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时间:2020-04-24
《基于EMD与Hilbert变换的舰艇空化调制信号检测方法-论文.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第26卷第3期海军工程大学学报V01.26NO.32014年6月JOURNALOFNAVALUNIVERSITYOFENGINEERINGJun.2014DOI:10.7495/j.issn.1009—3486.2014.03.002基于EMD与Hilbert变换的舰艇空化调制信号检测方法任安民,何琳,苏永生,毛荣富(1.海军工程大学船舶振动噪声重点实验室,武汉430033;2.海军工程大学动力工程学院,武汉430033)摘要:针对舰艇推进器空化噪声检测中调制特征弱、背景干扰强等问题,提出了一种基于时延相关降噪、经验模态分解(EMD)
2、和希尔波特(Hilbert)变换相结合的解调算法。该算法通过引入时延相关算法有效抑制了背景噪声,并利用EMD技术的自适应频带划分功能完成调制特征频带定位,实现了低信噪比条件下调制信号的有效检测。仿真试验证明:该方法在信噪比为一12dB、一15dB、一18dB条件下的检测效果明显优于传统的Hilbert变换等5种方法,且背景噪声干扰成分得到了有效抑制,调制信号检测效果显著提升。最后,通过推进器空化信号检测台架试验验证表明:该方法能够有效捕捉舰艇空化噪声信号中与转速、叶片数密切相关的调制特征。关键词:希尔波特变换;经验模态分解;时延相关;
3、解调技术中图分类号:U664.3;TP277文献标志码iA文章编号:1009—3486(2014)03—0007—06DetectionofcavitationcharacteristicswithdemodulationtechniquebasedonEMDandHilberttransformRENAn-miD,HELin,SUYong—sheng。,MAORong—fu(1.NationalKeyLaboratoryofShipVibration8LNoise,NavalUniv.ofEngineering,Wuhan43003
4、3,China;2.CollegeofPowerEngineering,NavalUniv.ofEngineering,Wuhan430033,China)Abstract:Tosolvetheproblemofweakmodulationcharacteristicsandstrongbackgroundnoiseap—pearinginthedetectionoffaultvibrationsignalofshippropellercavitation,ademodulationtechniqueisproposedbasedon
5、thedelay—relatednoisereduction,empiricalmodedecomposition(EMD)andHil—berttransform.Firstly,analysesaremadeofsixkindsofdemodulationalgorithmthatrefertothetra—ditiona1Hilberttransform,HilberttransformcombinedwithEMD,Hilberttransformcombinedwithrelatednoisereduction,Hilber
6、ttransformcombinedwithrelatedreductionnoise,EMDandHilberttransform,HilberttransformcombinedwithdelayassociationandHilberttransformcombinedwithdelayassociationwithEMD.Secondly,atthesignaltonoiseratiosof一12dB,一15dBand一18dB,themodulationsimulationdataiSdealtwithandthetimed
7、elayrelatedtothenoisereductionalgorithmisgreatlysuppressed.TheEMDadaptivefrequencytechnologycanfindthebestbandaccordingtodi—visionmodulationinherentcharacteristics,andmeanwhilethemodulatedsignaliSremarkablyim—proved.Finally,apropellermodeltestpumpneedstogothroughthecavi
8、tationvibrationsignalde—modulationanalysis.Theresultsshowthattheproposedsyntheticalgorithmcanwellidentifytheca
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