定位点分布对相机位姿解算精度影响分析

Influence analysis of location point distribution on solution accuracy of camera pose

针对单目相机位姿解算过程中,定位点的分布会对解算精度产生影响的问题,提出1种分析方法:基于奥普蒂·特拉克(OptiTrack)运动捕捉系统,建立相机位姿解算实验平台,分析定位点的不同构型对于位姿解算精度的影响;并提出人工标志的布设和点位选择的相关建议;最后采用位置精度衰减因子(PDOP)值对定位点构型进行描述。实验结果表明:PDOP值小于30时,82%以上的实验结果整体定位误差小于30 mm,65%以上的实验结果各个方向姿态角解算误差小于10′;在一定范围内,相机与定位点距离和定位误差成正相关;人工标志的布设应充分考虑点位的分布情况,保证每张照片中都存在至少4个构型良好的定位点;在定位点较多时,可以考虑根据相机的概略位置选择构型良好的定位点进行位姿解算,以提高解算精度。

Aiming at the problem that the distribution of the positioning points will affect the solution accuracy of the monocular camera's pose,the paper proposed an analysis method:an experimental platform for camera pose calculation based on the OptiTrack motion capture system was established,and the influence of different configurations of the positioning points on the pose solution accuracy was analyzed;then related suggestions for the placement of artificial marks and point selection were put forward;finally Position Dilution of Precision(PDOP)value was used to describe the point configuration.Experimental result showed that:when the PDOP value was less than 30,the overall positioning error of more than 82%experimental results would be less than 30 mm,and the attitude angle calculation error of more than 65%experimental results in all directions would be less than 10';in a certain range,the distance between camera and positioning points would be positively correlated with positioning error;the distribution of positioning points should be taken into full consideration in the placement of artificial markers to ensure at least four well-configured positioning points being in each photo;moreover,when there were many positioning points,it could be considered to select the positioning points with good configuration according to the general position of the camera for the pose calculation,thus improving the accuracy of the solution.