空间物体观测平动点轨道自主导航方法

Autonomous Navigation Method of Spacecraft in Libration Point Orbit Based on Space Objects Observations

针对地月平动点轨道航天器自主导航问题,提出一种基于空间物体观测的自主导航方法,空间物体是指运行在近地轨道的已编目目标。该方法利用航天器携带的星敏感器,测量北斗卫星相对于航天器的角信息,进而估计出最优的位置和速度。首先对星敏感器视场、地球遮挡和太阳干扰约束进行分析,筛选了可供观测使用的北斗卫星。然后利用Fisher信息矩阵对系统进行可观性分析,在初选结果的基础上选出最优观测目标。最后,以运行在地月平动点轨道的航天器为例进行仿真。仿真结果表明,在仿真时长为20h的情况下,其定位精度可收敛至1km以下。

In order to achieve the autonomous operation of spacecraft in the Earth-Moon libration point orbits,an autonomous navigation method using space objects observations was proposed in this paper.Space objects refer to the catalogued space targets orbiting the Earth.In this method,the motion states of spacecraft can be estimated according to the angles between the spacecraft and space objects.Firstly,the constraints of star sensor field of view,earth occlusion and solar interference were analyzed,and Beidou satellites for observation are selected.Next,Fisher information matrix was adopted to analyze the observability of the system,and the optimal observation targets were selected based on the observability analysis results.Finally,spacecraft in Earth-Moon libration point orbit were selected to verify the feasibility of the proposed autonomous navigation method.The simulation results show that the positioning accuracy of the proposed method can converge to less than lkm when the simulation time are 20 hours.