Improved Adaptive Integral-Sliding-Mode Fault-Tolerant Control for Hypersonic Vehicle With Actuator Fault

Abstract

In this paper, the problem of attitude control for hypersonic vehicle in the present of actuator fault and unknown uncertainties including modeling uncertainties, aerodynamic parameters uncertainties is investigated based on integral sliding mode technique. A fault-tolerant control (FTC) law is proposed consisting of three parts, an improved integral sliding mode(ISM) equivalent control law, a power reaching law and a new adaptive compensation control law. The proposed FTC possesses triple advantages. Firstly, when sliding mode is established, the proposed equivalent controller will offer faster convergence speed via introducing a switching condition into the conventional ISM control. Secondly, the adaptive compensation control law is presented considering both the unknown uncertainty and the unexpected actuator fault including additive fault and multiplicative fault. Finally, the boundness of bounded unknown uncertainty is no longer needed in advance. Simulation results show the effectiveness and the superiority of the proposed fault-tolerant controller on fast convergence speed and expected attitude tracking performance.