火星探测接近段的光学自主导航研究

Research on Optical Autonomous Navigation for Approach Phase of Mars Exploration

目前光学自主导航技术已成为深空探测计划中的重点研究对象.已有研究多侧重于光学自主导航技术在深空探测巡航段或是对小行星探测接近段中的应用,而关于大行星探测接近段光学自主导航技术的研究比较少.结合中国即将开展的火星探测计划,研究了探测器在火星探测接近段中利用火星进行光学自主导航的整个过程,提出了适用于接近段的动力学模型、光学观测模型及自主导航滤波算法.通过对自主导航系统的可观测性分析,证明了仅利用火星光学信息进行自主导航的可行性.仿真计算结果表明,在接近段,整个光学自主导航的持续时间约为40 h.在自主导航的最后5 h内,滤波结果稳定,探测器的总体位置误差在40 km以内,速度误差在0.25 m·s^(-1)以内.计算结果的精度满足实际任务需求,对中国火星探测计划具有直接的参考价值.

The optical autonomous navigation has recently become one of the key topics in inter- planetary space missions. According to the current research literature, most people only focused on the application of optical autonomous navigation for the cruise phase or the approach phase of asteroids exploration. The research for the approach phase of planets is rare. Based on the upcoming Mars exploration program of China, with the research of dynamics model, observation madel and filtering algorithm, the process of the optical autonomous navigation during the Mars approach phase is studied. Through the observability analysis of the navigation system, the feasibility of using Mars optical information only for autonomous navigation is proved. Simulation result showed that the total time of the optical autonomous navigation for approach phase is about 40 hours. In the last 5 hours, the filtering results are becoming stable. The overall position error is less than 40 km, and the velocity error is 0.25 m-s-1. The stability and accuracy of the results can meet the requirement of actual task, and is referencable for Chinese Mars exploration program.