航空学报 > 2024, Vol. 45 Issue (2): 328659-328659   doi: 10.7527/S1000-6893.2023.28659

基于松弛极线约束的月面复杂仿射变换图像匹配方法

刘传凯1,2,3(), 王沼翔1, 雷俊雄1, 张作宇2,3, 樊宽刚1, 张济韬2,3, 王晓雪2,3, 潘海朗4, 刘建国5   

  1. 1.江西理工大学 电气工程与自动化学院,赣州  341000
    2.北京航天飞行控制中心,北京  100194
    3.航天飞行动力学技术重点实验室,北京  100194
    4.南京理工大学 电子工程与光电技术学院,南京  210094
    5.帝国理工学院 地球科学工程系,伦敦 SW7 2AZ
  • 收稿日期:2023-03-07 修回日期:2023-04-06 接受日期:2023-06-01 出版日期:2023-06-12 发布日期:2023-06-09
  • 通讯作者: 刘传凯 E-mail:ckliu2005@126.com
  • 基金资助:
    国家自然科学基金(61972020);实验室基金(6142210200307)

An epipolar relaxation constrained matching algorithm of large-affined images for lunar rover with large span distance in a single movement

Chuankai LIU1,2,3(), Zhaoxiang WANG1, Junxiong LEI1, Zuoyu ZHANG2,3, Kuangang FAN1, Jitao ZHANG2,3, Xiaoxue WANG2,3, Hailang PAN4, Jianguo LIU5   

  1. 1.School of Electrical Engineering and Automation,Jiangxi University of Science and Technology,Ganzhou  341000,China
    2.Beijing Aerospace Control Center,Beijing  100194,China
    3.The Key Laboratory of Science and Technology on Aerospace Flight Dynamics,Beijing  100194,China
    4.School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing  210094,China
    5.Department of Earth Science and Engineering,Imperial College London,London SW7 2AZ,United Kingdom
  • Received:2023-03-07 Revised:2023-04-06 Accepted:2023-06-01 Online:2023-06-12 Published:2023-06-09
  • Contact: Chuankai LIU E-mail:ckliu2005@126.com
  • Supported by:
    National Natural Science Foundation of China(61972020);Foundation of Laboratory(6142210200307)

摘要:

月球车在月面巡视探测过程中采用大间距行进模式、以倾斜视角拍摄月面,导致相邻站点间所拍摄的月面图像重叠区域较小,并且在尺度、旋转上具有较大的差异;同时由于站点间图像仿射变换复杂、纹理相似度高且光照条件不一致,仅利用图像局部表观特征匹配极易发生错误。针对上述问题,提出了基于双向松弛极线约束的图像匹配算法,首先,将惯导测量的站点间近似相对位姿引入到成像光束的投影变换中,计算一个站点图像特征点在另一站点图像中对应的极线方程;其次,根据站点误差范围近似估计前后站图像中双向极线的松弛约束范围,构建限定在松弛约束范围内的匹配候选点集合;再次,利用FLANN算法进行特征匹配,选取同时满足双向松弛极线约束且相似度高的特征点对;最后,使用RANSAC算法进一步剔除错误匹配点,得到最终配对点集合。实验表明:上述算法在处理站点间大尺度、旋转变换月面图像匹配问题时,能够尽可能多地保留正确匹配点,极大提升匹配正确率和剔除无效匹配点,相比ASIFT等算法效果提升明显。

关键词: 月面探测, 月面图像, 仿射变换, 双向松弛极线约束, 图像配准

Abstract:

In the process of lunar surface exploration, Yutu-2 adopts a widely spaced travel mode and takes photos of the lunar surface from a tilted perspective, resulting in a small overlap area of the lunar surface images taken between neighboring sites, and large differences in scale and rotation. In addition, due to the complex image affine transformation between sites, high texture similarity and inconsistent illumination conditions, it is easy to make errors by matching only local apparent features of images. To address the above problems, this paper proposes an image matching algorithm based on the bi-directional relaxation polar line constraint. Firstly, the approximate relative poses between stations measured by inertial guidance are introduced into the projection transform of imaging beam, and the polar line equation corresponding to the feature points of one station image in another station image is calculated. Secondly, the bi-directional polar line relaxation constraint range in the front and back station images is estimated based on the station error range, and a set of matching candidates limited within the relaxation constraint range is constructed. Then, the FLANN algorithm is used to select the feature pairs that satisfy the bi-directional relaxation constraint and have high similarity. Finally, the RANSAC algorithm is used to further reject the wrong matching points and obtain the final set of matching points. The experiments show that when dealing with the problem of inter-site large scale and rotationally transformed lunar surface image matching, the proposed algorithm can retain as many correct matching points as possible, greatly improve the correct matching rate and eliminate invalid matching points, and has a significant improvement in effect compared with ASIFT and other algorithms.

Key words: lunar surface detection, lunar surface image, affine transformation, bilateral relaxation epipolar constraint, image registration

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