Stability And Robust Reliable Control For Classes Of Fuzzy Systems Based On T-S Fuzzy Model

The research of fuzzy control theory includes a series of main problems, such as the stability and the robustness analysis in fuzzy control,the system design approaches and the improvement of the system performance etc.Combining robust control theory, fault tolerant theory with H∞control theory, using Lyapunov function and linear matrix inequalities (LMI) method, the robust stability and reliable control problems of T-S fuzzy systems are discussed in detail in the dissertation. In addition, a switched fuzzy system is a switched system whose subsystems are all fuzzy systems. The switched fuzzy system is a kind of more complicated hybrid systems. This class of systems can often describe more precisely the continuous dynamics and discrete dynamics as well as their interactions in real-world systems.The research of switched fuzzy systems makes the scope of fuzzy system widely. The main contributions are as follows.First of all, the robust non-fragile control problem is studied for a class of uncertainty T-S dynamical fuzzy systems. The uncertainty T-S dynamical fuzzy system model is presented. Robust non-fragile controller of the continuous uncertain dynamical fuzzy system is designed by means of the Lyapunov function method. The global asymptotical stability conditions of the uncertainty dynamical fuzzy system are given based on LMIs.Then, the fault tolerant control design for uncertain discrete fuzzy systems with time-delay is considered by utilizing the fuzzy control method. For nonlinear discrete systems, the T-S model is constructed and the parametric uncertainty and time-delay terms are introduced to make the fuzzy model approach to the original system more exactly. The possessing integrity and robustness for actuator failure and sensor failure to closed-loop T-S fuzzy systems is guaranteed under the fuzzy control law by using Lyapunov method. The sufficient conditions for the closed-loop fuzzy system possess integrity against actuator failures and sensor failures are derived in terms of LMIs when the bounds for uncertainties exist.A model of uncertain switched fuzzy systems is discussed, in which each subsystem of switched systems is an uncertain fuzzy system, and the state feedback H∞robust control problem is studied. Based on LMIs and H∞control theory, the state feedback controller and the switching strategy are designed using multiple Lyapunov functions method. Closed-loop switched fuzzy systems have H∞performance index y with the designed switching strategy.The robust reliable control problem for a class of switched fuzzy systems is studied. When the upper bounds of the disturbances are unknown and the actuator is "serious failure", namely, the residual part of actuator can not make the original system stable, the roust fuzzy adaptive reliable controller is designed to ensure the relevant closed-loop system uniformly ultimately bounded, by using the switching technique and multiple Lyapunov functions method. Moreover, a switching strategy is given for the uncertain switched fuzzy system achieving system uniformly ultimately bounds.Trying to combine the robustly reliable control theory with the tracking control problem, the robust reliable tracking control problem of uncertain switched fuzzy systems is discussed. A roust fuzzy adaptive reliable controller is designed via using switching technique and multiple Lyapunov functions method. For all disturbances which the upper bounds are unknown, the tracking errors decrease uniformly asymptotically to zero by the designing of switching strategy.Finally, the results of the dissertation are summarized and the further research problems are point out.