野外空间坐标测量中的任意姿态多目相机快速标定  

Rapid calibration for multiple cameras with arbitrary attitude in field space coordinate measurement

作　　者：王向军[1,2] 张佳丽[1,2] 刘峰 于潼[1,2] WANG Xiang-jun;ZHANG Jia-li;LIU Feng;YU Tong(State Key Laboratory of Precision Measuring Technology and Instruments,Tianjin University,Tianjin 300072,China;Key Laboratory of MOEMS of the Ministry of Education,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]天津大学微光机电系统技术教育部重点实验室,天津300072

出　　处：《光学精密工程》2018年第2期503-510,共8页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.51575388)

摘　　要：针对野外复杂地形环境下,对于多个监测区域进行野外坐标测量的情况,提出一种利用双目立体视觉原理对相机3个姿态角及焦距同时进行现场校准的快速标定方法。该方法对传统的标定方法进行改进,可用于相机焦距、姿态未知的情况,对现场环境条件要求低,避免了传统标定方法中相机架设姿态受限的问题。首先通过选择合适的统一世界坐标系和坐标系旋转顺序,使标定得到的相机外参与相机姿态角对应。然后通过GPS测量得到两个标定点的世界坐标,将两个标定点的世界坐标和图像坐标代入成像模型,用最小二乘法解出相机的焦距和姿态角。在现场对其中一个监测区域进行实际测量验证,结果显示直径200 m的圆形监测区域内,相对误差优于0.38%。该方法工程应用性强,灵活度高,适用性广。In view of the complex terrain and the field coordinate measurements in multiple monitoring areas,a rapid calibration method based on the principle of binocular stereo vision for simultaneous calibration of three camera attitude angles and focal length was proposed.This method improved the traditional calibration method,so that it could be used for the situation that the camera focus and attitudes were all unknown,and had low requirement for field environment conditions.It avoided the problem of camera pose limitation in traditional calibration method.First,selected the unified world coordinate system and right coordinate rotation order,so that the calibration parameter equaled the corresponding camera attitude angles.Then,put the pixel coordinates and the world coordinates of two given points into camera imaging model,and the focal length and three attitude angles of the camera was solved by the least square method.The actual measurement and verification of one of the target areas were carried out on the spot.The results show that the relative error in the circular monitoring area of diameter 200 m is better than 0.38%.The method proposed is of high engineering applicability,and high flexibility and wide applicability.

关 键 词：双目视觉 摄像机快速标定 任意姿态 大视场 坐标测量 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] TP242.6[自动化与计算机技术—计算机科学与技术]