PURPOSE: To provide constantly excellent welding results even by a non-skilled person by executing the fuzzy inference in accordance with the preset control rules to determine the manipulated variable to set the output voltage.
CONSTITUTION: A wire 6 is fed to a part to be welded of the base metal 8 by a feeding equipment 7. The feeding speed of the wire 6 is set by a welding current setting device 9. The mean value and the standard deviation during the arc period to be measured during the welding are calculated. The manipulated variable of the output voltage to obtain the prescribed arc condition is inferred by a fuzzy controller 22 in accordance with the preset control rules by making the calculated results of computing elements 20, 21 as the input. Increase/decrease of the set value of the output voltage of the power source for welding is executed by a setting device 23 according to the output of the fuzzy controller 22. This constitution automatically changes the output voltage to an appropriate value even when the initial output voltage is set to any value.
TAGAMI HIROSHI
KASHIMA TAKAYUKI
