Control of Welding Processes.

Automatic welding processes are being used more and more in manufacturing, and this has led to an increased requirement for close control of the process. The objectives of welding control and the problems involved with such control are addressed. Because welding is such a complicated process, control strategies are needed to close the gap between what is desired by industry and what is practiced. Some of the variables in the process include the base material, joint preparation, controllability of the automated system, consistency of consumables, and welding environment. The importance of understanding the basic processes--arc physics, heat and fluid flow, solidification, and process disturbances, etc,--is emphasized. The state of the art in welding process modeling and the feasibility and need for adaptive control are described. At present, empirically derived models for some processes have and verified, systems based on fully integrated computer-aided design and manufacturing and adaptive controls can be achieved. Such a welding process simulation could permit the design engineer to know in advance the interaction of weldment preparation, fixture design, distortion, and mechanical properties and thus do a much better job of optimizing the entire process. Keywords Sensors, Joining, Process modeling.