小波轉換於轉子故障偵測之應用

The Application of Wavelet Transform on Diagonosis of Rotor Failure

王世明(Shih-Ming Wang) ； 羅明哲(Ming-Je Luo)

《中原學報》 29卷3期 (2001/09) Pp. 231-240

https://doi.org/10.6358/JCYU.200109.0231

摘要

具有轉子的精密機械，如渦輪機、電動機等，轉子一旦故障，將造成嚴重的經濟損失或安全顧慮。因此，有必要進行對轉子的監測和故障診斷。本研究中所發展的監測系統乃以位移計和加速規配合Hp3566，蒐集轉子的運轉振動訊號，經由Daubechies小波轉換後，再萃取特徵値：最大値、均方根値、平均値、峰値比（最大値與均方根値之比）；或傅利葉轉換後，再萃取特徵值：PSD(Power spectral density)之最大値、特徵頻率（最大峰値所在之頻率）作為轉子故障診斷之依據。小波轉換本質上是時域分析工具且具有區域性，可察覺微小的動態異常訊號；傅利葉轉換本質上是頻域分析工具且具有全域性，可觀察整體的穩態頻率變化。兩者彼此互補，提供了符合分析故障訊號之重要功能。
故障診斷方法主要是經由實驗收集主軸運轉正常訊號及三種含有故障之訊號（具異常外力衝擊，摩擦力，轉子不平衡），經訊號處理後，找出各訊號之特徵値，作為故障判斷之參考點。由於各故障參考點具分佈特性，當進行診斷時，偵錯系統針對所偵測之訊號進行處理，並以其特徵値之落點，判斷可能發生故障種類的機率。

關鍵字

小波轉換 ； 傅利葉轉換 ； 診斷

並列摘要

In order to avoid the loss or damage caused by the failure of the rotor system of power generator, it is necessary to have a efficient and reliable diagnosis system that can on-line detect the occurrence of failures. The methodology of diagnosis system development proposed in this study, is to process and analysis the vibration signals of the rotating rotor measured by capacitance probes and accelerometers.
The diagnosis method is developed for detecting three major failure causes: abnormal friction, imbalance of rotor, and external impact force. The diagnosis algorithem is first collecting the normal signal and failure signals, and converting the signal through wavelet transform and Fast Fourier Transform (FFT). Because the converted failure signals exhibit different characteristic value (ratio of peak value to root mean square value of signal), a distribution of these characteristic values is used as a diagnosis reference. When a diagnosis is executing, the characteristic value of the amplitude of converted failure signal is contrasted with the diagnosis reference. The possibility of occurrence for failure mode will, then, be calculated through the diagnosis system.

並列關鍵字

Wavelet transform ； Fourier transform ； diagnosis