An optimized method for calibration milling force coefficients and cutter run-out parameters in end milling process

Abstract

Abstract Accurate calibration milling force coefficients is essential for predicting milling forces and characterizing the milling state. Cutter run-out is an unavoidable phenomenon in end milling process, which affects the working state of the cutter and the machining accuracy of the work-piece. In this paper, an optimized method based on average force method is proposed to calibrate milling force coefficients and cutter run-out parameters in the end milling process. The whole calibration procedure is divided into three steps. Firstly, the average force method is used to preliminarily calibrate the milling force coefficients. Then, further optimization is carried out based on the coefficients calibrated by the average force method, average milling force equations are used and a calibration procedure is presented by defining an objective function which is utilized to limit the average forces error ratios between the calculated results and the measured results. Finally, the milling force coefficients obtained in the second step are used to calibrate the cutter run-out parameters, the instantaneous milling force equations are used and a calibration procedure is also presented by defining a new objective function with the minimum sum of squared errors between the instantaneous prediction results and the instantaneous measurement results. Compared with the average milling forces and the instantaneous milling force curves measured by experiments, the mean force error ratios of the presented method are much smaller than the average force method and the milling force curves simulated by the proposed method are more consistent.