【摘要】 在轨挠性卫星的工作环境恶劣，不仅有外部干扰和挠性附件振动引起的内部干扰影响本体的姿态，还可能发生执行器故障。针对存在外部干扰和执行器故障的挠性卫星，提出了一种基于故障估计器的容错控制策略。首先，针对未知的外部干扰和执行器故障构造辅助系统，并利用投影函数设计自适应故障估计器估计执行器效率损失因子，同时设计了基于参数自适应律的方法补偿外部干扰、挠性部件震荡引起的内部干扰和执行器加性故障。然后，借助估计信息设计了基于反步法的容错控制器，并利用Lyapunov方法分析了闭环系统的稳定性，进而确保研究的控制方法能够使得挠性卫星的姿态和角速度有效跟踪期望信号。最后，通过数值仿真对比验证了所设计控制器的有效性。该容错控制策略能保证挠性卫星在内外部干扰和执行器故障下的跟踪控制效果，具有实际应用价值。更多还原

【Abstract】 The working environment of flexible satellite in orbit is harsh, with not only external interference and internal interference caused by the vibration of the flexible appendage affect the attitude of the body, but also the actuator failure may occur. In this paper, a fault-tolerant control strategy based on fault estimator is proposed for flexible satellite with external interference and actuator fault. Firstly, an auxiliary system is constructed for unknown external interference and actuator fault, and an adaptive fault estimator is designed by using projection function to estimate the efficiency loss factor of the actuator. At the same time, a method based on parameter adaptive law is designed to compensate external interference, internal interference caused by vibration of flexible parts and additive fault of the actuator. Then, a fault-tolerant controller based on backstepping is designed by using the estimation information, and the stability of the closed-loop system is analyzed by using Lyapunov method, so as to ensure that the attitude and angular velocity of the flexible satellite can effectively track the desired signal. Finally, the effectiveness of the designed controller is verified by numerical simulation. The fault-tolerant control strategy has the ability to ensure the tracking control effect of flexible satellites under internal and external interference and actuator faults, and has practical application value.更多还原