面曝光快速成型制件几何尺寸的视觉测量方法  

Vision measurement method for geometrical dimension of mask projection stereolithography rapid prototyping parts

作　　者：巨孔亮 张鹏[1] 刘新颖 JU Kongliang;ZHANG Peng;LIU Xinying(Xi’an Polytechnic University,Xi’an 710048,China)

机构地区：[1]西安工程大学,陕西西安710048

出　　处：《现代电子技术》2022年第7期18-22,共5页Modern Electronics Technique

基　　金：陕西省科技厅重点研发项目(2020GY-172);西安市科技局项目(201805030YD8CG14-5)。

摘　　要：针对面曝光快速成型制件几何尺寸传统测量效率低、主观因素干扰较大等问题,提出基于机器视觉的面曝光快速成型制件几何尺寸测量方法。搭建了基于背光成像的视觉测量系统获取制件的图像信息,以标准量块对系统进行标定。采用最大类间方差与形态学算子提取制件各孔的轮廓区域特征,在连通区域基础上,通过面积周长比进行圆孔识别,建立基于圆孔区域像素点的直径测量模型。对非圆孔采用Hough变换提取边长特征,以最小二乘法拟合算法得到边长直线方程,计算各相邻边直线的交点,建立非圆孔的边长测量模型。实验结果表明,该方法实现了对面曝光快速成型制件中孔形的识别,进一步对不同孔形的几何尺寸进行测量,标准差小于0.025,各尺寸满足设计要求。In view of the low efficiency and serious subjective interference in the traditional measurement of the geometrical dimension of mask projection stereolithography(MPSLA)rapid prototyping parts,a machine vision based method for measuring the geometrical dimension of MPSLA rapid prototyping parts is proposed.A vision measurement system based on backlight imaging is built to obtain the image information of the parts.The system is calibrated by a standard gauge block.The maximum between-cluster variance method and morphological operator are used to extract the contour region features of each hole.On the basis of the connected regions,circular holes are identified by perimeter-to-area ratio,so as to establish a diameter measurement model based on the pixels in the region of circular holes.The Hough transform is used to extract the edge length features of the non-circular holes,the linear equation of side length is obtained by the least-square fitting method,and the intersection point of each adjacent edge line is calculated,so as to establish the side length measurement model of the non-circular hole.The experimental results show that the method can realize the recognition of the hole shape of the MPSLA rapid prototyping parts.And then,the geometric dimensions of the holes with different shapes were measured.It can be seen from the measurement that the standard deviation is less than 0.025,which satisfies the requirements of the design.

关 键 词：面曝光快速成型 机器视觉 连通区域 最小二乘拟合 HOUGH变换 孔径测量 边长测量 

分 类 号：TN911.73-34[电子电信—通信与信息系统] TP391[电子电信—信息与通信工程]