焊接缺陷检测论文图像处理技术在焊接缺陷检测中的应用.doc

焊接缺陷检测论文：图像处理技术在焊接缺陷检测中的应用【中文摘要】焊接缺陷检测系统在获取焊接缺陷图像的时候,由于外界各种干扰因素的影响,所获取的缺陷图像会造成缺陷特征不明显、边缘不清晰,影响焊接缺陷的正常判断和识别。因此,必须采用一定的图像处理技术,去除焊接缺陷图像中的噪声干扰,增强图像的对比度,提高图像的质量,以满足焊接缺陷正确判断和识别的需要。本文根据工程实际情况,在参考相关设备、查阅预处理相关资料的基础上,提出了焊接缺陷图像预处理系统的总体设计方案。通过对图像采集方法的研究,选择了焊接缺陷图像的采集设备,完成了常见的焊接缺陷图像的采集工作。根据焊接缺陷图像的特点,选择了图像预处理的内容和方法并运用Matlab工具对图像灰度化、图像增强、图像平滑、图像锐化等方法进行了实验对比验证,设计了确定了满足图像预处理需要的算法和相关参数,完成了焊接缺陷图像预处理系统的设计工作。同时,在WindowsXP环境下,利用Microsoft Visual Basic6.0语言对焊接缺陷图像预处理系统进行了开发实现,将Matlab产生的M文件直接编译成.EXE文件,实现VB与Matlab的无缝集成。应用该焊接缺陷图像预处理系统,对采集的焊接缺陷图像进行处理,可以得到噪声干扰少、图像对比度高、特征明显、边缘清晰的的焊接缺陷图像,为焊接缺陷的识别提供了保障。【英文摘要】During the image acquisition by the welding defect detection system, the welding defect images will have some quality problems such as the random noise generated by the image acquisition equipment, the fuzzy character and edge of the defects caused by low-contrast. All of the problems are due to the influence of the external environment,and the existence of these quality problems will impact the normal identification of the welding defect. Therefore, to meet the need of correct judgement and identification for welding defects,a certain image processing technology must be adopted to remove the image noise, increase the images contrast and improve the visual effects of the images.In this paper,by the actual situation of the project, a approach of preprocessing system for welding defect image is proposed and completed after searching related pre-processing information and relevant equipment. Through the research of image acquisition method,we choose the acquisition equipment of weld defect image, then complete the common welding defects in the work of the image acquisition.In this paper,according to the characteristics of welding defect images, the contents and methods of image preprocessing are chosen and Matlab tool is used for experiment contast and verification by using the methodolodgy of image grayscale, image enhancement, image smoothing, image sharpening, etc.,the algorithm and the relevant parameters of image pre-processing are designed and determined, the design work of the image weld defect preprocessing system is completed.At the same time,under the WindowsXP environment, the pre-processing system was developed to achieve the functional by using the Microsoft Visual Basic 6.0 Language. This system makes the Matlab M-Files translate and edit to the.EXE file directly to achieve the seamless integration comband VB and Matlab.Through the processing of the welding defect image pre-processing system, we get welding defect images with less noise disturbance, higher image contrast and better visual effects by the applicated images from this system,and provide the security for the identification of welding defects.【关键词】焊接缺陷检测 系统设计 图像采集 图像预处理 系统开发【英文关键词】Welding Defect Detection System Design Image Acquisition Image Pre-processing System Development【目录】图像处理技术在焊接缺陷检测中的应用摘要4-5ABSTRACT5目录6-9第1章 绪论9-171.1 焊接缺陷图像预处理的目的和意义9-111.1.1 焊接缺陷检测的目的和意义9-111.1.2 图像预处理的目的和意义111.2 国内外研究进展情况11-161.2.1 国外研究情况11-141.2.2 国内研究情况14-161.3 本课题开展的主要工作16-17第2章 数字图像处理基础理论及系统设计17-412.1 数字图像理论17-242.1.1 图像的获取172.1.2 图像的数字化17-182.1.3 数字图像的表示方法18-202.1.4 数字图像的文件格式20-242.2 常用的图像处理方法24-392.2.1 空域法24-382.2.2 变换域法38-392.3 系统总体设计39-402.4 本章小结40-41第3章 焊接缺陷的主要类型及预防41-453.1 焊接缺陷主要类型413.2 焊接缺陷原因分析与预防措施41-443.2.1 气孔41-423.2.2 夹渣42-433.2.3 未熔合433.2.4 焊口未焊透433.2.5 焊口根部焊瘤、凸出、凹陷43-443.2.6 内部裂纹443.3 本章小结44-45第4章 焊接缺陷图像的采集45-494.1 图像采集系统的设计45-474.1.1 数字图像采集方法45-464.1.2 X射线探测器的参数及选择46-474.2 焊接缺陷图像的采集47-484.3 本章小结48-49第5章 焊接缺陷图像的预处理系统设计49-695.1 概述495.2 预处理系统方法的选择49-605.2.1 焊接缺陷图像的灰度化49-505.2.2 焊接缺陷图像的增强50-545.2.3 焊接缺陷图像的平滑54-565.2.4