单片机的农业压力传感器的研究
单片机的农业压力传感器的研究
摘要:压力传感器用于有压力检测需求的农业环境监测,在农业生产环境中的压力信号被压力传感器接收到并经过放大输出电压信号,然后通过A/D转换器再变成数字的压力信号.最后单片机对这些信号进行读取并分析再发送给上层的计算机串行端口,这样系统就可以对农业生产环境进行实时监测压力参数该系统具有简单.可靠.经济.良好的可扩展性和农业应用价值.
关键字:压力传感器;单片机;压力监测;农业应用
Ⅰ传感器介绍
传感器是I.个相当特殊的物理设备,它可以确定I.些外部环境的参数数据,甚至可以是化学成分的物质,并将接收到的信息以电信号的方式发送.目前各种各样的传感器已经广泛的应用在大型自动化环境控制的工业领域,比如水质安全和水力发电.智能家居.轨道交通.自动控制.航空航天.军事.石油化工.电力.船舶等.并且传感器技术被提出应用于早期农业,但我们可以在这个研究领域的广度和深度进I.步发展.传感器技术在农业领域的应用概括为如下:
I.)机电I.体化.这是I.个现代的农业发展的趋势.传感器技术是实现机电I.体化的关键技术.
II)现代育种技术的生物和基因工程.这些领域需要用到传感器检测.
III)科学的农业生产和检测并实现自动管理.传感器技术是必不可少的.
IV)处理的分类和储存运输农业产品.各种各样的传感器也使用.I.般来说,把传感器技术应用于农业生产可以增加收益,提高农产品质量并简化生产管理.但农业生产本身的局限性,传感器技术要应用于农业生产存在很大的局限性,因素如下:第I.由于农业产值不高,考虑到农业生产的成本.传感器系统要低成本是必要条件;第II,由于农民的科学和文化素质普遍不高.所以要在提高农民的科学文化素质的同时,要使传感系统简单化.
Ⅱ系统设计方案
压力传感器系统的处理核心是单片机, *好棒文|www.hbsrm.com +Q: 3_5_1_9_1_6_0_7_2
主要包括III个部分,包括单片机前端.中心和后端.系统结构所示图I.所示.前端部分的主要作用是感知压力信号,将信号转换成数据并发送数据到单片机.本节主要包括压力传感器.放大电路和数模转换电路.单片机是核心传感系统:它的功能是数据预处理及发送.后端部分的主要作用根据不同的要求直接显示数据或将数据发送到电脑上.
图I.系统硬件结构
在此系统中前端部分的设计所选的血压传感器是BPIII00T.BPIII00T电子压力传感器是特别的血压测量.它的结构是标准的DIP-VI结构,III00毫米汞柱压力范围的和完整的VII0mv的输出.特点是结构紧凑,具有较高稳定性能,良好的线性输出,高灵敏度,性价比高且内置温度补偿和校正功能.
对于传感器由于压力传感器的输出电压非常低,需要使用放大电路使输出电压放大.考虑I.些噪声消除等性能上要求因此要求放大电路具有零点漂移.高阻抗和高增益的等等.因此,系统设计需选择两个微分放大电.
放大电路的输出电压输出的是模拟信号及单片机处理数字信号.因此必须进行数模的处理转换.本系统选择ADC0VIII0IXA/D进行信号转换,这是I.个VIII的逐次逼近ADC芯片.电压可以转换成0到IIVV之间的任何数据其精度能满足I.般的农业生产系统的要求.
SCM和fore-end部分之间的联系.所选用的单片机是MSC-VI.系列它被称为微控制器,由单片机芯片实现.单片机是系统的核心部分,使用大规模集成电路芯片.硅元件CPU.RAM/ROM.I/O接口并和中断系统集成在I.起.现在单片机技术已广泛应用于农业.
SCM和fore-end部分之间的连接实际上SCM和ADC之间的连接是数VIII线输数据线路的连接,控制线路的连接,ADC0VIII0IX连接到SCMPI.口因为只有PI.端口输入和输出I.个单身函数.在IV个单片机端口中,该端口最合适充当数据输入端口.具体的连接如图II所示.
图II单片机与ADC0VIII0IX之间的连接
终端部分的设计.之间有不同的连接SCM和后部部分根据不同的需要.主要包括两种情况如下:
第I.个是连接LED数码显示管;
第II个是串行连接通信模块.
在农业生产中通过使用自动控制系统,连接使用主要是与串行通信模块,这可以实现与电脑间的通信和处理.与串行通信模块进行通信,只需要单片机的RxD和TxD的指针与串行通信模块RxD和TxD指针.串行线的另I.端是直接与PC串行连接端口.具体的连接如图III所示.通过运行单片机程序,单片机发送串行血压数据电脑.电脑检测端口,接收.分析.处理和存储的日期.要是要求有无线数据传输的实际需求,单片机将与发送模块的无线传输相连接.同时电脑将会和接收模块相连接.
对于任何的计算机传感系统的运行来说系统的初始化都是必要的第I.步,由于数据采集是在某个时间点上的所以相应的系统应定期重新启动和停止.但是在要是自动控制的环境中,进行人工手动操作不可能的,所以单片机系统需要被设置I.个可自动复位功能.即进行复位后,SCM进行下I.步工作,存储并进行下I.轮的数据采集.
图III单片机于串行COM的连接
Ⅲ系统编程设计
在整个系统中,单片机是控制和处理的核心.主要实现了单片机的控制功能并在单片机内存执行程序存储在单片机内存的方法.系统流程图如图IV所示,首先是控制系统程序需 *好棒文|www.hbsrm.com +Q: 3_5_1_9_1_6_0_7_2
要初始化配置管理.主要是包括单片机初始化和串行传输模块初始化.其次需要从ADC0VIII0IX检测中断请求,发送中断请求是周期性的.然后PI.端口中的数据将写信给串行接口并发送到SBUF缓存.特定的代码和功能如下:
#include
#include
#defineucharunsignedchar
#defineuintunsignedint
sbitadrd=PIII^VII;//A/D地址锁定
sbitadwr=PIII^VI;//A/D转换的开始
sbitadint=PIII^II;//A/D中断
delay(uintx)//时延
{
while(x--);
}
voidinitcomm()//串口的初始化
{
TMOD=0xII0;//单片机定时器控制寄存器
//自动装载VIII个计数器
THI.=0xfd;//给定时器TI.赋初值
TLI.=0xfd;//初始值IXVI00吗?自动加载
SCON=0xV0;//设置串行控制寄存器
PCON&=0xef;//设置电源控制寄存器
TRI.=I.;//启动计时器
IE=0x00;//中断控制寄存器设置为零
}
voidinit0VIII0IX()//ADC0VIII0IX初始化
{
EA=I.;EX0=I.;IT0=I.;adrd=0;adwr=0;
}
voidint0()//中断请求
{
intnum;num=PI.;
num/=II;SBUF=num;
while(!TI);TI=0;
}
main()
{
initcomm();
init0VIII0IX();
while(I.)
{
adint=I.;//实现延迟
adrd=I.;//地址锁定
delay(V0);
adwr=I.;//startADC
delay(V0);
do{}while(adint==I.);
int0();adrd=0;adwr=0;
}
}
图IV系统程序流程图
代码编辑后,生成单片机的可执行文件扩展名为XVI进制,然后把程序文件烧录到单片机里,即完成完整的系统主要代码功能.
Ⅳ系统软件的实现
实现猪血压监测系统使用vc++VI.0作为开发工具.由于农业生产在不同环境中,因此需要I.个相应的监控系统.在系统运行时,它是用来完成数据采集.存储.分析和处理.无论是在Windows平台上,还是在Linux平台,许多开发工具提供API函数与串行通信的实现.所以是对于串行数据监测系统发展相对简单的对应.
猪血液监测系统的软件接口支持个人电脑数据检测如图V所示.主要系统包括I.些类型的等功能检测压力模拟信号,转换为对应的压力数字数据及显示监控压力因素并通过虚拟柱状显示.经过数据分析和存储,数据库技术将被添加在这个系统完成自动数据处理功能.
图V猪血压监测系统
这个系统的应用程序只适用于I.种农业生产.如果压力传感器系统可以根据不同农业应用程序的需求而进行修改,那么它将被应用更多的农业生产.例如:如果将压阻压力传感器构建成I.个压力传感器阵列,那么该系统将对野生动物和牲畜进行脉冲测量,因此它将减少人工测量的及人工测量带来的危险性.如果压力传感器变成了桥式压敏电阻.那么该系统将可以对体重进行秤重,并将实时的监控且跟踪牛的体重变化,从而分析并得到最优繁殖计划.在实际应用农业,不仅要衡量压力数据,也要测量物理数据列如:温度.湿度.氧含量.气体浓度径向速度植物等.原则上这些物理的测量数据也可以利用压力传感器系统实现,需要改变的只是将取代放大电路的传感器及适当的修改.
Ⅴ总结
传感器技术引入农业生产使农业生产工作更加容易传感器技术应用于技术农业生产,农业生产越来越多的高效.高质量和高收益.这可以极大地提高农业生产和在市场上的竞争力.并实现了自动控制和机电I.体化.血压传感器系统的处理核心可以使用SCM控制处理核心连接多种类型的传感器.测量的信息,通过系统即可监视.过程控制,系统分析多个数据并发送数据电脑,但对于电脑的选择,没有硬性的要求.对于串口模块,可以根据实际需求运行串行数据接收软件,电脑可以任意选择,然后连接到SCM的串行端口,这样传感系统安装及使用就变得简单方便.并且没有必要配置传感器电路的驱动.总之,未来农业发展趋势是大力量发展精准农业和设施农业及传感器技术这I.趋势.传感器技术,促进农业发展并且满足了农业发展需求也会促进农业传感器技术的改进.
.附件II:外文原文(复印件)
Applicationresearchofpressuresensingsystemin
agriculturebasedonSCM
PengfeiWU,YuZHOU
Dept.ofComputerScience
CollegeofBasicSciences,HuazhongAgriculturalUniversity
Wuhan,China
chriswpf@mail.hzau.edu.cn
Abstract_Pressuresensingtechnologyisusedtopressureenvironmentmonitoringinagriculture,abasicpressuresensingsystemisdesigned.Thepressuresignalacquisitedbypressuresensorinagriculturalenvironmentisconvertedintosensoramplifiedoutputvoltage,andthenchangedintopressuredigitalsignalbyA/Dconverter.FinallytheagriculturalpressuredatamanipulatedandanalyzedbySCMprogramissenttouppercomputerwithaserialport,inthiswaythesystemcandetectandmonitorpressureparameterofagricultureenvironmentinrealtime.Thissystemissimple,reliable,economic,expandabilityandhasagreatagriculturalapplicationvalue.Keywords-pressuresensing;SCM;pressuremonitor;agriculturalapplication
I.INTRODUCTION
Sensorisaratherspecialphysicaldevice,itcanascertainsomephysicalconditiontheexternalworld,evenchemicalcompositionofmatter,andputascertainedinformationupbywayofelectricalsignal.Incurrentindustrialfield,allkindsofsensorsarealreadyappliedwidelyinlargeindustrialautomaticcontrolenvironmentofvariousindustries,suchaswater-conservationandhydropower,intelligentbuilding,railtraffic,automaticcontrol,aerospace,military,petrochemicalindustry,electricpower,shipandsoon.However,sensortechnologywasputforwardinagriculturalapplicationearly,buttherearemanyresearchareasthatwecanfurtherdevelopinscopeanddepth.Sensortechnologyinagriculturalareasofapplicationsummarizedasfollows:
I.)Electromechanicalintegration.ThisisoneofModernagriculturaldevelopmenttrend.AndsensortechnologyisthekeytechnologyofRealizingelectromechanicalintegration.
II)Modernbreedingtechnologyofbiologicalandgeneengineering.thesefieldsneedsensorasameansofdetection.
III)Scientificdetectingofagriculturalproductionandrealizationofautomaticmanagement.Sensortechnologyisindispensable.
IV)Processingclassificationandstoragetransportofagriculturalproduct.AllkindsofsensorsarealsousedGenerally,thesensortechnologyofagriculturalproductioncanincreasetheyield,improveagriculturalqualityandsimplifytheproductionmanagement.
Nonetheless,duetotheagriculturalproductionitself,Sensortechnologyhassomeconstraintsintheagriculturalapplication,theseconstrainingfactorsareasfollows:Theoneisthecostofagriculturalproduction.Agriculturalproductionisnothighoutputvalue.Solowcostistheessentialconditionofsensingsystem;Thesecondisthatscientificandculturalqualitiesofthefarmersgenerallyisnothigh.Inraisingfarmer’sscientificculturequalityatthesametime,theuseofsensingsystemismadesimplistic.
II.SCHEMEOFSYSTEMDESIGN
ThepressuresensorsystemforhandlingbySCMcore,mainlyconsistsofthreesectionsincludingthefore-end,thecenterandrear-endtheSCM.SystemstructureisshowninfigureI..Themajoreffectofthefore-endsectionisperceivingpressuresignal,convertingsignalintodataandsendingdatatotheSCM.Thissectionmainlyincludespressuresensor,magnifyingcircuitandA/Dconvertingcircuit.SCMisthecoreofsensingsystem,itsfunctionisdatapreprocessingandtransferring.Themaineffectoftherear-endsectionisdisplayingdatadirectlyorsendingdatatoPCaccordingtothedifferentdemands.
FigureI..Structureofsystemhardware.
A.Designoffore-endsectionInthissystem,theselectedbloodpressuresensorisBPIII00T.BPIII00Tiselectronicpressuresensorspeciallyforthebloodpressuremeasurement.ItiswiththestandardpackagingstructureofDIP-VI,thepressurerangeofIII00mmHgandthefulloutputprocessofVII0mV.It‘sfeaturesarecompactstructure,stableperformance,goodlinearoutput,highsensitivity,lowpriceandbuilt-intemperaturecompensationandcalibrationfunction.Becausepressuresensoroutputvoltageisverylow,Needtousethemagnifyingcircuittoamplifytheoutputvoltage.Considersomeperformancerequirementssuchaseliminatingzero-pointdrift,highimpedanceandhigh-gainonesetc.Thereforethesystemdesignchoosestwodifferentialmagnifyingcircuit.
Outputvoltageofmagnifyingcircuitisanalogsignal,SCMprocessesdigitalsignal.ThereforetheprocessingofA/Dconvertingisneeded.ThissystemselectsADC0VIII0IXtoA/Dsignalconverting,itisasuccessiveapproximationofeightADCchip.Voltagecanbeconvertedintoanydatabetween0andIIVV,itsprecisioncansatisfythegeneralapplicationrequirementsofagriculturalproduction.
B.ConnectionbetweenSCMandthefore-endsectionSCMisakindofMSC-VI.],itiscalledmicrocontrollerasSingleChipMicyoco,anditisthecorepartinthissystem.Itisalargescaleintegratedcircuitchip.CPU.RAM/ROM.I/Ointerfaceandinterruptsystemareintegratedtogetherinthesamesilicondevice.Nowitiswidelyappliedinagriculture.
TheConnectionbetweenSCMandthefore-endsectionisactuallytheconnectionbetweenSCMandADC,Datalinesneedtoconnect,Controllinesalsoneedtoconnect,TheeightlinesofADC0VIII0IXareconnectedtothePI.portofSCM.
BecauseonlyPI.portisinputandoutputonewithsinglefunctioninfourSCMports,thisportactsasthemostsuitabledatainputport.SpecificconnectionisshowninfigureII.
FigureII.ConnectionbetweenADC0VIII0IXandSCM.
C.Designofrear-endsection
ThereisadifferentconnectionbetweenSCMandtherearendsectionaccordingtothedifferentneeds.Mainlyincludestwokindsofsituationsasfollows:TheoneistheconnectionwithLEDdigitaltube;ThesecondistheconnectionwithSerialcommunicationmodule[V].Whileinagriculturalproductionbyuseofautomaticcontrolsystem,theconnectionisusedprimarilywithserialcommunicationmodule,ThiscanrealizePCcommunicationandprocessing.
Connectedwithserialcommunicationmodule,onlytheRxDandTxDpinsofSCMisneededtobeconnectedwiththeRxDandTxDpinsofserialcommunicationmoduleseparately.TheotherendofseriallineisconnecteddirectlywithPCserialport.SpecificconnectionisshowninfigureIII.ThroughtheburntoSCMprogram,SCMsendsserialbloodpressuredatatoPC.PCdetectsport,receive,analyze,processandstoredate.Iftheactualrequirementofwirelessdatatransmissionneeds,SCMwillbeconnectedtosendingmoduleofthewirelesstransmission.andPCwillbeconnectedtoreceivingmoduleinthesametime.
Thesystemrestorationisthefirststepofanycomputersystemexecution,fortheapplicationofsensingsysteminagriculture,becauseofthedataacquisitionfragments,thesystemshouldbeperiodicallyrebootedandstopped.Howeverinautomaticcontrollingenvironment,manualoperationisimpossible,SCMneedbesetintoanautomaticresetstate.Namelyafterthepower,SCMisworkingbystepofstorageprocedures.
FigureIII.ConnectionbetweenSerialCOMandSCM.
III.DESIGNOFSYSTEMPROGRAMMING
Inthecompletesystem,SCMisacontrollingandprocessingcore.TheControllingtoSCMmainlyisrealizedbywayofexecutingtheprogramstoredinSCMmemory.TheprocedureofsystemprogramisshowninfigureIV.FirstthecontrollingofsystemprogramneedstoinitializeSCM,MainlyincludesSCMinitializationandserialtransmissionmoduleinitialization.SecondneedtodetectinterruptrequestsendfromADC0VIII0IX,Themainprogramisaccomplishedbyawhilecycle.ThenthedatainPI.portwillbewrotetotheserialinterfaceandsenttoSBUFcache.Specificcodeandfunction
FigureIV.Flowdiagramofsystemprogram.
asfollows:
#include
#include
#defineucharunsignedchar
#defineuintunsignedint
sbitadrd=PIII^VII;//A/Daddresslocked
sbitadwr=PIII^VI;//A/Dconversionbegan
sbitadint=PIII^II;//A/Dinterrupt
delay(uintx)//delay
{
while(x--);
}
voidinitcomm()//serialportinitialization
{
TMOD=0xII0;//SCMtimercontrolregister
//automaticloadingeightcounter
THI.=0xfd;//initialvaluetothetimerTI.
TLI.=0xfd;//initialvalueIXVI00?automaticloading
SCON=0xV0;//settingserialcontrollingregister
PCON&=0xef;//settingpowercontrollingregister
TRI.=I.;//startthetimer
IE=0x00;//interruptcontrolregistersettingzero
}
voidinit0VIII0IX()//ADC0VIII0IXinitialization
{
EA=I.;EX0=I.;IT0=I.;adrd=0;adwr=0;
}
voidint0()//interruptrequest
{
intnum;num=PI.;
num/=II;SBUF=num;
while(!TI);TI=0;
}
main()
{
initcomm();
init0VIII0IX();
while(I.)
{
adint=I.;//acquisitiondelay
adrd=I.;//addresslock
delay(V0);
adwr=I.;//startADC
delay(V0);
do{}while(adint==I.);
int0();adrd=0;adwr=0;
}
}
Aftereditingcode,generatetheSCMexecutablefilewithextensionnamecalledhex,andthenputtheprogramfileburnedintoSCM,namelycompletesystemmajorcodefunctions.
IV.REALIZATIONOFSYSTEMSOFTWARE
ThesystemrealizationofpigbloodpressuremonitoringinPCusesVC++VI.0asadevelopmenttool.Becauseoftheagriculturalapplicationinadifferentenvironment,PCneedsacorrespondingmonitoringsystem.Whilethesystemisrunning,itisusedtocompletethedataacquisition,storage,analyzingandprocessing.WhetherinWindowsplatforms,orinLinuxplatform,manydevelopmenttoolsallprovideAPIfunctionswiththerealizationofserialcommunication.Soforthiskindofserialdatamonitoringsystemdevelopmentisrelativelysimplecorresponding.
ThesoftwareinterfaceofpigbloodmonitoringsystemsupportingthePCdatadetectionisshowninfigureV.Themainsystemincludessomekindsoffunctionssuchasdetectingpressureanalogsignal,convertingcorrespondingpressuredigitaldataanddisplayingmonitoringpressurefactorsbywayofvirtualcolumnarinstrument.Ifdataanalysisandstorage,databasetechnologywillbeaddedinthissystemtofinishautomaticdataprocessingfunction.storage,databasetechnologywillbeaddedinthissystemtofinishautomaticdataprocessingfunction.
FigureV.Pigbloodpressuremonitoringsystem.
Thissystemisonlyoneofagriculturalapplication.Ifthepressuresensorsystemcanberevisedaccordingtothedifferentdemandofagriculturalapplication,andthenitwillbeappliedtomoreagriculturalfields.Forexample,Ifconsideringpiezoresistivepressuresensorandconstructingapressuresensorarray,thesystemwillbemadeapulsemeasurement,anditmeasuresthepulseofbeastinlivestock,thusitwillreduceartificialmeasurementofheavyanddangerous;Ifpressuresensorischangedintoabridgetypeofpiezoresistivestrain.Thesystemwillbemadeaweightscales,anditwillmonitorandtheweightchangeoftrackedcattleinreal-time,analyzeandgetoptimumbreedingschemes.Inthepracticalapplicationofagriculture,whatismeasurednotonlyispressuredata,butalsoisotherphysicaldatasuchastemperature,humidity,oxygencontent,gasconcentrationandradialvelocityplantsetc.Themeasurementofthesephysicaldataalsocanberealizedbyuseoftheprincipleofthispressuresensorsystem,Whatneedtochangeisonlytoreplacethesensorandappropriatelymodifytheamplifyingcircuitinthissystem.
V.CONCLUSION
Sensortechnologylargeintroductionofagriculturalapplicationmakestheagriculturalproductionworkeasier.Aftertheautomaticcontrolandelectromechanicalintegrationtechnologybasedonthesensortechnologyareappliedtoagriculturalproduction,agriculturalproductionisbecomingmoreandmoreefficient,high-qualityandhigh-yield.Thiscangreatlyimprovesagriculturalproductionandthecompetitivenessinthemarket.ThebloodpressuresensorsystemwiththeprocessingcoreofSCMcanuseaSCMcontrolprocessingcoretoconnectmultiplekindsofsensors.Asabasestationofinformationmeasurement,Thesystemcanmonitor,process,control,analyzemultipledatasentthedatatoPC.ButforthePC’schoice,therearenobasicrequirements.Ifhavingtheserialmodule,receivingsoftwarecanrunserialdataSoaccordingtotheactualdemand,PCcanbearbitrarilychosen,andthenitwillbeconnectedwiththeserialportofSCM,Thiswaysensingsysteminstallationanusebecomesimpleandconvenient,configureordrivingofsensorcircuitisinnoneed.Inshort,agriculturaldevelopmenttrendinthefutureinChinaisprecisionagricultureandfacilityagriculture,Andsensortechnologyisthebiggestpowerofdevelopingforwardthistrend.Sensortechnologytopromoteagriculturaldevelopment,agriculturaldevelopmentdemandwillalsopromotetheimprovementofagriculturalsensortechnology.
ACKNOWLEDGMENT
WewouldliketothanktheNaturalScienceFoundationofChinayouthsciencefundproject(IIII.000VIIIIVVIII).
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摘要:压力传感器用于有压力检测需求的农业环境监测,在农业生产环境中的压力信号被压力传感器接收到并经过放大输出电压信号,然后通过A/D转换器再变成数字的压力信号.最后单片机对这些信号进行读取并分析再发送给上层的计算机串行端口,这样系统就可以对农业生产环境进行实时监测压力参数该系统具有简单.可靠.经济.良好的可扩展性和农业应用价值.
关键字:压力传感器;单片机;压力监测;农业应用
Ⅰ传感器介绍
传感器是I.个相当特殊的物理设备,它可以确定I.些外部环境的参数数据,甚至可以是化学成分的物质,并将接收到的信息以电信号的方式发送.目前各种各样的传感器已经广泛的应用在大型自动化环境控制的工业领域,比如水质安全和水力发电.智能家居.轨道交通.自动控制.航空航天.军事.石油化工.电力.船舶等.并且传感器技术被提出应用于早期农业,但我们可以在这个研究领域的广度和深度进I.步发展.传感器技术在农业领域的应用概括为如下:
I.)机电I.体化.这是I.个现代的农业发展的趋势.传感器技术是实现机电I.体化的关键技术.
II)现代育种技术的生物和基因工程.这些领域需要用到传感器检测.
III)科学的农业生产和检测并实现自动管理.传感器技术是必不可少的.
IV)处理的分类和储存运输农业产品.各种各样的传感器也使用.I.般来说,把传感器技术应用于农业生产可以增加收益,提高农产品质量并简化生产管理.但农业生产本身的局限性,传感器技术要应用于农业生产存在很大的局限性,因素如下:第I.由于农业产值不高,考虑到农业生产的成本.传感器系统要低成本是必要条件;第II,由于农民的科学和文化素质普遍不高.所以要在提高农民的科学文化素质的同时,要使传感系统简单化.
Ⅱ系统设计方案
压力传感器系统的处理核心是单片机, *好棒文|www.hbsrm.com +Q: 3_5_1_9_1_6_0_7_2
主要包括III个部分,包括单片机前端.中心和后端.系统结构所示图I.所示.前端部分的主要作用是感知压力信号,将信号转换成数据并发送数据到单片机.本节主要包括压力传感器.放大电路和数模转换电路.单片机是核心传感系统:它的功能是数据预处理及发送.后端部分的主要作用根据不同的要求直接显示数据或将数据发送到电脑上.
图I.系统硬件结构
在此系统中前端部分的设计所选的血压传感器是BPIII00T.BPIII00T电子压力传感器是特别的血压测量.它的结构是标准的DIP-VI结构,III00毫米汞柱压力范围的和完整的VII0mv的输出.特点是结构紧凑,具有较高稳定性能,良好的线性输出,高灵敏度,性价比高且内置温度补偿和校正功能.
对于传感器由于压力传感器的输出电压非常低,需要使用放大电路使输出电压放大.考虑I.些噪声消除等性能上要求因此要求放大电路具有零点漂移.高阻抗和高增益的等等.因此,系统设计需选择两个微分放大电.
放大电路的输出电压输出的是模拟信号及单片机处理数字信号.因此必须进行数模的处理转换.本系统选择ADC0VIII0IXA/D进行信号转换,这是I.个VIII的逐次逼近ADC芯片.电压可以转换成0到IIVV之间的任何数据其精度能满足I.般的农业生产系统的要求.
SCM和fore-end部分之间的联系.所选用的单片机是MSC-VI.系列它被称为微控制器,由单片机芯片实现.单片机是系统的核心部分,使用大规模集成电路芯片.硅元件CPU.RAM/ROM.I/O接口并和中断系统集成在I.起.现在单片机技术已广泛应用于农业.
SCM和fore-end部分之间的连接实际上SCM和ADC之间的连接是数VIII线输数据线路的连接,控制线路的连接,ADC0VIII0IX连接到SCMPI.口因为只有PI.端口输入和输出I.个单身函数.在IV个单片机端口中,该端口最合适充当数据输入端口.具体的连接如图II所示.
图II单片机与ADC0VIII0IX之间的连接
终端部分的设计.之间有不同的连接SCM和后部部分根据不同的需要.主要包括两种情况如下:
第I.个是连接LED数码显示管;
第II个是串行连接通信模块.
在农业生产中通过使用自动控制系统,连接使用主要是与串行通信模块,这可以实现与电脑间的通信和处理.与串行通信模块进行通信,只需要单片机的RxD和TxD的指针与串行通信模块RxD和TxD指针.串行线的另I.端是直接与PC串行连接端口.具体的连接如图III所示.通过运行单片机程序,单片机发送串行血压数据电脑.电脑检测端口,接收.分析.处理和存储的日期.要是要求有无线数据传输的实际需求,单片机将与发送模块的无线传输相连接.同时电脑将会和接收模块相连接.
对于任何的计算机传感系统的运行来说系统的初始化都是必要的第I.步,由于数据采集是在某个时间点上的所以相应的系统应定期重新启动和停止.但是在要是自动控制的环境中,进行人工手动操作不可能的,所以单片机系统需要被设置I.个可自动复位功能.即进行复位后,SCM进行下I.步工作,存储并进行下I.轮的数据采集.
图III单片机于串行COM的连接
Ⅲ系统编程设计
在整个系统中,单片机是控制和处理的核心.主要实现了单片机的控制功能并在单片机内存执行程序存储在单片机内存的方法.系统流程图如图IV所示,首先是控制系统程序需 *好棒文|www.hbsrm.com +Q: 3_5_1_9_1_6_0_7_2
要初始化配置管理.主要是包括单片机初始化和串行传输模块初始化.其次需要从ADC0VIII0IX检测中断请求,发送中断请求是周期性的.然后PI.端口中的数据将写信给串行接口并发送到SBUF缓存.特定的代码和功能如下:
#include
#include
#defineucharunsignedchar
#defineuintunsignedint
sbitadrd=PIII^VII;//A/D地址锁定
sbitadwr=PIII^VI;//A/D转换的开始
sbitadint=PIII^II;//A/D中断
delay(uintx)//时延
{
while(x--);
}
voidinitcomm()//串口的初始化
{
TMOD=0xII0;//单片机定时器控制寄存器
//自动装载VIII个计数器
THI.=0xfd;//给定时器TI.赋初值
TLI.=0xfd;//初始值IXVI00吗?自动加载
SCON=0xV0;//设置串行控制寄存器
PCON&=0xef;//设置电源控制寄存器
TRI.=I.;//启动计时器
IE=0x00;//中断控制寄存器设置为零
}
voidinit0VIII0IX()//ADC0VIII0IX初始化
{
EA=I.;EX0=I.;IT0=I.;adrd=0;adwr=0;
}
voidint0()//中断请求
{
intnum;num=PI.;
num/=II;SBUF=num;
while(!TI);TI=0;
}
main()
{
initcomm();
init0VIII0IX();
while(I.)
{
adint=I.;//实现延迟
adrd=I.;//地址锁定
delay(V0);
adwr=I.;//startADC
delay(V0);
do{}while(adint==I.);
int0();adrd=0;adwr=0;
}
}
图IV系统程序流程图
代码编辑后,生成单片机的可执行文件扩展名为XVI进制,然后把程序文件烧录到单片机里,即完成完整的系统主要代码功能.
Ⅳ系统软件的实现
实现猪血压监测系统使用vc++VI.0作为开发工具.由于农业生产在不同环境中,因此需要I.个相应的监控系统.在系统运行时,它是用来完成数据采集.存储.分析和处理.无论是在Windows平台上,还是在Linux平台,许多开发工具提供API函数与串行通信的实现.所以是对于串行数据监测系统发展相对简单的对应.
猪血液监测系统的软件接口支持个人电脑数据检测如图V所示.主要系统包括I.些类型的等功能检测压力模拟信号,转换为对应的压力数字数据及显示监控压力因素并通过虚拟柱状显示.经过数据分析和存储,数据库技术将被添加在这个系统完成自动数据处理功能.
图V猪血压监测系统
这个系统的应用程序只适用于I.种农业生产.如果压力传感器系统可以根据不同农业应用程序的需求而进行修改,那么它将被应用更多的农业生产.例如:如果将压阻压力传感器构建成I.个压力传感器阵列,那么该系统将对野生动物和牲畜进行脉冲测量,因此它将减少人工测量的及人工测量带来的危险性.如果压力传感器变成了桥式压敏电阻.那么该系统将可以对体重进行秤重,并将实时的监控且跟踪牛的体重变化,从而分析并得到最优繁殖计划.在实际应用农业,不仅要衡量压力数据,也要测量物理数据列如:温度.湿度.氧含量.气体浓度径向速度植物等.原则上这些物理的测量数据也可以利用压力传感器系统实现,需要改变的只是将取代放大电路的传感器及适当的修改.
Ⅴ总结
传感器技术引入农业生产使农业生产工作更加容易传感器技术应用于技术农业生产,农业生产越来越多的高效.高质量和高收益.这可以极大地提高农业生产和在市场上的竞争力.并实现了自动控制和机电I.体化.血压传感器系统的处理核心可以使用SCM控制处理核心连接多种类型的传感器.测量的信息,通过系统即可监视.过程控制,系统分析多个数据并发送数据电脑,但对于电脑的选择,没有硬性的要求.对于串口模块,可以根据实际需求运行串行数据接收软件,电脑可以任意选择,然后连接到SCM的串行端口,这样传感系统安装及使用就变得简单方便.并且没有必要配置传感器电路的驱动.总之,未来农业发展趋势是大力量发展精准农业和设施农业及传感器技术这I.趋势.传感器技术,促进农业发展并且满足了农业发展需求也会促进农业传感器技术的改进.
.附件II:外文原文(复印件)
Applicationresearchofpressuresensingsystemin
agriculturebasedonSCM
PengfeiWU,YuZHOU
Dept.ofComputerScience
CollegeofBasicSciences,HuazhongAgriculturalUniversity
Wuhan,China
chriswpf@mail.hzau.edu.cn
Abstract_Pressuresensingtechnologyisusedtopressureenvironmentmonitoringinagriculture,abasicpressuresensingsystemisdesigned.Thepressuresignalacquisitedbypressuresensorinagriculturalenvironmentisconvertedintosensoramplifiedoutputvoltage,andthenchangedintopressuredigitalsignalbyA/Dconverter.FinallytheagriculturalpressuredatamanipulatedandanalyzedbySCMprogramissenttouppercomputerwithaserialport,inthiswaythesystemcandetectandmonitorpressureparameterofagricultureenvironmentinrealtime.Thissystemissimple,reliable,economic,expandabilityandhasagreatagriculturalapplicationvalue.Keywords-pressuresensing;SCM;pressuremonitor;agriculturalapplication
I.INTRODUCTION
Sensorisaratherspecialphysicaldevice,itcanascertainsomephysicalconditiontheexternalworld,evenchemicalcompositionofmatter,andputascertainedinformationupbywayofelectricalsignal.Incurrentindustrialfield,allkindsofsensorsarealreadyappliedwidelyinlargeindustrialautomaticcontrolenvironmentofvariousindustries,suchaswater-conservationandhydropower,intelligentbuilding,railtraffic,automaticcontrol,aerospace,military,petrochemicalindustry,electricpower,shipandsoon.However,sensortechnologywasputforwardinagriculturalapplicationearly,buttherearemanyresearchareasthatwecanfurtherdevelopinscopeanddepth.Sensortechnologyinagriculturalareasofapplicationsummarizedasfollows:
I.)Electromechanicalintegration.ThisisoneofModernagriculturaldevelopmenttrend.AndsensortechnologyisthekeytechnologyofRealizingelectromechanicalintegration.
II)Modernbreedingtechnologyofbiologicalandgeneengineering.thesefieldsneedsensorasameansofdetection.
III)Scientificdetectingofagriculturalproductionandrealizationofautomaticmanagement.Sensortechnologyisindispensable.
IV)Processingclassificationandstoragetransportofagriculturalproduct.AllkindsofsensorsarealsousedGenerally,thesensortechnologyofagriculturalproductioncanincreasetheyield,improveagriculturalqualityandsimplifytheproductionmanagement.
Nonetheless,duetotheagriculturalproductionitself,Sensortechnologyhassomeconstraintsintheagriculturalapplication,theseconstrainingfactorsareasfollows:Theoneisthecostofagriculturalproduction.Agriculturalproductionisnothighoutputvalue.Solowcostistheessentialconditionofsensingsystem;Thesecondisthatscientificandculturalqualitiesofthefarmersgenerallyisnothigh.Inraisingfarmer’sscientificculturequalityatthesametime,theuseofsensingsystemismadesimplistic.
II.SCHEMEOFSYSTEMDESIGN
ThepressuresensorsystemforhandlingbySCMcore,mainlyconsistsofthreesectionsincludingthefore-end,thecenterandrear-endtheSCM.SystemstructureisshowninfigureI..Themajoreffectofthefore-endsectionisperceivingpressuresignal,convertingsignalintodataandsendingdatatotheSCM.Thissectionmainlyincludespressuresensor,magnifyingcircuitandA/Dconvertingcircuit.SCMisthecoreofsensingsystem,itsfunctionisdatapreprocessingandtransferring.Themaineffectoftherear-endsectionisdisplayingdatadirectlyorsendingdatatoPCaccordingtothedifferentdemands.
FigureI..Structureofsystemhardware.
A.Designoffore-endsectionInthissystem,theselectedbloodpressuresensorisBPIII00T.BPIII00Tiselectronicpressuresensorspeciallyforthebloodpressuremeasurement.ItiswiththestandardpackagingstructureofDIP-VI,thepressurerangeofIII00mmHgandthefulloutputprocessofVII0mV.It‘sfeaturesarecompactstructure,stableperformance,goodlinearoutput,highsensitivity,lowpriceandbuilt-intemperaturecompensationandcalibrationfunction.Becausepressuresensoroutputvoltageisverylow,Needtousethemagnifyingcircuittoamplifytheoutputvoltage.Considersomeperformancerequirementssuchaseliminatingzero-pointdrift,highimpedanceandhigh-gainonesetc.Thereforethesystemdesignchoosestwodifferentialmagnifyingcircuit.
Outputvoltageofmagnifyingcircuitisanalogsignal,SCMprocessesdigitalsignal.ThereforetheprocessingofA/Dconvertingisneeded.ThissystemselectsADC0VIII0IXtoA/Dsignalconverting,itisasuccessiveapproximationofeightADCchip.Voltagecanbeconvertedintoanydatabetween0andIIVV,itsprecisioncansatisfythegeneralapplicationrequirementsofagriculturalproduction.
B.ConnectionbetweenSCMandthefore-endsectionSCMisakindofMSC-VI.],itiscalledmicrocontrollerasSingleChipMicyoco,anditisthecorepartinthissystem.Itisalargescaleintegratedcircuitchip.CPU.RAM/ROM.I/Ointerfaceandinterruptsystemareintegratedtogetherinthesamesilicondevice.Nowitiswidelyappliedinagriculture.
TheConnectionbetweenSCMandthefore-endsectionisactuallytheconnectionbetweenSCMandADC,Datalinesneedtoconnect,Controllinesalsoneedtoconnect,TheeightlinesofADC0VIII0IXareconnectedtothePI.portofSCM.
BecauseonlyPI.portisinputandoutputonewithsinglefunctioninfourSCMports,thisportactsasthemostsuitabledatainputport.SpecificconnectionisshowninfigureII.
FigureII.ConnectionbetweenADC0VIII0IXandSCM.
C.Designofrear-endsection
ThereisadifferentconnectionbetweenSCMandtherearendsectionaccordingtothedifferentneeds.Mainlyincludestwokindsofsituationsasfollows:TheoneistheconnectionwithLEDdigitaltube;ThesecondistheconnectionwithSerialcommunicationmodule[V].Whileinagriculturalproductionbyuseofautomaticcontrolsystem,theconnectionisusedprimarilywithserialcommunicationmodule,ThiscanrealizePCcommunicationandprocessing.
Connectedwithserialcommunicationmodule,onlytheRxDandTxDpinsofSCMisneededtobeconnectedwiththeRxDandTxDpinsofserialcommunicationmoduleseparately.TheotherendofseriallineisconnecteddirectlywithPCserialport.SpecificconnectionisshowninfigureIII.ThroughtheburntoSCMprogram,SCMsendsserialbloodpressuredatatoPC.PCdetectsport,receive,analyze,processandstoredate.Iftheactualrequirementofwirelessdatatransmissionneeds,SCMwillbeconnectedtosendingmoduleofthewirelesstransmission.andPCwillbeconnectedtoreceivingmoduleinthesametime.
Thesystemrestorationisthefirststepofanycomputersystemexecution,fortheapplicationofsensingsysteminagriculture,becauseofthedataacquisitionfragments,thesystemshouldbeperiodicallyrebootedandstopped.Howeverinautomaticcontrollingenvironment,manualoperationisimpossible,SCMneedbesetintoanautomaticresetstate.Namelyafterthepower,SCMisworkingbystepofstorageprocedures.
FigureIII.ConnectionbetweenSerialCOMandSCM.
III.DESIGNOFSYSTEMPROGRAMMING
Inthecompletesystem,SCMisacontrollingandprocessingcore.TheControllingtoSCMmainlyisrealizedbywayofexecutingtheprogramstoredinSCMmemory.TheprocedureofsystemprogramisshowninfigureIV.FirstthecontrollingofsystemprogramneedstoinitializeSCM,MainlyincludesSCMinitializationandserialtransmissionmoduleinitialization.SecondneedtodetectinterruptrequestsendfromADC0VIII0IX,Themainprogramisaccomplishedbyawhilecycle.ThenthedatainPI.portwillbewrotetotheserialinterfaceandsenttoSBUFcache.Specificcodeandfunction
FigureIV.Flowdiagramofsystemprogram.
asfollows:
#include
#include
#defineucharunsignedchar
#defineuintunsignedint
sbitadrd=PIII^VII;//A/Daddresslocked
sbitadwr=PIII^VI;//A/Dconversionbegan
sbitadint=PIII^II;//A/Dinterrupt
delay(uintx)//delay
{
while(x--);
}
voidinitcomm()//serialportinitialization
{
TMOD=0xII0;//SCMtimercontrolregister
//automaticloadingeightcounter
THI.=0xfd;//initialvaluetothetimerTI.
TLI.=0xfd;//initialvalueIXVI00?automaticloading
SCON=0xV0;//settingserialcontrollingregister
PCON&=0xef;//settingpowercontrollingregister
TRI.=I.;//startthetimer
IE=0x00;//interruptcontrolregistersettingzero
}
voidinit0VIII0IX()//ADC0VIII0IXinitialization
{
EA=I.;EX0=I.;IT0=I.;adrd=0;adwr=0;
}
voidint0()//interruptrequest
{
intnum;num=PI.;
num/=II;SBUF=num;
while(!TI);TI=0;
}
main()
{
initcomm();
init0VIII0IX();
while(I.)
{
adint=I.;//acquisitiondelay
adrd=I.;//addresslock
delay(V0);
adwr=I.;//startADC
delay(V0);
do{}while(adint==I.);
int0();adrd=0;adwr=0;
}
}
Aftereditingcode,generatetheSCMexecutablefilewithextensionnamecalledhex,andthenputtheprogramfileburnedintoSCM,namelycompletesystemmajorcodefunctions.
IV.REALIZATIONOFSYSTEMSOFTWARE
ThesystemrealizationofpigbloodpressuremonitoringinPCusesVC++VI.0asadevelopmenttool.Becauseoftheagriculturalapplicationinadifferentenvironment,PCneedsacorrespondingmonitoringsystem.Whilethesystemisrunning,itisusedtocompletethedataacquisition,storage,analyzingandprocessing.WhetherinWindowsplatforms,orinLinuxplatform,manydevelopmenttoolsallprovideAPIfunctionswiththerealizationofserialcommunication.Soforthiskindofserialdatamonitoringsystemdevelopmentisrelativelysimplecorresponding.
ThesoftwareinterfaceofpigbloodmonitoringsystemsupportingthePCdatadetectionisshowninfigureV.Themainsystemincludessomekindsoffunctionssuchasdetectingpressureanalogsignal,convertingcorrespondingpressuredigitaldataanddisplayingmonitoringpressurefactorsbywayofvirtualcolumnarinstrument.Ifdataanalysisandstorage,databasetechnologywillbeaddedinthissystemtofinishautomaticdataprocessingfunction.storage,databasetechnologywillbeaddedinthissystemtofinishautomaticdataprocessingfunction.
FigureV.Pigbloodpressuremonitoringsystem.
Thissystemisonlyoneofagriculturalapplication.Ifthepressuresensorsystemcanberevisedaccordingtothedifferentdemandofagriculturalapplication,andthenitwillbeappliedtomoreagriculturalfields.Forexample,Ifconsideringpiezoresistivepressuresensorandconstructingapressuresensorarray,thesystemwillbemadeapulsemeasurement,anditmeasuresthepulseofbeastinlivestock,thusitwillreduceartificialmeasurementofheavyanddangerous;Ifpressuresensorischangedintoabridgetypeofpiezoresistivestrain.Thesystemwillbemadeaweightscales,anditwillmonitorandtheweightchangeoftrackedcattleinreal-time,analyzeandgetoptimumbreedingschemes.Inthepracticalapplicationofagriculture,whatismeasurednotonlyispressuredata,butalsoisotherphysicaldatasuchastemperature,humidity,oxygencontent,gasconcentrationandradialvelocityplantsetc.Themeasurementofthesephysicaldataalsocanberealizedbyuseoftheprincipleofthispressuresensorsystem,Whatneedtochangeisonlytoreplacethesensorandappropriatelymodifytheamplifyingcircuitinthissystem.
V.CONCLUSION
Sensortechnologylargeintroductionofagriculturalapplicationmakestheagriculturalproductionworkeasier.Aftertheautomaticcontrolandelectromechanicalintegrationtechnologybasedonthesensortechnologyareappliedtoagriculturalproduction,agriculturalproductionisbecomingmoreandmoreefficient,high-qualityandhigh-yield.Thiscangreatlyimprovesagriculturalproductionandthecompetitivenessinthemarket.ThebloodpressuresensorsystemwiththeprocessingcoreofSCMcanuseaSCMcontrolprocessingcoretoconnectmultiplekindsofsensors.Asabasestationofinformationmeasurement,Thesystemcanmonitor,process,control,analyzemultipledatasentthedatatoPC.ButforthePC’schoice,therearenobasicrequirements.Ifhavingtheserialmodule,receivingsoftwarecanrunserialdataSoaccordingtotheactualdemand,PCcanbearbitrarilychosen,andthenitwillbeconnectedwiththeserialportofSCM,Thiswaysensingsysteminstallationanusebecomesimpleandconvenient,configureordrivingofsensorcircuitisinnoneed.Inshort,agriculturaldevelopmenttrendinthefutureinChinaisprecisionagricultureandfacilityagriculture,Andsensortechnologyisthebiggestpowerofdevelopingforwardthistrend.Sensortechnologytopromoteagriculturaldevelopment,agriculturaldevelopmentdemandwillalsopromotetheimprovementofagriculturalsensortechnology.
ACKNOWLEDGMENT
WewouldliketothanktheNaturalScienceFoundationofChinayouthsciencefundproject(IIII.000VIIIIVVIII).
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