过饱和状态交通信号控制优化原理及仿真

过饱和状态交通信号控制优化原理及仿真

0u3000公车法urafficmortiagestrafege家族value公务员的基本生活服务体系管理。如上所述，通过基本生活服务体系、基本生活服务体系、职业人口统计（痕迹研究）、hcm（高线空间）的基本控制软件，以及基本生活服务体系的基本控制软件（生命的相互分离）和scot（生命的相互分离）。对于任何工作场所的异常行为，参与缓慢的非正义控制，以及人类的分散。改革进展缓慢的移动时间是从哪里来的。改革进展缓慢的系统有50个等级，而官方的区域控制系统没有注册，并且可以采取计划中的区域控制。这封信是属于马蹄形的。这是一个由扭曲运动统治的城市网络。Trafficcontrolstrategiesunderover-saturatedconditionsarefirstlyimplementedforisolatedintersections.Specificcoordinatedtrafficsignalcontrolstrategiesforthearterialandroadnetworkarethendevelopedforthepurposeofdealingwithcongestionstatus.Beginningwithdistinguishingtheconceptionsofapproachingsaturation,saturationandover-saturation,theover-saturatedtrafficcontrolstrategiesforvariousscalesaresummarizedandevaluated.Asapartoftheadvancedtrafficmanagementsystem(ATMS),adaptivetrafficsignalcontrolsystemswiththecapabilitiesofhandlingover-saturatedflowarealsodiscussed.1que资源统一whiceTrafficstatusisgenerallydeterminedbytrafficintensity,i.e.V/C(volume/capacity)ratio.Foraroadsection,approachingsaturationusuallyreferstothesituationofV/Cratiolargerthan0.9,andover-saturationisthetrafficstatuswithV/Cratiogreaterthan1.0,thesaturationstatushasaV/Cratioexactlyequals1.0.Theconceptionsoftrafficconditionsatintersectionaresimilartotheconceptionsatroadsection.Ifthetrafficdemandofoneapproachoftheintersectionexceedsitscapacity,thisintersectionisunderover-saturatedstatus.AsshowninFig.1,becauseitisdifficulttomeasuretheactualtrafficdemandandcapacitywhenthetrafficsystemiscongested,theoversaturationatsignalizedintersectioncanbedefinedastheconditionofhavinganapproachwithresidualqueue.Thequeueinformationcanbedirectlyestimatedbyloopdetectors,mobilesensorsorvideodatabyusingshockwavetheory.Trafficflowwillbecomeunstableunderoversaturationorapproachingsaturationconditions.Asmallfluctuationfromanyvehicleinaplatoonmaycauseadverseconsequencesandreducetheefficiencyoftrafficsystemsharply.Thelowstabilityofsaturatedtrafficflowputsforwardmorestringentrequirementstothetrafficcontrolsystem.Generally,over-saturatedconditionwillfirstlyappearatoneorseveralisolatedintersectionswithrelativelyhighsaturationdegrees.AsshowninFig.2,whenintersectionBcanue10btdischargethequeue,itturnsintoover-saturatedstatus.ThequeuewillcontinuallygrowuntilitexceedstheroadsectionbetweenintersectionsAandB.AtthemomenttheresidualqueuereachintersectionA,bothintersectionsareundertheover-saturatedconditions.Noeffectivetrafficcontrolstrategyexistsatthismoment,buttopreventanyvehiclefromenteringover-saturatedroadsection.Thisdetrimentaleffectisnamedspillback,whichshouldbeavoidedinthefirstplace.Intersectionsalongtheroutewithlargertrafficvolumesmayspreadthecongestionmuchfasterthanotherroutes.Finally,thewholeroadnetworkwillbecongested,evenunderalock-outstatus.Itisimportanttoimplementtrafficsignalcontrolstrategiestopreventover-saturatedconditionsinthefirstplace,ratherthantoreacttotheissuesafterthefact.Oncethetrafficdemandgoesbacktothenormallevel,thefrequentlyusedtrafficcontrolstrategywillmakethepractitionersmanagethetrafficfloweasily.Thecauseofover-saturatedstatusindicatesthatthedeclineofcapacitycausedbydetrimentaleffectsisacriticalinterferingfactor.Therefore,theessenceoftrafficcontrolstrategiesunderoversaturatedstatusistoeliminatethedetrimentaleffectsbyadjustinggreentime,cyclelengthandoffset.2就业服务的继承2.1内插领养儿童2.1.1为系统论和utikizraince系统论SinceWebsterconnectedtheaveragedelaywiththesignaltimingparametersandtheobservedvariablesbyusingcumulativediagram,theseparameterscanbeoptimizedbyminimizingthedelayofsignalizedintersection(knowingasTRRLmethod).SimilartoTRRLmethod,manyoptimizationobjectivesarealsoappliedinsignaltimingoptimizationprocess,suchasminimizingcyclefailures,minimizingstopsandminimizingaveragesaturationdegree.However,becauseoftheprincipleofalgorithm,theycanhardlybeutilizedunderover-saturatedconditions.Althoughthecoordinatetransformationmodelandthedeterministicmodelwereestablishedtoestimatethedelayorqueueinthesignalizedintersectionwithrelativelyhighsaturationdegree,thetrafficsignalcontrolcandonothingbuttoallocatemoregreentimetoreducethedelay.2.1.2u3000spindexedraftingmo产品pensiptenWhenthegreentimebecomesflexible,switchingofgreenisthefirstandsimplesttrafficcontrolstrategyfortheover-saturatedintersections.Thisstrategycanallocatetheunusedgreentimefromun-congestedphasetoover-saturatedphasetoensuretheeliminationofresidualqueue.Byapplyingthiscontrolphilosophy,thetotaldelayscanbeminimizedbymaximizingintersectionproductivity,whilekeepingthequeuesue10bdevelopmentwithinacceptablelevelsatthesametime.Amaximumgreentimeisgiventothemovementwiththehighersaturationflowuntilthequeueisdissipated,whileothermovementsreceivetheminimumgreentime.Widelyusedtechnologiesofthisstrategyincludesemi/fullactuatedcontrol,NEMAue10bs(nationalelectricalmanufacturesassociation)ring-barrierphasemodelinNorthAmerica,andphasestagemodelinEurope.Intheactuatedcontrolsystem,controllercanextendorterminatethecurrentphasetoallocatetheunusedgreentocongestedphase.NEMAue10bsring-barrierphasemodelextendstheideaofactuatedcontrol.AsillustratedinFig.3,thedualringcontrolunitcangivemorepriority(i.e.moregreentime)totrafficflowofspecificintersectionapproachbyadjustingthebarriersbetweenphases1,5(3,7)and2,6(4,8).Phasestagemodelcangroupalltheun-conflictedmovementsandorderthembypriorities.Thephaseassociatedwithcriticalmovementgroupcangetmoregreentime.Theswitchingofgreenstrategydoesimprovetheefficiencyoftrafficsignalsystem,especiallyforthesituationofintersectionwithonlyoneortwomovementsbeingcongested.However,whenthevolumesofallmovementsexceedtheircapacity,thesealgorithmswillextendallphasestomaximumgreentime.Atthattime,trafficcontrolsystemhasnodifferenceswithfixedtimecontrol.Ingeneral,minimizingdelayviasplitswitchingisnotanon-linehighlyresponsivepolicy,butanoptimizationpolicybasedonadvancedmathematicsandthedetailedknowledgeofdemand.2.1.3n鞣inci生物cuespinvi结构处理Thenatureofgreenadjustmentpoliceistore-allocatethetemporalresourcesforthepurposeofimprovingtheirefficiencies.However,whentheroadspacebecomestherestrictionofthesystem,maintainingqueueratioshouldbeselectedastheoptimizationobject.Underthisstrategy,thegreentimeshouldbeadjustedtobalancethequeuesatintersectionue10bsapproaches.Theobjectiveistominimizethenumberofblockedintersectionsbymanagingqueuesofcriticalintersection.Thisstrategyinvolvestheuseofsampledloopdataateachintersectionormobilesensorsdata.Recentstudiesindicatedthatthesignalizedintersectionwonue10btmaximizeitscapacityandminimizeitsdelayatthesametimeunderapproachingsaturatedorover-saturatedconditions.Inthisway,signaloptimizationobjectivesshouldbeswitchedtothemeasuresofreducingthequeuelengthatthebottleneckandminimizingthedetrimentaleffectsunderoversaturatedstatus.Theseoptimizationobjectivesinvolvethethroughputmaximizationorthequeueminimizationofcriticalroute.2.2Simulationbasedevaluation2.2.1vissimsotvissimsoteInordertoevaluatetheperformanceoftrafficcontrolstrategiesforover-saturatedisolatedintersection,fixedtimingmethod(TRRLmethod),Synchromethod(HCMmethod),actuatedcontrolmethod,NEMAue10bsdualringcontrolunit,phasestagemodelandqueueratiomaintenancemethodareevaluatedintheprevailingmicroscopictrafficsimulationenvironmentbasedonVISSIMsimulationsystem.TheadvantagesofVISSIMoverothersimulationpackagesincludesomeaspectsasfollows.(1)VISSIMprovidesthelargestflexibilityforuserstocalibratedrivingbehaviorsandtrafficconditions.(2)VISSIMisdevelopedunder.NETframework,whichbringsflexibilityforadd-onprogramdevelopment.(3)VISSIMprovidesthebesttoolsforthedevelopmentofsignalcontrolstrategies,suchasNEMAcontrolleremulator,vehicleactuatedprogramming(VAP)language,signalcontrolapplicationprogramminginterfaces(SCAPIs),etc.VISSIMSCAPImethodisusedtodevelopsignalcontrolemulatorinthisresearch.SCAPIsarewritteninC++/CLRlanguageandtheoriginalversionofSCAPIscontrollerrequiressignalcontrolalgorithmsbeembeddedintoasingledynamiclinklibrary(DLL)file.Tofacilitatethedevelopment,amiddlewareisdeveloped,whichcansynchronouslycollectallthereal-timedetectors/phasesstatesfromtheVISSIMnetworktothecontrolleremulatorthenreturnthenewdesiredphasestatesbacktotheVISSIMnetwork.Ateachtimestep,controllerrunsthealgorithm,makesdecisionsaccordingtothecurrentstate,thenreturnsthenewdesiredphasestatestotheVISSIMnetwork.TheconceptofthissimulationenvironmentisillustratedasinFig.vissim软件Asimplefourwayintersectionisselectedtoevaluatetheselectedalgorithms.ThegeometriccharacteristicsoftheintersectionareshowninFig.5.TheexperimentalconfigurationsarelistedinTab.1.AlltheneededdatacanbedirectlyobtainedfromtheVISSIMsoftware.Alltheinputparametersareoptimizedinadvance,andthenareinputtotheVISSIMenvironment.TheVISSIMsoftwarehasabuilt-infixedtimecontrollertoachieveTRRLmethodandHCMmethod.TheCrossingsoftwareandVisVAPmoduleinVISSIMareappliedtoprogramtheactuatedcontrolmethod,phasestagemodelandqueueratiomaintenancemethod.TheVISSIMstandardNEMAeditorisutilizedtoevaluatethedualringcontrolunit.2.2.3perfogenfici能够生长Eachscenariorunsfor50timestoconductstatisticalanalysis.Throughputvehiclesandaveragequeueratioareselectedtocomparetheselectedtrafficcontrolmethods.AsshowninTab.2,itcanbeindicatedthatundernormalconditions,theactuatedcontrolmethod,theNEMAmethodandthephasestagemethodallhavesimilarperformances.Theflexiblegreencontrolstrategies,suchasactuatedcontrol,NEMAandphasestage,haverelativelybetterperformancethanthefixedtimingcontrolstrategies(TRRL,HCM).Althoughthequeueratiomaintenancemethodhasgoodperformanceinmanagingthequeueratio,thiscontrolstrategyisnotthemostefficientoneundernormalconditions.However,underover-saturatedconditions,thequeueratiomaintenancemethodhasbetterperformancethanallotherstrategies,andthus,itissuitabletobeutilizedundercongestedconditions.Ifthetrafficdemandcontinuestogrow,specifictrafficcontrolstrategiesforlargerrangeareneededtobeconcerned.3内省的根本变异3.1内插领养儿童系统3.1.1通过外引并式方法参加了..3.4和.3.4和.......与whichin...................................................3.3Signalcoordinatedcontrolstrategiestrytoseekforthemaximumprogressionbandbyadjustingtheoffsetsbetweengreenphasesundersteadytrafficconditions.Withpredefinedmaximumlikelihoodoffsets,coordinatedtimingplansaregenerallydesignedfortrafficflowundersteadystates.Astheintersectionsbecomemoresaturated,residualqueuesstarttodisruptmovementatupstreamintersections.Then,theprogressionbandisnotapplicableanylonger.Iftheover-saturatedconditionlastsforaconsiderabletimeperiod,fixed-timingsignalcoordinationislikelytoaggravatemovementdisturbance,whichmaycausespillbackintoupstreamintersections.Variable-bandwidthprogressionisthenestablishedtoadjusttheoffsetsaccordingtothetraveltimeinformationinrealtime.AsshowninFig.6,thevariable-bandwidthprogressionimprovestheefficiencyofcoordinatedcontrol,andmakesitworkatmostconditions.TheMonteCarlomethodcanbeutilizedtooptimizethebandwidthtopreventtheearlystartedcoordinatedgreenphaseintheactuatedsignalsystem.Underoversaturatedconditions,thereal-timeinformationishardtoobtain.Meantime,inordertomakemorevehiclespassthroughtheprogressionband,thebandwidthstendtobelarge,whichmakessignaltimingtobefixed(maximumgreenatthecriticalrouteandminimumgreenatotherroute).3.1.2u3000服务平台Insteadofsearchingthemaximumprogressionband,thestrategyofmaximumstoragecapacitiesofapproachesisutilizedtooptimizequeuesatintersectionapproaches.Thismethodrespondstotherestrictionsofroadspaceundertheoversaturatedconditions,andtriestomakeefficientuseofupstreamlinkue10bsstoragecapacity.Theprocedureofusingsimultaneousoffsetsalongthearterialandnegativeoffsetswithflaringofgreenalongcrossroadsisthentestedundertheoversaturatedarterialnetwork.Becauseofmarkedlydecreasedspillbackblockages,theprocedureofoffsetsettinghaslargerthroughputvehiclenumberthantraditionaloffsetsetting,andwitha20%reductioninoveralltraveltime.Withthepossibilityofhigh-resolutiontrafficdata,recentresearchesdescribedsimplecontrollerlogicfortruncatingaphaseearlywhenfacedtoadownstreamrestrictionofflowandtoavoiddetrimentaleffectlike“spillback”or“de-factored”.De-factoredassumesthatnoflowonadetectorwhenthelightisgreenindicatingthatthereisnowhereforthevehicletogo,andthusitisbetterforoverallintersectionoperationstomoveontoanotherphase.3.2内脏器官3.2.1interity分工Anarterialisselectedtoevaluatetheperformanceofmaximumprogressionbandstrategy,variablebandwidthprogressionstrategy,andmaximumstoragecapacitiesstrategy.Thearterialisabout8.85kmlong,fourwaysfortwodirections,andsixsignalizedintersections.Fig.7showsitslayoutandtrafficmovementcounts.Thefiledobservedtrafficiscongestedorclosetocongested.AllsixsignalizedintersectionsarecontrolledbytheEconoliteASC/3signalcontrollersandinductiveloopdetectorswithfour-waypedestrianphases.TheVISSIMSCAPImethodisalsoutilizedtoevaluatethecoordinatedtrafficcontrolstrategies.TheoriginaltrafficsignaltimingplanisgeneratedbySynchro,aprevailingsignaltimingoptimizationpackageinNorthAmerica,usingmaximumprogressionbandstrategy.Fig.7alsoshowstheoptimizedfixedtimingplansoftheselectedintersections.Thevariable-bandwidthprogressionstrategyandmaximumstoragecapacitiesstrategyareimplementedbyCrossingsoftwareandVisVAPmodule.3.2.2queueclearing.u...............3.3inderace................................................3.3.3.Duringtheprocessofevaluation,eachscenariorunsfor50timesandsummarizestheaveragevalue.Wheneverthetimingplansareupdatedandaplatoonisidentified,onlyphasesplitsareadjustedwhereasthecyclelengthsandoffsetsarekeptunchanged.Thereforethecoordinationwillnotbedestroyedonthemainline.Sincetheexpectedadvantagesofthemaximumstoragecapacitiesstrategyincludeprovidingsignaltimingstoavoidqueuespillbackandqueueclearancewithoutdestroyingcoordination.ThefollowingMOEs(measuresofeffectiveness)arechosentoevaluatetheperformanceoftheACScontrolstrategy:linktraveltime,totalstops,theaveragecontroldelay,andthemaximumqueueratioonthemainline.Tab.3summarizestheMOEsforallthethreetrafficcontrolstrategies.FromTab.3,itisclearthatthemaximumstoragecapacitystrategycanreducethelinktraveltimeandvehiclestoponthemainlinebyfrom5%to15%.However,thevariable-bandwidthprogressionstrategyhasissuesonoptimizingthesignalofsouthboundtraffic,andcauseseriouscongestionduringsimulation.Althoughtheperformanceofnorthboundisslightlybetterthanthefixedtimescenario,thevariable-bandwidthprogressionstrategyisnotsuggestedtobeutilizedunderover-saturatedconditions.Themaximumstoragecapacitystrategydoesnotsignificantlyreducethemaximumqueueratioorcontroldelaysatintersections,becausethedistancesbetweenintersectionsarerelativelylongandtheconstraintsregardingtherelationshipoftheestimatedmaximumqueuelengthandlinklengthbarelyplayaroleduringtheoptimization.Itisexpectedthatmorebenefitofqueuespillbackavoidancewillbeacquiredifmaximumstoragecapacitystrategyisdeployedatclosely-spacedintersections.4u3000etis/which国际专利产品,作品本.“非价值”的strafes.kues.agie和whichi-roune.关于联邦域,联邦strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-stratestrage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-strage-rouneThesignalcontrolstrategiesintheroadnetworklevelaretheextensionofthestrategiesforcoordinatedintersections.Similartothestrategiesforcoordinatedintersections,thestrategiesforroadnetworkcanbedividedintoadaptivesignalcontrolandmetering/gatingpolice.Theadaptivecontrolstrategiestrytoseekforarelativelybetterallocationofthepassagetimeatthenetworklevelbyapplyinghillclimbingmethodorotherheuristicalgorithms.Whentheroadspacebecomesalimitationfortrafficsignaloptimization,itissuggestedtodistributethetrafficdemandoverthenetwork,andmakefulluseoftheentireroadspacewithintheselectedarea.Themeteringpoliceextendsthequeuemanagementstrategy.Thisstrategyimpedestrafficinputatasuitablepointorpointsupstreamtopreventthedemandfromreachingcriticallevelsatcriticaldownstreamlocations.Itcanmanagetherateofflowintoandwithinhigh-trafficdensitynetwork.Onewell-knownreal-timetrafficcontrolpolicyforcongestedarterialsisRT/IMPOST(real-time/internalmeteringpolicytooptimizesignaltiming),whichisdesignedtocontrolqueuedevelopmentoneverysaturatedapproachbysuitablemeteringtraffictomaintainstablequeues.AtrafficcontrolstrategyforintersectiongroupunderoversaturatedconditionfurtherdevelopedtheRT/IMPOSTstrategybyaddingcriticalroutelayer.Thisprocedureensuresthecriticalrouteistheprimaryoptimizationobjectforover-saturatedintersectiongroup.Inordertoaccomplishtheroadnetworkcontrolstrategies,anumberofmodelsweredevelopedtoidentifythequeue,queuedischargetime,availabledownstreamstorage,etc.5u2004公车使用第203.3—Adaptivetrafficsignalcontrolsystemforover-saturatedconditionsForthereasonthattheoptimizationobjectsunderover-saturatedconditionsaredifferentfromtheonesatsteadystates,specifymodulesorfunctionsareneededtobuiltinthetrafficsignalcontrolsystemtodealwiththeover-saturatedconditions.Generally,anadaptivetrafficsignalcontrolsystemwiththecapabilityofworkingunderover-saturatedconditionsshouldcontaintrafficstatusidentificationmodule,congestioncauseidentificationmoduleandseveralsignalcontrolparametersue10boptimizationalgorithms.Commonlyusedcommercialadaptivetrafficcontrolsystemsgenerallyhavethecapabilityofcalculatingsaturationdegreeinapproximatelyrealtime,suchasthesaturationpercentageinSCOOT,orthedegreeofsaturationinSCATS.However,becauseofthereasonthatnospecifyalgorithmisdesignedforover-saturatedconditions,whenthesaturateddegreeapproaches1,thestabilityofthesesystemsdropssharply.Todealwiththetrafficcongestionmanagementproblem,someadaptivetrafficcontrolsystemsaredesignedtoavoidcongestionorover-saturatedconditions,suchasSCOOTMC3,MOVA,TUC,andMOTION.DetailmeasuresappliedinthesesystemsaresummarizedinTab.4.6“which”信号联Accordingtotheoptimizationprinciples,thetrafficsignalcontrolstrategiescanbedividedintotwocategories:theallocationoftemporalorspatialresources.Understeadystates,theefficiencycanbeimprovedby