tcas的工作原理How does TCAS work.docx

tcas的工作原理How does TCAS work.docx

《tcas的工作原理How does TCAS work.docx》由会员分享，可在线阅读，更多相关《tcas的工作原理How does TCAS work.docx（6页珍藏版）》请在冰豆网上搜索。

tcas的工作原理HowdoesTCASwork

tcas的工作原理（HowdoesTCASwork）

TheworkingprincipleofTCASandtheworkingprincipleofTCAS

Theaircraftcollisionavoidancesystem,theAmericanairlinesystemiscalledairtrafficwarningandcollisionavoidancesystem（TCAS:

TrafficAlertandCollisionAvoidance）

System）theEuropeanAeronauticsystemiscalledanAirborneCollisionAvoidanceSystem（ACAS:

Airborne,Collision,Avoidance）

（System））theactualmeaningandfunctionofthetwoarethesame.Thecollisionavoidancesystemcanshowthesituationaroundtheaircraftandprovidevoicealarmswhennecessary,whilehelpingdriversavoiddangeroussituationsinanappropriateway,whichcanhelppreventcatastrophicaccidents.

Let'stakeTCASasanexample.

TCAS'shistorycanbetracedbackto1955,whentheBendixAviationElectronics（nowpartofHoneyWellCompany）Dr.J.S.Morrellpublished"collisions"article.Theseincludethecomputeralgorithmfordeterminingthespeedofapproachingaircraft,whichisthebasisforthestudyofallcollisionavoidancesystems.In1960sand70s,thecompanydevelopedseveralprototypemachinesfortheUnitedStatesArmyandtheFederalAviationAdministration（FAA）,andacquiredtheFAA'sfirstidentificationoftheTCASinthelate80s.

TCASdeviceexterior

Principle:

Intheprincipleofdeterminingthenumber,headingandheightoftheaircraftbythetworadartransponder,theinterrogationdeviceismountedontheaircraft

Theaircraftcandisplaythedistancebetweeneachothersothatthedriverknowstheintervalsbetweentheaircraftflyinginacertainrangeandtakestimelymeasurestoavoidcollisions.Likethetworadar,theTCASsystemneedstobeequippedwithtranspondersontheaircraft.

Withreferencetothetworadar,thetypeofairtrafficcontrolradarcanbereferenced

Compositionandfunction:

TCASconsistsofinterrogator,transponder,transceiver,andcomputer.Monitoringrangeisgenerally30nauticalmilesahead,3000metersaboveandbelow,andsmallermonitoringinthesideandrear.Toreduceradiointerference,themanagementregulationslimitthepoweroftheTCAS.ItlimitstheforwardrangeoftheTCAStoabout45miles,whilethelateralandbackwarddistancesaremuchsmaller

TheTCASinterrogatorsendsoutapulsesignalcalledtheinterrogationsignal,similartothegroundlaunchedradartrafficcontrolsignal.Whenthetransponderoftheotheraircraftreceivestheinterrogationsignal,thetranspondersignalistransmitted.TheTCAScomputercalculatesthedistancebasedonthetimeintervalbetweenthetransmitsignalandtheacknowledgesignal.Atthesametime,accordingtothedirectionoftheantennatodeterminethedirectionofthedrivertoprovideinformationandwarning,thisinformationisdisplayedonthedriver'snavigationinformationdisplay.

TCASlanguagecanprovideadvicewarning,computercancalculatetheclosemonitorregionof30aircraftwithintheaircraftandtherisk,makethedriverhavetotakemeasuresto25-40seconds.（TCAStracks45aircraftanddisplaysupto30planesdependingonthepriorityoftheselectedtarget.）

TheadoptionofTCAShasimprovedflightsafety,andTCAShasbecomethestandardequipmentinthenewlyproducedlargeandmediumpassengeraircraft.

ClassificationanddifferentiationofTCAS:

TCASfallintotwocategories:

TCAS,I,andTCAS

II.Thetwosystemsshowairtrafficpatternssimilartothoseofmaps.Whenotherplanesapproach,twocategoriesofsystemscanprovideairtrafficreports（oradviceorrecommendations）（TA）.InTAmode,prerecordedsoundsbroadcast"Traffic,Traffic",whilesymbolsthatrepresentotherplaneschangeshapesandcolors.

TCAS

IIisamoreadvancedTCASwithadditionalfeaturescalledRA.WhenusingtheRAmethod,theTCASmayissueamotorcommandsuchas"Climb","Climb"or"Descend",or"Descent",orwilltellthedrivernottotakeamaneuver:

AirtrafficadvisoryTAwillbeissuedwhenthenearestpointoftheotheraircraftislessthan48seconds（Traffic）

Advisory）.Thenearestpointisthenearestspacebetweentwoplanes,basedonthecurrenttrackandspeedoftheaircraft.

Aftertheairtrafficadvisory,iftwoaircraftcontinuetoflyalongpotentiallydangeroustracks,thesystemwillprovideprocessingadviceRA（Resolution）about35secondsfromthenearestpoint

Advisory）.Symbolsrepresentingotherplanescanbecomefixedredsquares,accompaniedbyevasive,mobilevoicepromptssuchas"Climb"and"Climb".Thesystemalsodisplaystherequiredspeedwithagreenbarontheverticalspeedindicator.Thesemaneuversareoflittlemagnitudeandgenerallydonotattracttheattentionofpassengers.TheTCASIIonthesetwoplaneswillalsobecoordinatedtoavoidmaneuveringliketwoaircraftatthesametime.OnlyTCAS,ofcourse

TheIIandACASIIsystemshavethisfunctionality.ThereisnoRAwayintheTCA