基于激光光栅的焊口数字轮廓视觉测量

Vision measurement for digital contour of weld bore based on laser grating

为获取智能化焊接系统所需的基础数据,搭建了一套焊口数字轮廓的激光光栅视觉测量系统。通过对比不同工作距离和光栅投射角度下的条纹图像,确定了获取表征焊口轮廓光栅条纹图像的前提条件。探讨条纹连续扫描时,系统借助于条纹图像获取焊口轮廓信息的实现方法,建立的光栅扫描速度与摄像机曝光间隔时间算法为确定系统测量速度和精度提供了决策依据。探讨了基于条纹图像的分割和细化,获取了离散点三维坐标,通过三维重构建立焊口数字轮廓的实现方法。验证结果表明,该系统能够实时获取焊口的数字化轮廓,视觉测量的宽度值和深度值与人工测量结果的吻合度最高可达99.75%。

In order to gain the basic data for the intelligent welding system,a laser grating vision system is built to measure digital contour of weld bore. Firstly,through the fringe images are analyzed under different working distances and grating projection angles,the preconditions are determined for obtaining grating fringe images representing the contour of weld bore. At the same time,it is discussed how to obtain the information of weld bore contour by means of fringe images when fringes continuous scan. And the established algorithm of laser grating scanning speed and camera exposure interval time provides a decision basis for the determination of system measurement speed and accuracy. Secondly,based on the algorithm of segmentation and refinement of the fringe image,the three-dimensional coordinates of discrete point is gained,the digital contour of weld bore is established by the means of three-dimensional reconstruction. Finally,the verification results show that the system can obtain the digital contour of the weld bore in real time,and the coincidence degree of width or depth values is up to 99.75% between the visual measurement system and the manual measuring.