WorldWideScience

Sample records for resilient aircraft control

  1. Propulsion controlled aircraft computer

    Science.gov (United States)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  2. Quantitative resilience analysis through control design.

    Energy Technology Data Exchange (ETDEWEB)

    Sunderland, Daniel; Vugrin, Eric D.; Camphouse, Russell Chris (Sandia National Laboratories, Carlsbad, NM)

    2009-09-01

    Critical infrastructure resilience has become a national priority for the U. S. Department of Homeland Security. System resilience has been studied for several decades in many different disciplines, but no standards or unifying methods exist for critical infrastructure resilience analysis. Few quantitative resilience methods exist, and those existing approaches tend to be rather simplistic and, hence, not capable of sufficiently assessing all aspects of critical infrastructure resilience. This report documents the results of a late-start Laboratory Directed Research and Development (LDRD) project that investigated the development of quantitative resilience through application of control design methods. Specifically, we conducted a survey of infrastructure models to assess what types of control design might be applicable for critical infrastructure resilience assessment. As a result of this survey, we developed a decision process that directs the resilience analyst to the control method that is most likely applicable to the system under consideration. Furthermore, we developed optimal control strategies for two sets of representative infrastructure systems to demonstrate how control methods could be used to assess the resilience of the systems to catastrophic disruptions. We present recommendations for future work to continue the development of quantitative resilience analysis methods.

  3. Neural networks for aircraft control

    Science.gov (United States)

    Linse, Dennis

    1990-01-01

    Current research in Artificial Neural Networks indicates that networks offer some potential advantages in adaptation and fault tolerance. This research is directed at determining the possible applicability of neural networks to aircraft control. The first application will be to aircraft trim. Neural network node characteristics, network topology and operation, neural network learning and example histories using neighboring optimal control with a neural net are discussed.

  4. Next Generation Nuclear Plant Resilient Control System Functional Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lynne M. Stevens

    2010-07-01

    Control Systems and their associated instrumentation must meet reliability, availability, maintainability, and resiliency criteria in order for high temperature gas-cooled reactors (HTGRs) to be economically competitive. Research, perhaps requiring several years, may be needed to develop control systems to support plant availability and resiliency. This report functionally analyzes the gaps between traditional and resilient control systems as applicable to HTGRs, which includes the Next Generation Nuclear Plant; defines resilient controls; assesses the current state of both traditional and resilient control systems; and documents the functional gaps existing between these two controls approaches as applicable to HTGRs. This report supports the development of an overall strategy for applying resilient controls to HTGRs by showing that control systems with adequate levels of resilience perform at higher levels, respond more quickly to disturbances, increase operational efficiency, and increase public protection.

  5. Aircraft system modeling error and control error

    Science.gov (United States)

    Kulkarni, Nilesh V. (Inventor); Kaneshige, John T. (Inventor); Krishnakumar, Kalmanje S. (Inventor); Burken, John J. (Inventor)

    2012-01-01

    A method for modeling error-driven adaptive control of an aircraft. Normal aircraft plant dynamics is modeled, using an original plant description in which a controller responds to a tracking error e(k) to drive the component to a normal reference value according to an asymptote curve. Where the system senses that (1) at least one aircraft plant component is experiencing an excursion and (2) the return of this component value toward its reference value is not proceeding according to the expected controller characteristics, neural network (NN) modeling of aircraft plant operation may be changed. However, if (1) is satisfied but the error component is returning toward its reference value according to expected controller characteristics, the NN will continue to model operation of the aircraft plant according to an original description.

  6. Measuring Workload Weak Resilience Signals at a Rail Control Post

    NARCIS (Netherlands)

    Siegel, A.W.; Schraagen, J.M.C.

    2014-01-01

    OCCUPATIONAL APPLICATIONS This article describes an observational study at a rail control post to measure workload weak resilience signals. A weak resilience signal indicates a possible degradation of a system's resilience, which is defined as the ability of a complex socio-technical system to cope

  7. HTGR Resilient Control System Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Lynne M. Stevens

    2010-09-01

    A preeminent objective for corporate and government organizations is the protection of major investments, which is attained by achieving state awareness, a comprehensive understanding of security and safety, for critical infrastructures. Given the dependence of critical infrastructure on control systems for automation, the integrity of these systems and their ability to provide owner/operators a high degree of state awareness is essential in attaining a high degree of investment protection and public acceptance. Operators as well as government are therefore burdened to ensure they have a timely understanding of the status of their plant or all plants, respectively, to ensure efficient operations and investment and public protection. “This characterization is a significant objective that must consider many aspects of instrumentation, control, and intelligent systems in order to achieve the required result. These aspects include sensory, communication, analysis, decision, and human system interfaces necessary to achieve fusion of data and presentation of results that will provide an understanding of what issues are important and why.

  8. HTGR Resilient Control System Strategy

    International Nuclear Information System (INIS)

    Stevens, Lynne M.

    2010-01-01

    A preeminent objective for corporate and government organizations is the protection of major investments, which is attained by achieving state awareness, a comprehensive understanding of security and safety, for critical infrastructures. Given the dependence of critical infrastructure on control systems for automation, the integrity of these systems and their ability to provide owner/operators a high degree of state awareness is essential in attaining a high degree of investment protection and public acceptance. Operators as well as government are therefore burdened to ensure they have a timely understanding of the status of their plant or all plants, respectively, to ensure efficient operations and investment and public protection. 'This characterization is a significant objective that must consider many aspects of instrumentation, control, and intelligent systems in order to achieve the required result. These aspects include sensory, communication, analysis, decision, and human system interfaces necessary to achieve fusion of data and presentation of results that will provide an understanding of what issues are important and why.

  9. Nonclassical Flight Control for Unhealthy Aircraft

    Science.gov (United States)

    Lu, Ping

    1997-01-01

    This research set out to investigate flight control of aircraft which has sustained damage in regular flight control effectors, due to jammed control surfaces or complete loss of hydraulic power. It is recognized that in such an extremely difficult situation unconventional measures may need to be taken to regain control and stability of the aircraft. Propulsion controlled aircraft (PCA) concept, initiated at the NASA Dryden Flight Research Center. represents a ground-breaking effort in this direction. In this approach, the engine is used as the only flight control effector in the rare event of complete loss of normal flight control system. Studies and flight testing conducted at NASA Dryden have confirmed the feasibility of the PCA concept. During the course of this research (March 98, 1997 to November 30, 1997), a comparative study has been done using the full nonlinear model of an F-18 aircraft. Linear controllers and nonlinear controllers based on a nonlinear predictive control method have been designed for normal flight control system and propulsion controlled aircraft. For the healthy aircraft with normal flight control, the study shows that an appropriately designed linear controller can perform as well as a nonlinear controller. On the other hand. when the normal flight control is lost and the engine is the only available means of flight control, a nonlinear PCA controller can significantly increase the size of the recoverable region in which the stability of the unstable aircraft can be attained by using only thrust modulation. The findings and controller design methods have been summarized in an invited paper entitled.

  10. Glucocorticoids, epigenetic control and stress resilience

    Directory of Open Access Journals (Sweden)

    Johannes M.H.M. Reul

    2015-01-01

    Full Text Available Glucocorticoid hormones play a pivotal role in the response to stressful challenges. The surge in glucocorticoid hormone secretion after stress needs to be tightly controlled with characteristics like peak height, curvature and duration depending on the nature and severity of the challenge. This is important as chronic hyper- or hypo-responses are detrimental to health due to increasing the risk for developing a stress-related mental disorder. Proper glucocorticoid responses to stress are critical for adaptation. Therefore, the tight control of baseline and stress-evoked glucocorticoid secretion are important constituents of an organism's resilience. Here, we address a number of mechanisms that illustrate the multitude and complexity of measures safeguarding the control of glucocorticoid function. These mechanisms include the control of mineralocorticoid (MR and glucocorticoid receptor (GR occupancy and concentration, the dynamic control of free glucocorticoid hormone availability by corticosteroid-binding globulin (CBG, and the control exerted by glucocorticoids at the signaling, epigenetic and genomic level on gene transcriptional responses to stress. We review the beneficial effects of regular exercise on HPA axis and sleep physiology, and cognitive and anxiety-related behavior. Furthermore, we describe that, possibly through changes in the GABAergic system, exercise reduces the impact of stress on a signaling pathway specifically in the dentate gyrus that is strongly implicated in the behavioral response to that stressor. These observations underline the impact of life style on stress resilience. Finally, we address how single nucleotide polymorphisms (SNPs affecting glucocorticoid action can compromise stress resilience, which becomes most apparent under conditions of childhood abuse.

  11. Nonlinear adaptive neural controller for unstable aircraft

    OpenAIRE

    Suresh, S; Omkar, SN; Mani, V; Sundararajan, N

    2005-01-01

    A model reference indirect adaptive neural control scheme that uses both off-line and online learning strategies is proposed for an,unstable nonlinear aircraft controller design. The bounded-input-bounded-output stability requirement for the controller design is circumvented using an off-line, finite interval of time training scheme. The aircraft model is first identified using a neural network with linear filter (also known as time-delayed neural network) with the available input-output data...

  12. Fighter aircraft flight control technology design requirements

    Science.gov (United States)

    Nelson, W. E., Jr.

    1984-01-01

    The evolution of fighter aircraft flight control technology is briefly surveyed. Systems engineering, battle damage considerations for adaptive flutter suppression, in-flight simulation, and artificial intelligence are briefly discussed.

  13. Pilot Preferences on Displayed Aircraft Control Variables

    Science.gov (United States)

    Trujillo, Anna C.; Gregory, Irene M.

    2013-01-01

    The experiments described here explored how pilots want available maneuver authority information transmitted and how this information affects pilots before and after an aircraft failure. The aircraft dynamic variables relative to flight performance were narrowed to energy management variables. A survey was conducted to determine what these variables should be. Survey results indicated that bank angle, vertical velocity, and airspeed were the preferred variables. Based on this, two displays were designed to inform the pilot of available maneuver envelope expressed as bank angle, vertical velocity, and airspeed. These displays were used in an experiment involving control surface failures. Results indicate the displayed limitations in bank angle, vertical velocity, and airspeed were helpful to the pilots during aircraft surface failures. However, the additional information did lead to a slight increase in workload, a small decrease in perceived aircraft flying qualities, and no effect on aircraft situation awareness.

  14. Flight Controller Software Protects Lightweight Flexible Aircraft

    Science.gov (United States)

    2015-01-01

    Lightweight flexible aircraft may be the future of aviation, but a major problem is their susceptibility to flutter-uncontrollable vibrations that can destroy wings. Armstrong Flight Research Center awarded SBIR funding to Minneapolis, Minnesota-based MUSYN Inc. to develop software that helps program flight controllers to suppress flutter. The technology is now available for aircraft manufacturers and other industries that use equipment with automated controls.

  15. Intelligent control for autonomous aircraft missions

    Science.gov (United States)

    Neidhoefer, James Christian

    The focus of this dissertation is the design and implementation of a full-envelope, nonlinear aircraft controller that includes stability augmentation, tracking control, and autonomous path generation. The control system was demonstrated by using a 6 degree of freedom high performance aircraft model with nonlinear kinematics, full-envelope nonlinear aerodynamics, and first-order thrust and actuator dynamics. Ideas from the emerging field of intelligent control were used in the definition of the controller architecture. More specifically, "Levels of Intelligent Control" were used to provide a systematic structure for the architecture. Several ideas from the field of Artificial Intelligence were also used, including Neural Networks, Genetic Algorithms, and Adaptive Critics.

  16. Aircraft Landing and Attitude Control Using Dynamic Matrix Control

    Directory of Open Access Journals (Sweden)

    George Cristian Calugaru

    2017-06-01

    Full Text Available This paper proposes a method for an efficient control of the aircraft landing and attitude through Dynamic Matrix Control. The idea of MPC structures used in aircraft control has been well established during the last few years, but some aspects require further investigation. With this in mind, the paper proposes structures for aircraft landing and aircraft attitude control by using single DMC controllers for landing and respectively one DMC controller for each of the attitude axis (pitch attitude hold, bank angle hold and heading hold. The model used for analysis of the aircraft landing structure is based on the last phase of landing. Also, the model used to illustrate the attitude control is that of a pitch attitude hold system of a N250-100 aircraft. Simulations are performed for a variety of control and prediction horizons, taking into account the possibility of adding a weighting factor for the control actions. Apart from separate studies on step reference variations, for some use cases, a generic reference trajectory is provided as a control purpose of the system. Results show a better performance of the proposed method in terms of control surface transition and protection of the actuators involved and a better time response in stabilizing the aircraft attitude. Overall, the aspects shown ensure an improved aircraft attitude control and landing stabilization.

  17. Artificial Intelligence for Controlling Robotic Aircraft

    Science.gov (United States)

    Krishnakumar, Kalmanje

    2005-01-01

    A document consisting mostly of lecture slides presents overviews of artificial-intelligence-based control methods now under development for application to robotic aircraft [called Unmanned Aerial Vehicles (UAVs) in the paper] and spacecraft and to the next generation of flight controllers for piloted aircraft. Following brief introductory remarks, the paper presents background information on intelligent control, including basic characteristics defining intelligent systems and intelligent control and the concept of levels of intelligent control. Next, the paper addresses several concepts in intelligent flight control. The document ends with some concluding remarks, including statements to the effect that (1) intelligent control architectures can guarantee stability of inner control loops and (2) for UAVs, intelligent control provides a robust way to accommodate an outer-loop control architecture for planning and/or related purposes.

  18. Neural Networks in Nonlinear Aircraft Control

    Science.gov (United States)

    Linse, Dennis J.

    1990-01-01

    Recent research indicates that artificial neural networks offer interesting learning or adaptive capabilities. The current research focuses on the potential for application of neural networks in a nonlinear aircraft control law. The current work has been to determine which networks are suitable for such an application and how they will fit into a nonlinear control law.

  19. Active Noise Control in Propeller Aircraft

    OpenAIRE

    Johansson, Sven; Claesson, Ingvar

    2001-01-01

    A noisy environment dominated by low frequency noise can often be improved through the use of active noise control. This situation arises naturally in propeller aircraft where the propellers induce periodic low frequency noise inside the cabin. The cabin noise is typically rather high, and the passenger flight comfort could be improved considerably if this level were significantly reduced. This paper addresses same design aspects for multiple-reference active noise control systems based on th...

  20. Rebuilding Habitat and Shoreline Resilience through Improved Flood Control Project

    Science.gov (United States)

    Information about the SFBWQP Rebuilding Habitat and Shoreline Resilience through Improved Flood Control Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  1. Resilience

    Science.gov (United States)

    Resilience is an important framework for understanding and managing complex systems of people and nature that are subject to abrupt and nonlinear change. The idea of ecological resilience was slow to gain acceptance in the scientific community, taking thirty years to become widel...

  2. Rotor blade construction for circulation control aircraft

    Science.gov (United States)

    Carter, Sr., Donald R. (Inventor); Krauss, Timothy A. (Inventor); Sedlak, Matthew (Inventor)

    1986-01-01

    A circulation control aircraft rotor blade having a spanwise Coanda surface 16 and a plurality of spanwise extending flexible composite material panels 18 cooperating with the surface to define slots for the discharge of compressed air from within the blade with each panel having first flexure means 60 associated with screw adjustments 36 for establishing a slot opening preload and second flexure means 62 associated with screw adjustments 38 for establishing a slot maximum opening.

  3. Acoustic boundary control for quieter aircraft

    Science.gov (United States)

    Hirsch, Scott Michael

    1999-08-01

    There is a strong interest in reducing the volume of low- frequency noise in aircraft cabins. Active noise control (ANC), in which loudspeakers placed in the cabin are used to generate a sound field which will cancel these disturbances, is now a commercially available solution. A second control approach is active structural acoustic control (ASAC), which uses structural control forces to reduce sound transmitted into the cabin through the fuselage. Some of the goals of current research are to reduce the cost, weight, and bulk of these control systems, along with improving global control performance. This thesis introduces an acoustic boundary control (ABC) concept for active noise control in aircraft. This control strategy uses distributed actuator arrays along enclosure boundaries to reduce noise transmitted into the enclosure through the boundaries and to reduce global noise levels due to other disturbances. The motivation is to provide global pressure attenuation with small, lightweight control actuators. Analytical studies are conducted of acoustic boundary in two-dimensional and three-dimensional rectangular enclosures and in a finite cylindrical enclosure. The simulations provide insight into the control mechanisms of ABC and demonstrate potential advantages of ABC over traditional ANC and ASAC implementations. A key component of acoustic boundary control is the ``smart'' trim panel, a structurally modified aircraft trim panel for use as an acoustic control source. A prototype smart trim panel is built and tested. The smart trim panel is used as the control source in a real-time active noise control system in a laboratory- scale fuselage model. It is shown that the smart trim panel works as well as traditional loudspeakers for this application. A control signal scheduling approach is proposed which allows for a reduction in the computational burden of the real-time controller used in active noise control applications. This approach uses off-line system

  4. Active Aircraft Pylon Noise Control System

    Science.gov (United States)

    Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elmiligui, Alaa A. (Inventor)

    2017-01-01

    An active pylon noise control system for an aircraft includes a pylon structure connecting an engine system with an airframe surface of the aircraft and having at least one aperture to supply a gas or fluid therethrough, an intake portion attached to the pylon structure to intake a gas or fluid, a regulator connected with the intake portion via a plurality of pipes, to regulate a pressure of the gas or fluid, a plenum chamber formed within the pylon structure and connected with the regulator, and configured to receive the gas or fluid as regulated by the regulator, and a plurality of injectors in communication with the plenum chamber to actively inject the gas or fluid through the plurality of apertures of the pylon structure.

  5. Application of cognitive controls for unmanned aircraft

    Science.gov (United States)

    Walker, Gregory W.

    1996-05-01

    Cognitive computing refers to an emerging family of problem-solving methods that mimic the intelligence found in nature. The common goal of these methods is to crack tough problems that have resisted straightforward analytic solutions, such as intractable problems caused by combinatorial explosions. This paper describes the application of a combination of three of these methods, fuzzy logic, artificial neural networks, and genetic algorithms in a unique manner to provide a solution to rapidly develop flight control systems for unmanned aircraft. The environment resulting from the combination of these three methods has been successfully applied or is currently being applied to the flight control system development for four unmanned rotorcraft: a full scale Bell Helicopter UH-1H aerial target, an American Sportcopter Ultrasport 254 single sear ultralight helicopter, a custom developed 45 pound miniature helicopter operated by the Army at NASA Langley Research Center, and an electronic countermeasures decoy developed at the Naval Research Laboratory. Additional investigations have begun using this approach for the development of flight control system for fixed wing aircraft as either an autopilot for manned flight or as a controller for an unmanned vehicle. This paper gives a broad overview and technical description of these projects.

  6. Adaptive output feedback control of aircraft flexible modes

    OpenAIRE

    Ponnusamy, Sangeeth Saagar; Bordeneuve-Guibé, Joël

    2012-01-01

    The application of adaptive output feedback augmentative control to the flexible aircraft problem is presented. Experimental validation of control scheme was carried out using a three disk torsional pendulum. In the reference model adaptive control scheme, the rigid aircraft reference model and neural network adaptation is used to control structural flexible modes and compensate for the effects unmodeled dynamics and parametric variations of a classical high order large passenger aircraft. Th...

  7. Resilient controls for ordering uncertain prospects change and response

    CERN Document Server

    Pham, Khanh D

    2014-01-01

    Providing readers with a detailed examination of resilient controls in risk-averse decision, this monograph is aimed toward researchers and graduate students in applied mathematics and electrical engineering with a systems-theoretic concentration. This work contains a timely and responsive evaluation of reforms on the use of asymmetry or skewness pertaining to the restrictive family of quadratic costs that have been appeared in various scholarly forums.  Additionally, the book includes a discussion of the current and ongoing efforts in the usage of risk, dynamic game decision optimization and disturbance mitigation techniques with output feedback measurements tailored toward the worst-case scenarios. This work encompasses some of the current changes across uncertainty quantification, stochastic control communities, and the creative efforts that are being made to increase the understanding of resilient controls. Specific considerations are made in this book for the application of decision theory to resilient ...

  8. Control of Next Generation Aircraft and Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  9. F-15 PCA (Propulsion Controlled Aircraft) Simulation Cockpit

    Science.gov (United States)

    1990-01-01

    The F-15 PCA (Propulsion Controlled Aircraft) simulation was used from 1990 to 1993. It was used for the development of propulsion algorithms and piloting techniques (using throttles only) to be used for emergency flight control in the advent of a major flight control system failure on a multi-engine aircraft. Following this program with the Dryden F-15, similiar capabilities were developed for other aircraft, such as the B-720, Lear 24, B-727, C-402, and B-747.

  10. Flightworthy active control landing gear for a supersonic aircraft

    Science.gov (United States)

    Ross, I.

    1980-01-01

    A flightworthy active control landing gear system for a supersonic aircraft was designed to minimize aircraft loads during takeoff, impact, rollout, and taxi. The design consists of hydromechanical modifications to the existing gear and the development of a fail-safe electronic controller. analytical RESULTS INDICATE that for an aircraft sink rate of 0.914 m/sec (3 ft/sec) the system achieves a peak load reduction of 36% during landing impact.

  11. Robust Control of an Ill-Conditioned Aircraft

    DEFF Research Database (Denmark)

    Breslin, S.G.; Tøffner-Clausen, S.; Grimble, M.J.

    1996-01-01

    A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point.......A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point....

  12. Method and System for Active Noise Control of Tiltrotor Aircraft

    Science.gov (United States)

    Betzina, Mark D. (Inventor); Nguyen, Khanh Q. (Inventor)

    2003-01-01

    Methods and systems for reducing noise generated by rotating blades of a tiltrotor aircraft. A rotor-blade pitch angle associated with the tiltrotor aircraft can be controlled utilizing a swashplate connected to rotating blades of the tiltrotor aircraft. One or more Higher Harmonic Control (HHC) signals can be transmitted and input to a swashplate control actuator associated with the swashplate. A particular blade pitch oscillation (e.g., four cycles per revolution) is there-after produced in a rotating frame of reference associated with the rotating blades in response to input of an HHC signal to the swashplate control actuator associated with the swashplate to thereby reduce noise associated with the rotating blades of the tiltrotor aircraft. The HHC signal can be transmitted and input to the swashplate control actuator to reduce noise of the tiltrotor aircraft in response to a user input utilizing an open-loop configuration.

  13. Adaptive Backstepping Control and Safety Analysis for Modern Fighter Aircraft

    NARCIS (Netherlands)

    Van Oort, E.R.

    2011-01-01

    There exist many examples of aircraft incidents in which the pilots have successfully used the remaining control authority over an aircraft to save the airframe and its passengers and cargo from apparently hopeless failure conditions. Unfortunately, the opposite is also true. Several accidents

  14. Flying qualities and control system characteristics for superaugmented aircraft

    Science.gov (United States)

    Myers, T. T.; Mcruer, D. T.; Johnston, D. E.

    1984-01-01

    Aircraft-alone dynamics and superaugmented control system fundamental regulatory properties including stability and regulatory responses of the basic closed-loop systems; fundamental high and low frequency margins and governing factors; and sensitivity to aircraft and controller parameters are addressed. Alternative FCS mechanizations, and mechanizational side effects are also discussed. An overview of flying qualities considerations encompasses general pilot operations as a controller in unattended, intermittent and trim, and full-attention regulatory or command control; effective vehicle primary and secondary response properties to pilot inputs and disturbances; pilot control architectural possibilities; and comparison of superaugmented and conventional aircraft path responses for different forms of pilot control. Results of a simple experimental investigation into pilot dynamic behavior in attitude control of superaugmented aircraft configurations with high frequency time laps and time delays are presented.

  15. Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

    Science.gov (United States)

    Jorgensen, Charles; Wheeler, Kevin; Stepniewski, Slawomir; Norvig, Peter (Technical Monitor)

    2000-01-01

    This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

  16. Resilient Control System Execution Agent (ReCoSEA)

    Energy Technology Data Exchange (ETDEWEB)

    Craig G. Rieger; Kris Villez

    2012-08-01

    In an increasingly networked world, critical infrastructure systems suffer from two types of vulnerability. The first is the traditionally recognized problem of monitoring the systems for faults and failures, recognizing and analyzing data, and responding with real understanding to the problems of the system. Increasingly complex systems create the opportunity for single points of failure to cascade when inaccurate assessment of system health increases response time or leads to faulty analysis of the problems involved. A second problem involves vulnerability to cyber intrusion, in which bad actors can mask system deterioration or present false data about system status. A resilient system will protect stability, efficiency, and security. To ensure these three states, the system must react to changing conditions within the system with coordination: no one component of the system can be allowed to react to problems without real consideration of the effects of that action on other components within the system. Systems with multi-agent design typically have three layers of action, a management layer, a coordination layer, and an execution layer. A resilient multi-agent system will emphasize functions of the execution layer, which has the responsibility of initiating actions, monitoring, analyzing, and controlling its own processes, while feeding information back to the higher levels of management and coordination. The design concept of a resilient control system execution agent (ReCoSEA) grows out of these underpinnings, and through the use of computational intelligence techniques, this paper suggests an associated design methodology.

  17. A Risk Management Architecture for Emergency Integrated Aircraft Control

    Science.gov (United States)

    McGlynn, Gregory E.; Litt, Jonathan S.; Lemon, Kimberly A.; Csank, Jeffrey T.

    2011-01-01

    Enhanced engine operation--operation that is beyond normal limits--has the potential to improve the adaptability and safety of aircraft in emergency situations. Intelligent use of enhanced engine operation to improve the handling qualities of the aircraft requires sophisticated risk estimation techniques and a risk management system that spans the flight and propulsion controllers. In this paper, an architecture that weighs the risks of the emergency and of possible engine performance enhancements to reduce overall risk to the aircraft is described. Two examples of emergency situations are presented to demonstrate the interaction between the flight and propulsion controllers to facilitate the enhanced operation.

  18. Resilient guaranteed cost control of a power system

    Science.gov (United States)

    Soliman, Hisham M.; Soliman, Mostafa H.; Hassan, Mohammad. F.

    2013-01-01

    With the development of power system interconnection, the low-frequency oscillation is becoming more and more prominent which may cause system separation and loss of energy to consumers. This paper presents an innovative robust control for power systems in which the operating conditions are changing continuously due to load changes. However, practical implementation of robust control can be fragile due to controller inaccuracies (tolerance of resistors used with operational amplifiers). A new design of resilient (non-fragile) robust control is given that takes into consideration both model and controller uncertainties by an iterative solution of a set of linear matrix inequalities (LMI). Both uncertainties are cast into a norm-bounded structure. A sufficient condition is derived to achieve the desired settling time for damping power system oscillations in face of plant and controller uncertainties. Furthermore, an improved controller design, resilient guaranteed cost controller, is derived to achieve oscillations damping in a guaranteed cost manner. The effectiveness of the algorithm is shown for a single machine infinite bus system, and then, it is extended to multi-area power system. PMID:25685505

  19. Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft

    Science.gov (United States)

    Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John; Nespeca, Pascal

    2006-01-01

    This paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of a generic transport aircraft. Certain types of damage such as damage to one of the wings or horizontal stabilizers can cause the aircraft to become asymmetric, thus resulting in a coupling between the longitudinal and lateral motions. Flight dynamics for a general asymmetric aircraft is derived to account for changes in the center of gravity that can compromise the stability of the damaged aircraft. An iterative trim analysis for the translational motion is developed to refine the trim procedure by accounting for the effects of the control surface deflection. A hybrid direct-indirect neural network, adaptive flight control is proposed as an adaptive law for stabilizing the rotational motion of the damaged aircraft. The indirect adaptation is designed to estimate the plant dynamics of the damaged aircraft in conjunction with the direct adaptation that computes the control augmentation. Two approaches are presented 1) an adaptive law derived from the Lyapunov stability theory to ensure that the signals are bounded, and 2) a recursive least-square method for parameter identification. A hardware-in-the-loop simulation is conducted and demonstrates the effectiveness of the direct neural network adaptive flight control in the stability recovery of the damaged aircraft. A preliminary simulation of the hybrid adaptive flight control has been performed and initial data have shown the effectiveness of the proposed hybrid approach. Future work will include further investigations and high-fidelity simulations of the proposed hybrid adaptive Bight control approach.

  20. Application of nonlinear feedback control theory to supermaneuverable aircraft

    Science.gov (United States)

    Garrard, William L.; Enns, Dale F.

    1991-01-01

    Controlled flight at extremely high angles of attack, far exceeding the stall angle, and/or at high angular rates is sometimes referred to as supermaneuvering flight. The objective was to examine methods for design of control laws for aircraft performing supermaneuvers. Since the equations which govern the motion of aircraft during supermaneuvers are nonlinear, this study concentrated on nonlinear control law design procedures. The two nonlinear techniques considered were Nonlinear Quadratic Regulator (NLQR) theory and nonlinear dynamic inversion. A conventional gain scheduled proportional plus integral (P + I) controller was also developed to serve as a baseline design typical of current control laws used in aircraft. A mathematical model of a generic supermaneuverable aircraft was developed from data obtained from the literature. A detailed computer simulation of the aircraft was also developed. This simulation allowed the flying of proposed supermaneuvers and was used to evaluate the performance of the control law designs and to generate linearized models of the aircraft at different flight conditions.

  1. Longitudinal Control of an Aircraft Using Artificial Intelligence

    OpenAIRE

    S.N. Deepa; Sudha G

    2014-01-01

    In industrial control processes and in flight control systems PID have been widely used because of their simple structure and robust performance in a wide range of operating conditions. Along with classical controller artificial intelligence such as Fuzzy Logic Controller (FLC) algorithms have been used for the optimum design of PID controllers. In this paper, Hybrid Fuzzy PID controller is developed to improve the performance for longitudinal control of an aircraft dynamics. The hybrid co...

  2. Control Reallocation Strategies for Damage Adaptation in Transport Class Aircraft

    Science.gov (United States)

    Gundy-Burlet, Karen; Krishnakumar, K.; Limes, Greg; Bryant, Don

    2003-01-01

    This paper examines the feasibility, potential benefits and implementation issues associated with retrofitting a neural-adaptive flight control system (NFCS) to existing transport aircraft, including both cable/hydraulic and fly-by-wire configurations. NFCS uses a neural network based direct adaptive control approach for applying alternate sources of control authority in the presence of damage or failures in order to achieve desired flight control performance. Neural networks are used to provide consistent handling qualities across flight conditions, adapt to changes in aircraft dynamics and to make the controller easy to apply when implemented on different aircraft. Full-motion piloted simulation studies were performed on two different transport models: the Boeing 747-400 and the Boeing C-17. Subjects included NASA, Air Force and commercial airline pilots. Results demonstrate the potential for improving handing qualities and significantly increased survivability rates under various simulated failure conditions.

  3. Design of adaptive switching control for hypersonic aircraft

    Directory of Open Access Journals (Sweden)

    Xin Jiao

    2015-10-01

    Full Text Available This article proposes a novel adaptive switching control of hypersonic aircraft based on type-2 Takagi–Sugeno–Kang fuzzy sliding mode control and focuses on the problem of stability and smoothness in the switching process. This method uses full-state feedback to linearize the nonlinear model of hypersonic aircraft. Combining the interval type-2 Takagi–Sugeno–Kang fuzzy approach with sliding mode control keeps the adaptive switching process stable and smooth. For rapid stabilization of the system, the adaptive laws use a direct constructive Lyapunov analysis together with an established type-2 Takagi–Sugeno–Kang fuzzy logic system. Simulation results indicate that the proposed control scheme can maintain the stability and smoothness of switching process for the hypersonic aircraft.

  4. Imaged-Based Visual Servo Control for a VTOL Aircraft

    Directory of Open Access Journals (Sweden)

    Liying Zou

    2017-01-01

    Full Text Available This paper presents a novel control strategy to force a vertical take-off and landing (VTOL aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.

  5. Aircraft Turbine Engine Control Research at NASA Glenn Research Center

    Science.gov (United States)

    Garg, Sanjay

    2014-01-01

    This lecture will provide an overview of the aircraft turbine engine control research at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the current state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. The traditional engine control problem has been to provide a means to safely transition the engine from one steady-state operating point to another based on the pilot throttle inputs. With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects in partnership with other organizations within GRC and across NASA, other government agencies, the U.S. aerospace industry, and academia to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA programs under the Aeronautics Research Mission. The second part of the lecture provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges and the key progress to date are summarized. The technologies to be discussed include system level engine control concepts, gas path diagnostics, active component control, and distributed engine control architecture. The lecture will end with a futuristic perspective of how the various current technology developments will lead to an Intelligent and Autonomous Propulsion System requiring none to very minimum pilot interface

  6. The Role of Socialization, Effortful Control, and Ego Resiliency in French Adolescents' Social Functioning

    Science.gov (United States)

    Hofer, Claire; Eisenberg, Nancy; Reiser, Mark

    2010-01-01

    The relations among effortful control, ego resiliency, socialization, and social functioning were examined with a sample of 182 French adolescents (14-20 years old). Adolescents, their parents, and/or teachers completed questionnaires on these constructs. Effortful control and ego resiliency were correlated with adolescents' social functioning,…

  7. Feedback Linearized Aircraft Control Using Dynamic Cell Structure

    Science.gov (United States)

    Jorgensen, C. C.

    1998-01-01

    A Dynamic Cell Structure (DCS ) Neural Network was developed which learns a topology representing network (TRN) of F-15 aircraft aerodynamic stability and control derivatives. The network is combined with a feedback linearized tracking controller to produce a robust control architecture capable of handling multiple accident and off-nominal flight scenarios. This paper describes network and its performance for accident scenarios including differential stabilator lock, soft sensor failure, control, stability derivative variation, and turbulence.

  8. Mapping automotive like controls to a general aviation aircraft

    Science.gov (United States)

    Carvalho, Christopher G.

    The purpose of this thesis was to develop fly-by-wire control laws enabling a general aviation aircraft to be flown with automotive controls, i.e. a steering wheel and gas/brake pedals. There was a six speed shifter used to change the flight mode of the aircraft. This essentially allows the pilot to have control over different aspects of the flight profile such as climb/descend or cruise. A highway in the sky was used to aid in the navigation since it is not intuitive to people without flight experience how to navigate from the sky or when to climb and descend. Many believe that general aviation could become as widespread as the automobile. Every person could have a personal aircraft at their disposal and it would be as easy to operate as driving an automobile. The goal of this thesis is to fuse the ease of drivability of a car with flight of a small general aviation aircraft. A standard automotive control hardware setup coupled with variably autonomous control laws will allow new pilots to fly a plane as easily as driving a car. The idea is that new pilots will require very little training to become proficient with these controls. Pilots with little time to stay current can maintain their skills simply by driving a car which is typically a daily activity. A human factors study was conducted to determine the feasibility of the applied control techniques. Pilot performance metrics were developed to compare candidates with no aviation background and experienced pilots. After analyzing the relative performance between pilots and non-pilots, it has been determined that the control system is robust and easy to learn. Candidates with no aviation experience whatsoever can learn to fly an aircraft as safely and efficiently as someone with hundreds of hours of flight experience using these controls.

  9. Time-varying linear control for tiltrotor aircraft

    Directory of Open Access Journals (Sweden)

    Jing ZHANG

    2018-04-01

    Full Text Available Tiltrotor aircraft have three flight modes: helicopter mode, airplane mode, and transition mode. A tiltrotor has characteristics of highly nonlinear, time-varying flight dynamics and inertial/control couplings in its transition mode. It can transit from the helicopter mode to the airplane mode by tilting its nacelles, and an effective controller is crucial to accomplish tilting transition missions. Longitudinal dynamic characteristics of the tiltrotor are described by a nonlinear Lagrange-form model, which takes into account inertial/control couplings and aerodynamic interferences. Reference commands for airspeed velocity and attitude in the transition mode are calculated dynamically by visiting a command library which is founded in advance by analyzing the flight envelope of the tiltrotor. A Time-Varying Linear (TVL model is obtained using a Taylor-expansion based online linearization technique from the nonlinear model. Subsequently, based on an optimal control concept, an online optimization based control method with input constraints considered is proposed. To validate the proposed control method, three typical tilting transition missions are simulated using the nonlinear model of XV-15 tiltrotor aircraft. Simulation results show that the controller can be used to control the tiltrotor throughout its operating envelop which includes a transition flight, and can also deal with vertical gust disturbances. Keywords: Constrained optimal control, Inertia/control couplings, Tiltrotor aircraft, Time-varying control, Transition mode

  10. Bayesian Software Health Management for Aircraft Guidance, Navigation, and Control

    Science.gov (United States)

    Schumann, Johann; Mbaya, Timmy; Menghoel, Ole

    2011-01-01

    Modern aircraft, both piloted fly-by-wire commercial aircraft as well as UAVs, more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software. In this paper, we discuss the use of Bayesian networks (BNs) to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We will focus on the approach to develop reliable and robust health models for the combined software and sensor systems.

  11. Individual and collective climate control in aircraft cabins

    NARCIS (Netherlands)

    Jacobs, P.; Gids, W.F. de

    2006-01-01

    A new concept for aircraft cabin climatisation has been developed in which the seat is the main Indoor Air Quality (IAQ) and temperature control system for the passengers containing provisions for local supply and local exhaust of air. Direct supply of clean outside air in the breathing zone,

  12. Terminal Control Area Aircraft Scheduling and Trajectory Optimization Approaches

    Directory of Open Access Journals (Sweden)

    Samà Marcella

    2017-01-01

    Full Text Available Aviation authorities are seeking optimization methods to better use the available infrastructure and better manage aircraft movements. This paper deals with the realtime scheduling of take-off and landing aircraft at a busy terminal control area and with the optimization of aircraft trajectories during the landing procedures. The first problem aims to reduce the propagation of delays, while the second problem aims to either minimize the travel time or reduce the fuel consumption. Both problems are particularly complex, since the first one is NP-hard while the second one is nonlinear and a combined solution needs to be computed in a short-time during operations. This paper proposes a framework for the lexicographic optimization of the two problems. Computational experiments are performed for the Milano Malpensa airport and show the existing gaps between the performance indicators of the two problems when different lexicographic optimization approaches are considered.

  13. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    Science.gov (United States)

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  14. Dynamics and control of robotic aircraft with articulated wings

    Science.gov (United States)

    Paranjape, Aditya Avinash

    There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control

  15. Neutron radiography of aircraft composite flight control surfaces

    International Nuclear Information System (INIS)

    Lewis, W.J.; Bennett, L.G.I.; Chalovich, T.R.; Francescone, O.

    2001-01-01

    A small (20 kWth), safe, pool-type nuclear research reactor called the SLOWPOKE-2 is located at the Royal Military College of Canada (RMC). The reactor was originally installed for teaching, training, research and semi-routine analysis, specifically, neutron activation analysis. It was envisioned that the neutrons from the SLOWPOKE-2 could also be used for neutron radiography, and so a research program was initiated to develop this technology. Over a period of approximately 15 years, and through a series of successive modifications, a neutron radiography system (NRS) was developed. Once completed, several applications of the technology have been demonstrated, including the nondestructive examination of the composite flight control surfaces from the Canadian Air Force's primary jet fighter, the CF18 Hornet aircraft. An initial trial was setup to investigate the flight control surfaces of 3 aircraft, to determine the parameters for a final licensed system, and to compare the results to other nondestructive methods. Over 500 neutron radiographs were made for these first 3 aircraft, and moisture and corrosion were discovered in the honeycomb structure and hydration was found in the composite and adhesive layers. In comparison with other NDT methods, neutron radiography was the only method that could detect the small areas of corrosion and moisture entrapment. However, before examining an additional 7 aircraft, the recommended modifications to the NRS were undertaken. These modifications were necessary to accommodate the larger flight control surfaces safely by incorporating flexible conformable shielding. As well, to expedite inspections so that all flight control surfaces from one aircraft could be completed in less than two weeks, there was a need to decrease the exposure time by both faster film/conversion screen combinations and by incorporating the capability of near realtime, digital radioscopy. Finally, as there are no inspection specific image quality

  16. Robust nonlinear control of vectored thrust aircraft

    Science.gov (United States)

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

    1993-01-01

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

  17. 77 FR 65823 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Science.gov (United States)

    2012-10-31

    ... Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures... titled ``Table 3 to Sec. 87.23--Tier 6 NO X Standards for New Subsonic Turbofan or Turbojet Engines with... for New Subsonic Turbofan or Turbojet Engines With Rated Output Above 26.7 kN and the rated output (in...

  18. Integration of Predictive Display and Aircraft Flight Control System

    Directory of Open Access Journals (Sweden)

    Efremov A.V.

    2017-01-01

    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.

  19. Knowledge-based processing for aircraft flight control

    Science.gov (United States)

    Painter, John H.

    1991-01-01

    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.

  20. Flight Test of ASAC Aircraft Interior Noise Control System

    Science.gov (United States)

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

    1999-01-01

    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.

  1. Interactive aircraft flight control and aeroelastic stabilization

    Science.gov (United States)

    Weisshaar, T. A.

    1985-01-01

    Aeroservoelastic optimization techniques were studied to determine a methodology for maximization of the stable flight envelope of an idealized, actively controlled, flexible airfoil. The equations of motion for the airfoil were developed in state-space form to include time-domain representations of aerodynamic forces and active control. The development of an optimization scheme to stabilize the aeroelastic system over a range of airspeeds, including the design airspeed is outlined. The solution approach was divided in two levels: (1) the airfoil structure, with a design variable represented by the shear center position; and (2) the control system. An objective was stated in mathematical form and a search was conducted with the restriction that each subsystem be constrained to be optimal in some sense. Analytical expressions are developed to compute the changes in the eigenvalues of the closed-loop, actively controlled system. A stability index is constructed to ensure that stability is present at the design speed and at other airspeeds away from the design speed.

  2. Resilient distributed control in the presence of misbehaving agents in networked control systems.

    Science.gov (United States)

    Zeng, Wente; Chow, Mo-Yuen

    2014-11-01

    In this paper, we study the problem of reaching a consensus among all the agents in the networked control systems (NCS) in the presence of misbehaving agents. A reputation-based resilient distributed control algorithm is first proposed for the leader-follower consensus network. The proposed algorithm embeds a resilience mechanism that includes four phases (detection, mitigation, identification, and update), into the control process in a distributed manner. At each phase, every agent only uses local and one-hop neighbors' information to identify and isolate the misbehaving agents, and even compensate their effect on the system. We then extend the proposed algorithm to the leaderless consensus network by introducing and adding two recovery schemes (rollback and excitation recovery) into the current framework to guarantee the accurate convergence of the well-behaving agents in NCS. The effectiveness of the proposed method is demonstrated through case studies in multirobot formation control and wireless sensor networks.

  3. Modeling and control of active twist aircraft

    Science.gov (United States)

    Cramer, Nicholas Bryan

    The Wright Brothers marked the beginning of powered flight in 1903 using an active twist mechanism as their means of controlling roll. As time passed due to advances in other technologies that transformed aviation the active twist mechanism was no longer used. With the recent advances in material science and manufacturability, the possibility of the practical use of active twist technologies has emerged. In this dissertation, the advantages and disadvantages of active twist techniques are investigated through the development of an aeroelastic modeling method intended for informing the designs of such technologies and wind tunnel testing to confirm the capabilities of the active twist technologies and validate the model. Control principles for the enabling structural technologies are also proposed while the potential gains of dynamic, active twist are analyzed.

  4. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    Science.gov (United States)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  5. Motion Control of a Quadrotor Aircraft via Singular Perturbations

    Directory of Open Access Journals (Sweden)

    Salvador González-Vázquez

    2013-10-01

    Full Text Available In this paper, a new motion controller for a quadrotor aircraft is introduced. A reformulation of the control inputs of the dynamic model is discussed and then the control algorithm is given in a constructive form. The stability proof of the state space origin of the overall closed-loop system relies on the theory of singularly perturbed systems. Numerical simulations corroborate the viability of the proposed control scheme and the conclusions concerning stability. A set of simulations under practical conditions is also presented, where the system is affected by different types of disturbances and nonlinearities such as noise and actuator saturation.

  6. Application of AI methods to aircraft guidance and control

    Science.gov (United States)

    Hueschen, Richard M.; Mcmanus, John W.

    1988-01-01

    A research program for integrating artificial intelligence (AI) techniques with tools and methods used for aircraft flight control system design, development, and implementation is discussed. The application of the AI methods for the development and implementation of the logic software which operates with the control mode panel (CMP) of an aircraft is presented. The CMP is the pilot control panel for the automatic flight control system of a commercial-type research aircraft of Langley Research Center's Advanced Transport Operating Systems (ATOPS) program. A mouse-driven color-display emulation of the CMP, which was developed with AI methods and used to test the AI software logic implementation, is discussed. The operation of the CMP was enhanced with the addition of a display which was quickly developed with AI methods. The display advises the pilot of conditions not satisfied when a mode does not arm or engage. The implementation of the CMP software logic has shown that the time required to develop, implement, and modify software systems can be significantly reduced with the use of the AI methods.

  7. Neural network application to aircraft control system design

    Science.gov (United States)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural network as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research identified to enhance the practical applicability of neural networks to flight control design.

  8. Adaptive neural network motion control for aircraft under uncertainty conditions

    Science.gov (United States)

    Efremov, A. V.; Tiaglik, M. S.; Tiumentsev, Yu V.

    2018-02-01

    We need to provide motion control of modern and advanced aircraft under diverse uncertainty conditions. This problem can be solved by using adaptive control laws. We carry out an analysis of the capabilities of these laws for such adaptive systems as MRAC (Model Reference Adaptive Control) and MPC (Model Predictive Control). In the case of a nonlinear control object, the most efficient solution to the adaptive control problem is the use of neural network technologies. These technologies are suitable for the development of both a control object model and a control law for the object. The approximate nature of the ANN model was taken into account by introducing additional compensating feedback into the control system. The capabilities of adaptive control laws under uncertainty in the source data are considered. We also conduct simulations to assess the contribution of adaptivity to the behavior of the system.

  9. Robust Adaptive Neural Control of Morphing Aircraft with Prescribed Performance

    OpenAIRE

    Wu, Zhonghua; Lu, Jingchao; Shi, Jingping; Liu, Yang; Zhou, Qing

    2017-01-01

    This study proposes a low-computational composite adaptive neural control scheme for the longitudinal dynamics of a swept-back wing aircraft subject to parameter uncertainties. To efficiently release the constraint often existing in conventional neural designs, whose closed-loop stability analysis always necessitates that neural networks (NNs) be confined in the active regions, a smooth switching function is presented to conquer this issue. By integrating minimal learning parameter (MLP) tech...

  10. Preventing Loss of Aircraft Control : Aiding pilots in manual recovery from roll-limited situations

    NARCIS (Netherlands)

    Koolstra, H.J.

    2017-01-01

    Loss of aircraft lateral control can be problem, specifically when multi engine propeller aircraft are faced with an engine failure. Another, less frequent phenomena is the loss of lateral control in case of aircraft damage. In this thesis, a method is developed to determine the minimum required

  11. Real-time monitoring, prognosis, and resilient control for wind turbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhiwei; Sheng, Shuangwen

    2018-02-01

    This special issue aims to provide a platform for academic and industrial communities to report recent results and emerging research in real-time monitoring, fault diagnosis, prognosis, and resilient control and design of wind turbine systems. After a strict peer-review process, 20 papers were selected, which represent the most recent progress of the real-time monitoring, diagnosis, prognosis, and resilient control methods/techniques in wind turbine systems.

  12. Randomized controlled trial of the Resilience and Coping Intervention (RCI) with undergraduate university students.

    Science.gov (United States)

    Houston, J Brian; First, Jennifer; Spialek, Matthew L; Sorenson, Mary E; Mills-Sandoval, Toby; Lockett, McKenzie; First, Nathan L; Nitiéma, Pascal; Allen, Sandra F; Pfefferbaum, Betty

    2017-01-01

    The purpose of this pilot study was to evaluate the Resilience and Coping Intervention (RCI) with college students. College students (aged 18-23) from a large Midwest US university who volunteered for a randomized controlled trial during the 2015 spring semester. College students were randomly assigned to an intervention (n = 64) or a control (n = 65) group. Intervention participants received three 45-minute RCI sessions over subsequent weeks. All participants completed pre- and post-intervention assessments at the beginning of Week 1 and end of Week 3. Student resilience, coping, hope, stress, depression, and anxiety were assessed. RCI participants reported significantly more hope and less stress and depression from Week 1 to Week 3 compared with control participants. Results for resilience also approached statistical significance. Effect sizes were small to moderate. This study found preliminary evidence that RCI is an effective resilience intervention for use with college students.

  13. Knowledge-based processing for aircraft flight control

    Science.gov (United States)

    Painter, John H.; Glass, Emily; Economides, Gregory; Russell, Paul

    1994-01-01

    This Contractor Report documents research in Intelligent Control using knowledge-based processing in a manner dual to methods found in the classic stochastic decision, estimation, and control discipline. Such knowledge-based control has also been called Declarative, and Hybid. Software architectures were sought, employing the parallelism inherent in modern object-oriented modeling and programming. The viewpoint adopted was that Intelligent Control employs a class of domain-specific software architectures having features common over a broad variety of implementations, such as management of aircraft flight, power distribution, etc. As much attention was paid to software engineering issues as to artificial intelligence and control issues. This research considered that particular processing methods from the stochastic and knowledge-based worlds are duals, that is, similar in a broad context. They provide architectural design concepts which serve as bridges between the disparate disciplines of decision, estimation, control, and artificial intelligence. This research was applied to the control of a subsonic transport aircraft in the airport terminal area.

  14. Longitudinal automatic control system for a light weight aircraft

    Directory of Open Access Journals (Sweden)

    Cristian VIDAN

    2016-12-01

    Full Text Available This paper presents the design of an automatic control system for longitudinal axis of a light weight aircraft. To achieve this goal it is important to start from the mathematical model in longitudinal plane and then to determine the steady-state parameters for a given velocity and altitude. Using MATLAB Software the mathematical model in longitudinal plane was linearized and the system transfer functions were obtained. To determine the automatic control design we analyzed the stability of the linearized model for each input. After the stability problem was solved, using MATLAB-Simulink Software we designed the control system architecture and we considered that the objective for a stable flight was to continuously adjust the pitch angle θ through control of elevator and velocity through control of the throttle. Finally, we analyzed the performance of the designed longitudinal control system and the results highlighted in graphs outline that the purpose for which it was designed was fulfilled.

  15. Relations of parenting style to Chinese children’s effortful control, ego resilience, and maladjustment

    OpenAIRE

    EISENBERG, NANCY; CHANG, LEI; MA, YUE; HUANG, XIAORUI

    2009-01-01

    The purpose of the study was to examine the relations of authoritative parenting and corporal punishment to Chinese first and second graders’ effortful control (EC), impulsivity, ego resilience, and maladjustment, as well as mediating relations. A parent and teacher reported on children’s EC, impulsivity, and ego resilience; parents reported on children’s internalizing symptoms and their own parenting, and teachers and peers reported on children’s externalizing symptoms. Authoritative parenti...

  16. High Reliability Engine Control Demonstrated for Aircraft Engines

    Science.gov (United States)

    Guo, Ten-Huei

    1999-01-01

    For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

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

    OpenAIRE

    Gonzalo Garcia; Shahriar Keshmiri

    2013-01-01

    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 uncertainti...

  18. Integrated Robust and Resilient Control of Nuclear Power Plants for Operational Safety and High Performance

    Science.gov (United States)

    Jin, Xin; Ray, Asok; Edwards, Robert M.

    2010-04-01

    This paper presents an integrated robust and resilient control strategy to enhance the operational safety and performance of nuclear power plants. The objective of robust control is to minimize the sensitivity of plant operations to exogenous disturbances and internal faults while achieving a guaranteed level of performance with a priori specified bounds of uncertainties. On the other hand, the role of resilient control is to enhance plant recovery from unanticipated adverse conditions and faults as well as from emergency situations by altering its operational envelope in real time. In this paper, the issues of real-time resilient control of nuclear power plants are addressed for fast response during emergency operations while the features of the existing robust control technology are retained during normal operations under both steady-state and transient conditions. The proposed control methodology has been validated on the International Reactor Innovative & Secure (IRIS) simulator of nuclear power plants.

  19. Control Power Optimization using Artificial Intelligence for Forward Swept Wing and Hybrid Wing Body Aircraft

    OpenAIRE

    Adegbindin, Moustaine Kolawole Agnide

    2017-01-01

    Many futuristic aircraft such as the Hybrid Wing Body have numerous control surfaces that can result in large hinge moments, high actuation power demands, and large actuator forces/moments. Also, there is no unique relationship between control inputs and the aircraft response. Distinct sets of control surface deflections may result in the same aircraft response, but with large differences in actuation power. An Artificial Neural Network and a Genetic Algorithm were used here for the control a...

  20. Relations of parenting style to Chinese children’s effortful control, ego resilience, and maladjustment

    Science.gov (United States)

    EISENBERG, NANCY; CHANG, LEI; MA, YUE; HUANG, XIAORUI

    2009-01-01

    The purpose of the study was to examine the relations of authoritative parenting and corporal punishment to Chinese first and second graders’ effortful control (EC), impulsivity, ego resilience, and maladjustment, as well as mediating relations. A parent and teacher reported on children’s EC, impulsivity, and ego resilience; parents reported on children’s internalizing symptoms and their own parenting, and teachers and peers reported on children’s externalizing symptoms. Authoritative parenting and low corporal punishment predicted high EC, and EC mediated the relation between parenting and externalizing problems. In addition, impulsivity mediated the relation of corporal punishment to externalizing problems. The relation of parenting to children’s ego resilience was mediated by EC and/or impulsivity, and ego resilience mediated the relations of EC and impulsivity to internalizing problems. PMID:19338693

  1. Relations of parenting style to Chinese children's effortful control, ego resilience, and maladjustment.

    Science.gov (United States)

    Eisenberg, Nancy; Chang, Lei; Ma, Yue; Huang, Xiaorui

    2009-01-01

    The purpose of the study was to examine the relations of authoritative parenting and corporal punishment to Chinese first and second graders' effortful control (EC), impulsivity, ego resilience, and maladjustment, as well as mediating relations. A parent and teacher reported on children's EC, impulsivity, and ego resilience; parents reported on children's internalizing symptoms and their own parenting, and teachers and peers reported on children's externalizing symptoms. Authoritative parenting and low corporal punishment predicted high EC, and EC mediated the relation between parenting and externalizing problems. In addition, impulsivity mediated the relation of corporal punishment to externalizing problems. The relation of parenting to children's ego resilience was mediated by EC and/or impulsivity, and ego resilience mediated the relations of EC and impulsivity to internalizing problems.

  2. Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft

    Science.gov (United States)

    Gregory, Irene M.

    2001-01-01

    High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.

  3. Resilient Control Systems Practical Metrics Basis for Defining Mission Impact

    Energy Technology Data Exchange (ETDEWEB)

    Craig G. Rieger

    2014-08-01

    "Resilience” describes how systems operate at an acceptable level of normalcy despite disturbances or threats. In this paper we first consider the cognitive, cyber-physical interdependencies inherent in critical infrastructure systems and how resilience differs from reliability to mitigate these risks. Terminology and metrics basis are provided to integrate the cognitive, cyber-physical aspects that should be considered when defining solutions for resilience. A practical approach is taken to roll this metrics basis up to system integrity and business case metrics that establish “proper operation” and “impact.” A notional chemical processing plant is the use case for demonstrating how the system integrity metrics can be applied to establish performance, and

  4. Methodology for design of active controls for V/STOL aircraft

    Science.gov (United States)

    Meyer, G.; Cicolani, L.

    1976-01-01

    An effort to develop techniques for the design of integrated, fully automatic flight control systems for powered lift STOL and VTOL aircraft is described. The structure is discussed of the control system which has been developed to deal with the strong nonlinearities inherent in this class of aircraft, to admit automatic coupling with the advanced ATC requiring accurate execution of complex trajectories, and to admit a variety of active control tasks. The specific case considered is the Augmentor Wing Research Aircraft.

  5. Depressive Symptoms and Resilience among Pregnant Adolescents: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Danny Salazar-Pousada

    2010-01-01

    Full Text Available Background. Data regarding depression and resilience among adolescents is still lacking. Objective. To assess depressive symptoms and resilience among pregnant adolescents. Method. Depressive symptoms and resilience were assessed using two validated inventories, the 10-item Center for Epidemiologic Studies Short Depression Scale (CESD-10 and the 14-item Wagnild and Young Resilience Scale (RS, respectively. A case-control approach was used to compare differences between adolescents and adults. Results. A total of 302 pregnant women were enrolled in the study, 151 assigned to each group. Overall, 56.6% of gravids presented total CESD-10 scores 10 or more indicating depressed mood. Despite this, total CESD-10 scores and depressed mood rate did not differ among studied groups. Adolescents did however display lower resilience reflected by lower total RS scores and a higher rate of scores below the calculated median (P<.05. Logistic regression analysis could not establish any risk factor for depressed mood among studied subjects; however, having an adolescent partner (OR, 2.0 CI 95% 1.06–4.0, P=.03 and a preterm delivery (OR, 3.0 CI 95% 1.43–6.55, P=.004 related to a higher risk for lower resilience. Conclusion. In light of the findings of the present study, programs oriented at giving adolescents support before, during, and after pregnancy should be encouraged.

  6. Coordination control of quadrotor VTOL aircraft in three-dimensional space

    Science.gov (United States)

    Do, K. D.

    2015-03-01

    This paper presents a constructive design of distributed coordination controllers for a group of N quadrotor vertical take-off and landing (VTOL) aircraft in three-dimensional space. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to reduce singularities in the aircraft's dynamics. The coordination control design is based on a new bounded control design technique for second-order systems and new pairwise collision avoidance functions. The pairwise collision functions are functions of both relative positions and relative velocities between the aircraft instead of only their relative positions as in the literature. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Simulations illustrate the results.

  7. Conversion of the dual training aircraft (DC into single control advanced training aircraft (SC. Part I

    Directory of Open Access Journals (Sweden)

    Ioan ŞTEFĂNESCU

    2011-03-01

    Full Text Available Converting the DC school jet aircraft into SC advanced training aircraft - and use them forthe combat training of military pilots from the operational units, has become a necessity due to thebudget cuts for Air Force, with direct implications on reducing the number of hours of flight assignedto operating personnel for preparing and training.The purpose of adopting such a program is to reduce the number of flight hours allocated annuallyfor preparing and training in advanced stages of instruction, for every pilot, by more intensive use ofthis type of aircraft, which has the advantage of lower flight hour costs as compared to a supersoniccombat plane.

  8. Pivoting output unit control systems activated by jacks. [for controlling aircraft flaps

    Science.gov (United States)

    Belliere, P.

    1978-01-01

    An invention to be used for controlling aircraft flaps is described. It is applicable to control systems with two coaxial output units which pivot simultaneously with respect to two fixed units and which are activated by two opposed, straight coaxial jacks.

  9. High Assurance Control of Cyber-Physical Systems with Application to Unmanned Aircraft Systems

    Science.gov (United States)

    Kwon, Cheolhyeon

    With recent progress in the networked embedded control technology, cyber attacks have become one of the major threats to Cyber-Physical Systems (CPSs) due to their close integration of physical processes, computational resources, and communication capabilities. While CPSs have various applications in both military and civilian uses, their on-board automation and communication afford significant advantages over a system without such abilities, but these benefits come at the cost of possible vulnerability to cyber attacks. Traditionally, most cyber security studies in CPSs are mainly based on the computer security perspective, focusing on issues such as the trustworthiness of data flow, without rigorously considering the system's physical processes such as real-time dynamic behaviors. While computer security components are key elements in the hardware/software layer, these methods alone are not sufficient for diagnosing the healthiness of the CPSs' physical behavior. In seeking to address this problem, this research work proposes a control theoretic perspective approach which can accurately represent the interactions between the physical behavior and the logical behavior (computing resources) of the CPS. Then a controls domain aspect is explored extending beyond just the logical process of the CPS to include the underlying physical behavior. This approach will allow the CPS whose physical operations are robust/resilient to the damage caused by cyber attacks, successfully complementing the existing CPS security architecture. It is important to note that traditional fault-tolerant/robust control methods could not be directly applicable to achieve resiliency against malicious cyber attacks which can be designed sophisticatedly to spoof the security/safety monitoring system (note this is different from common faults). Thus, security issues at this layer require different risk management to detect cyber attacks and mitigate their impact within the context of a unified

  10. Robust Adaptive Neural Control of Morphing Aircraft with Prescribed Performance

    Directory of Open Access Journals (Sweden)

    Zhonghua Wu

    2017-01-01

    Full Text Available This study proposes a low-computational composite adaptive neural control scheme for the longitudinal dynamics of a swept-back wing aircraft subject to parameter uncertainties. To efficiently release the constraint often existing in conventional neural designs, whose closed-loop stability analysis always necessitates that neural networks (NNs be confined in the active regions, a smooth switching function is presented to conquer this issue. By integrating minimal learning parameter (MLP technique, prescribed performance control, and a kind of smooth switching strategy into back-stepping design, a new composite switching adaptive neural prescribed performance control scheme is proposed and a new type of adaptive laws is constructed for the altitude subsystem. Compared with previous neural control scheme for flight vehicle, the remarkable feature is that the proposed controller not only achieves the prescribed performance including transient and steady property but also addresses the constraint on NN. Two comparative simulations are presented to verify the effectiveness of the proposed controller.

  11. Application of robust control to a rotary-wing aircraft

    Science.gov (United States)

    Turkoglu, Ercument

    The thesis is concerned with the application of robust controller synthesis and analysis tools to a rotary-wing aircraft: the Bell 205 teetering-rotor helicopter. The Tioo loop-shaping approach is central to the work and two main issues concerned with its application will be considered. Firstly, the construction of diagonal (structured) and non- diagonal (unstructured) weighting functions will be considered. Secondly, the analysis of the implications of different weighting function structures in the controller implementation. A two stage cross-comparative analysis of a series of 1 Dof (Degree of Freedom) and 2 Dof controllers synthesized with both diagonal and non-diagonal weights using the Hqo loop- shaping technique will be presented for square and non-square multi input multi output, unstable, non-minimum phase and ill-conditioned models of the helicopter. Handling qualities of each control law augmented system will be assessed quantitatively and qualitatively. A quantitative analysis, in view of the specifications in ADS-33E, will be given based on a combination of flight data from in-flight tested controllers and, desk-top simula tions run on a fully augmented 12 Dof nonlinear helicopter model provided by QinetiQ, UK. A qualitative analysis will be given based on the pilot comments compiled (in view of the Cooper-Harper handling qualities rating scale) from the evaluated in-flight control laws.

  12. Human Factors and Data Fusion as Part of Control Systems Resilience

    Energy Technology Data Exchange (ETDEWEB)

    David I. Gertman

    2009-05-01

    Human performance and human decision making is counted upon as a crucial aspect of overall system resilience. Advanced control systems have the potential to provide operators and asset owners a wide range of data, deployed at different levels that can be used to support operator situation awareness. However, the sheer amount of data available can make it challenging for operators to assimilate information and respond appropriately. This paper reviews some of the challenges and issues associated with providing operators with actionable state awareness and argues for the over arching importance of integrating human factors as part of intelligent control systems design and implementation. It is argued that system resilience is improved by implementing human factors in operations and maintenance. This paper also introduces issues associated with resilience and data fusion and highlights areas in which human factors including field studies hold promise.

  13. High-order nonlinear differentiator and application to aircraft control

    Science.gov (United States)

    Wang, Xinhua; Shirinzadeh, Bijan

    2014-06-01

    In this paper, a high-order continuous nonlinear differentiator with lead compensation is presented based on finite-time stability. Not only the proposed high-order nonlinear differentiator can obtain the high-order derivatives of a signal, but also the chattering phenomenon can be reduced sufficiently. The parameters regulation is only required to be satisfied with Routh-Hurwitz Stability Criterion. The presented differentiator is a generalization of sliding mode differentiator and linear high-gain differentiator. The merits of the continuous differentiator include its simplicity, selecting parameters easily, restraining noises sufficiently, decreasing the phase shift and avoiding the chattering phenomenon. The theoretical results are confirmed by computer simulations and an experiment on a quadrotor aircraft: (i) the estimation of flying velocity and acceleration from the position measurement; (ii) a control law is designed based on the presented nonlinear differentiator to track a reference trajectory.

  14. Aeroelastic Flutter of Subsonic Aircraft Wing Section with Control Surface

    Directory of Open Access Journals (Sweden)

    Aeroelastic Flutter of Subsonic Aircraft Wing Section with Control Surface

    2015-12-01

    Full Text Available Aeroelastic flutter in aircraft mechanisms is unavoidable, essentially in the wing and control surface. In this work a three degree-of-freedom aeroelastic wing section with trailing edge flap is modeled numerically and theoretically. FLUENT code based on the steady finite volume is used for the prediction of the steady aerodynamic characteristics (lift, drag, pitching moment, velocity, and pressure distribution as well as the Duhamel formulation is used to model the aerodynamic loads theoretically. The system response (pitch, flap pitch and plunge was determined by integration the governing equations using MATLAB with a standard Runge–Kutta algorithm in conjunction with Henon’s method. The results are compared with previous experimental data. The results show that the aerodynamic loads and wing-flap system response are increased when increasing the flow speed. On the other hand the aeroelastic response led up to limit cycle oscillation when the flow equals or more than flutter speed.

  15. Control Surface Fault Diagnosis for Small Autonomous Aircraft

    DEFF Research Database (Denmark)

    Hansen, Søren; Blanke, Mogens

    2011-01-01

    Small unmanned aerial vehicles require a large degree of fault-tolerance in order to fulfil their duties in an satisfactory way, both with respect to economy and safety in operation. Small aerial vehicles are commonly constructed without much redundancy in hardware, primarily for reasons of cost...... on hardware or are analytical, and formulates residuals from which faults can be prognosed or diagnosed. An approach is suggested where detailed modelling is not needed but normal behaviour is learned from short segments of flight data using adaptive methods for learning. Statistical characterisation...... of distributions and change detection methods are employed to reach decisions about not-normal behaviour and it is shown how control surface faults can be diagnosed for a specific UAV without adding additional hardware to the platform. Only telemetry data from the aircraft is used together with a basic model...

  16. Fate control and well-being in Chinese rural people living with HIV: mediation effect of resilience.

    Science.gov (United States)

    Yu, Nancy Xiaonan; Zhang, Jianxin; Chow, Amy Y M; Chan, Celia H Y; Chan, Cecilia L W

    2017-01-01

    Fate control has been often misconceptualized as a superstitious belief and overlooked in health psychology. It is not known how this cultural belief might impact the well-being of Chinese people living with HIV. This study examined the protective role of fate control for well-being and the potential mediation effect of resilience. Participants in this study were rural patients who contracted HIV via commercial blood donation. In this cross-sectional survey, 250 participants completed measures of fate control, well-being, and resilience. The results showed that fate control and resilience were positively associated with well-being. Resilience mediated the association between fate control and well-being. Our findings provide insight into the adaptive function of fate control as a cognitive defensive mechanism and highlight the need to incorporate this cultural belief in developing culturally sensitive intervention programs for resilience enhancement tailored for this understudied population infected with HIV living in rural China.

  17. The Application of mu Analysis and Synthesis to the Control of an ASTOVL Aircraft

    DEFF Research Database (Denmark)

    Tøffner-Clausen, S.; Andersen, Palle; Breslin, S.G.

    1995-01-01

    A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point.......A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point....

  18. Spirituality in patients with advanced illness: The role of symptom control, resilience and social network.

    Science.gov (United States)

    Fombuena, Miguel; Galiana, Laura; Barreto, Pilar; Oliver, Amparo; Pascual, Antonio; Soto-Rubio, Ana

    2016-12-01

    In this study, we analyzed the relationships among clinical, emotional, social, and spiritual dimensions of patients with advanced illness. It was a cross-sectional study, with a sample of 108 patients in an advanced illness situation attended by palliative care teams. Statistically significant correlations were found between some dimensions of spirituality and poor symptomatic control, resiliency, and social support. In the structural model, three variables predicted spirituality: having physical symptoms as the main source of discomfort, resiliency, and social support. This work highlights the relevance of the relationships among spirituality and other aspects of the patient at the end of life. © The Author(s) 2015.

  19. Global Tracking Control of Quadrotor VTOL Aircraft in Three-Dimensional Space

    Directory of Open Access Journals (Sweden)

    Duc Khac Do

    2014-07-01

    Full Text Available This paper presents a method to design controllers that force a quadrotor vertical take-off and landing (VTOL aircraft to globally asymptotically track a reference trajectory in three-dimensional space. Motivated by the vehicle's steering practice, the roll and pitch angles are considered as immediate controls plus the total thrust force  provided by the aircraft's four rotors to control the position and yaw angle of the aircraft. The control design is based on the newly introduced one-step ahead backstepping, the standard backstepping and Lyapunov's direct methods. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to obtain global tracking control results. The paper also includes a design of observers that exponentially estimate the aircraft's linear velocity vector and disturbances. Simulations illustrate the results.

  20. Assessing and controlling the effect of aircraft on the environment: Pollution

    Science.gov (United States)

    Poppoff, I. G.; Grobman, J. S.

    1975-01-01

    The air pollution created by aircraft engines around airports and the global atmospheric problem of supersonic aircraft operating in the stratosphere are discussed. Methods for assessing the air pollution impact are proposed. The use of atmospheric models to determine the air pollution extent is described. Methods for controlling the emissions of aircraft engines are examined. Diagrams of the atmospheric composition resulting from exhaust gas emissions are developed.

  1. Total aircraft flight-control system - Balanced open- and closed-loop control with dynamic trim maps

    Science.gov (United States)

    Smith, G. A.; Meyer, G.

    1979-01-01

    The availability of the airborne digital computer has made possible a Total Aircraft Flight Control System (TAFCOS) that uses virtually the complete nonlinear propulsive and aerodynamic data for the aircraft to construct dynamic trim maps that represent an inversion of the aircraft model. The trim maps, in series with the aircraft, provide essentially a linear feed-forward path. Basically, open-loop trajectory control is employed with only a small perturbation feedback signal required to compensate for inaccuracy in the aircraft model and for external disturbances. Simulation results for application to an automatic carrier-landing system are presented. Flight-test results for a STOL aircraft operating automatically over a major portion of its flight regime are presented. The concept promises a more rapid and straightforward design from aerodynamic principles, particularly for highly nonlinear configurations, and requires substantially less digital computer capacity than conventional automatic flight-control system designs.

  2. Non-linear controls influence functions in an aircraft dynamics simulator

    Science.gov (United States)

    Guerreiro, Nelson M.; Hubbard, James E., Jr.; Motter, Mark A.

    2006-03-01

    In the development and testing of novel structural and controls concepts, such as morphing aircraft wings, appropriate models are needed for proper system characterization. In most instances, available system models do not provide the required additional degrees of freedom for morphing structures but may be modified to some extent to achieve a compatible system. The objective of this study is to apply wind tunnel data collected for an Unmanned Air Vehicle (UAV), that implements trailing edge morphing, to create a non-linear dynamics simulator, using well defined rigid body equations of motion, where the aircraft stability derivatives change with control deflection. An analysis of this wind tunnel data, using data extraction algorithms, was performed to determine the reference aerodynamic force and moment coefficients for the aircraft. Further, non-linear influence functions were obtained for each of the aircraft's control surfaces, including the sixteen trailing edge flap segments. These non-linear controls influence functions are applied to the aircraft dynamics to produce deflection-dependent aircraft stability derivatives in a non-linear dynamics simulator. Time domain analysis of the aircraft motion, trajectory, and state histories can be performed using these nonlinear dynamics and may be visualized using a 3-dimensional aircraft model. Linear system models can be extracted to facilitate frequency domain analysis of the system and for control law development. The results of this study are useful in similar projects where trailing edge morphing is employed and will be instrumental in the University of Maryland's continuing study of active wing load control.

  3. NDE of Damage in Aircraft Flight Control Surfaces

    International Nuclear Information System (INIS)

    Hsu, David K.; Barnard, Daniel J.; Dayal, Vinay

    2007-01-01

    Flight control surfaces on an aircraft, such as ailerons, flaps, spoilers and rudders, are typically adhesively bonded composite or aluminum honeycomb sandwich structures. These components can suffer from damage caused by hail stone, runway debris, or dropped tools during maintenance. On composites, low velocity impact damages can escape visual inspection, whereas on aluminum honeycomb sandwich, budding failure of the honeycomb core may or may not be accompanied by a disbond. This paper reports a study of the damage morphology in such structures and the NDE methods for detecting and characterizing them. Impact damages or overload failures in composite sandwiches with Nomex or fiberglass core tend to be a fracture or crinkle or the honeycomb cell wall located a distance below the facesheet-to-core bondline. The damage in aluminum honeycomb is usually a buckling failure, propagating from the top skin downward. The NDE methods used in this work for mapping out these damages were: air-coupled ultrasonic scan, and imaging by computer aided tap tester. Representative results obtained from the field will be shown

  4. Optimal PID Controller Tuning for Multivariable Aircraft Longitudinal Autopilot Based on Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Mostafa Lotfi Forushani

    2012-04-01

    Full Text Available This paper presents an optimized controller around the longitudinal axis of multivariable system in one of the aircraft flight conditions. The controller is introduced in order to control the angle of attack from the pitch attitude angle independently (that is required for designing a set of direct force-modes for the longitudinal axis based on particle swarm optimization (PSO algorithm. The autopilot system for military or civil aircraft is an essential component and in this paper, the autopilot system via 6 degree of freedom model for the control and guidance of aircraft in which the autopilot design will perform based on defining the longitudinal and the lateral-directional axes are supposed. The effectiveness of the proposed controller is illustrated by considering HIMAT aircraft. The simulation results verify merits of the proposed controller.

  5. Exploratory Studies in Generalized Predictive Control for Active Aeroelastic Control of Tiltrotor Aircraft

    Science.gov (United States)

    Kvaternik, Raymond G.; Juang, Jer-Nan; Bennett, Richard L.

    2000-01-01

    The Aeroelasticity Branch at NASA Langley Research Center has a long and substantive history of tiltrotor aeroelastic research. That research has included a broad range of experimental investigations in the Langley Transonic Dynamics Tunnel (TDT) using a variety of scale models and the development of essential analyses. Since 1994, the tiltrotor research program has been using a 1/5-scale, semispan aeroelastic model of the V-22 designed and built by Bell Helicopter Textron Inc. (BHTI) in 1981. That model has been refurbished to form a tiltrotor research testbed called the Wing and Rotor Aeroelastic Test System (WRATS) for use in the TDT. In collaboration with BHTI, studies under the current tiltrotor research program are focused on aeroelastic technology areas having the potential for enhancing the commercial and military viability of tiltrotor aircraft. Among the areas being addressed, considerable emphasis is being directed to the evaluation of modern adaptive multi-input multi- output (MIMO) control techniques for active stability augmentation and vibration control of tiltrotor aircraft. As part of this investigation, a predictive control technique known as Generalized Predictive Control (GPC) is being studied to assess its potential for actively controlling the swashplate of tiltrotor aircraft to enhance aeroelastic stability in both helicopter and airplane modes of flight. This paper summarizes the exploratory numerical and experimental studies that were conducted as part of that investigation.

  6. Flight control optimization from design to assessment application on the Cessna Citation X business aircraft =

    Science.gov (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

  7. Adaptive Neural Network Dynamic Inversion with Prescribed Performance for Aircraft Flight Control

    Directory of Open Access Journals (Sweden)

    Wendong Gai

    2013-01-01

    Full Text Available An adaptive neural network dynamic inversion with prescribed performance method is proposed for aircraft flight control. The aircraft nonlinear attitude angle model is analyzed. And we propose a new attitude angle controller design method based on prescribed performance which describes the convergence rate and overshoot of the tracking error. Then the model error is compensated by the adaptive neural network. Subsequently, the system stability is analyzed in detail. Finally, the proposed method is applied to the aircraft attitude tracking control system. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance in the transient and steady behavior.

  8. Nonlinear control design for slightly nonminimum phase systems - Application to V/STOL aircraft

    Science.gov (United States)

    Hauser, John; Sastry, Shankar; Meyer, George

    1992-01-01

    The paper describes the application of techniques of exact I/O linearization of nonlinear control systems to the flight control of V/STOL aircraft. It is seen that the application of the theory to this example is not straightforward; in particular, the direct application of the theory yielded an undesirable controller. The situation was remedied by neglecting the coupling between the rolling moment input to the aircraft dynamics and the dynamics along the y-axis. An approximate I/O linearization procedure developed for slightly nonminimum phase nonlinear systems is shown to be effective for V/STOL aircraft.

  9. [Self-esteem, resilience, locus of control and suicide risk in nursing students].

    Science.gov (United States)

    Montes-Hidalgo, Javier; Tomás-Sábado, Joaquín

    2016-01-01

    Assuming that suicide is the result of a series of factors acting cumulatively, the aim of this paper was to study the association of self-esteem, resilience and locus of control with the risk of suicidal behavior in a sample of nursing students. Observational, cross-sectional and correlational study with 186 nursing students who answered a questionnaire that contained, in addition to demographic data, the Spanish forms of Rosenberg self-esteem scale, the brief resilient coping scale, the Plutchik scale of suicide risk and the Rotter's internal-external locus of control scale. The scores of males and females are very similar on all scales except Locus of Control, where a significantly greater tendency of females attributed to external control. 6.4% of students have scores indicating suicide risk. Suicide risk scores correlated negatively and significantly with self-esteem and resilience and positively with locus of control. The multiple linear regression analysis identified self-esteem as the main variable related to suicide risk. The results suggest that students who have low self-esteem, have difficulty in adjusting to adverse situations and tend to the external attribution of the consequences of their actions may have an increased risk of suicidal behavior. Furthermore, the identification of self-esteem as the important factor involved in suicide risk can help in designing prevention programs. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  10. PeerShield: determining control and resilience criticality of collaborative cyber assets in networks

    Science.gov (United States)

    Cam, Hasan

    2012-06-01

    As attackers get more coordinated and advanced in cyber attacks, cyber assets are required to have much more resilience, control effectiveness, and collaboration in networks. Such a requirement makes it essential to take a comprehensive and objective approach for measuring the individual and relative performances of cyber security assets in network nodes. To this end, this paper presents four techniques as to how the relative importance of cyber assets can be measured more comprehensively and objectively by considering together the main variables of risk assessment (e.g., threats, vulnerabilities), multiple attributes (e.g., resilience, control, and influence), network connectivity and controllability among collaborative cyber assets in networks. In the first technique, a Bayesian network is used to include the random variables for control, recovery, and resilience attributes of nodes, in addition to the random variables of threats, vulnerabilities, and risk. The second technique shows how graph matching and coloring can be utilized to form collaborative pairs of nodes to shield together against threats and vulnerabilities. The third technique ranks the security assets of nodes by incorporating multiple weights and thresholds of attributes into a decision-making algorithm. In the fourth technique, the hierarchically well-separated tree is enhanced to first identify critical nodes of a network with respect to their attributes and network connectivity, and then selecting some nodes as driver nodes for network controllability.

  11. A review of in-flight detection and identification of aircraft icing and reconfigurable control

    Science.gov (United States)

    Caliskan, Fikret; Hajiyev, Chingiz

    2013-07-01

    The recent improvements and research on aviation have focused on the subject of aircraft safe flight even in the severe weather conditions. As one type of such weather conditions, aircraft icing considerably has negative effects on the aircraft flight performance. The risks of the iced aerodynamic surfaces of the flying aircraft have been known since the beginning of the first flights. Until recent years, as a solution for this event, the icing conditions ahead flight route are estimated from radars or other environmental sensors, hence flight paths are changed, or, if it exists, anti-icing/de-icing systems are used. This work aims at the detection and identification of airframe icing based on statistical properties of aircraft dynamics and reconfigurable control protecting aircraft from hazardous icing conditions. In this review paper, aircraft icing identification based on neural network (NN), batch least-squares algorithm, Kalman filtering (KF), combined NN/KF, and H∞ parameter identification techniques are investigated, and compared with each other. Following icing identification, reconfigurable control is applied for protecting the aircraft from hazardous icing conditions.

  12. Developments in Stochastic Fuel Efficient Cruise Control and Constrained Control with Applications to Aircraft

    Science.gov (United States)

    McDonough, Kevin K.

    The dissertation presents contributions to fuel-efficient control of vehicle speed and constrained control with applications to aircraft. In the first part of this dissertation a stochastic approach to fuel-efficient vehicle speed control is developed. This approach encompasses stochastic modeling of road grade and traffic speed, modeling of fuel consumption through the use of a neural network, and the application of stochastic dynamic programming to generate vehicle speed control policies that are optimized for the trade-off between fuel consumption and travel time. The fuel economy improvements with the proposed policies are quantified through simulations and vehicle experiments. It is shown that the policies lead to the emergence of time-varying vehicle speed patterns that are referred to as time-varying cruise. Through simulations and experiments it is confirmed that these time-varying vehicle speed profiles are more fuel-efficient than driving at a comparable constant speed. Motivated by these results, a simpler implementation strategy that is more appealing for practical implementation is also developed. This strategy relies on a finite state machine and state transition threshold optimization, and its benefits are quantified through model-based simulations and vehicle experiments. Several additional contributions are made to approaches for stochastic modeling of road grade and vehicle speed that include the use of Kullback-Liebler divergence and divergence rate and a stochastic jump-like model for the behavior of the road grade. In the second part of the dissertation, contributions to constrained control with applications to aircraft are described. Recoverable sets and integral safe sets of initial states of constrained closed-loop systems are introduced first and computational procedures of such sets based on linear discrete-time models are given. The use of linear discrete-time models is emphasized as they lead to fast computational procedures. Examples of

  13. Adaptive output feedback control based on neural networks: application to flexible aircraft control

    OpenAIRE

    Bordeneuve-Guibé, Joël; Bako, Laurent; Jeanneau, Matthieu

    2009-01-01

    One of the major challenges in aeronautical flexible structures control is the uncertain for the non stationary feature of the systems. Transport aircrafts are of unceasingly growing size but are made from increasingly light materials so that their motion dynamics present some flexible low frequency modes coupled to rigid modes. For reasons that range from fuel transfer to random flying conditions, the parameters of these planes may be subject to significative variations during a flight. A...

  14. Flexible aircraft control based on an adaptive output feedback control scheme

    OpenAIRE

    Bordeneuve-Guibé, Joël; Bako, Laurent; Miksch, Roland; Jeanneau, Matthieu

    2009-01-01

    One of the major challenges in aeronautical flexible structures control is the uncertain or the non stationary feature of the systems. Transport aircrafts are of unceasingly growing size but are made from increasingly light materials so that their motion dynamics present some flexible low frequency modes coupled to rigid modes. For reasons that range from fuel transfer to random flying conditions, the parameters of these planes may be subject to significative variations during a flight. A sin...

  15. Anomaly Detection for Resilient Control Systems Using Fuzzy-Neural Data Fusion Engine

    Energy Technology Data Exchange (ETDEWEB)

    Ondrej Linda; Milos Manic; Timothy R. McJunkin

    2011-08-01

    Resilient control systems in critical infrastructures require increased cyber-security and state-awareness. One of the necessary conditions for achieving the desired high level of resiliency is timely reporting and understanding of the status and behavioral trends of the control system. This paper describes the design and development of a neural-network based data-fusion system for increased state-awareness of resilient control systems. The proposed system consists of a dedicated data-fusion engine for each component of the control system. Each data-fusion engine implements three-layered alarm system consisting of: (1) conventional threshold-based alarms, (2) anomalous behavior detector using self-organizing maps, and (3) prediction error based alarms using neural network based signal forecasting. The proposed system was integrated with a model of the Idaho National Laboratory Hytest facility, which is a testing facility for hybrid energy systems. Experimental results demonstrate that the implemented data fusion system provides timely plant performance monitoring and cyber-state reporting.

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

    Science.gov (United States)

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

    1993-01-01

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

  17. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The increased aircraft safety potential of active flow control using synthetic jets - specifically, using synthetic jets on the leading edge of the wing to delay...

  18. Aircraft Command Control Communications and Navigation Systems, AFSC 2A4X3, OSSN: 2308

    National Research Council Canada - National Science Library

    1998-01-01

    1. Survey Coverage: The Aircraft Command Control Communications and Navigation Systems career ladder was surveyed to provide current job and task data for use in updating career ladder documents and training programs...

  19. Resilience of Urban Smart Grids Involving Multiple Control Loops

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Pillai, Jayakrishnan Radhakrishna; Schwefel, Hans-Peter

    2016-01-01

    Intelligent control of energy distribution grids is implemented via a hierarchy of control loops with different input values and different control targets, which also work on different time-scales. This control is enabled by a bi-directional communication flow, which can be interrupted due to ICT...... in island mode with a limited grid buffer capacity subjected to ICT attacks. First the interplay of four different control loops that all react to time-varying prices is analyzed. A co-simulation framework is applied to specifically investigate the sensitivity of the emergent grid behavior to extreme...... conditions on the the price signal communication which could be the result of ICT attacks. In a second step, we introduce a modified pricing scheme, where the energy price is locally influenced by the distribution grid conditions. We then analyze the behavior of this modified scheme when both up...

  20. Optimal nonlinear estimation for aircraft flight control in wind shear

    Science.gov (United States)

    Mulgund, Sandeep S.

    1994-01-01

    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.

  1. Climatic controls on ecosystem resilience: Postfire regeneration in the Cape Floristic Region of South Africa

    OpenAIRE

    Wilson, Adam M.; Latimer, Andrew M.; Silander, John A.

    2015-01-01

    © 2015, National Academy of Sciences. All rights reserved. Conservation of biodiversity and natural resources in a changing climate requires understanding what controls ecosystem resilience to disturbance. This understanding is especially important in the fire-prone Mediterranean systems of the world. The fire frequency in these systems is sensitive to climate, and recent climate change has resulted in more frequent fires over the last few decades. However, the sensitivity of postfire recover...

  2. Resilient Multi-Domain Command and Control: Enabling Solutions for 2025 with Virtual Reality

    Science.gov (United States)

    2017-04-16

    objects are placed in their perception, and behave as though they are a part of the environment.34 For example, a virtual showroom might feature a...headset that allows the operator to see and interact with a virtual car. The car would appear to be in the showroom . The operator could walk around...AIR WAR COLLEGE AIR UNIVERSITY RESILIENT MULTI-DOMAIN COMMAND AND CONTROL: ENABLING SOLUTIONS FOR 2025 WITH VIRTUAL REALITY by

  3. Controller Requirements for Uncoupled Aircraft Motion. Volume 2.

    Science.gov (United States)

    1984-09-01

    No. 1, Jan . 1978, pp. 304-316. 15. "The Artificial Feel System", BU AER Rept. AE-61-4V, May 1953. 16. Potocki , W. J., "Broad Outline of Aircraft...Human Pilot Behavior," AGARD-AG-188, Jan . 1974. 25. Jex, Henry R., Raymond E. Magdaleno, Wayne F. Jewell, Andrew Junker, and Grant McMillan, "Effects...Approach and Landing of a STOL Transport Aircraft," NASA TN D-7790, Jan . 1975. 33. Feinreich, B., Seckel, E., and Ellis, D. R., "In-Flight Simu- lation Study

  4. Adaptive Neural Network Dynamic Inversion with Prescribed Performance for Aircraft Flight Control

    OpenAIRE

    Gai, Wendong; Wang, Honglun; Zhang, Jing; Li, Yuxia

    2013-01-01

    An adaptive neural network dynamic inversion with prescribed performance method is proposed for aircraft flight control. The aircraft nonlinear attitude angle model is analyzed. And we propose a new attitude angle controller design method based on prescribed performance which describes the convergence rate and overshoot of the tracking error. Then the model error is compensated by the adaptive neural network. Subsequently, the system stability is analyzed in detail. Finally, the proposed meth...

  5. DISCRETE-TIME VARIABLE STRUCTURE CONTROLLER FOR AIRCRAFT FLIGHT ANGLE TRACKING

    OpenAIRE

    Iskrenovic-Momcilovic, Olivera

    2014-01-01

    The paper presents the longitudinal, short-period aircraft dynamics and its application on the climb angle tracking. For the aircraft flight angle tracking the stable system centre technique is developed for controlling the output in a discrete-time non-minimum phase causal system using the sliding mode control. The developed discrete-time stable system centre technique transforms the output tracking problem to a corresponding state variable tracking problem by asymptotically identifying the ...

  6. Control of flying flexible aircraft using control surfaces and dispersed piezoelectric actuators

    Science.gov (United States)

    Tuzcu, Ilhan; Meirovitch, Leonard

    2006-08-01

    The flight of relatively stiff aircraft can be adequately controlled by standard means, i.e., by the engine throttles and control surfaces. When the flexibility becomes a factor, the standard controls may not be sufficient. In several earlier papers, the authors have addressed the problem of dynamics and control of maneuvering flexible aircraft. Using a perturbation approach they separated the problem into a quasi-rigid flight dynamics problem for the flight variables, which tend to be large, and an extended perturbation problem for the perturbations in the flight variables and the elastic vibration, which tend to be small, where the second problem receives input from the first. It was suggested in the earlier papers that, in addition to the standard controls, the controls for the extended perturbation problem include actuators whose task is to control the vibration. In this paper, the possibility of controlling the vibration by means of piezoelectric actuators dispersed over the flexible structural components, and in particular over the wing and empennage, is explored. It is concluded that piezoelectric actuators can be effective in damping out vibration if adequate power sources can be provided. This is the first time that the feasibility of piezoelectric actuators has been investigated in a flight environment.

  7. Manual Throttles-Only Control Effectivity for Emergency Flight Control of Transport Aircraft

    Science.gov (United States)

    Stevens, Richard; Burcham, Frank W., Jr.

    2009-01-01

    If normal aircraft flight controls are lost, emergency flight control may be attempted using only the thrust of engines. Collective thrust is used to control flightpath, and differential thrust is used to control bank angle. One issue is whether a total loss of hydraulics (TLOH) leaves an airplane in a recoverable condition. Recoverability is a function of airspeed, altitude, flight phase, and configuration. If the airplane can be recovered, flight test and simulation results on several transport-class airplanes have shown that throttles-only control (TOC) is usually adequate to maintain up-and-away flight, but executing a safe landing is very difficult. There are favorable aircraft configurations, and also techniques that will improve recoverability and control and increase the chances of a survivable landing. The DHS and NASA have recently conducted a flight and simulator study to determine the effectivity of manual throttles-only control as a way to recover and safely land a range of transport airplanes. This paper discusses TLOH recoverability as a function of conditions, and TOC landability results for a range of transport airplanes, and some key techniques for flying with throttles and making a survivable landing. Airplanes evaluated include the B-747, B-767, B-777, B-757, A320, and B-737 airplanes.

  8. Design, analysis, and control of large transport aircraft utilizing engine thrust as a backup system for the primary flight controls

    Science.gov (United States)

    Gerren, Donna S.

    1993-01-01

    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).

  9. Longitudinal control of aircraft dynamics based on optimization of PID parameters

    Science.gov (United States)

    Deepa, S. N.; Sudha, G.

    2016-03-01

    Recent years many flight control systems and industries are employing PID controllers to improve the dynamic behavior of the characteristics. In this paper, PID controller is developed to improve the stability and performance of general aviation aircraft system. Designing the optimum PID controller parameters for a pitch control aircraft is important in expanding the flight safety envelope. Mathematical model is developed to describe the longitudinal pitch control of an aircraft. The PID controller is designed based on the dynamic modeling of an aircraft system. Different tuning methods namely Zeigler-Nichols method (ZN), Modified Zeigler-Nichols method, Tyreus-Luyben tuning, Astrom-Hagglund tuning methods are employed. The time domain specifications of different tuning methods are compared to obtain the optimum parameters value. The results prove that PID controller tuned by Zeigler-Nichols for aircraft pitch control dynamics is better in stability and performance in all conditions. Future research work of obtaining optimum PID controller parameters using artificial intelligence techniques should be carried out.

  10. Self-Guided Multimedia Stress Management and Resilience Training for Flight Controllers

    Science.gov (United States)

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

    2016-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Gonzalo Garcia

    2013-01-01

    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.

  12. Evaluation of laminar flow control systems for subsonic commercial transport aircraft: Executive summary

    Science.gov (United States)

    Pearce, W. E.

    1982-01-01

    An evaluation was made of laminar flow control (LFC) system concepts for subsonic commercial transport aircraft. Configuration design studies, performance analyses, fabrication development, structural testing, wind tunnel testing, and contamination-avoidance techniques were included. As a result of trade studies, a configuration with LFC on the upper wing surface only, utilizing an electron beam-perforated suction surface, and employing a retractable high-lift shield for contamination avoidance, was selected as the most practical LFC system. The LFC aircraft was then compared with an advanced turbulent aircraft designed for the same mission. This comparison indicated significant fuel savings.

  13. Hierarchical CBR for Multiple Aircraft Conflict Resolution in Air Traffic Control

    OpenAIRE

    Bonzano, Andrea; Cunningham, Padraig

    1998-01-01

    This is a preprint of an article published in Proceedings of 13th European Conference on Artificial Intelligence, ed. Henri Prade, John Wile, pp58-62, August 1998. In this paper we present a Case-Based Reasoning system that helps air traffic controllers to solve aircraft conflicts. In particular, we focus on the hierarchical aspect of the CBR system which is able to solve multiple aircraft conflicts, i.e. conflicts that involve three or more aircraft. It is not practical to bui...

  14. Optimized Aircraft Electric Control System Based on Adaptive Tabu Search Algorithm and Fuzzy Logic Control

    Directory of Open Access Journals (Sweden)

    Saifullah Khalid

    2016-09-01

    Full Text Available Three conventional control constant instantaneous power control, sinusoidal current control, and synchronous reference frame techniques for extracting reference currents for shunt active power filters have been optimized using Fuzzy Logic control and Adaptive Tabu search Algorithm and their performances have been compared. Critical analysis of Comparison of the compensation ability of different control strategies based on THD and speed will be done, and suggestions will be given for the selection of technique to be used. The simulated results using MATLAB model are presented, and they will clearly prove the value of the proposed control method of aircraft shunt APF. The waveforms observed after the application of filter will be having the harmonics within the limits and the power quality will be improved.

  15. More electric aircraft starter-generator system with utilization of hybrid modulated model predictive control

    OpenAIRE

    Yoeh, Seang Shen; Yang, Tao; Tarisciotti, Luca; Hill, Christopher Ian; Bozhko, Serhiy

    2016-01-01

    The current trend for future aircraft is the adoption of the More Electric Aircraft (MEA) concept. The electrical based starter-generator (S/G) system is one of the core ideas from the MEA concept. The PI based control scheme has been investigated in various papers for the permanent magnet based S/G system. Different control schemes are to be considered to improve the control performance of the S/G system. A type of non-linear control called Model Predictive Control (MPC) is considered for it...

  16. A Randomized Controlled Pilot Trial Investigating the Impact of a Workplace Resilience Program During a Time of Significant Organizational Change.

    Science.gov (United States)

    Rogerson, Shane; Meir, Rudi; Crowley-McHattan, Zac; McEwen, Kathryn; Pastoors, Rachel

    2016-04-01

    The aim of this study was to investigate the effectiveness of a short-term resilience intervention as measured by the Resilience at Work (RAW) scale. A 5-week resilience program was implemented with 28 volunteers and assessed by the 20-item RAW scale. The scale was administered electronically and participants were match paired into either a treatment or control group. Statistical analysis was conducted using a 2 × 2 group (Treatment, control) × time (pre, post) analysis of variance with repeated measures. Postintervention time point RAW total score was significantly greater in the treatment group (P < 0.01) and statistical significance was also achieved for four of the seven subscales. Employee resilience can be improved via specific educational and skills training requiring a total time commitment of just 5 hours, making this intervention feasible for most working environments.

  17. Commercial Aircraft Trajectory Planning based on Multiphase Mixed-Integer Optimal Control

    OpenAIRE

    Soler Arnedo, Manuel Fernando

    2017-01-01

    The main goal of this dissertation is to develop optimal control techniques for aircraft trajectory planning looking at reduction of fuel consumption, emissions and overfly charges in flight plans. The calculation of a flight plan involves the consideration of multiple factors. They can be classified as either continuous or discrete, and include nonlinear aircraft performance, atmospheric conditions, wind conditions, airspace structure, amount of departure fuel, and operational...

  18. An Aircraft Electric Power Testbed for Validating Automatically Synthesized Reactive Control Protocols

    OpenAIRE

    Rogersten, Robert; Xu, Huan; Ozay, Necmiye; Topcu, Ufuk; Murray, Richard M.

    2013-01-01

    Modern aircraft increasingly rely on electric power for subsystems that have traditionally run on mechanical power. The complexity and safety-criticality of aircraft electric power systems have therefore increased, rendering the design of these systems more challenging. This work is motivated by the potential that correct-by-construction reactive controller synthesis tools may have in increasing the effectiveness of the electric power system design cycle. In particular, we have built an exper...

  19. A discussion on the resilience of command and control regulation within regulatory behavior theories

    Directory of Open Access Journals (Sweden)

    K.P.V. O’Sullivan

    2012-03-01

    Full Text Available This paper provides the first insights into the factors that may drive the resilience of command and control regulation in modern policy making. We show how the forces of uncertainty and internal dynamics among customers, producers and regulators are the most dominate factors preventing the adoption of non-CAC regulations. Using case study evidence of internet regulation, we then integrate our analysis into the most prominent regulatory choice behavior theories and illustrate that regardless of the theory, these factors can help explain the dominance of command and control as a choice of regulation.

  20. Modifying Resilience Mechanisms in At-Risk Individuals: A Controlled Study of Mindfulness Training in Marines Preparing for Deployment

    Science.gov (United States)

    2014-01-01

    NAS, Segal ZV, Mayberg H, Bean J, McKeon D, Fatima Z, Anderson AK: Attending to the present: mindfulness meditation reveals distinct neural modes of...Article Modifying Resilience Mechanisms in At-Risk Individuals: A Controlled Study of Mindfulness Training in Marines Preparing for Deployment...and mental health. Few studies have examinedwhether interventions prior to deployment can improvemechanisms underlying resilience. Mindfulness -based

  1. Enhancing the stabilization of aircraft pitch motion control via intelligent and classical method

    Science.gov (United States)

    Lukman, H.; Munawwarah, S.; Azizan, A.; Yakub, F.; Zaki, S. A.; Rasid, Z. A.

    2017-12-01

    The pitching movement of an aircraft is very important to ensure passengers are intrinsically safe and the aircraft achieve its maximum stability. The equations governing the motion of an aircraft are a complex set of six nonlinear coupled differential equations. Under certain assumptions, it can be decoupled and linearized into longitudinal and lateral equations. Pitch control is a longitudinal problem and thus, only the longitudinal dynamics equations are involved in this system. It is a third order nonlinear system, which is linearized about the operating point. The system is also inherently unstable due to the presence of a free integrator. Because of this, a feedback controller is added in order to solve this problem and enhance the system performance. This study uses two approaches in designing controller: a conventional controller and an intelligent controller. The pitch control scheme consists of proportional, integral and derivatives (PID) for conventional controller and fuzzy logic control (FLC) for intelligent controller. Throughout the paper, the performance of the presented controllers are investigated and compared based on the common criteria of step response. Simulation results have been obtained and analysed by using Matlab and Simulink software. The study shows that FLC controller has higher ability to control and stabilize the aircraft's pitch angle as compared to PID controller.

  2. Final Rule for Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Science.gov (United States)

    EPA adopted emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

  3. Cyber-Physical Attack-Resilient Wide-Area Monitoring, Protection, and Control for the Power Grid

    Energy Technology Data Exchange (ETDEWEB)

    Ashok, Aditya; Govindarasu, Manimaran; Wang, Jianhui

    2017-07-01

    Cyber security and resiliency of Wide-Area Monitoring, Protection and Control (WAMPAC) applications is critically important to ensure secure, reliable, and economic operation of the bulk power system. WAMPAC relies heavily on the security of measurements and control commands transmitted over wide-area communication networks for real-time operational, protection, and control functions. Also, the current “N-1 security criteria” for grid operation is inadequate to address malicious cyber events and therefore it is important to fundamentally redesign WAMPAC and to enhance Energy Management System (EMS) applications to make them attack-resilient. In this paper, we propose an end-to-end defense-in-depth architecture for attack-resilient WAMPAC that addresses resilience at both the infrastructure layer and the application layers. Also, we propose an attack-resilient cyber-physical security framework that encompasses the entire security life cycle including risk assessment, attack prevention, attack detection, attack mitigation, and attack resilience. The overarching objective of this paper is to provide a broad scope that comprehensively describes most of the major research issues and potential solutions in the context of cyber-physical security of WAMPAC for the power grid.

  4. Adaptive Feedfoward Feedback Control Framework, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel approach is proposed for the suppression of the aircraft's structural vibration to increase the resilience of the flight control law in the presence of the...

  5. Adaptive Feedfoward Feedback Control Framework Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An Adaptive Feedforward and Feedback Control (AFFC) Framework is proposed to suppress the aircraft's structural vibrations and to increase the resilience of the...

  6. A knowledge-based system design/information tool for aircraft flight control systems

    Science.gov (United States)

    Mackall, Dale A.; Allen, James G.

    1991-01-01

    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.

  7. In-flight Fault Detection and Isolation in Aircraft Flight Control Systems

    Science.gov (United States)

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

    2005-01-01

    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.

  8. A Lightweight Loudspeaker for Aircraft Communications and Active Noise Control

    Science.gov (United States)

    Warnaka, Glenn E.; Kleinle, Mark; Tsangaris, Parry; Oslac, Michael J.; Moskow, Harry J.

    1992-01-01

    A series of new, lightweight loudspeakers for use on commercial aircraft has been developed. The loudspeakers use NdFeB magnets and aluminum alloy frames to reduce the weight. The NdFeB magnet is virtually encapsulated by steel in the new speaker designs. Active noise reduction using internal loudspeakers was demonstrated to be effective in 1983. A weight, space, and cost efficient method for creating the active sound attenuating fields is to use the existing cabin loudspeakers for both communication and sound attenuation. This will require some additional loudspeaker design considerations.

  9. Leveraging master-slave OpenFlow controller arrangement to improve control plane resiliency in SD-EONs.

    Science.gov (United States)

    Chen, Xiaoliang; Zhao, Bin; Ma, Shoujiang; Chen, Cen; Hu, Daoyun; Zhou, Wenshuang; Zhu, Zuqing

    2015-03-23

    In this paper, we study how to improve the control plane resiliency of software-defined elastic optical networks (SD-EONs) and design a master-slave OpenFlow (OF) controller arrangement. Specifically, we introduce two OF controllers (OF-Cs), i.e., the master and slave OF-Cs, and make them work in a collaborative way to protect the SD-EON against controller failures. We develop a controller communication protocol (CCP) to facilitate the cooperation of the two OF-Cs. With the CCP, the master OF-C (M-OF-C) can synchronize network status to the slave OF-C (S-OF-C) in real time, while S-OF-C can quickly detect the failure of M-OF-C and take over the network control and management (NC&M) tasks timely to avoid service disruption. We implement the proposed framework in an SD-EON control plane testbed built with high-performance servers, and perform NC&M experiments with different network failure scenarios to demonstrate its effectiveness. Experimental results indicate that the proposed system can restore services in both the data and control planes of SD-EON jointly while maintaining relatively good scalability. To the best of our knowledge, this is the first demonstration that realizes control plane resiliency in SD-EONs.

  10. Software-in-the-loop simulation of a quadcopter portion for hybrid aircraft control

    Science.gov (United States)

    Mansoor, Shoaib; Saedan, Mana

    2018-01-01

    In this paper, we present the design of the software-in-the-loop simulation framework for a quadcopter that is incorporated in our hybrid aircraft. The hybrid aircraft comprises a quad-copter and a fixed wing with one forward thrust rotor. We need to develop a split control system that utilizes a typical quadcopter controller to control four motors/propellers and a supervisor controller to control a forward thrust rotor. The supervisor controller shall take feedback signals from the quadcopter and will command the fifth rotor for stabilizing the hybrid aircraft and resolves problems like thrust saturation. The simulation simulates the control algorithm and verifies the quadcopter’s behavior using MATLAB and Simulink together. Achieving these results, we come to know how our hybrid controller will be implemented, what results to expect once the forward thrust rotor is attached to the quadcopter. The software-in-the-loop simulation of a quadcopter is one of the most effective methods for verifying overall control performance and safety of the hybrid aircraft before actual hardware implementation and flight test.

  11. Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

    Science.gov (United States)

    Bansal, Indar

    1993-01-01

    The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

  12. Distributed, Passivity-Based, Aeroservoelastic Control (DPASC) of Structurally Efficient Aircraft in the Presence of Gusts, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Control of extremely lightweight, long endurance aircraft poses a challenging aeroservoelastic (ASE) problem due to significantly increased flexibility, and...

  13. Distributed, Passivity-Based, Aeroservoelastic Control (DPASC) of Structurally Efficient Aircraft in the Presence of Gusts, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Control of extremely lightweight, long endurance aircraft poses a challenging aeroservoelastic (ASE) problem due to significantly increased flexibility, and...

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

    Science.gov (United States)

    Oh, Seyool

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

  15. Adaptive Neural Network Sliding Mode Control for Quad Tilt Rotor Aircraft

    OpenAIRE

    Yanchao Yin; Hongwei Niu; Xiaobao Liu

    2017-01-01

    A novel neural network sliding mode control based on multicommunity bidirectional drive collaborative search algorithm (M-CBDCS) is proposed to design a flight controller for performing the attitude tracking control of a quad tilt rotors aircraft (QTRA). Firstly, the attitude dynamic model of the QTRA concerning propeller tension, channel arm, and moment of inertia is formulated, and the equivalent sliding mode control law is stated. Secondly, an adaptive control algorithm is presented to eli...

  16. Control Power Optimization using Artificial Intelligence for Hybrid Wing Body Aircraft

    OpenAIRE

    Chhabra, Rupanshi

    2015-01-01

    Traditional methods of control allocation optimization have shown difficulties in exploiting the full potential of controlling a large array of control surfaces. This research investigates the potential of employing artificial intelligence methods like neurocomputing to the control allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts for minimizing control power, hinge moments, and actuator forces, while keeping the system weights within acceptable limits. The main obje...

  17. A manual control theory analysis of vertical situation displays for STOL aircraft

    Science.gov (United States)

    Baron, S.; Levison, W. H.

    1973-01-01

    Pilot-vehicle-display systems theory is applied to the analysis of proposed vertical situation displays for manual control in approach-to-landing of a STOL aircraft. The effects of display variables on pilot workload and on total closed-loop system performance was calculated using an optimal-control model for the human operator. The steep approach of an augmentor wing jet STOL aircraft was analyzed. Both random turbulence and mean-wind shears were considered. Linearized perturbation equations were used to describe longitudinal and lateral dynamics of the aircraft. The basic display configuration was one that abstracted the essential status information (including glide-slope and localizer errors) of an EADI display. Proposed flight director displays for both longitudinal and lateral control were also investigated.

  18. Status of Computational Aerodynamic Modeling Tools for Aircraft Loss-of-Control

    Science.gov (United States)

    Frink, Neal T.; Murphy, Patrick C.; Atkins, Harold L.; Viken, Sally A.; Petrilli, Justin L.; Gopalarathnam, Ashok; Paul, Ryan C.

    2016-01-01

    A concerted effort has been underway over the past several years to evolve computational capabilities for modeling aircraft loss-of-control under the NASA Aviation Safety Program. A principal goal has been to develop reliable computational tools for predicting and analyzing the non-linear stability & control characteristics of aircraft near stall boundaries affecting safe flight, and for utilizing those predictions for creating augmented flight simulation models that improve pilot training. Pursuing such an ambitious task with limited resources required the forging of close collaborative relationships with a diverse body of computational aerodynamicists and flight simulation experts to leverage their respective research efforts into the creation of NASA tools to meet this goal. Considerable progress has been made and work remains to be done. This paper summarizes the status of the NASA effort to establish computational capabilities for modeling aircraft loss-of-control and offers recommendations for future work.

  19. LMI–based robust controller design approach in aircraft multidisciplinary design optimization problem

    Directory of Open Access Journals (Sweden)

    Qinghua Zeng

    2015-07-01

    Full Text Available This article proposes a linear matrix inequality–based robust controller design approach to implement the synchronous design of aircraft control discipline and other disciplines, in which the variation in design parameters is treated as equivalent perturbations. Considering the complicated mapping relationships between the coefficient arrays of aircraft motion model and the aircraft design parameters, the robust controller designed is directly based on the variation in these coefficient arrays so conservative that the multidisciplinary design optimization problem would be too difficult to solve, or even if there is a solution, the robustness of design result is generally poor. Therefore, this article derives the uncertainty model of disciplinary design parameters based on response surface approximation, converts the design problem of the robust controller into a problem of solving a standard linear matrix inequality, and theoretically gives a less conservative design method of the robust controller which is based on the variation in design parameters. Furthermore, the concurrent subspace approach is applied to the multidisciplinary system with this kind of robust controller in the design loop. A multidisciplinary design optimization of a tailless aircraft as example is shown that control discipline can be synchronous optimal design with other discipline, especially this method will greatly reduce the calculated amount of multidisciplinary design optimization and make multidisciplinary design optimization results more robustness of flight performance.

  20. Adaptive Data-based Predictive Control for Short Take-off and Landing (STOL) Aircraft

    Science.gov (United States)

    Barlow, Jonathan Spencer; Acosta, Diana Michelle; Phan, Minh Q.

    2010-01-01

    Data-based Predictive Control is an emerging control method that stems from Model Predictive Control (MPC). MPC computes current control action based on a prediction of the system output a number of time steps into the future and is generally derived from a known model of the system. Data-based predictive control has the advantage of deriving predictive models and controller gains from input-output data. Thus, a controller can be designed from the outputs of complex simulation code or a physical system where no explicit model exists. If the output data happens to be corrupted by periodic disturbances, the designed controller will also have the built-in ability to reject these disturbances without the need to know them. When data-based predictive control is implemented online, it becomes a version of adaptive control. The characteristics of adaptive data-based predictive control are particularly appropriate for the control of nonlinear and time-varying systems, such as Short Take-off and Landing (STOL) aircraft. STOL is a capability of interest to NASA because conceptual Cruise Efficient Short Take-off and Landing (CESTOL) transport aircraft offer the ability to reduce congestion in the terminal area by utilizing existing shorter runways at airports, as well as to lower community noise by flying steep approach and climb-out patterns that reduce the noise footprint of the aircraft. In this study, adaptive data-based predictive control is implemented as an integrated flight-propulsion controller for the outer-loop control of a CESTOL-type aircraft. Results show that the controller successfully tracks velocity while attempting to maintain a constant flight path angle, using longitudinal command, thrust and flap setting as the control inputs.

  1. A smartphone application of alcohol resilience treatment for behavioral self-control training.

    Science.gov (United States)

    Yu, Fei; Albers, Jörg; Gao, Tian; Wang, Minghao; Bilberg, Arne; Stenager, Elsebeth

    2012-01-01

    High relapse rate is one of the most prominent problems in addiction treatment. Alcohol Resilience Treatment (ART), an alcohol addiction therapy, is based on Cue Exposure Treatment, which has shown promising results in preliminary studies. ART aims at optimizing the core area of relapse prevention, and intends to improve patients' capability to withstand craving of alcohol. This method emphasizes the interplay of resilience and resourcefulness. It contains 6 sessions with different topics according to the stage of treatment circuit, and each session consists of 6 steps. Due to the purity and structure of the treatment rationale, it is realistic, reasonable and manageable to transform the method into a smartphone application. An ART app in Android system and an accessory of bilateral tactile stimulation were developed and will be used in a study with behavioral self-control training. This paper presents the design and realization of the smartphone based ART application. The design of a pilot study, which is to examine the benefits of a smartphone application providing behavioral self-control training, is also reported in this paper.

  2. Adaptive NN Control for Multisteering Plane Aircraft with Dead Zone or Backlash Input Nonlinearity

    OpenAIRE

    Meng, Xiang-fei; Wang, Ying; Lv, Mao-long

    2017-01-01

    Considering that many factors such as actuator input dead zone, backlash, and external disturbance could affect the exactness of trajectory tracking, therewith a robust adaptive neural network control scheme on the basis of control allocation is proposed for the sake of tracking control of multisteering plane aircraft with actuator input dead zone or backlash nonlinearity. First of all, an actuator input dead zone or backlash nonlinearity control assignment model is established and the contro...

  3. Simulator Evaluation of Simplified Propulsion-Only Emergency Flight Control Systems on Transport Aircraft

    Science.gov (United States)

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

    1999-01-01

    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.

  4. Adaptive Control Using Neural Network Augmentation for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.; Williams-Hayes, Peggy; Karneshige, J. T.; Stachowiak, Susan J.

    2006-01-01

    Description of the performance of a simplified dynamic inversion controller with neural network augmentation follows. Simulation studies focus on the results with and without neural network adaptation through the use of an F-15 aircraft simulator that has been modified to include canards. Simulated control law performance with a surface failure, in addition to an aerodynamic failure, is presented. The aircraft, with adaptation, attempts to minimize the inertial cross-coupling effect of the failure (a control derivative anomaly associated with a jammed control surface). The dynamic inversion controller calculates necessary surface commands to achieve desired rates. The dynamic inversion controller uses approximate short period and roll axis dynamics. The yaw axis controller is a sideslip rate command system. Methods are described to reduce the cross-coupling effect and maintain adequate tracking errors for control surface failures. The aerodynamic failure destabilizes the pitching moment due to angle of attack. The results show that control of the aircraft with the neural networks is easier (more damped) than without the neural networks. Simulation results show neural network augmentation of the controller improves performance with aerodynamic and control surface failures in terms of tracking error and cross-coupling reduction.

  5. Network-Aware Reference Frame Control for Error-Resilient H.264/AVC Video Streaming Service

    Directory of Open Access Journals (Sweden)

    Hui-Seon Gang

    2016-01-01

    Full Text Available To provide high-quality video streaming services in a mobile communication network, a large bandwidth and reliable channel conditions are required. However, mobile communication services still encounter limited bandwidth and varying channel conditions. The streaming video system compresses video with motion estimation and compensation using multiple reference frames. The multiple reference frame structure can reduce the compressed bit rate of video; however, it can also cause significant error propagation when the video in the channel is damaged. Even though the streaming video system includes error-resilience tools to mitigate quality degradation, error propagation is inevitable because all errors can not be refreshed under the multiple reference frame structure. In this paper, a new network-aware error-resilient streaming video system is introduced. The proposed system can mitigate error propagation by controlling the number of reference frames based on channel status. The performance enhancement is demonstrated by comparing the proposed method to the conventional streaming system using static number of reference frames.

  6. Randomized controlled clinical trial on satisfaction with resilient denture liners among edentulous patients.

    Science.gov (United States)

    Kimoto, Suguru; Kitamura, Manabu; Kodaira, Maria; Yamamoto, Shirou; Ohno, Yousuke; Kawai, Yasuhiko; Kawara, Misao; Kobayashi, Kihei

    2004-01-01

    The purpose of this study was to measure patients' satisfaction and their preference between mandibular dentures with permanent silicone-based resilient denture liner (SR) and conventional heat-activated acrylic resin (AR), both opposed by acrylic resin-based maxillary complete dentures. Twenty-eight edentulous patients who had fulfilled selection criteria and provided informed consent were enrolled in this trial. Subjects were allocated randomly to either arm of cross-over groups (AR-SR/SR-AR), stratified by gender, using a random permuted block within the strata method. The AR-SR group received AR denture treatment followed by SR denture treatment. The SR-AR group received treatment in the reverse sequence. The primary outcome was patient satisfaction measured on 100-mm VAS, analyzed by two-way ANOVA and the Bonferroni multiple comparison as a post hoc test. The secondary outcome was patients' preference, evaluated by chi-square goodness-of-fit test. An intention-to-treat analysis was performed. Twenty-five subjects were enrolled in the analysis. There were no significant differences between AR and SR dentures 1, 2, and 3 months after the completion of control. Eighteen of 25 patients preferred SR dentures. Although there were no significant differences in patient satisfaction ratings between the two types of dentures, a significant majority of patients preferred those with a resilient denture liner.

  7. Air Traffic Controller Acceptability of Unmanned Aircraft System Detect-and-Avoid Thresholds

    Science.gov (United States)

    Mueller, Eric R.; Isaacson, Douglas R.; Stevens, Derek

    2016-01-01

    A human-in-the-loop experiment was conducted with 15 retired air traffic controllers to investigate two research questions: (a) what procedures are appropriate for the use of unmanned aircraft system (UAS) detect-and-avoid systems, and (b) how long in advance of a predicted close encounter should pilots request or execute a separation maneuver. The controller participants managed a busy Oakland air route traffic control sector with mixed commercial/general aviation and manned/UAS traffic, providing separation services, miles-in-trail restrictions and issuing traffic advisories. Controllers filled out post-scenario and post-simulation questionnaires, and metrics were collected on the acceptability of procedural options and temporal thresholds. The states of aircraft were also recorded when controllers issued traffic advisories. Subjective feedback indicated a strong preference for pilots to request maneuvers to remain well clear from intruder aircraft rather than deviate from their IFR clearance. Controllers also reported that maneuvering at 120 seconds until closest point of approach (CPA) was too early; maneuvers executed with less than 90 seconds until CPA were more acceptable. The magnitudes of the requested maneuvers were frequently judged to be too large, indicating a possible discrepancy between the quantitative UAS well clear standard and the one employed subjectively by manned pilots. The ranges between pairs of aircraft and the times to CPA at which traffic advisories were issued were used to construct empirical probability distributions of those metrics. Given these distributions, we propose that UAS pilots wait until an intruder aircraft is approximately 80 seconds to CPA or 6 nmi away before requesting a maneuver, and maneuver immediately if the intruder is within 60 seconds and 4 nmi. These thresholds should make the use of UAS detect and avoid systems compatible with current airspace procedures and controller expectations.

  8. Development and evaluation of a profile negotiation process for integrating aircraft and air traffic control automation

    Science.gov (United States)

    Green, Steven M.; Denbraven, Wim; Williams, David H.

    1993-01-01

    The development and evaluation of the profile negotiation process (PNP), an interactive process between an aircraft and air traffic control (ATC) that integrates airborne and ground-based automation capabilities to determine conflict-free trajectories that are as close to an aircraft's preference as possible, are described. The PNP was evaluated in a real-time simulation experiment conducted jointly by NASA's Ames and Langley Research Centers. The Ames Center/TRACON Automation System (CTAS) was used to support the ATC environment, and the Langley Transport Systems Research Vehicle (TSRV) piloted cab was used to simulate a 4D Flight Management System (FMS) capable aircraft. Both systems were connected in real time by way of voice and data lines; digital datalink communications capability was developed and evaluated as a means of supporting the air/ground exchange of trajectory data. The controllers were able to consistently and effectively negotiate nominally conflict-free vertical profiles with the 4D-equipped aircraft. The actual profiles flown were substantially closer to the aircraft's preference than would have been possible without the PNP. However, there was a strong consensus among the pilots and controllers that the level of automation of the PNP should be increased to make the process more transparent. The experiment demonstrated the importance of an aircraft's ability to accurately execute a negotiated profile as well as the need for digital datalink to support advanced air/ground data communications. The concept of trajectory space is proposed as a comprehensive approach for coupling the processes of trajectory planning and tracking to allow maximum pilot discretion in meeting ATC constraints.

  9. Technology for controlling emissions of oxides of nitrogen from supersonic cruise aircraft

    Science.gov (United States)

    Reck, G. M.; Rudey, R. A.

    1976-01-01

    Various experiments are sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling aircraft engine emissions into the upper atmosphere. Of particular concern are the oxide of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  10. Active aeroelastic control aspects of an aircraft wing by using synthetic jet actuators : Modeling, simulations, experiments

    NARCIS (Netherlands)

    Donnell, K.O.; Schober, S.; Stolk, M.; Marzocca, P.; De Breuker, R.; Abdalla, M.; Nicolini, E.; Gürdal, Z.

    2007-01-01

    This paper discusses modeling, simulations and experimental aspects of active aeroelastic control on aircraft wings by using Synthetic Jet Actuators (SJAs). SJAs, a particular class of zero-net mass-flux actuators, have shown very promising results in numerous aeronautical applications, such as

  11. Nonlinear Multivariate Spline-Based Control Allocation for High-Performance Aircraft

    NARCIS (Netherlands)

    Tol, H.J.; De Visser, C.C.; Van Kampen, E.; Chu, Q.P.

    2014-01-01

    High performance flight control systems based on the nonlinear dynamic inversion (NDI) principle require highly accurate models of aircraft aerodynamics. In general, the accuracy of the internal model determines to what degree the system nonlinearities can be canceled; the more accurate the model,

  12. Wing Shaping and Gust Load Controls of Flexible Aircraft: An LPV Approach

    Science.gov (United States)

    Hammerton, Jared R.; Su, Weihua; Zhu, Guoming; Swei, Sean Shan-Min

    2018-01-01

    In the proposed paper, the optimum wing shape of a highly flexible aircraft under varying flight conditions will be controlled by a linear parameter-varying approach. The optimum shape determined under multiple objectives, including flight performance, ride quality, and control effort, will be determined as well. This work is an extension of work done previously by the authors, and updates the existing optimization and utilizes the results to generate a robust flight controller.

  13. Nonlinear Multivariate Spline-Based Control Allocation for High-Performance Aircraft

    OpenAIRE

    Tol, H.J.; De Visser, C.C.; Van Kampen, E.; Chu, Q.P.

    2014-01-01

    High performance flight control systems based on the nonlinear dynamic inversion (NDI) principle require highly accurate models of aircraft aerodynamics. In general, the accuracy of the internal model determines to what degree the system nonlinearities can be canceled; the more accurate the model, the better the cancellation, and with that, the higher the performance of the controller. In this paper a new control system is presented that combines NDI with multivariate simplex spline based con...

  14. Development and Flight Testing of a Neural Network Based Flight Control System on the NF-15B Aircraft

    Science.gov (United States)

    Bomben, Craig R.; Smolka, James W.; Bosworth, John T.; Silliams-Hayes, Peggy S.; Burken, John J.; Larson, Richard R.; Buschbacher, Mark J.; Maliska, Heather A.

    2006-01-01

    The Intelligent Flight Control System (IFCS) project at the NASA Dryden Flight Research Center, Edwards AFB, CA, has been investigating the use of neural network based adaptive control on a unique NF-15B test aircraft. The IFCS neural network is a software processor that stores measured aircraft response information to dynamically alter flight control gains. In 2006, the neural network was engaged and allowed to learn in real time to dynamically alter the aircraft handling qualities characteristics in the presence of actual aerodynamic failure conditions injected into the aircraft through the flight control system. The use of neural network and similar adaptive technologies in the design of highly fault and damage tolerant flight control systems shows promise in making future aircraft far more survivable than current technology allows. This paper will present the results of the IFCS flight test program conducted at the NASA Dryden Flight Research Center in 2006, with emphasis on challenges encountered and lessons learned.

  15. Modeling and control for a blended wing body aircraft a case study

    CERN Document Server

    Schirrer, Alexander

    2015-01-01

    This book demonstrates the potential of the blended wing body (BWB) concept for significant improvement in both fuel efficiency and noise reduction and addresses the considerable challenges raised for control engineers because of characteristics like open-loop instability, large flexible structure, and slow control surfaces. This text describes state-of-the-art and novel modeling and control design approaches for the BWB aircraft under consideration. The expert contributors demonstrate how exceptional robust control performance can be achieved despite such stringent design constraints as guaranteed handling qualities, reduced vibration, and the minimization of the aircraft’s structural loads during maneuvers and caused by turbulence. As a result, this innovative approach allows the building of even lighter aircraft structures, and thus results in considerable efficiency improvements per passenger kilometer. The treatment of this large, complex, parameter-dependent industrial control problem highlights relev...

  16. Robust Propulsion Control for Improved Aircraft Safety Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Scientific Monitoring, Inc. proposes to develop a robust propulsion control approach to facilitate control law design and simulation-based validation. The proposed...

  17. Robust Command Filtered Adaptive Backstepping Control for a Quadrotor Aircraft

    Directory of Open Access Journals (Sweden)

    Yicheng Liu

    2018-01-01

    Full Text Available This paper addresses a robust trajectory tracking controller for an underactuated quadrotor with external bounded disturbances and unknown inertia parameters. Different from most of the existing control algorithms, the proposed method does not adopt the dual-loop scheme in which the design is divided into position control and attitude control. Instead, command filter backstepping is employed to design the controller based on the integrated motion model such that the stability can be guaranteed strictly for the flight control system. Furthermore, adaptive compensation and robust compensation are introduced to deal with the uncertainty of the inertia parameters and the external bounded disturbances, respectively. Finally, a similar skew symmetric structure is chosen as the desired structure of the closed-loop system to facilitate the analysis of the stability of the integrated system. Stability and robust performance of the designed controller are verified by Lyapunov stability theorem. Simulations are provided to validate the proposed controller.

  18. Artificial Intelligence Based Control Power Optimization on Tailless Aircraft. [ARMD Seedling Fund Phase I

    Science.gov (United States)

    Gern, Frank; Vicroy, Dan D.; Mulani, Sameer B.; Chhabra, Rupanshi; Kapania, Rakesh K.; Schetz, Joseph A.; Brown, Derrell; Princen, Norman H.

    2014-01-01

    Traditional methods of control allocation optimization have shown difficulties in exploiting the full potential of controlling large arrays of control devices on innovative air vehicles. Artificial neutral networks are inspired by biological nervous systems and neurocomputing has successfully been applied to a variety of complex optimization problems. This project investigates the potential of applying neurocomputing to the control allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts to minimize control power, hinge moments, and actuator forces, while keeping system weights within acceptable limits. The main objective of this project is to develop a proof-of-concept process suitable to demonstrate the potential of using neurocomputing for optimizing actuation power for aircraft featuring multiple independently actuated control surfaces. A Nastran aeroservoelastic finite element model is used to generate a learning database of hinge moment and actuation power characteristics for an array of flight conditions and control surface deflections. An artificial neural network incorporating a genetic algorithm then uses this training data to perform control allocation optimization for the investigated aircraft configuration. The phase I project showed that optimization results for the sum of required hinge moments are improved by more than 12% over the best Nastran solution by using the neural network optimization process.

  19. A model following inverse controller with adaptive compensation for General Aviation aircraft

    Science.gov (United States)

    Bruner, Hugh S.

    The theory for an adaptive inverse flight controller, suitable for use on General Aviation aircraft, is developed in this research. The objectives of this controller are to separate the normally coupled modes of the basic aircraft and thereby permit direct control of airspeed and flight-path angle, meet prescribed performance characteristics as defined by damping ratio and natural frequency, adapt to uncertainties in the physical plant, and be computationally efficient. The three basic elements of the controller are a linear prefilter, an inverse transfer function, and an adaptive neural network compensator. The linear prefilter shapes accelerations required of the overall system in order to achieve the desired system performance characteristics. The inverse transfer function is used to compute the aircraft control inputs required to achieve the necessary accelerations. The adaptive neural network compensator is used to compensate for modeling errors during design or real-time changes in the physical plant. This architecture is patterned after the work of Calise, but differs by not requiring dynamic feedback of the state variables. The controller is coded in ANSI C and integrated with a simulation of a typical General Aviation aircraft. Twenty-three cases are simulated to prove that the objectives for the controller are met. Among these cases are simulated stability and controllability failures in the physical plant, as well as several simulated failures of the neural network. With the exception of some bounded speed-tracking error, the controller is capable of continued flight with any foreseeable failure of the neural network. Recommendations are provided for follow-on investigations by other researchers.

  20. Fast and error-resilient coherent control in an atomic vapor

    Science.gov (United States)

    He, Yizun; Wang, Mengbing; Zhao, Jian; Qiu, Liyang; Wang, Yuzhuo; Fang, Yami; Zhao, Kaifeng; Wu, Saijun

    2017-04-01

    Nanosecond chirped pulses from an optical arbitrary waveform generator is applied to both invert and coherently split the D1 line population of potassium vapor within a laser focal volume of 2X105 μ m3. The inversion fidelity of f>96%, mainly limited by spontaneous emission during the nanosecond pulse, is inferred from both probe light transmission and superfluorescence emission. The nearly perfect inversion is uniformly achieved for laser intensity varying over an order of magnitude, and is tolerant to detuning error of more than 1000 times the D1 transition linewidth. We further demonstrate enhanced intensity error resilience with multiple chirped pulses and ``universal composite pulses''. This fast and robust coherent control technique should find wide applications in the field of quantum optics, laser cooling, and atom interferometry. This work is supported by National Key Research Program of China under Grant No. 2016YFA0302000, and NNSFC under Grant No. 11574053.

  1. CONTROL SYSTEM FOR UNMANNED AIRCRAFT EQUIPPED WITH ROBOTICS ARM

    Directory of Open Access Journals (Sweden)

    Alexei A. Margun

    2014-11-01

    Full Text Available The paper deals with the problem of control system synthesis for multi rotational UAV equipped with robotics arm. Control algorithm is proposed based on the method of feedback linearization and synthesis of proportional-differential controller with the real time computation of the inertia tensor and center of mass changes and compensation of the reactive torque generated by the dynamics of the manipulator. Quadrocopter with attached articulated manipulator is selected as a model of the control object. Systems of equations describing the behavior of considered dynamical system are obtained according to the Newton and Euler-Lagrange laws. Expressions are offered, defining the inertia tensor and the position of the system center of mass depending on the current position of the manipulator, and the torque acting on the quadrocopter from the manipulator. Feedback linearization with arm influence compensation on quadrocopter is applied for the resulting nonlinear coupled system. As a result, robot dynamics equations have been converted to a linear stationary system. Converted system control is achieved by a proportional-differential controller. Examined system simulation is done with control method described in the paper and the classical method based on a proportional-differential controller. Simulation results confirm the effectiveness of the proposed approach and demonstrate that the proposed approach provides higher accuracy of the tracking error, than control method by means of proportional-differential regulator.

  2. A systematic method of smooth switching LPV controllers design for a morphing aircraft

    Directory of Open Access Journals (Sweden)

    Jiang Weilai

    2015-12-01

    Full Text Available This paper is concerned with a systematic method of smooth switching linear parameter-varying (LPV controllers design for a morphing aircraft with a variable wing sweep angle. The morphing aircraft is modeled as an LPV system, whose scheduling parameter is the variation rate of the wing sweep angle. By dividing the scheduling parameter set into subsets with overlaps, output feedback controllers which consider smooth switching are designed and the controllers in overlapped subsets are interpolated from two adjacent subsets. A switching law without constraint on the average dwell time is obtained which makes the conclusion less conservative. Furthermore, a systematic algorithm is developed to improve the efficiency of the controllers design process. The parameter set is divided into the fewest subsets on the premise that the closed-loop system has a desired performance. Simulation results demonstrate the effectiveness of this approach.

  3. Adaptive Neural Control Based on High Order Integral Chained Differentiator for Morphing Aircraft

    OpenAIRE

    Wu, Zhonghua; Lu, Jingchao; Rajput, Jahanzeb; Shi, Jingping; Ma, Wen

    2015-01-01

    This paper presents an adaptive neural control for the longitudinal dynamics of a morphing aircraft. Based on the functional decomposition, it is reasonable to decompose the longitudinal dynamics into velocity and altitude subsystems. As for the velocity subsystem, the adaptive control is proposed via dynamic inversion method using neural network. To deal with input constraints, the additional compensation system is employed to help engine recover from input saturation rapidly. The highlight ...

  4. New Flight Control Technologies for Future Naval Aircraft.

    Science.gov (United States)

    1982-09-01

    normally share control of actuator position, while the third EHSV , SV3, is held in standby. Note that flows from SV1 and SV2 flow to the larger piston, and...and Vertical Canard Control Surfaces S69 NADC-82240-60 ccc 0 IfIc 4Y L l r - - - - - - - - - - - - -- 00L Ldd cm0 uC Go~ 70. NADC-82240-60 * EHSV ... EHSV SV3. A first failure of SV3 will lock the ISA on SV1 and SV2 control . . Hydraulic system failure correction is given precedence over all EHSV

  5. Final Rule for Control of Air Pollution from Aircraft and Aircraft Engines: Emission Standards and Test Procedures

    Science.gov (United States)

    EPA is amending the existing emission standards for oxides of nitrogen (NOx) for new commercial aircraft engines. These standards are equivalent to the NOx emission standards of the United Nations International Civil Aviation Organization (ICAO).

  6. Direct Final Rule for Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Science.gov (United States)

    This rule will adopt the current voluntary NOx and CO emissions standards of the United Nations International Civil Aviation Organization (ICAO), bringing the United States aircraft standards into alignment with the international standards.

  7. Aircraft Loss-of-Control Accident Prevention: Switching Control of the GTM Aircraft with Elevator Jam Failures

    Science.gov (United States)

    Chang, Bor-Chin; Kwatny, Harry G.; Belcastro, Christine; Belcastro, Celeste

    2008-01-01

    Switching control, servomechanism, and H2 control theory are used to provide a practical and easy-to-implement solution for the actuator jam problem. A jammed actuator not only causes a reduction of control authority, but also creates a persistent disturbance with uncertain amplitude. The longitudinal dynamics model of the NASA GTM UAV is employed to demonstrate that a single fixed reconfigured controller design based on the proposed approach is capable of accommodating an elevator jam failure with arbitrary jam position as long as the thrust control has enough control authority. This paper is a first step towards solving a more comprehensive in-flight loss-of-control accident prevention problem that involves multiple actuator failures, structure damages, unanticipated faults, and nonlinear upset regime recovery, etc.

  8. Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

    Science.gov (United States)

    DeLaat, John C.

    2011-01-01

    Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

  9. Launch Vehicle Manual Steering with Adaptive Augmenting Control In-flight Evaluations Using a Piloted Aircraft

    Science.gov (United States)

    Hanson, Curt

    2014-01-01

    An adaptive augmenting control algorithm for the Space Launch System has been developed at the Marshall Space Flight Center as part of the launch vehicles baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a proposed manual steering mode were investigated by giving the pilot trajectory deviation cues and pitch rate command authority.

  10. 22 CFR 123.8 - Special controls on vessels, aircraft and satellites covered by the U.S. Munitions List.

    Science.gov (United States)

    2010-04-01

    ... satellites covered by the U.S. Munitions List. 123.8 Section 123.8 Foreign Relations DEPARTMENT OF STATE... on vessels, aircraft and satellites covered by the U.S. Munitions List. (a) Transferring registration or control to a foreign person of any aircraft, vessel, or satellite on the U.S. Munitions List is an...

  11. Sliding Mode Fault Tolerant Control with Adaptive Diagnosis for Aircraft Engines

    Science.gov (United States)

    Xiao, Lingfei; Du, Yanbin; Hu, Jixiang; Jiang, Bin

    2018-03-01

    In this paper, a novel sliding mode fault tolerant control method is presented for aircraft engine systems with uncertainties and disturbances on the basis of adaptive diagnostic observer. By taking both sensors faults and actuators faults into account, the general model of aircraft engine control systems which is subjected to uncertainties and disturbances, is considered. Then, the corresponding augmented dynamic model is established in order to facilitate the fault diagnosis and fault tolerant controller design. Next, a suitable detection observer is designed to detect the faults effectively. Through creating an adaptive diagnostic observer and based on sliding mode strategy, the sliding mode fault tolerant controller is constructed. Robust stabilization is discussed and the closed-loop system can be stabilized robustly. It is also proven that the adaptive diagnostic observer output errors and the estimations of faults converge to a set exponentially, and the converge rate greater than some value which can be adjusted by choosing designable parameters properly. The simulation on a twin-shaft aircraft engine verifies the applicability of the proposed fault tolerant control method.

  12. Recent advance in nonlinear aeroelastic analysis and control of the aircraft

    Directory of Open Access Journals (Sweden)

    Xiang Jinwu

    2014-02-01

    Full Text Available A review on the recent advance in nonlinear aeroelasticity of the aircraft is presented in this paper. The nonlinear aeroelastic problems are divided into three types based on different research objects, namely the two dimensional airfoil, the wing, and the full aircraft. Different nonlinearities encountered in aeroelastic systems are discussed firstly, where the emphases is placed on new nonlinear model to describe tested nonlinear relationship. Research techniques, especially new theoretical methods and aeroelastic flutter control methods are investigated in detail. The route to chaos and the cause of chaotic motion of two-dimensional aeroelastic system are summarized. Various structural modeling methods for the high-aspect-ratio wing with geometric nonlinearity are discussed. Accordingly, aerodynamic modeling approaches have been developed for the aeroelastic modeling of nonlinear high-aspect-ratio wings. Nonlinear aeroelasticity about high-altitude long-endurance (HALE and fight aircrafts are studied separately. Finally, conclusions and the challenges of the development in nonlinear aeroelasticity are concluded. Nonlinear aeroelastic problems of morphing wing, energy harvesting, and flapping aircrafts are proposed as new directions in the future.

  13. Buffet induced structural/flight-control system interaction of the X-29A aircraft

    Science.gov (United States)

    Voracek, David F.; Clarke, Robert

    1991-01-01

    High angle-of-attack flight regime research is currently being conducted for modern fighter aircraft at the NASA Ames Research Center's Dryden Flight Research Facility. This flight regime provides enhanced maneuverability to fighter pilots in combat situations. Flight research data are being acquired to compare and validate advanced computational fluid dynamic solutions and wind-tunnel models. High angle-of-attack flight creates unique aerodynamic phenomena including wing rock and buffet on the airframe. These phenomena increase the level of excitation of the structural modes, especially on the vertical and horizontal stabilizers. With high gain digital flight-control systems, this structural response may result in an aeroservoelastic interaction. A structural interaction on the X-29A aircraft was observed during high angle-of-attack flight testing. The roll and yaw rate gyros sensed the aircraft's structural modes at 11, 13, and 16 Hz. The rate gyro output signals were then amplified through the flight-control laws and sent as commands to the flaperons and rudder. The flight data indicated that as the angle of attack increased, the amplitude of the buffet on the vertical stabilizer increased, which resulted in more excitation to the structural modes. The flight-control system sensors and command signals showed this increase in modal power at the structural frequencies up to a 30 degree angle-of-attack. Beyond a 30 degree angle-of-attack, the vertical stabilizer response, the feedback sensor amplitude, and control surface command signal amplitude remained relatively constant. Data are presented that show the increased modal power in the aircraft structural accelerometers, the feedback sensors, and the command signals as a function of angle of attack. This structural interaction is traced from the aerodynamic buffet to the flight-control surfaces.

  14. DCS-Neural-Network Program for Aircraft Control and Testing

    Science.gov (United States)

    Jorgensen, Charles C.

    2006-01-01

    A computer program implements a dynamic-cell-structure (DCS) artificial neural network that can perform such tasks as learning selected aerodynamic characteristics of an airplane from wind-tunnel test data and computing real-time stability and control derivatives of the airplane for use in feedback linearized control. A DCS neural network is one of several types of neural networks that can incorporate additional nodes in order to rapidly learn increasingly complex relationships between inputs and outputs. In the DCS neural network implemented by the present program, the insertion of nodes is based on accumulated error. A competitive Hebbian learning rule (a supervised-learning rule in which connection weights are adjusted to minimize differences between actual and desired outputs for training examples) is used. A Kohonen-style learning rule (derived from a relatively simple training algorithm, implements a Delaunay triangulation layout of neurons) is used to adjust node positions during training. Neighborhood topology determines which nodes are used to estimate new values. The network learns, starting with two nodes, and adds new nodes sequentially in locations chosen to maximize reductions in global error. At any given time during learning, the error becomes homogeneously distributed over all nodes.

  15. Evaluating the Handling Qualities of Flight Control Systems Including Nonlinear Aircraft and System Dynamics

    Science.gov (United States)

    Lin, Raymond Chao

    The handling qualities evaluation of nonlinear aircraft systems is an area of concern in loss-of-control (LOC) prevention. The Get Transfer Function (GetTF) method was demonstrated for evaluating the handling qualities of flight control systems and aircraft containing nonlinearities. NASA's Generic Transport Model (GTM), a nonlinear model of a civilian jet transport aircraft, was evaluated. Using classical techniques, the stability, control, and augmentation (SCAS) systems were designed to control pitch rate, roll rate, and airspeed. Hess's structural pilot model was used to model pilot dynamics in pitch and roll-attitude tracking. The simulated task was simultaneous tracking of, both, pitch and roll attitudes. Eight cases were evaluated: 1) gain increase of pitch-attitude command signal, 2) gain increase of roll-attitude command signal, 3) gain reduction of elevator command signal, 4) backlash in elevator actuator, 5) combination 3 and 4 in elevator actuator, 6) gain reduction of aileron command signal, 7) backlash in aileron actuator, and 8) combination of 6 and 7 in aileron actuator. The GetTF method was used to estimate the transfer function approximating a linear relationship between the proprioceptive signal of the pilot model and the command input. The transfer function was then used to predict the handling qualities ratings (HQR) and pilot-induced oscillation ratings (PIOR). The HQR is based on the Cooper-Harper rating scale. In pitch-attitude tracking, the nominal aircraft is predicted to have Level 2* HQRpitch and 2 exercise was also conducted to validate the structural pilot model.

  16. Effects of higher order control systems on aircraft approach and landing longitudinal handling qualities

    Science.gov (United States)

    Pasha, M. A.; Dazzo, J. J.; Silverthorn, J. T.

    1982-01-01

    An investigation of approach and landing longitudinal flying qualities, based on data generated using a variable stability NT-33 aircraft combined with significant control system dynamics is described. An optimum pilot lead time for pitch tracking, flight path angle tracking, and combined pitch and flight path angle tracking tasks is determined from a closed loop simulation using integral squared error (ISE) as a performance measure. Pilot gain and lead time were varied in the closed loop simulation of the pilot and aircraft to obtain the best performance for different control system configurations. The results lead to the selection of an optimum lead time using ISE as a performance criterion. Using this value of optimum lead time, a correlation is then found between pilot rating and performance with changes in the control system and in the aircraft dynamics. It is also shown that pilot rating is closely related to pilot workload which, in turn, is related to the amount of lead which the pilot must generate to obtain satisfactory response. The results also indicate that the pilot may use pitch angle tracking for the approach task and then add flight path angle tracking for the flare and touchdown.

  17. Variable-Speed Induction Motor Drives for Aircraft Environmental Control Compressors

    Science.gov (United States)

    Mildice, J. W.; Hansen, I. G.; Schreiner, K. E.; Roth, M. E.

    1996-01-01

    New, more-efficient designs for aircraft jet engines are not capable of supplying the large quantities of bleed air necessary to provide pressurization and air conditioning for the environmental control systems (ECS) of the next generation of large passenger aircraft. System analysis and engineering have determined that electrically-driven ECS can help to maintain the improved fuel efficiencies; and electronic controllers and induction motors are now being developed in a NASA/NPD SBIR Program to drive both types of ECS compressors. Previous variable-speed induction motor/controller system developments and publications have primarily focused on field-oriented control, with large transient reserve power, for maximum acceleration and optimum response in actuator and robotics systems. The application area addressed herein is characterized by slowly-changing inputs and outputs, small reserve power capability for acceleration, and optimization for maximum efficiency. This paper therefore focuses on the differences between this case and the optimum response case, and shows the development of this new motor/controller approach. It starts with the creation of a new set of controller requirements. In response to those requirements, new control algorithms are being developed and implemented in an embedded computer, which is integrated into the motor controller closed loop. Buffered logic outputs are used to drive the power switches in a resonant-technology, power processor/motor-controller, at switching/resonant frequencies high enough to support efficient high-frequency induction motor operation at speeds up to 50,000-RPA

  18. Adaptive control in an aircraft propulsion system and system integration with flight control; Kokukiyo enigne - tekio seigyo gijutsu oyobi hiko seigyo tono togo

    Energy Technology Data Exchange (ETDEWEB)

    Nagatome, S.; Seo, N.; Negoro, T.; Kaneda, S.; Matsushita, T.; Kono, Y.; Kanbe, K.; Fujiwara, K. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    2000-04-01

    Aircraft engine controllers incorporating computer technology have enabled the highly automated control of the entire engine system, and consequently have been put to practical use as Full-Authority Digital Electronic Control (FADEC). In future such FADEC technology will be evolved and combined into an Integrated Flight and Propulsion Control (IFPC) system which will automatically optimize the whole aircraft propulsion system. In this paper the application of the adaptive control, part of the IFPC technology, is described. (author)

  19. Design and evaluation of a robust dynamic neurocontroller for a multivariable aircraft control problem

    Science.gov (United States)

    Troudet, T.; Garg, S.; Merrill, W.

    1992-01-01

    The design of a dynamic neurocontroller with good robustness properties is presented for a multivariable aircraft control problem. The internal dynamics of the neurocontroller are synthesized by a state estimator feedback loop. The neurocontrol is generated by a multilayer feedforward neural network which is trained through backpropagation to minimize an objective function that is a weighted sum of tracking errors, and control input commands and rates. The neurocontroller exhibits good robustness through stability margins in phase and vehicle output gains. By maintaining performance and stability in the presence of sensor failures in the error loops, the structure of the neurocontroller is also consistent with the classical approach of flight control design.

  20. Knowledge-Based Aircraft Automation: Managers Guide on the use of Artificial Intelligence for Aircraft Automation and Verification and Validation Approach for a Neural-Based Flight Controller

    Science.gov (United States)

    Broderick, Ron

    1997-01-01

    The ultimate goal of this report was to integrate the powerful tools of artificial intelligence into the traditional process of software development. To maintain the US aerospace competitive advantage, traditional aerospace and software engineers need to more easily incorporate the technology of artificial intelligence into the advanced aerospace systems being designed today. The future goal was to transition artificial intelligence from an emerging technology to a standard technology that is considered early in the life cycle process to develop state-of-the-art aircraft automation systems. This report addressed the future goal in two ways. First, it provided a matrix that identified typical aircraft automation applications conducive to various artificial intelligence methods. The purpose of this matrix was to provide top-level guidance to managers contemplating the possible use of artificial intelligence in the development of aircraft automation. Second, the report provided a methodology to formally evaluate neural networks as part of the traditional process of software development. The matrix was developed by organizing the discipline of artificial intelligence into the following six methods: logical, object representation-based, distributed, uncertainty management, temporal and neurocomputing. Next, a study of existing aircraft automation applications that have been conducive to artificial intelligence implementation resulted in the following five categories: pilot-vehicle interface, system status and diagnosis, situation assessment, automatic flight planning, and aircraft flight control. The resulting matrix provided management guidance to understand artificial intelligence as it applied to aircraft automation. The approach taken to develop a methodology to formally evaluate neural networks as part of the software engineering life cycle was to start with the existing software quality assurance standards and to change these standards to include neural network

  1. Near-field noise prediction for aircraft in cruising flight: Methods manual. [laminar flow control noise effects analysis

    Science.gov (United States)

    Tibbetts, J. G.

    1979-01-01

    Methods for predicting noise at any point on an aircraft while the aircraft is in a cruise flight regime are presented. Developed for use in laminar flow control (LFC) noise effects analyses, they can be used in any case where aircraft generated noise needs to be evaluated at a location on an aircraft while under high altitude, high speed conditions. For each noise source applicable to the LFC problem, a noise computational procedure is given in algorithm format, suitable for computerization. Three categories of noise sources are covered: (1) propulsion system, (2) airframe, and (3) LFC suction system. In addition, procedures are given for noise modifications due to source soundproofing and the shielding effects of the aircraft structure wherever needed. Sample cases, for each of the individual noise source procedures, are provided to familiarize the user with typical input and computed data.

  2. The Effect of Modified Control Limits on the Performance of a Generic Commercial Aircraft Engine

    Science.gov (United States)

    Csank, Jeffrey T.; May, Ryan D.; Gou, Ten-Huei; Litt, Jonathan S.

    2012-01-01

    This paper studies the effect of modifying the control limits of an aircraft engine to obtain additional performance. In an emergency situation, the ability to operate an engine above its normal operating limits and thereby gain additional performance may aid in the recovery of a distressed aircraft. However, the modification of an engine s limits is complex due to the risk of an engine failure. This paper focuses on the tradeoff between enhanced performance and risk of either incurring a mechanical engine failure or compromising engine operability. The ultimate goal is to increase the engine performance, without a large increase in risk of an engine failure, in order to increase the probability of recovering the distressed aircraft. The control limit modifications proposed are to extend the rotor speeds, temperatures, and pressures to allow more thrust to be produced by the engine, or to increase the rotor accelerations and allow the engine to follow a fast transient. These modifications do result in increased performance; however this study indicates that these modifications also lead to an increased risk of engine failure.

  3. Design of LPV-Based Sliding Mode Controller with Finite Time Convergence for a Morphing Aircraft

    Directory of Open Access Journals (Sweden)

    Nuan Wen

    2017-01-01

    Full Text Available This paper proposes a finite time convergence sliding mode control (FSMC strategy based on linear parameter-varying (LPV methodology for the stability control of a morphing aircraft subject to parameter uncertainties and external disturbances. Based on the Kane method, a longitudinal dynamic model of the morphing aircraft is built. Furthermore, the linearized LPV model of the aircraft in the wing transition process is obtained, whose scheduling parameters are wing sweep angle and wingspan. The FSMC scheme is developed into LPV systems by applying the previous results for linear time-invariant (LTI systems. The sufficient condition in form of linear matrix inequality (LMI constraints is derived for the existence of a reduced-order sliding mode, in which the dynamics can be ensured to keep robust stability and L2 gain performance. The tensor-product (TP model transformation approach can be directly applied to solve infinite LMIs belonging to the polynomial parameter-dependent LPV system. Then, by the parameter-dependent Lyapunov function stability analysis, the synthesized FSMC is proved to drive the LPV system trajectories toward the predefined switching surface with a finite time arrival. Comparative simulation results in the nonlinear model demonstrate the robustness and effectiveness of this approach.

  4. Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

    Science.gov (United States)

    Cox, David E.; Cunningham, Kevin; Jordan, Thomas L.

    2012-01-01

    Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented.

  5. Integrated Flight/Structural Mode Control for Very Flexible Aircraft Using L1 Adaptive Output Feedback Controller

    Science.gov (United States)

    Che, Jiaxing; Cao, Chengyu; Gregory, Irene M.

    2012-01-01

    This paper explores application of adaptive control architecture to a light, high-aspect ratio, flexible aircraft configuration that exhibits strong rigid body/flexible mode coupling. Specifically, an L(sub 1) adaptive output feedback controller is developed for a semi-span wind tunnel model capable of motion. The wind tunnel mount allows the semi-span model to translate vertically and pitch at the wing root, resulting in better simulation of an aircraft s rigid body motion. The control objective is to design a pitch control with altitude hold while suppressing body freedom flutter. The controller is an output feedback nominal controller (LQG) augmented by an L(sub 1) adaptive loop. A modification to the L(sub 1) output feedback is proposed to make it more suitable for flexible structures. The new control law relaxes the required bounds on the unmatched uncertainty and allows dependence on the state as well as time, i.e. a more general unmatched nonlinearity. The paper presents controller development and simulated performance responses. Simulation is conducted by using full state flexible wing models derived from test data at 10 different dynamic pressure conditions. An L(sub 1) adaptive output feedback controller is designed for a single test point and is then applied to all the test cases. The simulation results show that the L(sub 1) augmented controller can stabilize and meet the performance requirements for all 10 test conditions ranging from 30 psf to 130 psf dynamic pressure.

  6. Dynamics Modeling and L1 Adaptive Control of a Transport Aircraft for Heavyweight Airdrop

    Directory of Open Access Journals (Sweden)

    Ri Liu

    2015-01-01

    Full Text Available The longitudinal nonlinear aircraft model with cargo extraction is derived using theoretical mechanics and flight mechanics. Furthermore, the nonlinear model is approximated by a semilinear time-varying system with the cargo disturbances viewed as unknown nonlinearities, both matched and unmatched types. On this basis, a novel autopilot inner-loop based on the LQR and L1 adaptive theory is developed to reject the unknown nonlinear disturbances caused by the cargo and also to accommodate uncertainties. Analysis shows that the controller can guarantee robustness in the presence of fast adaptation, without exciting control signal oscillations and gain scheduling. The overall control system is completed with the outer-loop altitude-hold control based on a PID controller. Simulations are conducted under the condition that one transport aircraft performs maximum load airdrop mission at the height of 82 ft, using single row single platform mode. The results show the good performance of the control scheme, which can meet the airdrop mission performance indexes well, even in the presence of ±20% aerodynamic uncertainties.

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

    Directory of Open Access Journals (Sweden)

    Linliang Guo

    2017-04-01

    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.

  8. Active control of counter-rotating open rotor interior noise in a Dornier 728 experimental aircraft

    Science.gov (United States)

    Haase, Thomas; Unruh, Oliver; Algermissen, Stephan; Pohl, Martin

    2016-08-01

    The fuel consumption of future civil aircraft needs to be reduced because of the CO2 restrictions declared by the European Union. A consequent lightweight design and a new engine concept called counter-rotating open rotor are seen as key technologies in the attempt to reach this ambitious goals. Bearing in mind that counter-rotating open rotor engines emit very high sound pressures at low frequencies and that lightweight structures have a poor transmission loss in the lower frequency range, these key technologies raise new questions in regard to acoustic passenger comfort. One of the promising solutions for the reduction of sound pressure levels inside the aircraft cabin are active sound and vibration systems. So far, active concepts have rarely been investigated for a counter-rotating open rotor pressure excitation on complex airframe structures. Hence, the state of the art is augmented by the preliminary study presented in this paper. The study shows how an active vibration control system can influence the sound transmission of counter-rotating open rotor noise through a complex airframe structure into the cabin. Furthermore, open questions on the way towards the realisation of an active control system are addressed. In this phase, an active feedforward control system is investigated in a fully equipped Dornier 728 experimental prototype aircraft. In particular, the sound transmission through the airframe, the coupling of classical actuators (inertial and piezoelectric patch actuators) into the structure and the performance of the active vibration control system with different error sensors are investigated. It can be shown that the active control system achieves a reduction up to 5 dB at several counter-rotating open rotor frequencies but also that a better performance could be achieved through further optimisations.

  9. Structural Aspects of Flexible Aircraft Control (les Aspects structuraux du controle actif et flexible des aeronefs)

    Science.gov (United States)

    2000-05-01

    Inc. Canadair Dr. E. SANCHIZ Military Aircraft Division Div. de Estructuras y Materiales 10,000 Cargo A-4 Street Laboratorio de Diseno y Analisis...Dynamics and Aeroelasticity Department CONSTRUCCIONES AERONAUTICAS S.A. Avda John Lennon Getafe, 28906 Madrid, Spain Summary Nomenclature for modal

  10. Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

    Science.gov (United States)

    Bendrick, Gregg A.; Kamine, Tovy Haber

    2008-01-01

    Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.

  11. Non-fragile switched H∞ control for morphing aircraft with asynchronous switching

    Directory of Open Access Journals (Sweden)

    Haoyu CHENG

    2017-06-01

    Full Text Available This paper deals with the problem of non-fragile linear parameter-varying (LPV H∞ control for morphing aircraft with asynchronous switching. The switched LPV model of morphing aircraft is established by Jacobian linearization approach according to the nonlinear model. The data missing is taken into account in the link from sensors to controllers and the link from controllers to actuators, which satisfies Bernoulli distribution. The non-fragile switched LPV controllers are constructed with consideration of the uncertainties of controllers and asynchronous switching phenomenon. The parameter-dependent Lyapunov functional method and mode-dependent average dwell time (MDADT method are combined to guarantee the stability and prescribed performance of the system. The sufficient conditions on the solvability of the problem are derived in the form of linear matrix inequalities (LMI. In order to achieve higher efficiency of the designing process, an algorithm is applied to divide the whole set into subsets automatically. Simulation results are provided to verify the effectiveness and superiority of the method in the paper.

  12. Adaptive NN Control for Multisteering Plane Aircraft with Dead Zone or Backlash Input Nonlinearity

    Directory of Open Access Journals (Sweden)

    Xiang-fei Meng

    2017-01-01

    Full Text Available Considering that many factors such as actuator input dead zone, backlash, and external disturbance could affect the exactness of trajectory tracking, therewith a robust adaptive neural network control scheme on the basis of control allocation is proposed for the sake of tracking control of multisteering plane aircraft with actuator input dead zone or backlash nonlinearity. First of all, an actuator input dead zone or backlash nonlinearity control assignment model is established and the control allocation equation is derived. Secondly, the system nonlinear uncertainty is compensated by means of radial basis function neural network, and a robust term is introduced to achieve robustness against external disturbance and system errors. Finally, by utilizing Lyapunov stability theorem, 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 on ICE101 multisteering plane aircraft demonstrate the outstanding tracking performance and strong robustness as well as effectiveness of the proposed approach, which can effectively overcome the adverse influence of dead zone, backlash nonlinearity, and external disturbance on the system.

  13. Aircraft Control Using Engine Thrust: A History of Learning TOC Real-Time

    Science.gov (United States)

    Cole, Jennifer H.; Batteas, Frank; Fullerton, Gordon

    2006-01-01

    A history of learning the operation of Throttles Only Control (TOC) to control an aircraft in real time using engine thrust is shown. The topics include: 1) Past TOC Accidents/Incidents; 2) 1972: DC-10 American Airlines; 3) May 1974: USAF B-52H; 4) April 1975: USAF C-5A; 5) April 1975: USAF C-5A; 6) 1981: USAF B-52G; 7) August 1985: JAL 123 B-747; 8) JAL 123 Survivor Story; 9) JAL 123 Investigation Findings; 10) July 1989: UAL 232 DC-10; 11) UAL 232 DC-10; 12) Eastwind 517 B-737; 13) November 2003: DHL A-300; 14) Historically, TOC has saved lives; 15) Automated Throttles-Only Control; 16) PCA Project; 17) Propulsion-Controlled Aircraft; 18) MD-11 PCA System and Flight Test Envelope; 19) MD-11 Simulation, PCA ILS-Soupled Landing Dispersion; 20) Throttles-Only Pitch and Roll Control Power; 21) PCA in Commercial Fleet; 22) Fall 2005: PCAR Project; 23) PCAR Background - TOC; and 24) PCAR Background - TOC.

  14. Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base

    Science.gov (United States)

    Mcruer, Duane T.; Myers, Thomas T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design stages starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. While theory and associated computational means are an important aspect of the design methodology, the lore, knowledge and experience elements, which guide and govern applications are critical features. This material is presented as summary tables, outlines, recipes, empirical data, lists, etc., which encapsulate a great deal of expert knowledge. Much of this is presented in topical knowledge summaries which are attached as Supplements. The composite of the supplements and the main body elements constitutes a first cut at a a Mark 1 Knowledge Base for manned-aircraft flight control.

  15. Neural adaptive control for vibration suppression in composite fin-tip of aircraft.

    Science.gov (United States)

    Suresh, S; Kannan, N; Sundararajan, N; Saratchandran, P

    2008-06-01

    In this paper, we present a neural adaptive control scheme for active vibration suppression of a composite aircraft fin tip. The mathematical model of a composite aircraft fin tip is derived using the finite element approach. The finite element model is updated experimentally to reflect the natural frequencies and mode shapes very accurately. Piezo-electric actuators and sensors are placed at optimal locations such that the vibration suppression is a maximum. Model-reference direct adaptive neural network control scheme is proposed to force the vibration level within the minimum acceptable limit. In this scheme, Gaussian neural network with linear filters is used to approximate the inverse dynamics of the system and the parameters of the neural controller are estimated using Lyapunov based update law. In order to reduce the computational burden, which is critical for real-time applications, the number of hidden neurons is also estimated in the proposed scheme. The global asymptotic stability of the overall system is ensured using the principles of Lyapunov approach. Simulation studies are carried-out using sinusoidal force functions of varying frequency. Experimental results show that the proposed neural adaptive control scheme is capable of providing significant vibration suppression in the multiple bending modes of interest. The performance of the proposed scheme is better than the H(infinity) control scheme.

  16. Lyapunov-based control of limit cycle oscillations in uncertain aircraft systems

    Science.gov (United States)

    Bialy, Brendan

    Store-induced limit cycle oscillations (LCO) affect several fighter aircraft and is expected to remain an issue for next generation fighters. LCO arises from the interaction of aerodynamic and structural forces, however the primary contributor to the phenomenon is still unclear. The practical concerns regarding this phenomenon include whether or not ordnance can be safely released and the ability of the aircrew to perform mission-related tasks while in an LCO condition. The focus of this dissertation is the development of control strategies to suppress LCO in aircraft systems. The first contribution of this work (Chapter 2) is the development of a controller consisting of a continuous Robust Integral of the Sign of the Error (RISE) feedback term with a neural network (NN) feedforward term to suppress LCO behavior in an uncertain airfoil system. The second contribution of this work (Chapter 3) is the extension of the development in Chapter 2 to include actuator saturation. Suppression of LCO behavior is achieved through the implementation of an auxiliary error system that features hyperbolic functions and a saturated RISE feedback control structure. Due to the lack of clarity regarding the driving mechanism behind LCO, common practice in literature and in Chapters 2 and 3 is to replicate the symptoms of LCO by including nonlinearities in the wing structure, typically a nonlinear torsional stiffness. To improve the accuracy of the system model a partial differential equation (PDE) model of a flexible wing is derived (see Appendix F) using Hamilton's principle. Chapters 4 and 5 are focused on developing boundary control strategies for regulating the bending and twisting deformations of the derived model. The contribution of Chapter 4 is the construction of a backstepping-based boundary control strategy for a linear PDE model of an aircraft wing. The backstepping-based strategy transforms the original system to a exponentially stable system. A Lyapunov-based stability

  17. Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic

    Science.gov (United States)

    Xu, Huan

    Cyber-physical systems integrate computation, networking, and physical processes. Substantial research challenges exist in the design and verification of such large-scale, distributed sensing, actuation, and control systems. Rapidly improving technology and recent advances in control theory, networked systems, and computer science give us the opportunity to drastically improve our approach to integrated flow of information and cooperative behavior. Current systems rely on text-based specifications and manual design. Using new technology advances, we can create easier, more efficient, and cheaper ways of developing these control systems. This thesis will focus on design considerations for system topologies, ways to formally and automatically specify requirements, and methods to synthesize reactive control protocols, all within the context of an aircraft electric power system as a representative application area. This thesis consists of three complementary parts: synthesis, specification, and design. The first section focuses on the synthesis of central and distributed reactive controllers for an aircraft elec- tric power system. This approach incorporates methodologies from computer science and control. The resulting controllers are correct by construction with respect to system requirements, which are formulated using the specification language of linear temporal logic (LTL). The second section addresses how to formally specify requirements and introduces a domain-specific language for electric power systems. A software tool automatically converts high-level requirements into LTL and synthesizes a controller. The final sections focus on design space exploration. A design methodology is proposed that uses mixed-integer linear programming to obtain candidate topologies, which are then used to synthesize controllers. The discrete-time control logic is then verified in real-time by two methods: hardware and simulation. Finally, the problem of partial observability and

  18. Design of a Symmetrical Quad-rotor Biplane Tail-Sitter Aircraft without Control Surfaces and Experimental Verification

    Directory of Open Access Journals (Sweden)

    Wang Hongyu

    2018-01-01

    Full Text Available This paper presents the design of a symmetrical quad-rotor biplane tail-sitter VTOL UAV (Vertical Take-off and Landing Unmanned Aerial Vehicle which is composed of four rotors and two symmetrically mounted fixed wings. This aircraft achieves high accuracy in the attitude control and smooth flight mode transition with four rotors rather than the conventional VTOL UAVs using control surfaces. The proposal of angled rotor mounting is adopted to address the issue of insufficient yaw control authority. The layout of symmetrically mounted fixed wings makes the aircraft have capability of rapid bidirectional flight mode transition to improve maneuverability. To validate the performance of the aircraft, simulation and flight experiments are both implemented. These results show that the aircraft has a rapid yaw response under condition of the stable attitude control. In comparative experiment, it is shown that the aircraft is more flexible than other similar configuration of aircrafts. This symmetrical quad-rotor biplane tail-sitter VTOL UAV will have a wide range of potential applications in the military and civilian areas due to its superior performance..

  19. Nonlinear stability and control study of highly maneuverable high performance aircraft, phase 2

    Science.gov (United States)

    Mohler, R. R.

    1992-01-01

    This research should lead to the development of new nonlinear methodologies for the adaptive control and stability analysis of high angle-of-attack aircraft such as the F18 (HARV). The emphasis has been on nonlinear adaptive control, but associated model development, system identification, stability analysis and simulation is performed in some detail as well. Various models under investigation for different purposes are summarized in tabular form. Models and simulation for the longitudinal dynamics have been developed for all types except the nonlinear ordinary differential equation model. Briefly, studies completed indicate that nonlinear adaptive control can outperform linear adaptive control for rapid maneuvers with large changes in alpha. The transient responses are compared where the desired alpha varies from 5 degrees to 60 degrees to 30 degrees and back to 5 degrees in all about 16 sec. Here, the horizontal stabilator is the only control used with an assumed first-order linear actuator with a 1/30 sec time constant.

  20. Application of modern control design methodology to oblique wing research aircraft

    Science.gov (United States)

    Vincent, James H.

    1991-01-01

    A Linear Quadratic Regulator synthesis technique was used to design an explicit model following control system for the Oblique Wing Research Aircraft (OWRA). The forward path model (Maneuver Command Generator) was designed to incorporate the desired flying qualities and response decoupling. The LQR synthesis was based on the use of generalized controls, and it was structured to provide a proportional/integral error regulator with feedforward compensation. An unexpected consequence of this design approach was the ability to decouple the control synthesis into separate longitudinal and lateral directional designs. Longitudinal and lateral directional control laws were generated for each of the nine design flight conditions, and gain scheduling requirements were addressed. A fully coupled 6 degree of freedom open loop model of the OWRA along with the longitudinal and lateral directional control laws was used to assess the closed loop performance of the design. Evaluations were performed for each of the nine design flight conditions.

  1. Agent-based Cyber Control Strategy Design for Resilient Control Systems: Concepts, Architecture and Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Craig Rieger; Milos Manic; Miles McQueen

    2012-08-01

    The implementation of automated regulatory control has been around since the middle of the last century through analog means. It has allowed engineers to operate the plant more consistently by focusing on overall operations and settings instead of individual monitoring of local instruments (inside and outside of a control room). A similar approach is proposed for cyber security, where current border-protection designs have been inherited from information technology developments that lack consideration of the high-reliability, high consequence nature of industrial control systems. Instead of an independent development, however, an integrated approach is taken to develop a holistic understanding of performance. This performance takes shape inside a multiagent design, which provides a notional context to model highly decentralized and complex industrial process control systems, the nervous system of critical infrastructure. The resulting strategy will provide a framework for researching solutions to security and unrecognized interdependency concerns with industrial control systems.

  2. Dynamics modeling and control of a transport aircraft for ultra-low altitude airdrop

    Directory of Open Access Journals (Sweden)

    Liu Ri

    2015-04-01

    Full Text Available The nonlinear aircraft model with heavy cargo moving inside is derived by using the separation body method, which can describe the influence of the moving cargo on the aircraft attitude and altitude accurately. Furthermore, the nonlinear system is decoupled and linearized through the input–output feedback linearization method. On this basis, an iterative quasi-sliding mode (SM flight controller for speed and pitch angle control is proposed. At the first-level SM, a global dynamic switching function is introduced thus eliminating the reaching phase of the sliding motion. At the second-level SM, a nonlinear function with the property of “smaller errors correspond to bigger gains and bigger errors correspond to saturated gains” is designed to form an integral sliding manifold, and the overcompensation of the integral term to big errors is weakened. Lyapunov-based analysis shows that the controller with strong robustness can reject both constant and time-varying model uncertainties. The performance of the proposed control strategy is verified in a maximum load airdrop mission.

  3. Projection-Based Adaptive Backstepping Control of a Transport Aircraft for Heavyweight Airdrop

    Directory of Open Access Journals (Sweden)

    Ri Liu

    2015-01-01

    Full Text Available An autopilot inner loop that combines backstepping control with adaptive function approximation is developed for airdrop operations. The complex nonlinear uncertainty of the aircraft-cargo model is factorized into a known matrix and an uncertainty function, and a projection-based adaptive approach is proposed to estimate this function. Using projection in the adaptation law bounds the estimated function and guarantees the robustness of the controller against time-varying external disturbances and uncertainties. The convergence properties and robustness of the control method are proved via Lyapunov theory. Simulations are conducted under the condition that one transport aircraft performs a maximum load airdrop task at a height of 82 ft, using single row single platform mode. The results show good performance and robust operation of the controller, and the airdrop mission performance indexes are satisfied, even in the presence of ±15% uncertainty in the aerodynamic coefficients, ±0.01 rad/s pitch rate disturbance, and 20% actuators faults.

  4. Robust active noise control in the loadmaster area of a military transport aircraft.

    Science.gov (United States)

    Kochan, Kay; Sachau, Delf; Breitbach, Harald

    2011-05-01

    The active noise control (ANC) method is based on the superposition of a disturbance noise field with a second anti-noise field using loudspeakers and error microphones. This method can be used to reduce the noise level inside the cabin of a propeller aircraft. However, during the design process of the ANC system, extensive measurements of transfer functions are necessary to optimize the loudspeaker and microphone positions. Sometimes, the transducer positions have to be tailored according to the optimization results to achieve a sufficient noise reduction. The purpose of this paper is to introduce a controller design method for such narrow band ANC systems. The method can be seen as an extension of common transducer placement optimization procedures. In the presented method, individual weighting parameters for the loudspeakers and microphones are used. With this procedure, the tailoring of the transducer positions is replaced by adjustment of controller parameters. Moreover, the ANC system will be robust because of the fact that the uncertainties are considered during the optimization of the controller parameters. The paper describes the necessary theoretic background for the method and demonstrates the efficiency in an acoustical mock-up of a military transport aircraft.

  5. Planform, aero-structural, and flight control optimization for tailless morphing aircraft

    Science.gov (United States)

    Molinari, Giulio; Arrieta, Andres F.; Ermanni, Paolo

    2015-04-01

    Tailless airplanes with swept wings rely on variations of the spanwise lift distribution to provide controllability in roll, pitch and yaw. Conventionally, this is achieved utilizing multiple control surfaces, such as elevons, on the wing trailing edge. As every flight condition requires different control moments (e.g. to provide pitching moment equilibrium), these surfaces are practically permanently displaced. Due to their nature, causing discontinuities, corners and gaps, they bear aerodynamic penalties, mostly in terms of shape drag. Shape adaptation, by means of chordwise morphing, has the potential of varying the lift of a wing section by deforming its profile in a way that minimizes the resulting drag. Furthermore, as the shape can be varied differently along the wingspan, the lift distribution can be tailored to each specific flight condition. For this reason, tailless aircraft appear as a prime choice to apply morphing techniques, as the attainable benefits are potentially significant. In this work, we present a methodology to determine the optimal planform, profile shape, and morphing structure for a tailless aircraft. The employed morphing concept is based on a distributed compliance structure, actuated by Macro Fiber Composite (MFC) piezoelectric elements. The multidisciplinary optimization is performed considering the static and dynamic aeroelastic behavior of the resulting structure. The goal is the maximization of the aerodynamic efficiency while guaranteeing the controllability of the plane, by means of morphing, in a set of flight conditions.

  6. Flow visualization of the wake of a transport aircraft model with lateral-control oscillations

    Science.gov (United States)

    Jordan, F. L., Jr.

    1983-01-01

    An exploratory flow visualization study conducted in the Langley Vortex Research Facility to investigate the effectiveness of lateral control surface oscillations as a potential method for wake vortex attenuation on a 0.03 scale model of a wide body jet transport aircraft is described. Effects of both asymmetric surface oscillation (control surfaces move as with normal lateral control inputs) and symmetric surface oscillation (control surfaces move in phase) are presented. The asymmetric case simulated a flight maneuver which was previously investigated on the transport aircraft during NASA/FAA flight tests and which resulted in substantial wake vortex attenuation. Effects on the model wake vortex systems were observed by propelling the model through a two dimensional smoke screen perpendicular to the model flight path. Results are presented as photographic time histories of the wake characteristics recorded with high speed still cameras. Effects of oscillation on the wake roll up are described in some detail, and the amount of vortex attenuation observed is discussed in comparative terms. Findings were consistent with flight test results in that only a small amount of rotation was observed in the wake for the asymmetric case. A possible aerodynamic mechanism contributing to this attenuation is suggested.

  7. Modal control theory and application to aircraft lateral handling qualities design

    Science.gov (United States)

    Srinathkumar, S.

    1978-01-01

    A multivariable synthesis procedure based on eigenvalue/eigenvector assignment is reviewed and is employed to develop a systematic design procedure to meet the lateral handling qualities design objectives of a fighter aircraft over a wide range of flight conditions. The closed loop modal characterization developed provides significant insight into the design process and plays a pivotal role in the synthesis of robust feedback systems. The simplicity of the synthesis algorithm yields an efficient computer aided interactive design tool for flight control system synthesis.

  8. Analytical study of interior noise control by fuselage design techniques on high-speed, propeller-driven aircraft

    Science.gov (United States)

    Revell, J. D.; Balena, F. J.; Koval, L. R.

    1980-01-01

    The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW.

  9. Tiltrotor noise reduction through flight trajectory management and aircraft configuration control

    Science.gov (United States)

    Gervais, Marc

    A tiltrotor can hover, takeoff and land vertically as well as cruise at high speeds and fly long distances. Because of these unique capabilities, tiltrotors are envisioned as an aircraft that could provide a solution to the issue of airport gridlock by operating on stub runways, helipads, or from smaller regional airports. However, during an approach-to-land a tiltrotor is susceptible to radiating strong impulsive noise, in particular, Blade-Vortex Interaction noise (BVI), a phenomenon highly dependent on the vehicle's performance-state. A mathematical model was developed to predict the quasi-static performance characteristics of a tiltrotor during a converting approach in the longitudinal plane. Additionally, a neural network was designed to model the acoustic results from a flight test of the XV-15 tiltrotor as a function of the aircraft's performance parameters. The performance model was linked to the neural network to yield a combined performance/acoustic model that is capable of predicting tiltrotor noise emitted during a decelerating approach. The model was then used to study noise trends associated with different combinations of airspeed, nacelle tilt, and flight path angle. It showed that BVI noise is the dominant noise source during a descent and that its strength increases with steeper descent angles. Strong BVI noise was observed at very steep flight path angles, suggesting that the tiltrotor's high downwash prevents the wake from being pushed above the rotor, even at such steep descent angles. The model was used to study the effects of various aircraft configuration and flight trajectory parameters on the rotor inflow, which adequately captured the measured BVI noise trends. Flight path management effectively constrained the rotor inflow during a converting approach and thus limited the strength of BVI noise. The maximum deceleration was also constrained by controlling the nacelle tilt-rate during conversion. By applying these constraints, low BVI noise

  10. An Optimal Augmented Monotonic Tracking Controller for Aircraft Engines with Output Constraints

    Directory of Open Access Journals (Sweden)

    Jiakun Qin

    2017-01-01

    Full Text Available This paper proposes a novel min-max control scheme for aircraft engines, with the aim of transferring a set of regulated outputs between two set-points, while ensuring a set of auxiliary outputs remain within prescribed constraints. In view of this, an optimal augmented monotonic tracking controller (OAMTC is proposed, by considering a linear plant with input integration, to enhance the ability of the control system to reject uncertainty in system parameters and ensure no crossing limits. The key idea is to use the eigenvalue and eigenvector placement method and genetic algorithms to shape the output responses. The approach is validated by numerical simulation. The results show that the designed OAMTC controller can achieve a satisfactory dynamic and steady performance and keep the auxiliary outputs within constraints in the transient regime.

  11. Aircraft Loss-of-Control: Analysis and Requirements for Future Safety-Critical Systems and Their Validation

    Science.gov (United States)

    Belcastro, Christine M.

    2011-01-01

    Loss of control remains one of the largest contributors to fatal aircraft accidents worldwide. Aircraft loss-of-control accidents are complex, resulting from numerous causal and contributing factors acting alone or more often in combination. Hence, there is no single intervention strategy to prevent these accidents. This paper summarizes recent analysis results in identifying worst-case combinations of loss-of-control accident precursors and their time sequences, a holistic approach to preventing loss-of-control accidents in the future, and key requirements for validating the associated technologies.

  12. Moving-Base Simulation Evaluation of Control/Display Integration Issues for ASTOVL Aircraft

    Science.gov (United States)

    Franklin, James A.

    1997-01-01

    A moving-base simulation has been conducted on the Vertical Motion Simulator at Ames Research Center using a model of an advanced, short takeoff and vertical landing (STOVL) lift fan fighter aircraft. This experiment expanded on investigations during previous simulations with this STOVL configuration with the objective of evaluating (1) control law modifications over the low speed flight envelope, (2) integration of the throttle inceptor with flight control laws that provide direct thrust command for conventional flight, vertical and short takeoff, and flightpath or vertical velocity command for transition, hover, and vertical landing, (3) control mode blending for pitch, roll, yaw, and flightpath control during transition from wing-borne to jet-borne flight, and (4) effects of conformal versus nonconformal presentation of flightpath and pursuit guidance symbology on the out-the-window display for low speed STOVL operations. Assessments were made for takeoff, transition, hover, and landing, including precision hover and landing aboard an LPH-type amphibious assault ship in the presence of winds and rough seas. Results yielded Level 1 pilot ratings for the flightpath and vertical velocity command modes for a range of land-based and shipboard operation and were consistent with previous experience with earlier control laws and displays for this STOVL concept. Control mode blending was performed over speed ranges in accord with the pilot's tasks and with the change of the basic aircraft's characteristics between wing-borne and hover flight. Blending of yaw control from heading command in hover to sideslip command in wing-borne flight performed over a broad speed range helped reduce yaw transients during acceleration through the low speed regime. Although the pilots appreciated conformality of flightpath and guidance symbols with the external scene during the approach, increased sensitivity of the symbols for lateral path tracking elevated the pilots' control activity

  13. Intelligent Materials Used in Hydraulic, Fuel, and Rudder Control Systems of Aircrafts

    Directory of Open Access Journals (Sweden)

    D. B. Chernov

    2017-01-01

    Full Text Available The device is really intelligent, only if it is capable to respond to changing external conditions. The devices, which "feel" the external environment and can change their characteristics, have many advantages compared to the conventional devices: they are more efficient, wear out more slowly, and have lower operating costs.The scope of smart products is truly infinite. Alloys with memory effect also apply to intellectual content. Natural piezoelectric crystals such as silicon dioxide (intellectual material have been known for over a hundred years. They have greater stiffness and can be used at high operating frequencies. Due to the direct piezoelectric effect, they have been successfully used as a strain gage. Later came artificial ceramic piezoelectric materials; they are used as mechanical transducers. Thus, an inverse piezoelectric effect is usually used. It consists in the change of dimensions when an electric field is applied. Control of intellectual structure can be provided by heat fluxes, electromagnetic, hydraulic or piezoelectric forces and through application of electro-rheological, and magneto-rheological fluids. The article examines the intellectual materials and technologies that are already in place or will find its application in aviation hydraulic and fuel systems and control systems of rudders (CSR of aircrafts in the near future.The paper considers in detail the shape memory effect alloys (SMEA as "intelligent" materials. Actuators made from SMEA have a number of advantages: high working power; large recoverable deformation; different types of strain (tensile, compressive, bending and torsional; most specific value of the work per unit mass. All the SMEA advantages may be well used for the so-called thermo-mechanical connections (TMС of pipelines where SMEA drawbacks in this application, practically, do not affect the quality of TMC. In aircraft engineering the TMC were first used in hydraulic systems of the aircraft TU204

  14. Understanding Resilience

    Directory of Open Access Journals (Sweden)

    Gang eWu

    2013-02-01

    Full Text Available Resilience is the ability to adapt successfully in the face of stress and adversity. Stressful life events, trauma and chronic adversity can have a substantial impact on brain function and structure, and can result in the development of PTSD, depression and other psychiatric disorders. However, most individuals do not develop such illnesses after experiencing stressful life events, and are thus thought to be resilient. Resilience as successful adaptation relies on effective responses to environmental challenges and ultimate resistance to the deleterious effects of stress, therefore a greater understanding of the factors that promote such effects is of great relevance. This review focuses on recent findings regarding genetic, epigenetic, developmental, psychosocial and neurochemical factors that are considered essential contributors to the development of resilience. Neural circuits and pathways involved in mediating resilience are also discussed. The growing understanding of resilience factors will hopefully lead to the development of new pharmacological and psychological interventions for enhancing resilience and mitigating the untoward consequences.

  15. An Enhanced Droop Control Scheme for Resilient Active Power Sharing in Paralleled Two-Stage PV Inverter Systems

    DEFF Research Database (Denmark)

    Liu, Hongpeng; Yang, Yongheng; Wang, Xiongfei

    2016-01-01

    generation) due to the intermittency. In that case, unbalance in active power generation may occur among the paralleled systems. Additionally, most droop-controlled systems have been assumed to be a single dc-ac inverter with a fixed dc input source. The dc-dc converter as the front-end of a two......-stage photovoltaic (PV) system has not been considered. In this paper, an enhanced droop scheme is thus proposed to address those issues, and the proposed scheme can enable resilient active power sharing in parallel two-stage PV inverter systems. Furthermore, a small-signal analysis for the proposed droop control...

  16. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    Science.gov (United States)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1996-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  17. Adaptive Neural Network Sliding Mode Control for Quad Tilt Rotor Aircraft

    Directory of Open Access Journals (Sweden)

    Yanchao Yin

    2017-01-01

    Full Text Available A novel neural network sliding mode control based on multicommunity bidirectional drive collaborative search algorithm (M-CBDCS is proposed to design a flight controller for performing the attitude tracking control of a quad tilt rotors aircraft (QTRA. Firstly, the attitude dynamic model of the QTRA concerning propeller tension, channel arm, and moment of inertia is formulated, and the equivalent sliding mode control law is stated. Secondly, an adaptive control algorithm is presented to eliminate the approximation error, where a radial basis function (RBF neural network is used to online regulate the equivalent sliding mode control law, and the novel M-CBDCS algorithm is developed to uniformly update the unknown neural network weights and essential model parameters adaptively. The nonlinear approximation error is obtained and serves as a novel leakage term in the adaptations to guarantee the sliding surface convergence and eliminate the chattering phenomenon, which benefit the overall attitude control performance for QTRA. Finally, the appropriate comparisons among the novel adaptive neural network sliding mode control, the classical neural network sliding mode control, and the dynamic inverse PID control are examined, and comparative simulations are included to verify the efficacy of the proposed control method.

  18. An integrated strategy for aircraft/airport noise abatement: A legal-institutional control act section 7 to the noise control act of 1972 and proposals based thereon

    Science.gov (United States)

    Mayo, L. H.

    1975-01-01

    The development of the aircraft noise control structure since the Griggs case of 1962 was examined. The Noise Control Act of 1972 is described which undertook to establish the legal-institutional framework within which an adequate aircraft/airport noise abatement program might be initiated with concern for full recognition of all the beneficial and detrimental consequences of air transportation and appropriate distribution of benefits and costs.

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

    CERN Document Server

    Hansson, Anders; Puyou, Guilhem

    2012-01-01

    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...

  20. Active Structural Acoustic Control in an Original A400M Aircraft Structure

    International Nuclear Information System (INIS)

    Koehne, C; Sachau, D; Renger, K

    2016-01-01

    Low frequency noise has always been a challenge in propeller driven aircraft. At low frequencies passive noise treatments are not as efficient as active noise reduction systems. The Helmut-Schmidt-University has built up a full-scale test rig with an original A400M aircraft structure. This provides a good opportunity to develop and test active noise reduction systems in a realistic environment. The currently installed system consists of mechanical actuators and acoustical sensors. The actuators are called TVAs (Tuneable Vibration Absorber) and contain two spring-mass systems whose natural frequencies are adjusted to the BPFs (Blade Passage Frequency) of the propellers. The TVAs are mounted to the frames and the force direction is normal to the skin. The sensors are condenser microphones which are attached to the primary structure of the airframe. The TVAs are equipped with signal processing devices. These components carry out Fourier transforms and signal amplification for the sensor data and actuator signals. The communication between the TVAs and the central control unit is implemented by the CAN Bus protocol and mainly consists of complex coefficients for the sensor and actuator data. This paper describes the basic structure of the system, the hardware set-up and function tests of the controller. (paper)

  1. Thermal Characterization of Defects in Aircraft Structures Via Spatially Controlled Heat Application

    Science.gov (United States)

    Cramer, K. Elliott; Winfree, William P.

    1997-01-01

    Recent advances in thermal imaging technology have spawned a number of new thermal NDE techniques that provide quantitative information about flaws in aircraft structures. Thermography has a number of advantages as an inspection technique. It is a totally noncontacting, nondestructive, imaging technology capable of inspecting a large area in a matter of a few seconds. The development of fast, inexpensive image processors have aided in the attractiveness of thermography as an NDE technique. These image processors have increased the signal to noise ratio of thermography and facilitated significant advances in post-processing. The resulting digital images enable archival records for comparison with later inspections thus providing a means of monitoring the evolution of damage in a particular structure. The National Aeronautics and Space Administration's Langley Research Center has developed a thermal NDE technique designed to image a number of potential flaws in aircraft structures. The technique involves injecting a small, spatially controlled heat flux into the outer surface of an aircraft. Images of fatigue cracking, bond integrity and material loss due to corrosion are generated from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to analyze the resulting thermal images. Spatial tailoring of the heat coupled with the analysis techniques represent a significant improvement in the delectability of flaws over conventional thermal imaging. Results of laboratory experiments on fabricated crack, disbond and material loss samples will be presented to demonstrate the capabilities of the technique. An integral part of the development of this technology is the use of analytic and computational modeling. The experimental results will be compared with these models to demonstrate the utility of such an approach.

  2. Intelligent adaptive nonlinear flight control for a high performance aircraft with neural networks.

    Science.gov (United States)

    Savran, Aydogan; Tasaltin, Ramazan; Becerikli, Yasar

    2006-04-01

    This paper describes the development of a neural network (NN) based adaptive flight control system for a high performance aircraft. The main contribution of this work is that the proposed control system is able to compensate the system uncertainties, adapt to the changes in flight conditions, and accommodate the system failures. The underlying study can be considered in two phases. The objective of the first phase is to model the dynamic behavior of a nonlinear F-16 model using NNs. Therefore a NN-based adaptive identification model is developed for three angular rates of the aircraft. An on-line training procedure is developed to adapt the changes in the system dynamics and improve the identification accuracy. In this procedure, a first-in first-out stack is used to store a certain history of the input-output data. The training is performed over the whole data in the stack at every stage. To speed up the convergence rate and enhance the accuracy for achieving the on-line learning, the Levenberg-Marquardt optimization method with a trust region approach is adapted to train the NNs. The objective of the second phase is to develop intelligent flight controllers. A NN-based adaptive PID control scheme that is composed of an emulator NN, an estimator NN, and a discrete time PID controller is developed. The emulator NN is used to calculate the system Jacobian required to train the estimator NN. The estimator NN, which is trained on-line by propagating the output error through the emulator, is used to adjust the PID gains. The NN-based adaptive PID control system is applied to control three angular rates of the nonlinear F-16 model. The body-axis pitch, roll, and yaw rates are fed back via the PID controllers to the elevator, aileron, and rudder actuators, respectively. The resulting control system has learning, adaptation, and fault-tolerant abilities. It avoids the storage and interpolation requirements for the too many controller parameters of a typical flight control

  3. Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

    Science.gov (United States)

    Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

    2016-06-01

    Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

  4. An experimental study of concurrent methods for adaptively controlling vertical tail buffet in high performance aircraft

    Science.gov (United States)

    Roberts, Patrick J.

    High performance twin-tail aircraft, like the F-15 and F/A-18, encounter a condition known as tail buffet. At high angles of attack, vortices are generated at the wing fuselage interface (shoulder) or other leading edge extensions. These vortices are directed toward the twin vertical tails. When the flow interacts with the vertical tail it creates pressure variations that can oscillate the vertical tail assembly. This results in fatigue cracks in the vertical tail assembly that can decrease the fatigue life and increase maintenance costs. Recently, an offset piezoceramic stack actuator was used on an F-15 wind tunnel model to control buffet induced vibrations at high angles of attack. The controller was based on the acceleration feedback control methods, In this thesis a procedure for designing the offset piezoceramic stack actuators is developed. This design procedure includes determining the quantity and type of piezoceramic stacks used in these actuators. The changes of stresses, in the vertical tail caused by these actuators during an active control, are investigated. In many cases, linear controllers are very effective in reducing vibrations. However, during flight, the natural frequencies of the vertical tail structural system changes as the airspeed increases. This in turn, reduces the effectiveness of a linear controller. Other causes such as the unmodeled dynamics and nonlinear effects due to debonds also reduce the effectiveness of linear controllers. In this thesis, an adaptive neural network is used to augment the linear controller to correct these effects.

  5. The Development of Human Factor Guidelines for Unmanned Aircraft System Control Stations

    Science.gov (United States)

    Hobbs, Alan

    2014-01-01

    Despite being referred to as unmanned some of the major challenges confronting unmanned aircraft systems (UAS) relate to human factors. NASA is conducting research to address the human factors relevant to UAS access to non-segregated airspace. This work covers the issues of pilot performance, interaction with ATC, and control station design. A major outcome of this research will be recommendations for human factors design guidelines for UAS control stations to support routine beyond-line-of-sight operations in the US national airspace system (NAS). To be effective, guidelines must be relevant to a wide range of systems, must not be overly prescriptive, and must not impose premature standardization on evolving technologies. In developing guidelines, we recognize that existing regulatory and guidance material may already provide adequate coverage of certain issues. In other cases suitable guidelines may be found in existing military or industry human factors standards. In cases where appropriate existing standards cannot be identified, original guidelines will be proposed.

  6. Preliminary control law and hardware designs for a ride quality augmentation system for commuter aircraft. Phase 2

    Science.gov (United States)

    Davis, D. J.; Linse, D. J.; Suikat, R.; Entz, D. P.

    1986-01-01

    The continued investigation of the design of Ride Quality Augmentation Systems (RQAS) for commuter aircraft is described. The purpose of these RQAS is the reduction of the vertical and lateral acceleration response of the aircraft due to atmospheric turbulence by the application of active control. The current investigations include the refinement of the sample data feedback control laws based on the control-rate-weighting and output-weighting optimal control design techniqes. These control designs were evaluated using aircraft time simulations driven by Dryden spectra turbulence. Fixed gain controllers were tested throughout the aircrft operating envelope. The preliminary design of the hardware modifications necessary to implement and test the RQAS on a commuter aircraft is included. These include a separate surface elevator and the flap modifications to provide both direct lift and roll control. A preliminary failure mode investigation was made for the proposed configuration. The results indicate that vertical acceleration reductions of 45% and lateral reductions of more than 50% are possible. A fixed gain controller appears to be feasible with only minor response degradation.

  7. FEATURES of NON-DESTRUCTIVE damage CONTROL OF aircraft parts made of composite MATERIALS at the enterprises of aviation industry

    Directory of Open Access Journals (Sweden)

    A. V. Kopylov

    2014-01-01

    Full Text Available The article describes the urgent problems which can arise at enterprises of aviation industries by the operating air during non-destructive damage control of products made of composite materials used in aircraft. The methods of control are very specific due to have a number of peculiarities in detecting damages in view of the complicated composite materials structure.

  8. A Distributed Resilient Autonomous Framework for Manned/Unmanned Trajectory-Based Operations, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Resilient Ops, working in collaboration with Metron Aviation, Inc., proposes to develop a prototype system for planning Unmanned Aircraft Systems (UAS) trajectories...

  9. Resilient ledelse

    OpenAIRE

    Rygh, Bjørn

    2015-01-01

    Master i styring og ledelse Denne masteroppgaven bygger på litteraturanalyse og intervju med forskere, lederutviklere, ledere og tillitsvalgte. Oppgaven utvikler en hypotese om en resilient lederstil, diskuterer om og hvordan ledere kan bidra til å bedre resiliens hos underordnede, samt identifiserer hva som kan kjennetegne resilient ledelse. Resilient ledelse kan defineres som det en leder gjør for å bedre de underordnedes evne til å få mer psykologisk motstandskraft, det vil si gjør d...

  10. NASA Unmanned Aircraft (UA) Control and Non-Payload Communication (CNPC) System Waveform Trade Studies

    Science.gov (United States)

    Chavez, Carlos; Hammel, Bruce; Hammel, Allan; Moore, John R.

    2014-01-01

    Unmanned Aircraft Systems (UAS) represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the National Airspace System (NAS). To address this deficiency, NASA has established a project called UAS Integration in the NAS (UAS in the NAS), under the Integrated Systems Research Program (ISRP) of the Aeronautics Research Mission Directorate (ARMD). This project provides an opportunity to transition concepts, technology, algorithms, and knowledge to the Federal Aviation Administration (FAA) and other stakeholders to help them define the requirements, regulations, and issues for routine UAS access to the NAS. The safe, routine, and efficient integration of UAS into the NAS requires new radio frequency (RF) spectrum allocations and a new data communications system which is both secure and scalable with increasing UAS traffic without adversely impacting the Air Traffic Control (ATC) communication system. These data communications, referred to as Control and Non-Payload Communications (CNPC), whose purpose is to exchange information between the unmanned aircraft and the ground control station to ensure safe, reliable, and effective unmanned aircraft flight operation. A Communications Subproject within the UAS in the NAS Project has been established to address issues related to CNPC development, certification and fielding. The focus of the Communications Subproject is on validating and allocating new RF spectrum and data link communications to enable civil UAS integration into the NAS. The goal is to validate secure, robust data links within the allocated frequency spectrum for UAS. A vision, architectural concepts, and seed requirements for the future commercial UAS CNPC system have been developed by RTCA Special Committee 203 (SC-203) in the process

  11. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    Science.gov (United States)

    Crider, Dennis; Foster, John V.

    2012-01-01

    In-flight loss of control remains the leading contributor to aviation accident fatalities, with stall upsets being the leading causal factor. The February 12, 2009. Colgan Air, Inc., Continental Express flight 3407 accident outside Buffalo, New York, brought this issue to the forefront of public consciousness and resulted in recommendations from the National Transportation Safety Board to conduct training that incorporates stalls that are fully developed and develop simulator standards to support such training. In 2010, Congress responded to this accident with Public Law 11-216 (Section 208), which mandates full stall training for Part 121 flight operations. Efforts are currently in progress to develop recommendations on implementation of stall training for airline pilots. The International Committee on Aviation Training in Extended Envelopes (ICATEE) is currently defining simulator fidelity standards that will be necessary for effective stall training. These recommendations will apply to all civil transport aircraft including straight-wing turboprop aircraft. Government-funded research over the previous decade provides a strong foundation for stall/post-stall simulation for swept-wing, conventional tail jets to respond to this mandate, but turboprops present additional and unique modeling challenges. First among these challenges is the effect of power, which can provide enhanced flow attachment behind the propellers. Furthermore, turboprops tend to operate for longer periods in an environment more susceptible to ice. As a result, there have been a significant number of turboprop accidents as a result of the early (lower angle of attack) stalls in icing. The vulnerability of turboprop configurations to icing has led to studies on ice accumulation and the resulting effects on flight behavior. Piloted simulations of these effects have highlighted the important training needs for recognition and mitigation of icing effects, including the reduction of stall margins

  12. Active vibration control by piezoceramic actuators on a jet aircraft partial frame structure

    Science.gov (United States)

    Lecce, Leonardo; Viscardi, Massimo; Cantoni, Stefania

    1996-04-01

    During the last five years, the Dept. of Aeronautical Engineering of the University of Naples, has carried out a lot of work, especially on the experimental side, focused on assessing the feasibility of an active vibration and noise control approach, based on the use of piezoceramic actuators and sensors bonded to different structural elements. This paper concerns an application of this technique relative to a partially curved stiff frame of a medium civil transport jet aircraft. The general procedure, as previously assessed on different test articles, requires as first step, the dynamic characterization of the test article, to best point out the target of control procedure in terms of deformed shapes relative to the frequency of most interest. The use of PZT piezoactuators to be bonded on the structure guarantee at the same time high actuators forces in front of a low weight increment. The hearth of the MIMO (Multi Input Multi Output) feedforward control algorithm that is usually applied, is then represented by an ANN (Artificial Neural Network) control algorithm that use the evaluation of experimental FRF as measured by reference accelerometer, to calculate the optimum control forces to be applied to the actuators to minimize a target cost function. Experimental results provided over 32 dB of overall vibration level reduction in a single controlled mode shape, without any spillover effect.

  13. Resilience versus "Resilient Individual": What Exactly Do We Study?

    Directory of Open Access Journals (Sweden)

    Jan Sebastian Novotný

    2014-07-01

    Full Text Available The nature and definition of resilience, despite the extensive 40 years of research, is still unclear. Currently is resilience seen as a personality trait, sum of the traits/factors, result of adaptation, or as a process. The concept of resilience as personality traits is usually tied to uni-dimensional or "simplex" theories of resistance as Hardiness, Sense of Control, Ego-Resiliency, Self-efficacy, Sense of Coherence, or specific personality traits. Multidimensional concepts see resilience as a complex of personality and social (environmental factors that work in interaction, complement or replace each other, and, in aggregate, create a comprehensive picture of resilience. The concept of resilience as the result of adaptation examines resilience in terms of the presence/absence of adverse/pathological manifestations, consequences and outcomes in relation to the earlier effect of stressful, risky or otherwise unfavorable situations. Finally, the concept of resilience as the process examines individual's response to risk factors or wounds that are present in the environment. Resilience is thus a process consisting of interactions between individual characteristics and the environment. Most experts and a large part of resilience research is based on the first three concepts that however explore how "resilient" the individual is rather than resilience itself, since they are based on "diagnosing" or at best dimensional, at worse dichotomous rating of the individual's resilience (within personality trait approach, or on the evaluation of the presence/absence of factors/source of resilience, thereby they are still holding the "diagnostic" approach (within multidimensional approach. Only the examination of processes, such as the ongoing interaction between these risk factors, resilience factors, outcomes (expressions of personality, behavior, presence of problems, etc. and other variables allows us to understand resilience (the true nature of how

  14. Validation of Safety-Critical Systems for Aircraft Loss-of-Control Prevention and Recovery

    Science.gov (United States)

    Belcastro, Christine M.

    2012-01-01

    Validation of technologies developed for loss of control (LOC) prevention and recovery poses significant challenges. Aircraft LOC can result from a wide spectrum of hazards, often occurring in combination, which cannot be fully replicated during evaluation. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of hazardous and uncertain conditions, and the validation framework must provide some measure of assurance that the new vehicle safety technologies do no harm (i.e., that they themselves do not introduce new safety risks). This paper summarizes a proposed validation framework for safety-critical systems, provides an overview of validation methods and tools developed by NASA to date within the Vehicle Systems Safety Project, and develops a preliminary set of test scenarios for the validation of technologies for LOC prevention and recovery

  15. Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

    Self-tuning aircraft engine models can be applied for control and health management applications. The self-tuning feature of these models minimizes the mismatch between any given engine and the underlying engineering model describing an engine family. This paper provides details of the construction of a self-tuning engine model centered on a piecewise linear Kalman filter design. Starting from a nonlinear transient aerothermal model, a piecewise linear representation is first extracted. The linearization procedure creates a database of trim vectors and state-space matrices that are subsequently scheduled for interpolation based on engine operating point. A series of steady-state Kalman gains can next be constructed from a reduced-order form of the piecewise linear model. Reduction of the piecewise linear model to an observable dimension with respect to available sensed engine measurements can be achieved using either a subset or an optimal linear combination of "health" parameters, which describe engine performance. The resulting piecewise linear Kalman filter is then implemented for faster-than-real-time processing of sensed engine measurements, generating outputs appropriate for trending engine performance, estimating both measured and unmeasured parameters for control purposes, and performing on-board gas-path fault diagnostics. Computational efficiency is achieved by designing multidimensional interpolation algorithms that exploit the shared scheduling of multiple trim vectors and system matrices. An example application illustrates the accuracy of a self-tuning piecewise linear Kalman filter model when applied to a nonlinear turbofan engine simulation. Additional discussions focus on the issue of transient response accuracy and the advantages of a piecewise linear Kalman filter in the context of validation and verification. The techniques described provide a framework for constructing efficient self-tuning aircraft engine models from complex nonlinear

  16. Adaptive Neural Control Based on High Order Integral Chained Differentiator for Morphing Aircraft

    Directory of Open Access Journals (Sweden)

    Zhonghua Wu

    2015-01-01

    Full Text Available This paper presents an adaptive neural control for the longitudinal dynamics of a morphing aircraft. Based on the functional decomposition, it is reasonable to decompose the longitudinal dynamics into velocity and altitude subsystems. As for the velocity subsystem, the adaptive control is proposed via dynamic inversion method using neural network. To deal with input constraints, the additional compensation system is employed to help engine recover from input saturation rapidly. The highlight is that high order integral chained differentiator is used to estimate the newly defined variables and an adaptive neural controller is designed for the altitude subsystem where only one neural network is employed to approximate the lumped uncertain nonlinearity. The altitude subsystem controller is considerably simpler than the ones based on backstepping. It is proved using Lyapunov stability theory that the proposed control law can ensure that all the tracking error converges to an arbitrarily small neighborhood around zero. Numerical simulation study demonstrates the effectiveness of the proposed strategy, during the morphing process, in spite of some uncertain system nonlinearity.

  17. Nonlinear stability and control study of highly maneuverable high performance aircraft

    Science.gov (United States)

    Mohler, R. R.

    1993-01-01

    This project is intended to research and develop new nonlinear methodologies for the control and stability analysis of high-performance, high angle-of-attack aircraft such as HARV (F18). Past research (reported in our Phase 1, 2, and 3 progress reports) is summarized and more details of final Phase 3 research is provided. While research emphasis is on nonlinear control, other tasks such as associated model development, system identification, stability analysis, and simulation are performed in some detail as well. An overview of various models that were investigated for different purposes such as an approximate model reference for control adaptation, as well as another model for accurate rigid-body longitudinal motion is provided. Only a very cursory analysis was made relative to type 8 (flexible body dynamics). Standard nonlinear longitudinal airframe dynamics (type 7) with the available modified F18 stability derivatives, thrust vectoring, actuator dynamics, and control constraints are utilized for simulated flight evaluation of derived controller performance in all cases studied.

  18. Reconfigurable Control with Neural Network Augmentation for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.

    2007-01-01

    This paper describes the performance of a simplified dynamic inversion controller with neural network supplementation. This 6 DOF (Degree-of-Freedom) simulation study focuses on the results with and without adaptation of neural networks using a simulation of the NASA modified F-15 which has canards. One area of interest is the performance of a simulated surface failure while attempting to minimize the inertial cross coupling effect of a [B] matrix failure (a control derivative anomaly associated with a jammed or missing control surface). Another area of interest and presented is simulated aerodynamic failures ([A] matrix) such as a canard failure. The controller uses explicit models to produce desired angular rate commands. The dynamic inversion calculates the necessary surface commands to achieve the desired rates. The simplified dynamic inversion uses approximate short period and roll axis dynamics. Initial results indicated that the transient response for a [B] matrix failure using a Neural Network (NN) improved the control behavior when compared to not using a neural network for a given failure, However, further evaluation of the controller was comparable, with objections io the cross coupling effects (after changes were made to the controller). This paper describes the methods employed to reduce the cross coupling effect and maintain adequate tracking errors. The IA] matrix failure results show that control of the aircraft without adaptation is more difficult [leas damped) than with active neural networks, Simulation results show Neural Network augmentation of the controller improves performance in terms of backing error and cross coupling reduction and improved performance with aerodynamic-type failures.

  19. Mapping Resilience

    DEFF Research Database (Denmark)

    Carruth, Susan

    2015-01-01

    Resilience theory is a growing discipline with great relevance for the discipline of planning, particularly in fields like energy planning that face great uncertainty and rapidly transforming contexts. Building on the work of the Stockholm Resilience Centre, this paper begins by outlining...... the relationship between resilience and energy planning, suggesting that planning in, and with, time is a core necessity in this domain. It then reviews four examples of graphically mapping with time, highlighting some of the key challenges, before tentatively proposing a graphical language to be employed...... by planners when aiming to construct resilient energy plans. It concludes that a graphical language has the potential to be a significant tool, flexibly facilitating cross-disciplinary communication and decision-making, while emphasising that its role is to support imaginative, resilient planning rather than...

  20. Research In Nonlinear Flight Control for Tiltrotor Aircraft Operating in the Terminal Area

    Science.gov (United States)

    Calise, A. J.; Rysdyk, R.

    1996-01-01

    The research during the first year of the effort focused on the implementation of the recently developed combination of neural net work adaptive control and feedback linearization. At the core of this research is the comprehensive simulation code Generic Tiltrotor Simulator (GTRS) of the XV-15 tilt rotor aircraft. For this research the GTRS code has been ported to a Fortran environment for use on PC. The emphasis of the research is on terminal area approach procedures, including conversion from aircraft to helicopter configuration. This report focuses on the longitudinal control which is the more challenging case for augmentation. Therefore, an attitude command attitude hold (ACAH) control augmentation is considered which is typically used for the pitch channel during approach procedures. To evaluate the performance of the neural network adaptive control architecture it was necessary to develop a set of low order pilot models capable of performing such tasks as, follow desired altitude profiles, follow desired speed profiles, operate on both sides of powercurve, convert, including flaps as well as mastangle changes, operate with different stability and control augmentation system (SCAS) modes. The pilot models are divided in two sets, one for the backside of the powercurve and one for the frontside. These two sets are linearly blended with speed. The mastangle is also scheduled with speed. Different aspects of the proposed architecture for the neural network (NNW) augmented model inversion were also demonstrated. The demonstration involved implementation of a NNW architecture using linearized models from GTRS, including rotor states, to represent the XV-15 at various operating points. The dynamics used for the model inversion were based on the XV-15 operating at 30 Kts, with residualized rotor dynamics, and not including cross coupling between translational and rotational states. The neural network demonstrated ACAH control under various circumstances. Future

  1. Automatic Life Saving Device in Commercial Aircrafts using Feedback Control System

    Directory of Open Access Journals (Sweden)

    Tennyson Samuel John

    2011-11-01

    Full Text Available Several safety devices have filled in the vacuous spaces in commercial airplanes which once did not possess such sophisticated mechanisms. Commercial airplanes have copious amount of instruments and electrical circuits to provide a proper control system inside the plane. A noteworthy invention in the early 80’s is the oxygen masks provided for every passenger during a plane crash or if the airplane is subjected to climatic disturbances while travelling a passenger manually uses the oxygen masks. The oxygen control system in the airplanes has proved very effective in providing an overall safety to the passengers. But the technique given below is far more advanced than the present scenario. A person suffering from a breathing ailment is succumbed to variations in the carbon dioxide levels. Thereby this CO2 is measured and using a feedback control loop, quick actions can be taken in order to provide quick aid to the ailing patient. These are completely automatic and hence it is advanced than the manual oxygen control system presently used in all commercial aircrafts. At the end of the day saving a life is what a humanistic approach is all about.

  2. Evaluation of Tactile Situation Awareness System as an Aid for Improving Aircraft Control During Periods of Impaired Vision

    Science.gov (United States)

    2009-06-01

    relationship of the aircraft to the horizon. 7 B. LITERATURE REVIEW Haptics is one of the first senses that humans encounter during...pilot during long transatlantic or transpacific flights if an alarm sounded or the other pilot at the controls needed assistance. How can the TSAS

  3. Linear matrix inequality-based nonlinear adaptive robust control with application to unmanned aircraft systems

    Science.gov (United States)

    Kun, David William

    Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known dynamic equations. Second, the final control law is valid in a larger region of operation, including far from the equilibrium states. And third, the procedure is largely methodical, requiring less expertise with gain tuning, which can be arduous for a novice engineer. Considering these facts, this thesis proposes a nonlinear controller design method that combines the advantages of adaptive robust control (ARC) with the powerful design tools of linear matrix inequalities (LMI). The ARC-LMI controller is designed with a discontinuous projection-based adaptation law, and guarantees a prescribed transient and steady state tracking performance for uncertain systems in the presence of matched disturbances. The norm of the tracking error is bounded by a known function that depends on the controller design parameters in a known form. Furthermore, the LMI-based part of the controller ensures the stability of the system while overcoming polytopic uncertainties, and minimizes the control effort. This can reduce the number of parameters that require adaptation, and helps to avoid control input saturation. These desirable characteristics make the ARC-LMI control algorithm well suited for the quadrotor UAS, which may have unknown parameters and may encounter external

  4. Resilience in aging: literature review.

    Science.gov (United States)

    Fontes, Arlete Portella; Neri, Anita Liberalesso

    2015-05-01

    Psychological resilience is comprised of an adaptive functioning standard before the current and accumulated risks of life. Furthermore, it has a comprehensive range of psychological resources which are essential to overcome adversities, such as personal competences, self-beliefs and interpersonal control which interact with the social networks support. The objectives are to show the concepts of psychological resilience in elderly, relative to dominant theoretical models and the main data about psychological resilience in aging, found in an international and Brazilian review from 2007 to 2013. The descriptors "resilience, psychological resilience and aging", "resiliência e envelhecimento, velhice e velho", were used in PubMed, PsychInfo, SciELO and Pepsic databases. Fifty three international and eleven national articles were selected. The international articles were classified in four categories: psychological and social coping resources, emotional regulation before stressing experiences, successful resilience and aging and correlates, and resilience measures. The Brazilian articles were grouped in three: psychological and social resources, resilience in carers and theory review. Articles on psychological resources and on emotional regulation prevailed as key factors associated with psychological resilience in aging.

  5. NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

    Science.gov (United States)

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

    2014-01-01

    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.

  6. Analysis of Loss of Control Parameters for Aircraft Maneuvering in General Aviation

    Directory of Open Access Journals (Sweden)

    Sameer Ud-Din

    2018-01-01

    Full Text Available A rapid increase in the occurrence of loss of control in general aviation has raised concern in recent years. Loss of control (LOC pertains to unique characteristics in which external and internal events act in conjunction. The Federal Aviation Administration (FAA has approved an Integrated Safety Assessment Model (ISAM for evaluating safety in the National Airspace System (NAS. ISAM consists of an event sequence diagram (ESD with fault trees containing numerous parameters, which is recognized as casual risk model. In this paper, we outline an integrated risk assessment framework to model maneuvering through cross-examining external and internal events. The maneuvering is in the critical flight phase with a high number of LOC occurrences in general aviation, where highly trained and qualified pilots failed to maintain aircraft control irrespective of the preventive nature of the events. Various metrics have been presented for evaluating the significance of these parameters to identify the most important ones. The proposed sensitivity analysis considers the accident, fatality, and risk reduction frequencies that assist in the decision-making process and foresees future risks from a general aviation perspective.

  7. Fault tolerant control based on interval type-2 fuzzy sliding mode controller for coaxial trirotor aircraft.

    Science.gov (United States)

    Zeghlache, Samir; Kara, Kamel; Saigaa, Djamel

    2015-11-01

    In this paper, a robust controller for a Six Degrees of Freedom (6 DOF) coaxial trirotor helicopter control is proposed in presence of defects in the system. A control strategy based on the coupling of the interval type-2 fuzzy logic control and sliding mode control technique are used to design a controller. The main purpose of this work is to eliminate the chattering phenomenon and guaranteeing the stability and the robustness of the system. In order to achieve this goal, interval type-2 fuzzy logic control has been used to generate the discontinuous control signal. The simulation results have shown that the proposed control strategy can greatly alleviate the chattering effect, and perform good reference tracking in presence of defects in the system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  8. 78 FR 37958 - Special Conditions: Cessna Aircraft Company, Model J182T; Electronic Engine Control System...

    Science.gov (United States)

    2013-06-25

    ..., 2012, Cessna Aircraft Company applied for an amendment to Type Certificate No. 3A13 to include the new... analysis would be incomplete because it would not include the effects of the aircraft supplied power and... behavior acceptable for part 33 certification may not be acceptable for part 23 certification. The Small...

  9. Simulation model for the Boeing 720B aircraft-flight control system in continuous flight.

    Science.gov (United States)

    1971-08-01

    A mathematical model of the Boeing 720B aircraft and autopilot has been derived. The model is representative of the 720B aircraft for continuous flight within a flight envelope defined by a Mach number of .4 at 20,000 feet altitude in a cruise config...

  10. A low cost maritime control aircraft-ship-weapons system. [antiship missile defense

    Science.gov (United States)

    Fluk, H.

    1981-01-01

    It is pointed out that the long-range antiship standoff missile is emerging as the foremost threat on the seas. Delivered by high speed bombers, surface ships, and submarines, a missile attack can be mounted against selected targets from any point on the compass. An investigation is conducted regarding the configuration of a system which could most efficiently identify and destroy standoff threats before they launch their weapons. It is found that by using ships for carrying and launching missiles, and employing aircraft with a powerful radar only for search and missile directing operations, aircraft cost and weight can be greatly reduced. The employment of V/STOL aircraft in preference to other types of aircraft makes it possible to use ships of smaller size for carrying the aircraft. However, in order to obtain an all-weather operational capability for the system, ships are selected which are still big enough to display the required stability in heavy seas.

  11. 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

    2017-06-01

    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.

  12. Analysis of control concepts for gas and shaft-coupled V/STOL aircraft lift fan systems

    Science.gov (United States)

    Sellers, J. F.; Hart, C. E.; Mihaloew, J. R.

    1977-01-01

    For lift-fan powered V/STOL aircraft, two unconventional propulsion system types were proposed. The first type uses fans connected by hot gas ducting, and the second type uses fans connected by cross shafting. An analytical study identified the basic steady-state and dynamic characteristics for each type of system. For the gas-coupled system, the control concepts analyzed were variable-area fan turbines and throttling valves in the ducting. For the shaft-coupled system, the control concepts analyzed were variable-pitch fans and variable fan inlet guide vanes. All of these concepts are capable of meeting V/STOL aircraft control moment and transient response requirements when appropriate propulsion controls are used.

  13. Water Resilience

    Science.gov (United States)

    The Drinking Water and Wastewater Resiliency site provides tools and resources for drinking water and wastewater utilities in the full spectrum of emergency management which includes prevention, mitigation, preparedness, response and recovery.

  14. The effects of angle-of-attack indication on aircraft control in the event of an airspeed indicator malfunction

    Science.gov (United States)

    Boesser, Claas Tido

    Analysis of accident data by the Federal Aviation Administration, the National Transportation Safety Board, and other sources show that loss of control is the leading cause of aircraft accidents. Further evaluation of the data indicates that the majority of loss of control accidents are caused by the aircraft stalling. In response to these data, the Federal Aviation Administration and the General Aviation Joint Steering Committee emphasize the importance of stall and angle-of-attack awareness during flight. The high-profile crash of Air France Flight 447, in which pilots failed to recover from a self-induced stall, reinforced concerns over the need for improved stall and angle-of-attack awareness and reinvigorated interest in the debate over the effectiveness of angle-of-attack information displays. Further support for aerodynamic information in the form of an angle-of-attack indicator comes from core cognitive engineering principles. These principles argue for the provision of information about system functioning and dynamics as a means to ensure a human is always in position to recover a system when technology is unable. The purpose of this research was to empirically evaluate the importance of providing pilots with feedback about fundamental aircraft aerodynamics, especially during non-standard situations and unexpected disturbances. An experiment was conducted using a flight simulator to test the effects of in-cockpit angle-of-attack indication on aircraft control following an airspeed indicator malfunction on final approach. Participants flew a final approach with a target airspeed range of 60 to 65 knots. Once participants slowed the aircraft for final approach, the airspeed indicator needle would be stuck at an indication of 70 knots. One group of participants flew the final approach with an angle-of-attack indicator while the other group lacked such an instrument. Examination of aircraft performance data along the final approach showed that, when confronted

  15. Risk and Resilience Factors in Coping with Daily Stress in Adulthood: The Role of Age, Self-Concept Incoherence, and Personal Control

    Science.gov (United States)

    Diehl, Manfred; Hay, Elizabeth L.

    2010-01-01

    This study observed young, middle-aged, and older adults (N = 239; M[subscript age] = 49.6 years; range = 18-89 years) for 30 consecutive days to examine the association between daily stress and negative affect, taking into account potential risk (i.e., self-concept incoherence) and resilience (i.e., age, perceived personal control) factors.…

  16. Noise Reduction Efforts for Special Operations C-130 Aircraft Using Active Synchrophaser Control

    National Research Council Canada - National Science Library

    Hammond, Daryl; McKinley, Richard; Hale, Bill

    1998-01-01

    .... A more complicated approach uses an active noise cancellation (ANC) system, which offers improved performance that can augment passive methods to significantly reduce both internal and external aircraft noise...

  17. Technical assessment of satellites for CONUS air traffic control Volume III: satellite-to-aircraft techniques

    Science.gov (United States)

    1974-02-17

    A number of satellite system techniques have been suggested as candidates to provide ATC surveillance, communication, and/or navigation service over CONUS. All techniques determine the aircraft positions by multilateration based on the arrival times ...

  18. Development of Novel, Optically-Based Instrumentation for Aircraft System Testing and Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact, robust, optically-based sensor for making temperature and multi-species concentration measurements in aircraft system ground and...

  19. Impact data from a transport aircraft during a controlled impact demonstration

    Science.gov (United States)

    Fasanella, E. L.; Alfaro-Bou, E.; Hayduk, R. J.

    1986-01-01

    On December 1, 1984, the FAA and NASA conducted a remotely piloted air-to-ground crash test of a Boeing 720 transport aircraft instrumented to measure crash loads of the structure and the anthropomorphic dummy passengers. Over 330 time histories of accelerations and loads collected during the Full-Scale Transport Controlled Impact Demonstration (CID) for the 1-sec period after initial impact are presented. Although a symmetric 1 deg. nose-up attitude with a 17 ft/sec sink rate was planned, the plane was yawed and rolled 13 deg. at initial (left-wing) impact. The first fuselage impact occurred near the nose wheel well with the nose pitched down 2.5 deg. Peak normal (vertical) floor accelerations were highest in the cockpit and forward cabin near the nose wheel well and were approximately 14G. The remaining cabin floor received normal acceleration peaks of 7G or less. The peak longitudinal floor accelerations showed a similar distribution, with the highest (7G) in the cockpit and forward cabin, decreasing to 4G or less toward the rear. Peak transverse floor accelerations ranged from about 5G in the cockpit to 1G in the aft fuselage.

  20. VERNAM CIPHER BASED METHOD OF PROTECTION FOR DATA TRANSFERRED BETWEEN UNMANNED AIRCRAFT AND GROUND CONTROL STATION

    Directory of Open Access Journals (Sweden)

    I. A. Avdonin

    2016-09-01

    Full Text Available The paper deals with questions of protection against unauthorized access to the data transmitted between unmanned aircraft vehicle (UAV and ground control station (GCS. This is due to the fact that standard instruments of network security sometimes provide security of not enough proper level or do not satisfy the restrictions connected with the features of UAV: limited computing resources of the UAV on-board computer and real-time operation. We have offered to use Vernam cipher (one-time pad as an additional measure for data protection. Vernam algorithm combines such advantages as theoretically proved absolute cryptographic security, ease of implementation, high speed of encryption and low processor load. It is especially important for large volumes of data encryption (e.g. video information. Within the bounds of experimental researches the technique is used based on cryptographic gamma of block cipher GOST 28147-89 in the Cipher Feedback Mode for a one-time pad generation. Application of Vernam cipher means the deletion of used one-time pad pages. The replacement of used one-time pad pages by cipher text is proposed for assurance of the above-named requirement and for simultaneous computer memory saving. It gives additionally the opportunity not only to save key sequences but also to accumulate encrypted data in the on-board computer memory. Realization of the offered method allows increasing the data protection level without engaging large computing power and memory capacity.

  1. En route position and time control of aircraft using Kalman filtering of radio aid data

    Science.gov (United States)

    Mcgee, L. A.; Christensen, J. V.

    1973-01-01

    Fixed-time-of-arrival (FTA) guidance and navigation is investigated as a possible technique capable of operation within much more stringent en route separation standards and offering significant advantages in safety, higher traffic densities, and improved scheduling reliability, both en route and in the terminal areas. This study investigated the application of FTA guidance previously used in spacecraft guidance. These FTA guidance techniques have been modified and are employed to compute the velocity corrections necessary to return an aircraft to a specified great-circle reference path in order to exercise en route time and position control throughout the entire flight. The necessary position and velocity estimates to accomplish this task are provided by Kalman filtering of data from Loran-C, VORTAC/TACAN, Doppler radar, radio or barometric altitude,and altitude rate. The guidance and navigation system was evaluated using a digital simulation of the cruise phase of supersonic and subsonic flights between San Francisco and New York City, and between New York City and London.

  2. A novel design of the heat exchanger of an aircraft's environmental controller

    Science.gov (United States)

    Shahbazian, Negin

    Redesign of a heat exchanger chassis of an aircraft's environmental controller developed by Honeywell was carried out using finite element analysis (FEA) to reduce overall cost and weight. Eight design alternatives were proposed to replace the current design and were evaluated using a decision matrix. Selected design involved introduction of bolted flanges into the chassis. Von-Mises stresses in the flanges and shear and tensile forces in the bolts were obtained by FEA using ANSYS. Flanges were further modified using safety margin and weight as optimization factors. The optimized flange contains a fluid passage with 0.08in wall thickness reduction and 0.14in passage length reduction. Furthermore, the overall weight was reduced by 0.026kg. After optimization, the margin of safety was improved from 0.041 to 0.580 for maximum operating pressure, and from -0.297 to 0.067 for burst pressure. The novel design accomplished weight and cost reduction along with improving the margins of safety.

  3. The effects of four days of intensive mindfulness meditation training (Templestay program) on resilience to stress: a randomized controlled trial.

    Science.gov (United States)

    Hwang, Wu Jeong; Lee, Tae Young; Lim, Kyung-Ok; Bae, Dahye; Kwak, Seoyeon; Park, Hye-Yoon; Kwon, Jun Soo

    2018-06-01

    The interest in mindfulness meditation interventions has surged due to their beneficial effects in fostering resilience and reducing stress in both clinical and non-clinical populations. However, the relaxation benefits that may occur while practicing mindfulness meditation and long-term benefits of these interventions remain unclear. Fifty-one participants were recruited and randomized into the experimental and control groups, which underwent 4 days of Intensive Meditation (Templestay program, n = 33) and Relaxation (Control, n = 18), respectively. The self-report measures of Cognitive and Affective Mindfulness Scale-Revised (CAMS) and the modified Korean version of the Resilience Quotient Test (RQT) were administered pre-, post- and 3 months after the intervention to measure participants' levels of mindfulness and resilience. Participants in both the Templestay program and Control groups showed significant increases in their scores on CAMS and RQT after completing the program. During the 3-month follow-up, a significant interaction effect of the intervention method and time was revealed for the individuals' CAMS and RQT scores. Our findings support the hypothesis that while relaxation practices may have certain stress reduction effects, the effects are predominantly mediated by the mindfulness meditation practice. Furthermore, the long-term benefits of increased resilience observed in the Templestay program group suggest that the practice may be a possible treatment strategy in clinical populations, such as patients with depression and anxiety.

  4. Individual Markers of Resilience in Train Traffic Control: The Role of Operators' Goals and Strategic Mental Models and Implications for Variation, Expertise, and Performance.

    Science.gov (United States)

    Lo, Julia C; Pluyter, Kari R; Meijer, Sebastiaan A

    2016-02-01

    The aim of this study was to examine individual markers of resilience and obtain quantitative insights into the understanding and the implications of variation and expertise levels in train traffic operators' goals and strategic mental models and their impact on performance. The Dutch railways are one of the world's most heavy utilized railway networks and have been identified to be weak in system and organizational resilience. Twenty-two train traffic controllers enacted two scenarios in a human-in-the-loop simulator. Their experience, goals, strategic mental models, and performance were assessed through questionnaires and simulator logs. Goals were operationalized through performance indicators and strategic mental models through train completion strategies. A variation was found between operators for both self-reported primary performance indicators and completion strategies. Further, the primary goal of only 14% of the operators reflected the primary organizational goal (i.e., arrival punctuality). An incongruence was also found between train traffic controllers' self-reported performance indicators and objective performance in a more disrupted condition. The level of experience tends to affect performance differently. There is a gap between primary organizational goals and preferred individual goals. Further, the relative strong diversity in primary operator goals and strategic mental models indicates weak resilience at the individual level. With recent and upcoming large-scale changes throughout the sociotechnical space of the railway infrastructure organization, the findings are useful to facilitate future railway traffic control and the development of a resilient system. © 2015, Human Factors and Ergonomics Society.

  5. Association between resilience and posttraumatic stress disorder among Brazilian victims of urban violence: a cross-sectional case-control study.

    Science.gov (United States)

    Teche, Stefania Pigatto; Barros, Alcina Juliana Soares; Rosa, Regis Goulart; Guimarães, Luciano Pinto; Cordini, Kariny Larissa; Goi, Julia Domingues; Hauck, Simone; Freitas, Lucia Helena

    2017-01-01

    This study investigated the association between resilience and posttraumatic stress disorder (PTSD) among Brazilian victims of urban violence. It also compared defense mechanisms, parental bonding, and childhood trauma between those who developed PTSD and those who did not. This cross-sectional case-control study included 66 adult subjects exposed to recent urban violence in southern Brazil - 33 with PTSD and 33 healthy controls matched by sex and age - who were administered the Resilience Scale, Defense Style Questionnaire, Parental Bonding Instrument, and Childhood Trauma Questionnaire. The statistical tests used were the McNemar test for categorical variables, the Wilcoxon signed-rank test for continuous asymmetric variables, and the paired Student t-test for continuous symmetric variables. The PTSD group showed lower total Resilience Scale scores compared with controls (128.4±20.7 vs. 145.8±13.1, respectively; p = 0.01), along with a lower ability to solve situations and lower personal values that give meaning to life (p = 0.019). They also had lower rates of mature defense mechanisms (p resilience, especially the ability to solve situations and having personal values that give meaning to life, immature defense mechanisms, and emotional and physical abuse in childhood are associated with PTSD in adult Brazilian victims of urban violence.

  6. Advanced nonlinear control: Robustness and stability with applications to aircraft flight control systems

    Science.gov (United States)

    Frye, Michael Takaichi

    This dissertation examines the problem of global decentralized control by output feedback for large-scale uncertain nonlinear systems whose subsystems are interconnected not only by their outputs but also by their unmeasurable states. Several innovative techniques will be developed to create decentralized output feedback controllers rendering the closed-loop systems globally asymptotically stable. This is accomplished by extending an output feedback domination design that requires only limited information about the nonlinear system. We will apply our design to lower, upper, and non-triangular nonlinear systems. A time-varying output feedback controller is also constructed for use with large-scale systems that have unknown parameters. Furthermore, a mixed large-scale system consisting of both lower and upper triangular systems is shown to be stabilizable by employing a combined high and low gain domination technique. The significance of our results is that we do not need to have prior information about the nonlinearities of the system. In addition, a new design technique was developed using homogeneous system theory, which allows for the design of nonsmooth controllers and observers to stabilize a class of feedforward system with uncontrollable and unobservable linearization. An example of a large-scale system is a group of autonomous airships performing the function of a temporary mobile cell phone network. An airship mobile cell phone network is a novel solution to the problem of maintaining communication during the advent of extensive damage to the communication infrastructure; be it from a flood, earthquake, hurricane, or terrorist attack. A first principle force-based dynamic model for the Tri-Turbofan Airship was developed and will be discussed in detail. The mathematical model was based on actual flight test data that has been collected at the Gait Analysis and Innovative Technologies Laboratory. This model was developed to research autonomous airship

  7. NASA/RAE collaboration on nonlinear control using the F-8C digital fly-by-wire aircraft

    Science.gov (United States)

    Butler, G. F.; Corbin, M. J.; Mepham, S.; Stewart, J. F.; Larson, R. R.

    1983-01-01

    Design procedures are reviewed for variable integral control to optimize response (VICTOR) algorithms and results of preliminary flight tests are presented. The F-8C aircraft is operated in the remotely augmented vehicle (RAV) mode, with the control laws implemented as FORTRAN programs on a ground-based computer. Pilot commands and sensor information are telemetered to the ground, where the data are processed to form surface commands which are then telemetered back to the aircraft. The RAV mode represents a singlestring (simplex) system and is therefore vulnerable to a hardover since comparison monitoring is not possible. Hence, extensive error checking is conducted on both the ground and airborne computers to prevent the development of potentially hazardous situations. Experience with the RAV monitoring and validation procedures is described.

  8. The DLR project Wirbelschleppe. Detecting, characterizing, controlling, attenuating, understanding, and predicting aircraft wake vortices

    Energy Technology Data Exchange (ETDEWEB)

    Holzaepfel, F. (ed.)

    2008-07-01

    This collection of reports presents an excerpt of the investigations that were performed in the framework of the DLR Projekt Wirbelschleppe. A similar sample of reports was presented as part of three dedicated wake vortex sessions accomplished at the 1{sup st} European Air and Space Conference (CEAS 2007) and Deutscher Luft- und Raumfahrtkongress 2007 in Berlin. The Projekt Wirbelschleppe was conducted in two phases in the time frame from 1999 to 2007 with the five contributing DLR Institutes: Institute of Atmospheric Physics, Institute of Aerodynamics and Flow Technology, Institute of Flight Systems, Institute of Flight Guidance, Institute of Robotics and Mechatronics and the Institute of Aeronautics and Astronautics of the University of Technology Berlin. The project unified a multitude of different aspects and disciplines of wake vortex research which can be characterized by four main themes: - minimization of wake vortices by measures at the aircraft; - development and demonstration of a system for wake vortex prediction and observation; - airborne wake vortex detection and active control; - integration of systems into air traffic control. The Projekt Wirbelschleppe greatly benefited from the European projects AWIATOR, ATC-Wake, Credos, C-Wake, Eurowake, FAR-Wake, FLYSAFE, I-Wake, S-Wake, WakeNet, WakeNet2-Europe, WakeNet3-Europe, and Wavenc. DLR's wake vortex activities will be continued in the Projekt Wetter and Fliegen (2008-2011): Because the current compilation represents only a limited extract of the accomplished work, it is completed by a list of references emerging from the project. (orig.)

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

    Science.gov (United States)

    Murphy, Patrick C.

    1996-01-01

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

  10. Stability, Transient Response, Control, and Safety of a High-Power Electric Grid for Turboelectric Propulsion of Aircraft

    Science.gov (United States)

    Armstrong, Michael; Ross, Christine; Phillips, Danny; Blackwelder, Mark

    2013-01-01

    This document contains the deliverables for the NASA Research and Technology for Aerospace Propulsion Systems (RTAPS) regarding the stability, transient response, control, and safety study for a high power cryogenic turboelectric distributed propulsion (TeDP) system. The objective of this research effort is to enumerate, characterize, and evaluate the critical issues facing the development of the N3-X concept aircraft. This includes the proposal of electrical grid architecture concepts and an evaluation of any needs for energy storage.

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

    Science.gov (United States)

    Murphy, Patrick C.

    1999-01-01

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

  12. Systematic review on tuberculosis transmission on aircraft and update of the European Centre for Disease Prevention and Control risk assessment guidelines for tuberculosis transmitted on aircraft (RAGIDA-TB).

    Science.gov (United States)

    Kotila, Saara M; Payne Hallström, Lara; Jansen, Niesje; Helbling, Peter; Abubakar, Ibrahim

    2016-01-01

    As a setting for potential tuberculosis (TB) transmission and contact tracing, aircraft pose specific challenges. Evidence-based guidelines are needed to support the related-risk assessment and contact-tracing efforts. In this study evidence of TB transmission on aircraft was identified to update the Risk Assessment Guidelines for TB Transmitted on Aircraft (RAGIDA-TB) of the European Centre for Disease Prevention and Control (ECDC). Electronic searches were undertaken from Medline (Pubmed), Embase and Cochrane Library until 19 July 2013. Eligible records were identified by a two-stage screening process and data on flight and index case characteristics as well as contact tracing strategies extracted. The systematic literature review retrieved 21 records. Ten of these records were available only after the previous version of the RAGIDA guidelines (2009) and World Health Organization guidelines on TB and air travel (2008) were published. Seven of the 21 records presented some evidence of possible in-flight transmission, but only one record provided substantial evidence of TB transmission on an aircraft. The data indicate that overall risk of TB transmission on aircraft is very low. The updated ECDC guidelines for TB transmission on aircraft have global implications due to inevitable need for international collaboration in contract tracing and risk assessment.

  13. EFT (Emotional Freedom Techniques) and Resiliency in Veterans at Risk for PTSD: A Randomized Controlled Trial.

    Science.gov (United States)

    Church, Dawson; Sparks, Terry; Clond, Morgan

    2016-01-01

    Prior research indicates elevated but subclinical posttraumatic stress disorder (PTSD) symptoms as a risk factor for a later diagnosis of PTSD. This study examined the progression of symptoms in 21 subclinical veterans. Participants were randomized into a treatment as usual (TAU) wait-list group and an experimental group, which received TAU plus six sessions of clinical emotional freedom techniques (EFT). Symptoms were assessed using the PCL-M (Posttraumatic Checklist-Military) on which a score of 35 or higher indicates increased risk for PTSD. The mean pretreatment score of participants was 39 ± 8.7, with no significant difference between groups. No change was found in the TAU group during the wait period. Afterward, the TAU group received an identical clinical EFT protocol. Posttreatment groups were combined for analysis. Scores declined to a mean of 25 (-64%, P < .0001). Participants maintained their gains, with mean three-month and six-month follow-up PCL-M scores of 27 (P < .0001). Similar reductions were noted in the depth and breadth of psychological conditions such as anxiety. A Cohen's d = 1.99 indicates a large treatment effect. Reductions in traumatic brain injury symptoms (P = .045) and insomnia (P = .004) were also noted. Symptom improvements were similar to those assessed in studies of PTSD-positive veterans. EFT may thus be protective against an increase in symptoms and a later PTSD diagnosis. As a simple and quickly learned self-help method, EFT may be a clinically useful element of a resiliency program for veterans and active-duty warriors. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Aircraft Multifunction Display and Control Systems: A New Quantitative Human Factors Design Method for Organizing Functions and Display Contents

    National Research Council Canada - National Science Library

    Francis, Gregory

    1997-01-01

    .... MFDCSs in aircraft cockpits use computer-generated graphics and symbology that have integrated and largely replaced the myriad discrete electromechanical flight instruments found in older aircraft...

  15. Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation

    Science.gov (United States)

    Glende, W. L. B.

    1974-01-01

    The design, fabrication and flight testing of a powered elevator system for the Augmentor Wing Jet STOL Research Aircraft (AWJSRA or Mod C-8A) are discussed. The system replaces a manual spring tab elevator control system that was unsatisfactory in the STOL flight regime. Pitch control in the AWJSRA is by means of a single elevator control surface. The elevator is used for both maneuver and trim control as the stabilizer is fixed. A fully powered, irreversible flight control system powered by dual hydraulic sources was designed. The existing control columns and single mechanical cable system of the AWJSRA have been retained as has been the basic elevator surface, except that the elevator spring tab is modified into a geared balance tab. The control surface is directly actuated by a dual tandem moving body actuator. Control signals are transmitted from the elevator aft quadrant to the actuator by a linkage system that includes a limited authority series servo actuator.

  16. A Theoretical Method of Determining the Control Gearing and Time Lag Necessary for a Specified Damping of an Aircraft Equipped with a Constant-Time-Lag Autopilot

    National Research Council Canada - National Science Library

    Gates, Ordway

    1951-01-01

    A method is presented for determining the control gearing and time lag necessary for a specified damping of the motions of an aircraft equipped with an autopilot having constant-time-lag characteristics...

  17. Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

    Science.gov (United States)

    DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

    2012-01-01

    Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to

  18. Developing a workplace resilience instrument.

    Science.gov (United States)

    Mallak, Larry A; Yildiz, Mustafa

    2016-05-27

    Resilience benefits from the use of protective factors, as opposed to risk factors, which are associated with vulnerability. Considerable research and instrument development has been conducted in clinical settings for patients. The need existed for an instrument to be developed in a workplace setting to measure resilience of employees. This study developed and tested a resilience instrument for employees in the workplace. The research instrument was distributed to executives and nurses working in the United States in hospital settings. Five-hundred-forty completed and usable responses were obtained. The instrument contained an inventory of workplace resilience, a job stress questionnaire, and relevant demographics. The resilience items were written based on previous work by the lead author and inspired by Weick's [1] sense-making theory. A four-factor model yielded an instrument having psychometric properties showing good model fit. Twenty items were retained for the resulting Workplace Resilience Instrument (WRI). Parallel analysis was conducted with successive iterations of exploratory and confirmatory factor analyses. Respondents were classified based on their employment with either a rural or an urban hospital. Executives had significantly higher WRI scores than nurses, controlling for gender. WRI scores were positively and significantly correlated with years of experience and the Brief Job Stress Questionnaire. An instrument to measure individual resilience in the workplace (WRI) was developed. The WRI's four factors identify dimensions of workplace resilience for use in subsequent investigations: Active Problem-Solving, Team Efficacy, Confident Sense-Making, and Bricolage.

  19. Crash response data system for the controlled impact demonstration (CID) of a full scale transport aircraft

    Science.gov (United States)

    Calloway, Raymond S.; Knight, Vernie H., Jr.

    NASA Langley's Crash Response Data System (CRDS) which is designed to acquire aircraft structural and anthropomorphic dummy responses during the full-scale transport CID test is described. Included in the discussion are the system design approach, details on key instrumentation subsystems and operations, overall instrumentation crash performance, and data recovery results. Two autonomous high-environment digital flight instrumentation systems, DAS 1 and DAS 2, were employed to obtain research data from various strain gage, accelerometer, and tensiometric sensors installed in the B-720 test aircraft. The CRDS successfully acquired 343 out of 352 measurements of dynamic crash data.

  20. Launch Vehicle Manual Steering with Adaptive Augmenting Control:In-Flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    Science.gov (United States)

    Hanson, Curt; Miller, Chris; Wall, John H.; VanZwieten, Tannen S.; Gilligan, Eric T.; Orr, Jeb S.

    2015-01-01

    An Adaptive Augmenting Control (AAC) algorithm for the Space Launch System (SLS) has been developed at the Marshall Space Flight Center (MSFC) as part of the launch vehicle's baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a potential manual steering mode were also investigated by giving the pilot trajectory deviation cues and pitch rate command authority, which is the subject of this paper. Two NASA research pilots flew a total of 25 constant pitch rate trajectories using a prototype manual steering mode with and without adaptive control, evaluating six different nominal and off-nominal test case scenarios. Pilot comments and PIO ratings were given following each trajectory and correlated with aircraft state data and internal controller signals post-flight.

  1. Recognizing resilience

    Science.gov (United States)

    Erika S. Svendsen; Gillian Baine; Mary E. Northridge; Lindsay K. Campbell; Sara S. Metcalf

    2014-01-01

    In 2012, a year after a devastating tornado hit the town of Joplin, Missouri, leaving 161 people dead and leveling Joplin High School and St. John's Hospital, President Obama addressed the graduating seniors: "There are a lot of stories here in Joplin of unthinkable courage and resilience. . . . [People in Joplin] learned that we have the power to...

  2. Analysis of control system responses for aircraft stability and efficient numerical techniques for real-time simulations

    Science.gov (United States)

    Stroe, Gabriela; Andrei, Irina-Carmen; Frunzulica, Florin

    2017-01-01

    The objectives of this paper are the study and the implementation of both aerodynamic and propulsion models, as linear interpolations using look-up tables in a database. The aerodynamic and propulsion dependencies on state and control variable have been described by analytic polynomial models. Some simplifying hypotheses were made in the development of the nonlinear aircraft simulations. The choice of a certain technique to use depends on the desired accuracy of the solution and the computational effort to be expended. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. The engine power dynamic response was modeled with an additional state equation as first order lag in the actual power level response to commanded power level was computed as a function of throttle position. The number of control inputs and engine power states varied depending on the number of control surfaces and aircraft engines. The set of coupled, nonlinear, first-order ordinary differential equations that comprise the simulation model can be represented by the vector differential equation. A linear time-invariant (LTI) system representing aircraft dynamics for small perturbations about a reference trim condition is given by the state and output equations present. The gradients are obtained numerically by perturbing each state and control input independently and recording the changes in the trimmed state and output equations. This is done using the numerical technique of central finite differences, including the perturbations of the state and control variables. For a reference trim condition of straight and level flight, linearization results in two decoupled sets of linear, constant-coefficient differential equations for longitudinal and lateral / directional motion. The linearization is valid for small perturbations about the reference trim

  3. Secondary outcomes of a school-based universal resiliency training for adolescents: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Tak, Y.R.; Kleinjan, M.; Lichtwarck-Aschoff, A.; Engels, R.C.M.E.

    2014-01-01

    BACKGROUND: The study investigated the long-term effectiveness of the adolescent cognitive behavioral resiliency training Op Volle Kracht (OVK) on the secondary outcomes: anxiety symptoms, hopelessness, happiness, life satisfaction, optimism, coping, self-efficacy, and school functioning. In

  4. Launch Vehicle Manual Steering with Adaptive Augmenting Control In-flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    Science.gov (United States)

    Hanson, Curt; Miller, Chris; Wall, John H.; Vanzwieten, Tannen S.; Gilligan, Eric; Orr, Jeb S.

    2015-01-01

    An adaptive augmenting control algorithm for the Space Launch System has been developed at the Marshall Space Flight Center as part of the launch vehicles baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a proposed manual steering mode were investigated by giving the pilot trajectory deviation cues and pitch rate command authority. Two NASA research pilots flew a total of twenty five constant pitch-rate trajectories using a prototype manual steering mode with and without adaptive control.

  5. The Use of a Satellite Communications System for Command and Control of the National Aeronautics and Space Administration Surrogate Unmanned Aerial System Research Aircraft

    Science.gov (United States)

    Howell, Charles T.; Jones, Frank; Hutchinson, Brian; Joyce, Claude; Nelson, Skip; Melum, Mike

    2017-01-01

    The NASA Langley Research Center has transformed a Cirrus Design SR22 general aviation (GA) aircraft into an Unmanned Aerial Systems (UAS) Surrogate research aircraft which has served for several years as a platform for unmanned systems research and development. The aircraft is manned with a Safety Pilot and a Research Systems Operator (RSO) that allows for flight operations almost any-where in the national airspace system (NAS) without the need for a Federal Aviation Administration (FAA) Certificate of Authorization (COA). The UAS Surrogate can be remotely controlled from a modular, transportable ground control station (GCS) like a true UAS. Ground control of the aircraft is accomplished by the use of data links that allow the two-way passage of the required data to control the aircraft and provide the GCS with situational awareness. The original UAS Surrogate data-link system was composed of redundant very high frequency (VHF) data radio modems with a maximum range of approximately 40 nautical miles. A new requirement was developed to extend this range beyond visual range (BVR). This new requirement led to the development of a satellite communications system that provided the means to command and control the UAS Surrogate at ranges beyond the limits of the VHF data links. The system makes use of the Globalstar low earth orbit (LEO) satellite communications system. This paper will provide details of the development, implementation, and flight testing of the satellite data communications system on the UAS Surrogate research aircraft.

  6. Scheduling and Delivering Aircraft to Departure Fixes in the NY Metroplex with Controller-Managed Spacing Tools

    Science.gov (United States)

    Chevalley, Eric; Parke, Bonny; Kraut, Josh M.; Bienert, Nancy; Omar, Faisal; Palmer, Everett A.

    2015-01-01

    In this paper, successful Time-Based Flow Management (TBFM) scheduling systems for arrivals are considered and adapted to apply to departures. We present a concept of operations that integrates Controller-Managed Spacing tools for departures (CMS-D) with existing tactical departure scheduling tools to coordinate demand at departure fixes in a metroplex environment. We tested our concept in a Human-in-the-Loop simulation and compared the effect of two scheduling conditions: 1) "Departure Scheduling" consisting of an emulation of the Integrated Departure and Arrival Capability (IDAC) where Towers and a Planner (Traffic Management Coordinator at the appropriate facility) coordinate aircraft scheduled takeoff times to departure fixes; and 2) "Arrival Sensitive Departure Scheduling" where, in addition, the Tower and Planner also consider arrival Scheduled Time of Arrivals (STAs) at the airport's dependent runway. Results indicate little difference between the two scheduling conditions, but a large difference between the No Tools and the two scheduling conditions with CMS-D tools. The scheduling/CMS-D tools conditions markedly reduced heading, speed clearances, and workload for controllers who were merging flows at the departure fixes. In the tool conditions, departure controllers conditioned departures earlier rather than later when aircraft were tied near the departure fixes. In the scheduling/CMS-D tools conditions, departures crossed the departure fixes 50 seconds earlier and with an 8% error rate (consisting of time ahead or behind desired time of arrival) compared to a 19% error rate in the No Tool condition. Two exploratory runs showed that similar beneficial effects can be obtained only with the CMS-D tools without scheduling takeoff times, but at the cost of a somewhat higher workload for controllers, indicating the benefits of pre-departure scheduling of aircraft with minimal delays. Hence, we found that CMS-D tools were very beneficial in the metroplex

  7. Structural development of laminar flow control aircraft chordwise wing joint designs

    Science.gov (United States)

    Fischler, J. E.; Jerstad, N. M.; Gallimore, F. H., Jr.; Pollard, T. J.

    1989-01-01

    For laminar flow to be achieved, any protuberances on the surface must be small enough to avoid transition to turbulent flow. However, the surface must have joints between the structural components to allow assembly or replacement of damaged parts, although large continuous surfaces can be utilized to minimize the number the number of joints. Aircraft structural joints usually have many countersunk bolts or rivets on the outer surface. To maintain no mismatch on outer surfaces, it is desirable to attach the components from the inner surface. It is also desirable for the panels to be interchangeable, without the need for shims at the joint, to avoid surface discontinuities that could cause turbulence. Fabricating components while pressing their outer surfaces against an accurate mold helps to ensure surface smoothness and continuity at joints. These items were considered in evaluating the advantages and disadvantages of the joint design concepts. After evaluating six design concepts, two of the leading candidates were fabricated and tested using many small test panels. One joint concept was also built and tested using large panels. The small and large test panel deflections for the leading candidate designs at load factors up to +1.5 g's were well within the step and waviness requirements for avoiding transition.The small panels were designed and tested for compression and tension at -65 F, at ambient conditions, and at 160 F. The small panel results for the three-rib and the sliding-joint concepts indicated that they were both acceptable. The three-rib concept, with tapered splice plates, was considered to be the most practical. A modified three-rib joint that combined the best attributes of previous candidates was designed, developed, and tested. This improved joint met all of the structural strength, surface smoothness, and waviness criteria for laminar flow control (LFC). The design eliminated all disadvantages of the initial three-rib concept except for

  8. Speech systems for autonomous unmanned aircraft: enabling autonomous unmanned aircraft to communicate in civil airspace

    CSIR Research Space (South Africa)

    Burger, CR

    2011-09-01

    Full Text Available Airspace control is currently based largely on the exchange of speech between aircraft and Air Traffic Service Units, or between aircraft themselves. ICAO regulatory guidelines make no distinction between unmanned and manned aircraft, implying...

  9. Resilient Salmon, Resilient Fisheries for British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    Michael C. Healey

    2009-06-01

    Full Text Available Salmon are inherently resilient species. However, this resiliency has been undermined in British Columbia by a century of centralized, command-and-control management focused initially on maximizing yield and, more recently, on economic efficiency. Community and cultural resiliency have also been undermined, especially by the recent emphasis on economic efficiency, which has concentrated access in the hands of a few and has disenfranchised fishery-dependent communities. Recent declines in both salmon stocks and salmon prices have revealed the systemic failure of the current management system. If salmon and their fisheries are to become viable again, radically new management policies are needed. For the salmon species, the emphasis must shift from maximizing yield to restoring resilience; for salmon fisheries, the emphasis must shift from maximizing economic efficiency to maximizing community and cultural resilience. For the species, an approach is needed that integrates harvest management, habitat management, and habitat enhancement to sustain and enhance resilience. This is best achieved by giving fishing and aboriginal communities greater responsibility and authority to manage the fisheries on which they depend. Co-management arrangements that involve cooperative ownership of major multistock resources like the Fraser River and Skeena River fisheries and community-based quota management of smaller fisheries provide ways to put species conservation much more directly in the hands of the communities most dependent on the well-being and resilience of these fisheries.

  10. Building resilience.

    Science.gov (United States)

    Seligman, Martin E P

    2011-04-01

    Failure is a familiar trauma in life, but its effects on people differ widely. Some reel, recover, and move on with their lives; others get bogged down by anxiety, depression, and fear of the future. Seligman, who is known as the father of positive psychology, has spent three decades researching failure, helplessness, and optimism. He created a program at the University of Pennsylvania to help young adults and children overcome anxiety and depression, and has worked with colleagues from around the world to develop a program for teaching resilience. That program is being tested by the U.S. Army, an organization of 1.1 million people where trauma is more common and more severe than in any corporate setting. Nevertheless, businesspeo-ple can draw lessons from resilience training, particularly in times of failure and stagnation. The program is called Comprehensive Soldier Fitness, and it has three components: the Global Assessment Tool, a test for psychological fitness (administered to more than 900,000 soldiers to date); self-improvement courses following the test; and "master resilience training" (MRT) for drill sergeants. MRT focuses on enhancing mental toughness, highlighting and honing strengths, and fostering strong relationships-core competencies for any successful manager.

  11. Quantifying resilience

    Science.gov (United States)

    Allen, Craig R.; Angeler, David G.

    2016-01-01

    The biosphere is under unprecedented pressure, reflected in rapid changes in our global ecological, social, technological and economic systems. In many cases, ecological and social systems can adapt to these changes over time, but when a critical threshold is surpassed, a system under stress can undergo catastrophic change and reorganize into a different state. The concept of resilience, introduced more than 40 years ago in the ecological sciences, captures the behaviour of systems that can occur in alternative states. The original definition of resilience forwarded by Holling (1973) is still the most useful. It defines resilience as the amount of disturbance that a system can withstand before it shifts into an alternative stable state. The idea of alternative stable states has clear and profound implications for ecological management. Coral reefs, for example, are high-diversity systems that provide key ecosystem services such as fisheries and coastal protection. Human impacts are causing significant, ongoing reef degradation, and many reefs have shifted from coral- to algal-dominated states in response to anthropogenic pressures such as elevated water temperatures and overfishing. Understanding and differentiating between the factors that help maintain reefs in coral-dominated states vs. those that facilitate a shift to an undesired algal-dominated state is a critical step towards sound management and conservation of these, and other, important social–ecological systems.

  12. A smartphone application of alcohol resilience treatment for behavioral self-control training

    DEFF Research Database (Denmark)

    Yu, Fei; Albers, Jörg; Gao, Tian

    2012-01-01

    of the treatment rationale, it is realistic, reasonable and manageable to transform the method into a smartphone application. An ART app in Android system and an accessory of bilateral tactile stimulation were developed and will be used in a study with behavioral self-control training. This paper presents...... the design and realization of the smartphone based ART application. The design of a pilot study, which is to examine the benefits of a smartphone application providing behavioral self-control training, is also reported in this paper....

  13. A Smartphone Application of Alcohol Resilience Treatment for Behavioral Self-Control Training

    DEFF Research Database (Denmark)

    Yu, Fei; Albers, Jörg; Gao, Tian

    2012-01-01

    of the treatment rationale, it is realistic, reasonable and manageable to transform the method into a smartphone application. An ART app in Android system and an accessory of bilateral tactile stimulation were developed and will be used in a study with behavioral self-control training. This paper presents...... the design and realization of the smartphone based ART application. The design of a pilot study, which is to examine the benefits of a smartphone application providing behavioral self-control training, is also reported in this paper....

  14. Proposed Rule and Related Materials for Control of Emissions of Air Pollution From Nonroad Diesel Engines Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures

    Science.gov (United States)

    EPA is proposing to adopt emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

  15. Evaluating resilience of DNP3-controlled SCADA systems against event buffer flooding

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Guanhua [Los Alamos National Laboratory; Nicol, David M [UNIV OF IL; Jin, Dong [UNIV OF IL

    2010-12-16

    The DNP3 protocol is widely used in SCADA systems (particularly electrical power) as a means of communicating observed sensor state information back to a control center. Typical architectures using DNP3 have a two level hierarchy, where a specialized data aggregator device receives observed state from devices within a local region, and the control center collects the aggregated state from the data aggregator. The DNP3 communication between control center and data aggregator is asynchronous with the DNP3 communication between data aggregator and relays; this leads to the possibility of completely filling a data aggregator's buffer of pending events, when a relay is compromised or spoofed and sends overly many (false) events to the data aggregator. This paper investigates how a real-world SCADA device responds to event buffer flooding. A Discrete-Time Markov Chain (DTMC) model is developed for understanding this. The DTMC model is validated by a Moebius simulation model and data collected on real SCADA testbed.

  16. Towards an Improved Pilot-Vehicle Interface for Highly Automated Aircraft: Evaluation of the Haptic Flight Control System

    Science.gov (United States)

    Schutte, Paul; Goodrich, Kenneth; Williams, Ralph

    2012-01-01

    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.

  17. Short-range optical air data measurements for aircraft control using rotational Raman backscatter.

    Science.gov (United States)

    Fraczek, Michael; Behrendt, Andreas; Schmitt, Nikolaus

    2013-07-15

    A first laboratory prototype of a novel concept for a short-range optical air data system for aircraft control and safety was built. The measurement methodology was introduced in [Appl. Opt. 51, 148 (2012)] and is based on techniques known from lidar detecting elastic and Raman backscatter from air. A wide range of flight-critical parameters, such as air temperature, molecular number density and pressure can be measured as well as data on atmospheric particles and humidity can be collected. In this paper, the experimental measurement performance achieved with the first laboratory prototype using 532 nm laser radiation of a pulse energy of 118 mJ is presented. Systematic measurement errors and statistical measurement uncertainties are quantified separately. The typical systematic temperature, density and pressure measurement errors obtained from the mean of 1000 averaged signal pulses are small amounting to < 0.22 K, < 0.36% and < 0.31%, respectively, for measurements at air pressures varying from 200 hPa to 950 hPa but constant air temperature of 298.95 K. The systematic measurement errors at air temperatures varying from 238 K to 308 K but constant air pressure of 946 hPa are even smaller and < 0.05 K, < 0.07% and < 0.06%, respectively. A focus is put on the system performance at different virtual flight altitudes as a function of the laser pulse energy. The virtual flight altitudes are precisely generated with a custom-made atmospheric simulation chamber system. In this context, minimum laser pulse energies and pulse numbers are experimentally determined, which are required using the measurement system, in order to meet measurement error demands for temperature and pressure specified in aviation standards. The aviation error margins limit the allowable temperature errors to 1.5 K for all measurement altitudes and the pressure errors to 0.1% for 0 m and 0.5% for 13000 m. With regard to 100-pulse-averaged temperature measurements, the pulse energy using 532 nm

  18. System data communication structures for active-control transport aircraft, volume 2

    Science.gov (United States)

    Hopkins, A. L.; Martin, J. H.; Brock, L. D.; Jansson, D. G.; Serben, S.; Smith, T. B.; Hanley, L. D.

    1981-01-01

    The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems.

  19. Resilience thinking: integrating resilience, adaptability and transformability

    Science.gov (United States)

    Carl Folke; Stephen R. Carpenter; Brian Walker; Marten Scheffer; Terry Chapin; Johan. Rockstrom

    2010-01-01

    Resilience thinking addresses the dynamics and development of complex social-ecological systems (SES). Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change and adapt yet remain within critical thresholds. Adaptability is part...

  20. Resilience Thinking: Integrating Resilience, Adaptability and Transformability

    NARCIS (Netherlands)

    Folke, C.; Carpenter, S.R.; Walker, B.; Scheffer, M.; Chapin, T.; Rockstrom, J.

    2010-01-01

    Resilience thinking addresses the dynamics and development of complex social-ecological systems (SES). Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change

  1. Risk and resilience factors in coping with daily stress in adulthood: the role of age, self-concept incoherence, and personal control.

    Science.gov (United States)

    Diehl, Manfred; Hay, Elizabeth L

    2010-09-01

    This study observed young, middle-aged, and older adults (N = 239; Mage = 49.6 years; range = 18-89 years) for 30 consecutive days to examine the association between daily stress and negative affect, taking into account potential risk (i.e., self-concept incoherence) and resilience (i.e., age, perceived personal control) factors. Results indicated that younger individuals and individuals with a more incoherent self-concept showed higher average negative affect across the study. As well, individuals reported higher negative affect on days that they experienced more stress than usual and on days that they reported less control than usual. These main effects were qualified by significant interactions. In particular, the association between daily stress and negative affect was stronger on days on which adults reported low control compared with days on which they reported high control (i.e., perceptions of control buffered stress). Reactivity to daily stress did not differ for individuals of different ages or for individuals with different levels of self-concept incoherence. Although all individuals reported higher negative affect on days on which they reported less control than usual, this association was more pronounced among younger adults. The current study helps to elucidate the role of risk and resilience factors when adults are faced with daily stress.

  2. Evaluating multicast resilience in carrier ethernet

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang

    2010-01-01

    This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the ackground for resilience mechanisms and their control and e present Carrier Ethernet...... resilience methods for linear nd ring networks. By simulation we show that the vailability of a multicast connection can be significantly increased by applying protection methods....

  3. Algorithm Design and Validation for Adaptive Nonlinear Control Enhancement (ADVANCE) Technology Development for Resilient Flight Control, Phase I

    Data.gov (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...

  4. Flight Results of the NF-15B Intelligent Flight Control System (IFCS) Aircraft with Adaptation to a Longitudinally Destabilized Plant

    Science.gov (United States)

    Bosworth, John T.

    2008-01-01

    Adaptive flight control systems have the potential to be resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. The goal for the adaptive system is to provide an increase in survivability in the event that these extreme changes occur. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane. The adaptive element was incorporated into a dynamic inversion controller with explicit reference model-following. As a test the system was subjected to an abrupt change in plant stability simulating a destabilizing failure. Flight evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to stabilize the vehicle and reestablish good onboard reference model-following. Flight evaluation with the simulated destabilizing failure and adaptation engaged showed improvement in the vehicle stability margins. The convergent properties of this initial system warrant additional improvement since continued maneuvering caused continued adaptation change. Compared to the non-adaptive system the adaptive system provided better closed-loop behavior with improved matching of the onboard reference model. A detailed discussion of the flight results is presented.

  5. Laboratory evaluation of airborne particulate control treatments for simulated aircraft crash recovery operations involving carbon fiber composite materials.

    Science.gov (United States)

    Ferreri, Matthew; Slagley, Jeremy; Felker, Daniel

    2015-01-01

    This study compared four treatment protocols to reduce airborne composite fiber particulates during simulated aircraft crash recovery operations. Four different treatments were applied to determine effectiveness in reducing airborne composite fiber particulates as compared to a "no treatment" protocol. Both "gold standard" gravimetric methods and real-time instruments were used to describe mass per volume concentration, particle size distribution, and surface area. The treatment protocols were applying water, wetted water, wax, or aqueous film-forming foam (AFFF) to both burnt and intact tickets of aircraft composite skin panels. The tickets were then cut using a small high-speed rotary tool to simulate crash recovery operations. Aerosol test chamber. None. Airborne particulate control treatments. Measures included concentration units of milligrams per cubic meter of air, particle size distribution as described by both count median diameter and mass median diameter and geometric standard deviation of particles in micrometers, and surface area concentration in units of square micrometers per cubic centimeter. Finally, a Monte Carlo simulation was run on the particle size distribution results. Comparison was made via one-way analysis of variance. A significant difference (pcrash recovery operations should include a treatment of the debris with water or wetted water. The resulting increase in particle size will make respiratory protection more effective in protecting the response crews.

  6. Fault Diagnosis for the Heat Exchanger of the Aircraft Environmental Control System Based on the Strong Tracking Filter

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system’s efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

  7. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  8. The Cognitive Challenges of Flying a Remotely Piloted Aircraft

    Science.gov (United States)

    Hobbs, Alan; Cardoza, Colleen; Null, Cynthia

    2016-01-01

    A large variety of Remotely Piloted Aircraft (RPA) designs are currently in production or in development. These aircraft range from small electric quadcopters that are flown close to the ground within visual range of the operator, to larger systems capable of extended flight in airspace shared with conventional aircraft. Before RPA can operate routinely and safely in civilian airspace, we need to understand the unique human factors associated with these aircraft. The task of flying an RPA in civilian airspace involves challenges common to the operation of other highly-automated systems, but also introduces new considerations for pilot perception, decision-making, and action execution. RPA pilots participated in focus groups where they were asked to recall critical incidents that either presented a threat to safety, or highlighted a case where the pilot contributed to system resilience or mission success. Ninety incidents were gathered from focus-groups. Human factor issues included the impact of reduced sensory cues, traffic separation in the absence of an out-the-window view, control latencies, vigilance during monotonous and ultra-long endurance flights, control station design considerations, transfer of control between control stations, the management of lost link procedures, and decision-making during emergencies. Some of these concerns have received significant attention in the literature, or are analogous to human factors of manned aircraft. The presentation will focus on issues that are poorly understood, and have not yet been the subject of extensive human factors study. Although many of the reported incidents were related to pilot error, the participants also provided examples of the positive contribution that humans make to the operation of highly-automated systems.

  9. Refining Trait Resilience: Identifying Engineering, Ecological, and Adaptive Facets from Extant Measures of Resilience.

    Directory of Open Access Journals (Sweden)

    John Maltby

    Full Text Available The current paper presents a new measure of trait resilience derived from three common mechanisms identified in ecological theory: Engineering, Ecological and Adaptive (EEA resilience. Exploratory and confirmatory factor analyses of five existing resilience scales suggest that the three trait resilience facets emerge, and can be reduced to a 12-item scale. The conceptualization and value of EEA resilience within the wider trait and well-being psychology is illustrated in terms of differing relationships with adaptive expressions of the traits of the five-factor personality model and the contribution to well-being after controlling for personality and coping, or over time. The current findings suggest that EEA resilience is a useful and parsimonious model and measure of trait resilience that can readily be placed within wider trait psychology and that is found to contribute to individual well-being.

  10. Refining Trait Resilience: Identifying Engineering, Ecological, and Adaptive Facets from Extant Measures of Resilience

    Science.gov (United States)

    Maltby, John; Day, Liz; Hall, Sophie

    2015-01-01

    The current paper presents a new measure of trait resilience derived from three common mechanisms identified in ecological theory: Engineering, Ecological and Adaptive (EEA) resilience. Exploratory and confirmatory factor analyses of five existing resilience scales suggest that the three trait resilience facets emerge, and can be reduced to a 12-item scale. The conceptualization and value of EEA resilience within the wider trait and well-being psychology is illustrated in terms of differing relationships with adaptive expressions of the traits of the five-factor personality model and the contribution to well-being after controlling for personality and coping, or over time. The current findings suggest that EEA resilience is a useful and parsimonious model and measure of trait resilience that can readily be placed within wider trait psychology and that is found to contribute to individual well-being. PMID:26132197

  11. Integration and In-Field Gains Selection of Flight and Navigation Controller for Remotely Piloted Aircraft System

    Directory of Open Access Journals (Sweden)

    Słowik Maciej

    2017-03-01

    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.

  12. Hybrid Active-Passive Systems for Control of Aircraft Interior Noise

    Science.gov (United States)

    Fuller, Chris R.; Palumbo, Dan (Technical Monitor)

    2002-01-01

    It was proposed to continue with development and application in the two active-passive areas of Active Tuned Vibration Absorbers (ATVA) and smart foam applied to the reduction of interior noise in aircraft. In general the work was focused on making both techniques more efficient, practical and robust thus increasing their application potential. The work was also concerned with demonstrating the potential of these two technologies under realistic implementations as well as understanding the fundamental physics of the systems. The proposed work consisted of a three-year program and was tightly coordinated with related work being carried out in the Structural Acoustics Branch at NASA LaRC. The work was supervised and coordinated through all phases by Prof Chris Fuller of Va Tech.

  13. A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation Strategies

    Science.gov (United States)

    Simon, Donald L.; Rinehart, Aidan W.; Jones, Scott M.

    2017-01-01

    Aircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a potential safety hazard. The aviation community is conducting research to understand this phenomena, and to identify avoidance and mitigation strategies to address the concern. To support this research, a dynamic turbofan engine model has been created to enable the development and evaluation of engine icing detection and control-based mitigation strategies. This model captures the dynamic engine response due to high ice water ingestion and the buildup of ice blockage in the engines low pressure compressor. It includes a fuel control system allowing engine closed-loop control effects during engine icing events to be emulated. The model also includes bleed air valve and horsepower extraction actuators that, when modulated, change overall engine operating performance. This system-level model has been developed and compared against test data acquired from an aircraft turbofan engine undergoing engine icing studies in an altitude test facility and also against outputs from the manufacturers customer deck. This paper will describe the model and show results of its dynamic response under open-loop and closed-loop control operating scenarios in the presence of ice blockage buildup compared against engine test cell data. Planned follow-on use of the model for the development and evaluation of icing detection and control-based mitigation strategies will also be discussed. The intent is to combine the model and control mitigation logic with an engine icing risk calculation tool capable of predicting the risk of engine icing based on current operating conditions. Upon detection of an operating region of risk for engine icing events, the control mitigation logic will seek to change the

  14. Flight Test Comparison of Different Adaptive Augmentations for Fault Tolerant Control Laws for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.; Hanson, Curtis E.; Lee, James A.; Kaneshige, John T.

    2009-01-01

    This report describes the improvements and enhancements to a neural network based approach for directly adapting to aerodynamic changes resulting from damage or failures. This research is a follow-on effort to flight tests performed on the NASA F-15 aircraft as part of the Intelligent Flight Control System research effort. Previous flight test results demonstrated the potential for performance improvement under destabilizing damage conditions. Little or no improvement was provided under simulated control surface failures, however, and the adaptive system was prone to pilot-induced oscillations. An improved controller was designed to reduce the occurrence of pilot-induced oscillations and increase robustness to failures in general. This report presents an analysis of the neural networks used in the previous flight test, the improved adaptive controller, and the baseline case with no adaptation. Flight test results demonstrate significant improvement in performance by using the new adaptive controller compared with the previous adaptive system and the baseline system for control surface failures.

  15. Cooperative synthesis of control and display augmentation for a STOL aircraft in the approach and landing task

    Science.gov (United States)

    Garg, Sanjay; Schmidt, David K.

    1988-01-01

    Application of the Cooperative methodology to synthesize control/display augmentation systems for the piloted longitudinal landing task with a modern, statically-unstable, fighter aircraft is considered. Starting with a control augmentation law which yields augmented vehicle dynamics that meet Level I handling qualities specifications, the effect of time-delay in the Head-up-display is studied using model-based criterion. This evaluation showed that even with 'good' conventional dynamics, a realistic value of display time-delay will cause significant deterioration in pilot workload and piloted-system performance. Application of the Cooperative methodology to control augmentation alone resulted in augmented vehicle dynamics which provide direct control of the flight path from the pilot stick. Analytical evaluation of these dynamics indicates that such dynamics might lead to improved pilot ratings over conventional dynamics, especially in the presence of time-delays in the system. Also, application of the methodology to simultaneous synthesis of control augmentation and flight director laws revealed that it might be advantageous to consider the control/display trade-off in the early design stages.

  16. Linear Extended State Observer-Based Motion Synchronization Control for Hybrid Actuation System of More Electric Aircraft

    Directory of Open Access Journals (Sweden)

    Xingjian Wang

    2017-10-01

    Full Text Available Moving towards the more electric aircraft (MEA, a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA into primary flight control. In the hybrid actuation system (HAS, an electro-hydraulic servo actuator (EHSA and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA.

  17. New Methodology for Optimal Flight Control Using Differential Evolution Algorithms Applied on the Cessna Citation X Business Aircraft – Part 1. Design and Optimization

    OpenAIRE

    Yamina BOUGHARI; Georges GHAZI; Ruxandra Mihaela BOTEZ; Florian THEEL

    2017-01-01

    Setting the appropriate controllers for aircraft stability and control augmentation systems are complicated and time consuming tasks. As in the Linear Quadratic Regulator method gains are found by selecting the appropriate weights or as in the Proportional Integrator Derivative control by tuning gains. A trial and error process is usually employed for the determination of weighting matrices, which is normally a time consuming procedure. Flight Control Law were optimized and designed by combin...

  18. Numerical Stability and Control Analysis Towards Falling-Leaf Prediction Capabilities of Splitflow for Two Generic High-Performance Aircraft Models

    Science.gov (United States)

    Charlton, Eric F.

    1998-01-01

    Aerodynamic analysis are performed using the Lockheed-Martin Tactical Aircraft Systems (LMTAS) Splitflow computational fluid dynamics code to investigate the computational prediction capabilities for vortex-dominated flow fields of two different tailless aircraft models at large angles of attack and sideslip. These computations are performed with the goal of providing useful stability and control data to designers of high performance aircraft. Appropriate metrics for accuracy, time, and ease of use are determined in consultations with both the LMTAS Advanced Design and Stability and Control groups. Results are obtained and compared to wind-tunnel data for all six components of forces and moments. Moment data is combined to form a "falling leaf" stability analysis. Finally, a handful of viscous simulations were also performed to further investigate nonlinearities and possible viscous effects in the differences between the accumulated inviscid computational and experimental data.

  19. Predicting visibility of aircraft.

    Science.gov (United States)

    Watson, Andrew; Ramirez, Cesar V; Salud, Ellen

    2009-05-20

    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.

  20. Temperature Controlled Aircraft Unit Load Devices: The Technological Response to Growing Global Air Cargo Cool Chain Requirements

    Directory of Open Access Journals (Sweden)

    Glenn Baxter

    2015-04-01

    Full Text Available Unit load devices (ULDs are pallets and containers which are used to carry air cargo, mail and passengers baggage on wide-body aircraft. Using an in-depth case study, an empirical investigation was undertaken to examine the recent technological developments and innovations in the temperature-controlled containers that are used extensively in the growing and highly important air cargo cool chains. The results demonstrated that advances in refrigeration systems and the use of composite materials used in the construction of these containers have enhanced the ability of key stakeholders to provide unbroken cool-chains. The study further demonstrated that the services and expertise of Envirotainer, the case company, as well as its strategic partnerships with key stakeholders, underpin its ability to deliver and capture value from its participation in the industry.

  1. Reconfigurable Control Design with Neural Network Augmentation for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.

    2007-01-01

    The viewgraphs present background information about reconfiguration control design, design methods used for paper, control failure survivability results, and results and time histories of tests. Topics examined include control reconfiguration, general information about adaptive controllers, model reference adaptive control (MRAC), the utility of neural networks, radial basis functions (RBF) neural network outputs, neurons, and results of investigations of failures.

  2. The Aircraft Attitude Robust Inversion Fault-tolerant Control Based on Observer

    Directory of Open Access Journals (Sweden)

    Zhou Hong-Cheng

    2014-09-01

    Full Text Available For attitude control system, based on instruction filter back-stepping techniques, a robust fault-tolerant control method is proposed. Firstly, attitude control system mathematical model is given, on this basis, the attitude control system under the modeling errors caused by uncertainty, external disturbances and control surfaces faults are considered. The fault tolerant control design involves two main units, one is auxiliary system design, the other is controller design using the auxiliary system. Finally, the simulation results show that the proposed method can make the tracking performance for flight control system.

  3. A randomized controlled trial of a resilience-based intervention on psychosocial well-being of children affected by HIV/AIDS: Effects at 6- and 12-month follow-up.

    Science.gov (United States)

    Li, Xiaoming; Harrison, Sayward E; Fairchild, Amanda J; Chi, Peilian; Zhao, Junfeng; Zhao, Guoxiang

    2017-10-01

    Global literature suggests that resilience-based interventions may yield improvements in psychosocial well-being for vulnerable children, but limited data are available regarding the efficacy of such interventions among children affected by parental HIV/AIDS. To evaluate initial efficacy of a multi-level resilience-based intervention among children affected by parental HIV/AIDS in China in improving children's psychosocial well-being and resilience-related outcomes. Seven hundred-ninety children, 6-17 years of age, were recruited from rural China. Children were either AIDS orphans or were living with one or two parents infected with HIV/AIDS. Children and primary caregivers were randomly assigned to participate in a 4-arm trial to evaluate the Child-Caregiver-Advocacy Resilience (ChildCARE) intervention. This resilience-based psychosocial intervention provides programming at three levels (child, caregiver, community). Survey data were collected at baseline, 6-months, and 12-months in order to examine efficacy of the child-only and child + caregiver arms in improving children's psychological resilience. Intervention groups displayed improvements in several resilience-related outcomes at 6- and 12-month follow-ups, including self-reported coping, hopefulness, emotional regulation, and self-control. The child-only intervention arm showed some fading of intervention effects by 12-months. Preliminary findings suggest that the ChildCARE intervention is efficacious in promoting psychosocial well-being of children affected by parental HIV/AIDS in rural China. Targeting both children and caregivers for psychosocial intervention may be effective in improving children's resilience. Additional evaluation and modifications, including the inclusion of booster sessions, should be considered to further strengthen the program. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Production Support Flight Control Computers: Research Capability for F/A-18 Aircraft at Dryden Flight Research Center

    Science.gov (United States)

    Carter, John F.

    1997-01-01

    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.

  5. Model-Based Control of a Nonlinear Aircraft Engine Simulation using an Optimal Tuner Kalman Filter Approach

    Science.gov (United States)

    Connolly, Joseph W.; Csank, Jeffrey Thomas; Chicatelli, Amy; Kilver, Jacob

    2013-01-01

    This paper covers the development of a model-based engine control (MBEC) methodology featuring a self tuning on-board model applied to an aircraft turbofan engine simulation. Here, the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) serves as the MBEC application engine. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC over a wide range of operating points. The on-board model is a piece-wise linear model derived from CMAPSS40k and updated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. Investigations using the MBEC to provide a stall margin limit for the controller protection logic are presented that could provide benefits over a simple acceleration schedule that is currently used in traditional engine control architectures.

  6. The Aircraft Morphing Program

    Science.gov (United States)

    Wlezien, R. W.; Horner, G. C.; McGowan, A. R.; Padula, S. L.; Scott, M. A.; Silcox, R. J.; Simpson, J. O.

    1998-01-01

    In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest- payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition.

  7. Essentials of aircraft armaments

    CERN Document Server

    Kaushik, Mrinal

    2017-01-01

    This book aims to provide a complete exposure about armaments from their design to launch from the combat aircraft. The book details modern ammunition and their tactical roles in warfare. The proposed book discusses aerodynamics, propulsion, structural as well as navigation, control, and guidance of aircraft armament. It also introduces the various types of ammunition developed by different countries and their changing trends. The book imparts knowledge in the field of design, and development of aircraft armaments to aerospace engineers and covers the role of the United Nations in peacekeeping and disarmament. The book will be very useful to researchers, students, and professionals working in design and manufacturing of aircraft armaments. The book will also serve air force and naval aspirants, and those interested in working on defence research and developments organizations. .

  8. Nonlinear Lateral Command Control Using Neural Network for F-16 Aircraft

    OpenAIRE

    Suresh, S; Kannan, N; Omkar, SN; Mani, V

    2005-01-01

    A discrete time neural network based lateral controller design for an F-16 nonlinear model is presented. The controller is designed using model reference indirect adaptive control and the input output representation and control law for nonlinear model are established using system theory. The input-output representation and control law are approximated using neural networks with linear filters. The design takes into account the multi input multi output nature of the lateral model. Roll rate an...

  9. 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.

    1998-01-01

    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

  10. The algorithmic details of polynomials application in the problems of heat and mass transfer control on the hypersonic aircraft permeable surfaces

    Science.gov (United States)

    Bilchenko, G. G.; Bilchenko, N. G.

    2018-03-01

    The hypersonic aircraft permeable surfaces heat and mass transfer effective control mathematical modeling problems are considered. The analysis of the control (the blowing) constructive and gasdynamical restrictions is carried out for the porous and perforated surfaces. The functions classes allowing realize the controls taking into account the arising types of restrictions are suggested. Estimates of the computational complexity of the W. G. Horner scheme application in the case of using the C. Hermite interpolation polynomial are given.

  11. Of resilient places: planning for urban resilience

    OpenAIRE

    Mehmood, Abid

    2016-01-01

    This paper argues that resilience of a place cannot necessarily be associated only with the level of its vulnerability to the environment or security. A place-based perspective to resilience helps understand the capacity of communities to withstand or adapt with change. Resilience of a place does not only refer to contingencies—such as formulating immediate responses to crisis situations or incidents such as earthquakes, floods or other disasters in vulnerable areas—but also considers long-te...

  12. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

    Science.gov (United States)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

  13. Resilience Thinking: Integrating Resilience, Adaptability and Transformability

    Directory of Open Access Journals (Sweden)

    Carl Folke

    2010-12-01

    Full Text Available Resilience thinking addresses the dynamics and development of complex social-ecological systems (SES. Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change and adapt yet remain within critical thresholds. Adaptability is part of resilience. It represents the capacity to adjust responses to changing external drivers and internal processes and thereby allow for development along the current trajectory (stability domain. Transformability is the capacity to cross thresholds into new development trajectories. Transformational change at smaller scales enables resilience at larger scales. The capacity to transform at smaller scales draws on resilience from multiple scales, making use of crises as windows of opportunity for novelty and innovation, and recombining sources of experience and knowledge to navigate social-ecological transitions. Society must seriously consider ways to foster resilience of smaller more manageable SESs that contribute to Earth System resilience and to explore options for deliberate transformation of SESs that threaten Earth System resilience.

  14. Aero-Effected Distributed Adaptive Control of Flexible Aircraft Using Active Bleed, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research focuses on the development of a new adaptive control methodology for active control of wing aerodynamic shape to effect distributed aerodynamic...

  15. Multi-Objective Flight Control for Drag Minimization and Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft

    Science.gov (United States)

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

    2017-01-01

    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

  16. 76 FR 68675 - Revisions to the Export Administration Regulations (EAR): Control of Aircraft and Related Items...

    Science.gov (United States)

    2011-11-07

    ... Administration's ongoing Export Control Reform Initiative, BIS published a proposed rule (76 FR 41958) (``the... Administration's ultimate Export Control Reform objectives. In order to reach more quickly the national security... Administration has stated since the beginning of the Export Control Reform Initiative that the reforms will be...

  17. Full Envelope Modular Adaptive Control of a Fighter Aircraft using Orthogonal Least Squares

    NARCIS (Netherlands)

    Van Oort, E.R.; Sonneveldt, L.; Chu, Q.P.; Mulder, J.A.

    2010-01-01

    A new adaptive nonlinear flight controller is designed for a high fidelity, six degrees of freedom F-16 model for the entire flight envelope. The design is based on a modular approach which separates the design of the control law and the online identifier. The control law design is based on

  18. 'Resilience thinking' in transport planning

    OpenAIRE

    Wang, JYT

    2015-01-01

    Resilience has been discussed in ecology for over forty years. While some aspects of resilience have received attention in transport planning, there is no unified definition of resilience in transportation. To define resilience in transportation, I trace back to the origin of resilience in ecology with a view of revealing the essence of resilience thinking and its relevance to transport planning. Based on the fundamental concepts of engineering resilience and ecological resilience, I define "...

  19. Rethinking resilience from indigenous perspectives.

    Science.gov (United States)

    Kirmayer, Laurence J; Dandeneau, Stéphane; Marshall, Elizabeth; Phillips, Morgan Kahentonni; Williamson, Karla Jessen

    2011-02-01

    The notions of resilience that have emerged in developmental psychology and psychiatry in recent years require systematic rethinking to address the distinctive cultures, geographic and social settings, and histories of adversity of indigenous peoples. In Canada, the overriding social realities of indigenous peoples include their historical rootedness to a specific place (with traditional lands, communities, and transactions with the environment) and the profound displacements caused by colonization and subsequent loss of autonomy, political oppression, and bureaucratic control. We report observations from an ongoing collaborative project on resilience in Inuit, Métis, Mi'kmaq, and Mohawk communities that suggests the value of incorporating indigenous constructs in resilience research. These constructs are expressed through specific stories and metaphors grounded in local culture and language; however, they can be framed more generally in terms of processes that include: regulating emotion and supporting adaptation through relational, ecocentric, and cosmocentric concepts of self and personhood; revisioning collective history in ways that valorize collective identity; revitalizing language and culture as resources for narrative self-fashioning, social positioning, and healing; and renewing individual and collective agency through political activism, empowerment, and reconciliation. Each of these sources of resilience can be understood in dynamic terms as emerging from interactions between individuals, their communities, and the larger regional, national, and global systems that locate and sustain indigenous agency and identity. This social-ecological view of resilience has important implications for mental health promotion, policy, and clinical practice.

  20. Building Resilience in Children

    Science.gov (United States)

    ... to succeed in life. That is why Kenneth Ginsburg, M.D., MS Ed, FAAP, a pediatrician specializing ... resilience in children, teens, and young adults. Dr. Ginsburg has identified seven “C”s of resilience, recognizing that “ ...

  1. Resiliant Space Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The task goal is to develop and demonstrate an innovative software architecture, the “Resilient Spacecraft Executive”, that will enable highly-resilient...

  2. Developing the resilience typology

    DEFF Research Database (Denmark)

    Simonsen, Daniel Morten

    2013-01-01

    There is a growing interest in resilience in internal crisis management and crisis communication. How an organization can build up resilience as a response to organisational crisis, at a time when the amount of crises seem only to increase, is more relevant than ever before. Nevertheless resilience...... is often perceived in the literature as something certain organisations have by definition, without further reflection on what it is that creates this resiliency. This article explores what it is that creates organisational resilience, and in view of the different understandings of the resilience...... phenomenon, develops a typology of resilience. Furthermore the resilience phenomenon is discussed against the definition of a crisis as a cosmological episode, and implications for future research is discussed and summarized....

  3. Experimental investigation of elastic mode control on a model of a transport aircraft

    Science.gov (United States)

    Abramovitz, M.; Heimbaugh, R. M.; Nomura, J. K.; Pearson, R. M.; Shirley, W. A.; Stringham, R. H.; Tescher, E. L.; Zoock, I. E.

    1981-01-01

    A 4.5 percent DC-10 derivative flexible model with active controls is fabricated, developed, and tested to investigate the ability to suppress flutter and reduce gust loads with active controlled surfaces. The model is analyzed and tested in both semispan and complete model configuration. Analytical methods are refined and control laws are developed and successfully tested on both versions of the model. A 15 to 25 percent increase in flutter speed due to the active system is demonstrated. The capability of an active control system to significantly reduce wing bending moments due to turbulence is demonstrated. Good correlation is obtained between test and analytical prediction.

  4. Distributed Control of Nonlinear Aircraft Structures Including Aerodynamic and Temperature Interactions

    National Research Council Canada - National Science Library

    Tzou, H

    2004-01-01

    .... Distributed sensing/actuation, thermoelectromechanical/control equations and boundary conditions including elastic, temperature, and piezoelectric couplings are derived and applied to distributed...

  5. Amphibious Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — A brief self composed research article on Amphibious Aircrafts discussing their use, origin and modern day applications along with their advantages and disadvantages...

  6. Resilience - A Concept

    Science.gov (United States)

    2016-04-05

    Image designed by Diane Fleischer Resilience —A CONCEPT Col Dennis J. Rensel, USAF (Ret.) Resilience takes on many definitions and ideas depending...upon who is speaking. Taking this one step further, consider resiliency as a concept that provides a holistic view of a system or capability, just...the assessment of the health of a network or system. The hypothesis is: resiliency is meaningful in the context of holistic assessments of

  7. ANALYSIS OF THE HUMAN FACTOR AT CONTROL OF THE MODERN AIRCRAFT

    Directory of Open Access Journals (Sweden)

    С.В. Павлова

    2012-12-01

    Full Text Available  Functional interaction features of the operator with a difficult control system have been considered at airplane control. Necessity of working out of vector model of the operator as integral part of difficult system has been revealed.

  8. Beyond Rigid Body: Integrated Structural Control of Extremely Lightweight Flexible Aircraft

    Science.gov (United States)

    Bosworth, John T.

    2013-01-01

    Integrated structural control of extremely lightweight vehicles will open a new paradigm and allow for performance increases. The X-56A Multi-Utility Technology Testbed (MUTT) vehicle will be used to evaluate and advance the state-of-the-art in modeling and control of this new class of aerospace vehicle.

  9. Arctic species resilience

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

    the predicted increase in climate variability. Whereas species may show relatively high phenological resilience to climate change per se, the resilience of systems may be more constrained by the inherent dependence through consumer-resource interactions across trophic levels. During the last 15 years...... and resources. This poster will present the conceptual framework for this project focusing on species resilience....

  10. Resilience among Military Youth

    Science.gov (United States)

    Easterbrooks, M. Ann; Ginsburg, Kenneth; Lerner, Richard M.

    2013-01-01

    In this article, the authors present their approach to understanding resilience among military connected young people, and they discuss some of the gaps in their knowledge. They begin by defining resilience, and then present a theoretical model of how young people demonstrate resilient functioning. Next they consider some of the research on…

  11. Warrior Resilience Training in Operation Iraqi Freedom: combining rational emotive behavior therapy, resiliency, and positive psychology.

    Science.gov (United States)

    Jarrett, Thomas

    2008-01-01

    Warrior Resilience Training (WRT) is an educational class designed to enhance Warrior resilience, thriving, and posttraumatic growth for Soldiers deployed in Operation Iraqi Freedom. Warrior Resilience Training uses rational emotive behavior therapy (REBT), Army leadership principles, and positive psychology as a vehicle for students to apply resilient philosophies derived from Army Warrior Ethos, Stoic philosophy, and the survivor and resiliency literature. Students in WRT are trained to focus upon virtue, character, and emotional self-regulation by constructing and maintaining a personal resiliency philosophy that emphasizes critical thinking, rationality, virtue, and Warrior Ethos. The author, an Army licensed clinical social worker, executive coach, REBT doctoral fellow, and former Special Forces noncommissioned officer, describes his initial experience teaching WRT during Operation Iraqi Freedom to combat medics and Soldiers from 2005 to 2006, and his experience as a leader of a combat stress control prevention team currently in Iraq offering mobile WRT classes in-theater. Warrior Resilience Training rationale, curriculum, variants (like Warrior Family Resilience Training), and feedback are included, with suggestions as to how behavioral health providers and combat stress control teams might better integrate their services with leaders, chaplains, and commands to better market combat stress resiliency, reduce barriers to care, and promote force preservation. Informal analysis of class feedback from 1168 respondents regarding WRT reception and utilization is examined.

  12. Integrated Reconfigurable Aero and Propulsion Control for Improved Flight Safety of Commercial Aircraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this project is to develop and test a novel innovative Integrated Reconfigurable Aero (i) Adaptive control design for the case of aero-only...

  13. Nonlinear robust control of hypersonic aircrafts with interactions between flight dynamics and propulsion systems.

    Science.gov (United States)

    Li, Zhaoying; Zhou, Wenjie; Liu, Hao

    2016-09-01

    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.

  14. Aircraft Control Augmentation and Health Monitoring Using FADS Technology, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I research proposal is aimed at demonstrating the feasibility of an innovative architecture comprising control augmentation and on-line health monitoring...

  15. Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

    Science.gov (United States)

    Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

    1972-01-01

    The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

  16. Identification and Control of Aircrafts using Multiple Models and Adaptive Critics

    Science.gov (United States)

    Principe, Jose C.

    2007-01-01

    We compared two possible implementations of local linear models for control: one approach is based on a self-organizing map (SOM) to cluster the dynamics followed by a set of linear models operating at each cluster. Therefore the gating function is hard (a single local model will represent the regional dynamics). This simplifies the controller design since there is a one to one mapping between controllers and local models. The second approach uses a soft gate using a probabilistic framework based on a Gaussian Mixture Model (also called a dynamic mixture of experts). In this approach several models may be active at a given time, we can expect a smaller number of models, but the controller design is more involved, with potentially better noise rejection characteristics. Our experiments showed that the SOM provides overall best performance in high SNRs, but the performance degrades faster than with the GMM for the same noise conditions. The SOM approach required about an order of magnitude more models than the GMM, so in terms of implementation cost, the GMM is preferable. The design of the SOM is straight forward, while the design of the GMM controllers, although still reasonable, is more involved and needs more care in the selection of the parameters. Either one of these locally linear approaches outperform global nonlinear controllers based on neural networks, such as the time delay neural network (TDNN). Therefore, in essence the local model approach warrants practical implementations. In order to call the attention of the control community for this design methodology we extended successfully the multiple model approach to PID controllers (still today the most widely used control scheme in the industry), and wrote a paper on this subject. The echo state network (ESN) is a recurrent neural network with the special characteristics that only the output parameters are trained. The recurrent connections are preset according to the problem domain and are fixed. In a

  17. An Aircraft Electric Power Testbed for Validating Automatically Synthesized Reactive Control Protocols

    Science.gov (United States)

    2013-01-01

    we describe our recently developed simulation models and a hardware testbed for validating reactive controllers synthesized using TuLiP [1], a...temporal logic planning toolbox, in order to investigate the validity of the assumptions made in controller synthesis. TuLiP is a collection of Python... TuLiP can be used to synthesize logic so that the satisfaction of certain safety requirements is guaranteed. The synthesized logic enables the contac

  18. Predicting Time Series Outputs and Time-to-Failure for an Aircraft Controller Using Bayesian Modeling

    Science.gov (United States)

    He, Yuning

    2015-01-01

    Safety of unmanned aerial systems (UAS) is paramount, but the large number of dynamically changing controller parameters makes it hard to determine if the system is currently stable, and the time before loss of control if not. We propose a hierarchical statistical model using Treed Gaussian Processes to predict (i) whether a flight will be stable (success) or become unstable (failure), (ii) the time-to-failure if unstable, and (iii) time series outputs for flight variables. We first classify the current flight input into success or failure types, and then use separate models for each class to predict the time-to-failure and time series outputs. As different inputs may cause failures at different times, we have to model variable length output curves. We use a basis representation for curves and learn the mappings from input to basis coefficients. We demonstrate the effectiveness of our prediction methods on a NASA neuro-adaptive flight control system.

  19. Design and flight experience with a digital fly-by-wire control system using Apollo guidance system hardware on an F-8 aircraft.

    Science.gov (United States)

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

    1972-01-01

    This paper discusses the design and initial flight tests of the first digital fly-by-wire system to be flown in an aircraft. The system, which used components from the Apollo guidance system, was installed in an F-8 aircraft. A lunar module guidance computer is the central element in the three-axis, single-channel, multimode, digital, primary control system. An electrohydraulic triplex system providing unaugmented control of the F-8 aircraft is the only backup to the digital system. Emphasis is placed on the digital system in its role as a control augmentor, a logic processor, and a failure detector. A sampled-data design synthesis example is included to demonstrate the role of various analytical and simulation methods. The use of a digital system to implement conventional control laws was shown to be practical for flight. Logic functions coded as an integral part of the control laws were found to be advantageous. Verification of software required an extensive effort, but confidence in the software was achieved. Initial flight results showed highly successful system operation, although quantization of pilot's stick and trim were areas of minor concern from the piloting standpoint.

  20. Making teams more resilient : Effects of shared transformational leadership training on resilience

    NARCIS (Netherlands)

    Kleij, R. van der; Molenaar, D.; Schraagen, J.M.

    2011-01-01

    Resilience is of great importance to teams operating in complex environments, such as command and control teams. Team resilience is the ability of teams to respond to sudden, unanticipated demands for performance quickly and with minimum decrement of performance. The objective of this study was to

  1. Gust load estimation and rejection with application to robust flight control design for HALE aircraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High Altitude Long Endurance (HALE) aircraft have garnered increased interest in recent years as they can serve several purposes, including many of the objectives of...

  2. Design of Prototype-Technology Evaluator and Research Aircraft (PTERA) Configuration for Loss of Control Flight Research, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Area-I team has developed and fabricated the unmanned Prototype-Technology Evaluation and Research Aircraft or PTERA ("ptera" being Greek for wing, or...

  3. Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines

    Data.gov (United States)

    National Aeronautics and Space Administration — Software-in-the-loop and hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and...

  4. Transient performance simulation of aircraft engine integrated with fuel and control systems

    International Nuclear Information System (INIS)

    Wang, C.; Li, Y.G.; Yang, B.Y.

    2017-01-01

    Highlights: • A new performance simulation method for engine hydraulic fuel systems is introduced. • Time delay of engine performance due to fuel system model is noticeable but small. • The method provides details of fuel system behavior in engine transient processes. • The method could be used to support engine and fuel system designs. - Abstract: A new method for the simulation of gas turbine fuel systems based on an inter-component volume method has been developed. It is able to simulate the performance of each of the hydraulic components of a fuel system using physics-based models, which potentially offers more accurate results compared with those using transfer functions. A transient performance simulation system has been set up for gas turbine engines based on an inter-component volume (ICV) method. A proportional-integral (PI) control strategy is used for the simulation of engine controller. An integrated engine and its control and hydraulic fuel systems has been set up to investigate their coupling effect during engine transient processes. The developed simulation system has been applied to a model aero engine. The results show that the delay of the engine transient response due to the inclusion of the fuel system model is noticeable although relatively small. The developed method is generic and can be applied to any other gas turbines and their control and fuel systems.

  5. Adaptive Control Law Development for Failure Compensation Using Neural Networks on a NASA F-15 Aircraft

    Science.gov (United States)

    Burken, John J.

    2005-01-01

    This viewgraph presentation covers the following topics: 1) Brief explanation of Generation II Flight Program; 2) Motivation for Neural Network Adaptive Systems; 3) Past/ Current/ Future IFCS programs; 4) Dynamic Inverse Controller with Explicit Model; 5) Types of Neural Networks Investigated; and 6) Brief example

  6. Interactive aircraft flight control and aeroelastic stabilization. [forward swept wing flight vehicles

    Science.gov (United States)

    Weisshaar, T. A.; Schmidt, D. K.

    1981-01-01

    Several examples are presented in which flutter involving interaction between flight mechanics modes and elastic wind bending occurs for a forward swept wing flight vehicle. These results show the basic mechanism by which the instability occurs and form the basis for attempts to actively control such a vehicle.

  7. Communications Technology Assessment for the Unmanned Aircraft System (UAS) Control and Non-Payload Communications (CNPC) Link

    Science.gov (United States)

    Bretmersky, Steven C.; Bishop, William D.; Dailey, Justin E.; Chevalier, Christine T.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is performing communications systems research for the Unmanned Aircraft System (UAS) in the National Airspace System (NAS) Project. One of the goals of the communications element is to select and test a communications technology for the UAS Control and Non-Payload Communications (CNPC) link. The GRC UAS Modeling and Simulation (M/S) Sub Team will evaluate the performance of several potential technologies for the CNPC link through detailed software simulations. In parallel, an industry partner will implement a technology in hardware to be used for flight testing. The task necessitated a technical assessment of existing Radio Frequency (RF) communications technologies to identify the best candidate systems for use as the UAS CNPC link. The assessment provides a basis for selecting the technologies for the M/S effort and the hardware radio design. The process developed for the technical assessments for the Future Communications Study1 (FCS) was used as an initial starting point for this assessment. The FCS is a joint Federal Aviation Administration (FAA) and Eurocontrol study on technologies for use as a future aeronautical communications link. The FCS technology assessment process methodology can be applied to the UAS CNPC link; however the findings of the FCS are not directly applicable because of different requirements between a CNPC link and a general aeronautical data link. Additional technologies were added to the potential technologies list from the State of the Art Unmanned Aircraft System Communication Assessment developed by NASA GRC2. This document investigates the state of the art of communications as related to UAS. A portion of the document examines potential communications systems for a UAS communication architecture. Like the FCS, the state of the art assessment surveyed existing communications technologies. It did not, however, perform a detailed assessment of the

  8. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

    Science.gov (United States)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

  9. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    Directory of Open Access Journals (Sweden)

    Shrivastava Sachin

    2015-01-01

    Full Text Available The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI in unidirectional fibrous laminates using Genetic-Algorithms (GA under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT. The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  10. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    Science.gov (United States)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC) skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI) in unidirectional fibrous laminates using Genetic-Algorithms (GA) under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT). The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  11. Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

    Directory of Open Access Journals (Sweden)

    Shrivastava Sachin

    2015-01-01

    Full Text Available A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA with an objective function to have minimum failure index (FI according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

  12. Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

    Science.gov (United States)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

  13. Air Traffic Control Capabilities: Opportunity to Utilize Automated Dependent Surveillance-Broadcast (ADS-B) Equipment on Aircraft for Military Air Traffic Control and Command and Control in Combat and Humanitarian Operations

    Science.gov (United States)

    2011-01-21

    Corresponding flight records are manually updated by the controller to build a physical or mental picture of the airspace environment.9 It is clear...article6988863.ece (accessed 17 December 2010). Borrelli , George. MITRE Corporation. ADS-B Link-16 Gateway Demonstration: An Investigation of a Low-Cost ADS-B...Option for Military Aircraft. MITRE Corporation, Bedford, MA. http://www.mitre.org/work/tech_papers/tech_papers_04/borrelli_adsb/ borrelli _adsb.pdf

  14. Adaptive Positive Position Feedback Control of Flexible Aircraft Structures Using Piezoelectric Actuators

    Science.gov (United States)

    2014-03-27

    Aeronautics and Space Administration. “F/A-18 High Alpha Research Vehicle”. http://www.nasa.gov/centers/ dryden /multimedia/imagegallery/F-18HARV/ index.html...lowerAccordion-set1-slide10, April 1989. 18 February 2014. [2] John D. Anderson. Fundamentals of Aerodynamics. McGraw-Hill, New York, 5th edition, 2011...Krishnakumar, John Kaneshige, and Pascal Nespeca. “Dynamics and Adaptive Control for Stability Recovery of Damaged Asymmetric Aircraft”. Technical report

  15. Advanced Aircraft Electrical System Control Technology Demonstrator. Phase I. Analysis and Preliminary Design.

    Science.gov (United States)

    1982-01-01

    parameters are used to logically select one of the sixteen load management levels. The level can also be selected manually . Figure 6 shows parameters which...with manual override. Control of the system is distributed among the PSP, GCUs, and ELMCs. As shov.n in Figure 13, each PC and DC bus in the ELMC has...PROCESSOR SYSTEM MASS MEMORY REMOTE TERMINALS FINITIALIZE AVIONICS PROCESSOR I INITIALIZE POWER SYSTEM PROCESO INITIALIZE ELMC/ERT AI RCRAFT ,,POWER UP

  16. A piloted evaluation of an oblique-wing research aircraft motion simulation with decoupling control laws

    Science.gov (United States)

    Kempel, Robert W.; Mcneill, Walter E.; Gilyard, Glenn B.; Maine, Trindel A.

    1988-01-01

    The NASA Ames Research Center developed an oblique-wing research plane from NASA's digital fly-by-wire airplane. Oblique-wing airplanes show large cross-coupling in control and dynamic behavior which is not present on conventional symmetric airplanes and must be compensated for to obtain acceptable handling qualities. The large vertical motion simulator at NASA Ames-Moffett was used in the piloted evaluation of a proposed flight control system designed to provide decoupled handling qualities. Five discrete flight conditions were evaluated ranging from low altitude subsonic Mach numbers to moderate altitude supersonic Mach numbers. The flight control system was effective in generally decoupling the airplane. However, all participating pilots objected to the high levels of lateral acceleration encountered in pitch maneuvers. In addition, the pilots were more critical of left turns (in the direction of the trailing wingtip when skewed) than they were of right turns due to the tendency to be rolled into the left turns and out of the right turns. Asymmetric side force as a function of angle of attack was the primary cause of lateral acceleration in pitch. Along with the lateral acceleration in pitch, variation of rolling and yawing moments as functions of angle of attack caused the tendency to roll into left turns and out of right turns.

  17. Analyses of Aircraft Responses to Atmospheric Turbulence

    NARCIS (Netherlands)

    Van Staveren, W.H.J.J.

    2003-01-01

    The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate

  18. High-temperature optically activated GaAs power switching for aircraft digital electronic control

    Science.gov (United States)

    Berak, J. M.; Grantham, D. H.; Swindal, J. L.; Black, J. F.; Allen, L. B.

    1983-01-01

    Gallium arsenide high-temperature devices were fabricated and assembled into an optically activated pulse-width-modulated power control for a torque motor typical of the kinds used in jet engine actuators. A bipolar heterojunction phototransistor with gallium aluminum arsenide emitter/window, a gallium arsenide junction field-effect power transistor and a gallium arsenide transient protection diode were designed and fabricated. A high-temperature fiber optic/phototransistor coupling scheme was implemented. The devices assembled into the demonstrator were successfully tested at 250 C, proving the feasibility of actuator-located switching of control power using optical signals transmitted by fibers. Assessments of the efficiency and technical merits were made for extension of this high-temperature technology to local conversion of optical power to electrical power and its control at levels useful for driving actuators. Optical power sources included in the comparisons were an infrared light-emitting diode, an injection laser diode, tungsten-halogen lamps and arc lamps. Optical-to-electrical power conversion was limited to photovoltaics located at the actuator. Impedance matching of the photovoltaic array to the load was considered over the full temperature range, -55 C to 260 C. Loss of photovoltaic efficiency at higher temperatures was taken into account. Serious losses in efficiency are: (1) in the optical source and the cooling which they may require in the assumed 125 C ambient, (2) in the decreased conversion efficiency of the gallium arsenide photovoltaic at 260 C, and (3) in impedance matching. Practical systems require improvements in these areas.

  19. Technique for Assessing the Stability and Controllability Characteristics of Naval Aircraft Systems Based on the Rational Combination of Modeling, Identification and Flight Experiments

    Directory of Open Access Journals (Sweden)

    S. V. Nikolaev

    2015-01-01

    Full Text Available The aim of this work is to improve test quality and reliability of modern naval aircraft for assessment of stability and controllability characteristics and test shortening. To achieve this goal it is necessary to develop an algorithmic, mathematical and methodological support of the flight trials and the mathematical modeling of controlled flight modes to determine the stability and controllability characteristics of the naval aircraft.The article analyses the problems related to determining the stability and controllability characteristics under flight tests, describes the technique to correct a mathematical model of aerodynamic characteristics and engine thrust forces of modern naval aircraft. It shows the importance of using algorithm to control the correctness of onboard measurements of flight parameters. The article presents new results of identification of the aircraft aerodynamic coefficients and proves that in identifying characteristics of the longitudinal control channel it is necessary to take into account the engine thrust forces. In the article the aerodynamic coefficients, obtained by identification methods, are compared with those in the original aerodynamic data Bank.An important and new component of the work described in the fourth part of the article, is a set of computer programmes, integrated into a common interface. The development of this software has greatly improved a processing technology of the flight experiment materials and identification of the aerodynamic characteristics of the aircraft.When applying the work results in the testing phase, the required characteristics of stability and controllability are determined by simulation, and identification provides the model refinement according to the flight data.The created technology of practical identification is used to verify and refine the mathematical models according to the flight experiment data. Thus, the result is a proven and refined model of the aircraft

  20. SILHIL Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines

    Science.gov (United States)

    Bole, Brian; Teubert, Christopher Allen; Cuong Chi, Quach; Hogge, Edward; Vazquez, Sixto; Goebel, Kai; George, Vachtsevanos

    2013-01-01

    Software-in-the-loop and Hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and cost-effective testing than what is practical to conduct with flight tests. A framework is described for the offline recreation of dynamic loads on simulated or physical aircraft powertrain components based on a real-time simulation of airframe dynamics running on a flight simulator, an inner-loop flight control policy executed by either an autopilot routine or a human pilot, and a supervisory fault management control policy. The creation of an offline framework for verifying and validating supervisory failure prognostics and decision making routines is described for the example of battery charge depletion failure scenarios onboard a prototype electric unmanned aerial vehicle.

  1. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    as their purchases of aircraft carrier systems, makes it more than likely that the country is preparing such an acquisition. China has territorial disputes in the South China Sea over the Spratly Islands and is also worried about the security of its sea lines of communications, by which China transports the majority...... of its foreign trade, as well as its oil imports, upon which the country is totally dependent. China therefore has good reasons for acquiring an aircraft carrier to enable it to protect its national interests. An aircraft carrier would also be a prominent symbol of China’s future status as a great power......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...

  2. Investigations of transonic buffet control on civil aircraft wing with the use of tangential jet blowing

    Science.gov (United States)

    Abramova, K. A.; Petrov, A. V.; Potapchick, A. V.; Soudakov, V. G.

    2016-10-01

    Numerical and experimental investigations of transonic buffet control by tangential jet blowing are presented. To suppress the shock-induced boundary layer separation and the buffet at transonic speeds, compressed air jet is blown through a small slot nozzle tangentially to the upper surface of the supercritical airfoil. Numerical simulations were carried out on the basis of the unsteady Reynolds averaged Navier-Stokes (URANS) equations. Experimental studies of the tangential jet blowing were performed in the transonic wind tunnel T-112 of TsAGI. Results show that the jet moves the shock downstream, increases lift, suppresses flow separation under shock foot and delays buffet onset.

  3. Vulnerability Analysis of the MAVLink Protocol for Command and Control of Unmanned Aircraft

    Science.gov (United States)

    2013-03-27

    the payload refers to a small Nerf™ football fastened to the UAV by a small pin that is released upon receipt of a “toggle servo” command from the...MHz band for personal communication (e.g., Australia, Brazil , New Zealand, South Africa, and most of Europe) [And13]. Many UAS manufacturers and...Nerf™ footballs [Hob13, Col13]. 50 Figure 4.1: Super Sky Surfer UAV In the field experiments, the autopilot is configured to control the ailerons with

  4. Aircraft parameter estimation

    Indian Academy of Sciences (India)

    With the evolution of high performance modern aircraft and spiraling developmental and experimental costs, the importance of flight validated databases for flight control design applications and for flight simulators has increased significantly in the recent past. Ground-based and in-flight simulators are increasingly used not ...

  5. Resilience in patients with psychotic disorder.

    Science.gov (United States)

    Bozikas, V; Parlapani, E

    2016-01-01

    The recovery movement differentiated clinical, which is related to disorder's symptoms, from personal recovery, which is outlined by a subjectively defined wellness state, characterised by hope and self-management. Schizophrenia research has long focused on risk factors and symptoms. The recovery movement triggered a focus shift from psychopathology towards better adjustment and growth despite living with schizophrenia. The recovery movement flourished parallel with positive psychology, the scientific study of ordinary human strengths and virtues investigating human motives and potentials. Understanding of human strengths could contribute to prevention or lessening of psychiatric disorders' devastating consequences, since optimism, sense of personal control and many other positive processes promote psychological health. Lately, the concepts of positive psychology have been implemented in schizophrenia research. Positive self-appraisals moderated suicidal ideation, even when patients experienced high levels of hopelessness.1 Additionally, among other factors, better self-images, internal locus of control (i.e. the perception that events in one's life relate to one's actions) and emphasis on personal efforts predicted a more favourable outcome in functioning of unmedicated patients.2 The concept of "resilience" is closely related to positive psychology. The American Psychological Association defines resilience as ''the process of adapting well in the face of adversity, trauma, threats or significant sources of stress''. The concept of resilience includes rebound from adversity.3 Determinants of resilience include biological, psychological, social and cultural factors that interact in a complex manner. The major manifestations of personal resilience are social competence, problem solving, autonomy and sense of purpose.5 Personality strengths that relate to resilience include high self-esteem, extroversion and optimism. Internal assets and personal competencies

  6. The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

    International Nuclear Information System (INIS)

    Rodrigues de Carvalho, Paulo Victor

    2011-01-01

    The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: → The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. → The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). → The analysis showed how, under normal conditions, the system was not able to control flight functions. → The findings shed some light about the resilience of Brazilian ATM system operation.

  7. Seeding Stress Resilience through Inoculation

    Directory of Open Access Journals (Sweden)

    Archana Ashokan

    2016-01-01

    Full Text Available Stress is a generalized set of physiological and psychological responses observed when an organism is placed under challenging circumstances. The stress response allows organisms to reattain the equilibrium in face of perturbations. Unfortunately, chronic and/or traumatic exposure to stress frequently overwhelms coping ability of an individual. This is manifested as symptoms affecting emotions and cognition in stress-related mental disorders. Thus environmental interventions that promote resilience in face of stress have much clinical relevance. Focus of the bulk of relevant neurobiological research at present remains on negative aspects of health and psychological outcomes of stress exposure. Yet exposure to the stress itself can promote resilience to subsequent stressful episodes later in the life. This is especially true if the prior stress occurs early in life, is mild in its magnitude, and is controllable by the individual. This articulation has been referred to as “stress inoculation,” reminiscent of resilience to the pathology generated through vaccination by attenuated pathogen itself. Using experimental evidence from animal models, this review explores relationship between nature of the “inoculum” stress and subsequent psychological resilience.

  8. A Recommended Methodology for Quantifying NDE/NDI Based on Aircraft Engine Experience (Le Projet de Methodologie Pour l’Evaluation du Controle Non- Destructif Fonde sur l’Experience Acquise sur les moteurs d’Avions)

    Science.gov (United States)

    1993-04-01

    A Recommended Methodology for Quantifying NDE/NDI Based on Aircraft Engine Experience--Translation(Le Projet de Methodologie Pour l’Evaluation du Controle Non-Destructif Fonde sur l’Experience Acquise sur les moteurs d’Avions)

  9. Resilience in disaster research

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus; Johannessen-Henry, Christine Tind; Raju, Emmanuel

    2015-01-01

    This paper explores the concept of resilience in disaster management settings in modern society. The diversity and relatedness of ‘resilience’ as a concept and as a process are reflected in its presentation through three ‘versions’: (i) pastoral care and the role of the church for victims...... of disaster trauma, (ii) federal policy and the US Critical Infrastructure Plan, and (iii) the building of resilient communities for disaster risk reduction practices. The three versions aim to offer characteristic expressions of resilience, as increasingly evident in current disaster literature....... In presenting resilience through the lens of these three versions, the article highlights the complexity in using resilience as an all-encompassing word. The article also suggests the need for understanding the nexuses between risk, vulnerability, and policy for the future of resilience discourse....

  10. Aircraft Trajectories Computation-Prediction-Control (La Trajectoire de l’Avion Calcul-Prediction-Controle). Volume 3

    Science.gov (United States)

    1990-05-01

    Concorde flight)", Rivista di Meteorologia Aeronautics, Vol. 31, p. 301-305, Italia, September 1971 (ATM) BENOIT A. "Applicability of the EROCOA trajectory...flight", Rivista di Meteorologia Aeronautics (Jan 1983) (WND) BENOIT A. (Program Chairman) "Air Traffic Control in Face of User’s Demand and Economy

  11. Psychological resilience contributes to low emotional distress in cancer patients.

    Science.gov (United States)

    Min, Jung-Ah; Yoon, Sujung; Lee, Chang-Uk; Chae, Jeong-Ho; Lee, Chul; Song, Kyo-Young; Kim, Tae-Suk

    2013-09-01

    Although a considerable number of cancer patients suffer from emotional distress which may have an impact on their quality of life, it still remains poorly understood which psychosocial factors contribute to individual vulnerabilities to emotional distress of cancer patients. Recently, resilience has been suggested as the capacity to cope with adversities like cancer. In this study, we investigated the relationships between resilience and emotional distress in cancer patients. One hundred fifty-two cancer patients who were consecutively hospitalized for their scheduled treatments at the Seoul St. Mary's Hospital were enrolled and completed the Connor-Davidson Resilience Scale and Hospital Anxiety Depression Scale to measure resilience and emotional distress. The relationships between the levels of psychological resilience and emotional distress were evaluated using univariate and multivariate logistic regression analyses. Psychological resilience levels were negatively associated with emotional distress after controlling for relevant covariates. The highest quartile of resilience level was associated with a 90% (adjusted odds ratio [OR] = 0.10, 95% confidence interval [CI] = 0.03-0.34, P cancer patients, resilience was also found to be a significant protective factor for emotional distress (adjusted OR = 0.14, 95% CI = 0.02-0.79, P = 0.02). The present study suggests that psychological resilience may independently contribute to low emotional distress in cancer patients. The relationship between resilience and emotional distress was also significant in the subgroup of metastatic cancer patients. Psychosocial interventions to enhance resilience might provide useful approaches to overcome cancer-related emotional distress.

  12. Systemic resilience model

    International Nuclear Information System (INIS)

    Lundberg, Jonas; Johansson, Björn JE

    2015-01-01

    It has been realized that resilience as a concept involves several contradictory definitions, both for instance resilience as agile adjustment and as robust resistance to situations. Our analysis of resilience concepts and models suggest that beyond simplistic definitions, it is possible to draw up a systemic resilience model (SyRes) that maintains these opposing characteristics without contradiction. We outline six functions in a systemic model, drawing primarily on resilience engineering, and disaster response: anticipation, monitoring, response, recovery, learning, and self-monitoring. The model consists of four areas: Event-based constraints, Functional Dependencies, Adaptive Capacity and Strategy. The paper describes dependencies between constraints, functions and strategies. We argue that models such as SyRes should be useful both for envisioning new resilience methods and metrics, as well as for engineering and evaluating resilient systems. - Highlights: • The SyRes model resolves contradictions between previous resilience definitions. • SyRes is a core model for envisioning and evaluating resilience metrics and models. • SyRes describes six functions in a systemic model. • They are anticipation, monitoring, response, recovery, learning, self-monitoring. • The model describes dependencies between constraints, functions and strategies

  13. The psychobiology of resilience.

    Science.gov (United States)

    Stein, Dan J

    2009-02-01

    Although adverse environments are well known to be a risk factor for psychopathology, many individuals respond adaptively to such environments. There is growing interest in the underlying mechanisms involved in such resilience. Several cognitive-affective processes may be involved, and these may be mediated by particular neuronal circuits and neurochemical systems. This article summarizes some of the relevant work on the role of fear conditioning, reward processing, and social behavior in resilience. There is a growing body of data on how particular gene-environment interactions affect these processes, and thus underpin resilience. Ultimately, a better understanding of the mechanisms underpinning resilience may lead to novel interventions.

  14. An FPGA-Based High-Speed Error Resilient Data Aggregation and Control for High Energy Physics Experiment

    Science.gov (United States)

    Mandal, Swagata; Saini, Jogender; Zabołotny, Wojciech M.; Sau, Suman; Chakrabarti, Amlan; Chattopadhyay, Subhasis

    2017-03-01

    Due to the dramatic increase of data volume in modern high energy physics (HEP) experiments, a robust high-speed data acquisition (DAQ) system is very much needed to gather the data generated during different nuclear interactions. As the DAQ works under harsh radiation environment, there is a fair chance of data corruption due to various energetic particles like alpha, beta, or neutron. Hence, a major challenge in the development of DAQ in the HEP experiment is to establish an error resilient communication system between front-end sensors or detectors and back-end data processing computing nodes. Here, we have implemented the DAQ using field-programmable gate array (FPGA) due to some of its inherent advantages over the application-specific integrated circuit. A novel orthogonal concatenated code and cyclic redundancy check (CRC) have been used to mitigate the effects of data corruption in the user data. Scrubbing with a 32-b CRC has been used against error in the configuration memory of FPGA. Data from front-end sensors will reach to the back-end processing nodes through multiple stages that may add an uncertain amount of delay to the different data packets. We have also proposed a novel memory management algorithm that helps to process the data at the back-end computing nodes removing the added path delays. To the best of our knowledge, the proposed FPGA-based DAQ utilizing optical link with channel coding and efficient memory management modules can be considered as first of its kind. Performance estimation of the implemented DAQ system is done based on resource utilization, bit error rate, efficiency, and robustness to radiation.

  15. Aircraft, road and railway traffic noise as risk factors for heart failure and hypertensive heart disease-A case-control study based on secondary data.

    Science.gov (United States)

    Seidler, Andreas; Wagner, Mandy; Schubert, Melanie; Dröge, Patrik; Römer, Karin; Pons-Kühnemann, Jörn; Swart, Enno; Zeeb, Hajo; Hegewald, Janice

    2016-11-01

    Several studies point to an elevated risk for cardiovascular diseases induced by traffic noise. We examined the association between aircraft, road traffic and railway noise and heart failure or hypertensive heart disease (HHD) in a large case-control study. The study population consisted of individuals that were insured by three large statutory health insurance funds in the Rhine-Main area of Germany. Based on insurance claims and prescription data, 104,145 cases of heart failure or HHD diagnosed 2006-10 were identified and compared with 654,172 control subjects. Address-specific exposure to aircraft, road and railway traffic noise in 2005 was estimated. Odds Ratios were calculated using logistic regression analysis, adjusted for age, sex, local proportion of persons receiving unemployment benefits, and individual socioeconomic status (available for 39% of the individuals). A statistically significant linear exposure-risk relationship with heart failure or hypertensive heart disease was found for aircraft traffic noise (1.6% risk increase per 10dB increase in the 24-h continuous noise level; 95% CI 0.3-3.0%), road traffic noise (2.4% per 10dB; 95% CI 1.6-3.2%), and railway noise (3.1% per 10dB; 95% CI 2.2-4.1%). For individuals with 24-h continuous aircraft noise levels traffic noise from various sources, even low risk increases for frequent diseases are relevant for the population as a whole. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Access and Resilience: Analyzing the Construction of Social Resilience to the Threat of Water Scarcity

    Directory of Open Access Journals (Sweden)

    Ruth Langridge

    2006-12-01

    Full Text Available Resilience is a vital attribute that characterizes a system's capacity to cope with stress. Researchers have examined the measurement of resilience in ecosystems and in social-ecological systems, and the comparative vulnerability of social groups. Our paper refocuses attention on the processes and relations that create social resilience. Our central proposition is that the creation of social resilience is linked to a community's ability to access critical resources. We explore this proposition through an analysis of how community resilience to the stress of water scarcity is influenced by historically contingent mechanisms to gain, control, and maintain access to water. Access is defined broadly as the ability of a community to actually benefit from a resource, and includes a wider range of relations than those derived from property rights alone. We provide a framework for assessing the construction of social resilience and use it to examine, first, the different processes and relations that enabled four communities in northern California to acquire access to water, and second, how access contributed to their differential levels of resilience to potential water scarcity. Legal water rights are extremely difficult to alter, and given the variety of mechanisms that can generate access, our study suggests that strengthening and diversifying a range of structural and relational mechanisms to access water can enhance a community's resilience to water scarcity.

  17. Antimicrobial resistance, infection control and planning for pandemics: the importance of knowledge transfer in healthcare resilience and emergency planning.

    Science.gov (United States)

    Cole, Jennifer

    Over the last 70 years, the efficacy, ready availability and relatively low cost of antimicrobial drugs - medicines that kill microorganisms such as bacteria and viruses or inhibit their multiplication, growth and pathogenic action - has led to their considerable overuse. It is estimated that nearly 50 per cent of all antimicrobial use in hospitals is unnecessary or inappropriate1 while in neonatal care, the figure is even higher, with infection confirmed in only five per cent of neonates treated with antibiotics.2 The more antimicrobials are used, the faster the microorganisms they target evolve into new, resistant strains, a natural process of evolution that threatens to undermine the tremendous life-saving potential of these drugs. Antimicrobial resistance (AMR) is a growing concern not only for the healthcare sector3 but also, increasingly, for security and resilience. Pandemic influenza, comparable only to 'Catastrophic terrorist attacks' at the top of the UK's National Risk Register4 may well result from the emergence of a strain that cannot be treated effectively with currently available drugs or from one that quickly develops resistance to the stockpiled countermeasures. Multidrug-resistant tuberculosis impacts on immigration policy, methicillin-resistant Staphylococcus aureus (MRSA), a major cause of hospital-acquired infections is an ongoing challenge for the health sector and the increase in drug-resistant strains of malaria is problematic both in its own right and as an additional consequence of climate change. AMR places a significant burden on international governments and tackling it requires changes to thinking across a number of government departments. In 2011, the Transatlantic Taskforce on Antimicrobial Resistance (TATFAR) published Recommendations for future collaboration between the US and EU1 and both the EU and the UK's Department of Health have recently developed new AMR strategies and Action Plans. This paper will explore the cross

  18. Breast cancer and exposure to aircraft, road, and railway-noise: a case-control study based on health insurance records.

    Science.gov (United States)

    Hegewald, Janice; Schubert, Melanie; Wagner, Mandy; Dröge, Patrik; Prote, Ursel; Swart, Enno; Möhler, Ulrich; Zeeb, Hajo; Seidler, Andreas

    2017-11-01

    Objectives Aircraft, road, and rail traffic noise can cause sleep disturbances. Since night work and shorter sleep durations have been linked to increased risks of breast cancer, we examined if 24-hour, or day- or night-time traffic noise exposure may also increase the risk of breast cancer. Methods To investigate the noise-related risks of breast cancer, the pseudonymized insurance records of three large statutory health companies (2005-2010) for women aged ≥40 years living in the region surrounding the Frankfurt international airport were analyzed with address-specific acoustic data representing aircraft, road, and rail-traffic noise. Noise exposure among women with incident breast cancer (N=6643) were compared with that of control subjects (N=471 596) using logistic regression and adjusting for age, hormone replacement therapy, education and occupation (only available for 27.9%), and a regional proportion of persons receiving long-term unemployment benefits as an ecological indicator of socioeconomic level. Analyses were also stratified according to estrogen receptor (ER) status. Results An increased odds ratio (OR) was observed for ER negative (ER-) tumors at 24-hour aircraft noise levels 55-59 dB [OR 55-59 dB 1.41, 95% confidence interval (CI) 1.04-1.90] but not for ER positive (ER+) breast cancers (OR 55-59 dB 0.95, 95% CI 0.75-1.20). Clear associations between road and rail traffic noise were not observed. Conclusions The results indicate increased aircraft noise may be an etiologic factor for ER- breast cancers. However, information regarding potential confounding factors was largely unattainable. Further research is required to understand how environmental noise may be involved in the pathogenesis of ER- breast cancers.

  19. How Resilience Works.

    Science.gov (United States)

    Coutu, Diane L.

    2002-01-01

    Looks at coping skills that carry people through life and why some have them and others do not. Suggests that resilience is a reflex, a way of facing and understanding the world, and that resilient people and companies face reality with staunchness, make meaning out of hardship, and improvise. (JOW)

  20. Multifractal resilience and viability

    Science.gov (United States)

    Tchiguirinskaia, I.; Schertzer, D. J. M.

    2017-12-01

    The term resilience has become extremely fashionable and there had been many attempts to provide operational definition and in fact metrics going beyond a set of more or less ad-hoc indicators. The viability theory (Aubin and Saint-Pierre, 2011) have been used to give a rather precise mathematical definition of resilience (Deffuant and Gilbert, 2011). However, it does not grasp the multiscale nature of resilience that is rather fundamental as particularly stressed by Folke et al (2010). In this communication, we first recall a preliminary attempt (Tchiguirinskaia et al., 2014) to define multifractal resilience with the help of the maximal probable singularity. Then we extend this multifractal approach to the capture basin of the viability, therefore the resilient basin. Aubin, J P, A. Bayen, and P Saint-Pierre (2011). Viability Theory. New Directions. Springer, Berlin,. Deffuant, G. and Gilbert, N. (eds) (2011) Viability and Resilience of Complex Systems. Springer Berlin.Folke, C., S R Carpenter, B Walker, M Sheffer, T Chapin, and J Rockstroem (2010). Resilience thinking: integrating re- silience, adaptability and transformability. Ecology and So- ciety, 14(4):20, Tchiguirinskaia,I., D. Schertzer, , A. Giangola-Murzyn and T. C. Hoang (2014). Multiscale resilience metrics to assess flood. Proceedings of ICCSA 2014, Normandie University, Le Havre, France -.

  1. Resilient health care

    DEFF Research Database (Denmark)

    Hollnagel, E.; Braithwaite, J.; Wears, R. L.

    . Whereas current safety approaches primarily aim to reduce or eliminate the number of things that go wrong, Resilient Health Care aims to increase and improve the number of things that go right. Just as the WHO argues that health is more than the absence of illness, so does Resilient Health Care argue...... rights reserved....

  2. Resilient Renewable Energy Microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Katherine H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DiOrio, Nicholas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Butt, Robert S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Allison [Unaffiliated

    2017-11-14

    This presentation for the Cable-Tec Expo 2017 offers information about how renewable microgrids can be used to increase resiliency. It includes information about why renewable energy battery diesel hybrids microgrids should be considered for backup power, how to estimate economic savings of microgrids, quantifying the resiliency gain of microgrids, and where renewable microgrids will be successful.

  3. Resilience in disaster research

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus; Johannessen-Henry, Christine Tind; Raju, Emmanuel

    2015-01-01

    of disaster trauma, (ii) federal policy and the US Critical Infrastructure Plan, and (iii) the building of resilient communities for disaster risk reduction practices. The three versions aim to offer characteristic expressions of resilience, as increasingly evident in current disaster literature...

  4. Cluster Decline and Resilience

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    -2011. Our longitudinal study reveals that technological lock-in and exit of key firms have contributed to impairment of the cluster’s resilience in adapting to disruptions. Entrepreneurship has a positive effect on cluster resilience, while multinational companies have contradicting effects by bringing...

  5. The Resilient Leader

    Science.gov (United States)

    Allison, Elle

    2012-01-01

    School leaders currently face so many challenges--some as basic as a lack of money to hire enough teachers--that they know they need to increase their resilience. According to Allison, who coaches school leaders, strong leaders know how important maintaining resilience is. They recognize when their reserves of hope--and those of their…

  6. From Risk to Resilience

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    This thesis investigates unpredictability in contemporary disaster and emergency management. The thesis traces the shift from risk thinking towards the resilience approach that has recently characterized the field. It asks how resilience manifests itself in practice and discusses how to incorporate...... this approach into preparedness planning to improve the ability of socio-technological systems to cope with unexpected disruptions. Those working in the field understand resilience as a broad umbrella term linked to risk thinking and concerned with flexible systems that are able to absorb and adapt...... resilience and complexity discourses in an attempt to conjoin the two concepts. This broad discussion leads into a case study of resilience thinking in contemporary disaster and emergency management: preparedness planning for long-term disruptions of the Øresund Bridge between Denmark and Sweden. Through...

  7. Zoogeomorphology and resilience theory

    Science.gov (United States)

    Butler, David R.; Anzah, Faisal; Goff, Paepin D.; Villa, Jennifer

    2018-03-01

    Zoogeomorphology, the study of animals as geomorphic agents, has been largely overlooked in the context of resilience theory and biogeomorphic systems. In this paper, examples are provided of the interactions between external landscape disturbances and zoogeomorphological agents. We describe cases in which naturally occurring zoogeomorphological agents occupy a landscape, and examine whether those zoogeomorphic agents provide resilience to a landscape or instead serve as a landscape stress capable of inducing a phase-state shift. Several cases are described whereby the presence of exotic (introduced) zoogeomorphic agents overwhelms a landscape and induce collapse. The impact of climate change on species with zoogeomorphological importance is discussed in the context of resilience of a landscape. We conclude with a summary diagram illustrating the relationships existing between zoogeomorphic impacts and landscape resilience in the context of our case studies, and speculate about the future of the study of zoogeomorphology in the framework of resilience theory.

  8. Developing an economical and reliable test for measuring the resilient modulus and Poisson's ratio of subgrade.

    Science.gov (United States)

    2010-11-01

    The resilient modulus and Poissons ratio of base and sublayers in highway use are : important parameters in design and quality control process. The currently used techniques : include CBR (California Bearing Ratio) test, resilient modulus test,...

  9. A Mission-Adaptive Variable Camber Flap Control System to Optimize High Lift and Cruise Lift-to-Drag Ratios of Future N+3 Transport Aircraft

    Science.gov (United States)

    Urnes, James, Sr.; Nguyen, Nhan; Ippolito, Corey; Totah, Joseph; Trinh, Khanh; Ting, Eric

    2013-01-01

    Boeing and NASA are conducting a joint study program to design a wing flap system that will provide mission-adaptive lift and drag performance for future transport aircraft having light-weight, flexible wings. This Variable Camber Continuous Trailing Edge Flap (VCCTEF) system offers a lighter-weight lift control system having two performance objectives: (1) an efficient high lift capability for take-off and landing, and (2) reduction in cruise drag through control of the twist shape of the flexible wing. This control system during cruise will command varying flap settings along the span of the wing in order to establish an optimum wing twist for the current gross weight and cruise flight condition, and continue to change the wing twist as the aircraft changes gross weight and cruise conditions for each mission segment. Design weight of the flap control system is being minimized through use of light-weight shape memory alloy (SMA) actuation augmented with electric actuators. The VCCTEF program is developing better lift and drag performance of flexible wing transports with the further benefits of lighter-weight actuation and less drag using the variable camber shape of the flap.

  10. Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations.

    Science.gov (United States)

    Cheng, Xuemin; Yang, Yikang; Hao, Qun

    2016-10-17

    The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1-5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

  11. Randomized controlled trial investigating the effect of an acrylic-based resilient liner on perceived chewing ability in edentulous patients wearing mandibular complete dentures.

    Science.gov (United States)

    Kimoto, Suguru; Kimoto, Katsuhiko; Gunji, Atsuko; Shinomiya, Mayako; Sawada, Tomofumi; Saita, Makiko; Kobayashi, Kihei

    2010-01-01

    The aim of this study was to investigate the effect of an acrylic-based resilient liner (ARL) on perceived chewing ability in patients using mandibular complete dentures compared with that of patients using mandibular complete dentures with a conventional acrylic resin (CAR). This randomized controlled trial was conducted at two centers from April 2004 to July 2006. Seventy-four subjects were randomly allocated to either the ARL or CAR group using a random permuted block method after obtaining written informed consent. A valid questionnaire listing 35 foods was used to evaluate the subjects' perceived chewing ability of each item, assessed according to the following scale: 0=cannot eat, 1=can eat with difficulty, and 2=can eat easily. If subjects did not eat the food because they disliked it or had not eaten it since first wearing dentures, they filled in a triangle or square, respectively. These figures were treated as a 0 during analysis. No significant differences were observed between the ARL and CAR groups. The perceived chewing ability of subjects with new complete dentures was significantly higher than that of those with their old complete dentures. The duration of edentulism was positively associated with perceived chewing ability. An ARL applied to mandibular complete dentures has no significant impact on the perceived chewing ability of edentulous patients in comparison to a CAR.

  12. Aircraft Steels

    Science.gov (United States)

    2009-02-19

    70 mm (0.4 x 0.4 x 2.8 in.) in L orientation with a Charpy notch at the mid-length for SCC test under four-point bending (ASTM F 1624- 95) TESTS ...MAXIMUM STRESS INTENSITY, Kmax, IN HIGH STRENGTH STEELS For the fatigue test in 3.5% NaCl solution, the FCG per cycle, da/dN, is converted to the...NAWCADPAX/TR-2009/12 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders 19 February 2009

  13. Teacher Resilience: Theorizing Resilience and Poverty

    Science.gov (United States)

    Ebersöhn, Liesel

    2014-01-01

    In this article, I hope to provide some novel insights into teacher resilience and poverty on the basis of ten-year long-term ethnographic participatory reflection and action data obtained from teachers (n?=?87) in rural (n?=?6) and urban (n?=?8) schools (n?=?14, high schools?=?4, primary schools?=?10) in three South African provinces. In…

  14. Foundations of resilience thinking.

    Science.gov (United States)

    Curtin, Charles G; Parker, Jessica P

    2014-08-01

    Through 3 broad and interconnected streams of thought, resilience thinking has influenced the science of ecology and natural resource management by generating new multidisciplinary approaches to environmental problem solving. Resilience science, adaptive management (AM), and ecological policy design (EPD) contributed to an internationally unified paradigm built around the realization that change is inevitable and that science and management must approach the world with this assumption, rather than one of stability. Resilience thinking treats actions as experiments to be learned from, rather than intellectual propositions to be defended or mistakes to be ignored. It asks what is novel and innovative and strives to capture the overall behavior of a system, rather than seeking static, precise outcomes from discrete action steps. Understanding the foundations of resilience thinking is an important building block for developing more holistic and adaptive approaches to conservation. We conducted a comprehensive review of the history of resilience thinking because resilience thinking provides a working context upon which more effective, synergistic, and systems-based conservation action can be taken in light of rapid and unpredictable change. Together, resilience science, AM, and EPD bridge the gaps between systems analysis, ecology, and resource management to provide an interdisciplinary approach to solving wicked problems. © 2014 Society for Conservation Biology.

  15. Resilience: Theory and Application.

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.L.; Haffenden, R.A.; Bassett, G.W.; Buehring, W.A.; Collins, M.J., III; Folga, S.M.; Petit, F.D.; Phillips, J.A.; Verner, D.R.; Whitfield, R.G. (Decision and Information Sciences)

    2012-02-03

    There is strong agreement among policymakers, practitioners, and academic researchers that the concept of resilience must play a major role in assessing the extent to which various entities - critical infrastructure owners and operators, communities, regions, and the Nation - are prepared to respond to and recover from the full range of threats they face. Despite this agreement, consensus regarding important issues, such as how resilience should be defined, assessed, and measured, is lacking. The analysis presented here is part of a broader research effort to develop and implement assessments of resilience at the asset/facility and community/regional levels. The literature contains various definitions of resilience. Some studies have defined resilience as the ability of an entity to recover, or 'bounce back,' from the adverse effects of a natural or manmade threat. Such a definition assumes that actions taken prior to the occurrence of an adverse event - actions typically associated with resistance and anticipation - are not properly included as determinants of resilience. Other analyses, in contrast, include one or more of these actions in their definitions. To accommodate these different definitions, we recognize a subset of resistance- and anticipation-related actions that are taken based on the assumption that an adverse event is going to occur. Such actions are in the domain of resilience because they reduce both the immediate and longer-term adverse consequences that result from an adverse event. Recognizing resistance- and anticipation-related actions that take the adverse event as a given accommodates the set of resilience-related actions in a clear-cut manner. With these considerations in mind, resilience can be defined as: 'the ability of an entity - e.g., asset, organization, community, region - to anticipate, resist, absorb, respond to, adapt to, and recover from a disturbance.' Because critical infrastructure resilience is important

  16. Racial Discrimination, Cultural Resilience, and Stress.

    Science.gov (United States)

    Spence, Nicholas D; Wells, Samantha; Graham, Kathryn; George, Julie

    2016-05-01

    Racial discrimination is a social determinant of health for First Nations people. Cultural resilience has been regarded as a potentially positive resource for social outcomes. Using a compensatory model of resilience, this study sought to determine if cultural resilience (compensatory factor) neutralized or offset the detrimental effect of racial discrimination (social risk factor) on stress (outcome). Data were collected from October 2012 to February 2013 (N = 340) from adult members of the Kettle and Stony Point First Nation community in Ontario, Canada. The outcome was perceived stress; risk factor, racial discrimination; and compensatory factor, cultural resilience. Control variables included individual (education, sociability) and family (marital status, socioeconomic status) resilience resources and demographics (age and gender). The model was tested using sequential regression. The risk factor, racial discrimination, increased stress across steps of the sequential model, while cultural resilience had an opposite modest effect on stress levels. In the final model with all variables, age and gender were significant, with the former having a negative effect on stress and women reporting higher levels of stress than males. Education, marital status, and socioeconomic status (household income) were not significant in the model. The model had R(2) = 0.21 and adjusted R(2) = 0.18 and semipartial correlation (squared) of 0.04 and 0.01 for racial discrimination and cultural resilience, respectively. In this study, cultural resilience compensated for the detrimental effect of racial discrimination on stress in a modest manner. These findings may support the development of programs and services fostering First Nations culture, pending further study. © The Author(s) 2016.

  17. Toward a digital resilience

    Directory of Open Access Journals (Sweden)

    Dawn J. Wright

    2016-02-01

    Full Text Available Abstract As we contend with human impacts on the biosphere, there is rightfully a great emphasis now on community adaptation and resilience to climate change. Recent innovations in information technologies and analyses are helping communities to become more resilient. However, not often discussed in this vein is a path toward digital resilience. If mapping and information tools are to help communities, it stands to reason that they must be resilient themselves, as well as the data that they are based on. In other words, digital tools can help make communities resilient by providing data, evidence-based advice on community decisions, etc., but the resilience of the tools themselves can also be an issue. Digital resilience means that to the greatest extent possible, data and tools should be freely accessible, interchangeable, operational, of high quality, and up-to-date so that they can help give rise to the resilience of communities or other entities using them. Given the speed at which humans are altering the biosphere, the usefulness and effectiveness of these technologies must keep pace. This article reviews and recommends three fundamental digital practices, particularly from the standpoint of geospatial data and for community resilience and policy-making. These are: (1 create and implement a culture that consistently shares not only data, but workflows and use cases with the data, especially within maps and geographic information systems or GIS; (2 use maps and other visuals to tell compelling stories that many different kinds of audiences will understand and remember; and (3 be more open to different kinds of partnerships to reduce project costs, yield better results, and foster public awareness and behavioral change.

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

    Science.gov (United States)

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

    2006-01-01

    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.

  19. Association between aircraft, road and railway traffic noise and depression in a large case-control study based on secondary data.

    Science.gov (United States)

    Seidler, Andreas; Hegewald, Janice; Seidler, Anna Lene; Schubert, Melanie; Wagner, Mandy; Dröge, Patrik; Haufe, Eva; Schmitt, Jochen; Swart, Enno; Zeeb, Hajo

    2017-01-01

    Few studies have examined the relationship between traffic noise and depression providing inconclusive results. This large case-control study is the first to assess and directly compare depression risks by aircraft, road traffic and railway noise. The study population included individuals aged ≥40 years that were insured by three large statutory health insurance funds and were living in the region of Frankfurt international airport. Address-specific exposure to aircraft, road and railway traffic noise in 2005 was estimated. Based on insurance claims and prescription data, 77,295 cases with a new clinical depression diagnosis between 2006 and 2010 were compared with 578,246 control subjects. For road traffic noise, a linear exposure-risk relationship was found with an odds ratio (OR) of 1.17 (95% CI=1.10-1.25) for 24-h continuous sound levels ≥70dB. For aircraft noise, the risk estimates reached a maximum OR of 1.23 (95% CI=1.19-1.28) at 50-55dB and decreased at higher exposure categories. For railway noise, risk estimates peaked at 60-65dB (OR=1.15, 95% CI=1.08-1.22). The highest OR of 1.42 (95% CI=1.33-1.52) was found for a combined exposure to noise above 50dB from all three sources. This study indicates that traffic noise exposure might lead to depression. As a potential explanation for the decreasing risks at high traffic noise levels, vulnerable people might actively cope with noise (e.g. insulate or move away). Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Resilience of the IMS system

    DEFF Research Database (Denmark)

    Kamyod, Chayapol; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2014-01-01

    The paper focuses on end-to-end resilience analysis of the IMS based network through the principal resilience parameters by using OPNET. The resilience behaviours of communication across multiple IMS domains are investigated at different communication scenarios and compared with previous state......-of-the-art. Moreover, the resilience effects when adding a redundancy of the S-CSCF unit are examined. The results disclose interesting resilience behaviours for long distance communications....

  1. Aviation and climate change : aircraft emissions expected to grow, but technological and operational improvements and government policies can help control emissions

    Science.gov (United States)

    2009-06-01

    A number of policy options to address aircraft emissions are available to governments and can be part of broader policies to address emissions from many sources including aircraft. Market-based measures can establish a price for emissions and provide...

  2. Formal aspects of resilience

    Directory of Open Access Journals (Sweden)

    Diana-Maria Drigă

    2015-12-01

    Full Text Available The concept of resilience has represented during the recent years a leading concern both in Romania, within the European Union and worldwide. Specialists in economics, management, finance, legal sciences, political sciences, sociology, psychology, grant a particular interest to this concept. Multidisciplinary research of resilience has materialized throughout the time in multiple conceptualizations and theorizing, but without being a consensus between specialists in terms of content, specificity and scope. Through this paper it is intended to clarify the concept of resilience, achieving an exploration of the evolution of this concept in ecological, social and economic environment. At the same time, the paper presents aspects of feedback mechanisms and proposes a formalization of resilience using the logic and mathematical analysis.

  3. Resilient Diffusive Clouds

    Science.gov (United States)

    2017-02-01

    RESILIENT DIFFUSIVE CLOUDS TRUSTEES OF DARTMOUTH COLLEGE FEBRUARY 2017 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC...To) SEP 2011 – SEP 2016 4. TITLE AND SUBTITLE RESILIENT DIFFUSIVE CLOUDS 5a. CONTRACT NUMBER FA8750-11-2-0257 5b. GRANT NUMBER N/A 5c. PROGRAM...diversified virtual machines. The concepts lead to a view of cloud computing in which vulnerabilities are different at every host, attackers cannot

  4. Resilience and reworking practices

    DEFF Research Database (Denmark)

    Hauge, Mads Martinus; Fold, Niels

    2016-01-01

    of this article is to shed light on the agency of individual workers involved in rapid industrialization processes. In this endeavor we draw inspiration from recent contributions that have integrated Cindi Katz's threefold categorization of agency as reworking, resilience and resistance. In combination...... and resilience can be conceptualized as transformative trajectories - workers’ situated knowledge and practices evolve and change over time and is conditioned by the specific labor market contexts through which the individual moves....

  5. New Methodology for Optimal Flight Control Using Differential Evolution Algorithms Applied on the Cessna Citation X Business Aircraft – Part 1. Design and Optimization

    Directory of Open Access Journals (Sweden)

    Yamina BOUGHARI

    2017-06-01

    Full Text Available Setting the appropriate controllers for aircraft stability and control augmentation systems are complicated and time consuming tasks. As in the Linear Quadratic Regulator method gains are found by selecting the appropriate weights or as in the Proportional Integrator Derivative control by tuning gains. A trial and error process is usually employed for the determination of weighting matrices, which is normally a time consuming procedure. Flight Control Law were optimized and designed by combining the Deferential Evolution algorithm, the Linear Quadratic Regulator method, and the Proportional Integral controller. 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 for different flight conditions. Furthermore the design and the clearance of the controllers over the flight envelope were automated using a Graphical User Interface, which offers to the designer, the flexibility to change the design requirements. In the aim of reducing time, and costs of the Flight Control Law design, one fitness function has been used for both optimizations, and using design requirements as constraints. Consequently the Flight Control Law design process complexity was reduced by using the meta-heuristic algorithm.

  6. Urban flooding and Resilience: concepts and needs

    Science.gov (United States)

    Gourbesville, Ph.

    2012-04-01

    During the recent years, a growing interest for resilience has been expressed in the natural disaster mitigation area and especially in the flood related events. The European Union, under the Seventh Framework Programme (FP7), has initiated several research initiatives in order to explore this concept especially for the urban environments. Under urban resilience is underlined the ability of system potentially exposed to hazard to resist, respond, recover and reflect up to stage which is enough to preserve level of functioning and structure. Urban system can be resilient to lot of different hazards. Urban resilience is defined as the degree to which cities are able to tolerate some disturbance before reorganizing around a new set of structures and processes (Holling 1973, De Bruijn 2005). The United Nation's International strategy for Disaster Reductions has defined resilience as "the capacity of a system, community or society potentially exposed to hazards to adapt, by resisting or changing in order to reach and maintain an acceptable level of functioning and structure. This is determined by the degree to which the social system is capable of organizing itself to increase this capacity for learning from past disasters for better future protection and to improve risk reduction measures."(UN/ISDR 2004). According to that, system should be able to accept the hazard and be able to recover up to condition that provides acceptable operational level of city structure and population during and after hazard event. Main elements of urban system are built environment and population. Physical characteristic of built environment and social characteristic of population have to be examined in order to evaluate resilience. Therefore presenting methodology for assessing flood resilience in urban areas has to be one of the focal points for the exposed cities. Strategies under flood management planning related to resilience of urban systems are usually regarding controlling runoff

  7. A mindfulness-based intervention to increase resilience to stress in university students (the Mindful Student Study): a pragmatic randomised controlled trial.

    Science.gov (United States)

    Galante, Julieta; Dufour, Géraldine; Vainre, Maris; Wagner, Adam P; Stochl, Jan; Benton, Alice; Lathia, Neal; Howarth, Emma; Jones, Peter B

    2018-02-01

    The rising number of young people going to university has led to concerns about an increasing demand for student mental health services. We aimed to assess whether provision of mindfulness courses to university students would improve their resilience to stress. We did this pragmatic randomised controlled trial at the University of Cambridge, UK. Students aged 18 years or older with no severe mental illness or crisis (self-assessed) were randomly assigned (1:1), via remote survey software using computer-generated random numbers, to receive either an 8 week mindfulness course adapted for university students (Mindfulness Skills for Students [MSS]) plus mental health support as usual, or mental health support as usual alone. Participants and the study management team were aware of group allocation, but allocation was concealed from the researchers, outcome assessors, and study statistician. The primary outcome was self-reported psychological distress during the examination period, as measured with the Clinical Outcomes in Routine Evaluation Outcome Measure (CORE-OM), with higher scores indicating more distress. The primary analysis was by intention to treat. This trial is registered with the Australia and New Zealand Clinical Trials Registry, number ACTRN12615001160527. Between Sept 28, 2015, and Jan 15, 2016, we randomly assigned 616 students to the MSS group (n=309) or the support as usual group (n=307). 453 (74%) participants completed the CORE-OM during the examination period and 182 (59%) MSS participants completed at least half of the course. MSS reduced distress scores during the examination period compared with support as usual, with mean CORE-OM scores of 0·87 (SD 0·50) in 237 MSS participants versus 1·11 (0·57) in 216 support as usual participants (adjusted mean difference -0·14, 95% CI -0·22 to -0·06; p=0·001), showing a moderate effect size (β -0·44, 95% CI -0·60 to -0·29; pstudents (95% CI four to ten) needed to be offered the MSS course to

  8. Artificial neural network modeling of damaged aircraft

    OpenAIRE

    Brunger, Clifford A.

    1994-01-01

    Approved for public release, distribution unlimited Aircraft design and control techniques rely on the proper modeling of the aircraft's equations of motion. Many of the variables used in these equations are aerodynamic coefficients which are obtained from scale models in wind tunnel tests. In order to model damaged aircraft, every aerodynamic coefficient must be determined for every possible damage mechanism in every flight condition. De...

  9. Protocol for the Mindful Student Study: a randomised controlled trial of the provision of a mindfulness intervention to support university students' well-being and resilience to stress

    Science.gov (United States)

    Dufour, Geraldine; Benton, Alice; Howarth, Emma; Vainre, Maris; Croudace, Timothy J; Stochl, Jan; Jones, Peter B

    2016-01-01

    Introduction Levels of stress in UK university students are high, with an increase in the proportion of students seeking help in recent years. Academic pressure is reported as a major trigger. Mindfulness training has been shown to reduce stress and is popular among students, but its effectiveness in this context needs to be ascertained. In this pragmatic randomised controlled trial, we hypothesise that the provision of a preventative mindfulness intervention in universities could reduce students' psychological distress during the examination period (primary outcome), improve their resilience to stress up to at least 1 year later, reduce their use of mental health support services and improve academic performance. Methods and analysis At least 550 University of Cambridge students free from active crises or severe mental illness will be randomised to joining an 8-week mindfulness course or to mental health provision as usual (one-to-one allocation rate). Psychological distress will be measured using the Clinical Outcomes in Routine Evaluation Outcome Measure at baseline, postintervention, examination term and 1-year follow-up. Other outcomes are use of mental health services, inability to sit examinations or special circumstance requests, examination grades, well-being, altruism and coping measured with ecological momentary assessment. Outcome assessment and intention-to-treat primary analysis using linear mixed models adjusted for baseline scores will be blind to intervention allocation. We will also conduct per-protocol, subgroup and secondary outcome analyses. An Independent Data Monitoring and Ethics Committee will be set up. We will systematically monitor for, and react to, possible adverse events. An advisory reference group will comprise student representatives, members of the University Counselling Service and other student welfare staff. Ethics and dissemination Approval has been obtained from Cambridge Psychology Research Ethics Committee (PRE.2015

  10. Social-ecological resilience and geomorphic systems

    Science.gov (United States)

    Chaffin, Brian C.; Scown, Murray

    2018-03-01

    can play formative roles during periods of collapse and reorganization. Large- and small-scale disturbances as well as large-scale system memory/capacity and small-scale innovation can have significant impacts on the trajectory of a reorganizing system (Gunderson and Holling, 2002; Chaffin and Gunderson, 2016). Attempts to measure the property of ecological resilience across complex systems amounts to attempts to measure the persistence of system-controlling variables, including processes, parameters, and important feedbacks, when the system is exposed to varying degrees of disturbance (Folke, 2016).

  11. An Enhanced Dual Droop Control Scheme for Resilient Active Power Sharing among Paralleled Two-Stage Converters

    DEFF Research Database (Denmark)

    Liu, Hongpeng; Yang, Yongheng; Wang, Xiongfei

    2017-01-01

    Traditional droop-controlled system has assumed that generators can always generate the powers demanded from them. This is true with conventional sources, where fuel supplies are usually planned in advance. For renewable sources, it may also be possible if energy storage is available. Energy...... cases, traditional droop scheme may not work well when its demanded power cannot be met by some renewable sources due to intermittency. When that happens, the system may become unstable with some sources progressively brought out of generation. To avoid such occurrence, an enhanced dual droop scheme...... is proposed for general two-stage converters with front rectifiers or dc-dc converters for conditioning powers from renewable sources and rear inverters for channeling powers to remote grids. Unlike the traditional droop scheme, the proposed dual droop scheme uses both dc-link voltage and generated powers...

  12. Application of a pilot control strategy identification technique to a joint FAA/NASA ground-based simulation of head-up displays for CTOL aircraft

    Science.gov (United States)

    Jewell, W. F.

    1982-01-01

    A technique for measuring a pilot's control strategy was developed, evaluated, and applied to a joint FAA-NASA ground-based simulation of two competing concepts of head-up displays for use in conventional takeoff and landing aircraft. The technique, called the Non-Intrusive Pilot Identification Program (NIPIP), estimates the pilot's input-output describing function and combined pilot-vehicle performance parameters such as crossover frequency and phase margin by using a time domain model of the pilot and a least-squares identification algorithm. NIPIP functions in realtime and uses a sliding time window to maintain freshness in the data; thus time-varying characteristics in the pilot's control strategy can be measured.

  13. Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract In modern fighter aircraft with statically unstable airframe designs, the flight control system is considered flight critical, i.e. the aircraft will...

  14. Intervention studies to foster resilience - A systematic review and proposal for a resilience framework in future intervention studies.

    Science.gov (United States)

    Chmitorz, A; Kunzler, A; Helmreich, I; Tüscher, O; Kalisch, R; Kubiak, T; Wessa, M; Lieb, K

    2018-02-01

    Psychological resilience refers to the phenomenon that many people are able to adapt to the challenges of life and maintain mental health despite exposure to adversity. This has stimulated research on training programs to foster psychological resilience. We evaluated concepts, methods and designs of 43 randomized controlled trials published between 1979 and 2014 which assessed the efficacy of such training programs and propose standards for future intervention research based on recent developments in the field. We found that concepts, methods and designs in current resilience intervention studies are of limited use to properly assess efficacy of interventions to foster resilience. Major problems are the use of definitions of resilience as trait or a composite of resilience factors, the use of unsuited assessment instruments, and inappropriate study designs. To overcome these challenges, we propose 1) an outcome-oriented definition of resilience, 2) an outcome-oriented assessment of resilience as change in mental health in relation to stressor load, and 3) methodological standards for suitable study designs of future intervention studies. Our proposals may contribute to an improved quality of resilience intervention studies and may stimulate further progress in this growing research field. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Resilience Indicator Summaries and Resilience Scores CNMI Excel database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Maps of relative classifications (low to high) for six resilience indicators and two anthropogenic stressors and a map of final relative resilience scores for 78...

  16. Resilience Indicator Summaries and Resilience Scores CNMI JPEG Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Maps of relative classifications (low to high) for six resilience indicators and two anthropogenic stressors and a map of final relative resilience scores for 78...

  17. A Randomized Controlled Trial of a Resilience-Based Intervention for Children Affected by Parental HIV: Educational Outcomes at 24-, 30-, and 36-Months

    Science.gov (United States)

    Harrison, Sayward E.; Li, Xiaoming; Zhang, JiaJia; Zhao, Junfeng; Zhao, Guoxiang

    2018-01-01

    Children of parents with human immunodeficiency virus (HIV) are at-risk for a variety of negative outcomes, including poor educational achievement. The multi-level, resilience-based "ChildCARE" intervention has been found to yield short-term improvement in a number of school-related variables for children affected by parental HIV.…

  18. Adaptive, dynamic, and resilient systems

    CERN Document Server

    Suri, Niranjan

    2015-01-01

    As the complexity of today's networked computer systems grows, they become increasingly difficult to understand, predict, and control. Addressing these challenges requires new approaches to building these systems. Adaptive, Dynamic, and Resilient Systems supplies readers with various perspectives of the critical infrastructure that systems of networked computers rely on. It introduces the key issues, describes their interrelationships, and presents new research in support of these areas.The book presents the insights of a different group of international experts in each chapter. Reporting on r

  19. Advancing empirical resilience research.

    Science.gov (United States)

    Kalisch, Raffael; Müller, Marianne B; Tüscher, Oliver

    2015-01-01

    We are delighted by the broad, intense, and fruitful discussion in reaction to our target article. A major point we take from the many comments is a prevailing feeling in the research community that we need significantly and urgently to advance resilience research, both by sharpening concepts and theories and by conducting empirical studies at a much larger scale and with a much more extended and sophisticated methodological arsenal than is the case currently. This advancement can be achieved only in a concerted international collaborative effort. In our response, we try to argue that an explicitly atheoretical, purely observational definition of resilience and a transdiagnostic, quantitative study framework can provide a suitable basis for empirically testing different competing resilience theories (sects. R1, R2, R6, R7). We are confident that it should be possible to unite resilience researchers from different schools, including from sociology and social psychology, behind such a pragmatic and theoretically neutral research strategy. In sections R3 to R5, we further specify and explain the positive appraisal style theory of resilience (PASTOR). We defend PASTOR as a comparatively parsimonious and translational theory that makes sufficiently concrete predictions to be evaluated empirically.

  20. Family Resilience in the Military

    Science.gov (United States)

    Meadows, Sarah O.; Beckett, Megan K.; Bowling, Kirby; Golinelli, Daniela; Fisher, Michael P.; Martin, Laurie T.; Meredith, Lisa S.; Osilla, Karen Chan

    2016-01-01

    Abstract Military life presents a variety of challenges to military families, including frequent separations and relocations as well as the risks that service members face during deployment; however, many families successfully navigate these challenges. Despite a recent emphasis on family resilience, the U.S. Department of Defense (DoD) does not have a standard and universally accepted definition of family resilience. A standard definition is a necessary for DoD to more effectively assess its efforts to sustain and improve family resilience. RAND authors reviewed the literature on family resilience and, in this study, recommend a definition that could be used DoD-wide. The authors also reviewed DoD policies related to family resilience, reviewed models that describe family resilience and identified key family resilience factors, and developed several recommendations for how family-resilience programs and policies could be managed across DoD. PMID:28083409

  1. Fishing for resilience

    Science.gov (United States)

    Pope, Kevin L.; Allen, Craig R.; Angeler, David G.

    2014-01-01

    Management approaches that focus on social–ecological systems—systems comprised of ecosystems, landscapes, and humans—are needed to secure the sustainability of inland recreational fisheries without jeopardizing the integrity of the underlying social and ecological components. Resilience management can be useful because it focuses on providing recreational capacity for fishermen under a variety of conditions while assuring that the social–ecological system is not pushed to a critical threshold that would result in a new, undesired system regime. Resilience management is based on a system perspective that accounts for the possible regimes a system could manifest. It aims to enhance system properties that allow continued maintenance of the system in a desired regime in which multiple goods and services, including recreational capacity, are provided. In this forum paper, we provide an overview of the potential of a resilience approach to the management of recreational fisheries and highlight the scientific and administrative challenges to its successful implementation.

  2. Resilience in IMS

    DEFF Research Database (Denmark)

    Kamyod, Chayapol; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2012-01-01

    Reliability evaluation of systems has been widely researched for improving system resilience especially in designing processes of a complex system. The convergence of different access networks is possible via IP Multimedia Subsystem (IMS) for development toward Next Generation Networks (NGNs......) and supporting always on services. Therefore, not only Quality of Service (QoS) but also resilience is required. In this paper, we attempt to evaluate and analyze end-to-end reliability of the IMS system using a model proposed as a combination of Reliability Block Diagram (RBD) and Markov Reward Models (MRMs......). The resilience of the IMS architecture is studied by applying 1:1 redundancy at different communication scenarios between end users within and across communication domains. The model analysis provides useful reliability characteristics of the system and can be further applied for system design processes....

  3. Resilience in adolescents with cancer

    OpenAIRE

    ISHIBASHI, Akiko; UEDA, Reiko

    2003-01-01

    Children and adolescents with cancer experience multiple stressors, evertheless some function well or are "resilient." Focusing on resilience in childhood cancer patients and understanding why and how resilience develops during the cancer experience is of great value . This knowledge may provide information to health care professionals to facilitate intervention for promoting resilience and improving quality of life in adolescents with cancer . The purpose of thisarticle is to review the lite...

  4. Metrics for energy resilience

    International Nuclear Information System (INIS)

    Roege, Paul E.; Collier, Zachary A.; Mancillas, James; McDonagh, John A.; Linkov, Igor

    2014-01-01

    Energy lies at the backbone of any advanced society and constitutes an essential prerequisite for economic growth, social order and national defense. However there is an Achilles heel to today's energy and technology relationship; namely a precarious intimacy between energy and the fiscal, social, and technical systems it supports. Recently, widespread and persistent disruptions in energy systems have highlighted the extent of this dependence and the vulnerability of increasingly optimized systems to changing conditions. Resilience is an emerging concept that offers to reconcile considerations of performance under dynamic environments and across multiple time frames by supplementing traditionally static system performance measures to consider behaviors under changing conditions and complex interactions among physical, information and human domains. This paper identifies metrics useful to implement guidance for energy-related planning, design, investment, and operation. Recommendations are presented using a matrix format to provide a structured and comprehensive framework of metrics relevant to a system's energy resilience. The study synthesizes previously proposed metrics and emergent resilience literature to provide a multi-dimensional model intended for use by leaders and practitioners as they transform our energy posture from one of stasis and reaction to one that is proactive and which fosters sustainable growth. - Highlights: • Resilience is the ability of a system to recover from adversity. • There is a need for methods to quantify and measure system resilience. • We developed a matrix-based approach to generate energy resilience metrics. • These metrics can be used in energy planning, system design, and operations

  5. Introduction 'Governance for Drought Resilience'

    NARCIS (Netherlands)

    Bressers, Nanny; Bressers, Johannes T.A.; Larrue, Corinne; Bressers, Hans; Bressers, Nanny; Larrue, Corinne

    2016-01-01

    This book is about governance for drought resilience. But that simple sentence alone might rouse several questions. Because what do we mean with drought, and how does that relate to water scarcity? And what do we mean with resilience, and why is resilience needed for tackling drought? And how does

  6. Experimenting for resilience

    DEFF Research Database (Denmark)

    Hagedorn-Rasmussen, Peter; Dupret, Katia

    Focusing on how an experimental approach to organizing may pave the way for organizational resilience, we explore opportunities and barriers of experimental organizing by following a concrete social experiment in civil society and discuss its adaptability in traditional organizations. The social...... experiment is called Civic Desire. The founders explicitly call for new ways of organizing that can develop social sustainability. We discuss how these experiments may create platforms of new unforeseen goals that organizations may choose to follow. In conclusion we argue for organizational resilience...

  7. Resilience and Complexity

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    2015-01-01

    This paper explores two key concepts: resilience and complexity. The first is understood as an emergent property of the latter, and their inter-relatedness is discussed using a three tier approach. First, by exploring the discourse of each concept, next, by analyzing underlying relationships and...... robust. Robustness is a property of simple or complicated systems characterized by predictable behavior, enabling the system to bounce back to its normal state following a perturbation. Resilience, however, is an emergent property of complex adaptive systems. It is suggested that this distinction...

  8. UAS in the NAS Air Traffic Controller Acceptability Study-1: The Effects of Horizontal Miss Distances on Simulated UAS and Manned Aircraft Encounters

    Science.gov (United States)

    Ghatas, Rania W.; Comstock, James R., Jr.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study examined air traffic controller acceptability ratings based on the effects of differing horizontal miss distances (HMDs) for encounters between UAS and manned aircraft. In a simulation of the Dallas/Fort Worth (DFW) East-side airspace, the CAS-1 experiment at NASA Langley Research Center enlisted fourteen recently retired DFW air traffic controllers to rate well-clear volumes based on differing HMDs that ranged from 0.5 NM to 3.0 NM. The controllers were tasked with rating these HMDs from "too small" to "too excessive" on a defined, 1-5, scale and whether these distances caused any disruptions to the controller and/or to the surrounding traffic flow. Results of the study indicated a clear favoring towards a particular HMD range. Controller workload was also measured. Data from this experiment and subsequent experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely and efficiently integrate UAS into the NAS.

  9. Protocol for the Mindful Student Study: a randomised controlled trial of the provision of a mindfulness intervention to support university students' well-being and resilience to stress.

    Science.gov (United States)

    Galante, Julieta; Dufour, Geraldine; Benton, Alice; Howarth, Emma; Vainre, Maris; Croudace, Timothy J; Wagner, Adam P; Stochl, Jan; Jones, Peter B

    2016-11-09

    Levels of stress in UK university students are high, with an increase in the proportion of students seeking help in recent years. Academic pressure is reported as a major trigger. Mindfulness training has been shown to reduce stress and is popular among students, but its effectiveness in this context needs to be ascertained. In this pragmatic randomised controlled trial, we hypothesise that the provision of a preventative mindfulness intervention in universities could reduce students' psychological distress during the examination period (primary outcome), improve their resilience to stress up to at least 1 year later, reduce their use of mental health support services and improve academic performance. At least 550 University of Cambridge students free from active crises or severe mental illness will be randomised to joining an 8-week mindfulness course or to mental health provision as usual (one-to-one allocation rate). Psychological distress will be measured using the Clinical Outcomes in Routine Evaluation Outcome Measure at baseline, postintervention, examination term and 1-year follow-up. Other outcomes are use of mental health services, inability to sit examinations or special circumstance requests, examination grades, well-being, altruism and coping measured with ecological momentary assessment. Outcome assessment and intention-to-treat primary analysis using linear mixed models adjusted for baseline scores will be blind to intervention allocation. We will also conduct per-protocol, subgroup and secondary outcome analyses. An Independent Data Monitoring and Ethics Committee will be set up. We will systematically monitor for, and react to, possible adverse events. An advisory reference group will comprise student representatives, members of the University Counselling Service and other student welfare staff. Approval has been obtained from Cambridge Psychology Research Ethics Committee (PRE.2015.060). Results will be published in peer-reviewed journals. A lay

  10. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2013-11-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to this issue, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for the latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. In this report the database was revised by adding aircraft accidents in 2011 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2012 database for the latest 20 years from 1992 to 2011. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for the latest 20 years from 1992 to 2011 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2012 revised database for the latest 20 years from 1992 to 2011 shows the followings. The trend of the 2012 database changes little as compared to the last year's report. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. The number of commercial aircraft accidents is 4 for large fixed-wing aircraft, 58 for small fixed-wing aircraft, 5 for large bladed aircraft and 99 for small bladed aircraft. The relevant accidents

  11. Can Resilience Thinking Inform Resilience Investments? Learning from Resilience Principles for Disaster Risk Reduction

    Directory of Open Access Journals (Sweden)

    Margot Hill Clarvis

    2015-07-01

    Full Text Available As the human and financial costs of natural disasters rise and state finances continue to deplete, increasing attention is being placed on the role of the private sector to support disaster and climate resilience. However, not only is there a recognised lack of private finance to fill this gap, but international institutional and financing bodies tend to prioritise specific reactive response over preparedness and general resilience building. This paper utilises the central tenets of resilience thinking that have emerged from scholarship on social-ecological system resilience as a lens through which to assess investing in disaster risk reduction (DRR for resilience. It draws on an established framework of resilience principles and examples of resilience investments to explore how resilience principles can actually inform decisions around DRR and resilience investing. It proposes some key lessons for diversifying sources of finance in order to, in turn, enhance “financial resilience”. In doing so, it suggests a series of questions to align investments with resilience building, and to better balance the achievement of the resilience principles with financial requirements such as financial diversification and replicability. It argues for a critical look to be taken at how resilience principles, which focus on longer-term systems perspectives, could complement the focus in DRR on critical and immediate stresses.

  12. Homebuilt aircraft crashes.

    Science.gov (United States)

    Hasselquist, A; Baker, S P

    1999-06-01

    While the number of general aviation crashes has decreased over the 5 yr prior to 1993, the total number of homebuilt aircraft crashes has increased by nearly 25%. Research was undertaken to analyze these crashes and identify causal factors or unique problems associated with homebuilt aircraft. Some 200 National Transportation Safety Board computer records and two-page descriptive briefs were analyzed for homebuilt aircraft crashes during 1993. Using descriptive epidemiology, variables were looked at in detail and comparisons were made with general aviation crashes during the-same year. Despite accounting for only 3% of all hours flown in general aviation certified aircraft for 1993, homebuilt aircraft accounted for 10% of the crashes and experienced a higher fatal crash rate. Crashes due to mechanical failure and crashes on takeoff and climb were more common in homebuilt aircraft as compared with general aviation. Other significant causal factors for homebuilt aircraft crashes included: minimal flight time in type specific aircraft, improper maintenance and improper design or assembly. Greater emphasis needs to be placed on educating homebuilt aircraft owners in the importance of following Federal Aviation Administration guidelines for certification and air worthiness testing. Understanding the aircraft's specifications and design limitations prior to the initial flight and properly maintaining the aircraft should also help to reverse the trend in the number of these crashes and subsequent lives lost. A system for assuring that all home-built aircraft are certified and more accurate reporting of flight hours are needed for accurate tracking of homebuilt aircraft crash rates.

  13. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2012-09-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to the report, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. This year, the database was revised by adding aircraft accidents in 2010 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2011 database for latest 20 years from 1991 to 2010. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for latest 20 years from 1991 to 2010 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2011 revised database for latest 20 years from 1991 to 2010 shows the followings. The trend of the 2011 database changes little as compared to the last year's one. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. 4 large fixed-wing aircraft accidents, 58 small fixed-wing aircraft accidents, 5 large bladed aircraft accidents and 114 small bladed aircraft accidents occurred. The relevant accidents for evaluating

  14. Measuring resilience in integrated planning

    DEFF Research Database (Denmark)

    Apneseth, K.; Wahl, A. M.; Hollnagel, E.

    2013-01-01

    This chapter demonstrates how a Resilience Analysis Grid (RAG) can be used to profile the performance of a company in terms of the four abilities that characterize a resilient organization. It describes the development of a new, RAG-based tool founded on Resilience Engineering principles that can...... be used to assess an organization's resilience. The tool was tested in a case study involving a company in the offshore oil and gas industry. The company had decided to adopt an Integrated Operations (IO) approach to operations and maintenance planning and the tool was used to evaluate the impact...... of the Integrated Planning (IPL) process on its resilience....

  15. Optimal Resilient Dynamic Dictionaries

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Brodal, Gerth Stølting; Moruz, Gabriel

    2007-01-01

    updates in $O(\\log n+\\delta)$ amortized time. Our dynamic dictionary also supports range queries in $O(\\log n+\\delta+t)$ worst case time, where $t$ is the size of the output. Finally, we show that every resilient search tree (with some reasonable properties) must take~$\\Omega(\\log n + \\delta)$ worst...

  16. [Resilience in old age].

    Science.gov (United States)

    Cárdenas-Jiménez, Andrea; López-Díaz, Alba L

    2011-06-01

    The aim of this study was to characterise and analyse articles published on resilience and old-age from 1990-2006. After a systematic search of five databases (Academic Search Premier-Ebsco Host, Medline, Psyc Articles, Ovid and Science Direct) 33 pieces of literature were included in the analysis. The selected articles had 31 different definitions of resilience, from eight disciplines, mainly health-related fields. It was also found that the research studied the association of resilience with individual (68 variables) and social/environmental factors (17 variables); the most frequent were age and health self-perception. Cultural and religious values were of special interest amongst the latter variables. The literature review demonstrated that resilience in old age is a topic having increasing research interest; this has been linked to various individual, social and cultural factors. However, this is a rapidly developing area that requires that a unified definition be established and that a theoretical and intervention model be created.

  17. Resilience of Amazonian forests

    NARCIS (Netherlands)

    Monteiro Flores, B.

    2016-01-01

    The Amazon has recently been portrayed as a resilient forest system based on quick recovery of biomass after human disturbance. Yet with climate change, the frequency of droughts and wildfires may increase, implying that parts of this massive forest may shift into a savanna state. Although the

  18. Multi-Sited Resilience

    DEFF Research Database (Denmark)

    Olwig, Mette Fog

    2012-01-01

    Participatory methods to build local resilience often involve the organization of local community groups. When global organizations use such methods, it reflects a desire to incorporate local agency. They thereby acknowledge the ability of a society to be innovative and adapt when faced with natu......Participatory methods to build local resilience often involve the organization of local community groups. When global organizations use such methods, it reflects a desire to incorporate local agency. They thereby acknowledge the ability of a society to be innovative and adapt when faced...... with natural disasters and climate change. In a globalized world, however, it is hard to discern what is “local” as global organizations play an increasingly visible and powerful role. This paper will argue that local understandings and practices of resilience cannot be disentangled from global understandings...... flooding in northern Ghana, this paper examines the mutual construction of “local” and “global” notions and practices of resilience through multi-sited processes. It is based on interviews and participant observation in multiple sites at the “local,” “regional” and “global” levels....

  19. Wellbeing And Resilience

    DEFF Research Database (Denmark)

    Harder, Susanne; Davidsen, Kirstine; MacBeth, Angus

    2015-01-01

    , 16 and 52 weeks in terms of evolution of very early indicators of developmental risk and resilience focusing on three possible environmental transmission mechanisms: stress, maternal caregiver representation, and caregiver-infant interaction. DISCUSSION: The study will provide data on very early risk...

  20. New pathways to resilience

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC

    droughts, floods, and heat waves, along with shifting rainfall patterns, threaten to overwhelm the natural resilience of African communities, risking livelihoods and food security. .... As of March 2012, 68Fellows have pursued advanced research through a scholarship program on adaptation to climate change. • 11people ...

  1. State Energy Resilience Framework

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Finster, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Pillon, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Petit, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Trail, J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    The energy sector infrastructure’s high degree of interconnectedness with other critical infrastructure systems can lead to cascading and escalating failures that can strongly affect both economic and social activities.The operational goal is to maintain energy availability for customers and consumers. For this body of work, a State Energy Resilience Framework in five steps is proposed.

  2. Childhood trauma and resilience in psoriatic patients: A preliminary report.

    Science.gov (United States)

    Crosta, Maria Luigia; De Simone, Clara; Di Pietro, Salvatore; Acanfora, Mariateresa; Caldarola, Giacomo; Moccia, Lorenzo; Callea, Antonino; Panaccione, Isabella; Peris, Ketty; Rinaldi, Lucio; Janiri, Luigi; Di Nicola, Marco

    2018-03-01

    Psoriasis is a chronic inflammatory skin disease with a complex etiology, involving the immune system, genetic factors, and external/internal triggers, with psychosomatic aspects. The aim of the study was to investigate childhood trauma and resilience in a psoriatic sample compared with healthy controls. Correlations between childhood trauma, resilience, quality of life, clinical data and psoriatic features were also evaluated. Seventy-seven psoriatic patients and seventy-six homogeneous healthy controls were enrolled. We used the Psoriasis Area and Severity Index (PASI) to assess the severity of psoriasis and the Skindex-29 to measure health-related quality of life. The psychometric battery included the Childhood Trauma Questionnaire (CTQ) and the Connor-Davidson Resilience Scale (CD-Risc) to assess trauma exposure and resilience, respectively. Psoriatic patients showed a significant prevalence of childhood trauma and a lower resilience level compared to healthy controls. Associations between traumatic experiences, low resilience and reduced quality of life in psoriatic subjects were also observed. A multidisciplinary approach is helpful to investigate clinical aspects, trigger factors and psychophysiological stress response in psoriatic subjects. Improving resilience with an early psychological intervention focused on self-motivation and strengthening of self-efficacy could facilitate the management of psoriasis. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Science and Technology at DHS: Resiliency of our Physical and Social Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, Mitchel

    2012-04-11

    Disasters affect us all. The challenge is to minimize the impact. Resilience has been defined as “Foster individual, community, and system robustness, adaptability, and capacity for rapid recovery.” The Department of Homeland Security’s (DHS) Science and Technology Directorate (S&T) provides new technologies, materials, controls, models, and other tools that promote resilience. More important, science and technology can contribute to shaping our resiliency blueprint by instilling scientific rigor into the processes that will shape our future. This presentation will review resiliency approaches, emerging technologies, and capability gaps for resilient communities and institutions.

  4. The development of a closed-loop flight controller with panel method integration for gust alleviation using biomimetic feathers on aircraft wings

    Science.gov (United States)

    Blower, Christopher J.; Lee, Woody; Wickenheiser, Adam M.

    2012-04-01

    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.

  5. Resilience: Building immunity in psychiatry

    Science.gov (United States)

    Shastri, Priyvadan Chandrakant

    2013-01-01

    The challenges in our personal, professional, financial, and emotional world are on rise, more so in developing countries and people will be longing for mental wellness for achieving complete health in their life. Resilience stands for one's capacity to recover from extremes of trauma and stress. Resilience in a person reflects a dynamic union of factors that encourages positive adaptation despite exposure to adverse life experiences. One needs to have a three-dimensional construct for understanding resilience as a state (what is it and how does one identify it?), a condition (what can be done about it?), and a practice (how does one get there?). Evaluating the level of resilience requires the measurement of internal (personal) and external (environmental) factors, taking into account that family and social environment variables of resilience play very important roles in an individual's resilience. Protection factors seem to be more important in the development of resilience than risk factors. Resilience is a process that lasts a lifetime, with periods of acquisition and maintenance, and reduction and loss for assessment. Overall, currently available data on resilience suggest the presence of a neurobiological substrate, based largely on genetics, which correlates with personality traits, some of which are configured via social learning. The major questions about resilience revolve around properly defining the concept, identifying the factors involved in its development and recognizing whether it is actually possible to immunize mental health against adversities. In the clinical field, it may be possible to identify predisposing factors or risk factors for psychopathologies and to develop new intervention strategies, both preventive and therapeutic, based on the concept of resilience. The preferred environments for application of resilience are health, education, and social policy and the right approach in integrating; it can be developed only with more research

  6. Aircraft Survivability. Spring 2011

    Science.gov (United States)

    2011-01-01

    panel exhibiting telltale signs and critical fragments were identified and collected. The weapon employed against the aircraft was correctly assessed...701C engines (for FCR- equipped Apache Longbows), and a fully integrated cockpit. In addition, the aircraft received improved survivability...sustained analytical contributions to improve the survivability and effectiveness of US military aircraft and weapon systems. These contributions

  7. Hydrologic resilience and Amazon productivity.

    Science.gov (United States)

    Ahlström, Anders; Canadell, Josep G; Schurgers, Guy; Wu, Minchao; Berry, Joseph A; Guan, Kaiyu; Jackson, Robert B

    2017-08-30

    The Amazon rainforest is disproportionately important for global carbon storage and biodiversity. The system couples the atmosphere and land, with moist forest that depends on convection to sustain gross primary productivity and growth. Earth system models that estimate future climate and vegetation show little agreement in Amazon simulations. Here we show that biases in internally generated climate, primarily precipitation, explain most of the uncertainty in Earth system model results; models, empirical data and theory converge when precipitation biases are accounted for. Gross primary productivity, above-ground biomass and tree cover align on a hydrological relationship with a breakpoint at ~2000 mm annual precipitation, where the system transitions between water and radiation limitation of evapotranspiration. The breakpoint appears to be fairly stable in the future, suggesting resilience of the Amazon to climate change. Changes in precipitation and land use are therefore more likely to govern biomass and vegetation structure in Amazonia.Earth system model simulations of future climate in the Amazon show little agreement. Here, the authors show that biases in internally generated climate explain most of this uncertainty and that the balance between water-saturated and water-limited evapotranspiration controls the Amazon resilience to climate change.

  8. The role of resilience and purpose in life in habituation to heat and cold pain.

    Science.gov (United States)

    Smith, Bruce W; Tooley, Erin M; Montague, Erica Q; Robinson, Amanda E; Cosper, Cynthia J; Mullins, Paul G

    2009-05-01

    This study examined the role of resilience in habituation to heat and cold pain in healthy women (n = 47). Heat and cold pain thresholds were each assessed across 5 equally spaced trials. Resilience, purpose in life, optimism, social support, and neuroticism were assessed using self-report measures. The hypothesis was that the resilience and the associated resilience factors would be positively related to habituation to heat and cold pain while controlling for neuroticism. Multilevel modeling was used to test the hypothesis. When considering each characteristic separately, resilience and purpose in life predicted greater habituation to heat pain while resilience, purpose in life, optimism, and social support predicted greater habituation to cold pain. When controlling for the other characteristics, both resilience and purpose in life predicted greater habituation to heat and cold pain. Resilience and associated characteristics such as a sense of purpose in life may be related to enhanced habituation to painful stimuli. Future research should further examine the relationship between resilience, purpose in life, and habituation to pain and determine whether psychosocial interventions that target resilience and purpose in life improve habituation and reduce vulnerability to chronic pain. This article showed that resilience and a sense of purpose in life were both related to the ability to habituate to heat and cold pain in healthy women. These personal characteristics may enhance habituation to pain by providing the confidence and motivation to persist in the face of painful stimuli.

  9. Aircraft agility maneuvers

    Science.gov (United States)

    Cliff, Eugene M.; Thompson, Brian G.

    1992-01-01

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

  10. Children restraint systems for civil aircraft.

    Science.gov (United States)

    1978-03-01

    Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

  11. Child restraint systems for civil aircraft.

    Science.gov (United States)

    1978-03-01

    Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

  12. Aircraft Test & Evaluation Facility (Hush House)

    Data.gov (United States)

    Federal Laboratory Consortium — The Aircraft Test and Evaluation Facility (ATEF), or Hush House, is a noise-abated ground test sub-facility. The facility's controlled environment provides 24-hour...

  13. NEW MODEL FOR QUANTIFICATION OF ICT DEPENDABLE ORGANIZATIONS RESILIENCE

    Directory of Open Access Journals (Sweden)

    Zora Arsovski

    2011-03-01

    Full Text Available Business environment today demands high reliable organizations in every segment to be competitive on the global market. Beside that, ICT sector is becoming irreplaceable in many fields of business, from the communication to the complex systems for process control and production. To fulfill those requirements and to develop further, many organizations worldwide are implementing business paradigm called - organizations resilience. Although resilience is well known term in many science fields, it is not well studied due to its complex nature. This paper is dealing with developing the new model for assessment and quantification of ICT dependable organizations resilience.

  14. Proposed Functional Architecture and Associated Benefits Analysis of a Common Ground Control Station for Unmanned Aircraft Systems

    Science.gov (United States)

    2010-03-01

    These activities consist of the Inputs, Controls, Outputs, and Mechanisms ( ICOM ). The input is an activity flow that enters the functional block...Interface HSC Helicopter Sea Combat HSM Helicopter Marine Strike IAA Incident Awareness and Assessment ICOM Inputs, Controls, Outputs, and Measures IDEF

  15. Quantifying resilience for resilience engineering of socio technical systems

    OpenAIRE

    Häring, Ivo; Ebenhöch, Stefan; Stolz, Alexander

    2016-01-01

    Resilience engineering can be defined to comprise originally technical, engineering and natural science approaches to improve the resilience and sustainability of socio technical cyber-physical systems of various complexities with respect to disruptive events. It is argued how this emerging interdisciplinary technical and societal science approach may contribute to civil and societal security research. In this context, the article lists expected benefits of quantifying resilience. Along the r...

  16. From resilience thinking to Resilience Planning: Lessons from practice.

    Science.gov (United States)

    Sellberg, M M; Ryan, P; Borgström, S T; Norström, A V; Peterson, G D

    2018-04-14

    Resilience thinking has frequently been proposed as an alternative to conventional natural resource management, but there are few studies of its applications in real-world settings. To address this gap, we synthesized experiences from practitioners that have applied a resilience thinking approach to strategic planning, called Resilience Planning, in regional natural resource management organizations in Australia. This case represents one of the most extensive and long-term applications of resilience thinking in the world today. We conducted semi-structured interviews with Resilience Planning practitioners from nine organizations and reviewed strategic planning documents to investigate: 1) the key contributions of the approach to their existing strategic planning, and 2) what enabled and hindered the practitioners in applying and embedding the new approach in their organizations. Our results reveal that Resilience Planning contributed to developing a social-ecological systems perspective, more adaptive and collaborative approaches to planning, and that it clarified management goals of desirable resource conditions. Applying Resilience Planning required translating resilience thinking to practice in each unique circumstance, while simultaneously creating support among staff, and engaging external actors. Embedding Resilience Planning within organizations implied starting and maintaining longer-term change processes that required sustained multi-level organizational support. We conclude by identifying four lessons for successfully applying and embedding resilience practice in an organization: 1) to connect internal "entrepreneurs" to "interpreters" and "networkers" who work across organizations, 2) to assess the opportunity context for resilience practice, 3) to ensure that resilience practice is a learning process that engages internal and external actors, and 4) to develop reflective strategies for managing complexity and uncertainty. Copyright © 2018 The Authors

  17. Unmanned Aircraft Systems Human-in-the-Loop Controller and Pilot Acceptability Study: Collision Avoidance, Self-Separation, and Alerting Times (CASSAT)

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Vincent, Michael J.; Consiglio, Maria C.; Munoz, Cesar; Chamberlain, James P.; Volk, Paul; Arthur, Keith E.

    2016-01-01

    The Federal Aviation Administration (FAA) has been mandated by the Congressional funding bill of 2012 to open the National Airspace System (NAS) to Unmanned Aircraft Systems (UAS). With the growing use of unmanned systems, NASA has established a multi-center "UAS Integration in the NAS" Project, in collaboration with the FAA and industry, and is guiding its research efforts to look at and examine crucial safety concerns regarding the integration of UAS into the NAS. Key research efforts are addressing requirements for detect-and-avoid (DAA), self-separation (SS), and collision avoidance (CA) technologies. In one of a series of human-in-the-loop experiments, NASA Langley Research Center set up a study known as Collision Avoidance, Self-Separation, and Alerting Times (CASSAT). The first phase assessed active air traffic controller interactions with DAA systems and the second phase examined reactions to the DAA system and displays by UAS Pilots at a simulated ground control station (GCS). Analyses of the test results from Phase I and Phase II are presented in this paper. Results from the CASSAT study and previous human-in-the-loop experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely, efficiently, and effectively integrate UAS into the NAS.

  18. Creating resilient SMEs

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus; Guay, Fanny

    2015-01-01

    According to the EU, during the past five years, small and medium enterprises (SMEs) have created 85% of new jobs and two-thirds of private sector employment in the region. SMEs are considered the backbone of the economy in Europe and represent more than 95% of enterprises in USA and Australia...... if certain criteria are met. With this in mind, this paper will be examining how to create resilient SMEs. A well-known concept in the field is business continuity management. BCM is defined as “a holistic management process that identifies potential threats to an organization and the impacts to business...... and efficient manner, including through the preservation and restoration of its essential basic structures and functions.” This paper will define resilience and business continuity management by retracing the origins of both concepts through time. It will then compare them by highlighting their similarities...

  19. Standardisation or Resilience?

    DEFF Research Database (Denmark)

    Zinck Pedersen, Kirstine

    2016-01-01

    stability and predictability is presently being challenged by critics who insist that healthcare systems are complex and changing entities, thereby shifting focus towards the healthcare organisation's resilient and adaptive capacities. Based on a close reading of predominant patient safety literature...... begin to address the uncertainty of medical practice as well as the necessary competences of healthcare professionals to act with ‘safety dispositions’ as a precondition for delivering safe care....

  20. The model of dynamics and control of modified optical scanning seeker in anti-aircraft rocket missile

    Science.gov (United States)

    Gapinski, Daniel; Koruba, Zbigniew; Krzysztofik, Izabela

    2014-04-01

    The paper presents the concept of a modified optical scanning seeker. Programmed and tracking controls have been developed with the simultaneous influence of external interferences from the direction of self-guiding rocket missile. The numerical analysis for the proposed scanning seeker has been conducted. It appears from the conducted research that the seeker maintains accurately the set direction in space despite the occurrence of large angular accelerations of the missile. Moreover, the control of the seeker's axis is done with sufficient accuracy for self-guidance with the use of small control moments.