临近空间飞行器的模型参考滑模容错控制

Model Reference Sliding Mode Fault-Tolerant Control for Near Space Vehicles

针对临近空间飞行器中未知的执行器控制效益损失和漂移故障,提出了一种模型参考滑模容错控制方法,保证故障系统对参考模型的稳定跟踪性能。利用跟踪误差系统设计容错控制器,首先构造积分滑模面,以增强系统鲁棒性并消除稳态误差;随后,在无需故障诊断单元的条件下设计模型参考滑模控制律,使其增益能实现自适应调节以处理未知故障影响,其中自适应律基于李雅普诺夫稳定性理论设计,保证闭环系统稳定。在临近空间飞行器纵向动力学模型上的仿真验证表明,该方法能处理执行器中发动机节流阀调节通道和升降舵偏转量通道的不同故障,保证系统获得满意的鲁棒容错跟踪性能。

To deal with the unknown actuator faults such as loss of effectiveness and free-floating for near space vehicles, a model refer ence sliding mode fault-tolerant control method is proposed to guarantee the stable model following performance. A fault-tolerant controller is designed based on the tracking error system. First, an integral sliding surface is constructed to strengthen the robustness and eliminate the steady error. Then, without requiring fault detection and diagnosis, the model reference sliding mode control law is proposed to deal with the effects of the unknown faults by adjusting the gain adaptively. The adaptive law is designed based on the Lyapunov theorem to guarantee the stability of the closed-loop system. Simulations implemented on the longitudinal dynamical model of near space vehicles show that, the proposed method can handle different actuator faults in the channel of throttle setting and elevator deflection to achieve the satisfied robust fault-tolerant tracking performance.