Brightness-Based Selection and Edge Detection-Based Enhancement Separation Algorithm for Low-Resolution Metal Transfer Images

Next-generation gas metal arc welding (GMAW) machines require the rapid metal transfer process be accurately monitored using a high-speed vision system and be feedback controlled. However, the necessity for high frame rate reduces the resolution achievable and bright welding arc makes it difficult to clearly image the metal transfer process. Processing of images for real-time monitoring of metal transfer process is thus challenging. To address this challenge, the authors analyzed the characteristics of metal transfer images in a novel modification of GMAW, referred to as double-electrode GMAW, and proposed an algorithm consisting of a system of effective steps to extract the needed droplet feedback information from high frame rate low-resolution metal transfer images. Experimental results verified the effectiveness of the proposed algorithm in automatically locating the droplet and computing the droplet size with an adequate accuracy.