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.

Measurement and estimation of the weld bead geometry in arc welding processes: the last 50 years of development

“…Among the methods proposed in the available literature [4][5][6], vision sensing is one of the promising solutions. The use of video cameras to measure the weld bead width and reinforcement is possible, as shown in [7][8][9][10][11]. These methods need optimal light conditions and are difficult to applicate in the industrial environment.…”

Computer Vision System for Welding Inspection of Liquefied Petroleum Gas Pressure Vessels Based on Combined Digital Image Processing and Deep Learning Techniques

“…Pinto-Lopera et al [ 17 ] proposed a system for measuring weld bead geometry by using a single high-speed camera and a long-pass optical filter. Soares et al [ 18 ] introduced a method for weld bead edge identification that allowed them to recognize discontinuities.…”

Real-Time Weld Quality Prediction Using a Laser Vision Sensor in a Lap Fillet Joint during Gas Metal Arc Welding

“…Visual systems are highly related to the automation of the welding processes, and vision-based monitoring systems have been mainly used and developed for tracking weld seam and inspecting weld quality [11][12][13]. For weld seam tracking, Zou et al [14,15] designed a laser vision seam tracking system that can determine weld feature points and obtain the three-dimensional (3D) coordinate values of these points in real-time based on the morphological image processing method and continuous convolution operator tracker (CCOT) object tracking algorithm.…”