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ID:40383711
大小:1011.96 KB
页数:9页
时间:2019-08-01
《!!!!!Nontarget Image-Based Technique for Small Cable 》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、NontargetImage-BasedTechniqueforSmallCableVibrationMeasurement12Y.F.JiandC.C.ChangAbstract:Inthispaper,aproof-of-conceptimage-basedtechniqueisproposedformeasuringsmallcablevibration.Thetechniqueanalyzesanimagesequenceofavibratingcablesegmentcapturedbyacamera.Anopticalßowmethodisusedtocalculate
2、variationofopticalintensityofanarbitraryselectedregionofinterestROIonthecableimagesequence.TheobtainedopticalßowvectorprovidesthedirectionofvibrationfortheROIonthecablesegment,whichthencanbeusedtoestimatedisplacementoftheROIontheimageplane.Furthermore,actualdisplacementoftheROIcanbeextracted
3、whensomeconditionsaremet.TheproposedtechniqueisvalidatedbothinthelaboratoryusingarigidpipeandintheÞeldonasmallpedestrianbridgecable.Resultsshowthatthetechniqueisabletomeasurethepipemotionandthecablevibrationaccurately.Theproposedtechniquerequiresonlyonecommercialcamera,andnopriorcameracalibrat
4、ionisneeded.Inaddition,theuseofanopticalßowmethodeliminatestheneedtoattachanytargettothecableandmakesthetechniqueveryeasytoimplement.Despitetheseadvantages,thetechniquestillneedsfurtherdevelopmentbeforeitcanbeappliedtolong-spanbridgecables.DOI:10.1061/ASCE1084-0702200813:134CEDatabasesub
5、jectheadings:Vibration;Displacement;Measurement;Bridges,cable-stayed.IntroductionexistintherecordsHudson1979.ThelaserDopplervibrometerhasalsobeenusedforcablevibrationmeasurementCunhaetal.Cablesareavitalload-carryingcomponentofcable-stayed2001.Thisdeviceisnoncontactandcanprovideaccuratedis-
6、bridgesandneedtobemonitoredandassessedperiodicallytoplacementmeasurementatmultiplelocationswithinitsapplicableensurethesafetyofthebridges.Bridgecablescomewithlowdistance.Whencableforceistheobjectofmeasurement,there-ßexuralrigidity,lowweight,andarelativelysmallcrosssection,centlydevelopedelectr
7、omagneticEMsensorsprovideamoreandhencearepronetowind,rain,andtrafÞc-inducedvibration.directandaccurateapproachWang2005.ThesensorsneedtobeAccelerometershavecommonlybeenusedtomeasurecablevi-placedaroundtheanchoragelocation,andtheircal
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