Abstract
This paper describes the dynamic behavior of feed drive systems at quadrant changes in circular motion, and then discuss about the generation model of quadrant glitches, which are often seen on the circular trajectories of NC machine tools. In this paper, the velocity and acceleration of the axis under circular interpolation motion were precisely measured by means of linear scales and servo-accelerometers, respectively. The velocity and acceleration at quadrant changes are simulated by a dynamic model which has two degrees of freedom. In addition, a friction model is newly proposed by considering the non-linear characteristics of friction force. From the experimental and simulation results, it is found that the proposed model well expresses the dynamic behavior of the axes, and that any axis does not stay at zero velocity when the motion direction changes. The Influence of the inertia of the feed drive mechanisms on quadrant glitches is also discussed through simulation results.
