The spot wellding process is subjected to many processing parameter variation, which affect the weld quality seriously. In order to compensate the weld quality deteriation due to process parameter variation, many attempts have been made to introduce process monitering and feed back control. But good performance was not revealed various welding conditions by using a conventional feed back control algorithms. This study represents a fuzzy logic control system that utilizes the electrode movement as a monitering parameter. The performance of the fuzzy logic control system was compared with that of the PI control system through real time compensation of shunt effect and nominal heat input variation. In order to find more good performance fuzzy logic control system, self-organizing fuzzy logic control of the spot welding process was also developed. The resukts show that the fuzzy logic control system has more improved performance than conventional PI control system and self-organizing fuzzy logic controller revise welding condition properly which is not suitable for high performance welding. Finally, self-organizing logic control show that the potential that could be applied to highly non-linear and complex control variable system.
