基于计算机视觉的零件平面几何尺寸测量方法的研究

发布时间：2019-05-29 00:05

【摘要】：计算机视觉检测技术因其优越的非接触性、无损性、高精度等特点,已经成为精密测试技术发展的一个重要方向。本文针对基于计算机视觉的零件平面几何尺寸测量方法展开研究,设计开发了能够测量三类零件平面几何尺寸的检测程序。具体研究工作如下:(1)视觉检测系统整体方案的设计:对于国内外计算机视觉方面的需求进行调查与研究,根据零件平面几何尺寸测量的要求做出了整体方案的设计。通过比较,选取合适的硬件器件。完成了实验平台的搭建以及视觉系统的标定。(2)检测图像处理算法设计:对于图像处理技术做了学习与研究,分析各种方法的基本原理,联系运用在实际图片中的处理效果,选取零件处理中需要的图像预处理算法。为后续零件平面几何尺寸测量做准备。(3)分析图像获得角点、直线以及圆弧特征,计算最终尺寸:研究零件几何尺寸测量中的关键技术,根据理论推导以及实际图像处理的效果,制定零件尺寸测量系统中所运用到的技术。对于只有圆的零件中可以采取最小二乘法拟合;对于多边形零件可以采用霍夫变换拟合零件的多边形边界来进行测量;对于圆弧与圆弧,直线与圆弧的零件可以通过霍夫变换直线拟合以及霍夫变换圆拟合,求解其交点坐标并得到圆弧的值。并计算最终尺寸。(4)开发检测软件,并进行检测:开发了检测系统软件,本系统通过读取零件图纸的DXF文件,提供尺寸。将零件放入测量系统进行平面几何尺寸测量。对前文中的算法进行实验验证与实验结果分析。
[Abstract]:Computer vision inspection technology has become an important direction of the development of precision testing technology because of its superior non-contact, non-destructive, high precision and so on. In this paper, the measuring method of plane geometric size of parts based on computer vision is studied, and a program is designed and developed, which can measure the plane geometric dimensions of three kinds of parts. The specific research work is as follows: (1) the design of the whole scheme of visual inspection system: according to the requirements of plane geometric size measurement of parts, the overall scheme is designed according to the investigation and research on the requirements of computer vision at home and abroad. Through comparison, the appropriate hardware devices are selected. The experimental platform and the calibration of visual system are completed. (2) the design of detection image processing algorithm: the image processing technology is studied and studied, and the basic principles of various methods are analyzed. According to the processing effect used in the actual picture, the image preprocessing algorithm needed in the part processing is selected. Prepare for the subsequent plane geometric size measurement of parts. (3) analyze the image to obtain corner, straight line and arc characteristics, calculate the final size: study the key technology in the geometric size measurement of parts, According to the theoretical derivation and the effect of actual image processing, the technology used in the part size measurement system is worked out. For the parts with only circle, the least square method can be used to fit, and the polygons can be measured by Hoff transformation to fit the polygons boundary of the parts. For arc and arc, the part of line and arc can be fitted by Hough transformation line fitting and Hough transformation circle fitting, and the coordinates of intersection point can be solved and the value of arc can be obtained. The final size is calculated. (4) the detection software is developed and the testing system software is developed. the system provides the size by reading the DXF file of the part drawings. Put the parts into the measuring system for plane geometric size measurement. The experimental verification and experimental results of the previous algorithm are carried out.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.41

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