【作者】 薛诚；

【导师】 樊丁； 石玗；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2008， 硕士

【摘要】 本课题的目的在于从普通CCD和高速摄像机拍摄的熔池和熔滴过渡图像中获取反映焊接质量的特征信息,为基于视觉的焊接过程质量控制提供关系模型。采用被动式视觉传感方法,分别利用CCD摄像机和高速摄像机配合窄带滤光片获取铝合金脉冲MIG焊熔池图像和铝合金双旁路复合电弧MIG焊熔池和熔滴过渡图像。采用数字图像处理技术,通过MATLAB软件编程,对熔池图像进行了边缘特征提取,对比分析各图像处理方法的结果,为熔池特征提取方法的选择提供依据。采用数字图像处理技术对铝合金双旁路复合电弧MIG焊熔滴过渡图像进行了颈缩和熔滴的边缘特征提取,并对比了各方法的提取结果,提出一种多算子检测叠加的边缘提取方法,得到了颈缩的轮廓信息。利用基于分离的亮度减法算法,提取出电弧中熔滴的边缘信息,为铝合金双旁路复合电弧MIG焊旁路电流与熔滴过渡特征信息建立关系奠定了基础。为了验证以上方法的可靠性,均与手工测量结果进行了对比。为研究铝合金双旁路复合电弧MIG焊熔滴过渡稳定性,对不同焊接规范下的颈缩变化进行了规律性分析。对不同旁路电流下熔滴下落过程中几何形状的变化和下落速度的分布分别进行了计算,并将结果进行了统计分析。为铝合金双旁路复合电弧MIG焊过程中旁路电流对系统稳定性的影响规律的研究和焊接过程质量控制提供了依据。更多还原

【Abstract】 The purpose of the subject is to acquire the useful quality characteristic information from the weld pool and the metal transfer image, which is gotten by ordinary CCD and high-speed camera, and build a good foundation for the welding quality control based on vision sensing.With a passive vision sensing method, a CCD camera was used to obtain the weld pool image of aluminum alloy pulsed MIG welding. And the high-speed camera was used in the process of aluminum alloy Dual Bypass MIG welding to have the weld pool and droplet image. These two kinds of camera both have a narrowband filter. The digital image-processing technology was used to detect the edge characteristic information from the weld pool image by MATLAB. The results were compared and analyzed in order to provide a choice of methods in practice. The digital image-processing technology was also used to detect the edge characteristic information of detachment and droplet from the metal transfer image in aluminum alloy Dual Bypass MIG welding. The results of every method were compared, and a new method of multi-arithmetic operators was invented and acquired clear edge information. The edge information of droplet was acquired by brightness and subtraction based separation algorithm. This will build a good foundation between bypass current and characteristic information of metal transfer for aluminum alloy Dual Bypass MIG welding. In order to check out the results, manual measurement was taken.In order to study the stability of metal transfer in aluminum alloy Dual Bypass MIG welding, the change of the size of necking which was in different welding procedures was analyzed. The change of droplet geometry and velocity in falling process with different bypass current was calculated and analyzed. These are all can be used to help study the affections between bypass current and stability of system and quality control.更多还原