卫星编队飞行中,从星星体上偏离质心的任意特征点,其相对位置和相对姿态运动耦合。本文针对任意点的相对状态估计问题,推导了耦合相对轨道动力学方程和无陀螺相对姿态动力学方程,并且基于PSD敏感器对主星上点光源的视线测量值,提出了基于特征点耦合动力学和质心传统动力学的两种相对状态估计策略。针对每种策略分别设计了EKF和UKF两种滤波算法对相对状态进行估计。最后通过数学仿真对算法的有效性进行了验证,并对其计算量进行了分析。结果表明,四种算法均能对特征点的相对状态进行较高精度的估计。
For satellite formation flight,the relative translational dynamics of an arbitrary point on a satellite body is coupled with rotational motion due to its bias from the center of mass.A coupled translational dynamics is derived to represent orbital motion,and the relative attitude motion is formulated by a rotational dynamics for no-gyro satellite.Based on the coupled dynamics of feature point and the traditional dynamics of center of mass,two strategies are proposed to estimate the relative attitude of the satellite and relative position of the feature point.The line-of-sight measurements from a PSD sensor are coupled with dynamical models both in an EKF and an UKF for each strategy,and simulations are carried out to test their performance and computation and load.Results indicate that all approaches can provide accurate relative position and attitude estimation.