Download or read book Lyapunov based Fault Tolerant Control of Quadrotor Unmanned Aerial Vehicles written by Xiaobing Zhang and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the theoretical development, simulation study and flight tests of a Lyapunov-based control approach for the Fault Tolerant Control (FTC) of a quadrotor unmanned aerial vehicle (UAV). Based on the derivation of nonlinear model of the dynamics of the quadrotor UAV, a Lyapunov-based control approach with fixed controller gains is proposed and firstly demonstrated through simulations of the quadrotor UAV for handling system parameter uncertainties. Secondly, this proposed Lyapunov-based approach with the selected controller gains is applied as a fault tolerant controller in the framework of a passive Fault Tolerant Control System (FTCS), for handling less severe faults occurring in the quadrotor UAV. Thirdly, the proposed new controller by Lyapunov-based adaptive control method for fault tolerant control of the quadrotor UAV is proposed to handle more severe faults. Finally, the Lyapunov-based control method has been implemented to the test bed, Qball-X4 Unmanned Aerial Vehicle, and the acceptable performances on altitude control have been achieved. In the thesis, simulation and flight testing results demonstrate that the FTCS with the Lyapunov-based approach has certain robustness for most of partial losses. However, the FTCS with Lyapunov-based adaptive control approach has advantages in accommodating more severe faults for, which may not be addressed by the Lyapunov-based approach.

Download or read book Fault Tolerant Cooperative Control of Unmanned Aerial Vehicles written by Ziquan Yu and published by Springer Nature. This book was released on 2023-12-06 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the fault-tolerant cooperative control (FTCC) of multiple unmanned aerial vehicles (multi-UAVs). It provides systematic and comprehensive descriptions of FTCC issues in multi-UAVs concerning faults, external disturbances, strongly unknown nonlinearities, and input saturation. Further, it addresses FTCC design from longitudinal motions to attitude motions, and outer-loop position motions of multi-UAVs. The book’s detailed control schemes can be used to enhance the flight safety of multi-UAVs. As such, the book offers readers an in-depth understanding of UAV safety in cooperative/formation flight and corresponding design methods. The FTCC methods presented here can also provide guidelines for engineers to improve the safety of aerospace engineering systems. The book offers a valuable asset for scientists and researchers, aerospace engineers, control engineers, lecturers and teachers, and graduates and undergraduates in the system and control community, especially those working in the field of UAV cooperation and multi-agent systems.

Download or read book Nonlinear and Fault tolerant Control Techniques for a Quadrotor Unmanned Aerial Vehicle written by Tong Li and published by . This book was released on 2011 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unmanned Aerial Vehicles (UAVs) have become more and more popular, and how to control them has become crucial. Although there are many different control methods that can be applied to the control of UAVs, nonlinear control techniques are more practical since the nonlinear features of most UAVs. In this thesis, as the first main contribution, three widely used nonlinear control techniques including Feedback Linearization Control (FLC), Sliding Mode Control (SMC), and Backstepping Control (BSC) are discussed, investigated, and designed in details and flight-tested on a unique quadrotor UAV (Qball-X4) test-bed available at the Networked Autonomous Vehicles (NAV) Lab in Concordia University. Each of these three control algorithms has its own features. The advantages and disadvantages are revealed through both simulation and experimental tests. Sliding mode control is well known for its capability of handling uncertainty, and is expected to be a robust controller on Qball-X4 UAV. Feedback linearization control and backstepping control are considered a bit weaker than sliding mode control. A comparison of these three controllers is carried out in both theoretical analysis and experimental results under same fault-free flight conditions. Testing results and comparison show the different features of different control methods, and provide a view on how to choose controller under a specific condition. Besides, safety and reliability of UAVs have been and will always be a critical issue in the aviation industry. Fault-Tolerant Control (FTC) has played an extremely important role towards UAVs' safety and reliability and the safety of group people if an unexpected crash occurred due to faults/damages of UAVs. Therefore, FTC has been a very active and quickly growing research and development field for UAVs and other safety-critical systems. Based on the use of sliding mode control technique, referred to as Fault-Tolerant SMC (FT-SMC) have been investigated, implemented, flight-tested and compared in the Qball-X4 test-bed and also simulation environment in both passive and active framework of FTC in the presence of different actuator faults/damages, as the second main contribution of this thesis work.

Download or read book Refined Safety Control of Unmanned Flight Vehicles via Fractional Order Calculus written by Ziquan Yu and published by CRC Press. This book was released on 2023-02-03 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph explores the safety of unmanned flight vehicles via the corresponding fault-tolerant control design methods. The authors analyse the safety control issues of unmanned flight vehicles, which include finite-time recovery against faults, concurrence of actuator faults and sensor faults, concurrence of actuator faults and wind effects, and faults encountered by a portion of unmanned flight vehicles in a distributed communication network. In addition, the commonly used simple but effective proportional-integral-derivative structure is also incorporated into the safety control design for unmanned flight vehicles. By using the fractional-order calculus, the developed safety control results are able to ensure flight safety and achieve the refined performance adjustments against faults and wind effects. The book will be of interest to 3rd/4th year undergraduate students, postgraduate and graduate students, researchers, academic staff, engineers of aircraft and unmanned flight vehicles.

Download or read book Autonomous Safety Control of Flight Vehicles written by Xiang Yu and published by CRC Press. This book was released on 2021-02-12 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerospace vehicles are by their very nature a crucial environment for safety-critical systems. By virtue of an effective safety control system, the aerospace vehicle can maintain high performance despite the risk of component malfunction and multiple disturbances, thereby enhancing aircraft safety and the probability of success for a mission. Autonomous Safety Control of Flight Vehicles presents a systematic methodology for improving the safety of aerospace vehicles in the face of the following occurrences: a loss of control effectiveness of actuators and control surface impairments; the disturbance of observer-based control against multiple disturbances; actuator faults and model uncertainties in hypersonic gliding vehicles; and faults arising from actuator faults and sensor faults. Several fundamental issues related to safety are explicitly analyzed according to aerospace engineering system characteristics; while focusing on these safety issues, the safety control design problems of aircraft are studied and elaborated on in detail using systematic design methods. The research results illustrate the superiority of the safety control approaches put forward. The expected reader group for this book includes undergraduate and graduate students but also industry practitioners and researchers. About the Authors: Xiang Yu is a Professor with the School of Automation Science and Electrical Engineering, Beihang University, Beijing, China. His research interests include safety control of aerospace engineering systems, guidance, navigation, and control of unmanned aerial vehicles. Lei Guo, appointed as "Chang Jiang Scholar Chair Professor", is a Professor with the School of Automation Science and Electrical Engineering, Beihang University, Beijing, China. His research interests include anti-disturbance control and filtering, stochastic control, and fault detection with their applications to aerospace systems. Youmin Zhang is a Professor in the Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, Québec, Canada. His research interests include fault diagnosis and fault-tolerant control, and cooperative guidance, navigation, and control (GNC) of unmanned aerial/space/ground/surface vehicles. Jin Jiang is a Professor in the Department of Electrical & Computer Engineering, Western University, London, Ontario, Canada. His research interests include fault-tolerant control of safety-critical systems, advanced control of power plants containing non-traditional energy resources, and instrumentation and control for nuclear power plants.

Download or read book Fault tolerant Flight Control and Guidance Systems written by Guillaume J. J. Ducard and published by Springer Science & Business Media. This book was released on 2009-05-14 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a complete overview of fault-tolerant flight control techniques. Discussion covers the necessary equations for the modeling of small UAVs, a complete system based on extended Kalman filters, and a nonlinear flight control and guidance system.

Download or read book Diagnostic and Fault tolerant Control Applied to an Unmanned Aerial Vehicle written by Abdel-Razzak Merheb and published by . This book was released on 2016 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unmanned Aerial Vehicles (UAV) are more and more popular for their civil and military applications. Classical control laws usually show weaknesses in the presence of parameter uncertainties, environmental disturbances, and actuator and sensor faults. Therefore, it is judicious to design a control law capable of stabilizing the UAV not only in the fault-free nominal cases, but also in the presence of disturbances and faults. In this thesis, a new bio-inspired search algorithm called Ecological Systems Algorithm (ESA) suitable for engineering optimization problems is developed. The algorithm is used over the thesis to find optimal gains for the fault tolerant controllers. Sliding Mode Control theory is used to develop two Passive Fault Tolerant Controllers for quadrotor UAVs: Regular and Cascaded SMC. Because Passive Controllers handle a few numbers of faults, an Active Sliding Mode Fault Tolerant Controller using Kalman Filter is developed. To overcome severe faults and failures, an emergency controller based on the Quadrotor-to-Trirotor conversion maneuver is developed. The Controllers developed so far (Passive, Active, and emergency controllers) are then integrated to form the Integrated Fault Tolerant Controller (IFTC). The IFTC is a powerful controller that is able to handle a wide number of faults, and save actuator resources as well as processor computational effort. Finally, Passive and Active Fault Tolerant Controllers are designed for octorotor UAVs based on First Order and Second Order Sliding Mode Control. The AFTC uses Dynamic and Pseudo-Inverse Control Allocation methods to redistribute the control effort among healthy actuators reducing the effect of fault.

Download or read book Fault Diagnosis and Fault tolerant Control of Quadrotor UAVs written by Remus C. Avram and published by . This book was released on 2016 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quadrotors represent a special class of Unmanned Aerial Vehicles (UAVs) and have attracted significant attention in recent years due to their potential in various military and civilian applications. However, due to their intrinsic fabrication process and component damage, quadrotors are prone to various type of faults. This dissertation presents the design, analysis, and experimental implementation of fault diagnosis, fault-tolerant control, and controller verification methods to achieve safety assurance and trusted autonomy of quadrotor UAVs. First, the issue of sensor faults is investigated under two different scenarios: (1) the case when all Euler angles are available for measurement; (2) the case when roll and pitch angles are not measurable and need to be estimated. Nonlinear adaptive estimators are designed to provide possible simultaneous accelerometer and gyroscope fault detection, isolation, and bias estimation. Next, the issue of fault-tolerant control of quadrotor UAV in the presence of actuator faults is considered. First, the design of an integrated fault diagnosis and accommodation scheme is investigated. Nonlinear adaptive thresholds are designed to improve the robustness of the fault detection and isolation algorithm. The fault diagnostic information is used for accommodating the effect of the faults. Second, a nonlinear adaptive fault-tolerant altitude and attitude controller is developed to automatically stabilize and recover tracking performance of the quadrotor, even in the presence of possible multiple simultaneous actuator faults. Compared with the first approach, the adaptive control framework is able to automatically accommodate the effects of actuator faults without the need of a fault diagnosis mechanism. Finally, a run-time assurance architecture is investigated for the verification and validation of the adaptive fault-tolerant altitude attitude controller. The algorithms are presented with a rigorous framework aimed at characterizing their performance properties. The above algorithms are implemented and evaluated using a real-time indoor quadrotor test environment. Experimental flight test results are shown to illustrate the effectiveness of the proposed methods.

Download or read book Fault Tolerant Flight Control of Unmanned Aerial Vehicles written by Iman Sadeghzadeh and published by . This book was released on 2015 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety, reliability and acceptable level of performance of dynamic control systems are the major keys in all control systems especially in safety-critical control systems. A controller should be capable of handling noises and uncertainties imposed to the controlled process. A fault-tolerant controller should be able to control a system with guaranteed stability and good or acceptable performance not only in normal operation conditions but also in the presence of partial faults or total failures that can be occurred in the components of the system. When a fault occurs in a system, it suddenly starts to behave in an unanticipated manner. Thereby, a fault-tolerant controller should be designed for being able to handle the fault and guarantee system stability and acceptable performance in the presence of faults/damages. This shows the importance and necessity of Fault-Tolerant Control (FTC) to safety-critical and even nowadays for some new and non-safety-critical systems. During recent years, Unmanned Aerial Vehicles (UAVs) have proved to play a significant role in military and civil applications. The success of UAVs in different missions guarantees the growing number of UAVs to be considerable in future. Reliability of UAVs and their components against faults and failures is one of the most important objectives for safety-critical systems including manned airplanes and UAVs. The reliability importance of UAVs is implied in the acknowledgement of the Office of the Secretary of Defense in the UAV Roadmap 2005-2030 by stating that, ?Improving UA [unmanned aircraft] reliability is the single most immediate and long-reaching need to ensure their success?. This statement gives a wide future scenery of safety, reliability and Fault-Tolerant Flight Control (FTFC) systems of UAVs. The main objective of this thesis is to investigate and compare some aspects of fault tolerant flight control techniques such as performance, robustness and capability of handling the faults and failures during the flight of UAVs. Several control techniques have been developed and tested on two main platforms at Concordia University for fault-tolerant control techniques development, implementation and flight test purposes: quadrotor and fixedwing UAVs. The FTC techniques developed are: Gain-Scheduled Proportional-Integral-Derivative (GS-PID), Control Allocation and Re-allocation (CA/RA), Model Reference Adaptive Control (MRAC), and finally the Linear Parameter Varying (LPV) control as an alternative and theoretically more comprehensive gain scheduling based control technique. The LPV technique is used to control the quadrotor helicopter for fault-free conditions. Also a GS-PID controller is used as a fault-tolerant controller and implemented on a fixedwing UAV in the presence of a stuck rudder failure case.

Download or read book Advanced Robust Nonlinear Control Approaches for Quadrotor Unmanned Aerial Vehicle written by Moussa Labbadi and published by Springer Nature. This book was released on 2021-09-14 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies selected advanced flight control schemes for an uncertain quadrotor unmanned aerial vehicle (UAV) systems in the presence of constant external disturbances, parametric uncertainties, measurement noise, time-varying external disturbances, and random external disturbances. Furthermore, in all the control techniques proposed in this book, it includes the simulation results with comparison to other nonlinear control schemes recently developed for the tracking control of a quadrotor UAV. The main contributions of the present book for quadrotor UAV systems are as follows: (i) the proposed control methods are based on the high-order sliding mode controller (SMC) and hybrid control algorithm with an optimization method. (ii) the finite-time control schemes are developed by using fast terminal SMC (FTSMC), nonsingular FTSMC (NFTSMC), global time-varying SMC, and adaptive laws. (iii) the fractional-order flight control schemes are developed by using the fractional-order calculus theory, super twisting algorithm, NFTSMC, and the SMC. This book covers the research history and importance of quadrotor system subject to system uncertainties, external wind disturbances, and noise measurements, as well as the research status of advanced flight control methods, adaptive flight control methods, and flight control based on fractional-order theory. The book would be interesting to most academic undergraduate, postgraduates, researchers on flight control for drones and applications of advanced controllers in engineering field. This book presents a must-survey for advanced finite-time control for quadrotor system. Some parts of this book have the potential of becoming the courses for the modelling and control of autonomous flying machines. Readers (academic researcher, undergraduate student, postgraduate student, MBA/executive, and education practitioner) interested in nonlinear control methods find this book an investigation. This book can be used as a good reference for the academic research on the control theory, drones, terminal sliding mode control, and related to this or used in Ph.D. study of control theory and their application in field engineering.

Download or read book Fault Diagnosis and Fault tolerant Control of Unmanned Aerial Vehicles written by Ban Wang and published by . This book was released on 2018 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the increasing demand for unmanned aerial vehicles (UAVs) in both military and civilian applications, critical safety issues need to be specially considered in order to make better and wider use of them. UAVs are usually employed to work in hazardous and complex environments, which may seriously threaten the safety and reliability of UAVs. Therefore, the safety and reliability of UAVs are becoming imperative for development of advanced intelligent control systems. The key challenge now is the lack of fully autonomous and reliable control techniques in face of different operation conditions and sophisticated environments. Further development of unmanned aerial vehicle (UAV) control systems is required to be reliable in the presence of system component faults and to be insensitive to model uncertainties and external environmental disturbances. This thesis research aims to design and develop novel control schemes for UAVs with consideration of all the factors that may threaten their safety and reliability. A novel adaptive sliding mode control (SMC) strategy is proposed to accommodate model uncertainties and actuator faults for an unmanned quadrotor helicopter. Compared with the existing adaptive SMC strategies in the literature, the proposed adaptive scheme can tolerate larger actuator faults without stimulating control chattering due to the use of adaptation parameters in both continuous and discontinuous control parts. Furthermore, a fuzzy logic-based boundary layer and a nonlinear disturbance observer are synthesized to further improve the capability of the designed control scheme for tolerating model uncertainties, actuator faults, and unknown external disturbances while preventing overestimation of the adaptive control parameters and suppressing the control chattering effect. Then, a cost-effective fault estimation scheme with a parallel bank of recurrent neural networks (RNNs) is proposed to accurately estimate actuator fault magnitude and an active fault-tolerant control (FTC) framework is established for a closed-loop quadrotor helicopter system. Finally, a reconfigurable control allocation approach is combined with adaptive SMC to achieve the capability of tolerating complete actuator failures with application to a modified octorotor helicopter. The significance of this proposed control scheme is that the stability of the closed-loop system is theoretically guaranteed in the presence of both single and simultaneous actuator faults.

Download or read book Robust Formation Control for Multiple Unmanned Aerial Vehicles written by Hao Liu and published by CRC Press. This book was released on 2022-12-01 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the authors’ recent research results on formation control problems, including time-varying formation, communication delays, fault-tolerant formation for multiple UAV systems with highly nonlinear and coupled, parameter uncertainties, and external disturbances. Differentiating from existing works, this book presents a robust optimal formation approach to designing distributed cooperative control laws for a group of UAVs, based on the linear quadratic regulator control method and the robust compensation theory. The proposed control method is composed of two parts: the nominal part to achieve desired tracking performance and the robust compensation part to restrain the influence of highly nonlinear and strongly coupled parameter uncertainties, and external disturbances on the global closed-loop control system. Furthermore, this book gives proof of their robust properties. The influence of communication delays and actuator fault tolerance can be restrained by the proposed robust formation control protocol, and the formation tracking errors can converge into a neighborhood of the origin bounded by a given constant in a finite time. Moreover, the book provides details about the practical application of the proposed method to design formation control systems for multiple quadrotors and tail-sitters. Additional features include a robust control method that is proposed to address the formation control problem for UAVs and theoretical and experimental research for the cooperative flight of the quadrotor UAV group and the tail-sitter UAV group. Robust Formation Control for Multiple Unmanned Aerial Vehicles is suitable for graduate students, researchers, and engineers in the system and control community, especially those engaged in the areas of robust control, UAV swarming, and multi-agent systems.

Download or read book Safety and Reliability in Cooperating Unmanned Aerial Systems written by Camille Alain Rabbath and published by World Scientific. This book was released on 2010 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. Introduction. 1.1. Unmanned aerial systems. 1.2. Cooperative control. 1.3. Contingencies -- 2. Health management for the individual vehicle : a review. 2.1. Passive and active fault-tolerant control systems. 2.2. Fault/failure detection and diagnosis. 2.3. Control reconfiguration. 2.4. FTC and FDD techniques for MAV and SUAV -- 3. Health monitoring and adaptation for UAS formations. 3.1. Models of vehicle dynamics, flight control, and faults. 3.2. Formation control. 3.3. Observer-based decentralized abrupt fault detector. 3.4. Signal-based decentralized non-abrupt fault detector. 3.5. UAV command adaptation. 3.6. Simulations and experiments -- 4. Decision making and health management for cooperating UAS. 4.1. Coordinated rendezvous of UAS formations. 4.2. Cooperation despite information flow faults. 4.3. Numerical simulations. 4.4. Distributed and parallel implementation of optimization algorithms

Download or read book Adaptive Hybrid Control of Quadrotor Drones written by Nihal Dalwadi and published by Springer Nature. This book was released on 2023-03-01 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the dynamics of a tail-sitter quadrotor and biplane quadrotor-type hybrid unmanned aerial vehicles (UAVs) and, based on it, various nonlinear controllers design like backstepping control (BSC), ITSMC (Integral Terminal Sliding Mode Control), and hybrid controller (BSC + ITSMC). It discusses single and multiple observer-based control strategies to handle external disturbances like wind gusts and estimate states. It covers the dynamics of slung load with a biplane quadrotor and a control architecture to handle the effect of partial rotor failure with wind gusts acting on it. An anti-swing control to prevent damage to the slung load and a deflecting surface-based total rotor failure compensation strategy to prevent damage to the biplane quadrotor are also discussed in this book. The monograph will be helpful for undergraduate and post-graduate students as well as researchers in their advanced studies.

Download or read book State Estimation and Control for Low cost Unmanned Aerial Vehicles written by Chingiz Hajiyev and published by Springer. This book was released on 2015-06-10 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses state estimation and control procedures for a low-cost unmanned aerial vehicle (UAV). The authors consider the use of robust adaptive Kalman filter algorithms and demonstrate their advantages over the optimal Kalman filter in the context of the difficult and varied environments in which UAVs may be employed. Fault detection and isolation (FDI) and data fusion for UAV air-data systems are also investigated, and control algorithms, including the classical, optimal, and fuzzy controllers, are given for the UAV. The performance of different control methods is investigated and the results compared. State Estimation and Control of Low-Cost Unmanned Aerial Vehicles covers all the important issues for designing a guidance, navigation and control (GNC) system of a low-cost UAV. It proposes significant new approaches that can be exploited by GNC system designers in the future and also reviews the current literature. The state estimation, control and FDI methods are illustrated by examples and MATLAB® simulations. State Estimation and Control of Low-Cost Unmanned Aerial Vehicles will be of interest to both researchers in academia and professional engineers in the aerospace industry. Graduate students may also find it useful, and some sections are suitable for an undergraduate readership.

Download or read book Fault Tolerant Control with Applications to Aircraft Using Linear Quadratic Design Framework written by Bin Yu and published by . This book was released on 2016 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety is one of the major concerns in the aviation community for both manned aircraft and unmanned aerial vehicles (UAVs). The safety issue of manned aircraft, such as commercial aircraft, has drawn great attentions especially after a series of disasters in recent decades. Safety and reliability issues of UAVs have also attracted significant attention due to their highly autonomous feature towards their future civilian applications. Focusing on the improvement of safety and reliability of aircraft, a fault-tolerant control (FTC) system is demanded to utilize the configured redundancy in an effective and efficient manner to increase the survivability of aircraft in the presence of faults/failures. This thesis aims to develop an effective FTC system to improve the security, reliability, and survivability of the faulty aircraft: manned aircraft and UAVs. In particular, the emphases are focused on improving the on-line fault-tolerant capability and the transient performance between faults occurrence and control re-configuration. In the existing fault-tolerant literature, several control approaches are developed to possess fault-tolerant capability in recent decades, such as sliding mode control (SMC), model reference adaptive control (MRAC), and model predictive control (MPC), just as examples. Different strategies have their specific benefits and drawbacks in addressing different aspects of fault-tolerant problems. However, there are still open problems in the fault-tolerant performance improvement, the transient behavior management, consideration of the interaction between FTC and fault detection and diagnosis (FDD), etc. For instance, MPC is recognized as a suitable inherent structure in synthesizing a FTC system due to its capability of addressing faults via solving constraints, reforming cost function, and updating model on-line. However, this on-line FTC capability introduces further challenges in terms of fault problem formulation, on-line computation, transient behavior before reconfiguration is triggered, etc. Designing an efficient FDD is also a challenge topic with respect to time response speed, accuracy, and reliability due to its interaction with a fault-tolerant controller. In the control design framework based on linear quadratic (LQ) cost function formulation, faults can be accommodated in both passive and active way. A passive FTC system is synthesized with a prescribed degree of stability LQ design technique. The state of the post-fault system is obtained through state-augmented extended Kalman filter (SAEKF), which is a combined technique with state and parameter estimation. In terms of reconfiguration capability, MPC is considered as a favorable active FTC strategy. In addition to MPC framework, the improvement of on-line computational efficiency motivates MPC to be used to perform fault-tolerant flight control. Furthermore, a Laguerre-function based MPC (LF-MPC) is presented to enhance the on-line fault-tolerant capability. The modification is based on a series of Laguerre functions to model the control trajectory with fewer parameters. In consequence, the computation load is reduced, which improves the real-time fault-tolerant capability in the framework of MPC. The FTC capability is further improved for accommodating the performance degradation during the transient period before the control reconfiguration. This approach is inspired by exponentially increasing weighting matrix used in linear quadratic regulator (LQR). Two platforms are used to perform the evaluation of the designed FTC system. A quadrotor UAV, named the Qball-X4, is utilized to test FTC designed with exponentially increasing weighing matrix LQ technique and FDD designed with SAEKF. The evaluation is conducted under the task of trajectory tracking in the presence of loss of control effectiveness (LOE) faults of actuators. The modified MPC is utilized to synthesize an active FTC system to accommodate the elevator stuck fault of a Boeing 747-100/200 benchmark model. The exponentially increasing weighing matrix LQ technique is further implemented in LF-MPC framework to improve the fault-tolerant capability before the control reconfiguration. A time delayed FDD is integrated into the evaluation process to present the effectiveness of the proposed FTC strategies. The designed FTC system is evaluated under the emergency landing task in the event of failure of elevators.

Download or read book Model free Approach for Control Fault Diagnosis and Fault tolerant Control written by Younes Al Younes and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objectives of this thesis consist of developing Control, Fault Detection and Diagnosis (FDD) and Fault-Tolerant Control (FTC) techniques based on a the Model-Free (MF) concept recently introduced in the literature. The proposed approaches are implemented, tested and validated on a quadrotor platform. The first step of this work consisted of the modelling of the quadrotor, and then analyzing, designing and implementing new robust control strategies based on the Model-Free Control (MFC) technique recently developed in the literature. The MFC algorithm helps compensating for disturbances and model uncertainties. The advantage of this recent concept is in the simplicity of the design of the controller by adding a control law using ultra-local models to the classical control techniques. To test and validate this new approach, the Linear-Quadratic-Regulator (LQR) and the Nonlinear-Integral-Backstepping (NIB) controllers have been considered by integrating the MFC concept to design a (LQR-MFC) and a (NIB-MFC), respectively. Both algorithms are validated through analytical and experimental procedures and the robustness checked and compared with respect to the initial controllers in the presence of disturbances and model uncertainties.The FDD is a very important step towards the development of FTC techniques. The FDD approach developed in this thesis is based on the residual generation between the measured outputs and the estimated outputs obtained using observers/estimators. Residuals are expected to be close to zero in the fault free case and deviate from zero in the presence of a fault or failure. However, as the residuals are generated using models, they highly depend on the quality of the model used and on the presence of disturbances which may lead to false alarms or to non-detections. A novel “intelligent estimator” inspired from the MF concept has been developed and used in order to improve the residual generation and the fault diagnostic. Two intelligent estimators have been designed by integrating the MF scheme with the state and Thau observers for Multi-Input-Multi-Output (MIMO) systems, where the intelligent Output-Estimator (iOE) represents the integration between the MF technique with the state observer, and the intelligent Thau Output-Estimator (iTOE) represents the augmentation of the MF technique with the Thau Observer. The estimation of the system outputs obtained using the iOE are then used to estimate the actuator and sensor faults. The estimation of the actuator faults is improved by using the ultra-local models. A structured algorithm is then developed and implemented in order to estimate sensor fault magnitudes using the residuals generated by the intelligent estimator. The results obtained from the fault detection and estimation are then used to compensate for the fault effect on the flight control performance. The implemented fault-tolerant control technique compensates for the actuator faults by adjusting the control law based on the fault estimation. In case a sensor fault is detected and estimated, the desired path is regenerated according to the estimated fault magnitude in order to compensate for the fault effect.The proposed algorithms are implemented and tested on the Qball-X4 quadrotor. The results of the real-time flight tests validate the proposed techniques and compensate for sensor and actuator faults. Footages of the flight tests are available online.