Fault Tolerant Control For Switched Linear Systems

This book presents up-to-date research and novel methodologies on fault diagnosis and fault tolerant control for switched linear systems. It provides a unified yet neat framework of filtering, fault detection, fault diagnosis and fault tolerant control of switched systems. It can therefore serve as a useful textbook for senior and/or graduate students who are interested in knowing the state-of-the-art of filtering, fault detection, fault diagnosis and fault tolerant control areas, as well as recent advances in switched linear systems.

This book approaches its subject matter in a way that provides Lyapunov function analysis and event-triggered design methods for switched dynamic systems in terms of sampled-data control, hysteresis switching control, and fault-tolerant control. This book presents several novel design methods on event-triggered control of switched linear systems, in which the events inclusively consist of not only switching itself but events occurring as the switched systems evolve. The features of our approaches lie in threefold: i) In the framework of sampled-data control, a bond between the sampling period and the average dwell time of the asynchronous switched linear neutral systems is revealed, with which stabilization conditions are derived for periodic sampling and event-triggered sampling mechanisms, respectively. ii) New event-triggered control strategies are proposed for switched linear systems and switched delay systems including switched neutral systems. The Zeno phenomenon can be excluded easily since the constant threshold can guarantee the existence of minimum positive lower bound between two continuous sampling intervals. iii). Two new fault-tolerant control methods are presented for switched cascade systems, with structural uncertainties existing in both system matrices and input matrices of the linear subsystems, by using the average dwell-time techniques. The proposed control design works on both the switched systems with actuator faults and its nominal systems (i.e., without actuator faults) without necessarily changing any structures and/or parameters of the proposed controllers. This book presents several systematical analysis and design methods for event-triggered control of switched systems in terms of the Lyapunov-based stability. It is of great significance to theoretical research and practical applications for switched systems. The book provides a unified framework of sampled-data control, including periodic sampled-data control and event-triggered control, and fault-tolerant control of switched systems. It serves as a useful book for researchers and graduate students who are interested in knowing the state of the art of analysis and synthesis of switched systems. In addition, it is also a useful source of up-to-date design methods for researchers who study switched dynamic systems and graduate students of control theory and control engineering.

This book focuses on the fault diagnosis observer design for the switched system. Model-based fault diagnosis and fault tolerant control are one of the most popular research directions in recent decades. It contains eight chapters. Every chapter is independent in the method of observer design, but all chapters are around the same topic. Besides, in each chapter, the model description and theoretical results are firstly provided, then some practical application examples are illustrated to prove the obtained results. The advanced theoretical methodologies will benefit researchers or engineers in the area of safety engineering and the arrangement of the structure will help the readers to understand the content easily.

In recent years, control systems have become more sophisticated in order to meet increased performance and safety requirements for modern technological systems. Engineers are becoming more aware that conventional feedback control design for a complex system may result in unsatisfactory performance, or even instability, in the event of malfunctions in actuators, sensors or other system components. In order to circumvent such weaknesses, new approaches to control system design have emerged which can tolerate component malfunctions while maintaining acceptable stability and performance. These types of control systems are often known as fault-tolerant control systems (FTCS). More precisely, FTCS are control systems which possess the ability to accommodate component failure automatically. Analysis and Synthesis of Fault-Tolerant Control Systems comprehensively covers the analysis and synthesis methods of fault tolerant control systems. It unifies the methods for developing controllers and filters for a wide class of dynamical systems and reports on the recent technical advances in design methodologies. MATLAB® is used throughout the book, to demonstrate methods of analysis and design. Key features: • Provides advanced theoretical methods and typical practical applications • Provides access to a spectrum of control design methods applied to industrial systems • Includes case studies and illustrative examples • Contains end-of-chapter problems Analysis and Synthesis of Fault-Tolerant Control Systems is a comprehensive reference for researchers and practitioners working in this area, and is also a valuable source of information for graduates and senior undergraduates in control, mechanical, aerospace, electrical and mechatronics engineering departments.

Fault-tolerant control theory is a well-studied topic but the use of the sets in detection, isolation and/or reconfiguration is rather tangential. The authors of this book propose a systematic analysis of the set-theoretic elements and devise approaches which exploit advanced elements within the field. The main idea is to translate fault detection and isolation conditions into those conditions involving sets. Furthermore, these are to be computed efficiently using positive invariance and reachability notions. Constraints imposed by exact fault control are used to define feasible references (which impose persistent excitation and, thus, non-convex feasible sets). Particular attention is given to the reciprocal influences between fault detection and isolation on the one hand, and control reconfiguration on the other. Contents 1. State of the Art in Fault-tolerant Control 2. Fault Detection and Isolation in Multisensor Systems 3. Residual Generation and Reference Governor Design 4. Reconfiguration of the Control Mechanism for Fault-tolerant Control 5. Related Problems and Applications About the Authors Florin Stoican received a B.E. degree from the “Politehnica” University of Bucharest, Romania, in 2008 and his PhD from SUPELEC, France in 2011. He held an ERCIM Postdoctoral Fellowship with NTNU Trondheim, Norway, in 2012, and is currently Assistant Professor at “Politehnica” University of Bucharest. His main interest is the fault tolerant control of dynamical systems through the prism of set theoretic elements. His current work involves further results in set theory and constrained optimization problems. Sorin Olaru received an M.S. degree from the “Politehnica” University of Bucharest, Romania, and both his PhD and Habilitation from University Paris XI, France, being awarded the European Commission Archimedes Prize in 2002. Since 2001 he has held different positions at INRIA and SUPELEC in France and visiting appointments at the University of Newcastle, Australia and NTNU Trondheim, Norway. He is currently Professor at SUPELEC, a member of the INRIA Disco team and senior member of IEEE. His research interests include optimization-based control design and the set-theoretic characterization of constrained dynamical systems.

In this thesis, we deal with the FTC design problem for a linear system with both input constraints and actuator faults. For the nominal system, a low-high gain controller is designed based on the Lyapunov stability theory and the solution of LMI. An iterative Ricatti equation algorithm is given to find such controller. Based on the designed controller, with the analysis of the linear system subject to actuator saturation, the invariant ellipsoids of attraction and performance regions are calculated. For the case that the initial state is not within the attraction region, a novel methodology based on the reference adjustment technique is proposed in the thesis to achieve large-region stabilization. For the system with certain actuator faults, the fault's influence is analyzed first, its size and the time when it happens will decide whether the system is stable or not and will influence the system's performance. Then two main FTC design methods (PFTC and AFTC) are used to cope with faults and actuator saturation together. The proposed PFTC and AFTC methods have both their restrictions when dealing with the input saturation problem: Since the passive fault-tolerant controller is designed for presumed faults, it can guarantee that the system operates with degraded performance in a small stability region which is decided by the worst fault case. For the AFTC method, the degraded performance caused by faults will be recovered by designing an observer to obtain the fault information. However, its control capability will be reduced due to the fault, and it is hard to analyze the system's stability region. Based on the existing performance analysis principle and the implementation results of PFTC and AFTC, a novel fault-tolerant control scheme based on the reference adjustment technique is proposed to guarantee the system's performance in an acceptable region. Several academic examples are taken all along the thesis to illustrate the methods. Finally, the methodology is applied to the path tracking problem of an autonomous electric vehicle (EV) which has four electromechanical wheel-driven (4WD vehicle) systems under normal and faulty conditions.

This book provides recent theoretical developments in and practical applications of fault diagnosis and fault tolerant control for complex dynamical systems, including uncertain systems, linear and nonlinear systems. Combining adaptive control technique with other control methodologies, it investigates the problems of fault diagnosis and fault tolerant control for uncertain dynamic systems with or without time delay. As such, the book provides readers a solid understanding of fault diagnosis and fault tolerant control based on adaptive control technology. Given its depth and breadth, it is well suited for undergraduate and graduate courses on linear system theory, nonlinear system theory, fault diagnosis and fault tolerant control techniques. Further, it can be used as a reference source for academic research on fault diagnosis and fault tolerant control, and for postgraduates in the field of control theory and engineering.

Positive systems are an important class of systems that frequently arise in application areas, such as in the chemical process industry, electronic circuit design, communication networks, and biology. The study of the stability of such systems differs from standard systems in that the analysis focuses only on the trajectories generated under positivity constraints. Switched positive systems also arise in a variety of applications. Examples can be found in TCP congestion control, in processes described by non-homogeneous Markov chains, in image processing, in biochemical networks, and so on. In comparison to general switched systems, that have received a lot of attention in the past years, the theory for positive switched systems is still in its infancy. Switched Positive Linear Systems studies the stability, performance evaluation, stabilization via switching control, and optimal control of (continuous-time and linear) positive switched systems. It provides a review of the results that have already been established in the literature. Other results, especially those related to norm computation and optimization, are new and are presented integrated with previous ones. Switched Positive Linear Systems provides a comprehensive and timely introduction to the study of such systems. Readers who are new to the topic will find everything required to understand such systems in a concise and accessible form.

This book delves into the complexities of fault estimation and fault-tolerant control for nonlinear time-delayed systems. Through the use of multiple-integral observers, it addresses fault estimation and active fault-tolerant control for time-delayed fuzzy systems with actuator faults and both actuator and sensor faults. Additionally, the book explores the use of sliding mode control to solve issues of sensor fault estimation, intermittent actuator fault estimation, and active fault-tolerant control for time-delayed switched fuzzy systems. Furthermore, it presents the use of H∞ guaranteed cost control for both time-delayed switched fuzzy systems and time-delayed switched fuzzy stochastic systems with intermittent actuator and sensor faults. Finally, the problem of delay-dependent finite-time fault-tolerant control for uncertain switched T-S fuzzy systems with multiple time-varying delays, intermittent process faults and intermittent sensor faults is studied. The research on fault estimation and tolerant control has drawn attention from engineers and scientists in various fields such as electrical, mechanical, aerospace, chemical, and nuclear engineering. The book provides a comprehensive framework for this topic, placing a strong emphasis on the importance of stability analysis and the impact of result conservatism on the design and implementation of observers and controllers. It is intended for undergraduate and graduate students interested in fault diagnosis and tolerant control technology, researchers studying time-varying delayed T-S fuzzy systems, and observer/controller design engineers working on system stability applications.

Guaranteeing a high system performance over a wide operating range is an important issue surrounding the design of automatic control systems with successively increasing complexity. As a key technology in the search for a solution, advanced fault detection and identification (FDI) is receiving considerable attention. This book introduces basic model-based FDI schemes, advanced analysis and design algorithms, and mathematical and control-theoretic tools. This second edition of Model-Based Fault Diagnosis Techniques contains: • new material on fault isolation and identification and alarm management; • extended and revised treatment of systematic threshold determination for systems with both deterministic unknown inputs and stochastic noises; • addition of the continuously-stirred tank heater as a representative process-industrial benchmark; and • enhanced discussion of residual evaluation which now deals with stochastic processes. Model-based Fault Diagnosis Techniques will interest academic researchers working in fault identification and diagnosis and as a text it is suitable for graduate students in a formal university-based course or as a self-study aid for practising engineers working with automatic control or mechatronic systems from backgrounds as diverse as chemical process and power engineering.