Science.gov

Sample records for robust flight scheduling

  1. Robust flight control of rotorcraft

    NASA Astrophysics Data System (ADS)

    Pechner, Adam Daniel

    With recent design improvement in fixed wing aircraft, there has been a considerable interest in the design of robust flight control systems to compensate for the inherent instability necessary to achieve desired performance. Such systems are designed for maximum available retention of stability and performance in the presence of significant vehicle damage or system failure. The rotorcraft industry has shown similar interest in adopting these reconfigurable flight control schemes specifically because of their ability to reject disturbance inputs and provide a significant amount of robustness for all but the most catastrophic of situations. The research summarized herein focuses on the extension of the pseudo-sliding mode control design procedure interpreted in the frequency domain. Application of the technique is employed and simulated on two well known helicopters, a simplified model of a hovering Sikorsky S-61 and the military's Black Hawk UH-60A also produced by Sikorsky. The Sikorsky helicopter model details are readily available and was chosen because it can be limited to pitch and roll motion reducing the number of degrees of freedom and yet contains two degrees of freedom, which is the minimum requirement in proving the validity of the pseudo-sliding control technique. The full order model of a hovering Black Hawk system was included both as a comparison to the S-61 helicopter design system and as a means to demonstrate the scaleability and effectiveness of the control technique on sophisticated systems where design robustness is of critical concern.

  2. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight scheduling and locating requirements... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a)...

  3. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight scheduling and locating requirements... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a)...

  4. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight scheduling and locating requirements... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a)...

  5. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight scheduling and locating requirements... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a)...

  6. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  7. Low Bandwidth Robust Controllers for Flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  8. Design of flight control systems via robust decoupled servomechanism theory

    NASA Technical Reports Server (NTRS)

    Wang, S.-H.; Davison, E. J.

    1979-01-01

    Decoupling theory and robust servomechanism theory are applied to the design of linear multivariable systems with large parameter variations. In addition to being approximately decoupled in the transient period, the over-all system achieves tracking and disturbance rejection robustly in the steady state. An example in flight control system is given.

  9. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1992-01-01

    During the final reporting period (Jun. - Dec. 1992), analyses of the longitudinal and lateral flying qualities were made for propulsive-only flight control (POFC) of a Boeing 720 aircraft model. Performance resulting from compensators developed using Quantitative Feedback Theory (QFT) is documented and analyzed. This report is a first draft of a thesis to be presented by graduate student Hwei-Lan Chou. The final thesis will be presented to NASA when it is completed later this year. The latest landing metrics related to bandwidth criteria and based on the Neal-Smith approach to flying qualities prediction were used in developing performance criteria for the controllers. The compensator designs were tested on the NASA simulator and exhibited adequate performance for piloted flight. There was no significant impact of QFT on performance of the propulsive-only flight controllers in either the longitudinal or lateral modes of flight. This was attributed to the physical limits of thrust available and the engine rate of response, both of whiih severely limited the available bandwidth of the closed-loop system.

  10. Robust Flutter Margin Analysis that Incorporates Flight Data

    NASA Technical Reports Server (NTRS)

    Lind, Rick; Brenner, Martin J.

    1998-01-01

    An approach for computing worst-case flutter margins has been formulated in a robust stability framework. Uncertainty operators are included with a linear model to describe modeling errors and flight variations. The structured singular value, mu, computes a stability margin that directly accounts for these uncertainties. This approach introduces a new method of computing flutter margins and an associated new parameter for describing these margins. The mu margins are robust margins that indicate worst-case stability estimates with respect to the defined uncertainty. Worst-case flutter margins are computed for the F/A-18 Systems Research Aircraft using uncertainty sets generated by flight data analysis. The robust margins demonstrate flight conditions for flutter may lie closer to the flight envelope than previously estimated by p-k analysis.

  11. Optimization models for flight test scheduling

    NASA Astrophysics Data System (ADS)

    Holian, Derreck

    with restriction removal is based on heuristic approaches to support the reality of flight test in both solution space and computational time. Exact methods for yielding an optimized solution will be discussed however they are not directly applicable to the flight test problem and therefore have not been included in the system.

  12. Robust Gain-Scheduled Fault Tolerant Control for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Gregory, Irene

    2007-01-01

    This paper presents an application of robust gain-scheduled control concepts using a linear parameter-varying (LPV) control synthesis method to design fault tolerant controllers for a civil transport aircraft. To apply the robust LPV control synthesis method, the nonlinear dynamics must be represented by an LPV model, which is developed using the function substitution method over the entire flight envelope. The developed LPV model associated with the aerodynamic coefficient uncertainties represents nonlinear dynamics including those outside the equilibrium manifold. Passive and active fault tolerant controllers (FTC) are designed for the longitudinal dynamics of the Boeing 747-100/200 aircraft in the presence of elevator failure. Both FTC laws are evaluated in the full nonlinear aircraft simulation in the presence of the elevator fault and the results are compared to show pros and cons of each control law.

  13. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service operations. (a) Requirement of notice. Scheduled international air services proposed to be operated...

  14. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service operations. (a) Requirement of notice. Scheduled international air services proposed to be operated...

  15. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service operations. (a) Requirement of notice. Scheduled international air services proposed to be operated...

  16. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service operations. (a) Requirement of notice. Scheduled international air services proposed to be operated...

  17. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service operations. (a) Requirement of notice. Scheduled international air services proposed to be operated...

  18. Individual differences in strategic flight management and scheduling

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Raby, Mireille

    1991-01-01

    A group of 30 instrument-rated pilots was made to fly simulator approaches to three airports under conditions of low, medium, and high workload conditions. An analysis is presently conducted of the difference in discrete task scheduling between the group of 10 highest and 10 lowest performing pilots in the sample; this categorization was based on the mean of various flight-profile measures. The two groups were found to differ from each other only in terms of the time when specific events were conducted, and of the optimality of scheduling for certain high-priority tasks. These results are assessed in view of the relative independence of task-management skills from aircraft-control skills.

  19. Multi-Agent Flight Simulation with Robust Situation Generation

    NASA Technical Reports Server (NTRS)

    Johnson, Eric N.; Hansman, R. John, Jr.

    1994-01-01

    A robust situation generation architecture has been developed that generates multi-agent situations for human subjects. An implementation of this architecture was developed to support flight simulation tests of air transport cockpit systems. This system maneuvers pseudo-aircraft relative to the human subject's aircraft, generating specific situations for the subject to respond to. These pseudo-aircraft maneuver within reasonable performance constraints, interact in a realistic manner, and make pre-recorded voice radio communications. Use of this system minimizes the need for human experimenters to control the pseudo-agents and provides consistent interactions between the subject and the pseudo-agents. The achieved robustness of this system to typical variations in the subject's flight path was explored. It was found to successfully generate specific situations within the performance limitations of the subject-aircraft, pseudo-aircraft, and the script used.

  20. Robust, Decoupled, Flight Control Design with Rate Saturating Actuators

    NASA Technical Reports Server (NTRS)

    Snell, S. A.; Hess, R. A.

    1997-01-01

    Techniques for the design of control systems for manually controlled, high-performance aircraft must provide the following: (1) multi-input, multi-output (MIMO) solutions, (2) acceptable handling qualities including no tendencies for pilot-induced oscillations, (3) a tractable approach for compensator design, (4) performance and stability robustness in the presence of significant plant uncertainty, and (5) performance and stability robustness in the presence actuator saturation (particularly rate saturation). A design technique built upon Quantitative Feedback Theory is offered as a candidate methodology which can provide flight control systems meeting these requirements, and do so over a considerable part of the flight envelope. An example utilizing a simplified model of a supermaneuverable fighter aircraft demonstrates the proposed design methodology.

  1. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations and rest... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.265 Flight time limitations and rest requirements: Scheduled operations. (a) No certificate...

  2. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations and rest... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.265 Flight time limitations and rest requirements: Scheduled operations. (a) No certificate...

  3. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations and rest... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.265 Flight time limitations and rest requirements: Scheduled operations. (a) No certificate...

  4. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations and rest... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.265 Flight time limitations and rest requirements: Scheduled operations. (a) No certificate...

  5. Mars Science Laboratory Flight Software Boot Robustness Testing Project Report

    NASA Technical Reports Server (NTRS)

    Roth, Brian

    2011-01-01

    On the surface of Mars, the Mars Science Laboratory will boot up its flight computers every morning, having charged the batteries through the night. This boot process is complicated, critical, and affected by numerous hardware states that can be difficult to test. The hardware test beds do not facilitate testing a long duration of back-to-back unmanned automated tests, and although the software simulation has provided the necessary functionality and fidelity for this boot testing, there has not been support for the full flexibility necessary for this task. Therefore to perform this testing a framework has been build around the software simulation that supports running automated tests loading a variety of starting configurations for software and hardware states. This implementation has been tested against the nominal cases to validate the methodology, and support for configuring off-nominal cases is ongoing. The implication of this testing is that the introduction of input configurations that have yet proved difficult to test may reveal boot scenarios worth higher fidelity investigation, and in other cases increase confidence in the robustness of the flight software boot process.

  6. 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.

  7. Nonlinear Robustness Analysis Tools for Flight Control Law Validation & Verification

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhijit

    Loss of control in flight is among the highest aviation accident categories for both the number of accidents and the number of fatalities. The flight controls community is seeking an improved validation tools for safety critical flight control systems. Current validation tools rely heavily on linear analysis, which ignore the inherent nonlinear nature of the aircraft dynamics and flight control system. Specifically, current practices in validating the flight control system involve gridding the flight envelope and checking various criteria based on linear analysis to ensure safety of the flight control system. The analysis and certification methods currently applied assume the aircrafts' dynamics is linear. In reality, the behavior of the aircraft is always nonlinear due to its aerodynamic characteristics and physical limitations imposed by the actuators. This thesis develops nonlinear analysis tools capable of certifying flight control laws for nonlinear aircraft dynamics. The proposed analysis tools can handle both the aerodynamic nonlinearities and the physical limitations imposed by the actuators in the aircrafts' dynamics. This proposed validation technique will extend and enrich the predictive capability of existing flight control law validation methods to analyze nonlinearities. The objective of this thesis is to provide the flight control community with an advanced set of analysis tools to reduce aviation fatalities and accidents rate.

  8. Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

    NASA Technical Reports Server (NTRS)

    Chamitoff, Gregory Errol

    1992-01-01

    Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

  9. Robust gain-scheduling for smart-structures in parallel robots

    NASA Astrophysics Data System (ADS)

    Algermissen, Stephan; Rose, Michael; Keimer, Ralf; Sinapius, Michael

    2009-03-01

    In the past years parallel robots demonstrated their capability in applications with high-dynamic trajectories. Smart-structures offer the potential to further increase the productivity of parallel robots by reducing disturbing vibrations caused by high dynamic loads effectively. To investigate parallel robots and their applications, including suitable control concepts for smart-structures, the Collaborative Research Center 562 was founded by the German Research Council (DFG). The latest prototype within this research center is called Triglide. It is a four degree of freedom (DOF) robot with three translational and one rotational DOF. It realizes an acceleration of 10 g* at the effector. In the structure of the robot six active rods and a tri-axial accelerometer are integrated to control effector vibrations in three translational DOF. The main challenge of this control application is the position dependent vibration behavior. A single robust controller is not able to gain satisfying performance within the entire workspace. Therefore a strategy for describing the vibration behavior by linearization at several operating points is developed. Behavior in-between is approximated by a linear approach. On a trajectory robust controllers in all operating points are smoothly switched by robust gain-scheduling. The scheduling parameters are fast varying and though a suitable stability proof is defined, based on Small-Gain approach. Several transformations enhance the results from Small-Gain Theorem and reduce the usual conservatism. Experimental data is used to show the improvements made.

  10. Real-Time Robust Adaptive Modeling and Scheduling for an Electronic Commerce Server

    NASA Astrophysics Data System (ADS)

    Du, Bing; Ruan, Chun

    With the increasing importance and pervasiveness of Internet services, it is becoming a challenge for the proliferation of electronic commerce services to provide performance guarantees under extreme overload. This paper describes a real-time optimization modeling and scheduling approach for performance guarantee of electronic commerce servers. We show that an electronic commerce server may be simulated as a multi-tank system. A robust adaptive server model is subject to unknown additive load disturbances and uncertain model matching. Overload control techniques are based on adaptive admission control to achieve timing guarantees. We evaluate the performance of the model using a complex simulation that is subjected to varying model parameters and massive overload.

  11. Wake Cycle Robustness of the Mars Science Laboratory Flight Software

    NASA Technical Reports Server (NTRS)

    Whitehill, Robert

    2011-01-01

    The Mars Science Laboratory (MSL) is a spacecraft being developed by the Jet Propulsion Laboratory (JPL) for the purpose of in-situ exploration on the surface of Mars. The objective of MSL is to explore and quantitatively assess a local region on the Martian surface as a habitat for microbial life, past or present. This objective will be accomplished through the assessment of the biological potential of at least one target environment, the characterization of the geology and geochemistry of the landing region, an investigation of the planetary process relevant to past habitability, and a characterization of surface radiation. For this purpose, MSL incorporates a total of ten scientific instruments for which functions are to include, among others, atmospheric and descent imaging, chemical composition analysis, and radiation measurement. The Flight Software (FSW) system is responsible for all mission phases, including launch, cruise, entry-descent-landing, and surface operation of the rover. Because of the essential nature of flight software to project success, each of the software modules is undergoing extensive testing to identify and correct errors.

  12. Reconfigurable Flight Control Design using a Robust Servo LQR and Radial Basis Function Neural Networks

    NASA Technical Reports Server (NTRS)

    Burken, John J.

    2005-01-01

    This viewgraph presentation reviews the use of a Robust Servo Linear Quadratic Regulator (LQR) and a Radial Basis Function (RBF) Neural Network in reconfigurable flight control designs in adaptation to a aircraft part failure. The method uses a robust LQR servomechanism design with model Reference adaptive control, and RBF neural networks. During the failure the LQR servomechanism behaved well, and using the neural networks improved the tracking.

  13. Robust Flight Path Determination for Mars Precision Landing Using Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Kohen, Hamid

    1997-01-01

    This paper documents the application of genetic algorithms (GAs) to the problem of robust flight path determination for Mars precision landing. The robust flight path problem is defined here as the determination of the flight path which delivers a low-lift open-loop controlled vehicle to its desired final landing location while minimizing the effect of perturbations due to uncertainty in the atmospheric model and entry conditions. The genetic algorithm was capable of finding solutions which reduced the landing error from 111 km RMS radial (open-loop optimal) to 43 km RMS radial (optimized with respect to perturbations) using 200 hours of computation on an Ultra-SPARC workstation. Further reduction in the landing error is possible by going to closed-loop control which can utilize the GA optimized paths as nominal trajectories for linearization.

  14. Utilizing Traveler Demand Modeling to Predict Future Commercial Flight Schedules in the NAS

    NASA Technical Reports Server (NTRS)

    Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

    2006-01-01

    The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

  15. Flying Schedule-Matching Descents to Explore Flight Crews' Perceptions of Their Load and Task Feasibility

    NASA Technical Reports Server (NTRS)

    Martin, Lynne Hazel; Sharma, Shivanjli; Lozito, Sharon; Kaneshige, John; Hayashi, Miwa; Dulchinos, Victoria

    2012-01-01

    Multiple studies have investigated the development and use of ground-based (controller) tools to manage and schedule traffic in future terminal airspace. No studies have investigated the impacts that such tools (and concepts) could have on the flight-deck. To begin to redress the balance, an exploratory study investigated the procedures and actions of ten Boeing-747-400 crews as they flew eight continuous descent approaches in the Los Angeles terminal airspace, with the descents being controlled using speed alone. Although the study was exploratory in nature, four variables were manipulated: speed changes, route constraints, clearance phraseology, and winds. Despite flying the same scenarios with the same events and timing, there was at least a 50 second difference in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The primary focus of this paper is the potential impact of ground scheduling tools on the flight crews performance and procedures. Crews reported "moderate to low" workload, on average; however, short periods of intense and high workload were observed. The non-flying pilot often reported a higher level of workload than the flying-pilot, which may be due to their increased interaction with the Flight Management Computer, when using the aircraft automation to assist with managing the descent clearances. It is concluded that ground-side tools and automation may have a larger impact on the current-day flight-deck than was assumed and that studies investigating this impact should continue in parallel with controller support tool development.

  16. Robust, Radiation Tolerant Command and Data Handling and Power System Electronics from NASA Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Nguyen, Hanson C.; Fraction, James; Ortiz-Acosta, Melyane; Dakermanji, George; Kercheval, Bradford P.; Hernandez-Pellerano, Amri; Kim, David S.; Jung, David S.; Meyer, Steven E.; Mallik, Udayan; Rush, Kurt D.; Farid, Faramarz; Olsen, James C.; Sparacino, Pietro A.

    2016-01-01

    The Goddard Modular Smallsat Architecture (GMSA) is developed at NASA Goddard Space Flight Center (GSFC) to address future reliability along with minimizing cost and schedule challenges for NASA Cubesat and Smallsat missions.

  17. Optimal search patterns in honeybee orientation flights are robust against emerging infectious diseases.

    PubMed

    Wolf, Stephan; Nicholls, Elizabeth; Reynolds, Andrew M; Wells, Patricia; Lim, Ka S; Paxton, Robert J; Osborne, Juliet L

    2016-01-01

    Lévy flights are scale-free (fractal) search patterns found in a wide range of animals. They can be an advantageous strategy promoting high encounter rates with rare cues that may indicate prey items, mating partners or navigational landmarks. The robustness of this behavioural strategy to ubiquitous threats to animal performance, such as pathogens, remains poorly understood. Using honeybees radar-tracked during their orientation flights in a novel landscape, we assess for the first time how two emerging infectious diseases (Nosema sp. and the Varroa-associated Deformed wing virus (DWV)) affect bees' behavioural performance and search strategy. Nosema infection, unlike DWV, affected the spatial scale of orientation flights, causing significantly shorter and more compact flights. However, in stark contrast to disease-dependent temporal fractals, we find the same prevalence of optimal Lévy flight characteristics (μ ≈ 2) in both healthy and infected bees. We discuss the ecological and evolutionary implications of these surprising insights, arguing that Lévy search patterns are an emergent property of fundamental characteristics of neuronal and sensory components of the decision-making process, making them robust against diverse physiological effects of pathogen infection and possibly other stressors. PMID:27615605

  18. Flight control application of new stability robustness bounds for linear uncertain systems

    NASA Technical Reports Server (NTRS)

    Yedavalli, Rama K.

    1993-01-01

    This paper addresses the issue of obtaining bounds on the real parameter perturbations of a linear state-space model for robust stability. Based on Kronecker algebra, new, easily computable sufficient bounds are derived that are much less conservative than the existing bounds since the technique is meant for only real parameter perturbations (in contrast to specializing complex variation case to real parameter case). The proposed theory is illustrated with application to several flight control examples.

  19. Multivariable flight control synthesis and literal robustness analysis for an aeroelastic vehicle

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.; Newman, Brett

    1990-01-01

    An integrated flight/aeroelastic control law is developed analytically for a hypothetical large supersonic transport aircraft in which the first aeroelastic mode frequency of the fuselage (6 rad/sec) is near the short-period mode (2 rad/sec). The approach employed is based on a linear-quadratic-regulator (LQR) formulation (yielding model-following state-feedback gains), followed by asymptotic loop-transfer recovery of LQR robustness (to produce an output-feedback control law). The derivation is outlined, and numerical results comparing the performance and multivariate stability robustness of the present controller with those of a classical controller are presented in graphs. The two controllers are shown to have similar characteristics, even with respect to the sources of limitations on robustness.

  20. Calculation of Flight Deck Interval Management Assigned Spacing Goals Subject to Multiple Scheduling Constraints

    NASA Technical Reports Server (NTRS)

    Robinson, John E.

    2014-01-01

    The Federal Aviation Administration's Next Generation Air Transportation System will combine advanced air traffic management technologies, performance-based procedures, and state-of-the-art avionics to maintain efficient operations throughout the entire arrival phase of flight. Flight deck Interval Management (FIM) operations are expected to use sophisticated airborne spacing capabilities to meet precise in-trail spacing from top-of-descent to touchdown. Recent human-in-the-loop simulations by the National Aeronautics and Space Administration have found that selection of the assigned spacing goal using the runway schedule can lead to premature interruptions of the FIM operation during periods of high traffic demand. This study compares three methods for calculating the assigned spacing goal for a FIM operation that is also subject to time-based metering constraints. The particular paradigms investigated include: one based upon the desired runway spacing interval, one based upon the desired meter fix spacing interval, and a composite method that combines both intervals. These three paradigms are evaluated for the primary arrival procedures to Phoenix Sky Harbor International Airport using the entire set of Rapid Update Cycle wind forecasts from 2011. For typical meter fix and runway spacing intervals, the runway- and meter fix-based paradigms exhibit moderate FIM interruption rates due to their inability to consider multiple metering constraints. The addition of larger separation buffers decreases the FIM interruption rate but also significantly reduces the achievable runway throughput. The composite paradigm causes no FIM interruptions, and maintains higher runway throughput more often than the other paradigms. A key implication of the results with respect to time-based metering is that FIM operations using a single assigned spacing goal will not allow reduction of the arrival schedule's excess spacing buffer. Alternative solutions for conducting the FIM operation

  1. Axial flow effects on robustness of vortical structures about actively deflected wings in flapping flight

    NASA Astrophysics Data System (ADS)

    Medina, Albert; Kweon, Jihoon; Choi, Haecheon; Eldredge, Jeff D.

    2012-11-01

    Flapping wing flight has garnered much attention in the past decade driven by our desire to understand capabilities observed in nature and to develop agile small-scale aerial vehicles. Nature has demonstrated the breadth of maneuverability achievable by flapping wing flight. However, despite recent advances the role of wing flexibility remains poorly understood. In an effort to develop a deeper understanding of wing deflection effects and to explore novel approaches to increasing leading-edge vortex robustness, this three-dimensional computational study explores the aerodynamics of low aspect ratio plates, in hovering kinematics, with isolated flexion lines undergoing prescribed deflection. Major flexion lines, recognized as the primary avenue for deflection in biological fliers, are isolated here in two distinct configurations, resulting in deflection about the wing root and the wing tip, respectively. Of interest is the interaction between axial flow along the span and the vortical structures about the wing. It is proposed that the modes of deflection explored may provide a means of axial flow control for favorably promoting LEV robustness over a broad range of flapping conditions, and provide insight into the nature of flexibility in flapping wing flight. National Science Foundation, National Research Foundation of Korea.

  2. A robust rotorcraft flight control system design methodology utilizing quantitative feedback theory

    NASA Technical Reports Server (NTRS)

    Gorder, Peter James

    1993-01-01

    Rotorcraft flight control systems present design challenges which often exceed those associated with fixed-wing aircraft. First, large variations in the response characteristics of the rotorcraft result from the wide range of airspeeds of typical operation (hover to over 100 kts). Second, the assumption of vehicle rigidity often employed in the design of fixed-wing flight control systems is rarely justified in rotorcraft where rotor degrees of freedom can have a significant impact on the system performance and stability. This research was intended to develop a methodology for the design of robust rotorcraft flight control systems. Quantitative Feedback Theory (QFT) was chosen as the basis for the investigation. Quantitative Feedback Theory is a technique which accounts for variability in the dynamic response of the controlled element in the design robust control systems. It was developed to address a Multiple-Input Single-Output (MISO) design problem, and utilizes two degrees of freedom to satisfy the design criteria. Two techniques were examined for extending the QFT MISO technique to the design of a Multiple-Input-Multiple-Output (MIMO) flight control system (FCS) for a UH-60 Black Hawk Helicopter. In the first, a set of MISO systems, mathematically equivalent to the MIMO system, was determined. QFT was applied to each member of the set simultaneously. In the second, the same set of equivalent MISO systems were analyzed sequentially, with closed loop response information from each loop utilized in subsequent MISO designs. The results of each technique were compared, and the advantages of the second, termed Sequential Loop Closure, were clearly evident.

  3. Flight control design using a blend of modern nonlinear adaptive and robust techniques

    NASA Astrophysics Data System (ADS)

    Yang, Xiaolong

    In this dissertation, the modern control techniques of feedback linearization, mu synthesis, and neural network based adaptation are used to design novel control laws for two specific applications: F/A-18 flight control and reusable launch vehicle (an X-33 derivative) entry guidance. For both applications, the performance of the controllers is assessed. As a part of a NASA Dryden program to develop and flight test experimental controllers for an F/A-18 aircraft, a novel method of combining mu synthesis and feedback linearization is developed to design longitudinal and lateral-directional controllers. First of all, the open-loop and closed-loop dynamics of F/A-18 are investigated. The production F/A-18 controller as well as the control distribution mechanism are studied. The open-loop and closed-loop handling qualities of the F/A-18 are evaluated using low order transfer functions. Based on this information, a blend of robust mu synthesis and feedback linearization is used to design controllers for a low dynamic pressure envelope of flight conditions. For both the longitudinal and the lateral-directional axes, a robust linear controller is designed for a trim point in the center of the envelope. Then by including terms to cancel kinematic nonlinearities and variations in the aerodynamic forces and moments over the flight envelope, a complete nonlinear controller is developed. In addition, to compensate for the model uncertainty, linearization error and variations between operating points, neural network based adaptation is added to the designed longitudinal controller. The nonlinear simulations, robustness and handling qualities analysis indicate that the performance is similar to or better than that for the production F/A-18 controllers. When the dynamic pressure is very low, the performance of both the experimental and the production flight controllers is degraded, but Level I handling qualities are still achieved. A new generation of Reusable Launch Vehicles

  4. Flight-Deck Strategies and Outcomes When Flying Schedule-Matching Descents

    NASA Technical Reports Server (NTRS)

    Kaneshige, John T.; Sharma, Shivanjli; Martin Lynne; Lozito, Sandra; Dulchinos, Victoria

    2013-01-01

    Recent studies at NASA Ames Research Center have investigated the development and use of ground-based (air traffic controller) tools to manage and schedule air traffic in future terminal airspace. An exploratory study was undertaken to investigate the impacts that such tools (and concepts) could have on the flight-deck. Ten Boeing 747-400 crews flew eight optimized profile descents in the Los Angeles terminal airspace, while receiving scripted current day and futuristic speed clearances, to ascertain their ability to fly schedulematching descents without prior training. Although the study was exploratory in nature, four variables were manipulated: route constraints, winds, speed changes, and clearance phraseology. Despite flying the same scenarios with the same events and timing, there were significant differences in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The focus of this paper is the examination of the crews' aircraft management strategies and outcomes. This includes potentially problematic human-automation interaction issues that may negatively impact arrival times, speed and altitude constraint compliance, and energy management efficiency.

  5. Integrated modeling and robust control for full-envelope flight of robotic helicopters

    NASA Astrophysics Data System (ADS)

    La Civita, Marco

    Robotic helicopters have attracted a great deal of interest from the university, the industry, and the military world. They are versatile machines and there is a large number of important missions that they could accomplish. Nonetheless, there are only a handful of documented examples of robotic-helicopter applications in real-world scenarios. This situation is mainly due to the poor flight performance that can be achieved and---more important---guaranteed under automatic control. Given the maturity of control theory, and given the large body of knowledge in helicopter dynamics, it seems that the lack of success in flying high-performance controllers for robotic helicopters, especially by academic groups and by small industries, has nothing to do with helicopters or control theory as such. The problem lies instead in the large amount of time and resources needed to synthesize, test, and implement new control systems with the approach normally followed in the aeronautical industry. This thesis attempts to provide a solution by presenting a modeling and control framework that minimizes the time, cost, and both human and physical resources necessary to design high-performance flight controllers. The work is divided in two main parts. The first consists of the development of a modeling technique that allows the designer to obtain a high-fidelity model adequate for both real-time simulation and controller design, with few flight, ground, and wind-tunnel tests and a modest level of complexity in the dynamic equations. The second consists of the exploitation of the predictive capabilities of the model and of the robust stability and performance guarantees of the Hinfinity loop-shaping control theory to reduce the number of iterations of the design/simulated-evaluation/flight-test-evaluation procedure. The effectiveness of this strategy is demonstrated by designing and flight testing a wide-envelope high-performance controller for the Carnegie Mellon University robotic

  6. Robust integrated flight/propulsion control design for a STOVL aircraft using H-infinity control design techniques

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay

    1993-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight/propulsion control (IFPC) system design for a supersonic STOVL fighter aircraft in transition flight. The emphasis is on formulating the H-infinity optimal control synthesis problem such that the critical requirements for the flight and propulsion systems are adequately reflected within the linear, centralized control problem formulation and the resulting controller provides robustness to modeling uncertainties and model parameter variations with flight condition. Detailed evaluation results are presented for a reduced order controller obtained from the improved H-infinity control design showing that the control design meets the specified nominal performance objective as well as provides stability robustness for variations in plant system dynamics with changes in aircraft trim speed within the transition flight envelope.

  7. Flight Test of the Engine Fuel Schedules of the X-43A Hyper-X Research Vehicles

    NASA Technical Reports Server (NTRS)

    Jones, Thomas

    2006-01-01

    The Hyper-X program flew two X-43A Hyper-X Research Vehicles (HXRVs) in 2004, referred to as Ship 2 and Ship 3. The scramjet engine of the X-43A research vehicle was autonomously controlled in flight to track a predetermined fueling schedule. Ship 2 flew at approximately Mach 7 and Ship 3 flew at approximately Mach 10.

  8. SUSI 62 A Robust and Safe Parachute Uav with Long Flight Time and Good Payload

    NASA Astrophysics Data System (ADS)

    Thamm, H. P.

    2011-09-01

    In many research areas in the geo-sciences (erosion, land use, land cover change, etc.) or applications (e.g. forest management, mining, land management etc.) there is a demand for remote sensing images of a very high spatial and temporal resolution. Due to the high costs of classic aerial photo campaigns, the use of a UAV is a promising option for obtaining the desired remote sensed information at the time it is needed. However, the UAV must be easy to operate, safe, robust and should have a high payload and long flight time. For that purpose, the parachute UAV SUSI 62 was developed. It consists of a steel frame with a powerful 62 cm3 2- stroke engine and a parachute wing. The frame can be easily disassembled for transportation or to replace parts. On the frame there is a gimbal mounted sensor carrier where different sensors, standard SLR cameras and/or multi-spectral and thermal sensors can be mounted. Due to the design of the parachute, the SUSI 62 is very easy to control. Two different parachute sizes are available for different wind speed conditions. The SUSI 62 has a payload of up to 8 kg providing options to use different sensors at the same time or to extend flight duration. The SUSI 62 needs a runway of between 10 m and 50 m, depending on the wind conditions. The maximum flight speed is approximately 50 km/h. It can be operated in a wind speed of up to 6 m/s. The design of the system utilising a parachute UAV makes it comparatively safe as a failure of the electronics or the remote control only results in the UAV coming to the ground at a slow speed. The video signal from the camera, the GPS coordinates and other flight parameters are transmitted to the ground station in real time. An autopilot is available, which guarantees that the area of investigation is covered at the desired resolution and overlap. The robustly designed SUSI 62 has been used successfully in Europe, Africa and Australia for scientific projects and also for agricultural, forestry and

  9. On-Line Mu Method for Robust Flutter Prediction in Expanding a Safe Flight Envelope for an Aircraft Model Under Flight Test

    NASA Technical Reports Server (NTRS)

    Lind, Richard C. (Inventor); Brenner, Martin J.

    2001-01-01

    A structured singular value (mu) analysis method of computing flutter margins has robust stability of a linear aeroelastic model with uncertainty operators (Delta). Flight data is used to update the uncertainty operators to accurately account for errors in the computed model and the observed range of aircraft dynamics of the aircraft under test caused by time-varying aircraft parameters, nonlinearities, and flight anomalies, such as test nonrepeatability. This mu-based approach computes predict flutter margins that are worst case with respect to the modeling uncertainty for use in determining when the aircraft is approaching a flutter condition and defining an expanded safe flight envelope for the aircraft that is accepted with more confidence than traditional methods that do not update the analysis algorithm with flight data by introducing mu as a flutter margin parameter that presents several advantages over tracking damping trends as a measure of a tendency to instability from available flight data.

  10. Two Reconfigurable Flight-Control Design Methods: Robust Servomechanism and Control Allocation

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Lu, Ping; Wu, Zheng-Lu; Bahm, Cathy

    2001-01-01

    Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the fight body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

  11. Robustness

    NASA Technical Reports Server (NTRS)

    Ryan, R.

    1993-01-01

    Robustness is a buzz word common to all newly proposed space systems design as well as many new commercial products. The image that one conjures up when the word appears is a 'Paul Bunyon' (lumberjack design), strong and hearty; healthy with margins in all aspects of the design. In actuality, robustness is much broader in scope than margins, including such factors as simplicity, redundancy, desensitization to parameter variations, control of parameter variations (environments flucation), and operational approaches. These must be traded with concepts, materials, and fabrication approaches against the criteria of performance, cost, and reliability. This includes manufacturing, assembly, processing, checkout, and operations. The design engineer or project chief is faced with finding ways and means to inculcate robustness into an operational design. First, however, be sure he understands the definition and goals of robustness. This paper will deal with these issues as well as the need for the requirement for robustness.

  12. Robustness Analysis and Reliable Flight Regime Estimation of an Integrated Resilent Control System for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine

    2008-01-01

    Formal robustness analysis of aircraft control upset prevention and recovery systems could play an important role in their validation and ultimate certification. As a part of the validation process, this paper describes an analysis method for determining a reliable flight regime in the flight envelope within which an integrated resilent control system can achieve the desired performance of tracking command signals and detecting additive faults in the presence of parameter uncertainty and unmodeled dynamics. To calculate a reliable flight regime, a structured singular value analysis method is applied to analyze the closed-loop system over the entire flight envelope. To use the structured singular value analysis method, a linear fractional transform (LFT) model of a transport aircraft longitudinal dynamics is developed over the flight envelope by using a preliminary LFT modeling software tool developed at the NASA Langley Research Center, which utilizes a matrix-based computational approach. The developed LFT model can capture original nonlinear dynamics over the flight envelope with the ! block which contains key varying parameters: angle of attack and velocity, and real parameter uncertainty: aerodynamic coefficient uncertainty and moment of inertia uncertainty. Using the developed LFT model and a formal robustness analysis method, a reliable flight regime is calculated for a transport aircraft closed-loop system.

  13. Flight Schedule and the Circadian Clock Influence on Sleep Loss During Overnight Cargo Operations

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Gregory, Kevin B.; Rosekind, Mark R.; Shafto, Michael G. (Technical Monitor)

    1995-01-01

    Thirty-four flight crew members were monitored before, during, and after two 8-day overnight cargo duty patterns which involved multiple flights at night crossing no more than one time zone per 24 h. Rectal temperature, heart rate, and wrist activity were recorded every 2 min. Sleep quantity and quality, and nap timing, were noted in a logbook. To reduce the masking effects of physical activity on temperature, 0.28 C was added to each subject's raw temperature data whenever he reported being asleep. For both masked and unmasked data, daily temperature minima were estimated from the multiple complex demodulated waveform. The temperature minima did not show a progressive adaptation to night duty, which was interrupted by a night off after 5 nights on one trip pattern and after 3 nights on the other. On duty days, the average temperature minimum delayed by about 3 h, occurring near the end of the duty period. Daytime sleep episodes averaged 2.9 h shorter than nighttime sleep episodes, and were rated as lighter, less restorative, and poorer overall. Fifty-three percent of subjects slept more than once per 24 h while they were on night duty, compared to 17% when able to sleep at night. The total sleep per 24 h on duty days averaged 1.2 h less than pretrip. Twenty-nine percent of subjects lost more than 2 h of sleep per 24 h across the 8-day duty patterns. After night duty, subjects awoke around 1400 local time, even when they had slept 2-3 h less than a normal nocturnal sleep episode. Consequently, the duration of morning sleep episodes was correlated with the off-duty time (multiple r(sup 2)=0.44, F=37.23, p less than 0.0001). Anecdotally, crew members complained of being unable to sleep longer and not feeling well-rested. These wakeups were clustered 6 h after the temperature minimum, which suggests that they may have been a response to the circadian wakeup signal. Daytime layovers in which crew members were able to sleep again in the evening ended later (0200

  14. Crash Rates of Scheduled Commuter and Air Carrier Flights Before and After a Regulatory Change

    PubMed Central

    Baker, Susan P.; Groff, Loren; Haaland, Wren; Qiang, Yandong; Rebok, George W.; Li, Guohua

    2010-01-01

    Introduction In 1997, in an effort to reduce the crash rate of scheduled commuter flights, the FAA required aircraft with 10–30 passenger seats to operate under stricter rules. Training and other requirements of 14 CFR Part 121 rules were applied to these midsize commuters, which previously had operated under the less strict Part 135 rules. Published crash rates obscured changes related to aircraft size. This research was undertaken to determine whether the rule change affected crash rates of aircraft with 10–30 passenger seats. Method We determined the number of passenger seats on each Part 135 or Part 121 aircraft that crashed between 1983 and 2007. For aircraft with < 10, 10–30, and > 30 seats, we estimated the numbers of departures and crash rates, adjusting for changes in total departures and numbers of in-service aircraft. Results The Part 135 crash rate tripled in 1997 when commuters with 10–30 seats were excluded, reflecting the administrative change. However, the crash rate of aircraft with 10–30 passenger seats began to decline 4 yr before the rule change; thereafter, their rate was lower than for larger aircraft. The fleet size of aircraft with 10–30 passenger seats increased from 1983 to 1997, then declined as they were replaced with larger aircraft in response to the rule change. Discussion No effect of the rule change on crash rates of 10–30-seat aircraft was apparent. The decline in their crash rates began before the rule change and may have been related to the 1992 requirement for ground proximity warning devices. PMID:19378909

  15. Constraint based scheduling for the Goddard Space Flight Center distributed Active Archive Center's data archive and distribution system

    NASA Technical Reports Server (NTRS)

    Short, Nick, Jr.; Bedet, Jean-Jacques; Bodden, Lee; Boddy, Mark; White, Jim; Beane, John

    1994-01-01

    The Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) has been operational since October 1, 1993. Its mission is to support the Earth Observing System (EOS) by providing rapid access to EOS data and analysis products, and to test Earth Observing System Data and Information System (EOSDIS) design concepts. One of the challenges is to ensure quick and easy retrieval of any data archived within the DAAC's Data Archive and Distributed System (DADS). Over the 15-year life of EOS project, an estimated several Petabytes (10(exp 15)) of data will be permanently stored. Accessing that amount of information is a formidable task that will require innovative approaches. As a precursor of the full EOS system, the GSFC DAAC with a few Terabits of storage, has implemented a prototype of a constraint-based task and resource scheduler to improve the performance of the DADS. This Honeywell Task and Resource Scheduler (HTRS), developed by Honeywell Technology Center in cooperation the Information Science and Technology Branch/935, the Code X Operations Technology Program, and the GSFC DAAC, makes better use of limited resources, prevents backlog of data, provides information about resources bottlenecks and performance characteristics. The prototype which is developed concurrently with the GSFC Version 0 (V0) DADS, models DADS activities such as ingestion and distribution with priority, precedence, resource requirements (disk and network bandwidth) and temporal constraints. HTRS supports schedule updates, insertions, and retrieval of task information via an Application Program Interface (API). The prototype has demonstrated with a few examples, the substantial advantages of using HTRS over scheduling algorithms such as a First In First Out (FIFO) queue. The kernel scheduling engine for HTRS, called Kronos, has been successfully applied to several other domains such as space shuttle mission scheduling, demand flow manufacturing, and avionics communications

  16. Robust gain-scheduling energy-to-peak control of vehicle lateral dynamics stabilisation

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Zhang, Xinjie; Wang, Junmin

    2014-03-01

    In this paper, we investigate the vehicle lateral dynamics stabilisation problem to enhance vehicle handling by considering time-varying longitudinal velocity. The longitudinal velocity is described by a polytope with finite vertices and a novel technique is proposed to reduce the number of vertices. Since the tyre dynamics is nonlinear, the cornering stiffness is represented via the norm-bounded uncertainty. Concerning the time-varying velocity and the nonlinear tyre model, a linear parameter-varying vehicle model is obtained. As the velocity and the states are measurable, a gain-scheduling state-feedback controller is introduced. In the lateral control, the sideslip angle is required to be as small as possible and the yaw rate is constrained to a certain level. Thus, the control objective is to minimise the sideslip angle while the yaw rate is under a prescribed level or constrain both the sideslip angle and the yaw rate to prescribed levels. To consider the transient response of the closed-loop system, the ?-stability is also employed in the energy-to-peak control. The optimal controller can be obtained by solving a set of linear matrix inequalities. A nonlinear vehicle model is utilised to illustrate the design procedure and the effectiveness of the proposed design method. Finally, simulations and comparisons are carried out to show the significant advantage of the designed controller. Compared to the open-loop system, the closed-loop system with the designed controller can achieve much smaller sideslip angle and the yaw rate is closer to the desired yaw rate from a reference model. Therefore, the vehicle safety and the handling are both improved in our simulation cases.

  17. Robust real time extraction of plane segments from time-of-flight camera images

    NASA Astrophysics Data System (ADS)

    Dalbah, Yosef; Koltermann, Dirk; Wahl, Friedrich M.

    2014-04-01

    We present a method that extracts plane segments from images of a time-of-flight camera. Future driver assistance systems rely on an accurate description of the vehicle's environment. Time-of-flight cameras can be used for environment perception and for the reconstruction of the environment. Since most structures in urban environments are planar, extracted plane segments from single camera images can be used for the creation of a global map. We present a method for real time detection of planar surface structures from time-of-flight camera data. The concept is based on a planar surface segmentation that serves as the fundament for a subsequent global planar surface extraction. The evaluation demonstrates the ability of the described algorithm to detect planar surfaces form depth data of complex scenarios in real time. We compare our methods to state of the art planar surface extraction algorithms.

  18. Control design for robust stability in linear regulators: Application to aerospace flight control

    NASA Technical Reports Server (NTRS)

    Yedavalli, R. K.

    1986-01-01

    Time domain stability robustness analysis and design for linear multivariable uncertain systems with bounded uncertainties is the central theme of the research. After reviewing the recently developed upper bounds on the linear elemental (structured), time varying perturbation of an asymptotically stable linear time invariant regulator, it is shown that it is possible to further improve these bounds by employing state transformations. Then introducing a quantitative measure called the stability robustness index, a state feedback conrol design algorithm is presented for a general linear regulator problem and then specialized to the case of modal systems as well as matched systems. The extension of the algorithm to stochastic systems with Kalman filter as the state estimator is presented. Finally an algorithm for robust dynamic compensator design is presented using Parameter Optimization (PO) procedure. Applications in a aircraft control and flexible structure control are presented along with a comparison with other existing methods.

  19. A Robust H ∞ Controller for an UAV Flight Control System

    PubMed Central

    López, J.; Dormido, R.; Dormido, S.; Gómez, J. P.

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements. PMID:26221622

  20. A Robust H ∞ Controller for an UAV Flight Control System.

    PubMed

    López, J; Dormido, R; Dormido, S; Gómez, J P

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements. PMID:26221622

  1. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques

    NASA Technical Reports Server (NTRS)

    Vetter, T. K.; Wells, S. R.; Hess, Ronald A.; Bacon, Barton (Technical Monitor); Davidson, John (Technical Monitor)

    2002-01-01

    A brief review of sliding model control is undertaken, with particular emphasis upon the effects of neglected parasitic dynamics. Sliding model control design is interpreted in the frequency domain. The inclusion of asymptotic observers and control 'hedging' is shown to reduce the effects of neglected parasitic dynamics. An investigation into the application of observer-based sliding mode control to the robust longitudinal control of a highly unstable is described. The sliding mode controller is shown to exhibit stability and performance robustness superior to that of a classical loop-shaped design when significant changes in vehicle and actuator dynamics are employed to model airframe damage.

  2. Aircraft motion and passenger comfort data from scheduled commercial airline flights

    NASA Technical Reports Server (NTRS)

    Gruesbeck, M. G.; Sullivan, D. F.

    1976-01-01

    Data concerning the ride quality of aircraft taken on board commercial airline flights was presented. Five types of data are included: (1) root mean square (RMS) values of linear acceleration, angular acceleration or angular velocities, along with passenger subjective evaluations, (2) power spectra for the motion in each of six degrees of freedom, (3) scattergrams showing the probability density of the rms accelerations in the vertical and transverse directions, (4) probability distributions of the motion, and (5) on board noise levels during takeoff, climb, cruise, and descent.

  3. Centripetal Acceleration Reaction: An Effective and Robust Mechanism for Flapping Flight in Insects

    PubMed Central

    Zhang, Chao; Hedrick, Tyson L.; Mittal, Rajat

    2015-01-01

    Despite intense study by physicists and biologists, we do not fully understand the unsteady aerodynamics that relate insect wing morphology and kinematics to lift generation. Here, we formulate a force partitioning method (FPM) and implement it within a computational fluid dynamic model to provide an unambiguous and physically insightful division of aerodynamic force into components associated with wing kinematics, vorticity, and viscosity. Application of the FPM to hawkmoth and fruit fly flight shows that the leading-edge vortex is the dominant mechanism for lift generation for both these insects and contributes between 72–85% of the net lift. However, there is another, previously unidentified mechanism, the centripetal acceleration reaction, which generates up to 17% of the net lift. The centripetal acceleration reaction is similar to the classical inviscid added-mass in that it depends only on the kinematics (i.e. accelerations) of the body, but is different in that it requires the satisfaction of the no-slip condition, and a combination of tangential motion and rotation of the wing surface. Furthermore, the classical added-mass force is identically zero for cyclic motion but this is not true of the centripetal acceleration reaction. Furthermore, unlike the lift due to vorticity, centripetal acceleration reaction lift is insensitive to Reynolds number and to environmental flow perturbations, making it an important contributor to insect flight stability and miniaturization. This force mechanism also has broad implications for flow-induced deformation and vibration, underwater locomotion and flows involving bubbles and droplets. PMID:26252016

  4. Centripetal Acceleration Reaction: An Effective and Robust Mechanism for Flapping Flight in Insects.

    PubMed

    Zhang, Chao; Hedrick, Tyson L; Mittal, Rajat

    2015-01-01

    Despite intense study by physicists and biologists, we do not fully understand the unsteady aerodynamics that relate insect wing morphology and kinematics to lift generation. Here, we formulate a force partitioning method (FPM) and implement it within a computational fluid dynamic model to provide an unambiguous and physically insightful division of aerodynamic force into components associated with wing kinematics, vorticity, and viscosity. Application of the FPM to hawkmoth and fruit fly flight shows that the leading-edge vortex is the dominant mechanism for lift generation for both these insects and contributes between 72-85% of the net lift. However, there is another, previously unidentified mechanism, the centripetal acceleration reaction, which generates up to 17% of the net lift. The centripetal acceleration reaction is similar to the classical inviscid added-mass in that it depends only on the kinematics (i.e. accelerations) of the body, but is different in that it requires the satisfaction of the no-slip condition, and a combination of tangential motion and rotation of the wing surface. Furthermore, the classical added-mass force is identically zero for cyclic motion but this is not true of the centripetal acceleration reaction. Furthermore, unlike the lift due to vorticity, centripetal acceleration reaction lift is insensitive to Reynolds number and to environmental flow perturbations, making it an important contributor to insect flight stability and miniaturization. This force mechanism also has broad implications for flow-induced deformation and vibration, underwater locomotion and flows involving bubbles and droplets. PMID:26252016

  5. Initial Investigations of Controller Tools and Procedures for Schedule-Based Arrival Operations with Mixed Flight-Deck Interval Management Equipage

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Cabrall, Christopher; Kupfer, Michael; Omar, Faisal G.; Prevot, Thomas

    2012-01-01

    NASA?s Air Traffic Management Demonstration-1 (ATD-1) is a multi-year effort to demonstrate high-throughput, fuel-efficient arrivals at a major U.S. airport using NASA-developed scheduling automation, controller decision-support tools, and ADS-B-enabled Flight-Deck Interval Management (FIM) avionics. First-year accomplishments include the development of a concept of operations for managing scheduled arrivals flying Optimized Profile Descents with equipped aircraft conducting FIM operations, and the integration of laboratory prototypes of the core ATD-1 technologies. Following each integration phase, a human-in-the-loop simulation was conducted to evaluate and refine controller tools, procedures, and clearance phraseology. From a ground-side perspective, the results indicate the concept is viable and the operations are safe and acceptable. Additional training is required for smooth operations that yield notable benefits, particularly in the areas of FIM operations and clearance phraseology.

  6. Evaluation of the Computer Aided Training Evaluation and Scheduling (CATES) Decision Model for Assessing Flight Task Proficiency.

    ERIC Educational Resources Information Center

    McDaniel, William C.; And Others

    The efficacy of the CATES system for making training decisions and determining student proficiency in Naval in-flight training proposed in an earlier study (Rankin and McDaniel, 1980) is compared with the present system of instructor judgments for performance assessment. The current study used 29 newly-designated naval aviators undergoing Fleet…

  7. Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity.

    PubMed

    Baird, Emily; Fernandez, Diana C; Wcislo, William T; Warrant, Eric J

    2015-01-01

    Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion-a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus. PMID:26578977

  8. Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity

    PubMed Central

    Baird, Emily; Fernandez, Diana C.; Wcislo, William T.; Warrant, Eric J.

    2015-01-01

    Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion—a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus. PMID:26578977

  9. Statistical Survey of Icing Data Measured on Scheduled Airline Flights over the United States and Canada from November 1951 to June 1952

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J

    1955-01-01

    A statistical survey and a preliminary analysis are made of icing data collected from scheduled flights over the United States and Canada from November 1951 to June 1952 by airline aircraft equipped with NACA pressure-type icing-rate meters. This interim report presents information obtained from a continuing program sponsored by the NACA with the cooperation of the airlines. An analysis of over 600 icing encounters logged by three airlines operating in the United States, one operating in Canada and one operating up the coast to Alaska, is presented. The icing conditions encountered provided relative frequencies of many icing-cloud variables, such as horizontal extent, vertical thickness, temperatures, icing rate, liquid-water content, and total ice accumulation. Liquid-water contents were higher than data from earlier research flights in layer-type clouds but slightly lower than previous data from cumulus clouds. Broken-cloud conditions, indicated by intermittent icing, accounted for nearly one-half of all the icing encounters. About 90 percent of the encounters did not exceed a distance of 120 miles, and continuous icing did not exceed 50 miles for 90 percent of the unbroken conditions. Icing cloud thicknesses measured during climbs and descents were less than 4500 feet for 90 percent of the vertical cloud traverses.

  10. Design and implementation of robust decentralized control laws for the ACES structure at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Collins, Emmanuel G., Jr.; Phillips, Douglas J.; Hyland, David C.

    1990-01-01

    Many large space system concepts will require active vibration control to satisfy critical performance requirements such as line-of-sight accuracy. In order for these concepts to become operational it is imperative that the benefits of active vibration control be practically demonstrated in ground based experiments. The results of the experiment successfully demonstrate active vibration control for a flexible structure. The testbed is the Active Control Technique Evaluation for Spacecraft (ACES) structure at NASA Marshall Space Flight Center. The ACES structure is dynamically traceable to future space systems and especially allows the study of line-of-sight control issues.

  11. Robust Hurwitz Stability and Performance Analysis of H-Infinity Controlled Forward-Velocity Dynamics of UAVs in Close Formation Flight Using Bounded Phase Conditions in a Kharitonov Framework

    NASA Astrophysics Data System (ADS)

    Johnson, Y.; Dasgupta, S.

    2014-07-01

    Multiple unmanned aerial vehicle (UAV) control in formation flight is comparatively a new research area in the field of aerospace engineering. In the proposed work, robust control techniques are implemented to maintain a fixed relative distance in horizontal and vertical direction with uniform pitch orientation in an uncertain leader-follower pattern of close formation flight platform. The forward velocity dynamics is of focal interest in this paper. H-infinity controllers are designed for leader control and its tracking. The robustness of the H-infinity controller is validated with Kharitonov related bounded phase conditions by forming interval polynomials.

  12. The scheduling techniques of ESP2

    NASA Technical Reports Server (NTRS)

    Jaap, John P.; Davis, Elizabeth K.

    1988-01-01

    The Mission Analysis Division of the Systems Analysis and Integration Laboratory at the Marshall Space Flight Center has developed a robust automatic scheduler which can produce detailed schedules for the multi-step activities required for payload operations on the Space Station. This scheduler, a part of the Expert Scheduling Program (ESP2), has five components: the bookkeeper, checker, loader, selector, and explainer. The bookkeeper maintains the usage profiles for nondepletable resources, consumables, equipment, crew, and the times of all the steps for the payload activities for several different schedules simultaneously. The checker searches the data maintained by the bookkeeper and finds times when the constraints of each step of an activity are satisfied. The loader is an expert system that uses the techniques of forward chaining, depth-first searching, and backtracking to manage the workings of the checker so that activities are placed in the schedule without violating constraints (such as crew, resources, and orbit opportunities). The checker searches the data maintained by the bookkeeper and finds times when the constraints of each step of an activity are satisfied. The loader is an expert system which uses the techniques of forward chaining, depth-first searching, and backtracking to manage the workings of the checker so that activities are placed in the schedule without violating the constraints. The selector has several methods of choosing the next activity for the loader to schedule. The explainer shows the user why an activity was or was not scheduled at a certain time; it offers a unique graphical explanation of how the expert system (the loader) works.

  13. Flexible Scheduling.

    ERIC Educational Resources Information Center

    Davis, Harold S.; Bechard, Joseph E.

    A flexible schedule allows teachers to change group size, group composition, and class length according to the purpose of the lesson. This pamphlet presents various "master" schedules for flexible scheduling: (1) Simple block schedules, (2) back-to-back schedules, (3) interdisciplinary schedules, (4) school-wide block schedules, (5) open-lab…

  14. Development of a Robust, High Current, Low Power Field Emission Electron Gun for a Spaceflight Reflectron Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Southard, Adrian E.; Getty, Stephanie A.; Feng, Steven; Glavin, Daniel P.; Auciello, Orlando; Sumant, Anirudha

    2012-01-01

    Carbon materials, including carbon nanotubes (CNTs) and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD), have been of considerable interest for field emission applications for over a decade. In particular, robust field emission materials are compelling for space applications due to the low power consumption and potential for miniaturization. A reflectron time-of-flight mass spectrometer (TOF-MS) under development for in situ measurements on the Moon and other Solar System bodies uses a field emitter to generate ions from gaseous samples, using electron ionization. For these unusual environments, robustness, reliability, and long life are of paramount importance, and to this end, we have explored the field emission properties and lifetime of carbon nanotubes and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) thin films, the latter developed and patented by Argonne National Laboratory. We will present recent investigations of N-UNCD as a robust field emitter, revealing that this material offers stable performance in high vacuum for up to 1000 hours with threshold voltage for emission of about 3-4 V/lJm and current densities in the range of tens of microA. Optimizing the mass resolution and sensitivity of such a mass spectrometer has also been enabled by a parallel effort to scale up a CNT emitter to an array measuring 2 mm x 40 mm. Through simulation and experiment of the new extended format emitter, we have determined that focusing the electron beam is limited due to the angular spread of the emitted electrons. This dispersion effect can be reduced through modification of the electron gun geometry, but this reduces the current reaching the ionization region. By increasing the transmission efficiency of the electron beam to the anode, we have increased the anode current by two orders of magnitude to realize a corresponding enhancement in instrument sensitivity, at a moderate cost to mass resolution. We will report recent experimental and

  15. A Genetic Algorithm Tool (splicer) for Complex Scheduling Problems and the Space Station Freedom Resupply Problem

    NASA Technical Reports Server (NTRS)

    Wang, Lui; Valenzuela-Rendon, Manuel

    1993-01-01

    The Space Station Freedom will require the supply of items in a regular fashion. A schedule for the delivery of these items is not easy to design due to the large span of time involved and the possibility of cancellations and changes in shuttle flights. This paper presents the basic concepts of a genetic algorithm model, and also presents the results of an effort to apply genetic algorithms to the design of propellant resupply schedules. As part of this effort, a simple simulator and an encoding by which a genetic algorithm can find near optimal schedules have been developed. Additionally, this paper proposes ways in which robust schedules, i.e., schedules that can tolerate small changes, can be found using genetic algorithms.

  16. Future aircraft networks and schedules

    NASA Astrophysics Data System (ADS)

    Shu, Yan

    2011-07-01

    Because of the importance of air transportation scheduling, the emergence of small aircraft and the vision of future fuel-efficient aircraft, this thesis has focused on the study of aircraft scheduling and network design involving multiple types of aircraft and flight services. It develops models and solution algorithms for the schedule design problem and analyzes the computational results. First, based on the current development of small aircraft and on-demand flight services, this thesis expands a business model for integrating on-demand flight services with the traditional scheduled flight services. This thesis proposes a three-step approach to the design of aircraft schedules and networks from scratch under the model. In the first step, both a frequency assignment model for scheduled flights that incorporates a passenger path choice model and a frequency assignment model for on-demand flights that incorporates a passenger mode choice model are created. In the second step, a rough fleet assignment model that determines a set of flight legs, each of which is assigned an aircraft type and a rough departure time is constructed. In the third step, a timetable model that determines an exact departure time for each flight leg is developed. Based on the models proposed in the three steps, this thesis creates schedule design instances that involve almost all the major airports and markets in the United States. The instances of the frequency assignment model created in this thesis are large-scale non-convex mixed-integer programming problems, and this dissertation develops an overall network structure and proposes iterative algorithms for solving these instances. The instances of both the rough fleet assignment model and the timetable model created in this thesis are large-scale mixed-integer programming problems, and this dissertation develops subproblem schemes for solving these instances. Based on these solution algorithms, this dissertation also presents

  17. NASA Schedule Management Handbook

    NASA Technical Reports Server (NTRS)

    2011-01-01

    The purpose of schedule management is to provide the framework for time-phasing, resource planning, coordination, and communicating the necessary tasks within a work effort. The intent is to improve schedule management by providing recommended concepts, processes, and techniques used within the Agency and private industry. The intended function of this handbook is two-fold: first, to provide guidance for meeting the scheduling requirements contained in NPR 7120.5, NASA Space Flight Program and Project Management Requirements, NPR 7120.7, NASA Information Technology and Institutional Infrastructure Program and Project Requirements, NPR 7120.8, NASA Research and Technology Program and Project Management Requirements, and NPD 1000.5, Policy for NASA Acquisition. The second function is to describe the schedule management approach and the recommended best practices for carrying out this project control function. With regards to the above project management requirements documents, it should be noted that those space flight projects previously established and approved under the guidance of prior versions of NPR 7120.5 will continue to comply with those requirements until project completion has been achieved. This handbook will be updated as needed, to enhance efficient and effective schedule management across the Agency. It is acknowledged that most, if not all, external organizations participating in NASA programs/projects will have their own internal schedule management documents. Issues that arise from conflicting schedule guidance will be resolved on a case by case basis as contracts and partnering relationships are established. It is also acknowledged and understood that all projects are not the same and may require different levels of schedule visibility, scrutiny and control. Project type, value, and complexity are factors that typically dictate which schedule management practices should be employed.

  18. Cost Estimation and Control for Flight Systems

    NASA Technical Reports Server (NTRS)

    Hammond, Walter E.; Vanhook, Michael E. (Technical Monitor)

    2002-01-01

    Good program management practices, cost analysis, cost estimation, and cost control for aerospace flight systems are interrelated and depend upon each other. The best cost control process cannot overcome poor design or poor systems trades that lead to the wrong approach. The project needs robust Technical, Schedule, Cost, Risk, and Cost Risk practices before it can incorporate adequate Cost Control. Cost analysis both precedes and follows cost estimation -- the two are closely coupled with each other and with Risk analysis. Parametric cost estimating relationships and computerized models are most often used. NASA has learned some valuable lessons in controlling cost problems, and recommends use of a summary Project Manager's checklist as shown here.

  19. Completable scheduling: An integrated approach to planning and scheduling

    NASA Technical Reports Server (NTRS)

    Gervasio, Melinda T.; Dejong, Gerald F.

    1992-01-01

    The planning problem has traditionally been treated separately from the scheduling problem. However, as more realistic domains are tackled, it becomes evident that the problem of deciding on an ordered set of tasks to achieve a set of goals cannot be treated independently of the problem of actually allocating resources to the tasks. Doing so would result in losing the robustness and flexibility needed to deal with imperfectly modeled domains. Completable scheduling is an approach which integrates the two problems by allowing an a priori planning module to defer particular planning decisions, and consequently the associated scheduling decisions, until execution time. This allows a completable scheduling system to maximize plan flexibility by allowing runtime information to be taken into consideration when making planning and scheduling decision. Furthermore, through the criteria of achievability placed on deferred decision, a completable scheduling system is able to retain much of the goal-directedness and guarantees of achievement afforded by a priori planning. The completable scheduling approach is further enhanced by the use of contingent explanation-based learning, which enables a completable scheduling system to learn general completable plans from example and improve its performance through experience. Initial experimental results show that completable scheduling outperforms classical scheduling as well as pure reactive scheduling in a simple scheduling domain.

  20. NASA launch schedule

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The National Aeronautics and Space Administration (NASA) has a record-setting launch schedule for 1984—10 space shuttle flights (see Table 1), 10 satellite deployments from the space shuttle in orbit and 12 unmanned missions using expendable launch vehicles. Also scheduled is the launch on March 1 for the National Oceanic and Atmospheric Administration of Landsat D‧, the nation's second earth resources satellite.The launch activity will begin February 3 with the launch of shuttle mission 41-B using the orbiter Challenger. Two communications satellites will be deployed from 41-B: Westar-VI, for Western Union, and Palapa B-2 for the government of Indonesia. The 8-day mission will feature the first shuttle landing at Kennedy Space Center in Florida; and the first flight of the Manned Maneuvering Unit, a self-contained, propulsive backpack that will allow astronauts to move about in space without being tethered to the spacecraft.

  1. Development of An Intelligent Flight Propulsion Control System

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Rysdyk, R. T.; Leonhardt, B. K.

    1999-01-01

    The initial design and demonstration of an Intelligent Flight Propulsion and Control System (IFPCS) is documented. The design is based on the implementation of a nonlinear adaptive flight control architecture. This initial design of the IFPCS enhances flight safety by using propulsion sources to provide redundancy in flight control. The IFPCS enhances the conventional gain scheduled approach in significant ways: (1) The IFPCS provides a back up flight control system that results in consistent responses over a wide range of unanticipated failures. (2) The IFPCS is applicable to a variety of aircraft models without redesign and,(3) significantly reduces the laborious research and design necessary in a gain scheduled approach. The control augmentation is detailed within an approximate Input-Output Linearization setting. The availability of propulsion only provides two control inputs, symmetric and differential thrust. Earlier Propulsion Control Augmentation (PCA) work performed by NASA provided for a trajectory controller with pilot command input of glidepath and heading. This work is aimed at demonstrating the flexibility of the IFPCS in providing consistency in flying qualities under a variety of failure scenarios. This report documents the initial design phase where propulsion only is used. Results confirm that the engine dynamics and associated hard nonlineaaities result in poor handling qualities at best. However, as demonstrated in simulation, the IFPCS is capable of results similar to the gain scheduled designs of the NASA PCA work. The IFPCS design uses crude estimates of aircraft behaviour. The adaptive control architecture demonstrates robust stability and provides robust performance. In this work, robust stability means that all states, errors, and adaptive parameters remain bounded under a wide class of uncertainties and input and output disturbances. Robust performance is measured in the quality of the tracking. The results demonstrate the flexibility of

  2. System/360 Computer Assisted Network Scheduling (CANS) System

    NASA Technical Reports Server (NTRS)

    Brewer, A. C.

    1972-01-01

    Computer assisted scheduling techniques that produce conflict-free and efficient schedules have been developed and implemented to meet needs of the Manned Space Flight Network. CANS system provides effective management of resources in complex scheduling environment. System is automated resource scheduling, controlling, planning, information storage and retrieval tool.

  3. Automated Platform Management System Scheduling

    NASA Technical Reports Server (NTRS)

    Hull, Larry G.

    1990-01-01

    The Platform Management System was established to coordinate the operation of platform systems and instruments. The management functions are split between ground and space components. Since platforms are to be out of contact with the ground more than the manned base, the on-board functions are required to be more autonomous than those of the manned base. Under this concept, automated replanning and rescheduling, including on-board real-time schedule maintenance and schedule repair, are required to effectively and efficiently meet Space Station Freedom mission goals. In a FY88 study, we developed several promising alternatives for automated platform planning and scheduling. We recommended both a specific alternative and a phased approach to automated platform resource scheduling. Our recommended alternative was based upon use of exactly the same scheduling engine in both ground and space components of the platform management system. Our phased approach recommendation was based upon evolutionary development of the platform. In the past year, we developed platform scheduler requirements and implemented a rapid prototype of a baseline platform scheduler. Presently we are rehosting this platform scheduler rapid prototype and integrating the scheduler prototype into two Goddard Space Flight Center testbeds, as the ground scheduler in the Scheduling Concepts, Architectures, and Networks Testbed and as the on-board scheduler in the Platform Management System Testbed. Using these testbeds, we will investigate rescheduling issues, evaluate operational performance and enhance the platform scheduler prototype to demonstrate our evolutionary approach to automated platform scheduling. The work described in this paper was performed prior to Space Station Freedom rephasing, transfer of platform responsibility to Code E, and other recently discussed changes. We neither speculate on these changes nor attempt to predict the impact of the final decisions. As a consequence some of our

  4. SO - SCHEDULE ORGANIZER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer SO, Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. SO contains the following primary menu that is displayed at the beginning of the program. The menu provides options: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds twenty-five groups of up to twenty-five names for each group. The other file holds twenty-five records, each of which may hold a task schedule title. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout; there is one for each input names file schedule group. The third output file holds the last schedule title deleted by

  5. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocations for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its applications to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  6. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  7. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  8. Scheduling game

    SciTech Connect

    Kleck, W

    1982-04-01

    Structuring a schedule - whether by Critical Path Method (CPM) or Precedence Charting System (PCS) - involves estimating the duration of one or more activities and arranging them in the most logical sequence. Given the start date, the completion date is relatively simple to determine. What is then so complicated about the process. It is complicated by the people involved - the people who make the schedules and the people who attempt to follow them. Schedules are an essential part of project management and construction contract administration. Much of the material available pertains to the mechanics of schedules, the types of logic networks, the ways that data can be generated and presented. This paper sheds light on other facets of the subject - the statistical and philosophical fundamentals involved in scheduling.

  9. ST - SCHEDULE TRACKER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST, and Schedule Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum numbers can be modified by the user. ST requires the VMS Operating System on DEC VAX and was written in PL/1 and DEC Command Language (DCL). The program requires a memory of 233KB. ST can be purchased separately or in a package (COSMIC Program COS-10021) containing SO, ST, and SRG. ST was developed in 1985.

  10. Mission scheduling

    NASA Technical Reports Server (NTRS)

    Gaspin, Christine

    1989-01-01

    How a neural network can work, compared to a hybrid system based on an operations research and artificial intelligence approach, is investigated through a mission scheduling problem. The characteristic features of each system are discussed.

  11. Miracle Flights

    MedlinePlus

    ... the perfect solution for your needs. Book A Flight Request a flight now Click on the link ... Now Make your donation today Saving Lives One Flight At A Time Miracle Flights provides free flights ...

  12. Anchorage Arrival Scheduling Under Off-Nominal Weather Conditions

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon; Chan, William N.; Mukherjee, Avijit

    2012-01-01

    Weather can cause flight diversions, passenger delays, additional fuel consumption and schedule disruptions at any high volume airport. The impacts are particularly acute at the Ted Stevens Anchorage International Airport in Anchorage, Alaska due to its importance as a major international portal. To minimize the impacts due to weather, a multi-stage scheduling process is employed that is iteratively executed, as updated aircraft demand and/or airport capacity data become available. The strategic scheduling algorithm assigns speed adjustments for flights that originate outside of Anchorage Center to achieve the proper demand and capacity balance. Similarly, an internal departure-scheduling algorithm assigns ground holds for pre-departure flights that originate from within Anchorage Center. Tactical flight controls in the form of airborne holding are employed to reactively account for system uncertainties. Real-world scenarios that were derived from the January 16, 2012 Anchorage visibility observations and the January 12, 2012 Anchorage arrival schedule were used to test the initial implementation of the scheduling algorithm in fast-time simulation experiments. Although over 90% of the flights in the scenarios arrived at Anchorage without requiring any delay, pre-departure scheduling was the dominant form of control for Anchorage arrivals. Additionally, tactical scheduling was used extensively in conjunction with the pre-departure scheduling to reactively compensate for uncertainties in the arrival demand. For long-haul flights, the strategic scheduling algorithm performed best when the scheduling horizon was greater than 1,000 nmi. With these long scheduling horizons, it was possible to absorb between ten and 12 minutes of delay through speed control alone. Unfortunately, the use of tactical scheduling, which resulted in airborne holding, was found to increase as the strategic scheduling horizon increased because of the additional uncertainty in the arrival times

  13. A planning language for activity scheduling

    NASA Technical Reports Server (NTRS)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart; Tong, G. Michael

    1991-01-01

    Mission planning and scheduling of spacecraft operations are becoming more complex at NASA. Described here are a mission planning process; a robust, flexible planning language for spacecraft and payload operations; and a software scheduling system that generates schedules based on planning language inputs. The mission planning process often involves many people and organizations. Consequently, a planning language is needed to facilitate communication, to provide a standard interface, and to represent flexible requirements. The software scheduling system interprets the planning language and uses the resource, time duration, constraint, and alternative plan flexibilities to resolve scheduling conflicts.

  14. Synthese et validation d'un systeme de commandes de vol robuste et autosequence

    NASA Astrophysics Data System (ADS)

    Lhachemi, Hugo

    Flight control system development remains a very challenging issue due to architectural complexity, stringent performance requirements, and strict certification processes. Such control systems must ensure the global stability and the required performance within the whole flight envelope, even in the presence of modeling errors, parametric uncertainties, environmental fluctuations, and disturbances. As the dynamic behavior of an aircraft is highly nonlinear and varies significantly with the fight condition, controller parameters must be adequately adjusted based on the operating point. Among the viable solutions for this purpose, one can find gain-scheduling control, which is one of the most well-known techniques widely adopted in aerospace industry. In addition, it is of practical interest from an industrial point of view to leverage the legacy accumulated in the past by imposing a priori the controller structure based on classical ight control system architectures. The present research project aims at developing a procedure for the design and the validation of robust gain-scheduled ight control systems with a fixed structure. This problem is located at the junction of three topics in control, namely synthesis of fixed-structure control systems, robust control, and LPV systems control in the gain-scheduling framework. In the first phase of this research project, a nonlinear dynamic model of an aircraft that explicitly takes into account mass and center of gravity (CG) position is established. This model is linearized around a trim condition in cruise ight. A numerical model of the F-16 Fighting Falcon is then derived and the impact of mass and CG position variations on the aircraft dynamics is analyzed. In the second phase, a method for the design of a robust and self-scheduled controller with a predefined architecture is proposed. Based on the multi-model synthesis capability of structured Hinfinity methods, robustness and gain-scheduling issues are both cast into

  15. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  16. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  17. 14 CFR § 1214.109 - Scheduling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Scheduling. § 1214.109 Section § 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  18. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  19. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  20. Prescribed Travel Schedules for Fatigue Management

    NASA Technical Reports Server (NTRS)

    Whitmire, Alexandra; Johnston, Smith; Lockley, Steven

    2011-01-01

    The NASA Fatigue Management Team is developing recommendations for managing fatigue during travel and for shift work operations, as Clinical Practice Guidelines for the Management of Circadian Desynchrony in ISS Operations. The Guidelines provide the International Space Station (ISS ) flight surgeons and other operational clinicians with evidence-based recommendations for mitigating fatigue and other factors related to sleep loss and circadian desynchronization. As much international travel is involved both before and after flight, the guidelines provide recommendations for: pre-flight training, in-flight operations, and post-flight rehabilitation. The objective of is to standardize the process by which care is provided to crewmembers, ground controllers, and other support personnel such as trainers, when overseas travel or schedule shifting is required. Proper scheduling of countermeasures - light, darkness, melatonin, diet, exercise, and medications - is the cornerstone for facilitating circadian adaptation, improving sleep, enhancing alertness, and optimizing performance. The Guidelines provide, among other things, prescribed travel schedules that outline the specific implementation of these mitigation strategies. Each travel schedule offers evidence based protocols for properly using the NASA identified countermeasures for fatigue. This presentation will describe the travel implementation schedules and how these can be used to alleviate the effects of jet lag and/or schedule shifts.

  1. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Mcgough, J.; Moses, K.; Klafin, J. F.

    1982-01-01

    The architecture, requirements, and system elements of an ultrareliable, advanced flight control system are described. The basic criteria are functional reliability of 10 to the minus 10 power/hour of flight and only 6 month scheduled maintenance. A distributed system architecture is described, including a multiplexed communication system, reliable bus controller, the use of skewed sensor arrays, and actuator interfaces. Test bed and flight evaluation program are proposed.

  2. 14 CFR 323.16 - Listings in schedule publications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Listings in schedule publications. 323.16... schedule publications. Each air carrier filing a notice under § 323.3 (a)(2), (a)(4), (a)(5), or (c) shall continue to list the affected flights in all generally-distributed schedule publications in which...

  3. 14 CFR 323.16 - Listings in schedule publications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Listings in schedule publications. 323.16... schedule publications. Each air carrier filing a notice under § 323.3 (a)(2), (a)(4), (a)(5), or (c) shall continue to list the affected flights in all generally-distributed schedule publications in which...

  4. Real-time analysis of aromatics in combustion engine exhaust by resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS): a robust tool for chassis dynamometer testing.

    PubMed

    Adam, T W; Clairotte, M; Streibel, T; Elsasser, M; Pommeres, A; Manfredi, U; Carriero, M; Martini, G; Sklorz, M; Krasenbrink, A; Astorga, C; Zimmermann, R

    2012-07-01

    Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated. PMID:22644155

  5. Mission Planning and Scheduling System for NASA's Lunar Reconnaissance Mission

    NASA Technical Reports Server (NTRS)

    Garcia, Gonzalo; Barnoy, Assaf; Beech, Theresa; Saylor, Rick; Cosgrove, Sager; Ritter, Sheila

    2009-01-01

    In the framework of NASA's return to the Moon efforts, the Lunar Reconnaissance Orbiter (LRO) is the first step. It is an unmanned mission to create a comprehensive atlas of the Moon's features and resources necessary to design and build a lunar outpost. LRO is scheduled for launch in April, 2009. LRO carries a payload comprised of six instruments and one technology demonstration. In addition to its scientific mission LRO will use new technologies, systems and flight operations concepts to reduce risk and increase productivity of future missions. As part of the effort to achieve robust and efficient operations, the LRO Mission Operations Team (MOT) will use its Mission Planning System (MPS) to manage the operational activities of the mission during the Lunar Orbit Insertion (LOI) and operational phases of the mission. The MPS, based on GMV's flexplan tool and developed for NASA with Honeywell Technology Solutions (prime contractor), will receive activity and slew maneuver requests from multiple science operations centers (SOC), as well as from the spacecraft engineers. flexplan will apply scheduling rules to all the requests received and will generate conflict free command schedules in the form of daily stored command loads for the orbiter and a set of daily pass scripts that help automate nominal real-time operations.

  6. National remote computational flight research facility

    NASA Technical Reports Server (NTRS)

    Rediess, Herman A.

    1989-01-01

    The extension of the NASA Ames-Dryden remotely augmented vehicle (RAV) facility to accommodate flight testing of a hypersonic aircraft utilizing the continental United States as a test range is investigated. The development and demonstration of an automated flight test management system (ATMS) that uses expert system technology for flight test planning, scheduling, and execution is documented.

  7. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  8. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  9. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  10. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  11. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  12. Unsupervised, Robust Estimation-based Clustering for Multispectral Images

    NASA Technical Reports Server (NTRS)

    Netanyahu, Nathan S.

    1997-01-01

    To prepare for the challenge of handling the archiving and querying of terabyte-sized scientific spatial databases, the NASA Goddard Space Flight Center's Applied Information Sciences Branch (AISB, Code 935) developed a number of characterization algorithms that rely on supervised clustering techniques. The research reported upon here has been aimed at continuing the evolution of some of these supervised techniques, namely the neural network and decision tree-based classifiers, plus extending the approach to incorporating unsupervised clustering algorithms, such as those based on robust estimation (RE) techniques. The algorithms developed under this task should be suited for use by the Intelligent Information Fusion System (IIFS) metadata extraction modules, and as such these algorithms must be fast, robust, and anytime in nature. Finally, so that the planner/schedule module of the IlFS can oversee the use and execution of these algorithms, all information required by the planner/scheduler must be provided to the IIFS development team to ensure the timely integration of these algorithms into the overall system.

  13. Intelligent flight control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1993-01-01

    The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.

  14. ASTER Scheduling Prioritization Function

    NASA Technical Reports Server (NTRS)

    Cohen, Ron

    1996-01-01

    ASTER schedules are generated by an automated scheduling system. This scheduler will generate psuedo-optimal schedules based on a priority scheme. This priority scheme is controlled by the Science Team.

  15. Flight Planning in the Cloud

    NASA Technical Reports Server (NTRS)

    Flores, Sarah L.; Chapman, Bruce D.; Tung, Waye W.; Zheng, Yang

    2011-01-01

    This new interface will enable Principal Investigators (PIs), as well as UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) members to do their own flight planning and time estimation without having to request flight lines through the science coordinator. It uses an all-in-one Google Maps interface, a JPL hosted database, and PI flight requirements to design an airborne flight plan. The application will enable users to see their own flight plan being constructed interactively through a map interface, and then the flight planning software will generate all the files necessary for the flight. Afterward, the UAVSAR team can then complete the flight request, including calendaring and supplying requisite flight request files in the expected format for processing by NASA s airborne science program. Some of the main features of the interface include drawing flight lines on the map, nudging them, adding them to the current flight plan, and reordering them. The user can also search and select takeoff, landing, and intermediate airports. As the flight plan is constructed, all of its components are constantly being saved to the database, and the estimated flight times are updated. Another feature is the ability to import flight lines from previously saved flight plans. One of the main motivations was to make this Web application as simple and intuitive as possible, while also being dynamic and robust. This Web application can easily be extended to support other airborne instruments.

  16. Mission Operations Planning and Scheduling System (MOPSS)

    NASA Technical Reports Server (NTRS)

    Wood, Terri; Hempel, Paul

    2011-01-01

    MOPSS is a generic framework that can be configured on the fly to support a wide range of planning and scheduling applications. It is currently used to support seven missions at Goddard Space Flight Center (GSFC) in roles that include science planning, mission planning, and real-time control. Prior to MOPSS, each spacecraft project built its own planning and scheduling capability to plan satellite activities and communications and to create the commands to be uplinked to the spacecraft. This approach required creating a data repository for storing planning and scheduling information, building user interfaces to display data, generating needed scheduling algorithms, and implementing customized external interfaces. Complex scheduling problems that involved reacting to multiple variable situations were analyzed manually. Operators then used the results to add commands to the schedule. Each architecture was unique to specific satellite requirements. MOPSS is an expert system that automates mission operations and frees the flight operations team to concentrate on critical activities. It is easily reconfigured by the flight operations team as the mission evolves. The heart of the system is a custom object-oriented data layer mapped onto an Oracle relational database. The combination of these two technologies allows a user or system engineer to capture any type of scheduling or planning data in the system's generic data storage via a GUI.

  17. Avco Lycoming emission and flight test results

    NASA Technical Reports Server (NTRS)

    Duke, L. C.

    1976-01-01

    The Avco Lycoming flight test program for reduced emissions was conducted to determine and document the lean fuel schedule limits for current production aircraft based on flight safety. Based on analysis of the emissions profile, Avco Lycoming proposed to evaluate the effect of leaner schedules in the idle/taxi, climb, and approach modes. These modes were selected as areas where it was felt that possible improvements could be made with the greatest improvement in cyclic emissions reduction. The fuel systems to produce these leaner stepped fuel schedules were tailored specifically for the flight test.

  18. Soviet and American flight directors for ASTP

    NASA Technical Reports Server (NTRS)

    1974-01-01

    These two men are flight directors for the joint U.S.-USSR Apollo Soyuz Test Project (ASTP) mission scheduled for July 1975. Cosmonaut Aleksey A. Yeliseyev (left) is the Soviet ASTP senior flight director; and M. P. Frank is the American ASTP senior flight director. They are seated beside a Docking Module training mock-up in bldg 35 at JSC. Cosmonaut Yeliseyev was head of a delegation of USSR flight controllers who were at JSC for two weeks of ASTP training.

  19. NASA Deep Space Network Operations Scheduling

    NASA Technical Reports Server (NTRS)

    Enari, D. M.

    1982-01-01

    The functioning of the Deep Space Network Operations Scheduling, Jet Propulsion Laboratory, CA is reviewed. The primary objectives of the Operations Scheduling are: to schedule the worldwide global allocation of ground communications, tracking facilities, and equipment; and to provide deep space telecommunications for command, tracking, telemetry, and control in support of flight mission operations and tests. Elements of the earth set are Deep Space Stations (DSS) which provide the telecommunications link between the earth and spacecraft; NASA Communications Network; Network Data Processing Area; Network Operations Control Area which provides operational direction to the DSS; Mission Control and Computing systems; and Mission Support areas which provide flight control of the spacecraft. Elements of the space set include mission priorities and requirements which determine the spacecraft queue for allocating network resources. Scheduling is discussed in terms of long-range (3 years), mid-range (8 weeks), and short-range (2 weeks).

  20. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  1. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  2. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  3. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  4. Robust Regression.

    PubMed

    Huang, Dong; Cabral, Ricardo; De la Torre, Fernando

    2016-02-01

    Discriminative methods (e.g., kernel regression, SVM) have been extensively used to solve problems such as object recognition, image alignment and pose estimation from images. These methods typically map image features ( X) to continuous (e.g., pose) or discrete (e.g., object category) values. A major drawback of existing discriminative methods is that samples are directly projected onto a subspace and hence fail to account for outliers common in realistic training sets due to occlusion, specular reflections or noise. It is important to notice that existing discriminative approaches assume the input variables X to be noise free. Thus, discriminative methods experience significant performance degradation when gross outliers are present. Despite its obvious importance, the problem of robust discriminative learning has been relatively unexplored in computer vision. This paper develops the theory of robust regression (RR) and presents an effective convex approach that uses recent advances on rank minimization. The framework applies to a variety of problems in computer vision including robust linear discriminant analysis, regression with missing data, and multi-label classification. Several synthetic and real examples with applications to head pose estimation from images, image and video classification and facial attribute classification with missing data are used to illustrate the benefits of RR. PMID:26761740

  5. Theoretical modeling and computational simulation of robust control for Mars aircraft

    NASA Astrophysics Data System (ADS)

    Oh, Seyool

    The focus of this dissertation is the development of control system design algorithms for autonomous operation of an aircraft in the Martian atmosphere. This research will show theoretical modeling and computational simulation of robust control and gain scheduling for a prototype Mars aircraft. A few hundred meters above the surface of Mars, the air density is less than 1% of the density of the Earth's atmosphere at sea level. However, at about 33 km (110,000 ft) above the Earth, the air density is similar to that near the surface of Mars. Marsflyer II was designed to investigate these flight regimes: 33 km above the Earth and the actual Mars environment. The fuselage for the preliminary design was cylindrical with a length of 2.59 m (8.49 ft), the wing span was 3.98 m (13.09 ft). The total weight of the demonstrator aircraft was around 4.54 kg (10.02 lb). Aircraft design tools have been developed based on successful aircraft for the Earth`s atmosphere. However, above Mars an airborne robotic explorer would encounter low Reynolds Number flow phenomena combined with high Mach numbers, a region that is unknown for normal Earth aerodynamic applications. These flows are more complex than those occurring at high Reynolds numbers. The performance of airfoils at low Reynolds numbers is poorly understood and generally results in unfavorable aerodynamic characteristics. Design and simulation tools for the low Reynolds number Martian environment could be used to develop Unmanned Aerial Vehicles (UAV). In this study, a robust control method is used to analyze a prototype Mars aircraft. The purpose of this aircraft is to demonstrate stability, control, and performance within a simulated Mars environment. Due to uncertainty regarding the actual Martian environment, flexibility in the operation of the aircraft`s control system is important for successful performance. The stability and control derivatives of Marsflyer II were obtained by using the Advanced Aircraft Analysis (AAA

  6. 78 FR 61446 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... for services of FAA Flight Standards Aviation Safety Inspectors outside the United States....

  7. 77 FR 60005 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... of charges for services of FAA Flight Standards Aviation Safety Inspectors outside the United...

  8. Scheduling Reconsidered (Again!)

    ERIC Educational Resources Information Center

    Hentschke, Guilbert C.; Fowler, William J.

    1974-01-01

    Computer technicians bring to school scheduling a certain naivete regarding the operation of schools. School administrators play a fundamental role of informing technicians about education scheduling needs. (Author)

  9. A manpower scheduling heuristic for aircraft maintenance application

    NASA Astrophysics Data System (ADS)

    Sze, San-Nah; Sze, Jeeu-Fong; Chiew, Kang-Leng

    2012-09-01

    This research studies a manpower scheduling for aircraft maintenance, focusing on in-flight food loading operation. A group of loading teams with flexible shifts is required to deliver and upload packaged meals from the ground kitchen to aircrafts in multiple trips. All aircrafts must be served within predefined time windows. The scheduling process takes into account of various constraints such as meal break allocation, multi-trip traveling and food exposure time limit. Considering the aircrafts movement and predefined maximum working hours for each loading team, the main objective of this study is to form an efficient roster by assigning a minimum number of loading teams to the aircrafts. We proposed an insertion based heuristic to generate the solutions in a short period of time for large instances. This proposed algorithm is implemented in various stages for constructing trips due to the presence of numerous constraints. The robustness and efficiency of the algorithm is demonstrated in computational results. The results show that the insertion heuristic more efficiently outperforms the company's current practice.

  10. Future Air Traffic Growth and Schedule Model User's Guide

    NASA Technical Reports Server (NTRS)

    Kimmel, William M. (Technical Monitor); Smith, Jeremy C.; Dollyhigh, Samuel M.

    2004-01-01

    The Future Air Traffic Growth and Schedule Model was developed as an implementation of the Fratar algorithm to project future traffic flow between airports in a system and of then scheduling the additional flights to reflect current passenger time-of-travel preferences. The methodology produces an unconstrained future schedule from a current (or baseline) schedule and the airport operations growth rates. As an example of the use of the model, future schedules are projected for 2010 and 2022 for all flights arriving at, departing from, or flying between all continental United States airports that had commercial scheduled service for May 17, 2002. Inter-continental US traffic and airports are included and the traffic is also grown with the Fratar methodology to account for their arrivals and departures to the continental US airports. Input data sets derived from the Official Airline Guide (OAG) data and FAA Terminal Area Forecast (TAF) are included in the examples of the computer code execution.

  11. Future Air Traffic Growth and Schedule Model, Supplement

    NASA Technical Reports Server (NTRS)

    Kimmel, William M. (Technical Monitor); Smith, Jeremy C.; Dollyhigh, Samuel M.

    2004-01-01

    The Future Air Traffic Growth and Schedule Model was developed as an implementation of the Fratar algorithm to project future traffic flow between airports in a system and of then scheduling the additional flights to reflect current passenger time-of-travel preferences. The methodology produces an unconstrained future schedule from a current (or baseline) schedule and the airport operations growth rates. As an example of the use of the model, future schedules are projected for 2010 and 2022 for all flights arriving at, departing from, or flying between all continental United States airports that had commercial scheduled service for May 17, 2002. Inter-continental US traffic and airports are included and the traffic is also grown with the Fratar methodology to account for their arrivals and departures to the continental US airports. Input data sets derived from the Official Airline Guide (OAG) data and FAA Terminal Area Forecast (TAF) are included in the examples of the computer code execution.

  12. Scheduling for Public Service in International Operations

    NASA Technical Reports Server (NTRS)

    Brenner, M. A.

    1972-01-01

    The factors involved in scheduling airline services for international operations are discussed. Charts are presented to show the transatlantic pattern of flights for a typical airline during the summer and winter months. The operations of a domestic airline operating overseas and a foreign airline operating to the United States are compared.

  13. SO/ST/SRG - SCHEDULING PROGRAMS

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Organizer contains a primary menu that is displayed at the beginning of the program. The menu provides options as follows: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds 25 groups of up to 25 names for each group. The other file holds 25 records. Each 60-character-long record holds a task schedule title or it is a blank entry. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout. There is one for each input names file schedule group. The third output file holds the schedule title of the last schedule title file deleted by the user. Schedule Tracker provides an effective method for tracking tasks that are "past due" and/or "near term". ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term

  14. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Greg

    2003-01-01

    Schedule risk assessments determine the likelihood of finishing on time. Each task in a schedule has a varying degree of probability of being finished on time. A schedule risk assessment quantifies these probabilities by assigning values to each task. This viewgraph presentation contains a flow chart for conducting a schedule risk assessment, and profiles applicable several methods of data analysis.

  15. The Block Scheduling Handbook.

    ERIC Educational Resources Information Center

    Queen, J. Allen

    Block scheduling encourages increased comprehensive immersion into subject matter, improved teacher-student relationships, and decreased disciplinary problems. While block scheduling may offer many advantages, moving to a block schedule from conventional scheduling can be a major adjustment for both students and teachers. This guide is intended to…

  16. Integrated flight/propulsion control design for a STOVL aircraft using H-infinity control design techniques

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Ouzts, Peter J.

    1991-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight propulsion control (IFPC) system design for a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft in transition flight. The emphasis is on formulating the H-infinity control design problem such that the resulting controller provides robustness to modeling uncertainties and model parameter variations with flight condition. Experience gained from a preliminary H-infinity based IFPC design study performed earlier is used as the basis to formulate the robust H-infinity control design problem and improve upon the previous design. Detailed evaluation results are presented for a reduced order controller obtained from the improved H-infinity control design showing that the control design meets the specified nominal performance objectives as well as provides stability robustness for variations in plant system dynamics with changes in aircraft trim speed within the transition flight envelope. A controller scheduling technique which accounts for changes in plant control effectiveness with variation in trim conditions is developed and off design model performance results are presented.

  17. Protocols for distributive scheduling

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.; Fox, Barry

    1993-01-01

    The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning.

  18. Combined Administration of MF59-Adjuvanted A/H5N1 Prepandemic and Seasonal Influenza Vaccines: Long-Term Antibody Persistence and Robust Booster Responses 1 Year after a One-Dose Priming Schedule

    PubMed Central

    Lopez, Pio; Caicedo, Yolanda; Sierra, Alexandra; Tilman, Sandrine; Clemens, Ralf

    2013-01-01

    Having previously demonstrated the feasibility of administering A/H5N1 and seasonal influenza vaccine antigens in an MF59-adjuvanted tetravalent formulation, we now report on long-term antibody persistence and responses to a booster dose of a combined seasonal-pandemic, tetravalent influenza vaccine in adults. The primary objective was the evaluation of responses to a booster dose of tetravalent influenza vaccine containing seasonal (A/H1N1, A/H3N2, and B) and avian (A/H5N1, clade 2) influenza virus strains administered to 265 healthy 18- to 40-year-old volunteers 1 year after priming with one or two clade 1 A/H5N1 doses. Secondary objectives were assessment of reactogenicity, safety, and antibody persistence 1 year after priming with a combined seasonal-pandemic, tetravalent vaccine. Responses to seasonal strains met all European licensure criteria; seroprotection rates were 94 to 100%, 100%, and 61 to 90% for A/H1N1, A/H3N2, and B strains, respectively. Anamnestic responses were observed against homologous and heterologous A/H5N1 strains whether priming with one or two A/H5N1 doses, with a monovalent A/H5N1 vaccine, or with a tetravalent vaccine. A single dose of MF59-adjuvanted A/H5N1 vaccine given alone or as part of a fixed combination with a seasonal influenza vaccine was sufficient to prime adult subjects, resulting in robust antigen-specific and cross-reactive antibody responses to heterologous booster immunization 1 year later. These data support the feasibility of incorporating prepandemic priming into seasonal influenza vaccination programs. (This study has been registered at clinicaltrials.gov under registration no. NCT00481065.) PMID:23536690

  19. Aspects of job scheduling

    NASA Technical Reports Server (NTRS)

    Phillips, K.

    1976-01-01

    A mathematical model for job scheduling in a specified context is presented. The model uses both linear programming and combinatorial methods. While designed with a view toward optimization of scheduling of facility and plant operations at the Deep Space Communications Complex, the context is sufficiently general to be widely applicable. The general scheduling problem including options for scheduling objectives is discussed and fundamental parameters identified. Mathematical algorithms for partitioning problems germane to scheduling are presented.

  20. Optimizing Operating Room Scheduling.

    PubMed

    Levine, Wilton C; Dunn, Peter F

    2015-12-01

    This article reviews the management of an operating room (OR) schedule and use of the schedule to add value to an organization. We review the methodology of an OR block schedule, daily OR schedule management, and post anesthesia care unit patient flow. We discuss the importance of a well-managed OR schedule to ensure smooth patient care, not only in the OR, but throughout the entire hospital. PMID:26610624

  1. Automated long-term scheduling for the SOFIA airborne observatory

    NASA Astrophysics Data System (ADS)

    Civeit, Thomas

    The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint US/German project to develop and operate a gyro-stabilized 2.5-meter telescope in a Boeing 747SP. SOFIA's first science observations were made in December 2010. During 2011, SOFIA accomplished 30 flights in the “ Early Science” program as well as a deployment to Germany. The next observing period, known as Cycle 1, is scheduled to begin in late fall 2012. It includes 46 science flights grouped in four multi-week observing campaigns spread through a 13-month span. Automation of the flight scheduling process offers a major challenge to the SOFIA mission operations. First because it is needed to mitigate its relatively high cost per unit observing time compared to space-borne missions. Second because automated scheduling techniques available for ground-based and space-based telescopes are inappropriate for an airborne observatory. Although serious attempts have been made in the past to solve part of the problem, until recently mission operations staff was still manually scheduling flights. We present in this paper a new automated solution for generating SOFIA's long-term schedules. We describe the constraints that should be satisfied to solve the SOFIA scheduling problem in the context of real operations. We establish key formulas required to efficiently calculate the aircraft course over ground when evaluating flight schedules. We describe the foundations of the SOFIA long-term scheduler, the constraint representation, and the random search based algorithm that generates observation and instrument schedules. Finally, we report on how the new long-term scheduler has been used in operations to date.

  2. Automated Long - Term Scheduling for the SOFIA Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Civeit, Thomas

    2013-01-01

    The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint US/German project to develop and operate a gyro-stabilized 2.5-meter telescope in a Boeing 747SP. SOFIA's first science observations were made in December 2010. During 2011, SOFIA accomplished 30 flights in the "Early Science" program as well as a deployment to Germany. The new observing period, known as Cycle 1, is scheduled to begin in 2012. It includes 46 science flights grouped in four multi-week observing campaigns spread through a 13-month span. Automation of the flight scheduling process offers a major challenge to the SOFIA mission operations. First because it is needed to mitigate its relatively high cost per unit observing time compared to space-borne missions. Second because automated scheduling techniques available for ground-based and space-based telescopes are inappropriate for an airborne observatory. Although serious attempts have been made in the past to solve part of the problem, until recently mission operations staff was still manually scheduling flights. We present in this paper a new automated solution for generating SOFIA long-term schedules that will be used in operations from the Cycle 1 observing period. We describe the constraints that should be satisfied to solve the SOFIA scheduling problem in the context of real operations. We establish key formulas required to efficiently calculate the aircraft course over ground when evaluating flight schedules. We describe the foundations of the SOFIA long-term scheduler, the constraint representation, and the random search based algorithm that generates observation and instrument schedules. Finally, we report on how the new long-term scheduler has been used in operations to date.

  3. Worst-case analysis and linear parameter-varying gain-scheduled control of aerospace systems

    NASA Astrophysics Data System (ADS)

    Shin, Jong-Yeob

    In this thesis, two main subjects are discussed. The first is a worst-case performance analysis, the second is a linear parameter varying (LPV) synthesis using a blending approach. On the first subject, a linear fractional transformation (LFT) model of the linearized X-38 Crew Return Vehicle (CRV) has been developed to facilitate the analysis of its flight control system. The LFT model represents uncertainty in nine aerodynamic stability derivatives at a given flight condition. The X-38 LFT model, combined with a controller at specific flight conditions, is used to determine the aerodynamic coefficients within a predefined set that result in the worst-case performance and worst-case gain/phase margins of the closed-loop system. LPV and mu controllers are synthesized for the X-38 CRV lateral-directional axes over the candidate flight envelope and compared with the baseline gain-scheduled classical control design. Worst-case analysis of the LPV and mu controllers are compared with the baseline gain-scheduled classical control design. Analysis and time simulations show that the LPV controller achieves significant performance and robustness improvements when compared to a linear mu controller and the baseline gain-scheduled controller. On the second subject, a quasi-LPV model of the F-16 longitudinal axes was developed using three methods: Jacobian linearization, state transformation and function substitution. Time simulations of quasi-LPV models show that the quasi-LPV models developed using state transformation and function substitution accurately represent the nonlinear dynamics of the F-16 longitudinal axes. In designing an LPV controller for the F-16 longitudinal axes, the function substitution quasi-LPV models are used since these quasi-LPV models can represent the nonlinear dynamics at non-trim points. Two LPV controllers are synthesized for the F-16 longitudinal axes for two separated flight envelopes: low and high altitude regions. Blending these controllers

  4. 14 CFR 415.129 - Flight safety system test data.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... applicant must reference the schedule to the time of liftoff for the first proposed flight attempt. (d... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Flight safety system test data. 415.129... Launch Vehicle From a Non-Federal Launch Site § 415.129 Flight safety system test data. (a) General....

  5. 14 CFR 415.129 - Flight safety system test data.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... applicant must reference the schedule to the time of liftoff for the first proposed flight attempt. (d... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Flight safety system test data. 415.129... Launch Vehicle From a Non-Federal Launch Site § 415.129 Flight safety system test data. (a) General....

  6. 14 CFR 415.129 - Flight safety system test data.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... applicant must reference the schedule to the time of liftoff for the first proposed flight attempt. (d... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Flight safety system test data. 415.129... Launch Vehicle From a Non-Federal Launch Site § 415.129 Flight safety system test data. (a) General....

  7. Supersonic Flight Dynamics Test 1 - Post-Flight Assessment of Simulation Performance

    NASA Technical Reports Server (NTRS)

    Dutta, Soumyo; Bowes, Angela L.; Striepe, Scott A.; Davis, Jody L.; Queen, Eric M.; Blood, Eric M.; Ivanov, Mark C.

    2015-01-01

    NASA's Low Density Supersonic Decelerator (LDSD) project conducted its first Supersonic Flight Dynamics Test (SFDT-1) on June 28, 2014. Program to Optimize Simulated Trajectories II (POST2) was one of the flight dynamics codes used to simulate and predict the flight performance and Monte Carlo analysis was used to characterize the potential flight conditions experienced by the test vehicle. This paper compares the simulation predictions with the reconstructed trajectory of SFDT-1. Additionally, off-nominal conditions seen during flight are modeled in post-flight simulations to find the primary contributors that reconcile the simulation with flight data. The results of these analyses are beneficial for the pre-flight simulation and targeting of the follow-on SFDT flights currently scheduled for summer 2015.

  8. Orion Exploration Flight Test-l (EFT -1) Absolute Navigation Design

    NASA Technical Reports Server (NTRS)

    Sud, Jastesh; Gay, Robert; Holt, Greg; Zanetti, Renato

    2014-01-01

    Scheduled to launch in September 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion Multi-Purpose-Crew-Vehicle (MPCV's) maiden flight dubbed "Exploration Flight Test -1" (EFT-1) intends to stress the system by placing the uncrewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented in the narrative with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs the UDUT decomposition approach. The design is substantiated by simulation results to show the expected performance.

  9. SRG - SCHEDULE REPORT GENERATOR COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Schedule Report Generator, SRG, are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are schedule for recent completion (near term). Schedule Reports Generator provides a simple method for generating periodic schedule reports. SRG enables an engineering manager to monitor tasks assigned to staff members on a weekly basis. SRG sorts three types of reports using one or more data fields as sort keys. One type is sorted using the calendar year as the primary key and the end date as the secondary key. Another type is sorted by flight number. A third type of report, Waterfall plots, is also generated by SRG using the end date as the sorting key. SRG requires as input a single file or two concatenated files with up to 400 single line entries. The user constructs the input file by using the LSE editor VAX utility prior to the execution of the program. The user is able to modify the current functional description text lines just displayed. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum

  10. Projecting Future Scheduled Airline Demand, Schedules and NGATS Benefits Using TSAM

    NASA Technical Reports Server (NTRS)

    Dollyhigh, Samuel; Smith, Jeremy; Viken, Jeff; Trani, Antonio; Baik, Hojong; Hinze, Nickolas; Ashiabor, Senanu

    2006-01-01

    The Transportation Systems Analysis Model (TSAM) developed by Virginia Tech s Air Transportation Systems Lab and NASA Langley can provide detailed analysis of the effects on the demand for air travel of a full range of NASA and FAA aviation projects. TSAM has been used to project the passenger demand for very light jet (VLJ) air taxi service, scheduled airline demand growth and future schedules, Next Generation Air Transportation System (NGATS) benefits, and future passenger revenues for the Airport and Airway Trust Fund. TSAM can project the resulting demand when new vehicles and/or technology is inserted into the long distance (100 or more miles one-way) transportation system, as well as, changes in demand as a result of fare yield increases or decreases, airport transit times, scheduled flight times, ticket taxes, reductions or increases in flight delays, and so on. TSAM models all long distance travel in the contiguous U.S. and determines the mode choice of the traveler based on detailed trip costs, travel time, schedule frequency, purpose of the trip (business or non-business), and household income level of the traveler. Demand is modeled at the county level, with an airport choice module providing up to three airports as part of the mode choice. Future enplanements at airports can be projected for different scenarios. A Fratar algorithm and a schedule generator are applied to generate future flight schedules. This paper presents the application of TSAM to modeling future scheduled air passenger demand and resulting airline schedules, the impact of NGATS goals and objectives on passenger demand, along with projections for passenger fee receipts for several scenarios for the FAA Airport and Airway Trust Fund.

  11. A Hybrid Cellular Genetic Algorithm for Multi-objective Crew Scheduling Problem

    NASA Astrophysics Data System (ADS)

    Jolai, Fariborz; Assadipour, Ghazal

    Crew scheduling is one of the important problems of the airline industry. This problem aims to cover a number of flights by crew members, such that all the flights are covered. In a robust scheduling the assignment should be so that the total cost, delays, and unbalanced utilization are minimized. As the problem is NP-hard and the objectives are in conflict with each other, a multi-objective meta-heuristic called CellDE, which is a hybrid cellular genetic algorithm, is implemented as the optimization method. The proposed algorithm provides the decision maker with a set of non-dominated or Pareto-optimal solutions, and enables them to choose the best one according to their preferences. A set of problems of different sizes is generated and solved using the proposed algorithm. Evaluating the performance of the proposed algorithm, three metrics are suggested, and the diversity and the convergence of the achieved Pareto front are appraised. Finally a comparison is made between CellDE and PAES, another meta-heuristic algorithm. The results show the superiority of CellDE.

  12. Dedicated heterogeneous node scheduling including backfill scheduling

    DOEpatents

    Wood, Robert R.; Eckert, Philip D.; Hommes, Gregg

    2006-07-25

    A method and system for job backfill scheduling dedicated heterogeneous nodes in a multi-node computing environment. Heterogeneous nodes are grouped into homogeneous node sub-pools. For each sub-pool, a free node schedule (FNS) is created so that the number of to chart the free nodes over time. For each prioritized job, using the FNS of sub-pools having nodes useable by a particular job, to determine the earliest time range (ETR) capable of running the job. Once determined for a particular job, scheduling the job to run in that ETR. If the ETR determined for a lower priority job (LPJ) has a start time earlier than a higher priority job (HPJ), then the LPJ is scheduled in that ETR if it would not disturb the anticipated start times of any HPJ previously scheduled for a future time. Thus, efficient utilization and throughput of such computing environments may be increased by utilizing resources otherwise remaining idle.

  13. Immunization Schedules for Adults

    MedlinePlus

    ... ACIP Vaccination Recommendations Why Immunize? Vaccines: The Basics Immunization Schedules for Adults in Easy-to-read Formats ... previous immunizations. View or Print a Schedule Recommended Immunizations for Adults (19 Years and Older) by Age ...

  14. Childhood Immunization Schedule

    MedlinePlus

    ... Recommendations Why Immunize? Vaccines: The Basics Instant Childhood Immunization Schedule Recommend on Facebook Tweet Share Compartir Get ... date. See Disclaimer for additional details. Based on Immunization Schedule for Children 0 through 6 Years of ...

  15. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Greg

    2003-01-01

    Schedule Risk Assessment needs to determine the probability of finishing on or before a given point in time. Task in a schedule should reflect the "most likely" duration for each task. IN reality, each task is different and has a varying degree of probability of finishing within or after the duration specified. Schedule risk assessment attempt to quantify these probabilities by assigning values to each task. Bridges the gap between CPM scheduling and the project's need to know the likelihood of "when".

  16. Reinforcement learning in scheduling

    NASA Technical Reports Server (NTRS)

    Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

    1994-01-01

    The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

  17. Analysis of Issues for Project Scheduling by Multiple, Dispersed Schedulers (distributed Scheduling) and Requirements for Manual Protocols and Computer-based Support

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.

    1991-01-01

    Although computerized operations have significant gains realized in many areas, one area, scheduling, has enjoyed few benefits from automation. The traditional methods of industrial engineering and operations research have not proven robust enough to handle the complexities associated with the scheduling of realistic problems. To address this need, NASA has developed the computer-aided scheduling system (COMPASS), a sophisticated, interactive scheduling tool that is in wide-spread use within NASA and the contractor community. Therefore, COMPASS provides no explicit support for the large class of problems in which several people, perhaps at various locations, build separate schedules that share a common pool of resources. This research examines the issue of distributing scheduling, as applied to application domains characterized by the partial ordering of tasks, limited resources, and time restrictions. The focus of this research is on identifying issues related to distributed scheduling, locating applicable problem domains within NASA, and suggesting areas for ongoing research. The issues that this research identifies are goals, rescheduling requirements, database support, the need for communication and coordination among individual schedulers, the potential for expert system support for scheduling, and the possibility of integrating artificially intelligent schedulers into a network of human schedulers.

  18. Parallel scheduling algorithms

    SciTech Connect

    Dekel, E.; Sahni, S.

    1983-01-01

    Parallel algorithms are given for scheduling problems such as scheduling to minimize the number of tardy jobs, job sequencing with deadlines, scheduling to minimize earliness and tardiness penalties, channel assignment, and minimizing the mean finish time. The shared memory model of parallel computers is used to obtain fast algorithms. 26 references.

  19. Block Scheduling. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2003-01-01

    What are the effects of block scheduling? Results of transitioning from traditional to block scheduling are mixed. Some studies indicate no change in achievement results, nor change in teachers' opinions about instructional strategies. Other studies show that block scheduling doesn't work well for Advanced Placement or Music courses, that "hard to…

  20. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... operations may schedule an airman for flight deck duty as a flight engineer, or navigator in a crew of...

  1. A neural based intelligent flight control system for the NASA F-15 flight research aircraft

    NASA Technical Reports Server (NTRS)

    Urnes, James M.; Hoy, Stephen E.; Ladage, Robert N.; Stewart, James

    1993-01-01

    A flight control concept that can identify aircraft stability properties and continually optimize the aircraft flying qualities has been developed by McDonnell Aircraft Company under a contract with the NASA-Dryden Flight Research Facility. This flight concept, termed the Intelligent Flight Control System, utilizes Neural Network technology to identify the host aircraft stability and control properties during flight, and use this information to design on-line the control system feedback gains to provide continuous optimum flight response. This self-repairing capability can provide high performance flight maneuvering response throughout large flight envelopes, such as needed for the National Aerospace Plane. Moreover, achieving this response early in the vehicle's development schedule will save cost.

  2. DSN Scheduling Engine

    NASA Technical Reports Server (NTRS)

    Clement, Bradley; Johnston, Mark; Wax, Allan; Chouinard, Caroline

    2008-01-01

    The DSN (Deep Space Network) Scheduling Engine targets all space missions that use DSN services. It allows clients to issue scheduling, conflict identification, conflict resolution, and status requests in XML over a Java Message Service interface. The scheduling requests may include new requirements that represent a set of tracks to be scheduled under some constraints. This program uses a heuristic local search to schedule a variety of schedule requirements, and is being infused into the Service Scheduling Assembly, a mixed-initiative scheduling application. The engine resolves conflicting schedules of resource allocation according to a range of existing and possible requirement specifications, including optional antennas; start of track and track duration ranges; periodic tracks; locks on track start, duration, and allocated antenna; MSPA (multiple spacecraft per aperture); arraying/VLBI (very long baseline interferometry)/delta DOR (differential one-way ranging); continuous tracks; segmented tracks; gap-to-track ratio; and override or block-out of requirements. The scheduling models now include conflict identification for SOA(start of activity), BOT (beginning of track), RFI (radio frequency interference), and equipment constraints. This software will search through all possible allocations while providing a best-effort solution at any time. The engine reschedules to accommodate individual emergency tracks in 0.2 second, and emergency antenna downtime in 0.2 second. The software handles doubling of one mission's track requests over one week (to 42 total) in 2.7 seconds. Further tests will be performed in the context of actual schedules.

  3. NASA scheduling technologies

    NASA Technical Reports Server (NTRS)

    Adair, Jerry R.

    1994-01-01

    This paper is a consolidated report on ten major planning and scheduling systems that have been developed by the National Aeronautics and Space Administration (NASA). A description of each system, its components, and how it could be potentially used in private industry is provided in this paper. The planning and scheduling technology represented by the systems ranges from activity based scheduling employing artificial intelligence (AI) techniques to constraint based, iterative repair scheduling. The space related application domains in which the systems have been deployed vary from Space Shuttle monitoring during launch countdown to long term Hubble Space Telescope (HST) scheduling. This paper also describes any correlation that may exist between the work done on different planning and scheduling systems. Finally, this paper documents the lessons learned from the work and research performed in planning and scheduling technology and describes the areas where future work will be conducted.

  4. Iterative modulo scheduling

    SciTech Connect

    Rau, B.R.

    1996-02-01

    Modulo scheduling is a framework within which algorithms for software pipelining innermost loops may be defined. The framework specifies a set of constraints that must be met in order to achieve a legal modulo schedule. A wide variety of algorithms and heuristics can be defined within this framework. Little work has been done to evaluate and compare alternative algorithms and heuristics for modulo scheduling from the viewpoints of schedule quality as well as computational complexity. This, along with a vague and unfounded perception that modulo scheduling is computationally expensive as well as difficult to implement, have inhibited its corporation into product compilers. This paper presents iterative modulo scheduling, a practical algorithm that is capable of dealing with realistic machine models. The paper also characterizes the algorithm in terms of the quality of the generated schedules as well as the computational incurred.

  5. Predicting scheduling success

    NASA Technical Reports Server (NTRS)

    Messing, Fredric

    1993-01-01

    This paper provides an analytical formulation to predict scheduling success for a class of problems frequently referred to as activity scheduling. Space Network communications scheduling is an example of activity scheduling. The principal assumption is that the activity start times are randomly distributed over the available time in the time line. The formulation makes it possible to estimate how much of the demand can be scheduled as a function of the demand, number of resources, activity duration, and activity flexibility. The paper includes computed results for a variety of resource and demand conditions. The results demonstrate that even with highly flexible activities, it is difficult to schedule demand greater than 60 percent of resources without the use of optimization and conflict resolution capabilities in the scheduling system.

  6. SOFIA's Choice: Automating the Scheduling of Airborne Observations

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Norvig, Peter (Technical Monitor)

    1999-01-01

    This paper describes the problem of scheduling observations for an airborne telescope. Given a set of prioritized observations to choose from, and a wide range of complex constraints governing legitimate choices and orderings, how can we efficiently and effectively create a valid flight plan which supports high priority observations? This problem is quite different from scheduling problems which are routinely solved automatically in industry. For instance, the problem requires making choices which lead to other choices later, and contains many interacting complex constraints over both discrete and continuous variables. Furthermore, new types of constraints may be added as the fundamental problem changes. As a result of these features, this problem cannot be solved by traditional scheduling techniques. The problem resembles other problems in NASA and industry, from observation scheduling for rovers and other science instruments to vehicle routing. The remainder of the paper is organized as follows. In 2 we describe the observatory in order to provide some background. In 3 we describe the problem of scheduling a single flight. In 4 we compare flight planning and other scheduling problems and argue that traditional techniques are not sufficient to solve this problem. We also mention similar complex scheduling problems which may benefit from efforts to solve this problem. In 5 we describe an approach for solving this problem based on research into a similar problem, that of scheduling observations for a space-borne probe. In 6 we discuss extensions of the flight planning problem as well as other problems which are similar to flight planning. In 7 we conclude and discuss future work.

  7. Identification and robust control of linear parameter-varying systems

    NASA Astrophysics Data System (ADS)

    Lee, Lawton Hubert

    This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear

  8. Space station payload operations scheduling with ESP2

    NASA Technical Reports Server (NTRS)

    Stacy, Kenneth L.; Jaap, John P.

    1988-01-01

    The Mission Analysis Division of the Systems Analysis and Integration Laboratory at the Marshall Space Flight Center is developing a system of programs to handle all aspects of scheduling payload operations for Space Station. The Expert Scheduling Program (ESP2) is the heart of this system. The task of payload operations scheduling can be simply stated as positioning the payload activities in a mission so that they collect their desired data without interfering with other activities or violating mission constraints. ESP2 is an advanced version of the Experiment Scheduling Program (ESP) which was developed by the Mission Integration Branch beginning in 1979 to schedule Spacelab payload activities. The automatic scheduler in ESP2 is an expert system that embodies the rules that expert planners would use to schedule payload operations by hand. This scheduler uses depth-first searching, backtracking, and forward chaining techniques to place an activity so that constraints (such as crew, resources, and orbit opportunities) are not violated. It has an explanation facility to show why an activity was or was not scheduled at a certain time. The ESP2 user can also place the activities in the schedule manually. The program offers graphical assistance to the user and will advise when constraints are being violated. ESP2 also has an option to identify conflict introduced into an existing schedule by changes to payload requirements, mission constraints, and orbit opportunities.

  9. Mixed-Integer Formulations for Constellation Scheduling

    NASA Astrophysics Data System (ADS)

    Valicka, C.; Hart, W.; Rintoul, M.

    Remote sensing systems have expanded the set of capabilities available for and critical to national security. Cooperating, high-fidelity sensing systems and growing mission applications have exponentially increased the set of potential schedules. A definitive lack of advanced tools places an increased burden on operators, as planning and scheduling remain largely manual tasks. This is particularly true in time-critical planning activities where operators aim to accomplish a large number of missions through optimal utilization of single or multiple sensor systems. Automated scheduling through identification and comparison of alternative schedules remains a challenging problem applicable across all remote sensing systems. Previous approaches focused on a subset of sensor missions and do not consider ad-hoc tasking. We have begun development of a robust framework that leverages the Pyomo optimization modeling language for the design of a tool to assist sensor operators planning under the constraints of multiple concurrent missions and uncertainty. Our scheduling models have been formulated to address the stochastic nature of ad-hoc tasks inserted under a variety of scenarios. Operator experience is being leveraged to select appropriate model objectives. Successful development of the framework will include iterative development of high-fidelity mission models that consider and expose various schedule performance metrics. Creating this tool will aid time-critical scheduling by increasing planning efficiency, clarifying the value of alternative modalities uniquely provided by multi-sensor systems, and by presenting both sets of organized information to operators. Such a tool will help operators more quickly and fully utilize sensing systems, a high interest objective within the current remote sensing operations community. Preliminary results for mixed-integer programming formulations of a sensor scheduling problem will be presented. Assumptions regarding sensor geometry

  10. Chandra mission scheduling on-orbit experience

    NASA Astrophysics Data System (ADS)

    Bucher, Sabina; Williams, Brent; Pendexter, Misty; Balke, David

    2008-07-01

    Scheduling observatory time to maximize both day-to-day science target integration time and the lifetime of the observatory is a formidable challenge. Furthermore, it is not a static problem. Of course, every schedule brings a new set of observations, but the boundaries of the problem change as well. As spacecraft ages, its capabilities may degrade. As in-flight experience grows, capabilities may expand. As observing programs are completed, the needs and expectations of the science community may evolve. Changes such as these impact the rules by which a mission scheduled. In eight years on orbit, the Chandra X-Ray Observatory Mission Planning process has adapted to meet the challenge of maximizing day-to-day and mission lifetime science return, despite a consistently evolving set of scheduling constraints. The success of the planning team has been achieved, not through the use of complex algorithms and optimization routines, but through processes and home grown tools that help individuals make smart short term and long term Mission Planning decisions. This paper walks through the processes and tools used to plan and produce mission schedules for the Chandra X-Ray Observatory. Nominal planning and scheduling, target of opportunity response, and recovery from on-board autonomous safing actions are all addressed. Evolution of tools and processes, best practices, and lessons learned are highlighted along the way.

  11. 14 CFR Table C to Part 117 - Flight Duty Period: Augmented Operations

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...—Flight Duty Period: Augmented Operations Scheduled time of start (acclimated time) Maximum flight duty... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight Duty Period: Augmented Operations C... (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS FLIGHT AND...

  12. Schedule-Organizer Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Organizer provides simple method for generating distribution lists. Contains readers' names for each task schedule defined by input files. Schedule Organizer (SO), Schedule Tracker (ST) (COSMIC program MSC-21526), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  13. The annealing robust backpropagation (ARBP) learning algorithm.

    PubMed

    Chuang, C C; Su, S F; Hsiao, C C

    2000-01-01

    Multilayer feedforward neural networks are often referred to as universal approximators. Nevertheless, if the used training data are corrupted by large noise, such as outliers, traditional backpropagation learning schemes may not always come up with acceptable performance. Even though various robust learning algorithms have been proposed in the literature, those approaches still suffer from the initialization problem. In those robust learning algorithms, the so-called M-estimator is employed. For the M-estimation type of learning algorithms, the loss function is used to play the role in discriminating against outliers from the majority by degrading the effects of those outliers in learning. However, the loss function used in those algorithms may not correctly discriminate against those outliers. In this paper, the annealing robust backpropagation learning algorithm (ARBP) that adopts the annealing concept into the robust learning algorithms is proposed to deal with the problem of modeling under the existence of outliers. The proposed algorithm has been employed in various examples. Those results all demonstrated the superiority over other robust learning algorithms independent of outliers. In the paper, not only is the annealing concept adopted into the robust learning algorithms but also the annealing schedule k/t was found experimentally to achieve the best performance among other annealing schedules, where k is a constant and is the epoch number. PMID:18249835

  14. Cost and schedule analytical techniques development

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This contract provided technical services and products to the Marshall Space Flight Center's Engineering Cost Office (PP03) and the Program Plans and Requirements Office (PP02) for the period of 3 Aug. 1991 - 30 Nov. 1994. Accomplishments summarized cover the REDSTAR data base, NASCOM hard copy data base, NASCOM automated data base, NASCOM cost model, complexity generators, program planning, schedules, NASA computer connectivity, other analytical techniques, and special project support.

  15. SOFIA'S Challenge: Scheduling Airborne Astronomy Observations

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy

    2005-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is NASA's next generation airborne astronomical observatory, and will commence operations in 2005. The facility consists of a 747-SP modified to accommodate a 2.5 meter telescope. SOFIA is expected to fly an average of 140 science flights per year over its 20 year lifetime. Depending on the nature of the instrument used during flight, 5-15 observations per flight are expected. The SOFIA telescope is mounted aft of the wings on the port side of the aircraft and is articulated through a range of 20deg to 60deg of elevation. The telescope has minimal lateral flexibility; thus, the aircraft must turn constantly to maintain the telescope's focus on an object during observations. A significant problem in future SOFIA operations is that of scheduling flights in support of observations. Investigators are expected to propose small numbers of observations, and many observations must be grouped together to make up single flights. Flight planning for the previous generation airborne observatory, the Kuiper Airborne Observatory (KAO), was done by hand; planners had to choose takeoff time, observations to perform, and decide on setup-actions (called "dead-legs") to position the aircraft prior to observing. This task frequently required between 6-8 hours to plan one flight The scope of the flight planning problem for supporting GI observations with the anticipated flight rate for SOFIA makes the manual approach for flight planning daunting. In response, we have designed an Automated Flight Planner (AFP) that accepts as input a set of requested observations, designated flight days, weather predictions and fuel limitations, and searches automatically for high-quality flight plans that satisfy all relevant aircraft and astronomer specified constraints. The AFP can generate one candidate flight plan in 5-10 minutes, of computation time, a feat beyond the capabilities of human flight planners. The rate at which the AFP can

  16. Applications of robust control theory - Educational implications

    NASA Technical Reports Server (NTRS)

    Dorato, P.; Yedavalli, R. K.

    1992-01-01

    A survey is made of applications of robust control theory to problems of flight control, control of flexible space structures, and engine control which have appeared in recent conferences and journals. An analysis is made of which theoretical techniques are most commonly used and what implications this has for graduate and undergraduate education in aerospace engineering.

  17. JWST planning and scheduling operations and concepts

    NASA Astrophysics Data System (ADS)

    Kinzel, Wayne M.

    2010-07-01

    The James Webb Space Telescope (JWST) will be a large infrared space observatory in orbit about the Sun-Earth second Lagrange Point. This paper provides an overview of the expected operational requirements imposed by the observatory's basic science activities (imaging, spectroscopy, coronography) and the operational issues associated with interleaving periodic engineering activities (Wave Front Sensing & Control activities, Momentum Unloads, and orbit Station Keeping) with the science observations. The planning and scheduling operations must maximize the overall science integration time while meeting the mission and observer specified constraints. The "Observation," "Visit," and Observation Template constructs are explained in the context of providing an interface to the Observer that provides the ability to specify complex observations, such as mosaics and cluster targets, while also minimizing specification errors and allowing planning and scheduling flexibility of the observations. The expected nominal planning and scheduling process including the creation and maintenance of the Long Range Plan (~1.25 year duration), the Short Term Schedules (~ three weeks), and the on-board Observation Plan (< 10 days) is described. The event-driven on-board operations of JWST and how the planning and scheduling process monitors and reacts to the onboard execution of the Observation Plan are described. Finally, the methods employed to allow for robust interfacing of scheduled real-time operations (for example, Station Keeping) with the Observation Plan and unplanned, but expected, modifications to the Observation Plan (for example, Target of Opportunity) are described.

  18. Integrated resource scheduling in a distributed scheduling environment

    NASA Technical Reports Server (NTRS)

    Zoch, David; Hall, Gardiner

    1988-01-01

    The Space Station era presents a highly-complex multi-mission planning and scheduling environment exercised over a highly distributed system. In order to automate the scheduling process, customers require a mechanism for communicating their scheduling requirements to NASA. A request language that a remotely-located customer can use to specify his scheduling requirements to a NASA scheduler, thus automating the customer-scheduler interface, is described. This notation, Flexible Envelope-Request Notation (FERN), allows the user to completely specify his scheduling requirements such as resource usage, temporal constraints, and scheduling preferences and options. The FERN also contains mechanisms for representing schedule and resource availability information, which are used in the inter-scheduler inconsistency resolution process. Additionally, a scheduler is described that can accept these requests, process them, generate schedules, and return schedule and resource availability information to the requester. The Request-Oriented Scheduling Engine (ROSE) was designed to function either as an independent scheduler or as a scheduling element in a network of schedulers. When used in a network of schedulers, each ROSE communicates schedule and resource usage information to other schedulers via the FERN notation, enabling inconsistencies to be resolved between schedulers. Individual ROSE schedules are created by viewing the problem as a constraint satisfaction problem with a heuristically guided search strategy.

  19. Robust Crossfeed Design for Hovering Rotorcraft

    NASA Technical Reports Server (NTRS)

    Catapang, David R.

    1993-01-01

    Control law design for rotorcraft fly-by-wire systems normally attempts to decouple angular responses using fixed-gain crossfeeds. This approach can lead to poor decoupling over the frequency range of pilot inputs and increase the load on the feedback loops. In order to improve the decoupling performance, dynamic crossfeeds may be adopted. Moreover, because of the large changes that occur in rotorcraft dynamics due to small changes about the nominal design condition, especially for near-hovering flight, the crossfeed design must be 'robust'. A new low-order matching method is presented here to design robust crossfeed compensators for multi-input, multi-output (MIMO) systems. The technique identifies degrees-of-freedom that can be decoupled using crossfeeds, given an anticipated set of parameter variations for the range of flight conditions of concern. Cross-coupling is then reduced for degrees-of-freedom that can use crossfeed compensation by minimizing off-axis response magnitude average and variance. Results are presented for the analysis of pitch, roll, yaw and heave coupling of the UH-60 Black Hawk helicopter in near-hovering flight. Robust crossfeeds are designed that show significant improvement in decoupling performance and robustness over nominal, single design point, compensators. The design method and results are presented in an easily used graphical format that lends significant physical insight to the design procedure. This plant pre-compensation technique is an appropriate preliminary step to the design of robust feedback control laws for rotorcraft.

  20. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  1. Automated telescope scheduling

    NASA Astrophysics Data System (ADS)

    Johnston, Mark D.

    1988-08-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  2. The range scheduling aid

    NASA Technical Reports Server (NTRS)

    Halbfinger, Eliezer M.; Smith, Barry D.

    1991-01-01

    The Air Force Space Command schedules telemetry, tracking and control activities across the Air Force Satellite Control network. The Range Scheduling Aid (RSA) is a rapid prototype combining a user-friendly, portable, graphical interface with a sophisticated object-oriented database. The RSA has been a rapid prototyping effort whose purpose is to elucidate and define suitable technology for enhancing the performance of the range schedulers. Designing a system to assist schedulers in their task and using their current techniques as well as enhancements enabled by an electronic environment, has created a continuously developing model that will serve as a standard for future range scheduling systems. The RSA system is easy to use, easily ported between platforms, fast, and provides a set of tools for the scheduler that substantially increases his productivity.

  3. Understanding Flight

    SciTech Connect

    Anderson, David

    2001-01-31

    Through the years the explanation of flight has become mired in misconceptions that have become dogma. Wolfgang Langewiesche, the author of 'Stick and Rudder' (1944) got it right when he wrote: 'Forget Bernoulli's Theorem'. A wing develops lift by diverting (from above) a lot of air. This is the same way that a propeller produces thrust and a helicopter produces lift. Newton's three laws and a phenomenon called the Coanda effect explain most of it. With an understanding of the real physics of flight, many things become clear. Inverted flight, symmetric wings, and the flight of insects are obvious. It is easy to understand the power curve, high-speed stalls, and the effect of load and altitude on the power requirements for lift. The contribution of wing aspect ratio on the efficiency of a wing, and the true explanation of ground effect will also be discussed.

  4. Columbia's first flight shakes down space transportation system

    NASA Technical Reports Server (NTRS)

    Garrett, D.; Young, D.; White, T.

    1981-01-01

    The first space shuttle mission is described. Topics include launch preparations, flight profile, trajectory, and landing operations. The spaceflight tracking and data network is discussed and the photography and television schedules are included.

  5. Radioastron flight operations

    NASA Technical Reports Server (NTRS)

    Altunin, V. I.; Sukhanov, K. G.; Altunin, K. R.

    1993-01-01

    Radioastron is a space-based very-long-baseline interferometry (VLBI) mission to be operational in the mid-90's. The spacecraft and space radio telescope (SRT) will be designed, manufactured, and launched by the Russians. The United States is constructing a DSN subnet to be used in conjunction with a Russian subnet for Radioastron SRT science data acquisition, phase link, and spacecraft and science payload health monitoring. Command and control will be performed from a Russian tracking facility. In addition to the flight element, the network of ground radio telescopes which will be performing co-observations with the space telescope are essential to the mission. Observatories in 39 locations around the world are expected to participate in the mission. Some aspects of the mission that have helped shaped the flight operations concept are: separate radio channels will be provided for spacecraft operations and for phase link and science data acquisition; 80-90 percent of the spacecraft operational time will be spent in an autonomous mode; and, mission scheduling must take into account not only spacecraft and science payload constraints, but tracking station and ground observatory availability as well. This paper will describe the flight operations system design for translating the Radioastron science program into spacecraft executed events. Planning for in-orbit checkout and contingency response will also be discussed.

  6. Aeroservoelastic Uncertainty Model Identification from Flight Data

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.

    2001-01-01

    Uncertainty modeling is a critical element in the estimation of robust stability margins for stability boundary prediction and robust flight control system development. There has been a serious deficiency to date in aeroservoelastic data analysis with attention to uncertainty modeling. Uncertainty can be estimated from flight data using both parametric and nonparametric identification techniques. The model validation problem addressed in this paper is to identify aeroservoelastic models with associated uncertainty structures from a limited amount of controlled excitation inputs over an extensive flight envelope. The challenge to this problem is to update analytical models from flight data estimates while also deriving non-conservative uncertainty descriptions consistent with the flight data. Multisine control surface command inputs and control system feedbacks are used as signals in a wavelet-based modal parameter estimation procedure for model updates. Transfer function estimates are incorporated in a robust minimax estimation scheme to get input-output parameters and error bounds consistent with the data and model structure. Uncertainty estimates derived from the data in this manner provide an appropriate and relevant representation for model development and robust stability analysis. This model-plus-uncertainty identification procedure is applied to aeroservoelastic flight data from the NASA Dryden Flight Research Center F-18 Systems Research Aircraft.

  7. Enabling a New Planning and Scheduling Paradigm

    NASA Technical Reports Server (NTRS)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Flight Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called "tasks models," from the scientists and technologists for the tasks that they want to be done. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, another cadre further modifies the models to be compatible with the scheduling engine. This last cadre also submits the models to the scheduling engine or builds the timeline manually to accommodate requirements that are expressed in notes. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components. (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphics methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models

  8. Power Extension Package (PEP) system definition extension, orbital service module systems analysis study. Volume 11: PEP, cost, schedules, and work breakdown structure dictionary

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Cost scheduling and funding data are presented for the reference design of the power extension package. Major schedule milestones are correlated with current Spacelab flight dates. Funding distributions provide for minimum expenditure during the first year of the project.

  9. SEP solar array shuttle flight experiment

    SciTech Connect

    Elms, R.V. Jr.; Young, L.E.; Hill, H.C.

    1981-01-01

    The design, fabrication, and ground verification testing project is underway at LMSC to support a SEP solar array shuttle flight experiment. A full-scale developmental SEP solar array wing is being refurbished for flight in an Orbiter scheduled for launch in early 1983. The experiment hardware design and the on-orbit test operations that are planned to meet the experiment objective are described. 1 ref.

  10. Schedule Analysis Software Saves Time for Project Planners

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Since the early 2000s, a resource management team at Marshall Space Flight Center has developed and improved the Schedule Test and Assessment Tool, a software add-on capable of analyzing, summarizing, and finding logic gaps in project schedules. Companies like Lanham, Maryland-based Vantage Systems Inc. use the tool to manage NASA projects, but it has also been released for free to more than 200 US companies, agencies, and other entities.

  11. The Probability of Small Schedule Values and Preference for Random-Interval Schedules

    PubMed Central

    Soreth, Michelle Ennis; Hineline, Philip N

    2009-01-01

    Preference for working on variable schedules and temporal discrimination were simultaneously examined in two experiments using a discrete-trial, concurrent-chains arrangement with fixed interval (FI) and random interval (RI) terminal links. The random schedule was generated by first sampling a probability distribution after the programmed delay to reinforcement on the FI schedule had elapsed, and thus the RI never produced a component schedule value shorter than the FI and maintained a rate of reinforcement half that of the FI. Despite these features, the FI was not strongly preferred. The probability of obtaining the smallest programmed delay to reinforcement on the RI schedule was manipulated in Experiment 1, and the interaction of this probability and initial link length was examined in Experiment 2. As the probability of obtaining small values in the RI increased, preference for the schedule increased while the discriminated time of reinforcer availability in the terminal link decreased. Both of these effects were attenuated by lengthening the initial links. The results support the view that in addition to the delay to reinforcement, the probability of obtaining a short delay is an important choice-affecting variable that likely contributes to the robust preferences for variable, as opposed to fixed, schedules of reinforcement. PMID:19230514

  12. Flight (Children's Books).

    ERIC Educational Resources Information Center

    Matthews, Susan; Reid, Rebecca; Sylvan, Anne; Woolard, Linda; Freeman, Evelyn B.

    1997-01-01

    Presents brief annotations of 43 children's books, grouped around the theme of flight: flights of imagination, flights across time and around the globe, flights of adventure, and nature's flight. (SR)

  13. Miracle Flights for Kids

    MedlinePlus

    ... today Saving Lives One Flight At A Time Miracle Flights provides free flights to distant specialized care and valuable second opinions. Miracle Flights Through June 2016 Flights Coordinated: 101,862 ...

  14. Automated aircraft scheduling methods in the near terminal area.

    NASA Technical Reports Server (NTRS)

    Tobias, L.

    1972-01-01

    A general scheduling algorithm for aircraft from terminal area entry to touchdown is developed. The method has the following novel features: (1) many speed classes of aircraft are considered and speed variations within classes and along portions of the flight path are permitted; (2) multiple paths are considered which may merge or diverge - the analysis is not restricted to a single runway nor to departures only; (3) landings are scheduled along conflict free flight paths in minimum time. The algorithm is currently being incorporated in a fast-time simulation of a STOL air traffic system.

  15. Cibola flight experiment satellite

    NASA Astrophysics Data System (ADS)

    Davies, P.; Liddle, Doug; Paffett, John; Sweeting, Martin; Curiel, A.; Sun, Wei; Eves, Stuart

    2004-11-01

    In order to achieve an "economy of scale" with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL's Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The British National Space Centre through the MOSAIC Small Satellite Initiative supported the development of GMP. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, and independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA's first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload

  16. A format for the interchange of scheduling models

    NASA Technical Reports Server (NTRS)

    Jaap, John P.; Davis, Elizabeth K.

    1994-01-01

    In recent years a variety of space-activity schedulers have been developed within the aerospace community. Space-activity schedulers are characterized by their need to handle large numbers of activities which are time-window constrained and make high demands on many scarce resources, but are minimally constrained by predecessor/successor requirements or critical paths. Two needs to exchange data between these schedulers have materialized. First, there is significant interest in comparing and evaluating the different scheduling engines to ensure that the best technology is applied to each scheduling endeavor. Second, there is a developing requirement to divide a single scheduling task among different sites, each using a different scheduler. In fact, the scheduling task for International Space Station Alpha (ISSA) will be distributed among NASA centers and among the international partners. The format used to interchange scheduling data for ISSA will likely use a growth version of the format discussed in this paper. The model interchange format (or MIF, pronounced as one syllable) discussed in this paper is a robust solution to the need to interchange scheduling requirements for space activities. It is highly extensible, human-readable, and can be generated or edited with common text editors. It also serves well the need to support a 'benchmark' data case which can be delivered on any computer platform.

  17. Data analysis with the DIANA meta-scheduling approach

    NASA Astrophysics Data System (ADS)

    Anjum, A.; McClatchey, R.; Willers, I.

    2008-07-01

    The concepts, design and evaluation of the Data Intensive and Network Aware (DIANA) meta-scheduling approach for solving the challenges of data analysis being faced by CERN experiments are discussed in this paper. Our results suggest that data analysis can be made robust by employing fault tolerant and decentralized meta-scheduling algorithms supported in our DIANA meta-scheduler. The DIANA meta-scheduler supports data intensive bulk scheduling, is network aware and follows a policy centric meta-scheduling. In this paper, we demonstrate that a decentralized and dynamic meta-scheduling approach is an effective strategy to cope with increasing numbers of users, jobs and datasets. We present 'quality of service' related statistics for physics analysis through the application of a policy centric fair-share scheduling model. The DIANA meta-schedulers create a peer-to-peer hierarchy of schedulers to accomplish resource management that changes with evolving loads and is dynamic and adapts to the volatile nature of the resources.

  18. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, R. W.

    1986-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  19. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, Richard W.

    1987-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  20. Surviving Block Scheduling.

    ERIC Educational Resources Information Center

    Haley, Marjorie

    A discussion of block scheduling for second language instruction looks at the advantages and disadvantages and offers some suggestions for classroom management and course organization. It is argued that block scheduling may offer a potential solution to large classes, insufficient time for labs, too little individualized instruction; few…

  1. Block Scheduling Revisited.

    ERIC Educational Resources Information Center

    Queen, J. Allen

    2000-01-01

    Successful block scheduling depends on provision of initial and ongoing instructional training. Teaching strategies should vary and include cooperative learning, the case method, the socratic seminar, synectics, concept attainment, the inquiry method, and simulations. Recommendations for maximizing block scheduling are outlined. (Contains 52…

  2. A Fluid Block Schedule

    ERIC Educational Resources Information Center

    Ubben, Gerald C.

    1976-01-01

    Achieving flexibility without losing student accountability is a challenge that faces every school. With a fluid block schedule, as described here, accountability is maintained without inhibiting flexibility. An additional advantage is that three levels of schedule decision making take some of the pressure off the principal. (Editor)

  3. Trimester Schedule. Research Brief

    ERIC Educational Resources Information Center

    Education Partnerships, Inc., 2012

    2012-01-01

    Why do a trimester schedule? With the advent of block scheduling, many high schools conducted research on utilizing that plan in a trimester format. There appeared to be three issues that most schools faced: (1) How to provide substantive instructional time that was not fragmented?; (2) How does the school climate contribute positively to…

  4. Range Scheduling Aid (RSA)

    NASA Technical Reports Server (NTRS)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  5. Scheduling: Seven Period Day

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2010-01-01

    Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

  6. DSN Resource Scheduling

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Baldwin, John

    2007-01-01

    TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface. TIGRAS has the capability to handle all DSN resource scheduling aspects from long-range to real time. TIGRAS assists NASA mission operations for DSN tracking of station equipment resource request processes from long-range load forecasts (ten years or longer), to midrange, short-range, and real-time (less than one week) emergency tracking plan changes. TIGRAS can be operated by NASA mission operations worldwide to make schedule requests for the DSN station equipment.

  7. Robust adaptive control of HVDC systems

    SciTech Connect

    Reeve, J.; Sultan, M. )

    1994-07-01

    The transient performance of an HVDC power system is highly dependent on the parameters of the current/voltage regulators of the converter controls. In order to better accommodate changes in system structure or dc operating conditions, this paper introduces a new adaptive control strategy. The advantages of automatic tuning for continuous fine tuning are combined with predetermined gain scheduling in order to achieve robustness for large disturbances. Examples are provided for a digitally simulated back-to-back dc system.

  8. On-Line Robust Modal Stability Prediction using Wavelet Processing

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.; Lind, Rick

    1998-01-01

    Wavelet analysis for filtering and system identification has been used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins is reduced with parametric and nonparametric time- frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data is used to reduce the effects of external disturbances and unmodeled dynamics. Parametric estimates of modal stability are also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. The F-18 High Alpha Research Vehicle aeroservoelastic flight test data demonstrates improved robust stability prediction by extension of the stability boundary beyond the flight regime. Guidelines and computation times are presented to show the efficiency and practical aspects of these procedures for on-line implementation. Feasibility of the method is shown for processing flight data from time- varying nonstationary test points.

  9. Robust nonlinear control of vectored thrust aircraft

    NASA Technical Reports Server (NTRS)

    Doyle, John C.; Murray, Richard; Morris, John

    1993-01-01

    An interdisciplinary program in robust control for nonlinear systems with applications to a variety of engineering problems is outlined. Major emphasis will be placed on flight control, with both experimental and analytical studies. This program builds on recent new results in control theory for stability, stabilization, robust stability, robust performance, synthesis, and model reduction in a unified framework using Linear Fractional Transformations (LFT's), Linear Matrix Inequalities (LMI's), and the structured singular value micron. Most of these new advances have been accomplished by the Caltech controls group independently or in collaboration with researchers in other institutions. These recent results offer a new and remarkably unified framework for all aspects of robust control, but what is particularly important for this program is that they also have important implications for system identification and control of nonlinear systems. This combines well with Caltech's expertise in nonlinear control theory, both in geometric methods and methods for systems with constraints and saturations.

  10. Characterization of Tactical Departure Scheduling in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Capps, Alan; Engelland, Shawn A.

    2011-01-01

    This paper discusses and analyzes current day utilization and performance of the tactical departure scheduling process in the National Airspace System (NAS) to understand the benefits in improving this process. The analysis used operational air traffic data from over 1,082,000 flights during the month of January, 2011. Specific metrics included the frequency of tactical departure scheduling, site specific variances in the technology's utilization, departure time prediction compliance used in the tactical scheduling process and the performance with which the current system can predict the airborne slot that aircraft are being scheduled into from the airport surface. Operational data analysis described in this paper indicates significant room for improvement exists in the current system primarily in the area of reduced departure time prediction uncertainty. Results indicate that a significant number of tactically scheduled aircraft did not meet their scheduled departure slot due to departure time uncertainty. In addition to missed slots, the operational data analysis identified increased controller workload associated with tactical departures which were subject to traffic management manual re-scheduling or controller swaps. An analysis of achievable levels of departure time prediction accuracy as obtained by a new integrated surface and tactical scheduling tool is provided to assess the benefit it may provide as a solution to the identified shortfalls. A list of NAS facilities which are likely to receive the greatest benefit from the integrated surface and tactical scheduling technology are provided.

  11. Job shop scheduling problem with late work criterion

    NASA Astrophysics Data System (ADS)

    Piroozfard, Hamed; Wong, Kuan Yew

    2015-05-01

    Scheduling is considered as a key task in many industries, such as project based scheduling, crew scheduling, flight scheduling, machine scheduling, etc. In the machine scheduling area, the job shop scheduling problems are considered to be important and highly complex, in which they are characterized as NP-hard. The job shop scheduling problems with late work criterion and non-preemptive jobs are addressed in this paper. Late work criterion is a fairly new objective function. It is a qualitative measure and concerns with late parts of the jobs, unlike classical objective functions that are quantitative measures. In this work, simulated annealing was presented to solve the scheduling problem. In addition, operation based representation was used to encode the solution, and a neighbourhood search structure was employed to search for the new solutions. The case studies are Lawrence instances that were taken from the Operations Research Library. Computational results of this probabilistic meta-heuristic algorithm were compared with a conventional genetic algorithm, and a conclusion was made based on the algorithm and problem.

  12. STS-109 Flight Day 2 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Footage shows the cargo bay of the Columbia Orbiter, including the rigid array carrier, the solar arrays to be installed on the Hubble Space Telescope, and the robotic arm. Close-up shots show several components of the flight support system. STS-109 Commander Scott Altman, Payload Commander John Grunsfeld, and Mission Specialist Nancy Currie are seen on the flight deck, and they answer questions about the stabilization of the freon flow, details of the upcoming rendezvous and capture of the Hubble Space Telescope, the scheduled spacewalks, and the social dynamics of the flight crew.

  13. Aviation Pilot Training I & II. Flight Syllabus. Field Review Copy.

    ERIC Educational Resources Information Center

    Upchurch, Richard

    This guide for aviation pilot training I and II begins with a course description, resource information, and a course outline. The syllabus is designed to be used concurrently with the ground school program. A minimum of 29 flights are scheduled with a minimum of 40 hours total flight time. Tasks/competencies are categorized into five concept/duty…

  14. 14 CFR 121.503 - Flight time limitations: Pilots: airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Pilots: airplanes... Operations § 121.503 Flight time limitations: Pilots: airplanes. (a) A certificate holder conducting supplemental operations may schedule a pilot to fly in an airplane for eight hours or less during any...

  15. ACTEX flight experiment: development issues and lessons learned

    NASA Astrophysics Data System (ADS)

    Schubert, S. R.

    1993-09-01

    The ACTEX flight experiment is scheduled for launch and to begin its on orbit operations in early 1994. The objective of the ACTEX experiment is to demonstrate active vibration control in space, using the smart structure technology. This paper discusses primarily the hardware development and program management issues associated with delivering low cost flight experiments.

  16. Air Traffic Control: Economics of Flight

    NASA Technical Reports Server (NTRS)

    Murphy, James R.

    2004-01-01

    Contents include the following: 1. Commercial flight is a partnership. Airlines. Pilots. Air traffic control. 2. Airline schedules and weather problems can cause delays at the airport. Delays are inevitable in de-regulated industry due to simple economics. 3.Delays can be mitigated. Build more runways/technology. Increase airspace supply. 4. Cost/benefit analysis determine justification.

  17. Laser data transfer flight experiment definition

    NASA Technical Reports Server (NTRS)

    Merritt, J. R.

    1975-01-01

    A set of laser communication flight experiments to be performed between a relay satellite, ground terminals, and space shuttles were synthesized and evaluated. Results include a definition of the space terminals, NASA ground terminals, test methods, and test schedules required to perform the experiments.

  18. Mechanisms for Robust Cognition.

    PubMed

    Walsh, Matthew M; Gluck, Kevin A

    2015-08-01

    To function well in an unpredictable environment using unreliable components, a system must have a high degree of robustness. Robustness is fundamental to biological systems and is an objective in the design of engineered systems such as airplane engines and buildings. Cognitive systems, like biological and engineered systems, exist within variable environments. This raises the question, how do cognitive systems achieve similarly high degrees of robustness? The aim of this study was to identify a set of mechanisms that enhance robustness in cognitive systems. We identify three mechanisms that enhance robustness in biological and engineered systems: system control, redundancy, and adaptability. After surveying the psychological literature for evidence of these mechanisms, we provide simulations illustrating how each contributes to robust cognition in a different psychological domain: psychomotor vigilance, semantic memory, and strategy selection. These simulations highlight features of a mathematical approach for quantifying robustness, and they provide concrete examples of mechanisms for robust cognition. PMID:25352094

  19. Optimal Schedules of Light Exposure for Rapidly Correcting Circadian Misalignment

    PubMed Central

    Serkh, Kirill; Forger, Daniel B.

    2014-01-01

    Jet lag arises from a misalignment of circadian biological timing with the timing of human activity, and is caused by rapid transmeridian travel. Jet lag's symptoms, such as depressed cognitive alertness, also arise from work and social schedules misaligned with the timing of the circadian clock. Using experimentally validated mathematical models, we develop a new methodology to find mathematically optimal schedules of light exposure and avoidance for rapidly re-entraining the human circadian system. In simulations, our schedules are found to significantly outperform other recently proposed schedules. Moreover, our schedules appear to be significantly more robust to both noise in light and to inter-individual variations in endogenous circadian period than other proposed schedules. By comparing the optimal schedules for thousands of different situations, and by using general mathematical arguments, we are also able to translate our findings into general principles of optimal circadian re-entrainment. These principles include: 1) a class of schedules where circadian amplitude is only slightly perturbed, optimal for dim light and for small shifts 2) another class of schedules where shifting occurs along the shortest path in phase-space, optimal for bright light and for large shifts 3) the determination that short light pulses are less effective than sustained light if the goal is to re-entrain quickly, and 4) the determination that length of daytime should be significantly shorter when delaying the clock than when advancing it. PMID:24722195

  20. STS-113 Flight Day 9 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This video shows the activities of the STS-113 (Jim Wetherbee, Commander; Paul Lockhart, Pilot; Michael Lopez-Alegria, John Herrington, Mission Specialists) crew during flight day 9. Also seen are the outgoing Expedition 5 (Valeri Korzun, Commander; Peggy Whitsun, ISS Science Officer/Flight Engineer; Sergei Treschev, Flight Engineer) and incoming Expedition 6 (Kenneth Bowersox, Commander; Donald Pettit, Nikolai Budarin, Flight Engineers) crews of the ISS (International Space Station). Flight day 9 is a relatively inactive day, with some off-time scheduled for crew bonding and enjoying views. Seven of the joint crew members, including Lopez-Alegria, Wetherbee, Herrington, and Whitsun, pose together and answer questions. Footage shows ISS Science Officers Whitsun and Pettit troubleshooting equipment. The video also contains a clear view of southern South America, a cloudy view of the South Pacific, and external footage of the ISS including the Canadarm robotic arm. The payload bay of the shuttle Endeavour is also shown.

  1. A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: I. Robust Linear Optimization and Robust Mixed Integer Linear Optimization

    PubMed Central

    Li, Zukui; Ding, Ran; Floudas, Christodoulos A.

    2011-01-01

    Robust counterpart optimization techniques for linear optimization and mixed integer linear optimization problems are studied in this paper. Different uncertainty sets, including those studied in literature (i.e., interval set; combined interval and ellipsoidal set; combined interval and polyhedral set) and new ones (i.e., adjustable box; pure ellipsoidal; pure polyhedral; combined interval, ellipsoidal, and polyhedral set) are studied in this work and their geometric relationship is discussed. For uncertainty in the left hand side, right hand side, and objective function of the optimization problems, robust counterpart optimization formulations induced by those different uncertainty sets are derived. Numerical studies are performed to compare the solutions of the robust counterpart optimization models and applications in refinery production planning and batch process scheduling problem are presented. PMID:21935263

  2. Scheduling and Utilization.

    ERIC Educational Resources Information Center

    Blakesley, James F.

    1982-01-01

    College scheduling system and operating procedure objectives influence efficient use of resources. Theoretical and practical considerations are outlined, including a step-by-step assessment of an institution's enrollment capacity and discussion of centralized or reassignable classrooms. (Author/MSE)

  3. Childhood Vaccine Schedule

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Childhood Vaccine Schedule Past Issues / Spring 2008 Table of Contents ... please turn Javascript on. When to Vaccinate What Vaccine Why Birth (or any age if not previously ...

  4. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Grego

    2004-01-01

    Schedule Risk Assessment (SRA) determines the probability of finishing on or before a given point in time. This viewgraph presentation introduces the prerequisites, probability distribution curves, special conditions, calculations, and results analysis for SRA.

  5. Distributed network scheduling

    NASA Technical Reports Server (NTRS)

    Clement, Bradley J.; Schaffer, Steven R.

    2005-01-01

    We investigate missions where communications resources are limited, requiring autonomous planning and execution. Unlike typical networks, spacecraft networks are also suited to automated planning and scheduling because many communications can be planned in advance.

  6. Initial Hardware Development Schedule

    NASA Technical Reports Server (NTRS)

    Culpepper, William X.

    1991-01-01

    The hardware development schedule for the Common Lunar Lander's (CLLs) tracking system is presented. Among the topics covered are the following: historical perspective, solution options, industry contacts, and the rationale for selection.

  7. Real-time adaptive aircraft scheduling

    NASA Technical Reports Server (NTRS)

    Kolitz, Stephan E.; Terrab, Mostafa

    1990-01-01

    One of the most important functions of any air traffic management system is the assignment of ground-holding times to flights, i.e., the determination of whether and by how much the take-off of a particular aircraft headed for a congested part of the air traffic control (ATC) system should be postponed in order to reduce the likelihood and extent of airborne delays. An analysis is presented for the fundamental case in which flights from many destinations must be scheduled for arrival at a single congested airport; the formulation is also useful in scheduling the landing of airborne flights within the extended terminal area. A set of approaches is described for addressing a deterministic and a probabilistic version of this problem. For the deterministic case, where airport capacities are known and fixed, several models were developed with associated low-order polynomial-time algorithms. For general delay cost functions, these algorithms find an optimal solution. Under a particular natural assumption regarding the delay cost function, an extremely fast (O(n ln n)) algorithm was developed. For the probabilistic case, using an estimated probability distribution of airport capacities, a model was developed with an associated low-order polynomial-time heuristic algorithm with useful properties.

  8. cFE/CFS (Core Flight Executive/Core Flight System)

    NASA Technical Reports Server (NTRS)

    Wildermann, Charles P.

    2008-01-01

    This viewgraph presentation describes in detail the requirements and goals of the Core Flight Executive (cFE) and the Core Flight System (CFS). The Core Flight Software System is a mission independent, platform-independent, Flight Software (FSW) environment integrating a reusable core flight executive (cFE). The CFS goals include: 1) Reduce time to deploy high quality flight software; 2) Reduce project schedule and cost uncertainty; 3) Directly facilitate formalized software reuse; 4) Enable collaboration across organizations; 5) Simplify sustaining engineering (AKA. FSW maintenance); 6) Scale from small instruments to System of Systems; 7) Platform for advanced concepts and prototyping; and 7) Common standards and tools across the branch and NASA wide.

  9. Computer-aided design of flight control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.; Sircar, Subrata

    1991-01-01

    A computer program is presented for facilitating the development and assessment of flight control systems, and application to a control design is discussed. The program is a computer-aided control-system design program based on direct digital synthesis of a proportional-integral-filter controller with scheduled linear-quadratic-Gaussian gains and command generator tracking of pilot inputs. The FlightCAD system concentrates on aircraft dynamics, flight-control systems, stability and performance, and has practical engineering applications.

  10. Prototype resupply scheduler

    NASA Technical Reports Server (NTRS)

    Tanner, Steve; Hughes, Angi; Byrd, Jim

    1987-01-01

    Resupply scheduling for the Space Station presents some formidable logistics problems. One of the most basic problems is assigning supplies to a series of shuttle resupply missions. A prototype logistics expert system which constructs resupply schedules was developed. This prototype is able to reconstruct feasible resupply plans. In addition, analysts can use the system to evaluate the impact of adding, deleting or modifying launches, cargo space, experiments, etc.

  11. Atmospheric reentry flight test of winged space vehicle

    NASA Astrophysics Data System (ADS)

    Inatani, Yoshifumi; Akiba, Ryojiro; Hinada, Motoki; Nagatomo, Makoto

    A summary of the atmospheric reentry flight experiment of winged space vehicle is presented. The test was conducted and carried out by the Institute of Space and Astronautical Science (ISAS) in Feb. 1992 in Kagoshima Space Center. It is the first Japanese atmospheric reentry flight of the controlled lifting vehicle. A prime objective of the flight is to demonstrate a high speed atmospheric entry flight capability and high-angle-of-attack flight capability in terms of aerodynamics, flight dynamics and flight control of these kind of vehicles. The launch of the winged vehicle was made by balloon and solid propellant rocket booster which was also the first trial in Japan. The vehicle accomplishes the lfight from space-equivalent condition to the atmospheric flight condition where reaction control system (RCS) attitude stabilization and aerodynamic control was used, respectively. In the flight, the vehicle's attitude was measured by both an inertial measurement unit (IMU) and an air data sensor (ADS) which were employed into an auto-pilot flight control loop. After completion of the entry transient flight, the vehicle experienced unexpected instability during the atmospheric decelerating flight; however, it recovered the attitude orientation and completed the transonic flight after that. The latest analysis shows that it is due to the ADS measurement error and the flight control gain scheduling; what happened was all understood. Some details of the test and the brief summary of the current status of the post flight analysis are presented.

  12. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  13. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  14. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  15. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  16. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  17. Matlab as a robust control design tool

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    1994-01-01

    This presentation introduces Matlab as a tool used in flight control research. The example used to illustrate some of the capabilities of this software is a robust controller designed for a single stage to orbit air breathing vehicles's ascent to orbit. The global requirements of the controller are to stabilize the vehicle and follow a trajectory in the presence of atmospheric disturbances and strong dynamic coupling between airframe and propulsion.

  18. Overview of the LaNCETS Flight Experiment and the CFD Analysis

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Bio, Trong

    2008-01-01

    LaCETS baseline flight study include: 29 high-quality nearfield shock structure probings at three Mach numbers; Shocks in exhaust plume measured; ! CFD study of simplified nozzle shows similar plume structures as flight data; ! Phase II flights scheduled for October 2008; and ! US Industry and Academia invited to participate in analysis, review, and assessment of LaNCETS data.

  19. 14 CFR Table B to Part 117 - Flight Duty Period: Unaugmented Operations

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... FLIGHT AND DUTY LIMITATIONS AND REST REQUIREMENTS: FLIGHTCREW MEMBERS (EFF. 1-4-14) Pt. 117, Table B Table B to Part 117—Flight Duty Period: Unaugmented Operations Scheduled time of start (acclimated time... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight Duty Period: Unaugmented...

  20. 75 FR 21044 - Notice of Centennial Challenges 2011 CAFE Green Flight Challenge

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... SPACE ADMINISTRATION Notice of Centennial Challenges 2011 CAFE Green Flight Challenge AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice of Centennial Challenges 2011 CAFE Green Flight... Flight Challenge is scheduled and teams that wish to compete may register. Centennial Challenges is...

  1. A Robust Biomarker

    NASA Technical Reports Server (NTRS)

    Westall, F.; Steele, A.; Toporski, J.; Walsh, M. M.; Allen, C. C.; Guidry, S.; McKay, D. S.; Gibson, E. K.; Chafetz, H. S.

    2000-01-01

    Polymers of bacterial origin, either through cell secretion or the degraded product of cell lysis, form isolated mucoidal strands as well as well-developed biofilms on interfaces. Biofilms are structurally and compositionally complex and are readily distinguishable from abiogenic films. These structures range in size from micrometers to decimeters, the latter occurring as the well-known, mineralised biofilms called stromatolites. Compositionally bacterial polymers are greater than 90 % water, with while the majority of the macromolecules forming the framework of the polymers consisting of polysaccharides (with and some nucteic acids and proteins). These macromolecules contain a vaste amount of functional groups, such as carboxyls, hydroxyls, and phosphoryls which are implicated in cation-binding. It is the elevated metal- binding capacity which provides the bacterial polymer with structural support and also helps to preserves it for up to 3.5 b.y. in the terrestrial rock record. The macromolecules, thus, can become rapidly mineralised and trapped in a mineral matrix. Through early and late diagenesis (bacterial degradation, burial, heat, pressure and time) they break down, losing the functional groups and, gradually, their hydrogen atoms. The degraded product is known as "kerogen". With further diagenesis and metamorphism, all the hydrogen atoms are lost and the carbonaceous matter becomes graphite. until the remnant carbonaceous material become graphitised. This last sentence reads a bit as if ALL these macromolecules break down and end up as graphite., but since we find 441 this is not true for all of the macromolecules. We have traced fossilised polymer and biofilms in rocks from throughout Earth's history, to rocks as old as the oldest being 3.5 b.y.-old. Furthermore, Time of Flight Secondary Ion Mass Spectrometry has been able to identify individual macromolecules of bacterial origin, the identities of which are still being investigated, in all the samples

  2. Dynamic Flight Envelope Assessment with Flight Safety Applications

    NASA Astrophysics Data System (ADS)

    Pandita, Rohit

    FDI filter and a geometric filter design are compared using the metrics and the results validated through simulation. This research was expanded to include synthesis, real-time implementation and flight validation of robust FDI filters for a small uninhabited aerial vehicle. The influence of different closed-loop controllers on FDI filter performance is investigated. A comparison is presented between simulation of the predicted FDI filter performance and flight experiment results.

  3. SPANR planning and scheduling

    NASA Astrophysics Data System (ADS)

    Freund, Richard F.; Braun, Tracy D.; Kussow, Matthew; Godfrey, Michael; Koyama, Terry

    2001-07-01

    SPANR (Schedule, Plan, Assess Networked Resources) is (i) a pre-run, off-line planning and (ii) a runtime, just-in-time scheduling mechanism. It is designed to support primarily commercial applications in that it optimizes throughput rather than individual jobs (unless they have highest priority). Thus it is a tool for a commercial production manager to maximize total work. First the SPANR Planner is presented showing the ability to do predictive 'what-if' planning. It can answer such questions as, (i) what is the overall effect of acquiring new hardware or (ii) what would be the effect of a different scheduler. The ability of the SPANR Planner to formulate in advance tree-trimming strategies is useful in several commercial applications, such as electronic design or pharmaceutical simulations. The SPANR Planner is demonstrated using a variety of benchmarks. The SPANR Runtime Scheduler (RS) is briefly presented. The SPANR RS can provide benefit for several commercial applications, such as airframe design and financial applications. Finally a design is shown whereby SPANR can provide scheduling advice to most resource management systems.

  4. Appliance Commitment for Household Load Scheduling

    SciTech Connect

    Du, Pengwei; Lu, Ning

    2011-06-30

    This paper presents a novel appliance commitment algorithm that schedules thermostatically-controlled household loads based on price and consumption forecasts considering users comfort settings to meet an optimization objective such as minimum payment or maximum comfort. The formulation of an appliance commitment problem was described in the paper using an electrical water heater load as an example. The thermal dynamics of heating and coasting of the water heater load was modeled by physical models; random hot water consumption was modeled with statistical methods. The models were used to predict the appliance operation over the scheduling time horizon. User comfort was transformed to a set of linear constraints. Then, a novel linear, sequential, optimization process was used to solve the appliance commitment problem. The simulation results demonstrate that the algorithm is fast, robust, and flexible. The algorithm can be used in home/building energy-management systems to help household owners or building managers to automatically create optimal load operation schedules based on different cost and comfort settings and compare cost/benefits among schedules.

  5. An induction into the design of flight test instrumentation systems. [factors affecting the development and design of flight test instrumentation systems

    NASA Technical Reports Server (NTRS)

    Dove, B. L.

    1974-01-01

    The development of flight test instrumentation systems based on specific requirements for the flight tests is discussed. The factors which influence the instrumentation system design are described. The use of a measurements list as a device for determining flight test requirements is explained. A block diagram of a typical flight test instrumentation system is provided. The effects of factors such as cost, schedule, personnel, accuracy, environmental qualifications, and reliability are analyzed.

  6. Automated Scheduling Via Artificial Intelligence

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  7. Schedule-Tracker Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Tracker provides effective method for tracking tasks "past due" and/or "near term". Generates reports for each responsible staff member having one or more assigned tasks falling within two listed categories. Schedule Organizer (SO) (COSMIC program MSC-21525), Schedule Tracker (ST), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  8. Shuttle program. STS-7 conceptual flight profile. IUS/TDRS-A

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Space Transportation System (STS) Flight Assignment Manifest has has scheduled a Tracking and Data Relay Satellite System (TDRSS) spacecraft for a February 1981 launch on STS Flight 7. The preliminary flight profile that conceptually implements the flight requirements and constraints levied by the STS, inertial upper stage (IUS), and the TDRS spacecraft is presented. The integrated major flight design guidelines and requirements used in the development of the flight profile are included together with a flight sequence of events and time line that describe the profile and reflect implementation of the integrated set of requirements.

  9. Robust Adaptive Control

    NASA Technical Reports Server (NTRS)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  10. 41 CFR 301-10.117 - May I keep compensation an airline gives me for voluntarily vacating my seat on my scheduled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... an airline gives me for voluntarily vacating my seat on my scheduled airline flight when the airline... compensation an airline gives me for voluntarily vacating my seat on my scheduled airline flight when the airline asks for volunteers? Yes: (a) If voluntarily vacating your seat will not interfere with...