Adaptive Control for EDM with Minimum-variance and Pole-placement Approach

In order to improve the performance of EDM, the most important issue is to develop a highly stable control system. This paper develops an adaptive control system to directly control the discharging time of EDM. A minimum-variance and pole-placement coupled strategy is used in the control strategy, based on real-time estimation of EDM process parameters. Experiments demonstrate that the control system can timely adjust the discharging time according to the gap states to maintain a stable and fast fabrication. It achieves a much deeper processing depth as well as improving the efficiency and stability compared to traditional machining. The adaptive system has actually obtained a long-playing and stable control effect.