火灾自动报警系统英文.docx
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火灾自动报警系统英文
AutomaticfirealarmsystembasedonMCU
Abstract:
Thepaperintroducedanautomaticwarehousefirea1armsystembasedonMCU.ThesystemwasmainlymadeupofATmega16,temperaturesensors,smokesensors,andEX-1autodialedalarmmodule.Inthesystem,temperaturesignalsweretransformedtoserialdata,andsmokesignalsweretransformedtovoltagesignals.AllthedatawereprocessedbyMCU.Whenthesurveillancesystemcheckedfireinwarehouse,alarmsignalwasturnon,meanwhilethemessagesweretransmittedtomanagersthroughEX-1.Applicationofthesystemwasconvenienttodealwithfirein-time,efficientlybywarehousemanager.
Keywords:
firealarmtransducer;smokesensorsystem;ATmega16;temperaturetransducer;smokesensor
I.INTRODUCTION
AutomaticfirealarmcontrolsystemhasexperiencedaprocessfromthesimpletothecomplexandintelligencesystemincreasinglyinChina.Thecharacteristicisautomaticfiredetectionandalarmtechnologyhasagreatprogressalongwithcomputinganddetectiontechnologydevelopment.Atpresent,automaticfirealarmcontrolsystemwasusedinbulkstorageplant,shoppingmalls,high-levelofficebuildings,hotelsandotherplaces.Theywereusedinanumberofcollectionsfocusedononeareaofintelligentalarmcontrolmethodwithhigherlevelsofbus-typealarmcontrolsystem,andinsomeresidentialareasandcommercialbuildingswereinstalledbyasingleautomaticfirealarmdetectiondevice.Thesealarmdetectiondevicesfailtoreportsometimes,ormisinformation.Itsreliabilityisnothighbecauseofusingsinglesensor.Therefore,itisneededtodevelopasimplestructure,lowcost,highreliability,fastresponding,automaticfiredetectionsystem.
II.GENERALPROJECTOFTHESYSTEM
ThehardwareblockdiagramshowninFigure1,hardwarebytemperaturesensors,smokesensors,signalprocessingmodule,MCUmodulesandautomaticalarmmodule.Nonelectricalquantitythatisthroughthesensingelementsensors(smokesensorsandtemperaturesensors)willbeon-sitetemperature,smokeandothernon-electricalsignalintoanelectricalsignal,aswellassignalsforsignalprocessingtoconvertanalogquantitytodigitalquantity.Finally,thesampleddatawereprocessedandcomparedwiththelimitsbyMCUsystem.Thissystemcanproducelocalandremoteauto-alarmsignals.
TemperatureIonization
Transducersmokedetector
signal
processing
PD0PD1
SCM
autoalarm
module
Tephoneel
Interface
…
Figure1.Automaticfirealarmsystemstructure
Ⅲ.THEHARDWARECOMPONENTS
A.Atmega16
ThesystemusedbytheU.S.Atmel’smicrocontrollerATmega16microcontroller.ATmega16isbasedontheAVRRISCarchitecturetoenhancelow-power8-bitCMOSmicrocontroller.Becauseofitsadvancedinstructionsetandasingleclockcycleinstructionexecutiontime,ATmega16datathroughputofupto1MIPS/MHz.Therebymitigatethesysteminthepowerandthecontradictionbetweentheprocessingrate.ATmega16hasthefollowingcharacteristics:
16Kbytesin-systemprogrammableFlash(withtheabilitytoreadandwriteatthesametime,thatis,RWW),512bytesEEPROM,1KbytesSRAM,32general-purposeI/Oportlines,32general-purposeworkingregisters,fortheJTAGboundaryscaninterface,supporttheon-chipdebuggingandprogramming,3hasamoreflexiblemodeoftimer/counter(T/C),chipinternal/externalinterrupts,programmableserialUSART,thereareinitialconditionsdetectoruniversalserialinterface,8-channel10-bitwithoptionaldifferentialinputstageprogrammablegain(TQFPpackage)oftheADC,withon-chiposcillatorofprogrammablewatchdogtimer,anSPIserialport,aswellassixcanbeselectedbysoftwarepower-savingmode.
ThechipisbasedonAtmelhigh-densitynonvolatilememorytechnologyproductionon-chipISPFlashallowstheprogrammemorythroughtheISPserialinterfaceorageneral-purposeprogrammerforprogramming;youcanalsorunontheAVRcoreamongthebootstraptoprogram.BootprogramcanuseanyinterfacetodownloadtheapplicationtotheFlashmemoryarea(ApplicationFlashMemory).ApplicationofFlashstorageareaisupdatedwhenthebootFlasharea(BootFlashMemory)programcontinuestorun,RWWoperationachieved.ATmega16tobecomeapowerfulmicrocontrollerby8-bitRISCCPUandthesystemprogrammableflashinasinglechip,formanyembeddedcontrolapplicationsprovidesaflexibleandcost-effectivesolution.ATmega16hasasetofprogrammingandsystemdevelopmenttools,including:
Clanguagecompiler,macroassembler,programdebugger/softwareemulator,emulatorsandevaluationboards.
B.TemperatureSensor
TemperaturesensormanufacturedbyDALLASSemiconductorDS18B20-typesingleintelligencetemperaturesensor,itsperformancefeaturesinclude:
1)Thissensorhavesingle-bus-specifictechnology,eitherthroughtheserialportcablealsothroughotherI/Oportlinesandcomputerinterfaces,withoutgoingthroughotherconversioncircuitsDirectoutputmeasuredtemperaturevalue(9-bitbinarynumber,withsignbit).
2)Temperaturerangeis-55℃~+125℃,measurementresolutionof0.0625℃.
3)Containing64asamendedthroughthelaser-read-onlymemoryROM.
4)FitavarietyofSCMorsystemmachine.
5)Userscansetseparatewayseachtemperatureupperandlowerlimit.
6)Includesparasiticpower.
DS18B20andthemainchipconnectiondiagramshowninFigure2:
DS18B20numberonepingrounded,thenonthe3rdpinhighandthe2ndpinthena5.1Kofthepull-upresistor,atthesametimereceivedasingleoutputsignalofthePD0pin.Pull-upistopulltheuncertaintysignalthrougharesistorembeddedinthehighplaces,resistanceatthesametimecurrent-limited.ProgramfromtheDQpininhighimpedancestatetoensurethatthebeginning,sothatyoucanpullonthepull-upresistortothehighDQ.Atthesametimethemainchipalsocanbeanexternalsitealarmbuzzer.
Figure2.ds18b20andthemainchipconnectiondiagram.
C.SmokeMonitoringModule
SmokesensorschooseHIS-07ionsmokedetectorswhentheflowthroughtheinsideandoutsidetheionizationchamberionizationelectronflowisunbalanced,collectorchargescurrentuntiltheionizationbalance.Inasmoke-freeornon-combustion,thecollectorbeingsubjecttotheimpactionizationcurrentstatisticalfluctuation,thepotentialtomaintainabalance.Ionizationcurrenthaveimpactwhenthesmokeintotheionizationchamber,easilyintotheionizationchambersmokeoutsidethaninsidetheionizationchamberoftheaffected,ionizationcurrentdeclineinandcollectortore-chargeuntilthenewequilibriumpotential,thispotentialchangecanbeusedtotriggerthealarmcircuit.TechnicalparameterssuchasTable1.
TABLEI.HIS-07IONSMOKESENSORTHCHNICALDATA
TableHeadTableColumnhead
Equilibriumpotentialcollector5.5±0.3V
Collectorpotentialwiththesmoke
Reducedlightrateof1%/ft0.6V
Reducedlightrateof4%/ft2.2V
Capacitor6PF
SmokesignalsareprocessedonthechipofchoiceistheMotorolacompany’sMC14468,MC14468forDIP16-pinpackage,containoscillator,timer,latch,alarmcontrollogiccircuit,highinputimpedancecomparatoretc.Whennotdetectedsmoke,MC14468internaloscillatorthatoscillationcycle1.67s.Each1.67scycletheinternalpowersupplyisprovidedtotheworkoftheentirechip.It’sallkeptdetectanysmokeinadditiontoLEDflashes,batteryvoltagealarmandsmokealarm.Theoscillatoroscillationperiodbecomes40mswhentheMC14448Oncedetectionsmoke,thistimepiezoelectricbuzzerdrivingcircuittostartoscillation,starttobeabletooutputtomaintainthehigh160msafterthecessationof80ms.Continuedduringthedetectionofsmokecessationofchanges,atthistimeifnotdetectedsmokebeeperwillnotbeissuedawarningsound.
Infigure3,theMC144681pinjointPD1pinofSCMwhentheionchamberoftheioncurrentasthesceneofsmokedetectionandchange,voltagechangegenerationaweakside-spreadseized15,bytheMC14468internallogicprocessingcircuitprocessing,thesmokeisdetectedby1pin-outhighmicrocontrollerforprocessing.13-pinthensliderheostatissettofacilitatedetectionsensitivitywhentheledflashesandthebuzzersoundedapiercingsoundofanaudioalarmwhenthedepartmenthasafirealarmsignal-based.
Infigure3,theMC144681pinjointPD1pinofSCMwhentheionchamberoftheioncurrentasthesceneofsmokedetectionandchange,voltagechangegenerationaweakside-spreadseized15,bytheMC14468internallogicprocessingcircuitprocessing,thesmokeisdetectedby1pin-outhighmicrocontrollerforprocessing.13-pinthensliderheostatissettofacilitatedetectionsensitivitywhentheledflashesandthebuzzersoundedapiercingsoundofanaudioalarmwhenthedepartmenthasafirealarmsignal-based.
Figure3.Smokedetectioncircuit
D.Auto-dialalarmmodule
Dial-upalarmmodulechoicesaretheEX-1dial-upmoduleisaDTMFsignalreceiving,storing,andsendingasintegrationcommunicationscircuits.Modulebuilt-inmicrocontrolleranddial-upmanagementprocesscanprovideuserswithavarietyofsignalinputandoutputports,insecurityalarm,signalacquisition,automaticcontrol,remotecommunicationandinformationtransmissionareassuchasflexibleapplication.5groupscanhavecellphoneorgroupofsevenlocaltelephonenumbersarestored,power-downisnotlost;Telephonelinestatusdetection,automaticfaultsignaloutput;Telephone/externalswitchingtwokindsofdial-upstatecontrol;Triggertime,ninetimesloopdialpresetnumbers;Toworkindependently,independentdial-up,donotrelyontelephoneandotherexternaldevices.
EX-1wiringdiagramshowninfigure4,ThePD4pintoconnectthemainchipHTO,themodulebegantodialalarmwhenPD4outputhighlevelsignal,PD5connectionON/OFFpininputishighlevelsignaltoopen