Modeling and adaptive control of EDM systems

Abstract

This paper theoretically and experimentally analyzes an existing electrical discharge machine (EDM) servo mechanism and describes modeling of the EDM process. A new EDM servo controller, the self-tuning regulator with P1 control, has been proposed. In this control system, a high-speed computer directly regulates the servo feed rate instead of servo reference voltage, according to the stochastic characteristics of the process. The time ratios of gap states detected and measured by an EDM gap monitor are used as the feedback signal. The algorithm of this control strategy is simpler and has better control performance than many other available EDM servo adaptive control systems. Extensive experiments show that the productivity achieved by this control system is 17% higher than the model reference adaptive controller and 10% higher than the self-tuning regulator, developed earlier by the authors, and almost 25–35% higher than the existing control system on the machine.