中文摘要：

针对铝合金MIG焊过程热积累作用强容易产生焊缝突然塌陷从而导致焊接过程失败的问题，建立电弧声信号传感系统并以焊接电弧声为研究对象，运用小波分析方法研究焊接电弧声信号与焊缝塌陷的相关性。研究表明电弧声信号的能量变化与焊缝塌陷有着明显的对应关系，电弧声总能量随着焊缝开始塌陷而增加，对电弧声进行小波分解发现不同频带有着不同的变化规律。研究结果为铝合金MIG焊实时焊接塌陷缺陷的检测提供一种新型有效的方法。

英文摘要：

In order to solve the problem of welding bead subsidence in aluminum alloy welding process, which is caused by strong thermal accumulating effect and always leads to serious defects in welding bead, an arc sound sensing system is built up. The wavelet methods are used to analyze the relationship between welding arc sound and subsidence of aluminum alloy MIG welding bead. The experimental results show that there is an obvious relation between the energy of arc sound signal and welding subsidence. The total energy of arc sound signal increases with the degree of subsidence of welding bead. The changing rules of the arc sounds energies varied when it is analyzed in different frequency bands. The study provides a new effective method for real-time detecting the subsidence of welding bead in aluminum alloy MIG welding process.