Digital Gap Monitor and Adaptive Integral Control for Auto-Jumping in EDM

Abstract

This paper reports a monitoring and adaptive integral control strategy for EDM to regulate the cycle time of the periodical retraction (jumping) of the tool electrode according to the gap condition. A digital EDM gap monitor has been developed to detect the time ratios of gap states with a resolution of 0.2 μs. The theoretical and experimental analysis of the effect of sensing parameter combinations on control aspects and performance of manual setting, integral control and adaptive integral control methods have been carried out. Experimental verification shows that the proposed system results in higher erosion rate, better machining stability, and complete avoidance of arc damage.