一种小天体软着陆中基于地表阴影区的跟踪算法

考虑到星体表面的阴影区在航天器软着陆小天体时可作为导航路标以及壁障参考区, 提出一种基于地表阴影区的跟踪算法. 首先利用状态参数将拍摄到的前后两帧图像矫正到相同的状态, 根据提出的二值化算法对图像的阴影区进行检测; 然后利用模板匹配找出阴影区的相关位置点, 并通过特征向量法找到相似性最大的位置点; 最后结合RANSAC算法去除错匹配对. 以两组433 Eros 的连续拍摄图像作为阴影区进行跟踪实验, 结果表明该算法具有一定的可行性.

Method of tracking for soft landing on small body based on shadow areas

Considering the shadow areas of the planet surface can be seen as the landmark in the process of guidance, navigation and control(GNC) and hazard avoidance when the spacecraft soft lands on the small body, a method of the shadow areas tracking is proposed. Firstly, with the attitude estimates that are supplied by the attitude-measuring instruments, the two consecutive frames of image are rectified to the same attitude, and the shadow areas are detected by using the proposed binary algorithm. Then, the high correlation points of the shadow areas are found by using the template matching algorithm, and the feature vectors of the high correlation points are extracted to find the most similar point. Finally, the false matches are removed by using of random sample consensus(RANSAC). Two groups of sequence images of 433 Eros are utilized to teste the performance of the proposed method, and the results show that the method can be used in the real sequence images of planet.