基于HALCON的板料成形网格应变的测量

Grid Strain Measurement in Sheet Metal Part Forming Based on HALCON

计算机视觉在网格应变测量领域的应用已成为研究热点,本实验是基于先进的图像处理软件HALCON,利用双目立体视觉原理,对印制有圆形网格的板料应变测量。首先采用印制有圆形标志点的平面标准标定板,对摄像机进行标定,获得摄像机的内外参数。采用基于NCC的匹配方法对左右图像特征点进行匹配,利用视差原理获得匹配点的三维坐标,对印制有圆形网格的板料进行三维重建。然后根据圆形网格变形后的椭圆长短轴的长度变化,计算得到真实应变,用OpenGL语言将应变可视化。

Computer vision application in the field of strain grid measuring has become a research topic, the study mainly measure strain to sheet metal with circular grid using the principle of binocular stereo vision based on advanced HALCON which is an image processing software. First calibrate the cameras with plane standard calibration plate to acquire the cameras＂ internal and external parameters.Matching feature points of left and right images by matching method based on NCC. Using the disparity principle to get three-dimensional coordinates of the matching points with which to conduct 3D reconstruction to the sheet metal part printed with circular grids.Then according to the length change of the elliptical axis after circular grid deformation, calculate the the true strain, and visualize each strain with OpenGL language.