【作者】 丁度坤；

【导师】 高向东；

【作者基本信息】 广东工业大学 ， 机械电子工程， 2007， 硕士

【摘要】 焊缝跟踪技术是自动电弧焊接的一个重要研究领域，实现精确的焊缝跟踪对于提高焊接质量具有非常重要的作用。而要实现精确的焊缝跟踪，焊缝偏差(即焊缝中心与电弧的偏差)检测技术是一个关键。目前国内外应用于自动焊接的传感器有许多种，其中机器视觉型传感器因其特有的优点成为最有应用前景的传感器。视觉传感式焊缝跟踪的一般方法是利用CCD(Charge Couple Device)传感器实时获取焊接图像，再利用图像处理技术提取熔池中心与熔池前端的焊缝位置信息，两者之间的差值就反映了当前时刻电弧与焊缝的偏差情况。本论文不同于传统的通过图像处理技术来直接获取焊缝偏差信息，而是选取熔池图像处理区域(包括了熔池前端与熔池前端部份焊缝)，并将熔池图像质心作为分析焊缝偏差的特性参量，研究利用熔池特性参数来建立焊缝偏差测量视觉模型的新方法。论文的研究基于一套焊缝跟踪实验系统，该系统主要包括CCD传感器、工作台、步进驱动与控制系统等装置。首先研究了焊前图像的焊缝识别技术，应用数学形态学较好地提取焊前图像的焊缝信息，为实现焊前示教型的焊缝跟踪提供依据。其次，针对焊前示教型焊缝跟踪系统的不足，研究实现实时焊缝跟踪的新方法。进行了不同工艺条件下的焊接试验，分析熔池前端区域质心差值与焊缝偏差之间的关系，并应用一元线性回归分析建立了熔池图像质心差值与焊缝偏差之间的关系模型，并对该模型进行了显著性与通用性检验。最后，进一步分析其它因素对焊缝偏差的影响，分析比较并抽取熔池图像的三个特性参数(熔池图像质心差值、质心位移、质心移动速度)作为输入变量，研究并应用神经网络建模技术建立了它们与焊缝偏差间的关系模型，对模型进行了精确性与通用性检验，该方法具有较好的理论与现实意义。更多还原

【Abstract】 Seam tracking technology is one of the important research issues in the field of theautomation of arc welding process, and accurate seam tracking can improve the weld quality.The technology of seam deviation detection, which is the deviation between the seam center andthe arc, is one of the key to realize accurate seam tracking. Nowadays there are many sensorsapplied in weld automation, and the machine vision sensor has become the most prospectivesensor for its special advantage.The traditional method of seam tracking based on machine vision is to catch weld imagereal time by CCD (Charge Couple Device) vision, and the information between the weld poolcenter and the seam has been acquired through image processing, whose dispersion reflects thedeviation between the arc and the seam at the moment. The thesis, which is different from thetraditional method getting the seam deviation information only by image processing, chooses aweld pool process region which includes the foreside of weld pool and the seam in front of thepool. Then the centroid of weld pool image is made as the characteristic parameter to analyze theseam deviation. And the new method is researched on how to set up the seam deviationmeasurement visual model by the pool characteristic parameters.The thesis has been researched by a set of seam tracking experiment apparatus, whichincludes the CCD sensor, the working platform, and the step drive control system and so on.Firstly the thesis researches the seam recognition technology of welding images. And theposition of the seam has been acquired by the morphology, which can supply the bases to realizethe demonstration welding.However, there are some disadvantages in the demonstration weld seam tracking system.So the thesis researches new methods to realize the real time seam tracking. Several experimentsunder different welding conditions have been undertaken in order to analyze the relation betweenthe centroid’s dispersion of the process region and seam deviation. The relation model betweenthem has been set up using the linear regression analysis. And the model’s salience andgenerality have been tested.In order to analyze other factors’ influence to seam deviation, the weld pool characteristic parameters, which are the dispersion of pool centroid, the centroid’s displacement and thecentroid’s speed, have been chosen as input data. And the visual model between the seamdeviation and weld pool characteristic parameters has been set up using the neural networktechnology. Finally, the visual measurement model’s accuracy and generality have been tested,and the result shows that the method has the signification of the theory and the realism.更多还原