Tingshu Hu – författare

Practicing Engineers, advanced graduate students and researchers in areas related to control engineering will find the systematic approach and new results useful. Some background in nonlinear control systems and a first year graduate course in linear systems and multivariable control would greatly facilitate the reading of this book. Every physical actuator is subject to saturation. When the actuator saturates, the performance of the control system designed without considering actuator saturation will seriously deteriorate. Currently there's surge of interest in increasing the practical applicability of control theory by incorporating the effect of saturation into the design of a control system. Control Systems with Actuator Saturation Analysis and Design examines the problem of actuator saturation in depth. The overall approach takes into account the saturation nonlinearities at the outset of the control design.In the case that a control law is designed a priori to meet either the performance or stability requirement, it analyzes the closed loop system under actuator saturation systematically and redesigns the controller in such a way that the preference is retained while stability is Improved. It also presents some related results on systems with state saturation or sensor saturation.

Saturation nonlinearities are ubiquitous in engineering systems. In control systems, every physical actuator or sensor is subject to saturation owing to its maximum and minimum limits. A digital filter is subject to saturation if it is implemented in a finite word length format. Saturation nonlinearities are also purposely introduced into engineering systems such as control sys­ tems and neural network systems. Regardless of how saturation arises, the analysis and design of a system that contains saturation nonlinearities is an important problem. Not only is this problem theoretically challenging, but it is also practically imperative. This book intends to study control systems with actuator saturation in a systematic way. It will also present some related results on systems with state saturation or sensor saturation. Roughly speaking, there are two strategies for dealing with actuator sat­ uration. The first strategy is to neglect the saturation in the first stage of the control design process, and then to add some problem-specific schemes to deal with the adverse effects caused by saturation. These schemes, known as anti-windup schemes, are typically introduced using ad hoc modifications and extensive simulations. The basic idea behind these schemes is to intro­ duce additional feedbacks in such a way that the actuator stays properly within its limits. Most of these schemes lead to improved performance but poorly understood stability properties.