摘要本论文针对3A21防锈铝双丝PMIG焊接过程，采用双CCD摄像机、近红外复合滤光-减光系统、图像采集卡和计算机等设备建立了一套熔池视觉传感系统，可以同时从熔池尾部和侧面两个方向传感视觉图像。
设计开发了双丝PMIG焊熔池图像的处理算法—Snake算法，Snake算法也称为主动轮廓模型算法，通过给定一个初始轮廓，然后对初始轮廓曲线进行能量最小化变形，使其锁定在待分割目标的边界上，从而提取出熔池的轮廓曲线。定义并分析了铝合金双丝PMIG焊熔池视觉图像的几何特征参数，较为准确地描述了双丝焊接熔池的形态，归纳出熔池图像几何特征参数与焊接工艺参数之间的对应关系，初步建立了几何特征参数与焊接质量之间的关系模型，当后拖角大致在75°-100°、熔池最大半长在60-80范围内时多为正常焊透状态，而当后拖角大于130°、熔池最大半长骤减至30以下时多为焊塌、焊穿状态，为基于视觉传感的铝合金双丝焊接质量智能控制提供了相关的技术基础。10283
关键词 双丝焊 焊接熔池 视觉传感 图像处理 Snake算法 特征分析
毕业设计说明书（论文）外文摘要
Title Image Feature Analysis of Aluminum Alloy Welding Pool in Double Wire PMIG Welding
Abstract
A vision detecting system of collecting image of welding pool was designed in the view of the PMIG of the aluminum alloy in this thesis. This detecting system consists of two industrial CCD cameras, the compound filter system, an image gathering card and a computer. It can get the image not only from the behind of the welding pool, but also from the side of the welding pool.
An image processing algorithm in the view of the image which was got from the process of the double wire automatic gas shield arc welding was developed. It was called snake based on the active contour models. It can extract the boundaries of the welding pool by giving an initial contour and deforming under minimum energy. Some geometry parameters of the welding pool were defined in order to accurately describe the morphological characteristics of the welding pool during the double wire automatic gas shield arc welding. After analysis, a corresponding relationship between the actual welding parameters and the geometry parameters which were gathered from the image was concluded. Besides the contrast model of the geometry parameters and the welding quality was established finally. When the rear angle ranges from 75°to 100°and the maximum half-length of the welding pool ranges from 60 to 80,the welding pool is normal. When the rear angle exceeds 130°or the maximum half-length sharply drops below 30,the welding pool is abnormal, such as burn-off. All of these conclusions would provide a technical foundation for the intelligent control of welding quality of the aluminum alloys in double wire automatic welding based on visual sensors.
Keywords double wire arc welding, welding pool, visual sensing, image processing, snake algorithm, characteristic analysis
目 次
1 引言 1
1.1 选题意义 1
1.2 铝合金的焊接应用现状 1
1.3 双丝焊接技术的研究现状 2
1.4 焊接过程中的视觉传感技术的研究现状 3
1.5 本课题的主要研究内容 5
2 双丝气体保护焊及其熔池视觉传感系统 6
2.1 系统组成 6
2.2 双丝焊接设备系统 6
2.3 双丝焊接工艺原理及熔池特点 8
2.4 熔池图像视觉传感系统 9 铝合金双丝PMIG焊熔池图像特征分析:http://www.751com.cn/cailiao/lunwen_9298.html