地月平动点拟周期轨道探测器自主导航方法研究

地月L2点的拟周期轨道可以用于实现与月球背面的持续通信，具有重要的科学研究价值和广阔的应用前景。针对地月L2点探测器所处的弱稳定拟周期轨道，论证了基于日地月信息的自主导航方法的可行性，并进行了深入分析。首先，推导了会合坐标系下带有星历的精确导航动力学方程；其次，针对弱稳定轨道不同于近地强稳定轨道的特性，在基于日地月方位信息导航的基础上，提出了三种敏感器组合方案。使用迭代最小二乘方法给出导航仿真结果，并结合非线性可辨识性理论对这三种情况下历元状态的可辨识性及可辨识度进行分析。最后，仿真结果表明，使用日地月敏感器以及对地多普勒雷达可以满足历元状态的可辨识性、导航的收敛性以及系统经济性的要求。

Autonomous Orbit Determination for Quasi Periodic Orbit about the Translunar Libration Point

The quasi periodic orbit about the translunar libration point can be used to establish a continuous communication link between the Earth and the far side of the Moon. In this paper, Sun Earth Moon autonomous navigation is implemented and investigated in the translunar libration point problem. Firstly, a new navigation dynamic model is proposed. Furthermore, due to the unstable nature of the translunar libration orbit, three sensor configuration cases for Sun Earth Moon autonomous navigation are studied. Simulation results of autonomous navigation are obtained by the iterative Least Squares Filtering. The nonlinear identifiability analysis is used to evaluate the identifiability and find an appropriate and robust sensor configuration for translunar libration probe. Finally, Simulations show that the sensor configuration of using directional data from the spacecraft to the Sun, the Earth and the Moon and one Doppler measurement can satisfy both the economical index and reliability.