小天体软着陆自主光学导航与制导方法研究

针对小天体软着陆任务自主性、实时性的需求,对软着陆小天体自主导航与制导问题进行了研究.提出了一种利用激光测距仪和光学导航相机跟踪目标着陆点的自主导航方案,利用测距矢量以及目标点之间的几何关系,确定着陆平面法向方向和目标点位置.分析期望的探测器下降轨迹特点,给出了一种基于制导变苗的脉冲控制制导律,通过对目标点视线与着陆平面法向矢量之间夹角的控制,将软着陆小天体控制分解为切向控制与法向控制两部分.最后,通过数学仿真对自主导航制导系统的性能进行了验证,结果表明该方法能够满足垂直软着陆的任务需要,实现高精度软着陆.

Autonomous Optical Navigation and Guide Method for Soft Landing on Small Bodies

Considering the requirement of autonomous and real-time for small body landing, the problem of autonomous navi-gation and guidance for descent to a small body is discussed. Based on laser range finder and optical navigation camera to track the target landing point, an autonomous optical navigation algorithm is built out. By using the geometry relation of measure vectors and target point, normal direction of the landing plane and the target point position are. obtained. In order to achieve vertical landing,the expecting descend trajectory characteristic is analyzed, and an impulse guidance and control law based on guide variable is pr-esented. The small body landing control is decomposed into the tangential and normal direction control, by means of restricting the angle between line of sight of target point and normal direction of the landing plane. Finally, performance of the autonomous navi-gation and guidance system is verified by using the numerical simulation. The results show that the proposed methods can achieve high precision soft landing mission.