Input–Output Based Fault Estimation for T-S Fuzzy Systems With Local Nonlinear Parts

This paper is concerned with the problem of fault estimation for a class of Takagi-Sugeno fuzzy systems with local nonlinear parts and actuator faults. The system matrices in consideration contain unknown components, whereas in most of the literature, the system matrices are required to be known completely. An input-output based fault-estimation approach for the fuzzy system is proposed, by which, the estimation error for time-varying faults can asymptotically converge to zero in the absence of disturbances. The estimation convergence is proved theoretically. Based on the information of fault estimation, the design of fault-tolerant controller can be updated online to compensate the fault effect on systems so as to maintain the original performance of the system. Numerical examples are given to show the effectiveness and merits of the proposed method.