摘要
机器视觉技术具有非接触、自动化、客观性、高精度等优点,并可与自动控制、网络通讯等技术结合使用来更有效的提高工业生产及制造的效率和自动化水平,在世界范围内被深入地研究,并获得了广泛应用。
本文基于电解加工对刀间隙的控制需求,将机器视觉技术用于电解加工对刀间隙的检测,构建了基于机器视觉的电解加工对刀间隙检测系统。
在研究了机器视觉系统的组成及其硬件设备的性能参数和选择方法的基础上,根据课题的需要,设计并搭建了电解间隙图像采集硬件系统,通过设置背景,调整光源和摄像头,可以应用该硬件系统采集到理想的试验图像。
在分析间隙图像和相关图像处理算法的基础上,选择了合适的图像处理方法,编写了间隙距离检测函数,实现了图像中间隙像素距离的检测。针对机器视觉系统的非线性畸变,对图像进行了矫正,明显的改善了图像的畸变程度。通过系统标定,把检测到的间隙像素尺寸简单有效转换成为以毫米为单位的实际尺寸。基于VC++6.0环境,开发了电解间隙检测的软件系统,实现了所使用的算法和功能。
为检验所搭建系统的性能和效果,分别对数控电解车削加工时使用线状阴极加工回转件和数控多轴电解加工时用球头阴极加工曲面的对刀间隙进行了检测试验,结果数据表明,检测结果与实际尺寸基本一致,达到了预期目标。
With the advantages of non-contaction, automation, objective, high precision, as well as being easy to combine with automatic control and communication technologies to improve the efficiency and automation level of industrial production and manufacturing, machine vision technology has been studied deeply and applied widely in worldwide.
In this paper, based on the requirement of controlling the initial electrochemical machining gap, as well as being adapt to the development of manufacturing technology, machine vision technology was used in the measurement of initial electrochemical machining gap, and the measurement system based on machine vision was built.
After studying the composition of machine vision system as well as the performance parameters and selection methods of the needed devices, a hardware system for image acquisition was designed and built. By setting the background, adjusting the light sources and camera, ideal experiment images can be captured with the system.
Based on the analysis of the gap images and the associated image processing algorithms, the appropriate image processing methods was selected, a function for gap distance measure was written, which can get the pixel distance of the gap in the image. For the non-linear distortion of machine vision system, an image rectification processing was conducted, which significantly reduced the distortion level of the image. And by use of system calibration, the pixel size of the gap detected first was transformed to the the actual size in millimeters. A software system which realize the algorithms and functions in use was developed in VC++6.0 enviroment.
In order to validate the system, experiments were carried on the initial gap of both electrochemical turning with line tool electrode and multi-axis electrochemical machining with spherical electrode, and the experimental data shows that the test results are basically consistent with the actual size and meet the expectations.
引文
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