Fuzzy control of wire feeder in pulse welding system

The paper presents a new method for the pulse welding, by which the arc welding power supply voltage is kept stable while the feeding speed is set to vary like a pulse, namely, to make the speedy feeding and low-speed feeding alternate. In the feeder, the couple closed-loop fuzzy control system is adopted for the wire-feeding speed control. In the inner closed-loop of the system, the adjustment is achieved with the motor current as the feedback signal while in the outer closed-loop the adjustment is achieved mainly by the actual speed of wire feeder as the feedback signal. The adjustment on rotating speed and the current relies on the fuzzy controller. Proven by the experiments, the feeder of such a kind is swift in system responding and when needed, the motor speed can be excellently steady. If the set signal is a pulse, the peak current and the base current alternate in the actual welding cases.