卫星编队飞行相对姿态控制

Relative attitude control in satellite formation flying

卫星编队飞行在轨执行任务时,除了对相对位置有特定要求外,还需根据不同任务需求保持一定的相对姿态,为此研究了两颗卫星相对姿态的保持控制。根据刚体运动学推导了两个星体坐标系之间的坐标转换矩阵,给出了从星始终指向主星所需的目标姿态和角速度。基于卫星姿态动力学给出了3个相互垂直安装的反作用轮的控制律,并利用Lyapunov稳定性理论证明了闭环系统的渐近稳定性。最后通过数值仿真验证了控制算法的正确性,其相对误差小于10-6。

Satellite formation flying missions require accurate relative attitude control as well as relative position control. The relative attitude control problem was analyzed by using the rigid body dynamics to determine the transfer matrix between the lead satellite and the following satellite positions to calculate the target attitude and rate of rotation of the following satellites. A control law for three perpendicular reaction wheels in the following satellites was then developed based on the satellite attitude dynamics. Lyapunov stability theory was used to prove the asymptotic stability of the closedloop control systems. The approach was verified using computer simulations. The result shows that the relative tolerance is less than 10-6.