Implementation of a two-stage algorithm for NG-GMAW seam tracking and oscillation width adaptation in pipeline welding

Abstract

Seam tracking and oscillation width adaptation could effectively reduce the sidewall fusion defects in automatic narrow-gap gas metal arc welding (NG-GMAW). This study proposes a twostage algorithm to realise seam tracking and oscillation width adaptation in NG-GMAW pipeline welding. The first stage involves using the principal component analysis (PCA) eigenvectors to adjust the oscillating centre, enabling seam tracking and oscillation width adaptation for the hot and fill layer. In the second stage, dataset was prepared based on the tracking data from the first stage, which can guide the welding torch trajectory for the cap layer. Experimental results show that the proposed scheme achieves seam tracking and oscillation width adaptation with an accuracy of 0.1 mm.

A Real-Time Monitoring Method for Droplet Transfer Frequency in Wire-Filled GTAW Based on Arc Sensing

“…Instead, with simple construction and no need for expensive equipment, arc sensors are economical [ 26 , 27 ]. During GTAW, the arc voltage value corresponds to the arc length unaffected by other complex disturbances, like arc light, spatter, and fog, so that the change rule of the arc length can be reflected by that of the arc voltage value with great performance stability and in real time [ 28 ].…”