基于小波频带能的脉冲VPPA焊接特征信号分析

Analysis of pulse variable polarity plasma arc welding characteristic signals based on wavelet band energy

采用小波分解方法,将典型VPPA、高频脉冲VPPA和高低频混合脉冲VPPA三种不同焊接方法对应的焊接电流分解到6种不同的频带。计算各个频带的平均频带能量,并对不同焊接方法的频带能量进行比较;同时比较不同焊接方法相同频带的平均能量。研究发现,加入高低频脉冲会对频带能量的分布产生影响,但整体频带能量分布较均匀,而在高频处低频脉冲对平均频带能量的分布影响比高频脉冲更为明显。

Wavelet decomposition method was used to decompose the welding current of VPPA,high frequency pulse VPPA and high-low-frequency pulse VPPA into 6 different bands.The average energy of each frequency bands in the different welding methods was calculated and compared,the average energy of same frequency bands for different welding methods was contrasted simultaneously.It is found that the addition of high and low frequency pulses will affect the distribution of frequency band energy,but the whole frequency distribution is well-distributed.It is more remarkable for high frequency the influence of low frequency pulses on the average frequency band energy than high frequency pulses.