A Novel Measurement and Qualification Method of GMAW Welding Fault Based on Digital Signals

Abstract

Online fault non-destructive detection is crucial to the fabrication of high quality products of welds. In this study, a novel method in the field of weld whose name is Mahalanobis Distance Measurement (MDM) is illustrated and employed to determine whether welding faults have occurred or not. This method is based on an arc method which is employed to get the information of welding voltage and welding current. Through analyzing the calculation results of Mahalanobis Distance of the welding voltage and current signals, the important information of welding process has been obtained. At the meanwhile, whether a fault has occurred or not is decided. In order to verify the effect of the performance of the different width of the gap on the results of Mahalanobis Distance, two widths of the gap generated artificially were chosen: one is 2 mm and the other is 3 mm. The results of the experiment have demonstrated that using the thinking of Mahalanobis Distance to measure the weld faults is feasible.