基于UKF算法的小卫星串行编队相对状态自主确定

摘要

基于星间测距和星间测角对小卫星编队进行自主相对状态确定.卫星编队采用圆轨道串行双星编队方式,Hill方程对此构型不再适用,文中以卫星在惯性坐标系下的轨道动力学方程为基础,详细推导出卫星的相对运动动力学模型,并建立测量方程.由于测量方程为非线性方程,为避免线性化误差,提高测量精度,采用无迹卡尔曼滤波(UKF)算法,以双星编队为例,进行了数学仿真. 仿真结果表明,该算法易于实现,并具有较高的精度.%The objective of the paper is to research the relative states autonomous determination of micro-satellites formation based on the measurements of inter-satellite distance and inter-satellite perspective. Based on the orbital dynamic equation of the inertial coordinate system, the relative motion dynamic model of the satellite is deduced in detail and the measurement equation is given for the circular orbit serial double satellites formation where Hill is no longer applicable for this formation. Since the measurement equation is a nonlinear equation, Unscented Kalman Filter (UKF) algorithm is used in order to avoid linearization error and improve the measurement accuracy, a mathematical simulation is conducted, and double satellites formation is used as an example. Simulation results indicate that the algorithm is easy to implement and has a high precision.