光子学报, 2013, 42 (11): 1334, 网络出版: 2013-12-16
一字线结构光三维测量模型的新型标定方法
A New Method for Calibrating Line Structuredlight 3D Measurement Model
结构光 平面靶标 标定 相机畸变 视觉测量 Structuredlight Planar target Calibration Lens distortion Machine vision measurement
摘要
建立了一字线结构光的机器视觉测量模型,并提出了基于改进的CCD相机标定法的结构光平面精确标定方法.根据结构光沿光平面法线方向的能量分布规律,采用高斯拟合法提取图像中光条中心点的亚像素坐标.标定时,在自由移动的平面靶标上建立局部世界坐标系,利用结构光光条与标靶的共面性,将通过相机标定参量计算得到的光条中心点的局部世界坐标转换到相机坐标系中.利用光平面上求得的标定点的三维坐标,实现了一字线结构光平面在相机坐标系下的优化估计.该方法考虑了影响测量模型准确度的因素,可以获取大量的用于标定光平面参量的标定点坐标.标准量块和轴颈的测量结果表明,该方法在实际应用中具有较高的准确度.
Abstract
A machine vision measurement model of line structuredlight was established. Based on the improved camera calibration method, an accurate calibration method of structuredlight plane was proposed. According to the distribution of the structuredlight′s energy along the normal direction of the light′s plane, Gauss fitting method was used to extract the subpixel coordinates of the light stripe′s center point on the image. In the calibration, the local world coordinate system was established on the surface of the freemoving planar target. Then, the local world coordinates of the stripe′s center point, which were obtained by the parameters of the camera calibration, were translated into the camera coordinate system. Using the obtained calibration points on the light plane, the plane of the structuredlight was estimated in the camera coordinate system. The factors that would affect the precision of the measurement model were fully considered in this method, which could achieve a large number of calibration points. From the measurement of standard gauge block and shaft diameter, this method has high precision in practice.
李冠楠, 谭庆昌, 寇莹, 张宇鹏. 一字线结构光三维测量模型的新型标定方法[J]. 光子学报, 2013, 42(11): 1334. LI Guannan, TAN Qingchang, KOU Ying, ZHANG Yupeng. A New Method for Calibrating Line Structuredlight 3D Measurement Model[J]. ACTA PHOTONICA SINICA, 2013, 42(11): 1334.