| Abstract Scope |
Gas metal arc welding is considered the benchmark process for efficiently and economically depositing metals onto substrates by melting automatically fed wire through an arc. However, it falls short of being ideal, as the heat imposed on the substrate is coupled with the mass (heat to melt the wire). Unnecessary, involuntary extra heat is imposed on the substrate as an adverse side effect of melting wire, leading to additional heat input, degradation of material properties, distortion, residual stress, and other issues that are especially critical for sheet metal welding and wire arc additive manufacturing (WAAM). The Double-Electrode Gas Metal Arc Welding (DE-GMAW), pioneered at the University of Kentucky, addresses this challenge by decoupling heat and mass through bypassing the cathode heat that would otherwise be imposed on the substrate. Effective bypassing necessitates a proper positioning of the bypass electrode relative to the melting wire—a position initially fixed based on welding conditions. However, this pre-fixed position changes dynamically with welding conditions that are subject to variations during manufacturing. To address this challenge, this paper introduces the robotization of DE-GMAW, investigates bypassing modes, identifies the desired mode, monitors the modes, proposes quantitative feedback, and learns from human welders. The robotized system is then employed to adaptively control DE-GMAW, ensuring continuous and effective bypassing. |