含钟差修正的脉冲星和太阳观测组合导航

为提高深空探测器巡航段的导航定位精度和钟差修正能力,提出一种利用X射线脉冲星和太阳观测信息的组合导航方法.利用脉冲星导航的脉冲到达时间测量值,同时利用太阳敏感器、分光计分别测量太阳视线矢量和探测器相对于太阳的径向速度,并将星载时钟钟差增广为状态变量,构建组合导航系统,利用基于扩展卡尔曼滤波的UD(Upper triangular matrix-Diagonal matrix)分解信息融合算法进行状态估计.仿真结果表明,该方法能有效解决因钟差漂移引起的导航滤波发散问题,同脉冲星导航相比,该方法提高了定位精度和钟差修正能力.

Integrated navigation based on pulsars and sun observation including clock error correction

In order to improve the accuracy of navigation and clock correction of a deep space probe during cruise phase, an integrated navigation method was advanced. By combining the X-ray pulsar based navigation(XPNAV) with the sun line-of-sight vector, and the radial velocity of the probe relative to the sun, an integrated navigation system was advanced by using information fusion, based on extended kalman filter(EKF). The state of atomic clock error was considered in the system model. The UD factorization algorithm was applied to control the rounding error. The simulation results demonstrate that this method can control the divergence rendered by the clock error in EKF. Compared with XPNAV, this method can provide a higher navigation precision and more effectively control the clock error.