使用非特制靶标实现线结构光平面标定

Calibration of line-structure light plane using non-specific target

为解决在线结构光测量系统中因缺少特制靶标而无法高精度标定线结构光平面的问题,基于立体视觉原理及线结构光测量系统提出了一种使用非特制靶标的线结构光平面标定方法。该方法采用非特制靶标,将靶标放置于线结构光平面上,利用视差法获取线结构光投影在靶标上形成的点云集,通过更换靶标姿态重复获取多个点云集。采用最小二乘法对所采集的多个点云集进行平面拟合,确定结构光平面参数进而完成对平面的标定。分别采用人体手臂和304钢板充当靶标利用所提出方法完成线结构光平面标定,用该标定的结构光平面进行5种正方形工件的尺寸测量,实验证明提出的标定方法测量精度平均约为±0.056 mm。该方法能够在不需要特制靶标的情况下完成标定,满足测量系统的精度要求。

High-precision calibration of a line-structure light plane can not be achieved if the measurement systems lack a target plane.To address this problem,this paper proposes a line-structure light plane cali⁃bration method using non-specific targets;this method is based on the principle of stereo vision and the linestructure light measurement system.First,a non-specialized target is placed on the line-structure light plane,and point clouds formed by projecting line-structure light on the target are acquired using the paral⁃lax method.Multiple point clouds are obtained by varying the posture of the non-specific target.The least squares method is then used to perform plane fitting on these collected multiple point cloud sets,and subse⁃quently,the structure light plane parameters are determined to complete plane calibration.A human arm and 304 steel plate were adopted as the targets,and the proposed method was used for the calibration of the line-structure light plane,where these targets were located.Using this calibrated line-structure light plane,the dimensions of five square workpieces were measured.The results indicate that the average mea⁃surement accuracy of the proposed calibration method is approximately±0.056 mm.This proves that themethod can be used for calibration,without requiring a special target,while also meeting the accuracy re⁃quirements of the measurement system.