Adaptive control of temperature in arc welding

The quality of a weld joint is strongly influenced by both the spatial distribution and temporal history of material temperature during the welding process. In order to obtain high quality welds, despite disturbances which would otherwise alter welding temperatures, we have successfully designed a temperature control system for consumable-electrode gas metal-arc welding. This paper describes the development of an inexpensive optical system for measuring weld temperatures and a pseudogradient adaptive algorithm for self-tuning a proportional-integral (PI) bead temperature controller. The performance of the closed-system is illustrated with experimental data