编队飞行卫星自主相对定轨研究

Autonomous Relative Orbit Determination for Satellite Formation Flying

卫星编队飞行相对轨道自主确定作为实现队形保持和控制的前提,是编队任务必须解决的关键技术问题。根据C-W方程的解析解描述编队卫星间的相对运动规律,选取星间距离信息与方位信息作为观测量,针对卫星编队飞行自主导航系统对精确性和实时性的要求,用超球面分布采样点变换(Spherical Simplex Unscented Transformation,SSUT)和Unscented卡尔曼滤波(UKF)相结合,提出了SSUT的UKF(SSUKF)导航滤波算法。由于SSUT减少了采样点个数,在保证滤波精度和标准UKF相当的条件下减轻了计算负担,完成了卫星编队相对轨道状态的自主确定,并结合仿真的轨道数据和测量数据进行了仿真,仿真结果说明实现了卫星编队优化的有效性和实时性。

As the premise of formation maintenance and control,autonomous relative orbit determination for satellite formation flying is the key technique that must be solved.In this paper,the analytical solution of C-W equation is used to describe the relative motion of satellite formation flying,and the inter-satellite distance measurement as well as orientation measurement is chosen as observation information.An improved unscented Kalman filter（UKF） algorithm based on spherical simplex unscented transformation（SSUT） is presented to satisfy the precision and real time requirements of formation flying autonomous navigation.The SSUT reduces the sigma points for the unscented transformation.Compared with the traditional UKF,the computational efficiency of spherical simplex unscented Kalman filter（SSUKF） is improved,without sacrificing the estimation precision,and the relative orbit states estimation for satellite formation flying is achieved.Simulation is done based on simulated orbit and measurement data and the validity of navigation method is illuminated.