Adaptive fault-tolerant control for a class of uncertain lower-triangular nonlinear systems with actuator failures

This paper studies the adaptive fault-tolerant control problem for a class of lower-triangular nonlinear systems with actuator failures and external disturbances. Without using back-stepping method and nonlinear approximation technique, a novel variable gain fault-tolerant controller with corresponding to adaptation laws is designed to compensate the effects of unknown faults including loss of effectiveness, outage, stuck and bias. It is proved that all the closed-loop signals are uniformly bounded, and the system states asymptotically converge to zero. The effectiveness of the proposed approach is verified by a numerical simulation example.