中国激光, 2013, 40 (10): 1008006, 网络出版: 2013-08-28
线激光人体三维扫描仪多传感器同步标定方法
Multi-Sensor Synchronous Calibration Method for Line Laser Human-Body 3D Scanner
机器视觉 同步标定 陶瓷量块 人体三维扫描仪 machine vision synchronous calibration ceramic gauge block human-body 3D scanner
摘要
为了快速准确标定线激光人体三维扫描仪,提出一种使用精密移动陶瓷量块标定靶的多传感器同步标定方法。利用线激光在陶瓷量块4个方向产生的V形光带顶点作为标定点,由位于扫描仪4个立轴上的8个CCD相机同时记录V形光带图,采用灰度质心算法和双直线拟合求交点的方法提取V形光带角点的亚像素坐标,与二维平移台对应的世界坐标,形成精密标定点对。基于针孔摄像机模型,采用Levenberg-Marquardt (LM)非线性优化算法得出每个CCD的标定矩阵,完成多传感器同步标定。使用与标定点坐标不同的特征点对标定结果进行了验证,结果表明,各传感器的平均投影误差优于0.3480 mm,标准差优于0.2524 mm。
Abstract
In order to calibrate line laser human-body 3D scanner quickly and accurately, a multi-sensor synchronous calibration method which uses ceramic gauge block is proposed. V-shaped laser stripe which is made by line laser projection on ceramic gauge block is used as calibration point. 8 CCDs are distributed on 4 uprights, and capture V-shaped light stripe simultaneously to record V-shaped laser stripe pattern. Use gray centroid algorithm and dual fitting line intersection method to extract the light band′s sub-pixel-precision center grid. In order to obtain precision calibration point grid pairs, the grids are paired with 2D translation stage′s world grids. Based on pinhole camera model and using Levenberg-Marquardt (LM) nonlinear optimization algorithm, all sensors′ calibration matrices are obtained. The calibration results are tested by feature points which are different from calibration points, and the result shows that all sensors′ average projection errors are less than 0.3480 mm, standard deviations are less than 0.2524 mm.
李云鹏, 田庆国, 张翔宇, 魏耀林, 葛宝臻. 线激光人体三维扫描仪多传感器同步标定方法[J]. 中国激光, 2013, 40(10): 1008006. Li Yunpeng, Tian Qingguo, Zhang Xiangyu, Wei Yaolin, Ge Baozhen. Multi-Sensor Synchronous Calibration Method for Line Laser Human-Body 3D Scanner[J]. Chinese Journal of Lasers, 2013, 40(10): 1008006.