Stabilization Control Design For Several Classes Of Switched Fuzzy Systems

A switched fuzzy system is a switched system whose subsystems are all fuzzy systems. Switched fuzzy systems are a new type of hybrid systems. Due to the co-existence of continuous dynamics, discrete dynamics and fuzzy feature, the study of switched fuzzy systems is very difficult and very few results have been available by now. Since switched fuzzy systems have extensive background in practice and significance in theory, the study of switched fuzzy systems can enrich both fuzzy system theory and switched system theory and provide potential new ideas and approaches for modeling, analysis and control of complex systems.The dissertation studies the issue of stabilization control design for several classes of switched fuzzy systems. The results include:For uncertain switched fuzzy systems, when the state is not available, a robust feedback controller and the observer-based switched laws are designed. For a non-switched fuzzy system, if a single controller can not stabilize the system, a switched scheme among candidate controllers is adopted to achieve stabilization and resolve the H∞control problem.Taking into account the control problems of switched fuzzy time-delay systems whose states can be measured or incompletely measured, a states feedback controller and observer-based feedback controller are designed respectively. Further sufficient conditions for asymptotic stability and the design of switched laws for the systems are presented.The states feedback controllers and the observer-based feedback controllers as well as the switching laws are designed for uncertain switched fuzzy systems with delays. When the controller gains suffer disturbances, sufficient conditions for the existence of non-fragile feedback controllers and the design of switched laws are given in the form of linear matrix inequalities by using multiple Lyapunov functions.Stabilization conditions and observer-based switching law design are presented for uncertain discrete-time switched fuzzy time-delay systems whose states are incompletely measured. For uncertain discrete-time switched fuzzy time-delay systems in the presence of disturbances in gains of the controllers a non-fragile feedback controller and the switching laws are designed and the matrix inequality conditions are put forward to make systems asymptotically stable.A model of switched fuzzy interconnected systems is presented and the related robust control problem is studied. The decentralized switching laws and decentralized controllers are designed via single Lyapunov function method and multiple Lyapunov functions method. In addition, conditions for stabilizability of the systems in the sense of decentralized states feedback controllers and decentralized switching laws are given.