ZigBee技术的无线火灾报警系统的构建
ZigBee技术的无线火灾报警系统的构建
摘要
本文指出了现在使用中的有线火灾自动报警系统的缺陷,以及构建无线火灾报警系统的需要性和可能性.IEEEVIII0II.I.V.IV的ZigBee技术及其特点的介绍.我们给出了I.个ZigBee技术构建无线火灾报警系统的方法,它包括结构,硬件和软件的设计.
关键字:ZigBee.无线传感器.火灾自动报警
I..简介
大部分当前使用的火灾自动报警系统传感器网络是CAN-BUS总线建立的,系统信号和数据是通过电缆传输的.与传统分布式电缆网络相比,总线网络在扩展性,施工难度和维护方面具有很大的提高,但是任然有很多缺陷,电缆和容易被腐蚀.老鼠咬坏.磨破,导致高故障率和误报警率.电缆传输距离也被限制,通常不能超过I.千米,否则衰减和干扰会导致系统传输失败.
我们这样设想,用无线传输方式构建火灾自动报警系统可以避免上述问题.这种无线信号传递方式可以增加报警信号传送距离.近些年随着微电子和无线通信技术的发展,这种技术可以实现.本文介绍I.种ZigBee技术构建火灾自动报警系统的方法.
II.ZigBee技术
ZigBee是IEEEVIII0II.I.V.IV的另I.种名称,是I.个发布于II00V年的无线网络协议.ZigBee技术是I.种双向无线传输技术,无线传输主要适应于自动控制和远程控制,它可以嵌入很多消费电子产品,家庭和建筑自动化设备,工业控制设备,各种传感设备,以及支持定位功能.ZigBee有如下特征:
低功耗,由于短的工作循环,它发送和接收信心的功耗很低,以及有睡眠状态.两个V#干电池可以支持I.个节点工作VI到IIIV个月,甚至更长.
低费用,极大的简化了协议和通信控制器的要求,取得较少的花费,系统的组件也很便宜,以及ZigBee协议的专利也是免费的.< *好棒文|www.hbsrm.com +Q: ^351916072*
br/>低传输率,它工作速度为IIV0kbps,满足低速传输率要求.
距离短,两个相邻节点之间的传输距离通常是I.0m到I.00m.如果增加RF传送功率,距离可达到I.到IIIkm.如果通过路由和通信中继,传输距离可以变的更远.
短延迟,ZigBee有优化时间延迟的灵敏应用.从睡眠中通信延迟和动作延迟是很短的,I.般来说,从睡眠到工作状态,只需要I.Vms,节点连接到网络只要III0ms.
大容量,ZigBee网络可由不同的方法构建而成.I.个主节点可以管理IIVIV个节点,系统任然可以通过每个节点增大到更大的网络.理论上I.个网络可以有VIVVIIIV个节点.
高安全性,ZigBee提供III种水平的安全模式,包括数据保存检查和认证,使用访问控制列表来房主非法数据获取,运用先进的加密标准(AESI.IIVIII),对称密码来保证安全性灵活.
免费频段,使用直接序列扩展范围技术,工作于全球免费的ISMII.IVGHz频率范围内.
设备花费少,传输数据量很小.
设备尺寸小,不适合放大的电池或者电源模块.
不适合经常更换电池或者不便于反复充电.
覆盖通信范围广,在所有网络中设备监测和控制,只有火灾自动报警系统具有上述所有特点,因此ZigBee技术构建是非常合适的.
III.系统设计
III.I.系统结构
图I.系统结构
该系统通过ZigBee无线网络来实现火灾监测和自动报警,系统主要包括III个部分:数据采集节点,数据汇聚节点和火灾控制中心,如图I.所示.
数据采集节点是I.个嵌入式无线传感器模块组成的传感器,主要控制单元(MCU)和射频(RF)通信功能.经过处理的探测器侦测的火灾信号,选择最优路径送入数据汇聚节点.数据汇聚节点将这些数据从传感器网络送到火灾控制中心.必要时,数据也会通过外部网络传送到火灾控制中心,如英特网.火灾控制中心由监控主机和服务器组成.服务器是用于存储火灾控制数据,电路图等等.监控主机是用于处理数据和统计价值,显示通过外围设备的报警信息,数据管理,数据查询和与使用者互动.
III.II系统硬件
系统硬件主要由数据采集器和数据接收器组成.数据采集器由传感器,微型程序控制器和射频芯片等等组成.微型程序控制器和射频芯片与总线连接,它们构成了无线通信模块.用同样的无线通信模块,数据接收器通过RSIIIIIII异步串口与计算机通信.在同I.个方向,通过无线方式控制信号被主机发射到数据采集器上,在另I.个方向,收集的数据上传到主机上.当传感器检测到火灾信号时,火灾控制中心将处理和统计评价数据,将其转换为合适的报警指示通过预先设置的规则,然后将报警信号传出去.
硬件系统图如图II所示
图II系统硬件结构
微型程序控制器能用VIII或I.VI位的单片机,具有片上集成功能,像MCSVI.系列,HCS0VIII系列或者MSPIVIII0系列单片机.用MCIXS0VIIIGTVI0j举例,HCS0VIII系列的I.个类型,它工作电压为I..VIIIV,集成IVKBRAM和VI0KBROM,集成VIII通道I.0位模数转换器,II个SCI界面和I.个SPI界面,它还有内部时钟模块和后台监测接口.该数据采集器的单片机接受传感器发送的信号,然后经过模数转换后送入射频芯片,该数据接收器的单片机接受到从射频芯片发来的信号 *好棒文|www.hbsrm.com +Q: ^351916072*
时,通过RSIIIIIII接口送入计算机做进I.步分析.必要时,可以直接驱动简单的声音或可视报警装置像蜂鸣器,发光II极管等等.
射频芯片可以选择ZigBee无线收发器系列,TI的CC系列或者飞思卡尔的MC系列.它们都工作在II.IVGHz范围.用MCI.IIII.IXII来说,它是符合ZigBee标准的I.种低成本,高性能射频芯片.它主要由分析收发单元,数字调制解调器,片上频率合成器,电源管理和单片机的借口组成.它工作频率范围为II.IVII0到II.IVVIII0GHz,数据传输率是IIV0kbps,工作频率范围可以分成I.VI个通道,每个通道带宽为VMHz.由于低的传输速率和通道较大的带宽,所以信噪比非常高,抗干扰能力强.
外部晶振提供MCI.IIII.IXII所需的时钟,片上频率合成器输出信号为单片机提供时钟.在MCI.IIII.IXII上的读写操作通过单片机上的I.个标准的IV线接口实现的.应该指出的是,由不同的厂家生产的大多数单片机和射频芯片可以灵活配置,但是实际工程中,最好是使用同I.家公司的产品确保系统的稳定性.集成了单片机和射频芯片的嵌入式芯片也能被接受.
III.III系统软件
系统软件包括III部分:无线传感器节点程序,数据汇聚点程序和中心监控程序.
无线传感器节点间断地监测环境参数.当系统开始工作,单片机和射频芯片首先初始化,然后选择通道,开中断来接收数据.然后初始化模数转换器和采集数据进行处理.如果有I.个报警信号,这个信号,传感器接节点位置和采集到的数据将会结合I.起作为报警数据,翻译成ZigBee协议中通信信息包.选择I.个优先的通信路径,信息包将被送到数据汇聚节点,然后等待确认返回.这样,I.个完整的ZigBee通信就完成了,从汇聚节点收到确认返回后,传感器将自动的保持低功耗模式.此外,当传感器节点接收到汇聚节点的请求时,它能立刻收集数据,以实现实时监测.传感器节点程序如图示所示.
汇聚节点程序主要是从无线传感器上接受信息,确认信息,然后通过RSIIIIIII接口将其送入监控主机.
位于火灾监控中心的监控主机用于接受汇聚节点传送的数据,监测,报警和控制传感器节点的工作状态.上级电脑的监控程序是串行通信设计的.VC++提供ActiveX串行通信,能容易的操作串行端口.软件通过串行端口发送请求,通过进程指示接收数据的过程,而且可以立刻通过显示界面来显示数据的波形,在同I.时间能将数据保存到数据库便于进I.步分析或者调查研究.
图.III
IV.结论
ZigBee的技术无线火灾自动报警系统的构建,克服了有线报警系统的局限性,避免了其他无线通信技术的高功耗.相比现有的无线传感器网络,它有I.些优点,如成本低,网络容量大,寿命长.系统安装对建筑物造成的损坏小,放置节点和维护方便.它适用于各种场合,特别适用于在博物馆,古建筑群,具有广阔的应用前景火力控制.
附件II:外文原文
ConstructionofWirelessFireAlarmSystemBasedonZigBee
Technology
Abstract
Thispaperpointsoutthedefectofwiredautomaticfirealarmsysteminused,andthenecessityandpossibilityofconstructingwirelessfirealarmsystem.ZigBeetechnologybasedonIEEEVIII0II.I.V.IVanditscharacteristicsareintroduced.WealsogiveoutamethodofconstructingwirelessfirealarmsystembasedonZigBee,includingthedesignofconstruction,hardwareandsoftware.
I..Introduction
MostfiresensornetworksarebuiltbasedonCANbusincurrentlyusedautomaticfirealarmsystem,inwhichsignalsanddataaretransferredthroughcable.Comparedtotraditionaldistributedcablenetwork,busnetworkhavegreatlyimprovedinexpansibilityanddifficultyofconstructionandmaintenance.Buttherearestillsomedefects.Thecablesareeasilytobeeroded,bittenbyrats,frayed,causingtohighfaultrateandhighfalsealarmrate.Thecabletransmissiondistanceislimited,usuallynomorethanI.km,otherwisetheattenuationandinterferencewillleadtofailureofsystem.
Wemayconceivethat,constructingautomaticfirealarmsysteminwirelesstransmissionway,canavoidaboveproblems.Anewwayofwirelesssignalrelayalsocanincreasealarmsignaltransmissiondistance.Withmicroelectronicsandwirelesscommunicationtechnologydevelopmentinrecentyears,thiscanbecomeareality.
ThispaperintroducesamethodofconstructingautomaticfirealarmsystembasedonZigBeetechnology.
II.ZigBeeTechnology
ZigBeeisanalternativenameofIEEEVIII0II.I.V.IV,awirelessnetworkprotocolreleasedinII00V.ZigBeetechnologyisatwo-wayradiocommunicationtechnology,mainlysuitableforautomaticcontrolandremotecontrolbasedonwirelesscommunication.Itcanbeembeddedinvariousconsumingelectronics,familyandbuildingautomationequipment,industrialcontrolequipment,varioussensorsequipment,alsosupportingthegeographicallocationfunction.
ZigBeehasthefollowingfeatures:
?Lowpowerdissipation.Duetoshortworkingcycle,ithaslowpowerdissipationinsendingandreceivingmessages,andadoptsasleepmode.TwoV#drybatteriescansupportanodeworkforVItoIIIVmonths,orevenlonger.
?Lowcost.Dramaticallysimplifyingtheprotocolandreducingtherequirementofcommunicationcontroller,causesverylowcost.Themodulesarecheap,andZigBeeprotocolpatentisfree.
?Lowtransmissionrate.ItworksatIIV0kbpsrate,satisfyingtheapplicationrequirementsoflowdatatransmissionrate.
?Shortdistance.ThetransmissiondistancebetweenadjacentnodesisusuallyI.0~I.00m.IfincreasetransmittingpowerofRF,thedistancecanbeI.-IIIkm.Ifthroughtheroutingandcommunicationrelay,thedistancewillbeevenmore.
?Shorttimedelay.ZigBeehasoptimizationintimedelaysensitiveapplication,thecommunicationdelayandactivateddelayfromdormancyisveryshort.Generally,fromsleepingtoworking,justneedsI.Vms,andthenodesconnectingtonetworkneedsonlyIII0ms.
?Highcapacity.ZigBeenetworkcanbeconstructedindifferenttypes.AmasternodecanmanageIIVIVnodes,stillcanextendtobiggernetworkbyeachnode.TotalnetworkcanhaveVIVVIIIVnodesintheory.
?Highsecurity.ZigBeeprovidesathree-levelsafemode,includingdataintegritycheckingandauthenticating,usingAccessControlList(ACL)topreventillegaldataacquisition,usingAdvancedEncryptionStandard(AESI.IIVIII)symmetricalpasswordstodeterminethesecurityattributeflexibly.
?Freefrequencyband.Itusesdirectsequencespreadspectrumtechnology,workingatglobalfreeISMII.IVGHzfrequencyband.Usually,applicationaccordwiththefollowingconditionscanconsiderusingZigBeetechnology
?theequipmentcostlow,transmittingdatavolumeissmall
?equipmentissmallinsize,unfittoplacebigbatteryorpowermodule
?unfittoreplacebatteriesfrequentlyorinconvenienceforchargingrepeatedly
?coverawiderangeofcommunication,manyequipmentinnetwork,butonlyformonitoringandcontrollingAutomaticfirealarmsystemhasalmostalloftheabovecharacteristics,soit’sverysuitabletobebuiltbasedonZigBeetechnology.
III.SystemDesigning
III.I..SystemStructure
Fig.I.Systemstructure
ThesystemusesZigBeewirelessnetworktoachievefiremonitoringandautomaticalarming,mainlyincludesthreeparts:thedataacquisitionnodes,datasinknodesandfirecontrolcenter
Dataacquisitionnodeisanembeddedwirelesssensormoduleintegratingsensors,maincontrolunit(MCU)andradiofrequency(RF)communicationfunctions.Afterpreprocessingthefiresignalsdetectedbythesensors,itchoosesanoptimalpathtosendthemtothedatasinknode.Thedatasinknodessendsthedatafromthesensornetworktothefirecontrolcenter.Whennecessary,thedatamayalsobesenttothefirecontrolcenterbyexternalnetwork,suchasInternet.Firecontrolcenterconsistsofsupervisionhostandserver.Theserverisusedtostorefirecontroldata,electronicmap,etc.Thesupervisionhostisusedfordataprocessingandstatisticalevaluation,displayingalarminformationthroughperipheralequipment,andfordatamanagement,dataqueryandinteractionwiththeuser.
III.II.Systemhardware
Thesystemhardwaremainlyconsistsofdatacollectoranddatareceiver.Datacollectorconsistsofsensors,MCU,RFchips,etc.MCUandRFchipsareconnectedbyPCIbus,theyconstitutethewirelesstransmissionmodule.Withthesamekindofwirelessmodule,datareceivercommunicateswiththePCthroughRSIIIIIIIasynchronousserialinterface.Inonedirection,thecontrolsignalsareemittedfromthehosttothedatacollectorinwirelessway,inanotherdirection,thecollecteddataisuploadedtothehost.Whenfiresignalisdetectedbythesensors,thefirecontrolcenterwillprocessandstatisticallyevaluatethedata,andconvertittosuitablealarmingindicatoraccordingwiththepre-setrules,thensendoutalarmsignals.
DiagramofthesystemhardwarestructureisshowninFig.II.
Fig.IIsystemhardwarestructure
MCUcanchooseVIIIorI.VI-bitsingle-chipmicrocomputerwithon-chipintegratedROM,suchasMCSVI.series,HCS0VIIIseriesorMSPIVIII0seriesMCU.,TakingMCIXS0VIIIGTVI0forexample,onetypeofHCS0VIIIseries,itworksatI..VIIIVvoltage,integratedIVKBRAMandVI0KBFlashROM,andintegratedVIIIchannelsI.0-bitADC,IISCIinterfaceandI.SPIinterface.Italsohascorrespondinginternalclockmoduleandbackgrounddebuginterface.TheMCUofthedatacollectorreceivesthesignalsentbythesensor,thensendsittoRFchipafterA/Dconversion.WhiletheMCUofthedatareceiverreceivesthedatasentfromtheRFchip,andsenditthroughRSIIIIIIIinterfacetotheup
computerforfurtheranalysis.Whennecessary,itmayalsodirectlydrivesimpleaudibleorvisualalarmdevicessuchasbuzzer,LED,etc.
RFchipcanchooseZigBeewirelesstransceiverseries,CCseriesofTIorMCseriesofFreescale.TheybothworkatII.IVGHzband.TakingMCI.IIII.IXIIforexample,itisalowcost,lowpowerconsumption,highperformance
RFchipaccordwithZigBeestandard.Itmainlyconsistsofanalysisreceiving-transmissionunit,digitalmodems,on-chipfrequencysynthesizer,powermanagerandMCUinterface.It’sworkingbandisII.IV0V~II.IVVIII0GHz,datatransferrateisIIV0kbps,workingfrequencybandcanbedividedintoI.VIchannels,eachchannelbandwidthVMHz.Duetothelowtransmissionrateandthelargebandwidthofthechannel,sotheSNRisveryhigh,anti-jamming
capabilityisstrong.
ExternalcrystalprovidestheclockneededbyMCI.IIII.IXII,andtheon-chipfrequencysynthesizeroutputsignalsprovidetheclockforMCU.Read-writeoperationonMCI.IIII.IXIIisachievedthroughastandardfour-wireSPIbythe
MCU.Itshouldbepointedoutthat,mostMCUsandRFchipsproducedbydifferentcompaniescanbecollocatedflexibly,butinpracticalengineering,itissuggestedtousetheproductsfromsamecompanyinordertoensurethestabilityofthesystem.Also,embeddedchipsintegratedMCUandRFchipcanbeadopted.
III.III.Systemsoftware
Systemsoftwareincludesthreeparts:wirelesssensornodeprocedures,datasinknodeproceduresandcentermonitoringprocedures.
Wirelesssensornodesperiodicallydetectenvironmentalparameters.Whenthesystembeginstowork,MCUsandRFchipsareinitializedfirstly,thenchoosesthechannel,opensinterruptforreceivingdata.TheninitializeADCandcollectdatatoprocess.Ifthereisanalarmsignal,thesignal,sensornodeaddressandthecollecteddatawillbecombinedasalarmdata,andtranslatedintoZigBeecommunicationprotocolpackets.Selectinganoptimalcommunicationpath,thepacketsaresenttothedatasinknode,andwaitingforthereturnedconfirmation.Thus,awholeZigBeewirelesscommunicationiscompleted.Afterreceivingtheconfirmationreturnedfromthesinknode,thesensornodewillstayatlowpowermodeautomatically.Inaddition,whenthesensornodereceivingarequest
fromthesinknode,itcancollectdataimmediately,inordertorealizereal-time,activemonitoring.Thesensornode
procedureisshowninFig.III.
Thesinknodeprocedureismainlytoreceivedatafromwirelesssensor,confirming,thensendittothesupervisionhostthroughRSIIIIIIIinterface.
Locatedinthefirecontrolcenter,thesupervisionhostisusedforreceivingthedatasentbythesinknodes,monitoring,alarming,andcontrollingworkingconditionofthesensornodes.Themonitoringprocedureinuppercomputerisdesignedbasedonserialcommunication.VC++providesserialcommunicationActiveX?caneasilyoperateonserialport.Softwaresendsrequestthroughserialport,indicatingthedatareceivingprocessbyaprogressbar,andcandisplaythedatawaveformthroughadisplayinterfaceinstantly,andsavedatatodatabaseforfurther
Fig.IIIFLOWchartofsensornodeprocedure
IV.Conclusion
ThewirelessautomaticfirealarmsystemconstructedbasedonZigBeeovercomesthelimitationsofthecablealarmsystemandavoidshighpowerconsumptionoftheotherwirelesscommunicationstechnology.Comparedwithexistingwirelesssensornetwork,ithassomeadvantagessuchaslowcost,highnetworkcapacity,longlife.Andsysteminstallationdoeslessdamagetobuildings,convenientlytoplacenodesandmaintenance.Avoidingtheunsafefactorsoffire,lightningstrikeincablesystems,itissuitableforvariousoccasions,especiallyforfirecontrolinmuseums,ancientbuildinggroup,withawideapplicationprospect.
摘要
本文指出了现在使用中的有线火灾自动报警系统的缺陷,以及构建无线火灾报警系统的需要性和可能性.IEEEVIII0II.I.V.IV的ZigBee技术及其特点的介绍.我们给出了I.个ZigBee技术构建无线火灾报警系统的方法,它包括结构,硬件和软件的设计.
关键字:ZigBee.无线传感器.火灾自动报警
I..简介
大部分当前使用的火灾自动报警系统传感器网络是CAN-BUS总线建立的,系统信号和数据是通过电缆传输的.与传统分布式电缆网络相比,总线网络在扩展性,施工难度和维护方面具有很大的提高,但是任然有很多缺陷,电缆和容易被腐蚀.老鼠咬坏.磨破,导致高故障率和误报警率.电缆传输距离也被限制,通常不能超过I.千米,否则衰减和干扰会导致系统传输失败.
我们这样设想,用无线传输方式构建火灾自动报警系统可以避免上述问题.这种无线信号传递方式可以增加报警信号传送距离.近些年随着微电子和无线通信技术的发展,这种技术可以实现.本文介绍I.种ZigBee技术构建火灾自动报警系统的方法.
II.ZigBee技术
ZigBee是IEEEVIII0II.I.V.IV的另I.种名称,是I.个发布于II00V年的无线网络协议.ZigBee技术是I.种双向无线传输技术,无线传输主要适应于自动控制和远程控制,它可以嵌入很多消费电子产品,家庭和建筑自动化设备,工业控制设备,各种传感设备,以及支持定位功能.ZigBee有如下特征:
低功耗,由于短的工作循环,它发送和接收信心的功耗很低,以及有睡眠状态.两个V#干电池可以支持I.个节点工作VI到IIIV个月,甚至更长.
低费用,极大的简化了协议和通信控制器的要求,取得较少的花费,系统的组件也很便宜,以及ZigBee协议的专利也是免费的.< *好棒文|www.hbsrm.com +Q: ^351916072*
br/>低传输率,它工作速度为IIV0kbps,满足低速传输率要求.
距离短,两个相邻节点之间的传输距离通常是I.0m到I.00m.如果增加RF传送功率,距离可达到I.到IIIkm.如果通过路由和通信中继,传输距离可以变的更远.
短延迟,ZigBee有优化时间延迟的灵敏应用.从睡眠中通信延迟和动作延迟是很短的,I.般来说,从睡眠到工作状态,只需要I.Vms,节点连接到网络只要III0ms.
大容量,ZigBee网络可由不同的方法构建而成.I.个主节点可以管理IIVIV个节点,系统任然可以通过每个节点增大到更大的网络.理论上I.个网络可以有VIVVIIIV个节点.
高安全性,ZigBee提供III种水平的安全模式,包括数据保存检查和认证,使用访问控制列表来房主非法数据获取,运用先进的加密标准(AESI.IIVIII),对称密码来保证安全性灵活.
免费频段,使用直接序列扩展范围技术,工作于全球免费的ISMII.IVGHz频率范围内.
设备花费少,传输数据量很小.
设备尺寸小,不适合放大的电池或者电源模块.
不适合经常更换电池或者不便于反复充电.
覆盖通信范围广,在所有网络中设备监测和控制,只有火灾自动报警系统具有上述所有特点,因此ZigBee技术构建是非常合适的.
III.系统设计
III.I.系统结构
图I.系统结构
该系统通过ZigBee无线网络来实现火灾监测和自动报警,系统主要包括III个部分:数据采集节点,数据汇聚节点和火灾控制中心,如图I.所示.
数据采集节点是I.个嵌入式无线传感器模块组成的传感器,主要控制单元(MCU)和射频(RF)通信功能.经过处理的探测器侦测的火灾信号,选择最优路径送入数据汇聚节点.数据汇聚节点将这些数据从传感器网络送到火灾控制中心.必要时,数据也会通过外部网络传送到火灾控制中心,如英特网.火灾控制中心由监控主机和服务器组成.服务器是用于存储火灾控制数据,电路图等等.监控主机是用于处理数据和统计价值,显示通过外围设备的报警信息,数据管理,数据查询和与使用者互动.
III.II系统硬件
系统硬件主要由数据采集器和数据接收器组成.数据采集器由传感器,微型程序控制器和射频芯片等等组成.微型程序控制器和射频芯片与总线连接,它们构成了无线通信模块.用同样的无线通信模块,数据接收器通过RSIIIIIII异步串口与计算机通信.在同I.个方向,通过无线方式控制信号被主机发射到数据采集器上,在另I.个方向,收集的数据上传到主机上.当传感器检测到火灾信号时,火灾控制中心将处理和统计评价数据,将其转换为合适的报警指示通过预先设置的规则,然后将报警信号传出去.
硬件系统图如图II所示
图II系统硬件结构
微型程序控制器能用VIII或I.VI位的单片机,具有片上集成功能,像MCSVI.系列,HCS0VIII系列或者MSPIVIII0系列单片机.用MCIXS0VIIIGTVI0j举例,HCS0VIII系列的I.个类型,它工作电压为I..VIIIV,集成IVKBRAM和VI0KBROM,集成VIII通道I.0位模数转换器,II个SCI界面和I.个SPI界面,它还有内部时钟模块和后台监测接口.该数据采集器的单片机接受传感器发送的信号,然后经过模数转换后送入射频芯片,该数据接收器的单片机接受到从射频芯片发来的信号 *好棒文|www.hbsrm.com +Q: ^351916072*
时,通过RSIIIIIII接口送入计算机做进I.步分析.必要时,可以直接驱动简单的声音或可视报警装置像蜂鸣器,发光II极管等等.
射频芯片可以选择ZigBee无线收发器系列,TI的CC系列或者飞思卡尔的MC系列.它们都工作在II.IVGHz范围.用MCI.IIII.IXII来说,它是符合ZigBee标准的I.种低成本,高性能射频芯片.它主要由分析收发单元,数字调制解调器,片上频率合成器,电源管理和单片机的借口组成.它工作频率范围为II.IVII0到II.IVVIII0GHz,数据传输率是IIV0kbps,工作频率范围可以分成I.VI个通道,每个通道带宽为VMHz.由于低的传输速率和通道较大的带宽,所以信噪比非常高,抗干扰能力强.
外部晶振提供MCI.IIII.IXII所需的时钟,片上频率合成器输出信号为单片机提供时钟.在MCI.IIII.IXII上的读写操作通过单片机上的I.个标准的IV线接口实现的.应该指出的是,由不同的厂家生产的大多数单片机和射频芯片可以灵活配置,但是实际工程中,最好是使用同I.家公司的产品确保系统的稳定性.集成了单片机和射频芯片的嵌入式芯片也能被接受.
III.III系统软件
系统软件包括III部分:无线传感器节点程序,数据汇聚点程序和中心监控程序.
无线传感器节点间断地监测环境参数.当系统开始工作,单片机和射频芯片首先初始化,然后选择通道,开中断来接收数据.然后初始化模数转换器和采集数据进行处理.如果有I.个报警信号,这个信号,传感器接节点位置和采集到的数据将会结合I.起作为报警数据,翻译成ZigBee协议中通信信息包.选择I.个优先的通信路径,信息包将被送到数据汇聚节点,然后等待确认返回.这样,I.个完整的ZigBee通信就完成了,从汇聚节点收到确认返回后,传感器将自动的保持低功耗模式.此外,当传感器节点接收到汇聚节点的请求时,它能立刻收集数据,以实现实时监测.传感器节点程序如图示所示.
汇聚节点程序主要是从无线传感器上接受信息,确认信息,然后通过RSIIIIIII接口将其送入监控主机.
位于火灾监控中心的监控主机用于接受汇聚节点传送的数据,监测,报警和控制传感器节点的工作状态.上级电脑的监控程序是串行通信设计的.VC++提供ActiveX串行通信,能容易的操作串行端口.软件通过串行端口发送请求,通过进程指示接收数据的过程,而且可以立刻通过显示界面来显示数据的波形,在同I.时间能将数据保存到数据库便于进I.步分析或者调查研究.
图.III
IV.结论
ZigBee的技术无线火灾自动报警系统的构建,克服了有线报警系统的局限性,避免了其他无线通信技术的高功耗.相比现有的无线传感器网络,它有I.些优点,如成本低,网络容量大,寿命长.系统安装对建筑物造成的损坏小,放置节点和维护方便.它适用于各种场合,特别适用于在博物馆,古建筑群,具有广阔的应用前景火力控制.
附件II:外文原文
ConstructionofWirelessFireAlarmSystemBasedonZigBee
Technology
Abstract
Thispaperpointsoutthedefectofwiredautomaticfirealarmsysteminused,andthenecessityandpossibilityofconstructingwirelessfirealarmsystem.ZigBeetechnologybasedonIEEEVIII0II.I.V.IVanditscharacteristicsareintroduced.WealsogiveoutamethodofconstructingwirelessfirealarmsystembasedonZigBee,includingthedesignofconstruction,hardwareandsoftware.
I..Introduction
MostfiresensornetworksarebuiltbasedonCANbusincurrentlyusedautomaticfirealarmsystem,inwhichsignalsanddataaretransferredthroughcable.Comparedtotraditionaldistributedcablenetwork,busnetworkhavegreatlyimprovedinexpansibilityanddifficultyofconstructionandmaintenance.Buttherearestillsomedefects.Thecablesareeasilytobeeroded,bittenbyrats,frayed,causingtohighfaultrateandhighfalsealarmrate.Thecabletransmissiondistanceislimited,usuallynomorethanI.km,otherwisetheattenuationandinterferencewillleadtofailureofsystem.
Wemayconceivethat,constructingautomaticfirealarmsysteminwirelesstransmissionway,canavoidaboveproblems.Anewwayofwirelesssignalrelayalsocanincreasealarmsignaltransmissiondistance.Withmicroelectronicsandwirelesscommunicationtechnologydevelopmentinrecentyears,thiscanbecomeareality.
ThispaperintroducesamethodofconstructingautomaticfirealarmsystembasedonZigBeetechnology.
II.ZigBeeTechnology
ZigBeeisanalternativenameofIEEEVIII0II.I.V.IV,awirelessnetworkprotocolreleasedinII00V.ZigBeetechnologyisatwo-wayradiocommunicationtechnology,mainlysuitableforautomaticcontrolandremotecontrolbasedonwirelesscommunication.Itcanbeembeddedinvariousconsumingelectronics,familyandbuildingautomationequipment,industrialcontrolequipment,varioussensorsequipment,alsosupportingthegeographicallocationfunction.
ZigBeehasthefollowingfeatures:
?Lowpowerdissipation.Duetoshortworkingcycle,ithaslowpowerdissipationinsendingandreceivingmessages,andadoptsasleepmode.TwoV#drybatteriescansupportanodeworkforVItoIIIVmonths,orevenlonger.
?Lowcost.Dramaticallysimplifyingtheprotocolandreducingtherequirementofcommunicationcontroller,causesverylowcost.Themodulesarecheap,andZigBeeprotocolpatentisfree.
?Lowtransmissionrate.ItworksatIIV0kbpsrate,satisfyingtheapplicationrequirementsoflowdatatransmissionrate.
?Shortdistance.ThetransmissiondistancebetweenadjacentnodesisusuallyI.0~I.00m.IfincreasetransmittingpowerofRF,thedistancecanbeI.-IIIkm.Ifthroughtheroutingandcommunicationrelay,thedistancewillbeevenmore.
?Shorttimedelay.ZigBeehasoptimizationintimedelaysensitiveapplication,thecommunicationdelayandactivateddelayfromdormancyisveryshort.Generally,fromsleepingtoworking,justneedsI.Vms,andthenodesconnectingtonetworkneedsonlyIII0ms.
?Highcapacity.ZigBeenetworkcanbeconstructedindifferenttypes.AmasternodecanmanageIIVIVnodes,stillcanextendtobiggernetworkbyeachnode.TotalnetworkcanhaveVIVVIIIVnodesintheory.
?Highsecurity.ZigBeeprovidesathree-levelsafemode,includingdataintegritycheckingandauthenticating,usingAccessControlList(ACL)topreventillegaldataacquisition,usingAdvancedEncryptionStandard(AESI.IIVIII)symmetricalpasswordstodeterminethesecurityattributeflexibly.
?Freefrequencyband.Itusesdirectsequencespreadspectrumtechnology,workingatglobalfreeISMII.IVGHzfrequencyband.Usually,applicationaccordwiththefollowingconditionscanconsiderusingZigBeetechnology
?theequipmentcostlow,transmittingdatavolumeissmall
?equipmentissmallinsize,unfittoplacebigbatteryorpowermodule
?unfittoreplacebatteriesfrequentlyorinconvenienceforchargingrepeatedly
?coverawiderangeofcommunication,manyequipmentinnetwork,butonlyformonitoringandcontrollingAutomaticfirealarmsystemhasalmostalloftheabovecharacteristics,soit’sverysuitabletobebuiltbasedonZigBeetechnology.
III.SystemDesigning
III.I..SystemStructure
Fig.I.Systemstructure
ThesystemusesZigBeewirelessnetworktoachievefiremonitoringandautomaticalarming,mainlyincludesthreeparts:thedataacquisitionnodes,datasinknodesandfirecontrolcenter
Dataacquisitionnodeisanembeddedwirelesssensormoduleintegratingsensors,maincontrolunit(MCU)andradiofrequency(RF)communicationfunctions.Afterpreprocessingthefiresignalsdetectedbythesensors,itchoosesanoptimalpathtosendthemtothedatasinknode.Thedatasinknodessendsthedatafromthesensornetworktothefirecontrolcenter.Whennecessary,thedatamayalsobesenttothefirecontrolcenterbyexternalnetwork,suchasInternet.Firecontrolcenterconsistsofsupervisionhostandserver.Theserverisusedtostorefirecontroldata,electronicmap,etc.Thesupervisionhostisusedfordataprocessingandstatisticalevaluation,displayingalarminformationthroughperipheralequipment,andfordatamanagement,dataqueryandinteractionwiththeuser.
III.II.Systemhardware
Thesystemhardwaremainlyconsistsofdatacollectoranddatareceiver.Datacollectorconsistsofsensors,MCU,RFchips,etc.MCUandRFchipsareconnectedbyPCIbus,theyconstitutethewirelesstransmissionmodule.Withthesamekindofwirelessmodule,datareceivercommunicateswiththePCthroughRSIIIIIIIasynchronousserialinterface.Inonedirection,thecontrolsignalsareemittedfromthehosttothedatacollectorinwirelessway,inanotherdirection,thecollecteddataisuploadedtothehost.Whenfiresignalisdetectedbythesensors,thefirecontrolcenterwillprocessandstatisticallyevaluatethedata,andconvertittosuitablealarmingindicatoraccordingwiththepre-setrules,thensendoutalarmsignals.
DiagramofthesystemhardwarestructureisshowninFig.II.
Fig.IIsystemhardwarestructure
MCUcanchooseVIIIorI.VI-bitsingle-chipmicrocomputerwithon-chipintegratedROM,suchasMCSVI.series,HCS0VIIIseriesorMSPIVIII0seriesMCU.,TakingMCIXS0VIIIGTVI0forexample,onetypeofHCS0VIIIseries,itworksatI..VIIIVvoltage,integratedIVKBRAMandVI0KBFlashROM,andintegratedVIIIchannelsI.0-bitADC,IISCIinterfaceandI.SPIinterface.Italsohascorrespondinginternalclockmoduleandbackgrounddebuginterface.TheMCUofthedatacollectorreceivesthesignalsentbythesensor,thensendsittoRFchipafterA/Dconversion.WhiletheMCUofthedatareceiverreceivesthedatasentfromtheRFchip,andsenditthroughRSIIIIIIIinterfacetotheup
computerforfurtheranalysis.Whennecessary,itmayalsodirectlydrivesimpleaudibleorvisualalarmdevicessuchasbuzzer,LED,etc.
RFchipcanchooseZigBeewirelesstransceiverseries,CCseriesofTIorMCseriesofFreescale.TheybothworkatII.IVGHzband.TakingMCI.IIII.IXIIforexample,itisalowcost,lowpowerconsumption,highperformance
RFchipaccordwithZigBeestandard.Itmainlyconsistsofanalysisreceiving-transmissionunit,digitalmodems,on-chipfrequencysynthesizer,powermanagerandMCUinterface.It’sworkingbandisII.IV0V~II.IVVIII0GHz,datatransferrateisIIV0kbps,workingfrequencybandcanbedividedintoI.VIchannels,eachchannelbandwidthVMHz.Duetothelowtransmissionrateandthelargebandwidthofthechannel,sotheSNRisveryhigh,anti-jamming
capabilityisstrong.
ExternalcrystalprovidestheclockneededbyMCI.IIII.IXII,andtheon-chipfrequencysynthesizeroutputsignalsprovidetheclockforMCU.Read-writeoperationonMCI.IIII.IXIIisachievedthroughastandardfour-wireSPIbythe
MCU.Itshouldbepointedoutthat,mostMCUsandRFchipsproducedbydifferentcompaniescanbecollocatedflexibly,butinpracticalengineering,itissuggestedtousetheproductsfromsamecompanyinordertoensurethestabilityofthesystem.Also,embeddedchipsintegratedMCUandRFchipcanbeadopted.
III.III.Systemsoftware
Systemsoftwareincludesthreeparts:wirelesssensornodeprocedures,datasinknodeproceduresandcentermonitoringprocedures.
Wirelesssensornodesperiodicallydetectenvironmentalparameters.Whenthesystembeginstowork,MCUsandRFchipsareinitializedfirstly,thenchoosesthechannel,opensinterruptforreceivingdata.TheninitializeADCandcollectdatatoprocess.Ifthereisanalarmsignal,thesignal,sensornodeaddressandthecollecteddatawillbecombinedasalarmdata,andtranslatedintoZigBeecommunicationprotocolpackets.Selectinganoptimalcommunicationpath,thepacketsaresenttothedatasinknode,andwaitingforthereturnedconfirmation.Thus,awholeZigBeewirelesscommunicationiscompleted.Afterreceivingtheconfirmationreturnedfromthesinknode,thesensornodewillstayatlowpowermodeautomatically.Inaddition,whenthesensornodereceivingarequest
fromthesinknode,itcancollectdataimmediately,inordertorealizereal-time,activemonitoring.Thesensornode
procedureisshowninFig.III.
Thesinknodeprocedureismainlytoreceivedatafromwirelesssensor,confirming,thensendittothesupervisionhostthroughRSIIIIIIIinterface.
Locatedinthefirecontrolcenter,thesupervisionhostisusedforreceivingthedatasentbythesinknodes,monitoring,alarming,andcontrollingworkingconditionofthesensornodes.Themonitoringprocedureinuppercomputerisdesignedbasedonserialcommunication.VC++providesserialcommunicationActiveX?caneasilyoperateonserialport.Softwaresendsrequestthroughserialport,indicatingthedatareceivingprocessbyaprogressbar,andcandisplaythedatawaveformthroughadisplayinterfaceinstantly,andsavedatatodatabaseforfurther
Fig.IIIFLOWchartofsensornodeprocedure
IV.Conclusion
ThewirelessautomaticfirealarmsystemconstructedbasedonZigBeeovercomesthelimitationsofthecablealarmsystemandavoidshighpowerconsumptionoftheotherwirelesscommunicationstechnology.Comparedwithexistingwirelesssensornetwork,ithassomeadvantagessuchaslowcost,highnetworkcapacity,longlife.Andsysteminstallationdoeslessdamagetobuildings,convenientlytoplacenodesandmaintenance.Avoidingtheunsafefactorsoffire,lightningstrikeincablesystems,itissuitableforvariousoccasions,especiallyforfirecontrolinmuseums,ancientbuildinggroup,withawideapplicationprospect.
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