Robust fault estimation for Takagi-Sugeno fuzzy systems with state time-varying delay

This paper deals with the problem of H-infinity robust fault estimation for a class of Takagi-Sugeno (T-S) fuzzy systems with state time-varying delay, sensor, and actuator faults. The faults considered in this paper are time-varying signals whose k-order derivatives with respect to time are bounded. Then, we propose a proportional multiple integral observer to achieve simultaneous estimation of system states and time-varying actuator and sensor faults. Furthermore, one less conservative delay-dependent sufficient condition for the existence of fault estimation observer is given in terms of linear matrix inequality. The disturbance attenuation is constrained to a given level using H-infinity performance index. Finally, simulation results of one numerical example is presented to show the effectiveness of the proposed method.