双体小行星探测协同光学导航方法研究

Two-spacecraft cooperative optical navigation for binary-asteroid exploration

双体小行星探测已成为当前深空探测的重要领域,提高双体小行星探测器的导航精度是该领域的研究重点之一.本文以球体-椭球体的双体小行星模型为背景,设计了一种基于双探测器对双体小行星光学观测信息和星间测量信息的自主协同导航方案.考虑到从星相对于主星的位置不确知会影响探测器的导航精度,本文设计了对从星状态进行扩展估计的导航滤波器.特别地,通过分析导航系统的可观测度和轨迹约束,本文重点研究了导航观测几何构型并优化导航信息,实现探测器和双体小行星的最优构型配置,从而使探测器沿优化轨迹飞行时导航性能最优,最后通过仿真分析并验证探测器沿优化轨迹飞行时的导航性能.以上研究方法和仿真结果可为我国未来小行星探测提供参考和支持.

Given the increasing importance of binary asteroids in the field of deep-space exploration,improving the navigation accuracy of the spacecraft has become a key focus of research.On the basis of the navigation information,such as optical observations of binary asteroids and inter-spacecraft measurements,an autonomous navigation scheme for a sphereellipsoid binary asteroid model was proposed herein.A navigation filter capable of extended estimation was also designed in consideration of the position uncertainty of the secondary asteroid with respect to the primary asteroid.This paper especially focused on the observational geometry optimization of the navigation information through the analysis of the observability of the navigation system and the trajectory constraints,which optimized the position configuration of the spacecraft and binary asteroids in order to improve navigation performance.Simulations were conducted to validate the effectiveness of the proposed method and to prove the advantages of navigation performance.The research methods and simulation results can provide reference and support for China’s binary-asteroid exploration in future.