Fault Tolerant Control Of Singular Lipschitz Systems With Actuator Saturation

Singular systems have found wide applications in engineering systems, social systems,economic systems, biological systems and so on. Due to their special properties, such asnon-strictly proper transfer functions, irregularity, impulses or non-causality, the analysisand control for singular systems have been extensively studied in the past several decades.Nearly all physical systems are subject to saturation constraint, such as actuator sat-uration or sensor saturation. It is known that such constraint may have adverse efects onthe performance and stability of a control system. Consequently, a great deal of attentionhas been focused on the stability analysis and controller design for systems with saturatingactuator.As we know, unexpected faults or failures of a control system may result in substantialdamage, and can even be hazardous to plant personnel. Therefore, much attention has beendevoted to fault tolerant control to improve the reliability of the system.This thesis deals with fault tolerant control of singular systems under actuator satura-tion. The main results are as follows:Firstly, we discuss fault tolerant control of singular Lipschitz systems under actua-tor saturation and L₂/L_∞disturbance. By designing a fixed-gain controller, the regularity,impulse-free, the existence and uniqueness of the solution as well as stability of the closed-loop system can be guaranteed. Meanwhile, we also study the L₂/L_∞performance of theclosed-loop system. The performance index can be optimized by solving the correspondingoptimization algorithm.Secondly, the adaptive fault tolerant control of singular Lipschitz systems under actua-tor saturation and L₂/L_∞disturbance is addressed. By introducing an adaptive mechanism,the proposed controller parameters are updated on-line automatically to compensate thefault efects on systems, which is superior to the fixed-gain controller.Finally, we extend our results to fault tolerant control of discrete-time singular systemunder actuator saturation. The uniqueness of the solution and the stability of the closed-loopsystems are investigated.