English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 78818/78818 (100%)
造訪人次 : 35008417      線上人數 : 1600
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋


    請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/63192


    題名: 智慧型診斷與希爾伯特黃變換於變轉速旋轉機械故障特徵分析與瞬時頻率之研究;Investigation of Intelligent Diagnostics and Hilbert-Huang Transform on Characteristic Instantaneous Frequencies of Faulted Rotary System under Variable Rotating Speed
    作者: 吳天堯
    貢獻者: 國立中央大學數據分析方法研究中心
    關鍵詞: 機械工程
    日期: 2012-12-01
    上傳時間: 2014-03-17 14:21:18 (UTC+8)
    出版者: 行政院國家科學委員會
    摘要: 研究期間:10108~10207;The objective of this research proposal is to extend the research of gear defects identification of the last NSC research project to other malfunction diagnosis in rotating machinery under variable rotation speed. Based on the preliminary results of the last NSC research project, the Hilbert-Huang Transform method combining the dimensionless instantaneous frequency normalization will be applied to diagnose the rotary malfunctions, such as bearing defects, shaft misalignment as well as component looseness. Through the proposed approach, the study will provide the detailed phenomenal explanation as well as the meaningful physical insight to the faulty vibration behaviors. Moreover, the collected fault features will be sifted for classification to achieve the intelligent fault detection and diagnosis of rotating machinery. Since the fault features of rotating machinery are governed by the shaft rotation speed, the vibration signals are highly non-stationary while the rotation speed is variable. Therefore, the characteristic frequencies of machine faults are not fixed. This makes the vibration analysis and fault diagnosis more difficult. To resolve this problem, the novel approach combining the dimensionless instantaneous frequency normalization and Hilbert-Huang Transform time-frequency analysis is proposed to examine the vibration signals of faulted machine in case of variable rotation speed. The non-stationary vibration signals become stationary through the dimensionless instantaneous frequency normalization. The factor of variable rotation speed will be also removed. The meaningful physical insight will be thus provided by the analysis results. A rotary test rig will be built in this research project. Different faults, such as defects in bearings, shaft misalignment and component looseness, are first artificially made in the experiment. The faults and malfunctions of rotating machinery will be simulated through experiment. With the faulted components in rotating machinery, the vibration signals are measured and analyzed in case of variable rotation speed. The fault features will be observed in Hilbert dimensionless frequency-time-energy distribution, marginal dimensionless frequency spectrum and dimensionless envelope spectrum. The degree of nonlinearity (DN) of the vibration signals will be calculated to quantify the levels of deterioration. The fault features and DN values will be collected in the fault diagnosis knowledge base of rotating machinery. The sifting process (principal component analysis, adaptive feature selection) is to select the significant fault features for classification. The classifiers (support vector machine, decision tree and artificial neural network) are utilized to identify the different fault types. Through the proposed approach, the intelligent fault detection and diagnosis of rotating machinery can be achieved, and hence it can provide the maintenance instructions for industrial applications.
    關聯: 財團法人國家實驗研究院科技政策研究與資訊中心
    顯示於類別:[數據分析方法研究中心 ] 研究計畫

    文件中的檔案:

    檔案 描述 大小格式瀏覽次數
    index.html0KbHTML879檢視/開啟


    在NCUIR中所有的資料項目都受到原著作權保護.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 隱私權政策聲明