小波分析在CO_2弧焊控制中的应用

Application of wavelet analysis in CO_2 welding control

作者针对小波分析的特点,将其两个重要特性应用于电弧焊控制中。一是利用小波变换模极大值来与检测信号的局部奇异性的关系特点,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,可用来提取焊接电压的波形特征及缩颈发生的特征信息。二是利用小波分析在信号处理上良好时域、频域局域性,对电弧传感方式下的摆动焊接电流进行了软阈值滤波,取得了良好的效果,消除了短路过渡所造成的峰值电流,提高了信噪比。

Two characteristic features of the wavelet analysis was applied in the CO2 welding voltage control. Firstly, based on the relationship between the signal local singularity and the wavelet transform modulus maximum, the welding voltage signal singularity was detected, resulting in the successful detection of the welding voltage mutation point and its degree. It can be used to extract the waveform characteristics of the welding voltage and the characterizing information about the liquid bridge pinch. Secondly, making use of the good time frequency characteristics of the wavelet analysis in the signal processing, the wavelet soft-threshold filtering of the swing CO2 welding voltage signal under the arc discharge sense was carried out, showing the possibility of removing the peak current of the short-circuit transition and improving the signal-to-noise ratio.