智能交通信号控制外文翻译.docx

智能交通信号控制外文翻译.docx

《智能交通信号控制外文翻译.docx》由会员分享，可在线阅读，更多相关《智能交通信号控制外文翻译.docx（23页珍藏版）》请在冰豆网上搜索。

智能交通信号控制外文翻译

《现代控制理论》

题目智能交通信号控制

学生姓名

学号

学院

专业

指导教师

二Ｏ一三年12月15日

IntelligentTrafficSignalControlUsingWirelessSensorNetworks

Vignesh.ViswanathanandVigneshwar.Santhanam

Abstract:

Thegrowingvehiclepopulationinalldevelopinganddevelopedcountriescallsforamajorchangeintheexistingtrafficsignalingsystems.Themostwidelyusedautomatedsystemusessimpletimerbasedoperationwhichisinefficientfornon-uniformtraffic.Advancedautomatedsystemsintestinguseimageprocessingtechniquesoradvancedcommunicationsystemsinvehiclestocommunicatewithsignalsandaskforrouting.Thismightnotbeimplementableindevelopingcountriesastheyprovetobecomplexandexpensive.Theconceptproposedinthispaperinvolvesuseofwirelesssensornetworkstosensepresenceoftrafficnearjunctionsandhenceroutethetrafficbasedontrafficdensityinthedesireddirection.Thissystemdoesnotrequireanysysteminvehiclessocanbeimplementedinanytrafficsystemeasily.Thissystemuseswirelesssensornetworkstechnologytosensevehiclesandamicrocontrollerbasedroutingalgorithmfortrafficmanagement.

Keywords:

Intelligenttrafficsignals,intelligentrouting,smartsignals,wirelesssensornetworks.

I.INTRODUCTION

Thetrafficdensityisescalatingatanalarmingrateindevelopingcountrieswhichcallsfortheneedofintelligenttrafficsignalstoreplacetheconventionalmanualandtimerbasedsystems.Experimentalsystemsinexistenceinvolveimageprocessingbaseddensityidentificationforroutingoftrafficwhichmightbeinefficientinsituationslikefog,rainordust.Theotherconceptualsystemwhichisbasedoninteractionofvehicleswithtrafficsignalsandeachotherrequirehardwaremodificationoneachvehicleandcannotbepracticallyimplementedincountries

likeIndiawhichhavealmost100millionvehiclesonroad[1].Thesystemproposedhereinvolveslocalizedtrafficroutingforeachintersectionbasedonwirelesssensornetworks.Theproposedsystemhasacentralcontrollerateveryjunctionwhichreceivesdatafromtinywirelesssensornodesplacedontheroad.Thesensornodeshavesensorsthatcandetectthepresenceofvehicleandthetransmitterwirelesslytransmitsthetrafficdensitytothecentralcontroller.Thecontrollermakesuseoftheproposedalgorithmtofindwaystoregulatetrafficefficiently.

II.THENEEDFORANALTERNATESYSTEM

Themostprevalenttrafficsignalingsystemindevelopingcountriesisthetimerbasedsystem.Thissysteminvolvesapredefinedtimesettingforeachroadatanintersection.Whilethismightproveeffectiveforlighttraffic,heavytrafficrequiresanadaptivesystemthatwillworkbasedonthedensityoftrafficoneachroad.Thefirstsystemproposedforadaptivesignalingwasbasedondigitalimageprocessingtechniques.Thissystemworksbasedonthecapturedvisualinputfromtheroadsandprocessingthemtofindwhichroadhasdensetraffic.Thissystemfailsduringenvironmentalinteractionlikerainorfog.Alsothissystemintestingdoesnotproveefficient.TheadvancedsystemintestingatPittsburgh[2]involvessignalscommunicatingwitheachotherandalsowiththevehicles.Theproposedsystemdoesnotrequireanetworkbetweensignalsandvehiclesandisastandalonesystemateachintersection.

III.THEPROPOSEDSYSTEM

Thispaperpresentstheconceptofintelligenttrafficroutingusingwirelesssensornetworks.Theprimaryelementsofthissystemarethesensornodesormotesconsistingofsensorsandatransmitter.Thesensorsinteractwiththephysicalenvironmentwhilethetransmitterpagesthesensor’sdatatothecentralcontroller.Thissysteminvolvesthe4x2arrayofsensornodesineachroad.Thissignifies4levelsoftrafficand2lanesineachroad.ThesensorsareultrasonicorIRbasedopticalsensorswhichtransmitsstatusbasedonpresenceofvehiclenearit.ThesensornodestransmitatspecifiedtimeintervalsviaZigBeeprotocoltothecentralcontrollerplacedateveryintersection.Thecontrollerreceivesthesignalandcomputeswhichroadandwhichlanehastobegivengreensignalbasedonthedensityoftraffic.Thecontrollermakesuseofthediscussedalgorithmtoperformtheintelligenttrafficrouting.

IV.COMPONENTSINVOLVEDINTHESYSTEM

Theproposedsysteminvolveswirelesssensornetworkswhicharecomprisedofthreebasiccomponents:

thesensornodesormotes,powersourceandacentralcontroller.ThemotesinturnarecomprisedofSensorsandtransceivermodule.Thesensorssensethevehiclesatintersectionsandtransceivertransmitthesensor’sdatatothecentralcontrollerthroughawirelessmedium.ThePowersourceprovidesthepowerneededforthesensornodesandismostlyregenerative.Thecentralcontrollerperformsallthecomputationsforthesensornetworks.Thecontrollerreceivestheinputfromallsensorsandprocessessimultaneouslytomaketherequireddecisions.

A.Sensors

Sensorsarehardwaredevicesthatproduceameasurableresponsetoachangeinaphysicalconditionliketemperatureorpressure.Sensorsmeasurephysicaldataoftheparametertobemonitored.Thecontinualanalogsignalproducedbythesensorsisdigitizedbyananalog-to-digitalconverterandsenttocontrollersforfurtherprocessing.Asensornodeshouldbesmallinsize,consumeextremelylowenergy,operateinhighvolumetricdensities,beautonomousandoperateunattended,andbeadaptivetotheenvironment.Aswirelesssensornodesaretypicallyverysmallelectronicdevices,theycanonlybeequippedwithalimitedpowersourceoflessthan0.5-2ampere-hourand1.2-3.7volts.Sensorsareclassifiedintothreecategories:

passiveOmni-directionalsensors;passivenarrow-beamsensors;andactivesensors[3].

Thesensorsareimplementedinthissystemplacedbeneaththeroadsinanintersectionoronthelanedividersoneachroad.Thesensorsareactiveobstacledetectorsthatdetectthepresenceofvehiclesintheirvicinity.ThesensorsaresetinfourlevelsoneachroadsignifyingfourlevelsoftrafficfromstartingfromtheSTOPline.Thefourthlevelindicateshighdensitytrafficandsignifieshigherpriorityfortheroadtothecontroller.ThesensorsrequiredforobstacledetectioncanbeeitherultrasonicorInfraredLASERbasedsensorsforbetterhigherefficiency.

B.Motes

Amote,alsoknownasasensornodeisanodeinawirelesssensornetworkthatiscapableofperformingsomeprocessing,gatheringsensoryinformationandcommunicatingwithotherconnectednodesinthenetwork.Themaincomponentsofasensornodeareamicrocontroller,transceiver,externalmemory,powersourceandoneormoresensors[3].

Fig.1BlockDiagramofaMote

C.NeedforMotes

TheprimaryresponsibilityofaMoteistocollectinformationfromthevariousdistributedsensorsinanyareaandtotransmitthecollectedinformationtothecentralcontrollerforprocessing.AnytypeofsensorscanbeincorporatedwiththeseMotesbasedontherequirements.Itisacompletelynewparadigmfordistributedsensinganditopensupafascinatingnewwaytolookatsensornetworks.

D.AdvantagesofMotes

●Thecoreofamoteisasmall,low-cost,low-powercontroller.

●Thecontrollermonitorsoneormoresensors.Itiseasytointerfaceallsortsofsensors,includingsensorsfortemperature,light,sound,position,acceleration,vibration,stress,weight,pressure,humidity,etc.withthemote.

●Thecontrollerconnectstothecentralcontrollerwitharadiolink.Themostcommonradiolinksallowamotetotransmitatadistanceofabout3to61meters.Powerconsumption,sizeandcostarethebarrierstolongerdistances.Sinceafundamentalconceptwithmotesistinysizeandassociatedtinycost,smallandlow-powerradiosarenormal.

●Asmotesshrinkinsizeandpowerconsumption,itispossibletoimaginesolarpowerorevensomethingexoticlikevibrationpowertokeepthemrunning.Itishardtoimaginesomethingassmallandinnocuousasamotesparkingarevolution,butthat'sexactlywhattheyhavedone.

●Motesarealsoeasytoprogram,eitherbyusingserialorEthernetcabletoconnecttotheprogrammingboardorbyusingOvertheAirProgramming（OTAP）.

Fig.2BlockDiagramoftheProposedSystem

E.Transceivers

SensornodesoftenmakeuseofISMband,whichgivesfreeradio,spectrumallocationandglobalavailability.Thepossiblechoicesofwirelesstransmissionmediaareradiofrequency（RF）,opticalcommunicationandinfrared.Lasersrequirelessenergy,butneedline-of-sightforcommunicationandaresensitivetoatmosphericconditions.Infrared,likelasers,needsnoantennabutitislimitedinitsbroadcastingcapacity.Radiofrequency-basedcommunicationisthemostrelevantthatfitsmostoftheWSNapplications.WSNstendtouselicense-freecommunicationfrequencies:

173,433,868,and915MHz;and2.4GHz.Thefunctionalityofbothtransmitterandreceiverarecombinedintoasingledeviceknownasatransceiver[3].

Tobringaboutuniquenessintransmittingandreceivingtoanyparticulardevicevariousprotocols/algorithmsaredevised.TheMotesareoftenareoftenprovidedwithpowerfultransmittersandreceiverscollectivelyknownastransceiversforbetterlongrangeoperationandalsotoachievebetterqualityoftransmission/receptioninanyenvironmentalconditions.

F.PowerSource

Thesensornodeconsumespowerforsensing,communicatinganddataprocessing.Moreenergyisrequiredfordatacommunicationthananyotherprocess.Powerisstoredeitherinbatteriesorcapacitors.Batteries,bothrechargeableandnon-rechargeable,arethemainsourceofpowersupplyforsensornodes.Cur