Robust adaptive fault tolerant control for a class of nonlinear systems with dynamic uncertainties

Abstract

In this paper, a robust adaptive backstepping control scheme is proposed for a class of nonlinear system with dynamic uncertainties and actuator faults. By introducing the dynamic signals to dominate the unmeasured states, the dynamic uncertainties are compensated by an adaptive controller with the constraint functions. Moreover, based on the bound estimation approach, the effect of the actuator faults can be tackled by the proposed control structure in spite of that the faults may change in different cases infinitely many times. It is shown that the tracking errors can converge to an arbitrarily small value by choosing the design parameters appropriately. Based on a combined quadratic Lyapunov function, the proof of the closed-loop system stability is completed. Several illustrative examples are employed and the simulation results demonstrate the effectiveness of the proposed method.