Sampled-data Control Of Fuzzy Time-delay Systems

Fuzzy control has been investigated in depth over the past few decades and recognized as a significant medium for the analysis of many nonlinear systems.In recent years,T-S fuzzy technology has been employed to many actual fields and attracted the attention of scholars.T-S fuzzy systems describe the nonlinear systems in the form of IF-THEN rules which utilize the fuzzy membership functions to represent the local linear input output relations.T-S fuzzy system is not only a sample and effective approach to control nonlinear systems,but also a flexible tool to bring all the advantage of linear system theories.In T-S fuzzy systems,the stability analysis is an important topic.System stability is the premise that the system can work normally.It is well known that the Lyapunov-Krasovskii functional(LKF)method is an effective analysis method to study the stability of fuzzy systems with time-varying delays.Recently sampled-data control has drawn more and more attention as a result of digital hardware technologies develop rapidly.Sampled-data control has greatly reduced the implementation cost and time,which only needs the features on the state of the system at the sampling pattern.Therefore,the control efficiency is greatly improved.In this paper,three different effective sampled-data controllers are designed for T-S fuzzy systems with uncertain terms to stabilize the system.The main research contents are as follows:Firstly,based on aperiodic memory sampled-data control,the non-fragile control of Markovian jump system described by T-S fuzzy model is studied.An improved delaydependent LKF is proposed,which covers all sampled intervals and delay information in the system and the controller,greatly reduce the conservatism of the results,a kind of nonfragile sampled-data controller was designed,and by using convex combination and linear matrix inequality(LMI)techniques,the sufficient conditions are obtained to guarantee the stochastic stability and H? performance of the closed-loop system.Secondly,studied the exponential stability and dissipativity of uncertain T-S fuzzy system under memory sampled-data control.By considering the influence of the uncertainties and time-varying delay,a new LKF is established and selecting the appropriate matrix inequality to deal with the derivative term.The exponential stability and dissipativity criterion of the uncertain fuzzy systems are obtained with less conservative.Solving the obtained linear matrix inequality by Matlab,an effective sampled-data controller gain matrix is obtained.Finally,the state feedback control of coupled memory sampled data satisfying Bernoulli distribution sequence is studied by using the delay-product-type augmented LyapunovKrasovskii functional method.A new two sides LKF is established.The integral inequality based on Wirtinger is selected and the weighted matrices are introduced to reduce the conservatism of the results.By using the extended convex combination technique,a new sufficient condition to guarantee the asymptotic stability of the closed-loop system is obtained.