非公共视场双目相机位姿标定  

Calibration of binocular camera with non-common field of view

作　　者：李勤文 倪首军 王志乾[1] 李建荣[1] 沈铖武[1,2] 杨文昌 刘玉生 LI Qin-wen;NI Shou-jun;WANG Zhi-qian;LI Jian-rong;SHEN Cheng-wu;YANG Wen-chang;LIU Yu-sheng(Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Institute of Space Launch Technology,Beijing 100076,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049 [3]北京航天发射技术研究所,北京100076

出　　处：《光学精密工程》2020年第12期2737-2744,共8页Optics and Precision Engineering

基　　金：吉林省科技厅技术攻关项目资助(No.20190302086GX,No.20200403067SF)。

摘　　要：针对现有双目位姿测量系统中仅有两个目标点,无法利用额外标定物对两个无公共视场相机进行标定的问题,提出一种无需改变系统结构,可以直接利用现有设备的双目相机位姿标定方法。首先固定两相机坐标系与公共目标坐标系的位置关系,通过多次移动标定物的方式得到多组坐标数据;然后,利用一种基于直接线性变换方法的改进算法对每个相机坐标系到公共目标坐标系的转换关系进行优化求解;最后,利用优化后的相机坐标系到公共目标坐标系的转换关系求得两个无公共视场相机坐标系之间的转换关系。利用两个相机坐标系之间的转换关系求得两目标点距离,并作为标定精度的评价指标。实验结果表明:当目标点处在各自相机视场范围内,相机与目标点之间的测量距离为700~1300 mm时,利用本文方法求得的目标点距离的均方差<0.2 mm,满足实际应用需求。For the existing binocular position and attitude measurement system with only two target points,it is impossible to use additional calibration objects to calibrate the two cameras without a common field of view.In this study,a calibration method for a binocular camera without changing the system structure and instead directly using the existing equipment was proposed.First,the relative position between the two camera coordinate systems and the common coordinate system was fixed,and multiple sets of coordinate data were acquired by moving the calibrator several times.An improved algorithm based on a direct linear transformation(DLT)method was used to optimize the relative transformation from each camera coordinate system to the common coordinate system.Finally,the relative conversion between the two camera coordinate systems was obtained using the optimized relative conversion from each camera coordinate system to the common coordinate system.The distance between the two target points could be obtained using the relative conversion between the two camera coordinate systems,and this distance was selected as the evaluation index of the calibration accuracy.The experimental results show that the mean square error of the distance between the target points obtained using this method is less than 0.2 mm,which meets the practical application requirements.

关 键 词：视觉测量 非公共视场 相机标定 直接线性变换 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]