基于小波變換的故障診斷信號(hào)非平穩(wěn)性分析

從工程角度,解釋小波變換的實(shí)際含義,并將其與傳統(tǒng)的傅里葉變換分析方法作比較,通過(guò)比較兩種基函數(shù)的時(shí)頻窗,顯示小波變換在時(shí)域和頻域都具有局部化特性,并且運(yùn)用可調(diào)的柔性窗可對(duì)高頻、低頻信號(hào)分別采取不同的尺度進(jìn)行分析,特別適合于分析奇異性強(qiáng)的機(jī)械故障診斷信號(hào)。以旋轉(zhuǎn)機(jī)械軸振動(dòng)信號(hào)為仿真分析對(duì)象,以Daubieches5階小波作為基小波,介紹了小波變換在故障診斷的信號(hào)非平穩(wěn)性分析中的應(yīng)用,并給出了奇異點(diǎn)檢測(cè)和瞬態(tài)過(guò)程檢測(cè)的仿真示例,體現(xiàn)了小波變換在故障診斷領(lǐng)域?qū)Ψ瞧椒€(wěn)信號(hào)的時(shí)域局部細(xì)節(jié)的刻劃能力。

Fromengineeringpointofview,practicalsignificationofwavelettransformationisexplainedand
comparedwithtraditionalFouriertransformation.Comparisonofthetime frequencywindowoftwofunctionindicatedcharacteriticofthetime-
frequencylocationandthemultiple-scaleanalyzationofthewavetransformation.
Baseonthat,theapplicationofwavelettransformationinfaultdiagnosistoanalysenonstationarityofrollerbearingvibrationsignalswithDaubiecheswave
etisintroduced.Andsimulationdemonstrationofsingular
pointsinspectionandtransientinspectionispresented.Theresultsshowthatwavelettransformationcandepict
locationdetailintimedomainofnonstationarysignal