Electrical discharge machining (EDM) is not limited to the strength and hardness of conductive materials, and is a non-contact special processing technology. In micro-EDM, there are problems such as untimely axial positioning, unstable inter-electrode machining voltage, and difficulty in discharging inter-electrode electric erosion products. This paper considers a magnetic actuator with fast response and high accuracy as the local actuator for a micro-EDM. By introducing a domain adjustment mechanism, a variable domain fuzzy PID controller was designed to control the inter-electrode voltage control system of the magnetic actuator for micro-EDM using an intelligent control strategy. During the micro-EDM machining process, the controlled magnetic actuator drives the tool electrode in the axial direction for rapid micro-positioning, thus maintaining effective inter-electrode machining voltage and achieving a high-speed and high precision EDM. Simulation and experimental results showed that compared with traditional micro-EDM, the machining efficiency of the variable domain fuzzy PID control magnetic actuator, and traditional micro-EDM cooperative control, was increased by 40%, the machining process was more stable, and the quality of the machined surface was better.

In this paper, a kind of electromagnetic actuator is developed which can solve the problem of in time controlling inter-electrode gap in traditional EDM. An incoming current in the coil of an electromagnetic actuator generates Lorentz forces that cause the electrode to move axially. When the electromagnetic actuator is working, electrode is actuated positioned quickly, and electrode is produced a displacement of plus or minus 1 mm by control. The experiment shows that the response time of the electromagnetic actuator can meet the machining requirements. The discharge probability is increased and the machining efficiency is improved.

Aiming at the efficiency and precision in micro electrical discharge machining (micro-EDM) is affected because the interpole voltage is unstable in conventional micro-EDM. This paper describes a five-degrees-of-freedom (5-DOF) controlled, wide-bandwidth, and high-precision magnetic levitation actuator. The conventional micro-EDM can install the actuator to maintain a stable interpole voltage between the electrode and workpiece to realize the high-speed micro-EDM. In this paper, the structure of the magnetic levitation actuator is designed, and the magnetic field characteristics are analyzed. On this basis, an integrator and regulator are used along with a controller with local current feedback to eliminate steady-state errors, stabilize the control system, and improve the bandwidth and positioning accuracy of the magnetic levitation actuator, and the dynamic performance of the actuator is evaluated. The experimental results show that the developed actuator has excellent positioning performance with micron-level positioning accuracy to meet the demand for the real-time, rapid, and accurate adjustment of the interpole gap during micro-EDM.

The efficiency and accuracy of conventional electrical discharge machining (EDM) is limited by the stability of the voltage between the poles. To improve the efficiency of EDM, this paper proposes a machining method that combines a self-developed 5-degree-of-freedom (5-DOF) controllable magnetic levitation actuator with a conventional EDM machine tool. The stability of the inter-pole voltage is improved by the actuator micro-adjustment the electrodes of the EDM machine tool. Firstly, an EDM control system with local current feedback and decoupling control elements is designed based on the EDM servo drive principle to improve the response speed and positioning accuracy of the actuator. Secondly, the actuator was connected to the spindle of a conventional EDM machine tool, and machining experiments were carried out. The experimental results showed that the EDM machine tool connected to the actuator could control the electrode position more quickly, adjust the discharge state quickly, and increase the number of discharges per unit time. The average machining speed increased from 1.108µm/s to 3.925µm/s, which is 3.54 times faster than conventional EDM. Finally, complex shape machining experiments were carried out and the machining results showed that by adjusting the target value of the radial direction of the actuator, the various trajectories of the electrode could be controlled to depict arbitrary shapes.

The e ciency and accuracy of conventional electrical discharge machining (EDM) is limited by the stability of the voltage between the poles. To improve the e ciency of EDM, this paper proposes a machining method that combines a self-developed 5-degree-of-freedom (5-DOF) controllable magnetic levitation actuator with a conventional EDM machine tool. The stability of the inter-pole voltage is improved by the actuator micro-adjustment the electrodes of the EDM machine tool. Firstly, an EDM control system with local current feedback and decoupling control elements is designed based on the EDM servo drive principle to improve the response speed and positioning accuracy of the actuator. Secondly, the actuator was connected to the spindle of a conventional EDM machine tool, and machining experiments were carried out. The experimental results showed that the EDM machine tool connected to the actuator could control the electrode position more quickly, adjust the discharge state quickly, and increase the number of discharges per unit time. The average machining speed increased from 1.108µm/s to 3.925µm/s, which is 3.54 times faster than conventional EDM. Finally, complex shape machining experiments were carried out and the machining results showed that by adjusting the target value of the radial direction of the actuator, the various trajectories of the electrode could be controlled to depict arbitrary shapes.