Feasibility Study of a Hybrid Spindle System with Ball and Active Magnetic Bearings for Quadrant Glitch Compensation During End Milling

Abstract

Quadrant glitches are caused by friction and motion loss on the feed axis of machine tools. A previously developed method of compensating for quadrant glitches using the feed axis in which the friction model and time series data are not consistent with the actual friction behavior has some problems, making it difficult to construct a feedback system with a high response problems such as a feed axis with a large lost motion. The ultimate goal of this study is to develop an innovative method of compensating for the quadrant glitches caused by the motion of the feed axis of the machine tool using a newly proposed hybrid spindle system with an active magnetic bearing at the end near the end mill and a ball bearing at the other end in combination with a proportional-integral-derivative controller. This study aims to verify the effectiveness of the proposed quadrant glitch compensation method through experiments on the motion of the end mill using a model experimental device for the hybrid spindle system. Through experiments, a quadrant glitch with a peak of 7 μm without compensation is decreased to 1 μm by applying the proposed method using the hybrid spindle system. The undercut error is also decreased by applying the proposed method.