Robust adaptive fault tolerant control for a class of Lipschitz nonlinear systems with actuator failure and disturbances

This article presents novel robust adaptive fault tolerant control strategies for the class of nonlinear Lipschitz systems in the presence of bounded matched or unmatched disturbances and actuator faults (failure, loss of effectiveness, and stuck). Two constructive algorithms, based on linear matrix inequalities with creatively using Lyapunov stability theory, are developed for online tuning of adaptive and fixed state feedback gains to stabilize the closed-loop control system asymptotically, to compensate actuator faults, and to attenuate disturbance effects. The resultant control schemes have simpler and constructive structures as compared with most existing methods. The merits of the proposed schemes have been verified by the simulation on an unstable nonlinear process subjected to actuator faults.