The welding process itself is a non-linear, multivariable, coupled physical metallurgical process that is easily perturbed. Improper welding parameter selection and welding process conditions will interfere with the welding process and affect the final welding quality. This study aims to identify and locate two types of welding interference, insufficient shielding gas and unremoved oxidation film on the base metal surface, during the Pulse Multi-Control Gas Metal Arc Welding (PMC GMAW) process of aluminum alloy. The Characteristic Intrinsic Mode Function (IMF), which is closely related to the short circuit transition process, was obtained by applying the Complementary Ensemble Empirical Mode Decomposition (CEEMD) method to the welding current signal measured during the welding process. Time and frequency domain analysis of the acquired characteristic IMF was then performed. The experimental results demonstrated that for a stable welding process, the frequency of the characteristic IMF is concentrated within a narrow range. The frequency spectrum of the characteristic IMF exhibits distinct variations under different types of welding interference. Based on this, the chronological arrangement of characteristic IMF components’ frequency spectrum allows for locating welding interferences by analyzing their abnormal signals within the reconstructed signal sequence.
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