机械产品焊接过程中受控脉冲穿孔等离子弧焊接小孔动态行为分析

将视觉传感器应用于受控脉冲穿孔等离子弧焊接技术,检测小孔的动态行为,为调整机械产品的焊接工艺参数提供依据。结果表明:一个脉冲周期会对应产生一个小孔,每个小孔都依次经历了出现、长大、缩小和闭合,且小孔位置偏移量由刚穿孔时的最大逐渐变为闭合时的最小。     

基于熔池红外图像实时跟踪焊缝宽度算法研究

在激光焊接过程中,激光焊机所附带的传感器能够准确实时地反映焊接过程,焊缝宽度的实时动态变化对于描述焊接质量起着至关重要的作用。焊缝宽度准确测量的研究有助于理解焊接过程,获得焊接质量控制模型。针对大功率光纤激光焊接,利用恰当的滤镜系统获得清晰的焊缝熔池图像,建立熔池红外传感跟踪系统。针对大功率光纤激光焊接304型不锈钢过程,研究一种通过熔池图像实时检测焊缝宽度变化的方法。利用高速摄像机获得熔池动态红外图像,通过一系列图像处理技术得到焊缝宽度的识别模型。解决了在金属处于高温下熔池与周边非熔化区的温度比较接近,很难用红外摄像来准确测量焊缝宽度的难题。试验结果表明,所建立的焊缝实际宽度测量模型测量效果良好。     

基于视觉的不锈钢Nd：YAG激光焊焊接熔池和小孔的图像处理

在激光焊接过程中存在众多干扰因素,为保证焊接质量,需要对激光焊进行质量控制。实现焊接质量控制的关键是表征焊接质量信息的获取,而焊接熔池和小孔包含丰富的焊接质量信息。针对不锈钢Nd：YAG激光焊,构建了同轴视觉检测系统,获得了熔池和小孔图像。根据熔池和小孔图像的特点,设计了图像处理算法,并分别针对熔池和小孔确定了搜索起始点和搜索准则。     

An approach of artificial neural network to robotic welding process modelling

Ａｎａｐｐｒｏａｃｈｏｆａｒｔｉｆｉｃｉａｌｎｅｕｒａｌｎｅｔｗｏｒｋｔｏｒｏｂｏｔｉｃｗｅｌｄｉｎｇｐｒｏｃｅｓｓｍｏｄｅｌｌｉｎｇ￥ＬｉＹａｎ（ＨａｒｂｉｎＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＷｅｌｄｉｎｇＪｏｈｎＮｏｒｒｉｓｈａｎｄＴ．Ｅ．Ｂ...     

CO2焊接熔池直接视觉图像传感研究

应用被动式视觉传感方法进行CO2焊焊接熔池的形状检测。为了消除弧光干扰并获得清晰的熔池图像,设计了由窄带滤光片、中性密度滤光片和普通焊接滤光片构成的复合滤光系统。基于CO2焊焊接弧光的光谱分布特征,首先确定了窄带滤光窗口机心波长为632．8nm。然后,通过实验确定了中性密度滤光片和普通焊接滤光片的规格,以及它们与窄带滤光片的最佳组合方式。图像检测实验结果表明,该复合滤光系统有效地消除了弧光干扰,获得了高质量的熔池图像。同时,对CO2焊焊接熔池的图像特征进行了初步分析,为进一步进行熔池图像处理和焊缝成型控制的研究奠定了基础。     

Relationship between sound signal and weld pool status in plasma arc welding

1　ＩＮＴＲＯＤＵＣＴＩＯＮＰｌａｓｍａａｒｃｗｅｌｄｉｎｇ (ＰＡＷ )ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅａｓｙｏｐｅｒａｔｉｏｎａｎｄｌｏｗｃｏｓｔａｍｏｎｇｔｈｅｈｉｇｈ ｅｎｅｒｇｙ ｄｅｎｓｉｔｙ ｂｅａｍ ｐｒｏｃｅｓｓｉｎｇｔｅｃｈｎｉｑｕｅｓ (ｆｏｒｅｘａｍｐｌｅ ,ｅｌｅｃｔｒｏｎｂｅａｍ ,ｌａｓｅｒａｎｄ ｐｌａｓｍａ) .ＰＡＷｉｓｗｉｄｅｌｙｕｓｅｄｉｎｗｅｌｄｉｎｇｏｆｓｔａｉｎｌｅｓｓｓｔｅｅｌ,ｈｉｇｈ ｎｉｃｋｅｌａｌｌｏｙｓ ,ｃａｒｂｏｎｓｔｅｅｌ,ｃｏｐｐｅｒ ,ｃｏｐｐｅｒ …     

VPPA焊接的焊缝成形稳定性控制的研究现状

变极性等离子孤焊的优点在于能够灵活调节特征工艺参数,如电流频率、正负半波电流幅值及时间比,以满足铝合金焊接时的阴极清理和实现小孔焊接的要求.因此,在航空航天铝合金结构的焊接中获得了广泛的应用.主要介绍了该焊接方法在焊缝成形稳定性控制方面的研究现状,主要分为预置参数开环控制方式、实时检测闭环控制方式和多参数信息融合反馈控...     

A vision tracking system of robot CO_2 short transfer welding

ＡｖｉｓｉｏｎｔｒａｃｋｉｎｇｓｙｓｔｅｍｏｆｒｏｂｏｔＣＯ_２ｓｈｏｒｔｔｒａｎｓｆｅｒｗｅｌｄｉｎｇＷｕＲｅｎｙｕ；ＷａｎｇＧｕｏｄｏｎｇａｎｄＬｉＸｉａｏｑｉ（ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ）ＺｈａｎｇＬｉａｎｃｈａｎｇ（ＭｏｔｏｒｏｌａＣ?..     

LabVIEW在机器人弧焊作业仿真中的应用

提出一种基于LabVIEW环境开发的虚拟控制台,用于控制弧焊机器人的作业仿真过程。根据系统的功能需求,设计了仿真系统的控制流程。建立了控制台功能模块,包括几何模型、运动模型及驱动数据、作业信息统计与采集,分析了功能模块间的相互关联、调用的方式。仿真模拟的结果表明,按上述设计的虚拟控制台能很好地实现对弧焊作业仿真过程的控制。     

Real-time monitoring of weld penetration quality in roboticarc welding process

It is of great significance to develop an intelligent monitoring system for weld penetration defects such as incomplete penetration and burn-through in real-time during robotic arc welding process. In this paper, robotic gas metal arc welding experiments are carried out on the mild steel test pieces with Vee-type groove. Through-the-arc sensing method is used to capture the transient values of the welding voltage and current. The raw data of the captured welding current and voltage are processed statistically, and the feature vector S10 is extracted to correlate the welding conditions to the weld penetration information. It lays foundation for intelligent monitoring of weld quality in robotic arc welding.     

Experimental determination of the weld penetration evolution in keyhole plasma arc welding

Keyhole plasma arc welding experiments are conducted to measure the weld geometry and penetration at different moments during the initial phase from igniting arc to quasi-steady state. Indirect information on keyhole formation and evolution in plasma arc welding can be extracted based on the weld macrophotograph at cross section. It has laid foundation to verify the mathematical models of keyhole plasma arc welding.     

水下焊接熔池采集过程中摄像机的标定

定标是计算机视觉系统中的一个重要问题,针对水下焊接熔池采集过程中的摄像机标定问题进行了研究.采用图像增强、细化等图像处理技术确定标定模板的图像坐标,从而实现了对摄像机的快速标定.试验表明该方法切实可行.     

Application of switch back welding to V groove MAG welding

The formation of stable back beads in a root pass weld during one side multi-layer welding is important to achieve high quality welded metal joints in MAG welding. The authors employed the switch back welding method for V groove joints without backing plates. In this switch back welding method, the torch moves forward and backward with an oscillation frequency of 2.5 Hz. In order to achieve this welding, personal computers control the conventional welding robot, the power source characteristic and the wire feeder unit. During the forward, the torch is weaving on the V groove gap without the weld pool. If the weaving width becomes wider than the proper width, the tip of the wire becomes high and a good back bead cannot be obtained. The weaving width is adjusted so as to get the proper width in the switch back welding. The suitability of the welding conditions for each root gap was verified by observation of the arc, the weld pool and the external appearance of back beads. A good back bead was obtained under V groove welding in 2–4 mm gap.     

视觉传感技术在机器人智能化焊接中的研究现状

随着我国《中国制造2025》战略实施,焊接制造领域经过"两化"融合的推动,正朝数字化、信息化、智能化制造转型,进而使焊接制造过程的信息需求量显著增加。围绕上海交通大学智能化焊接与材料精密制造研究所近年来在智能化焊接领域所取得的成果和关键技术应用等展开讨论,内容涉及基于视觉传感的焊接路径自主导引与规划、焊接动态过程液态熔池的智能表征和基于视觉传感的焊接全场高温应变的在线测量及多尺度计算。上述研究成果的工程应用,一定程度上丰富和发展了焊接智能化技术领域的内涵。期望展示的焊接视觉智能化传感研究成果为焊接智能制造的发展抛砖引玉。     

Geometric model of robotic arc welding for automatic programming

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｒｅｅｋｉｎｄｓｏｆｉｎｆｏｒｍａｔｉｏｎａｒｅｎｅｅｄｅｄｆｏｒａｕｔｏｍａｔｉｃｐｒｏｇｒａｍｍｉｎｇｏｆａｒｃｗｅｌｄｉｎｇｒｏｂｏｔ.(1)Ｇｅｏｍｅｔｒｉｃｉｎｆｏｒｍａｔｉｏｎｏｆｗｅｌｄｉｎｇｗｏｒｋｐｉｅｃｅ,ｉｎｃｌｕｄｉｎｇｇｅｏｍｅｔｒｉｃｉｎｆｏｒｍａｔｉｏｎｏｆｗｅｌｄｉｎｇｓｅａｍｆｏｒｗｅｌｄｉｎｇｐａｔｈｐｒｏｇｒａｍｍｉｎｇ,ｇｒｏｏｖｅｓｈａｐｅａｎｄｓｉｚｅｆｏｒｗｅｌｄｉｎｇｐａｒａｍｅｔｅｒｓｐｒｏｇｒａｍｍｉｎｇａｎｄｗｏｒｋ…     

Realizing precision pulse TIG welding with arc length control and visual image sensing based weld detection

Methods of arc length control and risual image based weld detection for precision pulse TIG welding were investigated. With a particular all-hardware circuit, arc voltage during peak current stage is sampled and integrated to indicate arc length, deviation of are length and adjusting parameters are calculated and output to drive a step motor directly.According to the features of welding image grabbed with CCD camera, a special algorithm was developed to detect the central line of weld fast and accurately. Then an application system were established, whose static arc length error is 0. 1 mm with 20 A average current and 1 mm given arc length, static detection precision of weld is 0. 01 mm, processing time of each image is less than 120 ms. Precision pulse TIG welding of some given thin stainless steel components with complicated curved surface was successfully realized.     

单片机控制脉冲等离子弧焊接系统的研制

为进行脉冲等离子弧焊接的研究，在实验室现有的直流等离子弧焊接系统的基础上引入单片机控制系统，对焊接电源的原给定控制电路进行改造，实现了焊接电流的脉冲控制。同时设计了单片机控制系统的键盘输入、LED显示等外围扩展电路。     

连续电流TIG焊熔池图像的低成本自动化检测

改进了普通CCD摄像机镜头,使物距、放大倍数的调节范围进一步扩大。通过试验和统计的方法,调整物距、光圈、快门等光学参数,增大景深,提高对比度,拍摄出了分辨率较高的熔池图像。对大量的焊接熔池图像进行了分析,根据图像的特点,设计出了不需要滤波的图像边缘检测算法,检测出了连续电流TIG焊接熔池的整个边缘。与激光频闪视觉检测仪拍摄的熔池图像进行了对比,结果表明该低成本自动化检测装置所拍摄的熔池图像也达到了较高的清晰度与对比度。     

三光路熔池图像的视觉注意特征提取

焊缝跟踪和熔透控制都是焊接质量控制中的重要部分.试验采用三光路视觉传感系统,在铝合金脉冲GTAW焊接过程中,三个光路同时采集熔池正前方、斜后方、斜下方图像,并投影到同一幅图像上.图像包含了焊缝、正面熔池和背面熔池等丰富的信息.采用视觉注意的方法找到图像各部分与熔池特征参数相关的小区域进行处理,将图像中包含的熔池特征参数提取出来.结果表明,视觉注意方法用于焊接过程中熔池特征的实时检测时,由于只处理感兴趣的小区域,比一般方法具有更高的明确性以及高效性.