一种利用激光跟踪仪标定线阵相机的方法  

A novel method for calibrating linear array cameras based on lasertracker

作　　者：孙博[1] 邾继贵[1] 任瑜[1] 郭寅[2] 杨学友[1] 

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]清华大学精密仪器系北京100084

出　　处：《光电子．激光》2014年第2期311-316,共6页Journal of Optoelectronics·Laser

基　　金：国家高技术研究发展计划“863计划”(2012AA041205);国家“十二五”科技支撑计划(2011BAF13B04)资助项目

摘　　要：为提高线阵相机的标定的灵活性和准确度,研究了一种利用激光跟踪仪辅助标定线阵相机的内参数和外方位参数的方法。借助激光跟踪仪测量靶标上的标记点获得靶标的位置和姿态,根据交比不变性质和空间坐标变换计算成像特征点的三维坐标。引入成像畸变模型补偿成像过程中产生的畸变,提高像点位置精度。应用优化算法估计待标定参数的精确解。本文方法解除了对靶标移动方向和距离的严格限制,允许靶标自由移动,既提高了标定工作的便利性又保证了成像特征点三维坐标的精度。标定过程中,使靶标均匀覆盖整个视场空间,能够更准确地反映相机参数。通过计算机仿真和实验验证了标定方法的可行性和稳定性,实验得到成像特征点重投影像点位置偏差均方根为0.21pixel。To make the linear array camera calibration more accurate and convenie nt,a novel calibration technique to determine the position,orientation and inner parameters of linear array cameras is proposed. This calibration technique uses a laser tracker to measure the pattern’s positi on and orientation.The 3-D coordinates of the feature points on the pattern are obtained based on cross-ra tio invariance and spatial coordinate transformation.A distortion model is built to correct the distortion generated in the projecting process,so the position accuracy of the image point is improved.Then parameter s are estimated by a nonlinear optimization algorithm.In this method,the pattern doesn′t need to mov e along a fixed axis strictly. And the pattern can be placed freely in the field of view of the linear array ca mera,which makes this calibration method become more flexible and accurate.In addition,the pattern i s uniformly placed in the whole field of view,which can describe the linear array camera model more accur ately.Finally,the calibration method is tested by both simulation and experiment.Both the simulation results and the experimental results show that this calibration method is feasible and robust.T he root mean square error of re-projected points is less than 0.21pixel.

关 键 词：线阵相机 标定 交比不变 激光跟踪仪 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]