中文摘要：

熔池振荡频率与焊缝全熔透状态有较为直接的物理对应关系,但熔池振荡频率的检测十分困难。针对该问题提出一种基于激光视觉的熔池振荡特征频率检测传感新方法。在介绍激光视觉法原理基础上,设计脉冲非熔化极气体保护焊（Gastungsten arc welding,GTAW）熔池振荡激光视觉传感试验系统。采集反映熔池振荡变化的视频图像,提出激光特征条纹的图像处理算法,并利用Matlab软件编写相应的程序获得熔池振荡波形,利用快速傅里叶变换提取出熔池振荡特征频率。试验结果表明,激光视觉法不仅成功实现脉冲GTAW熔池振荡信号的检测传感,而且克服了已有的脉冲GTAW熔池振荡检测法不能被用于连续焊接的缺陷。软件系统能够较准确地提取出熔池振荡特征频率、处理时间为20 ms,满足熔池振荡信号的实时检测要求,为连续脉冲GTAW熔透控制奠定了基础。

英文摘要：

There is a physical relationship between weld pool oscillation frequency and states of weld beam full penetration.But the detection of weld pool oscillation frequency is very hard.According to this problem,a new detecting and sensing method based laser vision for metal pool oscillation frequency is proposed.The method principle of laser vision is introduced and the experiment system of collecting weld pool oscillation signal for pulsed gas tungsten arc welding（GTAW） is designed.The video images which reflect weld pool oscillation variation are collected.An image processing algorithm used for dealing with the reflected laser lines image based Matlab software is designed and written,also weld pool oscillation waveform is captured by this algorithm.The weld pool oscillation characteristic frequency is extracted by Fast Fourier transform.The experimental results show that laser vision method not only can successfully accomplish detecting the oscillation frequency for pulsed GTAW,but also the defect of pre-detecting methods for pulsed GTAW weld pool oscillation which is not used for sequential welding is overcome.The oscillation characteristic frequency is detected by software system.The image processing algorithm elapses about time 20 ms and meet the real-time detecting requirement for metal pool oscillation.To further realize the continual pulsed GTAW penetration control laid a foundation.