Robust Fault-tolerant Control For Uncertain Time-delay Systems

Modern control systems are developing towards large and more complicated scale.Vast loss of wealth and lives is caused if system failures occur in this kind of controlsystems. It is important to improve reliability and safety of systems.Fault-tolerant controlpioneers a new way to enhance the reliability of complicated systems. Time delays anduncertainty are universal factors which affect the performance of fault-tolerant systems.Therefore, the research for uncertain robust fault-tolerant control systems with time-delayshas important theoretical and practical significance.This dissertation studies the problem of stability and robust fault-tolerant control foruncertain system with time-delays by constructing appropriate. A sufficient condition ofthe closed-loop fault system is given to show the robust integrity, and the design methodof robust fault-tolerant controller is obtained. Lyapunov-Krasovskii functional, combiningwith model transformation, linear matrix inequality(LMI) and integral inequality matrixmethod. The main works are as follows:Firstly, The problem of robust fault-tolerant control for the uncertain time-delaydiscrete system with state and control delays is investigated. A sufficient condition of theclosed-loop system is given to show the robust integrity, and the design method of robustfault-tolerant controller is obtained too.Secondly, for both cases of additive and multiplicative controller uncertainties, adelay-dependent non-fragile robust H∞robust fault-tolerant control problem foruncertain systems with time-varying delays is investigated. A sufficient condition of theclosed-loop system is given to show the internally stable, and the design method ofnon-fragile robust fault-tolerant controller is obtained too.Thirdly, the problem of H∞robust fault-tolerant control for uncertain descriptorMarkov jump systems with time delays is considered. Based on Lyapunov stability theory,integral inequality matrix and linear matrix inequality(LMI), the sufficient conditions andthe method of is given for the existence of H∞robust fault-tolerant controller which issatisfy toγbased on actuator failure with stochastic stableness. Fourthly, the H∞robust fault-tolerant control problem of a class of uncertaintime-delay system with Markov jump is studied. The sufficient condition for the existenceof mode-dependent H∞fault-tolerant controller is given by analyzing the reconstructedobserver system. Meanwhile, the design method of H∞fault-tolerant controller thatbased on observer isderived and described as an optimization one.