title: Real-Time Measurement of Width and Height of Weld Beads in GMAW Processes.
abstract: Associated to the weld quality, the weld bead geometry is one of the most important parameters in welding processes. It is a significant requirement in a welding project, especially in automatic welding systems where a specific width, height, or penetration of weld bead is needed. This paper presents a novel technique for real-time measuring of the width and height of weld beads in gas metal arc welding (GMAW) using a single high-speed camera and a long-pass optical filter in a passive vision system. The measuring method is based on digital image processing techniques and the image calibration process is based on projective transformations. The measurement process takes less than 3 milliseconds per image, which allows a transfer rate of more than 300 frames per second. The proposed methodology can be used in any metal transfer mode of a gas metal arc welding process and does not have occlusion problems. The responses of the measurement system, presented here, are in a good agreement with off-line data collected by a common laser-based 3D scanner. Each measurement is compare using a statistical Welch's t-test of the null hypothesis, which, in any case, does not exceed the threshold of significance level α = 0.01, validating the results and the performance of the proposed vision system.
authors.affiliation: Universidad Católica de Manizales, Facultad de Ingeniería y Arquitectura, Unidad Académica de Ciencias Naturales y Matemáticas, Manizales 170001, Colombia. jpinto@ucm.edu.co.
authors.forename: Jesús Emilio
authors.initials: JE
authors.lastname: Pinto-Lopera
authors.affiliation: Automation and Control Group in Manufacturing Processes-GRACO, Department of Mechanical Engineering, University of Brasilia, Brasilia DF 7191090, Brazil. jmmotta@unb.br.
authors.forename: José Mauricio
authors.initials: JM
authors.lastname: S T Motta
authors.affiliation: Automation and Control Group in Manufacturing Processes-GRACO, Department of Mechanical Engineering, University of Brasilia, Brasilia DF 7191090, Brazil. sadek@unb.br.
authors.forename: Sadek Crisostomo
authors.initials: SC
authors.lastname: Absi Alfaro
keywords: digital images processing; monitoring of GMAW process; passive vision; real-Time; weld bead geometry