Filtering And Control For Switched T-S Fuzzy Systems With Time-Dependent Switching

In past decades,switched systems have been widely investigated since they can be used to model many practical systems with switching features.In general,a switched system consists of a finite number of subsystems and a switching signal orchestrating the switching among them.The switched T-S fuzzy system is a class of switched nonlinear systems with all subsystems described by T-S fuzzy models.As a new type of hybrid systems,switched T-S fuzzy systems blend with the switched system and fuzzy control theories,which provides new strategies to deal with switched nonlinear systems.In this dissertation,the analysis and synthesis for switched T-S fuzzy systems are investigated under the time-dependent switching scheme.The main contents can be summarized as follows.By constructing a semi-time-dependent multiple Lyapunov-like function,the improved stability criteria for discrete-time switched T-S fuzzy systems are developed with the extended mode-dependent dwell-time switching.The developed stability criteria are applied to discrete-time switched T-S fuzzy systems with all stable,partly stable,or even all unstable subsystems.When considering the stability analysis for switched systems,a common requirement in existing results is that all subsystems are stable.The improved stability criteria release this constraint,which are more general.A revised multiple Lyapunov-like function is constructed to investigate the asynchronous filtering problem for discrete-time switched T-S fuzzy systems.First of all,the revised multiple Lyapunov-like function is chosen to be dependent on the mode of filters instead of subsystems,which is more consistent with the switching property of switched systems with asynchronous switching.Furthermore,a time scheduler is proposed,which is suitable for asynchronously switched systems.On this basis,the multiple Lyapunovlike function is further revised as a semi-time-dependent form.By using such a multiple Lyapunov-like function,the semi-time-dependent filters are designed for switched T-S fuzzy systems,which are helpful to achieve a more superior disturbance attenuation performance compared with using the traditional time-independent filters.The ?? filtering issue for continuous-time switched T-S fuzzy systems is investigate with the persistent dwell-time switching.The persistent dwell-time switching can cover the widely used dwell-time switching and average dwell-time switching as special cases.Meanwhile,the persistent dwell-time switching is capable of depicting slow switching and fast switching occurred successively in a switched system,which is more flexible and general.The event-triggered H_? control problem is investigated for a class of switched T-S fuzzy systems.The existence of asynchronous phenomenon is taken into account,and it is allowable that more than one switching occurs between two adjacent event-triggered instants,which releases the constraints in existing results.The finite-time H_? control problem for switched T-S fuzzy systems is addressed based on the dynamic event-triggered scheme.The dynamic event-triggered mechanism can efficiently reduce the triggered frequency compared with the conventional static one.Under the mode-dependent average dwell-time switching,the dynamic event-triggered mechanism and controllers are co-designed for switched T-S fuzzy systems,which can guarantee that the corresponding closed-loop system has a finite-time H_? performance.