基于脉冲星和小行星的组合导航在深空巡航段的应用

Integrated navigation based on X-ray pulsars and asteroids during interplanetary cruise

为提高航天器在深空探测巡航段的自主导航能力,提出一种利用脉冲星和小行星信息的自主导航系统。利用单X射线探测器测量脉冲星辐射的光子到达时间,利用导航相机获取小行星图像,经信号处理,获取脉冲星的脉冲到达时间和小行星中心点对应的像元像线,利用集中式扩展卡尔曼滤波算法进行状态估计,并修正星载时钟钟差。以美国"深空一号"任务深空巡航段轨道为例进行了仿真实验,仿真结果表明了该方法的有效性,能够完成深空探测器在巡航段的自主导航任务,同时,组合导航解决了基于小行星光学信息单独导航时的星载时钟钟差发散问题,且同光学导航相比,位置估计精度提高了57.18%。

To improve the autonomous navigation ability during interplanetary cruise,we designed an autonomous navigation system based on observing pulsars and asteroids.The X-ray pulsars were observed by an X-ray detector,and the images of asteroids were taken by the navigation camera.Thus the times of pulsars＇ pulse arrival and the pixels of asteroids were obtained through signal processing.The centralized Kalman filter was used to estimate the system＇s state.The onboard atomic clock error was corrected.The orbit in the Deep Space I mission was adopted to validate this navigation method.The numerical simulation results show that this method is very feasible in the interplanetary cruise phase.Moreover,this integrated navigation system can solve the problem of atomic clock error divergence when the optical navigation based on asteroids is applied independently.This method can improve the orbit determination accuracy by 57.18%.