A Jump Motion Velocity Planning Algorithm with Continuous Jerk for Electrical Discharge Machining

Abstract

In electrical discharge machining (EDM), a periodic jump motion of the electrode is adopted to reduce the concentration of debris within the discharge gap, which is produced from the material erosion through a series of electrical discharge occurring between the electrode and workpiece immersed in a dielectric fluid. Velocity planning is an important part in the design of a jump motion. However, existing velocity planning algorithms, such as the S-shaped feedrate planning, do not address the discontinuities in jerks. With a possibility of invoking vibrations in a machine, discontinuities in jerks are harmful to a stable discharge status. In this paper, a velocity planning algorithm with continuous jerks for jump motion is proposed, which takes into considerations constraints on the maximum velocity, jump heights and jerks of the Z-axis of a machine. With a sine curve is adopted as a jerk curve, the velocity profile can obtained through integration. Simulation and experimental results show that this proposed velocity planning algorithm achieves a better performance with a smoother jump motion and the stability and reliability is verified through an EDM machining for a deep slot.