【作者】 徐树英；

【导师】 黄劼；

【作者基本信息】 四川大学 ， 机械制造及其自动化， 2005， 硕士

【摘要】 现代先进制造技术的进步,要求测量技术向着高精度化、高速化和网络化方向发展。传统的检测方法已无法完全满足现代制造业的特殊要求。因此,基于机器视觉的非接触测量方法已成为新世纪精密测量技术的重要发展方向之一。 虚拟仪器(Virtul Instrument,Ⅳ)的理论自20世纪80年代建立以来,伴随着计算机技术与电子技术的发展,很快应用于实际生产测量,并在测量任务的适应性,系统构建的方便性及系统成本的低廉性等方面显出巨大的优势。因此,研究虚拟仪器机器视觉测量系统的构建方法和图像处理算法有较强的实用价值和理论意义。 本文以军工配套项目“球面孔系位置精密测量”和四川省科技厅应用基础研究项目“机器视觉及图像处理技术研究”为背景,提出了虚拟仪器球面孔位相对位置非接触式测量的系统方案。 “球面孔系位置精密测量”系统利用光学成像技术把球面孔系坐标的三维测量转换为二维测量,使用机械运动机构驱动CCD线阵和光栅传感器对球面圆孔进行图像采集。通过LabVIEW的图形化编程环境与计算机数字图像处理技术相结合对采集到的图像进行圆孔中心识别,并通过数学模型将圆孔中心的像素坐标转化为物理坐标,实现孔系位置测量,最终达到项目的要求。本文主要包括以下内容: 1.介绍球面孔系坐标非接触测量系统的组成结构、工作原理和工作过程。 提出了基于虚拟仪器球面孔系位置测量系统的软、硬件实现方案。更多还原

【Abstract】 With the development of modern advanced manufacturing technology, it requires the measurement method to be more high-precision, more high-speed. The traditional measurement method couldn’t satisfy the special request in the modern manufacturing. So the non-contact measurement method, which based on the machine vision, has become the developmental direction of high-precision measurement technology since the new century.The theories of Virtual Instruments(Ⅵ) which have been established since 1980s was applied to actual manufacture measurement with the development of the technology of computer and electro, and have tremendous superiorities in the applicability to measurement, the facility to system building and the low cost. These make it valuable and meaning to research on the way of building a machine vision method and image processing algorithms based on Ⅵ.This paper is based on the military industry cooperative project- Measurement of Positions for Hole Series on Curved Surface, and - Research on Machine Vision and Image Processing technology that is the App foundation item of the Science and Technology Department in Sichuan Province. And it raised the No-contact Measurement system project of Ⅵ Spherical Circular Hole Series.The precision measurement of Spherical Circular Hole Series system transformed the three-dimensional measurement on the coordinates of spherical circular hole series to planar measurement by the optical imaging technology, and applied mobile mechanism to drive CCD linear and raster sensor, which captured the images. By the LabVIEW Graphical Development Environment and computer digital image processing technology, this system software identified the center ofcircular hole in the image, and transformed the pixel coordinates to physical coordinates and ultimately reached the demand. The main contexts are as follows:Firstly, the paper introduced the elements and working principle and process of the measurement system, and how to realize the Spherical Circular Hole Series measurement system.Secondly, the paper particularly showed how to build the VI machine vision measurement system based on the Lab VIEW 7.1 and IMAQ Vision 7.1.Thirdly, considering the characteristics of the image capturing hardware, the way of building PC-DAQ VI image capturing module is raised by this paper.Finally, in the image processing and analysis module, the system software identified the hole type(through hole and blind hole) by computing the gray-level histogram; and through median filtering, edge detection, threshold selection, we found the center coordinates of spherical circular hole.After the research, we have built the machine vision measurement system model that based on VI. Only by making a little adjustment to the code diagram, can we measure other types of surface. All these bring the Vis’ merit into play, such as facility, and adaptability to task.更多还原