Modeling of a linear motor feed drive including pre-rolling friction and aperiodic cogging and ripple

Abstract

This work addresses the systematic modeling of a linear feed drive based on a linear synchronous motor, a helpful step in control design for precise machine tools using linear motors. The model considers the electrical dynamics, ripple, cogging effects and friction. For ripple and cogging, periodic and aperiodic behavior is analyzed, and simple models are proposed to reflect the observed behavior. Friction is represented by the generalized Maxwell-slip model cite{Al-Bender2005}, and the particular manner in which pre-rolling parameters and Stribeck curve were determined for the current system is shown here for completeness. Finally, the model shows a good performance both in simulation and feedforward control.