直流TIG焊熔透状态激光光电法实时检测

针对目前熔透检测方法存在的信噪比低、实时性差等缺点,提出了一种激光光电法可通过提取熔池表面特征参数实现直流TIG焊定点及连续焊接条件下熔透状态实时检测.介绍了该方法的原理,构建了直流TIG焊光电法电压信号检测及背面熔透同步摄像采集试验平台.采集了定点及连续焊接条件下电压信号与同步摄像图像,对比分析了电压信号与熔透状态的对应关系及电压信号的变化规律.结果表明:激光光电法采集的电压信号可以较好反映直流TIG焊熔透状态;利用熔透状态从未熔透转变为临界熔透时熔池表面由凸面突变为凹面,激光反射条纹快速聚焦,从而引起光电法电压信号迅速变化的现象,可以实现直流TIG焊熔透特征信号的精确识别与提取.

Real-time Detection for DC-TIG Weld Penetration State Through Laser Photoelectric Conversion Method

According to the disadvantages of the present detection methods of penetration, such as the low signal-to-noise ratio, the poor real-timeliness and the like, this paper proposes a laser photoelectric conversion method that the real-time detection for the DC-TIG weld penetration state under the condition of stationary and traveling weld can be realized by extracting characteristic parameters of the weld pool surface. The principle of the method was introduced and an experimental platform for the voltage signal detection was established using the DC-TIG laser photoelectric conversion method as well as the synchronous video collection of the penetration at the back, collecting the voltage signals and synchronous video images under the condition of stationary and traveling weld and analyzing the corresponding relationship between the voltage signals and the penetration state as well as the change rule of the voltage signals. Result shows that the voltages signals collected by using the laser photoelectric conversion method can reflect the DC-TIG weld penetration state well. When the weld penetration state changes from partial penetration to full penetration, the surface of the weld pool will change from convexity to concavity and the reflected laser stripes will focus quickly, causing the phenomenon of the rapid change of the voltage signals to realize the accurate recognition and extraction of the characteristic signals of the DC-TIG weld penetration.