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

Accurate calibration of the milling force coefficients is essential for predicting the 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. This paper proposes an optimized method based on the average force method to calibrate milling force coefficients and cutter run-out parameters in the end milling process. The entire calibration procedure is divided into three steps. First, the milling force coefficients are initially calibrated through the utilization of the average force method. 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 force 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. In comparison to the experimentally measured average milling forces and instantaneous milling force curves, the proposed method exhibits significantly smaller mean force error ratios than those of the average force method, while demonstrating improved agreement with the simulated milling force curves.