火灾报警器中英文文献翻译.docx

外文文献原稿和译文原稿Multiplesingle-chipmicrocomputerapproachtofiredetectionandmonitoringsystemA.J.AI-Khalili,MSc,PhDD.AI-Khalili,MSc,PhDM.S.Khassem,MScIndexingterm:Hazards,Design,PlantconditionmonitoringAbstract:Acompletesystemforfiredetectionandalarmmonitoringhasbeenproposedforcomplexplants.Thesystemusesmultiplesinglechiparchitectureattachedtoapartyline.Thecontrolalgorithmisbasedonatwo-levelhierarchyofdecisionmaking,thusthecomplexityisdistributed.Acompletecircuitdiagramisgivenforthelocalandthecentralstationwithrequirementsforthesoftwarestructure.Thedesigniskeptingeneralformsuchthatitcanbeadaptedtoamultitudeofplantconfigurations.Itisparticularlyshownhownewdevelopmentsintechnology,especiallyCMOSsinglechipdevices,areincorporatedinthesystemdesigntoreducethecomplexityoftheoverallhardware,e.g.bydecomposingthesystemsuchthatlowerlevelsofhierarchyareabletohavesomeautonomyindecisionmaking,andthusamorecomplexdecisionissolvedinasimpledistributedmethod.1DetectionandalarmdevicesAbasicfiredetectionsystemconsistsoftwoparts,detectionandannunciation.Anautomaticdetectiondevice,suchasaheat,smokeorflamedetector,ultravioletorinfrareddetectorsorflameflicker,isbasedondetectingthebyproductofacombustion.Smokedetectors,ofbothionizationandopticaltypes,arethemostcommonlyuseddetectordevices.WhenatypicaldetectorofthistypeentersthealarmstateitscurrentconsumptionincreasesfromthepAtothemArange(say,fromamere15pAinthedormantmodeto60mA)intheactivemode.Inmanydetectorsthedetectoroutputvoltageiswelldefinedundervariousoperatingconditions,suchasthoseTb1TmSldE°rVoMOUSS2giveninTableI.ThemoresensitivetheVoh9viDetectorcondition22vDtct(×4inc<cutc<xxt>ondetector,themoresusceptibleitistofalsealarms.13V-22Vdtciorisorm1 V-13Vdetctorsman4armstat2 VdetcorsmShoftOfCUKC(MMMlonInordertocontrolthedetectorprecisely,eitherofthefollowingmethodsisused:acoincidencetechniquecanbebuiltintothedetector,orafilteringtechniquesuchthatalogiccircuitbecomesactiveonlyifxalarmsaredetectedwithinatimeperiodT.Thedetectiontechniquedependsgreatlyonthelocationandplantbeingprotected;smokedetectorsareusedforsleepingareas,infraredorultravioletradiationareusedwhenflammableliquidsarebeinghandled,heatdetectorsareusedforfiresuppressionorextinguishingsystems.Ingeneral,lifeandpropertyprotectionhavedifferentapproaches.Alarmdevices,apartfromtheusualaudibleorvisiblealarms,mayincorporatesolidstatesoundreproductionandemergencyvoicecommunicationorprintersthatrecordtime,date,locationandotherinformationrequiredbythestandardcodeofpracticeforfireprotectionforcomplexplants.Heaviside4hasanexcellentreviewofalltypesofdetectorsandextinguishersystems.2.1 ControlphilosophyanddivisionoflabourOurcontrolphilosophyisimplementedhierarchically.Threelevelsofsystemhierarchyareimplemented,withtwolevelsofdecisionmaking.Thereisnocommunicationbetweenequipmentonthesamelevel.Interactionbetweenlevelsoccursbyupwardstransferofinformationregardingthestatusofthesubsystemsanddownwardstransferofcommands.ThisisshowninFig.1whereatlevel1isthecentralstationmicrocomputerandistheultimatedecisionmaker(whennotinmanualmode).Atlevel2arethelocalcontrollers,whichresideinthelocalstations.Atlevel3aretheactualdetectorsandactuators.Amanualmodeofoperationisprovidedatalllevels.Informationregardingthestatusofalldetectorsistransmittedonaperareabasistothelocalcontrollers.Theirinformationiscondensedandtransmittedupwardtothecentralmicrocomputer.Transferofstatusisalwaysunidirectionalandupwards.Transferofcommandsisalwaysunidirectionalanddownwards,withexpansionatthelocalcontrollevel.Thisapproachpreservesthestrictrulesofthehierarchyforexactmonitoringdetectionandalarmsystemsassociatedwithhighriskplants."SCFel Court4 philmo>y2/££ PItOCEEDINGS. Vol. 135. Pt. C, Nd I. FEVA Y /«MTheclassificationofthetwolayersofcontrolsisbaseduponlayersofdecisionmaking,withrespecttothefactsthat(a) Whenthedecisiontimecomes,themakingandimplementationofadecisioncannotbepostponed(b) Thedecisionshaveuncertainty(c) Itwillisolatelocaldecisions(e.g.locallyWemighthaveanalarmalthoughtheremaybeafaultwiththesystem)3 GeneralhardwareI:Fig.2depictsourdesigninthesimplestofforms.Thesystemusesanopenpartylineapproachwithfourconductorcablesgoinginaloopsharedbyalltheremotedevicesandthecontrolpanel.Thisapproachissimpleinconceptandiseconomicallyfeasible.However,onemajordisadvantageisthedependencyonasinglecableforpowerandsignaling.Incaseswherereliabilityisofextremeimportance,twooreventhreecablestakingdifferentroutesthroughoutthesystemmaybeconnectedinparallel.Fig.3givesthedrivercircuitryrequiredtoderiveanexpandablebus.Thisdesigntakesadvantageofrecentadvancesinthesinglechipmicrocomputertechnologytoreducetheinterfacebetweenthecentralstationandthelocalstations.FROMINPUT TO OUTPUT2.IEEPROCEEDINGS, Vol. 135, Pi.A central unit provides a centralized point to monitor andFig.4 Aznwff rrurt dttfrmtooutput (Xye£ ftP "3 ORTADCooeS»0V HfF IgtoOEr 321AEMHCHA<ooe 5tooct 42UC