Calibrating measured milling force during long-duration monitoring

Abstract

Piezoelectric force sensor is used to measure cutting force in most milling process to get important manufacturing information. However, the measured milling force may be not accurate due to the charge leak in piezoelectric sensor during long-duration monitoring, which will cause a zero-drift problem in measuring milling force. Measuring milling force with zero-drift problem, the measured average cutting force should be calibrated in order to get correct force information. In this study, the measured first harmonic force components are used to calibrate average cutting force components based on cutting force model. There are two steps in this method for calibrating average force components. The first step uses the measured first harmonic force components to extract the specific cutting constants from the ratio of the measured first harmonic force components in X and Y directions, and the second step utilizes the identified cutting constants to calibrate the average force components. The limitations of presented method are also discussed in this paper. The validity of the proposed method is confirmed through milling experiments.