Measurement of Oscillations in Partially Penetrated Weld Pools Through Spectral Analysis

Abstract

Sensors of the weld in progress are necessary to provide feedback control of the arc welding process. Signal processing of the arc voltage and current is proposed as a dynamic sensor of the welding process. Optimization of sampling parameters and excitation waveform were performed. The sensitivity of this technique to arc length and weld pool oscillation amplitude was determined. Weld pool oscillation frequencies were measured in stationary welds and correlated with weld pool size. Signal processing was shown to serve as a weld pool oscillation monitor for stationary welds on steel with helium shielding gas at arc lengths of up to 13 mm.