Development of programmable system on chip-based weld monitoring system for quality analysis of arc welding process

Abstract

Arc welding uses power sources of the constant current type having drooping characteristics or constant voltage characteristics. However, in reality, arc welding is a stochastic process due to random arc behaviour and metal transfer. The quality of a weld depends on the extent of these variations. The random signal amplitudes and time characteristics of the weldingsignal (voltage and current) allow a quality analysis of the welding process and disturbances. These random variations in current and voltage cannot be recorded with ordinary instruments. In the present work, a Programmable System on Chip based embedded Weld Monitoring System (WMS) with suitable software package was designed and developed to measure all the dynamic variations of welding voltage and current. Welding data were acquired using this WMS for the duration of 20 seconds at a sampling rate of 100,000 samples/s. The data obtained were filtered and subjected to the time domain and statistical analyses to evaluate various arc-welding parameters. The results obtained with WMS indicated that the same can be used for evaluating the welding consumables and assessing the skill of the welders. Thus, this work proposes a standalone, affordable, and an innovative tool for comprehensive on-line analysis of an arc-welding process.