CRC Press Adaptive Backstepping Control of Uncertain Systems with Actuator Failures, Subsystem Interactions, and Nonsmooth Nonlinearities

In practice, actuators often undergo failures and various factors influence its effectiveness. Also due to the increasing complexity of large-scale systems, subsystems are often interconnected, whereas the interactions between any two subsystems are difficult to deal with. This book details a series of new methodologies of designing and analyzing adaptive backstepping control systems involving treatment on actuator failures, subsystem interactions and nonsmooth nonlinearities. Moreover, it discusses some interesting open issues in adaptive failure accommodation, decentralized adaptive control and distributed adaptive coordinated control. Review "In practical control systems, actuators may inevitably undergo failures and a variety of nonsmooth nonlinearities, such as backlashes, hysteresis and dead-zones, influence their e ectiveness in executing the control commands. These actuator imperfections, often uncertain in time, pattern and values, can lead to deteriorated performance or even instability of the system if they are not well handled. In particular, when the system parameters are poorly known, the compensation problem becomes more complicated. Adaptive control has been proved to be a promising tool to solve the problem, but some important issues, such as guaranteeing transient performance of adaptive failure compensation control systems and accommodating intermittent failures, are still worth investigating. On the other hand, subsystems are often interconnected in large-scale systems of increasing complexity, whereas the interactions between any two subsystems are di□cult to identify or measure. The decentralized adaptive control technique is an e□cient and practical strategy for such interconnected systems. It is aimed at designing a local controller for each subsystem which uses only local information while the stability and performance of the whole system are guaranteed. Nevertheless, when adaptive control approaches are applied to deal with system uncertainties, the analysis of the entire system is quite challenging. Besides, advances in communication techniques enable information exchanges among distinct subsystems so that certain collective objectives, such as consensus and formation control, can be attained by designing subsystem interactions carefully. This book is a compilation of the latest results on designing and analyzing adaptive backstepping control systems involving treatment on actuator failures, subsystem interactions and nonsmooth nonlinearities. Some novel work related to adaptive failure compensation, decentralized adaptive control and distributed adaptive coordinated control is also discussed in this book. In this book the authors aim to introduce novel solutions to a number of hot-spot and challenging problems in the area of adaptive control. In the reviewer's opinion, it is a meaningful work for achieving this objective. This book is organized into 11 chapters. The first chapter is devoted to a brief introduction and elaborates the state of the art of related research areas and motivation of this work. The second chapter gives the concepts of adaptive backstepping control design and related analysis. The main content of this book, consisting of Chapters 3{10, provides the novel solutions adopting a backstepping design tool for a number of hot-spot and challenging problems in the area of adaptive control, which can be divided into two parts. The first part introduces three di erent backstepping-based adaptive actuator failure compensation methods for di erent cases. In Chapter 3, the relative degree restriction corresponding to the redundant actuators is relaxed by introducing a pre-filter, for each actuator, in designing an output-feedback controller for the systems with a total loss of e ectiveness (TLOE) type of failure. A set-point regulation problem for linear systems is considered to illustrate the design idea, and the result is extended to tracking control