Hybrid Fuzzy Adaptive Fault-Tolerant Control for a Class of Uncertain Nonlinear Systems With Unmeasured States

In this paper, a hybrid adaptive output feedback fault-tolerant control is investigated for a class of uncertain nonlinear systems with unmeasured states. The generalized fuzzy hyperbolic model is used to approximate the unknown nonlinear functions, and the fuzzy state estimator (FSE) is established for estimating the unmeasured states. Based on the backstepping and dynamic surface control technique, a novel adaptive control method is proposed by introducing the prediction errors between FSE and serial-parallel estimation model. It is proved that all the variables of the closed-loop systems are semi-globally uniformly ultimately bounded by Lyapunov approach, and the tracking errors can converge to a small neighborhood. Two simulation examples are used to illustrate the effectiveness of the proposed control method.