Sliding Mode Control And Stability Analysis Of Fuzzy Systems With Uncertainties

The T-S fuzzy model uses multiple linear systems to simulate a nonlinear system,and can represent highly complex nonlinear systems with fewer fuzzy rules.While in the actual system,it is often accompanied by a kind of uncertainties such as disturbance signals and disturbances,which affect the stability of the system,so sliding mode control is adopted to solve this problem.Sliding mode control is a special nonlinear control,which has the advantages of fast response and invariance to external disturbances,so it has been concerned by many scholars at home and abroad.In recent years,with the in-depth study of sliding mode control,sliding mode control theory has been further improved and widely used in a variety of complex power systems.Despite considerable achievements have been made in the research of sliding mode control for fuzzy nonlinear systems,some key problems are still significant challenges.In order to improve the sliding mode control theory of nonlinear systems,the research on sliding mode control of fuzzy nonlinear systems is still an indispensable part,so a class of fuzzy systems with uncertainties is studied in this paper.The sliding mode control method is mainly used.The main contents are as follows:In chapter 1,T-S fuzzy model,generalized Markov jump system and sliding mode control system are briefly introduced,and their basic concepts,research status and research significance are summarized.In chapter 2,for uncertain nonlinear time-delay T-S fuzzy systems,a fuzzy integral sliding surface with time delay is designed,which overcomes the disturbance caused by uncertainty and external signals.the sufficient conditions for the strict dissipation and asymptotic stability of the fuzzy integral sliding mode control system are given.In addition,a fuzzy integral sliding mode control law is proposed to drive the system trajectory to the fuzzy switching surface in the presence of uncertainty and external disturbance.In chapter 3,for observer-based nonlinear singular systems with time-delay,the system has unilateral Lipschitz nonlinear functions.A new fuzzy sliding surface function is designed to eliminate the same constraints of the input-output matrix.Through the design of fuzzy observer,the appropriate Lyapunov function,that is,the function with system state and observer error,is selected.By using linear matrix inequality,the onesided Lipschitz time-delay fuzzy descriptor system not only has regularity,impulse-free and stability,but also has ? performance.Finally,the observer-based sliding mode controller is designed and the corresponding controller design results are obtained.In chapter 4,for fuzzy generalized Markov jump systems with time-varying delays,an integral sliding surface function is designed,and an appropriate Lyapunov function is selected.Under the condition that the transfer rate is not completely known,by using the equivalent treatment method of addition and subtraction terms,and through the linear matrix inequality technique,it is obtained that the system is limited by the sliding surface with good admissibility and dissipation.Through the analysis of sliding mode dynamics,a sliding mode controller is designed for the case that the upper bound of matching uncertainty is unknown.Furthermore,an adaptive sliding mode controller is designed to drive the state trajectory of the system to a predefined sliding surface and maintain motion in a finite time.