摘  要：在现代工业中，窄间隙焊接方法在处理大厚板焊接问题中，表现出极高的优越性。与传统的焊接方法相比，它具有熔敷金属少，焊接残余应力小，焊缝成型好等多种优势。窄间隙焊接时，由于坡口加工精度不高、焊接热变形等因素影响，出现坡口宽度变化问题。为实现坡口侧壁的良好熔透，窄间隙焊接过程中需对坡口宽度进行实时适应控制。本研究室为改善窄间隙坡口侧壁熔透，提出了一种摇动电弧窄间隙焊接方法，该工艺可通过调节电弧摇动角度来适应坡口宽度变化。

本文基于摇动电弧窄间隙MAG焊方法，构建了变坡口窄间隙摇动电弧适应系统。确定以红外被动视觉识别传感作为坡口宽度检测的技术手段，合理选用了该方法所使用的CMOS相机、图像采集卡、滤光系统等。通过确定图像处理中的具体步骤，得到了清晰有效的坡口图像。提出了单帧双边同时检测算法，进行实验对坡口宽度进行提取，分析了坡口宽度检测精度及可能产生的干扰因素。

实验表明：本文设计的变坡口窄间隙摇动电弧的适应控制系统使用方便，可靠性高；设计的坡口检测算法精度高，坡口宽度检测最大误差率为2.6%，能够满足实际应用中的需要。

关键词：摇动电弧窄间隙焊接；变坡口；红外视觉传感；坡口宽度检测

Abstract：In modern industry, the narrow gap welding method shows a high degree of superiority in dealing with thick plate welding problems. Compared with the traditional welding method, it has a small amount of deposited metal, small welding residual stress, good welds and other advantages. When using narrow gap welding method, due to the groove processing accuracy is not high, thermal deformation of welding and other factors, the groove width will change. In order to realize the good penetration of the groove side wall, the width of the groove should be controlled in real time during the welding process. In order to improve the sidewall penetration of the narrow gap groove, this research laboratory proposed a method of swing arc narrow gap welding, which can adapt the change of the groove width by adjusting the arc swing angle.

In this paper, a narrow-gap swing arc adaptation system is constructed based on the method of narrow-gap MAG welding. The experience identifies

the infrared passive visual recognition sensor as the groove width detection technology, selecting reasonable instrument such as CMOS camera, image acquisition card, filter system. By determining the specific steps in the image processing, a clear and effective groove image is obtained. We proposed a kind of single frame bilateral simultaneous detection algorithm, caring out experiment to extract the groove width, analyzing accuracy of the detection of the groove width and the possible interference factors.

The experimental results show that the adaptive control system of variable groove swing arc is easy to use and practical. The groove detection algorithm has high precision and the maximum error rate of the groove width detection is 2.6%, which can meet the needs of practical application.

Key words: Swing arc narrow gap welding; Variable groove; Infrared visual sensing; Groove width detection

目  录

第一章 绪论 1

1.1 课题研究背景及意义 1

1.2 窄间隙焊接发展历程及其技术特点 1

1.3 窄间隙焊接研究现状 2

1.3.1 窄间隙埋弧焊（NG-SAW） 3

1.3.2 窄间隙TIG焊 4

1.3.3 窄间隙熔化极气体保护焊 4

1.4 摇动电弧窄间隙焊接方法 6

1.5 焊接过程适应控制视觉传感发展现状 7

1.6 本课题主要研究目的及内容 9

1.6.1 研究目的 9

1.6.2 研究内容 9

第二章 窄间隙焊接电弧摇动适应控制系统 10

2.1 总体构成 10

2.2 摇动电弧窄间隙MAG焊接系统 10

2.2.1 摇动电弧窄间隙焊炬 10