Friction Compensator for Feed Drive Systems Consisting of Bail Screw and Linear Ball Guide

摘要

Quadrant glitches are often observed on the circular trajectories of NC machine tools. In this study, a friction compensator that can compensate for the friction characteristics in a microscopic region is proposed. In the compensator, friction forces and torques are modeled using a simple mathematical model, and the estimated friction torque around the motor axis is added to the torque command. In order to evaluate the effectiveness of the proposed friction compensator, the compensator was applied to an actual feed drive system and its mathematical model. As the results of the experiments and simulations, it was confirmed that the proposed friction compensator can eliminate the quadrant glitches effectively, even if the radius and feed rate change.