Design Method for High-gain Control of Linear Motor Feed Drive Systems Using Virtual Linear Friction

This paper describes a method for stabilizing feed drive systems by introducing virtual friction characteristics having higher vibration damping with a friction compensator. The validity of the proposed friction compensator is verified by experiments using a one-axis feed drive system consisting of a rod type linear motor and linear roller guides. In addition, this paper proposes a control design method to determine the servo gains and the virtual friction parameters that lead to overshoot-free responses. It is confirmed that the step response curves under the servo gains and the virtual friction parameters determined by the proposed method have no overshoots and amplitude dependence due to the nonlinear friction characteristics.