Wavelet analysis in servo-gun electrode displacement measurement and welding quality control

Electrode displacement curve is an ideal parameter for servo-gun resistance spot welding (RSW) quality control. Electrode displacement curve was separated into trend curve and variation curve by wavelet analysis. Trend curve reflected whole quality of the RSW and variation curve reflected process consistency of the RSW. Electrode displacement curve after wavelet analysis provided good data groundwork for servo-gun RSW quality control.