H_? Control For A Class Of Networked Switched Fuzzy Systems

Networked switched fuzzy systems refer to a class of switched systems whose subsystems are fuzzy systems, and the information between each node is transmitted through the network. The study of networked switched fuzzy systems are based on switched systems theory and fuzzy systems theory, and also considered the effects of network. It has theoretical importance and extensive application value. In practical engineering, the transmission of information through the network will cause network induced delay and packet dropout which may affect the transient performance of the system, and even lead to instability. On the other hand, in practical industrial control, environmental factors can cause disturbance on the system in some degree, it will also bring about the bad performance index. Therefore, to study the stabilization problem and H? problem for networked switched fuzzy systems has theoretical and practical significance.In this thesis, we investigate the stabilization problem and H? control problem of a class of networked switched fuzzy systems by employing two different methods. The main results are as follows:Firstly, based on network induced delay and packet dropout problems in networked systems, we establish the mathematical model of networked switched fuzzy system; and then the stabilization problem of the system is studied. We construct the Lyapunov-Krasovskii functional and use liberty matrix methods, and then design a state feedback controller makes the system asymptotic stability with the max bound of network induced delay and packet dropout. An example is given to illustrate the effectiveness of the proposed method.Secondly, the problem of H? control problem for networked switched fuzzy systems is addressed. When there is interference on controlled object, the switching law is designed by the multiple Lyapunov functions technique, moreover, the parallel distributed compensation (PDC) controllers are designed not only to make the closed-loop networked switched fuzzy systems asymptotically stable, but also to guarantee the performance index of H? control. At last, an example is given to illustrate the effectiveness of the proposed method.Finally, the main results of the thesis are summarized. In addition, some open problems of the networked switched fuzzy systems and the shortcomings of the proposed methods are also discussed which deserve further study.