Download or read book Reconfigurable Flight Control System for Fighter Aircraft Using Mpc written by Bilal Siddiqui and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we studied Reconfigurable Flight Control Systems to achieve acceptable performance of a fighter aircraft, even in the event of wing damage to the aircraft at low speeds and high angle of attack, which is typical of many combat maneuvers. Equations of motion for the damaged aircraft were derived, which helped in building simulators. A new methodology for numerical prediction of aerodynamics of damaged aircraft was proposed and implemented. A baseline control system for undamaged aircraft was developed, and finally a reconfigurable flight control scheme was implemented to keep the aircraft flyable even after the damage. In this study we proposed a hybrid reconfigurable flight control system (RFCS) which was a fusion of active and passive techniques. We derived equations of motion for the damaged aircraft. The new approach to derivation lends insight into possible simplification in building simulators for damaged aircraft. A new methodology for better prediction of damaged aircraft aerodynamics. Fixed gain controller was found to be inadequate for controlling the damaged aircraft. For alleviating this a novel reconfigurable scheme based on MPC is evaluated.
Download or read book Fighter Aircraft Maneuver Limiting Using MPC Theory and Application written by Daniel Simon and published by Linköping University Electronic Press. This book was released on 2017-09-12 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flight control design for modern fighter aircraft is a challenging task. Aircraft are dynamical systems, which naturally contain a variety of constraints and nonlinearities such as, e.g., maximum permissible load factor, angle of attack and control surface deflections. Taking these limitations into account in the design of control systems is becoming increasingly important as the performance and complexity of the aircraft is constantly increasing. The aeronautical industry has traditionally applied feedforward, anti-windup or similar techniques and different ad hoc engineering solutions to handle constraints on the aircraft. However these approaches often rely on engineering experience and insight rather than a theoretical foundation, and can often require a tremendous amount of time to tune. In this thesis we investigate model predictive control as an alternative design tool to handle the constraints that arises in the flight control design. We derive a simple reference tracking MPC algorithm for linear systems that build on the dual mode formulation with guaranteed stability and low complexity suitable for implementation in real time safety critical systems. To reduce the computational burden of nonlinear model predictive control we propose a method to handle the nonlinear constraints, using a set of dynamically generated local inner polytopic approximations. The main benefit of the proposed method is that while computationally cheap it still can guarantee recursive feasibility and convergence. An alternative to deriving MPC algorithms with guaranteed stability properties is to analyze the closed loop stability, post design. Here we focus on deriving a tool based on Mixed Integer Linear Programming for analysis of the closed loop stability and robust stability of linear systems controlled with MPC controllers. To test the performance of model predictive control for a real world example we design and implement a standard MPC controller in the development simulator for the JAS 39 Gripen aircraft at Saab Aeronautics. This part of the thesis focuses on practical and tuning aspects of designing MPC controllers for fighter aircraft. Finally we have compared the MPC design with an alternative approach to maneuver limiting using a command governor.
Download or read book Reconfigurable Flight Control Designs with Application to the X 33 Vehicle written by John J. Burken and published by . This book was released on 1999 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the right body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.
Download or read book Reconfigurable Autopilot Design for a High Performance Aircraft Using Model Predictive Control written by Jose Pedro Ruiz and published by . This book was released on 2004 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The losses of military and civilian aircraft due to control surface failures have prompted research into controllers with a degree of reconfiguration. This thesis will describe a design approach incorporating Model Predictive Control (MPC) with a self updating model to achieve a level of reconfiguration in a generic high performance aircraft. MPC has the advantage of explicitly taking a model of the failed system and incorporating it into a receding horizon optimization problem. MPC also has the added benefits of allowing constraints on the inputs, outputs, and states of the system as well as tuning flexibility. This thesis describes the development of four types of MPC autopilots. A description of the controller implementation and failure implementation is also included. Each autopilot is subject to a surface failure during certain times in a sample maneuver and the resulting controller adaptation is analyzed. All MPC controllers are found to maintain good performance in the event of certain failures with an updated internal model. It is when the internal model is not updated that full performance is not recovered and in some cases, loss of the aircraft results.
Download or read book Application of Sliding Mode Methods to the Design of Reconfigurable Flight Control Systems written by Scott R. Wells and published by . This book was released on 2002 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. An overview of reconfigurable flight control is given, including a review of the current state-of-the-art within the subdisciplines of fault detection parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears promising due its property of invariance to matched uncertainty. An overview of SMC is given and its properties are demonstrated. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate SISO and MIMO designs. The third application is a linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.
Download or read book Reconfigurable Flight Control Systems for a Generic Fighter Aircraft written by Shahzad Aslam-Mir and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Digital Rate Controller for the Control Reconfigurable Combat Aircraft Design Using Quantitative Feedback Theory written by Kurt N. Neumann and published by . This book was released on 1988 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to develop a digital controller using Quantitative Feedback Theory for a fighter aircraft with unstable, nonminimum phase dynamics that meets performance specifications despite surface failures. Aircraft design trends for highly maneuverable fighter aircraft are relaxing stability requirements in order to increase performance in the transonic and supersonic regions. However, as a result, the aircraft is statically unstable in the subsonic region which makes the flight control system critical to flight safety. The conventional approach to the flight safety problem is to provide multiple redundancy throughout the fight control system. However, QFT provides an alternative to excessive hardware. The three controlled states are the pitch, roll, and yaw rates. A weighting matrix is derived which linearly combines the nine control surfaces into three control inputs. The plant is converted to a certain plane using the Hoffman algorithm. Three constant gain controllers and three prefilters are designed for a single flight condition of 0.9 Mach and 30000 ft altitude. The controllers and prefilters are transformed to the z plane for simulation purposes. The design is simulated with healthy plant and 24 combinations of surface failures. Keywords: Control theory, Multivariate control. (KR).
Download or read book Reconfigurable Flight Control System for a STOL Aircraft Using Quantitative Feedback Theory written by Bruce T. Clough (1LT, USAF.) and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Adaptive Methods for Reconfigurable Flight Control Systems Appendix I of 2 written by and published by . This book was released on 1995 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report discusses methods for the design of reconfigurable flight control systems. Model reference adaptive control algorithms were developed which allow for the rapid identification of aircraft parameters after failures or damages and for automatic control redesign. These algorithms are simple enough that they can be implemented in real-time with existing computers. Simulation results were obtained using a detailed nonlinear model of a fighter aircraft. The results demonstrate the ability of the adaptive algorithms to automatically readjust trim values after failures, to restore tracking of the pilot commands despite the loss of actuator effectiveness, and to coordinate the use of the remaining surfaces in order to maintain the decoupling between- the rotational axes. The report also discusses analytical results that were obtained during the course of the research regarding the stability and convergence properties of multivariable adaptive control algorithms, the use of averaging methods for the analysis of transient response and robustness, and the estimation of uncertainty in dynamic models. A modified recursive least-squares algorithm with forgetting factor is also described which gives fast adaptation under normal conditions while keeping the sensitivity to noise limited when signal to noise ratios are poor.
Download or read book Baade Bancroft written by and published by . This book was released on 1901 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Robust and Reconfigurable Flight Control System Design written by Wichai Siwakosit and published by . This book was released on 2001 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flight Control System for the CRCA Control Reconfigurable Combat Aircraft Using a Command Generator Tracker with PI Proportional Plus Integral Feedback and Kalman Filter written by Steven S. Payson and published by . This book was released on 1989 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research develops an integrated software design package useful in the synthesis of CGT/PI/KF control systems, and uses this software package to design and evaluate a longitudinal flight control system for the Control Reconfigurable Combat Aircraft (CRCA). The software package, called CGTPIKE and built with MATRIXx commands, allows for the synthesis and evaluation of a Command Generator Tracker (CGT) which provides inputs to the system and acts as a pre-compensator, and a regulator with proportional plus integral (PI) feedback which forces the system outputs to mimic the model output. The software also allows the incorporation of a Kalman filter for estimation of the system states. Certainty equivalence can be invoked by adopting the LQG assumptions, thereby allowing the Kalman filter to be designed independently of the CGT/PI controller. The total CGT/PI/KF controller can then be evaluated and the design refined. CGTPIKF is an interactive, menu-driven CAD package which can be used in the development of any CGT/PI/KF control system, regardless of application. A flight control system was designed for the CRCA air combat mode (ACM) entry using CGTPIKF. This control system was designed to force the aircraft to emulate a first order response in pitch rate. Theses. (rh).
Download or read book Reconfigurable Aircraft Flight Control System Via Robust Direct Adaptive Control written by C. M. Ha and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Automatic Flight Control Systems written by Thomas Lombaerts and published by BoD – Books on Demand. This book was released on 2012-01-18 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of flight control is inseparably linked to the history of aviation itself. Since the early days, the concept of automatic flight control systems has evolved from mechanical control systems to highly advanced automatic fly-by-wire flight control systems which can be found nowadays in military jets and civil airliners. Even today, many research efforts are made for the further development of these flight control systems in various aspects. Recent new developments in this field focus on a wealth of different aspects. This book focuses on a selection of key research areas, such as inertial navigation, control of unmanned aircraft and helicopters, trajectory control of an unmanned space re-entry vehicle, aeroservoelastic control, adaptive flight control, and fault tolerant flight control. This book consists of two major sections. The first section focuses on a literature review and some recent theoretical developments in flight control systems. The second section discusses some concepts of adaptive and fault-tolerant flight control systems. Each technique discussed in this book is illustrated by a relevant example.
Download or read book Retrofit Reconfigurable Flight Control System and the F A 18C written by and published by . This book was released on 2006 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Navy has completed the initial flight test of a Reconfigurable Control Law System (RCLAWS) on the F/A-18C. The purpose of reconfigurable control is to allow for the safe operation of an aircraft that has experienced a sudden change in aircraft dynamics resulting from aircraft damage or flight control effector damage. The RCLAWS utilized during this flight test are novel in that they are designed to augment the production flight control system instead of replacing it. In order to reduce verification and certification requirements, this retrofit reconfigurable methodology supplements pilot commands to compensate for undesirable aircraft dynamics instead of manipulating control surfaces directly. Through comparison of the aircraft's actual response to model data of the aircraft's desired response, the RCLAWS determines what commands need to be applied to produce the desired aircraft response. Flight test data have been collected to determine the viability of the in-line retrofit reconfigurable control method. Although flight data indicate a modest improvement within the limited flight test envelope, simulation analysis has indicated that the retrofit RCLAWS provide substantial improvements for more aggressive failures. Simulation shows RCLAWS has proven to reduce the aircrew workload in a recent catastrophic failure present in the F/A-18 community and provide predictable aircraft dynamics for a safe recovery.
Download or read book Flight Control System Reconfiguration Design Using Quantitative Feedback Theory written by P. B. Arnold and published by . This book was released on 1984 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative theory is used to develop control laws for the AFTI/F-16 with a reconfigurable flight control system. Compensators are synthesized to control pitch rate and roll rate through individually controlled elevators and flaperons. Robust control of these variables is required over a larger portion of the flight envelope despite flight control surface failures. Linearized aerodynamic data are used to develop the aircraft model in state-variable format. The longitudinal and lateral-directional equations are coupled in the control matrix. Individual control of the elevators and flaperons is obtained by dividing the dimensionalized control derivatives for a control surface pair in half and assigning each surface of the pair one-half of the total derivative value. The system with individually controlled surfaces represents a four input-two output system which is transformed into an equivalent two input-two output system for each control surface configuration and flight condition. Quantitative feedback theory is then applied to the equivalent systems. Originator-supplied keywords included: Inherent Reconfiguration; Loop Transmission; Flight control Systems; Quantitative Feedback Theory; Control Systems; Computer Programs; Theses.
Download or read book Design of a Reconfigurable Lateral Flight Control System for a C 135 Aircraft written by Colin Swaney and published by . This book was released on 1990 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
