model. An adaptive function approximation technique to improve the motion model while tracking is analyzed for its potential to track through various maneuvers. The basic function approximation technique is that of a Gaussian sum. The Gaussian sum approximates the function which represents the error between the initial static model and the actual model of the maneuver. The parameters of the Gaussian sum are identified on-line using a Kalman filter identification scheme. This scheme, used in conjunction with a Kalman filter tracker, creates a coupled technique that can improve the motion model quickly. This adaptive Gaussian sum approach to maneuver tracking has its performance analyzed for three maneuvers. These maneuvers include a maneuvering ballistic target, a target going through an s-curve, and real target with a multiple racetrack flight path. The results of these test cases demonstrate the capabilities of this approach to track maneuvering targets.

  8. Nonlinear Aerodynamic Modeling From Flight Data Using Advanced Piloted Maneuvers and Fuzzy Logic

    NASA Technical Reports Server (NTRS)

    Brandon, Jay M.; Morelli, Eugene A.

    2012-01-01

    Results of the Aeronautics Research Mission Directorate Seedling Project Phase I research project entitled "Nonlinear Aerodynamics Modeling using Fuzzy Logic" are presented. Efficient and rapid flight test capabilities were developed for estimating highly nonlinear models of airplane aerodynamics over a large flight envelope. Results showed that the flight maneuvers developed, used in conjunction with the fuzzy-logic system identification algorithms, produced very good model fits of the data, with no model structure inputs required, for flight conditions ranging from cruise to departure and spin conditions.

  9. Force oscillations simulating breathing maneuvers do not prevent force adaptation.

    PubMed

    Pascoe, Chris; Jiao, Yuekan; Seow, Chun Y; Paré, Peter D; Bossé, Ynuk

    2012-07-01

    Airway inflammation in patients with asthma exposes the airway smooth muscle (ASM) to a variety of spasmogens. These spasmogens increase ASM tone, which can lead to force adaptation. Length oscillations of ASM, which occur in vivo due to breathing maneuvers, can attenuate force adaptation. However, in the presence of tone, the force oscillations required to achieve these length oscillations may be unphysiologic (i.e., magnitude greater than the ones achieved due to the swings in transpulmonary pressure required for breathing). In the present study, we applied force oscillations simulating the tension oscillations experienced by the wall of a fourth-generation airway during tidal breathing with or without deep inspirations (DI) to ASM. The goal was to investigate whether force adaptation occurs in conditions mimicking breathing maneuvers. Tone was induced by carbachol (average, 20 nM), and the force-generating capacity of the ASM was assessed at 5-minute intervals before and after carbachol administration using electrical field stimulations (EFS). The results show that force oscillations applied before the introduction of tone had a small effect on the force produced by EFS (declined to 96.8% [P > 0.05] and 92.3% [P < 0.05] with and without DI, respectively). The tone induced by carbachol transiently decreased after a DI and declined significantly (P < 0.05) due to tidal breathing oscillations (25%). These force oscillations did not prevent force adaptation (gain of force of 11.2 ± 2.2 versus 13.5 ± 2.7 and 11.2 ± 3.0% in static versus dynamic conditions with or without DI, respectively). The lack of effect of simulated breathing maneuvers on force adaptation suggests that this gain in ASM force may occur in vivo and could contribute to the development of airway hyperresponsiveness. PMID:22323367

  10. Proximity Operations for Space Situational Awareness Spacecraft Rendezvous and Maneuvering using Numerical Simulations and Fuzzy Logic

    NASA Astrophysics Data System (ADS)

    Carrico, T.; Langster, T.; Carrico, J.; Alfano, S.; Loucks, M.; Vallado, D.

    The authors present several spacecraft rendezvous and close proximity maneuvering techniques modeled with a high-precision numerical integrator using full force models and closed loop control with a Fuzzy Logic intelligent controller to command the engines. The authors document and compare the maneuvers, fuel use, and other parameters. This paper presents an innovative application of an existing capability to design, simulate and analyze proximity maneuvers; already in use for operational satellites performing other maneuvers. The system has been extended to demonstrate the capability to develop closed loop control laws to maneuver spacecraft in close proximity to another, including stand-off, docking, lunar landing and other operations applicable to space situational awareness, space based surveillance, and operational satellite modeling. The fully integrated end-to-end trajectory ephemerides are available from the authors in electronic ASCII text by request. The benefits of this system include: A realistic physics-based simulation for the development and validation of control laws A collaborative engineering environment for the design, development and tuning of spacecraft law parameters, sizing actuators (i.e., rocket engines), and sensor suite selection. An accurate simulation and visualization to communicate the complexity, criticality, and risk of spacecraft operations. A precise mathematical environment for research and development of future spacecraft maneuvering engineering tasks, operational planning and forensic analysis. A closed loop, knowledge-based control example for proximity operations. This proximity operations modeling and simulation environment will provide a valuable adjunct to programs in military space control, space situational awareness and civil space exploration engineering and decision making processes.

  11. Study to define logic associated with CMGS to maneuver and stabilize an orbiting spacecraft

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A study was conducted to define the logic associated with the control moment gyroscopes to maneuver and stabilize an orbiting spacecraft. The study objectives are as follows: (1) to define mission requirements and feasible attitudes for a shuttle-like vehicle that will meet mission objectives, (2) to determine the control moment gyroscope (CMG) and system configurations that will best meet overall mission requirements, (3) to define all of the software required to manage and control the selected CMG systems, and (4) to verify by computer simulation the adequacy of the selected CMG system and specified software package in meeting the overall mission requirements.

  12. Adaptive formation flying maneuvers for multiple relative orbits

    NASA Astrophysics Data System (ADS)

    Saunders, Marc

    In order to extend and preserve the mission of an earth orbiting satellite it is imperative that the on board maneuvers do not waste propulsion but maneuver the spacecraft optimally. The challenge for ground stations is to plan maneuvers for spacecraft that will achieve a desired orbit while minimizing fuel costs. Increasing this challenge is the addition of specific keep-out zones (constraints on the spacecraft). For example, a low-earth orbiter (LEO) may need to maintain a specific orbit plane for a sun-synchronous imaging mission but it now has to contend with opposing debris. Computing a maneuver to avoid the debris could have consequences to the mission constraints and cause undesired affects to the desired orbit. The purpose of this research is to develop some techniques that can aid in finding some optimal maneuvers (or maneuvers that use the least amount of energy) and will maintain mission requirements while preserving constraints. Two different models will be developed that can minimize energy used in the maneuvers. The first model is a linear set of impulsive maneuvers derived from the Clohessy-Wilshire Equations. This model can be used as a targeting equation for targeting a specific relative orbit that also minimizes the total energy among a series of maneuvers. The second method is a nonlinear model using a Lyapunov Function in a feedback control loop; where the position of a spacecraft relative to a target orbit is minimized and the reference motion can be used to create keep-out zones.

  13. Adapting Covariance Propagation to Account for the Presence of Modeled and Unmodeled Maneuvers

    NASA Technical Reports Server (NTRS)

    Schiff, Conrad

    2006-01-01

    This paper explores techniques that can be used to adapt the standard linearized propagation of an orbital covariance matrix to the case where there is a maneuver and an associated execution uncertainty. A Monte Carlo technique is used to construct a final orbital covariance matrix for a 'propagate-burn-propagate' process that takes into account initial state uncertainty and execution uncertainties in the maneuver magnitude. This final orbital covariance matrix is regarded as 'truth' and comparisons between it and three methods using modified linearized covariance propagation are made. The first method accounts for the maneuver by modeling its nominal effect within the state transition matrix but excludes the execution uncertainty by omitting a process noise matrix from the computation. In the second method, the maneuver is not modeled but the uncertainty in its magnitude is accounted for by the inclusion of a process noise matrix. In the third method, which is essentially a hybrid of the first two, the nominal portion of the maneuver is included via the state transition matrix while a process noise matrix is used to account for the magnitude uncertainty. Since this method also correctly accounts for the presence of the maneuver in the nominal orbit, it is the best method for applications involving the computation of times of closest approach and the corresponding probability of collision, Pc. However, applications for the two other methods exist and are briefly discussed. Despite the fact that the process model ('propagate-burn-propagate') that was studied was very simple - point-mass gravitational effects due to the Earth combined with an impulsive delta-V in the velocity direction for the maneuver - generalizations to more complex scenarios, including high fidelity force models, finite duration maneuvers, and maneuver pointing errors, are straightforward and are discussed in the conclusion.

  14. Adapting Covariance Propagation to Account for the Presence of Modeled and Unmodeled Maneuvers

    NASA Technical Reports Server (NTRS)

    Schiff, Conrad

    2006-01-01

    This paper explores techniques that can be used to adapt the standard linearized propagation of an orbital covariance matrix to the case where there is a maneuver and an associated execution uncertainty. A Monte Carlo technique is used to construct a final orbital covariance matrix for a 'prop-burn-prop' process that takes into account initial state uncertainty and execution uncertainties in the maneuver magnitude. This final orbital covariance matrix is regarded as 'truth' and comparisons are made with three methods using modified linearized covariance propagation. The first method accounts for the maneuver by modeling its nominal effect within the state transition matrix but excludes the execution uncertainty by omitting a process noise matrix from the computation. The second method does not model the maneuver but includes a process noise matrix to account for the uncertainty in its magnitude. The third method, which is essentially a hybrid of the first two, includes the nominal portion of the maneuver via the state transition matrix and uses a process noise matrix to account for the magnitude uncertainty. The first method is unable to produce the final orbit covariance except in the case of zero maneuver uncertainty. The second method yields good accuracy for the final covariance matrix but fails to model the final orbital state accurately. Agreement between the simulated covariance data produced by this method and the Monte Carlo truth data fell within 0.5-2.5 percent over a range of maneuver sizes that span two orders of magnitude (0.1-20 m/s). The third method, which yields a combination of good accuracy in the computation of the final covariance matrix and correct accounting for the presence of the maneuver in the nominal orbit, is the best method for applications involving the computation of times of closest approach and the corresponding probability of collision, PC. However, applications for the two other methods exist and are briefly discussed. Although

  15. Adaptive chirp-Fourier transform for chirp estimation with applications in ISAR imaging of maneuvering targets

    NASA Astrophysics Data System (ADS)

    Xia, Xiang-Gen; Wang, Genyuan; Chen, Victor C.

    2001-03-01

    This paper first reviews some basic properties of the discrete chirp-Fourier transform and then present an adaptive chirp- Fourier transform, a generalization of the amplitude and phase estimation of sinusoids (APES) algorithm proposed by Li and Stoica for sinusoidal signals. We finally applied it to the ISAR imaging of maneuvering targets.

  16. An adaptive guidance logic for an aeroasisted orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Hill, O.

    1984-01-01

    The Orbital Transfer Vehicle (OTV) is to be employed for the delivery of a paylod to a high earth orbit, such as a geosynchronous orbit. Subsequently, the OTV is to return to a low earth parking orbit. The present investigation is concerned with an aeroassisted OTV (AOTV) which achieves the required reduction in velocity on its return to the parking orbit through aerodynamic braking. An adaptive guidance logic is employed to control and AOTV as it passes through the earth's upper atmosphere. Attention is given to details regarding the adaptive guidance logic, and a performance evaluation. It is found that the performance of the adaptive guidance logic is satisfactory for the considered conditions.

  17. An Adaptive Nonlinear Aircraft Maneuvering Envelope Estimation Approach for Online Applications

    NASA Technical Reports Server (NTRS)

    Schuet, Stefan R.; Lombaerts, Thomas Jan; Acosta, Diana; Wheeler, Kevin; Kaneshige, John

    2014-01-01

    A nonlinear aircraft model is presented and used to develop an overall unified robust and adaptive approach to passive trim and maneuverability envelope estimation with uncertainty quantification. The concept of time scale separation makes this method suitable for the online characterization of altered safe maneuvering limitations after impairment. The results can be used to provide pilot feedback and/or be combined with flight planning, trajectory generation, and guidance algorithms to help maintain safe aircraft operations in both nominal and off-nominal scenarios.

  18. Adaptive Training of Manual Control: 1. Comparison of Three Adaptive Variables and Two Logic Schemes.

    ERIC Educational Resources Information Center

    Norman, D. A.; And Others

    "Machine controlled adaptive training is a promising concept. In adaptive training the task presented to the trainee varies as a function of how well he performs. In machine controlled training, adaptive logic performs a function analogous to that performed by a skilled operator." This study looks at the ways in which gain-effective time constant…

  19. An adaptive guidance algorithm for an aerodynamically assisted orbital plane change maneuver. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Blissit, J. A.

    1986-01-01

    Using analysis results from the post trajectory optimization program, an adaptive guidance algorithm is developed to compensate for density, aerodynamic and thrust perturbations during an atmospheric orbital plane change maneuver. The maneuver offers increased mission flexibility along with potential fuel savings for future reentry vehicles. Although designed to guide a proposed NASA Entry Research Vehicle, the algorithm is sufficiently generic for a range of future entry vehicles. The plane change analysis provides insight suggesting a straight-forward algorithm based on an optimized nominal command profile. Bank angle, angle of attack, and engine thrust level, ignition and cutoff times are modulated to adjust the vehicle's trajectory to achieve the desired end-conditions. A performance evaluation of the scheme demonstrates a capability to guide to within 0.05 degrees of the desired plane change and five nautical miles of the desired apogee altitude while maintaining heating constraints. The algorithm is tested under off-nominal conditions of + or -30% density biases, two density profile models, + or -15% aerodynamic uncertainty, and a 33% thrust loss and for various combinations of these conditions.

  20. Maneuvering control and configuration adaptation of a biologically inspired morphing aircraft

    NASA Astrophysics Data System (ADS)

    Abdulrahim, Mujahid

    Natural flight as a source of inspiration for aircraft design was prominent with early aircraft but became marginalized as aircraft became larger and faster. With recent interest in small unmanned air vehicles, biological inspiration is a possible technology to enhance mission performance of aircraft that are dimensionally similar to gliding birds. Serial wing joints, loosely modeling the avian skeletal structure, are used in the current study to allow significant reconfiguration of the wing shape. The wings are reconfigured to optimize aerodynamic performance and maneuvering metrics related to specific mission tasks. Wing shapes for each mission are determined and related to the seagulls, falcons, albatrosses, and non-migratory African swallows on which the aircraft are based. Variable wing geometry changes the vehicle dynamics, affording versatility in flight behavior but also requiring appropriate compensation to maintain stability and controllability. Time-varying compensation is in the form of a baseline controller which adapts to both the variable vehicle dynamics and to the changing mission requirements. Wing shape is adapted in flight to minimize a cost function which represents energy, temporal, and spatial efficiency. An optimal control architecture unifies the control and adaptation tasks.

  1. Adaptive Process Control with Fuzzy Logic and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision-making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  2. Adaptive process control using fuzzy logic and genetic algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  3. Comparison of various schema of filter adaptivity for the tracking of maneuvering targets

    NASA Astrophysics Data System (ADS)

    Jouan, Alexandre; Bosse, Eloi; Simard, Marc-Alain; Shahbazian, Elisa

    1998-09-01

    Tracking maneuvering targets is a complex problem which has generated a great deal of effort over the past several years. It has now been well established that in terms of tracking accuracy, the Interacting Multiple Model (IMM) algorithm, where state estimates are mixed, performs significantly better for maneuvering targets than other types of filters. However, the complexity of the IMM algorithm can prohibit its use in these applications of which similar algorithms cannot provide the necessary accuracy and which can ont afford the computational load of IMM algorithm. This paper presents the evaluation of the tracking accuracy of a multiple model track filter using three different constant-velocity models running in parallel and a maneuver detector. The output estimate is defined by selecting the model whose likelihood function is lower than a target maneuver threshold.

  4. A new adaptive configuration of PID type fuzzy logic controller.

    PubMed

    Fereidouni, Alireza; Masoum, Mohammad A S; Moghbel, Moayed

    2015-05-01

    In this paper, an adaptive configuration for PID type fuzzy logic controller (FLC) is proposed to improve the performances of both conventional PID (C-PID) controller and conventional PID type FLC (C-PID-FLC). The proposed configuration is called adaptive because its output scaling factors (SFs) are dynamically tuned while the controller is functioning. The initial values of SFs are calculated based on its well-tuned counterpart while the proceeding values are generated using a proposed stochastic hybrid bacterial foraging particle swarm optimization (h-BF-PSO) algorithm. The performance of the proposed configuration is evaluated through extensive simulations for different operating conditions (changes in reference, load disturbance and noise signals). The results reveal that the proposed scheme performs significantly better over the C-PID controller and the C-PID-FLC in terms of several performance indices (integral absolute error (IAE), integral-of-time-multiplied absolute error (ITAE) and integral-of-time-multiplied squared error (ITSE)), overshoot and settling time for plants with and without dead time.

  5. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Montenegro, Justino (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of Field Programmable Gate Arrays (FPGA's) in the hardware implementation of fast digital signal processing functions. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used Proportional-Integral-Derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM- based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a Digital Signal Processor (DSP) device or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using DSP devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, Pulse Width Modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. An alternative is required for compact implementation of such functionality to withstand the harsh environment encountered on spacemap. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive-control algorithm

  6. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Monenegro, Justino (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used proportional-integral-derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM-based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a DSP (Digital Signal Processor) or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSP) devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. An alternative is required for compact implementation of such functionality to withstand the harsh environment

  7. Terra Maneuvers

    Atmospheric Science Data Center

    2013-03-12

    ... 00:00:15 2013/044/14:05:24 Drag Makeup Maneuver #71 69991 002 ... 00:00:30 2012/032/14:55:00 Drag Makeup Maneuver #65 64486 229 ... 00:00:30 2012/096/15:00:00 Drag Makeup Maneuver #66 65418 229 ...

  8. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream.

    PubMed

    Yusupbekov, N R; Marakhimov, A R; Igamberdiev, H Z; Umarov, Sh X

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach. PMID:27517081

  9. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream

    PubMed Central

    Marakhimov, A. R.; Igamberdiev, H. Z.; Umarov, Sh. X.

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach. PMID:27517081

  10. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream.

    PubMed

    Yusupbekov, N R; Marakhimov, A R; Igamberdiev, H Z; Umarov, Sh X

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach.

  11. Adaptive attitude control and momentum management for large-angle spacecraft maneuvers

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Sunkel, John W.

    1992-01-01

    The fully coupled equations of motion are systematically linearized around an equilibrium point of a gravity gradient stabilized spacecraft, controlled by momentum exchange devices. These equations are then used for attitude control system design of an early Space Station Freedom flight configuration, demonstrating the errors caused by the improper approximation of the spacecraft dynamics. A full state feedback controller, incorporating gain-scheduled adaptation of the attitude gains, is developed for use during spacecraft on-orbit assembly or operations characterized by significant mass properties variations. The feasibility of the gain adaptation is demonstrated via a Space Station Freedom assembly sequence case study. The attitude controller stability robustness and transient performance during gain adaptation appear satisfactory.

  12. The programmable (logic) controller: Adapting in an environment of change

    SciTech Connect

    Levine, P.S.

    1995-03-01

    Reports of the imminent death of the PLC (programmable logic controller) were greatly exaggerated, to paraphrase Mark Twain. In fact, the PLC is not only alive and working worldwide in thousands of applications, but it is also integrating well with related technologies. Long-term survival is a larger question - probably unanswerable given the pace of technological change. However, a few questions arise about the PLC today and in the immediate future: (1) What`s happening with programming languages? (2) Will there continue to be a {open_quotes}blurring of the lines{close_quotes} between the PLC and other technologies, and what role will software play in this integration? (3) How will the PLC`s cost and size affect the market?

  13. Embedding Knowledge Management into Business Logic of E-learning Platform for Obtaining Adaptivity

    NASA Astrophysics Data System (ADS)

    Burdescu, Dumitru Dan; Mihaescu, Marian Cristian; Logofatu, Bogdan

    Obtaining adaptivity is one of the main concerns in current e-Learning development. This chapter proposes a methodology for obtaining adaptivity by embedding knowledge management into the business logic of the e-Learning platform. Naïve Bayes classifier is used as machine learning algorithm for obtaining the resources that need to be further accessed by learners. The analysis is accomplished on a discipline that is well structured according to a concept map.

  14. Robust adaptive control of spacecraft proximity maneuvers under dynamic coupling and uncertainty

    NASA Astrophysics Data System (ADS)

    Sun, Liang; Huo, Wei

    2015-11-01

    This paper provides a solution for the position tracking and attitude synchronization problem of the close proximity phase in spacecraft rendezvous and docking. The chaser spacecraft must be driven to a certain fixed position along the docking port direction of the target spacecraft, while the attitude of the two spacecraft must be synchronized for subsequent docking operations. The kinematics and dynamics for relative position and relative attitude are modeled considering dynamic coupling, parametric uncertainties and external disturbances. The relative motion model has a new form with a novel definition of the unknown parameters. An original robust adaptive control method is developed for the concerned problem, and a proof of the asymptotic stability is given for the six degrees of freedom closed-loop system. A numerical example is displayed in simulation to verify the theoretical results.

  15. Logically rectangular finite volume methods with adaptive refinement on the sphere.

    PubMed

    Berger, Marsha J; Calhoun, Donna A; Helzel, Christiane; LeVeque, Randall J

    2009-11-28

    The logically rectangular finite volume grids for two-dimensional partial differential equations on a sphere and for three-dimensional problems in a spherical shell introduced recently have nearly uniform cell size, avoiding severe Courant number restrictions. We present recent results with adaptive mesh refinement using the GeoClaw software and demonstrate well-balanced methods that exactly maintain equilibrium solutions, such as shallow water equations for an ocean at rest over arbitrary bathymetry.

  16. Morphology analysis of EKG R waves using wavelets with adaptive parameters derived from fuzzy logic

    NASA Astrophysics Data System (ADS)

    Caldwell, Max A.; Barrington, William W.; Miles, Richard R.

    1996-03-01

    Understanding of the EKG components P, QRS (R wave), and T is essential in recognizing cardiac disorders and arrhythmias. An estimation method is presented that models the R wave component of the EKG by adaptively computing wavelet parameters using fuzzy logic. The parameters are adaptively adjusted to minimize the difference between the original EKG waveform and the wavelet. The R wave estimate is derived from minimizing the combination of mean squared error (MSE), amplitude difference, spread difference, and shift difference. We show that the MSE in both non-noise and additive noise environment is less using an adaptive wavelet than a static wavelet. Research to date has focused on the R wave component of the EKG signal. Extensions of this method to model P and T waves are discussed.

  17. Flight test results of the fuzzy logic adaptive controller-helicopter (FLAC-H)

    NASA Astrophysics Data System (ADS)

    Wade, Robert L.; Walker, Gregory W.

    1996-05-01

    The fuzzy logic adaptive controller for helicopters (FLAC-H) demonstration is a cooperative effort between the US Army Simulation, Training, and Instrumentation Command (STRICOM), the US Army Aviation and Troop Command, and the US Army Missile Command to demonstrate a low-cost drone control system for both full-scale and sub-scale helicopters. FLAC-H was demonstrated on one of STRICOM's fleet of full-scale rotary-winged target drones. FLAC-H exploits fuzzy logic in its flight control system to provide a robust solution to the control of the helicopter's dynamic, nonlinear system. Straight forward, common sense fuzzy rules governing helicopter flight are processed instead of complex mathematical models. This has resulted in a simplified solution to the complexities of helicopter flight. Incorporation of fuzzy logic reduced the cost of development and should also reduce the cost of maintenance of the system. An adaptive algorithm allows the FLAC-H to 'learn' how to fly the helicopter, enabling the control system to adjust to varying helicopter configurations. The adaptive algorithm, based on genetic algorithms, alters the fuzzy rules and their related sets to improve the performance characteristics of the system. This learning allows FLAC-H to automatically be integrated into a new airframe, reducing the development costs associated with altering a control system for a new or heavily modified aircraft. Successful flight tests of the FLAC-H on a UH-1H target drone were completed in September 1994 at the White Sands Missile Range in New Mexico. This paper discuses the objective of the system, its design, and performance.

  18. Feasibility of using adaptive logic networks to predict compressor unit failure

    SciTech Connect

    Armstrong, W.W.; Chungying Chu; Thomas, M.M.

    1995-12-31

    In this feasibility study, an adaptive logic network (ALN) was trained to predict failures of turbine-driven compressor units using a large database of measurements. No expert knowledge about compressor systems was involved. The predictions used only the statistical properties of the measurements and the indications of failure types. A fuzzy set was used to model measurements typical of normal operation. It was constrained by a requirement imposed during ALN training, that it should have a shape similar to a Gaussian density, more precisely, that its logarithm should be convex-up. Initial results obtained using this approach to knowledge discovery in the database were encouraging.

  19. Fluid Intelligence and Psychosocial Outcome: From Logical Problem Solving to Social Adaptation

    PubMed Central

    Huepe, David; Roca, María; Salas, Natalia; Canales-Johnson, Andrés; Rivera-Rei, Álvaro A.; Zamorano, Leandro; Concepción, Aimée; Manes, Facundo; Ibañez, Agustín

    2011-01-01

    Background While fluid intelligence has proved to be central to executive functioning, logical reasoning and other frontal functions, the role of this ability in psychosocial adaptation has not been well characterized. Methodology/Principal Findings A random-probabilistic sample of 2370 secondary school students completed measures of fluid intelligence (Raven's Progressive Matrices, RPM) and several measures of psychological adaptation: bullying (Delaware Bullying Questionnaire), domestic abuse of adolescents (Conflict Tactic Scale), drug intake (ONUDD), self-esteem (Rosenberg's Self Esteem Scale) and the Perceived Mental Health Scale (Spanish adaptation). Lower fluid intelligence scores were associated with physical violence, both in the role of victim and victimizer. Drug intake, especially cannabis, cocaine and inhalants and lower self-esteem were also associated with lower fluid intelligence. Finally, scores on the perceived mental health assessment were better when fluid intelligence scores were higher. Conclusions/Significance Our results show evidence of a strong association between psychosocial adaptation and fluid intelligence, suggesting that the latter is not only central to executive functioning but also forms part of a more general capacity for adaptation to social contexts. PMID:21957464

  20. Software for Autonomous Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Bristow, John; Folta, Dave; Hawkins, Al; Dell, Greg

    2004-01-01

    The AutoCon computer programs facilitate and accelerate the planning and execution of orbital control maneuvers of spacecraft while analyzing and resolving mission constraints. AutoCon-F is executed aboard spacecraft, enabling the spacecraft to plan and execute maneuvers autonomously; AutoCon-G is designed for use on the ground. The AutoCon programs utilize advanced techniques of artificial intelligence, including those of fuzzy logic and natural-language scripting, to resolve multiple conflicting constraints and automatically plan maneuvers. These programs can be used to satisfy requirements for missions that involve orbits around the Earth, the Moon, or any planet, and are especially useful for missions in which there are requirements for frequent maneuvers and for resolution of complex conflicting constraints. During operations, the software targets new trajectories, places and sizes maneuvers, and controls spacecraft burns. AutoCon-G provides a userfriendly graphical interface, and can be used effectively by an analyst with minimal training. AutoCon-F reduces latency and supports multiple-spacecraft and formation-flying missions. The AutoCon architecture supports distributive processing, which can be critical for formation- control missions. AutoCon is completely object-oriented and can easily be enhanced by adding new objects and events. AutoCon-F was flight demonstrated onboard GSFC's EO-1 spacecraft flying in formation with Landsat-7.

  1. Cassini's Maneuver Automation Software (MAS) Process: How to Successfully Command 200 Navigation Maneuvers

    NASA Technical Reports Server (NTRS)

    Yang, Genevie Velarde; Mohr, David; Kirby, Charles E.

    2008-01-01

    To keep Cassini on its complex trajectory, more than 200 orbit trim maneuvers (OTMs) have been planned from July 2004 to July 2010. With only a few days between many of these OTMs, the operations process of planning and executing the necessary commands had to be automated. The resulting Maneuver Automation Software (MAS) process minimizes the workforce required for, and maximizes the efficiency of, the maneuver design and uplink activities. The MAS process is a well-organized and logically constructed interface between Cassini's Navigation (NAV), Spacecraft Operations (SCO), and Ground Software teams. Upon delivery of an orbit determination (OD) from NAV, the MAS process can generate a maneuver design and all related uplink and verification products within 30 minutes. To date, all 112 OTMs executed by the Cassini spacecraft have been successful. MAS was even used to successfully design and execute a maneuver while the spacecraft was in safe mode.

  2. Adaptive logic networks in rehabilitation of persons with incomplete spinal cord injury

    SciTech Connect

    Armstrong, W.W. |

    1995-12-31

    Persons with incomplete spinal cord injury are generally at least partially paralyzed and are often unable to walk. Manually-controlled electrical stimulation has been used to act upon nerves or muscles to cause leg movement so such persons can achieve functional walking. They use crutches or a mobile walker for support, and initiate each stimulus by pressing a button. Artificial intelligence and machine learning techniques are now making it possible to automate the process of stimulus-initiation. Supervised training of an automatic system can be based on samples of correct stimulation given by the patient or by a therapist, accompanied by data from sensors indicating the state of the person`s body and its relation to the ground during walking. A major issue is generalization, i.e. whether the result of training can be used for control at a later time or in somewhat different circumstances. As the possibilities grow for increasing the number and variety of sensors on a patient, and for easily implanting more numerous stimulation channels, the need is increasing for powerful learning systems which can automatically develop effective and safe control algorithms. This paper explains the foundations of adaptive logic networks, and illustrates how they have been used to develop an experimental walking prosthesis used in a laboratory setting. Successful generalization has been observed using parameters from training which took place minutes to days earlier.

  3. Maneuver Automation Software

    NASA Technical Reports Server (NTRS)

    Uffelman, Hal; Goodson, Troy; Pellegrin, Michael; Stavert, Lynn; Burk, Thomas; Beach, David; Signorelli, Joel; Jones, Jeremy; Hahn, Yungsun; Attiyah, Ahlam; Illsley, Jeannette

    2009-01-01

    The Maneuver Automation Software (MAS) automates the process of generating commands for maneuvers to keep the spacecraft of the Cassini-Huygens mission on a predetermined prime mission trajectory. Before MAS became available, a team of approximately 10 members had to work about two weeks to design, test, and implement each maneuver in a process that involved running many maneuver-related application programs and then serially handing off data products to other parts of the team. MAS enables a three-member team to design, test, and implement a maneuver in about one-half hour after Navigation has process-tracking data. MAS accepts more than 60 parameters and 22 files as input directly from users. MAS consists of Practical Extraction and Reporting Language (PERL) scripts that link, sequence, and execute the maneuver- related application programs: "Pushing a single button" on a graphical user interface causes MAS to run navigation programs that design a maneuver; programs that create sequences of commands to execute the maneuver on the spacecraft; and a program that generates predictions about maneuver performance and generates reports and other files that enable users to quickly review and verify the maneuver design. MAS can also generate presentation materials, initiate electronic command request forms, and archive all data products for future reference.

  4. Performance Evaluation of Evasion Maneuvers for Parallel Approach Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Winder, Lee F.; Kuchar, James K.; Waller, Marvin (Technical Monitor)

    2000-01-01

    Current plans for independent instrument approaches to closely spaced parallel runways call for an automated pilot alerting system to ensure separation of aircraft in the case of a "blunder," or unexpected deviation from the a normal approach path. Resolution advisories by this system would require the pilot of an endangered aircraft to perform a trained evasion maneuver. The potential performance of two evasion maneuvers, referred to as the "turn-climb" and "climb-only," was estimated using an experimental NASA alerting logic (AILS) and a computer simulation of relative trajectory scenarios between two aircraft. One aircraft was equipped with the NASA alerting system, and maneuvered accordingly. Observation of the rates of different types of alerting failure allowed judgement of evasion maneuver performance. System Operating Characteristic (SOC) curves were used to assess the benefit of alerting with each maneuver.

  5. Adaptive Instrument Module: Space Instrument Controller "Brain" through Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Darrin, Ann Garrison; Conde, Richard; Chern, Bobbie; Luers, Phil; Jurczyk, Steve; Mills, Carl; Day, John H. (Technical Monitor)

    2001-01-01

    The Adaptive Instrument Module (AIM) will be the first true demonstration of reconfigurable computing with field-programmable gate arrays (FPGAs) in space, enabling the 'brain' of the system to evolve or adapt to changing requirements. In partnership with NASA Goddard Space Flight Center and the Australian Cooperative Research Centre for Satellite Systems (CRC-SS), APL has built the flight version to be flown on the Australian university-class satellite FEDSAT. The AIM provides satellites the flexibility to adapt to changing mission requirements by reconfiguring standardized processing hardware rather than incurring the large costs associated with new builds. This ability to reconfigure the processing in response to changing mission needs leads to true evolveable computing, wherein the instrument 'brain' can learn from new science data in order to perform state-of-the-art data processing. The development of the AIM is significant in its enormous potential to reduce total life-cycle costs for future space exploration missions. The advent of RAM-based FPGAs whose configuration can be changed at any time has enabled the development of the AIM for processing tasks that could not be performed in software. The use of the AIM enables reconfiguration of the FPGA circuitry while the spacecraft is in flight, with many accompanying advantages. The AIM demonstrates the practicalities of using reconfigurable computing hardware devices by conducting a series of designed experiments. These include the demonstration of implementing data compression, data filtering, and communication message processing and inter-experiment data computation. The second generation is the Adaptive Processing Template (ADAPT) which is further described in this paper. The next step forward is to make the hardware itself adaptable and the ADAPT pursues this challenge by developing a reconfigurable module that will be capable of functioning efficiently in various applications. ADAPT will take advantage of

  6. Rotor noise in maneuvering flight

    NASA Astrophysics Data System (ADS)

    Chen, Hsuan-Nien

    The objective of this research is to understand the physics of rotor noise in the maneuvering flight. To achieve this objective, an integrated noise prediction system is constructed, namely GenHel-MFW-PSU-WOPWOP. This noise prediction system includes a flight simulation code, a high fidelity free vortex-wake code, and a rotor acoustic prediction code. By using this noise prediction system, rotor maneuver noise characteristics are identified. Unlike periodic rotor noise, a longer duration is required to describe rotor maneuver noise. The variation of helicopter motion, blade motion and blade airloads are all influencing the noise prediction results in both noise level and directivity in the maneuvering flight. In this research, two types of rotor maneuver noise are identified, steady maneuver noise and transient maneuver noise. In the steady maneuver, rotor noise corresponds to a steady maneuver condition, which has nearly steady properties in flight dynamics and aerodynamics. Transient maneuver noise is the result of the transition between two steady maneuvers. In a transient maneuver, the helicopter experiences fluctuations in airload and helicopter angular rates, which lead to excess rotor noise. Even though the transient maneuver only exists for a fairly short period of time, the corresponding transient maneuver noise could be significant when compared to steady maneuver noise. The blade tip vortices also present complex behaviors in the transient maneuver condition. With stronger vortex circulation strength and the potential for vortex bundling, blade vortex-interaction (BVI) noise may increase significantly during a transient maneuver. In this research, it is shown that even with small pilot controls, significant BVI noise can be generated during a transient flight condition. Finally, through this research, the importance of transient maneuver noise is demonstrated and recognized.

  7. Artificial immune system approach for air combat maneuvering

    NASA Astrophysics Data System (ADS)

    Kaneshige, John; Krishnakumar, Kalmanje

    2007-04-01

    Since future air combat missions will involve both manned and unmanned aircraft, the primary motivation for this research is to enable unmanned aircraft with intelligent maneuvering capabilities. During air combat maneuvering, pilots use their knowledge and experience of maneuvering strategies and tactics to determine the best course of action. As a result, we try to capture these aspects using an artificial immune system approach. The biological immune system protects the body against intruders by recognizing and destroying harmful cells or molecules. It can be thought of as a robust adaptive system that is capable of dealing with an enormous variety of disturbances and uncertainties. However, another critical aspect of the immune system is that it can remember how previous encounters were successfully defeated. As a result, it can respond faster to similar encounters in the future. This paper describes how an artificial immune system is used to select and construct air combat maneuvers. These maneuvers are composed of autopilot mode and target commands, which represent the low-level building blocks of the parameterized system. The resulting command sequences are sent to a tactical autopilot system, which has been enhanced with additional modes and an aggressiveness factor for enabling high performance maneuvers. Just as vaccinations train the biological immune system how to combat intruders, training sets are used to teach the maneuvering system how to respond to different enemy aircraft situations. Simulation results are presented, which demonstrate the potential of using immunized maneuver selection for the purposes of air combat maneuvering.

  8. General and Specific Strategies Used to Facilitate Locomotor Maneuvers

    PubMed Central

    Wu, Mengnan; Matsubara, Jesse H.; Gordon, Keith E.

    2015-01-01

    People make anticipatory changes in gait patterns prior to initiating a rapid change of direction. How they prepare will change based on their knowledge of the maneuver. To investigate specific and general strategies used to facilitate locomotor maneuvers, we manipulated subjects’ ability to anticipate the direction of an upcoming lateral “lane-change” maneuver. To examine specific anticipatory adjustments, we observed the four steps immediately preceding a maneuver that subjects were instructed to perform at a known time in a known direction. We hypothesized that to facilitate a specific change of direction, subjects would proactively decrease margin of stability in the future direction of travel. Our results support this hypothesis: subjects significantly decreased lateral margin of stability by 69% on the side ipsilateral to the maneuver during only the step immediately preceding the maneuver. This gait adaptation may have improved energetic efficiency and simplified the control of the maneuver. To examine general anticipatory adjustments, we observed the two steps immediately preceding the instant when subjects received information about the direction of the maneuver. When the maneuver direction was unknown, we hypothesized that subjects would make general anticipatory adjustments that would improve their ability to actively initiate a maneuver in multiple directions. This second hypothesis was partially supported as subjects increased step width and stance phase hip flexion during these anticipatory steps. These modifications may have improved subjects’ ability to generate forces in multiple directions and maintain equilibrium during the onset and execution of the rapid maneuver. However, adapting these general anticipatory strategies likely incurred an additional energetic cost. PMID:26167931

  9. Adaptive neuro-fuzzy logic analysis based on myoelectric signals for multifunction prosthesis control.

    PubMed

    Favieiro, Gabriela W; Balbinot, Alexandre

    2011-01-01

    The myoelectric signal is a sign of control of the human body that contains the information of the user's intent to contract a muscle and, therefore, make a move. Studies shows that the Amputees are able to generate standardized myoelectric signals repeatedly before of the intention to perform a certain movement. This paper presents a study that investigates the use of forearm surface electromyography (sEMG) signals for classification of five distinguish movements of the arm using just three pairs of surface electrodes located in strategic places. The classification is done by an adaptive neuro-fuzzy inference system (ANFIS) to process signal features to recognize performed movements. The average accuracy reached for the classification of five motion classes was 86-98% for three subjects. PMID:22256169

  10. A fuzzy-logic based dual-purpose adaptive circuit for vibration control and energy harvesting using piezoelectric transducer

    NASA Astrophysics Data System (ADS)

    Liu, Zhe Peng; Li, Qing

    2013-04-01

    Due to their two-way electromechanical coupling effect, piezoelectric transducers can be used to synthesize passive vibration control schemes, e.g., RLC circuit with the integration of inductance and resistance elements that is conceptually similar to damped vibration absorber. Meanwhile, the wide usage of wireless sensors has led to the recent enthusiasm of developing piezoelectric-based energy harvesting devices that can convert ambient vibratory energy into useful electrical energy. It can be shown that the integration of circuitry elements such as resistance and inductance can benefit the energy harvesting capability. Here we explore a dual-purpose circuit that can facilitate simultaneous vibration suppression and energy harvesting. It is worth noting that the goal of vibration suppression and the goal of energy harvesting may not always complement each other. That is, the maximization of vibration suppression doesn't necessarily lead to the maximization of energy harvesting, and vice versa. In this research, we develop a fuzzy-logic based algorithm to decide the proper selection of circuitry elements to balance between the two goals. As the circuitry elements can be online tuned, this research yields an adaptive circuitry concept for the effective manipulation of system energy and vibration suppression. Comprehensive analyses are carried out to demonstrate the concept and operation.

  11. A sun-crown-sensor model and adapted C-correction logic for topographic correction of high resolution forest imagery

    NASA Astrophysics Data System (ADS)

    Fan, Yuanchao; Koukal, Tatjana; Weisberg, Peter J.

    2014-10-01

    Canopy shadowing mediated by topography is an important source of radiometric distortion on remote sensing images of rugged terrain. Topographic correction based on the sun-canopy-sensor (SCS) model significantly improved over those based on the sun-terrain-sensor (STS) model for surfaces with high forest canopy cover, because the SCS model considers and preserves the geotropic nature of trees. The SCS model accounts for sub-pixel canopy shadowing effects and normalizes the sunlit canopy area within a pixel. However, it does not account for mutual shadowing between neighboring pixels. Pixel-to-pixel shadowing is especially apparent for fine resolution satellite images in which individual tree crowns are resolved. This paper proposes a new topographic correction model: the sun-crown-sensor (SCnS) model based on high-resolution satellite imagery (IKONOS) and high-precision LiDAR digital elevation model. An improvement on the C-correction logic with a radiance partitioning method to address the effects of diffuse irradiance is also introduced (SCnS + C). In addition, we incorporate a weighting variable, based on pixel shadow fraction, on the direct and diffuse radiance portions to enhance the retrieval of at-sensor radiance and reflectance of highly shadowed tree pixels and form another variety of SCnS model (SCnS + W). Model evaluation with IKONOS test data showed that the new SCnS model outperformed the STS and SCS models in quantifying the correlation between terrain-regulated illumination factor and at-sensor radiance. Our adapted C-correction logic based on the sun-crown-sensor geometry and radiance partitioning better represented the general additive effects of diffuse radiation than C parameters derived from the STS or SCS models. The weighting factor Wt also significantly enhanced correction results by reducing within-class standard deviation and balancing the mean pixel radiance between sunlit and shaded slopes. We analyzed these improvements with model

  12. Automatic Pilot For Flight-Test Maneuvers

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Jones, Frank P.; Roncoli, Ralph B.

    1992-01-01

    Autopilot replaces pilot during automatic maneuvers. Pilot, based on ground, flies aircraft to required altitude, then turns control over to autopilot. Increases quality of maneuvers significantly beyond that attainable through remote manual control by pilot on ground. Also increases quality of maneuvers because it performs maneuvers faster than pilot could and because it does not have to repeat poorly executed maneuvers.

  13. Support and maneuvering device

    DOEpatents

    Wood, Richard L.

    1988-01-01

    A support and maneuvering device includes an elongated flexible inflatable enclosure having a fixed end and a movable end. The movable end is collapsible toward the fixed end to a contracted position when the enclosure is in a noninflated condition. Upon inflation, the movable end is movable away from the fixed end to an extended position. The movable end includes means for mounting an article such as a solar reflector thereon. The device also includes a plurality of position controlling means disposed about the movable end to effect adjusting movement of portions thereof by predetermined amounts and for controlling an angle at which the article disposed at the movable end is oriented. The plurality of position controlling means limits a suitable number degrees of freedom of the movable end for transmitting a steering motion thereto and for controlling the position thereof.

  14. Support and maneuvering device

    DOEpatents

    Wood, R.L.

    1987-03-23

    A support and maneuvering device includes an elongated flexible inflatable enclosure having a fixed end and a movable end. The movable end is collapsible toward the fixed end to a contracted position when the enclosure is in a noninflated condition. Upon inflation, the movable end is movable away from the fixed end to an extended position. The movable end includes means for mounting an article such as a solar reflector thereon. The device also includes a plurality of position controlling means disposed about the movable end to effect adjusting movement of portions thereof by predetermined amounts and for controlling an angle at which the article disposed at the movable end is oriented. The plurality of position controlling means limits a suitable number degrees of freedom of the movable end for transmitting a steering motion thereto and for controlling the position thereof. 9 figs.

  15. Aircraft agility maneuvers

    NASA Technical Reports Server (NTRS)

    Cliff, Eugene M.; Thompson, Brian G.

    1992-01-01

    A new dynamic model for aircraft motions is presented. This model can be viewed as intermediate between a point-mass model, in which the body attitude angles are control-like, and a rigid-body model, in which the body-attitude angles evolve according to Newton's Laws. Specifically, consideration is given to the case of symmetric flight, and a model is constructed in which the body roll-rate and the body pitch-rate are the controls. In terms of this body-rate model a minimum-time heading change maneuver is formulated. When the bounds on the body-rates are large the results are similar to the point-mass model in that the model can very quickly change the applied forces and produce an acceleration to turn the vehicle. With finite bounds on these rates, the forces change in a smooth way. This leads to a measurable effect of agility.

  16. 14 CFR 25.1507 - Maneuvering speed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  17. 14 CFR 25.1507 - Maneuvering speed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  18. 14 CFR 25.1507 - Maneuvering speed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  19. 14 CFR 25.1507 - Maneuvering speed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  20. 14 CFR 25.1507 - Maneuvering speed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  1. STS-134: Rendezvous Pitch Maneuver

    NASA Video Gallery

    On May 18, 2011, space shuttle Endeavour performed the Rendezvous Pitch Maneuver, or "backflip." With Commander Mark Kelly at the helm, Endeavour rotated 360 degrees backward to enable Internationa...

  2. STS-135: Rendezvous Pitch Maneuver

    NASA Video Gallery

    On July 10, 2011, space shuttle Atlantis performed the nine-minute Rendezvous Pitch Maneuver, or “backflip.” With Commander Chris Ferguson at the helm, Atlantis rotated 360 degrees backward to ...

  3. ARTEMIS Maneuvers into Lunar Orbit

    NASA Video Gallery

    This animation visualizes the maneuvers required to move the ARTEMIS spacecraft from their kidney-shaped paths on each side of the moon to orbiting the moon. It took one and a half years, over 90 o...

  4. STS-133: Rendezvous Pitch Maneuver

    NASA Video Gallery

    At 1:15 p.m. EST Saturday, space shuttle Discovery began the nine-minute Rendezvous Pitch Maneuver, or "backflip." With Commander Steve Lindsey at the helm, Discovery rotated 360 degrees backward t...

  5. Fuzzy logic control system to provide autonomous collision avoidance for Mars rover vehicle

    NASA Technical Reports Server (NTRS)

    Murphy, Michael G.

    1990-01-01

    NASA is currently involved with planning unmanned missions to Mars to investigate the terrain and process soil samples in advance of a manned mission. A key issue involved in unmanned surface exploration on Mars is that of supporting autonomous maneuvering since radio communication involves lengthy delays. It is anticipated that specific target locations will be designated for sample gathering. In maneuvering autonomously from a starting position to a target position, the rover will need to avoid a variety of obstacles such as boulders or troughs that may block the shortest path to the target. The physical integrity of the rover needs to be maintained while minimizing the time and distance required to attain the target position. Fuzzy logic lends itself well to building reliable control systems that function in the presence of uncertainty or ambiguity. The following major issues are discussed: (1) the nature of fuzzy logic control systems and software tools to implement them; (2) collision avoidance in the presence of fuzzy parameters; and (3) techniques for adaptation in fuzzy logic control systems.

  6. Maneuver Design and Calibration for the Genesis Spacecraft

    NASA Technical Reports Server (NTRS)

    Williams, Kenneth E.; Hong, Philip E.; Zietz, Richard P.; Han, Don

    2000-01-01

    Genesis is the fifth mission selected as part of NASA's Discovery Program. The objective of Genesis is to collect solar wind samples for a period of approximately two years while in a halo orbit about the Earth-Sun L I point. At the end of this period, the samples are to be returned to a specific recovery point on the Earth for subsequent analysis. This goal has never been attempted before and presents a formidable challenge in terms of mission design and operations, particularly planning and execution of propulsive maneuvers. To achieve a level of cost-effectiveness consistent with a Discovery-class mission, the Genesis spacecraft design was adapted to the maximum extent possible from designs used on earlier missions, such as Mars Global Surveyor (MGS) and Stardust, another sample collection mission. The spacecraft design for Genesis is shown. Spin stabilization was chosen for attitude control, in lieu of three-axis stabilization, with neither reaction wheels nor accelerometers included. This precludes closed-loop control of propulsive maneuvers and implies that any attitude changes, including spin changes and precessions, will behave like translational propulsive maneuvers and affect the spacecraft trajectory. Moreover, to minimize contamination risk to the samples collected, all thrusters were placed on the side opposite the sample collection canister. The orientation and characteristics of thrusters are indicated. For large maneuvers (>2.5 m/s), two 5 lbf thrusters will be used for delta v, with precession to the burn attitude, followed by spin-up from 1.6 to 10 rpm before the burn and spin down to 1.6 rpm afterwards, then precession back to the original spin attitude. For small maneuvers (<2.5 m/s), no spin change is needed and four 0.2 lbf thrusters are used for Av. Single or double 360 deg. precession changes are required whenever the desired delta v falls inside the two-way turn circle (about 0.4 m/s) based on the mass properties, spin rate and lever arm

  7. Dynamics of Voluntary Cough Maneuvers

    NASA Astrophysics Data System (ADS)

    Naire, Shailesh

    2008-11-01

    Voluntary cough maneuvers are characterized by transient peak expiratory flows (PEF) exceeding the maximum expiratory flow-volume (MEFV) curve. In some cases, these flows can be well in excess of the MEFV, generally referred to as supramaximal flows. Understanding the flow-structure interaction involved in these maneuvers is the main goal of this work. We present a simple theoretical model for investigating the dynamics of voluntary cough and forced expiratory maneuvers. The core modeling idea is based on a 1-D model of high Reynolds number flow through flexible-walled tubes. The model incorporates key ingredients involved in these maneuvers: the expiratory effort generated by the abdominal and expiratory muscles, the glottis and the flexibility and compliance of the lung airways. Variations in these allow investigation of the expiratory flows generated by a variety of single cough maneuvers. The model successfully reproduces PEF which is shown to depend on the cough generation protocol, the glottis reopening time and the compliance of the airways. The particular highlight is in simulating supramaximal PEF for very compliant tubes. The flow-structure interaction mechanisms behind these are discussed. The wave speed theory of flow limitation is used to characterize the PEF. Existing hypotheses of the origin of PEF, from cough and forced expiration experiments, are also tested using this model.

  8. Dispositional logic

    SciTech Connect

    Zadeh, L.A.

    1988-01-01

    The applicability of conventional mathematical analysis (based on the combination of two-valued logic and probability theory) to problems in which human judgment, perception, or emotions play significant roles is considered theoretically. It is shown that dispositional logic, a branch of fuzzy logic, has particular relevance to the common-sense reasoning typical of human decision-making. The concepts of dispositionality and usuality are defined analytically, and a dispositional conjunctive rule and dispositional modus ponens are derived. 7 references.

  9. Dispositional logic

    NASA Technical Reports Server (NTRS)

    Le Balleur, J. C.

    1988-01-01

    The applicability of conventional mathematical analysis (based on the combination of two-valued logic and probability theory) to problems in which human judgment, perception, or emotions play significant roles is considered theoretically. It is shown that dispositional logic, a branch of fuzzy logic, has particular relevance to the common-sense reasoning typical of human decision-making. The concepts of dispositionality and usuality are defined analytically, and a dispositional conjunctive rule and dispositional modus ponens are derived.

  10. 33 CFR 84.23 - Maneuvering light.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maneuvering light. 84.23 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.23 Maneuvering light. Notwithstanding the provisions of § 84.03(f), the maneuvering light described in Rule 34(b) shall be...

  11. 33 CFR 84.23 - Maneuvering light.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Maneuvering light. 84.23 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.23 Maneuvering light. Notwithstanding the provisions of § 84.03(f), the maneuvering light described in Rule 34(b) shall be...

  12. 33 CFR 84.23 - Maneuvering light.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Maneuvering light. 84.23 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.23 Maneuvering light. Notwithstanding the provisions of § 84.03(f), the maneuvering light described in Rule 34(b) shall be...

  13. 33 CFR 84.23 - Maneuvering light.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Maneuvering light. 84.23 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.23 Maneuvering light. Notwithstanding the provisions of § 84.03(f), the maneuvering light described in Rule 34(b) shall be...

  14. 33 CFR 84.23 - Maneuvering light.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Maneuvering light. 84.23 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.23 Maneuvering light. Notwithstanding the provisions of § 84.03(f), the maneuvering light described in Rule 34(b) shall be...

  15. Fuzzy logic and adaptive neuro-fuzzy inference system for characterization of contaminant exposure through selected biomarkers in African catfish.

    PubMed

    Karami, Ali; Keiter, Steffen; Hollert, Henner; Courtenay, Simon C

    2013-03-01

    This study represents a first attempt at applying a fuzzy inference system (FIS) and an adaptive neuro-fuzzy inference system (ANFIS) to the field of aquatic biomonitoring for classification of the dosage and time of benzo[a]pyrene (BaP) injection through selected biomarkers in African catfish (Clarias gariepinus). Fish were injected either intramuscularly (i.m.) or intraperitoneally (i.p.) with BaP. Hepatic glutathione S-transferase (GST) activities, relative visceral fat weights (LSI), and four biliary fluorescent aromatic compounds (FACs) concentrations were used as the inputs in the modeling study. Contradictory rules in FIS and ANFIS models appeared after conversion of bioassay results into human language (rule-based system). A "data trimming" approach was proposed to eliminate the conflicts prior to fuzzification. However, the model produced was relevant only to relatively low exposures to BaP, especially through the i.m. route of exposure. Furthermore, sensitivity analysis was unable to raise the classification rate to an acceptable level. In conclusion, FIS and ANFIS models have limited applications in the field of fish biomarker studies.

  16. A pilot in the loop analysis of helicopter acceleration/deceleration maneuvers

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.

    1982-01-01

    Helicopter flight acceleration/deceleration maneuvers are quantified and put to use in the fields of handling qualities, flight training and evaluation of simulator fidelity. The three specific cases include the normal speed change maneuver, the nap-of-the-Earth dash/quickstop, and the decelerating approach to hover. All of these maneuvers share common generic features in terms of pilot adaptation and mathematical description; yet each differs in terms of the essential feedback loop structure, implications for handling qualities requirements, and simulator fidelity criteria.

  17. Manned maneuvering unit latching mechanism

    NASA Technical Reports Server (NTRS)

    Allton, C. S.

    1980-01-01

    The astronaut/Manned Maneuvering Unit interface, which presented a challenging set of requirements for a latching mechanism, is described. A spring loaded cam segment with variable ratio pulley release actuator was developed to meet the requirements. To preclude jamming of the mechanism, special precautions were taken such as spring loaded bearing points and careful selection of materials to resist cold welding. The mechanism successfully passed a number of tests which partially simulated orbital conditions.

  18. Maneuver Optimization through Simulated Annealing

    NASA Astrophysics Data System (ADS)

    de Vries, W.

    2011-09-01

    We developed an efficient method for satellite maneuver optimization. It is based on a Monte Carlo (MC) approach in combination with Simulated Annealing. The former component enables us to consider all imaginable trajectories possible given the current satellite position and its available thrust, while the latter approach ensures that we reliably find the best global optimization solution. Furthermore, this optimization setup is eminently scalable. It runs efficiently on the current multi-core generation of desktop computers, but is equally at home on massively parallel high performance computers (HPC). The baseline method for desktops uses a modified two-body propagator that includes the lunar gravitational force, and corrects for nodal and apsidal precession. For the HPC environment, on the other hand, we can include all the necessary components for a full force-model propagation: higher gravitational moments, atmospheric drag, solar radiation pressure, etc. A typical optimization scenario involves an initial orbit and a destination orbit / trajectory, a time period under consideration, and an available amount of thrust. After selecting a particular optimization (e.g., least amount of fuel, shortest maneuver), the program will determine when and in what direction to burn by what amount. Since we are considering all possible trajectories, we are not constrained to any particular transfer method (e.g., Hohmann transfers). Indeed, in some cases gravitational slingshots around the Earth turn out to be the best result. The paper will describe our approach in detail, its complement of optimizations for single- and multi-burn sequences, and some in-depth examples. In particular, we highlight an example where it is used to analyze a sequence of maneuvers after the fact, as well as showcase its utility as a planning and analysis tool for future maneuvers.

  19. The maneuver search and the maneuver search trajectory framework of search heavy torpedo

    NASA Astrophysics Data System (ADS)

    Yin, Wenjin; Zhang, Jingyuan; Li, Jitao

    2016-01-01

    With the development of technology capability of submarine launching heavy torpedo and the demand of intellectualized combat, the paper raises the concept of torpedo maneuver search and analyses maneuver search opportunity. It is necessary to realize the long range heavy torpedo's maneuver search that heavy torpedo's maneuver search can cover the target's location error which results from launching platform's position precision and the target's intentional maneuver when the torpedo is launched. The technology framework of the heavy torpedo's maneuver search trajectory is set up.

  20. Direct lateral maneuvers in hawkmoths.

    PubMed

    Greeter, Jeremy S M; Hedrick, Tyson L

    2016-01-01

    We used videography to investigate direct lateral maneuvers, i.e. 'sideslips', of the hawkmoth Manduca sexta. M. sexta sideslip by rolling their entire body and wings to reorient their net force vector. During sideslip they increase net aerodynamic force by flapping with greater amplitude, (in both wing elevation and sweep), allowing them to continue to support body weight while rolled. To execute the roll maneuver we observed in sideslips, they use an asymmetric wing stroke; increasing the pitch of the roll-contralateral wing pair, while decreasing that of the roll-ipsilateral pair. They also increase the wing sweep amplitude of, and decrease the elevation amplitude of, the contralateral wing pair relative to the ipsilateral pair. The roll maneuver unfolds in a stairstep manner, with orientation changing more during downstroke than upstroke. This is due to smaller upstroke wing pitch angle asymmetries as well as increased upstroke flapping counter-torque from left-right differences in global reference frame wing velocity about the moth's roll axis. Rolls are also opposed by stabilizing aerodynamic moments from lateral motion, such that rightward roll velocity will be opposed by rightward motion. Computational modeling using blade-element approaches confirm the plausibility of a causal linkage between the previously mentioned wing kinematics and roll/sideslip. Model results also predict high degrees of axial and lateral damping. On the time scale of whole and half wing strokes, left-right wing pair asymmetries directly relate to the first, but not second, derivative of roll. Collectively, these results strongly support a roll-based sideslip with a high degree of roll damping in M. sexta. PMID:26740573

  1. Direct lateral maneuvers in hawkmoths

    PubMed Central

    Greeter, Jeremy S. M.; Hedrick, Tyson L.

    2016-01-01

    ABSTRACT We used videography to investigate direct lateral maneuvers, i.e. ‘sideslips’, of the hawkmoth Manduca sexta. M. sexta sideslip by rolling their entire body and wings to reorient their net force vector. During sideslip they increase net aerodynamic force by flapping with greater amplitude, (in both wing elevation and sweep), allowing them to continue to support body weight while rolled. To execute the roll maneuver we observed in sideslips, they use an asymmetric wing stroke; increasing the pitch of the roll-contralateral wing pair, while decreasing that of the roll-ipsilateral pair. They also increase the wing sweep amplitude of, and decrease the elevation amplitude of, the contralateral wing pair relative to the ipsilateral pair. The roll maneuver unfolds in a stairstep manner, with orientation changing more during downstroke than upstroke. This is due to smaller upstroke wing pitch angle asymmetries as well as increased upstroke flapping counter-torque from left-right differences in global reference frame wing velocity about the moth's roll axis. Rolls are also opposed by stabilizing aerodynamic moments from lateral motion, such that rightward roll velocity will be opposed by rightward motion. Computational modeling using blade-element approaches confirm the plausibility of a causal linkage between the previously mentioned wing kinematics and roll/sideslip. Model results also predict high degrees of axial and lateral damping. On the time scale of whole and half wing strokes, left-right wing pair asymmetries directly relate to the first, but not second, derivative of roll. Collectively, these results strongly support a roll-based sideslip with a high degree of roll damping in M. sexta. PMID:26740573

  2. Direct lateral maneuvers in hawkmoths.

    PubMed

    Greeter, Jeremy S M; Hedrick, Tyson L

    2016-01-01

    We used videography to investigate direct lateral maneuvers, i.e. 'sideslips', of the hawkmoth Manduca sexta. M. sexta sideslip by rolling their entire body and wings to reorient their net force vector. During sideslip they increase net aerodynamic force by flapping with greater amplitude, (in both wing elevation and sweep), allowing them to continue to support body weight while rolled. To execute the roll maneuver we observed in sideslips, they use an asymmetric wing stroke; increasing the pitch of the roll-contralateral wing pair, while decreasing that of the roll-ipsilateral pair. They also increase the wing sweep amplitude of, and decrease the elevation amplitude of, the contralateral wing pair relative to the ipsilateral pair. The roll maneuver unfolds in a stairstep manner, with orientation changing more during downstroke than upstroke. This is due to smaller upstroke wing pitch angle asymmetries as well as increased upstroke flapping counter-torque from left-right differences in global reference frame wing velocity about the moth's roll axis. Rolls are also opposed by stabilizing aerodynamic moments from lateral motion, such that rightward roll velocity will be opposed by rightward motion. Computational modeling using blade-element approaches confirm the plausibility of a causal linkage between the previously mentioned wing kinematics and roll/sideslip. Model results also predict high degrees of axial and lateral damping. On the time scale of whole and half wing strokes, left-right wing pair asymmetries directly relate to the first, but not second, derivative of roll. Collectively, these results strongly support a roll-based sideslip with a high degree of roll damping in M. sexta.

  3. Orbital maneuvers and space rendezvous

    NASA Astrophysics Data System (ADS)

    Butikov, Eugene I.

    2015-12-01

    Several possibilities of launching a space vehicle from the orbital station are considered and compared. Orbital maneuvers discussed in the paper can be useful in designing a trajectory for a specific space mission. The relative motion of orbiting bodies is investigated on examples of spacecraft rendezvous with the space station that stays in a circular orbit around the Earth. An elementary approach is illustrated by an accompanying simulation computer program and supported by a mathematical treatment based on fundamental laws of physics and conservation laws. Material is appropriate for engineers and other personnel involved in space exploration, undergraduate and graduate students studying classical physics and orbital mechanics.

  4. Optical gradient force assist maneuver.

    PubMed

    Artusio-Glimpse, Alexandra B; Wirth, Jacob H; Swartzlander, Grover A

    2016-09-01

    We describe an energy transfer process whereby a moving particle loses (or gains) kinetic energy upon interacting with the moving optical potential of a swept beam of light. This approach is akin to a gravitational assist maneuver for interplanetary satellite propulsion. Special consideration is given to the stopping condition. For analytical convenience, we examine the Rayleigh scattering regime, providing examples at small and large scattering angles. A 5% uncertainty in the initial particle speed and position has negligible effect on the slowing/speeding ability when the beam size is much larger than the particle. PMID:27607993

  5. Optimal Electrodynamic Tether Phasing Maneuvers

    NASA Technical Reports Server (NTRS)

    Bitzer, Matthew S.; Hall, Christopher D.

    2007-01-01

    We study the minimum-time orbit phasing maneuver problem for a constant-current electrodynamic tether (EDT). The EDT is assumed to be a point mass and the electromagnetic forces acting on the tether are always perpendicular to the local magnetic field. After deriving and non-dimensionalizing the equations of motion, the only input parameters become current and the phase angle. Solution examples, including initial Lagrange costates, time of flight, thrust plots, and thrust angle profiles, are given for a wide range of current magnitudes and phase angles. The two-dimensional cases presented use a non-tilted magnetic dipole model, and the solutions are compared to existing literature. We are able to compare similar trajectories for a constant thrust phasing maneuver and we find that the time of flight is longer for the constant thrust case with similar initial thrust values and phase angles. Full three-dimensional solutions, which use a titled magnetic dipole model, are also analyzed for orbits with small inclinations.

  6. Cassini-Huygens maneuver automation for navigation

    NASA Technical Reports Server (NTRS)

    Goodson, Troy; Attiyah, Amy; Buffington, Brent; Hahn, Yungsun; Pojman, Joan; Stavert, Bob; Strange, Nathan; Stumpf, Paul; Wagner, Sean; Wolff, Peter; Wong, Mau

    2006-01-01

    Many times during the Cassini-Huygens mission to Saturn, propulsive maneuvers must be spaced so closely together that there isn't enough time or workforce to execute the maneuver-related software manually, one subsystem at a time. Automation is required. Automating the maneuver design process has involved close cooperation between teams. We present the contribution from the Navigation system. In scope, this includes trajectory propagation and search, generation of ephemerides, general tasks such as email notification and file transfer, and presentation materials. The software has been used to help understand maneuver optimization results, Huygens probe delivery statistics, and Saturn ring-plane crossing geometry. The Maneuver Automation Software (MAS), developed for the Cassini-Huygens program enables frequent maneuvers by handling mundane tasks such as creation of deliverable files, file delivery, generation and transmission of email announcements, generation of presentation material and other supporting documentation. By hand, these tasks took up hours, if not days, of work for each maneuver. Automated, these tasks may be completed in under an hour. During the cruise trajectory the spacing of maneuvers was such that development of a maneuver design could span about a month, involving several other processes in addition to that described, above. Often, about the last five days of this process covered the generation of a final design using an updated orbit-determination estimate. To support the tour trajectory, the orbit determination data cut-off of five days before the maneuver needed to be reduced to approximately one day and the whole maneuver development process needed to be reduced to less than a week..

  7. Fuzzy logic

    NASA Technical Reports Server (NTRS)

    Zadeh, Lofti A.

    1988-01-01

    The author presents a condensed exposition of some basic ideas underlying fuzzy logic and describes some representative applications. The discussion covers basic principles; meaning representation and inference; basic rules of inference; and the linguistic variable and its application to fuzzy control.

  8. Orbit trim maneuver design and implementation for the 1975 Mars Viking Mission

    NASA Technical Reports Server (NTRS)

    Hintz, G. R.; Farless, D. L.; Adams, M. J.

    1978-01-01

    The Viking Mission included the insertion of two unmanned spacecraft into orbit about Mars and the deployment of a soft-lander from each. A description is presented of the adaptive design and implementation of the spacecraft propulsive maneuvers as these flights progressed, taking into account also the inflight results for the orbital phase of the primary Viking mission. The design process included the selection of target parameters and the minimization of both propellant usage and the effects of execution errors, while complying with mission and operational constraints. All maneuvers performed to trim the spacecraft orbits are considered. Attention is given to navigation requirements, geometry definitions and terminology, maneuver mechanization and constraints, and maneuver capability.

  9. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and the...-down pitching conditions is the sum of the balancing loads at V and the specified value of the normal... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering loads. 23.423 Section...

  10. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and the...-down pitching conditions is the sum of the balancing loads at V and the specified value of the normal... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maneuvering loads. 23.423 Section...

  11. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of...

  12. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of...

  13. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of...

  14. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of...

  15. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of...

  16. Temporal logics meet telerobotics

    NASA Technical Reports Server (NTRS)

    Rutten, Eric; Marce, Lionel

    1989-01-01

    The specificity of telerobotics being the presence of a human operator, decision assistance tools are necessary for the operator, especially in hostile environments. In order to reduce execution hazards due to a degraded ability for quick and efficient recovery of unexpected dangerous situations, it is of importance to have the opportunity, amongst others, to simulate the possible consequences of a plan before its actual execution, in order to detect these problematic situations. Hence the idea of providing the operator with a simulator enabling him to verify the temporal and logical coherence of his plans. Therefore, the power of logical formalisms is used for representation and deduction purposes. Starting from the class of situations that are represented, a STRIPS (the STanford Research Institute Problem Solver)-like formalism and its underlying logic are adapted to the simulation of plans of actions in time. The choice of a temporal logic enables to build a world representation, on which the effects of plans, grouping actions into control structures, will be transcribed by the simulation, resulting in a verdict and information about the plan's coherence.

  17. Tactical Maneuvering Using Immunized Sequence Selection

    NASA Technical Reports Server (NTRS)

    Kaneshige, John; KrishnaKumar, K.; Shung, Felix

    2003-01-01

    This paper describes a tactical maneuvering system that uses an artificial immune system based approach for selecting maneuver sequences. This approach combines the problem solving abilities of genetic algorithms with the memory retention characteristics of an immune system. Of significant importance here is the fact that the tactical maneuvering system can make time-critical decisions to accomplish near-term objectives within a dynamic environment. These objectives can be received from a human operator, autonomous executive, or various flight planning specialists. Simulation tests were performed using a high performance military aircraft model. Results demonstrate the potential of using immunized sequence selection in order to accomplish tactical maneuvering objectives ranging from flying to a location while avoiding unforeseen obstacles, to performing relative positioning in support of air combat maneuvering.

  18. Atmospheric maneuvering during Martian entry

    NASA Astrophysics Data System (ADS)

    Tauber, Michael E.; Bowles, Jeffrey V.; Yang, Lily

    A comparative-advantages study is made of two different Martian atmospheric entry maneuvers, on the basis of calculation results for the case of a vehicle with a maximum L/D ratio of 2.3. Entries from a highly elliptical Martian orbit at 5 km/sec are more difficult than those from a lower altitude and speed orbit at 3.5 km/sec, due to their more stringent guidance requirements. Efforts to reduce the deceleration for the higher speed entry by lift-modulation achieved a 40-percent reduction, but at the cost of a 50-percent decrease in lateral range. The lower-speed entry's gliding trajectory is noted to encounter a far more benign atmospheric environment.

  19. Energy Index For Aircraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Chidester, Thomas R. (Inventor); Lynch, Robert E. (Inventor); Lawrence, Robert E. (Inventor); Amidan, Brett G. (Inventor); Ferryman, Thomas A. (Inventor); Drew, Douglas A. (Inventor); Ainsworth, Robert J. (Inventor); Prothero, Gary L. (Inventor); Romanowski, Tomothy P. (Inventor); Bloch, Laurent (Inventor)

    2006-01-01

    Method and system for analyzing, separately or in combination, kinetic energy and potential energy and/or their time derivatives, measured or estimated or computed, for an aircraft in approach phase or in takeoff phase, to determine if the aircraft is or will be put in an anomalous configuration in order to join a stable approach path or takeoff path. A 3 reference value of kinetic energy andor potential energy (or time derivatives thereof) is provided, and a comparison index .for the estimated energy and reference energy is computed and compared with a normal range of index values for a corresponding aircraft maneuver. If the computed energy index lies outside the normal index range, this phase of the aircraft is identified as anomalous, non-normal or potentially unstable.

  20. Manned maneuvering unit: User's guide

    NASA Technical Reports Server (NTRS)

    Lenda, J. A.

    1978-01-01

    The space shuttle will provide an opportunity to extend and enhance the crew's inherent capabilities in orbit by allowing them to operate effectively outside of their spacecraft by means of extravehicular activity. For this role, the shuttle crew will have a new, easier to don and operate space suit with integral life support system, and a self-contained propulsive backpack. The backpack, called the manned maneuvering unit, will allow the crew to operate beyond the confines of the Shuttle cargo bay and fly to any part of their own spacecraft or to nearby free-flying payloads or structure. This independent mobility will be used to support a wide variety of activities including free-space transfer of cargo and personnel, inspection and monitoring of orbital operations, and construction and assembly of large structures in orbit.

  1. Orbital Maneuvering system design evolution

    NASA Technical Reports Server (NTRS)

    Gibson, C.; Humphries, C.

    1985-01-01

    Preliminary design considerations and changes made in the baseline space shuttle orbital maneuvering system (OMS) to reduce cost and weight are detailed. The definition of initial subsystem requirements, trade studies, and design approaches are considered. Design features of the engine, its injector, combustion chamber, nozzle extension and bipropellant valve are illustrated and discussed. The current OMS consists of two identical pods that use nitrogen tetroxide (NTO) and monomethylhydrazine (MMH) propellants to provide 1000 ft/sec of delta velocity for a payload of 65,000 pounds. Major systems are pressurant gas storage and control, propellant storage supply and quantity measurement, and the rocket engine, which includes a bipropellant valve, an injector/thrust chamber, and a nozzle. The subsystem provides orbit insertion, circularization, and on orbit and deorbit capability for the shuttle orbiter.

  2. Multi-Maneuver Clohessy-Wiltshire Targeting

    NASA Technical Reports Server (NTRS)

    Dannemiller, David P.

    2011-01-01

    Orbital rendezvous involves execution of a sequence of maneuvers by a chaser vehicle to bring the chaser to a desired state relative to a target vehicle while meeting intermediate and final relative constraints. Intermediate and final relative constraints are necessary to meet a multitude of requirements such as to control approach direction, ensure relative position is adequate for operation of space-to-space communication systems and relative sensors, provide fail-safe trajectory features, and provide contingency hold points. The effect of maneuvers on constraints is often coupled, so the maneuvers must be solved for as a set. For example, maneuvers that affect orbital energy change both the chaser's height and downrange position relative to the target vehicle. Rendezvous designers use experience and rules-of-thumb to design a sequence of maneuvers and constraints. A non-iterative method is presented for targeting a rendezvous scenario that includes a sequence of maneuvers and relative constraints. This method is referred to as Multi-Maneuver Clohessy-Wiltshire Targeting (MM_CW_TGT). When a single maneuver is targeted to a single relative position, the classic CW targeting solution is obtained. The MM_CW_TGT method involves manipulation of the CW state transition matrix to form a linear system. As a starting point for forming the algorithm, the effects of a series of impulsive maneuvers on the state are derived. Simple and moderately complex examples are used to demonstrate the pattern of the resulting linear system. The general form of the pattern results in an algorithm for formation of the linear system. The resulting linear system relates the effect of maneuver components and initial conditions on relative constraints specified by the rendezvous designer. Solution of the linear system includes the straight-forward inverse of a square matrix. Inversion of the square matrix is assured if the designer poses a controllable scenario - a scenario where the the

  3. An Autonomous Onboard Targeting Algorithm Using Finite Thrust Maneuvers

    NASA Technical Reports Server (NTRS)

    Scarritt, Sara K.; Marchand, Belinda G.; Weeks, Michael W.

    2009-01-01

    In earlier investigations, the adaptation and implementation of a modified two-level corrections process as the onboard targeting algorithm for the Trans-Earth Injection phase of Orion is presented. The objective of that targeting algorithm is to generate the times of ignition and magnitudes of the required maneuvers such that the desired state at entry interface is achieved. In an actual onboard flight software implementation, these times of ignition and maneuvers are relayed onto Flight Control for command and execution. Although this process works well when the burn durations or burn arcs are small, this might not be the case during a contingency situation when lower thrust engines are employed to perform the maneuvers. Therefore, a new version of the modified two-level corrections process is formulated to handle the case of finite burn arcs. This paper presents the development and formulation of that finite burn modified two-level corrections process which can again be used as an onboard targeting algorithm for the Trans-Earth Injection phase of Orion. Additionally, performance results and a comparison between the two methods are presented. The finite burn two-level corrector formulation presented here ensures the entry constraints at entry interface are still met without violating the available fuel budget, while still accounting for much longer burn times in its design.

  4. An Autonomous Onboard Targeting Algorithm Using Finite Thrust Maneuvers

    NASA Technical Reports Server (NTRS)

    Scarritt, Sara K.; Marchand, Belinda G.; Brown, Aaron J.; Tracy, William H.; Weeks, Michael W.

    2010-01-01

    In earlier investigations, the adaptation and implementation of a modified two-level corrections (or targeting) process as the onboard targeting algorithm for the Trans-Earth Injection phase of Orion is presented. The objective of that targeting algorithm is to generate the times of ignition and magnitudes of the required maneuvers such that the desired state at entry interface is achieved. In an actual onboard flight software implementation, these times of ignition and maneuvers are relayed onto Flight Control for command and execution. Although this process works well when the burn durations or burn arcs are small, this might not be the case during a contingency situation when lower thrust engines are employed to perform the maneuvers. Therefore, a new model for the two-level corrections process is formulated here to accommodate finite burn arcs. This paper presents the development and formulation of the finite burn two-level corrector, used as an onboard targeting algorithm for the Trans-Earth Injection phase of Orion. A performance comparison between the impulsive and finite burn models is also presented. The present formulation ensures all entry constraints are met, without violating the available fuel budget, while allowing for low-thrust scenarios with long burn durations.

  5. Fuzzy logic, neural networks, and soft computing

    NASA Technical Reports Server (NTRS)

    Zadeh, Lofti A.

    1994-01-01

    The past few years have witnessed a rapid growth of interest in a cluster of modes of modeling and computation which may be described collectively as soft computing. The distinguishing characteristic of soft computing is that its primary aims are to achieve tractability, robustness, low cost, and high MIQ (machine intelligence quotient) through an exploitation of the tolerance for imprecision and uncertainty. Thus, in soft computing what is usually sought is an approximate solution to a precisely formulated problem or, more typically, an approximate solution to an imprecisely formulated problem. A simple case in point is the problem of parking a car. Generally, humans can park a car rather easily because the final position of the car is not specified exactly. If it were specified to within, say, a few millimeters and a fraction of a degree, it would take hours or days of maneuvering and precise measurements of distance and angular position to solve the problem. What this simple example points to is the fact that, in general, high precision carries a high cost. The challenge, then, is to exploit the tolerance for imprecision by devising methods of computation which lead to an acceptable solution at low cost. By its nature, soft computing is much closer to human reasoning than the traditional modes of computation. At this juncture, the major components of soft computing are fuzzy logic (FL), neural network theory (NN), and probabilistic reasoning techniques (PR), including genetic algorithms, chaos theory, and part of learning theory. Increasingly, these techniques are used in combination to achieve significant improvement in performance and adaptability. Among the important application areas for soft computing are control systems, expert systems, data compression techniques, image processing, and decision support systems. It may be argued that it is soft computing, rather than the traditional hard computing, that should be viewed as the foundation for artificial

  6. Cassini Solstice Mission Maneuver Experience: Year One

    NASA Technical Reports Server (NTRS)

    Wagner, Sean V.; Arrieta, Juan; Ballard, Christopher G.; Hahn, Yungsun; Stumpf, Paul W.; Valerino, Powtawche N.

    2011-01-01

    The Cassini-Huygens spacecraft began its four-year Prime Mission to study Saturn's system in July 2004. Two tour extensions followed: a two-year Equinox Mission beginning in July 2008 and a seven-year Solstice Mission starting in September 2010. This paper highlights Cassini maneuver activities from June 2010 through June 2011, covering the transition from the Equinox to Solstice Mission. This interval included 38 scheduled maneuvers, nine targeted Titan flybys, three targeted Enceladus flybys, and one close Rhea flyby. In addition, beyond the demanding nominal navigation schedule, numerous unforeseen challenges further complicated maneuver operations. These challenges will be discussed in detail.

  7. 14 CFR 23.337 - Limit maneuvering load factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factors. 23.337... Flight Loads § 23.337 Limit maneuvering load factors. (a) The positive limit maneuvering load factor n... airplanes; or (3) 6.0 for acrobatic category airplanes. (b) The negative limit maneuvering load factor...

  8. 14 CFR 29.337 - Limit maneuvering load factor.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 29.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5...

  9. 14 CFR 27.337 - Limit maneuvering load factor.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 27.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5...

  10. A fuzzy logic based spacecraft controller for six degree of freedom control and performance results

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Hoblit, Jeffrey; Jani, Yashvant

    1991-01-01

    The development philosophy of the fuzzy logic controller is explained, details of the rules and membership functions used are given, and the early results of testing of the control system for a representative range of scenarios are reported. The fuzzy attitude controller was found capable of performing all rotational maneuvers, including rate hold and rate maneuvers. It handles all orbital perturbations very efficiently and is very responsive in correcting errors.

  11. Adaptive vehicle motion estimation and prediction

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Thorpe, Chuck E.

    1999-01-01

    Accurate motion estimation and reliable maneuver prediction enable an automated car to react quickly and correctly to the rapid maneuvers of the other vehicles, and so allow safe and efficient navigation. In this paper, we present a car tracking system which provides motion estimation, maneuver prediction and detection of the tracked car. The three strategies employed - adaptive motion modeling, adaptive data sampling, and adaptive model switching probabilities - result in an adaptive interacting multiple model algorithm (AIMM). The experimental results on simulated and real data demonstrate that our tracking system is reliable, flexible, and robust. The adaptive tracking makes the system intelligent and useful in various autonomous driving tasks.

  12. Nanomagnetic Logic

    NASA Astrophysics Data System (ADS)

    Carlton, David Bryan

    The exponential improvements in speed, energy efficiency, and cost that the computer industry has relied on for growth during the last 50 years are in danger of ending within the decade. These improvements all have relied on scaling the size of the silicon-based transistor that is at the heart of every modern CPU down to smaller and smaller length scales. However, as the size of the transistor reaches scales that are measured in the number of atoms that make it up, it is clear that this scaling cannot continue forever. As a result of this, there has been a great deal of research effort directed at the search for the next device that will continue to power the growth of the computer industry. However, due to the billions of dollars of investment that conventional silicon transistors have received over the years, it is unlikely that a technology will emerge that will be able to beat it outright in every performance category. More likely, different devices will possess advantages over conventional transistors for certain applications and uses. One of these emerging computing platforms is nanomagnetic logic (NML). NML-based circuits process information by manipulating the magnetization states of single-domain nanomagnets coupled to their nearest neighbors through magnetic dipole interactions. The state variable is magnetization direction and computations can take place without passing an electric current. This makes them extremely attractive as a replacement for conventional transistor-based computing architectures for certain ultra-low power applications. In most work to date, nanomagnetic logic circuits have used an external magnetic clocking field to reset the system between computations. The clocking field is then subsequently removed very slowly relative to the magnetization dynamics, guiding the nanomagnetic logic circuit adiabatically into its magnetic ground state. In this dissertation, I will discuss the dynamics behind this process and show that it is greatly

  13. Partitioning kinetic energy during freewheeling wheelchair maneuvers.

    PubMed

    Medola, Fausto O; Dao, Phuc V; Caspall, Jayme J; Sprigle, Stephen

    2014-03-01

    This paper describes a systematic method to partition the kinetic energy (KE) of a free-wheeling wheelchair. An ultralightweight rigid frame wheelchair was instrumented with two axle-mounted encoders and data acquisition equipment to accurately measure the velocity of the drive wheels. A mathematical model was created combining physical specifications and geometry of the wheelchair and its components. Two able-bodied subjects propelled the wheelchair over four courses that involved straight and turning maneuvers at differing speeds. The KE of the wheelchair was divided into three components: translational, rotational, and turning energy. This technique was sensitive to the changing contributions of the three energy components across maneuvers. Translational energy represented the major component of total KE in all maneuvers except a zero radius turn in which turning energy was dominant. Both translational and rotational energies are directly related to wheelchair speed. Partitioning KE offers a useful means of investigating the dynamics of a moving wheelchair. The described technique permits analysis of KE imparted to the wheelchair during maneuvers involving changes in speed and direction, which are most representative of mobility in everyday life. This technique can be used to study the effort required to maneuver different types and configurations of wheelchairs.

  14. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  15. Combinatorial optimization of long-term maneuver sequences applied to geostationary orbit control

    NASA Astrophysics Data System (ADS)

    Haerting, A.; Meixner, H.

    Eccentricity control schemes for geostationary satellites are discussed considering realistic mission profiles. The advantages of long-term maneuver planning are outlined in terms of fuel savings, number of maneuvers, orbit control accuracy and safety. The planning ahead of a dozen or more maneuvers involves, in particular, the selection of discrete alternatives such as thruster branches and time intervals. The proposed planning scheme is developed by heuristic augmentation taking the TVSat-2 spacecraft as an example. Then it is formalized in the framework of combinatorial optimization by adapting the method of simulated annealing to maneuver sequences. Results for TVSat-2 are shown and compared to actual mission experience. As a conclusion, optimal control of the eccentricity vector need not be along a sun-pointing perigee circle, but along a more sophisticated path depending on spacecraft characteristics. The number of double east-west maneuvers is reduced to two per year and these are scheduled when the eccentricity is smallest. The long-term planning scheme is also demonstrated for contingency analyses.

  16. Dawn Statistical Maneuver Design for Vesta Operations

    NASA Technical Reports Server (NTRS)

    Parcher, Daniel W.; Whiffen, Gregory J.

    2011-01-01

    In July of 2011 the Dawn spacecraft is scheduled to begin orbital operations at Vesta, a large main-belt asteroid. Dawn is a NASA Discovery mission that uses solar-electric low-thrust ion propulsion for both interplanetary cruise and orbital operations. Navigating between the Dawn project's four targeted science orbits at Vesta requires a plan that accounts for uncertainties not only in thrust execution, orbit determination, and other spacecraft forces, but also large uncertainties in characteristics of Vesta - such as the asteroid's gravity field and pole orientation. Accommodating these uncertainties requires strategic use of low-thrust maneuvers reserved for statistical trajectory corrections. This paper describes the placement and evaluation of low-thrust statistical maneuvers during two key phases of the Vesta mission along with a discussion of the tools, constraints, and methods used to plan those maneuvers.

  17. Cassini Maneuver Experience: Ending the Equinox Mission

    NASA Technical Reports Server (NTRS)

    Ballard, Christopher G.; Arrieta, Juan; Hahn, Yungsun; Stumpf, Paul W.; Wagner, Sean V.; Williams, Powtawche N.

    2010-01-01

    The Cassini-Huygens spacecraft was launched in 1997 on a mission to observe Saturn and its many moons. After a seven-year interplanetary cruise, it entered a Saturnian orbit for a four-year Prime Mission in 2004 and began a two-year Equinox Mission in 2008. It has been approved for another seven-year mission, the Solstice Mission, starting in October 2010. This paper highlights significant maneuver activities performed from July 2009 to June 2010. We present results for the 45 maneuvers during this time. The successful navigation of the Cassini orbiter can be attributed in part to the accurate maneuver performance, which has greatly exceeded pre-launch expectations.

  18. An algorithm for targeting finite burn maneuvers

    NASA Technical Reports Server (NTRS)

    Barbieri, R. W.; Wyatt, G. H.

    1972-01-01

    An algorithm was developed to solve the following problem: given the characteristics of the engine to be used to make a finite burn maneuver and given the desired orbit, when must the engine be ignited and what must be the orientation of the thrust vector so as to obtain the desired orbit? The desired orbit is characterized by classical elements and functions of these elements whereas the control parameters are characterized by the time to initiate the maneuver and three direction cosines which locate the thrust vector. The algorithm was built with a Monte Carlo capability whereby samples are taken from the distribution of errors associated with the estimate of the state and from the distribution of errors associated with the engine to be used to make the maneuver.

  19. Maneuver and buffet characteristics of fighter aircraft

    NASA Technical Reports Server (NTRS)

    Ray, E. J.; Mckinney, L. W.; Carmichael, J. G.

    1973-01-01

    Recent research efforts in the improvement of the maneuverability of fighter aircraft in the high-subsonic and transonic speed range are reviewed with emphasis on the factors affecting aerodynamic boundaries, such as maximum obtainable lift, buffet onset, pitchup, wing rock, and nose slice. The investigations were made using a general research configuration which encompassed a systematic matrix of wing-design parameters. These results illustrated the sensitivity of section and planform geometry to a selected design point. The incorporation of variable-geometry wing devices in the form of flaps or leading-edge slats was shown to provide controlled flow over a wide range of flight conditions and substantial improvements in maneuver capabilities. Additional studies indicated that the blending of a highly swept maneuver strake with an efficient, moderately swept wing offers a promising approach for improving maneuver characteristics at high angles of attack without excessive penalties in structural weight.

  20. Maneuver and buffet characteristics of fighter aircraft

    NASA Technical Reports Server (NTRS)

    Ray, E. J.; Mckinney, L. W.; Carmichael, J. G.

    1972-01-01

    The high subsonic and transonic characteristics of fighter aircraft and the factors affecting aerodynamic boundaries, such as maximum obtainable lift, buffet onset, pitchup, wing rock, and nose slice are discussed. Investigations were made using a general research configuration which encompassed a systematic matrix of wing design parameters. These results emphasized the sensitivity to section and planform geometry at the selected design point. The incorporation of variable-wing-geometry devices in the form of leading-edge slats or flaps was shown in a number of flight and wind-tunnel studies to provide controlled flow over a wide range of flight conditions and substantial improvements in maneuver capabilities. Additional studies indicated that the blending of a highly swept maneuver strake with an efficient moderately swept wing offers a promising approach for improving maneuver characteristics at high angles of attack without excessive penalties in structural weight.

  1. Maneuvering and control of flexible space robots

    NASA Technical Reports Server (NTRS)

    Meirovitch, Leonard; Lim, Seungchul

    1994-01-01

    This paper is concerned with a flexible space robot capable of maneuvering payloads. The robot is assumed to consist of two hinge-connected flexible arms and a rigid end-effector holding a payload; the robot is mounted on a rigid platform floating in space. The equations of motion are nonlinear and of high order. Based on the assumption that the maneuvering motions are one order of magnitude larger than the elastic vibrations, a perturbation approach permits design of controls for the two types of motion separately. The rigid-body maneuvering is carried out open loop, but the elastic motions are controlled closed loop, by means of discrete-time linear quadratic regulator theory with prescribed degree of stability. A numerical example demonstrates the approach. In the example, the controls derived by the perturbation approach are applied to the original nonlinear system and errors are found to be relatively small.

  2. Close approach maneuvers around an oblate planet

    NASA Astrophysics Data System (ADS)

    Oliveira, G. M. C.; Prado, A. F. B. A.; Sanchez, D. M.

    2015-10-01

    There are many applications of the close approach maneuvers in astronautics, and several missions used this technique in the last decades. In the present work, those close approach maneuvers are revisited, but now considering that the spacecraft passes around an oblate planet. This fact changes the distribution of mass of the planet, increasing the mass in the region of the equator, so increasing the gravitational forces in the equatorial plane. Since the present study is limited to planar trajectories, there is an increase in the variation of energy given by the maneuver. The planet Jupiter is used as the body for the close approach, but the value of J2 is varied in a large range to simulate situations of other celestial bodies that have larger oblateness, but the same mass ratio. This is particularly true in recent discovered exoplanets, and this first study can help the study of the dynamics around those bodies.

  3. Cassini Solstice Mission Maneuver Experience: Year Two

    NASA Technical Reports Server (NTRS)

    Arrieta, Juan; Ballard, Christopher G.; Hahn, Yungsun

    2012-01-01

    The Cassini Spacecraft was launched in October 1997 on a mission to observe Saturn and its moons; it entered orbit around Saturn in July 2004 for a nominal four-year Prime Mission, later augmented by two extensions: the Equinox Mission, from July 2008 through September 2010, and the Solstice Mission, from October 2010 through September 2017. This paper provides an overview of the maneuver activities from August 2011 through June 2012 which include the design of 38 Orbit Trim Maneuvers--OTM-288 through OTM-326-- for attaining 14 natural satellite encounters: seven with Titan, six with Enceladus, and one with Dione.

  4. Mars Science Laboratory Cruise Propulsion Maneuvering Operations

    NASA Technical Reports Server (NTRS)

    Baker, Raymond S.; Mizukami, Masahi; Barber, Todd J.

    2013-01-01

    Mars Science Laboratory "Curiosity" is NASA's most recent mission to Mars, launched in November 2011, and landed in August 2012. It is a subcompact car-sized nuclear powered rover designed for a long duration mission, with an extensive suite of science instruments. Entry, descent and landing used a unique "skycrane" concept. This report describes the propulsive maneuvering operations during cruise from Earth to Mars, to control attitudes and to target the vehicle for entry. The propulsion subsystem, mission operations, and flight performance are discussed. All trajectory control maneuvers were well within accuracy requirements, and all turns and spin corrections were nominal.

  5. Laparoscopic Pringle maneuver: how we do it?

    PubMed Central

    Lhuaire, Martin; Memeo, Riccardo; Pessaux, Patrick; Kianmanesh, Reza; Sommacale, Daniele

    2016-01-01

    Laparoscopic liver resection (LLR) is technically possible with new devices which allow a relatively bloodless liver parenchymal transection. Despite, the main concern remains intraoperative hemorrhage. Currently, perioperative excessive blood loss during LLR is difficult to control with necessity of laparotomy conversion. Moreover, major blood loss requires transfusion and increases postoperative morbidity and mortality. When in-flow is limited by the hepatic pedicle clamping, it reduces intraoperative blood loss. The Pringle maneuver, first described in 1908, is the simplest method of inflow occlusion and currently can be achieved during LLR. The purpose of this note was to describe two different modalities of Pringle maneuver used by two different teams during LLR. PMID:27500146

  6. LOGIC CIRCUIT

    DOEpatents

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  7. Muscular Control of Turning and Maneuvering in Jellyfish Bells

    NASA Astrophysics Data System (ADS)

    Hoover, Alexander; Miller, Laura; Griffith, Boyce

    2014-11-01

    Jellyfish represent one of the earliest and simplest examples of swimming by a macroscopic organism. Contractions of an elastic bell that expels water are driven by coronal swimming muscles. The re-expansion of the bell is passively driven by stored elastic energy. A current question in jellyfish propulsion is how the underlying neuromuscular organization of their bell allows for maneuvering. Using an immersed boundary framework, we will examine the mechanics of swimming by incorporating material models that are informed by the musculature present in jellyfish into a model of the elastic jellyfish bell in three dimensions. The fully-coupled fluid structure interaction problem is solved using an adaptive and parallelized version of the immersed boundary method (IBAMR). We then use this model to understand how variability in the muscular activation patterns allows for complicated swimming behavior, such as steering. We will compare the results of the simulations with the actual turning maneuvers of several species of jellyfish. Numerical flow fields will also be compared to those produced by actual jellyfish using particle image velocimetry (PIV).

  8. VIEW OF MANEUVER BOAT No. 2 AND CHANOINE WICKETS FROM ...

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

    VIEW OF MANEUVER BOAT No. 2 AND CHANOINE WICKETS FROM DAM GATE STRUCTURE. MANEUVER BOAT No. 2 IN BACKGROUND. LOOKING WEST NORTHWEST. - Illinois Waterway, Peoria Lock and Dam, 1071 Wesley Road, Creve Coeur, Tazewell County, IL

  9. Maneuver Warfare revisited: a plea for balance

    SciTech Connect

    Hamilton, M,R.

    1986-04-01

    This paper is a plea for balance in the current pursuit of understanding of the concept and the teaching of Maneuver Warfare. It specifically addresses the need for a more-complete analysis of some of the more-common historical examples commonly offered as examples of the supremecy of Maneuver Warfare. The paper in no way disagrees with the desirability of conducting the kinds of operations associated with the ill-defined concepts offered by advocates of Maneuver Warfare but suggests that the desirable results of historical battles may be too readily ascribed to the dynamic, offensive actions of the victorious side. Secondly, the paper points out the lack of utility and applicability of some common buzzwords being used in today's Army. Specifically assailed is the concept of turning within a decision cycle. The paper describes the reasons that this commonly used phrase has little applicability to ground warfare. Finally, the paper mentions the tendency for the Maneuver Warfare camp to cloud discussion of doctrine in a kind of intellectualism and elitism that has no use in forming the necessary consensus demanded by doctrine.

  10. 75 FR 49815 - Maneuvering Speed Limitation Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... (NPRM), Notice No. 09-10, published in the Federal Register on September 4, 2009 (74 FR 45777). In the.../fr/index.html . You can also get a copy by sending a request to the Federal Aviation Administration... Federal Aviation Administration 14 CFR Part 25 RIN 2120-AJ21 Maneuvering Speed Limitation Statement...

  11. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .../sec2) Nose-up pitching 1.0 +39nm÷V×(nm−1.5) Nose-down pitching nm −39nm÷V×(nm−1.5) where— (1) nm... exceeding the limit maneuvering load factor. The total horizontal surface load for both nose-up and...

  12. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .../sec2) Nose-up pitching 1.0 +39nm÷V×(nm−1.5) Nose-down pitching nm −39nm÷V×(nm−1.5) where— (1) nm... exceeding the limit maneuvering load factor. The total horizontal surface load for both nose-up and...

  13. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .../sec2) Nose-up pitching 1.0 +39nm÷V×(nm−1.5) Nose-down pitching nm −39nm÷V×(nm−1.5) where— (1) nm... exceeding the limit maneuvering load factor. The total horizontal surface load for both nose-up and...

  14. 32 CFR 644.137 - Maneuver agreements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with the exercise objectives and the force elements which participate. The Corps participates in the...), and United States Army Forces, Readiness Command (USCINCARRED) on acquisition of maneuver rights for... camp sites, field hospital sites and supply dumps), and buildings needed for warehouses, ordnance...

  15. Optimizing interplanetary trajectories with deep space maneuvers

    NASA Astrophysics Data System (ADS)

    Navagh, John

    1993-09-01

    Analysis of interplanetary trajectories is a crucial area for both manned and unmanned missions of the Space Exploration Initiative. A deep space maneuver (DSM) can improve a trajectory in much the same way as a planetary swingby. However, instead of using a gravitational field to alter the trajectory, the on-board propulsion system of the spacecraft is used when the vehicle is not near a planet. The purpose is to develop an algorithm to determine where and when to use deep space maneuvers to reduce the cost of a trajectory. The approach taken to solve this problem uses primer vector theory in combination with a non-linear optimizing program to minimize Delta(V). A set of necessary conditions on the primer vector is shown to indicate whether a deep space maneuver will be beneficial. Deep space maneuvers are applied to a round trip mission to Mars to determine their effect on the launch opportunities. Other studies which were performed include cycler trajectories and Mars mission abort scenarios. It was found that the software developed was able to locate quickly DSM's which lower the total Delta(V) on these trajectories.

  16. Hybrid guidance for maneuvering flight vehicles

    NASA Astrophysics Data System (ADS)

    Ling, Dehai

    1992-02-01

    This article puts forward one type of guidance option related to the maneuver programming of reentering flight vehicles. The option in question makes use of a radiation sensing system, precisely determining the location of the starting point of the reentering flight vehicle. Use is also made of strap-on type inertial guidance systems to control the impact points of flight vehicles. Maneuvering flight is an important direction in the development of the technology of strategic flight vehicles. It is possible to use it in sudden defense, adding programming, raising precision, and recovery. Maneuvering flight tests are capable of giving complete checks in all such areas as flight vehicle propulsion systems, materials structure, heat resistance systems, stability, guidance circuits, and attitude control systems. It is capable of carrying out experiments on different technological levels. Options which are relatively simple and easy to carry out are to make the reentering flight vehicle, within the longitudinal plane, fly maneuvers according to preset programs. Going through precise inertial guidance or celestial-inertial guidance systems, guidance is carried out on the flight vehicle in the main power stage, with controls and corrections to the free section flight orbital plane, such that the trajectory is capable of entering into the predicted reentry corridor. As far as initial flight tests are concerned, it is possible to make use of inertial guidance systems which already exist, relaxing the requirements for launch plane controls and lateral impact point deviations.

  17. 46 CFR 131.990 - Maneuvering characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS... condition of loading, assuming the following: (1) Calm weather—wind 10 knots or less, calm sea. (2) No... maneuvering information is based, are varied: (i) Calm weather—wind 10 knots or less, calm sea. (ii)...

  18. 23 CFR 660.517 - Maneuver area roads.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Maneuver area roads. 660.517 Section 660.517 Highways... PROGRAMS (DIRECT FEDERAL) Defense Access Roads § 660.517 Maneuver area roads. (a) Claims by a highway agency for costs incurred to restore, to their former condition, roads damaged by maneuvers involving...

  19. 23 CFR 660.517 - Maneuver area roads.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Maneuver area roads. 660.517 Section 660.517 Highways... PROGRAMS (DIRECT FEDERAL) Defense Access Roads § 660.517 Maneuver area roads. (a) Claims by a highway agency for costs incurred to restore, to their former condition, roads damaged by maneuvers involving...

  20. 23 CFR 660.517 - Maneuver area roads.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Maneuver area roads. 660.517 Section 660.517 Highways... PROGRAMS (DIRECT FEDERAL) Defense Access Roads § 660.517 Maneuver area roads. (a) Claims by a highway agency for costs incurred to restore, to their former condition, roads damaged by maneuvers involving...

  1. 23 CFR 660.517 - Maneuver area roads.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Maneuver area roads. 660.517 Section 660.517 Highways... PROGRAMS (DIRECT FEDERAL) Defense Access Roads § 660.517 Maneuver area roads. (a) Claims by a highway agency for costs incurred to restore, to their former condition, roads damaged by maneuvers involving...

  2. 23 CFR 660.517 - Maneuver area roads.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Maneuver area roads. 660.517 Section 660.517 Highways... PROGRAMS (DIRECT FEDERAL) Defense Access Roads § 660.517 Maneuver area roads. (a) Claims by a highway agency for costs incurred to restore, to their former condition, roads damaged by maneuvers involving...

  3. 14 CFR 23.1507 - Operating maneuvering speed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  4. 14 CFR 23.1507 - Operating maneuvering speed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  5. 14 CFR 23.1507 - Operating maneuvering speed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  6. 14 CFR 23.1507 - Operating maneuvering speed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  7. 14 CFR 23.1507 - Operating maneuvering speed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  8. 14 CFR 23.1567 - Flight maneuver placard.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flight maneuver placard. 23.1567 Section 23... Information Markings and Placards § 23.1567 Flight maneuver placard. (a) For normal category airplanes, there... the approved acrobatic maneuvers and the recommended entry airspeed for each. If inverted...

  9. 14 CFR 25.333 - Flight maneuvering envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flight maneuvering envelope. 25.333 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.333 Flight maneuvering envelope. (a) General. The strength requirements must be met at each combination...

  10. 14 CFR 23.337 - Limit maneuvering load factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Limit maneuvering load factors. 23.337... Flight Loads § 23.337 Limit maneuvering load factors. (a) The positive limit maneuvering load factor n... not be less than— (1) 0.4 times the positive load factor for the normal utility and...

  11. 14 CFR 25.1531 - Maneuvering flight load factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering flight load factors. 25.1531... Operating Limitations § 25.1531 Maneuvering flight load factors. Load factor limitations, not exceeding the positive limit load factors determined from the maneuvering diagram in § 25.333(b), must be established....

  12. 14 CFR 25.337 - Limit maneuvering load factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factors. 25.337... Conditions § 25.337 Limit maneuvering load factors. (a) Except where limited by maximum (static) lift... maneuvering load factors prescribed in this section. Pitching velocities appropriate to the corresponding...

  13. A feedback linearization approach to orbital maneuvers

    NASA Astrophysics Data System (ADS)

    Lee, Sanguk

    New methods for obtaining optimal orbital maneuvers of a space vehicle in total velocity change are described and applied. The elegance of Lambert's Theorem is combined with feedback linearization and linear optimal control to obtain solutions to nonlinear orbital maneuver problems. In particular, geocentric orbital maneuvers with finite-thrust acceleration are studied. The full nonlinear equations of motion are transformed exactly into a controllable linear set in Brunovsky canonical form by using feedback linearization and choosing the position vector as the fully observable output vector. These equations are used to pose a linear optimal tracking problem with a solution to the Lambert's impulsive-thrust two-point boundary-value problem as the reference orbit. The same procedure is used to force the space vehicle to follow a linear analytical solution to the continuous low-thrust orbital maneuver problem between neighboring orbits. Limits on thrust magnitudes are enforced by adjusting the weights on the states in the performance index, which is chosen to be the sum of integrals of the square sum of new control variables and the square sum of state variable errors from the reference trajectory. For comparison purpose, the feedback linearized equations are used to obtain a simple closed-form solution to an orbital maneuver problem without the use of a reference trajectory. In this case, the performance index was chosen as the integral of the square sum of new control variables only. Three different examples, coplanar rendezvous between neighboring orbits, large coplanar orbit transfer, and non-coplanar orbit transfer, are used to show the advantages of using the new methods introduced in this dissertation. The minimum-eccentricity orbit, Hohmann transfer orbit, and minimum energy orbit were used in turn as the reference trajectories. The principal problems encountered in using the new methods are the choices of the proper reference trajectory, a suitable time

  14. Novel vagal maneuver technique for termination of supraventricular tachycardias.

    PubMed

    Un, Haluk; Dogan, Mehmet; Uz, Omer; Isilak, Zafer; Uzun, Mehmet

    2016-01-01

    Hemodynamically unstable patients with supraventricular tachycardias (SVTs) should be treated with electrical cardioversion. If the patient is stable, acute termination of tachycardia can be achieved by vagal maneuvers or medical therapy. The Valsalva maneuver, carotid massage, and ice to the face are the most common vagal maneuvers. In our experience with patients, we observed that vagal stimulation increases with lying backward. Our suggested maneuver is based on quickly lying backward, from a seated position. Then, a short and powerful vagal stimulation occurs. Thus, SVT episodes can be terminated. Here we present our experience of a new maneuver for terminating SVT, with cases.

  15. Sonic boom focal zones due to tactical aircraft maneuvers

    NASA Astrophysics Data System (ADS)

    Plotkin, Kenneth J.

    1990-10-01

    A study has been conducted of the focal zone 'superbooms' associated with tactical maneuvers of military supersonic aircraft. Focal zone footprints were computed for 21 tactical maneuvers: two for the SR-71 and 19 for fighters engaged in air combat maneuver (ACM) training. These footprints provide quantitative results which may be used for environmental planning. A key finding of this study is that focus factors and footprint areas for high-g fighter maneuvers are substantially smaller than those for gentle maneuvers associated with larger aircraft.

  16. Vibration Characteristics of Squeeze Film Damper during Maneuver Flight

    NASA Astrophysics Data System (ADS)

    Wang, Siji; Liao, Mingfu; Li, Wei

    2015-05-01

    The rotor systems of an aero engine will endure additional centrifugal force and gyroscopic moment during maneuver flight. A maneuver fly mechanical simulator is designed and experimental investigations on dynamics of squeeze film damper (SFD) under the different additional centrifugal force and gyroscopic moment are carried out. The results show that the maneuver flight weaken effectiveness of the SFD, the additional centrifugal force and gyroscopic moment caused by maneuver flight will change film damping, film stiffness. And the influence of maneuver flight can be effective relieved by increasing the film clearance.

  17. Fuzzy logic controller optimization

    DOEpatents

    Sepe, Jr., Raymond B; Miller, John Michael

    2004-03-23

    A method is provided for optimizing a rotating induction machine system fuzzy logic controller. The fuzzy logic controller has at least one input and at least one output. Each input accepts a machine system operating parameter. Each output produces at least one machine system control parameter. The fuzzy logic controller generates each output based on at least one input and on fuzzy logic decision parameters. Optimization begins by obtaining a set of data relating each control parameter to at least one operating parameter for each machine operating region. A model is constructed for each machine operating region based on the machine operating region data obtained. The fuzzy logic controller is simulated with at least one created model in a feedback loop from a fuzzy logic output to a fuzzy logic input. Fuzzy logic decision parameters are optimized based on the simulation.

  18. Dynamic Tow Maneuver Orbital Launch Technique

    NASA Technical Reports Server (NTRS)

    Rutan, Elbert L. (Inventor)

    2014-01-01

    An orbital launch system and its method of operation use a maneuver to improve the launch condition of a booster rocket and payload. A towed launch aircraft, to which the booster rocket is mounted, is towed to a predetermined elevation and airspeed. The towed launch aircraft begins the maneuver by increasing its lift, thereby increasing the flight path angle, which increases the tension on the towline connecting the towed launch aircraft to a towing aircraft. The increased tension accelerates the towed launch aircraft and booster rocket, while decreasing the speed (and thus the kinetic energy) of the towing aircraft, while increasing kinetic energy of the towed launch aircraft and booster rocket by transferring energy from the towing aircraft. The potential energy of the towed launch aircraft and booster rocket is also increased, due to the increased lift. The booster rocket is released and ignited, completing the launch.

  19. Rendezvous radar for the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Locke, John W.; Olds, Keith A.; Quaid, Thomas

    1991-01-01

    The Rendezvous Radar Set (RRS) was designed at Motorola's Strategic Electronics Division in Chandler, Arizona, to be a key subsystem aboard NASA's Orbital Maneuvering Vehicle (OMV). The unmanned OMV, which was under development at TRW's Federal Systems Division in Redondo Beach, California, was designed to supplement the Shuttle's satellite delivery, retrieval, and maneuvering activities. The RRS was to be used to locate and then provide the OMV with vectoring information to the target satellite (or Shuttle or Space Station) to aid the OMV in making a minimum fuel consumption approach and rendezvous. The OMV development program was halted by NASA in 1990 just as parts were being ordered for the RRS engineering model. The paper presented describes the RRS design and then discusses new technologies, either under development or planned for development at Motorola, that can be applied to radar or alternative sensor solutions for the Automated Rendezvous and Capture problem.

  20. The Orbital Maneuvering Vehicle - A new capability

    NASA Technical Reports Server (NTRS)

    Arcilesi, Charles J.; Holliman, Charles T.

    1988-01-01

    NASA's Orbital Maneuvering Vehicle (OMV) is a reusable remotely-controlled spacecraft for support of orbiting platforms through such functions as satellite delivery, satellite retrieval, satellite reboost, controlled satellite deorbit, satellite inspection, and subsatellite missions. The OMV will be a critical component of the Space Station program's operational scenario; it will be able to operate either from the Space Shuttle Orbiter or the Space Station, and can also be space-based. The maiden flight of the first OMV is projected for 1993.

  1. Hydrodynamics of maneuvering bodies: LDRD final report

    SciTech Connect

    Kempka, S.N.; Strickland, J.H.

    1994-01-01

    The objective of the ``Hydrodynamics of Maneuvering Bodies`` LDRD project was to develop a Lagrangian, vorticity-based numerical simulation of the fluid dynamics associated with a maneuvering submarine. Three major tasks were completed. First, a vortex model to simulate the wake behind a maneuvering submarine was completed, assuming the flow to be inviscid and of constant density. Several simulations were performed for a dive maneuver, each requiring less than 20 cpu seconds on a workstation. The technical details of the model and the simulations are described in a separate document, but are reviewed herein. Second, a gridless method to simulate diffusion processes was developed that has significant advantages over previous Lagrangian diffusion models. In this model, viscous diffusion of vorticity is represented by moving vortices at a diffusion velocity, and expanding the vortices as specified by the kinematics for a compressible velocity field. This work has also been documented previously, and is only reviewed herein. The third major task completed was the development of a vortex model to describe inviscid internal wave phenomena, and is the focus of this document. Internal wave phenomena in the stratified ocean can affect an evolving wake, and thus must be considered for naval applications. The vortex model for internal wave phenomena includes a new formulation for the generation of vorticity due to fluid density variations, and a vortex adoption algorithm that allows solutions to be carried to much longer times than previous investigations. Since many practical problems require long-time solutions, this new adoption algorithm is a significant step toward making vortex methods applicable to practical problems. Several simulations are described and compared with previous results to validate and show the advantages of the new model. An overview of this project is also included.

  2. Hydrodynamics of maneuvering bodies: LDRD Final Report

    NASA Astrophysics Data System (ADS)

    Kempka, S. N.; Strickland, J. H.

    1994-01-01

    The objective of the 'Hydrodynamics of Maneuvering Bodies' LDRD project was to develop a Lagrangian, vorticity-based numerical simulation of the fluid dynamics associated with a maneuvering submarine. Three major tasks were completed. First, a vortex model to simulate the wake behind a maneuvering submarine was completed, assuming the flow to be inviscid and of constant density. Several simulations were performed for a dive maneuver, each requiring less than 20 cpu seconds on a workstation. The technical details of the model and the simulations are described in a separate document, but are reviewed herein. Second, a gridless method to simulate diffusion processes was developed that has significant advantages over previous Lagrangian diffusion models. In this model, viscous diffusion of vorticity is represented by moving vortices at a diffusion velocity, and expanding the vortices as specified by the kinematics for a compressible velocity field. This work was also documented previously and is only reviewed herein. The third major task completed was the development of a vortex model to describe inviscid internal wave phenomena and is the focus of this document. Internal wave phenomena in the stratified ocean can affect an evolving wake and thus, must be considered for naval applications. The vortex model for internal wave phenomena includes a new formulation for the generation of vorticity due to fluid density variations and a vortex adoption algorithm that allows solutions to be carried to much longer times than previous investigations. Since many practical problems require long-time solutions, this new adoption algorithm is a significant step toward making vortex methods applicable to practical problems. Several simulations are described and compared with previous results to validate and show the advantages of the new model. An overview of this project is also included.

  3. Identifying tacit strategies in aircraft maneuvers

    NASA Technical Reports Server (NTRS)

    Lewis, Charles M.; Heidorn, P. B.

    1991-01-01

    Two machine-learning methods are presently used to characterize the avoidance strategies used by skilled pilots in simulated aircraft encounters, and a general framework for the characterization of the strategic components of skilled behavior via qualitative representation of situations and responses is presented. Descriptions of pilot maneuvers that were 'conceptually equivalent' were ascertained by a concept-learning algorithm in conjunction with a classifier system that employed a generic algorithm; satisficing and 'buggy' strategies were thereby revealed.

  4. A wing concept for supersonic maneuvering

    NASA Technical Reports Server (NTRS)

    Mason, W. H.

    1983-01-01

    A theoretical and experimental program in which a wing concept for supersonic maneuvering was developed and then demonstrated experimentally in a series of wind tunnel tests is described. For the typical fighter wing, the problem of obtaining efficient lift at supersonic maneuvering C sub 's occurs due to development of a strong crossflow shock, and boundary layer separation. A natural means of achieving efficient supersonic maneuvering is based on controlling the non-linear inviscid crossflow on the wing in a manner analogous to the supercritical aerodynamic methods developed for transonic speeds. The application of supercritical aerodynamics to supersonic speeds is carried out using Supercritical Conical Camber (SC3). This report provides an aerodynamic analysis of the effort, with emphasis on wing design using non-linear aerodynamics. The substantial experimental data base is described in three separate wind tunnel reports, while two of the computer programs used in the work are also described in a separate report. Based on the development program it appears that a controlled supercritical crossflow can be obtained reliably on fighter-type wing planforms, with an associated drag due to lift reduction of about 20% projected using this concept.

  5. Identification of aerodynamic models for maneuvering aircraft

    NASA Technical Reports Server (NTRS)

    Chin, Suei; Lan, C. Edward

    1990-01-01

    Due to the requirement of increased performance and maneuverability, the flight envelope of a modern fighter is frequently extended to the high angle-of-attack regime. Vehicles maneuvering in this regime are subjected to nonlinear aerodynamic loads. The nonlinearities are due mainly to three-dimensional separated flow and concentrated vortex flow that occur at large angles of attack. Accurate prediction of these nonlinear airloads is of great importance in the analysis of a vehicle's flight motion and in the design of its flight control system. A satisfactory evaluation of the performance envelope of the aircraft may require a large number of coupled computations, one for each change in initial conditions. To avoid the disadvantage of solving the coupled flow-field equations and aircraft's motion equations, an alternate approach is to use a mathematical modeling to describe the steady and unsteady aerodynamics for the aircraft equations of motion. Aerodynamic forces and moments acting on a rapidly maneuvering aircraft are, in general, nonlinear functions of motion variables, their time rate of change, and the history of maneuvering. A numerical method was developed to analyze the nonlinear and time-dependent aerodynamic response to establish the generalized indicial function in terms of motion variables and their time rates of change.

  6. Aerodynamic Flow Control of a Maneuvering Airfoil

    NASA Astrophysics Data System (ADS)

    Brzozowski, Daniel P.; Culp, John; Glezer, Ari

    2010-11-01

    The unsteady aerodynamic forces and moments on a maneuvering, free-moving airfoil are varied in wind tunnel experiments by controlling vorticity generation/accumulation near the surface using hybrid synthetic jet actuators. The dynamic characteristics of the airfoil that is mounted on a 2-DOF traverse are controlled using position and attitude feedback loops that are actuated by servo motors. Bi-directional changes in the pitching moment are induced using controllable trapped vorticity concentrations on the suction and pressure surfaces near the trailing edge. The dynamic coupling between the actuation and the time-dependent flow field is characterized using simultaneous force and velocity measurements that are taken phase-locked to the commanded actuation waveform. The time scales associated with the actuation process is determined from PIV measurements of vorticity flux downstream of the trailing edge. Circulation time history shows that the entire flow over the airfoil readjusts within about 1.5 TCONV, which is about two orders of magnitude shorter than the characteristic time associated with the controlled maneuver of the wind tunnel model. This illustrates that flow-control actuation can be typically effected on time scales commensurate with the flow's convective time scale, and that the maneuver response is only limited by the inertia of the platform. Supported by AFSOR.

  7. Fuzzy branching temporal logic.

    PubMed

    Moon, Seong-ick; Lee, Kwang H; Lee, Doheon

    2004-04-01

    Intelligent systems require a systematic way to represent and handle temporal information containing uncertainty. In particular, a logical framework is needed that can represent uncertain temporal information and its relationships with logical formulae. Fuzzy linear temporal logic (FLTL), a generalization of propositional linear temporal logic (PLTL) with fuzzy temporal events and fuzzy temporal states defined on a linear time model, was previously proposed for this purpose. However, many systems are best represented by branching time models in which each state can have more than one possible future path. In this paper, fuzzy branching temporal logic (FBTL) is proposed to address this problem. FBTL adopts and generalizes concurrent tree logic (CTL*), which is a classical branching temporal logic. The temporal model of FBTL is capable of representing fuzzy temporal events and fuzzy temporal states, and the order relation among them is represented as a directed graph. The utility of FBTL is demonstrated using a fuzzy job shop scheduling problem as an example. PMID:15376850

  8. Venous return curves obtained from graded series of valsalva maneuvers

    NASA Technical Reports Server (NTRS)

    Mastenbrook, S. M., Jr.

    1974-01-01

    The effects were studied of a graded series of valsalva-like maneuvers on the venous return, which was measured transcutaneously in the jugular vein of an anesthetized dog, with the animal serving as its own control. At each of five different levels of central venous pressure, the airway pressure which just stopped venous return during each series of maneuvers was determined. It was found that this end-point airway pressure is not a good estimator of the animal's resting central venous pressure prior to the simulated valsalva maneuver. It was further found that the measured change in right atrial pressure during a valsalva maneuver is less than the change in airway pressure during the same maneuver, instead of being equal, as had been expected. Relative venous return curves were constructed from the data obtained during the graded series of valsalva maneuvers.

  9. Slew maneuvers of Spacecraft Control Laboratory Experiment (SCOLE)

    NASA Technical Reports Server (NTRS)

    Kakad, Yogendra P.

    1992-01-01

    This is the final report on the dynamics and control of slew maneuvers of the Spacecraft Control Laboratory Experiment (SCOLE) test facility. The report documents the basic dynamical equation derivations for an arbitrary large angle slew maneuver as well as the basic decentralized slew maneuver control algorithm. The set of dynamical equations incorporate rigid body slew maneuver and three dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interactions between the rigid shuttle and the flexible appendage. The equations are simplified and evaluated numerically to include the first ten flexible modes to yield a model for designing control systems to perform slew maneuvers. The control problem incorporates the nonlinear dynamical equations and is expressed in terms of a two point boundary value problem.

  10. Specifying Imperative ML-Like Programs Using Dynamic Logic

    NASA Astrophysics Data System (ADS)

    Maingaud, Séverine; Balat, Vincent; Bubel, Richard; Hähnle, Reiner; Miquel, Alexandre

    We present a logical system suited for specification and verification of imperative ML programs. The specification language combines dynamic logic (DL), explicit state updates and second-order functional arithmetic. Its proof system is based on a Gentzen-style sequent calculus (adapted to modal logic) with facilities for symbolic evaluation. We illustrate the system with some example, and give a full Kripke-style semantics in order to prove its correctness.

  11. Support and maneuvering apparatus for solar energy receivers

    DOEpatents

    Murphy, L.M.

    1988-07-28

    A support and maneuvering apparatus is disclosed for a solar energy receiving device adapted for receiving and concentrating solar energy and having a central axis extending through the center thereof. The apparatus includes a frame for mounting the perimeter of said solar energy receiving device. A support member extends along the central axis of the receiving device and has a base end passing through the center of the receiving device and an outer distal end adapted for carrying a solar energy receiving and conversion mechanism. A variable tension mechanism interconnects the support member with the frame to provide stiffening for the support member and the frame and to assist in the alignment of the frame to optimize the optical efficiency of the solar energy receiving device. A rotatable base is provided, and connecting members extend from the base for pivotable attachment to the frame at spaced positions therealong. Finally, an elevation assembly is connected to the receiving device for selectively pivoting the receiving about an axis defined between the attachment positions of the connecting members on the frame. 4 figs.

  12. Ride quality of terminal-area flight maneuvers

    NASA Technical Reports Server (NTRS)

    Schoonover, W. E., Jr.

    1975-01-01

    Complex terminal-area flight maneuvers being considered for airline operations may not be acceptable to passengers. To provide technology in this area, a series of flight experiments was conducted by NASA using the U. S. Air Force Total In-Flight Simulator (TIFS) aircraft to obtain subjective responses of a significant number of passenger test subjects to closely controlled and repeatable flight maneuvers. Regression analysis of the data produced a mathematical model which closely predicts mean passenger ride-comfort rating as a function of the rms six-degree-of-freedom aircraft motions during the maneuver. This ride-comfort model was exercised to examine various synthesized flight maneuvers.

  13. Large planar maneuvers for articulated flexible manipulators

    NASA Technical Reports Server (NTRS)

    Huang, Jen-Kuang; Yang, Li-Farn

    1988-01-01

    An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed-loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness of the proposed position control algorithms.

  14. Maneuver strategies for multi-planet missions.

    NASA Technical Reports Server (NTRS)

    Dwivedi, N. P.

    1972-01-01

    This paper compares a number of maneuver strategies for five multi-planet missions, including the single planet strategy of nulling the aim-plane and flight-time errors at the immediate target. Significant differences were found among the strategies in the amount of corrective propellant required and the residual miss at each target. In general, nulling or minimization of the residual miss at the next target was found to be superior to that at the immediate target, when error growth is not nulled early. The best strategy corrects aim-plane and flight-time errors at the next target.

  15. Maneuvering technology for advanced fighter aircraft

    NASA Technical Reports Server (NTRS)

    Alexander, Michael G.; Harris, Scott H.; Byers, Richard H.

    1992-01-01

    The need for increased maneuverability has its genesis from the first aerial combat engagement when two adversaries entangled themselves in a deadly aerial dance trying to gain the advantage over the other. It has only been in the past two decades that technologies have been investigated to increase aircraft control at maneuver attitudes that are typically dominated by highly separated flows. These separated flow regions are aggravated by advanced fighter aircraft shapes required to defeat an electronic enemy. This paper discusses passive and active devices that can be used to enhance the maneuverability of advanced fighter aircraft through vortex flow control, boundary layer control, and innovative flow manipulation.

  16. Prototype Conflict Alerting Logic for Free Flight

    NASA Technical Reports Server (NTRS)

    Yang, Lee C.; Kuchar, James K.

    1997-01-01

    This paper discusses the development of a prototype alerting system for a conceptual Free Flight environment. The concept assumes that datalink between aircraft is available and that conflicts are primarily resolved on the flight deck. Four alert stages are generated depending on the likelihood of a conflict. If the conflict is not resolved by the flight crews, Air Traffic Control is notified to take over separation authority. The alerting logic is based on probabilistic analysis through modeling of aircraft sensor and trajectory uncertainties. Monte Carlo simulations were used over a range of encounter situations to determine conflict probability. The four alert stages were then defined based on probability of conflict and on the number of avoidance maneuvers available to the flight crew. Preliminary results from numerical evaluations and from a piloted simulator study at NASA Ames Research Center are summarized.

  17. Digital Holographic Logic

    NASA Technical Reports Server (NTRS)

    Preston, K., Jr.

    1972-01-01

    The characteristics of the holographic logic computer are discussed. The holographic operation is reviewed from the Fourier transform viewpoint, and the formation of holograms for use in performing digital logic are described. The operation of the computer with an experiment in which the binary identity function is calculated is discussed along with devices for achieving real-time performance. An application in pattern recognition using neighborhood logic is presented.

  18. Foundations of logic programming

    SciTech Connect

    Lloyd, J.W.

    1987-01-01

    This is the second edition of the first book to give an account of the mathematical foundations of Logic Programming. Its purpose is to collect the basic theoretical results of Logic Programming, which have previously only been available in widely scattered research papers. In addition to presenting the technical results, the book also contains many illustrative examples. Many of the examples and problems are part of the folklore of Logic Programming and are not easily obtainable elsewhere.

  19. Fuzzy Logic Engine

    NASA Technical Reports Server (NTRS)

    Howard, Ayanna

    2005-01-01

    The Fuzzy Logic Engine is a software package that enables users to embed fuzzy-logic modules into their application programs. Fuzzy logic is useful as a means of formulating human expert knowledge and translating it into software to solve problems. Fuzzy logic provides flexibility for modeling relationships between input and output information and is distinguished by its robustness with respect to noise and variations in system parameters. In addition, linguistic fuzzy sets and conditional statements allow systems to make decisions based on imprecise and incomplete information. The user of the Fuzzy Logic Engine need not be an expert in fuzzy logic: it suffices to have a basic understanding of how linguistic rules can be applied to the user's problem. The Fuzzy Logic Engine is divided into two modules: (1) a graphical-interface software tool for creating linguistic fuzzy sets and conditional statements and (2) a fuzzy-logic software library for embedding fuzzy processing capability into current application programs. The graphical- interface tool was developed using the Tcl/Tk programming language. The fuzzy-logic software library was written in the C programming language.

  20. The manned maneuvering unit flight controller arm

    NASA Technical Reports Server (NTRS)

    Falkner, K. E.

    1983-01-01

    The Manned Maneuvering Unit (MMU) and its support equipment provide an extravehicular astronaut mobility, and the ability to work outside the confines of the Shuttle Orbiter payload bay. The MMU design requirements are based on the highly successful Skylab M-509 maneuvering unit. Design of the MMU was started as an R&D effort in April 1975 and Flight Hardware design was started in August 1979 to support a possible requirement for in-space inspection and repair of Orbiter thermal protection tiles. Subsequently, the qualification test and production activities were slowed, and the current projected earliest first flight is now STS-11 in January, 1984. The MMU propulsion subsystem provides complete redundancy with two identical "system". Each system contains a high pressure gaseous nitrogen tank, an isolation valve, a regulator, and twelve 1.7 lbf (7.5 N) thrusters. The thrusters are packaged to provide the crew member six-degree-of-freedom control in response to commands from translational and rotational hand controllers. This paper discusses the MMU control arm requirements, design, and developmental history.

  1. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers.

    PubMed

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-01-01

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system's performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions. PMID:27240369

  2. Maneuver of juvenile chinook salmon during feeding in streams

    NASA Astrophysics Data System (ADS)

    Peng, Jifeng

    2010-11-01

    Before they head to the ocean, juvenile chinook salmon O. tshawytscha habitat in freshwater rivers and feed on small invertebrates drifting in streams. During drift-feeding, these fish hold fairly steady positions in the flow facing upstream, and maneuver to intercept drifting prey as it passes. They have a large arsenal of maneuver modes, which presumably enable them to maximize prey encounter while keeping energy expense low. Moreover, because these fish often gather in schools, they utilize their maneuvers so that they do not invade others' territories. In this study, we measured three-dimensional motion of juvenile chinook salmon in situ during feeding. The kinematics of some of the widely-used maneuvers, including slow lateral motion, sharp U-shaped turn and fast S-shaped turn, were analyzed. A computational model based on ideal fluid theory was developed to estimate the dynamics of these maneuvers. Energetics of the maneuvers was evaluated, together with effects on prey encounter, in order to compare and explain the choices of maneuvers in different situations. The effects of neighbors in a fish school on individual maneuvers were also studied.

  3. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... needed to achieve the positive limit maneuvering load factor may not be less than: (1) For wheel controls... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Elevator control force in maneuvers. 23.155... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES...

  4. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... needed to achieve the positive limit maneuvering load factor may not be less than: (1) For wheel controls... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Elevator control force in maneuvers. 23.155... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES...

  5. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... needed to achieve the positive limit maneuvering load factor may not be less than: (1) For wheel controls... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Elevator control force in maneuvers. 23.155... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES...

  6. 14 CFR 25.1531 - Maneuvering flight load factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maneuvering flight load factors. 25.1531 Section 25.1531 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... positive limit load factors determined from the maneuvering diagram in § 25.333(b), must be established....

  7. 14 CFR 25.1531 - Maneuvering flight load factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maneuvering flight load factors. 25.1531 Section 25.1531 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... positive limit load factors determined from the maneuvering diagram in § 25.333(b), must be established....

  8. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers

    PubMed Central

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-01-01

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system’s performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions. PMID:27240369

  9. 14 CFR 25.331 - Symmetric maneuvering conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zero pitching acceleration... cockpit pitch control is suddenly moved to obtain extreme nose up pitching acceleration. In defining the... subsequent to the time when normal acceleration at the c.g. exceeds the positive limit maneuvering...

  10. 14 CFR 25.331 - Symmetric maneuvering conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zero pitching acceleration... cockpit pitch control is suddenly moved to obtain extreme nose up pitching acceleration. In defining the... subsequent to the time when normal acceleration at the c.g. exceeds the positive limit maneuvering...

  11. 14 CFR 25.331 - Symmetric maneuvering conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zero pitching acceleration... cockpit pitch control is suddenly moved to obtain extreme nose up pitching acceleration. In defining the... subsequent to the time when normal acceleration at the c.g. exceeds the positive limit maneuvering...

  12. 14 CFR 25.331 - Symmetric maneuvering conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zero pitching acceleration... cockpit pitch control is suddenly moved to obtain extreme nose up pitching acceleration. In defining the... subsequent to the time when normal acceleration at the c.g. exceeds the positive limit maneuvering...

  13. 14 CFR 25.331 - Symmetric maneuvering conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zero pitching acceleration... cockpit pitch control is suddenly moved to obtain extreme nose up pitching acceleration. In defining the... subsequent to the time when normal acceleration at the c.g. exceeds the positive limit maneuvering...

  14. Fundamentals of Digital Logic.

    ERIC Educational Resources Information Center

    Noell, Monica L.

    This course is designed to prepare electronics personnel for further training in digital techniques, presenting need to know information that is basic to any maintenance course on digital equipment. It consists of seven study units: (1) binary arithmetic; (2) boolean algebra; (3) logic gates; (4) logic flip-flops; (5) nonlogic circuits; (6)…

  15. Identifying Logical Necessity

    ERIC Educational Resources Information Center

    Yopp, David

    2010-01-01

    Understanding logical necessity is an important component of proof and reasoning for teachers of grades K-8. The ability to determine exactly where young students' arguments are faulty offers teachers the chance to give youngsters feedback as they progress toward writing mathematically valid deductive proofs. As defined, logical necessity is the…

  16. Logic Programming: PROLOG.

    ERIC Educational Resources Information Center

    Lopez, Antonio M., Jr.

    1989-01-01

    Provides background material on logic programing and presents PROLOG as a high-level artificial intelligence programing language that borrows its basic constructs from logic. Suggests the language is one which will help the educator to achieve various goals, particularly the promotion of problem solving ability. (MVL)

  17. Programmable Logic Controllers.

    ERIC Educational Resources Information Center

    Insolia, Gerard; Anderson, Kathleen

    This document contains a 40-hour course in programmable logic controllers (PLC), developed for a business-industry technology resource center for firms in eastern Pennsylvania by Northampton Community College. The 10 units of the course cover the following: (1) introduction to programmable logic controllers; (2) DOS primer; (3) prerequisite…

  18. Logic via Computer Programming.

    ERIC Educational Resources Information Center

    Wieschenberg, Agnes A.

    This paper proposed the question "How do we teach logical thinking and sophisticated mathematics to unsophisticated college students?" One answer among many is through the writing of computer programs. The writing of computer algorithms is mathematical problem solving and logic in disguise and it may attract students who would otherwise stop…

  19. Optical logic: an overview

    NASA Astrophysics Data System (ADS)

    Caulfield, H. John

    2005-05-01

    Progress of optical logic has been anything but uniform or even monotonic. The hope for "all optical computers" was largely abandoned after devastating critiques by Keyes. Over time, optical logic transformed into a very viable niche activity by the needs of optical communication for "all optical" logic and the advent of a critical component: the SOA or Semiconductor Optical Amplifier. I argue that a new phase in this uneven history can be defined - linear (single photon, not multiple entangled photon) quantum optical logic. These can perform conservative, reversible logic operations without energy or time penalties, but cascading requires the irreversible act of measurement, so only single devices or single layers can deliver those advantages.

  20. Microelectromechanical reprogrammable logic device

    PubMed Central

    Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.

    2016-01-01

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme. PMID:27021295

  1. Fuzziness in abacus logic

    NASA Astrophysics Data System (ADS)

    Malhas, Othman Qasim

    1993-10-01

    The concept of “abacus logic” has recently been developed by the author (Malhas, n.d.). In this paper the relation of abacus logic to the concept of fuzziness is explored. It is shown that if a certain “regularity” condition is met, concepts from fuzzy set theory arise naturally within abacus logics. In particular it is shown that every abacus logic then has a “pre-Zadeh orthocomplementation”. It is also shown that it is then possible to associate a fuzzy set with every proposition of abacus logic and that the collection of all such sets satisfies natural conditions expected in systems of fuzzy logic. Finally, the relevance to quantum mechanics is discussed.

  2. Microelectromechanical reprogrammable logic device

    NASA Astrophysics Data System (ADS)

    Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.

    2016-03-01

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme.

  3. Planar reorientation maneuvers of space multibody systems using internal controls

    NASA Technical Reports Server (NTRS)

    Reyhanoglu, Mahmut; Mcclamroch, N. H.

    1992-01-01

    In this paper a reorientation maneuvering strategy for an interconnection of planar rigid bodies in space is developed. It is assumed that there are no exogeneous torques, and torques generated by joint motors are used as means of control so that the total angular momentum of the multibody system is a constant, assumed to be zero in this paper. The maneuver strategy uses the nonintegrability of the expression for the angular momentum. We demonstrate that large-angle maneuvers can be designed to achieve an arbitrary reorientation of the multibody system with respect to an inertial frame. The theoretical background for carrying out the required maneuvers is briefly summarized. Specifications and computer simulations of a specific reorientation maneuver, and the corresponding control strategies, are described.

  4. Optimization of Maneuver Execution for Landsat-7 Routine Operations

    NASA Technical Reports Server (NTRS)

    Cox, E. Lucien, Jr.; Bauer, Frank H. (Technical Monitor)

    2000-01-01

    Multiple mission constraints were satisfied during a lengthy, strategic ascent phase. Once routine operations begin, the ongoing concern of maintaining mission requirements becomes an immediate priority. The Landsat-7 mission has tight longitude control box and Earth imaging that requires sub-satellite descending nodal equator crossing times to occur in a narrow 30minute range fifteen (15) times daily. Operationally, spacecraft maneuvers must'be executed properly to maintain mission requirements. The paper will discuss the importance of optimizing the altitude raising and plane change maneuvers, amidst known constraints, to satisfy requirements throughout mission lifetime. Emphasis will be placed not only on maneuver size and frequency but also on changes in orbital elements that impact maneuver execution decisions. Any associated trade-off arising from operations contingencies will be discussed as well. Results of actual altitude and plane change maneuvers are presented to clarify actions taken.

  5. Regulatory Conformance Checking: Logic and Logical Form

    ERIC Educational Resources Information Center

    Dinesh, Nikhil

    2010-01-01

    We consider the problem of checking whether an organization conforms to a body of regulation. Conformance is studied in a runtime verification setting. The regulation is translated to a logic, from which we synthesize monitors. The monitors are evaluated as the state of an organization evolves over time, raising an alarm if a violation is…

  6. Logical Thinking in College Students

    ERIC Educational Resources Information Center

    O'Brien, Thomas C.

    1973-01-01

    College students' responses to conditional syllogisms are used to analyze the students' interpretations of implication. Child's Logic'' was used much more frequently than Math Logic'' even after a one-semester course in logic. (JP)

  7. Maneuver Classification for Aircraft Fault Detection

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj C.; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.

    2003-01-01

    Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data provide a reasonable match to known examples of proper operation. In the domain of fault detection in aircraft, identifying all possible faulty and proper operating modes is clearly impossible. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. To develop such a system, we use flight data collected under a controlled test environment, subject to many sources of variability. We explain where our classifier fits into the envisioned fault detection system as well as experiments showing the promise of this classification subsystem.

  8. Analysis of ship maneuvering data from simulators

    NASA Astrophysics Data System (ADS)

    Frette, V.; Kleppe, G.; Christensen, K.

    2011-03-01

    We analyze complex manuevering histories of ships obtained from training sessions on bridge simulators. Advanced ships are used in fields like offshore oil exploration: dive support vessels, supply vessels, anchor handling vessels, tugs, cable layers, and multi-purpose vessels. Due to high demands from the operations carried out, these ships need to have very high maneuverability. This is achieved through a propulsion system with several thrusters, water jets, and rudders in addition to standard propellers. For some operations, like subsea maintenance, it is crucial that the ship accurately keeps a fixed position. Therefore, bridge systems usually incorporate equipment for Dynamic Positioning (DP). DP is a method to keep ships and semi submersible rigs in a fixed position using the propulsion systems instead of anchors. It may also be used for sailing a vessel from one position to another along a predefined route. Like an autopilot on an airplane, DP may operate without human involvement. The method relies on accurate determination of position from external reference systems like GPS, as well as a continuously adjusted mathematical model of the ship and external forces from wind, waves and currents. In a specific simulator exercise for offshore crews, a ship is to be taken up to an installation consisting of three nearby oil platforms connected by bridges (Frigg field, North Sea), where a subsea inspection is to be carried out. Due to the many degrees of freedom during maneuvering, including partly or full use of DP, the chosen routes vary significantly. In this poster we report preliminary results on representations of the complex maneuvering histories; representations that allow comparison between crew groups, and, possibly, sorting of the different strategic choices behind.

  9. X-31 in flight - Mongoose 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

  10. Support and maneuvering apparatus for solar energy receivers

    DOEpatents

    Murphy, Lawrence M.

    1989-01-01

    A support and maneuvering apparatus is disclosed for a solar energy receiving device adpated for receiving and concentrating solar energy and having a central axis extending through the center thereof. The apparatus includes a frame for mounting the perimeter of said solar energy receiving device. A support member extends along the central axis of the receiving device and has a base end passing through the center of the receiving device and an outer distal end adapted for carrying a solar energy receiving and conversion mechanism. A variable tension mechanism interconnects the support member with the frame to provide stiffening for the support member and the frame and to assist in the alignment of the frame to optimize the optical efficiency of the solar energy receiving device. A rotatable base is provided, and connecting members extend from the base for pivotable attachment to the frame at spaced positions therealong. Finally, an elevation assembly is connected to the receiving device for selectively pivoting the receiving device about an axis defined between the attachment positions of the connecting members on the frame.

  11. Dynamics of spacecraft control laboratory experiment (SCOLE) slew maneuvers

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

    This is the first of two reports on the dynamics and control of slewing maneuvers of the NASA Spacecraft Control Laboratory Experiment (SCOLE). In this report, the dynamics of slewing maneuvers of SCOLE are developed in terms of an arbitrary maneuver about any given axis. The set of dynamical equations incorporate rigid-body slew maneuver and three-dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interaction between the rigid shuttle and the flexible appendage. The final set of dynamical equations obtained for slewing maneuvers is highly nonlinear and coupled in terms of the flexible modes and the rigid-body modes. The equations are further simplified and evaluated numerically to include the first ten flexible modes and the SCOLE data to yield a model for designing control systems to perform slew maneuvers.

  12. Optimal conditions for interferometric imaging maneuvers in near-earth orbit

    NASA Astrophysics Data System (ADS)

    Yoo, Sung-Moon; Jung, Taehyun

    Satellite formation flying has been extensively investigated as a way to expand the capabili-ties of space missions focused on obtaining interferometric images. The use of fleets of small satellites, instead of a single monolithic satellite, enables space interferometry with a capability of high resolution imaging through a reconfiguration maneuver. The goal of this study is to compute and analyze the optimal conditions of an n-spacecraft formation to obtain high-quality interferometric images in near-Earth orbit. In order to achieve an optimal performance in an interferometric imaging system, a fuel amount during reconfiguration maneuver and the imag-ing capability should be considered simultaneously. In the present study, a general analytic solution for the fuel-optimal reconfiguration of satellite formation flying is adapted. Based on the analytic solutions, the image-quality index is calculated for the case of various reconfgura-tion parameters, which are the size of the formation, the number of satellites and the maneuver durations. For the comparison of the image-quality index, we assumed a midinfrared system located at geostationary orbit, which has advantages in detecting human bodies and acquiring information that cannot be found by imaging in visible light, such as temperatures of buildings and hot spots where engines or machinery could be hidden. The results of simulations provide the optimal criteria of reconfiguration parameters to acquire high-quality interferometric im-ages. Optimal conditions determined in this work make it possible to design an overall concept for the reconfiguration maneuver of satellite formation to get an optimal interferometric image.

  13. Reasoning, logic, and psychology.

    PubMed

    Stenning, Keith; van Lambalgen, Michiel

    2011-09-01

    We argue that reasoning has been conceptualized so narrowly in what is known as 'psychology of reasoning' that reasoning's relevance to cognitive science has become well-nigh invisible. Reasoning is identified with determining whether a conclusion follows validly from given premises, where 'valid' is taken to mean 'valid according to classical logic'. We show that there are other ways to conceptualize reasoning, more in line with current logical theorizing, which give it a role in psychological processes ranging from (verbal) discourse comprehension to (nonverbal) planning. En route we show that formal logic, at present marginalized in cognitive science, can be an extremely valuable modeling tool. In particular, there are cases in which probabilistic modeling must fail, whereas logical models do well. WIREs Cogni Sci 2011 2 555-567 DOI: 10.1002/wcs.134 For further resources related to this article, please visit the WIREs website.

  14. Soap Bubbles and Logic.

    ERIC Educational Resources Information Center

    Levine, Shellie-helane; And Others

    1986-01-01

    Introduces questions and activities involving soap bubbles which provide students with experiences in prediction and logic. Examines commonly held false conceptions related to the shapes that bubbles take and provides correct explanations for the phenomenon. (ML)

  15. Maneuver Design for the Juno Mission: Inner Cruise

    NASA Technical Reports Server (NTRS)

    Pavlak, Thomas A.; Frauenholz, Raymond B.; Bordi, John J.; Kangas, Julie A.; Helfrich, Clifford E.

    2014-01-01

    The Juno spacecraft launched in August 2011 and, following a successful Earth flyby in October 2013, is on course for a nominal orbit insertion at Jupiter in July 2016. This paper examines the design and execution of deterministic and statistical trajectory correction maneuvers during the first approximately 27 months of post-launch operations that defined the "Inner Cruise" phase of the Juno mission. Topics of emphasis include the two deep space maneuvers, Earth flyby altitude biasing strategy, and the sequence of trajectory correction maneuvers executed in the weeks prior to the successful Earth gravity assist.

  16. Cassini-Huygens Maneuver Experience: Ending the Prime Mission

    NASA Technical Reports Server (NTRS)

    Goodson, Troy D.; Ballard, Christopher G.; Gist, Emily M.; Hahn, Yungsun; Stumpf, Paul W.; Wagner, Sean V.; Williams, Powtawche N.

    2008-01-01

    The Cassini-Huygens spacecraft was launched in 1997 on a mission to observe Saturn and its many moons. After a seven-year cruise, it entered a Saturnian orbit for a four-year, prime mission. This paper highlights significant maneuver activities performed during the last year of the prime mission. Specifically, results of 42 recent maneuvers are presented. Many maneuvers have been skipped, saving fuel and flight team effort. The system has performed more accurately than the pre-launch expectations and requirements. This is in large part why the Cassini-Huygens spacecraft has been navigated with tremendous success during the prime mission.

  17. Object Correlation and Maneuver Detection Using Optimal Control Performance Metrics

    NASA Astrophysics Data System (ADS)

    Holzinger, M.; Scheeres, D.

    2010-09-01

    Object correlation and maneuver detection are persistent problems in space surveillance and space object catalog maintenance. This paper demonstrates the utility of using quadratic trajectory control cost, an analog to the trajectory L2-norm in control, as a distance metric with which to both correlate object tracks and detect maneuvers using Uncorrelated Tracks (UCTs), real-time sensor measurement residuals, and prior state uncertainty. State and measurement uncertainty are incorporated into the computation, and distributions of optimal control usage are computed. Both UCT correlation as well as maneuver detection are demonstrated in several scenarios Potential avenues for future research and contributions are summarized.

  18. Helicopter Pilot Performance for Discrete-maneuver Flight Tasks

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.; Bourne, S. M.; Hindson, W. S.

    1984-01-01

    This paper describes a current study of several basic helicopter flight maneuvers. The data base consists of in-flight measurements from instrumented helicopters using experienced pilots. The analysis technique is simple enough to apply without automatic data processing, and the results can be used to build quantitative matah models of the flight task and some aspects of the pilot control strategy. In addition to describing the performance measurement technqiue, some results are presented which define the aggressiveness and amplitude of maneuvering for several lateral maneuvers including turns and sidesteps.

  19. Early Mission Maneuver Operations for the Deep Space Climate Observatory

    NASA Technical Reports Server (NTRS)

    Roberts, Craig; Case, Sara; Reagoso, John

    2015-01-01

    DSCOVR Lissajous Orbit sized such that orbit track never extends beyond 15 degrees from Earth-Sun line (as seen from Earth). Requiring delta-V maneuvers, control orbit to obey a Solar Exclusion Zone (SEZ) cone of half-angle 4 degrees about the Earth-Sun line. Spacecraft should never be less than 4 degrees from solar center as seen from Earth. Following Lissajous Orbit Insertion (LOI), DSCOVR should be in an opening phase that just skirts the 4-degree SEZ. Maximizes time to the point where a closing Lissajous will require avoidance maneuvers to keep it out of the SEZ. Station keeping maneuvers should take no more than 15 minutes

  20. Constellation Mission Operation Working Group: ESMO Maneuver Planning Process Review

    NASA Technical Reports Server (NTRS)

    Moyer, Eric

    2015-01-01

    The Earth Science Mission Operation (ESMO) Project created an Independent Review Board to review our Conjunction Risk evaluation process and Maneuver Planning Process to identify improvements that safely manages mission conjunction risks, maintains ground track science requirements, and minimizes overall hours expended on High Interest Events (HIE). The Review Board is evaluating the current maneuver process which requires support by multiple groups. In the past year, there have been several changes to the processes although many prior and new concerns exist. This presentation will discuss maneuver process reviews and Board comments, ESMO assessment and path foward, ESMO future plans, recent changes and concerns.

  1. Fuzzy logic and neural network technologies

    NASA Technical Reports Server (NTRS)

    Villarreal, James A.; Lea, Robert N.; Savely, Robert T.

    1992-01-01

    Applications of fuzzy logic technologies in NASA projects are reviewed to examine their advantages in the development of neural networks for aerospace and commercial expert systems and control. Examples of fuzzy-logic applications include a 6-DOF spacecraft controller, collision-avoidance systems, and reinforcement-learning techniques. The commercial applications examined include a fuzzy autofocusing system, an air conditioning system, and an automobile transmission application. The practical use of fuzzy logic is set in the theoretical context of artificial neural systems (ANSs) to give the background for an overview of ANS research programs at NASA. The research and application programs include the Network Execution and Training Simulator and faster training algorithms such as the Difference Optimized Training Scheme. The networks are well suited for pattern-recognition applications such as predicting sunspots, controlling posture maintenance, and conducting adaptive diagnoses.

  2. Wakes of Maneuvering Bodies in Stratified Fluids

    NASA Astrophysics Data System (ADS)

    Voropayev, S. I.; Fernando, H. J.

    2007-05-01

    We present the results of experimental/theoretical studies on large momentum eddies generated in late wakes of unsteady moving self-propelled bodies in stratified fluids. The experiments were conducted with scaled submarine model at high Reynolds numbers (50,000), corresponding to the fully turbulent flow regime. Dye visualization and PIV were used for flow diagnostics. When a self-propelled body makes a maneuver, e.g. accelerates, it imparts net momentum on the surrounding fluid. We show that in a stratified fluid this leads to impulsive momentum wakes with large, long-lived coherent vortices in the late flows, which may be used as a signature for identification of submarine wakes in oceanic thermocline. First, we consider dynamics and properties of such wakes in a linearly stratified fluid and present a model that permits to predict the main flow characteristics. Second, we consider wakes in a two layer stratified fluid (analog of the upper ocean) and show that such wakes may penetrate to the water surface; we present a model for this phenomenon and propose criteria for the penetration of wake signatures to the water surface in terms of main governing parameters (signature contrast versus confinement number). Finally, we consider the evolution of such momentum wake eddies in the field of decaying background turbulence, which mimics the oceanic thermocline, and show that for the flow configuration studied the contrast number remains sufficiently large and detectable wake imprints survive for a long period of time. Some pertinent estimates for submarines cruising in the upper ocean are also given. For more details see [1-3]. This study was supported by grant from the Office of Naval Research. 1. Voropayev S.I., Fernando H.J.S., Smirnov S.A. & Morrison R.J. 2006. On surface signatures generated by submersed momentum sources. Phys. Fluids, under revision. 2. Voropayev S.I., Fernando H.J.S. & Morrison R.J. 2006. Dipolar eddies in a stratified turbulent flow. J. Fluid

  3. Adaptive sampler

    DOEpatents

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  4. Adaptive sampler

    DOEpatents

    Watson, Bobby L.; Aeby, Ian

    1982-01-01

    An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  5. The Impact of Maneuver Failures on the EOS Afternoon Constellation

    NASA Technical Reports Server (NTRS)

    Demarest, Peter

    2002-01-01

    The first four satellites, Aqua, CloudSat, Calipso, and Parasol, in NASA's EOS Afternoon constellation will fly in similar orbits within 4 minutes of each other. This study was undertaken to examine the effect of one or more missions failing to perform a scheduled orbit maintenance maneuver. Tools were developed to rapidly calculate the initial orbital elements for the satellites that established the formation. Baseline maneuver strategies were implemented to maintain the desired spacing of the satellites. Maneuver failures were examined and close approach opportunities were identified. It was found that close-approaches between CloudSat and Calipso could occur in less than one day after a missed maneuver if close coordination between the missions is not achieved.

  6. Deterministic optimal maneuver strategy for multi-target missions

    NASA Technical Reports Server (NTRS)

    Dwivedi, N. P.

    1975-01-01

    This paper presents an optimal strategy for making impulsive correction to a multi-target trajectory by a single maneuver. The concept of an optimal maneuver time is introduced. The choice of suitable weighting functions is explored to enable one to properly translate the subjective desire of mission success into an objective cost function whose minimization yields the optimal strategy. It is shown that a number of strategies previously formulated are derivable from one general expression. A number of other interesting properties of the optimal strategy are described. Numerical results are presented for a typical two-target mission. It is shown that the strategy formulated is optimal. For some perturbations, there exists an optimal maneuver time different from the time of initiation of the perturbation. That is, the physical properties of the trajectory can be exploited to select the optimal time of making a corrective maneuver.

  7. Investigation of Dynamic Flight Maneuvers With an Iced Tailplane

    NASA Technical Reports Server (NTRS)

    VanZante, Judith Foss; Ratvasky, Thomas P.

    1999-01-01

    A detailed analysis of two of the dynamic maneuvers, the pushover and elevator doublet, from the NASA/FAA Tailplane Icing Program are discussed. For this series of flight tests, artificial ice shapes were attached to the leading edge of the horizontal stabilizer of the NASA Lewis Research Center icing aircraft, a DHC-6 Twin Otter. The purpose of these tests was to learn more about ice-contaminated tailplane stall (ICTS), the known cause of 16 accidents resulting in 139 fatalities. The pushover has been employed by the FAA, JAA and Transport Canada for tailplane icing certification. This research analyzes the pushover and reports on the maneuver performance degradation due to ice shape severity and flap deflection. A repeatability analysis suggests tolerances for meeting the required targets of the maneuver. A second maneuver, the elevator doublet, is also studied.

  8. Rendezvous radar for the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Locke, John W.; Olds, Keith; Parks, Howard

    1991-01-01

    This paper describes the development of the Rendezvous Radar Set (RRS) for the Orbital Maneuvering Vehicle (OMV) for the National Aeronautics and Space Administration (NASA). The RRS was to be used to locate, and then provide vectoring information to, target satellites (or Shuttle or Space Station) to aid the OMV in making a minimum-fuel-consumption approach and rendezvous. The RRS design is that of an X-Band, all solid-state, monopulse tracking, frequency hopping, pulse-Doppler radar system. The development of the radar was terminated when the OMV prime contract to TRW was terminated by NASA. At the time of the termination, the development was in the circuit design stage. The system design was virtually completed, the PDR had been held. The RRS design was based on Motorola's experiences, both in the design and production of radar systems for the US Army and in the design and production of hi-rel communications systems for NASA space programs. Experience in these fields was combined with the latest digital signal processor and micro-processor technology to design a light-weight, low-power, spaceborne radar. The antenna and antenna positioner (gimbals) technology developed for the RRS is now being used in the satellite-to-satellite communication link design for Motorola's Iridium telecommunications system.

  9. Augmentation of maneuver performance by spanwise blowing

    NASA Technical Reports Server (NTRS)

    Erickson, G. E.; Campbell, J. F.

    1977-01-01

    A generalized wind tunnel model was tested to investigate new component concepts utilizing spanwise blowing to provide improved maneuver characteristics for advanced fighter aircraft. Primary emphasis was placed on high angle of attack performance, stability, and control at subsonic speeds. Spanwise blowing on a 44 deg swept trapezoidal wing resulted in leading edge vortex enhancement with subsequent large vortex-induced lift increments and drag polar improvements at the higher angles of attack. Small deflections of a leading edge flap delayed these lift and drag benefits to higher angles of attack. In addition, blowing was more effective at higher Mach numbers. Spanwise blowing in conjunction with a deflected trailing edge flap resulted in lift and drag benefits that exceeded the summation of the effects of each high lift device acting alone. Asymmetric blowing was an effective lateral control device at the higher angles of attack. Spanwise blowing on the wing reduced horizontal tail loading and improved the lateral-directional stability characteristics of a wing-horizontal tail-vertical tail configuration.

  10. An Immunized Aircraft Maneuver Selection System

    NASA Technical Reports Server (NTRS)

    Karr, Charles L.

    2003-01-01

    The objective of this project, as stated in the original proposal, was to develop an immunized aircraft maneuver selection (IAMS) system. The IAMS system was to be composed of computational and informational building blocks that resemble structures in natural immune systems. The ultimate goal of the project was to develop a software package that could be flight tested on aircraft models. This report describes the work performed in the first year of what was to have been a two year project. This report also describes efforts that would have been made in the final year to have completed the project, had it been continued for the final year. After introductory material is provided in Section 2, the end-of-year-one status of the effort is discussed in Section 3. The remainder of the report provides an accounting of first year efforts. Section 4 provides background information on natural immune systems while Section 5 describes a generic ar&itecture developed for use in the IAMS. Section 6 describes the application of the architecture to a system identification problem. Finally, Section 7 describes steps necessary for completing the project.

  11. Astronaut Alan Bean flies the Astronaut Maneuvering Equipment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Alan L. Bean, Skylab 3 commander, flies the M509 Astronaut Maneuvering Equipment in the foreward dome area of the Orbital Workshop (OWS) on the space station cluster in Earth orbit. Bean is strapped in to the back-mounted, hand-controlled Automatically Stabilized Maneuvering Unit (ASMU). This ASMU exerperiment is being done in shirt sleeves. The dome area where the experiment is conducted is about 22 feet in diameter and 19 feet from top to bottom.

  12. Astronaut Alan Bean flies the Astronaut Maneuvering Equipment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Alan L. Bean, Skylab 3 commander, flies the M509 Astronaut Maneuvering Equipment in the forward dome area of the Orbital Workshop (OWS) on the space station cluster in Earth orbit. Bean is strapped in to the back-mounted, hand-controlled Automatically Stabilized Maneuvering Unit (ASMU). This ASMU exerperiment is being done in shirt sleeves. The dome area where the experiment is conducted is about 22 feet in diameter and 19 feet from top to bottom.

  13. Spontaneous splenic rupture during Pringle maneuver in liver surgery.

    PubMed

    van Buijtenen, Jesse M; Lamme, Bas; Hesselink, Erik J

    2010-06-27

    During liver resection clamping of the hepato-duodenal ligament (the Pringle maneuver) is performed to reduce intraoperative blood-loss. During this maneuver acute portal hypertension may lead to spontaneous splenic rupture requiring rapid splenectomy in order to control blood loss. We present 2 case of patients with hemorrhage from the spleen during clamping for liver surgery. A review of the literature with an emphasis on the pathophysiology of splenic hemorrhage is presented. PMID:21161004

  14. Operational Experiences in Planning and Reconstructing Aqua Inclination Maneuvers

    NASA Technical Reports Server (NTRS)

    Rand, David; Reilly, Jacqueline; Schiff, Conrad

    2004-01-01

    As the lead satellite in NASA's growing Earth Observing System (EOS) PM constellation, it is increasingly critical that Aqua maintain its various orbit requirements. The two of interest for this paper are maintaining an orbit inclination that provides for a consistent mean local time and a semi-major Axis (SMA) that allows for ground track repeatability. Maneuvers to adjust the orbit inclination involve several flight dynamics constraints and complexities which make planning such maneuvers challenging. In particular, coupling between the orbital and attitude degrees of freedom lead to changes in SMA when changes in inclination are effected. A long term mission mean local time trend analysis was performed in order to determine the size and placement of the required inclination maneuvers. Following this analysis, detailed modeling of each burn and its Various segments was performed to determine its effects on the immediate orbit state. Data gathered from an inclination slew test of the spacecraft and first inclination maneuver uncovered discrepancies in the modeling method that were investigated and resolved. The new modeling techniques were applied and validated during the second spacecraft inclination maneuver. These improvements should position Aqua to successfully complete a series of inclination maneuvers in the fall of 2004. The following paper presents the events and results related

  15. 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

  16. IMAM algorithm for tracking maneuvering targets in clutter

    NASA Astrophysics Data System (ADS)

    Watson, Gregory A.

    1996-05-01

    Target tracking in clutter is difficult because there can be several contact-to-track associations for a given track update. The nearest neighbor approach is traditionally used but probabilistic methods, such as probabilistic data association (PDA), have since proved more capable. Tracks are also lost during maneuvers and the interacting multiple model (IMM) algorithm has been demonstrated to be effective at tracking maneuvering targets by responding to different target modes. By combining the IMM and PDA, the resulting algorithm responds to target maneuvers and is effective in clutter. The interacting multiple bias model (IMBM) algorithm is also an effective technique when tracking maneuvering targets but considers the target acceleration a system bias. The bias is estimated in an IMM algorithm framework and then used to compensate a constant velocity filter estimate. The integrated PDA filter will be incorporated into the IMBM algorithm and applied to tracking maneuvering targets in clutter. A performance comparison of IMM and IMBM techniques for tracking maneuvering targets in clutter will also be presented.

  17. Optimal diving maneuver strategy considering guidance accuracy for hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Zhu, Jianwen; Liu, Luhua; Tang, Guojian; Bao, Weimin

    2014-11-01

    An optimal maneuver strategy considering terminal guidance accuracy for hypersonic vehicle in dive phase is investigated in this paper. First, it derives the complete three-dimensional nonlinear coupled motion equation without any approximations based on diving relative motion relationship directly, and converts it into linear decoupled state space equation with the same relative degree by feedback linearization. Second, the diving guidance law is designed based on the decoupled equation to meet the terminal impact point and falling angle constraints. In order to further improve the interception capability, it constructs maneuver control model through adding maneuver control item to the guidance law. Then, an integrated performance index consisting of maximum line-of-sight angle rate and minimum energy consumption is designed, and optimal control is employed to obtain optimal maneuver strategy when the encounter time is determined and undetermined, respectively. Furthermore, the performance index and suboptimal strategy are reconstructed to deal with the control capability constraint and the serous influence on terminal guidance accuracy caused by maneuvering flight. Finally, the approach is tested using the Common Aero Vehicle-H model. Simulation results demonstrate that the proposed strategy can achieve high precision guidance and effective maneuver at the same time, and the indices are also optimized.

  18. Applications of fuzzy logic to control and decision making

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Jani, Yashvant

    1991-01-01

    Long range space missions will require high operational efficiency as well as autonomy to enhance the effectivity of performance. Fuzzy logic technology has been shown to be powerful and robust in interpreting imprecise measurements and generating appropriate control decisions for many space operations. Several applications are underway, studying the fuzzy logic approach to solving control and decision making problems. Fuzzy logic algorithms for relative motion and attitude control have been developed and demonstrated for proximity operations. Based on this experience, motion control algorithms that include obstacle avoidance were developed for a Mars Rover prototype for maneuvering during the sample collection process. A concept of an intelligent sensor system that can identify objects and track them continuously and learn from its environment is under development to support traffic management and proximity operations around the Space Station Freedom. For safe and reliable operation of Lunar/Mars based crew quarters, high speed controllers with ability to combine imprecise measurements from several sensors is required. A fuzzy logic approach that uses high speed fuzzy hardware chips is being studied.

  19. Diagnosable structured logic array

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  20. Cerebral hemodynamics during graded Valsalva maneuvers

    PubMed Central

    Perry, Blake G.; Cotter, James D.; Mejuto, Gaizka; Mündel, Toby; Lucas, Samuel J. E.

    2014-01-01

    The Valsalva maneuver (VM) produces large and abrupt changes in mean arterial pressure (MAP) that challenge cerebral blood flow and oxygenation. We examined the effect of VM intensity on middle cerebral artery blood velocity (MCAv) and cortical oxygenation responses during (phases I–III) and following (phase IV) a VM. Healthy participants (n = 20 mean ± SD: 27 ± 7 years) completed 30 and 90% of their maximal VM mouth pressure for 10 s (order randomized) whilst standing. Beat-to-beat MCAv, cerebral oxygenation (NIRS) and MAP across the different phases of the VM are reported as the difference from standing baseline. There were significant interaction (phase * intensity) effects for MCAv, total oxygenation index (TOI) and MAP (all P < 0.01). MCAv decreased during phases II and III (P < 0.01), with the greatest decrease during phase III (−5 ± 8 and −19 ± 15 cm·s−1 for 30 and 90% VM, respectively). This pattern was also evident in TOI (phase III: −1 ± 1 and −5 ± 4%, both P < 0.05). Phase IV increased MCAv (22 ± 15 and 34 ± 23 cm·s−1), MAP (15 ± 14 and 24 ± 17 mm Hg) and TOI (5 ± 6 and 7 ± 5%) relative to baseline (all P < 0.05). Cerebral autoregulation, indexed, as the %MCAv/%MAP ratio, showed a phase effect only (P < 0.001), with the least regulation during phase IV (2.4 ± 3.0 and 3.2 ± 2.9). These data illustrate that an intense VM profoundly affects cerebral hemodynamics, with a reactive hyperemia occurring during phase IV following modest ischemia during phases II and III. PMID:25309449

  1. Benchmarking emerging logic devices

    NASA Astrophysics Data System (ADS)

    Nikonov, Dmitri

    2014-03-01

    As complementary metal-oxide-semiconductor field-effect transistors (CMOS FET) are being scaled to ever smaller sizes by the semiconductor industry, the demand is growing for emerging logic devices to supplement CMOS in various special functions. Research directions and concepts of such devices are overviewed. They include tunneling, graphene based, spintronic devices etc. The methodology to estimate future performance of emerging (beyond CMOS) devices and simple logic circuits based on them is explained. Results of benchmarking are used to identify more promising concepts and to map pathways for improvement of beyond CMOS computing.

  2. Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats.

    PubMed

    Falk, Benjamin; Kasnadi, Joseph; Moss, Cynthia F

    2015-11-01

    Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture. PMID:26582935

  3. Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats

    PubMed Central

    Falk, Benjamin; Kasnadi, Joseph; Moss, Cynthia F.

    2015-01-01

    ABSTRACT Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture. PMID:26582935

  4. Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats.

    PubMed

    Falk, Benjamin; Kasnadi, Joseph; Moss, Cynthia F

    2015-11-01

    Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture.

  5. An Overview of Suomi NPP VIIRS Calibration Maneuvers

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Xiong, Xiaoxiong; Barnes, Robert A.; Patt, Frederick S.; Sun, Junqiang; Chiang, Kwofu

    2012-01-01

    The first Visible Infrared Imager Radiometer Suite (VIIRS) instrument was successfully launched on-board the Suomi National Polar-orbiting Partnership (SNPP) spacecraft on October 28, 2011. Suomi NPP VIIRS observations are made in 22 spectral bands, from the visible (VIS) to the long-wave infrared (LWIR), and are used to produce 22 Environmental Data Records (EDRs) with a broad range of scientific applications. The quality of these VIIRS EDRs strongly depends on the quality of its calibrated and geo-located Sensor Date Records (SDRs). Built with a strong heritage to the NASA's EOS MODerate resolution Imaging Spectroradiometer (MODIS) instrument, the VIIRS is calibrated on-orbit using a similar set of on-board calibrators (OBC), including a solar diffuser (SD) and solar diffuser stability monitor (SDSM) system for the reflective solar bands (RSB) and a blackbody (BB) for the thermal emissive bands (TEB). On-orbit maneuvers of the SNPP spacecraft provide additional calibration and characterization data from the VIIRS instrument which cannot be obtained pre-launch and are required to produce the highest quality SDRs. These include multi-orbit yaw maneuvers for the characterization of SD and SDSM screen transmission, quasi-monthly roll maneuvers to acquire lunar observations to track sensor degradation in the visible through shortwave infrared, and a driven pitch-over maneuver to acquire multiple scans of deep space to determine TEB response versus scan angle (RVS). This paper pro-vides an overview of these three SNPP calibration maneuvers. Discussions are focused on their potential calibration and science benefits, pre-launch planning activities, and on-orbit scheduling and implementation strategies. Results from calibration maneuvers performed during the Intensive Calibration and Validation (ICV) period for the VIIRS sensor are illustrated. Also presented in this paper are lessons learned regarding the implementation of calibration spacecraft maneuvers on follow

  6. Logic and Simulation.

    ERIC Educational Resources Information Center

    Straumanis, Joan

    A major problem in teaching symbolic logic is that of providing individualized and early feedback to students who are learning to do proofs. To overcome this difficulty, a computer program was developed which functions as a line-by-line proof checker in Sentential Calculus. The program, DEMON, first evaluates any statement supplied by the student…

  7. Quantum probabilistic logic programming

    NASA Astrophysics Data System (ADS)

    Balu, Radhakrishnan

    2015-05-01

    We describe a quantum mechanics based logic programming language that supports Horn clauses, random variables, and covariance matrices to express and solve problems in probabilistic logic. The Horn clauses of the language wrap random variables, including infinite valued, to express probability distributions and statistical correlations, a powerful feature to capture relationship between distributions that are not independent. The expressive power of the language is based on a mechanism to implement statistical ensembles and to solve the underlying SAT instances using quantum mechanical machinery. We exploit the fact that classical random variables have quantum decompositions to build the Horn clauses. We establish the semantics of the language in a rigorous fashion by considering an existing probabilistic logic language called PRISM with classical probability measures defined on the Herbrand base and extending it to the quantum context. In the classical case H-interpretations form the sample space and probability measures defined on them lead to consistent definition of probabilities for well formed formulae. In the quantum counterpart, we define probability amplitudes on Hinterpretations facilitating the model generations and verifications via quantum mechanical superpositions and entanglements. We cast the well formed formulae of the language as quantum mechanical observables thus providing an elegant interpretation for their probabilities. We discuss several examples to combine statistical ensembles and predicates of first order logic to reason with situations involving uncertainty.

  8. Effective Methods for Logic.

    ERIC Educational Resources Information Center

    Moore, Tim; Goldstein, Laurence

    1984-01-01

    Describes computer assisted instruction programs for teaching logic during first year philosophy courses at the University of Hong Kong. These programs include JOHN, which introduces Venn-diagrams for evaluating syllogistic arguments; LUDWIG, which introduces techniques for evaluating arguments in propositional calculus; and TIARA, which provides…

  9. Programmable Logic Application Notes

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Day, John H. (Technical Monitor)

    2001-01-01

    This report will be provided each quarter as a source for reliability, radiation results, NASA capabilities, and other information on programmable logic devices and related applications. This quarter will continue a series of notes concentrating on analysis techniques with this issue's section discussing the use of Root-Sum-Square calculations for digital delays.

  10. The Logic of Bundles

    NASA Astrophysics Data System (ADS)

    Harding, John; Yang, Taewon

    2015-12-01

    Since the work of Crown (J. Natur. Sci. Math. 15(1-2), 11-25 1975) in the 1970's, it has been known that the projections of a finite-dimensional vector bundle E form an orthomodular poset ( omp) {P}(E). This result lies in the intersection of a number of current topics, including the categorical quantum mechanics of Abramsky and Coecke (2004), and the approach via decompositions of Harding (Trans. Amer. Math. Soc. 348(5), 1839-1862 1996). Moreover, it provides a source of omps for the quantum logic program close to the Hilbert space setting, and admitting a version of tensor products, yet having important differences from the standard logics of Hilbert spaces. It is our purpose here to initiate a basic investigation of the quantum logic program in the vector bundle setting. This includes observations on the structure of the omps obtained as {P}(E) for a vector bundle E, methods to obtain states on these omps, and automorphisms of these omps. Key theorems of quantum logic in the Hilbert setting, such as Gleason's theorem and Wigner's theorem, provide natural and quite challenging problems in the vector bundle setting.

  11. The Logic of Evaluation.

    ERIC Educational Resources Information Center

    Welty, Gordon A.

    The logic of the evaluation of educational and other action programs is discussed from a methodological viewpoint. However, no attempt is made to develop methods of evaluating programs. In Part I, the structure of an educational program is viewed as a system with three components--inputs, transformation of inputs into outputs, and outputs. Part II…

  12. Radiation tolerant combinational logic cell

    NASA Technical Reports Server (NTRS)

    Maki, Gary R. (Inventor); Gambles, Jody W. (Inventor); Whitaker, Sterling (Inventor)

    2009-01-01

    A system has a reduced sensitivity to Single Event Upset and/or Single Event Transient(s) compared to traditional logic devices. In a particular embodiment, the system includes an input, a logic block, a bias stage, a state machine, and an output. The logic block is coupled to the input. The logic block is for implementing a logic function, receiving a data set via the input, and generating a result f by applying the data set to the logic function. The bias stage is coupled to the logic block. The bias stage is for receiving the result from the logic block and presenting it to the state machine. The state machine is coupled to the bias stage. The state machine is for receiving, via the bias stage, the result generated by the logic block. The state machine is configured to retain a state value for the system. The state value is typically based on the result generated by the logic block. The output is coupled to the state machine. The output is for providing the value stored by the state machine. Some embodiments of the invention produce dual rail outputs Q and Q'. The logic block typically contains combinational logic and is similar, in size and transistor configuration, to a conventional CMOS combinational logic design. However, only a very small portion of the circuits of these embodiments, is sensitive to Single Event Upset and/or Single Event Transients.

  13. Orbital maneuvers around irregular shaped bodies

    NASA Astrophysics Data System (ADS)

    Venditti, Flaviane; Rocco, E. M.; Almeida Prado, A. B.

    2013-05-01

    Abstract (2,250 Maximum Characters): In the solar system there are many small bodies called asteroids. The large majority of these bodies are located in the asteroid belt, between the orbits of the planets Mars and Jupiter. The Near- Earth Objects, or NEOs, are objects with perihelion below 1.3AU, which include comets and asteroids. The NEOs are considered to have orbits passing close to the Earth’s orbit and, in the case of asteroids, are called Near-Earth Asteroids (NEAs). Among the NEAs there are bodies considered potentially hazardous asteroids (PHAs), whose minimum orbit intersection distance with Earth is 0.05AU and that have absolute magnitude (H) of 22, which would mean an asteroid of at least 110-240 meters, depending on its albedo. One of the major characteristic of the asteroids is the irregular shape, causing the dynamics of orbits around these bodies to be different from a spherical shaped one. The fact that an object is not spherical generates a perturbation on the gravitational field. The disturbing force can be determined considering the shape of the specific body. A satellite orbiting this body would suffer the effects of this perturbation, but knowing the disturbing force, it’s possible to correct and control the orbit according to the desired mission. The polyhedron method is a traditional way to model an asteroid by dividing the object into smaller parts. The data used on this work are composed by a combination of triangular faces. The total disturbing force is a sum of the force on each piece of the model. Therefore, after the simulations are obtained, it’s possible to apply the desired corrections of the perturbation using continuous low thrust in closed loop, making it possible to perform maneuvers near these bodies. One of the important applications of the study shown above is in the ASTER mission, that is under study by INPE and several other Brazilian academic institutions, which goal is to send a spacecraft to an asteroid and then

  14. Using Mean Orbit Period in Mars Reconnaissance Orbiter Maneuver Design

    NASA Technical Reports Server (NTRS)

    Chung, Min-Kun J.; Menon, Premkumar R.; Wagner, Sean V.; Williams, Jessica L.

    2014-01-01

    Mars Reconnaissance Orbiter (MRO) has provided communication relays for a number of Mars spacecraft. In 2016 MRO is expected to support a relay for NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft. In addition, support may be needed by another mission, ESA's ExoMars EDL Demonstrator Module's (EDM), only 21 days after the InSight coverage. The close proximity of these two events presents a unique challenge to a conventional orbit synchronization maneuver where one deterministic maneuver is executed prior to each relay. Since the two events are close together and the difference in required phasing between InSight and EDM may be up to half an orbit (yielding a large execution error), the downtrack timing error can increase rapidly at the EDM encounter. Thus, a new maneuver strategy that does not require a deterministic maneuver in-between the two events (with only a small statistical cleanup) is proposed in the paper. This proposed strategy rests heavily on the stability of the mean orbital period. The ability to search and set the specified mean period is fundamental in the proposed maneuver design as well as in understanding the scope of the problem. The proposed strategy is explained and its result is used to understand and solve the problem in the flight operations environment.

  15. Investigation of piloting aids for manual control of hypersonic maneuvers

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Phillips, Michael R.; Person, Lee H., Jr.

    1995-01-01

    An investigation of piloting aids designed to provide precise maneuver control for an air-breathing hypersonic vehicle is described. Stringent constraints and nonintuitive high-speed flight effects associated with maneuvering in the hypersonic regime raise the question of whether manual control of such a vehicle should even be considered. The objectives of this research were to determine the extent of manual control that is desirable for a vehicle maneuvering in this regime and to identify the form of aids that must be supplied to the pilot to make such control feasible. A piloted real-time motion-based simulation of a hypersonic vehicle concept was used for this study, and the investigation focused on a single representative cruise turn maneuver. Piloting aids, which consisted of an auto throttle, throttle director, autopilot, flight director, and two head-up display configurations, were developed and evaluated. Two longitudinal control response types consisting of a rate-command/attitude-hold system and a load factor-rate/load-factor-hold system were also compared. The complete set of piloting aids, which consisted of the autothrottle, throttle director, and flight director, improved the average Cooper-Harper flying qualities ratings from 8 to 2.6, even though identical inner-loop stability and control augmentation was provided in all cases. The flight director was determined to be the most critical of these aids, and the cruise turn maneuver was unachievable to adequate performance specifications in the absence of this flight director.

  16. Rotational maneuver of ferromagnetic nanowires for cell manipulation.

    PubMed

    Zhao, Yi; Zeng, Hansong

    2009-09-01

    1-D magnetic nanowires provide a powerful tool for investigating biological systems because such nanomaterials possess unique magnetic properties, which allow effective manipulation of cellular and subcellular objects. In this study, we report the rotational maneuver of ferromagnetic nanowires and their applications in cell manipulation. The rotational maneuver is studied under two different suspension conditions. The rotation of nanowires in the fluid is analyzed using Stokes flow assumption. Experimental results show that when the nanowires develop contacts with the bottom surfaces, the rotational maneuver under a modest external magnetic field can generate rapid lateral motion. The floating nanowires, on the other hand, do not exhibit substantial lateral displacements. Cell manipulation using skeletal myoblasts C2C12 shows that living cells can be manipulated efficiently on the bottom surface by the rotational maneuver of the attached nanowires. We also demonstrate the use of rotational maneuver of nanowires for creating 3-D nanowire clusters and multicellular clusters. This study is expected to add to the knowledge of nanowire-based cell manipulation and contribute to a full spectrum of control strategies for efficient use of nanowires for micro-total-analysis. It may also facilitate mechanobiological studies at cellular level, and provide useful insights for development of 3-D in vivo-like multicellular models for various applications in tissue engineering.

  17. Sandia ATM SONET Interface Logic

    1994-07-21

    SASIL is used to program the EPLD's (Erasable Programmable Logic Devices) and PAL's (Programmable Array Logic) that make up a large percentage of the Sandia ATM SONET Interface (OC3 version) for the INTEL Paragon.

  18. Conditional Logic and Primary Children.

    ERIC Educational Resources Information Center

    Ennis, Robert H.

    Conditional logic, as interpreted in this paper, means deductive logic characterized by "if-then" statements. This study sought to investigate the knowledge of conditional logic possessed by primary children and to test their readiness to learn such concepts. Ninety students were designated the experimental group and participated in a 15-week…

  19. Maneuver Planning for Conjunction Risk Mitigation with Ground-track Control Requirements

    NASA Technical Reports Server (NTRS)

    McKinley, David

    2008-01-01

    The planning of conjunction Risk Mitigation Maneuvers (RMM) in the presence of ground-track control requirements is analyzed. Past RMM planning efforts on the Aqua, Aura, and Terra spacecraft have demonstrated that only small maneuvers are available when ground-track control requirements are maintained. Assuming small maneuvers, analytical expressions for the effect of a given maneuver on conjunction geometry are derived. The analytical expressions are used to generate a large trade space for initial RMM design. This trade space represents a significant improvement in initial maneuver planning over existing methods that employ high fidelity maneuver models and propagation.

  20. On spacecraft maneuvers control subject to propellant engine modes.

    PubMed

    Mazinan, A H

    2015-09-01

    The paper attempts to address a new control approach to spacecraft maneuvers based upon the modes of propellant engine. A realization of control strategy is now presented in engine on mode (high thrusts as well as further low thrusts), which is related to small angle maneuvers and engine off mode (specified low thrusts), which is also related to large angle maneuvers. There is currently a coarse-fine tuning in engine on mode. It is shown that the process of handling the angular velocities are finalized via rate feedback system in engine modes, where the angular rotations are controlled through quaternion based control (QBCL)strategy in engine off mode and these ones are also controlled through an optimum PID (OPIDH) strategy in engine on mode.

  1. A Maneuvering Flight Noise Model for Helicopter Mission Planning

    NASA Technical Reports Server (NTRS)

    Greenwood, Eric; Rau, Robert; May, Benjamin; Hobbs, Christopher

    2015-01-01

    A new model for estimating the noise radiation during maneuvering flight is developed in this paper. The model applies the Quasi-Static Acoustic Mapping (Q-SAM) method to a database of acoustic spheres generated using the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique. A method is developed to generate a realistic flight trajectory from a limited set of waypoints and is used to calculate the quasi-static operating condition and corresponding acoustic sphere for the vehicle throughout the maneuver. By using a previously computed database of acoustic spheres, the acoustic impact of proposed helicopter operations can be rapidly predicted for use in mission-planning. The resulting FRAME-QS model is applied to near-horizon noise measurements collected for the Bell 430 helicopter undergoing transient pitch up and roll maneuvers, with good agreement between the measured data and the FRAME-QS model.

  2. Attitude-Control Algorithm for Minimizing Maneuver Execution Errors

    NASA Technical Reports Server (NTRS)

    Acikmese, Behcet

    2008-01-01

    A G-RAC attitude-control algorithm is used to minimize maneuver execution error in a spacecraft with a flexible appendage when said spacecraft must induce translational momentum by firing (in open loop) large thrusters along a desired direction for a given period of time. The controller is dynamic with two integrators and requires measurement of only the angular position and velocity of the spacecraft. The global stability of the closed-loop system is guaranteed without having access to the states describing the dynamics of the appendage and with severe saturation in the available torque. Spacecraft apply open-loop thruster firings to induce a desired translational momentum with an extended appendage. This control algorithm will assist this maneuver by stabilizing the attitude dynamics around a desired orientation, and consequently minimize the maneuver execution errors.

  3. On spacecraft maneuvers control subject to propellant engine modes.

    PubMed

    Mazinan, A H

    2015-09-01

    The paper attempts to address a new control approach to spacecraft maneuvers based upon the modes of propellant engine. A realization of control strategy is now presented in engine on mode (high thrusts as well as further low thrusts), which is related to small angle maneuvers and engine off mode (specified low thrusts), which is also related to large angle maneuvers. There is currently a coarse-fine tuning in engine on mode. It is shown that the process of handling the angular velocities are finalized via rate feedback system in engine modes, where the angular rotations are controlled through quaternion based control (QBCL)strategy in engine off mode and these ones are also controlled through an optimum PID (OPIDH) strategy in engine on mode. PMID:26117285

  4. Severe turbulence and maneuvering from airline flight records

    NASA Technical Reports Server (NTRS)

    Wingrove, R. C.; Basch, R. E., Jr.

    1992-01-01

    Digital flight records from reported clear-air turbulence incidents are used to determine winds, to determine maneuver G loads, and to analyze control problems. Severe turbulence is found downwind of mountains and thunderstorms associated with vortices in atmospheric waves. It is also found in strong updrafts above thunderstorm buildups that are not detected by onboard weather radar. An important finding is that there are large maneuvering loads in over half of the reported clear-air turbulence incidents. Maneuvering loads are determined through an analysis of the short-term variations in elevator deflection and aircraft pitch angle. For altitude control in mountain waves the results indicate that small pitch angle changes with proper timing are sufficient to counter the vertical winds. For airspeed control in strong mountain waves, however, there is neither the available thrust nor the quickness in engine response necessary to counter the large and rapid variations in horizontal wind.

  5. Operational Challenges In TDRS Post-Maneuver Orbit Determination

    NASA Technical Reports Server (NTRS)

    Laing, Jason; Myers, Jessica; Ward, Douglas; Lamb, Rivers

    2015-01-01

    The GSFC Flight Dynamics Facility (FDF) is responsible for daily and post maneuver orbit determination for the Tracking and Data Relay Satellite System (TDRSS). The most stringent requirement for this orbit determination is 75 meters total position accuracy (3-sigma) predicted over one day for Terra's onboard navigation system. To maintain an accurate solution onboard Terra, a solution is generated and provided by the FDF Four hours after a TDRS maneuver. A number of factors present challenges to this support, such as maneuver prediction uncertainty and potentially unreliable tracking from User satellities. Reliable support is provided by comparing an extended Kalman Filter (estimated using ODTK) against a Batch Least Squares system (estimated using GTDS).

  6. Orbital maneuver optimization using time-explicit power series

    NASA Astrophysics Data System (ADS)

    Thorne, James D.

    2011-05-01

    Orbital maneuver transfer time optimization is traditionally accomplished using direct numerical sampling to find the mission design with the lowest delta-v requirements. The availability of explicit time series solutions to the Lambert orbit determination problem allows for the total delta-v of a series of orbital maneuvers to be expressed as an algebraic function of only the individual transfer times. The delta-v function is then minimized for a series of maneuvers by finding the optimal transfer times for each orbital arc. Results are shown for the classical example of the Hohmann transfer, a noncoplanar transfer as well as an interplanetary fly-by mission to the asteroids Pallas and Juno.

  7. [Study on anti +Gx respiratory maneuver and its training method].

    PubMed

    Xue, Yue-ying; You, Guang-xing; Wu, Bin; Liu, Xing-hua; Lu, Sheng-qiang; Xie, Bao-sheng

    2002-12-01

    Objective. To study the anti +Gx respiratory maneuver and its training method. Method. Seven young male subjects undertook the anti +Gx respiratory maneuver training. Their +Gx tolerances were examined on human centrifuge before and after training. The change of respiratory type, breath rate, electrocardiogram, heart rate, arterial oxygen saturation (SaO2), subjective symptom and vision were real-time monitored during the +Gx tolerance examination. Result. Compared with pre-training, the +Gx tolerance increased after training (P<0.05). Dyspnea and chest pain disappeared or obviously lightened and the magnitude of decrease of SaO2 decreased significantly (P<0.05). Conclusion. The above results suggested that the anti +Gx respiratory maneuver can effectively eliminate or alleviate dyspnea and chest pain induced by +Gx stress and increase human +Gx tolerance.

  8. A prescription for the Epley maneuver: www.youtube.com?

    PubMed Central

    Burke, James F.; Skolarus, Lesli E.; Callaghan, Brian C.; Fife, Terry D.; Baloh, Robert W.; Fendrick, A. Mark

    2012-01-01

    Objectives: Video-sharing Web sites are being used for information about common conditions including dizziness. The Epley maneuver (EM) is a simple and effective treatment for benign paroxysmal positional vertigo (BPPV) of the posterior canal. However, the maneuver is underused in routine care. In this study, we aimed to describe and analyze the available information about the EM on youtube.com. Methods: A YouTube search was performed on August 31, 2011, for videos that demonstrated the entire EM. Detailed data were abstracted from each video and corresponding Web site. Videos were rated on the accuracy of the maneuver by 2 authors, with differences resolved by adjudication. Comments posted by viewers were assessed for themes regarding video use. Results: Of the 3,319 videos identified, 33 demonstrated the EM. The total number of hits for all videos was 2,755,607. The video with the most hits (802,471) was produced by the American Academy of Neurology. Five of the videos accounted for 85% of all the hits. The maneuver demonstration was rated as accurate in 64% (21) of the videos. Themes derived from the 424 posted comments included patients self-treating with the maneuver after reviewing the videos, and providers using the videos as a prescribed treatment or for educational purposes. Conclusion: Accurate video demonstration of the Epley maneuver is available and widely viewed on YouTube. Video-sharing media may be an important way to disseminate effective interventions such as the EM. The impact of video Web sites on outcomes and costs of care is not known and warrants future study. PMID:22826542

  9. Adaptive sensor fusion using genetic algorithms

    SciTech Connect

    Fitzgerald, D.S.; Adams, D.G.

    1994-08-01

    Past attempts at sensor fusion have used some form of Boolean logic to combine the sensor information. As an alteniative, an adaptive ``fuzzy`` sensor fusion technique is described in this paper. This technique exploits the robust capabilities of fuzzy logic in the decision process as well as the optimization features of the genetic algorithm. This paper presents a brief background on fuzzy logic and genetic algorithms and how they are used in an online implementation of adaptive sensor fusion.

  10. Research in digital adaptive flight controllers

    NASA Technical Reports Server (NTRS)

    Kaufman, H.

    1976-01-01

    A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Both explicit controllers which directly utilize parameter identification and implicit controllers which do not require identification were considered. Extensive analytical and simulation efforts resulted in the recommendation of two explicit digital adaptive flight controllers. Interface weighted least squares estimation procedures with control logic were developed using either optimal regulator theory or with control logic based upon single stage performance indices.

  11. The Logic of Life

    NASA Astrophysics Data System (ADS)

    Pascal, Robert; Pross, Addy

    2016-04-01

    In this paper we propose a logical connection between the physical and biological worlds, one resting on a broader understanding of the stability concept. We propose that stability manifests two facets - time and energy, and that stability's time facet, expressed as persistence, is more general than its energy facet. That insight leads to the logical formulation of the Persistence Principle, which describes the general direction of material change in the universe, and which can be stated most simply as: nature seeks persistent forms. Significantly, the principle is found to express itself in two mathematically distinct ways: in the replicative world through Malthusian exponential growth, and in the `regular' physical/chemical world through Boltzmann's probabilistic considerations. By encompassing both `regular' and replicative worlds, the principle appears to be able to help reconcile two of the major scientific theories of the 19th century - the Second Law of Thermodynamics and Darwin's theory of evolution - within a single conceptual framework.

  12. The Logic of Life

    NASA Astrophysics Data System (ADS)

    Pascal, Robert; Pross, Addy

    2016-11-01

    In this paper we propose a logical connection between the physical and biological worlds, one resting on a broader understanding of the stability concept. We propose that stability manifests two facets - time and energy, and that stability's time facet, expressed as persistence, is more general than its energy facet. That insight leads to the logical formulation of the Persistence Principle, which describes the general direction of material change in the universe, and which can be stated most simply as: nature seeks persistent forms. Significantly, the principle is found to express itself in two mathematically distinct ways: in the replicative world through Malthusian exponential growth, and in the `regular' physical/chemical world through Boltzmann's probabilistic considerations. By encompassing both `regular' and replicative worlds, the principle appears to be able to help reconcile two of the major scientific theories of the 19th century - the Second Law of Thermodynamics and Darwin's theory of evolution - within a single conceptual framework.

  13. Maneuver Acoustic Flight Test of the Bell 430 Helicopter

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Snider, Royce; Greenwood, Eric; Baden, Joel

    2012-01-01

    A cooperative flight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July, 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 data points over 10 test days and compiled an extensive data base of dynamic maneuver measurements. Three microphone configurations with up to 31 microphones in each configuration were used to acquire acoustic data. Aircraft data included DGPS, aircraft state and rotor state information. This paper provides an overview of the test.

  14. Astronaut Alan Bean flies the Astronaut Maneuvering Equipment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Alan L. Bean, Skylab 3 commander, flies the M509 Astronaut Maneuvering Equipment in the foreward dome area of the Orbital Workshop (OWS) on the space station cluster in Earth orbit. Bean is strapped in to the back-mounted, hand-controlled Automatically Stabilized Maneuvering Unit (ASMU). He is wearing a pressure suit for this run of the M509 experiment, but other ASMU tests are done in shirt sleeves. The dome area where the experiment is conducted is about 22 feet in diameter and 19 feet from top to bottom.

  15. An Independent and Coordinated Criterion for Kinematic Aircraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Hagen, George

    2014-01-01

    This paper proposes a mathematical definition of an aircraft-separation criterion for kinematic-based horizontal maneuvers. It has been formally proved that kinematic maneu- vers that satisfy the new criterion are independent and coordinated for repulsiveness, i.e., the distance at closest point of approach increases whether one or both aircraft maneuver according to the criterion. The proposed criterion is currently used in NASA's Airborne Coordinated Resolution and Detection (ACCoRD) set of tools for the design and analysis of separation assurance systems.

  16. Active Control of Solar Array Dynamics During Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Ross, Brant A.; Woo, Nelson; Kraft, Thomas G.; Blandino, Joseph R.

    2016-01-01

    Recent NASA mission plans require spacecraft to undergo potentially significant maneuvers (or dynamic loading events) with large solar arrays deployed. Therefore there is an increased need to understand and possibly control the nonlinear dynamics in the spacecraft system during such maneuvers. The development of a nonlinear controller is described. The utility of using a nonlinear controller to reduce forces and motion in a solar array wing during a loading event is demonstrated. The result is dramatic reductions in system forces and motion during a 10 second loading event. A motion curve derived from the simulation with the closed loop controller is used to obtain similar benefits with a simpler motion control approach.

  17. Programmable Logic Application Notes

    NASA Technical Reports Server (NTRS)

    Katz, Richard

    1998-01-01

    This column will be provided each quarter as a source for reliability, radiation results, NASA capabilities, and other information on programmable logic devices and related applications. This quarter's column will include some announcements and some recent radiation test results and evaluations of interest. Specifically, the following topics will be covered: the Military and Aerospace Applications of Programmable Devices and Technologies Conference to be held at GSFC in September, 1998, proton test results, heavy ion test results, and some total dose results.

  18. Neurocontrol and fuzzy logic: Connections and designs

    NASA Technical Reports Server (NTRS)

    Werbos, Paul J.

    1991-01-01

    Artificial neural networks (ANNs) and fuzzy logic are complementary technologies. ANNs extract information from systems to be learned or controlled, while fuzzy techniques mainly use verbal information from experts. Ideally, both sources of information should be combined. For example, one can learn rules in a hybrid fashion, and then calibrate them for better whole-system performance. ANNs offer universal approximation theorems, pedagogical advantages, very high-throughput hardware, and links to neurophysiology. Neurocontrol - the use of ANNs to directly control motors or actuators, etc. - uses five generalized designs, related to control theory, which can work on fuzzy logic systems as well as ANNs. These designs can copy what experts do instead of what they say, learn to track trajectories, generalize adaptive control, and maximize performance or minimize cost over time, even in noisy environments. Design tradeoffs and future directions are discussed throughout.

  19. User acceptance of cooperative maneuver-based driving--a summary of three studies.

    PubMed

    Kauer, Michaela; Franz, Benjamin; Schreiber, Michael; Bruder, Ralph; Geyer, Sebastian

    2012-01-01

    Modern cars offer drivers support with the help of a number of driver assistance systems. Those systems aim to relieve drivers through assumption of sub parts of the driving task (e.g. in case of an Adaptive Cruise Control by regulation of vehicle speed and time gap to preceding vehicle). Today, systems are controlled and monitored separately which leads to efforts to combine the functionality of all systems in an overlying assistance for drivers. The approach of the University of Technology Darmstadt is called Conduct-by-Wire and can be seen as a cooperative maneuver-based driving paradigm, where the driver gives maneuver command to the systems which are automatically executed. This paper summarizes the results of three studies which investigated the user acceptance of this driving paradigm. Overall, it can be said that the acceptance of the system depends on personal traits of the driver and on the driving situation. Almost all participants are willing to use Conduct-by- Wire for routine tasks such as commuting, which makes the systems interesting for company cars. Still, there remain a number of drivers who are not willing to use such a highly automated system at all.

  20. Reducing Formation-Keeping Maneuver Costs for Formation Flying Satellites in Low-Earth Orbit

    NASA Technical Reports Server (NTRS)

    Hamilton, Nicholas

    2001-01-01

    Several techniques are used to synthesize the formation-keeping control law for a three-satellite formation in low-earth orbit. The objective is to minimize maneuver cost and position tracking error. Initial reductions are found for a one-satellite case by tuning the state-weighting matrix within the linear-quadratic-Gaussian framework. Further savings come from adjusting the maneuver interval. Scenarios examined include cases with and without process noise. These results are then applied to a three-satellite formation. For both the one-satellite and three-satellite cases, increasing the maneuver interval yields a decrease in maneuver cost and an increase in position tracking error. A maneuver interval of 8-10 minutes provides a good trade-off between maneuver cost and position tracking error. An analysis of the closed-loop poles with respect to varying maneuver intervals explains the effectiveness of the chosen maneuver interval.

  1. Ship operation and failure mode analysis using a maneuver simulator

    NASA Astrophysics Data System (ADS)

    Cabrerizo-Morales, Miguel Angel; Molina, Rafael; de los Santos, Francisco; Camarero, Alberto

    2013-04-01

    In a ship or floating structure operation the agents that contribute to the systems behaviour are not only those derived from fluid-structure interaction, but also the ones linked to mooring-control line set-up evolution and human interaction. Therefore, the analysis of such systems is affected by boundary conditions that change during a complete operation. Frequently, monitoring techniques in laboratory (model) and field (prototype) are based in different instrumental techniques adding difficulty to data comparison and, in some cases, inducing precision and repeatability errors. For this reason, the main aim of this study is to develop the methods and tools to achieve a deep knowledge of those floating systems and obtain capabilities to optimize their operationally thresholds. This abstract presents a methodology and an instrumental system applicable both in field and laboratory: SRECMOCOS Project (Small scale REal-time Caisson MOnitoring and COntrol System). SRECMOCOS compiles three modules. For the monitoring and control of the structure it has been developed a synchronized open and modular microcontroller-based electronic system that comprises sensors, to monitor agents and reactions, and actuators to perform pertinent actions after processing the sensors' data. A secondary objective has been to design and implement a global scaled simulator (1:22), at the 3D basin of The Harbour Research Lab at Technical University of Madrid, in which climatic agents and those derived from the rig/maneuvering setup and the structural design were included. The particular case of Campamento's drydock, in Algeciras Bay (Spain), has been used to apply and validate the methodology. SRECMOCOS Project conjugates control, monitoring and wireless communication systems in a real time basis, offering the possibility to register and simulate all the parameters involved in port operations. This approach offers a step forward into a monitoring strategy to be included in monitoring

  2. Control of Spacecraft Control Laboratory Experiment (SCOLE) slew maneuvers

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

    This is the second report of a set of two reports on the dynamics and control of slewing maneuvers of NASA Spacecraft Control Laboratory Experiment (SCOLE). The control problem of slewing maneuvers of SCOLE is developed in terms of an arbitrary maneuver about any given axis. The control system is developed for the combined problem of rigid-body slew maneuver and vibration suppression of flexible appendage. The control problem is formulated by incorporating the nonlinear equations derived in the previous report and is expressed in terms of a two-point boundary value problem utilizing a quadratic type of performance index. The two-point boundary value problem is solved as a hierarchical control problem with the overall system being split in terms of two subsystems, namely the slewing of the entire assembly and the vibration suppression of the flexible antenna. The coupling variables between the two dynamical subsystems are identified and these two subsystems for control purposes are treated independently in parallel at the first level. Then the state-space trajectory of the combined problem is optimized at the second level.

  3. Maneuvering and stability performance of a robotic tuna.

    PubMed

    Anderson, Jamie M; Chhabra, Narender K

    2002-02-01

    The Draper Laboratory Vorticity Control Unmanned Undersea Vehicle (VCUUV) is the first mission-scale, autonomous underwater vehicle that uses vorticity control propulsion and maneuvering. Built as a research platform with which to study the energetics and maneuvering performance of fish-swimming propulsion, the VCUUV is a self-contained free swimming research vehicle which follows the morphology and kinematics of a yellowfin tuna. The forward half of the vehicle is comprised of a rigid hull which houses batteries, electronics, ballast and hydraulic power unit. The aft section is a freely flooded articulated robot tail which is terminated with a lunate caudal fin. Utilizing experimentally optimized body and tail kinematics from the MIT RoboTuna, the VCUUV has demonstrated stable steady swimming speeds up to 1.2 m/sec and aggressive maneuvering trajectories with turning rates up to 75 degrees per second. This paper summarizes the vehicle maneuvering and stability performance observed in field trials and compares the results to predicted performance using theoretical and empirical techniques.

  4. 14 CFR 23.1567 - Flight maneuver placard.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... clear view of the pilot stating: “No acrobatic maneuvers, including spins, approved.” (b) For utility...); and (2) For those airplanes that do not meet the spin requirements for acrobatic category airplanes, an additional placard in clear view of the pilot stating: “Spins Prohibited.” (c) For...

  5. Enhanced Pseudo-Waypoint Guidance for Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Carson, John; Acikmese, behcet

    2008-01-01

    An enhanced version of the scheme reported in "Pseudo-Waypoint Guidance for Proximity Spacecraft Maneuvers" (NPO-42753), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 73 was developed. To recapitulate: the scheme provides algorithms for guidance and control (G&C) of a spacecraft maneuvering near a small astronomical body. The open-loop guidance problem is solved in advance or in real time by use of the pseudo-waypoint generation (PWG) method. Feedback control is implemented to track PWG trajectories, in a manner that enables updating of G&C in a model-predictive manner. The scheme includes silent periods following each thruster firing. The original version of the scheme provides for a fire-first, followed-by-silence sequence, which is disadvantageous in that the silence after final firing precludes reduction of any remaining velocity error -- an unacceptable result in the case of a maneuver for which a specific final velocity is required. In the enhanced version, the scheme is augmented with a fire-second technique, so that the final velocity can be established with a much higher precision because both the guidance and feedback firing can be performed and ceased at the final maneuver time.

  6. Pseudo-Waypoint Guidance for Proximity Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Acikmese, Ahmet; Carson, John M., III

    2007-01-01

    A paper describes algorithms for guidance and control (G&C) of a spacecraft maneuvering near a planet, moon, asteroid, comet, or other small astronomical body. The algorithms were developed following a model-predictive-control approach along with a convexification of the governing dynamical equations, control constraints, and trajectory and state constraints.

  7. Skill Development for Maneuvering on the Information Highway.

    ERIC Educational Resources Information Center

    Mosley, Barbra; Edwards, Gloria

    To help students learn to navigate the information superhighway, a 2-hour pilot program with 10 hours of guided access time was developed to test a method for teaching the basics of maneuvering the superhighway and extracting information once located. This pilot was designed as a two-part instructional session. The first instructional session…

  8. Detail view of a starboard Orbiter Maneuvering and Reaction Control ...

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

    Detail view of a starboard Orbiter Maneuvering and Reaction Control Systems pod, removed from the orbiter and in it's carrier/transport vehicle at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. 14 CFR 27.337 - Limit maneuvering load factor.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Limit maneuvering load factor. 27.337 Section 27.337 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... ranging from a positive limit of 3.5 to a negative limit of −1.0; or (b) Any positive limit...

  10. 14 CFR 29.337 - Limit maneuvering load factor.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Limit maneuvering load factor. 29.337 Section 29.337 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... ranging from a positive limit of 3.5 to a negative limit of −1.0; or (b) Any positive limit...

  11. Transient Structured Distance as a Maneuver in Marital Therapy

    ERIC Educational Resources Information Center

    Greene, Bernard L.; And Others

    1973-01-01

    Experience with 73 cases has shown the value of Transient Structured Distance as a maneuver in marriage therapy. While the TSD is a radical form of intervention with risks of anxiety reactions, homosexual panic, or divorce, it has proved effective with difficult forms of acute or chronic marital disharmony. (Author)

  12. 33 CFR 157.450 - Maneuvering and vessel status information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information. 157.450 Section 157.450 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... CARRYING OIL IN BULK Interim Measures for Certain Tank Vessels Without Double Hulls Carrying Petroleum Oils § 157.450 Maneuvering and vessel status information. A tankship owner, master, or operator shall...

  13. Vibration suppression of fixed-time jib crane maneuvers

    SciTech Connect

    Parker, G.G.; Petterson, B.; Dohrmann, C.R.; Robinett, R.D.

    1995-02-01

    A jib crane consists of a pendulum-like end line attached to a rotatable jib. Within this general category of cranes there exist devices with multiple degrees of freedom including variable load-line length and variable jib length. These cranes are commonly used for construction and transportation applications. Point-to-point payload maneuvers using jib cranes are performed so as not to excite the spherical pendulum modes of their cable and payload assemblies. Typically, these pendulum modes, although time-varying, exhibit low frequencies. The resulting maneuvers are therefore performed slowly, contributing to high construction and transportation costs. The crane considered here consists of a spherical pendulum attached to a rigid jib. The other end of the jib is attached to a direct drive motor for generating rotational motion. A general approach is presented for determining the open-loop trajectories for the jib rotation for accomplishing fixed-time, point-to-point, residual oscillation free, symmetric maneuvers. These residual oscillation free trajectories purposely excite the pendulum modes in such a way that at the end of the maneuver the oscillatory degrees of freedom are quiescent. Simulation results are presented with experimental verification.

  14. LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. ...

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

    LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. 1, AND DAM. NOTE LOWER LOCK GATE IN FOREGROUND. LOOKING NORTH NORTHEAST. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

  15. EOS Terra Terra Constellation Exit/Future Maneuver Plans Update

    NASA Technical Reports Server (NTRS)

    Mantziaras, Dimitrios

    2016-01-01

    This EOS Terra Constellation Exit/Future Maneuver Plans Update presentation will discuss brief history of Terra EOM work; lifetime fuel estimates; baseline vs. proposed plan origin; resultant exit orbit; baseline vs. proposed exit plan; long term orbit altitude; revised lifetime proposal and fallback options.

  16. Normative data on phases of the Valsalva maneuver

    NASA Technical Reports Server (NTRS)

    Denq, J. C.; O'Brien, P. C.; Low, P. A.

    1998-01-01

    The phases of the Valsalva maneuver have well-known pathophysiology, and are used in the evaluation of adrenergic function. Because scant normative data is available, we have evaluated normative data for the Valsalva maneuver in control subjects. The patient, supine, performed the Valsalva maneuver maintaining an expiratory pressure of 40 mm Hg for 15 seconds. We reviewed 188 Valsalva maneuver recordings of normal control subjects, and recordings were excluded if two reproducible recordings were not obtained, or if expiratory pressure was <30 mm Hg or < 10 seconds. One hundred and three recordings were acceptable for analysis; 47 female and 56 male subjects, age in years (mean +/- SD) was 52.2+/-17.3 and 44.8+/-17.3, respectively. The association of expiratory pressure with age (P < 0.001) and gender ( P < 0.001) was complex, expressed as a parabola in both men and women, but resulted in phases I and III that were not significantly different. An increase in age resulted in a progressively more negative phase II_E (P < 0.05) and attenuation of phase II_L (P < 0.01). An increase in supine blood pressure resulted in a significantly more negative phase II_E (P < 0.001) and a lower phase IV. Phase IV is unaffected by age and gender.

  17. Hohmann-Hohmann and Hohmann-Phasing Cooperative Rendezvous Maneuvers

    NASA Astrophysics Data System (ADS)

    Dutta, Atri; Tsiotras, Panagiotis

    2009-01-01

    We consider the problem of cooperative rendezvous between two satellites in circular orbits, given a fixed time for the rendezvous to be completed, and assuming a circular rendezvous orbit. We investigate two types of cooperative maneuvers for which analytical solutions can be obtained. One is the case of two Hohmann transfers, henceforth referred to as HHCM, while the other, henceforth referred to as HPCM, is the case of a Hohmann transfer and a phasing maneuver. For the latter case we derive conditions on the phasing angle that make a HPCM rendezvous cheaper than a cooperative rendezvous on an orbit that is different than either the original orbits of the two participating satellites. It is shown that minimizing the fuel expenditure is equivalent to minimizing a weighted sum of the Δ Vs of the two orbital transfers, the weights being determined by the mass and engine characteristics of the satellites. Our results show that, if the time of rendezvous allows for a Hohmann transfer between the orbits of the satellites, the optimal rendezvous is either a noncooperative Hohmann transfer or a Hohmann-phasing cooperative maneuver. In both of these cases, the maneuver costs are determined analytically. A numerical example verifies these observations. Finally, we demonstrate the utility of this study for Peer-to-Peer (P2P) refueling of satellites residing in two different circular orbits.

  18. Orbit determination across unknown maneuvers using the essential Thrust-Fourier-Coefficients

    NASA Astrophysics Data System (ADS)

    Ko, Hyun Chul; Scheeres, Daniel J.

    2016-01-01

    Any maneuver performed by a satellite transitioning between two arbitrary orbital states can be represented as an equivalent maneuver involving Thrust-Fourier-Coefficients (TFCs). With a selected TFC set as a basis, a thrust acceleration can be constructed to interpolate two unconnected states across an unknown maneuver. This representation technique with TFCs enables us to facilitate the analytical propagation of uncertainties of the satellite state. This approach allows for the usage of existing pre-maneuver orbit estimation to compute the orbit solution after the unknown maneuver. In this paper, we applied this approach to orbit determination (OD) problems across unknown maneuvers by appending different combinations of TFCs to the state vector in the batch filter. The aim is to investigate how different maneuver representations with different TFC sets affect the OD solution across unknown maneuvers. Simulation results show that each TFC set provides different representations of the unknown perturbing acceleration, which yields varying magnitudes of delta velocity for a given maneuver. However, OD solutions across unknown maneuvers using different TFC sets display equivalent performance over the post-maneuver arc as long as those TFC sets are capable of generating the apparent secular motion caused by a given unknown maneuver.

  19. Formal Logic and Flowchart for Diagnosis Validity Verification and Inclusion in Clinical Decision Support Systems

    NASA Astrophysics Data System (ADS)

    Sosa, M.; Grundel, L.; Simini, F.

    2016-04-01

    Logical reasoning is part of medical practice since its origins. Modern Medicine has included information-intensive tools to refine diagnostics and treatment protocols. We are introducing formal logic teaching in Medical School prior to Clinical Internship, to foster medical practice. Two simple examples (Acute Myocardial Infarction and Diabetes Mellitus) are given in terms of formal logic expression and truth tables. Flowcharts of both diagnostic processes help understand the procedures and to validate them logically. The particularity of medical information is that it is often accompanied by “missing data” which suggests to adapt formal logic to a “three state” logic in the future. Medical Education must include formal logic to understand complex protocols and best practices, prone to mutual interactions.

  20. Maneuvering hydrodynamics of fish and small underwater vehicles.

    PubMed

    Bandyopadhyay, Promode R

    2002-02-01

    The understanding of fish maneuvering and its application to underwater rigid bodies are considered. The goal is to gain insight into stealth. The recent progress made in NUWC is reviewed. Fish morphology suggests that control fins for maneuverability have unique scalar relationships irrespective of their speed type. Maneuvering experiments are carried out with fish that are fast yet maneuverable. The gap in maneuverability between fish and small underwater vehicles is quantified. The hydrodynamics of a dorsal fin based brisk maneuvering device and a dual flapping foil device, as applied to rigid cylindrical bodies, are described. The role of pectoral wings in maneuvering and station keeping near surface waves is discussed. A pendulum model of dolphin swimming is presented to show that body length and tail flapping frequency are related. For nearly neutrally buoyant bodies, Froude number and maneuverability are related. Analysis of measurements indicates that the Strouhal number of dolphins is a constant. The mechanism of discrete and deterministic vortex shedding from oscillating control surfaces has the property of large amplitude unsteady forcing and an exquisite phase dependence, which makes it inherently amenable to active control for precision maneuvering. Theoretical control studies are carried out to demonstrate the feasibility of maneuverability of biologically inspired bodies under surface waves. The application of fish hydrodynamics to the silencing of propulsors is considered. Two strategies for the reduction of radiated noise are developed. The effects of a reduction of rotational rate are modeled. The active cambering of blades made of digitally programmable artificial muscles, and their thrust enhancement, are demonstrated. Next, wake momentum filling is carried out by artificial muscles at the trailing edge of a stator blade of an upstream stator propulsor, and articulating them like a fish tail. A reduction of radiated noise, called blade tonals

  1. Managing Medical Logic Modules.

    PubMed Central

    Aguirre, A. R.; Roderer, N. K.

    1991-01-01

    A key element of IAIMS development at the Columbia Presbyterian Medical Center (CPMC) is the Medical Logic Module (MLM), designed to provide decision support to clinical users. A standard has been established for MLMs, and a number of institutions have agreed in principle to share them. At CPMC, MLMs are under development and MLMs from other institutions are being reviewed. The Columbia Health Sciences Library has developed a management system for MLMs which supports both internal development and sharing of MLMs among institutions. This paper describes the elements of the MLM management system. PMID:1807599

  2. Flexible programmable logic module

    DOEpatents

    Robertson, Perry J.; Hutchinson, Robert L.; Pierson, Lyndon G.

    2001-01-01

    The circuit module of this invention is a VME board containing a plurality of programmable logic devices (PLDs), a controlled impedance clock tree, and interconnecting buses. The PLDs are arranged to permit systolic processing of a problem by offering wide data buses and a plurality of processing nodes. The board contains a clock reference and clock distribution tree that can drive each of the PLDs with two critically timed clock references. External clock references can be used to drive additional circuit modules all operating from the same synchronous clock reference.

  3. Programmable Logic Application Notes

    NASA Technical Reports Server (NTRS)

    Katz, Richard

    1999-01-01

    This column will be provided each quarter as a source for reliability, radiation results, NASA capabilities, and other information on programmable logic devices and related applications. This quarter the focus is on some experimental data on low voltage drop out regulators to support mixed 5 and 3.3 volt systems. A discussion of the Small Explorer WIRE spacecraft will also be given. Lastly, we show take a first look at robust state machines in Hardware Description Languages (VHDL) and their use in critical systems. If you have information that you would like to submit or an area you would like discussed or researched, please give me a call or e-mail.

  4. An SEU immune logic family

    NASA Technical Reports Server (NTRS)

    Canaris, J.

    1991-01-01

    A new logic family, which is immune to single event upsets, is described. Members of the logic family are capable of recovery, regardless of the shape of the upsetting event. Glitch propagation from an upset node is also blocked. Logic diagrams for an Inverter, Nor, Nand, and Complex Gates are provided. The logic family can be implemented in a standard, commercial CMOS process with no additional masks. DC, transient, static power, upset recovery and layout characteristics of the new family, based on a commercial 1 micron CMOS N-Well process, are described.

  5. Proceedings of the Second Joint Technology Workshop on Neural Networks and Fuzzy Logic, volume 2

    NASA Technical Reports Server (NTRS)

    Lea, Robert N. (Editor); Villarreal, James A. (Editor)

    1991-01-01

    Documented here are papers presented at the Neural Networks and Fuzzy Logic Workshop sponsored by NASA and the University of Texas, Houston. Topics addressed included adaptive systems, learning algorithms, network architectures, vision, robotics, neurobiological connections, speech recognition and synthesis, fuzzy set theory and application, control and dynamics processing, space applications, fuzzy logic and neural network computers, approximate reasoning, and multiobject decision making.

  6. A Framework for Characterizing Students' Thinking about Logical Statements and Truth Tables

    ERIC Educational Resources Information Center

    Hawthorne, Casey; Rasmussen, Chris

    2015-01-01

    While a significant amount of research has been devoted to exploring why university students struggle applying logic, limited work can be found on how students actually make sense of the notational and structural components used in association with logic. We adapt the theoretical framework of unitizing and reification, which have been effectively…

  7. A geostationary longitude acquisition planning algorithm. [for maneuver planning of geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Petruzzo, C. J.; Bryant, W. C., Jr.; Nickerson, K. G.

    1977-01-01

    The paper is concerned with the phase of the geosynchronous mission termed station acquisition, which involves the maneuvering of a spacecraft to its geostationary longitude by means of the spacecraft propulsion system. An algorithm which assists in maneuver planning is described, and examples of its use are presented. The algorithm can be applied when sequences of more than three maneuvers are to be expected. While, in general, three maneuvers are sufficient to achieve the desired end conditions when orbital mechanics are the only consideration, operational considerations may add constraints resulting in an increased number of maneuvers required.

  8. Fuzzy logic and coarse coding using programmable logic devices

    NASA Astrophysics Data System (ADS)

    Brooks, Geoffrey

    2009-05-01

    Naturally-occurring sensory signal processing algorithms, such as those that inspired fuzzy-logic control, can be integrated into non-naturally-occurring high-performance technology, such as programmable logic devices, to realize novel bio-inspired designs. Research is underway concerning an investigation into using field programmable logic devices (FPLD's) to implement fuzzy logic sensory processing. A discussion is provided concerning the commonality between bio-inspired fuzzy logic algorithms and coarse coding that is prevalent in naturally-occurring sensory systems. Undergraduate design projects using fuzzy logic for an obstacle-avoidance robot has been accomplished at our institution and other places; numerous other successful fuzzy logic applications can be found as well. The long-term goal is to leverage such biomimetic algorithms for future applications. This paper outlines a design approach for implementing fuzzy-logic algorithms into reconfigurable computing devices. This paper is presented in an effort to connect with others who may be interested in collaboration as well as to establish a starting point for future research.

  9. Intelligent neural network and fuzzy logic control of industrial and power systems

    NASA Astrophysics Data System (ADS)

    Kuljaca, Ognjen

    The main role played by neural network and fuzzy logic intelligent control algorithms today is to identify and compensate unknown nonlinear system dynamics. There are a number of methods developed, but often the stability analysis of neural network and fuzzy control systems was not provided. This work will meet those problems for the several algorithms. Some more complicated control algorithms included backstepping and adaptive critics will be designed. Nonlinear fuzzy control with nonadaptive fuzzy controllers is also analyzed. An experimental method for determining describing function of SISO fuzzy controller is given. The adaptive neural network tracking controller for an autonomous underwater vehicle is analyzed. A novel stability proof is provided. The implementation of the backstepping neural network controller for the coupled motor drives is described. Analysis and synthesis of adaptive critic neural network control is also provided in the work. Novel tuning laws for the system with action generating neural network and adaptive fuzzy critic are given. Stability proofs are derived for all those control methods. It is shown how these control algorithms and approaches can be used in practical engineering control. Stability proofs are given. Adaptive fuzzy logic control is analyzed. Simulation study is conducted to analyze the behavior of the adaptive fuzzy system on the different environment changes. A novel stability proof for adaptive fuzzy logic systems is given. Also, adaptive elastic fuzzy logic control architecture is described and analyzed. A novel membership function is used for elastic fuzzy logic system. The stability proof is proffered. Adaptive elastic fuzzy logic control is compared with the adaptive nonelastic fuzzy logic control. The work described in this dissertation serves as foundation on which analysis of particular representative industrial systems will be conducted. Also, it gives a good starting point for analysis of learning abilities of

  10. Fuzzy Logic Particle Tracking

    NASA Technical Reports Server (NTRS)

    2005-01-01

    A new all-electronic Particle Image Velocimetry technique that can efficiently map high speed gas flows has been developed in-house at the NASA Lewis Research Center. Particle Image Velocimetry is an optical technique for measuring the instantaneous two component velocity field across a planar region of a seeded flow field. A pulsed laser light sheet is used to illuminate the seed particles entrained in the flow field at two instances in time. One or more charged coupled device (CCD) cameras can be used to record the instantaneous positions of particles. Using the time between light sheet pulses and determining either the individual particle displacements or the average displacement of particles over a small subregion of the recorded image enables the calculation of the fluid velocity. Fuzzy logic minimizes the required operator intervention in identifying particles and computing velocity. Using two cameras that have the same view of the illumination plane yields two single exposure image frames. Two competing techniques that yield unambiguous velocity vector direction information have been widely used for reducing the single-exposure, multiple image frame data: (1) cross-correlation and (2) particle tracking. Correlation techniques yield averaged velocity estimates over subregions of the flow, whereas particle tracking techniques give individual particle velocity estimates. For the correlation technique, the correlation peak corresponding to the average displacement of particles across the subregion must be identified. Noise on the images and particle dropout result in misidentification of the true correlation peak. The subsequent velocity vector maps contain spurious vectors where the displacement peaks have been improperly identified. Typically these spurious vectors are replaced by a weighted average of the neighboring vectors, thereby decreasing the independence of the measurements. In this work, fuzzy logic techniques are used to determine the true

  11. Fifth-wheel fork truck adapter

    NASA Technical Reports Server (NTRS)

    Smith, P. L.

    1969-01-01

    Standard fifth wheel mounted on a rectangular steel structure adapted for use with a fork lift truck provides a fast, safe, and economical way of maneuvering semitrailers in close quarters at plants and warehouses. One operator can move and locate a semitrailer without dismounting from a fork lift truck.

  12. Applications of adaptive state estimation theory

    NASA Technical Reports Server (NTRS)

    Moose, R. L.; Vanlandingham, H. F.; Mccabe, D. H.

    1980-01-01

    Two main areas of application of adaptive state estimation theory are presented. Following a review of the basic estimation approach, its application to both the control of nonlinear plants and to the problem of tracking maneuvering targets is presented. Results are brought together from these two areas of investigation to provide insight into the wide range of possible applications of the general estimation method.

  13. Reversible logic gates on Physarum Polycephalum

    SciTech Connect

    Schumann, Andrew

    2015-03-10

    In this paper, we consider possibilities how to implement asynchronous sequential logic gates and quantum-style reversible logic gates on Physarum polycephalum motions. We show that in asynchronous sequential logic gates we can erase information because of uncertainty in the direction of plasmodium propagation. Therefore quantum-style reversible logic gates are more preferable for designing logic circuits on Physarum polycephalum.

  14. Quantificational logic of context

    SciTech Connect

    Buvac, Sasa

    1996-12-31

    In this paper we extend the Propositional Logic of Context, to the quantificational (predicate calculus) case. This extension is important in the declarative representation of knowledge for two reasons. Firstly, since contexts are objects in the semantics which can be denoted by terms in the language and which can be quantified over, the extension enables us to express arbitrary first-order properties of contexts. Secondly, since the extended language is no longer only propositional, we can express that an arbitrary predicate calculus formula is true in a context. The paper describes the syntax and the semantics of a quantificational language of context, gives a Hilbert style formal system, and outlines a proof of the system`s completeness.

  15. Molecular logic circuits.

    PubMed

    Balzani, Vincenzo; Credi, Alberto; Venturi, Margherita

    2003-01-13

    Miniaturization has been an essential ingredient in the outstanding progress of information technology over the past fifty years. The next, perhaps ultimate, limit of miniaturization is that of molecules, which are the smallest entities with definite size, shape, and properties. Recently, great effort has been devoted to design and investigate molecular-level systems that are capable of transferring, processing, and storing information in binary form. Some of these nanoscale devices can, in fact, perform logic operations of remarkable complexity. This research--although far from being transferred into technology--is attracting interest, as the nanometer realm seems to be out of reach for the "top-down" techniques currently available to microelectronics industry. Moreover, such studies introduce new concepts in the "old" field of chemistry and stimulate the ingenuity of researchers engaged in the "bottom-up" approach to nanotechnology.

  16. Contingencies, logic, and learning.

    PubMed

    Bower, T G

    1997-01-01

    A logical analysis of operant learning is presented. In total, the analysis makes a number of predictions that are different from the predictions of any other theory. Individual predictions can be explained by other theories, but the pattern of predictions is unique. Some tests of the predictions of the analysis with human newborns are described. The analysis predicts increased variance in sucking with the introduction of continuous reinforcement. This does occur. The analysis predicts a decreased rate of sucking with a shift from continuous to partial reinforcement. This does occur. The analysis predicts an increased rate of sucking with a shift from continuous reinforcement to continuous plus noncontingent reinforcement. Due to methodological deficiencies, we have been unable to test this prediction. However, it has been confirmed by others. The most exciting prediction of the analysis is a rapid way of producing extinction. That has not been tested with newborns; however, there is confirmatory evidence in the literature.

  17. A Logical Process Calculus

    NASA Technical Reports Server (NTRS)

    Cleaveland, Rance; Luettgen, Gerald; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    This paper presents the Logical Process Calculus (LPC), a formalism that supports heterogeneous system specifications containing both operational and declarative subspecifications. Syntactically, LPC extends Milner's Calculus of Communicating Systems with operators from the alternation-free linear-time mu-calculus (LT(mu)). Semantically, LPC is equipped with a behavioral preorder that generalizes Hennessy's and DeNicola's must-testing preorder as well as LT(mu's) satisfaction relation, while being compositional for all LPC operators. From a technical point of view, the new calculus is distinguished by the inclusion of: (1) both minimal and maximal fixed-point operators and (2) an unimple-mentability predicate on process terms, which tags inconsistent specifications. The utility of LPC is demonstrated by means of an example highlighting the benefits of heterogeneous system specification.

  18. The New Quantum Logic

    NASA Astrophysics Data System (ADS)

    Griffiths, Robert B.

    2014-06-01

    It is shown how all the major conceptual difficulties of standard (textbook) quantum mechanics, including the two measurement problems and the (supposed) nonlocality that conflicts with special relativity, are resolved in the consistent or decoherent histories interpretation of quantum mechanics by using a modified form of quantum logic to discuss quantum properties (subspaces of the quantum Hilbert space), and treating quantum time development as a stochastic process. The histories approach in turn gives rise to some conceptual difficulties, in particular the correct choice of a framework (probabilistic sample space) or family of histories, and these are discussed. The central issue is that the principle of unicity, the idea that there is a unique single true description of the world, is incompatible with our current understanding of quantum mechanics.

  19. Molecular logic circuits.

    PubMed

    Balzani, Vincenzo; Credi, Alberto; Venturi, Margherita

    2003-01-13

    Miniaturization has been an essential ingredient in the outstanding progress of information technology over the past fifty years. The next, perhaps ultimate, limit of miniaturization is that of molecules, which are the smallest entities with definite size, shape, and properties. Recently, great effort has been devoted to design and investigate molecular-level systems that are capable of transferring, processing, and storing information in binary form. Some of these nanoscale devices can, in fact, perform logic operations of remarkable complexity. This research--although far from being transferred into technology--is attracting interest, as the nanometer realm seems to be out of reach for the "top-down" techniques currently available to microelectronics industry. Moreover, such studies introduce new concepts in the "old" field of chemistry and stimulate the ingenuity of researchers engaged in the "bottom-up" approach to nanotechnology. PMID:12596465

  20. Does dragonfly's abdomen flexion help with fast turning maneuvers?

    NASA Astrophysics Data System (ADS)

    Liu, Geng; Li, Chengyu; Dong, Haibo; Flow Simulation Research Group Team

    2013-11-01

    Dragonflies are able to achieve fast turning maneuvers during take-off flights. Both asymmetric wing flapping and abdomen flexion have been observed during the fast turning. It's widely thought that the asymmetric wing beats are responsible of producing the aerodynamic moment needed for the body rotation. However, the dynamic effect of the abdomen flexion is not clear yet. In this study, an integrated experimental and computational approach is used to study the underlying dynamic effect of dragonfly abdomen flexion. It's found that dragonfly abdomen tended to bend towards the same side as the body reorienting to. Quantitative analysis have shown that during take-off turning maneuver the abdomen flexion can modulate the arm of force by changing the position of the center of mass relative to the thorax. As a result, roll and yaw moments produced by the wing flapping can be enhanced. This work is supported by NSF CBET-1313217. This work is supported by NSF CBET-1313217.

  1. Visual display aid for orbital maneuvering - Design considerations

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1993-01-01

    This paper describes the development of an interactive proximity operations planning system that allows on-site planning of fuel-efficient multiburn maneuvers in a potential multispacecraft environment. Although this display system most directly assists planning by providing visual feedback to aid visualization of the trajectories and constraints, its most significant features include: (1) the use of an 'inverse dynamics' algorithm that removes control nonlinearities facing the operator, and (2) a trajectory planning technique that separates, through a 'geometric spreadsheet', the normally coupled complex problems of planning orbital maneuvers and allows solution by an iterative sequence of simple independent actions. The visual feedback of trajectory shapes and operational constraints, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool provides an example of operator-assisted optimization of nonlinear cost functions.

  2. Heterogeneous Multiple Sensors Joint Tracking of Maneuvering Target in Clutter

    PubMed Central

    Wu, Panlong; Li, Xingxiu; Kong, Jianshou; Liu, Jiale

    2015-01-01

    To solve the problem of tracking maneuvering airborne targets in the presence of clutter, an improved interacting multiple model probability data association algorithm (IMMPDA-MDCM) using radar/IR sensors fusion is proposed. Under the architecture of the proposed algorithm, the radar/IR centralized fusion tracking scheme of IMMPDA-MDCM is designed to guarantee the observability of the target state. The interacting multiple model (IMM) deals with the model switching. The modified debiased converted measurement (MDCM) filter accounts for non-linearity in the dynamic system models, and reduces the effect of measurement noise on the covariance effectively. The probability data association (PDA) handles data association and measurement uncertainties in clutter. The simulation results show that the proposed algorithm can improve the tracking precision for maneuvering target in clutters, and has higher tracking precision than the traditional IMMPDA based on EKF and IMMPDA based on DCM algorithm. PMID:26193279

  3. Guidance law against maneuvering targets with intercept angle constraint.

    PubMed

    Xiong, Shaofeng; Wang, Weihong; Liu, Xiaodong; Wang, Sen; Chen, Zengqiang

    2014-07-01

    This study explores the guidance law against maneuvering targets with the intercept angle constraint. The limitation of the traditional guidance law, which simply treats the unknown target acceleration as zero, has been analyzed. To reduce this limitation, a linear extended state observer is constructed to estimate the acceleration of the maneuvering target to enhance the tracking performance of the desired intercept angle. Furthermore, a nonsingular terminal sliding mode control scheme is adopted to design the sliding surface, which is able to avoid the singularity in the terminal phase of guidance. Simulation results have demonstrated that the proposed guidance law outperforms the traditional guidance law in the sense that more accurate intercept angle can be achieved.

  4. Thermally-Constrained Fuel-Optimal ISS Maneuvers

    NASA Technical Reports Server (NTRS)

    Bhatt, Sagar; Svecz, Andrew; Alaniz, Abran; Jang, Jiann-Woei; Nguyen, Louis; Spanos, Pol

    2015-01-01

    Optimal Propellant Maneuvers (OPMs) are now being used to rotate the International Space Station (ISS) and have saved hundreds of kilograms of propellant over the last two years. The savings are achieved by commanding the ISS to follow a pre-planned attitude trajectory optimized to take advantage of environmental torques. The trajectory is obtained by solving an optimal control problem. Prior to use on orbit, OPM trajectories are screened to ensure a static sun vector (SSV) does not occur during the maneuver. The SSV is an indicator that the ISS hardware temperatures may exceed thermal limits, causing damage to the components. In this paper, thermally-constrained fuel-optimal trajectories are presented that avoid an SSV and can be used throughout the year while still reducing propellant consumption significantly.

  5. Broken-Plane Maneuver Applications for Earth to Mars Trajectories

    NASA Technical Reports Server (NTRS)

    Abilleira, Fernando

    2007-01-01

    Optimization techniques are critical when investigating Earth to Mars trajectories since they have the potential of reducing the total (delta)V of a mission. A deep space maneuver (DSM) executed during the cruise may improve a trajectory by reducing the total mission V. Nonetheless, DSMs not only may improve trajectory performance (from an energetic point of view) but also open up new families of trajectories that would satisfy very specific mission requirements not achievable with ballistic trajectories. In the following pages, various specific examples showing the potential advantages of the usage of broken plane maneuvers will be introduced. These examples correspond to possible scenarios for Earth to Mars trajectories during the next decade (2010-2020).

  6. Optimal Variable-Structure Control Tracking of Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Crassidis, John L.; Vadali, Srinivas R.; Markley, F. Landis

    1999-01-01

    An optimal control approach using variable-structure (sliding-mode) tracking for large angle spacecraft maneuvers is presented. The approach expands upon a previously derived regulation result using a quaternion parameterization for the kinematic equations of motion. This parameterization is used since it is free of singularities. The main contribution of this paper is the utilization of a simple term in the control law that produces a maneuver to the reference attitude trajectory in the shortest distance. Also, a multiplicative error quaternion between the desired and actual attitude is used to derive the control law. Sliding-mode switching surfaces are derived using an optimal-control analysis. Control laws are given using either external torque commands or reaction wheel commands. Global asymptotic stability is shown for both cases using a Lyapunov analysis. Simulation results are shown which use the new control strategy to stabilize the motion of the Microwave Anisotropy Probe spacecraft.

  7. Single step optimization of manipulator maneuvers with variable structure control

    NASA Technical Reports Server (NTRS)

    Chen, N.; Dwyer, T. A. W., III

    1987-01-01

    One step ahead optimization has been recently proposed for spacecraft attitude maneuvers as well as for robot manipulator maneuvers. Such a technique yields a discrete time control algorithm implementable as a sequence of state-dependent, quadratic programming problems for acceleration optimization. Its sensitivity to model accuracy, for the required inversion of the system dynamics, is shown in this paper to be alleviated by a fast variable structure control correction, acting between the sampling intervals of the slow one step ahead discrete time acceleration command generation algorithm. The slow and fast looping concept chosen follows that recently proposed for optimal aiming strategies with variable structure control. Accelerations required by the VSC correction are reserved during the slow one step ahead command generation so that the ability to overshoot the sliding surface is guaranteed.

  8. Design and analysis of a supersonic penetration/maneuvering fighter

    NASA Technical Reports Server (NTRS)

    Child, R. D.

    1975-01-01

    The design of three candidate air combat fighters which would cruise effectively at freestream Mach numbers of 1.6, 2.0, and 2.5 while maintaining good transonic maneuvering capability, is considered. These fighters were designed to deliver aerodynamically controlled dogfight missiles at the design Mach numbers. Studies performed by Rockwell International in May 1974 and guidance from NASA determined the shape and size of these missiles. The principle objective of this study is the aerodynamic design of the vehicles; however, configurations are sized to have realistic structures, mass properties, and propulsion systems. The results of this study show that air combat fighters in the 15,000 to 23,000 pound class would cruise supersonically on dry power and still maintain good transonic maneuvering performance.

  9. Time efficient spacecraft maneuver using constrained torque distribution

    NASA Astrophysics Data System (ADS)

    Cao, Xibin; Yue, Chengfei; Liu, Ming; Wu, Baolin

    2016-06-01

    This paper investigates the time efficient maneuver of rigid satellites with inertia uncertainty and bounded external disturbance. A redundant cluster of four reaction wheels is used to control the spacecraft. To make full use of the controllability and avoid frequent unload for reaction wheels, a maximum output torque and maximum angular momentum constrained torque distribution method is developed. Based on this distribution approach, the maximum allowable acceleration and velocity of the satellite are optimized during the maneuvering. A novel braking curve is designed on the basis of the optimization strategy of the control torque distribution. A quaternion-based sliding mode control law is proposed to render the state to track the braking curve strictly. The designed controller provides smooth control torque, time efficiency and high control precision. Finally, practical numerical examples are illustrated to show the effectiveness of the developed torque distribution strategy and control methodology.

  10. Programmable Logic Controllers. Teacher Edition.

    ERIC Educational Resources Information Center

    Rauh, Bob; Kaltwasser, Stan

    These materials were developed for a seven-unit secondary or postsecondary education course on programmable logic controllers (PLCs) that treats most of the skills needed to work effectively with PLCs as programming skills. The seven units of the course cover the following topics: fundamentals of programmable logic controllers; contracts, timers,…

  11. Japanese Logic Puzzles and Proof

    ERIC Educational Resources Information Center

    Wanko, Jeffrey J.

    2009-01-01

    An understanding of proof does not start in a high school geometry course. Rather, attention to logical reasoning throughout a student's school experience can help the development of proof readiness. In the spirit of problem solving, the author has begun to use some Japanese logic puzzles other than sudoku to help students develop additional…

  12. Dynamic wake distortion model for helicopter maneuvering flight

    NASA Astrophysics Data System (ADS)

    Zhao, Jinggen

    A new rotor dynamic wake distortion model, which can be used to account for the rotor transient wake distortion effect on inflow across the rotor disk during helicopter maneuvering and transitional flight in both hover and forward flight conditions, is developed. The dynamic growths of the induced inflow perturbation across rotor disk during different transient maneuvers, such as a step pitch or roll rate, a step climb rate and a step change of advance ratio are investigated by using a dynamic vortex tube analysis. Based on the vortex tube results, a rotor dynamic wake distortion model, which is expressed in terms of a set of ordinary differential equations, with rotor longitudinal and lateral wake curvatures, wake skew and wake spacing as states, is developed. Also, both the Pitt-Peters dynamic inflow model and the Peters-He finite state inflow model for axial or forward flight are augmented to account for rotor dynamic wake distortion effect during helicopter maneuvering flight. To model the aerodynamic interaction among main rotor, tail rotor and empennage caused by rotor wake curvature effect during helicopter maneuvering flight, a reduced order model based on a vortex tube analysis is developed. Both the augmented Pitt-Peters dynamic inflow model and the augmented Peters-He finite state inflow model, combined with the developed dynamic wake distortion model, together with the interaction model are implemented in a generic helicopter simulation program of UH-60 Black Hawk helicopter and the simulated vehicle control responses in both time domain and frequency domain are compared with flight test data of a UH-60 Black Hawk helicopter in both hover and low speed forward flight conditions.

  13. Differential Evolution Optimization for Targeting Spacecraft Maneuver Plans

    NASA Technical Reports Server (NTRS)

    Mattern, Daniel

    2016-01-01

    Previous analysis identified specific orbital parameters as being safer for conjunction avoidance for the TDRS fleet. With TDRS-9 being considered an at-risk spacecraft, a potential conjunction concern was raised should TDRS-9 fail while at a longitude of 12W. This document summarizes the analysis performed to identify if these specific orbital parameters could be targeted using the remaining drift-termination maneuvers for the relocation of TDRS-9 from 41W longitude to 12W longitude.

  14. Efficient Reorientation Maneuvers for Spacecraft with Multiple Articulated Payloads

    NASA Technical Reports Server (NTRS)

    Mcclamroch, N. Harris

    1993-01-01

    A final report is provided which describes the research program during the period 3 Mar. 1992 to 3 Jun. 1993. A summary of the technical research questions that were studied and of the main results that were obtained is given. The specific outcomes of the research program, including both educational impacts as well as research publications, are listed. The research is concerned with efficient reorientation maneuvers for spacecraft with multiple articulated payloads.

  15. 14 CFR 25.337 - Limit maneuvering load factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... factor n for any speed up to Vn may not be less than 2.1+24,000/ (W +10,000) except that n may not be less than 2.5 and need not be greater than 3.8—where W is the design maximum takeoff weight. (c) The negative limit maneuvering load factor— (1) May not be less than −1.0 at speeds up to V C; and (2)...

  16. 14 CFR 25.337 - Limit maneuvering load factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... factor n for any speed up to Vn may not be less than 2.1+24,000/ (W +10,000) except that n may not be less than 2.5 and need not be greater than 3.8—where W is the design maximum takeoff weight. (c) The negative limit maneuvering load factor— (1) May not be less than −1.0 at speeds up to V C; and (2)...

  17. A Summary of the Pioneer 10 Maneuver Strategy

    NASA Technical Reports Server (NTRS)

    Frauenholz, R. B.; Ball, J. E.

    1972-01-01

    The Pioneer Project placed a number of interesting and precise requirements on the navigation of the Pioneer 10 spacecraft flyby mission to Jupiter during 1972-1973. To satisfy these requirements the Pioneer navigation team employed a number of versatile computer programs to evaluate the strategies and maneuver sequences required to execute midcourse corrections. The Pioneer 10 mission objectives and the midcourse strategies used to satisfy these objectives are summarized.

  18. Stability and control of maneuvering high-performance aircraft

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.; Berry, P. W.

    1977-01-01

    The stability and control of a high-performance aircraft was analyzed, and a design methodology for a departure prevention stability augmentation system (DPSAS) was developed. A general linear aircraft model was derived which includes maneuvering flight effects and trim calculation procedures for investigating highly dynamic trajectories. The stability and control analysis systematically explored the effects of flight condition and angular motion, as well as the stability of typical air combat trajectories. The effects of configuration variation also were examined.

  19. Flow Modulation and Force Control in Insect Fast Maneuver

    NASA Astrophysics Data System (ADS)

    Li, Chengyu; Dong, Haibo; Zhang, Wen; Gai, Kuo

    2012-11-01

    In this work, an integrated study combining high-speed photogrammetry and direct numerical simulation (DNS) is used to study free flying insects in fast maneuver. Quantitative measurement has shown the significant differences between quad-winged flyers such as dragonfly and damselfly and two-winged flyers such as cicada. Comparisons of unsteady 3D vortex formation and associated aerodynamic force production reveal the different mechanisms used by insects in fast turn. This work is supported by NSF CBET-1055949.

  20. Nucleic acid based logical systems.

    PubMed

    Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong

    2014-05-12

    Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.

  1. Fuzzy logic for fault diagnosis

    NASA Astrophysics Data System (ADS)

    Comly, James B.; Bonissone, Piero P.; Dausch, Mark E.

    1991-02-01

    Advanced real-time digital controls for complex plants or processes will use a model (an " Observer" ) which predicts the values for sensor readings expected from the actual plant these vote as alternate " sensors" if the real ones fail. We are exploring further use of the Observer for real-time embedded diagnostics based on high speed fuzzy logic chips just becoming available. We have established a Fuzzy Inferencing Test Bed for fuzzy logic applications. It uses a set of development tools which allow applications to be built and tested against simulated systems and then ported directly to a high speed fuzzy logic chip. With the Fuzzy Inferencing Test we investigate very high speed fuzzy logic to: isolate faults using static information and early fault information that evolves rapidly in time validate and smooth readings from redundant sensors and smoothly select alternate control modes in intelligent controllers. This paper reports our experience with fuzzy logic in these kinds of applications.

  2. Power optimization in logic isomers

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    Logic isomers are labeled, 2-isomorphic graphs that implement the same logic function. Logic isomers may have significantly different power requirements even though they have the same number of transistors in the implementation. The power requirements of the isomers depend on the transition activity of the input signals. The power requirements of isomorphic graph isomers of n-input NAND and NOR gates are shown. Choosing the less power-consuming isomer instead of the others can yield significant power savings. Experimental results on a ripple-carry adder are presented to show that the implementation using the least power-consuming isomers requires approximately 10 percent less power than the implementation using the most power-consuming isomers. Simulations of other random logic designs also confirm that designs using less power-consuming isomers can reduce the logic power demand by approximately 10 percent as compared to designs using more power-consuming isomers.

  3. Optical programmable Boolean logic unit.

    PubMed

    Chattopadhyay, Tanay

    2011-11-10

    Logic units are the building blocks of many important computational operations likes arithmetic, multiplexer-demultiplexer, radix conversion, parity checker cum generator, etc. Multifunctional logic operation is very much essential in this respect. Here a programmable Boolean logic unit is proposed that can perform 16 Boolean logical operations from a single optical input according to the programming input without changing the circuit design. This circuit has two outputs. One output is complementary to the other. Hence no loss of data can occur. The circuit is basically designed by a 2×2 polarization independent optical cross bar switch. Performance of the proposed circuit has been achieved by doing numerical simulations. The binary logical states (0,1) are represented by the absence of light (null) and presence of light, respectively.

  4. Optimal scheduling of multispacecraft refueling based on cooperative maneuver

    NASA Astrophysics Data System (ADS)

    Du, Bingxiao; Zhao, Yong; Dutta, Atri; Yu, Jing; Chen, Xiaoqian

    2015-06-01

    The scheduling of multispacecraft refueling based on cooperative maneuver in a circular orbit is studied in this paper. In the proposed scheme, both of the single service vehicle (SSV) and the target satellite (TS) perform the orbital transfer to complete the rendezvous at the service places. When a TS is refueled by the SSV, it returns to its original working slot to continue its normal function. In this way, the SSV refuels the TS one by one. A MINLP model for the mission is first built, then a two-level hybrid optimization approach is proposed for determining the strategy, and the optimal solution is successfully obtained by using an algorithm which is a combination of Multi-island Genetic Algorithm and Sequential Quadratic Programming. Results show the cooperative strategy can save around 27.31% in fuel, compared with the non-cooperative strategy in which only the SSV would maneuver in the example considered. Three conclusions can be drawn based on the numerical simulations for the evenly distributed constellations. Firstly, in the cooperative strategy one of the service positions is the initial location of the SSV, other service positions are also target slots, i.e. not all targets need to maneuver, and there may be more than one TS serviced in a given service position. Secondly, the efficiency gains for the cooperative strategy are higher for larger transferred fuel mass. Thirdly, the cooperative strategy is less efficient for targets with larger spacecraft mass.

  5. Alveolar recruitment maneuvers: are your patients missing out?

    PubMed

    Hartland, Benjamin L; Newell, Timothy J; Damico, Nicole

    2014-08-01

    Awake, spontaneously breathing humans sigh on average 9 to 10 times per hour. The sigh is a normal homeostatic reflex proposed to maintain pulmonary compliance and decrease the formation of atelectasis by recruiting collapsed alveoli. The induction and maintenance of anesthesia with muscle paralysis and a fixed tidal volume abolish the sigh. Without periodic sighs, patients are left susceptible to atelectasis and its negative sequelae. The prevalence of atelectasis has been estimated to be as high as 100% in patients undergoing general anesthesia. A strong correlation between atelectasis and postoperative pulmonary complications has been demonstrated. Postoperative pulmonary complications lengthen hospital stays and increase healthcare costs. Alveolar recruitment maneuvers, which make up one component of open lung ventilation, have been described as vital capacity breaths, double tidal volume breaths, and sigh breaths. These simple maneuvers result in a sustained increase in airway pressure that serves to recruit collapsed alveoli and improve arterial oxygenation. This article examines the literature regarding the application of alveolar recruitment maneuvers in the perioperative setting. The format is a series of clinically oriented questions posed to help the reader translate available evidence into practice.

  6. Control integration concept for hypersonic cruise-turn maneuvers

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Lallman, Frederick J.

    1992-01-01

    Piloting difficulties associated with conducting aircraft maneuvers in hypersonic flight are caused in part by the nonintuitive nature of the aircraft response and the stringent constraints anticipated on allowable angle of attack and dynamic pressure variations. An approach is documented that provides precise, coordinated maneuver control during excursions from a hypersonic cruise flight path and the necessary flight condition constraints. The approach is to achieve specified guidance commands by resolving altitude and cross range errors into a load factor and bank angle command by using a coordinate transformation that acts as an interface between outer and inner loop flight controls. This interface, referred to as a 'resolver', applies constraints on angle of attack and dynamic pressure perturbations while prioritizing altitude regulation over cross range. An unpiloted test simulation, in which the resolver was used to drive inner loop flight controls, produced time histories of responses to guidance commands and atmospheric disturbances at Mach numbers of 6, 10, 15, and 20. Angle of attack and throttle perturbation constraints, combined with high speed flight effects and the desire to maintain constant dynamic pressure, significantly impact the maneuver envelope for a hypersonic vehicle.

  7. Capturing and analyzing wheelchair maneuvering patterns with mobile cloud computing.

    PubMed

    Fu, Jicheng; Hao, Wei; White, Travis; Yan, Yuqing; Jones, Maria; Jan, Yih-Kuen

    2013-01-01

    Power wheelchairs have been widely used to provide independent mobility to people with disabilities. Despite great advancements in power wheelchair technology, research shows that wheelchair related accidents occur frequently. To ensure safe maneuverability, capturing wheelchair maneuvering patterns is fundamental to enable other research, such as safe robotic assistance for wheelchair users. In this study, we propose to record, store, and analyze wheelchair maneuvering data by means of mobile cloud computing. Specifically, the accelerometer and gyroscope sensors in smart phones are used to record wheelchair maneuvering data in real-time. Then, the recorded data are periodically transmitted to the cloud for storage and analysis. The analyzed results are then made available to various types of users, such as mobile phone users, traditional desktop users, etc. The combination of mobile computing and cloud computing leverages the advantages of both techniques and extends the smart phone's capabilities of computing and data storage via the Internet. We performed a case study to implement the mobile cloud computing framework using Android smart phones and Google App Engine, a popular cloud computing platform. Experimental results demonstrated the feasibility of the proposed mobile cloud computing framework.

  8. A Fuel-Efficient Conflict Resolution Maneuver for Separation Assurance

    NASA Technical Reports Server (NTRS)

    Bowe, Aisha Ruth; Santiago, Confesor

    2012-01-01

    Automated separation assurance algorithms are envisioned to play an integral role in accommodating the forecasted increase in demand of the National Airspace System. Developing a robust, reliable, air traffic management system involves safely increasing efficiency and throughput while considering the potential impact on users. This experiment seeks to evaluate the benefit of augmenting a conflict detection and resolution algorithm to consider a fuel efficient, Zero-Delay Direct-To maneuver, when resolving a given conflict based on either minimum fuel burn or minimum delay. A total of twelve conditions were tested in a fast-time simulation conducted in three airspace regions with mixed aircraft types and light weather. Results show that inclusion of this maneuver has no appreciable effect on the ability of the algorithm to safely detect and resolve conflicts. The results further suggest that enabling the Zero-Delay Direct-To maneuver significantly increases the cumulative fuel burn savings when choosing resolution based on minimum fuel burn while marginally increasing the average delay per resolution.

  9. Closed-Loop Aerodynamic Flow Control of a Maneuvering Airfoil

    NASA Astrophysics Data System (ADS)

    Brzozowski, Daniel P.; Culp, John R.; Glezer, Ari

    2011-11-01

    The unsteady interaction between trailing edge aerodynamic flow control and airfoil motion in pitch and plunge is investigated in wind tunnel experiments using a 2-DOF traverse which enables application of time-dependent external torque and forces by servo motors. The global aerodynamic forces and moments are regulated by controlling vorticity generation and accumulation near the surface using hybrid synthetic jet actuators. The dynamic coupling between the actuation and the time-dependent flow field is characterized using simultaneous force and velocity measurements that are taken phase-locked to the commanded actuation waveform. The effect of the unsteady motion on the model-embedded flow control is assessed in unsteady several maneuvers. Circulation time history that is estimated from a PIV wake survey shows that the entire flow over the airfoil readjusts within about 1.5 TCONV, which is about two orders of magnitude shorter than the characteristic time associated with the controlled maneuver of the wind tunnel model. This illustrates that flow-control actuation can be typically effected on time scales that are commensurate with the flow's convective time scale, and that the maneuver response is primarily limited by the inertia of the platform.

  10. PM Science Working Group Meeting on Spacecraft Maneuvers

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.

    1997-01-01

    The EOS PM Science Working Group met on May 6, 1997, to examine the issue of spacecraft maneuvers. The meeting was held at NASA Goddard Space Flight Center and was attended by the Team Leaders of all four instrument science teams with instruments on the PM-1 spacecraft, additional representatives from each of the four teams, the PM Project management, and random others. The meeting was chaired by the PM Project Scientist and open to all. The meeting was called in order to untangle some of the concerns raised over the past several months regarding whether or not the PM-1 spacecraft should undergo spacecraft maneuvers to allow the instruments to obtain deep-space views. Two of the Science Teams, those for the Moderate-Resolution Imaging Spectroradiometer (MODIS) and the Clouds and the Earth's Radiant Energy System (CERES), had strongly expressed the need for deep-space views in order to calibrate their instruments properly and conveniently. The other two teams, those for the Advanced Microwave Scanning Radiometer (AMSR-E) and the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU), and the Humidity Sounder for Brazil (HSB), had expressed concerns that the maneuvers involve risks to the instruments and undesired gaps in the data sets.

  11. Trajectory Control of Rendezvous with Maneuver Target Spacecraft

    NASA Technical Reports Server (NTRS)

    Zhou, Zhinqiang

    2012-01-01

    In this paper, a nonlinear trajectory control algorithm of rendezvous with maneuvering target spacecraft is presented. The disturbance forces on the chaser and target spacecraft and the thrust forces on the chaser spacecraft are considered in the analysis. The control algorithm developed in this paper uses the relative distance and relative velocity between the target and chaser spacecraft as the inputs. A general formula of reference relative trajectory of the chaser spacecraft to the target spacecraft is developed and applied to four different proximity maneuvers, which are in-track circling, cross-track circling, in-track spiral rendezvous and cross-track spiral rendezvous. The closed-loop differential equations of the proximity relative motion with the control algorithm are derived. It is proven in the paper that the tracking errors between the commanded relative trajectory and the actual relative trajectory are bounded within a constant region determined by the control gains. The prediction of the tracking errors is obtained. Design examples are provided to show the implementation of the control algorithm. The simulation results show that the actual relative trajectory tracks the commanded relative trajectory tightly. The predicted tracking errors match those calculated in the simulation results. The control algorithm developed in this paper can also be applied to interception of maneuver target spacecraft and relative trajectory control of spacecraft formation flying.

  12. Global Precipitation Measurement (GPM) Orbit Design and Autonomous Maneuvers

    NASA Technical Reports Server (NTRS)

    Folta, David; Mendelsohn, Chad; Mailhe, Laurie

    2003-01-01

    The NASA Goddard Space Flight Center's Global Precipitation Measurement (GPM) mission must meet the challenge of measuring worldwide precipitation every three hours. The GPM core spacecraft, part of a constellation, will be required to maintain a circular orbit in a high drag environment at a near-critical inclination. Analysis shows that a mean orbit altitude of 407 km is necessary to prevent ground track repeating. Combined with goals to minimize maneuver operation impacts to science data collection and to enable reasonable long-term orbit predictions, the GPM project has decided to fly the GSFC autonomous maneuver system, AutoCon(TM). This system is a follow-up version of the highly successful New Millennium Program technology flown onboard the Earth Observing-1 formation flying mission. This paper presents the driving science requirements and goals of the GPM mission and shows how they will be met. Selection of the mean semi-major axis, eccentricity, and the AV budget for several ballistic properties are presented. The architecture of the autonomous maneuvering system to meet the goals and requirements is presented along with simulations using GPM parameters. Additionally, the use of the GPM autonomous system to mitigate possible collision avoidance and to aid other spacecraft systems during navigation outages is explored.

  13. Severe Turbulence and Maneuvering from Airline Flight Records

    NASA Technical Reports Server (NTRS)

    Wingrove, Rodney C.; Bach, R. E., Jr.

    1994-01-01

    Digital flight records from reported clear-air turbulence incidents are used to determine winds and turbulence, to determine maneuver g loads, and to analyze control problems. Many cases of severe turbulence are found downwind of mountains and thunderstorms where sharp, sudden jolts are associated with vortices in atmospheric waves. Other cases of severe turbulence are round in strong updrafts above thunderstorm buildups that may be undetected by onboard weather radar. An important finding is that there are large maneuvering loads in over half of the reported clear-air turbulence incidents. Maneuvering loads are determined through an analysis of the short-term variations in elevator deflection and aircraft pitch angle. For altitude control in mountain waves the results indicate that small pitch angle changes with proper timing are sufficient to counter variations in vertical wind. For airspeed control in strong mountain waves, however, there is neither the available thrust nor the quickness in engine response necessary to counter the large variations in winds.

  14. Aerodynamic role of dynamic wing morphing in hummingbird maneuvering flight

    NASA Astrophysics Data System (ADS)

    Ren, Yan; Shallcross, Gregory; Dong, Haibo; Deng, Xinyan; Tobalske, Bret; Flow Simulation Research Group Team; Bio-robotics lab Collaboration; University of Montana Flight Laboratory Collaboration

    2014-11-01

    The flexibility and deformation of hummingbird wing gives hummingbird a great degree of control over fluid forces in flapping flight. Unlike insect wing's passive deformation, hummingbird wing employs a more complicated wing morphing mechanism through both active muscle control and passive feather-air interaction, which results in highly complex 3D wing topology variations during the unsteady flight. Three camera high speed (1000 fps) high resolution digital video was taken and digitized to measure 3D wing conformation in all its complexity during steady flying and maneuvering. Results have shown that the dynamic wing morphing is more prominent in maneuvering flight. Complicated cambering and twisting patterns are observed along the wing pitching axis. A newly developed immersed boundary method which realistically models wing-joint-body of the hummingbird is then employed to simulate the flow associated with dynamic morphing. The simulations provide a first of its kind glimpse of the fluid and vortex dynamics associated with dynamic wing morphing and aerodynamic force computations allow us to gain a better understanding of force producing mechanisms in hummingbird maneuvering flight. This work is supported by AFOSR FA9550-12-1-007 and NSF CEBT-1313217.

  15. Maneuver Performance Enhancement for an Advanced Fighter/Attack Aircraft

    NASA Technical Reports Server (NTRS)

    Samuels, Jeff; Langan, Kevin J.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    A small scale wind tunnel test of a realistic fighter configuration has been completed in NASA Ames' 7'x10' wind tunnel. This test was part of the Fighter Lift and Control (FLAC) program, a joint NASA - USAF research program, involving small and large-scale wind-tunnel tests and computational analysis of unique lift augmentation and control devices. The goal of this program is to enhance the maneuver and control capability of next-generation Air Force multi-role fighter aircraft with low-observables geometries. The principal objective of this test was to determine the effectiveness of passive boundary layer control devices at increasing L/D at sustained maneuver lift coefficients. Vortex generators (VGs) were used to energize the boundary layer to prevent or delay separation. Corotating vanes, counter-rotating vanes, and Wheeler Wishbone VGs were used in the vicinity of the leading and trailing edge flap hinge lines. Principle test parameters were leading and trailing edge flap deflections, and location, size, spacing, and orientation for each VG type. Gurney flaps were also tested. Data gathered include balance force and moment data, surface pressures, and flow visualization for characterizing flow behavior and locating separation lines. Results were quite different for the two best flap configurations tested. All VG types tested showed improvement (up to 5%) in maneuver L/D with flaps at LE=20 degrees, TE=0 degrees. The same VGs degraded performance, in all but a few cases, with flaps at LE=15 degrees, TE=10 degrees.

  16. Fuzzy logic in control systems: Fuzzy logic controller. I, II

    NASA Technical Reports Server (NTRS)

    Lee, Chuen Chien

    1990-01-01

    Recent advances in the theory and applications of fuzzy-logic controllers (FLCs) are examined in an analytical review. The fundamental principles of fuzzy sets and fuzzy logic are recalled; the basic FLC components (fuzzification and defuzzification interfaces, knowledge base, and decision-making logic) are described; and the advantages of FLCs for incorporating expert knowledge into a control system are indicated. Particular attention is given to fuzzy implication functions, the interpretation of sentence connectives (and, also), compositional operators, and inference mechanisms. Applications discussed include the FLC-guided automobile developed by Sugeno and Nishida (1985), FLC hardware systems, FLCs for subway trains and ship-loading cranes, fuzzy-logic chips, and fuzzy computers.

  17. The Logic of Reachability

    NASA Technical Reports Server (NTRS)

    Smith, David E.; Jonsson, Ari K.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    In recent years, Graphplan style reachability analysis and mutual exclusion reasoning have been used in many high performance planning systems. While numerous refinements and extensions have been developed, the basic plan graph structure and reasoning mechanisms used in these systems are tied to the very simple STRIPS model of action. In 1999, Smith and Weld generalized the Graphplan methods for reachability and mutex reasoning to allow actions to have differing durations. However, the representation of actions still has some severe limitations that prevent the use of these techniques for many real-world planning systems. In this paper, we 1) separate the logic of reachability from the particular representation and inference methods used in Graphplan, and 2) extend the notions of reachability and mutual exclusion to more general notions of time and action. As it turns out, the general rules for mutual exclusion reasoning take on a remarkably clean and simple form. However, practical instantiations of them turn out to be messy, and require that we make representation and reasoning choices.

  18. Suicide as social logic.

    PubMed

    Kral, M J

    1994-01-01

    Although suicide is not viewed as a mental disorder per se, it is viewed by many if not most clinicians, researchers, and lay people as a real or natural symptom of depression. It is at least most typically seen as the unfortunate, severe, yet logical end result of a chain of negative self-appraisals, negative events, and hopelessness. Extending an approach articulated by the early French sociologist Gabriel Tarde, in this paper I argue that suicide is merely an idea, albeit a very bad one, having more in common with societal beliefs and norms regarding such things as divorce, abortion, sex, politics, consumer behavior, and fashion. I make a sharp contrast between perturbation and lethality, concepts central to Edwin S. Shneidman's theory of suicide. Evidence supportive of suicide as an idea is discussed based on what we are learning from the study of history and culture, and about contagion/cluster phenomena, media/communication, and choice of method. It is suggested that certain individuals are more vulnerable to incorporate the idea and act of suicide into their concepts of self, based on the same principles by which ideas are spread throughout society. Just as suicide impacts on society, so does society impact on suicide.

  19. Formalized Epistemology, Logic, and Grammar

    NASA Astrophysics Data System (ADS)

    Bitbol, Michel

    The task of a formal epistemology is defined. It appears that a formal epistemology must be a generalization of "logic" in the sense of Wittgenstein's Tractatus. The generalization is required because, whereas logic presupposes a strict relation between activity and language, this relation may be broken in some domains of experimental enquiry (e.g., in microscopic physics). However, a formal epistemology should also retain a major feature of Wittgenstein's "logic": It must not be a discourse about scientific knowledge, but rather a way of making manifest the structures usually implicit in knowledge-gaining activity. This strategy is applied to the formalism of quantum mechanics.

  20. Monocular distance estimation with optical flow maneuvers and efference copies: a stability-based strategy.

    PubMed

    de Croon, Guido C H E

    2016-02-01

    The visual cue of optical flow plays an important role in the navigation of flying insects, and is increasingly studied for use by small flying robots as well. A major problem is that successful optical flow control seems to require distance estimates, while optical flow is known to provide only the ratio of velocity to distance. In this article, a novel, stability-based strategy is proposed for monocular distance estimation, relying on optical flow maneuvers and knowledge of the control inputs (efference copies). It is shown analytically that given a fixed control gain, the stability of a constant divergence control loop only depends on the distance to the approached surface. At close distances, the control loop starts to exhibit self-induced oscillations. The robot can detect these oscillations and hence be aware of the distance to the surface. The proposed stability-based strategy for estimating distances has two main attractive characteristics. First, self-induced oscillations can be detected robustly by the robot and are hardly influenced by wind. Second, the distance can be estimated during a zero divergence maneuver, i.e., around hover. The stability-based strategy is implemented and tested both in simulation and on board a Parrot AR drone 2.0. It is shown that the strategy can be used to: (1) trigger a final approach response during a constant divergence landing with fixed gain, (2) estimate the distance in hover, and (3) estimate distances during an entire landing if the robot uses adaptive gain control to continuously stay on the 'edge of oscillation.' PMID:26740501

  1. Monocular distance estimation with optical flow maneuvers and efference copies: a stability-based strategy.

    PubMed

    de Croon, Guido C H E

    2016-01-07

    The visual cue of optical flow plays an important role in the navigation of flying insects, and is increasingly studied for use by small flying robots as well. A major problem is that successful optical flow control seems to require distance estimates, while optical flow is known to provide only the ratio of velocity to distance. In this article, a novel, stability-based strategy is proposed for monocular distance estimation, relying on optical flow maneuvers and knowledge of the control inputs (efference copies). It is shown analytically that given a fixed control gain, the stability of a constant divergence control loop only depends on the distance to the approached surface. At close distances, the control loop starts to exhibit self-induced oscillations. The robot can detect these oscillations and hence be aware of the distance to the surface. The proposed stability-based strategy for estimating distances has two main attractive characteristics. First, self-induced oscillations can be detected robustly by the robot and are hardly influenced by wind. Second, the distance can be estimated during a zero divergence maneuver, i.e., around hover. The stability-based strategy is implemented and tested both in simulation and on board a Parrot AR drone 2.0. It is shown that the strategy can be used to: (1) trigger a final approach response during a constant divergence landing with fixed gain, (2) estimate the distance in hover, and (3) estimate distances during an entire landing if the robot uses adaptive gain control to continuously stay on the 'edge of oscillation.'

  2. Orbit Maneuver Compensation of KAGUYA for Its Safe and Accurate Lunar Transfer

    NASA Astrophysics Data System (ADS)

    Kawakatsu, Yasuhiro; Terada, Hiroshi; Matsuoka, Masatoshi; Ohnishi, Takafumi

    Reported in this paper are the results of the orbit maneuver compensation in KAGUYA's Lunar transfer. Because of the uncoupled allocation of the attitude control thrusters, extra velocity increment (δv ) is induced whenever KAGUYA performs an orbit maneuver. Since the observed level of δv was unacceptable range from the point of maneuver accuracy requirement, it was compensated by means of deducting estimated δv from the orbit maneuver command. The δv estimation model was updated step-by-step during the Lunar transfer, which leaded to significant improvement of the orbit maneuver accuracy and resulted in the omission of the last trajectory correction maneuver. The method of the compensation and its results are introduced in detail.

  3. Cassini Orbit Trim Maneuvers at Saturn - Overview of Attitude Control Flight Operations

    NASA Technical Reports Server (NTRS)

    Burk, Thomas A.

    2011-01-01

    The Cassini spacecraft has been in orbit around Saturn since July 1, 2004. To remain on the planned trajectory which maximizes science data return, Cassini must perform orbit trim maneuvers using either its main engine or its reaction control system thrusters. Over 200 maneuvers have been executed on the spacecraft since arrival at Saturn. To improve performance and maintain spacecraft health, changes have been made in maneuver design command placement, in accelerometer scale factor, and in the pre-aim vector used to align the engine gimbal actuator prior to main engine burn ignition. These and other changes have improved maneuver performance execution errors significantly since 2004. A strategy has been developed to decide whether a main engine maneuver should be performed, or whether the maneuver can be executed using the reaction control system.

  4. A Semi-Empirical Noise Modeling Method for Helicopter Maneuvering Flight Operations

    NASA Technical Reports Server (NTRS)

    Greenwood, Eric; Schmitz, Fredric; Sickenberger, Richard D.

    2012-01-01

    A new model for Blade-Vortex Interaction noise generation during maneuvering flight is developed in this paper. Acoustic and performance data from both flight and wind tunnels are used to derive a non-dimensional and analytical performance/acoustic model that describes BVI noise in steady flight. The model is extended to transient maneuvering flight (pure pitch and roll transients) by using quasisteady assumptions throughout the prescribed maneuvers. Ground noise measurements, taken during maneuvering flight of a Bell 206B helicopter, show that many of the noise radiation details are captured. The result is a computationally efficient Blade-Vortex Interaction noise model with sufficient accuracy to account for transient maneuvering flight. The code can be run in real time to predict transient maneuver noise and is suitable for use in an acoustic mission-planning tool.

  5. Using the Two-Burn Escape Maneuver for Fast Transfers in the Solar System and Beyond

    NASA Technical Reports Server (NTRS)

    Adams, Robert B.; Richardson, Georgia A.

    2010-01-01

    The two-burn maneuver to escape the gravitational pull of a central body is described. The maneuver, originally suggested by Hermann Oberth, improves efficiency considerably for a wide range of missions of interest in space exploration and scientific investigation. A clear delineation of when the maneuver is more effective is given, as are methods to extract the most advantage when using the maneuver. Some examples are given of how this maneuver can enable exploration of the outer solar system, near interstellar space, and crewed missions to Mars and beyond. The maneuver has the potential to halve the required infrastructure associated with a crewed mission to Mars and achieve increased solar escape velocities with existing spacecraft technologies.

  6. Maneuvering Rotorcraft Noise Prediction: A New Code for a New Problem

    NASA Technical Reports Server (NTRS)

    Brentner, Kenneth S.; Bres, Guillaume A.; Perez, Guillaume; Jones, Henry E.

    2002-01-01

    This paper presents the unique aspects of the development of an entirely new maneuver noise prediction code called PSU-WOPWOP. The main focus of the code is the aeroacoustic aspects of the maneuver noise problem, when the aeromechanical input data are provided (namely aircraft and blade motion, blade airloads). The PSU-WOPWOP noise prediction capability was developed for rotors in steady and transient maneuvering flight. Featuring an object-oriented design, the code allows great flexibility for complex rotor configuration and motion (including multiple rotors and full aircraft motion). The relative locations and number of hinges, flexures, and body motions can be arbitrarily specified to match the any specific rotorcraft. An analysis of algorithm efficiency is performed for maneuver noise prediction along with a description of the tradeoffs made specifically for the maneuvering noise problem. Noise predictions for the main rotor of a rotorcraft in steady descent, transient (arrested) descent, hover and a mild "pop-up" maneuver are demonstrated.

  7. Knowledge representation in fuzzy logic

    NASA Technical Reports Server (NTRS)

    Zadeh, Lotfi A.

    1989-01-01

    The author presents a summary of the basic concepts and techniques underlying the application of fuzzy logic to knowledge representation. He then describes a number of examples relating to its use as a computational system for dealing with uncertainty and imprecision in the context of knowledge, meaning, and inference. It is noted that one of the basic aims of fuzzy logic is to provide a computational framework for knowledge representation and inference in an environment of uncertainty and imprecision. In such environments, fuzzy logic is effective when the solutions need not be precise and/or it is acceptable for a conclusion to have a dispositional rather than categorical validity. The importance of fuzzy logic derives from the fact that there are many real-world applications which fit these conditions, especially in the realm of knowledge-based systems for decision-making and control.

  8. Neural nets for adaptive filtering and adaptive pattern recognition

    SciTech Connect

    Widrow, B.; Winter, R.

    1988-03-01

    The fields of adaptive signal processing and adaptive neural networks have been developing independently but have that adaptive linear combiner (ALC) in common. With its inputs connected to a tapped delay line, the ALC becomes a key component of an adaptive filter. With its output connected to a quantizer, the ALC becomes an adaptive threshold element of adaptive neuron. Adaptive threshold elements, on the other hand, are the building blocks of neural networks. Today neural nets are the focus of widespread research interest. Areas of investigation include pattern recognition and trainable logic. Neural network systems have not yet had the commercial impact of adaptive filtering. The commonality of the ALC to adaptive signal processing and adaptive neural networks suggests the two fields have much to share with each other. This article describes practical applications of the ALC in signal processing and pattern recognition.

  9. Differences in glance behavior between drivers using a rearview camera, parking sensor system, both technologies, or no technology during low-speed parking maneuvers.

    PubMed

    Kidd, David G; McCartt, Anne T

    2016-02-01

    This study characterized the use of various fields of view during low-speed parking maneuvers by drivers with a rearview camera, a sensor system, a camera and sensor system combined, or neither technology. Participants performed four different low-speed parking maneuvers five times. Glances to different fields of view the second time through the four maneuvers were coded along with the glance locations at the onset of the audible warning from the sensor system and immediately after the warning for participants in the sensor and camera-plus-sensor conditions. Overall, the results suggest that information from cameras and/or sensor systems is used in place of mirrors and shoulder glances. Participants with a camera, sensor system, or both technologies looked over their shoulders significantly less than participants without technology. Participants with cameras (camera and camera-plus-sensor conditions) used their mirrors significantly less compared with participants without cameras (no-technology and sensor conditions). Participants in the camera-plus-sensor condition looked at the center console/camera display for a smaller percentage of the time during the low-speed maneuvers than participants in the camera condition and glanced more frequently to the center console/camera display immediately after the warning from the sensor system compared with the frequency of glances to this location at warning onset. Although this increase was not statistically significant, the pattern suggests that participants in the camera-plus-sensor condition may have used the warning as a cue to look at the camera display. The observed differences in glance behavior between study groups were illustrated by relating it to the visibility of a 12-15-month-old child-size object. These findings provide evidence that drivers adapt their glance behavior during low-speed parking maneuvers following extended use of rearview cameras and parking sensors, and suggest that other technologies which

  10. Differences in glance behavior between drivers using a rearview camera, parking sensor system, both technologies, or no technology during low-speed parking maneuvers.

    PubMed

    Kidd, David G; McCartt, Anne T

    2016-02-01

    This study characterized the use of various fields of view during low-speed parking maneuvers by drivers with a rearview camera, a sensor system, a camera and sensor system combined, or neither technology. Participants performed four different low-speed parking maneuvers five times. Glances to different fields of view the second time through the four maneuvers were coded along with the glance locations at the onset of the audible warning from the sensor system and immediately after the warning for participants in the sensor and camera-plus-sensor conditions. Overall, the results suggest that information from cameras and/or sensor systems is used in place of mirrors and shoulder glances. Participants with a camera, sensor system, or both technologies looked over their shoulders significantly less than participants without technology. Participants with cameras (camera and camera-plus-sensor conditions) used their mirrors significantly less compared with participants without cameras (no-technology and sensor conditions). Participants in the camera-plus-sensor condition looked at the center console/camera display for a smaller percentage of the time during the low-speed maneuvers than participants in the camera condition and glanced more frequently to the center console/camera display immediately after the warning from the sensor system compared with the frequency of glances to this location at warning onset. Although this increase was not statistically significant, the pattern suggests that participants in the camera-plus-sensor condition may have used the warning as a cue to look at the camera display. The observed differences in glance behavior between study groups were illustrated by relating it to the visibility of a 12-15-month-old child-size object. These findings provide evidence that drivers adapt their glance behavior during low-speed parking maneuvers following extended use of rearview cameras and parking sensors, and suggest that other technologies which

  11. Heat exchanger expert system logic

    NASA Technical Reports Server (NTRS)

    Cormier, R.

    1988-01-01

    The reduction is described of the operation and fault diagnostics of a Deep Space Network heat exchanger to a rule base by the application of propositional calculus to a set of logic statements. The value of this approach lies in the ease of converting the logic and subsequently implementing it on a computer as an expert system. The rule base was written in Process Intelligent Control software.

  12. Fuzzy logic and neural networks

    SciTech Connect

    Loos, J.R.

    1994-11-01

    Combine fuzzy logic`s fuzzy sets, fuzzy operators, fuzzy inference, and fuzzy rules - like defuzzification - with neural networks and you can arrive at very unfuzzy real-time control. Fuzzy logic, cursed with a very whimsical title, simply means multivalued logic, which includes not only the conventional two-valued (true/false) crisp logic, but also the logic of three or more values. This means one can assign logic values of true, false, and somewhere in between. This is where fuzziness comes in. Multi-valued logic avoids the black-and-white, all-or-nothing assignment of true or false to an assertion. Instead, it permits the assignment of shades of gray. When assigning a value of true or false to an assertion, the numbers typically used are {open_quotes}1{close_quotes} or {open_quotes}0{close_quotes}. This is the case for programmed systems. If {open_quotes}0{close_quotes} means {open_quotes}false{close_quotes} and {open_quotes}1{close_quotes} means {open_quotes}true,{close_quotes} then {open_quotes}shades of gray{close_quotes} are any numbers between 0 and 1. Therefore, {open_quotes}nearly true{close_quotes} may be represented by 0.8 or 0.9, {open_quotes}nearly false{close_quotes} may be represented by 0.1 or 0.2, and {close_quotes}your guess is as good as mine{close_quotes} may be represented by 0.5. The flexibility available to one is limitless. One can associate any meaning, such as {open_quotes}nearly true{close_quotes}, to any value of any granularity, such as 0.9999. 2 figs.

  13. Optically controllable molecular logic circuits

    SciTech Connect

    Nishimura, Takahiro Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-07-06

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  14. Computing and Visualizing Reachable Volumes for Maneuvering Satellites

    SciTech Connect

    Jiang, M; de Vries, W H; Pertica, A J; Olivier, S S

    2011-09-11

    Detecting and predicting maneuvering satellites is an important problem for Space Situational Awareness. The spatial envelope of all possible locations within reach of such a maneuvering satellite is known as the Reachable Volume (RV). As soon as custody of a satellite is lost, calculating the RV and its subsequent time evolution is a critical component in the rapid recovery of the satellite. In this paper, we present a Monte Carlo approach to computing the RV for a given object. Essentially, our approach samples all possible trajectories by randomizing thrust-vectors, thrust magnitudes and time of burn. At any given instance, the distribution of the 'point-cloud' of the virtual particles defines the RV. For short orbital time-scales, the temporal evolution of the point-cloud can result in complex, multi-reentrant manifolds. Visualization plays an important role in gaining insight and understanding into this complex and evolving manifold. In the second part of this paper, we focus on how to effectively visualize the large number of virtual trajectories and the computed RV. We present a real-time out-of-core rendering technique for visualizing the large number of virtual trajectories. We also examine different techniques for visualizing the computed volume of probability density distribution, including volume slicing, convex hull and isosurfacing. We compare and contrast these techniques in terms of computational cost and visualization effectiveness, and describe the main implementation issues encountered during our development process. Finally, we will present some of the results from our end-to-end system for computing and visualizing RVs using examples of maneuvering satellites.

  15. Command shaping for residual vibration free crane maneuvers

    SciTech Connect

    Parker, G.G.; Petterson, B.; Dohrmann, C.; Robinett, R.D.

    1995-07-01

    Cranes used in the construction and transportation industries are generally devices with multiple degrees of freedom including variable load-line length, variable jib length (usually via a trolley), and variable boom angles. Point-to-point payload maneuvers using cranes are performed so as not to excite the spherical pendulum modes of their cable and payload assemblies. Typically, these pendulum modes, although time-varying, exhibit low frequencies. Current crane maneuvers are therefore performed slowly contributing to high construction and transportation costs. This investigation details a general method for applying command shaping to various multiple degree of freedom cranes such that the payload moves to a specified point without residual oscillation. A dynamic programming method is used for general command shaping for optimal maneuvers. Computationally, the dynamic programming approach requires order M calculations to arrive at a solution, where M is the number of discretizations of the input commands. This feature is exploited for the crane command shaping problem allowing for rapid calculation of command histories. Fast generation of commands is a necessity for practical use of command shaping for the applications described in this work. These results are compared to near-optimal solutions where the commands are linear combinations of acceleration pulse basis functions. The pulse shape is required due to hardware requirements. The weights on the basis functions are chosen as the solution to a parameter optimization problem solved using a Recursive Quadratic Programming technique. Simulation results and experimental verification for a variable load-line length rotary crane are presented using both design procedures.

  16. Parallel Anisotropic Tetrahedral Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Darmofal, David L.

    2008-01-01

    An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

  17. Development of a Smooth Trajectory Maneuver Method to Accommodate the Ares I Flight Control Constraints

    NASA Technical Reports Server (NTRS)

    Pinson, Robin M.; Schmitt, Terri L.; Hanson, John M.

    2008-01-01

    Six degree-of-freedom (DOF) launch vehicle trajectories are designed to follow an optimized 3-DOF reference trajectory. A vehicle has a finite amount of control power that it can allocate to performing maneuvers. Therefore, the 3-DOF trajectory must be designed to refrain from using 100% of the allowable control capability to perform maneuvers, saving control power for handling off-nominal conditions, wind gusts and other perturbations. During the Ares I trajectory analysis, two maneuvers were found to be hard for the control system to implement; a roll maneuver prior to the gravity turn and an angle of attack maneuver immediately after the J-2X engine start-up. It was decided to develop an approach for creating smooth maneuvers in the optimized reference trajectories that accounts for the thrust available from the engines. A feature of this method is that no additional angular velocity in the direction of the maneuver has been added to the vehicle after the maneuver completion. This paper discusses the equations behind these new maneuvers and their implementation into the Ares I trajectory design cycle. Also discussed is a possible extension to adjusting closed-loop guidance.

  18. Development of control laws for a flight test maneuver autopilot for an F-15 aircraft

    NASA Technical Reports Server (NTRS)

    Alag, G. S.; Duke, E. L.

    1985-01-01

    An autopilot can be used to provide precise control to meet the demanding requirements of flight research maneuvers with high-performance aircraft. The development of control laws within the context of flight test maneuver requirements is discussed. The control laws are developed using eigensystem assignment and command generator tracking. The eigenvalues and eigenvectors are chosen to provide the necessary handling qualities, while the command generator tracking enables the tracking of a specified state during the maneuver. The effectiveness of the control laws is illustrated by their application to an F-15 aircraft to ensure acceptable aircraft performance during a maneuver.

  19. Analysis of Transfer Maneuvers from Initial Circular Orbit to a Final Circular or Elliptic Orbit

    NASA Astrophysics Data System (ADS)

    Sharaf, M. A.; Saad, A. S.

    2016-04-01

    In the present paper an analysis of the transfer maneuvers from initial circular orbit to a final circular or elliptic orbit was developed to study the problem of impulsive transfers for space missions. It considers planar maneuvers using newly derived equations. With these equations, comparisons of circular and elliptic maneuvers are made. This comparison is important for the mission designers to obtain useful mappings showing where one maneuver is better than the other. In this aspect, we developed this comparison throughout ten results, together with some graphs to show their meaning.

  20. Space Shuttle OMS engine valve technology. [Orbital Maneuvering System

    NASA Technical Reports Server (NTRS)

    Wichmann, H.

    1974-01-01

    Valve technology program to determine shutoff valve concepts suitable for the Orbital Maneuvering System (OMS) engine of the Space Shuttle. The tradeoff studies selected the electric torque motor operated dual poppet and ball valves as the most desirable valve concepts for the OMS Engine Shutoff Valve. A prototype of one of these concepts was built and subjected to a design verification program. A number of unique features were designed to include the required contamination insensitivity, operating fluid compatibility, decontamination capability, minimum maintenance requirement and long service life capability.

  1. Sequential Probability Ratio Test for Collision Avoidance Maneuver Decisions

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Markley, F. Landis

    2010-01-01

    When facing a conjunction between space objects, decision makers must chose whether to maneuver for collision avoidance or not. We apply a well-known decision procedure, the sequential probability ratio test, to this problem. We propose two approaches to the problem solution, one based on a frequentist method, and the other on a Bayesian method. The frequentist method does not require any prior knowledge concerning the conjunction, while the Bayesian method assumes knowledge of prior probability densities. Our results show that both methods achieve desired missed detection rates, but the frequentist method's false alarm performance is inferior to the Bayesian method's

  2. The aerodynamics of free-flight maneuvers in Drosophila.

    PubMed

    Fry, Steven N; Sayaman, Rosalyn; Dickinson, Michael H

    2003-04-18

    Using three-dimensional infrared high-speed video, we captured the wing and body kinematics of free-flying fruit flies as they performed rapid flight maneuvers. We then "replayed" the wing kinematics on a dynamically scaled robotic model to measure the aerodynamic forces produced by the wings. The results show that a fly generates rapid turns with surprisingly subtle modifications in wing motion, which nonetheless generate sufficient torque for the fly to rotate its body through each turn. The magnitude and time course of the torque and body motion during rapid turns indicate that inertia, not friction, dominates the flight dynamics of insects.

  3. Pseudosteady-state analysis of nonlinear aircraft maneuvers

    NASA Technical Reports Server (NTRS)

    Young, J. W.; Schy, A. A.; Johnson, K. G.

    1980-01-01

    An analytical method was developed for studying the combined effects of rotational coupling and nonlinear aerodynamics on aircraft response for specified control inputs. The method involves the simultaneous solution of two nonlinear equations which are functions of angle attack, roll rate, and control inputs. The method was applied to a number of maneuvers for a fighter-type aircraft. Time history responses verified the usefulness of the analysis for predicting a variety of response characteristics caused by interacting nonlinear aerodynamic and inertial effects, including spin conditions.

  4. Near Earth Asteroid redirect missions based on gravity assist maneuver

    NASA Astrophysics Data System (ADS)

    Ledkov, Anton; Shustov, Boris M.; Eismont, Natan; Boyarsky, Michael; Nazirov, Ravil; Fedyaev, Konstantin

    During last years several events attracted world community attention to the hazards of hitting the Earth by sky objects. One of these objects is Apophis asteroid what was expected with nonzero probability to hit the Earth in 2036. Luckily after more precise measurements this event is considered as practically improbable. But the other object has really reached the Earth, entered the atmosphere in the Chelyabinsk area and caused vast damages. After this the hazardous near Earth objects problem received practical confirmation of the necessity to find the methods of its resolution. The methods to prevent collision of the dangerous sky object with the Earth proposed up to now look not practical enough if one mentions such as gravitational tractor or changing the reflectivity of the asteroid surface. Even the method supposing the targeting of the spacecraft to the hazardous object in order to deflect it from initial trajectory by impact does not work because its low mass as compared with the mass of asteroid to be deflected. For example the mass of the Apophis is estimated to be about 40 million tons but the spacecraft which can be launched to intercept the asteroid using contemporary launchers has the mass not more than 5 tons. So the question arises where to find the heavier projectile which is possible to direct to the dangerous object? The answer proposed in our paper is very simple: to search it among small near Earth asteroids. As small ones we suppose those which have the cross section size not more than 12-15 meters and mass not exceeding 1500 -1700 tons. According to contemporary estimates the number of such asteroids is not less than 100000. The other question is how to redirect such asteroid to the dangerous one. In the paper the possibilities are studied to use for that purpose gravity assist maneuvers near Earth. It is shown that even among asteroids included in contemporary catalogue there are the ones which could be directed to the trajectory of the

  5. The Orbital Maneuvering Vehicle Training Facility visual system concept

    NASA Technical Reports Server (NTRS)

    Williams, Keith

    1989-01-01

    The purpose of the Orbital Maneuvering Vehicle (OMV) Training Facility (OTF) is to provide effective training for OMV pilots. A critical part of the training environment is the Visual System, which will simulate the video scenes produced by the OMV Closed-Circuit Television (CCTV) system. The simulation will include camera models, dynamic target models, moving appendages, and scene degradation due to the compression/decompression of video signal. Video system malfunctions will also be provided to ensure that the pilot is ready to meet all challenges the real-world might provide. One possible visual system configuration for the training facility that will meet existing requirements is described.

  6. Error Analysis and Trajectory Correction Maneuvers of Lunar Transfer Orbit

    NASA Astrophysics Data System (ADS)

    Zhao, Yu-hui; Hou, Xi-yun; Liu, Lin

    2013-10-01

    For a returnable lunar probe, this paper studies the characteristics of both the Earth-Moon transfer orbit and the return orbit. On the basis of the error propagation matrix, the linear equation to estimate the first midcourse trajectory correction maneuver (TCM) is figured out. Numerical simulations are performed, and the features of error propagation in lunar transfer orbit are given. The advantages, disadvantages, and applications of two TCM strategies are discussed, and the computation of the second TCM of the return orbit is also simulated under the conditions at the reentry time.

  7. Error Analysis and Trajectory Correction Maneuvers of Lunar Transfer Orbit

    NASA Astrophysics Data System (ADS)

    Zhao, Y. H.; Hou, X. Y.; Liu, L.

    2013-05-01

    For the sample return lunar missions and human lunar exploration, this paper studies the characteristics of both the Earth-Moon transfer orbit and the return orbit. On the basis of the error propagation matrix, the linear equation to estimate the first midcourse trajectory correction maneuver (TCM) is figured out. Numerical simulations are performed, and the features of error propagation in lunar transfer orbit are given. The advantages, disadvantages, and applications of two TCM strategies are discussed, and the computation of the second TCM of the return orbit is also simulated under the conditions at the reentry time.

  8. Flight simulator fidelity assessment in a rotorcraft lateral translation maneuver

    NASA Technical Reports Server (NTRS)

    Hess, R. A.; Malsbury, T.; Atencio, A., Jr.

    1992-01-01

    A model-based methodology for assessing flight simulator fidelity in closed-loop fashion is exercised in analyzing a rotorcraft low-altitude maneuver for which flight test and simulation results were available. The addition of a handling qualities sensitivity function to a previously developed model-based assessment criteria allows an analytical comparison of both performance and handling qualities between simulation and flight test. Model predictions regarding the existence of simulator fidelity problems are corroborated by experiment. The modeling approach is used to assess analytically the effects of modifying simulator characteristics on simulator fidelity.

  9. Safe Maneuvering Envelope Estimation Based on a Physical Approach

    NASA Technical Reports Server (NTRS)

    Lombaerts, Thomas J. J.; Schuet, Stefan R.; Wheeler, Kevin R.; Acosta, Diana; Kaneshige, John T.

    2013-01-01

    This paper discusses a computationally efficient algorithm for estimating the safe maneuvering envelope of damaged aircraft. The algorithm performs a robust reachability analysis through an optimal control formulation while making use of time scale separation and taking into account uncertainties in the aerodynamic derivatives. This approach differs from others since it is physically inspired. This more transparent approach allows interpreting data in each step, and it is assumed that these physical models based upon flight dynamics theory will therefore facilitate certification for future real life applications.

  10. OMV: A simplified mathematical model of the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Teoh, W.

    1984-01-01

    A model of the orbital maneuvering vehicle (OMV) is presented which contains several simplications. A set of hand controller signals may be used to control the motion of the OMV. Model verification is carried out using a sequence of tests. The dynamic variables generated by the model are compared, whenever possible, with the corresponding analytical variables. The results of the tests show conclusively that the present model is behaving correctly. Further, this model interfaces properly with the state vector transformation module (SVX) developed previously. Correct command sentence sequences are generated by the OMV and and SVX system, and these command sequences can be used to drive the flat floor simulation system at MSFC.

  11. Application of linear logic to simulation

    NASA Astrophysics Data System (ADS)

    Clarke, Thomas L.

    1998-08-01

    Linear logic, since its introduction by Girard in 1987 has proven expressive and powerful. Linear logic has provided natural encodings of Turing machines, Petri nets and other computational models. Linear logic is also capable of naturally modeling resource dependent aspects of reasoning. The distinguishing characteristic of linear logic is that it accounts for resources; two instances of the same variable are considered differently from a single instance. Linear logic thus must obey a form of the linear superposition principle. A proportion can be reasoned with only once, unless a special operator is applied. Informally, linear logic distinguishes two kinds of conjunction, two kinds of disjunction, and also introduces a modal storage operator that explicitly indicates propositions that can be reused. This paper discuses the application of linear logic to simulation. A wide variety of logics have been developed; in addition to classical logic, there are fuzzy logics, affine logics, quantum logics, etc. All of these have found application in simulations of one sort or another. The special characteristics of linear logic and its benefits for simulation will be discussed. Of particular interest is a connection that can be made between linear logic and simulated dynamics by using the concept of Lie algebras and Lie groups. Lie groups provide the connection between the exponential modal storage operators of linear logic and the eigen functions of dynamic differential operators. Particularly suggestive are possible relations between complexity result for linear logic and non-computability results for dynamical systems.

  12. Fuzzy logic control of an AGV

    NASA Astrophysics Data System (ADS)

    Kelkar, Nikhal; Samu, Tayib; Hall, Ernest L.

    1997-09-01

    Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of a modular autonomous mobile robot controller. The controller incorporates a fuzzy logic approach for steering and speed control, a neuro-fuzzy approach for ultrasound sensing (not discussed in this paper) and an overall expert system. The advantages of a modular system are related to portability and transportability, i.e. any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. This cart has full speed control with guidance provided by a vision system and obstacle avoidance using ultrasonic sensors. The speed and steering fuzzy logic controller is supervised by a 486 computer through a multi-axis motion controller. The obstacle avoidance system is based on a micro-controller interfaced with six ultrasonic transducers. This micro- controller independently handles all timing and distance calculations and sends a steering angle correction back to the computer via the serial line. This design yields a portable independent system in which high speed computer communication is not necessary. Vision guidance is accomplished with a CCD camera with a zoom lens. The data is collected by a vision tracking device that transmits the X, Y coordinates of the lane marker to the control computer. Simulation and testing of these systems yielded promising results. This design, in its modularity, creates a portable autonomous fuzzy logic controller applicable to any mobile vehicle with only minor adaptations.

  13. Fuzzy logic control of telerobot manipulators

    NASA Technical Reports Server (NTRS)

    Franke, Ernest A.; Nedungadi, Ashok

    1992-01-01

    Telerobot systems for advanced applications will require manipulators with redundant 'degrees of freedom' (DOF) that are capable of adapting manipulator configurations to avoid obstacles while achieving the user specified goal. Conventional methods for control of manipulators (based on solution of the inverse kinematics) cannot be easily extended to these situations. Fuzzy logic control offers a possible solution to these needs. A current research program at SRI developed a fuzzy logic controller for a redundant, 4 DOF, planar manipulator. The manipulator end point trajectory can be specified by either a computer program (robot mode) or by manual input (teleoperator). The approach used expresses end-point error and the location of manipulator joints as fuzzy variables. Joint motions are determined by a fuzzy rule set without requiring solution of the inverse kinematics. Additional rules for sensor data, obstacle avoidance and preferred manipulator configuration, e.g., 'righty' or 'lefty', are easily accommodated. The procedure used to generate the fuzzy rules can be extended to higher DOF systems.

  14. SRMS Assisted Docking and Undocking for the Orbiter Repair Maneuver

    NASA Technical Reports Server (NTRS)

    Quiocho, Leslie J.; Briscoe, Timothy J.; Schliesing, John A.; Braman, Julia M.

    2005-01-01

    As part of the Orbiter Repair Maneuver (ORM) planned for Return to Flight (RTF) operations, the Shuttle Remote Manipulator System (SRMS) must undock the Orbiter, maneuver it through a complex trajectory at extremely low rates, present it to an EVA crewman at the end of the Space Station Remote Manipulator System to perform the Thermal Protection System (TPS) repair, and then retrace back through the trajectory to dock the Orbiter with the Orbiter Docking System (ODs). The initial and final segments of this operation involve the interaction between the SRMS, ISS, Orbiter and ODs. This paper first provides an overview of the Monte-Carlo screening analysis for the installation (both nominal and contingency), including the variation of separation distance, misalignment conditions, SRMS joint/brake parameter characteristics, and PRCS jet combinations and corresponding thrust durations. The resulting 'optimum' solution is presented based on trade studies between predicted capture success and integrated system loads. This paper then discusses the upgrades to the APAS math model associated with the new SRMS assisted undocking technique and reviews simulation results for various options investigated for either the active and passive separation of the ISS from the Orbiter.

  15. Robust Aerial Object Tracking in High Dynamic Flight Maneuvers

    NASA Astrophysics Data System (ADS)

    Nussberger, A.; Grabner, H.; van Gool, L.

    2015-08-01

    Integrating drones into the civil airspace is one of the biggest challenges for civil aviation, responsible authorities and involved com- panies around the world in the upcoming years. For a full integration into non-segregated airspace such a system has to provide the capability to automatically detect and avoid other airspace users. Electro-optical cameras have proven to be an adequate sensor to detect all types of aerial objects, especially for smaller ones such as gliders or paragliders. Robust detection and tracking of approaching traffic on a potential collision course is the key component for a successful avoidance maneuver. In this paper we focus on the aerial object tracking during dynamic flight maneuvers of the own-ship where accurate attitude information corresponding to the camera images is essential. Because the 'detect and avoid' functionality typically extends existing autopilot systems the received attitude measurements have unknown delays and dynamics. We present an efficient method to calculate the angular rates from a multi camera rig which we fuse with the delayed attitude measurements. This allows for estimating accurate absolute attitude angles for every camera frame. The proposed method is further integrated into an aerial object tracking framework. A detailed evaluation of the pipeline on real collision encounter scenarios shows that the multi camera rig based attitude estimation enables the correct tracking of approaching traffic during dynamic flight, at which the tracking framework previously failed.

  16. Synthetic C-start maneuver in fish-like swimming

    NASA Astrophysics Data System (ADS)

    Zenit, R.; Godoy-Diana, R.

    2013-11-01

    We investigate the mechanics of the unsteady fish-like swimming maneuver using a simplified experimental model in a water tank. A flexible foil (which emulates the fish body) is impulsively actuated by rotating a cylindrical rod that holds the foil. This rod constitutes the head of the swimmer and is mounted through the shaft of the driving motor on an rail with an air bearing. The foil is initially positioned at a start angle and then rapidly rotated to a final angle, which coincides with the free-moving direction of the rail. As the foil rotates, it pushes the surrounding fluid, it deforms and stores elastic energy which drive the recovery of the straight body shape after the motor actuation has stopped; during the rotation, a trust force is induced which accelerates the array. We measure the resulting escape velocity and acceleration as a function of the beam stiffness, size, initial angle, etc. Some measurements of the velocity field during the escape were obtained using a PIV technique. The measurements agree well with a simple mechanical model that quantifies the impulse of the maneuver. The objective of this work is to understand the fundamental mechanisms of thrust generation in unsteady fast-start swimming. We acknowledge support of EADS Foundation through the project ``Fluids and elasticity in biomimetic propulsion'' and of the Chaire Total for RZ as a visiting professor at ESPCI ParisTech.

  17. Orbital maneuvering vehicle teleoperation and video data compression

    NASA Technical Reports Server (NTRS)

    Jones, Steve

    1989-01-01

    The Orbital Maneuvering Vehicle (OMV) and concepts of teleoperation and video data compression as applied to OMV design and operation are described. The OMV provides spacecraft delivery, retrieval, reboost, deboost and viewing services, with ground-control or Space Station operation, through autonomous navigation and pilot controlled maneuvers. Communications systems are comprised of S-band RF command, telemetry, and compressed video data links through the TDRSS and GSTDN networks. The control console video monitors display a monochrome image at an update rate of five frames per second. Depending upon the mode of operation selected by the pilot, the video resolution is either 255 x 244 pixels, or 510 x 244 pixels. Since practically all video image redundancy is removed by the compression process, the video reconstruction is particularly sensitive to data transmission bit errors. Concatenated Reed-Solomon and convolution coding are used with helical data interleaving for error detection and correction, and an error-containment process minimizes the propagation of error effects throughout the video image. Video sub-frame replacement is used, in the case of a non-correctable error or error burst, to minimize the visual impact to the pilot.

  18. Propulsive Maneuver Design for the 2007 Mars Phoenix Lander Mission

    NASA Technical Reports Server (NTRS)

    Raofi, Behzad; Bhat, Ramachandra S.; Helfrich, Cliff

    2008-01-01

    On May 25, 2008, the Mars Phoenix Lander (PHX) successfully landed in the northern planes of Mars in order to continue and complement NASA's "follow the water" theme as its predecessor Mars missions, such as Mars Odyssey (ODY) and Mars Exploration Rovers, have done in recent years. Instruments on the lander, through a robotic arm able to deliver soil samples to the deck, will perform in-situ and remote-sensing investigations to characterize the chemistry of materials at the local surface, subsurface, and atmosphere. Lander instruments will also identify the potential history of key indicator elements of significance to the biological potential of Mars, including potential organics within any accessible water ice. Precise trajectory control and targeting were necessary in order to achieve the accurate atmospheric entry conditions required for arriving at the desired landing site. The challenge for the trajectory control maneuver design was to meet or exceed these requirements in the presence of spacecraft limitations as well as other mission constraints. This paper describes the strategies used, including the specialized targeting specifically developed for PHX, in order to design and successfully execute the propulsive maneuvers that delivered the spacecraft to its targeted landing site while satisfying the planetary protection requirements in the presence of flight system constraints.

  19. Control and dynamics of a flexible spacecraft during stationkeeping maneuvers

    NASA Technical Reports Server (NTRS)

    Liu, D.; Yocum, J.; Kang, D. S.

    1991-01-01

    A case study of a spacecraft having flexible solar arrays is presented. A stationkeeping attitude control mode using both earth and rate gyro reference signals and a flexible vehicle dynamics modeling and implementation is discussed. The control system is designed to achieve both pointing accuracy and structural mode stability during stationkeeping maneuvers. Reduction of structural mode interactions over the entire mode duration is presented. The control mode using a discrete time observer structure is described to show the convergence of the spacecraft attitude transients during Delta-V thrusting maneuvers without preloading thrusting bias to the onboard control processor. The simulation performance using the three axis, body stabilized nonlinear dynamics is provided. The details of a five body dynamics model are discussed. The spacecraft is modeled as a central rigid body having cantilevered flexible antennas, a pair of flexible articulated solar arrays, and to gimballed momentum wheels. The vehicle is free to undergo unrestricted rotations and translations relative to inertial space. A direct implementation of the equations of motion is compared to an indirect implementation that uses a symbolic manipulation software to generate rigid body equations.

  20. Independent Orbiter Assessment (IOA): Analysis of the manned maneuvering unit

    NASA Technical Reports Server (NTRS)

    Bailey, P. S.

    1986-01-01

    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 (PCIs). To preserve indepedence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Manned Maneuvering Unit (MMU) hardware. The MMU is a propulsive backpack, operated through separate hand controllers that input the pilot's translational and rotational maneuvering commands to the control electronics and then to the thrusters. The IOA analysis process utilized available MMU hardware drawings and schematics for defining hardware subsystems, assemblies, components, and hardware items. Final levels of detail were evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the worst case severity of the effect for each identified failure mode. The IOA analysis of the MMU found that the majority of the PCIs identified are resultant from the loss of either the propulsion or control functions, or are resultant from inability to perform an immediate or future mission. The five most severe criticalities identified are all resultant from failures imposed on the MMU hand controllers which have no redundancy within the MMU.

  1. Valsalva maneuver: Insights into baroreflex modulation of human sympathetic activity

    NASA Technical Reports Server (NTRS)

    Smith, Michael L.; Eckberg, Dwain L.; Fritsch, Janice M.; Beightol, Larry A.; Ellenbogen, Kenneth A.

    1991-01-01

    Valsalva's maneuver, voluntary forced expiration against a closed glottis, is a well-characterized research tool, used to assess the integrity of human autonomic cardiovascular control. Valsalva straining provokes a stereotyped succession of alternating positive and negative arterial pressure and heart rate changes mediated in part by arterial baroreceptors. Arterial pressure changes result primarily from fluctuating levels of venous return to the heart and changes of sympathetic nerve activity. Muscle sympathetic activity was measured directly in nine volunteers to explore quantitatively the relation between arterial pressure and human sympathetic outflow during pressure transients provoked by controlled graded Valsalva maneuvers. Our results underscore several properties of sympathetic regulation during Valsalva straining. First, muscle sympathetic nerve activity changes as a mirror image of changes in arterial pressure. Second, the magnitude of sympathetic augmentation during Valsalva straining predicts phase 4 arterial pressure elevations. Third, post-Valsalva sympathetic inhibition persists beyond the return of arterial and right atrial pressures to baseline levels which reflects an alteration of the normal relation between arterial pressure and muscle sympathetic activity. Therefore, Valsalva straining may have some utility for investigating changes of reflex control of sympathetic activity after space flight; however, measurement of beat-to-beat arterial pressure is essential for this use. The utility of this technique in microgravity can not be determined from these data. Further investigations are necessary to determine whether these relations are affected by the expansion of intrathoracic blood volume associated with microgravity.

  2. Control System and Flexible Satellite Interaction During Orbit Transfer Maneuver

    NASA Technical Reports Server (NTRS)

    daSilva, Adenilson Roberto; GadelhadeSouza, Luiz Carlos

    1998-01-01

    In this paper the interaction between the attitude control system and the flexible structure of an artificial satellite during orbit transfer maneuver has been investigated. The satellite was modeled by a rigid central body with one or more flexible appendages. The dynamics equations were obtained by Lagrangean approach. The flexible appendages were treated as clamped-free beam and its displacement was discretized by assumed- mode method. In order to transfer the satellite, a typical Hohmann transfer and a burn-coast-burn strategy were used and the attitude was controlled by an on-off controller. During transfer procedure a global analysis of satellite has been done, such as: performance of control system, influence of elastic response in control system, thruster firing frequency, fuel consumption and variation of orbital elements. In order to avoid the interaction with structure motion, a control system with bandwidth of one decade bellow the fundamental frequency was used. In the simulations the firing frequency was evaluated in an approximately way but kept below the fundamental frequency of the structure. The control system has kept the attitude below the specifications. As a result, the orbit transfer maneuvering has been done correctly without excessive excitation of flexible appendage.

  3. Independent Orbiter Assessment (IOA): Analysis of the orbital maneuvering system

    NASA Technical Reports Server (NTRS)

    Prust, C. D.; Paul, D. J.; Burkemper, V. J.

    1987-01-01

    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 Orbital Maneuvering System (OMS) hardware are documented. The OMS provides the thrust to perform orbit insertion, orbit circularization, orbit transfer, rendezvous, and deorbit. The OMS is housed in two independent pods located one on each side of the tail and consists of the following subsystems: Helium Pressurization; Propellant Storage and Distribution; Orbital Maneuvering Engine; and Electrical Power Distribution and Control. The IOA analysis process utilized available OMS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluted and analyzed for possible failure modes and effects. Criticality was asigned based upon the severity of the effect for each failure mode.

  4. Single and dual burn maneuvers for low earth orbit maintenance

    NASA Astrophysics Data System (ADS)

    Hernandez, Andrew A.

    1994-12-01

    Optimal control theory suggests maintaining an orbital altitude band for Low-Earth-Orbiting (LEO) satellites using periodic thrusting than forced Keplerian motion, i.e. a trajectory obtained by thrust-drag cancellation. Designing guidance algorithm for orbit maintenance is complicated by the nonlinearities associated with orbital motion. An algorithm developed previously using thrusters firing significantly off the direction of motion successfully maintains an orbital band, but is very inefficient. This thesis develops two different control strategies based on the osculating orbital parameters. taking a conservative approach to keeping within altitude limitations. Thrust is in the local horizontal plane along the direction of flight. Single and dual burn maneuvers are considered for various bandwidths and thruster sizes. The dual burn strategy is somewhat close to a Hohmann transfer. The specified orbital band is generally maintained, with some cases slightly exceeding the upper limit. Propellant consumptions for both maneuvers is significantly better than previous methods. This thesis shows that forward firing thrusters can be used with osculating orbital parameters to obtain efficiencies within forced Keplerian motion values.

  5. Learning evasive maneuvers using evolutionary algorithms and neural networks

    NASA Astrophysics Data System (ADS)

    Kang, Moung Hung

    In this research, evolutionary algorithms and recurrent neural networks are combined to evolve control knowledge to help pilots avoid being struck by a missile, based on a two-dimensional air combat simulation model. The recurrent neural network is used for representing the pilot's control knowledge and evolutionary algorithms (i.e., Genetic Algorithms, Evolution Strategies, and Evolutionary Programming) are used for optimizing the weights and/or topology of the recurrent neural network. The simulation model of the two-dimensional evasive maneuver problem evolved is used for evaluating the performance of the recurrent neural network. Five typical air combat conditions were selected to evaluate the performance of the recurrent neural networks evolved by the evolutionary algorithms. Analysis of Variance (ANOVA) tests and response graphs were used to analyze the results. Overall, there was little difference in the performance of the three evolutionary algorithms used to evolve the control knowledge. However, the number of generations of each algorithm required to obtain the best performance was significantly different. ES converges the fastest, followed by EP and then by GA. The recurrent neural networks evolved by the evolutionary algorithms provided better performance than the traditional recommendations for evasive maneuvers, maximum gravitational turn, for each air combat condition. Furthermore, the recommended actions of the recurrent neural networks are reasonable and can be used for pilot training.

  6. Adaptive Controller Adaptation Time and Available Control Authority Effects on Piloting

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna; Gregory, Irene

    2013-01-01

    Adaptive control is considered for highly uncertain, and potentially unpredictable, flight dynamics characteristic of adverse conditions. This experiment looked at how adaptive controller adaptation time to recover nominal aircraft dynamics affects pilots and how pilots want information about available control authority transmitted. Results indicate that an adaptive controller that takes three seconds to adapt helped pilots when looking at lateral and longitudinal errors. The controllability ratings improved with the adaptive controller, again the most for the three seconds adaptation time while workload decreased with the adaptive controller. The effects of the displays showing the percentage amount of available safe flight envelope used in the maneuver were dominated by the adaptation time. With the displays, the altitude error increased, controllability slightly decreased, and mental demand increased. Therefore, the displays did require some of the subjects resources but these negatives may be outweighed by pilots having more situation awareness of their aircraft.

  7. Applying Dynamical Systems Theory to Optimize Libration Point Orbit Stationkeeping Maneuvers for WIND

    NASA Technical Reports Server (NTRS)

    Brown, Jonathan M.; Petersen, Jeremy D.

    2014-01-01

    NASA's WIND mission has been operating in a large amplitude Lissajous orbit in the vicinity of the interior libration point of the Sun-Earth/Moon system since 2004. Regular stationkeeping maneuvers are required to maintain the orbit due to the instability around the collinear libration points. Historically these stationkeeping maneuvers have been performed by applying an incremental change in velocity, or (delta)v along the spacecraft-Sun vector as projected into the ecliptic plane. Previous studies have shown that the magnitude of libration point stationkeeping maneuvers can be minimized by applying the (delta)v in the direction of the local stable manifold found using dynamical systems theory. This paper presents the analysis of this new maneuver strategy which shows that the magnitude of stationkeeping maneuvers can be decreased by 5 to 25 percent, depending on the location in the orbit where the maneuver is performed. The implementation of the optimized maneuver method into operations is discussed and results are presented for the first two optimized stationkeeping maneuvers executed by WIND.

  8. Modeling helicopter near-horizon harmonic noise due to transient maneuvers

    NASA Astrophysics Data System (ADS)

    Sickenberger, Richard D.

    A new first principles model has been developed to estimate the external harmonic noise radiation for a helicopter performing transient maneuvers in the longitudinal plane. This model, which simulates the longitudinal fuselage dynamics, main rotor blade flapping, and far field acoustics, was validated using in-flight measurements and recordings from ground microphones during a full-scale flight test featuring a Bell 206B-3 helicopter. The flight test was specifically designed to study transient maneuvers. The validated model demonstrated that the flapping of the main rotor blades does not significantly affect the acoustics radiated by the helicopter during maneuvering flight. Furthermore, the model also demonstrated that Quasi-Static Acoustic Mapping (Q-SAM) methods can be used to reliably predict the noise radiated during transient maneuvers. The model was also used to identify and quantify the contributions of main rotor thickness noise, low frequency loading noise, and blade-vortex interaction (BVI) noise during maneuvering flight for the Bell 206B-3 helicopter. Pull-up and push-over maneuvers from pure longitudinal cyclic and pure collective control inputs were investigated. The contribution of thickness noise and low frequency loading noise during maneuvering flight was found to depend on the orientation of the tip-path plane relative to the observer. The contribution of impulsive BVI noise during maneuvering flight was found to depend on the inflow through the main rotor and the orientation of the tip-path plane relative to the observer.

  9. 46 CFR 35.20-40 - Maneuvering characteristics-T/OC.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Maneuvering characteristics-T/OC. 35.20-40 Section 35.20-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Navigation § 35.20-40 Maneuvering characteristics—T/OC. For each ocean and coastwise tankship of 1,600 gross tons...

  10. 32 CFR Appendix C to Part 552 - Authorized Activities for Fort Lewis Maneuver Area Access

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Authorized Activities for Fort Lewis Maneuver Area Access C Appendix C to Part 552 National Defense Department of Defense (Continued) DEPARTMENT OF.... 552, App. C Appendix C to Part 552—Authorized Activities for Fort Lewis Maneuver Area Access...

  11. Detail view of the "underside" of the Orbiter Maneuvering/Reaction Control ...

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

    Detail view of the "underside" of the Orbiter Maneuvering/Reaction Control Systems pod looking at the two spherical propellant tanks for the Reaction Control System, and the elongated propellant tanks for the Orbiter Maneuvering System. This view was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  12. 32 CFR 552.38 - Acquisition of maneuver agreements for Army commanders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Acquisition of maneuver agreements for Army commanders. 552.38 Section 552.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Real Estate and Interest Therein § 552.38 Acquisition of maneuver agreements for Army commanders....

  13. 32 CFR 552.38 - Acquisition of maneuver agreements for Army commanders.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Acquisition of maneuver agreements for Army commanders. 552.38 Section 552.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Real Estate and Interest Therein § 552.38 Acquisition of maneuver agreements for Army commanders....

  14. Orbital Maneuvering System Design and Performance for the Magnetosperic Multiscale Formation

    NASA Technical Reports Server (NTRS)

    Queen, Steven; Chai, Dean; Placanica, Sam

    2015-01-01

    Once in science mission orbits, the four 0.12-km diameter observatories plan to form a tetrahedron with as little as 4-km of separation between spacecraft. The stated operational goal of maneuvering the fleet is no more often than once every two weeks (on average). Derived maneuvering accuracy requirement levied on the ACS

  15. 32 CFR 552.38 - Acquisition of maneuver agreements for Army commanders.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 3 2013-07-01 2013-07-01 false Acquisition of maneuver agreements for Army commanders. 552.38 Section 552.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Real Estate and Interest Therein § 552.38 Acquisition of maneuver agreements for Army commanders....

  16. 32 CFR 552.38 - Acquisition of maneuver agreements for Army commanders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 3 2014-07-01 2014-07-01 false Acquisition of maneuver agreements for Army commanders. 552.38 Section 552.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Real Estate and Interest Therein § 552.38 Acquisition of maneuver agreements for Army commanders....

  17. 32 CFR 552.38 - Acquisition of maneuver agreements for Army commanders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Acquisition of maneuver agreements for Army commanders. 552.38 Section 552.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Real Estate and Interest Therein § 552.38 Acquisition of maneuver agreements for Army commanders....

  18. Teaching Cardiac Autonomic Function Dynamics Employing the Valsalva (Valsalva-Weber) Maneuver

    ERIC Educational Resources Information Center

    Junqueira, Luiz Fernando, Jr.

    2008-01-01

    In this report, a brief history of the Valsalva (Valsalva-Weber) maneuver is outlined, followed by an explanation on the use of this approach for the evaluation of cardiac autonomic function based on underlying heart rate changes. The most important methodological and interpretative aspects of the Valsalva-Weber maneuver are critically updated,…

  19. The Generation of Cues Based on a Maneuver Analysis. Technical Report.

    ERIC Educational Resources Information Center

    Gerlach, Vernon; And Others

    A model for the systematic generation of verbal instructional cues is presented. The model utilizes a task analytic procedure referred to as "Maneuver Analysis," which is outlined and applied to the maneuver Vertical S-A. The cues generated on this basis are compared to current operational cues as found in "How to Fly" manuals, such as ATCM 5k-4…

  20. Logic, probability, and human reasoning.

    PubMed

    Johnson-Laird, P N; Khemlani, Sangeet S; Goodwin, Geoffrey P

    2015-04-01

    This review addresses the long-standing puzzle of how logic and probability fit together in human reasoning. Many cognitive scientists argue that conventional logic cannot underlie deductions, because it never requires valid conclusions to be withdrawn - not even if they are false; it treats conditional assertions implausibly; and it yields many vapid, although valid, conclusions. A new paradigm of probability logic allows conclusions to be withdrawn and treats conditionals more plausibly, although it does not address the problem of vapidity. The theory of mental models solves all of these problems. It explains how people reason about probabilities and postulates that the machinery for reasoning is itself probabilistic. Recent investigations accordingly suggest a way to integrate probability and deduction.

  1. Fuzzy logic particle tracking velocimetry

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1993-01-01

    Fuzzy logic has proven to be a simple and robust method for process control. Instead of requiring a complex model of the system, a user defined rule base is used to control the process. In this paper the principles of fuzzy logic control are applied to Particle Tracking Velocimetry (PTV). Two frames of digitally recorded, single exposure particle imagery are used as input. The fuzzy processor uses the local particle displacement information to determine the correct particle tracks. Fuzzy PTV is an improvement over traditional PTV techniques which typically require a sequence (greater than 2) of image frames for accurately tracking particles. The fuzzy processor executes in software on a PC without the use of specialized array or fuzzy logic processors. A pair of sample input images with roughly 300 particle images each, results in more than 200 velocity vectors in under 8 seconds of processing time.

  2. Statistical approach to linewidth control in a logic fab

    NASA Astrophysics Data System (ADS)

    Pitter, Michael; Doleschel, Bernhard; Eibl, Ludwig; Steinkirchner, Erwin; Grassmann, Andreas

    1999-04-01

    We designed an adaptive line width controller specially tailored to the needs of a highly diversified logic fab. Simulations of different controller types fed with historic CD data show advantages of an SPC based controller over a Run by Run controller. This result confirms the SPC assumption that as long as a process is in statistical control, changing the process parameters will only increase the variability of the output.

  3. A Logical Approach to Entanglement

    NASA Astrophysics Data System (ADS)

    Das, Abhishek

    2016-05-01

    In this paper we innovate a logical approach to develop an intuition regarding the phenomenon of quantum entanglement. In the vein of the logic introduced we substantiate that particles that were entangled in the past will be entangled in perpetuity and thereby abide a rule that restricts them to act otherwise. We also introduce a game and by virtue of the concept of Nash equilibrium we have been able to show that entangled particles will mutually correspond to an experiment that is performed on any one of the particle.

  4. The semantics of fuzzy logic

    NASA Technical Reports Server (NTRS)

    Ruspini, Enrique H.

    1991-01-01

    Summarized here are the results of recent research on the conceptual foundations of fuzzy logic. The focus is primarily on the principle characteristics of a model that quantifies resemblance between possible worlds by means of a similarity function that assigns a number between 0 and 1 to every pair of possible worlds. Introduction of such a function permits one to interpret the major constructs and methods of fuzzy logic: conditional and unconditional possibility and necessity distributions and the generalized modus ponens of Zadeh on the basis of related metric relationships between subsets of possible worlds.

  5. A Logical Approach to Entanglement

    NASA Astrophysics Data System (ADS)

    Das, Abhishek

    2016-10-01

    In this paper we innovate a logical approach to develop an intuition regarding the phenomenon of quantum entanglement. In the vein of the logic introduced we substantiate that particles that were entangled in the past will be entangled in perpetuity and thereby abide a rule that restricts them to act otherwise. We also introduce a game and by virtue of the concept of Nash equilibrium we have been able to show that entangled particles will mutually correspond to an experiment that is performed on any one of the particle.

  6. Logic programming and metadata specifications

    NASA Technical Reports Server (NTRS)

    Lopez, Antonio M., Jr.; Saacks, Marguerite E.

    1992-01-01

    Artificial intelligence (AI) ideas and techniques are critical to the development of intelligent information systems that will be used to collect, manipulate, and retrieve the vast amounts of space data produced by 'Missions to Planet Earth.' Natural language processing, inference, and expert systems are at the core of this space application of AI. This paper presents logic programming as an AI tool that can support inference (the ability to draw conclusions from a set of complicated and interrelated facts). It reports on the use of logic programming in the study of metadata specifications for a small problem domain of airborne sensors, and the dataset characteristics and pointers that are needed for data access.

  7. Teaching cardiac autonomic function dynamics employing the Valsalva (Valsalva-Weber) maneuver.

    PubMed

    Junqueira, Luiz Fernando

    2008-03-01

    In this report, a brief history of the Valsalva (Valsalva-Weber) maneuver is outlined, followed by an explanation on the use of this approach for the evaluation of cardiac autonomic function based on underlying heart rate changes. The most important methodological and interpretative aspects of the Valsalva-Weber maneuver are critically updated, and some guidelines are established for simple application of the maneuver in a teaching or research laboratory setting. These include the hemodynamic and cardiac autonomic mechanisms involved, technical aspects such as the intensity and duration of the expiratory straining, frequency of maneuver sessions, training and posture of the individuals tested, different time- and grade change-dependent indexes of heart interval variation, and clinical application of the maneuver.

  8. Orbital Maneuvering Vehicle (OMV) missions applications and systems requirements

    NASA Technical Reports Server (NTRS)

    Huber, W. G.; Cramblit, D. C.

    1984-01-01

    The routine delivery of large payloads to low earth orbit has become a reality with the Space Transportation System (STS). However, once earth orbit has been achieved, orbit transfer operations represent an inefficient use of the Space Shuttle. The Orbital Maneuvering Vehicle (OMV) will add a new and needed dimension to STS capabilities. Utilized in a reusable manner, the OMV is needed to deliver and retrieve satellites to and from orbital altitudes or inclinations beyond the practical limits of the Space Shuttle and to support basic Space Station activities. The initial OMV must also be designed to permit the addition of future mission kits to support the servicing, module changeout, or refueling of satellites in Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO), and the retrieval and deorbit of space debris. This paper addresses the mission needs along with the resulting performance implications, design requirements and operational capabilities imposed on the OMV planned for use in the late 1980s.

  9. Teleoperator Maneuvering System (TMS) mission applications and benefits

    NASA Technical Reports Server (NTRS)

    Cramblit, D. C.; Turner, J. R.

    1984-01-01

    Studies conducted by NASA have shown that the operating range of the Shuttle can be substantially increased and cost of payload operation be decreased by making use of the Teleoperator Maneuvering System (TMS). The TMS is remotely controlled, free-flying, orbital mini-tug vehicle capable of performing a wide range of remote satellite services missions. It can operate out of the Shuttle cargo bay, from a space station, or on top of an upper stage like Centaur. For high energy missions up to and including geostationary orbit, the TMS propulsion stage will augment the Transfer Orbit Stage (TOS) recently proposed for commercial development in providing an effective low-cost second-stage system for delivering intermediate sized payloads to geosynchronous orbit (GEO). Attention is given to TMS capabilities for both long duration and short term orbital missions, taking into account also Space Station support operations.

  10. A FMCW Radar Ranging Device for the Teleoperator Maneuvering System

    NASA Technical Reports Server (NTRS)

    Mcdonald, M. W.

    1983-01-01

    A frequency-modulated continuous wave radar system is under development in the Communications Systems Branch of the Information and Electronic Systems Laboratory at Marshall Space Flight Center. The radar unit is being designed for use on the teleoperator maneuvering system. Its function is to provide millimeter-level accuracy in range and range rate measurements out to a range of thirty meters. This will facilitate soft docking with accuracy. This report is an updating of previous developments reported on this system. An innovation in the system is the utilization of a standard reference signal generated by shunting a portion of the radar energy into a shorted coaxial delay line. The regular radar target return signal is constantly compared with the reference signal to provide internal error compensation. Within a five meter range, a limit imposed by present laboratory dimensions, the radar system exhibits reliable accuracy with range error less than 0.2%.

  11. Slew maneuver dynamics of the Spacecraft Control Laboratory experiment

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

    Mathematical expressions for slew maneuver dynamics are presented. The total kinetic energy expression of the system is given as T = T(0) + T(1) + T(2), where T(0), T(1), and T(2) refer to the kinetic energies of the shuttle, the flexible beam, and the tip mass (the reflector), respectively. The specific equations for each of these are defined and integrated into the total energy expression. Using the chain rule in the Lagrange equations and an expression allowing the transformation of the orbiter angular velocity from the inertial frame to the body-fixed frame, the rotational equations are obtained. Finally, the vibration equations for the beam are derived, again using the Lagrange equations.

  12. Differential maneuvering simulator data reduction and analysis software

    NASA Technical Reports Server (NTRS)

    Beasley, G. P.; Sigman, R. S.

    1972-01-01

    A multielement data reduction and analysis software package has been developed for use with the Langley differential maneuvering simulator (DMS). This package, which has several independent elements, was developed to support all phases of DMS aircraft simulation studies with a variety of both graphical and tabular information. The overall software package is considered unique because of the number, diversity, and sophistication of the element programs available for use in a single study. The purpose of this paper is to discuss the overall DMS data reduction and analysis package by reviewing the development of the various elements of the software, showing typical results that can be obtained, and discussing how each element can be used.

  13. Visual display aid for orbital maneuvering - Experimental evaluation

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1993-01-01

    An interactive proximity operations planning system, which allows on-site planning of fuel-efficient, multiburn maneuvers in a potential multispacecraft environment, has been experimentally evaluated. An experiment has been carried out in which nonastronaut operators with brief initial training were required to plan a trajectory to retrieve an object accidentally separated from a dual-keel Space Station, for a variety of different orbital situations. The experiments have shown that these operators were able to plan workable trajectories, satisfying a number of operational constraints. Fuel use and planning time were strongly correlated, both with the angle at which the object was separated and with the existence of spatial constraints. Planning behavior was found to be strongly operator-dependent. This finding calls for the need for standardizing planning strategies through operator training or the use of semiautomated planning schemes.

  14. Behavior learning in differential games and reorientation maneuvers

    NASA Astrophysics Data System (ADS)

    Satak, Neha

    method is the Direct Approximation of Value Function (DAVF) method. In this method, unlike the CSR method, the player formulates an objective function for the opponent but does not formulates a strategy directly; rather, indirectly the player assumes that the opponent is playing optimally. Thus, a value function satisfying the HJB equation corresponding to the opponent's cost function exists. The DAVF method finds an approximate solution for the value function based on previous observations of the opponent's control. The approximate solution to the value function is then used to predict the opponent's future behavior. Game examples in which only a single player is learning its opponent's behavior are simulated. Subsequently, examples in which both players in a two-player game are learning each other's behavior are simulated. In the second part of this research, a reorientation control maneuver for a spinning spacecraft will be developed. This will aid the application of behavior learning and differential games concepts to the specific scenario involving multiple spinning spacecraft. An impulsive reorientation maneuver with coasting will be analytically designed to reorient the spin axis of the spacecraft using a single body fixed thruster. Cooperative maneuvers of multiple spacecraft optimizing fuel and relative orientation will be designed. Pareto optimality concepts will be used to arrive at mutually agreeable reorientation maneuvers for the cooperating spinning spacecraft.

  15. Optimal maneuvers at supersonic speeds in a vertical plane

    NASA Technical Reports Server (NTRS)

    Vinh, N. X.; Lin, C. F.

    1981-01-01

    This paper presents several optimal maneuvers of supersonic aircraft in a vertical plane. The general dimensionless equations of motion are derived and the computation of the optimal trajectories are carried out using the aerodynamics and engine characteristics of a light-weight fighter called the supercruiser. Because of the normalizing of the control variables, namely, the load factor and the thrust-to-weight ratio, the results applied to any supersonic aircraft. The optimality of the singular thrust control and the optimal junction of different subarcs are discussed. The proposed method of computing the optimal trajectory is very efficient and makes explicit the selection of the optimal control. The technique should be useful for performance assessment of supersonic aircraft with potential for implementation of onboard flight control system.

  16. Optimal control of aeroassisted plane change maneuver using feedback expansions

    NASA Technical Reports Server (NTRS)

    Mishne, D.; Speyer, J. L.

    1986-01-01

    A guidance law for an aeroassisted plane change maneuver is developed by an asymptotic expansion technique using a small parameter which essentially represents the ratio of the inertial forces to the atmospheric forces. This guidance law minimizes the energy loss while meeting terminal constraints on the altitude, flight path angle, and heading angle. By neglecting the inertial forces, the resulting optimization problem is integrable and can be determined in closed form. This zeroth-order solution is the first term in an asymptotic series solution of the Hamilton-Jacobi-Bellman equation. The remaining terms are determined from the solution of a first-order, linear partial differential equation whose solution requires only quadrature integration. Our initial results in using this guidance scheme are encouraging.

  17. Orbital Maneuvering Vehicle (OMV) plume and plume effects study

    NASA Technical Reports Server (NTRS)

    Smith, Sheldon D.

    1991-01-01

    The objective was to characterize the Orbital Maneuvering Vehicle (OMV) propulsion and attitude control system engine exhaust plumes and predict the resultant plume impingement pressure, heat loads, forces, and moments. Detailed description is provided of the OMV gaseous nitrogen (GN2) thruster exhaust plume flow field characteristics calculated with the RAMP2 snd SFPGEN computer codes. Brief descriptions are included of the two models, GN2 thruster characteristics and RAMP2 input data files. The RAMP2 flow field could be recalculated by other organizations using the information presented. The GN2 flow field can be readily used by other organizations who are interested in GN2 plume induced environments which require local flow field properties which can be supplied using the SFPGEN GN2 model.

  18. Control and structural optimization for maneuvering large spacecraft

    NASA Technical Reports Server (NTRS)

    Chun, H. M.; Turner, J. D.; Yu, C. C.

    1990-01-01

    Presented here are the results of an advanced control design as well as a discussion of the requirements for automating both the structures and control design efforts for maneuvering a large spacecraft. The advanced control application addresses a general three dimensional slewing problem, and is applied to a large geostationary platform. The platform consists of two flexible antennas attached to the ends of a flexible truss. The control strategy involves an open-loop rigid body control profile which is derived from a nonlinear optimal control problem and provides the main control effort. A perturbation feedback control reduces the response due to the flexibility of the structure. Results are shown which demonstrate the usefulness of the approach. Software issues are considered for developing an integrated structures and control design environment.

  19. Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Markley, F. Landis

    2013-01-01

    A document discusses sequential probability ratio tests that explicitly allow decision-makers to incorporate false alarm and missed detection risks, and are potentially less sensitive to modeling errors than a procedure that relies solely on a probability of collision threshold. Recent work on constrained Kalman filtering has suggested an approach to formulating such a test for collision avoidance maneuver decisions: a filter bank with two norm-inequality-constrained epoch-state extended Kalman filters. One filter models the null hypotheses that the miss distance is inside the combined hard body radius at the predicted time of closest approach, and one filter models the alternative hypothesis. The epoch-state filter developed for this method explicitly accounts for any process noise present in the system. The method appears to work well using a realistic example based on an upcoming, highly elliptical orbit formation flying mission.

  20. Intelligent adaptive structures

    NASA Technical Reports Server (NTRS)

    Wada, Ben K.

    1990-01-01

    'Intelligent Adaptive Structures' (IAS) refers to structural systems whose geometric and intrinsic structural characteristics can be automatically changed to meet mission requirements with changing operational scenarios. An IAS is composed of actuators, sensors, and a control logic; these are integrated in a distributed fashion within the elements of the structure. The IAS concepts thus far developed for space antennas and other precision structures should be applicable to civil, marine, automotive, and aeronautical structural systems.

  1. Estimate of avoidance maneuver rate for HASTOL tether boost facility

    NASA Astrophysics Data System (ADS)

    Forward, Robert L.

    2002-01-01

    The Hypersonic Airplane Space Tether Orbital Launch (HASTOL) Architecture uses a hypersonic airplane (or reusable launch vehicle) to carry a payload from the surface of the Earth to 150 km altitude and a speed of Mach 17. The hypersonic airplane makes a rendezvous with the grapple at the tip of a long, rotating, orbiting space tether boost facility, which picks up the payload from the airplane. Release of the payload at the proper point in the tether rotation boosts the payload into a higher orbit, typically into a Geosynchronous Transfer Orbit (GTO), with lower orbits and Earth escape other options. The HASTOL Tether Boost Facility will have a length of 636 km. Its center of mass will be in a 604 km by 890 km equatorial orbit. It is estimated that by the time of the start of operations of the HASTOL Tether Boost facility in the year 2020, there will be 500 operational spacecraft using the same volume of space as the HASTOL facility. These operational spacecraft would likely be made inoperative by an impact with one of the lines in the multiline HASTOL Hoytether™ and should be avoided. There will also be non-operational spacecraft and large pieces of orbital debris with effective size greater than five meters in diameter that could cut a number of lines in the HASTOL Hoytether™, and should also be avoided. It is estimated, using two different methods and combining them, that the HASTOL facility will need to make avoidance maneuvers about once every four days if the 500 operational spacecraft and large pieces of orbital debris greater than 5 m in diameter, were each protected by a 2 km diameter miss distance protection sphere. If by 2020, the ability to know the positions of operational spacecraft and large pieces of orbital debris improved to allow a 600 m diameter miss distance protection sphere around each object, then the number of HASTOL facility maneuvers needed drops to one every two weeks. .

  2. Is there central fatigue during simulated air combat maneuvering?

    PubMed

    Bain, B; Jacobs, I; Buick, F

    1995-01-01

    This study tested the hypothesis that repeated exposure to high levels of +Gz acceleration, in conjunction with repeated execution of an Anti-G Straining Maneuver (AGSM), causes central fatigue, presumably by impairing central nervous system (CNS) function. We speculated that central fatigue would impair the ability to recruit sufficient musculature at the intensity required to perform an adequate anti-G straining maneuver. Central fatigue was evaluated by measuring maximal force generation and surface electromyographic activity of leg extensor muscles before, during, and immediately upon termination of an SACM, and comparing these values to those obtained when the muscles were electrically stimulated during maximal voluntary contractions (MVCs). We assumed that any observed increase in force generation during the MVCs, caused by the stimulation, would indicate central fatigue. G-tolerance time was 230 +/- 172 s. Hypoxia was induced by the SACM as the arterial oxygen saturation decreased significantly from 97% to 90%. In spite of this hypoxia, there was no significant change in MVC force when the pre- and post-SACM values were compared. Electrical stimulation during the MVC's did not cause an increase in force generation. The average forces generated during the +7 Gz phase of the SACM were only about 35% of MVC force. This force value did not change significantly during the SACM. The results indicate that the inability to continue to perform the AGSM during an SACM is not likely due to central fatigue or to fatigue of the large skeletal muscle groups we have examined.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Proceedings of the Second Joint Technology Workshop on Neural Networks and Fuzzy Logic, volume 1

    NASA Technical Reports Server (NTRS)

    Lea, Robert N. (Editor); Villarreal, James (Editor)

    1991-01-01

    Documented here are papers presented at the Neural Networks and Fuzzy Logic Workshop sponsored by NASA and the University of Houston, Clear Lake. The workshop was held April 11 to 13 at the Johnson Space Flight Center. Technical topics addressed included adaptive systems, learning algorithms, network architectures, vision, robotics, neurobiological connections, speech recognition and synthesis, fuzzy set theory and application, control and dynamics processing, space applications, fuzzy logic and neural network computers, approximate reasoning, and multiobject decision making.

  4. Gateways to Writing Logical Arguments

    ERIC Educational Resources Information Center

    McCann, Thomas M.

    2010-01-01

    Middle school and high school students have a conception of what the basic demands of logic are, and they draw on this understanding in anticipating certain demands of parents and teachers when the adolescents have to defend positions. At the same time, many adolescents struggle to "write" highly elaborated arguments. Teaching students lessons in…

  5. The Logic of Research Evaluation

    ERIC Educational Resources Information Center

    Scriven, Michael; Coryn, Chris L. S.

    2008-01-01

    The authors offer suggestions about logical distinctions often overlooked in the evaluation of research, beginning with a strong plea not to treat technology as applied science, and especially not to treat research in technology as important only if it makes a contribution to scientific knowledge. They argue that the frameworks illustrated in this…

  6. Current Mode Logic Fan Out

    2011-05-07

    Current mode logic is used in high speed timing systems for particle accelerators due to the fast rise time of the electrical signal. This software provides the necessary documentation to produce multiple copies of a single input for distribution to multiple devices. This software supports the DOE mission by providing a method for producing high speed signals in accelerator timing systems.

  7. Surface-emitting laser logic

    SciTech Connect

    Olbright, G.R.; Bryan, R.P.; Brennan, T.M.; Lear, K.; Poirier, G.E.; Fu, W.S. ); Jewell, J.L.; Lee, Y.H. )

    1990-10-31

    We describe a new class of optical logic devices which consist of integrated phototransistors and surface-emitting lasers. The devices function as optical neurons having high gain and, as arrays, are ideal for neural networks, parallel optical signal processing and optical computing applications. 3 refs., 3 figs.

  8. The Logic of Quantum Measurements

    NASA Astrophysics Data System (ADS)

    Vanni, Leonardo; Laura, Roberto

    2013-07-01

    We apply our previously developed formalism of contexts of histories, suitable to deal with quantum properties at different times, to the measurement process. We explore the logical implications which are allowed by the quantum theory, about the realization of properties of the microscopic measured system, before and after the measurement process with a given pointer value.

  9. Miniaturization of magnetic logic circuitry

    NASA Technical Reports Server (NTRS)

    Baba, P. D.

    1969-01-01

    Magnetic logic circuit design features two ferrite materials, with different formulation and magnetic characteristics, which are bonded into a continuous structure by preparing the materials as a slurry and using the doctor blade method to form flexible ferrite sheets. After firing, the sintering process was continuous across the bond.

  10. Logical Empiricism, Politics, and Professionalism

    ERIC Educational Resources Information Center

    Edgar, Scott

    2009-01-01

    This paper considers George A. Reisch's account of the role of Cold War political forces in shaping the apolitical stance that came to dominate philosophy of science in the late 1940s and 1950s. It argues that at least as early as the 1930s, Logical Empiricists such as Rudolf Carnap already held that philosophy of science could not properly have…

  11. Generic physical protection logic trees

    SciTech Connect

    Paulus, W.K.

    1981-10-01

    Generic physical protection logic trees, designed for application to nuclear facilities and materials, are presented together with a method of qualitative evaluation of the trees for design and analysis of physical protection systems. One or more defense zones are defined where adversaries interact with the physical protection system. Logic trees that are needed to describe the possible scenarios within a defense zone are selected. Elements of a postulated or existing physical protection system are tagged to the primary events of the logic tree. The likelihood of adversary success in overcoming these elements is evaluated on a binary, yes/no basis. The effect of these evaluations is propagated through the logic of each tree to determine whether the adversary is likely to accomplish the end event of the tree. The physical protection system must be highly likely to overcome the adversary before he accomplishes his objective. The evaluation must be conducted for all significant states of the site. Deficiencies uncovered become inputs to redesign and further analysis, closing the loop on the design/analysis cycle.

  12. Mathematical Induction: Deductive Logic Perspective

    ERIC Educational Resources Information Center

    Dogan, Hamide

    2016-01-01

    Many studies mentioned the deductive nature of Mathematical Induction (MI) proofs but almost all fell short in explaining its potential role in the formation of the misconceptions reported in the literature. This paper is the first of its kind looking at the misconceptions from the perspective of the abstract of the deductive logic from one's…

  13. Logical Reasoning and Retrieval Performance.

    ERIC Educational Resources Information Center

    Allen, Bryce

    1993-01-01

    A study of logical reasoning ability of endusers searching a CD-ROM index and its correlation to searching performance was conducted at the University of Illinois at Urbana-Champaign. Findings showed a correlation between cognitive skills and citation selection and indicated that computer system design can be improved using a cognitive engineering…

  14. Boggle Logic Puzzles: Minimal Solutions

    ERIC Educational Resources Information Center

    Needleman, Jonathan

    2013-01-01

    Boggle logic puzzles are based on the popular word game Boggle played backwards. Given a list of words, the problem is to recreate the board. We explore these puzzles on a 3 x 3 board and find the minimum number of three-letter words needed to create a puzzle with a unique solution. We conclude with a series of open questions.

  15. Program Theory Evaluation: Logic Analysis

    ERIC Educational Resources Information Center

    Brousselle, Astrid; Champagne, Francois

    2011-01-01

    Program theory evaluation, which has grown in use over the past 10 years, assesses whether a program is designed in such a way that it can achieve its intended outcomes. This article describes a particular type of program theory evaluation--logic analysis--that allows us to test the plausibility of a program's theory using scientific knowledge.…

  16. Propulsion System and Orbit Maneuver Integration in CubeSats: Trajectory Control Strategies Using Micro Ion Propulsion

    NASA Technical Reports Server (NTRS)

    Hudson, Jennifer; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Propulsion System and Orbit Maneuver Integration in CubeSats project aims to solve the challenges of integrating a micro electric propulsion system on a CubeSat in order to perform orbital maneuvers and control attitude. This represents a fundamentally new capability for CubeSats, which typically do not contain propulsion systems and cannot maneuver far beyond their initial orbits.

  17. Learning fuzzy logic control system

    NASA Technical Reports Server (NTRS)

    Lung, Leung Kam

    1994-01-01

    The performance of the Learning Fuzzy Logic Control System (LFLCS), developed in this thesis, has been evaluated. The Learning Fuzzy Logic Controller (LFLC) learns to control the motor by learning the set of teaching values that are generated by a classical PI controller. It is assumed that the classical PI controller is tuned to minimize the error of a position control system of the D.C. motor. The Learning Fuzzy Logic Controller developed in this thesis is a multi-input single-output network. Training of the Learning Fuzzy Logic Controller is implemented off-line. Upon completion of the training process (using Supervised Learning, and Unsupervised Learning), the LFLC replaces the classical PI controller. In this thesis, a closed loop position control system of a D.C. motor using the LFLC is implemented. The primary focus is on the learning capabilities of the Learning Fuzzy Logic Controller. The learning includes symbolic representation of the Input Linguistic Nodes set and Output Linguistic Notes set. In addition, we investigate the knowledge-based representation for the network. As part of the design process, we implement a digital computer simulation of the LFLCS. The computer simulation program is written in 'C' computer language, and it is implemented in DOS platform. The LFLCS, designed in this thesis, has been developed on a IBM compatible 486-DX2 66 computer. First, the performance of the Learning Fuzzy Logic Controller is evaluated by comparing the angular shaft position of the D.C. motor controlled by a conventional PI controller and that controlled by the LFLC. Second, the symbolic representation of the LFLC and the knowledge-based representation for the network are investigated by observing the parameters of the Fuzzy Logic membership functions and the links at each layer of the LFLC. While there are some limitations of application with this approach, the result of the simulation shows that the LFLC is able to control the angular shaft position of the

  18. ISAR imaging of maneuvering targets based on the range centroid Doppler technique.

    PubMed

    Lv, Xiaolei; Xing, Mengdao; Wan, Chunru; Zhang, Shouhong

    2010-01-01

    A new inverse synthetic aperture radar (ISAR) imaging approach is presented for application in situations where the maneuverability of noncooperative target is not too severe and the Doppler variation of subechoes from scatterers can be approximated as a first-order polynomial. The proposed algorithm is referred to as the range centroid Doppler (RCD) ISAR imaging technique and is based on the stretch Keystone-Wigner transform (SKWT). The SKWT introduces a stretch weight factor containing a range of chirp rate into the autocorrelation function of each cross-range profile and uses a 1-D interpolation of the phase history which we call stretch keystone formatting. The processing simultaneously eliminates the effects of linear frequency migration for all signal components regardless of their unknown chirp rate in time-frequency plane, but not for the noise or for the cross terms. By utilizing this novel technique, clear ISAR imaging can be achieved for maneuvering targets without an exhaustive search procedure for the motion parameters. Performance comparison is carried out to evaluate the improvement of the RCD technique versus other methods such as the conventional range Doppler (RD) technique, the range instantaneous Doppler (RID) technique, and adaptive joint time-frequency (AJTF) technique. Examples provided demonstrate the effectiveness of the RCD technique with both simulated and experimental ISAR data.

  19. A Therapeutic Maneuver for Oropharyngeal Dysphagia in Patients with Parkinson’s Disease

    PubMed Central

    Felix, Valter Nilton; Corrêa, Sabrina Mello Alves; Soares, Renato José

    2008-01-01

    OBJECTIVE This study investigates resources to provide better conditions for oropharyngeal swallowing for improvement in the quality of life of Parkinson’s disease patients. METHOD Three men and one woman with an average age of 70.25 years had been afflicted with Parkinson’s disease for an average of 9.25 years. The patients were submitted to a rehabilitation program for oropharyngeal dysphagia after a clinical evaluation of swallowing. The rehabilitation program consisted of daily sessions for two consecutive weeks during which a biofeedback resource adapted especially for this study was used. The patients were then reevaluated for swallowing ability at follow-up. RESULTS The patients presenting difficulties with swallowing water displayed no such problems after rehabilitation. Only one patient exhibited slow oral transit of food and other discrete oropharyngeal food remnants when swallowing a biscuit. The sample variance was used to analyze the pressure measurements, demonstrating a numerical similarity of the results obtained with the swallowing of saliva or of biscuits (VAR = 4.41). A statistical difference was observed between the swallowing of saliva and biscuits, showing a significant pressure increase at the end of the rehabilitation program (p < 0.001). CONCLUSION The effortful swallow maneuver reinforced by using biofeedback appears to be a therapeutic resource in the rehabilitation of oropharyngeal dysphagia in Parkinson’s disease patients. PMID:18925327

  20. System identification and sensorimotor determinants of flight maneuvers in an insect

    NASA Astrophysics Data System (ADS)

    Sponberg, Simon; Hall, Robert; Roth, Eatai

    Locomotor maneuvers are inherently closed-loop processes. They are generally characterized by the integration of multiple sensory inputs and adaptation or learning over time. To probe sensorimotor processing we take a system identification approach treating the underlying physiological systems as dynamic processes and altering the feedback topology in experiment and analysis. As a model system, we use agile hawk moths (Manduca sexta), which feed from real and robotic flowers while hovering in mid air. Moths rely on vision and mechanosensation to track floral targets and can do so at exceptionally low luminance levels despite hovering being a mechanically unstable behavior that requires neural feedback to stabilize. By altering the sensory environment and placing mechanical and visual signals in conflict we show a surprisingly simple linear summation of visual and mechanosensation produces a generative prediction of behavior to novel stimuli. Tracking performance is also limited more by the mechanics of flight than the magnitude of the sensory cue. A feedback systems approach to locomotor control results in new insights into how behavior emerges from the interaction of nonlinear physiological systems.

  1. Relay Protection and Automation Systems Based on Programmable Logic Integrated Circuits

    SciTech Connect

    Lashin, A. V. Kozyrev, A. V.

    2015-09-15

    One of the most promising forms of developing the apparatus part of relay protection and automation devices is considered. The advantages of choosing programmable logic integrated circuits to obtain adaptive technological algorithms in power system protection and control systems are pointed out. The technical difficulties in the problems which today stand in the way of using relay protection and automation systems are indicated and a new technology for solving these problems is presented. Particular attention is devoted to the possibility of reconfiguring the logic of these devices, using programmable logic integrated circuits.

  2. Automated interpretation of LIBS spectra using a fuzzy logic inference engine.

    PubMed

    Hatch, Jeremy J; McJunkin, Timothy R; Hanson, Cynthia; Scott, Jill R

    2012-03-01

    Automated interpretation of laser-induced breakdown spectroscopy (LIBS) data is necessary due to the plethora of spectra that can be acquired in a relatively short time. However, traditional chemometric and artificial neural network methods that have been employed are not always transparent to a skilled user. A fuzzy logic approach to data interpretation has now been adapted to LIBS spectral interpretation. Fuzzy logic inference rules were developed using methodology that includes data mining methods and operator expertise to differentiate between various copper-containing and stainless steel alloys as well as unknowns. Results using the fuzzy logic inference engine indicate a high degree of confidence in spectral assignment.

  3. Set-Theory and Logic in School

    ERIC Educational Resources Information Center

    Kapadia, Ramesh

    1976-01-01

    The author argues that the emphasis on logic and set theory in the school mathematics program is unnecessary and possibly harmful. He discusses briefly the relationships between semantics and logic. (SD)

  4. Computerized logic design of digital circuits

    NASA Technical Reports Server (NTRS)

    Sussow, S.; Oglesby, R.

    1973-01-01

    This manual presents a computer program that performs all the work required for the logic design of digital counters or sequential circuits and the simplification of Boolean logic expressions. The program provides both the experienced and inexperienced logic designer with a comprehensive logic design capability. The manual contains Boolean simplification and sequential design theory, detailed instructions for use of the program, a large number of illustrative design examples, and complete program documentation.

  5. Inlet Flow Characteristics During Rapid Maneuvers for an F/A-18A Airplane

    NASA Technical Reports Server (NTRS)

    Steenken, William G.; Williams, John G.; Walsh, Kevin R.

    1999-01-01

    The F404-GE-400 engine powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the characteristics of inlet airflow during rapid aircraft maneuvers. A study of the degree of similarity between inlet data obtained during rapid aircraft maneuvers and inlet data obtained at steady aerodynamic attitudes was conducted at the maximum engine airflow of approximately 145 Ibm/sec using a computer model that was generated from inlet data obtained during steady aerodynamic maneuvers. Results show that rapid-maneuver inlet recoveries agreed very well with the recoveries obtained at equivalent stabilized angle-of-attack conditions. The peak dynamic circumferential distortion values obtained during rapid maneuvers agreed within 0.01 units of distortion over the 10 - 38 degree angle of attack range with the values obtained during steady aerodynamic maneuvers while similar agreement was found for the peak dynamic radial distortion values up to 29 degrees angle-of-attack. Exceedences of the rapid-maneuver peak dynamic circumferential distortion values relative to the peak distortion model values at steady attitudes occurred only at low or negative angles of attack and were inconsequential from an engine-stability assessment point of view. The results of this study validate the current industry practice of testing at steady aerodynamic conditions to characterize inlet recovery and peak dynamic distortion levels.

  6. A Monte Carlo error analysis program for near-Mars, finite-burn, orbital transfer maneuvers

    NASA Technical Reports Server (NTRS)

    Green, R. N.; Hoffman, L. H.; Young, G. R.

    1972-01-01

    A computer program was developed which performs an error analysis of a minimum-fuel, finite-thrust, transfer maneuver between two Keplerian orbits in the vicinity of Mars. The method of analysis is the Monte Carlo approach where each off-nominal initial orbit is targeted to the desired final orbit. The errors in the initial orbit are described by two covariance matrices of state deviations and tracking errors. The function of the program is to relate these errors to the resulting errors in the final orbit. The equations of motion for the transfer trajectory are those of a spacecraft maneuvering with constant thrust and mass-flow rate in the neighborhood of a single body. The thrust vector is allowed to rotate in a plane with a constant pitch rate. The transfer trajectory is characterized by six control parameters and the final orbit is defined, or partially defined, by the desired target parameters. The program is applicable to the deboost maneuver (hyperbola to ellipse), orbital trim maneuver (ellipse to ellipse), fly-by maneuver (hyperbola to hyperbola), escape maneuvers (ellipse to hyperbola), and deorbit maneuver.

  7. Intrathoracic pressure changes after Valsalva strain and other maneuvers: implications for divers with patent foramen ovale.

    PubMed

    Balestra, C; Germonpré, P; Marroni, A

    1998-01-01

    Scuba divers with patent foramen ovale (PFO) may be at risk for paradoxical nitrogen gas emboli when performing maneuvers that cause a rebound blood loading to the right atrium. We measured the rise and fall in intrathoracic pressure (ITP) during various maneuvers in 15 divers. The tests were standard isometric exercises (control), forceful coughing, knee bend (with and without respiration blocked), and Valsalva maneuver (maximal, gradually increased to reach control ITP, and as performed by divers to equalize middle ear pressure). All the maneuvers, as well as the downward slope of ITP at the release phase, were related to the control value. ITP levels were significantly higher than the standard isometric effort during a breath-hold knee bend (172%, P < 0.001), cough (133%, P < 0.05), and maximal Valsalva (136%, P < 0.05) whereas "usual" Valsalva maneuvers produced ITPs significantly lower than the standard (28%, P < 0.001). The downward slope of the pressure release curve was not significantly different among the different maneuvers (P < 0.1447). We conclude that maneuvers other than the usual divers' Valsalva are more likely to cause post-release central blood shift, both by the levels of ITP reached and by the time during which these ITPs are sustained. Divers (especially with PFO) should be advised to refrain from strenuous leg, arm, or abdominal exercise after decompression dives.

  8. Selective Inflow Occlusion Technique Versus Intermittent Pringle Maneuver in Hepatectomy for Large Hepatocellular Carcinoma

    PubMed Central

    Zhu, Peng; Zhang, Binhao; Wang, Rui; Mei, Bin; Cheng, Qi; Chen, Lin; Wei, Gang; Xu, Da-feng; Yu, Jie; Xiao, Hua; Zhang, Bi-xiang; Chen, Xiao-ping

    2015-01-01

    Abstract Selective inflow occlusion (SIO) maneuver preserved inflow of nontumorous liver and was supposed to protect liver function. This study aims to evaluate whether SIO maneuver is superior to Pringle maneuver in patients undergoing partial hepatectomy with large hepatocellular carcinomas (HCCs). Between January 2008 and May 2012, 656 patients underwent large HCC resections and were divided into 2 groups: intermittent Pringle maneuver (IP) group (n = 336) and SIO group (n = 320). Operative parameters, postoperative laboratory tests, and morbidity and mortality were analyzed. In comparison to the IP maneuver, the SIO maneuver significantly decreased intraoperative blood loss (473 vs 691 mL, P = 0.001) and transfusion rates (11.3% vs 28.6%, P = 0.006). The rate of major complication between the 2 groups was comparable (22.6% vs 18.8%, P = 0.541). Patients with moderate/severe cirrhosis, total bilirubin > 17 μmol/L, or HBV DNA> = 104 copy/mL in SIO group resulted in lower major complication rates. The SIO maneuver is a safe and effective technique for large HCC resections. In patients with moderate/severe cirrhosis, total bilirubin > 17 μmol/L, or HBV DNA> = 104 copy/mL, the SIO technique is preferentially recommended. PMID:26683942

  9. Precision Closed-Loop Orbital Maneuvering System Design and Performance for the Magnetospheric Multiscale Formation

    NASA Technical Reports Server (NTRS)

    Chai, Dean J.; Queen, Steven Z.; Placanica, Samuel J.

    2015-01-01

    NASAs Magnetospheric Multiscale (MMS) mission successfully launched on March 13,2015 (UTC) consists of four identically instrumented spin-stabilized observatories that function as a constellation to study magnetic reconnection in space. The need to maintain sufficiently accurate spatial and temporal formation resolution of the observatories must be balanced against the logistical constraints of executing overly-frequent maneuvers on a small fleet of spacecraft. These two considerations make for an extremely challenging maneuver design problem. This paper focuses on the design elements of a 6-DOF spacecraft attitude control and maneuvering system capable of delivering the high-precision adjustments required by the constellation designers specifically, the design, implementation, and on-orbit performance of the closed-loop formation-class maneuvers that include initialization, maintenance, and re-sizing. The maneuvering control system flown on MMS utilizes a micro-gravity resolution accelerometer sampled at a high rate in order to achieve closed-loop velocity tracking of an inertial target with arc-minute directional and millimeter-per second magnitude accuracy. This paper summarizes the techniques used for correcting bias drift, sensor-head offsets, and centripetal aliasing in the acceleration measurements. It also discusses the on-board pre-maneuver calibration and compensation algorithms as well as the implementation of the post-maneuver attitude adjustments.

  10. STS-57 MS3 Wisoff, in EMU and atop the RMS, is maneuvered in OV-105's PLB

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Backdropped against the blackness of space, Mission Specialist 3 (MS3) Peter J.K. Wisoff, wearing an extravehicular mobility unit (EMU), stands on a portable foot restraint (PFR) (manipulator foot restrait (MFR)) attached to the end of the remote manipulator system (RMS). Wisoff is being maneuvered above Endeavour's, Orbiter Vehicle (OV) 105's, payload bay (PLB) as part of Detailed Test Objective 1210 extravehicular activity (EVA) procedures. The PFR is attached to the RMS end effector via a PFR attachment device (PAD). DTO 1210 results will assist in refining several procedures being developed to service the Hubble Space Telescope (HST) on mission STS-61 in December 1993. In the foreground are the open spacelab (SL) adapter tunnel EV hatch and the SPACEHAB-01 (Commercial Middeck Augmentation Module (CMAM). Only partially visible behind SPACEHAB-01 is the Superfluid Helium Onorbit Transfer (SHOOT) payload liquid helium dewar assembly.

  11. Dynamic Frames in Java Dynamic Logic

    NASA Astrophysics Data System (ADS)

    Schmitt, Peter H.; Ulbrich, Mattias; Weiß, Benjamin

    In this paper we present a realisation of the concept of dynamic frames in a dynamic logic for verifying Java programs. This is achieved by treating sets of heap locations as first class citizens in the logic. Syntax and formal semantics of the logic are presented, along with sound proof rules for modularly reasoning about method calls and heap dependent symbols using specification contracts.

  12. Logics of Business Education for Sustainability

    ERIC Educational Resources Information Center

    Andersson, Pernilla; Öhman, Johan

    2016-01-01

    This paper explores various kinds of logics of "business education for sustainability" and how these "logics" position the subject business person, based on eight teachers' reasoning of their own practices. The concept of logics developed within a discourse theoretical framework is employed to analyse the teachers' reasoning.…

  13. Piaget's Logic of Meanings: Still Relevant Today

    ERIC Educational Resources Information Center

    Wavering, Michael James

    2011-01-01

    In his last book, "Toward a Logic of Meanings" (Piaget & Garcia, 1991), Jean Piaget describes how thought can be categorized into a form of propositional logic, a logic of meanings. The intent of this article is to offer this analysis by Piaget as a means to understand the language and teaching of science. Using binary propositions, conjunctions,…

  14. An adaptive fuzzy controller for permanent-magnet AC servo drives

    SciTech Connect

    Le-Huy, H.

    1995-12-31

    This paper presents a theoretical study on a model-reference adaptive fuzzy logic controller for vector-controlled permanent-magnet ac servo drives. In the proposed system, fuzzy logic is used to implement the direct controller as well as the adaptation mechanism. The operation of the direct fuzzy controller and the fuzzy logic based adaptation mechanism is studied. The control performance of the adaptive fuzzy controller is evaluated by simulation for various operating conditions. The results are compared with that provided by a non-adaptive fuzzy controller. The implementation of proposed adaptive fuzzy controller is discussed.

  15. Applications of Logic Coverage Criteria and Logic Mutation to Software Testing

    ERIC Educational Resources Information Center

    Kaminski, Garrett K.

    2011-01-01

    Logic is an important component of software. Thus, software logic testing has enjoyed significant research over a period of decades, with renewed interest in the last several years. One approach to detecting logic faults is to create and execute tests that satisfy logic coverage criteria. Another approach to detecting faults is to perform mutation…

  16. Fuzzy Logic Based Autonomous Parallel Parking System with Kalman Filtering

    NASA Astrophysics Data System (ADS)

    Panomruttanarug, Benjamas; Higuchi, Kohji

    This paper presents an emulation of fuzzy logic control schemes for an autonomous parallel parking system in a backward maneuver. There are four infrared sensors sending the distance data to a microcontroller for generating an obstacle-free parking path. Two of them mounted on the front and rear wheels on the parking side are used as the inputs to the fuzzy rules to calculate a proper steering angle while backing. The other two attached to the front and rear ends serve for avoiding collision with other cars along the parking space. At the end of parking processes, the vehicle will be in line with other parked cars and positioned in the middle of the free space. Fuzzy rules are designed based upon a wall following process. Performance of the infrared sensors is improved using Kalman filtering. The design method needs extra information from ultrasonic sensors. Starting from modeling the ultrasonic sensor in 1-D state space forms, one makes use of the infrared sensor as a measurement to update the predicted values. Experimental results demonstrate the effectiveness of sensor improvement.

  17. Passenger comfort during terminal-area flight maneuvers. M.S. Thesis.

    NASA Technical Reports Server (NTRS)

    Schoonover, W. E., Jr.

    1976-01-01

    A series of flight experiments was conducted to obtain passenger subjective responses to closely controlled and repeatable flight maneuvers. In 8 test flights, reactions were obtained from 30 passenger subjects to a wide range of terminal-area maneuvers, including descents, turns, decelerations, and combinations thereof. Analysis of the passenger rating variance indicated that the objective of a repeatable flight passenger environment was achieved. Multiple linear regression models developed from the test data were used to define maneuver motion boundaries for specified degrees of passenger acceptance.

  18. High alpha feedback control for agile half-loop maneuvers of the F-18 airplane

    NASA Technical Reports Server (NTRS)

    Stalford, Harold

    1988-01-01

    A nonlinear feedback control law for the F/A-18 airplane that provides time-optimal or agile maneuvering of the half-loop maneuver at high angles of attack is given. The feedback control law was developed using the mathematical approach of singular perturbations, in which the control devices considered were conventional aerodynamic control surfaces and thrusting. The derived nonlinear control law was used to simulate F/A-18 half-loop maneuvers. The simulated results at Mach 0.6 and 0.9 compared well with pilot simulations conducted at NASA.

  19. Effects of automobile steering characteristics on driver/vehicle system performance in discrete maneuvers

    NASA Technical Reports Server (NTRS)

    Klein, R. H.; Mcruer, D. T.

    1975-01-01

    A series of discrete maneuver tasks were used to evaluate the effects of steering gain and directional mode dynamic parameters on driver/vehicle responses. The importance and ranking of these parameters were evaluated through changes in subjective driver ratings and performance measures obtained from transient maneuvers such as a double lane change, an emergency lane change, and an unexpected obstacle. The unexpected obstacle maneuver proved more sensitive to individual driver differences than to vehicle differences. Results were based on full scale tests with an experienced test driver evaluating many different dynamic configurations plus seventeen ordinary drivers evaluating six key configurations.

  20. Out-of-plane orbital maneuvers using swing-bys with the Moon

    NASA Astrophysics Data System (ADS)

    Neto, J. B. S.; Prado, A. F. B. A.; Formiga, J. K. S.

    2015-10-01

    This paper has the goal of showing some cases of plane change maneuvers using a swing-by with the Moon to decrease the magnitude of the impulses used, when compared to a classical Hohmann maneuver. The analytical model is based on the "patched-conics" approach, where a series of "two-body" problems is considered to build the whole maneuver. A study of the effects of the semi-major axes of the transfer orbits were made, to complete some previous studies made in the literature. The results show that, for some final inclinations, the use of the swing-by in the Moon is really advantageous.

  1. Fuzzy Versions of Epistemic and Deontic Logic

    NASA Technical Reports Server (NTRS)

    Gounder, Ramasamy S.; Esterline, Albert C.

    1998-01-01

    Epistemic and deontic logics are modal logics, respectively, of knowledge and of the normative concepts of obligation, permission, and prohibition. Epistemic logic is useful in formalizing systems of communicating processes and knowledge and belief in AI (Artificial Intelligence). Deontic logic is useful in computer science wherever we must distinguish between actual and ideal behavior, as in fault tolerance and database integrity constraints. We here discuss fuzzy versions of these logics. In the crisp versions, various axioms correspond to various properties of the structures used in defining the semantics of the logics. Thus, any axiomatic theory will be characterized not only by its axioms but also by the set of properties holding of the corresponding semantic structures. Fuzzy logic does not proceed with axiomatic systems, but fuzzy versions of the semantic properties exist and can be shown to correspond to some of the axioms for the crisp systems in special ways that support dependency networks among assertions in a modal domain. This in turn allows one to implement truth maintenance systems. For the technical development of epistemic logic, and for that of deontic logic. To our knowledge, we are the first to address fuzzy epistemic and fuzzy deontic logic explicitly and to consider the different systems and semantic properties available. We give the syntax and semantics of epistemic logic and discuss the correspondence between axioms of epistemic logic and properties of semantic structures. The same topics are covered for deontic logic. Fuzzy epistemic and fuzzy deontic logic discusses the relationship between axioms and semantic properties for these logics. Our results can be exploited in truth maintenance systems.

  2. The Logic Behind Feynman's Paths

    NASA Astrophysics Data System (ADS)

    García Álvarez, Edgardo T.

    The classical notions of continuity and mechanical causality are left in order to reformulate the Quantum Theory starting from two principles: (I) the intrinsic randomness of quantum process at microphysical level, (II) the projective representations of symmetries of the system. The second principle determines the geometry and then a new logic for describing the history of events (Feynman's paths) that modifies the rules of classical probabilistic calculus. The notion of classical trajectory is replaced by a history of spontaneous, random and discontinuous events. So the theory is reduced to determining the probability distribution for such histories accordingly with the symmetries of the system. The representation of the logic in terms of amplitudes leads to Feynman rules and, alternatively, its representation in terms of projectors results in the Schwinger trace formula.

  3. An Embedded Reconfigurable Logic Module

    NASA Technical Reports Server (NTRS)

    Tucker, Jerry H.; Klenke, Robert H.; Shams, Qamar A. (Technical Monitor)

    2002-01-01

    A Miniature Embedded Reconfigurable Computer and Logic (MERCAL) module has been developed and verified. MERCAL was designed to be a general-purpose, universal module that that can provide significant hardware and software resources to meet the requirements of many of today's complex embedded applications. This is accomplished in the MERCAL module by combining a sub credit card size PC in a DIMM form factor with a XILINX Spartan I1 FPGA. The PC has the ability to download program files to the FPGA to configure it for different hardware functions and to transfer data to and from the FPGA via the PC's ISA bus during run time. The MERCAL module combines, in a compact package, the computational power of a 133 MHz PC with up to 150,000 gate equivalents of digital logic that can be reconfigured by software. The general architecture and functionality of the MERCAL hardware and system software are described.

  4. Nanowire NMOS Logic Inverter Characterization.

    PubMed

    Hashim, Yasir

    2016-06-01

    This study is the first to demonstrate characteristics optimization of nanowire N-Channel Metal Oxide Semiconductor (NW-MOS) logic inverter. Noise margins and inflection voltage of transfer characteristics are used as limiting factors in this optimization. A computer-based model used to produce static characteristics of NW-NMOS logic inverter. In this research two circuit configuration of NW-NMOS inverter was studied, in first NW-NMOS circuit, the noise margin for (low input-high output) condition was very low. For second NMOS circuit gives excellent noise margins, and results indicate that optimization depends on applied voltage to the inverter. Increasing gate to source voltage with (2/1) nanowires ratio results better noise margins. Increasing of applied DC load transistor voltage tends to increasing in decreasing noise margins; decreasing this voltage will improve noise margins significantly. PMID:27427653

  5. Computation of Hypersonic Flow about Maneuvering Vehicles with Changing Shapes

    SciTech Connect

    Ferencz, R M; Felker, F F; Castillo, V M

    2004-02-23

    Vehicles moving at hypersonic speeds have great importance to the National Security. Ballistic missile re-entry vehicles (RV's) travel at hypersonic speeds, as do missile defense intercept vehicles. Despite the importance of the problem, no computational analysis method is available to predict the aerodynamic environment of maneuvering hypersonic vehicles, and no analysis is available to predict the transient effects of their shape changes. The present state-of-the-art for hypersonic flow calculations typically still considers steady flow about fixed shapes. Additionally, with present computational methods, it is not possible to compute the entire transient structural and thermal loads for a re-entry vehicle. The objective of this research is to provide the required theoretical development and a computational analysis tool for calculating the hypersonic flow about maneuvering, deforming RV's. This key enabling technology will allow the development of a complete multi-mechanics simulation of the entire RV flight sequence, including important transient effects such as complex flight dynamics. This will allow the computation of the as-delivered state of the payload in both normal and unusual operational environments. This new analysis capability could also provide the ability to predict the nonlinear, transient behavior of endo-atmospheric missile interceptor vehicles to the input of advanced control systems. Due to the computational intensity of fluid dynamics for hypersonics, the usual approach for calculating the flow about a vehicle that is changing shape is to complete a series of steady calculations, each with a fixed shape. However, this quasi-steady approach is not adequate to resolve the frequencies characteristic of a vehicle's structural dynamics. Our approach is to include the effects of the unsteady body shape changes in the finite-volume method by allowing for arbitrary translation and deformation of the control volumes. Furthermore, because the Eulerian

  6. All-optical symmetric ternary logic gate

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay

    2010-09-01

    Symmetric ternary number (radix=3) has three logical states (1¯, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript.

  7. Adaptive Controller Effects on Pilot Behavior

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Gregory, Irene M.; Hempley, Lucas E.

    2014-01-01

    Adaptive control provides robustness and resilience for highly uncertain, and potentially unpredictable, flight dynamics characteristic. Some of the recent flight experiences of pilot-in-the-loop with an adaptive controller have exhibited unpredicted interactions. In retrospect, this is not surprising once it is realized that there are now two adaptive controllers interacting, the software adaptive control system and the pilot. An experiment was conducted to categorize these interactions on the pilot with an adaptive controller during control surface failures. One of the objectives of this experiment was to determine how the adaptation time of the controller affects pilots. The pitch and roll errors, and stick input increased for increasing adaptation time and during the segment when the adaptive controller was adapting. Not surprisingly, altitude, cross track and angle deviations, and vertical velocity also increase during the failure and then slowly return to pre-failure levels. Subjects may change their behavior even as an adaptive controller is adapting with additional stick inputs. Therefore, the adaptive controller should adapt as fast as possible to minimize flight track errors. This will minimize undesirable interactions between the pilot and the adaptive controller and maintain maneuvering precision.

  8. a Modal Logic of Indiscernibility

    NASA Astrophysics Data System (ADS)

    Krause, Décio Arenhart, Jonas R. Becker; Merlussi, Pedro

    This paper is a continuation of the authors' attempts to deal with the notion of indistinguishability (or indiscernibility) from a logical point of view. Now we introduce a two-sorted first-order modal logic to enable us to deal with objects of two different species. The intended interpretation is that objects of one of the species obey the rules of standard S5, while the objects of the other species obey only the rules of a weaker notion of indiscernibility. Quantum mechanics motivates the development. The basic idea is that in the `actual' world things may be indiscernible but in another accessible world they may be distinguished in some way. That is, indistinguishability needs not be seen as a necessary relation. Contrariwise, things might be distinguished in the `actual' world, but they may be indiscernible in another world. So, while two quantum systems may be entangled in the actual world, in some accessible world, due to a measurement, they can be discerned, and on the other hand, two initially separated quantum systems may enter in a state of superposition, losing their individualities. Two semantics are sketched for our system. The first is constructed within a standard set theory (the ZFC system is assumed at the metamathematics). The second one is constructed within the theory of quasi-sets, which we believe suits better the purposes of our logic and the mathematical treatment of certain situations in quantum mechanics. Some further philosophically related topics are considered.

  9. Cosmic logic: a computational model

    NASA Astrophysics Data System (ADS)

    Vanchurin, Vitaly

    2016-02-01

    We initiate a formal study of logical inferences in context of the measure problem in cosmology or what we call cosmic logic. We describe a simple computational model of cosmic logic suitable for analysis of, for example, discretized cosmological systems. The construction is based on a particular model of computation, developed by Alan Turing, with cosmic observers (CO), cosmic measures (CM) and cosmic symmetries (CS) described by Turing machines. CO machines always start with a blank tape and CM machines take CO's Turing number (also known as description number or Gödel number) as input and output the corresponding probability. Similarly, CS machines take CO's Turing number as input, but output either one if the CO machines are in the same equivalence class or zero otherwise. We argue that CS machines are more fundamental than CM machines and, thus, should be used as building blocks in constructing CM machines. We prove the non-computability of a CS machine which discriminates between two classes of CO machines: mortal that halts in finite time and immortal that runs forever. In context of eternal inflation this result implies that it is impossible to construct CM machines to compute probabilities on the set of all CO machines using cut-off prescriptions. The cut-off measures can still be used if the set is reduced to include only machines which halt after a finite and predetermined number of steps.

  10. Teleoperator Maneuvering System (TMS) benefits assessment study. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Teleoperator Maneuvering System (TMS) versus integral spacecraft propulsion, spacecraft maintenance, cost benefits, launch prices, integral propulsion length penalties, remote maintenance versus EVA, potential weight reduction benefits, basing mode, mission models and payload requirements, and program profitability are discussed.

  11. Aerodynamic Characteristics of an Aerospace Vehicle During a Subsonic Pitch-Over Maneuver

    NASA Technical Reports Server (NTRS)

    Kleb, William L.

    1996-01-01

    Time-dependent CFD has been used to predict aerospace vehicle aerodynamics during a subsonic rotation maneuver. The inviscid 3D3U code is employed to solve the 3-D unsteady flow field using an unstructured grid of tetrahedra. As this application represents a challenge to time-dependent CFD, observations concerning spatial and temporal resolution are included. It is shown that even for a benign rotation rate, unsteady aerodynamic effects are significant during the maneuver. Possibly more significant, however, the rotation maneuver creates ow asymmetries leading to yawing moment, rolling moment, and side force which are not present in the quasi-steady case. A series of steady solutions at discrete points in the maneuver are also computed for comparison with wind tunnel measurements and as a means of quantifying unsteady effects.

  12. Global Optimization of N-Maneuver, High-Thrust Trajectories Using Direct Multiple Shooting

    NASA Technical Reports Server (NTRS)

    Vavrina, Matthew A.; Englander, Jacob A.; Ellison, Donald H.

    2016-01-01

    The performance of impulsive, gravity-assist trajectories often improves with the inclusion of one or more maneuvers between flybys. However, grid-based scans over the entire design space can become computationally intractable for even one deep-space maneuver, and few global search routines are capable of an arbitrary number of maneuvers. To address this difficulty a trajectory transcription allowing for any number of maneuvers is developed within a multi-objective, global optimization framework for constrained, multiple gravity-assist trajectories. The formulation exploits a robust shooting scheme and analytic derivatives for computational efficiency. The approach is applied to several complex, interplanetary problems, achieving notable performance without a user-supplied initial guess.

  13. A Computer Simulation of the System-Wide Effects of Parallel-Offset Route Maneuvers

    NASA Technical Reports Server (NTRS)

    Lauderdale, Todd A.; Santiago, Confesor; Pankok, Carl

    2010-01-01

    Most aircraft managed by air-traffic controllers in the National Airspace System are capable of flying parallel-offset routes. This paper presents the results of two related studies on the effects of increased use of offset routes as a conflict resolution maneuver. The first study analyzes offset routes in the context of all standard resolution types which air-traffic controllers currently use. This study shows that by utilizing parallel-offset route maneuvers, significant system-wide savings in delay due to conflict resolution of up to 30% are possible. It also shows that most offset resolutions replace horizontal-vectoring resolutions. The second study builds on the results of the first and directly compares offset resolutions and standard horizontal-vectoring maneuvers to determine that in-trail conflicts are often more efficiently resolved by offset maneuvers.

  14. Efficacy of Epley's Maneuver in Treating BPPV Patients: A Prospective Observational Study

    PubMed Central

    Gaur, Sushil; Awasthi, Sanjeev Kumar; Bhadouriya, Sunil Kumar Singh; Saxena, Rohit; Pathak, Vivek Kumar; Bisht, Mamta

    2015-01-01

    Vertigo and balance disorders are among the most common symptoms encountered in patients who visit ENT outpatient department. This is associated with risk of falling and is compounded in elderly persons with other neurologic deficits and chronic medical problems. BPPV is the most common cause of peripheral vertigo. BPPV is a common vestibular disorder leading to significant morbidity, psychosocial impact, and medical costs. The objective of Epley's maneuver, which is noninvasive, inexpensive, and easily administered, is to move the canaliths out of the canal to the utricle where they no longer affect the canal dynamics. Our study aims to analyze the response to Epley's maneuver in a series of patients with posterior canal BPPV and compares the results with those treated exclusively by medical management alone. Even though many studies have been conducted to prove the efficacy of this maneuver, this study reinforces the validity of Epley's maneuver by comparison with the medical management. PMID:26495002

  15. Method to maintain artificial gravity during transfer maneuvers for tethered spacecraft

    NASA Astrophysics Data System (ADS)

    Martin, Kaela M.; Landau, Damon F.; Longuski, James M.

    2016-03-01

    Artificial gravity has long been proposed to limit the harmful effects of the micro-gravity environment on human crews during mission to Mars. A tethered spacecraft spinning at 4 rpm (to avoid motion sickness) provides an attractive configuration. However, if the spacecraft is required to spin down for impulsive maneuvers and then spin up for interplanetary travel, the propellant cost may be unacceptably high. This paper proposes a maneuver that is performed while the spacecraft is spinning thus avoiding additional spin-down and spin-up maneuvers. A control law is provided to achieve the required ΔV while maintaining spin rate. A hypothetical human mission from Earth to Mars is analyzed using the new maneuver which, in this example, may save over 700 kg of propellant.

  16. Global Optimization of N-Maneuver, High-Thrust Trajectories Using Direct Multiple Shooting

    NASA Technical Reports Server (NTRS)

    Vavrina, Matthew A.; Englander, Jacob A.; Ellison, Donald H.

    2015-01-01

    The performance of impulsive, gravity-assist trajectories often improves with the inclusion of one or more maneuvers between flybys. However, grid-based scans over the entire design space can become computationally intractable for even one deep-space maneuver, and few global search routines are capable of an arbitrary number of maneuvers. To address this difficulty a trajectory transcription allow-ing for any number of maneuvers is developed within a multi-objective, global optimization framework for constrained, multiple gravity-assist trajectories. The formulation exploits a robust shooting scheme and analytic derivatives for com-putational efficiency. The approach is applied to several complex, interplanetary problems, achieving notable performance without a user-supplied initial guess.

  17. Understanding the Role of Moment-of-Inertia Variation in Insect Flight Maneuvers

    NASA Astrophysics Data System (ADS)

    Lin, Tiras; Mittal, Rajat; Zheng, Lingxiao; Hedrick, Tyson

    2011-11-01

    The objective of this study is to gain insights into insect flight maneuvers and, in particular, the role that changes in body moment-of-inertia might play during these maneuvers. High-speed, high-resolution videogrammetry is used to quantify the trajectory and body conformation of Painted Lady butterflies during flight maneuvers; the 3D kinematics of the center-of-masses of the various body parts of the insect are determined experimentally. Measurements of the mass properties of the insect are then made and used to parameterize a simple flight dynamics model of the butterfly. Even though the mass of the flapping wings is small compared to the total mass of the insect, these experiments and subsequent analyses indicate that changes in moment-of-inertia during flight are large enough to have a noticeable impact on the maneuvers of these insects. Research is supported by NSF and AFOSR.

  18. 76 FR 8319 - Special Conditions: Gulfstream Model GVI Airplane; Design Roll Maneuver Requirement for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... Roll Maneuver Requirement for Electronic Flight Controls AGENCY: Federal Aviation Administration (FAA... airplanes. These design features include an electronic flight control system that provides roll control of the airplane through pilot inputs to the flight ] computers. These proposed special conditions...

  19. Efficacy of Epley's Maneuver in Treating BPPV Patients: A Prospective Observational Study.

    PubMed

    Gaur, Sushil; Awasthi, Sanjeev Kumar; Bhadouriya, Sunil Kumar Singh; Saxena, Rohit; Pathak, Vivek Kumar; Bisht, Mamta

    2015-01-01

    Vertigo and balance disorders are among the most common symptoms encountered in patients who visit ENT outpatient department. This is associated with risk of falling and is compounded in elderly persons with other neurologic deficits and chronic medical problems. BPPV is the most common cause of peripheral vertigo. BPPV is a common vestibular disorder leading to significant morbidity, psychosocial impact, and medical costs. The objective of Epley's maneuver, which is noninvasive, inexpensive, and easily administered, is to move the canaliths out of the canal to the utricle where they no longer affect the canal dynamics. Our study aims to analyze the response to Epley's maneuver in a series of patients with posterior canal BPPV and compares the results with those treated exclusively by medical management alone. Even though many studies have been conducted to prove the efficacy of this maneuver, this study reinforces the validity of Epley's maneuver by comparison with the medical management. PMID:26495002

  20. Independent Orbiter Assessment (IOA): Assessment of the manned maneuvering unit

    NASA Technical Reports Server (NTRS)

    Huynh, M.; Duffy, R. E.; Saiidi, M. J.

    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 Manned Maneuvering Unit (MMU) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contain within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Martin Marietta FMEA/CIL Post 51-L updates. A discussion of each discrepancy from the comparison is provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. The results of this comparison for the Orbiter MMU hardware are documented. The IOA product for the MMU analysis consisted of 204 failure mode worksheets that resulted in 95 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 179 FMEAs and 110 CIL items. This comparison produced agreement on all 121 FMEAs which caused differences in 92 CIL items.