基于陆标图像的天体定点着陆信息融合导航方法

要安全准确着陆于地外天体指定地点,探测器在下降过程需实时精确确定其相对位置和速度.针对惯性导航结合斜距和相对速度测量的导航方式不能修正相对水平位置估计的缺点,以及多敏感器测量信息融合问题,提出基于陆标图像和协方差交叉算法的天体定点着陆自主导航方法.将光学成像敏感器加入到组合导航系统中,用于测量探测器相对陆标的视线方向以获得关键的相对水平位置信息.在状态估计时采用基于协方差交叉的分布式扩展卡尔曼滤波对多源测量信息作最优融合,提高算法的精度和鲁棒性.通过数学仿真验证了该方法的有效性.

Information-Fusion-Integrated Navigation for Celestial Body Pinpoint Landing Based on Landmark Image

During a safety and accurately celestial body pinpoint landing, the spacecraft must real-timely and precisely determine its relative position and velocity to the body. To overcome the disadvantage that the slant range and the relative velocity measurements can＇ t well revise the horizontal position estimation obtained by inertia navigation, and to fuse multi-source information, an autonomous navigation method for celestial body pinpoint landing is proposed based on landmarks image and covariance intersection algo- rithm. In this method, an optical camera is added to the integrated navigation system, and takes pictures of landmarks to obtain the essential horizontal position information. To esitmate the states, a distributed extended Kalman filter based on the covariance intersection is used to fuse the multi-source information optimally, which can improve the precision and the robustness. Numerical simulations demonstrate the ef- fectiveness of the proposed approach.