ARC WELDING PROCESS SIGNATURE VISUALIZATION AND ANALYSIS

摘要

Arc voltage-current population (histogram) density two dimensional color plots are generated for various arc welding processes, including CV spray, CV short-circuiting, pulsed MIG, AC submerged arc, tubular electrodes, Surface Tension Transfer~(~R) (STT~(~R)), and stick electrode in pipe welding. Actual voltage and current signals are recorded at a sufficiently high sampling rate (50 KHz or higher). Each voltage-current data pair, or data in combination with its first order derivates (e.g. dv/dt, di/dt) is digitized to a pixel location on a raster image area. The occurrences of data pairs at each location are accumulated for a fixed weld time. Color models (e.g. RGB) are used to represent the histogram depth, based on normalized density, from "warm to cold", as a signature of each welding process. Attractors in the short region and the arc region are identified, and the transition between regions, such as between short and arc, is animated and analyzed statistically. Applications such as welding process stability and welding procedure optimization, derived from digital image processing techniques, are illustrated.