Research Of Intelligent Control Method And Stability Analysis For Switched Fuzzy Systems

The switched fuzzy system is a further optimization for the switching fuzzy model.All the subsystems of this system are composed of T-S fuzzy systems.The switching law switches among the sub-fuzzy systems controlled by the controller.Compared with the switching fuzzy system,the switched fuzzy system does not depend on the regional rules,and has the ability of optimizing secondary fuzzy rules into first-order fuzzy rules.Therefore,it's suitable for more complex actual systems.In this paper,the switched fuzzy system is used as the controlled object.The Lyapunov function is combined with the linear matrix inequality(LMI)method to study the fault-tolerant control,memory state feedback control and reliable control of the controlled object.The main study contents are as follows:First of all,considering a class of switched fuzzy system,which contains control delays and uncertainties,the output feedback control problem is studied depending on characteristics of this system.A switching law and an output feedback controller are designed to keep the system stable.The simulation results of numerical examples demonstrate the effectiveness of the research method.Secondly,when the actuator is "serious failure" and the controlled object has control time-delay,according to the above characteristics,the output feedback reliable control problem for the switched fuzzy system is studied.Making an output feedback reliable controller and switching strategy to ensure that the controlled object can still be asymptotically stable.Thirdly,based on the above part,considering the case where the switched fuzzy system model and the input contain both time-delays and the actuator is "serious failure",the switching law and the output feedback robust reliable controller are designed.Switching technique is used to switch among portions of the actuator that has not failed,which makes the system have certain anti-interference.The criterion for the asymptotic stability of the switched fuzzy system is given.Then,the memoryless state feedback controller of the time-delay system cannot simultaneously consider the memoryless and memory items in the system.Therefore,the memoryless state feedback controller has certain limitations and is more conservative.The memory state feedback control of time-varying switched fuzzy system based on T-S fuzzy model is studied to solve the above problems.Designing a memory state feedback controller,switching law and selecting a more general Lyapunov-Krasovskii functional method make the proposed switched fuzzy system asymptotically stable.Next,for a class of input uncertain switched fuzzy system,the design method of robust controller is considered,and the switching strategy is designed to ensure the stability of the controlled object.Numerical example is given to illustrate the correctness of the proposed method and compare its effectiveness with the classical PDC method.And then,a class of time-delay switched fuzzy system with unknown nonlinear disturbance is studied.Memory state feedback robust fault-tolerant controller and the switching law in the failure mode of the actuator are designed.Multiple Lyapunov function is combined with the method of LMI to get the system asymptotic stability criterion.Finally,the non-fragile robust and memory state feedback control problem for switched fuzzy system with time-varying delays is studied.The nonlinear perturbation norm described in this controlled object is bounded and unknown.The switching law and a non-fragile memory state feedback controller are designed.This controller is composed of two different gain terms.The simulation of the numerical example shows that the controlled object is asymptotically stable for all allowed parameter uncertainties.