基于滑模迭代学习律的航天器姿态控制

Spacecraft attitude control scheme based on sliding mode controller with iterative learning law

针对航天器姿控系统长期运行期间因执行部件老化或故障引起性能下降的情形,设计了一种基于滑模迭代学习率姿态自主容错抗扰控制方案。采用虚拟控制输入设计了滑模控制器,以确保故障发生后系统能精确跟踪参考运动轨迹;通过李亚普诺夫稳定性分析,设计了新的自适应迭代学习率,根据系统跟踪误差,在线确定控制器参数以应对执行器故障和外部干扰的影响。数值仿真实验表明,该方法可以有效进行故障检测和干扰补偿。

To address the problem of the degradation of actuation effectiveness caused by actuator deflection or fault in the attitude and orbit control system （AOCS） of spacecraft on-orbit, an attitude fault-tolerant and anti-disturbance control scheme is proposed based on a sliding mode controller with iterative learning law, in which the pseudo control input is used to design the sliding mode controller to ensure the AOCS tracks a refe- rence trajectory precisely after some faults occur. By analyzing the Lyapunov stability, a novel adaptive iterative learning law is developed, which, in terms of the tracking error, determines some parameters in controller on- line to deal with the actuator failure and external disturbance. Numerical simulation experiments show that the fault-tolerant and anti-disturbance controller can ameliorate actuation malfunction and compensate the influence of external disturbance effectively.