自動回歸 移動平均 모델에 의한 엔드밀 切削力의 모드分析

Abstract

A Mode Analysis of End-milling Force using ARMA Model

Jong-Do Kim

Department of Mechatronics Engineering, The Graduate School, Pukyong National University

ABSTRACT

At first in this study, a mode analysis of uncoupled and coupled system was discussed using frequency response function(FRF). The eigen-mode range of FRF analysis is consistent with conventional FFT in spectrum. Also, the numerical responses of displacement, velocity and acceleration for second order uncoupled and coupled system were obtained using the Runge-Kutta-Gill method and each response was used for the calculation of FRF for two systems. Using the separated and mixed response of first and second mode in example, its FRF was analysed for the prediction of the two systems and its mode shape was calculated by solving the eigen problem. Also analytical realization of two systems were introduced using recursive parametric modeling analysis. In this study, two new recursive approaches (RLSM, REIVM) were adopted for the on-line system identification and monitoring of a two systems. In this regard, a comparative assessment of two recursive time series modeling algorithms was discussed. Secondly in this study, an analytical realization of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive modeling algorithm (RLSM, REIVM) and the natural mode for real part and imaginary one was discussed. This recursive approach (RLSM, REIVM) can be adopted for the on-line system identification and monitoring of an end-milling for this purpose. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF and mode analysis. Also the FRF was analysed for the prediction of a end-milling system using recursive algorithm. As results, these algorithms were successful in each condition for the detection of natural modes of end-milling. After numerical analysis of the FRF, the tooth passing frequency was discriminated in these FRFs, power spectrum and mathematical mode calculation.