摘要
玉兔2号月球车在月面巡视探测中,因斜坡凹坑众多使得行驶滑移严重.导航点的精确定位是路径规划的前提,也是月球车安全行驶的保障.玉兔2号月球车月面行进采用大间距行进模式,相邻导航点之间大多相距7 m以上,使得前后站图像的缩放尺度差异较大,如何从前后站序列成像中选出最优配对图像以实现特征匹配与定位解算的全自动是导航点定位的关键.本文在分析站点距离和成像倾角对图像重叠度、重叠区尺度变换等因素影响的基础上,提出并建立了图像像素的空间分辨率(单个像素对应月面区域的尺寸)与摄影光线长度和观测面法线方向角的关系模型,给出了不同站点距离和成像距离条件下图像重叠与缩放的定量关系,设计了站点距离、最优配对图像和匹配可行性的计算策略,从根本上确立了站点距离与成像距离对导航点定位的影响关系.结合嫦娥四号任务数据,对上述模型和分析的有效性进行验证,确立了上述方法对工程任务的指导意义.
In Chang’E-4 lunar exploration mission,Yutu 2 lunar rover slipped a lot in each movement,influenced by many slopes and pits on the lunar surface.Precise localization of rover in each stopping position is the precondition of path planning,which can guide a safe movement.Since Yutu 2 lunar rover moves station by station and each pair of adjacent stations has a distance of more than seven meters,the images acquired by the Yutu 2 lunar rover in two adjacent stations are very different in scale,which makes correspondence of feature points in these images very difficult to be found.In order to handle this problem,this paper analyzes the overlaps and scale transforms of images from the two adjacent stations with respect to station distances and imaging angles,and build the mapping relationship from the length of photographic ray and the angle between the ray and the surface normal to the spatial resolutions of each image pixel,which quantificationally describes the overlaps and scale transforms of images in the condition of different station and imaging distances.Thus,the influences to localization of rover from station distances and imaging distances is evaluated and established,which could be utilized to guide a more effective image registration and visual localization.With the images acquired by Yutu 2 rover in Chang’E-4 mission,the proposed method is validated by experiments.
作者
刘传凯
王泰杰
董卫华
苏建华
孙军
杨旭
王晓雪
郭祥艳
袁春强
万文辉
刘召芹
LIU ChuanKai;WANG TaiJie;DONG WeiHua;SU JianHua;SUN Jun;YANG Xu;WANG XiaoXue;GUO XiangYan;YUAN ChunQiang;WAN WenHui;LIU ZhaoQin(Beijing Aerospace Control Center,Beijing 100190,China;The Key Laboratory of Science and Technology on Aerospace Flight Dynamics,Beijing 100190,China;School of Electrical Engineering and Automation,Jiangxi University of Science and Technology,Ganzhou 341000,China;Institute of Automation,Chinese Academy of Sciences,Beijing 100190,China;Institute of Remote Sensing and Digital Earth,Chinese Academy of Sciences,Beijing 100094,China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2019年第11期1275-1285,共11页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:61773047)资助项目
关键词
嫦娥四号
月球车视觉定位
大倾角成像图像匹配
成像尺度分析
Chang’E-4 mission
visual localization of lunar rover
matching of large-scale transform images
image scale analysis
