执行器卡死并失效的航天器姿态稳定控制

Sliding Mode Fault Tolerant Attitude Control for Flexible Spacecraft under Actuator Fault

考虑挠性航天器执行器卡死与部分失效故障下的姿态控制问题,提出了一种滑模容错控制法。该方法采用自适应技术在线估计系统不确定参数,且该控制器的设计不需要任何在线或离线的故障信息,能够完全独立于地面站的支持。基于Lyapunov方法从理论上证明了该控制器不但能够有效地处理执行器故障,而且保证了闭环系统的全局渐近稳定,实现对姿态的高精度控制。最后将该方法应用于某型挠性航天器的姿态稳定任务中,仿真结果验证了该方法的有效性。

A sliding mode fault tolerant controller is developed for flexible spacecraft attitude stabilization control in the presence of partial loss of actuator effectiveness fault and actuator stuck fault. Adaptive control is employed to estimate system uncertainties and unknown parameters. In contrast to traditional fault tolerant control methods, the proposed control law does not require any knowledge of the actuator faults and is implemented without ground station support. The Lyapunov stability analysis shows that the resulting closed-loop attitude system is globally asymptotically stable with high attitude accuracy, also the possible actuator fault are effectively compensated. Numerical simulation results of an applica- tion to flexible spacecraft are presented to verify the closed-loop performance benefiting from the control law derived here.