Sample records for survivable flight control

  1. Robust Flight Controllers. (United States)


    Institute of Technology, Wright-Patterson Air force Base, Ohio, December, 1982. 31. Roskam , J. Airplane Flight Dynamics and Automatic Flight Controls...Lawrence, Kansas: Roskam Aviation and Engineering, 1979. 171 " APPENDIX A: Generic Controller Format Al. Introduction In Chapter II, the idea of a

  2. A flight control through unstable flapping flight (United States)

    Iima, Makoto; Yokoyama, Naoto; Hirai, Norio; Senda, Kei


    We have studied a flight control in a two-dimensional flapping flight model for insects. In this model, the model of center-of-mass can move in both horizontal and vertical directions according to the hydrodynamic force generated by flapping. Under steady flapping, the model converges to steady flight states depending on initial conditions. We demonstrate that simple changes in flapping motion, a finite-time stop of flapping, results in changes in the vortex structures, and the separation of two steady flight state by a quasi-steady flight. The model's flight finally converges to one of the final states by way of the quasi-steady state, which is not observed as a (stable) steady flight. The flight dynamic has been also analyzed. KAKENHI (23540433, 22360105, 21340019) and CREST No. PJ74100011.

  3. Digital flight control systems (United States)

    Caglayan, A. K.; Vanlandingham, H. F.


    The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

  4. Survivability via Control Objectives

    Energy Technology Data Exchange (ETDEWEB)



    Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.

  5. Flight Control of Flexible Aircraft (United States)

    Nguyen, Nhan T.


    This presentation presents an overview of flight control research for flexible high aspect wing aircraft in support of the NASA ARMD Advanced Air Transport Technology (AATT) project. It summarizes multi-objective flight control technology being developed for drag optimization, flutter suppression, and maneuver and gust load alleviation.

  6. Navy AV-8B Crash Survivable Flight Incident Recorder (CSFIR)

    National Research Council Canada - National Science Library


    ...) met at the Naval Air Weapons Development Center, Building P302, China Lake, CA for a Program Review I Technical Interchange Meeting in support of the AV-8B Crash Survivable Flight Incident Recorder System (CSFIR...

  7. Crash Survivable Flight Data Recording System Study. (United States)


    checklist (before StaL- fled In Appendix B of this Part- IfD Each flight recorder required by Ins engines for the purpose of fljg- (1) Time, altitude...gisetrici&I power glictli dse of this sucetion must meet be installed so that- from the bus ithat provides, the mai- Me uffinh-um Performsnce Btandard

  8. Haploid deletion strains of Saccharomyces cerevisiae that determine survival during space flight (United States)

    Johanson, Kelly; Allen, Patricia L.; Gonzalez-Villalobos, Romer A.; Nesbit, Jacqueline; Nickerson, Cheryl A.; Höner zu Bentrup, Kerstin; Wilson, James W.; Ramamurthy, Rajee; D'Elia, Riccardo; Muse, Kenneth E.; Hammond, Jeffrey; Freeman, Jake; Stodieck, Louis S.; Hammond, Timothy G.


    This study identifies genes that determine survival during a space flight, using the model eukaryotic organism, Saccharomyces cerevisiae. Select strains of a haploid yeast deletion series grew during storage in distilled water in space, but not in ground based static or clinorotation controls. The survival advantages in space in distilled water include a 133-fold advantage for the deletion of PEX19, a chaperone and import receptor for newly- synthesized class I peroxisomal membrane proteins, to 77-40 fold for deletion strains lacking elements of aerobic respiration, isocitrate metabolism, and mitochondrial electron transport. Following automated addition of rich growth media, the space flight was associated with a marked survival advantage of strains with deletions in catalytically active genes including hydrolases, oxidoreductases and transferases. When compared to static controls, space flight was associated with a marked survival disadvantage of deletion strains lacking transporter, antioxidant and catalytic activity. This study identifies yeast deletion strains with a survival advantage during storage in distilled water and space flight, and amplifies our understanding of the genes critical for survival in space.

  9. Online Learning Flight Control for Intelligent Flight Control Systems (IFCS) (United States)

    Niewoehner, Kevin R.; Carter, John (Technical Monitor)


    The research accomplishments for the cooperative agreement 'Online Learning Flight Control for Intelligent Flight Control Systems (IFCS)' include the following: (1) previous IFC program data collection and analysis; (2) IFC program support site (configured IFC systems support network, configured Tornado/VxWorks OS development system, made Configuration and Documentation Management Systems Internet accessible); (3) Airborne Research Test Systems (ARTS) II Hardware (developed hardware requirements specification, developing environmental testing requirements, hardware design, and hardware design development); (4) ARTS II software development laboratory unit (procurement of lab style hardware, configured lab style hardware, and designed interface module equivalent to ARTS II faceplate); (5) program support documentation (developed software development plan, configuration management plan, and software verification and validation plan); (6) LWR algorithm analysis (performed timing and profiling on algorithm); (7) pre-trained neural network analysis; (8) Dynamic Cell Structures (DCS) Neural Network Analysis (performing timing and profiling on algorithm); and (9) conducted technical interchange and quarterly meetings to define IFC research goals.

  10. 14 CFR 29.151 - Flight controls. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight controls. 29.151 Section 29.151 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Flight Characteristics § 29.151 Flight controls. (a...

  11. 14 CFR 27.151 - Flight controls. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight controls. 27.151 Section 27.151 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.151 Flight controls. (a...

  12. A benchmark for fault tolerant flight control evaluation (United States)

    Smaili, H.; Breeman, J.; Lombaerts, T.; Stroosma, O.


    A large transport aircraft simulation benchmark (REconfigurable COntrol for Vehicle Emergency Return - RECOVER) has been developed within the GARTEUR (Group for Aeronautical Research and Technology in Europe) Flight Mechanics Action Group 16 (FM-AG(16)) on Fault Tolerant Control (2004 2008) for the integrated evaluation of fault detection and identification (FDI) and reconfigurable flight control strategies. The benchmark includes a suitable set of assessment criteria and failure cases, based on reconstructed accident scenarios, to assess the potential of new adaptive control strategies to improve aircraft survivability. The application of reconstruction and modeling techniques, based on accident flight data, has resulted in high-fidelity nonlinear aircraft and fault models to evaluate new Fault Tolerant Flight Control (FTFC) concepts and their real-time performance to accommodate in-flight failures.

  13. Robust flight control of rotorcraft (United States)

    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.

  14. F-15 IFCS Intelligent Flight Control System (United States)

    Bosworth, John T.


    This viewgraph presentation gives a detailed description of the F-15 aircraft, flight tests, aircraft performance and overall advanced neural network based flight control technologies for aerospace systems designs.

  15. Morphing Flight Control Surface for Advanced Flight Performance Project (United States)

    National Aeronautics and Space Administration — In this SBIR project, a new Morphing Flight Control Surface (MFCS) will be developed. The distinction of the research effort is that the SenAnTech team will employ...

  16. Survivability of SCADA Control Loop

    NARCIS (Netherlands)

    Camacho, José; de Boer, Pieter-Tjerk; Remke, Anne Katharina Ingrid


    The endorsement of information technologies for critical infrastructures control introduces new threats in their security and surveillance. Along with certain level of protection against attacks, it is desirable for critical processes to survive even if they succeed. A stochastic Petri Nets-based

  17. Remote radio control of insect flight

    Directory of Open Access Journals (Sweden)

    Hirotaka Sato


    Full Text Available We demonstrated the remote control of insects in free flight via an implantable radio-equipped miniature neural stimulating system. The pronotum mounted system consisted of neural stimulators, muscular stimulators, a radio transceiver-equipped microcontroller and a microbattery. Flight initiation, cessation and elevation control were accomplished through neural stimulus of the brain which elicited, suppressed or modulated wing oscillation. Turns were triggered through the direct muscular stimulus of either of the basalar muscles. We characterized the response times, success rates, and free-flight trajectories elicited by our neural control systems in remotely-controlled beetles. We believe this type of technology will open the door to in-flight perturbation and recording of insect flight responses.

  18. 14 CFR 23.865 - Fire protection of flight controls, engine mounts, and other flight structure. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fire protection of flight controls, engine... COMMUTER CATEGORY AIRPLANES Design and Construction Fire Protection § 23.865 Fire protection of flight controls, engine mounts, and other flight structure. Flight controls, engine mounts, and other flight...

  19. 14 CFR 25.865 - Fire protection of flight controls, engine mounts, and other flight structure. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fire protection of flight controls, engine... Design and Construction Fire Protection § 25.865 Fire protection of flight controls, engine mounts, and other flight structure. Essential flight controls, engine mounts, and other flight structures located in...

  20. Distributed Flight Controls for UAVs Project (United States)

    National Aeronautics and Space Administration — Two novel flight control actuation concepts for UAV applications are proposed for prototype development, both of which incorporate shape memory alloy (SMA) wires as...

  1. Distributed Flight Controls for UAVs Project (United States)

    National Aeronautics and Space Administration — Two novel flight control actuation concepts for UAV applications are proposed for research and development, both of which incorporate shape memory alloy (SMA) wires...

  2. Compound control methodology for flight vehicles

    CERN Document Server

    Xia, Yuanqing


    “Compound Control Methodology for Flight Vehicles” focuses on new control methods for flight vehicles. In this monograph the concept of compound control is introduced. It is demonstrated that both Sliding Mode Control (SMC) and Active Disturbance Rejection Control (ADRC) have their own advantages and limitations, i.e., chattering of SMC and the observability of extended state observer (ESO), respectively. It is shown that compound control combines their advantages and improves the performance of the closed-loop systems. The book is self-contained, providing sufficient mathematical foundations for understanding the contents of each chapter. It will be of significant interest to scientists and engineers engaged in the field of flight vehicle control.

  3. Structural Pain Compensating Flight Control (United States)

    Miller, Chris J.


    The problem of control command and maneuver induced structural loads is an important aspect of any control system design. Designers must design the aircraft structure and the control architecture to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to build the structure with high margins, restrict control surface commands to known good combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage.

  4. Aircraft digital flight control technical review (United States)

    Davenport, Otha B.; Leggett, David B.


    The Aircraft Digital Flight Control Technical Review was initiated by two pilot induced oscillation (PIO) incidents in the spring and summer of 1992. Maj. Gen. Franklin (PEO) wondered why the Air Force development process for digital flight control systems was not preventing PIO problems. Consequently, a technical review team was formed to examine the development process and determine why PIO problems continued to occur. The team was also to identify the 'best practices' used in the various programs. The charter of the team was to focus on the PIO problem, assess the current development process, and document the 'best practices.' The team reviewed all major USAF aircraft programs with digital flight controls, specifically, the F-15E, F-16C/D, F-22, F-111, C-17, and B-2. The team interviewed contractor, System Program Office (SPO), and Combined Test Force (CTF) personnel on these programs. The team also went to NAS Patuxent River to interview USN personnel about the F/A-18 program. The team also reviewed experimental USAF and NASA systems with digital flight control systems: X-29, X-31, F-15 STOL and Maneuver Technology Demonstrator (SMTD), and the Variable In-Flight Stability Test Aircraft (VISTA). The team also discussed the problem with other experts in the field including Ralph Smith and personnel from Calspan. The major conclusions and recommendations from the review are presented.

  5. Flight control electronics reliability/maintenance study (United States)

    Dade, W. W.; Edwards, R. H.; Katt, G. T.; Mcclellan, K. L.; Shomber, H. A.


    Collection and analysis of data are reported that concern the reliability and maintenance experience of flight control system electronics currently in use on passenger carrying jet aircraft. Two airlines B-747 airplane fleets were analyzed to assess the component reliability, system functional reliability, and achieved availability of the CAT II configuration flight control system. Also assessed were the costs generated by this system in the categories of spare equipment, schedule irregularity, and line and shop maintenance. The results indicate that although there is a marked difference in the geographic location and route pattern between the airlines studied, there is a close similarity in the reliability and the maintenance costs associated with the flight control electronics.

  6. NASA develops new digital flight control system (United States)

    Mewhinney, Michael


    This news release reports on the development and testing of a new integrated flight and propulsion automated control system that aerospace engineers at NASA's Ames Research Center have been working on. The system is being tested in the V/STOL (Vertical/Short Takeoff and Landing) Systems Research Aircraft (VSRA).

  7. Advanced transport operating system software upgrade: Flight management/flight controls software description (United States)

    Clinedinst, Winston C.; Debure, Kelly R.; Dickson, Richard W.; Heaphy, William J.; Parks, Mark A.; Slominski, Christopher J.; Wolverton, David A.


    The Flight Management/Flight Controls (FM/FC) software for the Norden 2 (PDP-11/70M) computer installed on the NASA 737 aircraft is described. The software computes the navigation position estimates, guidance commands, those commands to be issued to the control surfaces to direct the aircraft in flight based on the modes selected on the Advanced Guidance Control System (AGSC) mode panel, and the flight path selected via the Navigation Control/Display Unit (NCDU).

  8. 14 CFR 121.543 - Flight crewmembers at controls. (United States)


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight crewmembers at controls. 121.543... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.543 Flight crewmembers at controls. (a) Except as provided in paragraph (b) of this section, each required flight crewmember on...

  9. Cost Estimation and Control for Flight Systems (United States)

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


    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.

  10. In-flight cabin smoke control. (United States)

    Eklund, T I


    Fatal accidents originating from in-flight cabin fires comprise only about 1% of all fatal accidents in the civil jet transport fleet. Nevertheless, the impossibility of escape during flight accentuates the hazards resulting from low visibility and toxic gases. Control of combustion products in an aircraft cabin is affected by several characteristics that make the aircraft cabin environment unique. The aircraft fuselage is pressurized in flight and has an air distribution system which provides ventilation jets from the ceiling level air inlets running along the cabin length. A fixed quantity of ventilation air is metered into the cabin and air discharge is handled primarily by pressure controlling outflow valves in the rear lower part of the fuselage. Earlier airplane flight tests on cabin smoke control used generators producing minimally buoyant smoke products that moved with and served as a telltales for overall cabin ventilation flows. Analytical studies were done with localized smoke production to predict the percent of cabin length that would remain smoke-free during continuous generation. Development of a buoyant smoke generator allowed simulation of a fire plume with controllable simulated temperature and heat release rates. Tests on a Boeing 757, modified to allow smoke venting out through the top of the cabin, showed that the buoyant smoke front moved at 0.46m/s (1.5ft/sec) with and 0.27m/sec (0.9ft/sec) against, the axial ventilation airflow. Flight tests in a modified Boeing 727 showed that a ceiling level counterflow of about 0.55m/sec (1.8ft/sec) was required to arrest the forward movement of buoyant smoke. A design goal of 0.61m/s (2ft/sec) axial cabin flow would require a flow rate of 99m3/min (3500ft3/min) in a furnished Boeing 757. The current maximum fresh air cabin ventilation flow is 78m3/min (2756 ft3/min). Experimental results indicate that buoyancy effects cause smoke movement behaviour that is not predicted by traditional design analyses and

  11. Selected Flight Test Results for Online Learning Neural Network-Based Flight Control System (United States)

    Williams-Hayes, Peggy S.


    The NASA F-15 Intelligent Flight Control System project team developed a series of flight control concepts designed to demonstrate neural network-based adaptive controller benefits, with the objective to develop and flight-test control systems using neural network technology to optimize aircraft performance under nominal conditions and stabilize the aircraft under failure conditions. This report presents flight-test results for an adaptive controller using stability and control derivative values from an online learning neural network. A dynamic cell structure neural network is used in conjunction with a real-time parameter identification algorithm to estimate aerodynamic stability and control derivative increments to baseline aerodynamic derivatives in flight. This open-loop flight test set was performed in preparation for a future phase in which the learning neural network and parameter identification algorithm output would provide the flight controller with aerodynamic stability and control derivative updates in near real time. Two flight maneuvers are analyzed - pitch frequency sweep and automated flight-test maneuver designed to optimally excite the parameter identification algorithm in all axes. Frequency responses generated from flight data are compared to those obtained from nonlinear simulation runs. Flight data examination shows that addition of flight-identified aerodynamic derivative increments into the simulation improved aircraft pitch handling qualities.

  12. Technology research for digital flight control (United States)

    Carestia, R. A.


    The use of advanced digital systems for flight control and guidance for a specific mission is investigated. The research areas include advanced electronic system architectures, tests with the global positioning system (GPS) in a helicopter, and advanced integrated systems concept for rotorcraft. Emphasis is on a search and rescue mission, differential global positioning systems to provide a data base of performance information for navigation, and a study to determine the present usage and trends of microcomputers and microcomputer components in the avionics industries.

  13. 14 CFR 23.673 - Primary flight controls. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Primary flight controls. 23.673 Section 23.673 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Control Systems § 23.673 Primary flight controls. Primary flight controls are those used by the pilot for...

  14. Survival of the fastest: Evolving wings for flapping flight (United States)

    Ramananarivo, Sophie; Mitchel, Thomas; Ristroph, Leif


    To optimize flapping flight with regard to wing shape, we use an evolutionary or genetic algorithm to improve the forward speed of 3d-printed wings or hydrofoils that heave up-and-down and self-propel within water. In this scheme, ``genes'' are mathematical parameters specifying wing shape, and ``breeding'' involves the merging and mutation of genes from two parent wings to form a child. A wing's swimming speed is its ``fitness'', which dictates the likelihood of breeding and thus passing on its genes to the next generation. We find that this iterative process leads to marked improvements in relatively few generations, and several distinct shape features are shared among the fastest wings. We also investigate the favorable flow structures produced by these elite swimmers and compare their shape and performance to biologically evolved wings, fins, tails, and flippers.

  15. Balancing Training Techniques for Flight Controller Certification (United States)

    Gosling, Christina


    Training of ground control teams has been a difficult task in space operations. There are several intangible skills that must be learned to become the steely eyed men and women of mission control who respond to spacecraft failures that can lead to loss of vehicle or crew if handled improperly. And as difficult as training is, it can also be costly. Every day, month or year an operator is in training, is a day that not only they are being trained without direct benefit to the organization, but potentially an instructor or mentor is also being paid for hours spent assisting them. Therefore, optimization of the training flow is highly desired. Recently the Expedition Division (DI) at Johnson Space Flight Center has recreated their training flows for the purpose of both moving to an operator/specialist/instructor hierarchy and to address past inefficiencies in the training flow. This paper will discuss the types of training DI is utilizing in their new flows, and the balance that has been struck between the ideal learning environments and realistic constraints. Specifically, the past training flow for the ISS Attitude Determination and Control Officer will be presented, including drawbacks that were encountered. Then the new training flow will be discussed and how a new approach utilizes more training methods and teaching techniques. We will look at how DI has integrated classes, workshops, checkouts, module reviews, scenarios, OJT, paper sims, Mini Sims, and finally Integrated Sims to balance the cost and timing of training a new flight controller.

  16. Quadrocopter Control Design and Flight Operation (United States)

    Karwoski, Katherine


    A limiting factor in control system design and analysis for spacecraft is the inability to physically test new algorithms quickly and cheaply. Test flights of space vehicles are costly and take much preparation. As such, EV41 recently acquired a small research quadrocopter that has the ability to be a test bed for new control systems. This project focused on learning how to operate, fly, and maintain the quadrocopter, as well as developing and testing protocols for its use. In parallel to this effort, developing a model in Simulink facilitated the design and analysis of simple control systems for the quadrocopter. Software provided by the manufacturer enabled testing of the Simulink control system on the vehicle.

  17. 14 CFR 125.311 - Flight crewmembers at controls. (United States)


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight crewmembers at controls. 125.311... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations § 125.311 Flight crewmembers at controls. (a) Except as provided in paragraph (b) of this section, each...

  18. Advanced Transport Operating System (ATOPS) Flight Management/Flight Controls (FM/FC) software description (United States)

    Wolverton, David A.; Dickson, Richard W.; Clinedinst, Winston C.; Slominski, Christopher J.


    The flight software developed for the Flight Management/Flight Controls (FM/FC) MicroVAX computer used on the Transport Systems Research Vehicle for Advanced Transport Operating Systems (ATOPS) research is described. The FM/FC software computes navigation position estimates, guidance commands, and those commands issued to the control surfaces to direct the aircraft in flight. Various modes of flight are provided for, ranging from computer assisted manual modes to fully automatic modes including automatic landing. A high-level system overview as well as a description of each software module comprising the system is provided. Digital systems diagrams are included for each major flight control component and selected flight management functions.

  19. Missile flight control using active flexspar actuators (United States)

    Barrett, Ronald M.; Gross, R. Steven; Brozoski, Fred


    A new type of subsonic missile flight control surface using piezoelectric flexspar actuators is presented. The flexspar design uses an aerodynamic shell which is pivoted at the quarter-chord about a graphite main spar. The shell is pitched up and down by a piezoelectric bender element which is rigidly attached to a base mount and allowed to rotate freely at the tip. The element curvature, shell pitch deflection and torsional stiffness are modeled using laminated plate theory. A one-third scale TOW 2B missile model was used as a demonstration platform. A static wing of the missile was replaced with an active flexspar wing. The 1' X 2.7' active flight control surface was powered by a bi-morph bender with 5-mil PZT-5H sheets. Bench and wind tunnel testing showed good correlation between theory and experiment and static pitch deflections in excess of +/- 14 degree(s). A natural frequency of 78.5 rad/s with a break frequency of 157 rad/s was measured. Wind tunnel tests revealed no flutter or divergence tendencies. Maximum changes in lift coefficient were measured at (Delta) CL equals +/- .73 which indicates that terminal and initial missile load factors may be increased by approximately 3.1 and 12.6 g's respectively, leading to a greatly reduced turn radius of only 2,400 ft.

  20. Effects of space flight on locomotor control (United States)

    Bloomberg, Jacob J.; Layne, Charles S.; McDonald, P. Vernon; Peters, Brian T.; Huebner, William P.; Reschke, Millard F.; Berthoz, Alain; Glasauer, Stefan; Newman, Dava; Jackson, D. Keoki


    In the microgravity environment of spaceflight, the relationship between sensory input and motor output is altered. During prolonged missions, neural adaptive processes come into play to recalibrate central nervous system function, thereby permitting new motor control strategies to emerge in the novel sensory environment of microgravity. However, the adaptive state achieved during spaceflight is inappropriate for a unit gravity environment and leads to motor control alterations upon return to Earth that include disturbances in locomotion. Indeed, gait and postural instabilities following the return to Earth have been reported in both U.S. astronauts and Russian cosmonauts even after short duration (5- to 10-day) flights. After spaceflight, astronauts may: (1) experience the sensation of turning while attempting to walk a straight path, (2) encounter sudden loss of postural stability, especially when rounding corners, (3) perceive exaggerated pitch and rolling head movements during walking, (4) experience sudden loss of orientation in unstructured visual environments, or (5) experience significant oscillopsia during locomotion.

  1. Intelligent Flight Control System and Aeronautics Research at NASA Dryden (United States)

    Brown, Nelson A.


    This video presentation reviews the F-15 Intelligent Flight Control System and contains clips of flight tests and aircraft performance in the areas of target tracking, takeoff and differential stabilators. Video of the APG milestone flight 1g formation is included.

  2. Micropropulsion Systems for Precision Controlled Space Flight

    DEFF Research Database (Denmark)

    Larsen, Jack

    Space science is subject to a constantly increasing demand for larger coherence lengths or apertures of the space observation systems, which in turn translates into a demand for increased dimensions and subsequently cost and complexity of the systems. When this increasing demand reaches...... the pratical limitations of increasing the physical dimensions of the spacecrafts, the observation platforms will have to be distributed on more spacecrafts flying in very accurate formations. Consequently, the observation platform becomes much more sensitive to disturbances from the space environment....... This project is thus concentrating on developing a method by which an entire, ecient, control system compensating for the disturbances from the space environment and thereby enabling precision formation flight can be realized. The space environment is initially studied and the knowledge gained is used...

  3. Introduction to Aerial Vehicle Flight Mechanics, Stability and Control


    Knowles, K.


    This article provides an introduction to Section 5.1 on flight mechanics and dynamics, stability and control, and navigation. It introduces some basic concepts of flight control, and static and dynamic stability. Some particular features of vertical or short take-off and landing (V/STOL) aircraft flight control, not covered elsewhere in this Section, are discussed briefly. The other articles in this Section are introduced.

  4. H/OZ: PFD and Collaborative Flight Control System Project (United States)

    National Aeronautics and Space Administration — With aircraft automation increasingly able to control flight autonomously, situational awareness and engagement of the crew can suffer. To improve aviation safety...

  5. Integrating Space Flight Resource Management Skills into Technical Lessons for International Space Station Flight Controller Training (United States)

    Baldwin, Evelyn


    The Johnson Space Center s (JSC) International Space Station (ISS) Space Flight Resource Management (SFRM) training program is designed to teach the team skills required to be an effective flight controller. It was adapted from the SFRM training given to Shuttle flight controllers to fit the needs of a "24 hours a day/365 days a year" flight controller. More recently, the length reduction of technical training flows for ISS flight controllers impacted the number of opportunities for fully integrated team scenario based training, where most SFRM training occurred. Thus, the ISS SFRM training program is evolving yet again, using a new approach of teaching and evaluating SFRM alongside of technical materials. Because there are very few models in other industries that have successfully tied team and technical skills together, challenges are arising. Despite this, the Mission Operations Directorate of NASA s JSC is committed to implementing this integrated training approach because of the anticipated benefits.

  6. Flight Control of the High Altitude Wind Power System

    NARCIS (Netherlands)

    Podgaets, A.R.; Ockels, W.J.


    Closed loop Laddermill flight control problem is considered in this paper. Laddermill is a high altitude kites system for energy production. The kites have been simulated as rigid bodies and the cable as a thin elastic line. Euler angles and cable speed are controls. Flight control is written as a

  7. An Introduction to Multivariable Flight Control System Design (United States)


    Sparks Siva S. Banda CONTROL DYNAMICS BRANCH FLIGHT CONTROL DIVISION FINAL REPORT FOP, PERIGD JAN 92 - OCT 92 APPROVED FOR PUBLIC RELEASE...and Aatomnatic Flight Controls, Part 1, Roskam Aviation and Engineering Corporation, Ottawa, KA, 1982. [2.4] "Miliitary Specification - Flying Qualities

  8. Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control (United States)

    Baer-Riedhart, Jennifer L.; Landy, Robert J.


    The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

  9. Experience with synchronous and asynchronous digital control systems. [for flight (United States)

    Regenie, Victoria A.; Chacon, Claude V.; Lock, Wilton P.


    Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

  10. A unified flight control methodology for a compound rotorcraft in fundamental and aerobatic maneuvering flight (United States)

    Thorsen, Adam

    This study investigates a novel approach to flight control for a compound rotorcraft in a variety of maneuvers ranging from fundamental to aerobatic in nature. Fundamental maneuvers are a class of maneuvers with design significance that are useful for testing and tuning flight control systems along with uncovering control law deficiencies. Aerobatic maneuvers are a class of aggressive and complex maneuvers with more operational significance. The process culminating in a unified approach to flight control includes various control allocation studies for redundant controls in trim and maneuvering flight, an efficient methodology to simulate non-piloted maneuvers with varying degrees of complexity, and the setup of an unconventional control inceptor configuration along with the use of a flight simulator to gather pilot feedback in order to improve the unified control architecture. A flight path generation algorithm was developed to calculate control inceptor commands required for a rotorcraft in aerobatic maneuvers. This generalized algorithm was tailored to generate flight paths through optimization methods in order to satisfy target terminal position coordinates or to minimize the total time of a particular maneuver. Six aerobatic maneuvers were developed drawing inspiration from air combat maneuvers of fighter jet aircraft: Pitch-Back Turn (PBT), Combat Ascent Turn (CAT), Combat Descent Turn (CDT), Weaving Pull-up (WPU), Combat Break Turn (CBT), and Zoom and Boom (ZAB). These aerobatic maneuvers were simulated at moderate to high advance ratios while fundamental maneuvers of the compound including level accelerations/decelerations, climbs, descents, and turns were investigated across the entire flight envelope to evaluate controller performance. The unified control system was developed to allow controls to seamlessly transition between manual and automatic allocations while ensuring that the axis of control for a particular inceptor remained constant with flight

  11. Cassini Attitude Control Flight Software: from Development to In-Flight Operation (United States)

    Brown, Jay


    The Cassini Attitude and Articulation Control Subsystem (AACS) Flight Software (FSW) has achieved its intended design goals by successfully guiding and controlling the Cassini-Huygens planetary mission to Saturn and its moons. This paper describes an overview of AACS FSW details from early design, development, implementation, and test to its fruition of operating and maintaining spacecraft control over an eleven year prime mission. Starting from phases of FSW development, topics expand to FSW development methodology, achievements utilizing in-flight autonomy, and summarize lessons learned during flight operations which can be useful to FSW in current and future spacecraft missions.

  12. Haptic-Multimodal Flight Control System Update (United States)

    Goodrich, Kenneth H.; Schutte, Paul C.; Williams, Ralph A.


    The rapidly advancing capabilities of autonomous aircraft suggest a future where many of the responsibilities of today s pilot transition to the vehicle, transforming the pilot s job into something akin to driving a car or simply being a passenger. Notionally, this transition will reduce the specialized skills, training, and attention required of the human user while improving safety and performance. However, our experience with highly automated aircraft highlights many challenges to this transition including: lack of automation resilience; adverse human-automation interaction under stress; and the difficulty of developing certification standards and methods of compliance for complex systems performing critical functions traditionally performed by the pilot (e.g., sense and avoid vs. see and avoid). Recognizing these opportunities and realities, researchers at NASA Langley are developing a haptic-multimodal flight control (HFC) system concept that can serve as a bridge between today s state of the art aircraft that are highly automated but have little autonomy and can only be operated safely by highly trained experts (i.e., pilots) to a future in which non-experts (e.g., drivers) can safely and reliably use autonomous aircraft to perform a variety of missions. This paper reviews the motivation and theoretical basis of the HFC system, describes its current state of development, and presents results from two pilot-in-the-loop simulation studies. These preliminary studies suggest the HFC reshapes human-automation interaction in a way well-suited to revolutionary ease-of-use.

  13. A system look at electromechanical actuation for primary flight control

    NARCIS (Netherlands)

    Lomonova, E.A.


    An overview is presented of the emergence of the ALL Electric flight control system (FCS) or power-by-wire (PBW) concept. The concept of fly-by-power refers to the actuator using electrical rather than hydraulic power. The development of the primary flight control Electromechanical Actuators (EMAs)

  14. Framework Based Guidance Navigation and Control Flight Software Development (United States)

    McComas, David


    This viewgraph presentation describes NASA's guidance navigation and control flight software development background. The contents include: 1) NASA/Goddard Guidance Navigation and Control (GN&C) Flight Software (FSW) Development Background; 2) GN&C FSW Development Improvement Concepts; and 3) GN&C FSW Application Framework.

  15. Automatic Reverse Engineering of Private Flight Control Protocols of UAVs

    Directory of Open Access Journals (Sweden)

    Ran Ji


    Full Text Available The increasing use of civil unmanned aerial vehicles (UAVs has the potential to threaten public safety and privacy. Therefore, airspace administrators urgently need an effective method to regulate UAVs. Understanding the meaning and format of UAV flight control commands by automatic protocol reverse-engineering techniques is highly beneficial to UAV regulation. To improve our understanding of the meaning and format of UAV flight control commands, this paper proposes a method to automatically analyze the private flight control protocols of UAVs. First, we classify flight control commands collected from a binary network trace into clusters; then, we analyze the meaning of flight control commands by the accumulated error of each cluster; next, we extract the binary format of commands and infer field semantics in these commands; and finally, we infer the location of the check field in command and the generator polynomial matrix. The proposed approach is validated via experiments on a widely used consumer UAV.

  16. PTS performance by flight- and control-group macaques (United States)

    Washburn, D. A.; Rumbaugh, D. M.; Richardson, W. K.; Gulledge, J. P.; Shlyk, G. G.; Vasilieva, O. N.


    A total of 25 young monkeys (Macaca mulatta) were trained with the Psychomotor Test System, a package of software tasks and computer hardware developed for spaceflight research with nonhuman primates. Two flight monkeys and two control monkeys were selected from this pool and performed a psychomotor task before and after the Bion 11 flight or a ground-control period. Monkeys from both groups showed significant disruption in performance after the 14-day flight or simulation (plus one anesthetized day of biopsies and other tests), and this disruption appeared to be magnified for the flight animal.

  17. Formation Flight Control for Aerial Refueling (United States)


    Microbiotics , Inc. The IMU data were recorded on a flight of a Cessna 172, and a representative time slice was reproduced for all of the simulations...nothing about. The final position relative Data Source: Flight Test MIDG II IMU Cessna 172 Microbiotics , Inc. 48 to the boom will obviously...Embedded PC ATH-400 Athena Diamond Systems, Inc GPS Receiver Card JNS100 OEM Javad Navigation Systems MEMS IMU MIDG II INS/GPS Microbiotics , Inc UHF

  18. Hover flight control of helicopter using optimal control theory

    Directory of Open Access Journals (Sweden)



    Full Text Available This paper represents the optimal control theory and its application to the full scale helicopters. Generally the control of a helicopter is a hard task, because its system is very nonlinear, coupled and sensitive to the control inputs and external disturbances which might destabilize the system. As a result of these instabilities, it is essential to use a control process that helps to improve the systems performance, confirming stability and robustness. The main objective of this part is to develop a control system design technique using Linear Quadratic Regulator (LQR to stabilize the helicopter near hover flight. In order to achieve this objective, firstly, the nonlinear model of the helicopter is linearized using small disturbance theory. The linear optimal control theory is applied to the linearized state space model of the helicopter to design the LQR controller. To clarify robustness of the controller, the effects of external wind gusts and mass change are taken into concern. Wind gusts are taken as disturbances in all directions which are simulated as a sine wave. Many simulations were made to validate and verify the response of the linear controller of the helicopter. The results show that the use of an optimal control process as LQR is a good solution for MIMO helicopter system, achieving a good stabilization and refining the final behavior of the helicopter and handling the external wind gusts disturbances as shown in the different simulations.

  19. A Review of Wind Tunnel Based Virtual Flight Testing Techniques for Evaluation of Flight Control Systems

    Directory of Open Access Journals (Sweden)

    Min Huang


    Full Text Available Wind tunnel based Virtual Flight Testing (VFT is a dynamic wind tunnel test for evaluating flight control systems (FCS proposed in recent decades. It integrates aerodynamics, flight dynamics, and FCS as a whole and is a more realistic and reliable method for FCS evaluation than traditional ground evaluation methods, such as Hardware-in-the-Loop Simulation (HILS. With FCS evaluated by VFT before flight test, the risk of flight test will be further reduced. In this paper, the background, progress, and prospects of VFT are systematically summarized. Specifically, the differences among VFT, traditional dynamic wind tunnel methods, and traditional FCS evaluation methods are introduced in order to address the advantages of evaluating FCS with VFT. Secondly, the progress of VFT is reviewed in detail. Then, the test system and key technologies of VFT for FCS evaluation are analyzed. Lastly, the prospects of VFT for evaluating FCS are described.

  20. Somatosensory Substrates of Flight Control in Bats

    Directory of Open Access Journals (Sweden)

    Kara L. Marshall


    Full Text Available Flight maneuvers require rapid sensory integration to generate adaptive motor output. Bats achieve remarkable agility with modified forelimbs that serve as airfoils while retaining capacity for object manipulation. Wing sensory inputs provide behaviorally relevant information to guide flight; however, components of wing sensory-motor circuits have not been analyzed. Here, we elucidate the organization of wing innervation in an insectivore, the big brown bat, Eptesicus fuscus. We demonstrate that wing sensory innervation differs from other vertebrate forelimbs, revealing a peripheral basis for the atypical topographic organization reported for bat somatosensory nuclei. Furthermore, the wing is innervated by an unusual complement of sensory neurons poised to report airflow and touch. Finally, we report that cortical neurons encode tactile and airflow inputs with sparse activity patterns. Together, our findings identify neural substrates of somatosensation in the bat wing and imply that evolutionary pressures giving rise to mammalian flight led to unusual sensorimotor projections.

  1. The integrated manual and automatic control of complex flight systems (United States)

    Schmidt, David K.


    Research dealt with the general area of optimal flight control synthesis for manned flight vehicles. The work was generic; no specific vehicle was the focus of study. However, the class of vehicles generally considered were those for which high authority, multivariable control systems might be considered, for the purpose of stabilization and the achievement of optimal handling characteristics. Within this scope, the topics of study included several optimal control synthesis techniques, control-theoretic modeling of the human operator in flight control tasks, and the development of possible handling qualities metrics and/or measures of merit. Basic contributions were made in all these topics, including human operator (pilot) models for multi-loop tasks, optimal output feedback flight control synthesis techniques; experimental validations of the methods developed, and fundamental modeling studies of the air-to-air tracking and flared landing tasks.

  2. Integrated assurance assessment of a reconfigurable digital flight control system (United States)

    Ness, W. G.; Davis, R. M.; Benson, J. W.; Smith, M. K.; Eldredge, D.


    The integrated application of reliability, failure effects and system simulator methods in establishing the airworthiness of a flight critical digital flight control system (DFCS) is demonstrated. The emphasis was on the mutual reinforcement of the methods in demonstrating the system safety.

  3. Hybrid Adaptive Flight Control with Model Inversion Adaptation (United States)

    Nguyen, Nhan


    This study investigates a hybrid adaptive flight control method as a design possibility for a flight control system that can enable an effective adaptation strategy to deal with off-nominal flight conditions. The hybrid adaptive control blends both direct and indirect adaptive control in a model inversion flight control architecture. The blending of both direct and indirect adaptive control provides a much more flexible and effective adaptive flight control architecture than that with either direct or indirect adaptive control alone. The indirect adaptive control is used to update the model inversion controller by an on-line parameter estimation of uncertain plant dynamics based on two methods. The first parameter estimation method is an indirect adaptive law based on the Lyapunov theory, and the second method is a recursive least-squares indirect adaptive law. The model inversion controller is therefore made to adapt to changes in the plant dynamics due to uncertainty. As a result, the modeling error is reduced that directly leads to a decrease in the tracking error. In conjunction with the indirect adaptive control that updates the model inversion controller, a direct adaptive control is implemented as an augmented command to further reduce any residual tracking error that is not entirely eliminated by the indirect adaptive control.

  4. Performance evaluation and design of flight vehicle control systems

    CERN Document Server

    Falangas, Eric T


    This book will help students, control engineers and flight dynamics analysts to model and conduct sophisticated and systemic analyses of early flight vehicle designs controlled with multiple types of effectors and to design and evaluate new vehicle concepts in terms of satisfying mission and performance goals. Performance Evaluation and Design of Flight Vehicle Control Systems begins by creating a dynamic model of a generic flight vehicle that includes a range of elements from airplanes and launch vehicles to re-entry vehicles and spacecraft. The models may include dynamic effects dealing with structural flexibility, as well as dynamic coupling between structures and actuators, propellant sloshing, and aeroelasticity, and they are typically used for control analysis and design. The book shows how to efficiently combine different types of effectors together, such as aero-surfaces, TVC, throttling engines and RCS, to operate as a system by developing a mixing logic atrix. Methods of trimming a vehicle controll...

  5. Flight-testing of the self-repairing flight control system using the F-15 highly integrated digital electronic control flight research facility (United States)

    Stewart, James F.; Shuck, Thomas L.


    Flight tests conducted with the self-repairing flight control system (SRFCS) installed on the NASA F-15 highly integrated digital electronic control aircraft are described. The development leading to the current SRFCS configuration is highlighted. Key objectives of the program are outlined: (1) to flight-evaluate a control reconfiguration strategy with three types of control surface failure; (2) to evaluate a cockpit display that will inform the pilot of the maneuvering capacity of the damage aircraft; and (3) to flight-evaluate the onboard expert system maintenance diagnostics process using representative faults set to occur only under maneuvering conditions. Preliminary flight results addressing the operation of the overall system, as well as the individual technologies, are included.

  6. Integrated Flight Path Planning System and Flight Control System for Unmanned Helicopters

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Lin


    Full Text Available This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS and the Flight Control System (FCS. The FPPS finds the shortest flight path by the A-Star (A* algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM.

  7. SERCA control of cell death and survival. (United States)

    Chemaly, Elie R; Troncone, Luca; Lebeche, Djamel


    Intracellular calcium (Ca2+) is a critical coordinator of various aspects of cellular physiology. It is increasingly apparent that changes in cellular Ca2+ dynamics contribute to the regulation of normal and pathological signal transduction that controls cell growth and survival. Aberrant perturbations in Ca2+ homeostasis have been implicated in a range of pathological conditions, such as cardiovascular diseases, diabetes, tumorigenesis and steatosis hepatitis. Intracellular Ca2+ concentrations are therefore tightly regulated by a number of Ca2+ handling enzymes, proteins, channels and transporters located in the plasma membrane and in Ca2+ storage organelles, which work in concert to fine tune a temporally and spatially precise Ca2+ signal. Chief amongst them is the sarco/endoplasmic reticulum (SR/ER) Ca2+ ATPase pump (SERCA) which actively re-accumulates released Ca2+ back into the SR/ER, therefore maintaining Ca2+ homeostasis. There are at least 14 different SERCA isoforms encoded by three ATP2A1-3 genes whose expressions are species- and tissue-specific. Altered SERCA expression and activity results in cellular malignancy and induction of ER stress and ER stress-associated apoptosis. The role of SERCA misregulation in the control of apoptosis in various cell types and disease setting with prospective therapeutic implications is the focus of this review. Ca2+ is a double edge sword for both life as well as death, and current experimental evidence supports a model in which Ca2+ homeostasis and SERCA activity represent a nodal point that controls cell survival. Pharmacological or genetic targeting of this axis constitutes an incredible therapeutic potential to treat different diseases sharing similar biological disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. In-flight Fault Detection and Isolation in Aircraft Flight Control Systems (United States)

    Azam, Mohammad; Pattipati, Krishna; Allanach, Jeffrey; Poll, Scott; Patterson-Hine, Ann


    In this paper we consider the problem of test design for real-time fault detection and isolation (FDI) in the flight control system of fixed-wing aircraft. We focus on the faults that are manifested in the control surface elements (e.g., aileron, elevator, rudder and stabilizer) of an aircraft. For demonstration purposes, we restrict our focus on the faults belonging to nine basic fault classes. The diagnostic tests are performed on the features extracted from fifty monitored system parameters. The proposed tests are able to uniquely isolate each of the faults at almost all severity levels. A neural network-based flight control simulator, FLTZ(Registered TradeMark), is used for the simulation of various faults in fixed-wing aircraft flight control systems for the purpose of FDI.

  9. Reduction of Flight Control System/Structural Mode Interaction Project (United States)

    National Aeronautics and Space Administration — A novel approach is proposed for reducing the degree of interaction of a high gain flight control system with the airframe structural vibration modes, representing a...

  10. Real Time Control Software for Electromagnetic Formation Flight Project (United States)

    National Aeronautics and Space Administration — We propose the development of a maintainable and evolvable real-time control software system for Electromagnetic Formation Flight (EMFF). EMFF systems use...

  11. Application of nonlinear transformations to automatic flight control (United States)

    Meyer, G.; Su, R.; Hunt, L. R.


    The theory of transformations of nonlinear systems to linear ones is applied to the design of an automatic flight controller for the UH-1H helicopter. The helicopter mathematical model is described and it is shown to satisfy the necessary and sufficient conditions for transformability. The mapping is constructed, taking the nonlinear model to canonical form. The performance of the automatic control system in a detailed simulation on the flight computer is summarized.

  12. Formation Flight Control System for In-Flight Sweet Spot Estimation

    NARCIS (Netherlands)

    Brodecki, M.; Subbarao, K.; Chu, Q.P.


    A formation flight control system has been designed that addresses the unique environment encountered by aircraft flying in formation and in the upwash of the leading aircraft. In order to test the control system a simulation environment has been created that adequately represents the aerodynamic

  13. Surviving space flight: case study on MELiSSA's CIII nitrifying compartment (United States)

    Ilgrande, Chiara; Lasseur, Christophe; Mastroleo, Felice; Paille, Christel; Leys, Natalie; Morozova, Julia; Ilyin, Vyacheslav; Clauwaert, Peter; Christiaens, Marlies E. R.; Lindeboom, Ralph E. F.; Vlaeminck, Siegfried; Prat, Delphine; Arroyo, Jose M. C.; Conincx, Ilse; Van Hoey, Olivier; Roume, Hugo; Udert, Kai; Sas, Benedikt


    Space synthetic biology offers key opportunities for long-term space missions. Planets mining, terraformation, space medicine and Life Support technologies would all benefit from an integrative biological approach. However, space is a harsh environment for life: microgravity, temperature, UV and cosmic radiation can affect the health and functionality of microorganisms and plants, possibly preventing the optimal performance of the systems. The European Space Agency's Life Support System (MELiSSA) has been developed as a model for future long term Space missions and Space habitation. MELiSSA is a 5 compartment artificial ecosystem with microorganisms and higher, that aims at completely recycling gas, liquid and solid waste. In this study, the survival and functional activity after Lower Earth Orbit conditions of microbial nitrogen conversions, relevant for MELiSSA's CIII compartment, was tested. Synthetic communities containing Nitrosomonas europeae, Nitrosomonas ureae, Nitrobacter winogradskyi, Nitrospira moscoviensis and Cupriavidus pinatubonensis were exposed to the Lower Earth Orbit conditions of the International Space Station (ISS) for 7 days. Nitrosomonas europeae, Nitrobacter winogradskyi, Cupriavidus pinatubonensis, and three mixed communities (a urine nitrification sludge, a sludge containing aerobic ammonia oxidizing bacteria and anammox bacteria (OLAND), and an aquaculture sludge containing ammonia oxidizing archaea) were exposed to Lower Earth Orbit conditions for 44 days. Survival after both space flights was demonstrated because nitritation, nitratation, denitrification and anammox activity could be restored at a rate comparable to ground storage conditions. Our results validate the potential survival feasibility and suggest future space applications for N-related microorganisms.

  14. Fiber optic signal collection system for primary flight control applications (United States)

    Harper, Sandy L.


    The FOPMN is a fiber-optic signal collection system for primary flight control applications. An avionics bay protected electro-optic interface unit transmits light down fiber optic cable to an optical sensor housed in the harsh environment of a hydraulic actuator. The interface unit also receives the sensor's reflected pattern and calculates independent positions from the multiplexed signals. This paper discusses the FOPMN method for fiber-optically sensing and multiplexing two channels of position of a TEF actuator's main ram cylinder. Currently installed in NASA Dryden's SRA F/A-18, the FOPMN has accumulated approximately 15 hours of flight time. A performance comparison is made between the FOPMN positions and the flight control computer's feedback mechanism (the actuator LVDTs). Included is a discussion of some of the lessons learned as a result of testing the FOPMN in the lab and in flight. The FOPMN is well on its way to proving itself as a robust fiber optic system with the ability to multiplex numerous optical sensors for primary flight control. The success of the FOPMN leads to the second phase of the project--optical loop closure. Our goal for this phase is to have four FOPMN sensor channels on the main ram and/or the main control valve of the actuator to serve as the quad redundant feedback mechanism for flight control.

  15. Age and Expertise Effects in Aviation Decision Making and Flight Control in a Flight Simulator (United States)

    Kennedy, Quinn; Taylor, Joy L.; Reade, Gordon; Yesavage, Jerome A.


    Introduction Age (due to declines in cognitive abilities necessary for navigation) and level of aviation expertise are two factors that may affect aviation performance and decision making under adverse weather conditions. We examined the roles of age, expertise, and their relationship on aviation decision making and flight control performance during a flight simulator task. Methods Seventy-two IFR-rated general aviators, aged 19–79 yr, made multiple approach, holding pattern entry, and landing decisions while navigating under Instrument Flight Rules weather conditions. Over three trials in which the fog level varied, subjects decided whether or not to land the aircraft. They also completed two holding pattern entries. Subjects’ flight control during approaches and holding patterns was measured. Results Older pilots (41+ yr) were more likely than younger pilots to land when visibility was inadequate (older pilots’ mean false alarm rate: 0.44 vs 0.25). They also showed less precise flight control for components of the approach, performing 0.16 SD below mean approach scores. Expertise attenuated an age-related decline in flight control during holding patterns: older IFR/CFI performed 0.73 SD below mean score; younger IFR/CFI, younger CFII/ATP, older CFII/ATP: 0.32, 0.26, 0.03 SD above mean score. Additionally, pilots with faster processing speed (by median split) had a higher mean landing decision false alarm rate (0.42 vs 0.28), yet performed 0.14 SD above the mean approach control score. Conclusions Results have implications regarding specialized training for older pilots and for understanding processes involved in older adults’ real world decision making and performance. PMID:20464816

  16. Controlled flight of a biologically inspired, insect-scale robot. (United States)

    Ma, Kevin Y; Chirarattananon, Pakpong; Fuller, Sawyer B; Wood, Robert J


    Flies are among the most agile flying creatures on Earth. To mimic this aerial prowess in a similarly sized robot requires tiny, high-efficiency mechanical components that pose miniaturization challenges governed by force-scaling laws, suggesting unconventional solutions for propulsion, actuation, and manufacturing. To this end, we developed high-power-density piezoelectric flight muscles and a manufacturing methodology capable of rapidly prototyping articulated, flexure-based sub-millimeter mechanisms. We built an 80-milligram, insect-scale, flapping-wing robot modeled loosely on the morphology of flies. Using a modular approach to flight control that relies on limited information about the robot's dynamics, we demonstrated tethered but unconstrained stable hovering and basic controlled flight maneuvers. The result validates a sufficient suite of innovations for achieving artificial, insect-like flight.

  17. Design and Analysis of Morpheus Lander Flight Control System (United States)

    Jang, Jiann-Woei; Yang, Lee; Fritz, Mathew; Nguyen, Louis H.; Johnson, Wyatt R.; Hart, Jeremy J.


    The Morpheus Lander is a vertical takeoff and landing test bed vehicle developed to demonstrate the system performance of the Guidance, Navigation and Control (GN&C) system capability for the integrated autonomous landing and hazard avoidance system hardware and software. The Morpheus flight control system design must be robust to various mission profiles. This paper presents a design methodology for employing numerical optimization to develop the Morpheus flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics and propellant slosh. Under the assumption that the Morpheus time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time control systems in the presence of parametric uncertainty. Both control gains in the inner attitude control loop and guidance gains in the outer position control loop are designed to maximize the vehicle performance while ensuring robustness. The flight control system designs provided herein have been demonstrated to provide stable control systems in both Draper Ares Stability Analysis Tool (ASAT) and the NASA/JSC Trick-based Morpheus time domain simulation.


    Directory of Open Access Journals (Sweden)

    Svitlana Pavlova


    Full Text Available Purpose: The aim of this study is to develop a method for compensating the effects of failures of the aircraft automatic control system during the flight. Methods: This article reviews an approach based on the methods of theory of absolute nonlinear invariance. Results: In this paper, we present the example of a case of compensation of failure of the elevator with using the solution of the equation of the absolute invariance for pitch angle. Synthesis of automatic control device of aircraft orientation angles based on the analysis of the equations of the absolute nonlinear invariance is presented. Discussion: The use of the reconfiguration of the aircraft control system to ensure its survivability in flight is a perspective direction. However, the development of the concept of motion control of the aircraft with the use of the theory of absolute invariance will allow to realize an effective developed aircraft control method that will have advantages compared with the existing methods.

  19. Floral resource limitation severely reduces butterfly survival, condition and flight activity in simplified agricultural landscapes. (United States)

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans


    Agricultural intensification has a strong negative impact on farmland biodiversity (including flower-visiting insects), but understanding the mechanisms involved in this requires experimental work. We document the impact of nectar limitation on the performance of a flower-visiting insect, the meadow brown butterfly Maniola jurtina. We conducted two types of experiments: a field experiment in agricultural landscapes with grasslands of different management intensity and an experiment in outdoor flight cages in which the nectar supply was simulated. For the field experiment, we introduced an array of nectar resources in intensively managed, nectar-poor meadows and in extensively managed, flower-rich grasslands and counted flower visitors. Despite higher butterfly abundance in the extensive meadows, our introduced nectar sources were more frequently visited in intensive meadows, indicating the lack of floral resources. The 48-h confinement under nectar-poor conditions in the flight cages had a strong negative effect on body condition, flight activity and lifetime survival compared to butterflies under nectar-rich conditions. Female lifespan was reduced by 22% and male lifespan even by 43%. Agricultural landscapes that provide limited amounts of floral nectar, and no high-quality, preferred nectar sources relative to the needs of the flower-visiting species, may create ecological sinks. Regards an insect's performance, the simple presence of nectar is not necessarily functionally adequate. The effectiveness of agri-environmental schemes for flower-visiting insects (e.g. flower strips) could be improved based on ecological and evolutionary insights on the effects of specific nectar quantities and qualities.

  20. Adaptive and Resilient Flight Control System for a Small Unmanned Aerial System

    Directory of Open Access Journals (Sweden)

    Gonzalo Garcia


    Full Text Available The main purpose of this paper is to develop an onboard adaptive and robust flight control system that improves control, stability, and survivability of a small unmanned aerial system in off-nominal or out-of-envelope conditions. The aerodynamics of aircraft associated with hazardous and adverse onboard conditions is inherently nonlinear and unsteady. The presented flight control system improves functionalities required to adapt the flight control in the presence of aircraft model uncertainties. The fault tolerant inner loop is enhanced by an adaptive real-time artificial neural network parameter identification to monitor important changes in the aircraft’s dynamics due to nonlinear and unsteady aerodynamics. The real-time artificial neural network parameter identification is done using the sliding mode learning concept and a modified version of the self-adaptive Levenberg algorithm. Numerically estimated stability and control derivatives are obtained by delta-based methods. New nonlinear guidance logic, stable in Lyapunov sense, is developed to guide the aircraft. The designed flight control system has better performance compared to a commercial off-the-shelf autopilot system in guiding and controlling an unmanned air system during a trajectory following.

  1. Formation feedback control of UAV flight (United States)

    Stegall, Stephen

    This thesis is a study of formation control with autonomous unmanned aerial vehicles using the formation as feedback. There is also an investigation of formation methods presenting insight into different algorithms for formations. A rigid formation is achieved using a proportional-derivative virtual structure with a formation feedback controller. There is an emphasis on stick controlled aerodynamics. The rigid formation is verified by a simulation of a longitudinal model. Formation control ideas are presented for rigid formations.

  2. Hybrid adaptive ascent flight control for a flexible launch vehicle (United States)

    Lefevre, Brian D.

    For the purpose of maintaining dynamic stability and improving guidance command tracking performance under off-nominal flight conditions, a hybrid adaptive control scheme is selected and modified for use as a launch vehicle flight controller. This architecture merges a model reference adaptive approach, which utilizes both direct and indirect adaptive elements, with a classical dynamic inversion controller. This structure is chosen for a number of reasons: the properties of the reference model can be easily adjusted to tune the desired handling qualities of the spacecraft, the indirect adaptive element (which consists of an online parameter identification algorithm) continually refines the estimates of the evolving characteristic parameters utilized in the dynamic inversion, and the direct adaptive element (which consists of a neural network) augments the linear feedback signal to compensate for any nonlinearities in the vehicle dynamics. The combination of these elements enables the control system to retain the nonlinear capabilities of an adaptive network while relying heavily on the linear portion of the feedback signal to dictate the dynamic response under most operating conditions. To begin the analysis, the ascent dynamics of a launch vehicle with a single 1st stage rocket motor (typical of the Ares 1 spacecraft) are characterized. The dynamics are then linearized with assumptions that are appropriate for a launch vehicle, so that the resulting equations may be inverted by the flight controller in order to compute the control signals necessary to generate the desired response from the vehicle. Next, the development of the hybrid adaptive launch vehicle ascent flight control architecture is discussed in detail. Alterations of the generic hybrid adaptive control architecture include the incorporation of a command conversion operation which transforms guidance input from quaternion form (as provided by NASA) to the body-fixed angular rate commands needed by the

  3. F-8C digital CCV flight control laws (United States)

    Hartmann, G. L.; Hauge, J. A.; Hendrick, R. C.


    A set of digital flight control laws were designed for the NASA F-8C digital fly-by-wire aircraft. The control laws emphasize Control Configured Vehicle (CCV) benefits. Specific pitch axis objectives were improved handling qualities, angle-of-attack limiting, gust alleviation, drag reduction in steady and maneuvering flight, and a capability to fly with reduced static stability. The lateral-directional design objectives were improved Dutch roll damping and turn coordination over a wide range in angle-of-attack. An overall program objective was to explore the use of modern control design methodilogy to achieve these specific CCV benefits. Tests for verifying system integrity, an experimental design for handling qualities evaluation, and recommended flight test investigations were specified.

  4. A benchmark for fault tolerant flight control evaluation

    NARCIS (Netherlands)

    Smaili, H.; Breeman, J.; Lombaerts, T.; Stroosma, O.


    A large transport aircraft simulation benchmark (REconfigurable COntrol for Vehicle Emergency Return ? RECOVER) has been developed within the GARTEUR (Group for Aeronautical Research and Technology in Europe) Flight Mechanics Action Group 16 (FM-AG(16)) on Fault Tolerant Control (2004 2008) for the

  5. Flight Test Results for the F-16XL With a Digital Flight Control System (United States)

    Stachowiak, Susan J.; Bosworth, John T.


    In the early 1980s, two F-16 airplanes were modified to extend the fuselage length and incorporate a large area delta wing planform. These two airplanes, designated the F-16XL, were designed by the General Dynamics Corporation (now Lockheed Martin Tactical Aircraft Systems) (Fort Worth, Texas) and were prototypes for a derivative fighter evaluation program conducted by the United States Air Force. Although the concept was never put into production, the F-16XL prototypes provided a unique planform for testing concepts in support of future high-speed supersonic transport aircraft. To extend the capabilities of this testbed vehicle the F-16XL ship 1 aircraft was upgraded with a digital flight control system. The added flexibility of a digital flight control system increases the versatility of this airplane as a testbed for aerodynamic research and investigation of advanced technologies. This report presents the handling qualities flight test results covering the envelope expansion of the F-16XL with the digital flight control system.

  6. Controlling chaotic transients: Yorke's game of survival

    DEFF Research Database (Denmark)

    Aguirre, Jacobo; D'ovidio, Francesco; Sanjuán, Miguel A. F.


    . This problem is focused as a two-person, mathematical game between two players called "the protagonist" and "the adversary." The protagonist's goal is to survive. He can lose but cannot win; the best he can do is survive to play another round, struggling ad infinitum. In the absence of actions by either player...... knows the action of the adversary in choosing his response and is permitted to choose the initial point x(0) of the game. We use the "slope 3" tent map in an example of this problem. We show that it is possible for the protagonist to survive....

  7. Digital flight control software design requirements. [for space shuttle orbiter (United States)


    The objective of the integrated digital flight control system is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effects by using an executive routine/function subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the GN and C computer complex and is equally insensitive to the characteristics of the processor configuration. The integrated structure of the control system and the DFCS executive routine which embodies that structure are described. The specific estimation and control algorithms used in the various mission phases are shown. Attitude maneuver routines that interface with the DFCS are also described.

  8. An Investigation of Open Loop Flight Control Equations of Motion Used to Predict Flight Control Surface Deflections at Non-Steady State Trim Conditions (Project HAVE TRIM)

    National Research Council Canada - National Science Library

    Miller, Gary


    This report presents the results of Project HAVE TRIM, An Investigation of Open Loop Flight Control Equations of Motion Used To Predict Flight Control Surface Deflections at Non-Steady State Trim Conditions...

  9. Qualitative Functional Decomposition Analysis of Evolved Neuromorphic Flight Controllers

    Directory of Open Access Journals (Sweden)

    Sanjay K. Boddhu


    Full Text Available In the previous work, it was demonstrated that one can effectively employ CTRNN-EH (a neuromorphic variant of EH method methodology to evolve neuromorphic flight controllers for a flapping wing robot. This paper describes a novel frequency grouping-based analysis technique, developed to qualitatively decompose the evolved controllers into explainable functional control blocks. A summary of the previous work related to evolving flight controllers for two categories of the controller types, called autonomous and nonautonomous controllers, is provided, and the applicability of the newly developed decomposition analysis for both controller categories is demonstrated. Further, the paper concludes with appropriate discussion of ongoing work and implications for possible future work related to employing the CTRNN-EH methodology and the decomposition analysis techniques presented in this paper.

  10. The aerodynamics and control of free flight manoeuvres in Drosophila. (United States)

    Dickinson, Michael H; Muijres, Florian T


    A firm understanding of how fruit flies hover has emerged over the past two decades, and recent work has focused on the aerodynamic, biomechanical and neurobiological mechanisms that enable them to manoeuvre and resist perturbations. In this review, we describe how flies manipulate wing movement to control their body motion during active manoeuvres, and how these actions are regulated by sensory feedback. We also discuss how the application of control theory is providing new insight into the logic and structure of the circuitry that underlies flight stability.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. © 2016 The Author(s).

  11. Neural control and precision of flight muscle activation in Drosophila. (United States)

    Lehmann, Fritz-Olaf; Bartussek, Jan


    Precision of motor commands is highly relevant in a large context of various locomotor behaviors, including stabilization of body posture, heading control and directed escape responses. While posture stability and heading control in walking and swimming animals benefit from high friction via ground reaction forces and elevated viscosity of water, respectively, flying animals have to cope with comparatively little aerodynamic friction on body and wings. Although low frictional damping in flight is the key to the extraordinary aerial performance and agility of flying birds, bats and insects, it challenges these animals with extraordinary demands on sensory integration and motor precision. Our review focuses on the dynamic precision with which Drosophila activates its flight muscular system during maneuvering flight, considering relevant studies on neural and muscular mechanisms of thoracic propulsion. In particular, we tackle the precision with which flies adjust power output of asynchronous power muscles and synchronous flight control muscles by monitoring muscle calcium and spike timing within the stroke cycle. A substantial proportion of the review is engaged in the significance of visual and proprioceptive feedback loops for wing motion control including sensory integration at the cellular level. We highlight that sensory feedback is the basis for precise heading control and body stability in flies.

  12. Flight Control System Reliability and Maintainability Investigations (United States)


    CONTROL SYSTEM, Honeywell, Inc., NASA-CR-913, NASA. 24. Dexter, E. M., DiCamillo , C. V., Kaufman, L. A., Van Dusen, C. and Wills, S. D., APPLICATION OF...15-003R, February 1967, AD-651 104. 61. Dexter, E. M., Wills, S. D., DiCamillo , C. V., Kaufman, L. A., and Van Dusen, C, APPLICATION OF...Levels) 91 TABLE A-3. AH-IG COMMON COLLECTIVE LINKAGE - FAILURE KATES Component Failure Rate * Failure Rate Per Component Quantity Per

  13. Potential benefits of propulsion and flight control integration for supersonic cruise vehicles (United States)

    Berry, D. T.; Schweikhard, W. G.


    Typical airframe/propulsion interactions such as Mach/altitude excursions and inlet unstarts are reviewed. The improvements in airplane performance and flight control that can be achieved by improving the interfaces between propulsion and flight control are estimated. A research program to determine the feasibility of integrating propulsion and flight control is described. This program includes analytical studies and YF-12 flight tests.

  14. Automated Control of Endotracheal Tube Cuff Pressure during Simulated Flight (United States)


    control. Each flight used a new ETT for each experimental condition. Each ETT was lubricated with Surgilube (Fougera Pharmaceuticals Inc., Melville...and recorded to a personal computer for later analysis . The models were taken to 8,000 feet and then to 16,000 feet at 2,500 ft/min. Pressure was

  15. Multimodel Predictive Control Approach for UAV Formation Flight

    Directory of Open Access Journals (Sweden)

    Chang-jian Ru


    Full Text Available Formation flight problem is the most important and interesting problem of multiple UAVs (unmanned aerial vehicles cooperative control. In this paper, a novel approach for UAV formation flight based on multimodel predictive control is designed. Firstly, the state equation of relative motion is obtained and then discretized. By the geometrical method, the characteristic points of state are determined. Afterwards, based on the linearization technique, the standard linear discrete model is obtained at each characteristic state point. Then, weighted model set is proposed using the idea of T-S (Takagi-Sugeno fuzzy control and the predictive control is carried out based on the multimodel method. Finally, to verify the performance of the proposed method, two different simulation scenarios are performed.

  16. STS-30 JSC Mission Control Center (MCC) Flight Control Room (FCR) activity (United States)


    During STS-30, Flight Director Ronald D. Dittemore (standing) looks over the Spacecraft Communicator (CAPCOM) console manned by astronauts Michael A. Baker (right) and G. David Low in JSC's Mission Control Center (MCC) Bldg 30 Flight Control Room (FCR). Low reviews checklist as Baker prepares to engage switch.

  17. Heavy Lift Helicopter Flight Control System. Volume III. Automatic Flight Control System Development and Feasibility Demonstration (United States)


    CORT PIN UP TF1IS P’Ae’,f W flh r I’M P.U,,o, J ORT DOCUMENTATION PAGE CIOM) NT’UTIN ONS k 2(.V7ACC ~SýI.)N NO. kC I PI N r I A r A LC NI,’, I G...strating the feasibility to manually (following flight directo . cormands) or automatically fly the aircraft down an approach path terminating in a

  18. Knowledge-based processing for aircraft flight control (United States)

    Painter, John H.


    The purpose is to develop algorithms and architectures for embedding artificial intelligence in aircraft guidance and control systems. With the approach adopted, AI-computing is used to create an outer guidance loop for driving the usual aircraft autopilot. That is, a symbolic processor monitors the operation and performance of the aircraft. Then, based on rules and other stored knowledge, commands are automatically formulated for driving the autopilot so as to accomplish desired flight operations. The focus is on developing a software system which can respond to linguistic instructions, input in a standard format, so as to formulate a sequence of simple commands to the autopilot. The instructions might be a fairly complex flight clearance, input either manually or by data-link. Emphasis is on a software system which responds much like a pilot would, employing not only precise computations, but, also, knowledge which is less precise, but more like common-sense. The approach is based on prior work to develop a generic 'shell' architecture for an AI-processor, which may be tailored to many applications by describing the application in appropriate processor data bases (libraries). Such descriptions include numerical models of the aircraft and flight control system, as well as symbolic (linguistic) descriptions of flight operations, rules, and tactics.

  19. Survival trial design and monitoring using historical controls. (United States)

    Wu, Jianrong; Xiong, Xiaoping


    In this paper, we propose a multistage group sequential procedure to design survival trials using historical controls. The formula for the number of events required for historical control trial designs is derived. Furthermore, a transformed information time is proposed for trial monitoring. An example is given to illustrate the application of the proposed methods to survival trial designs using historical controls. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Pigeons (C. livia Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight

    Directory of Open Access Journals (Sweden)

    Ivo G. Ros


    Full Text Available Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns. We observe that periods of angular head stabilization alternate with rapid head repositioning movements (head saccades, and confirm that control of head motion is decoupled from aerodynamic and inertial forces acting on the bird's continuously rotating body during turning flapping flight. Visual cues inferred from head saccades correlate with changes in flight trajectory; whereas the magnitude of neck bending predicts angular changes in body position. The control of head motion to stabilize a pigeon's gaze may therefore facilitate extraction of important motion cues, in addition to offering mechanisms for controlling body and wing movements. Strong similarities between the sensory flight control of birds and insects may also inspire novel designs of robust controllers for human-engineered autonomous aerial vehicles.

  1. A potential role for bat tail membranes in flight control.

    Directory of Open Access Journals (Sweden)

    James D Gardiner


    Full Text Available Wind tunnel tests conducted on a model based on the long-eared bat Plecotus auritus indicated that the positioning of the tail membrane (uropatagium can significantly influence flight control. Adjusting tail position by increasing the angle of the legs ventrally relative to the body has a two-fold effect; increasing leg-induced wing camber (i.e., locally increased camber of the inner wing surface and increasing the angle of attack of the tail membrane. We also used our model to examine the effects of flying with and without a tail membrane. For the bat model with a tail membrane increasing leg angle increased the lift, drag and pitching moment (nose-down produced. However, removing the tail membrane significantly reduced the change in pitching moment with increasing leg angle, but it had no significant effect on the level of lift produced. The drag on the model also significantly increased with the removal of the tail membrane. The tail membrane, therefore, is potentially important for controlling the level of pitching moment produced by bats and an aid to flight control, specifically improving agility and manoeuvrability. Although the tail of bats is different from that of birds, in that it is only divided from the wings by the legs, it nonetheless, may, in addition to its prey capturing function, fulfil a similar role in aiding flight control.

  2. Hummingbird flight stability and control in freestream turbulent winds. (United States)

    Ravi, Sridhar; Crall, James D; McNeilly, Lucas; Gagliardi, Susan F; Biewener, Andrew A; Combes, Stacey A


    Airflow conditions close to the Earth's surface are often complex, posing challenges to flight stability and control for volant taxa. Relatively little is known about how well flying animals can contend with complex, adverse air flows, or about the flight control mechanisms used by animals to mitigate wind disturbances. Several recent studies have examined flight in the unsteady von Kármán vortex streets that form behind cylinders, generating flow disturbances that are predictable in space and time; these structures are relatively rare in nature, because they occur only the immediate, downstream vicinity of an object. In contrast, freestream turbulence is characterized by rapid, unpredictable flow disturbances across a wide range of spatial and temporal scales, and is nearly ubiquitous in natural habitats. Hummingbirds are ideal organisms for studying the influence of freestream turbulence on flight, as they forage in a variety of aerial conditions and are powerful flyers. We filmed ruby-throated hummingbirds (Archilochus colubris) maintaining position at a feeder in laminar and strongly turbulent (intensity ∼15%) airflow environments within a wind tunnel and compared their mean kinematics of the head, body, tail and wing, as well as variability in these parameters. Hummingbirds exhibited remarkably stable head position and orientation in both smooth and turbulent flow while maintaining position at the feeder. However, the hummingbird's body was less stable in turbulent flow and appeared to be most sensitive to disturbances along the mediolateral axis, displaying large lateral accelerations, translations and rolling motions during flight. The hummingbirds mitigated these disturbances by increasing mean wing stroke amplitude and stroke plane angle, and by varying these parameters asymmetrically between the wings and from one stroke to the next. They also actively varied the orientation and fan angle of the tail, maintaining a larger mean fan angle when flying in

  3. First controlled vertical flight of a biologically inspired microrobot

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Arancibia, Nestor O; Ma, Kevin Y; Greenberg, Jack D; Wood, Robert J [School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138 (United States); Galloway, Kevin C, E-mail:, E-mail:, E-mail:, E-mail:, E-mail: [Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115 (United States)


    In this paper, we present experimental results on altitude control of a flying microrobot. The problem is approached in two stages. In the first stage, system identification of two relevant subsystems composing the microrobot is performed, using a static flapping experimental setup. In the second stage, the information gathered through the static flapping experiments is employed to design the controller used in vertical flight. The design of the proposed controller relies on the idea of treating an exciting signal as a subsystem of the microrobot. The methods and results presented here are a key step toward achieving total autonomy of bio-inspired flying microrobots.

  4. Stability and control modelling. [helicopters in near hovering flight (United States)

    Curtiss, H. C., Jr.


    This paper discusses the influence of rotor dynamics and dynamic inflow on the stability and control characteristics of single rotor helicopters in near hovering flight. Body attitude and rate feedback gain limitations which arise due to rotor dynamics and dynamic inflow are discussed. It is shown that attitude feedback gain is limited primarily by body-flap coupling and rate gain is limited by the lag degrees of freedom. Dynamic inflow is shown to produce significant changes in the modes of motion.

  5. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging (United States)

    Tahmasian, Sevak; Woolsey, Craig A.


    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  6. Linear Time Invariant Models for Integrated Flight and Rotor Control (United States)

    Olcer, Fahri Ersel


    Recent developments on individual blade control (IBC) and physics based reduced order models of various on-blade control (OBC) actuation concepts are opening up opportunities to explore innovative rotor control strategies for improved rotor aerodynamic performance, reduced vibration and BVI noise, and improved rotor stability, etc. Further, recent developments in computationally efficient algorithms for the extraction of Linear Time Invariant (LTI) models are providing a convenient framework for exploring integrated flight and rotor control, while accounting for the important couplings that exist between body and low frequency rotor response and high frequency rotor response. Formulation of linear time invariant (LTI) models of a nonlinear system about a periodic equilibrium using the harmonic domain representation of LTI model states has been studied in the literature. This thesis presents an alternative method and a computationally efficient scheme for implementation of the developed method for extraction of linear time invariant (LTI) models from a helicopter nonlinear model in forward flight. The fidelity of the extracted LTI models is evaluated using response comparisons between the extracted LTI models and the nonlinear model in both time and frequency domains. Moreover, the fidelity of stability properties is studied through the eigenvalue and eigenvector comparisons between LTI and LTP models by making use of the Floquet Transition Matrix. For time domain evaluations, individual blade control (IBC) and On-Blade Control (OBC) inputs that have been tried in the literature for vibration and noise control studies are used. For frequency domain evaluations, frequency sweep inputs are used to obtain frequency responses of fixed system hub loads to a single blade IBC input. The evaluation results demonstrate the fidelity of the extracted LTI models, and thus, establish the validity of the LTI model extraction process for use in integrated flight and rotor control

  7. Iron Cross Reaction Control Flight Simulator - test in hangar (United States)


    In the mid-1950s -- after the X-1 had exceeded the speed of sound, the D-558-II had doubled that speed, and the X-2 had flown to a speed of Mach 3.2 (3.2 times the speed of sound) -- the problem of maintaining control of a vehicle at the low dynamic pressures found at high altitudes became real. As the development of larger rocket engines than those used in the X-1, X-2, and D-558-II became a virtual certainty, travel to near-orbital and orbital velocities lay on the horizon. It became natural to investigate alternative means to control an aircraft for low dynamic pressures where aerodynamic controls would be inadequate (even absent for orbital flight outside the atmosphere). Consequently, the High-Speed Flight Station (HSFS--predecessor of the NASA Dryden Flight Research Center) began pioneering work on simulating and then flying with reaction controls in the last years of the National Advisory Committee for Aeronautics (NACA) and the first years of its successor, the National Aeronautics and Space Administration (NASA). The HSFS began a two-phase study. One phase involved a fixed-base effort with an analog computer to solve the equations of motion needed for simulation; the other used a mechanical simulator in which the 'pilot' actually experienced the motions produced by the reaction-control jets. The 'pilot' operated the simulator through a single control stick that -- unusually for the time -- controlled three axes with one device. The stick controlled pitch by fore and aft movements, roll by lateral movements, and yaw through thumb movements. The simulator, shown in the video clip, was known as the 'Iron Cross.' It simulated the X-1B, which was equipped with reaction controls. Although the X-1B flew three missions with reaction controls, it developed fatigue cracks in a propellant tank and had to be retired from flight status. Subsequently, an F-104 equipped with reaction controls flew at relatively low dynamic pressures. Between the simulation studies with

  8. Production Support Flight Control Computers: Research Capability for F/A-18 Aircraft at Dryden Flight Research Center (United States)

    Carter, John F.


    NASA Dryden Flight Research Center (DFRC) is working with the United States Navy to complete ground testing and initiate flight testing of a modified set of F/A-18 flight control computers. The Production Support Flight Control Computers (PSFCC) can give any fleet F/A-18 airplane an in-flight, pilot-selectable research control law capability. NASA DFRC can efficiently flight test the PSFCC for the following four reasons: (1) Six F/A-18 chase aircraft are available which could be used with the PSFCC; (2) An F/A-18 processor-in-the-loop simulation exists for validation testing; (3) The expertise has been developed in programming the research processor in the PSFCC; and (4) A well-defined process has been established for clearing flight control research projects for flight. This report presents a functional description of the PSFCC. Descriptions of the NASA DFRC facilities, PSFCC verification and validation process, and planned PSFCC projects are also provided.

  9. F-15 Intelligent Flight Control System and Aeronautics Research at NASA Dryden (United States)

    Brown, Nelson A.


    This viewgraph presentation reviews the F-15 Intelligent Flight Control System and Aeronautics including Autonomous Aerial Refueling Demonstrations, X-48B Blended Wing Body, F-15 Quiet Spike, and NF-15 Intelligent Flight Controls.

  10. Unfalsified Control; Application to automatic flight control system design

    Directory of Open Access Journals (Sweden)

    Adrian-Mihail STOICA


    Full Text Available Unfalsified Control Theory has been developed to provide a way for avoiding modeling uncertainties in controller design. It belongs to the class of control methods called Adaptive Supervisory Switching Control, which work by introducing in the control scheme a supervisory unit which chooses, from a set of candidate controllers the one most suited for the current plant. Unfalsified Control works by using a switching logic that dispenses with the need for a-priori knowledge of the dynamic model. At discrete moments of time, using the input/output data recorded up to that point, the supervisory calculates for each candidate controller a performance index, and compares it to a given threshold. Controllers surpassing that threshold are removed from the candidate controller set. This process is called falsification. If the controller in the loop is one such falsified controller it is replaced. In this paper we investigate the suitability of this method for aeronautical control applications. We review the theory behind this control scheme and adapt it to the case of controlling a fighter aircraft. We also provide a case study, where we test this control scheme on a simulated fighter aircraft.

  11. The aerodynamics and control of free flight manoeuvres in Drosophila (United States)

    Muijres, Florian T.


    A firm understanding of how fruit flies hover has emerged over the past two decades, and recent work has focused on the aerodynamic, biomechanical and neurobiological mechanisms that enable them to manoeuvre and resist perturbations. In this review, we describe how flies manipulate wing movement to control their body motion during active manoeuvres, and how these actions are regulated by sensory feedback. We also discuss how the application of control theory is providing new insight into the logic and structure of the circuitry that underlies flight stability. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528778

  12. Analysis and Design of Launch Vehicle Flight Control Systems (United States)

    Wie, Bong; Du, Wei; Whorton, Mark


    This paper describes the fundamental principles of launch vehicle flight control analysis and design. In particular, the classical concept of "drift-minimum" and "load-minimum" control principles is re-examined and its performance and stability robustness with respect to modeling uncertainties and a gimbal angle constraint is discussed. It is shown that an additional feedback of angle-of-attack or lateral acceleration can significantly improve the overall performance and robustness, especially in the presence of unexpected large wind disturbance. Non-minimum-phase structural filtering of "unstably interacting" bending modes of large flexible launch vehicles is also shown to be effective and robust.

  13. Flight Control Design for a Tailless Aircraft Using Eigenstructure Assignment

    Directory of Open Access Journals (Sweden)

    Clara Nieto-Wire


    assignment designs for the ICE aircraft, we consider the phugoid mode, thrust vectoring, and stability margins. We show how to simultaneously stabilize the phugoid mode, satisfy MIL-F-8785C mode specifications, and satisfy MIL-F-9490D phase and gain margin specifications. We also use a cstar command system that is preferable to earlier pitch-rate command systems. Finally, we present simulation results of the combined longitudinal/lateral flight control system using a full 6DOF nonlinear simulation with approximately 20,000 values for the aerodynamic coefficients. Our simulation includes limiters on actuator deflections, deflection rates, and control system integrators.

  14. Controlling Precision Stepper Motors in Flight Using (Almost) No Parts (United States)

    Randall, David


    This concept allows control of high-performance stepper motors with minimal parts count and minimal flight software complexity. Although it uses a small number of common flight-qualified parts and simple control algorithms, it is capable enough to meet demanding system requirements. Its programmable nature makes it trivial to implement changes to control algorithms both during integration & test and in flight. Enhancements such as microstepping, half stepping, back-emf compensation, and jitter reduction can be tailored to the requirements of a large variety of stepper motor based applications including filter wheels, focus mechanisms, antenna tracking subsystems, pointing and mobility. The hardware design (using an H-bridge motor controller IC) was adapted from JPL's MER mission, still operating on Mars. This concept has been fully developed and incorporated into the MCS instrument on MRO, currently operating in Mars orbit. It has been incorporated into the filter wheel mechanism and linear stage (focus) mechanism for the AMT instrument. On MCS/MRO, two of these circuits control the elevation and azimuth of the MCS telescope/radiometer assembly, allowing the instrument to continuously monitor the limb of the Martian atmosphere. Implementation on MCS/MRO resulted in a 4:1 reduction in the volume and mass required for the motor driver electronics (100:25 square inches of PCB space), producing a very compact instrument. In fact, all of the electronics for the MCS instrument are packaged within the movable instrument structure. It also saved approximately 3 Watts of power. Most importantly, the design enabled MCS to meet very its stringent maximum allowable torque disturbance requirements.

  15. 75 FR 3959 - Fifth Meeting-RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ...: Automatic Flight Guidance and Control meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The meeting... hereby given for a Special Committee 220: Automatic Flight Guidance and Control meeting. The agenda will...

  16. 76 FR 22163 - Tenth Meeting: RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ... meeting: Automatic Flight Guidance and Control. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The... Committee 220, Automatic Flight Guidance and Control. Agenda Tuesday May 10-Thursday, May 12, 2011...

  17. 75 FR 59326 - Eighth Meeting-RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ...: Automatic Flight Guidance and Control meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The meeting...., Appendix 2), notice is hereby given for a Special Committee 220: Automatic Flight Guidance and Control...

  18. 75 FR 15770 - Sixth Meeting-RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ...: Automatic Flight Guidance and Control meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The meeting... Committee 220: Automatic Flight Guidance and Control meeting. The agenda will include: Welcome/Agenda...

  19. 76 FR 38742 - Eleventh Meeting: RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ... Committee 220 Meeting: Automatic Flight Guidance and Control. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control DATES... Appendix 2), notice is hereby given for a Special Committee 220, Automatic Flight Guidance and Control...

  20. 75 FR 36471 - Seventh Meeting-RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ...: Automatic Flight Guidance and Control meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The meeting...), notice is hereby given for a Special Committee 220: Automatic Flight Guidance and ] Control meeting. The...

  1. Visual Flight Control of a Quadrotor Using Bioinspired Motion Detector

    Directory of Open Access Journals (Sweden)

    Lei Zhang


    Full Text Available Motion detection in the fly is extremely fast with low computational requirements. Inspired from the fly's vision system, we focus on a real-time flight control on a miniquadrotor with fast visual feedback. In this work, an elaborated elementary motion detector (EMD is utilized to detect local optical flow. Combined with novel receptive field templates, the yaw rate of the quadrotor is estimated through a lookup table established with this bioinspired visual sensor. A closed-loop control system with the feedback of yaw rate estimated by EMD is designed. With the motion of the other degrees of freedom stabilized by a camera tracking system, the yaw-rate of the quadrotor during hovering is controlled based on EMD feedback under real-world scenario. The control performance of the proposed approach is compared with that of conventional approach. The experimental results demonstrate the effectiveness of utilizing EMD for quadrotor control.

  2. Hover flight control of helicopter using optimal control theory




    This paper represents the optimal control theory and its application to the full scale helicopters. Generally the control of a helicopter is a hard task, because its system is very nonlinear, coupled and sensitive to the control inputs and external disturbances which might destabilize the system. As a result of these instabilities, it is essential to use a control process that helps to improve the systems performance, confirming stability and robustness. The main objective of this part is to ...

  3. Design and Testing of Flight Control Laws on the RASCAL Research Helicopter (United States)

    Frost, Chad R.; Hindson, William S.; Moralez. Ernesto, III; Tucker, George E.; Dryfoos, James B.


    Two unique sets of flight control laws were designed, tested and flown on the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A Black Hawk helicopter. The first set of control laws used a simple rate feedback scheme, intended to facilitate the first flight and subsequent flight qualification of the RASCAL research flight control system. The second set of control laws comprised a more sophisticated model-following architecture. Both sets of flight control laws were developed and tested extensively using desktop-to-flight modeling, analysis, and simulation tools. Flight test data matched the model predicted responses well, providing both evidence and confidence that future flight control development for RASCAL will be efficient and accurate.

  4. Analysis of Airborne Delay Characteristics of Flights Controlled by Ground-Holding: Case of the Flights to Tokyo International Airport

    National Research Council Canada - National Science Library

    HIRATA, Terumitsu; SHIMIZU, Azumanosuke; MIMURA, Daichi; YAI, Tetsuo


    The purpose of this paper is to examine the actual situation of the delay characteristics of the flights controlled by Ground-Holding which arrived at Tokyo International Airport (Haneda Airport (HND...

  5. Fuzzy logic-based flight control system design (United States)

    Nho, Kyungmoon

    The application of fuzzy logic to aircraft motion control is studied in this dissertation. The self-tuning fuzzy techniques are developed by changing input scaling factors to obtain a robust fuzzy controller over a wide range of operating conditions and nonlinearities for a nonlinear aircraft model. It is demonstrated that the properly adjusted input scaling factors can meet the required performance and robustness in a fuzzy controller. For a simple demonstration of the easy design and control capability of a fuzzy controller, a proportional-derivative (PD) fuzzy control system is compared to the conventional controller for a simple dynamical system. This thesis also describes the design principles and stability analysis of fuzzy control systems by considering the key features of a fuzzy control system including the fuzzification, rule-base and defuzzification. The wing-rock motion of slender delta wings, a linear aircraft model and the six degree of freedom nonlinear aircraft dynamics are considered to illustrate several self-tuning methods employing change in input scaling factors. Finally, this dissertation is concluded with numerical simulation of glide-slope capture in windshear demonstrating the robustness of the fuzzy logic based flight control system.

  6. Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane (United States)


    Flight evaluation in an F-15 aircraft by digital electronic engine control (DEEC) was investigated. Topics discussed include: system description, F100 engine tests, effects of inlet distortion on static pressure probe, flight tests, digital electronic engine control fault detection and accommodation flight evaluation, flight evaluation of a hydromechanical backup control, augmentor transient capability of an F100 engine, investigation of nozzle instability, real time in flight thrust calculation, and control technology for future aircraft propulsion systems. It is shown that the DEEC system is a powerful and flexible controller for the F100 engine.

  7. Digital system identification and its application to digital flight control (United States)

    Kotob, S.; Kaufman, H.


    On-line system identification of linear discrete systems for implementation in a digital adaptive flight controller is considered by the conventional extended Kalman filter and a decoupling process in which the linear state estimation problem and the linear parameter identification problem are each treated separately and alternately. Input requirements for parameter identifiability are established using the standard conditions of observability for a time variant system. Experimental results for simulated linearized lateral aircraft motion are included along with the effect of different initialization and updating procedures for the priming trajectory used by the filter.

  8. Development of a Design Methodology for Reconfigurable Flight Control Systems (United States)

    Hess, Ronald A.; McLean, C.


    A methodology is presented for the design of flight control systems that exhibit stability and performance-robustness in the presence of actuator failures. The design is based upon two elements. The first element consists of a control law that will ensure at least stability in the presence of a class of actuator failures. This law is created by inner-loop, reduced-order, linear dynamic inversion, and outer-loop compensation based upon Quantitative Feedback Theory. The second element consists of adaptive compensators obtained from simple and approximate time-domain identification of the dynamics of the 'effective vehicle' with failed actuator(s). An example involving the lateral-directional control of a fighter aircraft is employed both to introduce the proposed methodology and to demonstrate its effectiveness and limitations.

  9. Flight Test of ASAC Aircraft Interior Noise Control System (United States)

    Palumbo, Dan; Cabell, Ran; Cline, John; Sullivan, Brenda


    A flight test is described in which an active structural/acoustic control system reduces turboprop induced interior noise on a Raytheon Aircraft Company 1900D airliner. Control inputs to 21 inertial force actuators were computed adaptively using a transform domain version of the multichannel filtered-X LMS algorithm to minimize the mean square response of 32 microphones. A combinatorial search algorithm was employed to optimize placement of the force actuators on the aircraft frame. Both single frequency and multi-frequency results are presented. Reductions of up to 15 dB were obtained at the blade passage frequency (BPF) during single frequency control tests. Simultaneous reductions of the BPF and next 2 harmonics of 10 dB, 2.5 dB and 3.0 dB, were obtained in a multi-frequency test.

  10. 75 FR 80886 - Ninth Meeting-RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ...: Automatic Flight Guidance and Control meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 220: Automatic Flight Guidance and Control. DATES: The meeting... Federal Aviation Administration Ninth Meeting--RTCA Special Committee 220: Automatic Flight Guidance and...

  11. 75 FR 77569 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode... (United States)


    ...; Electronic Flight Control System Mode Annunciation AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... special condition is proposed to ensure appropriate mode recognition by the flight crew for events which significantly change the operating mode of the electronic flight control system. Discussion of Proposed Special...

  12. 76 FR 14795 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode... (United States)


    ...; Electronic Flight Control System Mode Annunciation. AGENCY: Federal Aviation Administration (FAA), DOT... needed to ensure appropriate mode recognition by the flight crew for events which significantly change the operating mode of the electronic flight control system. Discussion of Comments Notice of proposed...

  13. In-Flight Validation of a Pilot Rating Scale for Evaluating Failure Transients in Electronic Flight Control Systems (United States)

    Kalinowski, Kevin F.; Tucker, George E.; Moralez, Ernesto, III


    Engineering development and qualification of a Research Flight Control System (RFCS) for the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A has motivated the development of a pilot rating scale for evaluating failure transients in fly-by-wire flight control systems. The RASCAL RFCS includes a highly-reliable, dual-channel Servo Control Unit (SCU) to command and monitor the performance of the fly-by-wire actuators and protect against the effects of erroneous commands from the flexible, but single-thread Flight Control Computer. During the design phase of the RFCS, two piloted simulations were conducted on the Ames Research Center Vertical Motion Simulator (VMS) to help define the required performance characteristics of the safety monitoring algorithms in the SCU. Simulated failures, including hard-over and slow-over commands, were injected into the command path, and the aircraft response and safety monitor performance were evaluated. A subjective Failure/Recovery Rating (F/RR) scale was developed as a means of quantifying the effects of the injected failures on the aircraft state and the degree of pilot effort required to safely recover the aircraft. A brief evaluation of the rating scale was also conducted on the Army/NASA CH-47B variable stability helicopter to confirm that the rating scale was likely to be equally applicable to in-flight evaluations. Following the initial research flight qualification of the RFCS in 2002, a flight test effort was begun to validate the performance of the safety monitors and to validate their design for the safe conduct of research flight testing. Simulated failures were injected into the SCU, and the F/RR scale was applied to assess the results. The results validate the performance of the monitors, and indicate that the Failure/Recovery Rating scale is a very useful tool for evaluating failure transients in fly-by-wire flight control systems.

  14. Gryphon M3 system: integration of MEMS for flight control (United States)

    Huang, Adam; Folk, Chris; Ho, Chih-Ming; Liu, Z.; Chu, Wesley W.; Xu, Yong; Tai, Yu-Chong


    By using distributed arrays of micro-actuators as effectors, micro-sensors to detect the optimal actuation location, and microelectronics to provide close loop feedback decisions, a low power control system has been developed for controlling a UAV. Implementing the Microsensors, Microactuators, and Microelectronics leads to what is known as a M3 (M-cubic) system. This project involves demonstrating the concept of using small actuators (approximately micron-millimeter scale) to provide large control forces for a large-scale system (approximately meter scale) through natural flow amplification phenomenon. This is theorized by using fluid separation phenomenon, vortex evolution, and vortex symmetry on a delta wing aircraft. By using MEMS actuators to control leading edge vortex separation and growth, a desired aerodynamic force can be produced about the aircraft for flight control. Consequently, a MEMS shear stress sensor array was developed for detecting the leading edge separation line where leading edge vortex flow separation occurs. By knowing the leading edge separation line, a closely coupled micro actuation from the effectors can cause the required separation that leads to vortex control. A robust and flexible balloon type actuator was developed using pneumatic pressure as the actuation force. Recently, efforts have started to address the most elusive problem of amplified distributed control (ADC) through data mining algorithms. Preliminary data mining results are promising and this part of the research is ongoing. All wind tunnel data used the baseline 56.5 degree(s) sweepback delta wing with root chord of 31.75 cm.

  15. Modified shuffled frog leaping algorithm optimized control for air-breathing hypersonic flight vehicle

    Directory of Open Access Journals (Sweden)

    Bingbing Liang


    Full Text Available This article addresses the flight control problem of air-breathing hypersonic vehicles and proposes a novel intelligent algorithm optimized control method. To achieve the climbing, cruising and descending flight control of the air-breathing hypersonic vehicle, an engineering-oriented flight control system based on a Proportional Integral Derivative (PID method is designed for the hypersonic vehicle, which including the height loop, the pitch angle loop and the velocity loop. Moreover, as a variant of nature-inspired algorithm, modified shuffled frog leaping algorithm is presented to optimize the flight control parameters and is characterized by better exploration and exploitation than the standard shuffled frog leaping algorithm. A nonlinear model of air-breathing hypersonic vehicle is used to verify the dynamic characteristics achieved by the intelligent flight control system. Simulation results demonstrate that the proposed swarm intelligence optimized PID controllers are effective in achieving better flight trajectory and velocity control performance than the traditional controllers.

  16. Fault Tolerant Flight Control Using Sliding Modes and Subspace Identification-Based Predictive Control

    KAUST Repository

    Siddiqui, Bilal A.


    In this work, a cascade structure of a time-scale separated integral sliding mode and model predictive control is proposed as a viable alternative for fault-tolerant control. A multi-variable sliding mode control law is designed as the inner loop of the flight control system. Subspace identification is carried out on the aircraft in closed loop. The identified plant is then used for model predictive controllers in the outer loop. The overall control law demonstrates improved robustness to measurement noise, modeling uncertainties, multiple faults and severe wind turbulence and gusts. In addition, the flight control system employs filters and dead-zone nonlinear elements to reduce chattering and improve handling quality. Simulation results demonstrate the efficiency of the proposed controller using conventional fighter aircraft without control redundancy.

  17. H/OZ: PFD and Collaborative Flight Control System Project (United States)

    National Aeronautics and Space Administration — Researchers at the Institute for Human and Machine Cognition invented OZ, a primary flight display that provides a single, unified graphic display of critical flight...

  18. A predictive model of flight crew performance in automated air traffic control and flight management operations (United States)


    Prepared ca. 1995. This paper describes Air-MIDAS, a model of pilot performance in interaction with varied levels of automation in flight management operations. The model was used to predict the performance of a two person flight crew responding to c...


    Directory of Open Access Journals (Sweden)

    M. Bäumker


    Full Text Available The acquisition of photogrammetric image data by means of Unmanned Aerial Vehicles (UAV has developed in recent years to an interesting new measurement method especially for small to medium sizes of objects. In addition the latest developments in the field of navigation systems (GNSS, of inertial sensors and other sensors in combination with powerful and easy to program microcontrollers have made a major contribution to this. In particular, the development of MEMS sensors has triggered the boom of the UAV and has given decisively influence and it is still going on. The integration of sensors on a single board not only enables a cost-effective manufacturing and mass production, but also the use in accordance with small, lightweight UAV. The latest developments on a 50 mm × 50 mm-sized circuit board combine the sensors and the microcontroller for the flight control and flight navigation. Both the board and the microcontroller are easy to program and maintain several interfaces for connecting additional sensors, such as GNSS, ultrasonic sensors and telemetry. This article presents the UAV system of the Bochum University of Applied Sciences, the used sensors and the obtained results for accurate georeferencing.

  20. Implementation of a Helicopter Flight Simulator with Individual Blade Control (United States)

    Zinchiak, Andrew G.


    Nearly all modern helicopters are designed with a swashplate-based system for control of the main rotor blades. However, the swashplate-based approach does not provide the level of redundancy necessary to cope with abnormal actuator conditions. For example, if an actuator fails (becomes locked) on the main rotor, the cyclic inputs are consequently fixed and the helicopter may become stuck in a flight maneuver. This can obviously be seen as a catastrophic failure, and would likely lead to a crash. These types of failures can be overcome with the application of individual blade control (IBC). IBC is achieved using the blade pitch control method, which provides complete authority of the aerodynamic characteristics of each rotor blade at any given time by replacing the normally rigid pitch links between the swashplate and the pitch horn of the blade with hydraulic or electronic actuators. Thus, IBC can provide the redundancy necessary for subsystem failure accommodation. In this research effort, a simulation environment is developed to investigate the potential of the IBC main rotor configuration for fault-tolerant control. To examine the applications of IBC to failure scenarios and fault-tolerant controls, a conventional, swashplate-based linear model is first developed for hover and forward flight scenarios based on the UH-60 Black Hawk helicopter. The linear modeling techniques for the swashplate-based helicopter are then adapted and expanded to include IBC. Using these modified techniques, an IBC based mathematical model of the UH-60 helicopter is developed for the purposes of simulation and analysis. The methodology can be used to model and implement a different aircraft if geometric, gravimetric, and general aerodynamic data are available. Without the kinetic restrictions of the swashplate, the IBC model effectively decouples the cyclic control inputs between different blades. Simulations of the IBC model prove that the primary control functions can be manually

  1. Piloted Simulator Evaluation Results of New Fault-Tolerant Flight Control Algorithm

    NARCIS (Netherlands)

    Lombaerts, T.J.J.; Smaili, M.H.; Stroosma, O.; Chu, Q.P.; Mulder, J.A.; Joosten, D.A.


    A high fidelity aircraft simulation model, reconstructed using the Digital Flight Data Recorder (DFDR) of the 1992 Amsterdam Bijlmermeer aircraft accident (Flight 1862), has been used to evaluate a new Fault-Tolerant Flight Control Algorithm in an online piloted evaluation. This paper focuses on the

  2. Neuroinspired control strategies with applications to flapping flight (United States)

    Dorothy, Michael Ray

    This dissertation is centered on a theoretical, simulation, and experimental study of control strategies which are inspired by biological systems. Biological systems, along with sufficiently complicated engineered systems, often have many interacting degrees of freedom and need to excite large-displacement oscillations in order to locomote. Combining these factors can make high-level control design difficult. This thesis revolves around three different levels of abstraction, providing tools for analysis and design. First, we consider central pattern generators (CPGs) to control flapping-flight dynamics. The key idea here is dimensional reduction - we want to convert complicated interactions of many degrees of freedom into a handful of parameters which have intuitive connections to the overall system behavior, leaving the control designer unconcerned with the details of particular motions. A rigorous mathematical and control theoretic framework to design complex three-dimensional wing motions is presented based on phase synchronization of nonlinear oscillators. In particular, we show that flapping-flying dynamics without a tail or traditional aerodynamic control surfaces can be effectively controlled by a reduced set of central pattern generator parameters that generate phase-synchronized or symmetry-breaking oscillatory motions of two main wings. Furthermore, by using a Hopf bifurcation, we show that tailless aircraft (inspired by bats) alternating between flapping and gliding can be effectively stabilized by smooth wing motions driven by the central pattern generator network. Results of numerical simulation with a full six-degree-of-freedom flight dynamic model validate the effectiveness of the proposed neurobiologically inspired control approach. Further, we present experimental micro aerial vehicle (MAV) research with low-frequency flapping and articulated wing gliding. The importance of phase difference control via an abstract mathematical model of central

  3. MISSE Thermal Control Materials with Comparison to Previous Flight Experiments (United States)

    Finckenor, Miria; Pippin, H. Gary; Frey, George


    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF).

  4. Flexibility and control of thorax deformation during hawkmoth flight. (United States)

    Ando, Noriyasu; Kanzaki, Ryohei


    The interaction between neuromuscular systems and body mechanics plays an important role in the production of coordinated movements in animals. Lepidopteran insects move their wings by distortion of the thorax structure via the indirect flight muscles (IFMs), which are activated by neural signals at every stroke. However, how the action of these muscles affects thorax deformation and wing kinematics is poorly understood. We measured the deformation of the dorsal thorax (mesonotum) of tethered flying hawkmoths, Agrius convolvuli, using a high-speed laser profilometer combined with simultaneous recordings of electromyograms and wing kinematics. We observed that locally amplified mesonotum deformation near the wing hinges ensures sufficient wing movement. Furthermore, phase asymmetry in IFM activity leads to phase asymmetry in mesonotum oscillations and wingbeats. Our results revealed the flexibility and controllability of the single structure of the mesonotum by neurogenic action of the IFMs. © 2016 The Author(s).

  5. Selecting a software development methodology. [of digital flight control systems (United States)

    Jones, R. E.


    The state of the art analytical techniques for the development and verification of digital flight control software is studied and a practical designer oriented development and verification methodology is produced. The effectiveness of the analytic techniques chosen for the development and verification methodology are assessed both technically and financially. Technical assessments analyze the error preventing and detecting capabilities of the chosen technique in all of the pertinent software development phases. Financial assessments describe the cost impact of using the techniques, specifically, the cost of implementing and applying the techniques as well as the relizable cost savings. Both the technical and financial assessment are quantitative where possible. In the case of techniques which cannot be quantitatively assessed, qualitative judgements are expressed about the effectiveness and cost of the techniques. The reasons why quantitative assessments are not possible will be documented.

  6. Flight Dynamics and Control of Elastic Hypersonic Vehicles Uncertainty Modeling (United States)

    Chavez, Frank R.; Schmidt, David K.


    It has been shown previously that hypersonic air-breathing aircraft exhibit strong aeroelastic/aeropropulsive dynamic interactions. To investigate these, especially from the perspective of the vehicle dynamics and control, analytical expressions for key stability derivatives were derived, and an analysis of the dynamics was performed. In this paper, the important issue of model uncertainty, and the appropriate forms for representing this uncertainty, is addressed. It is shown that the methods suggested in the literature for analyzing the robustness of multivariable feedback systems, which as a prerequisite to their application assume particular forms of model uncertainty, can be difficult to apply on real atmospheric flight vehicles. Also, the extent to which available methods are conservative is demonstrated for this class of vehicle dynamics.

  7. A mathematical perspective on flight dynamics and control

    CERN Document Server

    L'Afflitto, Andrea


    This brief presents several aspects of flight dynamics, which are usually omitted or briefly mentioned in textbooks, in a concise, self-contained, and rigorous manner. The kinematic and dynamic equations of an aircraft are derived starting from the notion of the derivative of a vector and then thoroughly analysed, interpreting their deep meaning from a mathematical standpoint and without relying on physical intuition. Moreover, some classic and advanced control design techniques are presented and illustrated with meaningful examples. Distinguishing features that characterize this brief include a definition of angular velocity, which leaves no room for ambiguities, an improvement on traditional definitions based on infinitesimal variations. Quaternion algebra, Euler parameters, and their role in capturing the dynamics of an aircraft are discussed in great detail. After having analyzed the longitudinal- and lateral-directional modes of an aircraft, the linear-quadratic regulator, the linear-quadratic Gaussian r...

  8. Launch vehicle flight control augmentation using smart materials and advanced composites (CDDF Project 93-05) (United States)

    Barret, C.


    The Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability such as the Saturn vehicles and flight control such as on the Redstone. Recently, due to aft center-of-gravity locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that is provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability, and payload capability. In the Saturn era, NASA went to the Moon with 300 sq ft of aerodynamic surfaces on the Saturn V. Since those days, the wealth of smart materials and advanced composites that have been developed allow for the design of very lightweight, strong, and innovative launch vehicle flight control surfaces. This paper presents an overview of the advanced composites and smart materials that are directly applicable to launch vehicle control surfaces.

  9. Launch vehicle flight control augmentation using smart materials and advanced composites (CDDF Project 93-05) (United States)

    Barret, C.


    The Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability such as the Saturn vehicles and flight control such as on the Redstone. Recently, due to aft center-of-gravity locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that is provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability, and payload capability. In the Saturn era, NASA went to the Moon with 300 sq ft of aerodynamic surfaces on the Saturn V. Since those days, the wealth of smart materials and advanced composites that have been developed allow for the design of very lightweight, strong, and innovative launch vehicle flight control surfaces. This paper presents an overview of the advanced composites and smart materials that are directly applicable to launch vehicle control surfaces.

  10. Performance of active vibration control technology: the ACTEX flight experiments (United States)

    Nye, T. W.; Manning, R. A.; Qassim, K.


    This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I (ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 °C to 129 °C. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed

  11. Mentoring SFRM: A New Approach to International Space Station Flight Control Training (United States)

    Huning, Therese; Barshi, Immanuel; Schmidt, Lacey


    The Mission Operations Directorate (MOD) of the Johnson Space Center is responsible for providing continuous operations support for the International Space Station (ISS). Operations support requires flight controllers who are skilled in team performance as well as the technical operations of the ISS. Space Flight Resource Management (SFRM), a NASA adapted variant of Crew Resource Management (CRM), is the competency model used in the MOD. ISS flight controller certification has evolved to include a balanced focus on development of SFRM and technical expertise. The latest challenge the MOD faces is how to certify an ISS flight controller (Operator) to a basic level of effectiveness in 1 year. SFRM training uses a twopronged approach to expediting operator certification: 1) imbed SFRM skills training into all Operator technical training and 2) use senior flight controllers as mentors. This paper focuses on how the MOD uses senior flight controllers as mentors to train SFRM skills.

  12. Practical Application of a Subscale Transport Aircraft for Flight Research in Control Upset and Failure Conditions (United States)

    Cunningham, Kevin; Foster, John V.; Morelli, Eugene A.; Murch, Austin M.


    Over the past decade, the goal of reducing the fatal accident rate of large transport aircraft has resulted in research aimed at the problem of aircraft loss-of-control. Starting in 1999, the NASA Aviation Safety Program initiated research that included vehicle dynamics modeling, system health monitoring, and reconfigurable control systems focused on flight regimes beyond the normal flight envelope. In recent years, there has been an increased emphasis on adaptive control technologies for recovery from control upsets or failures including damage scenarios. As part of these efforts, NASA has developed the Airborne Subscale Transport Aircraft Research (AirSTAR) flight facility to allow flight research and validation, and system testing for flight regimes that are considered too risky for full-scale manned transport airplane testing. The AirSTAR facility utilizes dynamically-scaled vehicles that enable the application of subscale flight test results to full scale vehicles. This paper describes the modeling and simulation approach used for AirSTAR vehicles that supports the goals of efficient, low-cost and safe flight research in abnormal flight conditions. Modeling of aerodynamics, controls, and propulsion will be discussed as well as the application of simulation to flight control system development, test planning, risk mitigation, and flight research.

  13. Flight Control Design for an Autonomous Rotorcraft Using Pseudo-Sliding Mode Control and Waypoint Navigation (United States)

    Mallory, Nicolas Joseph

    The design of robust automated flight control systems for aircraft of varying size and complexity is a topic of continuing interest for both military and civilian industries. By merging the benefits of robustness from sliding mode control (SMC) with the familiarity and transparency of design tradeoff offered by frequency domain approaches, this thesis presents pseudo-sliding mode control as a viable option for designing automated flight control systems for complex six degree-of-freedom aircraft. The infinite frequency control switching of SMC is replaced, by necessity, with control inputs that are continuous in nature. An introduction to SMC theory is presented, followed by a detailed design of a pseudo-sliding mode control and automated flight control system for a six degree-of-freedom model of a Hughes OH6 helicopter. This model is then controlled through three different waypoint missions that demonstrate the stability of the system and the aircraft's ability to follow certain maneuvers despite time delays, large changes in model parameters and vehicle dynamics, actuator dynamics, sensor noise, and atmospheric disturbances.

  14. A flight investigation of static stability, control augmentation, and flight director influences on helicopter IFR handling qualities (United States)

    Lebacqz, J. V.; Weber, J. M.; Corliss, L. D.


    A flight experiment was conducted using the NASA-Army V/STOLAND UH-1H variable-stability helicopter to investigate the influence of several longitudinal-static-stability, control-augmentation, and flight-director parameters on helicopter flying qualities during terminal area operations in instrument conditions. This experiment, which was part of a joint NASA/FAA program pertaining to helicopter IFR airworthiness, was designed to corroborate and extend previous ground simulation results obtained in this program. Variations examined included stable and neutral longitudinal control position gradients, rate-damping and attitude-command augmentation, and raw data versus flight-director displays. Pilot rating results agreed excellently with the ground simulation data, indicating an adequate instrument capability with rate-damping augmentation and neutral statics and the need for pitch-roll attitude augmentation to achieve a satisfactory system.

  15. Functional integration of vertical flight path and speed control using energy principles (United States)

    Lambregts, A. A.


    A generalized automatic flight control system was developed which integrates all longitudinal flight path and speed control functions previously provided by a pitch autopilot and autothrottle. In this design, a net thrust command is computed based on total energy demand arising from both flight path and speed targets. The elevator command is computed based on the energy distribution error between flight path and speed. The engine control is configured to produce the commanded net thrust. The design incorporates control strategies and hierarchy to deal systematically and effectively with all aircraft operational requirements, control nonlinearities, and performance limits. Consistent decoupled maneuver control is achieved for all modes and flight conditions without outer loop gain schedules, control law submodes, or control function duplication.

  16. The role of flight progress strips in en route air traffic control : a time-series analysis. (United States)


    Paper flight progress strips (FPSs) are currently used in the United States en route air traffic control system to document flight information. Impending automation will replace these paper strips with electronic flight data entries. In this observat...

  17. CX3CR1-dependent renal macrophage survival promotes Candida control and host survival (United States)

    Lionakis, Michail S.; Swamydas, Muthulekha; Fischer, Brett G.; Plantinga, Theo S.; Johnson, Melissa D.; Jaeger, Martin; Green, Nathaniel M.; Masedunskas, Andrius; Weigert, Roberto; Mikelis, Constantinos; Wan, Wuzhou; Lee, Chyi-Chia Richard; Lim, Jean K.; Rivollier, Aymeric; Yang, John C.; Laird, Greg M.; Wheeler, Robert T.; Alexander, Barbara D.; Perfect, John R.; Gao, Ji-Liang; Kullberg, Bart-Jan; Netea, Mihai G.; Murphy, Philip M.


    Systemic Candida albicans infection causes high morbidity and mortality and is associated with neutropenia; however, the roles of other innate immune cells in pathogenesis are poorly defined. Here, using a mouse model of systemic candidiasis, we found that resident macrophages accumulated in the kidney, the main target organ of infection, and formed direct contacts with the fungus in vivo mainly within the first few hours after infection. Macrophage accumulation and contact with Candida were both markedly reduced in mice lacking chemokine receptor CX3CR1, which was found almost exclusively on resident macrophages in uninfected kidneys. Infected Cx3cr1–/– mice uniformly succumbed to Candida-induced renal failure, but exhibited clearance of the fungus in all other organs tested. Renal macrophage deficiency in infected Cx3cr1–/– mice was due to reduced macrophage survival, not impaired proliferation, trafficking, or differentiation. In humans, the dysfunctional CX3CR1 allele CX3CR1-M280 was associated with increased risk of systemic candidiasis. Together, these data indicate that CX3CR1-mediated renal resident macrophage survival is a critical innate mechanism of early fungal control that influences host survival in systemic candidiasis. PMID:24177428

  18. Insect-Inspired Flight Control for Unmanned Aerial Vehicles (United States)

    Thakoor, Sarita; Stange, G.; Srinivasan, M.; Chahl, Javaan; Hine, Butler; Zornetzer, Steven


    Flight-control and navigation systems inspired by the structure and function of the visual system and brain of insects have been proposed for a class of developmental miniature robotic aircraft called "biomorphic flyers" described earlier in "Development of Biomorphic Flyers" (NPO-30554), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 54. These form a subset of biomorphic explorers, which, as reported in several articles in past issues of NASA Tech Briefs ["Biomorphic Explorers" (NPO-20142), Vol. 22, No. 9 (September 1998), page 71; "Bio-Inspired Engineering of Exploration Systems" (NPO-21142), Vol. 27, No. 5 (May 2003), page 54; and "Cooperative Lander-Surface/Aerial Microflyer Missions for Mars Exploration" (NPO-30286), Vol. 28, No. 5 (May 2004), page 36], are proposed small robots, equipped with microsensors and communication systems, that would incorporate crucial functions of mobility, adaptability, and even cooperative behavior. These functions are inherent to biological organisms but are challenging frontiers for technical systems. Biomorphic flyers could be used on Earth or remote planets to explore otherwise difficult or impossible to reach sites. An example of an exploratory task of search/surveillance functions currently being tested is to obtain high-resolution aerial imagery, using a variety of miniaturized electronic cameras. The control functions to be implemented by the systems in development include holding altitude, avoiding hazards, following terrain, navigation by reference to recognizable terrain features, stabilization of flight, and smooth landing. Flying insects perform these and other functions remarkably well, even though insect brains contains fewer than 10(exp -4) as many neurons as does the human brain. Although most insects have immobile, fixed-focus eyes and lack stereoscopy (and hence cannot perceive depth directly), they utilize a number of ingenious strategies for perceiving, and navigating in, three dimensions. Despite

  19. Oxygen Generation System Laptop Bus Controller Flight Software (United States)

    Rowe, Chad; Panter, Donna


    The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.

  20. Analysis of helicopter flight dynamics through modeling and simulation of primary flight control actuation system (United States)

    Nelson, Hunter Barton

    A simplified second-order transfer function actuator model used in most flight dynamics applications cannot easily capture the effects of different actuator parameters. The present work integrates a nonlinear actuator model into a nonlinear state space rotorcraft model to determine the effect of actuator parameters on key flight dynamics. The completed actuator model was integrated with a swashplate kinematics where step responses were generated over a range of key hydraulic parameters. The actuator-swashplate system was then introduced into a nonlinear state space rotorcraft simulation where flight dynamics quantities such as bandwidth and phase delay analyzed. Frequency sweeps were simulated for unique actuator configurations using the coupled nonlinear actuator-rotorcraft system. The software package CIFER was used for system identification and compared directly to the linearized models. As the actuator became rate saturated, the effects on bandwidth and phase delay were apparent on the predicted handling qualities specifications.

  1. Survival (United States)

    U.S. Geological Survey, Department of the Interior — These data provide information on the survival of California red-legged frogs in a unique ecosystem to better conserve this threatened species while restoring...

  2. Flight control optimization from design to assessment application on the Cessna Citation X business aircraft = (United States)

    Boughari, Yamina

    New methodologies have been developed to optimize the integration, testing and certification of flight control systems, an expensive process in the aerospace industry. This thesis investigates the stability of the Cessna Citation X aircraft without control, and then optimizes two different flight controllers from design to validation. The aircraft's model was obtained from the data provided by the Research Aircraft Flight Simulator (RAFS) of the Cessna Citation business aircraft. To increase the stability and control of aircraft systems, optimizations of two different flight control designs were performed: 1) the Linear Quadratic Regulation and the Proportional Integral controllers were optimized using the Differential Evolution algorithm and the level 1 handling qualities as the objective function. The results were validated for the linear and nonlinear aircraft models, and some of the clearance criteria were investigated; and 2) the Hinfinity control method was applied on the stability and control augmentation systems. To minimize the time required for flight control design and its validation, an optimization of the controllers design was performed using the Differential Evolution (DE), and the Genetic algorithms (GA). The DE algorithm proved to be more efficient than the GA. New tools for visualization of the linear validation process were also developed to reduce the time required for the flight controller assessment. Matlab software was used to validate the different optimization algorithms' results. Research platforms of the aircraft's linear and nonlinear models were developed, and compared with the results of flight tests performed on the Research Aircraft Flight Simulator. Some of the clearance criteria of the optimized H-infinity flight controller were evaluated, including its linear stability, eigenvalues, and handling qualities criteria. Nonlinear simulations of the maneuvers criteria were also investigated during this research to assess the Cessna

  3. Design and flight performance of hybrid underwater glider with controllable wings

    Directory of Open Access Journals (Sweden)

    Yanhui Wang


    Full Text Available Hybrid underwater glider combines motion modes of traditional autonomous underwater glider and those of autonomous underwater vehicles. Different motion modes need different flight performance, including flight efficiency, static stability, and maneuverability. Conventional hybrid underwater glider with fixed wings can’t achieve optimal flight performance in one flight mission demanding various motion modes. In this article, controllable wings for hybrid underwater glider Petrel II are designed. Angle of attack, sweep angle, and aspect ratio of controllable wings can be changed to adapt to different motion modes. Kinematics and dynamics models of Petrel II are established based on multibody theory. Motion simulations of Petrel II with different wing configurations are conducted in three motion modes, including glide motion, spiral motion, and horizontal turning motion. The simulation results show the impact of wing parameters on flight performance. Field trials demonstrate that the controllable wings can improve the flight performance.

  4. A Hybrid Flight Control for a Simulated Raptor-30 V2 Helicopter

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer


    Full Text Available This paper presents a hybrid flight control system for a single rotor simulated Raptor-30 V2 helicopter. Hybrid intelligent control system, combination of the conventional and intelligent control methodologies, is applied to small model helicopter. The proposed hybrid control used PID as a traditional control and fuzzy as an intelligent control so as to take the maximum advantage of advanced control theory. The helicopter?s model used; comes from X-Plane flight simulator and their hybrid flight control system was simulated using MATLAB/SIMULINK in a simulation platform. X-Plane is also used to visualize the performance of this proposed autopilot design. Through a series of numerous experiments, the operation of hybrid control system was investigated. Results verified that the proposed hybrid control has an excellent performance at hovering flight mode.

  5. 76 FR 50809 - Eleventh Meeting: RTCA Special Committee 220: Automatic Flight Guidance and Control (United States)


    ... Federal Aviation Administration Eleventh Meeting: RTCA Special Committee 220: Automatic Flight Guidance and Control AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Correction of Notice of RTCA Special Committee 220 meeting: Automatic Flight Guidance and Control. SUMMARY: The FAA is issuing this...

  6. 76 FR 79754 - Twelfth Meeting: RTCA Special Committee 220, Automatic Flight Guidance and Control (United States)


    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 220, Automatic Flight Guidance and Control AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Notice of RTCA Special Committee 220, Automatic Flight Guidance and Control. SUMMARY: The FAA is issuing...

  7. Pseudo Control Hedging and its Application for Safe Flight Envelope Protection

    NARCIS (Netherlands)

    Lombaerts, T.J.J.; Looye, G.H.N.; Chu, Q.P.; Mulder, J.A.


    This paper describes how the previously developed concept of Pseudo Control Hedging (PCH) can be integrated in a Fault Tolerant Flight Controller (FTFC) as a safe flight envelope protection system of the first degree. This PCH algorithm adapts the reference model for the system output in case of

  8. An Integrated Approach to Aircraft Modelling and Flight Control Law Design

    NARCIS (Netherlands)

    Looye, G.H.N.


    The design of flight control laws (FCLs) for automatic and manual (augmented) control of aircraft is a complicated task. FCLs have to fulfil large amounts of performance criteria and must work reliably in all flight conditions, for all aircraft configurations, and in adverse weather conditions.

  9. failure analysis of a uav flight control system using markov analysis

    African Journals Online (AJOL)



    Jan 1, 2016 ... airframe aerodynamics. This paper focuses on UAV flight control system. Chen et al studied the Probabilistic Safety Analysis of a. Flight Control System based on Bayesian Network [8]. Their results revealed that the Bayesian Network provide a simple and intuitive measure to deal with the safety analysis of ...

  10. Use of the Pseudo-Inverse for Design of a Reconfigurable Flight Control System. (United States)


    Control Laws for the A-7D, Digitac II Aircraft, Master’s Thesis, Air Force Institute of Technology, Wright-Patterson AFB OH, December 1980. 3. Roskam , Jan...Airplane Flight Dynamics and Automatic Flight Controls, Part I. Lawrence KS: Roskam Aviation and Engineering Corporation, 1979. 4. Jane’s All The

  11. Flight Test of Composite Model Reference Adaptive Control (CMRAC) Augmentation Using NASA AirSTAR Infrastructure (United States)

    Gregory, Irene M.; Gadient, ROss; Lavretsky, Eugene


    This paper presents flight test results of a robust linear baseline controller with and without composite adaptive control augmentation. The flight testing was conducted using the NASA Generic Transport Model as part of the Airborne Subscale Transport Aircraft Research system at NASA Langley Research Center.

  12. Model and Sensor Based Nonlinear Adaptive Flight Control with Online System Identification

    NARCIS (Netherlands)

    Sun, L.G.


    Consensus exists that many loss-of-control (LOC) in flight accidents caused by severe aircraft damage or system failure could be prevented if flight performance could be recovered using the valid and remaining control authorities. However, the safe maneuverability of a post-failure aircraft will

  13. Optimal nonlinear estimation for aircraft flight control in wind shear (United States)

    Mulgund, Sandeep S.


    The most recent results in an ongoing research effort at Princeton in the area of flight dynamics in wind shear are described. The first undertaking in this project was a trajectory optimization study. The flight path of a medium-haul twin-jet transport aircraft was optimized during microburst encounters on final approach. The assumed goal was to track a reference climb rate during an aborted landing, subject to a minimum airspeed constraint. The results demonstrated that the energy loss through the microburst significantly affected the qualitative nature of the optimal flight path. In microbursts of light to moderate strength, the aircraft was able to track the reference climb rate successfully. In severe microbursts, the minimum airspeed constraint in the optimization forced the aircraft to settle on a climb rate smaller than the target. A tradeoff was forced between the objectives of flight path tracking and stall prevention.

  14. Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology (United States)

    Chamitoff, Gregory Errol


    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.

  15. Status of a digital integrated propulsion/flight control system for the YF-12 airplane (United States)

    Reukauf, P. J.; Burcham, F. W., Jr.; Holzman, J. K.


    The NASA Flight Research Center is engaged in a program with the YF-12 airplane to study the control of interactions between the airplane and the propulsion system. The existing analog air data computer, autothrottle, autopilot, and inlet control system are to be converted to digital systems by using a general purpose airborne computer and interface unit. First, the existing control laws will be programmed in the digital computer and flight tested. Then new control laws are to be derived from a dynamic propulsion model and a total force and moment aerodynamic model to integrate the systems. These control laws are to be verified in a real time simulation and flight tested.

  16. Rationale for selection of a flight control system for lift cruise fan V/STOL aircraft (United States)

    Konsewicz, R. K.


    Various features of the lift cruise fan V/STOL concept are briefly reviewed. The ability to operate from small ships in adverse weather, low visibility, and rough sea conditions is emphasized as is the need for a highly capable, flexible, and reliabile flight control system. A three channel control by wire, digital flight control system is suggested. The requirement for automatic flight control, the advantage of control by wire implementation, the preference for a digital computer, and the need for three channel redundancy are among the factors discussed.

  17. Matched survival data in a co-twin control design

    DEFF Research Database (Denmark)

    Gerster, Mette; Madsen, Mia; Andersen, Per Kragh


    When using the co-twin control design for analysis of event times, one needs a model to address the possible within-pair association. One such model is the shared frailty model in which the random frailty variable creates the desired within-pair association. Standard inference for this model......-effects models for survival in matched pairs. Fitting this model to data generated from the frailty model provides consistent and asymptotically normal estimates of regression coefficients, no matter whether the independence assumption is met....

  18. Flight Tests of a Ministick Controller in an F/A-18 Airplane (United States)

    Stoliker, Patrick C.; Carter, John


    In March of 1999, five pilots performed flight tests to evaluate the handling qualities of an F/A-18 research airplane equipped with a small-displacement center stick (ministick) controller that had been developed for the JAS 39 Gripen airplane (a fighter/attack/ reconnaissance airplane used by the Swedish air force). For these tests, the ministick was installed in the aft cockpit (see figure) and production support flight control computers (PSFCCs) were used as interfaces between the controller hardware and the standard F/A-18 flight-control laws. The primary objective of the flight tests was to assess any changes in handling qualities of the F/A-18 airplane attributable to the mechanical characteristics of the ministick. The secondary objective was to demonstrate the capability of the PSFCCs to support flight-test experiments.

  19. Data Acquistion Controllers and Computers that can Endure, Operate and Survive Cryogenic Temperatures Project (United States)

    National Aeronautics and Space Administration — Current and future NASA exploration flight missions require Avionics systems, Computers, Controllers and Data processing units that are capable of enduring extreme...

  20. Integrated digital flight-control system for the space shuttle orbiter (United States)


    The integrated digital flight control system is presented which provides rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the GN&C computer complex and is equally insensitive to the characteristics of the processor configuration. The integrated structure of the control system and the DFCS executive routine which embodies that structure are described along with the input and output. The specific estimation and control algorithms used in the various mission phases are given.

  1. A manned maneuvering unit proximity operations planning and flight guidance display and control system (United States)

    Gershzohn, Gary R.; Sirko, Robert J.; Zimmerman, K.; Jones, A. D.


    This task concerns the design, development, testing, and evaluation of a new proximity operations planning and flight guidance display and control system for manned space operations. A forecast, derivative manned maneuvering unit (MMU) was identified as a candidate for the application of a color, highway-in-the-sky display format for the presentation of flight guidance information. A silicon graphics 4D/20-based simulation is being developed to design and test display formats and operations concepts. The simulation includes the following: (1) real-time color graphics generation to provide realistic, dynamic flight guidance displays and control characteristics; (2) real-time graphics generation of spacecraft trajectories; (3) MMU flight dynamics and control characteristics; (4) control algorithms for rotational and translational hand controllers; (5) orbital mechanics effects for rendezvous and chase spacecraft; (6) inclusion of appropriate navigation aids; and (7) measurement of subject performance. The flight planning system under development provides for: (1) selection of appropriate operational modes, including minimum cost, optimum cost, minimum time, and specified ETA; (2) automatic calculation of rendezvous trajectories, en route times, and fuel requirements; (3) and provisions for manual override. Man/machine function allocations in planning and en route flight segments are being evaluated. Planning and en route data are presented on one screen composed of two windows: (1) a map display presenting a view perpendicular to the orbital plane, depicting flight planning trajectory and time data attitude display presenting attitude and course data for use en route; and (2) an attitude display presenting local vertical-local horizontal attitude data superimposed on a highway-in-the-sky or flight channel representation of the flight planned course. Both display formats are presented while the MMU is en route. In addition to these displays, several original display

  2. An Electronic Workshop on the Performance Seeking Control and Propulsion Controlled Aircraft Results of the F-15 Highly Integrated Digital Electronic Control Flight Research Program (United States)

    Powers, Sheryll Goecke (Compiler)


    Flight research for the F-15 HIDEC (Highly Integrated Digital Electronic Control) program was completed at NASA Dryden Flight Research Center in the fall of 1993. The flight research conducted during the last two years of the HIDEC program included two principal experiments: (1) performance seeking control (PSC), an adaptive, real-time, on-board optimization of engine, inlet, and horizontal tail position on the F-15; and (2) propulsion controlled aircraft (PCA), an augmented flight control system developed for landings as well as up-and-away flight that used only engine thrust (flight controls locked) for flight control. In September 1994, the background details and results of the PSC and PCA experiments were presented in an electronic workshop, accessible through the Dryden World Wide Web ( and as a compact disk.

  3. A Multi-Layer Intelligent Loss-of-Control Prevention System (LPS) for Flight Control Applications Project (United States)

    National Aeronautics and Space Administration — The main objective of the proposed work is to design and develop a multi-layer intelligent Loss-of-control Prevention System (LPS) for flight control applications....

  4. En route air traffic controllers' use of flight progress strips : a graph-theoretic analysis. (United States)


    In the United States, flight data are represented on a paper Flight Progress Strip (FPS). The role of the FPS has recently attracted attention because of plans to automate this aspect of air traffic control. The communication activities and FPS activ...

  5. Development of an Air-to-Air Refueling Automatic Flight Control System Using Quantitative Feedback Theory (United States)


    Rosrm, Jan . Airplane Flight Dynamics and Automatic Flight Controls, Part I. Roskam Aviation and Engineering Corp., 1982. 11. Military Specification...udchn o j’ mc°n and yea’, if available (e.g. 1 limitations or special markings in all capitals (e.g Jan 88). Must (,e a, least the yea, NOFORN, REL

  6. Experimental Flight Characterization of a Canard-Controlled, Subsonic Missile (United States)


    estimation algorithm are plotted. The Approved for public release; distribution is unlimited. 20 vehicle natural frequency and trim amplification ...during this flight. A resonance condition occurs as the roll rate and vehicle natural frequencies line up. The trim amplification factor increases...sensitivities), and atmospheric (density, sound speed) and flow speed measurements. These coefficients were combined with the aerodynamic angles Insert Video

  7. A Survey on Open-Source Flight Control Platforms of Unmanned Aerial Vehicle

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Skriver, Martin; Jin, Jie


    Recently, Unmanned Aerial Vehicle (UAV), so-called drones, have gotten a lot of attention in academic research and commercial applications due to their simple structure, ease of operations and low-cost hardware components. Flight controller, embedded electronics component, represents the core part...... of the drone. It aims at performing the main operations of the drone (e.g., autonomous control and navigation). There are various types of flight controllers and each of them has its own characteristics and features. This paper presents an extensive survey on the publicly available open-source flight...

  8. A Survey on Open-Source Flight Control Platforms of Unmanned Aerial Vehicle

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Skriver, Martin; Jin, Jie


    of the drone. It aims at performing the main operations of the drone (e.g., autonomous control and navigation). There are various types of flight controllers and each of them has its own characteristics and features. This paper presents an extensive survey on the publicly available open-source flight......Recently, Unmanned Aerial Vehicle (UAV), so-called drones, have gotten a lot of attention in academic research and commercial applications due to their simple structure, ease of operations and low-cost hardware components. Flight controller, embedded electronics component, represents the core part...

  9. Improved methods in neural network-based adaptive output feedback control, with applications to flight control (United States)

    Kim, Nakwan

    Utilizing the universal approximation property of neural networks, we develop several novel approaches to neural network-based adaptive output feedback control of nonlinear systems, and illustrate these approaches for several flight control applications. In particular, we address the problem of non-affine systems and eliminate the fixed point assumption present in earlier work. All of the stability proofs are carried out in a form that eliminates an algebraic loop in the neural network implementation. An approximate input/output feedback linearizing controller is augmented with a neural network using input/output sequences of the uncertain system. These approaches permit adaptation to both parametric uncertainty and unmodeled dynamics. All physical systems also have control position and rate limits, which may either deteriorate performance or cause instability for a sufficiently high control bandwidth. Here we apply a method for protecting an adaptive process from the effects of input saturation and time delays, known as "pseudo control hedging". This method was originally developed for the state feedback case, and we provide a stability analysis that extends its domain of applicability to the case of output feedback. The approach is illustrated by the design of a pitch-attitude flight control system for a linearized model of an R-50 experimental helicopter, and by the design of a pitch-rate control system for a 58-state model of a flexible aircraft consisting of rigid body dynamics coupled with actuator and flexible modes. A new approach to augmentation of an existing linear controller is introduced. It is especially useful when there is limited information concerning the plant model, and the existing controller. The approach is applied to the design of an adaptive autopilot for a guided munition. Design of a neural network adaptive control that ensures asymptotically stable tracking performance is also addressed.

  10. Design of Launch Vehicle Flight Control Systems Using Ascent Vehicle Stability Analysis Tool (United States)

    Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedossian, Nazareth; Hall, Charles; Jackson, Mark


    A launch vehicle represents a complicated flex-body structural environment for flight control system design. The Ascent-vehicle Stability Analysis Tool (ASAT) is developed to address the complicity in design and analysis of a launch vehicle. The design objective for the flight control system of a launch vehicle is to best follow guidance commands while robustly maintaining system stability. A constrained optimization approach takes the advantage of modern computational control techniques to simultaneously design multiple control systems in compliance with required design specs. "Tower Clearance" and "Load Relief" designs have been achieved for liftoff and max dynamic pressure flight regions, respectively, in the presence of large wind disturbances. The robustness of the flight control system designs has been verified in the frequency domain Monte Carlo analysis using ASAT.

  11. F-8 digital fly-by-wire flight test results viewed from an active controls perspective (United States)

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


    The results of the NASA F-8 digital fly-by-wire flight test program are presented, along with the implications for active controls applications. The closed loop performance of the digital control system agreed well with the sampled-data system design predictions. The digital fly-by-wire mechanization also met pilot flying qualities requirements. The advantages of mechanizing the control laws in software became apparent during the flight program and were realized without sacrificing overall system reliability. This required strict software management. The F-8 flight test results are shown to be encouraging in light of the requirements that must be met by control systems for flight-critical active controls applications.

  12. Autonomous Close Formation Flight Control with Fixed Wing and Quadrotor Test Beds

    Directory of Open Access Journals (Sweden)

    Caleb Rice


    Full Text Available Autonomous formation flight is a key approach for reducing energy cost and managing traffic in future high density airspace. The use of Unmanned Aerial Vehicles (UAVs has allowed low-budget and low-risk validation of autonomous formation flight concepts. This paper discusses the implementation and flight testing of nonlinear dynamic inversion (NLDI controllers for close formation flight (CFF using two distinct UAV platforms: a set of fixed wing aircraft named “Phastball” and a set of quadrotors named “NEO.” Experimental results show that autonomous CFF with approximately 5-wingspan separation is achievable with a pair of low-cost unmanned Phastball research aircraft. Simulations of the quadrotor flight also validate the design of the NLDI controller for the NEO quadrotors.

  13. Simulation Training Versus Real Time Console Training for New Flight Controllers (United States)

    Heaton, Amanda


    For new flight controllers, the two main learning tools are simulations and real time console performance training. These benefit the new flight controllers in different ways and could possibly be improved. Simulations: a) Allow for mistakes without serious consequences. b) Lets new flight controllers learn the working style of other new flight controllers. c) Lets new flight controllers eventually begin to feel like they have mastered the sim world, so therefore they must be competent in the real time world too. Real time: a) Shows new flight controllers some of the unique problems that develop and have to be accounted for when dealing with certain payloads or systems. b) Lets new flight controllers experience handovers - gathering information from the previous shift on what the room needs to be aware of and what still needs to be done. c) Gives new flight controllers confidence that they can succeed in the position they are training for when they can solve real anomalies. How Sims could be improved and more like real-time ops for the ISS Operations Controller position: a) Operations Change Requests to review. b) Fewer anomalies (but still more than real time for practice). c) Payload Planning Manager Handover sheet for the E-1 and E-3 reviews. d) Flight note in system with at least one comment to verify for the E-1 and E-3 reviews How the real time console performance training could be improved for the ISS Operations Controller position: a) Schedule the new flight controller to be on console for four days but with a different certified person each day. This will force them to be the source of knowledge about every OCR in progress, everything that has happened in those few days, and every activity on the timeline. Constellation program flight controllers will have to learn entirely from simulations, thereby losing some of the elements that they will need to have experience with for real time ops. It may help them to practice real time console performance training

  14. Bifurcation Tools for Flight Dynamics Analysis and Control System Design Project (United States)

    National Aeronautics and Space Administration — Modern bifurcation analysis methods have been proposed for investigating flight dynamics and control system design in highly nonlinear regimes and also for the...

  15. Robust flight control using incremental nonlinear dynamic inversion and angular acceleration prediction

    NARCIS (Netherlands)

    Sieberling, S.; Chu, Q.P.; Mulder, J.A.


    This paper presents a flight control strategy based on nonlinear dynamic inversion. The approach presented, called incremental nonlinear dynamic inversion, uses properties of general mechanical systems and nonlinear dynamic inversion by feeding back angular accelerations. Theoretically, feedback of

  16. Bifurcation Tools for Flight Dynamics Analysis and Control System Design Project (United States)

    National Aeronautics and Space Administration — The purpose of the project is the development of a computational package for bifurcation analysis and advanced flight control of aircraft. The development of...

  17. Self-Repairing Flight Control System for Online Health Monitoring and Recovery Project (United States)

    National Aeronautics and Space Administration — In this SBIR project, a reliable self-repairing Flight Control System (FCS) will be developed. To achieve this goal, an artificial Neural Network based Sensor...

  18. Human factors considerations in the design and evaluation of flight deck displays and controls (United States)


    The objective of this effort is to have a single source document for human factors regulatory and guidance material for flight deck displays and controls, in the interest of improving aviation safety. This document identifies guidance on human factor...

  19. Design and simulation of flight control system for man-portable micro reconnaissance quadcopter (United States)

    Yin, Xinfan; Zhang, Daibing; Fang, Qiang; Shen, Lincheng


    The quadcopter has been widely used in the field of aerial photography and environmental detection, because of its advantages of VTOL, simple structure, and easy-control. In the field of urban anti-terrorism or special operations, micro reconnaissance quadcpter has its unique advantages such as all-weather taking off and landing, small noise and so on, and it is very popular with special forces and riot police. This paper aims at the flight control problem of the micro quadcopter, for the purposes of attitude stabilization control and trajectory tracking control of the micro quadcopter, first, the modeling of the micro quadcopter is presented. And using the MATLAB/SIMULINK toolbox to build the flight controller of the micro quadcopter, and then simulation analysis and real flight test are given. The results of the experiment show that the designed PID controller can correct the flight attitude shift effectively and track the planned tracks well, and can achieve the goal of stable and reliable flight of the quadcopter. It can be a useful reference for the flight control system design of future special operations micro UAV.

  20. Simulator Evaluation of Simplified Propulsion-Only Emergency Flight Control Systems on Transport Aircraft (United States)

    Burcham, Frank W., Jr.; Kaneshige, John; Bull, John; Maine, Trindel A.


    With the advent of digital engine control systems, considering the use of engine thrust for emergency flight control has become feasible. Many incidents have occurred in which engine thrust supplemented or replaced normal aircraft flight controls. In most of these cases, a crash has resulted, and more than 1100 lives have been lost. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control capability. Using this PCA system, an F-15 and an MD-11 airplane have been landed without using any flight controls. In simulations, C-17, B-757, and B-747 PCA systems have also been evaluated successfully. These tests used full-authority digital electronic control systems on the engines. Developing simpler PCA systems that can operate without full-authority engine control, thus allowing PCA technology to be installed on less capable airplanes or at lower cost, is also a desire. Studies have examined simplified ?PCA Ultralite? concepts in which thrust control is provided using an autothrottle system supplemented by manual differential throttle control. Some of these concepts have worked well. The PCA Ultralite study results are presented for simulation tests of MD-11, B-757, C-17, and B-747 aircraft.

  1. Flight Services and Aircraft Access: Active Flow Control Vertical Tail and Insect Accretion and Mitigation Flight Test (United States)

    Whalen, Edward A.


    This document serves as the final report for the Flight Services and Aircraft Access task order NNL14AA57T as part of NASA Environmentally Responsible Aviation (ERA) Project ITD12A+. It includes descriptions of flight test preparations and execution for the Active Flow Control (AFC) Vertical Tail and Insect Accretion and Mitigation (IAM) experiments conducted on the 757 ecoDemonstrator. For the AFC Vertical Tail, this is the culmination of efforts under two task orders. The task order was managed by Boeing Research & Technology and executed by an enterprise-wide Boeing team that included Boeing Research & Technology, Boeing Commercial Airplanes, Boeing Defense and Space and Boeing Test and Evaluation. Boeing BR&T in St. Louis was responsible for overall Boeing project management and coordination with NASA. The 757 flight test asset was provided and managed by the BCA ecoDemonstrator Program, in partnership with Stifel Aircraft Leasing and the TUI Group. With this report, all of the required deliverables related to management of this task order have been met and delivered to NASA as summarized in Table 1. In addition, this task order is part of a broader collaboration between NASA and Boeing.

  2. Development of a Model Following Control Law for Inflight Simulation and Flight Controls Research (United States)

    Takahashi, Mark; Fletcher, Jay; Aiken, Edwin W. (Technical Monitor)


    The U.S. Army and NASA are currently developing the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) at the Ames Research Center. RASCAL, shown in Figure 1, is a UH-60, which is being modified in a phased development program to have a research fly-by-wire flight control system, and an advanced navigation research platform. An important part of the flight controls and handling qualities research on RASCAL will be an FCS design for the aircraft to achieve high bandwidth control responses and disturbance rejection characteristics. Initially, body states will be used as feedbacks, but research into the use of rotor states will also be considered in later stages to maximize agility and maneuverability. In addition to supporting flight controls research, this FCS design will serve as the inflight simulation control law to support basic handling qualities, guidance, and displays research. Research in high bandwidth controls laws is motivated by the desire to improve the handling qualities in aggressive maneuvering and in severely degraded weather conditions. Naturally, these advantages will also improve the quality of the model following, thereby improving the inflight simulation capabilities of the research vehicle. High bandwidth in the control laws provides tighter tracking allowing for higher response bandwidths which can meet handling qualities requirements for aggressive maneuvering. System sensitivity is also reduced preventing variations in the response from the vehicle due to changing flight conditions. In addition, improved gust rejection will result from this reduced sensitivity. The gust rejection coupled with a highly stable system will make more precise maneuvering and pointing possible in severely degraded weather conditions. The difficulty in achieving higher bandwidths from the control laws in the feedback and in the responses arises from the complexity of the models that are needed to produce a satisfactory design. In this case, high

  3. Stable Hovering Flight for a Small Unmanned Helicopter Using Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer


    Full Text Available Stable hover flight control for small unmanned helicopter under light air turbulent environment is presented. Intelligent fuzzy logic is chosen because it is a nonlinear control technique based on expert knowledge and is capable of handling sensor created noise and contradictory inputs commonly encountered in flight control. The fuzzy nonlinear control utilizes these distinct qualities for attitude, height, and position control. These multiple controls are developed using two-loop control structure by first designing an inner-loop controller for attitude angles and height and then by establishing outer-loop controller for helicopter position. The nonlinear small unmanned helicopter model used comes from X-Plane simulator. A simulation platform consisting of MATLAB/Simulink and X-Plane© flight simulator was introduced to implement the proposed controls. The main objective of this research is to design computationally intelligent control laws for hovering and to test and analyze this autopilot for small unmanned helicopter model on X-Plane under ideal and mild turbulent condition. Proposed fuzzy flight controls are validated using an X-Plane helicopter model before being embedded on actual helicopter. To show the effectiveness of the proposed fuzzy control method and its ability to cope with the external uncertainties, results are compared with a classical PD controller. Simulated results show that two-loop fuzzy controllers have a good ability to establish stable hovering for a class of unmanned rotorcraft in the presence of light turbulent environment.

  4. A knowledge-based system design/information tool for aircraft flight control systems (United States)

    Mackall, Dale A.; Allen, James G.


    Research aircraft have become increasingly dependent on advanced electronic control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objective. This integration is being accomplished through electronic control systems. Systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary object is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences are reviewed of three highly complex, integrated aircraft programs: the X-29 forward swept wing; the advanced fighter technology integration (AFTI) F-16; and the highly maneuverable aircraft technology (HiMAT) program. Significant operating technologies, and the design errors which cause them, is examined to help identify what functions a system design/informatin tool should provide to assist designers in avoiding errors.

  5. Aerodynamics of ski jumping flight and its control: I. Experiments (United States)

    Jung, Daehan; Bang, Kyeongtae; Kim, Heesu; Ahn, Eunhye; Choi, Haecheon


    In a ski jumping competition, it is essential to analyze the effect of various posture parameters of a ski jumper to achieve a longer flight distance. For this purpose, we construct a model of a ski jumper by using three-dimensional surface data obtained by scanning a ski jumper's body (Mr. Chil-Ku Kang, member of the Korean national team). An experiment on this model is conducted in a wind tunnel. We consider four posture parameters (forward leaning angle, ski opening angle, ski rolling angle, and ski spacing) and measure the drag and lift forces for various flight postures at various angles of attack (α = 0° - 40°) and Reynolds numbers (Re = 5.4 × 105 - 1.6 × 106) based on the length of the jump ski. Then, we derive optimum values of posture parameters for maximum lift-to-drag ratio using a response surface method. We also conduct a full-scale wind tunnel experiment with members of the Korean national team and confirm the results obtained from the experiment on the model. Supported by the NRF program (2014M3C1B1033848).

  6. Aerodynamics of ski jumping flight and its control: II. Simulations (United States)

    Lee, Jungil; Lee, Hansol; Kim, Woojin; Choi, Haecheon


    In a ski jumping competition, it is essential to analyze the effect of various posture parameters of a ski jumper to achieve a longer flight distance. For this purpose, we conduct a large eddy simulation (LES) of turbulent flow past a model ski jumper which is obtained by 3D scanning a ski jumper's body (Mr. Chil-Ku Kang, member of the Korean national team). The angle of attack of the jump ski is 30° and the Reynolds number based on the length of the jump ski is 540,000. The flow statistics including the drag and lift coefficients in flight are in good agreements with our own experimental data. We investigate the flow characteristics such as the flow separation and three-dimensional vortical structures and their effects on the drag and lift. In addition to LES, we construct a simple geometric model of a ski jumper where each part of the ski jumper is modeled as a canonical bluff body such as the sphere, cylinder and flat plate, to find its optimal posture. The results from this approach will be compared with those by LES and discussed. Supported by NRF program (2014M3C1B1033848, 2014R1A1A1002671).

  7. NASA flight controllers - Meeting cultural and leadership challenges on the critical path to mission success (United States)

    Clement, James L., Jr.; Ritsher, Jennifer Boyd


    As part of its preparation for missions to the Moon and Mars, NASA has identified high priority critical path roadmap (CPR) questions, two of which focus on the performance of mission control personnel. NASA flight controllers have always worked in an incredibly demanding setting, but the International Space Station poses even more challenges than prior missions. We surveyed 14 senior ISS flight controllers and a contrasting sample of 12 more junior controllers about the management and cultural challenges they face and the most effective strategies for addressing them. There was substantial consensus among participants on some issues, such as the importance of building a personal relationship with Russian colleagues. Responses from junior and senior controllers differed in some areas, such as training. We frame the results in terms of two CPR questions. We aim to use our results to improve flight controller training.


    Directory of Open Access Journals (Sweden)

    Evgenii E. Nechaev


    Full Text Available This article discusses various options for air traffic management at low flight intensity airports and airports located remotely in the North, where air traffic control service is not necessary.There are some examples of already implemented concepts in foreign countries: such as remote control tower, which allows to control air traffic, being at a considerable distance from the airport. Such a remote control tower is already put into operation at the Örnsköldsvik airport (Sweden. The prospects of this system development in other countries are observed in this article. A remote control tower will also appear in the United States in the nearest future. Also the paper considers the pros and cons of this system and its effect on flight safety.Moreover, there are given the examples of using non-towered and uncontrolled airports, where air traffic control service is not provided. This kind of airports is partly used in the USA and in New Zealand. The article describes flight procedures in the area of uncontrolled airports, including visual flight rules and instrument flight rules.We also analyze the possibilities of remote control towers and uncontrolled airports adaptation in the Russian Federation. It is a very important problem for Russia because most airports do not provide more than 10 movements per day. But air traffic control service exists in all airports.

  9. Simulator investigations of side-stick controller/stability and control augmentation systems for night nap-of-earth flight (United States)

    Landis, K. H.; Aiken, E. W.


    Several night nap-of-the-earth mission tasks were evaluated using a helmet-mounted display which provided a limited field-of-view image with superimposed flight control symbology. A wide range of stability and control augmentation designs was investigated. Variations in controller force-deflection characteristics and the number of axes controlled through an integrated side-stick controller were studied. In general, a small displacement controller is preferred over a stiffstick controller particularly for maneuvering flight. Higher levels of stability augmentation were required for IMC tasks to provide handling qualities comparable to those achieved for the same tasks conducted under simulated visual flight conditions. Previously announced in STAR as N82-23216

  10. Design, analysis, and control of large transport aircraft utilizing engine thrust as a backup system for the primary flight controls (United States)

    Gerren, Donna S.


    A review of accidents that involved the loss of hydraulic flight control systems serves as an introduction to this project. In each of the accidents--involving transport aircraft such as the DC-10, the C-5A, the L-1011, and the Boeing 747--the flight crew attempted to control the aircraft by means of thrust control. Although these incidents had tragic endings, in the absence of control power due to primary control system failure, control power generated by selective application of engine thrust has proven to be a viable alternative. NASA Dryden has demonstrated the feasibility of controlling an aircraft during level flight, approach, and landing conditions using an augmented throttles-only control system. This system has been successfully flown in the flight test simulator for the B-720 passenger transport and the F-15 air superiority fighter and in actual flight tests for the F-15 aircraft. The Douglas Aircraft Company is developing a similar system for the MD-11 aircraft. The project's ultimate goal is to provide data for the development of thrust control systems for mega-transports (600+ passengers).

  11. Development of control laws for a flight test maneuver autopilot for an F-15 aircraft (United States)

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


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

  12. A Multiple Agent Model of Human Performance in Automated Air Traffic Control and Flight Management Operations (United States)

    Corker, Kevin; Pisanich, Gregory; Condon, Gregory W. (Technical Monitor)


    A predictive model of human operator performance (flight crew and air traffic control (ATC)) has been developed and applied in order to evaluate the impact of automation developments in flight management and air traffic control. The model is used to predict the performance of a two person flight crew and the ATC operators generating and responding to clearances aided by the Center TRACON Automation System (CTAS). The purpose of the modeling is to support evaluation and design of automated aids for flight management and airspace management and to predict required changes in procedure both air and ground in response to advancing automation in both domains. Additional information is contained in the original extended abstract.

  13. A simple active controller to suppress helicopter air resonance in hover and forward flight (United States)

    Friedmann, P. P.; Takahashi, M. D.


    A coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. This model is used to illustrate the effect of unsteady aerodynamics, forward flight, and torsional flexibility on air resonance. Next, a nominal configuration, which experiences air resonance in forward flight, is selected. A simple multivariable compensator using conventional swashplate inputs and a single body roll rate measurement is then designed. The controller design is based on a linear estimator in conjunction with optimal feedback gains, and the design is done in the frequency domain using the loop-transfer recovery method. The controller is shown to suppress the air resonance instability throughout wide range helicopter loading conditions and forward flight speeds.

  14. The mitochondrial uniporter controls fight or flight heart rate increases. (United States)

    Wu, Yuejin; Rasmussen, Tyler P; Koval, Olha M; Joiner, Mei-Ling A; Hall, Duane D; Chen, Biyi; Luczak, Elizabeth D; Wang, Qiongling; Rokita, Adam G; Wehrens, Xander H T; Song, Long-Sheng; Anderson, Mark E


    Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate.

  15. Control of neural stem cell survival by electroactive polymer substrates.

    Directory of Open Access Journals (Sweden)

    Vanessa Lundin

    Full Text Available Stem cell function is regulated by intrinsic as well as microenvironmental factors, including chemical and mechanical signals. Conducting polymer-based cell culture substrates provide a powerful tool to control both chemical and physical stimuli sensed by stem cells. Here we show that polypyrrole (PPy, a commonly used conducting polymer, can be tailored to modulate survival and maintenance of rat fetal neural stem cells (NSCs. NSCs cultured on PPy substrates containing different counter ions, dodecylbenzenesulfonate (DBS, tosylate (TsO, perchlorate (ClO(4 and chloride (Cl, showed a distinct correlation between PPy counter ion and cell viability. Specifically, NSC viability was high on PPy(DBS but low on PPy containing TsO, ClO(4 and Cl. On PPy(DBS, NSC proliferation and differentiation was comparable to standard NSC culture on tissue culture polystyrene. Electrical reduction of PPy(DBS created a switch for neural stem cell viability, with widespread cell death upon polymer reduction. Coating the PPy(DBS films with a gel layer composed of a basement membrane matrix efficiently prevented loss of cell viability upon polymer reduction. Here we have defined conditions for the biocompatibility of PPy substrates with NSC culture, critical for the development of devices based on conducting polymers interfacing with NSCs.

  16. Combined model- and rule-based controller synthesis with application to helicopter flight (United States)

    Jiang, Tian-Yue

    This thesis deals with synthesis of combined (nonlinear) model-based and (fuzzy logic) rule-based controllers, along with their applications to helicopter flight control problem. The synthesis involves superimposing two control techniques in order to meet both stability and performance objectives. One is model-based control technique, which is based on inversion of an approximate model of the real system. The other is rule-based control technique that adaptively cancels the inversion errors caused by the approximate model inversion. There are two major aspects of the research effort in this thesis. The first is the development of the adaptive rule-based (fuzzy logic) controllers. The linguistic rule weights and defuzzification output weights in the controllers are adapted for ultimate boundedness of the tracking errors. Numerical results from a helicopter flight control problem indicate improvement and demonstrate effectiveness of the control technique. The second aspect of this research work is the extension of the synthesis to account for control limits. In this thesis, a control saturation related rule-bank in conjunction with the adaptive fuzzy logic controller is designed to trade-off system performance for closed-loop stability when the tendency towards control amplitude and/or rate saturation is detected. Simulation results from both a fixed-wing aircraft trajectory control problem and a helicopter flight control problem show the effectiveness of the synthesis method and the resulting controller in avoiding control saturations.

  17. Initial virtual flight test for a dynamically similar aircraft model with control augmentation system

    Directory of Open Access Journals (Sweden)

    Linliang Guo


    Full Text Available To satisfy the validation requirements of flight control law for advanced aircraft, a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel. A 3-degree-of-freedom gimbal, ventrally installed in the model, was used in conjunction with an actively controlled dynamically similar model of aircraft, which was equipped with the inertial measurement unit, attitude and heading reference system, embedded computer and servo-actuators. The model, which could be rotated around its center of gravity freely by the aerodynamic moments, together with the flow field, operator and real time control system made up the closed-loop testing circuit. The model is statically unstable in longitudinal direction, and it can fly stably in wind tunnel with the function of control augmentation of the flight control laws. The experimental results indicate that the model responds well to the operator’s instructions. The response of the model in the tests shows reasonable agreement with the simulation results. The difference of response of angle of attack is less than 0.5°. The effect of stability augmentation and attitude control law was validated in the test, meanwhile the feasibility of virtual flight test technique treated as preliminary evaluation tool for advanced flight vehicle configuration research was also verified.

  18. Flight dynamics and control using folding wingtips: an experimental study


    Mills, Josh; Ajaj, Rafic


    This paper presents an experimental investigation on using FOLDing wingtips sERving as cONtrol effectorS (FOLDERONS) for a mini Unmanned Aerial Vehicle (UAV). A representative off-the-shelf mini-UAV with a conventional configuration was selected. The main theme of this paper is to utilise FOLDERONS as a control effector (mainly in roll) to augment the control authority of conventional control surfaces. Furthermore, the impact of actuation rate on the effectiveness of FOLDERONS is assessed. Th...

  19. International Space Station Mechanisms and Maintenance Flight Control Documentation and Training Development (United States)

    Daugherty, Colin C.


    International Space Station (ISS) crew and flight controller training documentation is used to aid in training operations. The Generic Simulations References SharePoint (Gen Sim) site is a database used as an aid during flight simulations. The Gen Sim site is used to make individual mission segment timelines, data, and flight information easily accessible to instructors. The Waste and Hygiene Compartment (WHC) training schematic includes simple and complex fluid schematics, as well as overall hardware locations. It is used as a teaching aid during WHC lessons for both ISS crew and flight controllers. ISS flight control documentation is used to support all aspects of ISS mission operations. The Quick Look Database and Consolidated Tool Page are imagery-based references used in real-time to help the Operations Support Officer (OSO) find data faster and improve discussions with the Flight Director and Capsule Communicator (CAPCOM). A Quick Look page was created for the Permanent Multipurpose Module (PMM) by locating photos of the module interior, labeling specific hardware, and organizing them in schematic form to match the layout of the PMM interior. A Tool Page was created for the Maintenance Work Area (MWA) by gathering images, detailed drawings, safety information, procedures, certifications, demonstration videos, and general facts of each MWA component and displaying them in an easily accessible and consistent format. Participation in ISS mechanisms and maintenance lessons, mission simulation On-the-Job Training (OJT), and real-time flight OJT was used as an opportunity to train for day-to-day operations as an OSO, as well as learn how to effectively respond to failures and emergencies during mission simulations and real-time flight operations.

  20. The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock

    Directory of Open Access Journals (Sweden)

    Natalie Leys


    Full Text Available Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50% and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES, showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions.

  1. ISS emergency scenarios and a virtual training simulator for Flight Controllers (United States)

    Uhlig, Thomas; Roshani, Frank-Cyrus; Amodio, Ciro; Rovera, Alessandro; Zekusic, Nikola; Helmholz, Hannes; Fairchild, Matthew


    The current emergency response concept for the International Space Station (ISS) includes the support of the Flight Control Team. Therefore, the team members need to be trained in emergencies and the corresponding crew procedures to ensure a smooth collaboration between crew and ground. In the case where the astronaut and ground personnel training is not collocated it is a challenging endeavor to ensure and maintain proper knowledge and skills for the Flight Control Team. Therefore, a virtual 3D simulator at the Columbus Control Center (Col-CC) is presented, which is used for ground personnel training in the on-board emergency response. The paper briefly introduces the main ISS emergency scenarios and the corresponding response strategy, details the resulting learning objectives for the Flight Controllers and elaborates on the new simulation method, which will be used in the future. The status of the 3D simulator, first experiences and further plans are discussed.

  2. Coyote removal, understory cover, and survival of white-tailed deer neonates: Coyote Control and Fawn Survival

    Energy Technology Data Exchange (ETDEWEB)

    Kilgo, John C. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Vukovich, Mark [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ray, H. Scott [USDA Forest Service, Savannah River; New Ellenton, SC (United States); Shaw, Christopher E. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ruth, Charles [South Carolina Dept. of Natural Resources, Columbia, SC (United States)


    Predation by coyotes (Canis latrans) on white-tailed deer (Odocoileus virginianus) neonates has led to reduced recruitment in many deer populations in southeastern North America. This low recruitment combined with liberal antlerless deer harvest has resulted in declines in some deer populations, and consequently, increased interest in coyote population control. We investigated whether neonate survival increased after coyote removal, whether coyote predation on neonates was additive to other mortality sources, and whether understory vegetation density affected neonate survival. We monitored neonate survival for 4 years prior to (2006–2009) and 3 years during (2010–2012) intensive coyote removal on 3 32-km2 units on the United States Department of Energy’s Savannah River Site, South Carolina. We removed 474 coyotes (1.63 coyotes/km2 per unit per year), reducing coyote abundance by 78% from pre-removal levels. The best model (wi = 0.927) describing survival probability among 216 radio-collared neonates included a within-year quadratic time trend variable, date of birth, removal treatment, and a varying removal year effect. Under this model, survival differed between pre-treatment and removal periods and it differed among years during the removal period, being >100% greater than pre-treatment survival (0.228) during the first removal year (0.513), similar to pre-treatment survival during the second removal year (0.202), and intermediate during the third removal year (0.431). Despite an initial increase, the overall effect of coyote removal on neonate survival was modest. Mortality rate attributable to coyote predation was lowest during the first removal year (0.357) when survival was greatest, but the mortality rate from all other causes did not differ between the pretreatment period and any year during removals, indicating that coyote predation acted as an additive source of mortality. Survival probability was not related to

  3. Mechanics of Flapping Flight: Analytical Formulations of Unsteady Aerodynamics, Kinematic Optimization, Flight Dynamics, and Control (United States)

    Taneja, Jayant Kumar

    Electricity is an indispensable commodity to modern society, yet it is delivered via a grid architecture that remains largely unchanged over the past century. A host of factors are conspiring to topple this dated yet venerated design: developments in renewable electricity generation technology, policies to reduce greenhouse gas emissions, and advances in information technology for managing energy systems. Modern electric grids are emerging as complex distributed systems in which a portfolio of power generation resources, often incorporating fluctuating renewable resources such as wind and solar, must be managed dynamically to meet uncontrolled, time-varying demand. Uncertainty in both supply and demand makes control of modern electric grids fundamentally more challenging, and growing portfolios of renewables exacerbate the challenge. We study three electricity grids: the state of California, the province of Ontario, and the country of Germany. To understand the effects of increasing renewables, we develop a methodology to scale renewables penetration. Analyzing these grids yields key insights about rigid limits to renewables penetration and their implications in meeting long-term emissions targets. We argue that to achieve deep penetration of renewables, the operational model of the grid must be inverted, changing the paradigm from load-following supplies to supply-following loads. To alleviate the challenge of supply-demand matching on deeply renewable grids, we first examine well-known techniques, including altering management of existing supply resources, employing utility-scale energy storage, targeting energy efficiency improvements, and exercising basic demand-side management. Then, we create several instantiations of supply-following loads -- including refrigerators, heating and cooling systems, and laptop computers -- by employing a combination of sensor networks, advanced control techniques, and enhanced energy storage. We examine the capacity of each load

  4. Pre- and post-flight-test models versus measured skyship-500 control responses (United States)

    Jex, Henry R.; Magdaleno, Raymond E.; Gelhausen, Paul; Tischler, Mark B.


    The dynamical equations-of-motion (EOM) for cruising airships require nonconventional terms to account for buoyancy and apparent-mass-effects, but systematic validation of these equations against flight data is not available. Using a candidate set of EOM, three comparisons are made with carefully-measured describing functions derived from frequency-sweep flight tests on the Skyship-500 airship. The first compares the pre-flight predictions to the data; the second compares the 'best-fit' equations to data at each of two airspeeds and the third compared the ability to extrapolate from one condition to another via airship-specific scaling laws. Two transient responses are also compared. The generally good results demonstrate that fairly simple, perturbation equation models are adequate for many types of flight-control analysis and flying quality evaluations of cruising airships.

  5. The method to increase an adequacy and exactitude of the tracking of controlled airplane flight

    Directory of Open Access Journals (Sweden)

    В. М. Васильєв


    Full Text Available The method to increase the adequacy and exactitude of trajectory estimates for tracking of controlled flight is proposed. The method of a solution of a non-linearity problem is also offered when imitate in trajectory estimation algorithm a control signal which includes nonlinear functions of restriction. The results of computer simulation are demonstrated

  6. On the synthesis of sliding mode controller for the autopilot design of free flight system (United States)

    Devika K., B.; Thomas, Susy


    Today's rapid growth in air transportation demand leads to the problem of congestion in air traffic routes. In recent years, free flight concept is widely discussed as the solution to this problem. Free flight is a decentralized method of air traffic management, in which each aircraft has the freedom to self optimize its own route. Conflict detection and its subsequent resolution are the major challenges in the realization of this concept. Today's modern navigation and surveillance equipment can ensure accurate conflict predictions. Once a conflict is detected, it should be avoided through suitable conflict avoidance maneuvers. An autopilot capable of initiating these conflict free maneuvers should be a necessary part of any aircraft in free flight to ensure conflict avoided flight. Controller design based on Sliding Mode Control (SMC) strategy is presented in this paper for the purpose of free flight autopilot implementation. Since SMC has the inherent property of robustness in sliding mode, it can ensure a highly efficient autopilot design. Conventional and reaching law approaches of SMC design are considered here for controller design. Conventional SMC technique usually exhibits an unacceptable phenomenon, viz., chattering. Reaching law approaches for SMC design are being investigated here so as to identify an appropriate strategy that can ensure near chattering free operation. Considering typical free flight conflict avoidance modes of operation, the performance of all the considered SMC strategies are compared through simulation studies. The comparison is based on their ability to reduce chattering and the effectiveness in ensuring quick conflict resolution maneuvers, so that an efficient controller for free flight autopilot system can be recommended.

  7. An integrated user-oriented laboratory for verification of digital flight control systems: Features and capabilities (United States)

    Defeo, P.; Doane, D.; Saito, J.


    A Digital Flight Control Systems Verification Laboratory (DFCSVL) has been established at NASA Ames Research Center. This report describes the major elements of the laboratory, the research activities that can be supported in the area of verification and validation of digital flight control systems (DFCS), and the operating scenarios within which these activities can be carried out. The DFCSVL consists of a palletized dual-dual flight-control system linked to a dedicated PDP-11/60 processor. Major software support programs are hosted in a remotely located UNIVAC 1100 accessible from the PDP-11/60 through a modem link. Important features of the DFCSVL include extensive hardware and software fault insertion capabilities, a real-time closed loop environment to exercise the DFCS, an integrated set of software verification tools, and a user-oriented interface to all the resources and capabilities.

  8. A unique integrated flight testing facility for advanced control/display research (United States)

    Batson, V. M.; Hatfield, J. J.; Novack, N. E.


    NASA is engaged in programs aimed at developing avionic concepts and systems technology for air transportation systems of the 1980's and beyond. A part of these programs is related to the development of advanced concepts and avionics technology for integrated displays and controls. In support of these efforts an interactive Flight Display Research System (FDRS) has been developed as an integral part of integrated flight test facilities which have been used in evaluation studies of integrated display and control concepts in support of a VTOL Approach and Landing Technology (VALT) program and current Terminal Configured Vehicle (TCV) program. A description is provided of several of the advanced integrated display and control concepts that have evolved within the VALT, TCV, and general aviation programs, as well as the integrated flight test facilities.

  9. NASA Marshall Space Flight Center Controls Systems Design and Analysis Branch (United States)

    Gilligan, Eric


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

  10. Optimization Based Clearance of Flight Control Laws A Civil Aircraft Application

    CERN Document Server

    Hansson, Anders; Puyou, Guilhem


    This book summarizes the main achievements of the EC funded 6th Framework Program project COFCLUO – Clearance of Flight Control Laws Using Optimization. This project successfully contributed to the achievement of a top-level objective to meet society’s needs for a more efficient, safer and environmentally friendly air transport by providing new techniques and tools for the clearance of flight control laws. This is an important part of the certification and qualification process of an aircraft – a costly and time-consuming process for the aeronautical industry.   The overall objective of the COFCLUO project was to develop and apply optimization techniques to the clearance of flight control laws in order to improve efficiency and reliability. In the book, the new techniques are explained and benchmarked against traditional techniques currently used by the industry. The new techniques build on mathematical criteria derived from the certification and qualification requirements together with suitable models...

  11. Simpler ISS Flight Control Communications and Log Keeping via Social Tools and Techniques (United States)

    Scott, David W.; Cowart, Hugh; Stevens, Dan


    The heart of flight operations control involves a) communicating effectively in real time with other controllers in the room and/or in remote locations and b) tracking significant events, decisions, and rationale to support the next set of decisions, provide a thorough shift handover, and troubleshoot/improve operations. International Space Station (ISS) flight controllers speak with each other via multiple voice circuits or loops, each with a particular purpose and constituency. Controllers monitor and/or respond to several loops concurrently. The primary tracking tools are console logs, typically kept by a single operator and not visible to others in real-time. Information from telemetry, commanding, and planning systems also plays into decision-making. Email is very secondary/tertiary due to timing and archival considerations. Voice communications and log entries supporting ISS operations have increased by orders of magnitude because the number of control centers, flight crew, and payload operations have grown. This paper explores three developmental ground system concepts under development at Johnson Space Center s (JSC) Mission Control Center Houston (MCC-H) and Marshall Space Flight Center s (MSFC) Payload Operations Integration Center (POIC). These concepts could reduce ISS control center voice traffic and console logging yet increase the efficiency and effectiveness of both. The goal of this paper is to kindle further discussion, exploration, and tool development.

  12. Integrated modeling and robust control for full-envelope flight of robotic helicopters (United States)

    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

  13. Air Traffic Control: Weak Computer Security Practices Jeopardize Flight Safety (United States)


    Given the paramount importance of computer security of Air Traffic Control (ATC) systems, Congress asked the General Accounting Office to determine (1) whether the Fedcral Aviation Administration (FAA) is effectively managing physical security at ATC...

  14. Tilt-rotor flutter control in cruise flight (United States)

    Nasu, Ken-Ichi


    Tilt-rotor flutter control under cruising operation is analyzed. The rotor model consists of a straight fixed wing, a pylon attached to the wingtip, and a three-blade rotor. The wing is cantilevered to the fuselage and is allowed to bend forward and upward. It also has a torsional degree of freedom about the elastic axis. Each rotor blade has two bending degrees of freedom. Feedback of wingtip velocity and acceleration to cyclic pitch is investigated for flutter control, using strip theory and linearized equations of motion. To determine the feedback gain, an eigenvalue analysis is performed. A second, independent, timewise calculation is conducted to evaluate the control law while employing more sophisticated aerodynamics. The effectiveness of flutter control by cyclic pitch change was confirmed.

  15. Neural control and precision of flight muscle activation in Drosophila


    Lehmann, Fritz-Olaf; Bartussek, Jan


    Precision of motor commands is highly relevant in a large context of various locomotor behaviors, including stabilization of body posture, heading control and directed escape responses. While posture stability and heading control in walking and swimming animals benefit from high friction via ground reaction forces and elevated viscosity of water, respectively, flying animals have to cope with comparatively little aerodynamic friction on body and wings. Although low frictional damping in fligh...

  16. Heavy Lift Helicopter Flight Control System. Volume 1. Production Recommendations (United States)


    2 5 BITE 34 Panels 37 Load Monitor - Swashplate Servo Actuator 37 Fault Isolation 39 Characteristics 40 DELS Equipment 47 COCKPIT CONTROL...Single Channel) 16 5 Simplified Block Diagram of DELS 1’^ 6 DELS Equipment Diagram -’-^ 7 DELS Signal Flow 21 8 Swashplate Servoactuator...Interface Diagram 16 DELS Kinematics ^-^ n DELS Control Unit Front Face 48 18 Stall Damper Unit ^^ 19 Swashplate Servoactuator Manifold

  17. Integration of Predictive Display and Aircraft Flight Control System

    Directory of Open Access Journals (Sweden)

    Efremov A.V.


    Full Text Available The synthesis of predictive display information and direct lift control system are considered for the path control tracking tasks (in particular landing task. The both solutions are based on pilot-vehicle system analysis and requirements to provide the highest accuracy and lowest pilot workload. The investigation was carried out for cases with and without time delay in aircraft dynamics. The efficiency of the both ways for the flying qualities improvement and their integration is tested by ground based simulation.

  18. Flight operations control center lessons learned for the delta clipper experimental rocket (United States)

    Voglewede, Steven D.; Brown, Kevin R.


    This paper summarizes the lessons learned from the operations of the Flight Operations Control Center (FOCC) for the NASA Delta Clipper Experimental (DC-X) single-stage rocket. Also, observations and suggested future enhancements are described for the FOCC Real-Time Data System (RTDS), its components, ground support equipment interfaces, and the FOCC itself. The objective of the FOCC was to streamline flight control operations to more closely resemble the flight deck of a commercial airliner. For the advanced configuration of DC-X and the DC-XA, the FOCC was modified into a physically isolated ground "cockpit" occupied by the flight manager and deputy flight manager, who serve as the ground-based pilot and copilot for the experimental single-stage rocket. The third member of the flight crew, the ground systems manager, operates the vehicle fueling and high-pressure gas loading systems from a separate ground support station on the request of the flight manager. This arrangement was a direct result of lessons learned from the earlier DC-X program. The Real-Time Data System (RTDS), which includes three-dimensional monitoring, color-coded graphical displays and various cockpit controls is highlighted. Lessons learned from the DC-X ground-based application software use, FOCC development, and ground support equipment operations are also discussed. The original Delta Clipper (DC-X) program, completed in July 1995, demonstrated that the cost of traditional rocket launch operations could be substantially reduced through rapid prototyping development, ground automation, and vehicle built-in health monitoring. The new DC-XA FOCC design emphasizes reduced operating costs to meet the overall program goal of providing low-cost affordable access to space in the future.

  19. Preliminary Design and Analysis of the ARES Atmospheric Flight Vehicle Thermal Control System (United States)

    Gasbarre, J. F.; Dillman, R. A.


    The Aerial Regional-scale Environmental Survey (ARES) is a proposed 2007 Mars Scout Mission that will be the first mission to deploy an atmospheric flight vehicle (AFV) on another planet. This paper will describe the preliminary design and analysis of the AFV thermal control system for its flight through the Martian atmosphere and also present other analyses broadening the scope of that design to include other phases of the ARES mission. Initial analyses are discussed and results of trade studies are presented which detail the design process for AFV thermal control. Finally, results of the most recent AFV thermal analysis are shown and the plans for future work are discussed.

  20. Analysis of Control Strategies for Aircraft Flight Upset Recovery (United States)

    Crespo, Luis G.; Kenny, Sean P.; Cox, David E.; Muri, Daniel G.


    This paper proposes a framework for studying the ability of a control strategy, consisting of a control law and a command law, to recover an aircraft from ight conditions that may extend beyond the normal ight envelope. This study was carried out (i) by evaluating time responses of particular ight upsets, (ii) by evaluating local stability over an equilibrium manifold that included stall, and (iii) by bounding the set in the state space from where the vehicle can be safely own to wings-level ight. These states comprise what will be called the safely recoverable ight envelope (SRFE), which is a set containing the aircraft states from where a control strategy can safely stabilize the aircraft. By safe recovery it is implied that the tran- sient response stays between prescribed limits before converging to a steady horizontal ight. The calculation of the SRFE bounds yields the worst-case initial state corresponding to each control strategy. This information is used to compare alternative recovery strategies, determine their strengths and limitations, and identify the most e ective strategy. In regard to the control law, the authors developed feedback feedforward laws based on the gain scheduling of multivariable controllers. In regard to the command law, which is the mechanism governing the exogenous signals driving the feed- forward component of the controller, we developed laws with a feedback structure that combines local stability and transient response considera- tions. The upset recovery of the Generic Transport Model, a sub-scale twin-engine jet vehicle developed by NASA Langley Research Center, is used as a case study.

  1. Control and flight test of a tilt-rotor unmanned aerial vehicle

    Directory of Open Access Journals (Sweden)

    Chao Chen


    Full Text Available Tilt-rotor unmanned aerial vehicles have attracted increasing attention due to their ability to perform vertical take-off and landing and their high-speed cruising abilities, thereby presenting broad application prospects. Considering portability and applications in tasks characterized by constrained or small scope areas, this article presents a compact tricopter configuration tilt-rotor unmanned aerial vehicle with full modes of flight from the rotor mode to the fixed-wing mode and vice versa. The unique multiple modes make the tilt-rotor unmanned aerial vehicle a multi-input multi-output, non-affine, multi-channel cross coupling, and nonlinear system. Considering these characteristics, a control allocation method is designed to make the controller adaptive to the full modes of flight. To reduce the cost, the accurate dynamic model of the tilt-rotor unmanned aerial vehicle is not obtained, so a full-mode flight strategy is designed in view of this situation. An autonomous flight test was conducted, and the results indicate the satisfactory performance of the control allocation method and flight strategy.

  2. Robust Predictive Functional Control for Flight Vehicles Based on Nonlinear Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Yinhui Zhang


    Full Text Available A novel robust predictive functional control based on nonlinear disturbance observer is investigated in order to address the control system design for flight vehicles with significant uncertainties, external disturbances, and measurement noise. Firstly, the nonlinear longitudinal dynamics of the flight vehicle are transformed into linear-like state-space equations with state-dependent coefficient matrices. And then the lumped disturbances are considered in the linear structure predictive model of the predictive functional control to increase the precision of the predictive output and resolve the intractable mismatched disturbance problem. As the lumped disturbances cannot be derived or measured directly, the nonlinear disturbance observer is applied to estimate the lumped disturbances, which are then introduced to the predictive functional control to replace the unknown actual lumped disturbances. Consequently, the robust predictive functional control for the flight vehicle is proposed. Compared with the existing designs, the effectiveness and robustness of the proposed flight control are illustrated and validated in various simulation conditions.

  3. Western Aeronautical Test Range (WATR) Mission Control Gold Room During X-29 Flight (United States)


    The mission control Gold room is seen here during a research flight of the X-29 at the Dryden Flight Research Center, Edwards, California. All aspects of a research mission are monitored from one of two of these control rooms at Dryden. Dryden and its control rooms are part of the Western Aeronautical Test Range (WATR). The WATR consists of a highly automated complex of computer controlled tracking, telemetry, and communications systems and control room complexes that are capable of supporting any type of mission ranging from system and component testing, to sub-scale and full-scale flight tests of new aircraft and reentry systems. Designated areas are assigned for spin/dive tests; corridors are provided for low, medium, and high-altitude supersonic flight; and special STOL/VSTOL facilities are available at Ames Moffett and Crows Landing. Special use airspace, available at Edwards, covers approximately twelve thousand square miles of mostly desert area. The southern boundary lies to the south of Rogers Dry Lake, the western boundary lies midway between Mojave and Bakersfield, the northern boundary passes just south of Bishop, and the eastern boundary follows about 25 miles west of the Nevada border except in the northern areas where it crosses into Nevada. Two X-29 aircraft, featuring one of the most unusual designs in aviation history, flew at the Ames-Dryden Flight Research Facility (now the Dryden Flight Research Center, Edwards, California) from 1984 to 1992. The fighter-sized X-29 technology demonstrators explored several concepts and technologies including: the use of advanced composites in aircraft construction; variable-camber wing surfaces; a unique forward- swept wing and its thin supercritical airfoil; strakes; close-coupled canards; and a computerized fly-by-wire flight control system used to maintain control of the otherwise unstable aircraft. Research results showed that the configuration of forward-swept wings, coupled with movable canards, gave

  4. Mentoring SFRM: A New Approach to International Space Station Flight Controller Training (United States)

    Huning, Therese; Barshi, Immanuel; Schmidt, Lacey


    The Mission Operations Directorate (MOD) of the Johnson Space Center is responsible for providing continuous operations support for the International Space Station (ISS). Operations support requires flight controllers who are skilled in team performance as well as the technical operations of the ISS. Space Flight Resource Management (SFRM), a NASA adapted variant of Crew Resource Management (CRM), is the competency model used in the MOD. ISS flight controller certification has evolved to include a balanced focus on development of SFRM and technical expertise. The latest challenge the MOD faces is how to certify an ISS flight controller (operator) to a basic level of effectiveness in 1 year. SFRM training uses a two-pronged approach to expediting operator certification: 1) imbed SFRM skills training into all operator technical training and 2) use senior flight controllers as mentors. This paper focuses on how the MOD uses senior flight controllers as mentors to train SFRM skills. Methods: A mentor works with an operator throughout the training flow. Inserted into the training flow are guided-discussion sessions and on-the-job observation opportunities focusing on specific SFRM skills, including: situational leadership, conflict management, stress management, cross-cultural awareness, self care and team care while on-console, communication, workload management, and situation awareness. The mentor and operator discuss the science and art behind the skills, cultural effects on skills applications, recognition of good and bad skills applications, recognition of how skills application changes subtly in different situations, and individual goals and techniques for improving skills. Discussion: This mentoring program provides an additional means of transferring SFRM knowledge compared to traditional CRM training programs. Our future endeavors in training SFRM skills (as well as other organization s) may benefit from adding team performance skills mentoring. This paper

  5. Case Study: Test Results of a Tool and Method for In-Flight, Adaptive Control System Verification on a NASA F-15 Flight Research Aircraft (United States)

    Jacklin, Stephen A.; Schumann, Johann; Guenther, Kurt; Bosworth, John


    Adaptive control technologies that incorporate learning algorithms have been proposed to enable autonomous flight control and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments [1-2]. At the present time, however, it is unknown how adaptive algorithms can be routinely verified, validated, and certified for use in safety-critical applications. Rigorous methods for adaptive software verification end validation must be developed to ensure that. the control software functions as required and is highly safe and reliable. A large gap appears to exist between the point at which control system designers feel the verification process is complete, and when FAA certification officials agree it is complete. Certification of adaptive flight control software verification is complicated by the use of learning algorithms (e.g., neural networks) and degrees of system non-determinism. Of course, analytical efforts must be made in the verification process to place guarantees on learning algorithm stability, rate of convergence, and convergence accuracy. However, to satisfy FAA certification requirements, it must be demonstrated that the adaptive flight control system is also able to fail and still allow the aircraft to be flown safely or to land, while at the same time providing a means of crew notification of the (impending) failure. It was for this purpose that the NASA Ames Confidence Tool was developed [3]. This paper presents the Confidence Tool as a means of providing in-flight software assurance monitoring of an adaptive flight control system. The paper will present the data obtained from flight testing the tool on a specially modified F-15 aircraft designed to simulate loss of flight control faces.

  6. Investigation of Practical Flight Control Systems for Small Aircraft

    NARCIS (Netherlands)

    Falkena, W.


    Personal air transportation utilizing small aircraft is a market that is expected to grow significantly in the near future. However, seventy times more accidents occur in this segment as compared with the commercial aviation sector. The majority of these accidents is related to handling and control

  7. Application of an integrated flight/propulsion control design methodology to a STOVL aircraft (United States)

    Garg, Sanjay; Mattern, Duane L.


    The application of an emerging Integrated Flight/Propulsion Control design methodology to a STOVL aircraft in transition flight is reported. The methodology steps consist of: (1) design of a centralized feedback controller to provide command tracking and stability and performance robustness considering the fully integrated airframe/propulsion model as one high-order system; (2) partition of the centralized controller into a decentralized, hierarchical form compatible with implementation requirements; and (3) design of command shaping prefilters from pilot control effectors to commanded variables to provide the overall desired response to pilot inputs. Intermediate design results using this methodology are presented, the complete point control design with the propulsion system operating schedule and limit protection logic included is evaluated for sample pilot control inputs, and the response is compared with that of an 'ideal response model' derived from Level I handling qualities requirements.

  8. A review of supersonic cruise flight path control experience with the YF-12 aircraft (United States)

    Berry, D. T.; Gilyard, G. B.


    Flight research with the YF-12 aircraft indicates that solutions to many handling qualities problems of supersonic cruise are at hand. Airframe/propulsion system interactions in the Dutch roll mode can be alleviated by the use of passive filters or additional feedback loops in the propulsion and flight control systems. Mach and altitude excursions due to atmospheric temperature fluctuations can be minimized by the use of a cruise autothrottle. Autopilot instabilities in the altitude hold mode have been traced to angle of attack-sensitive static ports on the compensated nose boom. For the YF-12, the feedback of high-passed pitch rate to the autopilot resolves this problem. Manual flight path control is significantly improved by the use of an inertial rate of climb display in the cockpit.

  9. Development of Analysis Tools for Certification of Flight Control Laws (United States)


    In Proc. Conf. on Decision and Control, pages 881-886, Bahamas, 2004. [7] G. Chesi, A. Garulli, A. Tesi , and A. Vicino. LMI-based computation of...Minneapolis, MN, 2006, pp. 117-122. [10] G. Chesi, A. Garulli, A. Tesi . and A. Vicino, "LMI-based computation of optimal quadratic Lyapunov functions...Convex Optimization. Cambridge Univ. Press. Chesi, G., A. Garulli, A. Tesi and A. Vicino (2005). LMI-based computation of optimal quadratic Lyapunov

  10. Singular perturbations and time scales in the design of digital flight control systems (United States)

    Naidu, Desineni S.; Price, Douglas B.


    The results are presented of application of the methodology of Singular Perturbations and Time Scales (SPATS) to the control of digital flight systems. A block diagonalization method is described to decouple a full order, two time (slow and fast) scale, discrete control system into reduced order slow and fast subsystems. Basic properties and numerical aspects of the method are discussed. A composite, closed-loop, suboptimal control system is constructed as the sum of the slow and fast optimal feedback controls. The application of this technique to an aircraft model shows close agreement between the exact solutions and the decoupled (or composite) solutions. The main advantage of the method is the considerable reduction in the overall computational requirements for the evaluation of optimal guidance and control laws. The significance of the results is that it can be used for real time, onboard simulation. A brief survey is also presented of digital flight systems.

  11. Using Automatic Code Generation in the Attitude Control Flight Software Engineering Process (United States)

    McComas, David; O'Donnell, James R., Jr.; Andrews, Stephen F.


    This paper presents an overview of the attitude control subsystem flight software development process, identifies how the process has changed due to automatic code generation, analyzes each software development phase in detail, and concludes with a summary of our lessons learned.

  12. Cost and benefits design optimization model for fault tolerant flight control systems (United States)

    Rose, J.


    Requirements and specifications for a method of optimizing the design of fault-tolerant flight control systems are provided. Algorithms that could be used for developing new and modifying existing computer programs are also provided, with recommendations for follow-on work.

  13. SILEX ground segment control facilities and flight operations (United States)

    Demelenne, Benoit; Tolker-Nielsen, Toni; Guillen, Jean-Claude


    The European Space Agency is going to conduct an inter orbit link experiment which will connect a low Earth orbiting satellite and a Geostationary satellite via optical terminals. This experiment has been called SILEX (Semiconductor Inter satellite Link Experiment). Two payloads have been built. One called PASTEL (PASsager de TELecommunication) has been embarked on the French Earth observation satellite SPOT4 which has been launched successfully in March 1998. The future European experimental data relay satellite ARTEMIS (Advanced Relay and TEchnology MISsion), which will route the data to ground, will carry the OPALE terminal (Optical Payload Experiment). The European Space Agency is responsible for the operation of both terminals. Due to the complexity and experimental character of this new optical technology, the development, preparation and validation of the ground segment control facilities required a long series of technical and operational qualification tests. This paper is presenting the operations concept and the early results of the PASTEL in orbit operations.

  14. Self-Guided Multimedia Stress Management and Resilience Training for Flight Controllers (United States)

    Rose, R. D.; Zbozinek, T. D.; Hentschel, P. G.; Smith, S, M.; O'Brien J.; Oftedal, A.; Craske, M. G.


    Stress and anxiety-related problems are among the most common and costly behavioral health problems in society, and for those working in operational environments (i.e. astronauts, flight controllers, military) this can seriously impact crew performance, safety, and wellbeing. Technology-based interventions are effective for treating behavioral health problems, and can significantly improve the delivery of evidence-based health care. This study is evaluating the effectiveness, usefulness, and usability of a self-guided multimedia stress management and resilience training program in a randomized controlled trial (RCT) with a sample of flight controllers at Johnson Space Center. The intervention, SMART-OP (Stress Management and Resilience Training for Optimal Performance), is a six-session, cognitive behavioral-based computer program that uses self-guided, interactive activities to teach skills that can help individuals build resilience and manage stress. In a prior RCT with a sample of stressed but otherwise healthy individuals, SMART-OP reduced perceived stress and increased perceived control over stress in comparison to an Attention Control (AC) group. SMART-OP was rated as "highly useful" and "excellent" in usability and acceptability. Based on a-amylase data, individuals in SMART-OP recovered quicker and more completely from a social stress test as compared to the AC group [1]. In the current study, flight controllers are randomized either to receive SMART-OP training, or to a 6-week waitlist control period (WLC) before beginning SMART-OP. Eligible participants include JSC flight controllers and instructors without any medical or psychiatric disorder, but who are stressed based on self-report. Flight controllers provide a valid analog sample to astronauts in that they work in an operational setting, use similar terminology to astronauts, are mission-focused, and work under the same broader work culture. The study began in December 2014, and to date 79 flight

  15. Development of helicopter attitude axes controlled hover flight without pilot assistance and vehicle crashes (United States)

    Simon, Miguel

    In this work, we show how to computerize a helicopter to fly attitude axes controlled hover flight without the assistance of a pilot and without ever crashing. We start by developing a helicopter research test bed system including all hardware, software, and means for testing and training the helicopter to fly by computer. We select a Remote Controlled helicopter with a 5 ft. diameter rotor and 2.2 hp engine. We equip the helicopter with a payload of sensors, computers, navigation and telemetry equipment, and batteries. We develop a differential GPS system with cm accuracy and a ground computerized navigation system for six degrees of freedom (6-DoF) free flight while tracking navigation commands. We design feedback control loops with yet-to-be-determined gains for the five control "knobs" available to a flying radio-controlled (RC) miniature helicopter: engine throttle, main rotor collective pitch, longitudinal cyclic pitch, lateral cyclic pitch, and tail rotor collective pitch. We develop helicopter flight equations using fundamental dynamics, helicopter momentum theory and blade element theory. The helicopter flight equations include helicopter rotor equations of motions, helicopter rotor forces and moments, helicopter trim equations, helicopter stability derivatives, and a coupled fuselage-rotor helicopter 6-DoF model. The helicopter simulation also includes helicopter engine control equations, a helicopter aerodynamic model, and finally helicopter stability and control equations. The derivation of a set of non-linear equations of motion for the main rotor is a contribution of this thesis work. We design and build two special test stands for training and testing the helicopter to fly attitude axes controlled hover flight, starting with one axis at a time and progressing to multiple axes. The first test stand is built for teaching and testing controlled flight of elevation and yaw (i.e., directional control). The second test stand is built for teaching and

  16. A nonlinear trajectory command generator for a digital flight-control system (United States)

    Cicolani, L. S.; Weissenberger, S.


    Operational application of the command generator (CG) was examined in detail in a simulation of a flight control system with the augmentor wing jet STOL research aircraft. The basic repertoire of single axis maneuvers and operational constraints are discussed, and the system behavior is tested on a rigorous STOL approach path and as affected by various approximations in the CG synthesis and types of disturbances found in the operational environment. The simulation results indicate that a satisfactory nonlinear system with general maneuvering capabilities throughout the flight envelope was developed which satisfies the basic design objectives while maintaining a practicable degree of simplicity.

  17. Stability Assessment and Tuning of an Adaptively Augmented Classical Controller for Launch Vehicle Flight Control (United States)

    VanZwieten, Tannen; Zhu, J. Jim; Adami, Tony; Berry, Kyle; Grammar, Alex; Orr, Jeb S.; Best, Eric A.


    Recently, a robust and practical adaptive control scheme for launch vehicles [ [1] has been introduced. It augments a classical controller with a real-time loop-gain adaptation, and it is therefore called Adaptive Augmentation Control (AAC). The loop-gain will be increased from the nominal design when the tracking error between the (filtered) output and the (filtered) command trajectory is large; whereas it will be decreased when excitation of flex or sloshing modes are detected. There is a need to determine the range and rate of the loop-gain adaptation in order to retain (exponential) stability, which is critical in vehicle operation, and to develop some theoretically based heuristic tuning methods for the adaptive law gain parameters. The classical launch vehicle flight controller design technics are based on gain-scheduling, whereby the launch vehicle dynamics model is linearized at selected operating points along the nominal tracking command trajectory, and Linear Time-Invariant (LTI) controller design techniques are employed to ensure asymptotic stability of the tracking error dynamics, typically by meeting some prescribed Gain Margin (GM) and Phase Margin (PM) specifications. The controller gains at the design points are then scheduled, tuned and sometimes interpolated to achieve good performance and stability robustness under external disturbances (e.g. winds) and structural perturbations (e.g. vehicle modeling errors). While the GM does give a bound for loop-gain variation without losing stability, it is for constant dispersions of the loop-gain because the GM is based on frequency-domain analysis, which is applicable only for LTI systems. The real-time adaptive loop-gain variation of the AAC effectively renders the closed-loop system a time-varying system, for which it is well-known that the LTI system stability criterion is neither necessary nor sufficient when applying to a Linear Time-Varying (LTV) system in a frozen-time fashion. Therefore, a

  18. Pointing Control System for a High Precision Flight Telescope

    Energy Technology Data Exchange (ETDEWEB)



    A pointing control system is developed and tested for a flying gimbaled telescope. The two-axis pointing system is capable of sub-microradian pointing stability and high accuracy in the presence of large host vehicle jitter. The telescope also has high agility--it is capable of a 50-degree retarget (in both axes simultaneously) in less than 2 seconds. To achieve the design specifications, high-accuracy, high-resolution, two-speed resolvers were used, resulting in gimbal-angle measurements stable to 1.5 microradians. In addition, on-axis inertial angle displacement sensors were mounted on the telescope to provide host-vehicle jitter cancellation. The inertial angle sensors are accurate to about 100 nanoradians, but do not measure low frequency displacements below 2 Hz. The gimbal command signal includes host-vehicle attitude information, which is band-limited. This provides jitter data below 20 Hz, but includes a variable latency between 15 and 25 milliseconds. One of the most challenging aspects of this design was to combine the inertial-angle-sensor data with the less perfect information in the command signal to achieve maximum jitter reduction. The optimum blending of these two signals, along with the feedback compensation were designed using Quantitative Feedback Theory.

  19. Sleep patterns among shift-working flight controllers of the International Space Station: an observational study on the JAXA Flight Control Team. (United States)

    Mizuno, Koh; Matsumoto, Akiko; Aiba, Tatsuya; Abe, Takashi; Ohshima, Hiroshi; Takahashi, Masaya; Inoue, Yuichi


    Flight controllers of the International Space Station (ISS) are engaged in shift work to provide 24-h coverage to support ISS systems. The purpose of this study was to investigate the prevalence and associated factors of shift work sleep disorder (SWSD) among Japanese ISS flight controllers. A questionnaire study was conducted using the Standard Shiftwork Index to evaluate sleep-related problems and possible associated variables. Among 52 respondents out of 73 flight controllers, 30 subjects were identified as night shift workers who worked 3 or more night shifts per month. Those night shift workers who answered "almost always" to questions about experiencing insomnia or excessive sleepiness in any case of work shifts and days off were classified as having SWSD. Additionally, 7 night shift workers participated in supplemental wrist actigraphy data collection for 7 to 8 days including 3 to 4 days of consecutive night shifts. Fourteen of 30 night shift workers were classified as having SWSD. Significant group differences were observed where the SWSD group felt that night shift work was harder and reported more frequent insomniac symptoms after a night shift. However, no other variables demonstrated remarkable differences between groups. Actigraphy results characterized 5 subjects reporting better perceived adaptation as having regular daytime sleep, for 6 to 9 h in total, between consecutive night shifts. On the other hand, 2 subjects reporting perceived maladaptation revealed different sleep patterns, with longer daytime sleep and large day-to-day variation in daytime sleep between consecutive night shifts, respectively. As the tasks for flight control require high levels of alertness and cognitive function, several characteristics, namely shift-working schedule (2 to 4 consecutive night shifts), very short break time (5 to 10 min/h) during work shifts, and cooperative work with onboard astronauts during the evening/night shift, accounted for increasing

  20. Sliding Mode Observer and Control Design with Adaptive Parameter Estimation for a Supersonic Flight Vehicle

    Directory of Open Access Journals (Sweden)

    M. Bahrami


    Full Text Available Design and synthesis of a nonlinear generic supersonic flight vehicle longitudinal dynamics control for angle-of-attack, AOA, output tracking in the atmospheric flight is presented based on sliding mode control. A sliding mode observer is invoked to estimate AOA which is difficult to measure in practice. Large parameter uncertainties accommodation envisaged by designing adaptive mechanisms for both the control and observer and high chattering authority due to large deviations of aerodynamic coefficients arising from wind-tunnel measurements are inhibited. The employed method enables the sliding mode control design to exhibit the desired dynamic properties during the entire output-tracking process. Simulations results are presented to demonstrate the performance, robustness, and stability.

  1. Automatic Flight Control System Design of Level Change Mode for a Large Aircraft

    Directory of Open Access Journals (Sweden)

    Huajun Gong


    Full Text Available The level change mode is an essential part of large civil aircraft automatic flight control systems. In cruise, with the decrease of the plane's weight caused by fuel consumption and the influence of bad weather, such as thunderstorms, the level change mode is required to solve this problem. This work establishes a nonlinear model of large aircraft, takes level changed from 9500m to 10100m as an example to design control laws for the level change mode in cruise. The classical engineering method is used to design longitudinal and lateral control laws synthetically. The flight qualities are considered in the design process. Simulation results indicate the control laws can meet design requirements and have a good anti-gust performance.

  2. Development and flight test results of an autothrottle control system at Mach 3 cruise (United States)

    Gilyard, G. B.; Burken, J. J.


    Flight test results obtained with the original Mach hold autopilot designed the YF-12C airplane which uses elevator control and a newly developed Mach hold system having an autothrottle integrated with an altitude hold autopilot system are presented. The autothrottle tests demonstrate good speed control at high Mach numbers and high altitudes while simultaneously maintaining control over altitude and good ride qualities. The autothrottle system was designed to control either Mach number or knots equivalent airspeed (KEAS). Excellent control of Mach number or KEAS was obtained with the autothrottle system when combined with altitude hold. Ride qualities were significantly better than with the conventional Mach hold system.

  3. Aerodynamics, sensing and control of insect-scale flapping-wing flight (United States)

    Shyy, Wei; Kang, Chang-kwon; Chirarattananon, Pakpong; Ravi, Sridhar; Liu, Hao


    There are nearly a million known species of flying insects and 13 000 species of flying warm-blooded vertebrates, including mammals, birds and bats. While in flight, their wings not only move forward relative to the air, they also flap up and down, plunge and sweep, so that both lift and thrust can be generated and balanced, accommodate uncertain surrounding environment, with superior flight stability and dynamics with highly varied speeds and missions. As the size of a flyer is reduced, the wing-to-body mass ratio tends to decrease as well. Furthermore, these flyers use integrated system consisting of wings to generate aerodynamic forces, muscles to move the wings, and sensing and control systems to guide and manoeuvre. In this article, recent advances in insect-scale flapping-wing aerodynamics, flexible wing structures, unsteady flight environment, sensing, stability and control are reviewed with perspective offered. In particular, the special features of the low Reynolds number flyers associated with small sizes, thin and light structures, slow flight with comparable wind gust speeds, bioinspired fabrication of wing structures, neuron-based sensing and adaptive control are highlighted. PMID:27118897

  4. Aerodynamics, sensing and control of insect-scale flapping-wing flight. (United States)

    Shyy, Wei; Kang, Chang-Kwon; Chirarattananon, Pakpong; Ravi, Sridhar; Liu, Hao


    There are nearly a million known species of flying insects and 13 000 species of flying warm-blooded vertebrates, including mammals, birds and bats. While in flight, their wings not only move forward relative to the air, they also flap up and down, plunge and sweep, so that both lift and thrust can be generated and balanced, accommodate uncertain surrounding environment, with superior flight stability and dynamics with highly varied speeds and missions. As the size of a flyer is reduced, the wing-to-body mass ratio tends to decrease as well. Furthermore, these flyers use integrated system consisting of wings to generate aerodynamic forces, muscles to move the wings, and sensing and control systems to guide and manoeuvre. In this article, recent advances in insect-scale flapping-wing aerodynamics, flexible wing structures, unsteady flight environment, sensing, stability and control are reviewed with perspective offered. In particular, the special features of the low Reynolds number flyers associated with small sizes, thin and light structures, slow flight with comparable wind gust speeds, bioinspired fabrication of wing structures, neuron-based sensing and adaptive control are highlighted.

  5. On the internal stability of non-linear dynamic inversion: application to flight control

    Czech Academy of Sciences Publication Activity Database

    Alam, M.; Čelikovský, Sergej


    Roč. 11, č. 12 (2017), s. 1849-1861 ISSN 1751-8644 R&D Projects: GA ČR(CZ) GA17-04682S Institutional support: RVO:67985556 Keywords : flight control * non-linear dynamic inversion * stability Subject RIV: BC - Control Systems Theory Impact factor: 2.536, year: 2016 http:// library

  6. Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight (United States)

    Clement, Gilles; Wood, Scott J.


    This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

  7. Self-contained high-authority control for miniature flight systems (United States)

    Knowles, Gareth J.; Bird, Ross W.; Barrett, Ron


    UAV's, UCAV's, miniaturized munitions and smart bombs have a variety of objectives clamoring for easement of weight/volume restrictions. These include anti-jam, explosive, servo control, electronics packaging, GPS and other required functions. The possibility of freeing up valuable real estate in the missile itself is most attractive for such applications. QorTek has developed the first self-contained high authority control surface to replace externally activated steering fins or canards. These flight actuation systems require only external control signal and power. Moreover, the technology easily scales to micro munitions. Because of their unique composite structure, these powerful solid-state devices offer exceptional performance in a durable package suitable for miniature munitions. The purpose of this paper is to discuss new breakthroughs in piezo-actuated technology that minimize vol./weight enabling a self-contained flight control actuation system that eliminates the need for servo controls. The presentation will focus on the new design that enables integration into high angular displacement actuation into a graphite epoxy fabricated RALA flight control actuator that can handle the aerodynamic loading conditions.

  8. Survival of egg-laying controlling neuroendocrine cells during reproductive senescence of a mollusc

    NARCIS (Netherlands)

    Janse, C.


    During brain aging neuronal degradation occurs. In some neurons this may result in degeneration and cell death, still other neurons may survive and maintain their basic properties. The present study deals with survival of the egg-laying controlling neuroendocrine caudodorsal cells (CDCs) during

  9. Shuttle Flight Operations Contract Generator Maintenance Facility Land Use Control Implementation Plan (LUCIP) (United States)

    Applegate, Joseph L.


    This Land Use Control Implementation Plan (LUCIP) has been prepared to inform current and potential future users of the Kennedy Space Center (KSC) Shuttle Flight Operations Contract Generator Maintenance Facility (SFOC; SWMU 081; "the Site") of institutional controls that have been implemented at the Site1. Although there are no current unacceptable risks to human health or the environment associated with the SFOC, an institutional land use control (LUC) is necessary to prevent human health exposure to antimony-affected groundwater at the Site. Controls will include periodic inspection, condition certification, and agency notification.

  10. Flight Investigation of the Effectiveness of an Automatic Aileron Trim Control Device for Personal Airplanes (United States)

    Phillips, William H; Kuehnel, Helmut A; Whitten, James B


    A flight investigation to determine the effectiveness of an automatic aileron trim control device installed in a personal airplane to augment the apparent spiral stability has been conducted. The device utilizes a rate-gyro sensing element in order to switch an on-off type of control that operates the ailerons at a fixed rate through control centering springs. An analytical study using phase-plane and analog-computer methods has been carried out to determine a desirable method of operation for the automatic trim control.

  11. Adaptive Augmenting Control Flight Characterization Experiment on an F/A-18 (United States)

    VanZwieten, Tannen S.; Orr, Jeb S.; Wall, John H.; Gilligan, Eric T.


    This paper summarizes the Adaptive Augmenting Control (AAC) flight characterization experiments performed using an F/A-18 (TN 853). AAC was designed and developed specifically for launch vehicles, and is currently part of the baseline autopilot design for NASA's Space Launch System (SLS). The scope covered here includes a brief overview of the algorithm (covered in more detail elsewhere), motivation and benefits of flight testing, top-level SLS flight test objectives, applicability of the F/A-18 as a platform for testing a launch vehicle control design, test cases designed to fully vet the AAC algorithm, flight test results, and conclusions regarding the functionality of AAC. The AAC algorithm developed at Marshall Space Flight Center is a forward loop gain multiplicative adaptive algorithm that modifies the total attitude control system gain in response to sensed model errors or undesirable parasitic mode resonances. The AAC algorithm provides the capability to improve or decrease performance by balancing attitude tracking with the mitigation of parasitic dynamics, such as control-structure interaction or servo-actuator limit cycles. In the case of the latter, if unmodeled or mismodeled parasitic dynamics are present that would otherwise result in a closed-loop instability or near instability, the adaptive controller decreases the total loop gain to reduce the interaction between these dynamics and the controller. This is in contrast to traditional adaptive control logic, which focuses on improving performance by increasing gain. The computationally simple AAC attitude control algorithm has stability properties that are reconcilable in the context of classical frequency-domain criteria (i.e., gain and phase margin). The algorithm assumes that the baseline attitude control design is well-tuned for a nominal trajectory and is designed to adapt only when necessary. Furthermore, the adaptation is attracted to the nominal design and adapts only on an as-needed basis

  12. The orphan nuclear hormone receptor ERRβ controls rod photoreceptor survival (United States)

    Onishi, Akishi; Peng, Guang-Hua; Poth, Erin M.; Lee, Daniel A.; Chen, Jichao; Alexis, Uel; de Melo, Jimmy; Chen, Shiming; Blackshaw, Seth


    Mutation of rod photoreceptor-enriched transcription factors is a major cause of inherited blindness. We identified the orphan nuclear hormone receptor estrogen-related receptor β (ERRβ) as selectively expressed in rod photoreceptors. Overexpression of ERRβ induces expression of rod-specific genes in retinas of wild-type as well as Nrl−/− mice, which lack rod photoreceptors. Mutation of ERRβ results in dysfunction and degeneration of rods, whereas inverse agonists of ERRβ trigger rapid rod degeneration, which is rescued by constitutively active mutants of ERRβ. ERRβ coordinates expression of multiple genes that are rate-limiting regulators of ATP generation and consumption in photoreceptors. Furthermore, enhancing ERRβ activity rescues photoreceptor defects that result from loss of the photoreceptor-specific transcription factor Crx. Our findings demonstrate that ERRβ is a critical regulator of rod photoreceptor function and survival, and suggest that ERRβ agonists may be useful in the treatment of certain retinal dystrophies. PMID:20534447

  13. Contrasting Perspectives Of Junior versus Senior NASA ISS Flight Controllers On Leadership And Cultural Issues (United States)

    Clement, James L.; Boyd, J. E.; Saylor, S.; Kanas, N.


    NASA flight controllers have always worked in a very demanding environment, but the International Space Station (ISS) poses even more challenges than prior missions. A recent NASA/Ames survey by Parke and Orasanu of NASA/Johnson flight controllers uncovered concerns about communications problems between American personnel and their international counterparts. To better understand these problems, we interviewed 14 senior and 12 junior ISS flight controllers at NASA/Johnson about leadership and cultural challenges they face and strategies for addressing these challenges. The qualitative interview data were coded and tabulated. Here we present quantitative analyses testing for differences between junior and senior controllers. Based on nonparametric statistical tests comparing responses across groups, the senior controllers were significantly more aware of the impact of working in dispersed teams, the context of constant change, and the upcoming multilateral challenges, while junior controllers were more aware of language and cultural issues. We consider our findings in light of other studies of controllers and other known differences between senior and junior controllers. For example, the fact that senior controllers had their formative early experience controlling pre-ISS short-duration Shuttle missions seems to have both positive and negative aspects, which are supported by our data. Our findings may also reflect gender differences, but we cannot unconfound this effect in our data because all the senior respondents were males. Many of the junior-senior differences are not only due to elapsed time on the job, but also due to a cohort effect. The findings of this study should be used for training curricula tailored differently for junior and senior controllers.

  14. Design and Experiment of Flight Path Control System of Unmanned Autogyro

    Directory of Open Access Journals (Sweden)

    Wang Song


    Full Text Available This paper presents the architecture of flight tracking control system for unmanned autogyro, and designs the control law based on the control characteristics of unmanned autogyro. To reduce the lift force loss during turning and maintain the altitude, the feedforward control method of pitching rudder for propeller is adopted (during rolling; To reduce the influence of propeller anti-twisting effect on the roll attitude and course, feedforward control method of the propeller rolling rudder (during throttle changing, is adopted; to reduce the slide slipping and achieve coordinated turning, a hybrid control strategy of the yaw rudder and rolling rud-der of propeller is developed. The flying platform is built to verify the flying. It is proved that this control system can effectively control the altitude and horizontal path of the unmanned autogyro, the control accuracy is better than ± 5m.

  15. A robust rotorcraft flight control system design methodology utilizing quantitative feedback theory (United States)

    Gorder, Peter James


    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.

  16. Human stick balancing: Tuning Lèvy flights to improve balance control (United States)

    Cabrera, Juan Luis; Milton, John G.


    State-dependent, or parametric, noise is an essential component of the neural control mechanism for stick balancing at the fingertip. High-speed motion analysis in three dimensions demonstrates that the controlling movements made by the fingertip during stick balancing can be described by a Lévy flight. The Lévy index, α, is approximately 0.9; a value close to optimal for a random search. With increased skill, the index α does not change. However, the tails of the Lévy distribution become broader. These observations suggest a Lévy flight that is truncated by the properties of the nervous and musculoskeletal system; the truncation decreasing as skill level increases. Measurements of the cross-correlation between the position of the tip of the stick and the fingertip demonstrate that the role of closed-loop feedback changes with increased skill. Moreover, estimation of the neural latencies for stick balancing show that for a given stick length, the latency increases with skill level. It is suggested that the neural control for stick balancing involves a mechanism in which brief intervals of consciously generated, corrective movements alternate with longer intervals of prediction-free control. With learning the truncation of the Lévy flight becomes better optimized for balance control and hence the time between successive conscious corrections increases. These observations provide the first evidence that changes in a Lévy flight may have functional significance for the nervous system. This work has implications for the control of balancing problems ranging from falling in the elderly to the design of two-legged robots and earthquake proof buildings.

  17. Investigation of controlled flight into terrain : aircraft accidents involving turbine-powered aircraft with six or more passenger seats flying under FAR part 91 flight rules and the potential for their prevention by ground proximity warning systems (United States)


    This two-volume study documents an investigation of controlled flight into terrain (CFIT) aircraft accidents involving turbine-powered aircraft with six or more passenger seats flying under Federal Aviation Regulations (FAR) Part 91 flight rules, and...

  18. Prognostic factors for local control and survival after radiotherapy of metastatic spinal cord compression

    NARCIS (Netherlands)

    Rades, Dirk; Fehlauer, Fabian; Schulte, Rainer; Veninga, Theo; Stalpers, Lukas J. A.; Basic, Hiba; Bajrovic, Amira; Hoskin, Peter J.; Tribius, Silke; Wildfang, Ingeborg; Rudat, Volker; Engenhart-Cabilic, Rita; Karstens, Johann H.; Alberti, Winfried; Dunst, Juergen; Schild, Steven E.


    To evaluate potential prognostic factors for local control and survival after radiotherapy of metastatic spinal cord compression (MSCC). The following potential prognostic factors were investigated retrospectively in 1,852 patients irradiated for MSCC: age, sex, performance status, primary tumor,

  19. Children with cancer with different survival perspectives: defensiveness, control strategies, and psychological adjustment

    NARCIS (Netherlands)

    Grootenhuis, M. A.; Last, B. F.


    The main objective of the present study was to investigate whether children with cancer with different survival perspectives differ in their psychological adjustment, defensiveness and their use of cognitive control strategies. Furthermore, the study investigated which variables predict emotional

  20. An assessment of various side-stick controller/stability and control augmentation systems for night nap-of-Earth flight using piloted simulation (United States)

    Landis, K. H.; Aiken, E. W.


    Several night nap-of-the-earth mission tasks were evaluated using a helmet-mounted display which provided a limited field-of-view image with superimposed flight control symbology. A wide range of stability and control augmentation designs was investigated. Variations in controller force-deflection characteristics and the number of axes controlled through an integrated side-stick controller were studied. In general, a small displacement controller is preferred over a stiffstick controller particularly for maneuvering flight. Higher levels of stability augmentation were required for IMC tasks to provide handling qualities comparable to those achieved for the same tasks conducted under simulated visual flight conditions.


    Directory of Open Access Journals (Sweden)


    Full Text Available The article deals with methods of forecasting the level of aviation safety operation of aircraft systems on the basis of methods of evaluation the risks of negative situations as a consequence of a functional loss of initial properties of the system with critical violations of standard modes of the aircraft. Mathematical Models of Risks as a Danger Measure of Discrete Random Events in Aviation Systems are presented. Technological Schemes and Structure of Risk Control Proce- dures without the Probability are illustrated as Methods of Risk Management System in Civil Aviation. The assessment of the level of safety and quality and management of aircraft, made not only from the standpoint of reliability (quality and consumer properties, but also from the position of ICAO on the basis of a risk-based approach. According to ICAO, the security assessment is performed by comparing the calculated risk with an acceptable level. The approach justifies the use of qualitative evaluation techniques safety in the forms of proactive forecasted and predictive risk management adverse impacts to aviation operations of various kinds, including the space sector and nuclear energy. However, for the events such as accidents and disasters, accidents with the aircraft, fighters in a training flight, during the preparation of the pilots on the training aircraft, etc. there is no required statistics. Density of probability distribution (p. d. f. of these events are only hypothetical, unknown with "hard tails" that completely eliminates the application of methods of confidence intervals in the traditional approaches to the assessment of safety in the form of the probability analysis.

  2. A hybrid approach to robustness analyses of flight control laws in re-entry applications (United States)

    Tancredi, Urbano; Grassi, Michele; Corraro, Federico; Filippone, Edoardo; Verde, Leopoldo


    The present paper aims at improving the efficiency of the robustness analyses of flight control laws with respect to conventional techniques, especially when applied to vehicles following time-varying reference trajectories, such as in an atmospheric re-entry. A nonlinear robustness criterion is proposed, stemming from the practical stability framework, which allows dealing effectively with such cases. A novel approach is presented, which exploits the convexity of linear time varying systems, coupled to an approximate description of the original nonlinear system by a certain number of its time-varying linearizations. The suitability of the approximating systems is evaluated in a probabilistic fashion making use of the unscented transformation technique. The effectiveness and potentials of the method are ascertained by application to the robustness analysis of the longitudinal flight control laws of the Italian Aerospace Research Center (CIRA) experimental vehicle USV.

  3. The use of minimum order state observers in digital flight-control systems. (United States)

    Montgomery, R. C.; Hatch, H. G., Jr.


    This paper deals with the problem of selecting the 'arbitrary' design parameters of digital state observers when they are being used as a part of a digital flight-control system. A cost index is developed which indicates the output noise caused by input quantization due to analog-to-digital conversion. The cost index assumes that the input quantization error is uniformly distributed over the least-significant-bit of the conversion. Formulas relating the cost index to the observer design parameters are presented. The cost index is minimized with respect to the design parameters using a conjugate gradient algorithm. An example of the theory is presented in which a digital observer is designed so that a satisfactory digital flight-control system is obtained starting from an unacceptable one.

  4. Flight Test Results on the Stability and Control of the F-15 Quiet Spike(TradeMark) Aircraft (United States)

    Moua, Cheng M.; McWherter, Shaun C.; Cox, Timothy H.; Gera, Joe


    The Quiet Spike F-15B flight research program investigated supersonic shock reduction using a 24-ft sub-scale telescoping nose boom on an F-15B airplane. The program primary flight test objective was to collect flight data for aerodynamic and structural models validation up to 1.8 Mach. Other objectives were to validate the mechanical feasibility of a morphing fuselage at the operational conditions and determine the near-field shock wave characterization. The stability and controls objectives were to assess the effect of the spike on the stability, controllability, and handling qualities of the aircraft and to ensure adequate stability margins across the entire research flight envelop. The two main stability and controls issues were the effects of the telescoping nose boom influenced aerodynamics on the F-15B aircraft flight dynamics and air data and angle of attack sensors. This paper reports on the stability and controls flight envelope clearance methods and flight test analysis of the F-15B Quiet Spike. Brief pilot commentary on typical piloting tasks, approach and landing, refueling task, and air data sensitivity to the flight control system are also discussed in this report.

  5. Biochemical Control With Radiotherapy Improves Overall Survival in Intermediate and High-Risk Prostate Cancer Patients Who Have an Estimated 10-Year Overall Survival of >90%

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, Christopher, E-mail: [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Centre, Vancouver, BC (Canada); Liu, Mitchell; Tyldesley, Scott; Morris, W. James [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Centre, Vancouver, BC (Canada); Joffres, Michel [Department of Health Sciences, Simon Fraser University, Surrey, BC (Canada); Khaira, Mandip; Kwan, Winkle [Department of Radiation Oncology, British Columbia Cancer Agency, Fraser Valley Centre, Surrey, BC (Canada); Moiseenko, Vitali [Department of Medical Physics, British Columbia Cancer Agency, Vancouver Centre, Vancouver, BC (Canada); Pickles, Thomas [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Centre, Vancouver, BC (Canada)


    Purpose: To identify subgroups of patients with carcinoma of the prostate treated with radical radiotherapy that have improved overall survival when disease is biochemically controlled. Methods and Materials: A cohort of 1,060 prostate cancer patients treated with radical radiotherapy was divided into nine subgroups based on National Comprehensive Cancer Network risk category and estimated 10-year overall survival (eOS 10y) derived from the age adjusted Charlson Comorbidity Index. Patients with and without biochemical control were compared with respect to overall survival. Actuarial estimates of overall survival were calculated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used for analysis of overall survival. Results: Median follow-up was 125 months (range, 51-176 months). Only the subgroups with high or intermediate risk disease and an eOS 10y of >90% had a statistically significantly improved overall survival when prostate cancer was biochemically controlled. In all other groups, biochemical control made no significant difference to overall survival. In the subgroup with high-risk disease and eOS 10y >90%, actuarial overall survival was 86.3% (95% confidence interval [CI] 78.5%-94.1%) and 62.1% (95% CI 52.9%-71.3%) for patients with biochemical control and biochemical relapse respectively (p = 0.002). In the intermediate risk group with eOS >90%, actuarial overall survival was 95.3% (95% CI 89.0%-100%) and 79.8% (95% CI 68.0%-91.6%) for biochemically controlled and biochemically relapsed patients (p = 0.033). On multivariate analysis, National Comprehensive Cancer Network risk group (p = 0.005), biochemical control (p = 0.033) and eOS 10y (p < 0.001) were statistically significant. Conclusion: Biochemical control translates into improved overall survival in patients with high or intermediate risk disease and an estimated 10-year overall survival of >90%.

  6. Optimal Control Allocation with Load Sensor Feedback for Active Load Suppression, Flight-Test Performance (United States)

    Miller, Christopher J.; Goodrick, Dan


    The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads to specified values. This technique has been implemented and flown on the National Aeronautics and Space Administration Full-scale Advanced Systems Testbed aircraft. The flight tests illustrate that the approach achieves the desired performance and show promising potential benefits. The flights also uncovered some important issues that will need to be addressed for production application.


    Directory of Open Access Journals (Sweden)



    Full Text Available This paper describes the performance of a simplified dynamic controller with fuzzy logic controllers. The six degree-of-freedom simulation study focuses on the results with and without fuzzy logic controller. One area of interest is the performance of a simulated the cross coupling effect. The controller uses explicit models to produce the desired commands. In this paper the effect of the cross-coupling between channels on the overall performance of the flight system has been considered. Two fuzzy controllers have been added to the system to improve its performance. This paper presents the development and simulation of a modified system is presented using MatLab Simulink. Also it focuses on the use of fuzzy logic controller in model-based control of multiple-input, multiple-output systems. Here, we address the question of how the overall performance of the system is affected when both fuzzy logic controllers are applied at the same time. Simulation and experimental results of a flight system , as an illustrative example, are presented.

  8. EVA Wiki - Transforming Knowledge Management for EVA Flight Controllers and Instructors (United States)

    Johnston, Stephanie S.; Alpert, Brian K.; Montalvo, Edwin James; Welsh, Lawrence Daren; Wray, Scott; Mavridis, Costa


    The EVA Wiki was recently implemented as the primary knowledge database to retain critical knowledge and skills in the EVA Operations group at NASA's Johnson Space Center by ensuring that information is recorded in a common, easy to search repository. Prior to the EVA Wiki, information required for EVA flight controllers and instructors was scattered across different sources, including multiple file share directories, SharePoint, individual computers, and paper archives. Many documents were outdated, and data was often difficult to find and distribute. In 2011, a team recognized that these knowledge management problems could be solved by creating an EVA Wiki using MediaWiki, a free and open-source software developed by the Wikimedia Foundation. The EVA Wiki developed into an EVA-specific Wikipedia on an internal NASA server. While the technical implementation of the wiki had many challenges, one of the biggest hurdles came from a cultural shift. Like many enterprise organizations, the EVA Operations group was accustomed to hierarchical data structures and individually-owned documents. Instead of sorting files into various folders, the wiki searches content. Rather than having a single document owner, the wiki harmonized the efforts of many contributors and established an automated revision controlled system. As the group adapted to the wiki, the usefulness of this single portal for information became apparent. It transformed into a useful data mining tool for EVA flight controllers and instructors, as well as hundreds of others that support EVA. Program managers, engineers, astronauts, flight directors, and flight controllers in differing disciplines now have an easier-to-use, searchable system to find EVA data. This paper presents the benefits the EVA Wiki has brought to NASA's EVA community, as well as the cultural challenges it had to overcome.

  9. Development of neutron radioscopy for the inspection of CF188 flight control surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Chalovich, T.R. E-mail:; Bennett, L.G.I.; Lewis, W.J.; Brenizer, J.S


    Neutron radioscopy, using a cooled charged coupled device (CCD) camera and a neutron-sensitive scintillation screen, was developed at the SLOWPOKE-2 Facility at the Royal Military College (RMC) to detect water ingress into the composite layers and the aluminium honeycomb core in flight control surfaces on the CF188 Hornet aircraft. The response of the CCD camera system was tested at different neutron fluxes utilising the SLOWPOKE-2 at RMC and the Breazeale Nuclear Reactor at Pennsylvania State University.

  10. Bio-Inspired Integrated Sensing and Control Flapping Flight for Micro Aerial Vehicles (United States)


    experimentation of engineered flapping flight. A robotic bat with 8 motors has been developed and installed on a 3-DOF pendulum [B1]. This AFOSR project...metric which is based entirely on a steady maneuver [61]. It is also an important benchmark to evaluate the efficacy of a yaw control mechanism. 3.2...capability of the wings. The foam table on which the aircraft is resting is not part of the airframe. modified version of the commerically

  11. Commonality of flight control systems for support of European telecommunications missions (United States)

    Debatin, Kurt


    This paper is concerned with the presentation of mission-independent software systems that provide a common software platform to ground data systems for mission operations. The objectives of such common software platforms are to reduce the cost of the development of mission-dedicated software systems and to increase the level of reliability of the ground data systems for mission operations. In accordance with this objective, the Multi-Satellite Support System (MSSS) was developed at the European Space Operations Center (ESOC). Between 1975 and 1992, the MSSS provided support to 16 European Space Agency (ESA) missions, among them very demanding science missions such as GEOS, EXOSAT, and Giotto. The successful support of these missions proved the validity of the MSSS concept with its extended mission-independent platform. This paper describes the MSSS concept and focuses on the wide use of MSSS as a flight control system for geosynchronous telecommunications satellites. Reference is made to more than 15 telecommunications missions that are operated from Western Europe using flight control systems with an underlying MSSS concept, demonstrating the benefits of a commonly used software platform. Finally, the paper outlines the design of the new generation of flight control systems, which is being developed at ESOC for this decade, following a period of more than 15 years of MSSS support.

  12. Identification of Fungal Colonies on Ground Control and Flight Veggie Plant Pillows (United States)

    Scotten, Jessica E.; Hummerick, Mary E.; Khodadad, Christina L.; Spencer, Lashelle E.; Massa, Gioia D.


    The Veggie system focuses on growing fresh produce that can be harvested and consumed by astronauts. The microbial colonies in each Veggie experiment are evaluated to determine the safety level of the produce and then differences between flight and ground samples. The identifications of the microbial species can detail risks or benefits to astronaut and plant health. Each Veggie ground or flight experiment includes six plants grown from seeds that are glued into wicks in Teflon pillows filled with clay arcillite and fertilizer. Fungal colonies were isolated from seed wicks, growth media, and lettuce (cv. 'Outredgeous') roots grown in VEG-01B pillows on ISS and in corresponding ground control pillows grown in controlled growth chambers. The colonies were sorted by morphology and identified using MicroSeq(TM) 500 16s rDNA Bacterial Identification System and BIOLOG GEN III MicroPlate(TM). Health risks for each fungal identification were then assessed using literature sources. The goal was to identify all the colonies isolated from flight and ground control VEG-01B plants, roots, and rooting medium and compare the resulting identifications.

  13. Tether dynamics and control results for tethered satellite system's initial flight (United States)

    Chapel, Jim D.; Flanders, Howard

    The recent Tethered Satellite System-1 (TSS-1) mission has provided a wealth of data concerning the dynamics of tethered systems in space and has demonstrated the effectiveness of operational techniques designed to control these dynamics. In this paper, we review control techniques developed for managing tether dynamics, and discuss the results of using these techniques for the Tethered Satellite System's maiden flight on STS-46. In particular, the flight results of controlling libration dynamics, string dynamics, and slack tether are presented. These results show that tether dynamics can be safely managed. The overall stability of the system was found to be surprisingly good even at relatively short tether lengths. In fact, the system operated in passive mode at a tether length of 256 meters for over 9 hours. Only monitoring of the system was required during this time. Although flight anomalies prevented the planned deployment to 20 km, the extended operations at shorter tether lengths have proven the viability of using tethers in space. These results should prove invaluable in preparing for future missions with tethered objects in space.

  14. Real-Time Reliability Verification for UAV Flight Control System Supporting Airworthiness Certification. (United States)

    Xu, Haiyang; Wang, Ping


    In order to verify the real-time reliability of unmanned aerial vehicle (UAV) flight control system and comply with the airworthiness certification standard, we proposed a model-based integration framework for modeling and verification of time property. Combining with the advantages of MARTE, this framework uses class diagram to create the static model of software system, and utilizes state chart to create the dynamic model. In term of the defined transformation rules, the MARTE model could be transformed to formal integrated model, and the different part of the model could also be verified by using existing formal tools. For the real-time specifications of software system, we also proposed a generating algorithm for temporal logic formula, which could automatically extract real-time property from time-sensitive live sequence chart (TLSC). Finally, we modeled the simplified flight control system of UAV to check its real-time property. The results showed that the framework could be used to create the system model, as well as precisely analyze and verify the real-time reliability of UAV flight control system.

  15. A passion for space adventures of a pioneering female NASA flight controller

    CERN Document Server

    Dyson, Marianne J


    Marianne J. Dyson recounts for us a time when women were making the first inroads into space flight control, a previously male-dominated profession. The story begins with the inspiration of the Apollo 11 landing on the Moon and follows the challenges of pursuing a science career as a woman in the 70s and 80s, when it was far from an easy path.  Dyson relates the first five space shuttle flights from the personal perspective of mission planning and operations in Houston at the Johnson Space Center, based almost exclusively on original sources such as journals and NASA weekly activity reports. The book’s historical details about astronaut and flight controller training exemplify both the humorous and serious aspects of space operations up through the Challenger disaster, including the almost unknown fire in Mission Control during STS-5 that nearly caused an emergency entry of the shuttle.  From an insider with a unique perspective and credentials to match, this a must-read for anyone interested in the worki...

  16. First-In-Flight Full-Scale Application of Active Flow Control: The XV-15 Tiltrotor Download Reduction

    National Research Council Canada - National Science Library

    Nagib, Hassan M; Kiedaisch, John W; Wygnanski, Israel J; Stalker, Aaron D; Wood, Tom; McVeigh, Michael A


    ... Helicopter and Boeing under the sponsorship of the Micro-Adaptive Flow control (MAFC) program of DARPA. The over six hours of flight tests successfully achieved the two goals and documented reduction in the download forces by 9 to 14%, thereby demonstrating for the first time the aerodynamic principals of AFC extend to full-scale flight.

  17. Tribally Controlled Community College Libraries: A Paradigm for Survival. (United States)

    Patterson, Lotsee; Taylor, Rhonda Harris


    This study reports on the results of a mail survey administered to tribally controlled college libraries during 1993, just before the colleges were granted federal land-grant college status. Highlights include the historical development of the institutions operated by Native American Indian tribes; budgets; staff; services; computer utilization;…

  18. Damage control resuscitation in combination with damage control laparotomy: a survival advantage. (United States)

    Duchesne, Juan C; Kimonis, Katerina; Marr, Alan B; Rennie, Kelly V; Wahl, Georgia; Wells, Joel E; Islam, Tareq M; Meade, Peter; Stuke, Lance; Barbeau, James M; Hunt, John P; Baker, Christopher C; McSwain, Norman E


    Damage control laparotomy (DCL) improves outcomes when used in patients with severe hemorrhage. Correction of coagulopathy with close ratio resuscitation while limiting crystalloid forms a new methodology known as damage control resuscitation (DCR). We hypothesize a survival advantage in DCL patients managed with DCR when compared with DCL patients managed with conventional resuscitation efforts (CRE). This study is a 4-year retrospective study of all DCL patients who required >or=10 units of packed red blood cells (PRBC) during surgery. A 2-year period after institution of DCR (DCL and DCR) was compared with the preceding 2 years (DCL and CRE). Univariate analysis of continuous data was done with Student's t test followed by multiple logistic regression. One Hundred twenty-four and 72 patients were managed during the DCL and CRE and DCL and DCR time periods, respectively. Baseline patient characteristics of age, Injury Severity Score, % penetrating, blood pressure, hemoglobin, base deficit, and INR were similar between groups. There was no difference in quantity of intraoperative PRBC utilization between DCL and CRE and DCL and DCR study periods: 21.7 units versus 25.5 units (p = 0.53); however, when compared with DCL and CRE group, patients in the DCL and DCR group received less intraoperative crystalloids, 4.7 L versus 14.2 L (p = 0.009); more fresh frozen plasma (FFP), 18.2 versus 6.4 (p = 0.002); a closer FFP to PRBC ratio, 1 to 1.2 versus 1 to 4.2 (p = 0.002); platelets to PRBC ratio, 1:2.3 versus 1:5.9 (0.002); shorter mean trauma intensive care unit length of stay, 11 days versus 20 days (p = 0.01); and greater 30-day survival, 73.6% versus 54.8% (p ratio; 95% confidence interval: 0.19 (0.05-0.33), p = 0.005). This is the first civilian study that analyses the impact of DCR in patients managed with DCL. During the DCL and DCR study period more PRBC, FFP, and platelets with less crystalloid solution was used intraoperatively. DCL and DCR were associated with

  19. Influence of a controlled environment simulating an in-flight airplane cabin on dry eye disease. (United States)

    Tesón, Marisa; González-García, María J; López-Miguel, Alberto; Enríquez-de-Salamanca, Amalia; Martín-Montañez, Vicente; Benito, María Jesús; Mateo, María Eugenia; Stern, Michael E; Calonge, Margarita


    To evaluate symptoms, signs, and the levels of 16 tears inflammatory mediators of dry eye (DE) patients exposed to an environment simulating an in-flight air cabin in an environmental chamber. Twenty DE patients were exposed to controlled environment simulating an in-flight airplane cabin (simulated in-flight condition [SIC]) of 23°C, 5% relative humidity, localized air flow, and 750 millibars (mb) of barometric pressure. As controls, 15 DE patients were subjected to a simulated standard condition (SSC) of 23°C, 45% relative humidity, and 930 mb. A DE symptoms questionnaire, diagnostic tests, and determination of 16 tear molecules by multiplex bead array were performed before and 2 hours after exposure. After SIC exposure, DE patients became more symptomatic, suffered a significant (P ≤ 0.05) decrease in tear stability (tear break up time) (from 2.18 ± 0.28 to 1.53 ± 0.20), and tear volume (phenol red thread test), and a significant (P ≤ 0.05) increase in corneal staining, both globally (0.50 ± 0.14 before and 1.25 ± 0.19 after) and in each area (Baylor scale). After SSC, DE patients only showed a mild, but significant (P ≤ 0.05), increase in central and inferior corneal staining. Consistently, tear levels of IL-6 and matrix metalloproteinase (MMP)-9 significantly increased and tear epidermal growth factor (EGF) significantly decreased (P ≤ 0.05) only after SIC. The controlled adverse environment conditions in this environmental chamber can simulate the conditions in which DE patients might be exposed during flight. As this clearly impaired their lacrimal functional unit, it would be advisable that DE patients use therapeutic strategies capable of ameliorating these adverse episodes.

  20. Controlling Redox Status for Stem Cell Survival, Expansion, and Differentiation

    Directory of Open Access Journals (Sweden)

    Sébastien Sart


    Full Text Available Reactive oxygen species (ROS have long been considered as pathological agents inducing apoptosis under adverse culture conditions. However, recent findings have challenged this dogma and physiological levels of ROS are now considered as secondary messengers, mediating numerous cellular functions in stem cells. Stem cells represent important tools for tissue engineering, drug screening, and disease modeling. However, the safe use of stem cells for clinical applications still requires culture improvements to obtain functional cells. With the examples of mesenchymal stem cells (MSCs and pluripotent stem cells (PSCs, this review investigates the roles of ROS in the maintenance of self-renewal, proliferation, and differentiation of stem cells. In addition, this work highlights that the tight control of stem cell microenvironment, including cell organization, and metabolic and mechanical environments, may be an effective approach to regulate endogenous ROS generation. Taken together, this paper indicates the need for better quantification of ROS towards the accurate control of stem cell fate.

  1. An Advanced Fly-By-Wire Flight Control System for the RASCAL Research Rotorcraft: Concept to Reality (United States)

    Rediess, Nicholas A.; Dones, Fernando; McManus, Bruce L.; Ulmer, Lon; Aiken, Edwin W. (Technical Monitor)


    Design features of a new fly-by-wire flight control system for the Rotorcraft-Aircrew Systems Concepts Airborne Laboratory (RASCAL) are described. Using a UH-60A Black Hawk helicopter as a baseline vehicle, the RASCAL will be a flying laboratory capable of supporting the research requirements of major NASA and Army guidance, control, and display research programs. The paper describes the research facility requirements of these pro-rams and the design implementation of the research flight control system (RFCS), with emphasis on safety-of-flight, adaptability to multiple requirements and performance considerations.

  2. A feasibility study regarding the addition of a fifth control to a rotorcraft in-flight simulator (United States)

    Turner, Simon; Andrisani, Dominick, II


    The addition of a large movable horizontal tail surface to the control system of a rotorcraft in-flight simulator being developed from a Sikorsky UH-60A Black Hawk Helicopter is evaluated. The capabilities of the control surface as a trim control and as an active control are explored. The helicopter dynamics are modeled using the Generic Helicopter simulation program developed by Sikorsky Aircraft. The effect of the horizontal tail on the helicopter trim envelope is examined by plotting trim maps of the aircraft attitude and controls as a function of the flight speed and horizontal tail incidence. The control power of the tail surface relative to that of the other controls is examined by comparing control derivatives extracted from the simulation program over the flight speed envelope. The horizontal tail's contribution as an active control is evaluated using an explicit model following control synthesis involving a linear model of the helicopter in steady, level flight at a flight speed of eighty knots. The horizontal tail is found to provide additional control flexibility in the longitudinal axis. As a trim control, it provides effective control of the trim pitch attitude at mid to high forward speeds. As an active control, the horizontal tail provides useful pitching moment generating capabilities at mid to high forward speeds.

  3. An investigation of side-stick-controller/stability and control-augmentation system requirements for helicopter terrain flight under reduced visibility conditions (United States)

    Landis, K. H.; Glusman, S. I.; Aiken, E. W.; Hilbert, K. B.


    Simulation of the reduced visibility tasks is effected by providing the pilot with a visually coupled, helmet-mounted display of flight-control symbols superimposed upon terrain-board imagery. Forward-flight, low-speed, and precision-hover control modes are implemented, and a method is developed for the blending of control laws between each control mode. An investigation is made of the variations in the level of integration of primary control functions on a single side-stick controller. For most of the flight tasks investigated, separated controller configurations are preferred to a single, fully integrated side-stick device. Satisfactory handling qualities over all controller configurations are attained only for a precision-hover task conducted with a high level of stability and control augmentation. For most tasks flown with the helmet-mounted display significant degradation in handling qualities occurs relative to the identical tasks flown under visual flight conditions.

  4. Comparison of Controller and Flight Deck Algorithm Performance During Interval Management with Dynamic Arrival Trees (STARS) (United States)

    Battiste, Vernol; Lawton, George; Lachter, Joel; Brandt, Summer; Koteskey, Robert; Dao, Arik-Quang; Kraut, Josh; Ligda, Sarah; Johnson, Walter W.


    Managing the interval between arrival aircraft is a major part of the en route and TRACON controller s job. In an effort to reduce controller workload and low altitude vectoring, algorithms have been developed to allow pilots to take responsibility for, achieve and maintain proper spacing. Additionally, algorithms have been developed to create dynamic weather-free arrival routes in the presence of convective weather. In a recent study we examined an algorithm to handle dynamic re-routing in the presence of convective weather and two distinct spacing algorithms. The spacing algorithms originated from different core algorithms; both were enhanced with trajectory intent data for the study. These two algorithms were used simultaneously in a human-in-the-loop (HITL) simulation where pilots performed weather-impacted arrival operations into Louisville International Airport while also performing interval management (IM) on some trials. The controllers retained responsibility for separation and for managing the en route airspace and some trials managing IM. The goal was a stress test of dynamic arrival algorithms with ground and airborne spacing concepts. The flight deck spacing algorithms or controller managed spacing not only had to be robust to the dynamic nature of aircraft re-routing around weather but also had to be compatible with two alternative algorithms for achieving the spacing goal. Flight deck interval management spacing in this simulation provided a clear reduction in controller workload relative to when controllers were responsible for spacing the aircraft. At the same time, spacing was much less variable with the flight deck automated spacing. Even though the approaches taken by the two spacing algorithms to achieve the interval management goals were slightly different they seem to be simpatico in achieving the interval management goal of 130 sec by the TRACON boundary.

  5. A novel non-uniform control vector parameterization approach with time grid refinement for flight level tracking optimal control problems. (United States)

    Liu, Ping; Li, Guodong; Liu, Xinggao; Xiao, Long; Wang, Yalin; Yang, Chunhua; Gui, Weihua


    High quality control method is essential for the implementation of aircraft autopilot system. An optimal control problem model considering the safe aerodynamic envelop is therefore established to improve the control quality of aircraft flight level tracking. A novel non-uniform control vector parameterization (CVP) method with time grid refinement is then proposed for solving the optimal control problem. By introducing the Hilbert-Huang transform (HHT) analysis, an efficient time grid refinement approach is presented and an adaptive time grid is automatically obtained. With this refinement, the proposed method needs fewer optimization parameters to achieve better control quality when compared with uniform refinement CVP method, whereas the computational cost is lower. Two well-known flight level altitude tracking problems and one minimum time cost problem are tested as illustrations and the uniform refinement control vector parameterization method is adopted as the comparative base. Numerical results show that the proposed method achieves better performances in terms of optimization accuracy and computation cost; meanwhile, the control quality is efficiently improved. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Tracking error constrained robust adaptive neural prescribed performance control for flexible hypersonic flight vehicle

    Directory of Open Access Journals (Sweden)

    Zhonghua Wu


    Full Text Available A robust adaptive neural control scheme based on a back-stepping technique is developed for the longitudinal dynamics of a flexible hypersonic flight vehicle, which is able to ensure the state tracking error being confined in the prescribed bounds, in spite of the existing model uncertainties and actuator constraints. Minimal learning parameter technique–based neural networks are used to estimate the model uncertainties; thus, the amount of online updated parameters is largely lessened, and the prior information of the aerodynamic parameters is dispensable. With the utilization of an assistant compensation system, the problem of actuator constraint is overcome. By combining the prescribed performance function and sliding mode differentiator into the neural back-stepping control design procedure, a composite state tracking error constrained adaptive neural control approach is presented, and a new type of adaptive law is constructed. As compared with other adaptive neural control designs for hypersonic flight vehicle, the proposed composite control scheme exhibits not only low-computation property but also strong robustness. Finally, two comparative simulations are performed to demonstrate the robustness of this neural prescribed performance controller.

  7. Continuous Recursive Sliding Mode Control for Hypersonic Flight Vehicle with Extended Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Yunjie Wu


    Full Text Available A continuous recursive sliding mode controller (CRSMC with extended disturbance observer (EDO is proposed for the longitudinal dynamics of a generic hypersonic flight vehicle (HFV in the presence of multiple uncertainties under control constraints. Firstly, sliding mode tracking controller based on a set of novel recursive sliding mode manifolds is presented, in which the chattering problem is reduced. The CRSMC possesses the merits of both nonsingular terminal sliding mode controller (NTSMC and high-order sliding mode controller (HOSMC. Then antiwindup controller is designed according to the input constraints, which adds a dynamic compensation factor in the CRSMC. For the external disturbance of system, an improved disturbance observer based on extended disturbance observer (EDO is designed. The external disturbance is estimated by the disturbance observer and the estimated value is regarded as compensation in CRSMC for disturbance. The stability of the proposed scheme is analyzed by Lyapunov function theory. Finally, numerical simulation is conducted for cruise flight dynamics of HFV, where altitude is 110000 ft, velocity is 15060 ft/s, and Mach is 15. Simulation results show the validity of the proposed approach.

  8. Hierarchical flight control system synthesis for rotorcraft-based unmanned aerial vehicles (United States)

    Shim, Hyunchul

    the identification, control and general operation. A high-fidelity helicopter model is established with the lumped-parameter approach. With the lift and torque aerodynamic model of the main and tail rotors, a nonlinear simulation model is first constructed. The control models of the RUAVs used in our research are derived by the application of a time-domain parametric identification method to the flight data of target RUAVs. Two distinct control theories, namely classical control theory and modern linear robust control theory, are applied to the identified model. The proposed controllers are validated in a nonlinear simulation environment and tested in a series of test flights. With the successful implementation of the low-level vehicle controller, the guidance layer is designed. The waypoint navigator, which decides the adequate flight mode and the associated reference trajectory, serves as an intermediary between the low-level vehicle control layer and the high-level mission-planning layer. In order to interpret the abstract mission planning to commands that are compatible with the low-level structure, a novel framework called Vehicle Control Language (VCL) is developed. The key idea of VCL is to provide a mission-independent methodology to describe given flight patterns. The VCL processor and vehicle control layer are integrated into the hierarchical control structure, which is the backbone of our intelligent UAV system. The proposed idea is validated in the simulation environment and then fully tested in a series of flight tests.

  9. A framework for the analysis of airframe/engine interactions and integrated flight/propulsion control (United States)

    Schmidt, David K.; Schierman, John D.


    Potential sources of airframe/engine interactions are explored for aircraft subject to the study of integrated flight/propulsion control. A quasi-linear framework for the analysis of these dynamical interactions between the airframe and engine systems is presented. This analysis can be used to quantify, in a meaningful way, the magnitude of the interactions between the airframe and engine systems, determine if these interactions are significant to warrant further consideration in the control law synthesis, and if so, what are the critical frequency ranges where problems may occur due to these interactions. Justification for the use of this method, along with the assumptions, conditions, and restrictions that apply are discussed.

  10. Automatic Flight Control System Design of Level Change Mode for a Large Aircraft


    Huajun Gong; Ziyang Zhen; Xin Li; Ju Jiang; Xinhua Wang


    The level change mode is an essential part of large civil aircraft automatic flight control systems. In cruise, with the decrease of the plane’s weight caused by fuel consumption and the influence of bad weather, such as thunderstorms, the level change mode is required to solve this problem. This work establishes a nonlinear model of large aircraft, takes level changed from 9500m to 10100m as an example to design control laws for the level change mode in cruise. The classical engineering meth...

  11. Bioinspired morphing wings for extended flight envelope and roll control of small drones. (United States)

    Di Luca, M; Mintchev, S; Heitz, G; Noca, F; Floreano, D


    Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aerodynamic profile. Several bird species solve this problem by changing the shape of their wings to adapt to the different aerodynamic requirements. Here, we describe a novel morphing wing design composed of artificial feathers that can rapidly modify its geometry to fulfil different aerodynamic requirements. We show that a fully deployed configuration enhances manoeuvrability while a folded configuration offers low drag at high speeds and is beneficial in strong headwinds. We also show that asymmetric folding of the wings can be used for roll control of the drone. The aerodynamic performance of the morphing wing is characterized in simulations, in wind tunnel measurements and validated in outdoor flights with a small drone.

  12. Bioinspired morphing wings for extended flight envelope and roll control of small drones (United States)

    Heitz, G.; Noca, F.; Floreano, D.


    Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aerodynamic profile. Several bird species solve this problem by changing the shape of their wings to adapt to the different aerodynamic requirements. Here, we describe a novel morphing wing design composed of artificial feathers that can rapidly modify its geometry to fulfil different aerodynamic requirements. We show that a fully deployed configuration enhances manoeuvrability while a folded configuration offers low drag at high speeds and is beneficial in strong headwinds. We also show that asymmetric folding of the wings can be used for roll control of the drone. The aerodynamic performance of the morphing wing is characterized in simulations, in wind tunnel measurements and validated in outdoor flights with a small drone. PMID:28163882

  13. Conceptual Inquiry of the Space Shuttle and International Space Station GNC Flight Controllers (United States)

    Kranzusch, Kara


    The concept of Mission Control was envisioned by Christopher Columbus Kraft in the 1960's. Instructed to figure out how to operate human space flight safely, Kraft envisioned a room of sub-system experts troubleshooting problems and supporting nominal flight activities under the guidance of one Flight Director who is responsible for the success of the mission. To facilitate clear communication, MCC communicates with the crew through a Capsule Communicator (CAPCOM) who is an astronaut themselves. Gemini 4 was the first mission to be supported by such a MCC and successfully completed the first American EVA. The MCC seen on television is called the Flight Control Room (FCR, pronounced ficker) or otherwise known as the front room. While this room is the most visible aspect, it is a very small component of the entire control center. The Shuttle FCR is known as the White FCR (WFCR) and Station's as FCR-1. (FCR-1 was actually the first FCR built at JSC which was used through the Gemini, Apollo and Shuttle programs until the WFCR was completed in 1992. Afterwards FCR-1 was refurbished first for the Life Sciences Center and then for the ISS in 2006.) Along with supporting the Flight Director, each FCR operator is also the supervisor for usually two or three support personnel in a back room called the Multi-Purpose Support Room (MPSR, pronounced mipser). MPSR operators are more deeply focused on their specific subsystems and have the responsible to analyze patterns, and diagnose and assess consequences of faults. The White MPSR (WMPSR) operators are always present for Shuttle operations; however, ISS FCR controllers only have support from their Blue MPSR (BMPSR) while the Shuttle is docked and during critical operations. Since ISS operates 24-7, the FCR team reduces to a much smaller Gemini team of 4-5 operators for night and weekend shifts when the crew is off-duty. The FCR is also supported by the Mission Evaluation Room (MER) which is a collection of contractor engineers

  14. Application of sliding mode methods to the design of reconfigurable flight control systems (United States)

    Wells, Scott Russell

    Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. A comprehensive overview of reconfigurable flight control is given, including a review of the current state-of-the-art within the subdisciplines of fault detection, parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears very promising due its property of invariance to matched uncertainty. An overview of sliding mode control is given and its remarkable properties are demonstrated by example. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer in the feedback path. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate a SISO pitch rate tracking controller. It is also used to demonstrate a MIMO lateral-directional roll rate tracking controller. The last application is a full linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.

  15. Description and Flight Test Results of the NASA F-8 Digital Fly-by-Wire Control System (United States)


    A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

  16. Fuzzy robust nonlinear control approach for electro-hydraulic flight motion simulator

    Directory of Open Access Journals (Sweden)

    Han Songshan


    Full Text Available A fuzzy robust nonlinear controller for hydraulic rotary actuators in flight motion simulators is proposed. Compared with other three-order models of hydraulic rotary actuators, the proposed controller based on first-order nonlinear model is more easily applied in practice, whose control law is relatively simple. It not only does not need high-order derivative of desired command, but also does not require the feedback signals of velocity, acceleration and jerk of hydraulic rotary actuators. Another advantage is that it does not rely on any information of friction, inertia force and external disturbing force/torque, which are always difficult to resolve in flight motion simulators. Due to the special composite vane seals of rectangular cross-section and goalpost shape used in hydraulic rotary actuators, the leakage model is more complicated than that of traditional linear hydraulic cylinders. Adaptive multi-input single-output (MISO fuzzy compensators are introduced to estimate nonlinear uncertain functions about leakage and bulk modulus. Meanwhile, the decomposition of the uncertainties is used to reduce the total number of fuzzy rules. Different from other adaptive fuzzy compensators, a discontinuous projection mapping is employed to guarantee the estimation process to be bounded. Furthermore, with a sufficient number of fuzzy rules, the controller theoretically can guarantee asymptotic tracking performance in the presence of the above uncertainties, which is very important for high-accuracy tracking control of flight motion simulators. Comparative experimental results demonstrate the effectiveness of the proposed algorithm, which can guarantee transient performance and better final accurate tracking in the presence of uncertain nonlinearities and parametric uncertainties.

  17. Digital adaptive model following flight control. [using fighter aircraft mathematical model-following algorithm (United States)

    Alag, G. S.; Kaufman, H.


    Simple mechanical linkages are often unable to cope with the many control problems associated with high performance aircraft maneuvering over a wide flight envelope. One procedure for retaining uniform handling qualities over such an envelope is to implement a digital adaptive controller. Towards such an implementation an explicit adaptive controller, which makes direct use of online parameter identification, has been developed and applied to the linearized equations of motion for a typical fighter aircraft. The system is composed of an online weighted least squares identifier, a Kalman state filter, and a single stage real model following control law. The corresponding control gains are readily adjustable in accordance with parameter changes to ensure asymptotic stability if the conditions for perfect model following are satisfied and stability in the sense of boundedness otherwise.

  18. Flight Tests of Autopilot Integrated with Fault-Tolerant Control of a Small Fixed-Wing UAV

    Directory of Open Access Journals (Sweden)

    Shuo Wang


    Full Text Available A fault-tolerant control scheme for the autopilot of the small fixed-wing UAV is designed and tested by the actual flight experiments. The small fixed-wing UAV called Xiang Fei is developed independently by Nanjing University of Aeronautics and Astronautics. The flight control system is designed based on an open-source autopilot (Pixhawk. Real-time kinematic (RTK GPS is introduced due to its high accuracy. Some modifications on the longitudinal and lateral guidance laws are achieved to improve the flight control performance. Moreover, a data fusion based fault-tolerant control scheme is integrated in altitude control and speed control for altitude sensor failure and airspeed sensor failure, which are the common problems for small fixed-wing UAV. Finally, the real flight experiments are implemented to test the fault-tolerant control based autopilot of UAV. Real flight test results are given and analyzed in detail, which show that the fixed-wing UAV can track the desired altitude and speed commands during the whole flight process including takeoff, climbing, cruising, gliding, landing, and wave-off by the fault-tolerant control based autopilot.

  19. Post-buckled precompressed (PBP) elements : A new class of flight control actuators enhancing high-speed autonomous VTOL MAVs

    NARCIS (Netherlands)

    Barrett, R.; McMurtry, R.; Vos, R.; Tiso, P.; De Breuker, R.


    This paper describes a new class of flight control actuators using Post-Buckled Precompressed (PBP) piezoelectric elements. These actuators are designed to produce significantly higher deflection and force levels than conventional piezoelectric actuator elements. Classical laminate plate theory

  20. The Final Count Down: A Review of Three Decades of Flight Controller Training Methods for Space Shuttle Mission Operations (United States)

    Dittermore, Gary; Bertels, Christie


    Operations of human spaceflight systems is extremely complex; therefore, the training and certification of operations personnel is a critical piece of ensuring mission success. Mission Control Center (MCC-H), at the Lyndon B. Johnson Space Center in Houston, Texas, manages mission operations for the Space Shuttle Program, including the training and certification of the astronauts and flight control teams. An overview of a flight control team s makeup and responsibilities during a flight, and details on how those teams are trained and certified, reveals that while the training methodology for developing flight controllers has evolved significantly over the last thirty years the core goals and competencies have remained the same. In addition, the facilities and tools used in the control center have evolved. Changes in methodology and tools have been driven by many factors, including lessons learned, technology, shuttle accidents, shifts in risk posture, and generational differences. Flight controllers share their experiences in training and operating the space shuttle. The primary training method throughout the program has been mission simulations of the orbit, ascent, and entry phases, to truly train like you fly. A review of lessons learned from flight controller training suggests how they could be applied to future human spaceflight endeavors, including missions to the moon or to Mars. The lessons learned from operating the space shuttle for over thirty years will help the space industry build the next human transport space vehicle.

  1. Stability and control issues associated with lightly loaded rotors autorotating in high advance ratio flight (United States)

    Rigsby, James Michael

    Interest in high speed rotorcraft has directed attention toward the slowed-rotor, high advance ratio compound autogyro concept as evidenced by the current DARPA Heliplane project. The behavior of partially unloaded rotors, autorotating at high advance ratio is not well understood and numerous technical issues must be resolved before the vehicle can be realized. Autorotation in helicopters usually indicates an emergency loss of power. For the concept vehicle autorotation is the normal working state of the rotor. The necessity for a reduction in rotor speed with increasing flight speed results in high advance ratio operation where the retreating side of the rotor is dominated by the reverse flow region. Further, rotor speed changes also affect the rotor dynamics and the associated hub moments generated by cyclic flapping. The result is rotor characteristics that vary widely depending on advance ratio. In the present work, rotor behavior is characterized in terms of issues relevant to the control system conceptual design and the rotor impact on the intrinsic vehicle flight dynamics characteristics. A series of trim, stability, and control analyses, based on features inherent in the concept vehicle, are performed. Trends are identified through parametric variation of rotor operating conditions, augmented by inclusion of the sensitivities to blade mass and blade stiffness properties. In this research, non-linear models, including the rotor speed degree of freedom, were created and analyzed with FLIGHTLAB(TM) rotorcraft modeling software. Performance analysis for rotors trimmed to autorotate with zero average hub pitching and rolling moments indicates reduced rotor thrust is achieved primarily through rotor speed reduction at lower shaft incidence angle, and imposing hub moment trim constraints results in a thrust increment sign reversal with collective pitch angle above advance ratio mu ˜ 1.0. Swashplate control perturbations from trim indicate an increase in control

  2. A History of Suction-Type Laminar Flow Control with Emphasis on Flight Research (United States)

    Braslow, Albert L.


    Laminar-flow control is an area of aeronautical research that has a long history at NASA's Langley Research Center, Dryden Flight Research Center, their predecessor organizations, and elsewhere. In this monograph, the author, who spent much of his career at Langley working with this research, presents a history of that portion of laminar-flow technology known as active laminar-flow control, which employs suction of a small quantity of air through airplane surfaces. This important technique offers the potential for significant reduction in drag and, thereby, for large increases in range or reductions in fuel usage for aircraft. For transport aircraft, the reductions in fuel consumed as a result of laminar-flow control may equal 30 percent of present consumption. Given such potential, it is obvious that active laminar-flow control with suction is an important technology. In this study, the author covers the early history of the subject and brings the story all the way to the mid-1990s with an emphasis on flight research, much of which has occurred at Dryden. This is an important monograph that not only encapsulates a lot of history in a brief compass but also does so in language that is accessible to non-technical readers. NASA is publishing it in a format that will enable it to reach the wide audience the subject deserves.

  3. Space Flight and Manual Control: Implications for Sensorimotor Function on Future Missions (United States)

    Reschke, Millard F.; Kornilova, Ludmila; Tomilovskaya, Elena; Parker, Donald E.; Leigh, R. John; Kozlovskaya, Inessa


    Control of vehicles, and other complex mechanical motion systems, is a high-level integrative function of the central nervous system (CNS) that requires good visual acuity, eye-hand coordination, spatial (and, in some cases, geographic) orientation perception, and cognitive function. Existing evidence from space flight research (Paloski, 2008, Clement and Reschke 2008, Reschke et al., 2007) demonstrates that the function of each of these systems is altered by removing (and subsequently by reintroducing) a gravitational field that can be sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, navigation, and coordination of movements. Furthermore, much of the operational performance data collected as a function of space flight has not been available for independent analysis, and those data that have been reviewed are equivocal owing to uncontrolled environmental and/or engineering factors. Thus, our current understanding, when it comes to manual control, is limited primarily to a review of those situations where manual control has been a factor. One of the simplest approaches to the manual control problem is to review shuttle landing data. See the Figure below for those landing for which we have Shuttle velocities over the runway threshold.

  4. Sliding mode disturbance observer-enhanced adaptive control for the air-breathing hypersonic flight vehicle (United States)

    An, Hao; Wang, Changhong; Fidan, Baris


    This paper presents a backstepping procedure to design an adaptive controller for the air-breathing hypersonic flight vehicle (AHFV) subject to external disturbances and actuator saturations. In each step, a sliding mode exact disturbance observer (SMEDO) is exploited to exactly estimate the lumped disturbance in finite time. Specific dynamics are introduced to handle the possible actuator saturations. Based on SMEDO and introduced dynamics, an adaptive control law is designed, along with the consideration on ;explosion of complexity; in backstepping design. The developed controller is equipped with fast disturbance rejection and great capability to accommodate the saturated actuators, which also lead to a wider application scope. A simulation study is provided to show the effectiveness and superiority of the proposed controller.

  5. Cancer with diabetes: prevalence, metabolic control, and survival in an academic oncology practice. (United States)

    Karlin, Nina J; Dueck, Amylou C; Cook, Curtiss B


    To determine the prevalence of diabetes mellitus, glycemic control, and impact of diabetes on overall survival in an academic oncology practice. Data on cancer patients (1999 to 2008) were retrieved from the institutional cancer registry and linked to electronic files to obtain diabetes status and hemoglobin A1c (A1C) values within the first 6 months of cancer diagnosis. Overall survival by cancer type with and without diabetes was compared using Cox regression. Excluding skin and hematologic malignancies, 15,951 cancer cases were identified. Overall diabetes prevalence was 6.8% (n = 1,090), declining over time (Pcancers (7.6% [68 of 899]). Patients with diabetes were older (mean age, 70 versus 66 years; Pcancer patients was 6.8% and did not differ across cancer types (P = 0.80). Only 58.6% (331 of 565) of diabetic cancer patients had all A1C cancer diagnosis. Pancreatic cancer patients with coexisting diabetes had better overall survival than pancreatic cancer patients without diabetes (hazard ratio, 0.60; 95% confidence interval 0.44 to 0.80; Pcancer patients had worse overall survival than prostate cancer patients without diabetes (hazard ratio, 1.36; 95% confidence interval 1.05 to 1.76; P = 0.02). In this academic oncology practice, diabetes was common, glycemic control often was suboptimal, and survival varied by cancer type. Additional study is needed to optimize glucose management and investigate mechanisms underlying age, sex, and survival differences.

  6. Distributed Sharing of Functionalities and Resources in Survivable GMPLS-controlled WSONs

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Cerutti, I.; Muñoz, R.


    at the physical layer (i.e., quality of transmission, QoT) and at the upper layer also in the case of a failure (i.e., survivability). This paper aims to apply the sharing concept to a WSON with QoT and survivability requirements (against single-link failures). QoT is guaranteed by resorting to regeneration...... is exploited to ensure survivability against single-link failures and make the sharing of network resources (regenerators and wavelengths) possible. The paper presents a novel distributed scheme (DISTR) for reservation of regenerators and wavelengths in generalized multi-protocol label switching controlled...... WSONs, in order to ensure the required level of QoT and survivability. Novel objects and selection strategies for the resource reservation protocol with traffic engineering extensions are proposed and evaluated. The DISTR scheme effectively combines regeneration and WC points, leading to a noticeable...

  7. Generation of the pitch moment during the controlled flight after takeoff of fruitflies.

    Directory of Open Access Journals (Sweden)

    Mao Wei Chen

    Full Text Available In the present paper, the controlled flight of fruitflies after voluntary takeoff is studied. Wing and body kinematics of the insects after takeoff are measured using high-speed video techniques, and the aerodynamic force and moment are calculated by the computational fluid dynamics method based on the measured data. How the control moments are generated is analyzed by correlating the computed moments with the wing kinematics. A fruit-fly has a large pitch-up angular velocity owing to the takeoff jump and the fly controls its body attitude by producing pitching moments. It is found that the pitching moment is produced by changes in both the aerodynamic force and the moment arm. The change in the aerodynamic force is mainly due to the change in angle of attack. The change in the moment arm is mainly due to the change in the mean stroke angle and deviation angle, and the deviation angle plays a more important role than the mean stroke angle in changing the moment arm (note that change in deviation angle implies variation in the position of the aerodynamic stroke plane with respect to the anatomical stroke plane. This is unlike the case of fruitflies correcting pitch perturbations in steady free flight, where they produce pitching moment mainly by changes in mean stroke angle.

  8. UAV-Based L-Band SAR with Precision Flight Path Control (United States)

    Madsen, Soren N.; Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Muellerschoen, Ron; Lou, Yunling; Rosen, Paul


    NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also know as differential interferometric measurements. Differential interferometry can provide key displacement measurements, important for the scientific studies of Earthquakes and volcanoes. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The radar will be designed to operate on a UAV (Unmanned Arial Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus build by Scaled Composites. The application requires control of the flight path to within a 10 meter tube to support repeat track and formation flying measurements. The design is fully polarimetric with an 80 MHz bandwidth (2 meter range resolution) and 16 kilometer range swath. The antenna is an electronically steered array to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. The system will nominally operate at 45,000 ft. The program started out as a Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

  9. Consensus of satellite cluster flight using an energy-matching optimal control method (United States)

    Luo, Jianjun; Zhou, Liang; Zhang, Bo


    This paper presents an optimal control method for consensus of satellite cluster flight under a kind of energy matching condition. Firstly, the relation between energy matching and satellite periodically bounded relative motion is analyzed, and the satellite energy matching principle is applied to configure the initial conditions. Then, period-delayed errors are adopted as state variables to establish the period-delayed errors dynamics models of a single satellite and the cluster. Next a novel satellite cluster feedback control protocol with coupling gain is designed, so that the satellite cluster periodically bounded relative motion consensus problem (period-delayed errors state consensus problem) is transformed to the stability of a set of matrices with the same low dimension. Based on the consensus region theory in the research of multi-agent system consensus issues, the coupling gain can be obtained to satisfy the requirement of consensus region and decouple the satellite cluster information topology and the feedback control gain matrix, which can be determined by Linear quadratic regulator (LQR) optimal method. This method can realize the consensus of satellite cluster period-delayed errors, leading to the consistency of semi-major axes (SMA) and the energy-matching of satellite cluster. Then satellites can emerge the global coordinative cluster behavior. Finally the feasibility and effectiveness of the present energy-matching optimal consensus for satellite cluster flight is verified through numerical simulations.

  10. Calculated hovering helicopter flight dynamics with a circulation-controlled rotor (United States)

    Johnson, W.; Chopra, I.


    The flight dynamics of a hovering helicopter with a circulation-controlled rotor are analyzed. The influence of the rotor blowing coefficient on the calculated eigenvalues of the helicopter motion is examined for a range of values of the rotor lift and the blade flap frequency. The control characteristics of a helicopter with a circulation-controlled rotor are discussed. The principal effect of the blowing is a reduction in the rotor speed stability derivative. Above a critical level of blowing coefficient, which depends on the flap frequency and rotor lift, negative speed stability is produced and the dynamic characteristics of the helicopter are radically altered. The handling qualities of a helicopter with negative speed stability are probably unacceptable without a stability augmentation system.

  11. Design and flight experience with a digital fly-by-wire control system in an F-8 airplane (United States)

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


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

  12. Novel SiL evaluation of an optimal H∞ controller on the stability of a MAV in flight simulator (United States)

    Sampaio, Rafael C. B.; Becker, Marcelo; Siqueira, Adriano A. G.; Freschi, Leonardo W.; Montanher, Marcelo P.

    This paper introduces a novel methodology to assist the evaluation of control algorithms for MAVs (Micro Aerial Vehicles) using Software-in-the-Loop (SiL) based flight simulation. The originality of this paper is to use © Microsoft Flight Simulator (MSFS) as the environment to embed both the dynamic and graphic models of © Ascending Technologies Pelican MAV flying robot. The resulting is a reliable model of the Pelican quadrotor. The full duplex communication between the virtual aircraft and the control algorithm is achieved by a custom C++/C software named FVMS (Flight Variables Management System), developed by Aerial Robots Team (ART), which is able to reach (read/write) a great number of flight variables from MSFS. To illustrate the effectiveness of such method, we first completely present FVMS architecture and main features. Later, the synthesis and then the application of the optimal H∞ robust control algorithm and its operation into the FVMS SiL context are explained. Regarding MAVs control evaluation, SiL simulation considerably contributes to save battery time, to ease control synthesis and prototyping and to prevent accidents during tests with the real robot. The final goal is to evaluate the stability of the Pelican platform in hovering tasks in flight simulation focusing on the efficiency of FVMS to properly run the optimal H∞ robust control algorithm. The SiL control of the MAV has proven FVMS capabilities, which may be extended to assist the design of other classes of controllers.

  13. The Right Stuff: A Look Back at Three Decades of Flight Controller Training for Space Shuttle Mission Operations (United States)

    Dittemore, Gary D.


    Operations of human spaceflight systems is extremely complex, therefore the training and certification of operations personnel is a critical piece of ensuring mission success. Mission Control Center (MCC-H), at the Lyndon B. Johnson Space Center, in Houston, Texas manages mission operations for the Space Shuttle Program, including the training and certification of the astronauts and flight control teams. This paper will give an overview of a flight control team s makeup and responsibilities during a flight, and details on how those teams are trained and certified. The training methodology for developing flight controllers has evolved significantly over the last thirty years, while the core goals and competencies have remained the same. In addition, the facilities and tools used in the control center have evolved. These changes have been driven by many factors including lessons learned, technology, shuttle accidents, shifts in risk posture, and generational differences. Flight controllers will share their experiences in training and operating the Space Shuttle throughout the Program s history. A primary method used for training Space Shuttle flight control teams is by running mission simulations of the orbit, ascent, and entry phases, to truly "train like you fly." The reader will learn what it is like to perform a simulation as a shuttle flight controller. Finally, the paper will reflect on the lessons learned in training for the shuttle program, and how those could be applied to future human spaceflight endeavors. These endeavors could range from going to the moon or to Mars. The lessons learned from operating the space shuttle for over thirty years will help the space industry build the next human transport space vehicle and inspire the next generation of space explorers.

  14. Abdicating power for control: a precision timing strategy to modulate function of flight power muscles (United States)

    Sponberg, S.; Daniel, T. L.


    Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power–phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left–right pairs of flight muscles normally fire precisely, within 0.5–0.6 ms of each other; (ii) during a yawing optomotor response, left—right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left–right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left—right timing differences. Because many organisms also have muscles operating with high power–phase gains (Δpower/Δphase), this motor control strategy may be ubiquitous in locomotor systems. PMID:22833272

  15. Abdicating power for control: a precision timing strategy to modulate function of flight power muscles. (United States)

    Sponberg, S; Daniel, T L


    Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power-phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left-right pairs of flight muscles normally fire precisely, within 0.5-0.6 ms of each other; (ii) during a yawing optomotor response, left-right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left-right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left-right timing differences. Because many organisms also have muscles operating with high power-phase gains (Δ(power)/Δ(phase)), this motor control strategy may be ubiquitous in locomotor systems.

  16. Monte Carlo based protocol for cell survival and tumour control probability in BNCT. (United States)

    Ye, S J


    A mathematical model to calculate the theoretical cell survival probability (nominally, the cell survival fraction) is developed to evaluate preclinical treatment conditions for boron neutron capture therapy (BNCT). A treatment condition is characterized by the neutron beam spectra, single or bilateral exposure, and the choice of boron carrier drug (boronophenylalanine (BPA) or boron sulfhydryl hydride (BSH)). The cell survival probability defined from Poisson statistics is expressed with the cell-killing yield, the 10B(n,alpha)7Li reaction density, and the tolerable neutron fluence. The radiation transport calculation from the neutron source to tumours is carried out using Monte Carlo methods: (i) reactor-based BNCT facility modelling to yield the neutron beam library at an irradiation port; (ii) dosimetry to limit the neutron fluence below a tolerance dose (10.5 Gy-Eq); (iii) calculation of the 10B(n,alpha)7Li reaction density in tumours. A shallow surface tumour could be effectively treated by single exposure producing an average cell survival probability of 10(-3)-10(-5) for probable ranges of the cell-killing yield for the two drugs, while a deep tumour will require bilateral exposure to achieve comparable cell kills at depth. With very pure epithermal beams eliminating thermal, low epithermal and fast neutrons, the cell survival can be decreased by factors of 2-10 compared with the unmodified neutron spectrum. A dominant effect of cell-killing yield on tumour cell survival demonstrates the importance of choice of boron carrier drug. However, these calculations do not indicate an unambiguous preference for one drug, due to the large overlap of tumour cell survival in the probable ranges of the cell-killing yield for the two drugs. The cell survival value averaged over a bulky tumour volume is used to predict the overall BNCT therapeutic efficacy, using a simple model of tumour control probability (TCP).

  17. Population-based cancer survival in the United States: Data, quality control, and statistical methods. (United States)

    Allemani, Claudia; Harewood, Rhea; Johnson, Christopher J; Carreira, Helena; Spika, Devon; Bonaventure, Audrey; Ward, Kevin; Weir, Hannah K; Coleman, Michel P


    Robust comparisons of population-based cancer survival estimates require tight adherence to the study protocol, standardized quality control, appropriate life tables of background mortality, and centralized analysis. The CONCORD program established worldwide surveillance of population-based cancer survival in 2015, analyzing individual data on 26 million patients (including 10 million US patients) diagnosed between 1995 and 2009 with 1 of 10 common malignancies. In this Cancer supplement, we analyzed data from 37 state cancer registries that participated in the second cycle of the CONCORD program (CONCORD-2), covering approximately 80% of the US population. Data quality checks were performed in 3 consecutive phases: protocol adherence, exclusions, and editorial checks. One-, 3-, and 5-year age-standardized net survival was estimated using the Pohar Perme estimator and state- and race-specific life tables of all-cause mortality for each year. The cohort approach was adopted for patients diagnosed between 2001 and 2003, and the complete approach for patients diagnosed between 2004 and 2009. Articles in this supplement report population coverage, data quality indicators, and age-standardized 5-year net survival by state, race, and stage at diagnosis. Examples of tables, bar charts, and funnel plots are provided in this article. Population-based cancer survival is a key measure of the overall effectiveness of services in providing equitable health care. The high quality of US cancer registry data, 80% population coverage, and use of an unbiased net survival estimator ensure that the survival trends reported in this supplement are robustly comparable by race and state. The results can be used by policymakers to identify and address inequities in cancer survival in each state and for the United States nationally. Cancer 2017;123:4982-93. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U

  18. Electrical, Electronic, and Electromechanical (EEE) parts management and control requirements for NASA space flight programs (United States)


    This document establishes electrical, electronic, and electromechanical (EEE) parts management and control requirements for contractors providing and maintaining space flight and mission-essential or critical ground support equipment for NASA space flight programs. Although the text is worded 'the contractor shall,' the requirements are also to be used by NASA Headquarters and field installations for developing program/project parts management and control requirements for in-house and contracted efforts. This document places increased emphasis on parts programs to ensure that reliability and quality are considered through adequate consideration of the selection, control, and application of parts. It is the intent of this document to identify disciplines that can be implemented to obtain reliable parts which meet mission needs. The parts management and control requirements described in this document are to be selectively applied, based on equipment class and mission needs. Individual equipment needs should be evaluated to determine the extent to which each requirement should be implemented on a procurement. Utilization of this document does not preclude the usage of other documents. The entire process of developing and implementing requirements is referred to as 'tailoring' the program for a specific project. Some factors that should be considered in this tailoring process include program phase, equipment category and criticality, equipment complexity, and mission requirements. Parts management and control requirements advocated by this document directly support the concept of 'reliability by design' and are an integral part of system reliability and maintainability. Achieving the required availability and mission success objectives during operation depends on the attention given reliability and maintainability in the design phase. Consequently, it is intended that the requirements described in this document are consistent with those of NASA publications

  19. 3-Axis magnetic control: flight results of the TANGO satellite in the PRISMA mission (United States)

    Chasset, C.; Noteborn, R.; Bodin, P.; Larsson, R.; Jakobsson, B.


    PRISMA implements guidance, navigation and control strategies for advanced formation flying and rendezvous experiments. The project is funded by the Swedish National Space Board and run by OHB-Sweden in close cooperation with DLR, CNES and the Danish Technical University. The PRISMA test bed consists of a fully manoeuvrable MANGO satellite as well as a 3-axis controlled TANGO satellite without any Δ V capability. PRISMA was launched on the 15th of June 2010 on board DNEPR. The TANGO spacecraft is the reference satellite for the experiments performed by MANGO, either with a "cooperative" or "non-cooperative" behaviour. Small, light and low-cost were the keywords for the TANGO design. The attitude determination is based on Sun sensors and magnetometers, and the active attitude control uses magnetic torque rods only. In order to perform the attitude manoeuvres required to fulfil the mission objectives, using any additional gravity gradient boom to passively stabilize the spacecraft was not allowed. After a two-month commissioning phase, TANGO separated from MANGO on the 11th of August 2010. All operational modes have been successfully tested, and the pointing performance in flight is in accordance with expectations. The robust Sun Acquisition mode reduced the initial tip-off rate and placed TANGO into a safe attitude in TANGO points its GPS antenna towards zenith with sufficient accuracy to track as many GPS satellites as MANGO. At the same time, it points its solar panel towards the Sun, and all payload equipments can be switched on without any restriction. This paper gives an overview of the TANGO Attitude Control System design. It then presents the flight results in the different operating modes. Finally, it highlights the key elements at the origin of the successful 3-axis magnetic control strategy on the TANGO satellite.

  20. In-Flight Active Wave Cancelation with Delayed-x-LMS Control Algorithm in a Laminar Boundary Layer (United States)

    Simon, Bernhard; Fabbiane, Nicolo; Nemitz, Timotheus; Bagheri, Shervin; Henningson, Dan; Grundmann, Sven


    This manuscript demonstrates the first successful application of the delayed-x-LMS (dxLMS) control algorithm for TS-wave cancelation. Active wave cancelation of two-dimensional broad-band Tollmien-Schlichting (TS) disturbances is performed with a single DBD plasma actuator. The experiments are conducted in flight on the pressure side of a laminar flow wing glove, mounted on a manned glider. The stability properties of the controller are investigated in detail with experimental flight data, DNS and stability analysis of the boundary layer. Finally, a model-free approach for dxLMS operation is introduced to operate the controller as a "black box" system, which automatically adjusts the controller settings based on a group speed measurement of the disturbance wave packets. The modified dxLMS controller is operated without a model and is able to adapt to varying conditions that may occur during flight in atmosphere. DFG No.GR3524/4-1.

  1. NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development (United States)

    Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.


    Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges. This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system. The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis. The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort.

  2. New Methodology for Optimal Flight Control using Differential Evolution Algorithms applied on the Cessna Citation X Business Aircraft – Part 2. Validation on Aircraft Research Flight Level D Simulator

    Directory of Open Access Journals (Sweden)

    Yamina BOUGHARI


    Full Text Available In this paper the Cessna Citation X clearance criteria were evaluated for a new Flight Controller. The Flight Control Law were optimized and designed for the Cessna Citation X flight envelope by combining the Deferential Evolution algorithm, the Linear Quadratic Regulator method, and the Proportional Integral controller during a previous research presented in part 1. The optimal controllers were used to reach satisfactory aircraft’s dynamic and safe flight operations with respect to the augmentation systems’ handling qualities, and design requirements. Furthermore the number of controllers used to control the aircraft in its flight envelope was optimized using the Linear Fractional Representations features. To validate the controller over the whole aircraft flight envelope, the linear stability, eigenvalue, and handling qualities criteria in addition of the nonlinear analysis criteria were investigated during this research to assess the business aircraft for flight control clearance and certification. The optimized gains provide a very good stability margins as the eigenvalue analysis shows that the aircraft has a high stability, and a very good flying qualities of the linear aircraft models are ensured in its entire flight envelope, its robustness is demonstrated with respect to uncertainties due to its mass and center of gravity variations.

  3. Flight evaluation of the transonic stability and control characteristics of an airplane incorporating a supercritical wing (United States)

    Matheny, N. W.; Gatlin, D. H.


    A TF-8A airplane was equipped with a transport type supercritical wing and fuselage fairings to evaluate predicted performance improvements for cruise at transonic speeds. A comparison of aerodynamic derivatives extracted from flight and wind tunnel data showed that static longitudinal stability, effective dihedral, and aileron effectiveness, were higher than predicted. The static directional stability derivative was slower than predicted. The airplane's handling qualities were acceptable with the stability augmentation system on. The unaugmented airplane exhibited some adverse lateral directional characteristics that involved low Dutch roll damping and low roll control power at high angles of attack and roll control power that was greater than satisfactory for transport aircraft at cruise conditions. Longitudinally, the aircraft exhibited a mild pitchup tendency. Leading edge vortex generators delayed the onset of flow separation, moving the pitchup point to a higher lift coefficient and reducing its severity.

  4. Performance of Swashplateless Ultralight Helicopter Rotor with Trailing-edge Flaps for Primary Flight Control (United States)

    Shen, Jin-Wei; Chopra, Inderjit


    The objective of present study is to evaluate the rotor performance, trailing-edge deflections and actuation requirement of a helicopter rotor with trailing-edge flap system for primary flight control. The swashplateless design is implemented by modifying a two-bladed teetering rotor of an production ultralight helicopter through the use of plain flaps on the blades, and by replacing the pitch link to fixed system control system assembly with a root spring. A comprehensive rotorcraft analysis based on UMARC is carried out to obtain the results for both the swashplateless and a conventional baseline rotor configuration. The predictions show swashplateless configuration achieve superior performance than the conventional rotor attributed from reduction of parasite drag by eliminating swashplate mechanic system. It is indicated that optimal selection of blade pitch index angle, flap location, length, and chord ratio reduces flap deflections and actuation requirements, however, has virtually no effect on rotor performance.

  5. Management of redundancy in flight control systems using optimal decision theory (United States)


    The problem of using redundancy that exists between dissimilar systems in aircraft flight control is addressed. That is, using the redundancy that exists between a rate gyro and an accelerometer--devices that have dissimilar outputs which are related only through the dynamics of the aircraft motion. Management of this type of redundancy requires advanced logic so that the system can monitor failure status and can reconfigure itself in the event of one or more failures. An optimal decision theory was tutorially developed for the management of sensor redundancy and the theory is applied to two aircraft examples. The first example is the space shuttle and the second is a highly maneuvering high performance aircraft--the F8-C. The examples illustrate the redundancy management design process and the performance of the algorithms presented in failure detection and control law reconfiguration.

  6. Multi-Objective Flight Control for Drag Minimization and Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft (United States)

    Nguyen, Nhan; Ting, Eric; Chaparro, Daniel; Drew, Michael; Swei, Sean


    As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight material could be offset by less optimal aerodynamic performance at off-design flight conditions. Performance Adaptive Aeroelastic Wing (PAAW) technology can potentially address these technical challenges for future flexible wing transports. PAAW technology leverages multi-disciplinary solutions to maximize the aerodynamic performance payoff of future adaptive wing design, while addressing simultaneously operational constraints that can prevent the optimal aerodynamic performance from being realized. These operational constraints include reduced flutter margins, increased airframe responses to gust and maneuver loads, pilot handling qualities, and ride qualities. All of these constraints while seeking the optimal aerodynamic performance present themselves as a multi-objective flight control problem. The paper presents a multi-objective flight control approach based on a drag-cognizant optimal control method. A concept of virtual control, which was previously introduced, is implemented to address the pair-wise flap motion constraints imposed by the elastomer material. This method is shown to be able to satisfy the constraints. Real-time drag minimization control is considered to be an important consideration for PAAW technology. Drag minimization control has many technical challenges such as sensing and control. An initial outline of a real-time drag minimization control has already been developed and will be further investigated in the future. A simulation study of a multi-objective flight control for a flight path angle command with aeroelastic mode suppression and drag

  7. Pelvis Ewing sarcoma: Local control and survival in the modern era. (United States)

    Ahmed, Safia K; Robinson, Steven I; Arndt, Carola A S; Petersen, Ivy A; Haddock, Michael G; Rose, Peter S; Issa Laack, Nadia N


    Local control for Ewing sarcoma (ES) has improved in modern studies. However, it is unclear if these gains have also been achieved for pelvis tumors. The purpose of this study is to evaluate local control and survival in pelvis ES patients treated in the modern era. All pelvis ES patients diagnosed from 1990 to 2012 and seen at Mayo Clinic were identified. Factors relevant to survival and local control were analyzed. The cohort consisted of 48 patients. Fifty-two percent had metastatic disease at diagnosis. The 5-year overall survival and event-free survival was 73% and 65%, respectively, for localized disease. The 5-year cumulative incidence of local recurrence was 19%, with a 26% incidence for radiation, 13% for surgery, and 0% for surgery + radiation (P = 0.54). All local failures occurred in-field. Sacral involvement by tumor trended toward a higher incidence of local recurrence (hazard ratio 3.06, P = 0.09). Patients treated with definitive radiation doses ≥5,600 cGy had a lower incidence of local recurrence (17% vs. 28%, P = 0.61). Our study demonstrates excellent survival for localized tumors in the modern era. Anatomical localization within the pelvis likely correlates with outcomes. Local control remains problematic, especially for patients treated with definitive radiation. Though statistically not significant, surgery + radiation and definitive radiation dose ≥5,600 cGy were associated with the lowest incidence of local failure, suggesting treatment intensification may improve local control for pelvis ES. © 2017 Wiley Periodicals, Inc.

  8. A Piloted Simulator Investigation of Side-Stick Controller/Stability and Control Augmentation System Requirements for Helicopter Visual Flight Tasks, (United States)


    Simulation Program: Vol- flight handling qualities without pilot selection, ume I-Mathematical Model", NASA the contril laws required automatic phasing...acteristics and level of stability and control The Phase 2 simulation experiment, the subject augmentation on handling qualities for several of this paper...handling qualities under VMC and empha- speed and forward flight control laws were im- sized tasks which represented elements of the plemented, and a

  9. An integrated Rotorcraft Avionics/Controls Architecture to support advanced controls and low-altitude guidance flight research (United States)

    Jacobsen, Robert A.; Doane, Douglas H.; Eshow, Michelle M.; Aiken, Edwin W.; Hindson, William S.


    Salient design features of a new NASA/Army research rotorcraft--the Rotorcraft-Aircrew Systems Concepts Airborne Laboratory (RASCAL) are described. Using a UH-60A Black Hawk helicopter as a baseline vehicle, the RASCAL will be a flying laboratory capable of supporting the research requirements of major NASA and Army guidance, control, and display research programs. The paper describes the research facility requirements of these programs together with other critical constraints on the design of the research system. Research program schedules demand a phased development approach, wherein specific research capability milestones are met and flight research projects are flown throughout the complete development cycle of the RASCAL. This development approach is summarized, and selected features of the research system are described. The research system includes a real-time obstacle detection and avoidance system which will generate low-altitude guidance commands to the pilot on a wide field-of-view, color helmet-mounted display and a full-authority, programmable, fault-tolerant/fail-safe, fly-by-wire flight control system.

  10. Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report (United States)

    Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.


    regularity of flight. Only recently has radiofrequency (RF) spectrum been allocated by the International Telecommunications Union specifically for commercial UA C2, LOS communication (L-Band: 960 to 1164 MHz, and C-Band: 5030 to 5091 MHz). The safe and efficient integration of UA into the NAS requires the use of protected RF spectrum allocations and a new data communications system that is both secure and scalable to accommodate the potential growth of these new aircraft. Data communications for UA-referred to as control and non-payload communications (CNPC)-will be used to exchange information between a UA and a ground station (GS) to ensure safe, reliable, and effective UA flight operation. The focus of this effort is on validating and allocating new RF spectrum and data link communications to enable civil UA integration into the NAS. Through a cost-sharing cooperative agreement with Rockwell Collins, Inc., the NASA Glenn Research Center is exploring and performing the necessary development steps to realize a prototype UA CNPC system. These activities include investigating signal waveforms and access techniques, developing representative CNPC radio hardware, and executing relevant testing and validation activities. There is no intent to manufacture the CNPC end product, rather the goals are to study, demonstrate, and validate a typical CNPC system that will allow safe and efficient communications within the L-Band and C-Band spectrum allocations. The system is addressing initial "seed" requirements from RTCA, Inc., Special Committee 203 (SC-203) and is on a path to Federal Aviation Administration certification. This report provides results from the flight testing campaign of the Rockwell Collins Generation 1 prototype radio, referred hereafter as the "radio." The radio sets operate within the 960- to 977-MHz frequency band with both air and ground radios using identical hardware. Flight tests involved one aircraft and one GS. Results include discussion of aircraft flight

  11. Piloted simulation tests of propulsion control as backup to loss of primary flight controls for a mid-size jet transport (United States)

    Bull, John; Mah, Robert; Davis, Gloria; Conley, Joe; Hardy, Gordon; Gibson, Jim; Blake, Matthew; Bryant, Don; Williams, Diane


    Failures of aircraft primary flight-control systems to aircraft during flight have led to catastrophic accidents with subsequent loss of lives (e.g. , DC-1O crash, B-747 crash, C-5 crash, B-52 crash, and others). Dryden Flight Research Center (DFRC) investigated the use of engine thrust for emergency flight control of several airplanes, including the B-720, Lear 24, F-15, C-402, and B-747. A series of three piloted simulation tests have been conducted at Ames Research Center to investigate propulsion control for safely landing a medium size jet transport which has experienced a total primary flight-control failure. The first series of tests was completed in July 1992 and defined the best interface for the pilot commands to drive the engines. The second series of tests was completed in August 1994 and investigated propulsion controlled aircraft (PCA) display requirements and various command modes. The third series of tests was completed in May 1995 and investigated PCA full-flight envelope capabilities. This report describes the concept of a PCA, discusses pilot controls, displays, and procedures; and presents the results of piloted simulation evaluations of the concept by a cross-section of air transport pilots.

  12. Computational Model of Human and System Dynamics in Free Flight: Studies in Distributed Control Technologies (United States)

    Corker, Kevin M.; Pisanich, Gregory; Lebacqz, J. Victor (Technical Monitor)


    This paper presents a set of studies in full mission simulation and the development of a predictive computational model of human performance in control of complex airspace operations. NASA and the FAA have initiated programs of research and development to provide flight crew, airline operations and air traffic managers with automation aids to increase capacity in en route and terminal area to support the goals of safe, flexible, predictable and efficient operations. In support of these developments, we present a computational model to aid design that includes representation of multiple cognitive agents (both human operators and intelligent aiding systems). The demands of air traffic management require representation of many intelligent agents sharing world-models, coordinating action/intention, and scheduling goals and actions in a potentially unpredictable world of operations. The operator-model structure includes attention functions, action priority, and situation assessment. The cognitive model has been expanded to include working memory operations including retrieval from long-term store, and interference. The operator's activity structures have been developed to provide for anticipation (knowledge of the intention and action of remote operators), and to respond to failures of the system and other operators in the system in situation-specific paradigms. System stability and operator actions can be predicted by using the model. The model's predictive accuracy was verified using the full-mission simulation data of commercial flight deck operations with advanced air traffic management techniques.

  13. Using Web 2.0 (and Beyond?) in Space Flight Operations Control Centers (United States)

    Scott, David W.


    Word processing was one of the earliest uses for small workstations, but we quickly learned that desktop computers were far more than e-typewriters. Similarly, "Web 2.0" capabilities, particularly advanced search engines, chats, wikis, blogs, social networking, and the like, offer tools that could significantly improve our efficiency at managing the avalanche of information and decisions needed to operate space vehicles in realtime. However, could does not necessarily equal should. We must wield two-edged swords carefully to avoid stabbing ourselves. This paper examines some Web 2.0 tools, with an emphasis on social media, and suggests which ones might be useful or harmful in real-time space operations co rnotl environments, based on the author s experience as a Payload Crew Communicator (PAYCOM) at Marshall Space Flight Center s (MSFC) Payload Operations Integration Center (POIC) for the International Space Station (ISS) and on discussions with other space flight operations control organizations and centers. There is also some discussion of an offering or two that may come from beyond the current cyber-horizon.

  14. Application of a sensitivity analysis technique to high-order digital flight control systems (United States)

    Paduano, James D.; Downing, David R.


    A sensitivity analysis technique for multiloop flight control systems is studied. This technique uses the scaled singular values of the return difference matrix as a measure of the relative stability of a control system. It then uses the gradients of these singular values with respect to system and controller parameters to judge sensitivity. The sensitivity analysis technique is first reviewed; then it is extended to include digital systems, through the derivation of singular-value gradient equations. Gradients with respect to parameters which do not appear explicitly as control-system matrix elements are also derived, so that high-order systems can be studied. A complete review of the integrated technique is given by way of a simple example: the inverted pendulum problem. The technique is then demonstrated on the X-29 control laws. Results show linear models of real systems can be analyzed by this sensitivity technique, if it is applied with care. A computer program called SVA was written to accomplish the singular-value sensitivity analysis techniques. Thus computational methods and considerations form an integral part of many of the discussions. A user's guide to the program is included. The SVA is a fully public domain program, running on the NASA/Dryden Elxsi computer.

  15. Cellular Decomposition Based Hybrid-Hierarchical Control Systems with Applications to Flight Management Systems (United States)

    Caines, P. E.


    The work in this research project has been focused on the construction of a hierarchical hybrid control theory which is applicable to flight management systems. The motivation and underlying philosophical position for this work has been that the scale, inherent complexity and the large number of agents (aircraft) involved in an air traffic system imply that a hierarchical modelling and control methodology is required for its management and real time control. In the current work the complex discrete or continuous state space of a system with a small number of agents is aggregated in such a way that discrete (finite state machine or supervisory automaton) controlled dynamics are abstracted from the system's behaviour. High level control may then be either directly applied at this abstracted level, or, if this is in itself of significant complexity, further layers of abstractions may be created to produce a system with an acceptable degree of complexity at each level. By the nature of this construction, high level commands are necessarily realizable at lower levels in the system.

  16. Prostate cancer control and survival in Vietnam veterans exposed to Agent Orange. (United States)

    Everly, Lydia; Merrick, Gregory S; Allen, Zachariah A; Butler, Wayne M; Wallner, Kent; Lief, Jonathan H; Galbreath, Robert W; Adamovich, Edward


    In this study, we evaluated the impact of Agent Orange exposure on survival in Vietnam Veterans undergoing prostate brachytherapy. From May 1995 to January 2005, 81 Vietnam veterans (29 with Agent Orange exposure and 52 without) and 433 nonveterans of comparable age (mean age, 58 years) underwent prostate brachytherapy. The mean follow-up was 5.0 years. Biochemical progression-free survival (bPFS) was defined as a prostate-specific antigen (PSA)Agent Orange-exposed men were least likely to remain biochemically controlled (89.5%, 100%, and 97.2% in Agent Orange-exposed, nonexposed veterans, and nonveterans, respectively, p=0.012). No significant differences in cause-specific (CSS) (p=0.832) or overall survival (OS) (p=0.363) were discerned. In multivariate analysis, CSS was best predicted by Gleason Score and day 0 D(90), whereas Gleason Score, % positive biopsies, and D(90) predicted for bPFS. None of the evaluated parameters predicted for OS, however, a trend was identified for better OS in younger patients and those with a higher D(90). In addition, Agent Orange exposure did not predict for any of the survival parameters. To date, 22 patients have died (metastatic prostate cancer two, second malignancies nine, cardiovascular disease eight, trauma two, and pulmonary one). In this cohort of prostate brachytherapy patients, Agent Orange exposure did not statistically impact survival in multivariate analysis.

  17. A Hybrid Sensor Based Backstepping Control Approach with its Application to Fault-Tolerant Flight Control

    NARCIS (Netherlands)

    Sun, L.G.; De Visser, C.C.; Chu, Q.P.; Falkena, W.


    Recently, an incremental type sensor based backstepping (SBB) control approach, based on singular perturbation theory and Tikhonov’s theorem, has been proposed. This Lyapunov function based method uses measurements of control variables and less model knowledge, and it is not susceptible to the model

  18. Guidance, Navigation and Control (GN and C) Design Overview and Flight Test Results from NASA's Max Launch Abort System (MLAS) (United States)

    Dennehy, Cornelius J.; Lanzi, Raymond J.; Ward, Philip R.


    The National Aeronautics and Space Administration Engineering and Safety Center designed, developed and flew the alternative Max Launch Abort System (MLAS) as risk mitigation for the baseline Orion spacecraft launch abort system already in development. The NESC was tasked with both formulating a conceptual objective system design of this alternative MLAS as well as demonstrating this concept with a simulated pad abort flight test. Less than 2 years after Project start the MLAS simulated pad abort flight test was successfully conducted from Wallops Island on July 8, 2009. The entire flight test duration was 88 seconds during which time multiple staging events were performed and nine separate critically timed parachute deployments occurred as scheduled. This paper provides an overview of the guidance navigation and control technical approaches employed on this rapid prototyping activity; describes the methodology used to design the MLAS flight test vehicle; and lessons that were learned during this rapid prototyping project are also summarized.

  19. The effects of risk perception and flight experience on airline pilots' locus of control with regard to safety operation behaviors. (United States)

    You, Xuqun; Ji, Ming; Han, Haiyan


    The primary objective of this paper was to integrate two research traditions, social cognition approach and individual state approach, and to understand the relationships between locus of control (LOC), risk perception, flight time, and safety operation behavior (SOB) among Chinese airline pilots. The study sample consisted of 193 commercial airline pilots from China Southern Airlines Ltd. The results showed that internal locus of control directly affected pilot safety operation behavior. Risk perception seemed to mediate the relationship between locus of control and safety operation behaviors, and total flight time moderated internal locus of control. Thus, locus of control primarily influences safety operation behavior indirectly by affecting risk perception. The total effect of internal locus of control on safety behaviors is larger than that of external locus of control. Furthermore, the safety benefit of flight experience is more pronounced among pilots with high internal loci of control in the early and middle flight building stages. Practical implications for aviation safety and directions for future research are also discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Towards an Improved Pilot-Vehicle Interface for Highly Automated Aircraft: Evaluation of the Haptic Flight Control System (United States)

    Schutte, Paul; Goodrich, Kenneth; Williams, Ralph


    The control automation and interaction paradigm (e.g., manual, autopilot, flight management system) used on virtually all large highly automated aircraft has long been an exemplar of breakdowns in human factors and human-centered design. An alternative paradigm is the Haptic Flight Control System (HFCS) that is part of NASA Langley Research Center s Naturalistic Flight Deck Concept. The HFCS uses only stick and throttle for easily and intuitively controlling the actual flight of the aircraft without losing any of the efficiency and operational benefits of the current paradigm. Initial prototypes of the HFCS are being evaluated and this paper describes one such evaluation. In this evaluation we examined claims regarding improved situation awareness, appropriate workload, graceful degradation, and improved pilot acceptance. Twenty-four instrument-rated pilots were instructed to plan and fly four different flights in a fictitious airspace using a moderate fidelity desktop simulation. Three different flight control paradigms were tested: Manual control, Full Automation control, and a simplified version of the HFCS. Dependent variables included both subjective (questionnaire) and objective (SAGAT) measures of situation awareness, workload (NASA-TLX), secondary task performance, time to recognize automation failures, and pilot preference (questionnaire). The results showed a statistically significant advantage for the HFCS in a number of measures. Results that were not statistically significant still favored the HFCS. The results suggest that the HFCS does offer an attractive and viable alternative to the tactical components of today s FMS/autopilot control system. The paper describes further studies that are planned to continue to evaluate the HFCS.

  1. Identification of M2/F3 stability and control derivatives from flight data containing gust effects (United States)

    Stepner, D. E.; Mehra, R. K.


    The application of the maximum likelihood identification technique to M2/F3 lifting body flight data containing wind gust effects is discussed. With the objective of this effort being the identification of the stability and control derivatives, it is shown first that the output error technique (or modified Newton-Raphson) fails to fit the recorded data accurately. The means of applying the maximum likelihood technique to this problem are then discussed and the results given which indicate an accurate fit to the data. The question of derivative signs opposite to the wind tunnel values is then addressed and the results of three techniques for dealing with this problem are presented. These techniques are a priori weighting, fixing parameter values, and rank deficient inverses.

  2. Integration and In-Field Gains Selection of Flight and Navigation Controller for Remotely Piloted Aircraft System

    Directory of Open Access Journals (Sweden)

    Słowik Maciej


    Full Text Available In the paper the implementation process of commercial flight and navigational controller in own aircraft is shown. The process of autopilot integration were performed for the fixed-wing type of unmanned aerial vehicle designed in high-wing and pull configuration of the drive. The above equipment were integrated and proper software control algorithms were chosen. The correctness of chosen hardware and software solution were verified in ground tests and experimental flights. The PID controllers for longitude and latitude controller channels were selected. The proper deflections of control surfaces and stabilization of roll, pitch and yaw angles were tested. In the next stage operation of telecommunication link and flight stabilization were verified. In the last part of investigations the preliminary control gains and configuration parameters for roll angle control loop were chosen. This enable better behavior of UAV during turns. Also it affected other modes of flight such as loiter (circle around designated point and auto mode where the plane executed a pre-programmed mission.

  3. Modeling, Simulation, and Flight Test for Automatic Flight Control of the Condor Hybrid-Electric Remote Piloted Aircraft (United States)


    Design Tool ....................................................................... 7 2.2.3 SIG Rascal Program...Kestrel Lateral Control (Christiansen, 2004) ...................................................... 6 Figure 4: SIG Rascal 110 (Farrell, 2009...67 Table 10: SIG Rascal PID Gains

  4. Integrated Flight Control and Flow Control Using Synthetic Jet Arrays (Postprint) (United States)


    Glezer [5] [6] and Cannelle and Amitay [7]. The effectiveness of fluidic actuators based on synthetic jets is derived from the interaction of these...Control of Flow Separation by Sound,” AIAA Paper 1984-2298, 9th Aeroacoustics Conference, Williamsburg, VA, Oct. 1984. 2. Amitay, M. and Cannelle , F...excitation control of synthetic jet actuators,” U.S. Patent 6,412,732 B1, July 2, 2002. 7. Cannelle , F. and Amitay, M., “Synthetic Jets: Spatial Evolution

  5. Steroid hormone control of cell death and cell survival: molecular insights using RNAi.

    Directory of Open Access Journals (Sweden)

    Suganthi Chittaranjan


    Full Text Available The insect steroid hormone ecdysone triggers programmed cell death of obsolete larval tissues during metamorphosis and provides a model system for understanding steroid hormone control of cell death and cell survival. Previous genome-wide expression studies of Drosophila larval salivary glands resulted in the identification of many genes associated with ecdysone-induced cell death and cell survival, but functional verification was lacking. In this study, we test functionally 460 of these genes using RNA interference in ecdysone-treated Drosophila l(2mbn cells. Cell viability, cell morphology, cell proliferation, and apoptosis assays confirmed the effects of known genes and additionally resulted in the identification of six new pro-death related genes, including sorting nexin-like gene SH3PX1 and Sox box protein Sox14, and 18 new pro-survival genes. Identified genes were further characterized to determine their ecdysone dependency and potential function in cell death regulation. We found that the pro-survival function of five genes (Ras85D, Cp1, CG13784, CG32016, and CG33087, was dependent on ecdysone signaling. The TUNEL assay revealed an additional two genes (Kap-alpha3 and Smr with an ecdysone-dependent cell survival function that was associated with reduced cell death. In vitro, Sox14 RNAi reduced the percentage of TUNEL-positive l(2mbn cells (p<0.05 following ecdysone treatment, and Sox14 overexpression was sufficient to induce apoptosis. In vivo analyses of Sox14-RNAi animals revealed multiple phenotypes characteristic of aberrant or reduced ecdysone signaling, including defects in larval midgut and salivary gland destruction. These studies identify Sox14 as a positive regulator of ecdysone-mediated cell death and provide new insights into the molecular mechanisms underlying the ecdysone signaling network governing cell death and cell survival.

  6. What Drives Bird Vision? Bill Control and Predator Detection Overshadow Flight

    Directory of Open Access Journals (Sweden)

    Graham R. Martin


    Full Text Available Although flight is regarded as a key behavior of birds this review argues that the perceptual demands for its control are met within constraints set by the perceptual demands of two other key tasks: the control of bill (or feet position, and the detection of food items/predators. Control of bill position, or of the feet when used in foraging, and timing of their arrival at a target, are based upon information derived from the optic flow-field in the binocular region that encompasses the bill. Flow-fields use information extracted from close to the bird using vision of relatively low spatial resolution. The detection of food items and predators is based upon information detected at a greater distance and depends upon regions in the retina with relatively high spatial resolution. The tasks of detecting predators and of placing the bill (or feet accurately, make contradictory demands upon vision and these have resulted in trade-offs in the form of visual fields and in the topography of retinal regions in which spatial resolution is enhanced, indicated by foveas, areas, and high ganglion cell densities. The informational function of binocular vision in birds does not lie in binocularity per se (i.e., two eyes receiving slightly different information simultaneously about the same objects but in the contralateral projection of the visual field of each eye. This ensures that each eye receives information from a symmetrically expanding optic flow-field centered close to the direction of the bill, and from this the crucial information of direction of travel and time-to-contact can be extracted, almost instantaneously. Interspecific comparisons of visual fields between closely related species have shown that small differences in foraging techniques can give rise to different perceptual challenges and these have resulted in differences in visual fields even within the same genus. This suggests that vision is subject to continuing and relatively rapid

  7. What Drives Bird Vision? Bill Control and Predator Detection Overshadow Flight. (United States)

    Martin, Graham R


    Although flight is regarded as a key behavior of birds this review argues that the perceptual demands for its control are met within constraints set by the perceptual demands of two other key tasks: the control of bill (or feet) position, and the detection of food items/predators. Control of bill position, or of the feet when used in foraging, and timing of their arrival at a target, are based upon information derived from the optic flow-field in the binocular region that encompasses the bill. Flow-fields use information extracted from close to the bird using vision of relatively low spatial resolution. The detection of food items and predators is based upon information detected at a greater distance and depends upon regions in the retina with relatively high spatial resolution. The tasks of detecting predators and of placing the bill (or feet) accurately, make contradictory demands upon vision and these have resulted in trade-offs in the form of visual fields and in the topography of retinal regions in which spatial resolution is enhanced, indicated by foveas, areas, and high ganglion cell densities. The informational function of binocular vision in birds does not lie in binocularity per se (i.e., two eyes receiving slightly different information simultaneously about the same objects) but in the contralateral projection of the visual field of each eye. This ensures that each eye receives information from a symmetrically expanding optic flow-field centered close to the direction of the bill, and from this the crucial information of direction of travel and time-to-contact can be extracted, almost instantaneously. Interspecific comparisons of visual fields between closely related species have shown that small differences in foraging techniques can give rise to different perceptual challenges and these have resulted in differences in visual fields even within the same genus. This suggests that vision is subject to continuing and relatively rapid natural selection

  8. Repetitive transarterial chemoembolization (TACE) of liver metastases from gastric cancer: Local control and survival results

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J., E-mail: [Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe-University Frankfurt (Germany); Gruber-Rouh, Tatjana; Eichler, Katrin [Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe-University Frankfurt (Germany); Nour-Eldin, Nour-Eldin A. [Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe-University Frankfurt (Germany); Department of Radiology, Faculty of Medicine, Cairo University, Cairo (Egypt); Trojan, Jörg [Department of Internal Medicine I, Johann Wolfgang Goethe-University Frankfurt (Germany); Zangos, Stephan [Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe-University Frankfurt (Germany); Naguib, Nagy N.N. [Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe-University Frankfurt (Germany); Radiology Department, Faculty of Medicine, Alexandria University, Alexandria (Egypt)


    Objective: To evaluate the local tumor control and survival data after transarterial chemoembolization with different drug combinations in the palliative treatment of patients with liver metastases of gastric cancer. Materials and methods: The study was retrospectively performed. 56 patients (mean age, 52.4) with unresectable liver metastases of gastric cancer who did not respond to systemic chemotherapy were repeatedly treated with TACE in 4-week intervals. In total, 310 chemoembolization procedures were performed (mean, 5.5 sessions per patient). The local chemotherapy protocol consisted of mitomycin alone (30.4%), mitomycin and gemcitabine (33.9%), or mitomycin, gemcitabine and cisplatin (35.7%). Embolization was performed with lipiodol and starch microspheres. Local tumor response was evaluated by MRI according to RECIST. Survival data from first chemoembolization were calculated according to the Kaplan–Meier method. Results: The local tumor control was: complete response in 1.8% (n = 1), partial response in 1.8% (n = 1), stable disease in 51.8% (n = 29) and progressive disease in 44.6% (n = 25) of patients. The 1-, 2-, and 3-year survival rate from the start of chemoembolization were 58%, 38%, and 23% respectively. The median and mean survival times were 13 and 27.1 months. A Statistically significant difference between patients treated with different chemotherapy protocols was noted (ρ = 0.045) with the best survival time in the mitomycin, gemcitabine and cisplatin group. Conclusion: Transarterial chemoembolization is a minimally invasive therapy option for palliative treatment of liver metastases in patients with gastric cancer.

  9. Controls on Arctic sea ice from first-year and multi-year survival rates

    Energy Technology Data Exchange (ETDEWEB)

    Hunke, Jes [Los Alamos National Laboratory


    The recent decrease in Arctic sea ice cover has transpired with a significant loss of multi year ice. The transition to an Arctic that is populated by thinner first year sea ice has important implications for future trends in area and volume. Here we develop a reduced model for Arctic sea ice with which we investigate how the survivability of first year and multi year ice control the mean state, variability, and trends in ice area and volume.

  10. Flying Qualities Flight Testing of Digital Flight Control Systems. Flight Test Techniques Series - Volume 21 (les Essais en vol des performances des systemes de ommande de vol numeriques) (United States)


    the control paths. These build tests utilize an automated ground test facility known as the Automatic Test Equipment (ATE), which contains its leur sécurité. Note de traduction : l’auteur insiste lourdement dans le 2ème paragraphe sur la préparation des essais et l’analyse des... automatically switched functions are operated. All onboard transmitters are exercised across their frequency range at normal and, where possible, at

  11. Contamination Control and Hardware Processing Solutions at Marshall Space Flight Center (United States)

    Burns, DeWitt H.; Hampton, Tammy; Huey, LaQuieta; Mitchell, Mark; Norwood, Joey; Lowrey, Nikki


    The Contamination Control Team of Marshall Space Flight Center's Materials and Processes Laboratory supports many Programs/ Projects that design, manufacture, and test a wide range of hardware types that are sensitive to contamination and foreign object damage (FOD). Examples where contamination/FOD concerns arise include sensitive structural bondline failure, critical orifice blockage, seal leakage, and reactive fluid compatibility (liquid oxygen, hydrazine) as well as performance degradation of sensitive instruments or spacecraft surfaces such as optical elements and thermal control systems. During the design phase, determination of the sensitivity of a hardware system to different types or levels of contamination/FOD is essential. A contamination control and FOD control plan must then be developed and implemented through all phases of ground processing, and, sometimes, on-orbit use, recovery, and refurbishment. Implementation of proper controls prevents cost and schedule impacts due to hardware damage or rework and helps assure mission success. Current capabilities are being used to support recent and on-going activities for multiple Mission Directorates / Programs such as International Space Station (ISS), James Webb Space Telescope (JWST), Space Launch System (SLS) elements (tanks, engines, booster), etc. The team also advances Green Technology initiatives and addresses materials obsolescence issues for NASA and external customers, most notably in the area of solvent replacement (e.g. aqueous cleaners containing hexavalent chrome, ozone depleting chemicals (CFC s and HCFC's), suspect carcinogens). The team evaluates new surface cleanliness inspection and cleaning technologies (e.g. plasma cleaning), and maintains databases for processing support materials as well as outgassing and optical compatibility test results for spaceflight environments.

  12. A study for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft (United States)

    Chen, R. T. N.; Daughaday, H.; Andrisani, D., II; Till, R. D.; Weingarten, N. C.


    The results of a feasibility study and preliminary design for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft are documented. Active control functions which can be demonstrated on the TIFS aircraft and the cost of preparing, equipping, and operating the TIFS aircraft for active control technology development are determined. It is shown that the TIFS aircraft is as a suitable test bed for inflight research and validation of many ACT concepts.

  13. Multi-Exciter Vibroacoustic Simulation of Hypersonic Flight Vibration

    Energy Technology Data Exchange (ETDEWEB)



    Many aerospace structures must survive severe high frequency, hypersonic, random vibration during their flights. The random vibrations are generated by the turbulent boundary layer developed along the exterior of the structures during flight. These environments have not been simulated very well in the past using a fixed-based, single exciter input with an upper frequency range of 2 kHz. This study investigates the possibility of using acoustic ardor independently controlled multiple exciters to more accurately simulate hypersonic flight vibration. The test configuration, equipment, and methodology are described. Comparisons with actual flight measurements and previous single exciter simulations are also presented.

  14. Aircraft automatic digital flight control system with inversion of the model in the feed-forward path (United States)

    Smith, G. A.; Meyer, G.


    A full-flight-envelope automatic trajectory control system concept is being investigated at Ames Research Center. This concept was developed for advanced aircraft configurations with severe nonlinear characteristics. A feature of the system is an inverse of the complete nonlinear aircraft model as part of the feed-forward control path. Simulation and flight tests have been reported at previous Digital Avionics Systems conferences. A new method for the continuous real-time inversion of the aircraft model using a Newton-Raphson trim algorithm instead of the original inverse table look-up procedure has been developed. The results of a simulation study of a vertical attitude takeoff and landing aircraft using the new inversion technique are presented. Maneuvers were successfully carried out in all directions in the vertical-attitude hover mode. Transition runs from conventional flight through the region of lift-curve-slope reversal at an angle of attack of about 32 deg and to hover at zero speed in the vertical attitude showed satisfactory transient response. Simulations were also conducted in conventional flight at high subsonic speed in steep climb and with turns up to 4 g. Successful flight tests of the system with the new model-inversion technique in a UH-1H helicopter have recently been carried out.

  15. In-Flight Guidance, Navigation, and Control Performance Results for the GOES-16 Spacecraft (United States)

    Chapel, Jim; Stancliffe, Devin; Bevacqua, Tim; Winkler, Stephen; Clapp, Brian; Rood, Tim; Freesland, Doug; Reth, Alan; Early, Derrick; Walsh, Tim; hide


    The Geostationary Operational Environmental Satellite-R Series (GOES-R), which launched in November 2016, is the first of the next generation geostationary weather satellites. GOES-R provides 4 times the resolution, 5 times the observation rate, and 3 times the number of spectral bands for Earth observations compared with its predecessor spacecraft. Additionally, Earth relative and Sun-relative pointing and pointing stability requirements are maintained throughout reaction wheel desaturation events and station keeping activities, allowing GOES-R to provide continuous Earth and sun observations. This paper reviews the pointing control, pointing stability, attitude knowledge, and orbit knowledge requirements necessary to realize the ambitious Image Navigation and Registration (INR) objectives of GOES-R. This paper presents a comparison between low-frequency on-orbit pointing results and simulation predictions for both the Earth Pointed Platform (EPP) and Sun Pointed Platform (SPP). Results indicate excellent agreement between simulation predictions and observed on-orbit performance, and compliance with pointing performance requirements. The EPP instrument suite includes 6 seismic accelerometers sampled at 2 KHz, allowing in-flight verification of jitter responses and comparison back to simulation predictions. This paper presents flight results of acceleration, shock response spectrum (SRS), and instrument line of sight responses for various operational scenarios and instrument observation modes. The results demonstrate the effectiveness of the dual-isolation approach employed on GOES-R. The spacecraft provides attitude and rate data to the primary Earth-observing instrument at 100 Hz, which are used to adjust instrument scanning. The data must meet accuracy and latency numbers defined by the Integrated Rate Error (IRE) requirements. This paper discusses the on-orbit IRE results, showing compliance to these requirements with margin. During the spacecraft checkout

  16. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data (United States)

    Krening, Samantha C.


    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  17. Flight Verification of Direct Digital Drive for an Advanced Flight Control Actuation System (AFCAS) in the T-2C Aircraft. (United States)


    clock oscillator, power on reset timer, and memory decoding logic. - 1024 Bytes of RAM. - Sockets for up to 4096 bytes of Alterable Read Only Memory ( AROM ...REQUIREMENTS +5 VDC AT 1.1A (MAX) WITHOUT AROMs /ROMs +12 VDC AT 20mA (MAX) -12 VDC AT 25mA (MAX) WIIH FOUR AROMs /ROMs +5 VDC AT 1.3A (MAX) +12 VDC AT...Control Actuation System I Amp Ampere ’ AROM Alterable Read Only Memory 3 Aux Auxiliary I OC Degrees Celsius cc/min cubic centimeters per minute I c

  18. Two-year survival of ART restorations placed in elderly patients: A randomised controlled clinical trial. (United States)

    da Mata, Cristiane; Allen, P Finbarr; McKenna, Gerald; Cronin, Michael; O'Mahony, Denis; Woods, Noel


    Older dentate adults are a high caries risk group who could potentially benefit from the use of the atraumatic restorative treatment (ART). This study aimed to compare the survival of ART and a conventional restorative technique (CT) using rotary instruments and a resin-modified glass-ionomer for restoring carious lesions as part of a preventive and restorative programme for older adults after 2 years. In this randomised controlled clinical trial, 99 independently living adults (65-90 years) with carious lesions were randomly allocated to receive either ART or conventional restorations. The survival of restorations was assessed by an independent and blinded examiner 6 months, 1 year and 2 years after restoration placement. Ninety-six (67.6%) and 121 (76.6%) restorations were assessed in the ART and CT groups, respectively, after 2 years. The cumulative restoration survival percentages after 2 years were 85.4% in the ART and 90.9% in the CT group. No statistically significant between group differences were detected (p=0.2050, logistic regression analysis). In terms of restoration survival, ART was as effective as a conventional restorative approach to treat older adults after 2 years. This technique could be a useful tool to provide dental care for older adults particularly in the non-clinical setting. ( ISRCTN 76299321). The results of this study show that ART presented survival rates similar to conventional restorations in older adults. ART appears to be a cost-effective way to provide dental care to elderly patients, particularly in out of surgery facilities, such as nursing homes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. [Introduction of hazard analysis and critical control points (HACCP) principles at the flight catering food production plant]. (United States)

    Popova, A Yu; Trukhina, G M; Mikailova, O M

    In the article there is considered the quality control and safety system implemented in the one of the largest flight catering food production plant for airline passengers and flying squad. The system for the control was based on the Hazard Analysis And Critical Control Points (HACCP) principles and developed hygienic and antiepidemic measures. There is considered the identification of hazard factors at stages of the technical process. There are presented results of the analysis data of monitoring for 6 critical control points over the five-year period. The quality control and safety system permit to decline food contamination risk during acceptance, preparation and supplying of in-flight meal. There was proved the efficiency of the implemented system. There are determined further ways of harmonization and implementation for HACCP principles in the plant.

  20. Pilot Control Behavior Discrepancies Between Real and Simulated Flight Caused by Limited Motion Stimuli

    NARCIS (Netherlands)

    Zaal, P.M.T.


    Flight simulators provide a flexible, efficient, and safe environment for research and training at much lower costs than real flight. The ultimate validity of any simulation would be achieved when – for a particular task – human cognitive and psychomotor behavior in the simulator corresponds

  1. A digital-analog hybrid system and its application to the automatic flight control system simulation research (United States)


    The characteristics of a digital-analog hybrid system composed of a DJS-8 digital computer and a HMJ-200 analog computer are described as well as its applications to simulation research for an automatic flight control system. A hybrid computational example is included to illustrate the application.

  2. History of Suction-Type Laminar-Flow Control with Emphasis on Flight Resrearch: Monographs in Aerospace History Number 13 (United States)

    Braslow, A. L.


    The paper contains the following sections: Foreword; Preface; Laminar-Flow Control Concepts and Scope of Monograph; Early Research on Suction-Type Laminar-Flow Control (Research from the 1930s through the War Years; Research from after World War II to the Mid-1960s); Post X-21 Research on Suction-Type Laminar-Flow Control; Status of Laminar-Flow Control Technology in the Mid-1990s; Glossary; Document 1-Aeronautics Panel, AACB, R&D Review, Report of the Subpanel on Aeronautic Energy Conservation/Fuels; Document 2-Report of Review Group on X-21A Laminar Flow Control Program; Document 3-Langley Research Center Announcement, Establishment of Laminar Flow Control Working Group; Document 4-Intercenter Agreement for Laminar Flow Control Leading Edge Glove Flights, LaRC and DFRC; Document 5-Flight Report NLF-144, of AFTIF-111 Aircraft with the TACT Wing Modified by a Natural Laminar Flow Glove; Document 6-Flight Record, F-16XL Supersonic Laminar Flow Control Aircraft; Index; and About the Author.

  3. Survival of Batrachochytrium dendrobatidis in Water: Quarantine and Disease Control Implications (United States)

    Speare, Richard


    Amphibian chytridiomycosis is an emerging infectious disease of amphibians thought to be moved between countries by trade in infected amphibians. The causative fungus, Batrachochytrium dendrobatidis, produces aquatic, motile zoospores; infections have been achieved in experiments by exposing amphibians to water containing zoospores. However, the ability of this fungus to survive in the environment in the absence of an amphibian host is unknown. We show that B. dendrobatidis will survive in tap water and in deionized water for 3 and 4 weeks, respectively. In lake water, infectivity was observed for 7 weeks after introduction. The knowledge that water can remain infective for up to 7 weeks is important for the formulation of disease control and quarantine strategies for the management of water that has been in contact with amphibians. PMID:12967488

  4. A piloted simulator investigation of side-stick controller/stability and control augmentation system requirements for helicopter visual flight tasks (United States)

    Landis, K. H.; Dunford, P. J.; Aiken, E. W.; Hilbert, K. B.


    A piloted simulator experiment was conducted to assess the effects of side-stick controller characteristics and level of stability and control augmentation on handling qualities for several low-altitude control tasks. Visual flight tasks were simulated using four-window computer-generated imagery depicting either a nap-of-the-earth course or a runway with obstacles positioned to provide a slalom course. Both low speed and forward flight control laws were implemented, and a method for automatically switching control modes was developed. Variations in force-deflection characteristics and the number of axes controlled through an integrated side-stick were investigated. With high levels of stability and control augmentation, a four-axis controller with small-deflection in all four axes achieved satisfactory handling qualities for low-speed tasks.

  5. A review of adaptive change in musculoskeletal impedance during space flight and associated implications for postflight head movement control (United States)

    McDonald, P. V.; Bloomberg, J. J.; Layne, C. S.


    We present a review of converging sources of evidence which suggest that the differences between loading histories experienced in 1-g and weightlessness are sufficient to stimulate adaptation in mechanical impedance of the musculoskeletal system. As a consequence of this adaptive change we argue that we should observe changes in the ability to attenuate force transmission through the musculoskeletal system both during and after space flight. By focusing attention on the relation between human sensorimotor activity and support surfaces, the importance of controlling mechanical energy flow through the musculoskeletal system is demonstrated. The implications of such control are discussed in light of visual-vestibular function in the specific context of head and gaze control during postflight locomotion. Evidence from locomotory biomechanics, visual-vestibular function, ergonomic evaluations of human vibration, and specific investigations of locomotion and head and gaze control after space flight, is considered.

  6. The Total In-Flight Simulator (TIFS) aerodynamics and systems: Description and analysis. [maneuver control and gust alleviators (United States)

    Andrisani, D., II; Daughaday, H.; Dittenhauser, J.; Rynaski, E.


    The aerodynamics, control system, instrumentation complement and recording system of the USAF Total In/Flight Simulator (TIFS) airplane are described. A control system that would allow the ailerons to be operated collectively, as well as, differentially to entrance the ability of the vehicle to perform the dual function of maneuver load control and gust alleviation is emphasized. Mathematical prediction of the rigid body and the flexible equations of longitudinal motion using the level 2.01 FLEXSTAB program are included along with a definition of the vehicle geometry, the mass and stiffness distribution, the calculated mode frequencies and mode shapes, and the resulting aerodynamic equations of motion of the flexible vehicle. A complete description of the control and instrumentation system of the aircraft is presented, including analysis, ground test and flight data comparisons of the performance and bandwidth of the aerodynamic surface servos. Proposed modification for improved performance of the servos are also presented.

  7. Tumor volume as a prognostic factor for local control and overall survival in advanced larynx cancer. (United States)

    Timmermans, Adriana J; Lange, Charlotte A H; de Bois, Josien A; van Werkhoven, Erik; Hamming-Vrieze, Olga; Hilgers, Frans J M; van den Brekel, Michiel W M


    Tumor volume has been postulated to be an important prognostic factor for oncological outcome after radiotherapy or chemoradiotherapy. This postulate was retrospectively investigated in a consecutively treated cohort of T3-T4 larynx cancer patients. Retrospective cohort study. For 166 patients with T3-T4 larynx cancer (1999-2008), pretreatment computed tomography and magnetic resonance imaging scans were available for tumor volume delineation. Patients were treated with radiotherapy, chemoradiotherapy, or total laryngectomy with postoperative radiotherapy. Both a dedicated head and neck radiologist and the first author determined all tumor volumes. Statistical analysis was by Kaplan-Meier plots and Cox proportional hazard models. Patients with T3 larynx cancer had significantly smaller tumor volumes than patients with T4 larynx cancer (median = 8.1 cm(3) and 15.8 cm(3), respectively; P < .0001). In the group treated with total laryngectomy and postoperative radiotherapy, no association was found between tumor volume and local or locoregional control or overall survival. In the group treated with radiotherapy, a nonsignificant trend was observed between local control and tumor volume. In the chemoradiotherapy group, however, a significant impact of tumor volume was found on local control (hazard ratio = 1.07; 95% confidence interval = 1.01-1.13; P = .028). Tumor volume was not significantly associated with local control, locoregional control, or overall survival in the surgically treated group. In the group treated with radiotherapy, there was no statistically significant association, but a trend was observed between local control and tumor volume. Only in patients treated with concurrent chemoradiotherapy was a significant impact of tumor volume on local control found. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  8. An Adaptive Dynamic Surface Controller for Ultralow Altitude Airdrop Flight Path Angle with Actuator Input Nonlinearity

    Directory of Open Access Journals (Sweden)

    Mao-long Lv


    Full Text Available In the process of ultralow altitude airdrop, many factors such as actuator input dead-zone, backlash, uncertain external atmospheric disturbance, and model unknown nonlinearity affect the precision of trajectory tracking. In response, a robust adaptive neural network dynamic surface controller is developed. As a result, the aircraft longitudinal dynamics with actuator input nonlinearity is derived; the unknown nonlinear model functions are approximated by means of the RBF neural network. Also, an adaption strategy is used to achieve robustness against model uncertainties. Finally, it has been proved that all the signals in the closed-loop system are bounded and the tracking error converges to a small residual set asymptotically. Simulation results demonstrate the perfect tracking performance and strong robustness of the proposed method, which is not only applicable to the actuator with input dead-zone but also suitable for the backlash nonlinearity. At the same time, it can effectively overcome the effects of dead-zone and the atmospheric disturbance on the system and ensure the fast track of the desired flight path angle instruction, which overthrows the assumption that system functions must be known.

  9. Piloted Simulation Tests of Propulsion Control as Backup to Loss of Primary Flight Controls for a B747-400 Jet Transport (United States)

    Bull, John; Mah, Robert; Hardy, Gordon; Sullivan, Barry; Jones, Jerry; Williams, Diane; Soukup, Paul; Winters, Jose


    Partial failures of aircraft primary flight control systems and structural damages to aircraft during flight have led to catastrophic accidents with subsequent loss of lives (e.g. DC-10, B-747, C-5, B-52, and others). Following the DC-10 accident at Sioux City, Iowa in 1989, the National Transportation Safety Board recommended 'Encourage research and development of backup flight control systems for newly certified wide-body airplanes that utilize an alternate source of motive power separate from that source used for the conventional control system.' This report describes the concept of a propulsion controlled aircraft (PCA), discusses pilot controls, displays, and procedures; and presents the results of a PCA piloted simulation test and evaluation of the B747-400 airplane conducted at NASA Ames Research Center in December, 1996. The purpose of the test was to develop and evaluate propulsion control throughout the full flight envelope of the B747-400 including worst case scenarios of engine failures and out of trim moments. Pilot ratings of PCA performance ranged from adequate to satisfactory. PCA performed well in unusual attitude recoveries at 35,000 ft altitude, performed well in fully coupled ILS approaches, performed well in single engine failures, and performed well at aft cg. PCA performance was primarily limited by out-of-trim moments.

  10. Environmental control of phase transition and polyp survival of a massive-outbreaker jellyfish.

    Directory of Open Access Journals (Sweden)

    Laura Prieto

    Full Text Available A number of causes have been proposed to account for the occurrence of gelatinous zooplankton (both jellyfish and ctenophore blooms. Jellyfish species have a complex life history involving a benthic asexual phase (polyp and a pelagic sexual phase (medusa. Strong environmental control of jellyfish life cycles is suspected, but not fully understood. This study presents a comprehensive analysis on the physicochemical conditions that control the survival and phase transition of Cotylorhiza tuberculata; a scyphozoan that generates large outbreaks in the Mediterranean Sea. Laboratory experiments indicated that the influence of temperature on strobilation and polyp survival was the critical factor controlling the capacity of this species to proliferate. Early life stages were less sensitive to other factors such as salinity variations or the competitive advantage provided by zooxanthellae in a context of coastal eutrophication. Coherently with laboratory results, the presence/absence of outbreaks of this jellyfish in a particular year seems to be driven by temperature. This is the first time the environmental forcing of the mechanism driving the life cycle of a jellyfish has been disentangled via laboratory experimentation. Projecting this understanding to a field population under climatological variability results in a pattern coherent with in situ records.

  11. Social equity in perinatal survival: a case-control study at hospitals in Kigali, Rwanda. (United States)

    Musafili, Aimable; Essén, Birgitta; Baribwira, Cyprien; Selling, Katarina Ekholm; Persson, Lars-Åke


    Rwanda has invested heavily in improving maternal and child health, but knowledge is limited regarding social equity in perinatal survival. We analysed whether perinatal mortality risks differed between social groups in hospitals in the country's capital. A case-control study was carried out on singleton births aged at least 22 weeks of gestation and born in district or tertiary referral hospitals in Kigali from July 2013 to May 2014. Perinatal deaths were recorded as they occurred, with the next two surviving neonates born in the same hospital selected as controls. Conditional logistic regression was used to determine social determinants of perinatal death after adjustments for potential confounders. We analysed 234 perinatal deaths and 468 controls. Rural residence was linked to an increased risk of perinatal death (OR = 3.31, 95% CI 1.43-7.61), but maternal education or household asset score levels were not. Having no health insurance (OR = 2.11, 95% CI 0.91-4.89) was associated with an increased risk of perinatal death, compared to having community health insurance. Living in a rural area and having no health insurance were associated with an increased risk of perinatal mortality rates in the Rwandan capital, but maternal education and household assets were not. ©2015 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.

  12. IMRT for Sinonasal Tumors Minimizes Severe Late Ocular Toxicity and Preserves Disease Control and Survival

    Energy Technology Data Exchange (ETDEWEB)

    Duprez, Frederic, E-mail: [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Madani, Indira; Morbee, Lieve [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Bonte, Katrien; Deron, Philippe; Domjan, Vilmos [Department of Head and Neck Surgery, Ghent University Hospital, Ghent (Belgium); Boterberg, Tom; De Gersem, Werner; De Neve, Wilfried [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)


    Purpose: To report late ocular (primary endpoint) and other toxicity, disease control, and survival (secondary endpoints) after intensity-modulated radiotherapy (IMRT) for sinonasal tumors. Methods and Materials: Between 1998 and 2009, 130 patients with nonmetastatic sinonasal tumors were treated with IMRT at Ghent University Hospital. Prescription doses were 70 Gy (n = 117) and 60-66 Gy (n = 13) at 2 Gy per fraction over 6-7 weeks. Most patients had adenocarcinoma (n = 82) and squamous cell carcinoma (n = 23). One hundred and one (101) patients were treated postoperatively. Of 17 patients with recurrent tumors, 9 were reirradiated. T-stages were T1-2 (n = 39), T3 (n = 21), T4a (n = 38), and T4b (n = 22). Esthesioneuroblastoma was staged as Kadish A, B, and C in 1, 3, and 6 cases, respectively. Results: Median follow-up was 52, range 15-121 months. There was no radiation-induced blindness in 86 patients available for late toxicity assessment ({>=}6 month follow-up). We observed late Grade 3 tearing in 10 patients, which reduced to Grade 1-2 in 5 patients and Grade 3 visual impairment because of radiation-induced ipsilateral retinopathy and neovascular glaucoma in 1 patient. There was no severe dry eye syndrome. The worst grade of late ocular toxicity was Grade 3 (n = 11), Grade 2 (n = 31), Grade 1 (n = 33), and Grade 0 (n = 11). Brain necrosis and osteoradionecrosis occurred in 6 and 1 patients, respectively. Actuarial 5-year local control and overall survival were 59% and 52%, respectively. On multivariate analysis local control was negatively affected by cribriform plate and brain invasion (p = 0.044 and 0.029, respectively) and absence of surgery (p = 0.009); overall survival was negatively affected by cribriform plate and orbit invasion (p = 0.04 and <0.001, respectively) and absence of surgery (p = 0.001). Conclusions: IMRT for sinonasal tumors allowed delivering high doses to targets at minimized ocular toxicity, while maintaining disease control and survival

  13. Rapid Development of Guidance, Navigation, and Control Core Flight System Software Applications Using Simulink Models Project (United States)

    National Aeronautics and Space Administration — We will demonstrate the usefulness of SIL for GSFC missions by attempting to compile the SIL source code with an autocoded sample GNC application flight software....

  14. Low-Cost, Integrated Ground Test, Simulation, and Flight Control Development Environment Project (United States)

    National Aeronautics and Space Administration — An important mission for NASA is the development of revolutionary flight concepts and technology. The development of Micro unmanned air vehicles (MAVs) and Mars...

  15. Automated En Route Air Traffic Control Algorithmic Specifications. Volume 3. Flight Plan Conflict Probe, (United States)


    esatabli shed in the current AIC system and may be used in future documents describing later versions of AERA. In the text and in local tables in this volume...probe and to FALSE otherwise. In case of a trial probe, the variable Real Subject_FlId contains the flight identifier of the flighbt being probeao used to avoid detecting potential conflicts of the trial trajectory and the actual trajectory of the flight being trial probed. ( Real

  16. Control of Homeostasis and Dendritic Cell Survival by the GTPase RhoA

    DEFF Research Database (Denmark)

    Li, Shuai; Dislich, Bastian; Brakebusch, Cord H


    Tissues accommodate defined numbers of dendritic cells (DCs) in highly specific niches where different intrinsic and environmental stimuli control DC life span and numbers. DC homeostasis in tissues is important, because experimental changes in DC numbers influence immunity and tolerance toward...... various immune catastrophes and inflammation. However, the precise molecular mechanisms regulating DC life span and homeostasis are unclear. We report that the GTPase RhoA controls homeostatic proliferation, cytokinesis, survival, and turnover of cDCs. Deletion of RhoA strongly decreased the numbers of CD...... findings identify RhoA as a central regulator of DC homeostasis, and its deletion decreases DC numbers below critical thresholds for immune protection and homeostasis, causing aberrant compensatory DC proliferation....

  17. Controlled banked turns in coleopteran flight measured by a miniature wireless inertial measurement unit. (United States)

    Li, Yao; Cao, Feng; Thang Vo Doan, Tat; Sato, Hirotaka


    The mechanisms and principles of insect flight have long been investigated by researchers working on micro and nano air vehicles (MAVs/NAVs). However, studies of insect flight maneuvers require high speed filming and high spatial resolution in a small experimental space, or the tethering of the insect to a fixed place. Under such artificial conditions, the insects may deviate its flying behavior from that of regular flight. In this study, we mounted a tiny wireless system, or 'backpack', on live beetles (Mecynorrhina torquata; length 62 ± 8 mm; mass 7.4 ± 1.3 g) freely flying in a large laboratory space. The backpack contains a micro inertial measurement unit (IMU) that was especially designed and manufactured for this purpose. Owing to the small mass (∼1.30 g) and dimensions (∼2.3 cm(2)) of the backpack and the high accuracy of the IMU, we could remotely record the beetle in free flight. The free flight data revealed a strong linear correlation between the roll angle and yaw angular velocity. The strength of the correlation was quantified by the correlation coefficients and mean values. The change in roll angle preceded the change in yaw angular velocity. Moreover, there were frequent fluctuations in the roll angular velocity, which were uncorrelated with the yaw angular velocity. Apart from the strong correlation, these findings imply that Mecynorrhina torquata actively manipulates its roll rotation without coupling to the yaw rotation.

  18. Multi-Input Multi-Output Flight Control System Design for the YF-16 Using Nonlinear QFT and Pilot Compensation (United States)


    Roskam points out that the trend toward the design of unstable airframes is ex- pected to continue, with design emphasis placed primarily on performance...11]. 1-8 Roskam stated that total human interaction with the flight control system can be de- scribed by two quantities: "The first, that portion of...models have been generated basically in the form of a lead-lag filter and time delay. Additionally, Roskam [16:10.12-10.15] has provided some important

  19. Vision based guidance and flight control in problems of aerial tracking (United States)

    Stepanyan, Vahram

    The use of visual sensors in providing the necessary information for the autonomous guidance and navigation of the unmanned-air vehicles (UAV) or micro-air vehicles (MAV) applications is inspired by biological systems and is motivated first of all by the reduction of the navigational sensor cost. Also, visual sensors can be more advantageous in military operations since they are difficult to detect. However, the design of a reliable guidance, navigation and control system for aerial vehicles based only on visual information has many unsolved problems, ranging from hardware/software development to pure control-theoretical issues, which are even more complicated when applied to the tracking of maneuvering unknown targets. This dissertation describes guidance law design and implementation algorithms for autonomous tracking of a flying target, when the information about the target's current position is obtained via a monocular camera mounted on the tracking UAV (follower). The visual information is related to the target's relative position in the follower's body frame via the target's apparent size, which is assumed to be constant, but otherwise unknown to the follower. The formulation of the relative dynamics in the inertial frame requires the knowledge of the follower's orientation angles, which are assumed to be known. No information is assumed to be available about the target's dynamics. The follower's objective is to maintain a desired relative position irrespective of the target's motion. Two types of guidance laws are designed and implemented in the dissertation. The first one is a smooth guidance law that guarantees asymptotic tracking of a target, the velocity of which is viewed as a time-varying disturbance, the change in magnitude of which has a bounded integral. The second one is a smooth approximation of a discontinuous guidance law that guarantees bounded tracking with adjustable bounds when the target's acceleration is viewed as a bounded but otherwise

  20. Global neural dynamic surface tracking control of strict-feedback systems with application to hypersonic flight vehicle. (United States)

    Xu, Bin; Yang, Chenguang; Pan, Yongping


    This paper studies both indirect and direct global neural control of strict-feedback systems in the presence of unknown dynamics, using the dynamic surface control (DSC) technique in a novel manner. A new switching mechanism is designed to combine an adaptive neural controller in the neural approximation domain, together with the robust controller that pulls the transient states back into the neural approximation domain from the outside. In comparison with the conventional control techniques, which could only achieve semiglobally uniformly ultimately bounded stability, the proposed control scheme guarantees all the signals in the closed-loop system are globally uniformly ultimately bounded, such that the conventional constraints on initial conditions of the neural control system can be relaxed. The simulation studies of hypersonic flight vehicle (HFV) are performed to demonstrate the effectiveness of the proposed global neural DSC design.

  1. Functional testing of space flight induced changes in tonic motor control by using limb-attached excitation and load devices (United States)

    Gallasch, Eugen; Kozlovskaya, Inessa


    Long term space flights induce atrophy and contractile changes on postural muscles such effecting tonic motor control. Functional testing of tonic motor control structures is a challenge because of the difficulties to deliver appropriate test forces on crew members. In this paper we propose two approaches for functional testing by using limb attached loading devices. The first approach is based on a frequency and amplitude controllable moving magnet exciter to deliver sinusoidal test forces during limb postures. The responding limb deflection is recorded by an embedded accelerometer to obtain limb impedance. The second approach is based on elastic limb loading to evoke self-excited oscillations during arm extensions. Here the contraction force at the oscillation onset provides information about limb stiffness. The rationale for both testing approaches is based on Feldman's λ-model. An arm expander based on the second approach was probed in a 6-month MIR space flight. The results obtained from the load oscillations, confirmed that this device is well suited to capture space flight induced neuromuscular changes.

  2. Ornithopter flight stabilization (United States)

    Dietl, John M.; Garcia, Ephrahim


    The quasi-steady aerodynamics model and the vehicle dynamics model of ornithopter flight are explained, and numerical methods are described to capture limit cycle behavior in ornithopter flight. The Floquet method is used to determine stability in forward flight, and a linear discrete-time state-space model is developed. This is used to calculate stabilizing and disturbance-rejecting controllers.

  3. Stability and Controls Analysis and Flight Test Results of a 24-Foot Telescoping Nose Boom on an F-15B Airplane (United States)

    Moua, Cheng M.; Cox, Timothy H.; McWherter, Shaun C.


    The Quiet Spike(TradeMark) F-15B flight research program investigated supersonic shock reduction using a 24-ft telescoping nose boom on an F-15B airplane. The program goal was to collect flight data for model validation up to 1.8 Mach. In the area of stability and controls, the primary concerns were to assess the potential destabilizing effect of the oversized nose boom on the stability, controllability, and handling qualities of the airplane and to ensure adequate stability margins across the entire research flight envelope. This paper reports on the stability and control analytical methods, flight envelope clearance approach, and flight test results of the F-15B telescoping nose boom configuration. Also discussed are brief pilot commentary on typical piloting tasks and refueling tasks.

  4. Comparative Effectiveness of Cancer Control and Survival after Robot-Assisted versus Open Radical Prostatectomy. (United States)

    Hu, Jim C; O'Malley, Padraic; Chughtai, Bilal; Isaacs, Abby; Mao, Jialin; Wright, Jason D; Hershman, Dawn; Sedrakyan, Art


    Robot-assisted surgery has been rapidly adopted in the U.S. for prostate cancer. Its adoption has been driven by market forces and patient preference, and debate continues regarding whether it offers improved outcomes to justify the higher cost relative to open surgery. We examined the comparative effectiveness of robot-assisted vs open radical prostatectomy in cancer control and survival in a nationally representative population. This population based observational cohort study of patients with prostate cancer undergoing robot-assisted radical prostatectomy and open radical prostatectomy during 2003 to 2012 used data captured in the SEER (Surveillance, Epidemiology, and End Results)-Medicare linked database. Propensity score matching and time to event analysis were used to compare all cause mortality, prostate cancer specific mortality and use of additional treatment after surgery. A total of 6,430 robot-assisted radical prostatectomies and 9,161 open radical prostatectomies performed during 2003 to 2012 were identified. The use of robot-assisted radical prostatectomy increased from 13.6% in 2003 to 2004 to 72.6% in 2011 to 2012. After a median followup of 6.5 years (IQR 5.2-7.9) robot-assisted radical prostatectomy was associated with an equivalent risk of all cause mortality (HR 0.85, 0.72-1.01) and similar cancer specific mortality (HR 0.85, 0.50-1.43) vs open radical prostatectomy. Robot-assisted radical prostatectomy was also associated with less use of additional treatment (HR 0.78, 0.70-0.86). Robot-assisted radical prostatectomy has comparable intermediate cancer control as evidenced by less use of additional postoperative cancer therapies and equivalent cancer specific and overall survival. Longer term followup is needed to assess for differences in prostate cancer specific survival, which was similar during intermediate followup. Our findings have significant quality and cost implications, and provide reassurance regarding the adoption of more

  5. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.


    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved

  6. Proportional Plus Integral Control of Aircraft for Automated Maneuvering Formation Flight (United States)


    375.5 374-- --- - ------- - - 373.5 0 10 20 30 40 50 60 70 80 90 100 tin. (seconds) 50001 4 0 0 0...4 0-- --- 6 0--- --- - 0--- -1 0-- --- - ISO ~ ~ ~ tm (se---- ----------------- --d ---: ---)--- Figur A-- Time -- Repos and---- Flight

  7. Wright Brothers National Memorial: Site of the First Controlled Powered Flight. Teaching with Historic Places. (United States)

    Olio, Brenda K.

    Wilbur and Orville Wright undertook the first test airplane flight on December 17, 1903, at the Outer Banks of North Carolina. Their success represented the culmination of four years of painstaking research and trials in which they designed and improved their flying machines at home in Dayton, Ohio, and tested them each year near Kitty Hawk, North…

  8. An LQG Up-and Away Flight Control Design for the STOL F-15 Aircraft. (United States)


    Second Edition). New York: McGraw-Hill, 1984. 19. Roskam , J. Flight Dynamics. Kansas: Roskam Aviation and Engineering, 1972. 20. Sheehan, K. A...Include A ,ova Code) Peter S. Maybeck, B.S., Ph.D. 513-255-3576 AFIT/ENG DO FORM 1473. 83 APR EDITION OF 1 JAN 73 IS OBSOLETE. UNCLASSIFIED S- SECURITY

  9. L1 Adaptive Control Law for Flexible Space Launch Vehicle and Proposed Plan for Flight Test Validation (United States)

    Kharisov, Evgeny; Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira


    This paper explores application of the L1 adaptive control architecture to a generic flexible Crew Launch Vehicle (CLV). Adaptive control has the potential to improve performance and enhance safety of space vehicles that often operate in very unforgiving and occasionally highly uncertain environments. NASA s development of the next generation space launch vehicles presents an opportunity for adaptive control to contribute to improved performance of this statically unstable vehicle with low damping and low bending frequency flexible dynamics. In this paper, we consider the L1 adaptive output feedback controller to control the low frequency structural modes and propose steps to validate the adaptive controller performance utilizing one of the experimental test flights for the CLV Ares-I Program.

  10. Real-Time Adaptive Algorithms for Flight Control Diagnostics and Prognostics Project (United States)

    National Aeronautics and Space Administration — The overall objective of this research program is to improve the affordability, survivability, and service life of next generation aircraft through the use of ADAPT...

  11. Simulacioni model sistema za upravljanje letom protivbrodske rakete / Model for simulating the flight control system of a antiship missile

    Directory of Open Access Journals (Sweden)

    Nebojša N. Gaćeša


    Full Text Available U radu je analiziran program za simulaciju sistema za upravljanje letom protivbrodske rakete sa radarskom glavom za samonavođenje. Analiziran je matematički model rakete, model autopilota i model cilja. Ovakvim pristupom dobijen je rezultat koji omogućava uspostavljanje realnijeg procesa praćenja leta konkretne protivbrodske rakete, budući da upravljanje letom rakete na celoj trajektoriji ima znatne prednosti u odnosu na nevođene projektile, pre svega zbog mogućnosti gađanja pokretnih ciljeva. Simulacioni model upravljanja letom rakete pruža mogućnosti za dalje proučavanje ove klase raketa. / The paper analyzes a program for simulating the flight control of an antiship missile with the radar seeker. The paper analyzes a mathematic missile model an autopilot model and a target model. Thus obtained results enable a more realistic process of flight tracking of a particular antiship missile as the missile guidance along the whole trajectory provides many advantages over unguided projectiles, primarily because of the possibility to fire at moving targets. The flight control simulation model enables further study of this missile class.

  12. Chasing behaviour and optomotor following in free-flying male blowflies: flight performance and interactions of the underlying control systems

    Directory of Open Access Journals (Sweden)

    Christine Trischler


    Full Text Available The chasing behaviour of male blowflies after small targets belongs to the most rapid and virtuosic visually guided behaviours found in nature. Since in a structured environment any turn towards a target inevitably leads to a displacement of the entire retinal image in the opposite direction, it might evoke optomotor following responses counteracting the turn. To analyse potential interactions between the control systems underlying chasing behaviour and optomotor following, respectively, we performed behavioural experiments on male blowflies and examined the characteristics of the two flight control systems in isolation and in combination. Three findings are particularly striking. (i The characteristic saccadic flight and gaze style – a distinctive feature of blowfly cruising flights – is largely abandoned when the entire visual surroundings move around the fly; in this case flies tend to follow the moving pattern in a relatively continuous and smooth way. (ii When male flies engage in following a small target, they also employ a smooth pursuit strategy. (iii Although blowflies are reluctant to fly at high background velocities, the performance and dynamical characteristics of the chasing system are not much affected when the background moves in either the same or in the opposite direction as the target. Hence, the optomotor following response is largely suppressed by the chasing system and does not much impair chasing performance.


    Directory of Open Access Journals (Sweden)

    Yaroslav Kondrashov


    Full Text Available Abstract. According to the results of measurements on board of Unmanned Aerial Vehicle the distancevector D is formed in the inertial coordinate system, and in mathematical modeling - in the Greenwichsystem of coordinates. The velocity vector k V is formed by the navigation system in the trajectory coordinatesystem. Defined by this way the initial conditions gives the possibility to predict the terminal parameters offlight (descent of Unmanned Aerial Vehicle.Keywords: control system of the unmanned aerial vehicle flight path and landing, motion parameters,termination control.

  14. Preliminary Effect of Synthetic Vision Systems Displays to Reduce Low-Visibility Loss of Control and Controlled Flight Into Terrain Accidents (United States)

    Glaab, Louis J.; Takallu, Mohammad A.


    An experimental investigation was conducted to study the effectiveness of Synthetic Vision Systems (SVS) flight displays as a means of eliminating Low Visibility Loss of Control (LVLOC) and Controlled Flight Into Terrain (CFIT) accidents by low time general aviation (GA) pilots. A series of basic maneuvers were performed by 18 subject pilots during transition from Visual Meteorological Conditions (VMC) to Instrument Meteorological Conditions (IMC), with continued flight into IMC, employing a fixed-based flight simulator. A total of three display concepts were employed for this evaluation. One display concept, referred to as the Attitude Indicator (AI) replicated instrumentation common in today's General Aviation (GA) aircraft. The second display concept, referred to as the Electronic Attitude Indicator (EAI), featured an enlarged attitude indicator that was more representative of a glass display that also included advanced flight symbology, such as a velocity vector. The third concept, referred to as the SVS display, was identical to the EAI except that computer-generated terrain imagery replaced the conventional blue-sky/brown-ground of the EAI. Pilot performance parameters, pilot control inputs and physiological data were recorded for post-test analysis. Situation awareness (SA) and qualitative pilot comments were obtained through questionnaires and free-form interviews administered immediately after the experimental session. Initial pilot performance data were obtained by instructor pilot observations. Physiological data (skin temperature, heart rate, and muscle flexure) were also recorded. Preliminary results indicate that far less errors were committed when using the EAI and SVS displays than when using conventional instruments. The specific data example examined in this report illustrates the benefit from SVS displays to avoid massive loss of SA conditions. All pilots acknowledged the enhanced situation awareness provided by the SVS display concept. Levels of

  15. Charts for Estimating Tail-rotor Contribution to Helicopter Directional Stability and Control in Low-Speed Flight (United States)

    Amer, Kenneth B; Gessow, Alfred


    Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds. The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented. The charts indicate, and flight tests confirm, that the region of vortex roughness which is familiar for the main rotor is also encountered by the tail rotor and that prolonged operation at the corresponding flight conditions would be difficult.

  16. Preliminary system design study for a digital fly-by-wire flight control system for an F-8C aircraft (United States)

    Seacord, C. L.; Vaughn, D. K.


    The design of a fly-by-wire control system having a mission failure probability of less than one millionth failures per flight hour is examined. Emphasis was placed on developing actuator configurations that would improve the system performance, and consideration of the practical aspects of sensor/computer and computer/actuator interface implementation. Five basic configurations were defined as appropriate candidates for the F-8C research aircraft. Options on the basic configurations were included to cover variations in flight sensors, redundancy levels, data transmission techniques, processor input/output methods, and servo actuator arrangements. The study results can be applied to fly by wire systems for transport aircraft in general and the space shuttle.

  17. Guidance and Control Design Considerations for Low-Altitude and Terminal-Area Flight (United States)


    responses, developed by Boeing Corp. used for an Indication of handling qualities1 Ct - Lift curve slope, per radian Fs - SUck force, lb.. G(s...Conference; SP-itl6, 1971*. 2. DICK , A. 0.; and BAILEY, George: A Comparison Between Oculometer Data and Pilot Opinion on the Usefulness of... mom POSITION UPDATE MODE IDD IDD IDD ADD IXX IDD IDD CROSSnUCK ERROR. K Mean and standard deviation of autopilot lateral axl: flight

  18. Flight Dynamics and Control of a Morphing UAV: Bio inspired by Natural Fliers (United States)


    filler was used to create a smooth aerodynamic finish. The gap reduction module was 3D printed out of ABS plastic to allow complex internal geometry...maintenance. The spars were then bonded into the gap reduction module and wingtip section to form the final component. Plastic covers were secured onto the...Aircraft Engineer weekly, vol. 65. Flight and Aircraft Engi- neer, January 1954. [2] Advisory Council for Aviation Research and Innovation in Europe

  19. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 2. Noise Control (United States)


    due to the cabin acoustics and the second due to some specified external noise source. For a modal solution, the structural deflection w(., t) is taken...the source and cabin acoustics differ for each method to be discussed in later sections of this chapter. The structural models and approach to...over TL or flight testing. The panel area under study can interact with the noise source, adjacent structure, and cabin acoustics in a realistic manner

  20. Survival of pathogenic enterohemorrhagic Escherichia coli (EHEC) and control with calcium oxide in frozen meat products. (United States)

    Ro, Eun Young; Ko, Young Mi; Yoon, Ki Sun


    This study investigated both the level of microbial contamination and the presence of enterohemorrhagic Escherichia coli (EHEC) in frozen meat products, followed by the evaluation of its survival over 180 days under frozen temperature. We also examined the effect of calcium oxide on the populations of EHEC, E. coli O157:H7 and EPEC under both 10 °C and -18 °C storage conditions. Afterward, the morphological changes occurring in EHEC cells in response to freezer storage temperature and calcium oxide (CaO) treatments were examined using transmission electron microscopy. Among the frozen meat products tested, the highest contamination levels of total aerobic counts, coliforms and E. coli were observed in pork cutlets. Examination showed that 20% of the frozen meat products contained virulence genes, including verotoxin (VT) 1 and 2. Over 180 days of frozen storage and after 3 freeze-thaw cycles, the population of EHEC did not change regardless of the type of products or initial inoculated concentration, indicating the strong survival ability of EHEC. Subsequent testing revealed that the growth of three pathogenic E. coli strains was completely inhibited in meat patties prepared with 1% CaO, stored at 10 °C. However, the addition of 2% CaO was necessary to control the survival of EHEC, E. coli O157:H7 and EPEC in meat patties stored at -18 °C. CaO reduced the population of E. coli O157:H7 more effectively than the other EHEC and EPEC strains at both 10 °C and -18 °C. Transmission electron microscopy analysis revealed that exposed EHEC cells were resistant to the freezer storage temperature, although some cells incurred injury and death after several freeze-thaw cycles. Most of the cells exposed to CaO were found to have died or lost their cellular integrity and membranes, indicating that CaO has the potential to be used as a powerful antimicrobial agent for manufacturing frozen meat products. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Flight dynamics of some Lepidoptera species of sugar beet and possibilities their control (Transylvania-Romania

    Directory of Open Access Journals (Sweden)

    Muresanu Felicia


    Full Text Available In this paper, the authors present the obtained results regarding the flight dynamics of some Lepidoptera species in sugar beet crops in Transylvania (the central part of Romania. In order to limit the appearance of mentioned pests to the economic threshold, Trichogramma spp. were obtained in laboratory conditions at ARDS Turda and SBRDS Brasov. The experiments were conducted in production areas on 0,5 ha minimum for each variant. The variants included four Trichogramma species: T. dendrolimi, T. evanescens, T. maidis, T. buesi that were manually released three times: the first release, 10.000 individuals/ha, the second, 120.000 individuals/ha and the third, 150.000 individuals/ha. The first release was performed at the beginning of the Lepidoptera flight, the second at the maximum flight and the third 5 days after the second. The efficiency of T. maidis was between 75-90%, of T. evanescens, it was between 73-88%, of T. dendrolimi, it was between 85-92% and of T. buesi 79-82%. Among the Trichogramma species utilized, T. dendrolimi and T. evanescens were very efficient in the reduction of mentioned pests. Root production was significantly higher compared to the untreated variant, 4,0-4,7 t/ha more were recorded after the application of biological treatments with T. evanescens and T. dendrolimi.

  2. Predictions of Control Inputs, Periodic Responses and Damping Levels of an Isolated Experimental Rotor in Trimmed Flight (United States)

    Gaonkar, G. H.; Subramanian, S.


    Since the early 1990s the Aeroflightdynamics Directorate at the Ames Research Center has been conducting tests on isolated hingeless rotors in hover and forward flight. The primary objective is to generate a database on aeroelastic stability in trimmed flight for torsionally soft rotors at realistic tip speeds. The rotor test model has four soft inplane blades of NACA 0012 airfoil section with low torsional stiffness. The collective pitch and shaft tilt are set prior to each test run, and then the rotor is trimmed in the following sense: the longitudinal and lateral cyclic pitch controls are adjusted through a swashplate to minimize the 1/rev flapping moment at the 12 percent radial station. In hover, the database comprises lag regressive-mode damping with pitch variations. In forward flight the database comprises cyclic pitch controls, root flap moment and lag regressive-mode damping with advance ratio, shaft angle and pitch variations. This report presents the predictions and their correlation with the database. A modal analysis is used, in which nonrotating modes in flap bending, lag bending and torsion are computed from the measured blade mass and stiffness distributions. The airfoil aerodynamics is represented by the ONERA dynamic stall models of lift, drag and pitching moment, and the wake dynamics is represented by a state-space wake model. The trim analysis of finding, the cyclic controls and the corresponding, periodic responses is based on periodic shooting with damped Newton iteration; the Floquet transition matrix (FTM) comes out as a byproduct. The stabillty analysis of finding the frequencies and damping levels is based on the eigenvalue-eigenvector analysis of the FTM. All the structural and aerodynamic states are included from modeling to trim analysis. A major finding is that dynamic wake dramatically improves the correlation for the lateral cyclic pitch control. Overall, the correlation is fairly good.

  3. Motion of the two-control airplane in rectilinear flight after initial disturbances with introduction of controls following an exponential law (United States)

    Klemin, Alexander


    An airplane in steady rectilinear flight was assumed to experience an initial disturbance in rolling or yawing velocity. The equations of motion were solved to see if it was possible to hasten recovery of a stable airplane or to secure recovery of an unstable airplane by the application of a single lateral control following an exponential law. The sample computations indicate that, for initial disturbances complex in character, it would be difficult to secure correlation with any type of exponential control. The possibility is visualized that the two-control operation may seriously impair the ability to hasten recovery or counteract instability.

  4. A real-time engineering software system for failure detection and isolation of self-repairing flight control system (United States)

    Deng, Juan; Ai, Jianliang; Gao, Min; Luo, Changhang


    This paper introduces a real-time Failure Detection and Isolation (FDI) software system of Self-Repairing Flight Control System (SRFCS) that is developed by Institute of Vehicle Design of Fudan University. An algorithm of adopting the method of parity space to get residual sequences and the theory of residual vector data fusion is applied to detecting and isolating the abrupt change failures of SRFCS, especially the actuators' failures, single control surface's failures and multiple failures. The system follows the theory of object-oriented software design by adopting the design idea of modularization and uses Dynamic Link Library (DLL) widely so that it is easy to replant new modules and extend its ability freely. The interface of this system is friendly and the operation on it is convenient. In this paper, the system is applied to the flight control system of some type of fighter of Chinese Air Force and the results show that this software system can detect single control surface's failures within 0.125 seconds (10 sampling periods) and actuators' failures within 0.0625 seconds (5 sampling periods) under strong noise circumstances. The test results based on the simulated data prove the validity of the theory, the robust and real time property of the developed software.

  5. A frequency domain stability analysis of a phase plane control system. [for Space Shuttle on-orbit flight (United States)

    Hattis, P. D.; Kubiak, E. T.; Penchuk, A. N.


    A describing function is used to model a phase plane controller which is part of the Space Shuttle on-orbit Reaction Control System autopilot. A frequency domain stability analysis of the closed-loop control system is applied to a study of potential flight control system interaction with the Orbiter and a class of payloads deployed from a tilt table. Phase-gain plot techniques are used to show that expansion of phase plane angular rate limits and stiffening of the tilt table pivot do not always enhance system stability. Instability region approximations are mapped as a function of rate limit, payload geometry, jet used, and natural frequency of the pivot. Comparison of the describing function analysis with simulation results shows excellent correlation.

  6. Combined modality treatment improves tumor control and overall survival in patients with early stage Hodgkin's lymphoma: a systematic review

    DEFF Research Database (Denmark)

    Herbst, Christine; Rehan, Fareed A; Brillant, Corinne


    . We thus performed a systematic review with meta-analysis of randomized controlled trials comparing chemotherapy alone with CMT in patients with early stage Hodgkin's lymphoma with respect to response rate, tumor control and overall survival (OS). We searched Medline, EMBASE and the Cochrane Library....... These trials underlined the results of the main analysis. In conclusion, adding radiotherapy to chemotherapy improves tumor control and OS in patients with early stage Hodgkin's lymphoma....

  7. SpaceOps 2012 Plus 2: Social Tools to Simplify ISS Flight Control Communications and Log Keeping (United States)

    Cowart, Hugh S.; Scott, David W.


    A paper written for the SpaceOps 2012 Conference (Simplify ISS Flight Control Communications and Log Keeping via Social Tools and Techniques) identified three innovative concepts for real time flight control communications tools based on social mechanisms: a) Console Log Tool (CoLT) - A log keeping application at Marshall Space Flight Center's (MSFC) Payload Operations Integration Center (POIC) that provides "anywhere" access, comment and notifications features similar to those found in Social Networking Systems (SNS), b) Cross-Log Communication via Social Techniques - A concept from Johnsson Space Center's (JSC) Mission Control Center Houston (MCC-H) that would use microblogging's @tag and #tag protocols to make information/requests visible and/or discoverable in logs owned by @Destination addressees, and c) Communications Dashboard (CommDash) - A MSFC concept for a Facebook-like interface to visually integrate and manage basic console log content, text chat streams analogous to voice loops, text chat streams dedicated to particular conversations, generic and position-specific status displays/streams, and a graphically based hailing display. CoLT was deployed operationally at nearly the same time as SpaceOps 2012, the Cross- Log Communications idea is currently waiting for a champion to carry it forward, and CommDash was approved as a NASA Iinformation Technoloby (IT) Labs project. This paper discusses lessons learned from two years of actual CoLT operations, updates CommDash prototype development status, and discusses potential for using Cross-Log Communications in both MCC-H and/or POIC environments, and considers other ways for synergizing console applcations.

  8. Survival of Listeria monocytogenes on fresh blueberries (Vaccinium corymbosum) stored under controlled atmosphere and ozone. (United States)

    Concha-Meyer, Anibal; Eifert, Joseph; Williams, Robert; Marcy, Joseph; Welbaum, Gregory


    Listeria monocytogenes is a foodborne pathogen that represents a high risk for consumers because it can grow under refrigeration conditions and can also develop acid tolerance. Fresh blueberries are hand-picked, packed, and transported under refrigeration without receiving a microbial inactivation treatment. The aim of this work was to study the survival of L. monocytogenes in fresh highbush blueberries stored at 4 or 12 °C under different controlled atmosphere conditions, including air (control); 5% O2, 15% CO2, 80% N2 (controlled atmosphere storage [CAS]); or ozone gas (O3), 4 ppm at 4 °C or 2.5 ppm at 12 °C, at high relative humidity (90 to 95%) for a total of 10 days. Fresh blueberries inside a plastic clamshell were spot inoculated with the bacteria and were stored at 4 or 12 °C in isolated cabinets under air, CAS, and O3 atmospheric conditions. Samples were evaluated on days 0, 1, 4, 7, and 10 for microbial growth using modified Oxford agar. CAS did not delay or inhibit L. monocytogenes growth in fresh blueberries after 10 days. O3 achieved 3- and 2-log reductions when compared with air treatment at 4 and 12 °C, respectively. Low concentrations of O3 together with proper refrigeration temperature can ensure product safety throughout transportation. O3 is a strong antimicrobial that safely decomposes to oxygen and water without leaving residues and can be used as an alternative method to prevent bacterial growth during a long transport period.

  9. Design, analysis, and control of a large transport aircraft utilizing selective engine thrust as a backup system for the primary flight control. Ph.D. Thesis (United States)

    Gerren, Donna S.


    A study has been conducted to determine the capability to control a very large transport airplane with engine thrust. This study consisted of the design of an 800-passenger airplane with a range of 5000 nautical miles design and evaluation of a flight control system, and design and piloted simulation evaluation of a thrust-only backup flight control system. Location of the four wing-mounted engines was varied to optimize the propulsive control capability, and the time constant of the engine response was studied. The goal was to provide level 1 flying qualities. The engine location and engine time constant did not have a large effect on the control capability. The airplane design did meet level 1 flying qualities based on frequencies, damping ratios, and time constants in the longitudinal and lateral-directional modes. Project pilots consistently rated the flying qualities as either level 1 or level 2 based on Cooper-Harper ratings. However, because of the limited control forces and moments, the airplane design fell short of meeting the time required to achieve a 30 deg bank and the time required to respond a control input.

  10. Flight data identification of six degree-of-freedom stability and control derivatives of a large crane type helicopter (United States)

    Tomaine, R. L.


    Flight test data from a large 'crane' type helicopter were collected and processed for the purpose of identifying vehicle rigid body stability and control derivatives. The process consisted of using digital and Kalman filtering techniques for state estimation and Extended Kalman filtering for parameter identification, utilizing a least squares algorithm for initial derivative and variance estimates. Data were processed for indicated airspeeds from 0 m/sec to 152 m/sec. Pulse, doublet and step control inputs were investigated. Digital filter frequency did not have a major effect on the identification process, while the initial derivative estimates and the estimated variances had an appreciable effect on many derivative estimates. The major derivatives identified agreed fairly well with analytical predictions and engineering experience. Doublet control inputs provided better results than pulse or step inputs.

  11. c-Myb regulates NOX1/p38 to control survival of colorectal carcinoma cells. (United States)

    Pekarčíková, Lucie; Knopfová, Lucia; Beneš, Petr; Šmarda, Jan


    The c-Myb transcription factor is important for maintenance of immature cells of many tissues including colon epithelium. Overexpression of c-Myb occurring in colorectal carcinomas (CRC) as well as in other cancers often marks poor prognosis. However, the molecular mechanism explaining how c-Myb contributes to progression of CRC has not been fully elucidated. To address this point, we investigated the way how c-Myb affects sensitivity of CRC cells to anticancer drugs. Using CRC cell lines expressing exogenous c-myb we show that c-Myb protects CRC cells from the cisplatin-, oxaliplatin-, and doxorubicin-induced apoptosis, elevates reactive oxygen species via up-regulation of NOX1, and sustains the pro-survival p38 MAPK pathway. Using pharmacological inhibitors and gene silencing of p38 and NOX1 we found that these proteins are essential for the protective effect of c-Myb and that NOX1 acts upstream of p38 activation. In addition, our result suggests that transcription of NOX1 is directly controlled by c-Myb and these genes are strongly co-expressed in human tumor tissue of CRC patients. The novel c-Myb/NOX1/p38 signaling axis that protects CRC cells from chemotherapy described in this study could provide a new base for design of future therapies of CRC. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Technology research for strapdown inertial experiment and digital flight control and guidance (United States)

    Carestia, R. A.; Cottrell, D. E.


    A helicopter flight-test program to evaluate the performance of Honeywell's Tetrad - a strapdown, laser gyro, inertial navitation system is discussed. The results of 34 flights showed a mean final navigational velocity error of 5.06 knots, with a standard deviation of 3.84 knots; a corresponding mean final position error of 2.66 n.mi., with a standard deviation of 1.48 n.m.; and a modeled mean-position-error growth rate for the 34 tests of 1.96 knots, with a standard deviation of 1.09 knots. Tetrad's four-ring laser gyros provided reliable and accurate angular rate sensing during the test program and on sensor failures were detected during the evaluation. Criteria suitable for investigating cockpit systems in rotorcraft were developed. This criteria led to the development of two basic simulators. The first was a standard simulator which could be used to obtain baseline information for studying pilot workload and interactions. The second was an advanced simulator which integrated the RODAAS developed by Honeywell into this simulator. The second area also included surveying the aerospace industry to determine the level of use and impact of microcomputers and related components on avionics systems.

  13. New insights into insect's silent flight. Part II: sound source and noise control (United States)

    Xue, Qian; Geng, Biao; Zheng, Xudong; Liu, Geng; Dong, Haibo


    The flapping flight of aerial animals has excellent aerodynamic performance but meanwhile generates low noise. In this study, the unsteady flow and acoustic characteristics of the flapping wing are numerically investigated for three-dimensional (3D) models of Tibicen linnei cicada at free forward flight conditions. Single cicada wing is modelled as a membrane with prescribed motion reconstructed by Wan et al. (2015). The flow field and acoustic field around the flapping wing are solved with immersed-boundary-method based incompressible flow solver and linearized-perturbed-compressible-equations based acoustic solver. The 3D simulation allows examination of both directivity and frequency composition of the produced sound in a full space. The mechanism of sound generation of flapping wing is analyzed through correlations between acoustic signals and flow features. Along with a flexible wing model, a rigid wing model is also simulated. The results from these two cases will be compared to investigate the effects of wing flexibility on sound generation. This study is supported by NSF CBET-1313217 and AFOSR FA9550-12-1-0071.

  14. Flight of the Chinese white pine beetle (Coleoptera: Scolytidae) in relation to sex, body weight and energy reserve. (United States)

    Chen, H; Li, Z; Bu, S H; Tian, Z Q


    The flight distance, flight time and individual flight activities of males and females of Dendroctonus armandi were recorded during 96-h flight trials using a flight mill system. The body weight, glucose, glycogen and lipid content of four treatments (naturally emerged, starved, phloem-fed and water-fed) were compared among pre-flight, post-flight and unflown controls. There was no significant difference between males and females in total flight distance and flight time in a given 24-h period. The flight distance and flight time of females showed a significant linear decline as the tethered flying continued, but the sustained flight ability of females was better than that of males. The females had higher glycogen and lipid content than the males; however, there was no significant difference between both sexes in glucose content. Water-feeding and phloem-feeding had significant effects on longevity, survival days and flight potential of D. armandi, which resulted in longer feeding days, poorer flight potential and lower energy substrate content. Our results demonstrate that flight distances in general do not differ between water-fed and starved individuals, whereas phloem-fed females and males fly better than water-fed and starved individuals.

  15. Transition from LDR to HDR brachytherapy for cervical cancer: Evaluation of tumor control, survival, and toxicity. (United States)

    Romano, K D; Pugh, K J; Trifiletti, D M; Libby, B; Showalter, T N

    In 2012, our institution transitioned from low-dose-rate (LDR) brachytherapy to high dose-rate (HDR) brachytherapy. We report clinical outcomes after brachytherapy for cervical cancer at our institution over a continuous 10-year period. From 2004 to 2014, 258 women (184 LDR and 74 HDR) were treated with tandem and ovoid brachytherapy in the multidisciplinary management of International Federation of Gynecology and Obstetrics Stages IA-IVB cervical cancer. Clinical and treatment-related prognostic factors including age, stage, smoking status, relevant doses, and toxicity data were recorded. Median followup for the LDR and HDR groups was 46 months and 12 months, respectively. The majority of patients (92%) received external beam radiotherapy as well as concurrent chemotherapy (83%) before the start of brachytherapy. For all stages, the 1-year local control and overall survival (OS) rates were comparable between the LDR and HDR groups (87% vs. 81%, p = 0.12; and 75% vs. 85%, p = 0.16), respectively. Factors associated with OS on multivariate analysis include age, stage, and nodal involvement. On multivariate analysis, severe toxicity (acute or chronic) was higher with HDR than LDR (24% vs. 10%, p = 0.04). Additional prognostic factors associated with increased severe toxicity include former/current smokers and total dose to lymph nodes. This comparative retrospective analysis of a large cohort of women treated with brachytherapy demonstrates no significant difference in OS or local control between the LDR and HDR. Acute and chronic toxicity increased shortly after the implementation of HDR, highlighting the importance of continued refinement of HDR methods, including integrating advanced imaging. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. Design, analysis and control of large transports so that control of engine thrust can be used as a back-up of the primary flight controls. Ph.D. Thesis (United States)

    Roskam, Jan; Ackers, Deane E.; Gerren, Donna S.


    A propulsion controlled aircraft (PCA) system has been developed at NASA Dryden Flight Research Center at Edwards Air Force Base, California, to provide safe, emergency landing capability should the primary flight control system of the aircraft fail. As a result of the successful PCA work being done at NASA Dryden, this project investigated the possibility of incorporating the PCA system as a backup flight control system in the design of a large, ultra-high capacity megatransport in such a way that flight path control using only the engines is not only possible, but meets MIL-Spec Level 1 or Level 2 handling quality requirements. An 800 passenger megatransport aircraft was designed and programmed into the NASA Dryden simulator. Many different analysis methods were used to evaluate the flying qualities of the megatransport while using engine thrust for flight path control, including: (1) Bode and root locus plot analysis to evaluate the frequency and damping ratio response of the megatransport; (2) analysis of actual simulator strip chart recordings to evaluate the time history response of the megatransport; and (3) analysis of Cooper-Harper pilot ratings by two NaSA test pilots.

  17. Fecundity, survival, and growth of the seahorse Hippocampus ingens (Pisces: Syngnathidae under semi-controlled conditions

    Directory of Open Access Journals (Sweden)

    A.A Ortega-Salas


    Full Text Available Estudiamos la fecundidad, supervivencia, y crecimiento del caballito de mar, Hippocampus ingens en condiciones semi-controladas. Tres machos reproductores silvestres de 14.8, 24.5 y 32.0 g produjeron 1 598, 1 703 y 1 658 jóvenes. La densidad utilizada fue de 12 jóvenes por acuario de 60 l. Se agruparon en 1, 12 y 20 días de nacidos por acuario. La supervivencia fue de 78.5, 38.1 y 41.0 % en 35 días. Se les alimentó con una mezcla de rotíferos B. plicatilis y nauplios de Artemia para después transferirlos a estanques de 100 000 l a una densidad de 50/1 000 l, donde se les alimentó con Artemia adulta durante 60 días más. Crecieron de un promedio de 0.7, 1.5, y 2.7 a 4.5, 5.4 6.7 cm, respectivamente, en 95 días. La temperatura del agua marina utilizada varió de 17 a 23 ºC.We studied fecundity, survival, and growth of the seahorse Hippocampus ingens under semi-controlled conditions. Three wild brood stock mature males of 14.8, 24.5, and 32.0 g released 1 598, 1 703, and 1 658 juveniles. Juvenile stocking densities of 12 were settled in 60-l aquariums in groups of 1, 12, and 20 days old organisms. The rate of survival was 21.5, 61.9, and 59.0 %, respectively, in 35 days. Juveniles were fed a mix diet of rotifers B. plicatilis and Artemia nauplii, then they were transferred to a cement tank of 100 000 l at a density of 50/1 000 l and fed with live adult Artemia for 60 days more. They grew from an average of 0.7, 1.5, and 2.7 to 4.5, 5.4, and 6.7 cm, respectively, in 95 days. The seawater temperature varied from 17 to 23 ºC. Rev. Biol. Trop. 54 (4: 1099-1102. Epub 2006 Dec. 15.

  18. Nonlinear Dynamic Inversion Baseline Control Law: Flight-Test Results for the Full-scale Advanced Systems Testbed F/A-18 Airplane (United States)

    Miller, Christopher J.


    A model reference nonlinear dynamic inversion control law has been developed to provide a baseline controller for research into simple adaptive elements for advanced flight control laws. This controller has been implemented and tested in a hardware-in-the-loop simulation and in flight. The flight results agree well with the simulation predictions and show good handling qualities throughout the tested flight envelope with some noteworthy deficiencies highlighted both by handling qualities metrics and pilot comments. Many design choices and implementation details reflect the requirements placed on the system by the nonlinear flight environment and the desire to keep the system as simple as possible to easily allow the addition of the adaptive elements. The flight-test results and how they compare to the simulation predictions are discussed, along with a discussion about how each element affected pilot opinions. Additionally, aspects of the design that performed better than expected are presented, as well as some simple improvements that will be suggested for follow-on work.

  19. An Experimental Evaluation of Generalized Predictive Control for Tiltrotor Aeroelastic Stability Augmentation in Airplane Mode of Flight (United States)

    Kvaternik, Raymond G.; Piatak, David J.; Nixon, Mark W.; Langston, Chester W.; Singleton, Jeffrey D.; Bennett, Richard L.; Brown, Ross K.


    The results of a joint NASA/Army/Bell Helicopter Textron wind-tunnel test to assess the potential of Generalized Predictive Control (GPC) for actively controlling the swashplate of tiltrotor aircraft to enhance aeroelastic stability in the airplane mode of flight are presented. GPC is an adaptive time-domain predictive control method that uses a linear difference equation to describe the input-output relationship of the system and to design the controller. The test was conducted in the Langley Transonic Dynamics Tunnel using an unpowered 1/5-scale semispan aeroelastic model of the V-22 that was modified to incorporate a GPC-based multi-input multi-output control algorithm to individually control each of the three swashplate actuators. Wing responses were used for feedback. The GPC-based control system was highly effective in increasing the stability of the critical wing mode for all of the conditions tested, without measurable degradation of the damping in the other modes. The algorithm was also robust with respect to its performance in adjusting to rapid changes in both the rotor speed and the tunnel airspeed.

  20. Dental Implant Survival and Complication Rate over 2 Years for Individuals with Poorly Controlled Type 2 Diabetes Mellitus. (United States)

    Eskow, Caroline C; Oates, Thomas W


    Emerging evidence suggests that implant therapy may be a viable option for diabetic individuals with elevated glycemic levels. The purpose of this 2 year observational study was to evaluate survival and clinical complications of dental implants following placement in type 2 diabetes individuals having poor glycemic control. Adult participants (n = 24) with poorly controlled type 2 diabetes (8.0% ≤ HbA1c ≤ 12.0%) received two or more transgingival dental implants. Survival was evaluated after 1 (23 participants, 72 implants) and 2 (20 participants, 59 implants) years. Clinical complications were evaluated in 18 participants (52 implants) after 21-34 months. Relationships between complications and stratified HbA1c levels were assessed using Pearson's correlation test. Survival rates were 98.6% (71/72 implants) after 1 year and 96.6% (57/59 implants) after 2 years. Complications were identified in 29% of participants with peri-implant mucositis, the most common event. Complications correlated directly with number of implants across HbA1c strata (0.42, R2  = 0.66). There was no correlation between HbA1c and the occurrences of complications or mucositis. This 2-year evaluation supports the broader application of implant therapy in type 2 diabetes individuals with poor glycemic control in demonstrating high survival rates with limited complications. © 2016 Wiley Periodicals, Inc.

  1. Alterations in erythrocyte survival parameters in rats after 19.5 days aboard Cosmos 782 (United States)

    Leon, H. A.; Serova, L. V.; Cummins, J.; Landaw, S. A.


    Rats were subjected to 19.5 days of weightless space flight aboard the Soviet biosatellite, Cosmos 782. Based on the output of CO-14, survival parameters of a cohort of erythrocytes labeled 15.5 days preflight were evaluated upon return from orbit. These were compared to vivarium control rats injected at the same time. Statistical evaluation indicates that all survival factors were altered by the space flight. The mean potential lifespan, which was 63.0 days in the control rats, was decreased to 59.0 days in the flight rats, and random hemolysis was increased three-fold in the flight rats. The measured size of the cohort was decreased, lending further support to the idea that hemolysis was accelerated during some portion of the flight. A number of factors that might be contributory to these changes are discussed, including forces associated with launch and reentry, atmospheric and environmental parameters, dietary factors, radiation, and weightlessness.

  2. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques (United States)

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


    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.

  3. Enabling efficient vertical takeoff/landing and forward flight of unmanned aerial vehicles: Design and control of tandem wing-tip mounted rotor mechanisms (United States)

    Mancuso, Peter Timothy

    Fixed-wing unmanned aerial vehicles (UAVs) that offer vertical takeoff and landing (VTOL) and forward flight capability suffer from sub-par performance in both flight modes. Achieving the next generation of efficient hybrid aircraft requires innovations in: (i) power management, (ii) efficient structures, and (iii) control methodologies. Existing hybrid UAVs generally utilize one of three transitioning mechanisms: an external power mechanism to tilt the rotor-propulsion pod, separate propulsion units and rotors during hover and forward flight, or tilt body craft (smaller scale). Thus, hybrid concepts require more energy compared to dedicated fixed-wing or rotorcraft UAVs. Moreover, design trade-offs to reinforce the wing structure (typically to accommodate the propulsion systems and enable hover, i.e. tilt-rotor concepts) adversely impacts the aerodynamics, controllability and efficiency of the aircraft in both hover and forward flight modes. The goal of this research is to develop more efficient VTOL/ hover and forward flight UAVs. In doing so, the transition sequence, transition mechanism, and actuator performance are heavily considered. A design and control methodology was implemented to address these issues through a series of computer simulations and prototype benchtop tests to verify the proposed solution. Finally, preliminary field testing with a first-generation prototype was conducted. The methods used in this research offer guidelines and a new dual-arm rotor UAV concept to designing more efficient hybrid UAVs in both hover and forward flight.

  4. The Analysis of the Contribution of Human Factors to the In-Flight Loss of Control Accidents (United States)

    Ancel, Ersin; Shih, Ann T.


    In-flight loss of control (LOC) is currently the leading cause of fatal accidents based on various commercial aircraft accident statistics. As the Next Generation Air Transportation System (NextGen) emerges, new contributing factors leading to LOC are anticipated. The NASA Aviation Safety Program (AvSP), along with other aviation agencies and communities are actively developing safety products to mitigate the LOC risk. This paper discusses the approach used to construct a generic integrated LOC accident framework (LOCAF) model based on a detailed review of LOC accidents over the past two decades. The LOCAF model is comprised of causal factors from the domain of human factors, aircraft system component failures, and atmospheric environment. The multiple interdependent causal factors are expressed in an Object-Oriented Bayesian belief network. In addition to predicting the likelihood of LOC accident occurrence, the system-level integrated LOCAF model is able to evaluate the impact of new safety technology products developed in AvSP. This provides valuable information to decision makers in strategizing NASA's aviation safety technology portfolio. The focus of this paper is on the analysis of human causal factors in the model, including the contributions from flight crew and maintenance workers. The Human Factors Analysis and Classification System (HFACS) taxonomy was used to develop human related causal factors. The preliminary results from the baseline LOCAF model are also presented.

  5. Species-specific control of acoustic gaze by echolocating bats, Rhinolophus ferrumequinum nippon and Pipistrellus abramus, during flight. (United States)

    Yamada, Yasufumi; Hiryu, Shizuko; Watanabe, Yoshiaki


    Based on the characteristics of the ultrasounds they produce, echolocating bats can be categorized into two main types: broadband FM (frequency modulated) and narrowband CF (constant frequency) echolocators. In this study, we recorded the echolocation behavior of a broadband FM (Pipistrellus abramus) and a narrowband CF echolocator species (Rhinolophus ferrumequinum nippon) while they explored an unfamiliar space in a laboratory chamber. During flight, P. abramus smoothly shifted its acoustic gaze in relation to its flight direction, whereas R. ferrumequinum nippon frequently shifted its acoustic gaze from side to side. The distribution of the acoustic gazes of R. ferrumequinum nippon was twice as wide as that of P. abramus. Furthermore, R. ferrumequinum nippon produced double pulses twice as often as P. abramus. Because R. ferrumequinum nippon has a horizontal beam width (-6 dB off-axis angle) half as wide (±20.8 ± 6.0°) as that of P. abramus (±38.3 ± 6.0°), it appears to double the width of its acoustical field of view by shifting its acoustic gaze further off-axis and emitting direction-shifted double pulses. These results suggest that broadband FM and narrowband CF bats actively control their acoustic gazes in a species-specific manner based on the acoustic features of their echolocation signals.

  6. Prognostic Factors for Outcomes of In-Flight Sudden Cardiac Arrest on Commercial Airlines. (United States)

    Alves, Paulo M; DeJohn, Charles A; Ricaurte, Eduard M; Mills, William D

    In-flight cardiac arrest (IFCA) is a relatively rare but challenging event. Outcomes and prognostic factors are not entirely understood for victims of IFCAs in commercial aviation. This was a retrospective cohort study of airline passengers who experienced IFCA. Demographic and operational variables were studied to identify association in a multivariate logistic regression model with the outcome of survival-to-hospital. In-flight medical emergencies were processed by a ground-based medical center. Subsequent comparisons were made between reported shockable-rhythm (RSR) and reported non-shockable-rhythm (RNSR) groups. Logistic regression was also used to identify predictors for shock advised and flight diversions using a case control study design. Significant predictors for survival-to-hospital were RSR and remaining flight time to destination. The percentage of RSR cases was 24.6%. The survival to hospital admission was 22.7% (22/97) for passengers in RSR compared with 2.4% (7/297) in the RNSR group. The adjusted odds ratio for survival-to-hospital for the RSR group compared to the RNSR group was 13.6 (5.5-33.5). The model showed odds for survival to hospital decreased with longer scheduled remaining flight duration with adjusted OR = 0.701 (0.535-0.920) per hour increase. No correlation between diversions and survival for RSR cases was found. Survival-to-hospital from IFCAs is best when an RSR is present. The percentage of RSR cases was lower than in other out-of-hospital cardiac arrest (OHCA) settings, which suggests delayed discovery. Flight diversions did not significantly affect resuscitation outcome. We emphasize good quality cardio-pulmonary resuscitation (CPR) and early defibrillation as key factors for IFCA survival. Alves PM, DeJohn CA, Ricaurte EM, Mills WD. Prognostic factors for outcomes of in-flight sudden cardiac arrest on commercial airlines. Aerosp Med Hum Perform. 2016; 87(10):862-868.

  7. Aircraft automatic-flight-control system with inversion of the model in the feed-forward path using a Newton-Raphson technique for the inversion (United States)

    Smith, G. A.; Meyer, G.; Nordstrom, M.


    A new automatic flight control system concept suitable for aircraft with highly nonlinear aerodynamic and propulsion characteristics and which must operate over a wide flight envelope was investigated. This exact model follower inverts a complete nonlinear model of the aircraft as part of the feed-forward path. The inversion is accomplished by a Newton-Raphson trim of the model at each digital computer cycle time of 0.05 seconds. The combination of the inverse model and the actual aircraft in the feed-forward path alloys the translational and rotational regulators in the feedback path to be easily designed by linear methods. An explanation of the model inversion procedure is presented. An extensive set of simulation data for essentially the full flight envelope for a vertical attitude takeoff and landing aircraft (VATOL) is presented. These data demonstrate the successful, smooth, and precise control that can be achieved with this concept. The trajectory includes conventional flight from 200 to 900 ft/sec with path accelerations and decelerations, altitude changes of over 6000 ft and 2g and 3g turns. Vertical attitude maneuvering as a tail sitter along all axes is demonstrated. A transition trajectory from 200 ft/sec in conventional flight to stationary hover in the vertical attitude includes satisfactory operation through lift-cure slope reversal as attitude goes from horizontal to vertical at constant altitude. A vertical attitude takeoff from stationary hover to conventional flight is also demonstrated.

  8. Protecting and rescuing the effectors: roles of differentiation and survival in the control of memory T cell development

    Directory of Open Access Journals (Sweden)

    Sema eKurtulus


    Full Text Available Vaccines, arguably the single most important intervention in improving human health, have exploited the phenomenon of immunological memory. The elicitation of memory T cells is often an essential part of successful long-lived protective immunity. Our understanding of T cell memory has been greatly aided by the development of TCR Tg mice and MHC tetrameric staining reagents that have allowed the precise tracking of antigen-specific T cell responses. Indeed, following acute infection or immunization, naïve T cells undergo a massive expansion culminating in the generation of a robust effector T cell population. This peak effector response is relatively short-lived and, while most effector T cells die by apoptosis, some remain and develop into memory cells. Although the molecular mechanisms underlying this cell fate decision remain incompletely defined, substantial progress has been made, particularly with regards to CD8+ T cells. For example, the effector CD8+ T cells generated during a response are heterogeneous, consisting of cells with more or less potential to develop into full-fledged memory cells. Development of CD8+ T cell memory is regulated by the transcriptional programs that control the differentiation and survival of effector T cells. While the type of antigenic stimulation and level of inflammation control effector CD8+ T cell differentiation, availability of cytokines and their ability to control expression and function of Bcl-2 family members governs their survival. These distinct differentiation and survival programs may allow for finer therapeutic intervention to control both the quality and quantity of CD8+ T cell memory. Effector to memory transition of CD4+ T cells is less well characterized than CD8+ T cells, emerging details will be discussed. This review will focus on the recent progress made in our understanding of the mechanisms underlying the development of T cell memory with an emphasis on factors controlling survival of

  9. Online Optimization-Based Predictive Flight Control Using First-Order Methods

    NARCIS (Netherlands)

    Ferranti, L.


    In fields such as aerospace or automotive, the use of classical control methods such as PID is still significant. The presence of constraints, however, impacts on the performance of these controllers that are usually designed to avoid constraint saturation. MPC techniques are the obvious alternative

  10. Flight control of fruit flies: dynamic response to optic flow and headwind. (United States)

    Lawson, Kiaran K K; Srinivasan, Mandyam V


    Insects are magnificent fliers that are capable of performing many complex tasks such as speed regulation, smooth landings and collision avoidance, even though their computational abilities are limited by their small brain. To investigate how flying insects respond to changes in wind speed and surrounding optic flow, the open-loop sensorimotor response of female Queensland fruit flies ( Bactrocera tryoni ) was examined. A total of 136 flies were exposed to stimuli comprising sinusoidally varying optic flow and air flow (simulating forward movement) under tethered conditions in a virtual reality arena. Two responses were measured: the thrust and the abdomen pitch. The dynamics of the responses to optic flow and air flow were measured at various frequencies, and modelled as a multicompartment linear system, which accurately captured the behavioural responses of the fruit flies. The results indicate that these two behavioural responses are concurrently sensitive to changes of optic flow as well as wind. The abdomen pitch showed a streamlining response, where the abdomen was raised higher as the magnitude of either stimulus was increased. The thrust, in contrast, exhibited a counter-phase response where maximum thrust occurred when the optic flow or wind flow was at a minimum, indicating that the flies were attempting to maintain an ideal flight speed. When the changes in the wind and optic flow were in phase (i.e. did not contradict each other), the net responses (thrust and abdomen pitch) were well approximated by an equally weighted sum of the responses to the individual stimuli. However, when the optic flow and wind stimuli were presented in counterphase, the flies seemed to respond to only one stimulus or the other, demonstrating a form of 'selective attention'. © 2017. Published by The Company of Biologists Ltd.

  11. Association of Body Composition With Survival and Locoregional Control of Radiotherapy-Treated Head and Neck Squamous Cell Carcinoma. (United States)

    Grossberg, Aaron J; Chamchod, Sasikarn; Fuller, Clifton D; Mohamed, Abdallah S R; Heukelom, Jolien; Eichelberger, Hillary; Kantor, Michael E; Hutcheson, Katherine A; Gunn, G Brandon; Garden, Adam S; Frank, Steven; Phan, Jack; Beadle, Beth; Skinner, Heath D; Morrison, William H; Rosenthal, David I


    Major weight loss is common in patients with head and neck squamous cell carcinoma (HNSCC) who undergo radiotherapy (RT). How baseline and posttreatment body composition affects outcome is unknown. To determine whether lean body mass before and after RT for HNSCC predicts survival and locoregional control. Retrospective study of 2840 patients with pathologically proven HNSCC undergoing curative RT at a single academic cancer referral center from October 1, 2003, to August 31, 2013. One hundred ninety patients had computed tomographic (CT) scans available for analysis of skeletal muscle (SM). The effect of pre-RT and post-RT SM depletion (defined as a CT-measured L3 SM index of less than 52.4 cm2/m2 for men and less than 38.5 cm2/m2 for women) on survival and disease control was evaluated. Final follow-up was completed on September 27, 2014, and data were analyzed from October 1, 2014, to November 29, 2015. Primary outcomes were overall and disease-specific survival and locoregional control. Secondary analyses included the influence of pre-RT body mass index (BMI) and interscan weight loss on survival and recurrence. Among the 2840 consecutive patients who underwent screening, 190 had whole-body positron emission tomography-CT or abdominal CT scans before and after RT and were included for analysis. Of these, 160 (84.2%) were men and 30 (15.8%) were women; their mean (SD) age was 57.7 (9.4) years. Median follow up was 68.6 months. Skeletal muscle depletion was detected in 67 patients (35.3%) before RT and an additional 58 patients (30.5%) after RT. Decreased overall survival was predicted by SM depletion before RT (hazard ratio [HR], 1.92; 95% CI, 1.19-3.11; P = .007) and after RT (HR, 2.03; 95% CI, 1.02-4.24; P = .04). Increased BMI was associated with significantly improved survival (HR per 1-U increase in BMI, 0.91; 95% CI, 0.87-0.96; P < .001). Weight loss without SM depletion did not affect outcomes. Post-RT SM depletion was more substantive in

  12. Demonstration of the Dynamic Flowgraph Methodology using the Titan 2 Space Launch Vehicle Digital Flight Control System (United States)

    Yau, M.; Guarro, S.; Apostolakis, G.


    Dynamic Flowgraph Methodology (DFM) is a new approach developed to integrate the modeling and analysis of the hardware and software components of an embedded system. The objective is to complement the traditional approaches which generally follow the philosophy of separating out the hardware and software portions of the assurance analysis. In this paper, the DFM approach is demonstrated using the Titan 2 Space Launch Vehicle Digital Flight Control System. The hardware and software portions of this embedded system are modeled in an integrated framework. In addition, the time dependent behavior and the switching logic can be captured by this DFM model. In the modeling process, it is found that constructing decision tables for software subroutines is very time consuming. A possible solution is suggested. This approach makes use of a well-known numerical method, the Newton-Raphson method, to solve the equations implemented in the subroutines in reverse. Convergence can be achieved in a few steps.

  13. Ergonomic problems regarding the interactive touch input via screens in onboard and ground-based flight control (United States)

    Holzhausen, K. P.; Gaertner, K. P.


    A significant problem concerning the integration of display and switching functions is related to the fact that numerous informative data which have to be processed by man must be read from only a few display devices. A satisfactory ergonomic design of integrated display devices and keyboards is in many cases difficult, because not all functions which can be displayed and selected are simultaneously available. A technical solution which provides an integration of display and functional elements on the basis of the highest flexibility is obtained by using a cathode ray tube with a touch-sensitive screen. The employment of an integrated data input/output system is demonstrated for the cases of onboard and ground-based flight control. Ergonomic studies conducted to investigate the suitability of an employment of touch-sensitive screens are also discussed.

  14. 14 CFR 91.109 - Flight instruction; Simulated instrument flight and certain flight tests. (United States)


    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight instruction; Simulated instrument flight and certain flight tests. 91.109 Section 91.109 Aeronautics and Space FEDERAL AVIATION... throwover control wheel in place of fixed, dual controls of the elevator and ailerons when— (1) The...

  15. Intraocular pressure control and corneal graft survival after implantation of Ahmed valve device in high-risk penetrating keratoplasty. (United States)

    Almousa, Radwan; Nanavaty, Mayank A; Daya, Sheraz M; Lake, Damian B


    To analyze the control of intraocular pressure (IOP) and corneal graft survival after implantation of Ahmed glaucoma device (AGD) in eyes that had high-risk penetrating keratoplasty (PK). This is a retrospective noncomparative case series of 59 eyes that had high-risk PK and underwent AGD insertion. The primary outcome measures are the control of IOP between 6 and 21 mm Hg and corneal graft survival. The secondary outcome measures are risk factors associated with IOP control and corneal graft survival. The mean IOP reduced significantly after the AGD procedure (26.45 ± 6.8 mm Hg preoperatively vs. 16.85 ± 7.4 mm Hg, 16.95 ± 4.6 mm Hg, 17.97 ± 5.7 mm Hg, 15.78 ± 5.2 mm Hg, and 15.59 ± 5.5 mm Hg, at 1 month, 6 months, 1 year, 2 years, and at the last follow-up postoperatively; P IOP control was successful in 44 eyes (75.8%). IOP control was successful in 96% of the eyes at 1 year, 87% at 2 years, 83% at 3 years, and 83% at 5 years. The percentage of clear corneal grafts after 1, 2, 3, and 5 years following the AGD insertion were 87%, 77%, 65%, and 47%, respectively. Further surgery after AGD insertion was associated with 1.79 times greater risk of failure of IOP control. AGD was effective in controlling the IOP associated with high-risk PK over a 5-year period. Postvalve surgery doubles the risk of failure of IOP control.

  16. Survival analysis of postoperative nausea and vomiting in patients receiving patient-controlled epidural analgesia

    Directory of Open Access Journals (Sweden)

    Shang-Yi Lee


    Conclusion: Survival analysis using Cox regression showed that the average consumption of opioids played an important role in postoperative nausea and vomiting, a result not found by logistic regression. Therefore, the incidence of postoperative nausea and vomiting in patients cannot be reliably determined on the basis of a single visit at one point in time.

  17. Integrated Reconfigurable Aero and Propulsion Control for Improved Flight Safety of Commercial Aircraft Project (United States)

    National Aeronautics and Space Administration — The main objective of this project is to develop and test a novel innovative Integrated Reconfigurable Aero & Propulsion Control (IRAP) system that achieves...

  18. Intelligent, Semi-Automated Procedure Aid (ISAPA) for ISS Flight Control Project (United States)

    National Aeronautics and Space Administration — We propose to develop the Intelligent, Semi-Automated Procedure Aid (ISAPA) intended for use by International Space Station (ISS) ground controllers to increase the...

  19. Nonlinear robust control of hypersonic aircrafts with interactions between flight dynamics and propulsion systems. (United States)

    Li, Zhaoying; Zhou, Wenjie; Liu, Hao


    This paper addresses the nonlinear robust tracking controller design problem for hypersonic vehicles. This problem is challenging due to strong coupling between the aerodynamics and the propulsion system, and the uncertainties involved in the vehicle dynamics including parametric uncertainties, unmodeled model uncertainties, and external disturbances. By utilizing the feedback linearization technique, a linear tracking error system is established with prescribed references. For the linear model, a robust controller is proposed based on the signal compensation theory to guarantee that the tracking error dynamics is robustly stable. Numerical simulation results are given to show the advantages of the proposed nonlinear robust control method, compared to the robust loop-shaping control approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Robust Adaptive Flight Control Design of Air-breathing Hypersonic Vehicles (United States)


    proposed by Qian and Jiaxue [2010] with the help of the neural network. Other six-DOF model of AHV are presented by Vick [2014], Chamitoff [1992]. The...adap- tive robust controller is derived by Rollins et al. [2013], using dynamic inversion technique for the model proposed by Vick [2014]. Further, the...Barrier lyapunov functions for the control of output-constrained nonlinear systems. Automatica, 45(4):918–927, 2009. Tyler J Vick . Geometry Modeling

  1. Investigation of Drive-Reinforcement Learning and Application of Learning to Flight Control (United States)


    subsections present the details of the fixed, adaptive, and learning components of the angular rate and f controllers. qc .__ - _ _ 4 .] - pqr - Veil ...E C’r’,P ) X -- (0 C"f + B ((Y’VT’ + C’r)) rk (0 (4 4- C ) (6.26) 6.2.2 Learning Control Flor the nonhnt;1r SYySt.1n, the output Ykc 1, (Q.274) nuist

  2. Fully automatic guidance and control for rotorcraft nap-of-the-Earth flight following planned profiles. Volume 1: Real-time piloted simulation (United States)

    Clement, Warren F.; Gorder, Peter J.; Jewell, Wayne F.


    Developing a single-pilot, all-weather nap-of-the-earth (NOE) capability requires fully automatic NOE (ANOE) navigation and flight control. Innovative guidance and control concepts are investigated in a four-fold research effort that: (1) organizes the on-board computer-based storage and real-time updating of NOE terrain profiles and obstacles in course-oriented coordinates indexed to the mission flight plan; (2) defines a class of automatic anticipative pursuit guidance algorithms and necessary data preview requirements to follow the vertical, lateral, and longitudinal guidance commands dictated by the updated flight profiles; (3) automates a decision-making process for unexpected obstacle avoidance; and (4) provides several rapid response maneuvers. Acquired knowledge from the sensed environment is correlated with the forehand knowledge of the recorded environment (terrain, cultural features, threats, and targets), which is then used to determine an appropriate evasive maneuver if a nonconformity of the sensed and recorded environments is observed. This four-fold research effort was evaluated in both fixed-based and moving-based real-time piloted simulations, thereby, providing a practical demonstration for evaluating pilot acceptance of the automated concepts, supervisory override, manual operation, and re-engagement of the automatic system. Volume one describes the major components of the guidance and control laws as well as the results of the piloted simulations. Volume two describes the complete mathematical model of the fully automatic guidance system for rotorcraft NOE flight following planned flight profiles.

  3. Sensitivity analysis of automatic flight control systems using singular value concepts (United States)

    Herrera-Vaillard, A.; Paduano, J.; Downing, D.


    A sensitivity analysis is presented that can be used to judge the impact of vehicle dynamic model variations on the relative stability of multivariable continuous closed-loop control systems. The sensitivity analysis uses and extends the singular-value concept by developing expressions for the gradients of the singular value with respect to variations in the vehicle dynamic model and the controller design. Combined with a priori estimates of the accuracy of the model, the gradients are used to identify the elements in the vehicle dynamic model and controller that could severely impact the system's relative stability. The technique is demonstrated for a yaw/roll damper stability augmentation designed for a business jet.

  4. Effects of LDEF flight exposure on selected polymeric films and thermal control coatings (United States)

    Slemp, Wayne S.; Young, Philip R.; Shen, James Y.


    The characterization of polymeric films and thermal control coatings which were exposed for five years and ten months to the low-Earth environment is reported. Changes in solar absorptance, thermal emittance, and transmission are compared to laboratory control specimens. Sputter-deposited metallic coatings are shown to eliminate atomic oxygen erosion of resin matrix composite materials. The effects of long-term atomic oxygen exposure to metallized FEP Teflon film is characterized. Chemical characterization of polymeric films indicates that although surface erosion occurs, the molecular structure of the basic polymeric film has not changed significantly in response to this exposure.

  5. Development of a Smooth Trajectory Maneuver Method to Accommodate the Ares I Flight Control Constraints (United States)

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


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

  6. Live Virtual Constructive (LVC): Interface Control Document (ICD) for the LVC Gateway. [Flight Test 3 (United States)

    Jovic, Srba


    This Interface Control Document (ICD) documents and tracks the necessary information required for the Live Virtual and Constructive (LVC) systems components as well as protocols for communicating with them in order to achieve all research objectives captured by the experiment requirements. The purpose of this ICD is to clearly communicate all inputs and outputs from the subsystem components.

  7. Childhood craniopharyngioma: survival, local control, endocrine and neurologic function following radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Danoff, B.F.; Cowchock, F.S.; Kramer, S.


    Between 1961 and 1978, 19 patients with a diagnosis of childhood or teenage craniopharyngioma received supervoltage radiotherapy. All patients had previously undergone either partial surgical resection (10 patients), total gross resection (3 patients), or aspiration and biopsy (6 patients). Fourteen patients were treated primarily and five were treated for recurrence. The five-year survival was 73% with a 10-year survival of 64%. Sixteen percent developed a recurrence following radiotherapy. Long term effects were assesed in terms of neurologic, intellectual, psychological and endocrine function. Seventy-nine percent had none or minimal neurologic disability. The mean full scale IQ for the group was 90. There were no additional endocrine deficiencies that could be directly attributed to radiation. Behavioral disorders occurred in 50%. These results are at least comparable, if not superior, to those of surgery.

  8. Effect of pathologic fractures on survival in multiple myeloma patients: a case control study

    Directory of Open Access Journals (Sweden)

    Yilmaz Mustafa


    Full Text Available Abstract Background Multiple Myeloma (MM is a B cell neoplasm characterized by the clonal proliferation of plasma cells. Skeletal complications are found in up to 80% of myeloma patients at presentation and are major cause of morbidity. Methods 49 patients were enrolled with MM admitted to Black Sea Technical University Hospital between 2002–2005. Pathologic fractures (PFs were determined and the patients with or without PF were followed up minumum 3 years for survival analysis. Results PF was observed in 24 patients (49% and not observed in 25 patients (51%. The risk of death was increased in the patients with PF compared with patients who had no fractures. While overall survival was 17.6 months in the patients with PFs, it was 57.3 months in the patients with no PFs. Conclusion These findings suggest that PFs may induce reduced survival and increased mortality in the MM patients, however, larger sample size is essential to draw clearer conclusions added to these data.

  9. IIB osteosarcoma. Current management, local control, and survival statistics--São Paulo, Brazil. (United States)

    Petrilli, S; Penna, V; Lopes, A; Figueiredo, M T; Gentil, F C


    Ninety-two patients with IIB osteosarcoma of the extremities were treated with intraarterial (IA) cisplatinum (CDDP) followed by surgery [amputation (61.6%) or resection with endoprosthesis (38.4%)]. Postoperative chemotherapy alternating adriamycin and CDDP was used. The total three-year survival was 62.1%, and the disease-free survival was 41.1%. The pathologic evaluation of the degree of tumor necrosis in response to the IA CDDP showed that in 53.2%, the necrosis was over 90%. The multivariate analysis of prognostic factors has shown that the highest survival was among females with tumors smaller than 15 cm. Patients with lesions equal to or larger than 15 cm were three times as likely to die of the disease. A second, more aggressive study is now underway, in which high dose methotrexate (HDMTX) is preoperatively combined with adriamycin and CDDP. Following operation, ifosfamide is added to the cases with a smaller degree of tumor necrosis, while the other group of patients will continue with HDMTX, in addition to CDDP and adriamycin (these last two drugs are used in both arms). Until now, complete remission has been achieved in 82% and 86%, respectively, with a follow-up examination varying from four to 26 months (average, 14 months). This is of extreme importance, because the majority of the authors' patients have tumors at initial evaluation larger than 10 cm in diameter.

  10. Algorithm Design and Validation for Adaptive Nonlinear Control Enhancement (ADVANCE) Technology Development for Resilient Flight Control Project (United States)

    National Aeronautics and Space Administration — SSCI proposes to develop and test a framework referred to as the ADVANCE (Algorithm Design and Validation for Adaptive Nonlinear Control Enhancement), within which...

  11. Cassini Orbit Trim Maneuvers at Saturn - Overview of Attitude Control Flight Operations (United States)

    Burk, Thomas A.


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

  12. Two-Aircraft optimal control problem. The in-flight noise reduction*, **

    Directory of Open Access Journals (Sweden)

    Ndimubandi Jean


    Full Text Available The aim of this paper is to present and solve a mathematical model of a two-aircraft optimal control problem reducing the noise on the ground during the approach. The mathematical modelization of this problem is a non-convex optimal control governed by ordinary non-linear differential equations. To solve this problem, A direct method and a Runge-Kutta RK4 discretization schema are used. This discretization schema is chosed because it is a sufficiently high order and it does-not require computation of the partial derivatives of the aircraft dynamic. The Nonlinear Interior point Trust Region Optimization solver KNITRO is applied. A large set of numerical experiments is presented. The obtained results give feasible trajectories with a significant noise reduction.

  13. Design of linear quadratic regulator (LQR) control system for flight stability of LSU-05 (United States)

    Purnawan, Heri; Mardlijah; Budi Purwanto, Eko


    Lapan Surveillance UAV-05 (LSU-05) is an unmanned aerial vehicle designed to cruise time in 6 hours and cruise velocity about 30 m/s. Mission of LSU-05 is surveillance for researchs and observations such as traffics and disaster investigations. This paper aims to design a control system on the LSU-05 to fly steadily. The methods used to stabilize LSU-05 is Linear Quadratic Regulator (LQR). Based on LQR controller, there is obtained transient response for longitudinal motion, td = 0.221s, tr = 0.419s, ts = 0.719s, tp = 1.359s, and Mp = 0%. In other hand, transient response for lateral-directional motion showed that td = 0.186s, tr = 0.515s, ts = 0.87s, tp = 2.02s, and Mp = 0%. The result of simulation showed a good performance for this method.

  14. Flight Dynamics Simulation Modeling and Control of a Large Flexible Tiltrotor Aircraft (United States)


    Maryland with Waffles in the chair next to me sleeping . Our lunchtime walks and his companionship during the day made the entire process much more...and the force feel system (FFS) on. The FFS aids the pilot in overcoming control system inertia and frictional forces during hover. It also allows...instead a location where mass moments of inertia re- main constant. The multi-body formulation used in this dissertation is derived from Reference 78

  15. Design of Optimal Flight Controller for Generic Linearised Missile Model in Hypersonic Regime (United States)


    while keeping the actuator efforts (for deflecting aileron , elevator and rudder) small. In the computer simulation, the missile model is subject to...tracking the desired lateral accelerations and roll rate, where the control inputs are aileron , elevator and rudder deflections. The optimal LQR design... plane . We deal with these dominant zeros and their effects in the next section. As for the high-altitude high-speed run (see Figure 7) the response is

  16. The development of a closed-loop flight controller with panel method integration for gust alleviation using biomimetic feathers on aircraft wings (United States)

    Blower, Christopher J.; Lee, Woody; Wickenheiser, Adam M.


    This paper presents the development of a biomimetic closed-loop flight controller that integrates gust alleviation and flight control into a single distributed system. Modern flight controllers predominantly rely on and respond to perturbations in the global states, resulting in rotation or displacement of the entire aircraft prior to the response. This bio-inspired gust alleviation system (GAS) employs active deflection of electromechanical feathers that react to changes in the airflow, i.e. the local states. The GAS design is a skeletal wing structure with a network of featherlike panels installed on the wing's surfaces, creating the airfoil profile and replacing the trailing-edge flaps. In this study, a dynamic model of the GAS-integrated wing is simulated to compute gust-induced disturbances. The system implements continuous adjustment to flap orientation to perform corrective responses to inbound gusts. MATLAB simulations, using a closed-loop LQR integrated with a 2D adaptive panel method, allow analysis of the morphing structure's aerodynamic data. Non-linear and linear dynamic models of the GAS are compared to a traditional single control surface baseline wing. The feedback loops synthesized rely on inertial changes in the global states; however, variations in number and location of feather actuation are compared. The bio-inspired system's distributed control effort allows the flight controller to interchange between the single and dual trailing edge flap profiles, thereby offering an improved efficiency to gust response in comparison to the traditional wing configuration. The introduction of aero-braking during continuous gusting flows offers a 25% reduction in x-velocity deviation; other flight parameters can be reduced in magnitude and deviation through control weighting optimization. Consequently, the GAS demonstrates enhancements to maneuverability and stability in turbulent intensive environments.

  17. The Norwegian dietary guidelines and colorectal cancer survival (CRC-NORDIET) study: a food-based multicentre randomized controlled trial. (United States)

    Henriksen, Hege Berg; Ræder, Hanna; Bøhn, Siv Kjølsrud; Paur, Ingvild; Kværner, Ane Sørlie; Billington, Siv Åshild; Eriksen, Morten Tandberg; Wiedsvang, Gro; Erlund, Iris; Færden, Arne; Veierød, Marit Bragelien; Zucknick, Manuela; Smeland, Sigbjørn; Blomhoff, Rune


    Colorectal cancer survivors are not only at risk for recurrent disease but also at increased risk of comorbidities such as other cancers, cardiovascular disease, diabetes, hypertension and functional decline. In this trial, we aim at investigating whether a diet in accordance with the Norwegian food-based dietary guidelines and focusing at dampening inflammation and oxidative stress will improve long-term disease outcomes and survival in colorectal cancer patients. This paper presents the study protocol of the Norwegian Dietary Guidelines and Colorectal Cancer Survival study. Men and women aged 50-80 years diagnosed with primary invasive colorectal cancer (Stage I-III) are invited to this randomized controlled, parallel two-arm trial 2-9 months after curative surgery. The intervention group (n = 250) receives an intensive dietary intervention lasting for 12 months and a subsequent maintenance intervention for 14 years. The control group (n = 250) receives no dietary intervention other than standard clinical care. Both groups are offered equal general advice of physical activity. Patients are followed-up at 6 months and 1, 3, 5, 7, 10 and 15 years after baseline. The study center is located at the Department of Nutrition, University of Oslo, and patients are recruited from two hospitals within the South-Eastern Norway Regional Health Authority. Primary outcomes are disease-free survival and overall survival. Secondary outcomes are time to recurrence, cardiovascular disease-free survival, compliance to the dietary recommendations and the effects of the intervention on new comorbidities, intermediate biomarkers, nutrition status, physical activity, physical function and quality of life. The current study is designed to gain a better understanding of the role of a healthy diet aimed at dampening inflammation and oxidative stress on long-term disease outcomes and survival in colorectal cancer patients. Since previous research on the role of diet for

  18. Chromatic signals control proboscis movements during hovering flight in the hummingbird hawkmoth Macroglossum stellatarum.

    Directory of Open Access Journals (Sweden)

    Joaquín Goyret

    Full Text Available Most visual systems are more sensitive to luminance than to colour signals. Animals resolve finer spatial detail and temporal changes through achromatic signals than through chromatic ones. Probably, this explains that detection of small, distant, or moving objects is typically mediated through achromatic signals. Macroglossum stellatarum are fast flying nectarivorous hawkmoths that inspect flowers with their long proboscis while hovering. They can visually control this behaviour using floral markings known as nectar guides. Here, we investigate whether this is mediated by chromatic or achromatic cues. We evaluated proboscis placement, foraging efficiency, and inspection learning of naïve moths foraging on flower models with coloured markings that offered either chromatic, achromatic or both contrasts. Hummingbird hawkmoths could use either achromatic or chromatic signals to inspect models while hovering. We identified three, apparently independent, components controlling proboscis placement: After initial contact, 1 moths directed their probing towards the yellow colour irrespectively of luminance signals, suggesting a dominant role of chromatic signals; and 2 moths tended to probe mainly on the brighter areas of models that offered only achromatic signals. 3 During the establishment of the first contact, naïve moths showed a tendency to direct their proboscis towards the small floral marks independent of their colour or luminance. Moths learned to find nectar faster, but their foraging efficiency depended on the flower model they foraged on. Our results imply that M. stellatarum can perceive small patterns through colour vision. We discuss how the different informational contents of chromatic and luminance signals can be significant for the control of flower inspection, and visually guided behaviours in general.

  19. Flight Control System Analysis and Design for a Remotely Piloted Vehicle with Thrust Vectoring Unit. (United States)


    state from yaw damper b Wing span (ft) C Coefficient matrix for model watching C Output matrix c Specd of sound (ft/sec) c Mecan aerodynamic chord (ft...objectives would in- clude such traits as: low observability, high lethality and survivabil- ity, STOL capability, and lastly, air-to-air and air-to...2:47, 129-130 and 12:3606, 668). The peak vallues were high . This s te co-d rcnthe sl1m: a eIspeed and 1 ar,)e control surface effoctiveness. -- The

  20. Application of an Adaptive Clustering Network to Flight Control of a Fighter Aircraft. Phase 1 (United States)


    54 for SS-7. These are the seven Fibonacci Number Series, from 3 to 54 in which each value is the sum of the preceding two values. These have no...gaussian function. Sufficient neurons are added to assure that at least one or more overlapping radii cover the locus of input states traversed by the...the command state region, with sufficient overlap for 1 to 5 neurons to influence each control action. xi. To cover the NC-input state space (here, Qc

  1. Multicriteria Gain Tuning for Rotorcraft Flight Controls (also entitled The Development of the Conduit Advanced Control System Design and Evaluation Interface with a Case Study Application Fly by Wire Helicopter Design) (United States)

    Biezad, Daniel


    Handling qualities analysis and control law design would seem to be naturally complimenting components of aircraft flight control system design, however these two closely coupled disciplines are often not well integrated in practice. Handling qualities engineers and control system engineers may work in separate groups within an aircraft company. Flight control system engineers and handling quality specialists may come from different backgrounds and schooling and are often not aware of the other group's research. Thus while the handling qualities specifications represent desired aircraft response characteristics, these are rarely incorporated directly in the control system design process. Instead modem control system design techniques are based on servo-loop robustness specifications, and simple representations of the desired control response. Comprehensive handling qualities analysis is often left until the end of the design cycle and performed as a check of the completed design for satisfactory performance. This can lead to costly redesign or less than satisfactory aircraft handling qualities when the flight testing phase is reached. The desire to integrate the fields of handling qualities and flight,control systems led to the development of the CONDUIT system. This tool facilitates control system designs that achieve desired handling quality requirements and servo-loop specifications in a single design process. With CONDUIT, the control system engineer is now able to directly design and control systems to meet the complete handling specifications. CONDUIT allows the designer to retain a preferred control law structure, but then tunes the system parameters to meet the handling quality requirements.

  2. Modelling and simulation of flight control electromechanical actuators with special focus on model architecting, multidisciplinary effects and power flows

    Directory of Open Access Journals (Sweden)

    Jian Fu


    Full Text Available In the aerospace field, electromechanical actuators are increasingly being implemented in place of conventional hydraulic actuators. For safety-critical embedded actuation applications like flight controls, the use of electromechanical actuators introduces specific issues related to thermal balance, reflected inertia, parasitic motion due to compliance and response to failure. Unfortunately, the physical effects governing the actuator behaviour are multidisciplinary, coupled and nonlinear. Although numerous multi-domain and system-level simulation packages are now available on the market, these effects are rarely addressed as a whole because of a lack of scientific approaches for model architecting, multi-purpose incremental modelling and judicious model implementation. In this publication, virtual prototyping of electromechanical actuators is addressed using the Bond-Graph formalism. New approaches are proposed to enable incremental modelling, thermal balance analysis, response to free-run or jamming faults, impact of compliance on parasitic motion, and influence of temperature. A special focus is placed on friction and compliance of the mechanical transmission with fault injection and temperature dependence. Aileron actuation is used to highlight the proposals for control design, energy consumption and thermal analysis, power network pollution analysis and fault response.

  3. Adaptive structures flight experiments (United States)

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  4. Ultrashort pulse lasers applied to propulsion/control in space- and atmospheric-flight (United States)

    Kremeyer, Kevin


    An impulse measurement device and analysis package was conceived, designed, constructed, tested, and demonstrated to be capable of: measuring nanoNewton-seconds to milliNewton-seconds of impulse due to laser-ablation; being transported as carry-on baggage; set-up and tear-down times of less than an hour; target exchange times of less than two minutes (targets can be ablated at multiple positions for thousands of shots); measurements in air and in vacuum; error of just a few percent; repeatability over a wide range of potential systematic error sources; and time between measurements, including ring-down and analysis, of less than 30 seconds. The instrument consists of a cantilever (i.e. leaf spring), whose time-dependent displacement/oscillation is measured and analyzed to determine the impulse imparted by a laser pulse to a target. These shapes are readily/commercially available, and any target material can be used, provided it can be fashioned in the form of a cantilever, or as a coating/film/tape, suitable for mounting on a cantilever of known geometry. The instrument was calibrated both statically and dynamically, and measurements were performed on brass, steel, and Aluminum, using laser pulses of ~7ns, ~500ps, and ~500fs. The results agree well with those published in the literature, with surface effects, atmosphere, and pre-/post-pulses demonstrating interesting effects and indicating areas for further study. In addition to exploring space-propulsion applications, measurements were performed to explore the strong beneficial effects of depositing lines of energy ahead of supersonic and hypersonic vehicles. This deposition creates a low-density channel, through which a vehicle can travel with dramatically reduced drag. Temperature and pressure are both also reduced on the front surfaces of the vehicle, while density and pressure are increased at the vehicle base. When applied off-center, this technique can be used to control the vehicle, employing the entire

  5. Design and Flight Test of a Cable Angle Feedback Control System for Improving Helicopter Slung Load Operations at Low Speed (United States)


    to your library of slung load references. The RASCAL group was critical to making the flight tests for this research happen. Thanks to Jay Fletcher...94 Figure 8-1. RASCAL 1553 muxbus extension...maneuver in flight (5K, 56ft sling). .. 107 Figure 8-8. RASCAL software-in-the-loop development facility

  6. DASMAT-Delft University Aircraft Simulation Model and Analysis Tool : A Matlab/Simulink Environment for Flight Dynamics and Control Analysis

    NARCIS (Netherlands)

    Van der Linden, C.A.A.M.


    Computer Assisted Design (CAD) environments have become important devices for the design and evaluation of flight control systems. For general use, different aircraft and operational conditions should be easily implemented in such a CAD environment and it should be equipped with a set of simulation

  7. Predicting Minimum Control Speed on the Ground (VMCG) and Minimum Control Airspeed (VMCA) of Engine Inoperative Flight Using Aerodynamic Database and Propulsion Database Generators (United States)

    Hadder, Eric Michael

    There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more. However, there are very limited ways to predict and calculate the minimum control speeds of an airplane in engine inoperative flight. There are simple solutions, as well as complicated solutions, yet there is neither standard technique nor consistency throughout the aerospace industry. To further complicate this subject, airplane designers have the option of using an Automatic Thrust Control System (ATCS), which directly alters the minimum control speeds of an airplane. This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA. This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part

  8. Applications of Payload Directed Flight (United States)

    Ippolito, Corey; Fladeland, Matthew M.; Yeh, Yoo Hsiu


    Next generation aviation flight control concepts require autonomous and intelligent control system architectures that close control loops directly around payload sensors in manner more integrated and cohesive that in traditional autopilot designs. Research into payload directed flight control at NASA Ames Research Center is investigating new and novel architectures that can satisfy the requirements for next generation control and automation concepts for aviation. Tighter integration between sensor and machine requires definition of specific sensor-directed control modes to tie the sensor data directly into a vehicle control structures throughout the entire control architecture, from low-level stability- and control loops, to higher level mission planning and scheduling reasoning systems. Payload directed flight systems can thus provide guidance, navigation, and control for vehicle platforms hosting a suite of onboard payload sensors. This paper outlines related research into the field of payload directed flight; and outlines requirements and operating concepts for payload directed flight systems based on identified needs from the scientific literature.'

  9. Cause-specific mortality in professional flight crew and air traffic control officers: findings from two UK population-based cohorts of over 20,000 subjects. (United States)

    De Stavola, Bianca L; Pizzi, Costanza; Clemens, Felicity; Evans, Sally Ann; Evans, Anthony D; dos Santos Silva, Isabel


    Flight crew are exposed to several potential occupational hazards. This study compares mortality rates in UK flight crew to those in air traffic control officers (ATCOs) and the general population. A total of 19,489 flight crew and ATCOs were identified from the UK Civil Aviation Authority medical records and followed to the end of 2006. Consented access to medical records and questionnaire data provided information on demographic, behavioral, clinical, and occupational variables. Standardized mortality ratios (SMR) were estimated for these two occupational groups using the UK general population. Adjusted mortality hazard ratios (HR) for flight crew versus ATCOs were estimated via Cox regression models. A total of 577 deaths occurred during follow-up. Relative to the general population, both flight crew (SMR 0.32; 95% CI 0.30, 0.35) and ATCOs (0.39; 0.32, 0.47) had lower all-cause mortality, mainly due to marked reductions in mortality from neoplasms and cardiovascular diseases, although flight crew had higher mortality from aircraft accidents (SMR 42.8; 27.9, 65.6). There were no differences in all-cause mortality (HR 0.99; 95% CI 0.79, 1.25), or in mortality from any major cause, between the two occupational groups after adjustment for health-related variables, again except for those from aircraft accidents. The latter ratios, however, declined with increasing number of hours. The low all-cause mortality observed in both occupational groups relative to the general population is consistent with a strong "healthy worker effect" and their low prevalence of smoking and other risk factors. Mortality among flight crew did not appear to be influenced by occupational exposures, except for a rise in mortality from aircraft accidents.

  10. Brief reports: Controlling the survival of human pluripotent stem cells by small molecule-based targeting of topoisomerase II alpha. (United States)

    Ben-David, Uri; Cowell, Ian G; Austin, Caroline A; Benvenisty, Nissim


    Pluripotent-specific inhibitors (PluriSIns) make a powerful tool to study the mechanisms controlling the survival of human pluripotent stem cells (hPSCs). Here, we characterize the mechanism of action of PluriSIn#2, a compound that selectively eliminates undifferentiated hPSCs, while sparing various other cell types derived from them. Toxicogenomic analysis predicts this compound to be a topoisomerase inhibitor. Gene expression analyses reveal that one of the human topoisomerase enzymes, topoisomerase II alpha (TOP2A), is uniquely expressed in hPSCs: TOP2A is highly expressed in undifferentiated cells, is downregulated during their differentiation, and its expression depends on the expression of core pluripotency transcription factors. Furthermore, siRNA-based knockdown of TOP2A in undifferentiated hPSCs results in their cell death, revealing that TOP2A expression is required for the survival of these cells. We find that PluriSIn#2 does not directly inhibit TOP2A enzymatic activity, but rather selectively represses its transcription, thereby significantly reducing TOP2A protein levels. As undifferentiated hPSCs require TOP2A activity for their survival, TOP2A inhibition by PluriSIn#2 thus causes their cell death. Therefore, TOP2A dependency can be harnessed for the selective elimination of tumorigenic hPSCs from culture. © 2014 AlphaMed Press.

  11. Application of variable structure system theory to aircraft flight control. [AV-8A and the Augmentor Wing Jet STOL Research Aircraft (United States)

    Calise, A. J.; Kadushin, I.; Kramer, F.


    The current status of research on the application of variable structure system (VSS) theory to design aircraft flight control systems is summarized. Two aircraft types are currently being investigated: the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), and AV-8A Harrier. The AWJSRA design considers automatic control of longitudinal dynamics during the landing phase. The main task for the AWJSRA is to design an automatic landing system that captures and tracks a localizer beam. The control task for the AV-8A is to track velocity commands in a hovering flight configuration. Much effort was devoted to developing computer programs that are needed to carry out VSS design in a multivariable frame work, and in becoming familiar with the dynamics and control problems associated with the aircraft types under investigation. Numerous VSS design schemes were explored, particularly for the AWJSRA. The approaches that appear best suited for these aircraft types are presented. Examples are given of the numerical results currently being generated.

  12. Altered G{sub 1} checkpoint control determines adaptive survival responses to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Boothman, David A.; Meyers, Mark; Odegaard, Eric; Wang, Meizhi [Department of Human Oncology, University of Wisconsin-Madison, Madison, WI (United States)


    Adaptive survival responses (ASRs) are observed when cells become more resistant to a high dose of a cytotoxic agent after repeated low dose exposures to that agent or another genotoxic agent. Confluent (G{sub 0}/G{sub 1}) human normal (GM2936B, GM2937A, AG2603, IMR-90), cancer-prone (XPV2359), and neoplastic (U1-Mel, HEp-2, HTB-152) cells were primed with repeated low doses of X-rays (ranging from 0.05-10 cGy/day for 4 days), then challenged with a high dose (290-450 cGy) on day 5. U1-Mel and HEp-2 cells showed greater than 2-fold transient survival enhancement when primed with 1-10 cGy. ASRs in U1-Mel or HEp-2 cells were blocked by cycloheximide or actinomycin D. Increases in cyclins A and D1 mRNAs were noted in primed compared to unirradiated U1-Mel and HEp-2 cells; however, only cyclin A protein levels increased. Cyclin D1 and proliferating cell nuclear antigen (PCNA) protein levels were constitutively elevated in HEp-2 and U1-Mel cells, compared to the other human normal and neoplastic cells examined, and were not altered by low or high doses of radiation. Low dose primed U1-Mel cells entered S-phase 4-6 h faster than unprimed U1-Mel cells upon low-density replating. Similar responses in terms of survival recovery, transcript and protein induction, and altered cell cycle regulation were not observed in the other human normal, cancer-prone or neoplastic cells examined. We hypothesize that only certain human cells can adapt to ionizing radiation by progressing to a point later in G{sub 1} (the A point) where DNA repair processes and radioresistance can be induced. ASRs in human cells correlated well with constitutively elevated levels of PCNA and cyclin D1, as well as inducibility of cyclin A. We propose that a protein complex composed of cyclin D1, PCNA, and possibly cyclin A may play a role in cell cycle regulation and DNA repair, which determine ASRs in human cells.

  13. Peak-Seeking Control For Reduced Fuel Consumption: Flight-Test Results For The Full-Scale Advanced Systems Testbed FA-18 Airplane (United States)

    Brown, Nelson


    A peak-seeking control algorithm for real-time trim optimization for reduced fuel consumption has been developed by researchers at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center to address the goals of the NASA Environmentally Responsible Aviation project to reduce fuel burn and emissions. The peak-seeking control algorithm is based on a steepest-descent algorithm using a time-varying Kalman filter to estimate the gradient of a performance function of fuel flow versus control surface positions. In real-time operation, deflections of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of an F/A-18 airplane are used for optimization of fuel flow. Results from six research flights are presented herein. The optimization algorithm found a trim configuration that required approximately 3 percent less fuel flow than the baseline trim at the same flight condition. This presentation also focuses on the design of the flight experiment and the practical challenges of conducting the experiment.

  14. Combination of immortalization and inducible death strategies to generate a human mesenchymal stromal cell line with controlled survival

    Directory of Open Access Journals (Sweden)

    Paul Bourgine


    By combining the opposite concepts of ‘induced-life’ and ‘inducible-death’, we generated a hMSCs line with defined properties and allowing for temporally controlled survival. The cell line represents a relevant tool for medical discovery in regenerative medicine and a potential means to address availability, standardization and safety requirements in cell & gene therapy. The concept of a hTERT-iCasp9 combination, here explored in the context of hMSCs, could be extended to other types of progenitor/stem cells.

  15. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project, UAS Control and Non-Payload Communication System Phase-1 Flight Test Results (United States)

    Griner, James H.


    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the prototype radio development, and results from phase 1 flight tests conducted during 2013.

  16. Simulated flight path control of fighter pilots and novice subjects at +3 Gz in a human centrifuge. (United States)

    Dalecki, Marc; Bock, Otmar; Guardiera, Simon


    We have previously shown that subjects produce exaggerated manual forces in +3 Gz. When subjects execute discrete flight path changes in a flight simulator, their performance is less stable in +3 Gz than in +1 Gz. Here we explore whether Gz-related deficits are found with continuous flight path changes. Novice subjects and fighter pilots sat in a high-fidelity flight simulator equipped with the reproduction of the Eurofighter 2000 cockpit, including the realistic flight stick, and pursued continuous altitude changes of a target airplane in +1 Gz and +3 Gz. Subjects also produced verbal responses in a Stroop task. Pursuit and Stroop tasks were administered alone and concurrently. Flight instability increased in +3 Gz compared to +1 Gz in novices (+46%), but not in pilots (+3%), and even there only during the first minute. Flight performance improved after the first minute in both subject groups. Stroop reaction time was higher in novices (+5.27%) than in pilots (+3.77%) at +3 Gz. Dual-task costs did not differ between groups or Gz levels. Deficits of force production in high Gz are largely compensated for when subjects apply forces to produce a continuously changing flight path. This compensation seems not to require additional cognitive resources and may be achieved by using visual feedback. Force production deficits in high Gz seem to have no appreciable effects on flight performance and cognitive load of experienced pilots using a force-plus-displacement stick in +3 Gz. It remains to be shown whether this conclusion extends to purely isometric sticks and to higher Gz levels.

  17. Damage control resuscitation is associated with a reduction in resuscitation volumes and improvement in survival in 390 damage control laparotomy patients. (United States)

    Cotton, Bryan A; Reddy, Neeti; Hatch, Quinton M; LeFebvre, Eric; Wade, Charles E; Kozar, Rosemary A; Gill, Brijesh S; Albarado, Rondel; McNutt, Michelle K; Holcomb, John B


    To determine whether implementation of damage control resuscitation (DCR) in patients undergoing damage control laparotomy (DCL) translates into improved survival. DCR aims at preventing coagulopathy through permissive hypotension, limiting crystalloids and delivering higher ratios of plasma and platelets. Previous work has focused only on the impact of delivering higher ratios (1:1:1). A retrospective cohort study was performed on all DCL patients admitted between January 2004 and August 2010. Patients were divided into pre-DCR implementation and DCR groups and were excluded if they died before completion of the initial laparotomy. The lethal triad was defined as immediate postoperative temperature less than 95°F, international normalized ratio more than 1.5, or a pH less than 7.30. A total of 390 patients underwent DCL. Of these, 282 were pre-DCR and 108 were DCR. Groups were similar in demographics, injury severity, admission vitals, and laboratory values. DCR patients received less crystalloids (median: 14 L vs 5 L), red blood cells (13 U vs 7 U), plasma (11 U vs 8 U), and platelets (6 U vs 0 U) in 24 hours, all P lethal triad upon intensive care unit arrival (80% vs 46%, P < 0.001). 24-hour and 30-day survival was higher with DCR (88% vs 97%, P = 0.006 and 76% vs 86%, P = 0.03). Multivariate analysis controlling for age, injury severity, and emergency department variables, demonstrated DCR was associated with a significant increase in 30-day survival (OR: 2.5, 95% CI: 1.10-5.58, P = 0.028). In patients undergoing DCL, implementation of DCR reduces crystalloid and blood product administration. More importantly, DCR is associated with an improvement in 30-day survival.

  18. To fly or not to fly: high flight costs in a large sea duck do not imply an expensive lifestyle. (United States)

    Pelletier, David; Guillemette, Magella; Grandbois, Jean-Marc; Butler, Patrick J


    A perennial question in ornithology is whether flight has evolved mostly to facilitate access to food or as an anti-predator strategy. However, flight is an expensive mode of locomotion and species using flight regularly are associated with an expensive lifestyle. Using heart rate (HR) data loggers implanted in 13 female common eiders (Somateria mollissima), our objective was to test the hypothesis that a high level of flight activity increases their energy budget. We used the long-term recording (seven months) of HR as an index of energy expenditure and the HR flight signature to compile all flight events. Our results indicate that the eider is one of the thriftiest volant birds with only 10 minutes of flight time per day. Consequently, we were not able to detect any effect of flight activity on their energy budget despite very high flight costs (123-149 W), suggesting that flight was controlled by energy budget limitations. However, the low flight activity of that species may also be related to their prey landscape requiring few or no large-scale movements. Nevertheless, we suggest that the (fitness) benefits of keeping flight ability in this species exceed the costs by allowing a higher survival in relation to predation and environmental harshness.

  19. Bat flight: aerodynamics, kinematics and flight morphology. (United States)

    Hedenström, Anders; Johansson, L Christoffer


    Bats evolved the ability of powered flight more than 50 million years ago. The modern bat is an efficient flyer and recent research on bat flight has revealed many intriguing facts. By using particle image velocimetry to visualize wake vortices, both the magnitude and time-history of aerodynamic forces can be estimated. At most speeds the downstroke generates both lift and thrust, whereas the function of the upstroke changes with forward flight speed. At hovering and slow speed bats use a leading edge vortex to enhance the lift beyond that allowed by steady aerodynamics and an inverted wing during the upstroke to further aid weight support. The bat wing and its skeleton exhibit many features and control mechanisms that are presumed to improve flight performance. Whereas bats appear aerodynamically less efficient than birds when it comes to cruising flight, they have the edge over birds when it comes to manoeuvring. There is a direct relationship between kinematics and the aerodynamic performance, but there is still a lack of knowledge about how (and if) the bat controls the movements and shape (planform and camber) of the wing. Considering the relatively few bat species whose aerodynamic tracks have been characterized, there is scope for new discoveries and a need to study species representing more extreme positions in the bat morphospace. © 2015. Published by The Company of Biologists Ltd.

  20. Survival variability of controls and definition of imaging endpoints for longitudinal follow-up of pancreatic ductal adenocarcinoma in rats. (United States)

    Akladios, Cherif; Ignat, Mihaela; Mutter, Didier; Aprahamian, Marc


    The 3Rs guideline is the gold standard for ethics in animal experimentation. Two of those rules, namely refinement and reduction, require further improvement. The objective of this study was to define pathways to better compliance with these prerequisites. Two methods which move us in this direction are: (1) using small animal imaging techniques for pancreatic ductal adenocarcinoma (PDAC) follow-up and (2) reduction of the number of control animals included in a study of PDAC progression under treatment. Firstly, we used MicroCT scan to diagnose events showing PDAC progression prior to any clinical symptoms to thereby define more humane endpoints identifiable before any painful phenomenon is observed. Secondly, in order to test the hypothesis of using a reference control group in all preclinical studies of a new treatment of PDAC, we investigated the stability of the results obtained with the control groups in three successive identical studies comparing placebo and gemcitabine in tumor-bearing Lewis rats. Two imaging endpoints were found. The first was the observation of a liver metastasis assessing PDAC diffusion and, earlier than liver metastasis, the presence of bands of fluid along the flanks, with more or less a medial displacement of bowel and solid viscera, reflecting a peritoneal ascites. Results of the longitudinal follow-up of rats in the gemcitabine study revealed heterogeneity in the survival rate in the three control groups, as opposed to the survival rate in the three treated groups which did not differ statistically. As a result, the significance of improved survival with chemotherapy varied greatly according to the control group used for the comparison, ranging from no impact to a highly significant effect. The early detection by the means of animal imaging of one or more signs indicating the onset of a critical step in the development of the disease (e.g., ascites or/and metastasis) allows the researcher to prevent the occurrence of animal pain