UIO-Based Fault Diagnosis Design in Finite-Frequency Domain for Discrete-Time T-S Fuzzy Systems*

In this paper, the problem of fuzzy unknown input observer (FUIO)-based fault estimation in finite-frequency domain for discrete-time Takagi-Sugeno fuzzy systems is studied. Firstly, a FUIO is proposed to achieve fault estimation by using a finite frequency range technique instead of an entire frequency method, which is robust against the effect of the external disturbance. The gain matrices of the FUIO are obtained by solving linear matrix inequalities. Finally, simulation results of a discrete-time nonlinear system are presented to illustrate the effectiveness of the proposed strategy.