测试科学与仪器2017，Vol.8Issue(4)：354-363,10.DOI:10.3969/j.issn.1674-8042.2017.04.008
基于单目视觉的激光光束方向标定研究
Calibration of laser beam direction based on monocular vision
摘要
Abstract
In the laser displacement sensors measurement system,the laser beam direction is an important parameter.Particu-larly,the azimuth and pitch angles are the most important parameters to a laser beam.In this paper,based on monocular vi-sion,a laser beam direction measurement method is proposed.First,place the charge coupled device (CCD)camera above the base plane,and adjust and fix the camera position so that the optical axis is nearly perpendicular to the base plane.The monoc-ular vision localization model is established by using circular aperture calibration board.Then the laser beam generating device is placed and maintained on the base plane at fixed position.At the same time a special target block is placed on the base plane so that the laser beam can project to the special target and form a laser spot.The CCD camera placed above the base plane can acquire the laser spot and the image of the target block clearly,so the two-dimensional (2D)image coordinate of the centroid of the laser spot can be extracted by correlation algorithm.The target is moved at an equal distance along the laser beam direction, and the spots and target images of each moving under the current position are collected by the CCD camera.By using the rele-vant transformation formula and combining the intrinsic parameters of the target block,the 2D coordinates of the gravity center of the spot are converted to the three-dimensional (3D)coordinate in the base plane.Because of the moving of the target,the 3D coordinates of the gravity center of the laser spot at different positions are obtained,and these 3D coordinates are synthe-sized into a space straight line to represent the laser beam to be measured.In the experiment,the target parameters are meas-ured by high-precision instruments,and the calibration parameters of the camera are calibrated by a high-precision calibration board to establish the corresponding positioning model.The measurement accuracy is mainly guaranteed by the monocular vi-sion positioning accuracy and the gravity center extraction accuracy.The experimental results show the maximum error of the angle between laser beams reaches to 0.04°and the maximum error of beam pitch angle reaches to 0.02°.关键词
单目视觉/激光光束方向/坐标转换/激光位移传感器Key words
monocular vision/laser beam direction/coordinate transformation/laser displacement sensor分类
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王仲,杨桐郁,王磊,付鲁华,刘常杰..基于单目视觉的激光光束方向标定研究[J].测试科学与仪器,2017,8(4):354-363,10.基金项目
National Science and Technology Major Project of China (No.2016ZX04003001) （No.2016ZX04003001）
Tianjin Research Program of Application Foun-dation and Advanced Technology (No.14JCZDJC39700) （No.14JCZDJC39700）
