Vibration suppression control for electrical discharge machine by using relative displacement and velocity feed back

In order to suppress the instability in a fully-closed-loop of the positioning servo, we proposed a new controller which feeds back the relative displacement and the relative velocity from the motor to the positioning table. A stability condition is investigated in the 2-DOF model that is the basis of the fully-closed-loop system, and the precise effect of the controller is examined in a 4-DOF model of an actual electrical discharge machine. Operation of an actual machining test clarifies the effectiveness of the proposed controller.