轮胎压力监测中英文对照外文翻译文献.docx

轮胎压力监测中英文对照外文翻译文献.docx

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轮胎压力监测中英文对照外文翻译文献

中英文资料外文翻译文献

参考文献

MonitoringtheTirePressureatCarsUsingPassiveSAWSensors

Abstract：

Inourpaperwepresenttheapplicationofsurfaceacousticwave（SAW）sensorstothecontinuousmanitaringofthetirepressureinroadvehicles.Withthese,thetirepressurecanbereadoutineveryphaseofdriving.Weshowtheimplementedprototypesetupformeasurementofthetirepressure,theappliedSAWsensors,improvedversionsandtheinterrogationsetup.Theproblemsinpracticalapplicationarediscussed.Experimentalresultsmeasuringthetirepressureduringtestridesarepresented.

INTRODUCTION

Operatingaroadvehicle,amalfunctionofthetiresinmotionduetoatirepuncturecancauseseriousaccidentsandendangerhumanlife.Furthermore,nowadaysmanufacturersofcarstrytosavethesparewheelinvehicles.Usuallyitonlycostsweightandspace,thereforeityieldsahigherfuelconsumption,althoughitwillberequiredlessthanonetimeinmorethantenyearsofacar'slife.Thisonlycanbedone,iftheairpressureinthetirescanbemeasuredevenduringdriving.Currentlyusedsensorscontainactivecomponents,poweredbyaLithiumbattery.Themassofthesesensorassembliesisabout20gramscausinghighdynamicload.Afewyearsago,wirelessIyinterrogableSAWdevicesfarsensorapplicationswereinvented.[1，2,3].UsinganoneportSAWdelaylineconnectedtoanantennaonly,

anRFinterrogationsignalisfedintoandthesensorresponse,carryingthesensorinformationisretransmittedwirelesslytotheinterrogator.Thesesensorsarecapableformeasurementoftemperature,mechanicalload,forceanddisplacement,etc.Theadvantageis,thatSAWsensorsaretotallypassivedevicesandcontainneitherpowersupplynorsemiconductors.Theywithstandtemperaturesuptoseveralhundredsofdegreecentigrades,theirlifetimeismuchlongerthanthatofbatterypoweredsystems.Further,invehiclesstrongelectromagneticpollutionisgeneratedbyignitionsystemsetc.SAWsensorsoperatewithoutriskofdamageeveninroughenvironments.FirstwediscusspressuremeasurementemployingSAWsensorswithwirelessinterrogation.Wepresentsometypesofsensorassembliesandtheinterrogationsystem.Nextwediscusstheimplementationintothecarandthenwepresentexperimentallyresults.Finallyabriefsummaryconcludesthecontentofthepaper.

SAWPRESSURESENSORS

TheelectricalbehaviourofapassiveSAWpressuresensoralwaysisthatofaoneportdelaylinewithmultiplereflectorsoraresonator,respectively.Inthedelaylinecase,theinterrogatortransmitsaburstsignal,thesensorrespondswithachainofbursts,oneforeveryreflectorarrangedatthesubstrate'ssurface.Thedifferentialdelaybetweentwoormoreresponsesignalsisevaluated.Tomeasuresomephysicalvalue,theparameterhastobeconvertedintoachangeofsensor'ssurfacelengthorsurfaceacousticwave'svelocity,respectively.ThedelayrioftheresponseofareflectoriistheratioofSAWpropagationlengthLionthesubstrate'ssurfaceandpropagationvelocityv,.Affectingthesensorwithameasurandcausesascalingofthesensor'sresponsetobeobservedasindividualdelayshiftsArioftheresponsesignalssioriginatingfrotmhereflectorsi.Mechanicalmeasurandscanbecollectedbyloadingthesensormechanically.Apartfromstretchingandcompressing,utilizedforwirelessmeasurementoftorque,etc.theSAWsensor'ssubstratecanbebent.Pressurecanaffectthesensorbybendingamembrane,shiftingtheedgeofasensorfixedontheotherside.Herethesensorisloadedtobebentduetoashiftofthecenterofamembraneloadedbythepressure.Ontheotherhandthesensorcandirectlybefittedtothemembraneorapiezoelectric

membranerepresentingtheSAWsubstratecanbeused.Figure1showsthesemethods.

Fig.1:

a）Membraneconvertingpressuretoshiftbending

theSAWsensor（SAWS）

b）SAWsensorfittedtothemembrane

Thenextstepistocoverthesensormembranebyacapconsistingofaspacerframeandaquartzcoverplate.ThisyieldsanintegratedpressurechamberSAWsensor[4]（fig.2）.

Fig.2:

IntegratedpressurechamberSAWsensor

ThecoverprotectstheSAWgeneratingmetallicstructurefromoxidationandthesurfacefromdust.ThecavitycanbefiIledwithagasatreferencepressure.Ifthecavityisevacuated,absolutepressurevaluescanbemeasured.MeasurementismadebyinterrogationusingsimpleRFburstsignals.Theresponseimpulsesareevaluatedinmagnitudeandphase.Bendingthemembraneduetopressureloadyieldsaphaseshiftofforinstance100degreeforlo4Pascal.Withthistheairpressureincartirescanbemeasuredwitharesolutioonfapprox.IO'Pascal（0.01Bar）.Toreducetheamountofdatatoprocess,fortheimplementationincarstheresolutionwasreducedto50mBar.

IMPLEMENTATION

Thefirstprototypeusedfortheexperimentalmeasuremenwtsasapressurechamberwithamembranemadeofbrass.Thesensorunitwasfittedtoahubcapandwasconnectedtothevalvebyapressureassembly（fig.3）.

Fig.3:

Firstprototypeofpressurechamberfor

measurementoftirepressure

Forserialmanufacturethesensorsystem~havetobemuchsmallerandabletobeintegratedinthetire.Thereforeweimplementedtheintegratedpressurechamber（fig.2）intothetire.Thesensorwasfixedtotherim,themetallicvalveshaftwasusedasthesensor'santenna（fig.4）.

Fig.4:

Integratedpressurechamberfixedtotherim,

valveusedasantenna

Foirmprovedimplementationasensorassemblyonlyfittedtothevalvewasdeveloped（fig.5）.Thetotalmassoftheunitisonlyafewgrams,thedynamicloadissmallevendrivingathighspeed.

Fig.5:

Pressuresensorforfittingintothevalveshaft

Thcearbasedinterrogationsystemusesspacediversitytodistinguishthesensorsinthetires.Thereforebeloweverycarwinganantennahastobeemployed.Weusedcoaxialcables,hutitisdifficultandexpensivetousethemincars.Ourinvestigationsshowtheapplicabilityoftwistedpairwirestoo.

Fig.6:

Interrogationantennaoncar

Formeasurementwedevelopedasmallsizedinterrogationsystemtransmittingburstsandlookingforthephaseshiftbetweentheresponsesignalbursts.ThesystemwascontrolledbyaonechipmicrocontrollerandabisletodisplaythemeasurementresultonaLCDdisplay.Infig.7aphotographofthesystemisshown.

Fig.7:

Systemforwirelessinterrogationofpassive

SAWsensors（50x100x160mm’）

MEASUREMENTRESULTS

TotestoursensorsandoursystemwemadealotoftestrideswithintheareaandaroundthecityofVienna.Theinterrogationsystemwascoupledtoa

laptopcomputer.Thepressurevaluesweremeasuredandrecordedtoafile.Thefigures8and9showcharacteristicbehaviouroftirepressurefordifferentdrivingconditions.Duetotheshocksfromaruggedlane,intheleftpartoffig.8theabsolutepressurevalueswingsaroundthemeanvaluebytheleastsignificantbit,0.05Bar.Thenarrowhigherpeaksoftirepressurebelongtobrakingmaneuvers（thesensorwasmountedtoafrontwheel）.Thelongerincreaseoftirepressureandthefollowingperiodofdecayisduetoridingoveracurbstone.Thesystemshowedhighreliabilityevenwhendrivinginaheavysnowstorm.tirepressure[Bar]

Fig.8:

Tirepressurefordifferentdrivingconditions

Infigure9thepressureintherightfrontwheelcanbeobservedzoomedintimewhilepassingatwotrackgradecrossingwithanadjacentwaterchannelacrossthelane.Duetothedilapidatedarrangementofthegradecrossing,hardshocksaretransmittedtothecarbodycausinghardpressureshocksinthetires.

Fig.9:

Tirepressurecrossingagradecrossingwith

twotracksandawaterchannelacrossthelane

DISCUSSION

SAWsensorswithwirelesslyinterrogationarefreeofmaintenanceandwithstandhighthermalandmechanicalload.Themeasurementperformanceiscomparabletothatofcompetitors.TheeffortincarbasedsystemishigherforSAWsensors,sincetheactivesensorunitstransmitpreconditioneddigitalinformationcontainingpressurevalueandsensorThemajoradvantageofSAWdevicesinidentification.applications,wherehighrevolutionspertimeoccur,istheirlowmass.Thecentrifugalforceism.v*/r,withthemassm,thevelocityvandtheradiusr.Tominimizedynamicmechanicalload,themassofasystemappliedtorotatingpartsshouldbeaslowaspossible.Whereasconventionalsensorunitsfortirepressuremeasurementshaveamassofapprox.20grams,theintegratedpressuresensoritself（fig.5）hasamassoflessthanonegram.ThecompleteSAWsensorunit'smassinworstcaseisonlyafewgrams.ConventionalsystemsarepoweredbyaLithiumbattery.Incaseofaworntire,sincethebatterycannotbechecked,thesensorshouldbereplacedtoo,yieldingproblemsofwastedisposal.Forasystemintegratedinthecarelectronic,itisneedlesstodisplaythepressureofeachtirecontinuously.Here,onlyamalfunctionshouldtriggeranalert.Thesystem'sdisplaycanbecanceled,reducingsystem'scost.

CONCLUSION

TheadvantagewsofpassiveSAWsensorsmakethwemellsuitedforvehicularapplications.Especiallyformeasurementoftirepressurelowmassandthefactthattheyarefreeofmaintenancemakethemtobesuperioroverthecompetitors.TheSAWsensorsforpressuremeasurement,theimplementationintiresandthesystemfor

interrogationwerediscussed.Experimentalresultsoutofalotofmeasurementrideswerepresented.

REFERENCES

[l]Reindl,F.Muller,C.Ruppel,WE.BulstandF.Seifert,Passivesurfacewavesensorswhichcanbe.wirelesslyinterrogated,InternationalPatentApplWO93/13495（1992）.

[2]SeifertF.,BulstW.E.,RuppelC.,Mechanicalsensorsbasedonsurfaceacousticwaves,SensorsandActuators,A44（1994）231-239

[3]G.Scholl,T.Ostertag,L.Reindl,H.Scherr,0.Sczesny,U.Wolff,WirelessSAWSensorsforRemoteMeasure