Enhancement of Feed Drive Dynamics of NC Machine Tools by Actively Controlled Sliding Guideway

Abstract

In this paper, we propose a simple sliding guideway with a hydraulically operated brake unit, which can control sliding friction force on a feed drive system. The sliding friction force is controlled by the brake force command generated from velocity information of a table and/or a servomotor. The damping control laws of DVFB (Direct velocity feedback) and RVFB (Relative velocity feedback) are analyzed to provide the adequate damping for ballscrew drives. These damping control laws are implemented in the brake force control unit and the dynamic performance of a ballscrew drive is measured. Structural vibration of the ballscrew drive can be successfully controlled by this actively controlled sliding guideway in experiments.