基于脉冲星和太阳敏感器的日地系Halo轨道组合导航研究

为提高平动点轨道探测器的自主导航能力,提出一种利用X射线脉冲星和太阳敏感器的导航算法. 利用X射线脉冲星导航理论,用X射线探测器测量X射线脉冲到达时间,同时利用太阳敏感器测量太阳视线方向矢量,建立导航系统观测方程. 在高精度星历模型下,对日地系Halo轨道建立数学模型,利用二级微分修正方法获取地球质心惯性系下的标称轨道,利用基于UD分解的联邦Unscented卡尔曼滤波方法进行状态估计,并研究了摄动因素对导航结果的影响. 仿真结果表明,该方法能够完成日地系平动点轨道的自主导航,并且比X射线脉冲星单独导航具有更高的导航精度. 

Integrated Navigation Based on Pulsar and Sun Sensor in Sun-Earth Halo Orbit

To improve the performance of autonomous navigation in the Halo orbits, an integrated navigation system based on X-ray pulsars and sun sensor was proposed. For X-ray pulsar-based navigation (XNAV), the X-ray pulse time of arrival could be measured by the X-ray detector. The sun sensor was used to obtain the line-of-sight vector towards sun. The full ephemeris dynamics model of the Halo orbit in sun-earth system was established. The nominal Halo orbit in the earth-centric inertial coordinate system was calculated using two-level differential correction method. The state of the navigation system was estimated via the federated unscented Kalman filter (UKF) based on UD factorization. Several perturbation factors were discussed in the simulation. Simulation results show that the proposed integrated navigation scheme is feasible in sun-earth Halo orbit. Compared with the XNAV navigation, the navigation accuracy is improved.