小卫星执行机构故障鲁棒容错姿态跟踪控制

Robust fault-tolerant attitude tracking control for a small satellite with actuator failures

针对小卫星在轨运行中存在干扰力矩与执行器故障姿态跟踪控制问题,提出一种反步自适应滑模变结构鲁棒容错控制方法.将反步控制和滑模变结构控制相结合,利用自适应算法估计执行器故障失效因子最小值、偏差型故障最大值和干扰值,在不进行故障检测和分离情况下,实现系统的容错控制和干扰抑制.基于Lyapunov方法从理论上证明系统的稳定性.将该方法用于小卫星的状态跟踪控制,仿真结果表明,控制器对部分失效和偏差型故障具有较强的容错能力和鲁棒性.

In order to solve the question of attitude tracking problem of a small satellite with external disturbances and actuator failures, this paper proposes an adaptive backstepping fault-tolerant control law. The method combines backstepping and adaptive sliding mode control schemes, in which the bound of disturbances are not required. An adaptive scheme is designed to estimate the minimum of actuators＇ fault and the maximum of control action produced by the actuator that is out of control, such that the fault detection and isolation algorithm is not needed. Lyapunov stability analysis shows that the closed-loop system is proved to be globally asymptotically stable. The simulation results show that the method can achieve expected tracking performance and has great fault-tolerant capability and robustness.