高速公路交通仿真软件开发_英文_

1917©Vol.19No.1720079JournalofSystemSimulationSep.,2007•4049•MotorwayTrafficSimulationSoftwareDevelopmentHUANGQiang,LIANGXiaoFeng,ZHUYingYing(CollegeofInformationEngineering,ShenzhenUniversity,Shenzhen518060,China)Abstract:Atrafficmodelwithtrafficflow,roaduserbehaviorandvehicledynamicmodelwasdesignedprovidingcomputersimulationoftrafficflowonatypicalsectionofmotorwayintheUK.Firstabriefdescriptionofthemotorwaynetworkitselfwasgiven,alongwithadiscussionofUKdrivingconventions.Followingthis,theprincipleofmicroscopicsimulationandtherepresentationofroaduserswerediscussed.Drivermodelsforbothcarfollowingandlanechangingweredeveloped.Themicroscopicparametersinthedrivermodelswereoptimizedtofitthesimulationresultswithexistingempiricaldata.Agraphicaluserinterface(GUI)-basedsimulationsoftwarepackagewasdevelopedbasedonthetrafficmodelandprovidedsupportfortestingandassessmentofthevehiclecontrolsystem.Keywords:motorwaytraffic;simulationsoftware;GUI;vehiclecontrolsystem(,518060)TP391.9A1004-731X(2007)17-4049-06Introduction1ThefirstmotorwaytobeopenedintheUKwasatwo-lane,8.25-milelongsectionofroadcalledtheM6in1958.Sincethisdate,therehasbeenasteadyandconsistentriseinboththenumberofmotorways,thetotallengthofmotorwaysandtheamountoftrafficflowinguponthem.Currentlythereareapproximately100motorwaystotalingover3500Km,withtheamountoflanesvaryingbetweentwouptoeightinsomeareas.Thisstudyisconcernedwiththesimulationofastraight,three-lanesectionofroadwithReceived:2006-07-03Revised:2006-12-14Fundationitems:NationalNaturalScienceFoundationofChina(60501026);NaturalScienceFoundationofGuangdongProvince,China(5301029);ResearchandEducationFoundationofShenzhenUniversity(200513,A20050311)Biography:HuangQiang(1977-),male,BeiHaicityGuangXiprovince,Ph.D,associateprofessor,researchinterests:safety-criticaldistributedreal-timeembeddedsystemLiangXiaoFeng(1984-),femaleGuangDongprovinceMasterresearchonembeddedsystemZhuYingYing1976-female,ShanDongprovince,Ph.D,associateprofessor,researchonreal-timesignalprocessing.nojunctionsandamaximumgradientof7%whichiscurrentlythedesignmaximumallowedbylegislation.DrivingconventionconsideredwithinthisworkisbytheUKtrafficlegislationthatmotoristsshoulddriveontheleft,andwhendrivingonthemotorwaytheyshouldkeeptotheKLEWO(KeepLeftExceptWhenOvertaking)system.Additionally,thespeedlimitonmanysectionsofthemotorwaysisrestrictedto70Mphforpassengervehiclesand60MphforHeavyGoodsVehicles(HGV’s)andLorries[2].Itisalsoknownthattrafficflowsandcompositionvarydependingonthetimeofday,thedayofweekandeventhemonthofyear,andevenvarydependingonwhichsectionanddirectionofmotorwayisbeingconsidered.Eachoftheseobservationswillhavetobeconsideredintheimplementationofaneffectivesimulation.Thepaperisorganizedasfollows:section1presentstheoverallsimulationprinciple,section2describesthedriverbehaviormodel,section3presentsthelanechangingwithtrafficflowmodeling,section41917Vol.19No.1720079Sep.,2007•4050•givesthesystemoptimizationandsimulationresult.1SimulationPrincipleThesimulationinvolvesamicroscopicrepresentationofroadusers.Theyarerepresentedoveratwo-kilometersectionofroad,atthecenterofwhichwilllaythehostvehicle,whichistobecontrolledbythevehicleembeddedcontrolsystem.Thedynamicsofeachroaduserwillbeevaluatedwithrespecttothehostvehicle.Asthesimulationevolves,fastervehicleswillexitthesimulationsectionreferencetothehostvehicle’sfront,whileslowervehicleswillexittotherear.Whenthisoccurs,newvehiclewillbeaddedwithrandomlygeneratedspeedtothesimulationsection.Ifthedesiredspeedisgreaterthanthatofthehostvehiclethenewlyaddedvehiclewillentertherearofthesimulationandviceversa.ThesimulationprincipleisshowninFigure1.HostVehicleVehicleLane1Lane2Lane30-500-10005001000VelocityVhVelocityV2VelocityV1SimulationHorizonSimulationHorizon-440YCo-ordinates(FixedFrame)XCo-ordinates(MovingFrame)Figure1SimulationprincipleInordertorepresentroadusers,asimplifieddynamicmodelisemployed.Thecar-followingmodelgeneratestheaccelerationsignalα,whichactsasthemaininputtothemodel.Thedynamicsarerepresentedby(1).),min(max221αα=−=VVVxh(1)x1isthevehiclepositionwithinthesimulationsection,V2isthevehiclevelocity,Vhisthehostvehiclevelocity.Forthepurposeofrealisticsimulation,theaccelerationsignalissaturatedatamaximumlevelαmaxforbothaccelerationandbraking.Therearemanyfactorsthatcouldaffecttheperformanceofaccelerationandbraking.Previousresearch[3]hasindicatedthatasimplespeed-dependentmaximumissufficienttoprovidearealisticmodel.Withinthissimulationalineardependenceisassumed.Forpassengervehicles,relationshipsforlevelgroundaccelerationandbrakingarerepresentedby(2).2_max22_max240.07/4.50.023/acclbrakelxmsxmsαα=−=−(2)SimilarlytheHGV’srelationshipsforlevelgroundaccelerationandbrakingaregivenby(3).2_max22_max220.05/30.017/acclbrakelxmsxmsαα=−=−(3)Toincorporatetheeffectofroadgradient,asimpleformulaisusedtomodifythelevelgroundaccelerationα1maxtogetherwiththefinalmaximumaccelerationincorporatedtheeffectsofweatherconditionsaregivenby(4).2maxmax2maxmax/100/glgGgmsmsαααµα=−=(4)Table1showsthetypicalvaluesofµforagivensetofweathercondit