CO_2焊短路过渡过程缩颈信息的小波提取

Extracting necking down information in CO_2 arc welding short-circuiting transfer processing with wavelet methods

在CO2 气体保护焊过程中 ,利用表面张力过渡方法解决焊接过程中的飞溅问题时 ,准确地提取缩颈形成时刻这一信息是非常关键的。在缩颈形成的瞬间 ,电弧电压曲线先出现一个上凹的拐点 ,然后再急剧上升。若能从电弧电压信号中提取出拐点发生时突变的信息 ,则可望提取到缩颈发生的特征信息。作者利用小波分析方法具有良好的时域、频域局域性 ,能够很好地检测信号的局部奇异性的特点 ,对电弧电压信号进行了局部奇异性的检测。结果表明 ,小波分析方法可检测到电弧电压信号发生拐点时的位置及突变程度 ,可准确地提取出缩颈发生的特征信息。

It is vital for reducing the spatter with surface tension transfer methods in CO2 arc welding to extract the information of necking down. Once the necking down came into being, the arc voltage curve will create a push-up inflexion, and then, the arc voltage curve sharply rise. If this arc voltage saltation information can be extracted, we will get the characteristic information of necking down formation. Because wavelet methods have merits of local property in time domain and frequency domain, this paper studied the signal locality and singularity with wavelet methods. The study proved that wavelet methods could check the position and intensity of signal saltation. This method can accurately extract the characteristic information of necking down formation in CO2 arc welding short circuiting transfer.