Multiple intermittent fault estimation and tolerant control for switched T-S fuzzy stochastic systems with multiple time-varying delays

Abstract

This paper focuses on the observer-based fault estimation (FE) and active dynamic output feedback controller design for switched Takagi–Sugeno (T-S) fuzzy Itô stochastic systems against multiple time-varying delays as well as intermittent actuator faults and sensor faults. External disturbances are also considered. First, a novel descriptor sliding mode observer (SMO) is investigated to establish the error dynamics. Compared with the existing results, the proposed observer could be utilized to more cases and applied to a wider scope. Next, in light of the online FE information, a fault tolerant controller is suggested to make the closed-loop system mean-square exponentially stable. Furthermore, a novel piecewise fuzzy Lyapunov function is depicted and then the delay dependent sufficient conditions can be got by linear matrix inequalities (LMIs). The designed SMO has less conservatism than the existing ones. The reachability of the sliding mode surface in the estimation error space is assured under the adopted method. And the finite-time boundedness (FTB) issue is discussed. At last, a simulation example is acquired to validate the novelty and validity of the method proposed in the paper.