WEDM-adaptive control with a multiple input model for indentification of workpiece height

The variation in power density during wire electrical discharge machining (WEDM) results in reduced productivity and wire rupture. This paper presents a WEDM adaptive control system that optimizes on-line the sparking frequency by estimating the workpiece height with a new multiple input model. This model describes the dynamic and stochastic relationships between average gap feedback voltage and spark frequency and machine table feed rate. Extensive experiments have been carried out to verify the new model. The proposed system correctly identifies the workpiece height and avoids the sudden rise in the estimated height found in existing system.