Intelligent Arc Voltage Control

摘要

In gas tungsten arc welding (GTAW), traditional automatic voltage control (AVC) systems frequently exhibit unstable operation when ramping up and ramping down the welding current to obtain high quality crack-free weld starts and stops. Because there is a nonlinear relationship between the welding parameters (arc voltage, current, and arc length), it is difficult to model the system dynamics for all possible welding conditions. Therefore, an AVC that has a fixed voltage set point cannot adequately maintain the arc length if the arc current changes over a wide range. In this paper an intelligent arc voltage controller based on fuzzy and adaptive control methods is designed to maintain stability while the arc current is ramping up or down. The experimental results show that the controller designed can successfully stabilize the system operation and prevent damage to the workpiece during the critical upslope/downslope portions of the weld.