毕业设计外文资料及翻译智能交通信号灯模拟控制系统设计

1、1外文资料AgentcontrolledtrafficlightsIntroductionThequalityof(urban)trafficcontrolsystemsisdeterminedbythematchbetweenthecontrolschemaandtheactualtrafficpatterns.Iftrafficpatternschange,whattheyusuallydo,theeffectivenessisdeterminedbythewayinwhichthesystemadaptstothesechanges.Whenthisabilitytoadaptbecomesanintegralpartofthetrafficcontrolunititcanreactbettertochangesintrafficconditions.Adjustingatrafficcontrolunitisacostlyandtimelyaffairifitinvolveshumanattention.Thehypothesisisthatitmightofferaddit。

2、ionalbenefitusingself-evaluatingandself-adjustingtrafficcontrolsystems.Thereisalreadyamarketforanurbantrafficcontrolsystemthatisabletoreactiftheenvironmentchanges;thesocalledadaptivesystems.Realadaptivesystemswillneedpro-activecalculatedtrafficinformationandcycleplans-basedonthesecalculatedtrafficconditions-tobeupdatedfrequently.Ourresearchoftheusabilityofagenttechnologywithintrafficcontrolcanbesplitintotwoparts.Firstthereisatheoreticalpartintegratingagenttechnologyandtrafficcontrol.Thefinalstag。

3、eofthisresearchfocusesonpracticalissueslikeimplementationandperformance.Herewepresenttheconceptsofagenttechnologyappliedtodynamictrafficcontrol.Currentlywearedesigningalayeredmodelofanagentbasedurbantrafficcontrolsystem.Wewillelaborateonthatinthelastchapters.AdaptiveurbantrafficcontrolAdaptivesignalcontrolsystemsmusthaveacapabilitytooptimisethetrafficflowbyadjustingthetrafficsignalsbasedoncurrenttraffic.Allusedtrafficsignalcontrolmethodsarebasedonfeed-backalgorithmsusingtrafficdemanddata-varying。

4、fromyearstoacoupleofminutes-inthepast.Currentadaptivesystemsoftenoperateonthebasisofadaptivegreenphasesandflexibleco-ordinationin(sub)networksbasedonmeasuredtrafficconditions(e.g.,UTOPIA-spot,SCOOT).Thesemethodsarestillnotoptimalwheretrafficdemandchangesrapidlywithinashorttimeinterval.Thebasicpremiseisthatexistingsignalplangenerationtoolsmakerationaldecisionsaboutsignalplansundervaryingconditions;butalmostnoneofthecurrentavailabletoolsbehavepro-activelyorhavemeta-rulesthatmaychangebehaviourofthe。

5、controllerincorporatedintothesystem.Thenextlogicalstepfortrafficcontrolistheinclusionofthesemeta-rulesandproactiveandgoal-orientedbehaviour.Thekeyaspectsofimprovedcontrol,forwhichcontributionsfromartificialintelligenceandartificialintelligentagentscanbeexpected,includethecapabilityofdealingwithconflictingobjectives;thecapabilityofmakingpro-activedecisionsonthebasisoftemporalanalysis;theabilityofmanaging,learning,selfadjustingandrespondingtonon-recurrentandunexpectedevents(Ambrosinoetal..,1994).W。

6、hatareintelligentagents?2Agenttechnologyisanewconceptwithintheartificialintelligence(AI).TheagentparadigminAIisbaseduponthenotionofreactive,autonomous,internally-motivatedentitiesthatinhabitdynamic,notnecessarilyfullypredictableenvironments(Weiss,1999).Autonomyistheabilitytofunctionasanindependentunitoveranextendedperiodoftime,performingavarietyofactionsnecessarytoachievepre-designatedobjectiveswhilerespondingtostimuliproducedbyintegrallycontainedsensors(Ziegler,1990).Multi-AgentSystemscanbechar。

7、acterisedbytheinteractionofmanyagentstryingtosolveavarietyofproblemsinaco-operativefashion.BesidesAI,intelligentagentsshouldhavesomeadditionalattributestosolveproblemsbyitselfinreal-time;understandinformation;havegoalsandintentions;drawdistinctionsbetweensituations;generalise;synthesisenewconceptsand/orideas;modeltheworldtheyoperateinandplanandpredictconsequencesofactionsandevaluatealternatives.Theproblemsolvingcomponentofanintelligentagentcanbearule-basedsystembutcanalsobeaneuralnetworkorafuzzy。

8、expertsystem.Itmaybeobviousthatfindingafeasiblesolutionisanecessityforanagent.Oftenlocaloptimaindecentralisedsystems,arenottheglobaloptimum.Thisproblemisnoteasilysolved.Thesolutionhastobefoundbytailoringtheinteractionmechanismortohaveasupervisingagentco-ordinatingtheoptimisationprocessoftheotheragents.IntelligentagentsinUTC,ahelpfulparadigmAgenttechnologyisapplicableindifferentfieldswithinUTC.Theonesmostimportantmentioningare:informationagents,agentsfortrafficsimulationandtrafficcontrol.Currentl。

9、y,mostapplicationsofintelligentagentsareinformationagents.Theycollectinformationviaanetwork.Withspecialdesignedagentsuserspecificinformationcanbeprovided.Inurbantraffictheseintelligentagentsareuseableindeliveringinformationaboutweather,trafficjams,publictransport,routeclosures,bestroutes,etc.totheuserviaaPersonalTravelAssistant.Agenttechnologycanalsobeusedforaggregatingdataforfurtherdistribution.Agentsandmultiagentsystemsarecapableofsimulatingcomplexsystemsfortrafficsimulation.Thesesystemsoftenu。

10、seoneagentforeverytrafficparticipant(inasimilarwayasobjectorientedprogramsoftenuseobjects).Theapplicationofagentsin(Urban)TrafficControlistheonethathasourprimeinterest.Hereweultimatelywanttouseagentsforpro-activetrafficlightcontrolwithon-lineoptimisation.Signalplansthenwillbedeterminedbasedonpredictedandmeasureddetectordataandwillbetunedwithadjoiningagents.Themostpromisingaspectsofagenttechnology,theflexibilityandpro-activebehaviour,giveUTCthepossibilityofbetteranticipationoftraffic.CurrentUTCisn。