WEDM Identification and Adaptive Control for Variable-Height Components

Wire rupture in wire EDM is caused by high temperature due to high power density determined by discharge frequency and workpiece height. This paper reports a new WEDM adaptive control system that monitors and controls the spark frequency according to the on-line identified workpiece height. The workpiece height is estimated by using a non-linear discrete model relating cutting speed with spark frequency. This system controls the spark frequency at optimal levels to avoid wire rupture and to maintain the maximum productivity. The error of the workpiece height identification is 1 mm and the response to changes in workpiece height is 1 second.