Fault-tolerant tracking control for nonlinear observer-extended high-order fully-actuated systems

Abstract

In the paper, a fault-tolerant tracking control strategy is proposed for a class of nonlinear high-order fully-actuated systems (HOFASs) with multiplicative and additive actuator faults. Different from general state space methods, HOFAS approaches can achieve global stability through specific nonlinear control laws, and maintain the fully-actuated and uncoupled characteristics of most physical objects. Starting from the HOFAS tracking error dynamics, a tracking differentiator is designed to solve the reference signal and its derivatives numerically. Furthermore, a specific extended state observer is firstly embedded into the HOFAS, which expands the application scenarios of the HOFAS theory. Based on Lyapunov stability theory, a fully-actuated fault-tolerant control technique is presented to ensure the uniformly ultimately bounded stability of the tracking error. A numerical comparative experiment fully illustrates the effectiveness of the proposed strategy.