Development of a Prototype 3D Measuring and Judging System to Improve the Accuracy of Visual Inspection of Weld Bead Appearance and to Digitise Inspection Results for Welder Qualification Tests

Abstract

This study is concerned with the development of a system for automatically carrying out visual inspections of the external appearance of welders in the welder's skills certification examination, without requiring extensive experience in visual inspections, and presents the results of the development of a prototype of such a system. The developed system handles the weld bead shape measured with a 3D scanner as point data in 3D space, and matches it with the evaluation criteria for the welder qualification test, such as bead width, reinforcement of weld height and undercut depth, to enable a pass/fail decision to be made immediately after the test is taken. In addition, the joint geometry can be stored as high-precision point cloud digital data, allowing another visual inspection to be carried out even after the specimen has been processed for bending tests after visual inspection