基于干扰力矩补偿的空间飞行器姿态控制方法

Attitude Control Method of Spacecraft based on Compensation of Disturbance Torques

考虑质心漂移、轨控推力偏心和推力偏移这几个引起干扰力矩的主要误差源,建立了空间飞行器的姿态动力学方程,选取惯组测得的角速度作为量测变量,通过可观测性秩条件对该系统的可观测性进行了分析,证明各姿态控制通道的总轨控干扰力矩均可观。基于扩展卡尔曼滤波,对空间飞行器轨控发动机引起的干扰力矩进行在线估计,并进一步在姿态控制中对其做出补偿。数学仿真的结果表明,扩展卡尔曼滤波能够实现较高的估计精度,且干扰力矩补偿后的姿态控制效果有了明显改善。

In consideration of the major error sources including variations of vehicle center of gravity,thrust misalignments and offsets of divert thrusters,the attitude dynamics equation of spacecraft is established.The angular rate obtained by inertial measurement units is selected as the measurement variable.The observability of the system is analyzed using the observability rank condition,and proved that the total disturbance torque caused by divert thrusters of each attitude control channel is observable.The disturbance torque caused by divert thrusters is estimated online based on extended Kalman filter and further compensated in the attitude control.The results of mathematical simulation indicate that extended Kalman filter can achieve high estimation accuracy and the attitude control effect has been significantly improved with disturbance torque compensation.