临近空间飞行器的自适应积分滑模容错控制

Adaptive Integral Sliding Mode Fault-tolerant Control for Near Space Vehicles

为提高临近空间飞行器的安全性和可靠性,针对飞行器中未知的执行器故障,提出了一种自适应积分滑模容错控制方法。设计积分滑模面,使滑动模态运动起始于系统的初始状态,进一步增强系统的鲁棒性。构造自适应滑模容错控制律,处理执行器故障的影响。在自适应律中定义一个非线性函数,利用积分滑模面的动态变化检测故障的发生,并激发自适应律实现控制增益的自动调整。基于李雅普诺夫稳定性理论证明了系统的渐近稳定性。仿真验证在临近空间飞行器的纵向动力学模型上进行,结果表明该方法具有期望的容错跟踪性能。

In order to improve the security and reliable of the near space vehicles,an adaptive integral sliding mode fault-tolerant control method is proposed to deal with the unknown actuator faults.An integral sliding mode surface is designed to guarantee the sliding mode motion starting from the initial time instance.As a result,the robustness of the system can be strengthened further.The adaptive sliding mode fault tolerant control law is proposed to deal with the actuator faults.A nonlinear function,where an adaptive law is triggered to achieve the on-line computing of the control gain,is defined to detect the faults by the unexpected increasing of the integral sliding surface.The asymptotical stability of the system is proved by Lyapunov stability theory.Simulations implemented on the longitudinal dynamic model of the near space vehicles show that the system can get the expected fault-tolerant tracking property by using the proposed fault-tolerant control method.