Crack Identification and Trajectory Planning for Automatic Gas Metal Arc Welding

Abstract

Gas metal arc welding process has the capability of producing high quality, all position welding, and is easily adaptable for automated welding applications. Repair welding of random cracks on existing assembly/structure through automatic welding would need real time crack/gap identification and weld path generation. In this work, an image processing-based system is presented for identifying the crack geometry. Graphical user interfaces are also developed to take necessary user inputs required at different stages for crack identification, predicting weld bead dimension, and weld path generation. Based on the identified crack geometry and predicted weld bead feature, linear and curved weld path planning methodology is proposed. The proposed modules are validated for a case study by successfully generating the desired weld paths. Different natures of velocity profiles are considered to appraise the role on motion behaviour and a suitable profile is selected for reducing the jerks at sharp corners/via points on the weld path and maintaining uniform bead geometry.