切削異常之線上診斷及控制系統之研究

The Study of On-line Diagnosis and Control System for Abnormal Cutting

陳定國(Ding-Guo Chen)

指導教授 ： 王世明

中原大學/工學院/機械工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500670

摘要

近年來金屬加工技術不斷提升，在高速化生產及精密加工要求下，發揮高速銑削必須避免刀具的刃口積屑（build-up edge）與顫振（chatter）發生等異常振動之不利因素。本研究所研發之系統主要分成五部份：訊號擷取系統、線上監控系統、刃口積屑診斷系統、提升切削效率系統、顫振預測與抑制系統。訊號擷取系統是利用LabVIEW程式語言撰寫訊號擷取程式並搭配NI公司之DAQ卡、動態訊號擷取盒SC-2345、位移計蒐集切削之振動位移訊號。線上監控系統對於切削動態訊號做即時運算與判斷；刃口積屑診斷系統則判斷異常振動訊號來診斷是否發生刃口積屑；提升切削效率系統主要是根據順滑函數來決定是否提高進給速率；顫振預測系統則是對振動位移取小波轉換後的平均細節係數、佐以頻譜分析高頻率振動與計算振動位移量的增減趨勢來即時預測是否即將發生顫振；顫振抑制系統則是以改變主軸轉速方式產生不同相位之振動波紋以消耗刀具中所累積之能量，來達到穩定切削系統的目的。研究最後也整合了各子系統，建立一操作方便的智慧型系統來偵測異常振動與提高切削效率，並進行了實機切削系統驗證。

關鍵字

表面粗糙度 ； 銑削 ； 顫振預測 ； 小波轉換 ； 順滑層 ； 顫振抑制 ； 刃口積屑

並列摘要

Machining technology has been continuously improved in recent years. In order to bring high-speed milling into fully play, it must avoid unfavorable factors during machining process, such as build-up edge and chatter vibration. In this study, an integrating system composed of five sub-systems: signal collecting system, signal on-line monitoring system, build-up edge detection system, improvement machining efficiency system, chatter suppression and prediction system, was developed. Signal collecting system was developed with LabView software to on-line collect the vibration displacement. The on-line monitoring system converts collected dynamic signals and computes the associated characteristic values for diagnosis. With Fast Fourier Analysis, the system can detect build-up edge phenomenon according to the characteristics of vibration displacement and frequency. By adopting sliding mode control theory, a hyper plane was built to make the decision to online improve the machining efficiency by which both of the feedrate and spindle speed may be increased. In addition, by implementing Wavelet transform and Fast Fourier Analysis a chatter suppression and prediction system was built to monitor and predict the occurrence of chatter during machining process. As the occurrence of chatter is predicted, spindle speed will be changed and chip load of the cutter be also reduced to stabilize the cutting dynamics. The system automatically generates input signal for spindle speed change with SC-2345 dynamic signal processing card. Finally several cutting experiments were conducted to verify the effectiveness and feasibility of the developed system. The experimental results have shown that the system can effectively predict and suppress the chatter and improve the machining efficiency.

並列關鍵字

Milling ； Surface roughness ； Sliding layer ； Chatter prediction ； Build-up edge ； Wavelet transform ； Chatter suppression

參考文獻

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[15] 謝祥永，“切削顫振之順滑模式及遠端監控之研究”，私立中原大學機械工程研究所碩士論文，2004

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