连续焊接P-GTAW熔池振荡频率激光光电转换实时检测系统

Real-time measurement system based on laser photoelectric conversion for detecting weld pool oscillation frequency in continuous P-GTAW

钨极氩弧焊(GTAW)熔池振荡频率与熔池体积具有直接物理对应关系,但振荡频率检测十分困难.为此,提出了一种基于光电转换原理的激光光电转换法用于连续脉冲钨极氩弧焊(P-GTAW)熔池振荡频率的实时检测并搭建了试验平台.采集了激光光电转换法熔池振荡电压信号和图像激光视觉法的激光条纹视频,并对比分析了两种方法的优缺点.结果表明,图像激光视觉法具有较强抗干扰能力、信噪比高,但算法复杂,很难用于实时检测;激光光电转换法具有高采样率、处理速度快、设备简单、信噪比高等特点,能够满足对熔池振荡信号的实时检测及后续熔透控制.

There exists a direct relationship between the weld pool oscillation frequency and volume of weld pool. But the detection of oscillation frequency in on-time travelling condition is difficult. In order to detect the oscillation frequency in realtime,a new laser photoelectric conversion method was proposed.Several experiments with travelling welding condition were conducted and the frequency was extracted by Fast Fourier Transform. The results show that image laser-vision method has a strong anti-disturbing ability and high signal-to-noise while the defect of image process is complex and real-time detection becomes worse. The laser photoelectric conversion method with high sampling rate,high processing speed and simple device can completely satisfy the requirement of measuring the oscillation frequency of weld pool in practical welding process.