| Summary: | 碩士 === 中原大學 === 機械工程研究所 === 93 === 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.
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