外文科技文献.docx

外文科技文献.docx

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外文科技文献

DEVELOPMENTOFAFREE-FLIGHTSIMULATIONINFRASTRUCTURE

EricS.Miles

PaulC.Davis

SeagullTechnology,Inc.

16400LarkAve.,LosGatos,CA95032

DavidJ.Wing

NASALangleyResearchCenter

Hampton,VA23681

ABSTRACT

Inanticipationofaprojectedriseindemandforairtransportation,NASAandtheFAAareresearchingnewair-traffic-management（ATM）conceptsthatfallundertheparadigmknownbroadlyas“freeflight”.ThispaperdocumentsthesoftwaredevelopmentandengineeringeffortsinprogressbySeagullTechnology,todevelopafree-flightsimulation（FFSIM）thatisintendedtohelpNASAresearcherstestmature-stateconceptsforfreeflight,otherwisereferredtointhispaperasdistributedair/groundtrafficmanagement（DAGTM）.Underdevelopmentisadistributed,humanin-the-loopsimulationtoolthatiscomprehensiveinitsconsiderationofcurrentandenvisionedcommunication,navigationandsurveillance（CNS）components,andwillallowevaluationofcriticalairandgroundtrafficmanagementtechnologiesfromanoverallsystemsperspective.TheFFSIMinfrastructureisdesignedtoincorporateallthreemajorcomponentsoftheATMtriad:

aircraftflightdecks,airtrafficcontrol（ATC）,and（eventually）airlineoperationalcontrol（AOC）centers.

INTRODUCTION

Overthepasttwentyyears,increaseddemandforairtravelhasoutpacedthedesignoftheNationalAirspaceSystem（NAS）.Insufficientcapacity,limitedaccess,andexcessiveoperatingrestrictionshaveledtosignificantincreasesinusercostsanddelaysandanoveralldecreaseinefficiencyforallusers1.Furthermore,themarketdemandforairtravelisexpectedtoincreaseseveral-foldinthecomingdecade.RecenttechnologicaladvancesnowprovidetheopportunitytoredesigntheNAStosubstantiallyincreaseitscapacitytoaccommodateairtrafficgrowthandtoprovidesubstantialoperationalflexibilitytoairspaceusers,whilemaintaining,andpossiblyimproving,safety.

Figure1:

TheFFSIMinfrastructureisdesignedtoincorporateallthreemajorcomponentsoftheATMtriad:

aircraftflightdecks,airtrafficcontrol（ATC）,andairlineoperationalcontrol（AOC）centers.

AbroadconceptofNASoperationsknownas“freeflight”,proposedbytheRTCA1in1995,mayprovidetheseandotherbenefitsthroughapplicationofnewtechnologiesandprocedures.Theprimarydifferencebetweentoday’sdirectroute-clearanceapproachandfreeflightwillbethepilot’sabilitytooperatetheflightwithouttherequirementtofollowspecificroute,speed,andaltitudeclearances.Inmaturevisionsoffreeflight,theflightcrewofproperlyequippedaircraftwouldbegiventheauthoritytomaneuveratwillwhilebroadcastingtheirintentionstoothersystemparticipantsandmaintainingresponsibilityforensuringminimumseparationstandardsaremet.Aircraftwithouttheequipmentnecessaryforperformingthesefunctionswouldreceiveclearancesfromthegroundthroughvoiceordatalinkcommunications,andseparationassuranceresponsibilityfortheseaircraftwouldremainwiththeground-basedairtrafficserviceprovider（ATSP）.Thisdistributionofresponsibilityandauthoritywillbereferredtointhispaperasdistributedair/groundtrafficmanagement（DAGTM）.

Inrecentyears,theATMcommunityhasbeenfocusedonthedevelopmentoftechnologiesandevolutionaryimprovementsinefficiencyandcapacitybasedonthecurrentmodeofgroundbasedairtrafficcontrol.TheCenter-TRACONAutomationSystem（CTAS）underdevelopmentbyNASA2,3willprovideairtrafficcontrollersasetoftoolstobettermanageschedulingandsequencingofaircraftintotheterminalareawithcontinuousupdatingtotherunwaythreshold.LimitedimplementationofCTASandothertoolsisunderwaythroughtheFAA’sFreeFlightPhaseIprogram.IsolateddemonstrationsandevaluationsofotherairbornetechnologiesrelatedtotheadvancementofATMareunderwayintheFAA’sSafeFlight21project.

IncontrasttothedevelopmentofindividualairborneandATMtechnologies,lessattentionhasbeengiventodatetoestablishingtheoverallsystemfeasibilityofmature-statefree-flightconceptsandtheintegrationofessentialunderlyingCNScomponents.TheworkdocumentedinthispaperleveragesthesepastandexistingairborneandATMresearchendeavorswhilefillingavoidintheATMresearchcommunitybyprovidingamechanismforevaluatingthesystem-levelfeasibilityoffree-flightoperationsandtheintegrationofenablingtechnologies,includingCNScomponentsanddecisionsupporttools（DSTs）,forboththeflightcrewandtheairtrafficserviceprovidersontheground.

RELATEDDEVELOPMENTS

SeveralrecentandcurrentdevelopmenteffortsarerelevanttotheFFSIMinfrastructuredevelopment.Theeffortsarebrieflydescribedbelow,andtheconnectionofeachtoFFSIMdevelopmentorNASAresearchisidentified.Athoroughdiscussionoftheseendeavorsisbeyondthescopeofthispaper.

GroundATMDecisionSupportTools

NASAresearchershavebeendevelopingandfieldtestingCTAS,aDSTforground-basedair-trafficmanagement2,3.CorecomponentsofCTASareleveragedintheFFSIMinfrastructuretoprovidethesituationdisplayfortheATSPstation.（Thenotioninfreeflightofdistributingtrafficmanagementfunctionsbetweenthegroundandtheairleadstothere-designationofairtrafficcontrollertoairtrafficserviceprovider.）InclusionoftheseCTAScorecomponentsallowsforeventualexpansiontoincludeCTAScomponentssuchastheTrafficManagementAdvisor（TMA）forschedulingandEn-route/DescentAdvisor（E/DA）forATSPdecisionsupport.

FlightSimulationTools

NASAhasdevelopedaversatilePC-basedsimulationofatransport-categoryaircraftcalled“FastWin”（FMS-AutoflightSimulationToolsforWindows）4.FastWinincludesanaircraftperformancemodel,aFlightManagementSystem（FMS）model,ControlDisplayUnit（CDU）,ModeControlPanel（MCP）,andprimarycockpitdisplays.FastWinisintegratedintotheFFSIMinfrastructureasthecorecomponentoftheresearchpilotstation.

Logiconpreviouslydevelopedasoftwaresimulationtoolentitled“PseudoAircraftSystems”（PAS）toserveasatargetgenerationfacilityandpseudo-pilotstationwithalow-fidelityauto-pilotcapabilityforCTASdevelopmentexperiments5.ThePASsoftwareisusedintheFFSIMinfrastructuretomanagetrafficscenarios,togeneratetargets,andtoprovidetheabilityforahumanoperatortocontrolmultiplepseudo-pilots.

TheNationalAerospaceLaboratoryofTheNetherlands（NLR）iscurrentlyconductingextensiveATMresearchactivitiesthroughhumanin-the-loopsimulation.NotablesimulationtoolsdevelopedbyNLRincludeTMX,atarget-aircraftgenerator;AIRSIM,aninterfacetoasinglepilotstation;andNARSIM,adistributedsimulationeffortaimedatinvestigatingtheEuropeanversionoffreeflight6.AcloseworkingrelationshiphasbeenestablishedbetweenSeagullandNLRtoexploitlessonslearnedduringtheirresearchandtoaccelerateFFSIMdesignanddevelopment.NASAandNLRareexploringacollaborativeapproachtofree-flightresearchwithactivitiesstartingin1999.

EurocontrolhasalsobeenveryactiveinATMresearch.EffortsrelevanttoFFSIMinclude:

OASIS,agenericsimulationinfrastructurebasedontheCommonObjectRequestBrokerArchitecture（CORBA）;ESCAPE,adistributedairtrafficcontrol（ATC）simulationthatusesOASIS;andFREER,afour-partresearchprogramthatissimulating,developing,andflight-testingaprototypesystemforfully-autonomousaircraftoperations.

Figure2:

TheFFSIMinfrastructureisadistributedsimulationtoolcapableofprovidingacomprehensivemodelofcurrentandenvisionedair-traffic-managementoperationswithfuturecommunication,navigation,andsurveillancecapabilities.

ConflictDetectionandResolution

Numerousorganizationshavedevelopedsoftwarealgorithmsforconflictdetectionandresolution（CD&R）7.SeagullTechnologyhasdevelopedasolutionapproachthatcanbeappliedinbothgroundandairbornecontexts8.MIThasperformedsignificantresearchinCD&R9,10.LincolnLaboratoryatMITdevelopedaself-organizationalapproachforconflictresolution11.Thislastapproach,combinedwithconflictdetectionbasedonaircraftstateinformationandflightplans,wasimplementedasaninitialdecision-aidingprototypesysteminFFSIMfortheflightdeckandtheATSPbyLockheedMartinAeronauticalSystems12.

CNSModeling

MITLincolnLabshasextensivelystudiedtheautomaticdependentsurveillance–broadcast（ADS-B）concept13,14.ThesetheoreticalandempiricalstudiesofADS-B,whichincludemessage-collisionmodeling,areleveragedintheFFSIMrepresentationoftheCNSinfrastructure.NASAGlennResearchCenteriscurrentlydevelopinghigh-fidelityparametricmodelsforcommunicationmechanismssuchasModeS,VHFDatalink（VDL）Modes2,3,and4,etc.ManyofthesemodelswillbeincorporatedintoFFSIMtopermitassessmentofdesignrequirementsforfreeflightapplicationofthesetechnologies.

FFSIMINFRASTRUCTUREANDRESEARCHCAPABILITIES

TheFFSIMinfrastructureisuniqueinthatitprovidessystem-levelintegrationandmodelingoftechnologiesvitalforfreeflightwithsufficientfidelityforassessingtheirimpactonthefeasibilityoffree-flightoperations.FFSIMprovidesahumanin-the-loopenvironmentwhereseveralresearch-subjectpilotsflysimulatedaircraftthroughsimulatedairspacemanagedbyoneormoreresearch-subjectATSPs.Thehuman-subjectpilotsandATSPsmayhavetheassistanceofprototypeDSTsprovidingseparationassuranceandothernavigationfunctionsandmaycommunicatebyvoiceordigitalcommunications.CNStechnologiesaremodeledwithmoderaterealismtoallowtheprocessesofcommunication,navigation,andsurveillancetoo