航天器自适应快速非奇异终端滑模容错控制

Adaptive non-singular fast terminal sliding mode based tolerant control for spacecraft

针对存在外部干扰、转动惯量矩阵不确定以及执行器故障的航天器姿态跟踪控制问题,本文提出了基于自适应快速非奇异终端滑模的有限时间收敛故障容错控制方案.通过引入能够避免奇异点,且具有有限时间收敛特性的快速非奇异终端滑模面,设计了满足多约束条件有限时间收敛的姿态跟踪容错控制律,利用参数自适应方法使控制器不依赖转动惯量和外部干扰的上界信息.Lyapunov稳定性分析表明:在存在外部干扰、转动惯量矩阵不确定以及执行器故障等约束条件下,本文设计的控制律能够保证闭环系统的快速收敛性,而且对执行器故障具有良好的容错性能.数值仿真校验了该控制律在姿态跟踪控制中的优良性能.

Finite-time convergence fault tolerant control strategies based on adaptive non-singular fast terminal sliding mode are proposed for spacecraft attitude tracking control subject to external disturbances, inertia uncertainties and actuator faults. A finite-time fault-tolerant attitude tracking controller meets the multi-constraints is developed by introducing a nonsingular fast terminal sliding mode, which can convergence in finite-time and avoid singularities. It is further shown that the controller is independent from a prior knowledge of spacecraft inertia or upper bound of external disturbances with parameter adaptations. The Lyapunov stability analysis shows that the controller designed in this paper can guarantee the fast convergence of the closed-loop system, and has a good fault tolerant performance for actuator faults under multi constraintson external disturbances, inertia uncertainties and actuator faults. Numerical simulation has verified the good performance of the controller in the attitude tracking control.