FAST ADAPTIVE FAULT ESTIMATION AND ACCOMMODATION FOR NONLINEAR TIME-VARYING DELAY SYSTEMS

This paper studies the problem of fault estimation and accommodation for a class of nonlinear time-varying, delay systems using adaptive fault diagnosis observer (AFDO). A novel fast adaptive fault estimation (FAFE) algorithm that does not need the derivative of the Output vector is proposed to enhance the performance of fault estimation. Meanwhile, a delay-dependent criteria is obtained with the purpose of reducing the conservatism of the AFDO design. On the basis of fault estimation, an observer-based fault-tolerant controller is designed to guarantee the stability of the closed-loop system. In terms of matrix inequality, we derive Sufficient conditions for the existence of the adaptive observer and fault-tolerant controller. Simulation results are presented to illustrate the efficiency of the proposed method.