Adaptive output feedback fault-tolerant control of switched fuzzy systems

This paper investigated the adaptive fault-tolerant control problem for a class of switched Takagi-Sugeno fuzzy systems. The considered switched fuzzy systems contain unmeasured states and actuator failures. In the control design, a switched state observer is designed to estimate the unmeasured states. Under the parallel-distributed compensation (PDC) design scheme and using the online estimation of actuator faults, an adaptive fuzzy fault-tolerant control scheme is proposed, in which a compensation control term is introduced in order to reduce the effect of actuator faults. Utilizing the estimated states and a segmentation of state space, the switching law is constructed. The sufficient conditions for ensuring the asymptotic stability of the switched fuzzy systems are proposed and formulated in the form of linear matrix inequalities (LMIs). By using the single Lyapunov function method, it is proved that the proposed control approach can guarantee the asymptotic stability of the closed-loop system. One practical example and a numerical example are given to illustrate the effectiveness of the proposed control method.