自动化专业外文文献

DevelopmentofSensorNewTechnologySensorisonekindcomponentwhichcantransformthephysicalquantity,chemistryquantityandthebiomassintoelectricalsignal.Theoutputsignalhasthedifferentformslikethevoltage,theelectriccurrent,thefrequency,thepulseandsoon,whichcansatisfythesignaltransmission,processing,recording,anddemonstrationandcontroldemands.Soitistheautomaticdetectionsystemandintheautomaticcontrolindustry.IfautomaticTechnologyisusedwider,thensensorismoreimportant.Severalkeywordsofthesensor ：1SensorElementsAlthoughthereareexception,mostsensorconsistofasensingelementandaconversionorcontrolelement.Forexample,diaphragms,bellows,straintubesandrings,bourdontubes,andcantileversaresensingelementswhichrespondtochangesinpressureorforceandconvertthesephysicalquantitiesintoadisplacement.Thisdisplacementmaythenbeusedtochangeanelectricalparametersuchasvoltage,resistance,capacitance,orinductance.Suchcombinationofmechanicalandelectricalelementsformelectromechanicaltransducingdevicesorsensor.Similarcombinationcanbemadeforotherenergyinputsuchasthermal.Photo,magneticandchemical,givingthermoelectric,photoelectric,electromaanetic,andelectrochemicalsensorrespectively.2SensorSensitivityTherelationshipbetweenthemeasuredandthesensoroutputsignalisusuallyobtainedbycalibrationtestsandisreferredtoasthesensorsensitivityK1=output-signalincrement/measuredincrement.Inpractice,thesensorsensitivityisusuallyknown,and,bymeasuringtheoutputsignal,theinputquantityisdeterminedfrominput=output-signalincrement/K1.3CharacteristicsofanIdealSensorThehighsensorshouldexhibitthefollowingcharacteristics.(a)highfidelity-thesensoroutputwaveformshapebeafaithfulreproductionofthemeasured;thereshouldbeminimumdistortion.(b)Thereshouldbeminimuminterferencewiththequantitybeingmeasured;thepresenceofthesensorshouldnotalterthemeasuredinanyway.(c)Size.Thesensormustbecapableofbeingplacedexactlywhereitisneeded.精选文库(d)Thereshouldbealinearrelationshipbetweenthemeasuredandthesensorsignal.(e)Thesensorshouldhaveminimumsensitivitytoexternaleffects,pressuresensor,forexample,areoftensubjectedtoexternaleffectssuchvibrationandtemperature.(f)Thenaturalfrequencyofthesensorshouldbewellseparatedfromthefrequencyandharmonicsofthemeasurand.Sensorscanbedividedintothefollowingcategories：1ElectricalSensorElectricalsensorexhibitmanyoftheidealcharacteristics.Inadditiontheyofferhighsensitivityaswellaspromotingthepossibleofremoteindicationormesdurement.Electricalsensorcanbedividedintotwodistinctgroups:(a)variable-control-parametertypes,whichinclude:(i)resistance(ii)capacitance(iii)inductance(iv)mutual-inductancetypesThesesensorallrelyonexternalexcitationvoltagefortheiroperation.(b)self-generatingtypes,whichinclude(i)electromagnetic(ii)thermoelectric(iii)photoemissive(iv)piezo-electrictypesTheseallthemselvesproduceanoutputvoltageinresponsetothemeasurandinputandtheireffectsarereversible.Forexample,apiezo-electricsensornormallyproducesanoutputvoltageinresponsetothedeformationofacrystallinematerial;however,ifanalternatingvoltageisappliedacrossthematerial,thesensorexhibitsthereversibleeffectbydeformingorvibratingatthefrequencyofthealternatingvoltage.2ResistanceSensorResistancesensormaybedividedintotwogroups,asfollows:(i)Thosewhichexperiencealargeresistancechange,measuredbyusingpotential-dividermethods.Potentiometersareinthisgroup.(ii)Thosewhichexperienceasmallresistancechange,measuredbybridge-circuitmethods.Examplesofthisgroupincludestraingaugesandresistancethermometers.— 2精选文库3CapacitiveSensorThecapacitancecanthusmadetovarybychangingeithertherelativepermittivity,theeffectivearea,orthedistanceseparatingtheplates.Thecharacteristiccurvesindicatethatvariationsofareaandrelativepermittivitygivealinearrelationshiponlyoverasmallrangeofspacings.ThusthesensitivityishighforsmallvaluesofUnlikethepotentionmeter,thevariable-distancecapacitivesensorhasaninfiniteresolutionmakingitmostsuitableformeasuringsmallincrementsofdisplacementorquantitieswhichmaybechangedtoproduceadisplacement.4InductiveSensorTheinductancecanthusbemadetovarybychangingthereluctanceoftheinductivecircuit.Measuringtechniquesusedwithcapacitiveandinductivesensor:(a)A.C.excitedbridgesusingdifferentialcapacitorsinductors.(b)A.C.potentiometercircuitsfordynamicmeasurements.(c)D.C.circuitstogiveavoltageproportionaltovelocityforacapacitor.(d)Frequency-modulationmethods,wherethechangeofCorLvariesthefrequencyofanoscillationcircuit.Importantfeaturesofcapacitiveandinductivesensorareasfollows:(i)resolutioninfinite(ii)accuracy0.1%±offullscaleisquoted(iii)displacementranges25*10-6mto10-3m(iv)risetimelessthan50uspossibleTypicalmeasurandsaredisplacement,pressure,vibration,sound,andliquidlevel.5LinearVariable-differentialTtransformer6Piezo-electricSensor7ElectromagneticSensor8ThermoelectricSensor9PhotoelectricCells10MechanicalSensorandSensingElementsIninformationage,theinformationindustryincludesinformationgathering,transmission,processthreeparts,namelysensortechnology,communication,computertechnology.Becauseofultralargescaleintegratedcircuit’rapidsdevelopmentafterhavingbeendevelopedModerncomputertechnologyandcommunication,notonlyrequestssensorprecisionreliability,speedof— 3精选文库responseandgaininformationcontentrequestmoreandmorehighbutalsorequestsitscosttobeinexpensive.Theobvioustraditionalsensoriseliminatedgraduallybecauseofthefunction,thecharacteristic,thevolume,thecostandsoon.Asworlddevelopmanycountriesarespeedinguptothesensornewtechnology’researchandthedevelopment,andallhasobtainedtheenormousbreakthrough.Nowthesensornewtechnologydevelopmentmainlyhasfollowingseveralaspects:Usingthephysicalphenomenon,thechemicalreaction,thebiologicaleffectasthesensorprinciplethereforetheresearcheswhichdiscoveredthenewphenomenonandtheneweffectarethesensortechnologicalimprovingways.itisimportantstudiestodevelopednewsensor’thesfoundation.JapaneseSharpCorporationusesthesuperconductivitytechnologytodevelopsuccessfullythehightemperaturesuperconductivitymagneticsensorandgetthesensortechnologysignificantbreakthrough.Itssensitivityissohighandonlyinferiorinthesuperconductivityquantuminterferencecomponent.Itsmanufacturecraftisfarsimplerthanthesuperconductivityquantuminterferencecomponent.Mayuseinmagnetismimageformationtechnology.Soithasthewidespreadpromotedvalue.Usingtheimmunebodyandtheantigenmeetsoneanothercompoundwhentheelectrodesurface.Itcancausetheelectrodepotentialchangeandusethisphenomenontobepossibletogeneratetheimmunitysensor.Theimmunitysensormakeswiththiskindofimmunebodymaytosomeorganisminwhetherhasthiskindofantoriginalworkinspection.Likemayinspectsomebodywiththehepatitisvirusimmunebodywhethercontractsthehepatitis,playstoisfast,theaccuraterole.TheUSUCsixthbranchhasdevelopedthiskindofsensor.Thesensormaterialistheimportantfoundationforsensortechnology,becausethematerialsscienceisprogressiveandthepeoplemaymakeeachkindofnewsensorForexamplemakingthetemperaturesensorwiththehighpolymerthinfilm;Theopticalfibercanmakethepressure,thecurrentcapacity,thetemperature,thedisplacementandsoonthemanykindsofsensors;Makingthepressuretransmitterwiththeceramics.Thehighpolymercanbecometheproportionadsorptionandthereleasehydrogenalongwiththeenvironmentrelativehumiditysize.Thehighpolymerelectricityliesbetween— 4精选文库theconstanttobesmall,thehydrogencanenhancethepolymerthecoefficientofdialecticalloss.Makingthecapacitorthehighpolymerdielectricmedium,determinestheelectriccapacitycapecitythechange,thenobtainstherelativehumidity.Makingtheplasmausingthisprincipletogatherthelegitimatepolystyrenefilmtemperaturesensorbelow,ithasthecharacteristic.Measuredthewetscopeiswide;Thetemperaturerangeiswide,mayreach-400℃~+1,500 ℃;Thespeedofresponseisquick,issmallerthan1S;Thesizeissmall,mayuseinthesmallspacemeasuringwet;Thetemperaturecoefficientissmall.Theceramicelectriccapacitytypepressuretransmitterisonekinddoesnothavetheintermediaryfluidthedrytypepressuretransmitter.Usestheadvancedceramictechnology,theheavyfilmelectronictechnology,itstechnicalperformanceisstable,theyeardriftingquantityissmallerthan0.1%F.S,warmfloatsissmallerthan±0.15%/10K,anti-overloadsstrongly,mayreachthemeasuringrangeseveralhundredtimes.Thesurveyscopemayfrom0to60mpa.GermanE+HCorporationandtheAmericanKahloCorporationproductisattheleadingposition.Theopticalfiberapplicationissendthematerialsignificantbreakthrough,itsusesinmostearlytheopticalcommunicationtechniques.Intheopticalcommunicationusediscoveredworksasenvironmentalconditionchangeandsoonthetemperature,pres-sure,electricfield,magneticfield,causesthefiberoptictransmissionlightwaveintensity,thephase,thefrequency,changeandsoonthepolarizationcondition,thesurveylightwavequantitychange,mayknowcausestheselightwavephysicalquantitytheandsoonquantitativechangetemperature,pressure,electricfield,magneticfieldsize,usestheseprinciplestobepossibletodeveloptheopticalfibersensor.Theopticalfibersensorandthetraditionalsensorcomparehasmanycharacteristics:Sensitivityhigh,thestructuresimple,thevolumesmall,anti-corrosive,theelectricinsulationgood,thepathofraysmaybecurving,beadvantageousfortherealizationtelemeterandsoon.OpticalfibersensorJapanisintheadvancedlevel.LikeIdecIzumiCorporationandSunxCorporation.Theopticalfibersendreceiverandtheintegratedpathofraystechnologyunify,acceleratestheopticalfibersensortechnologydevelopment.Willintegratethepathofray’scomponenttoreplacetheoriginalopticspartandthepassivelightcomponent;— 5精选文库enabletheopticalfibersensortohavethehighbandwidth,thelowsignalprocessingvoltage,thereliabilityhigh,thecostwillbelow.Insemiconductortechnologyprocessingmethodoxygenation,thephotoetchang,theproliferation,thedeposition,theplaneelectroncraft,variousguidescorrosionandsteamsplates,thesputteringthinfilmandsoon,thesehaveallintroducedtothesensormanufacture.Thushasproducedeachkindofnewsensor,likemakesthesiliconmicrosensorusingthesemiconductortechnology,makesthefastresponseusingthethinfilmcraftthegastobesensitive,thewetsensitivesensor,theusesputteringthinfilmcraftsystempressuretransmitterandsoon..TheJapanesehorizontalrivercompanyusesvariousguides’corrosiontechnologytocarryonthehighaccuracythreedimensionalprocessing;thesystemhelpsthesiliconresonancetypepressuretransmitter.ThecorepartiallypressestworesonantLiangbythefeelingwhichabovethesilicondiaphragmandthesilicondiaphragmmanufacturestoform,tworesonantLiang'sfrequencydifferencecorrespondencedifferentpressure,measuresthepressurewiththefrequencydifferencemethod,mayeliminatetheerrorwhichfactorandsoonambienttemperaturebrings.Whenambienttemperaturechange,tworesonantLiangfrequenciesandtheamplitudevariationaresame,aftertwofrequencydifferences,itssamechangequantitycancounterbalancemutually.It’ssurveymosthighaccuracymayreach0.01%FS.AmericanSiliconMicrostructureInc.(SMI)thecompanydevelopsaseriesoflowends,linearin0.1%to0.In65%scopesiliconmicropressuretransmitter,thelowestfullmeasuringrangeis0.15psi(1KPa),itmakestakethesiliconasthematerial,hastheuniquethreedimensionalstructure,thelightslightmachine-finishing,makesthewheatstonebridgemanytimeswiththeetchingonthesilicondiaphragm,whenabovesiliconchipstress,ithasthedistortion,theresistanceproducespressestheanti-effectbuttolosethebridgebalance,theoutputandthepressurebecomestheproportiontheelectricalsignal.Suchsiliconmicrosensoristhefronttechnologywhichnowthesensordevelops,Itsessentialfeatureisthesensitiveunitvolumeisamicronmagnitude,Isthetraditionalsensorseveraldozens,several1%.Inaspectandsoonindustrycontrol,aerospacedomain,biomedicinehasthevitalrole,like— 6精选文库ontheairplanetheusemayreducetheairplaneweight,reducestheenergy.Anothercharacteristiciscanbesensitiveissmallsurveyed,maymakethebloodpressurepressuretransmitter.TheChineseaviationmaincorporationBeijingobservationandcontroltechnicalresearchinstitute,thedevelopmentCYJseriessplashesthanksthemembranepressuretransmitterisusestheionsputteringcrafttoprocessthemetalstraingauge,ithasovercomethenonmetallicstraingaugeeasilythetemperatureinfluenceinsufficiency,hasthehighstability,issuitableineachkindofsituation,ismeasuredthemediumscopewidely,butalsoovercamethetraditionlowlytogluetheprecisionwhichthetypebrought,sluggishbig,shortcomingandsoonslowchange,hadtheprecisionhigh,there-liabilityishigh,thevolumesmallcharacteristic,widelyusedindomainandsoonaviation,petroleum,chemicalindustry,medicalservice.Integratesthesensorthesuperiorityisthetraditionalsensorisunabletoachieve,itisasimplesensornotmerely,itinatthesametimetheauxiliarycircuitpartandsendthepartwillintegrateontogetherthechip,willcauseittohavethecalibration,tocompensate,fromthediagnosisandthenetworkcorrespondencefunction,itmightreducethecost,thegaininyield,thiskindofbloodpressuresensorwhichAmericanLUCAS,NOVASENSORCorporationwilldevelop,eachweekwillbeabletoproduce10,000.Theintellectualizedsensorisonekindofbeltmicroprocessorsensor,isachievementwhichthemicrocomputerandthesensorunifies,ithasatthesametimetheexamination,thejudgmentandtheinformationprocessingfunction,compareswiththetraditionalsensorhasverymanycharacteristics:Hasthejudgmentandtheinformationprocessingfunction,cancarryontherevision,theerrortotheobservedvaluecompensates,thusenhancementmeasuringaccuracy;Mayrealizethemulti-sensormultiparameterssurvey;Hasfromthediagnosisandfromthecalibrationfunction,enhancesthereliability;Thesurveydatamaydepositandwithdraw,easytooperate;Hasthedatacommunicationinterface,canandthemicrocomputerdirectcommunication.Thesensor,thesignaladjustmentelectriccircuit,themonolithicintegratedcircuitintegrationformsultralarge-scaleintegratedonachiptheseniorintelligencesensor.AmericanHONYWELLCorporationST-3000intelligence— 7精选文库sensor,thechipsizeonlythenhas3×4×2mm3,usesthesemiconductor craft,makesCPU,EPROM,thestaticpressure,thedifferentialpressure,thetemperatureontheidenticalchipandsoonthreekindofsensitiveunits.Theintellectualizedsensorresearchandthedevelopment,USisattheleadingposition.AmericanSpaceAgencywhendevelopmentspaceshipcalledthiskindofsensorforthecleversensor(SmartSensor),onthespaceshipthiskindofsensorisextremelyimportant.Ourcountryinthisaspectresearchanddevelopmentalsoverybackwardmainlyisbecauseourcountrysemiconductorintegratedcircuittechnologicallevelislimited.Thesensor’developmentsischangingdayafterdaysinceespeciallythe80'shumanitieshaveenteredintothehighindustrializationtheinformationage,sensortechno-logytorenewal,highertechnologicaldevelopment.US,Japanandsoondevelopedcountrysensortechnologicaldevelopmentquickest,ourcountrybecausethefoundationisweak,thesensortechnologycompareswiththesedevelopedcountrieshasthebigdisparity.Therefore,weshouldenlargetothesensorengineeringresearch,thedevelopmentinvestment,causesourcountrysensortechnologyandtheforeigndisparityreduces,promotesourcountryinstrumentmeasuringapplianceindustryandfromthetechnicaldevelopment.——From《SensorTechnologyHandbook》,JonWilson,Newnes— 8精选文库传感器新技术的发展传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。如果把计算机比作大脑，那么传感器则相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。自动化程度越高，系统对传感器要求越高。传感器的几个关键词：传感器元件除特例外，大多数的传感器都由敏感元件、转换元件或控制元件组成。如振动膜、波纹管、应力管和应力环、低音管和悬臂都是敏感元件，它们对压力和力作出响应把物理量转变成位移。然后位移可以改变电参数，如电压、电阻、电容或者感应系数。机械式和电子式元件合并形成机电式传感设备或传感器。这样的组合可用来输入能量信号。热的，光的，磁的和化学的相互结合产生的热电式、光电式、电磁式和电化学式传感器。传感器灵敏度通过校正测量系统获得的被测物理量和传感器输出信号的关系叫做传感器灵敏度K1，也就是K1=输出信号增量/测量增量。实际中，传感器的灵敏度是已知的，并且通过测量输出信号，输入量由下式决定，输入量 =输出信号增量/K1。理想传感器的特性a）高保真性：传感器输出波形应该真实可靠地再现被测量，并且失真很小。b）可测量最小的干扰，任何时候传感器的出现不能改变被测量。c）尺寸：传感器必须能正确地放在所需的地方。d）被测量和传感器信号之间应该有一个线性关系。e）传感器对外部影响的灵敏度应该小，例如压力传感器经常受到外部振动和温度的影响。f）传感器的固有频率应该避开被测量的频率和谐波。传感器可分为以下几类：电传感器电传感器具有许多理想特性。它们不仅实现远程测量和显示，还能提供高灵敏度。电传感器可分为两大类。（a）变参数型，包括：— 9精选文库i）电阻式；ii)电容式；iii)自感应式；v)互感应式；这些传感器的工作依靠外部电压。b）自激型，包括：i）电磁式；ii）热电式；iii）光栅式；iv）压电式。这些传感器根据测量输入值产生输出电压，而且这一过程是可逆的。比如，在一般情况下，压电式传感器可根据晶体材料的变形产生一个输出电压；但是，如果在材料上施加一个可变电压，传感器可以通过变形或与变电压同频率的振动来体现可逆效应。电阻式传感器电阻式传感器可以分为两大类：i)那些表现为大电阻变化的物理量可通过分压方式进行测量，电位器就属于此类。ii）那些表现为小电阻变化的物理量可通过桥电路方式进行测量，这一类包括应变仪和电阻温度计。电容式传感器电容量随着相对介电常数、截面面积、或者极板间的距离的变化而变化。电容的特征曲线表明，在空间的一段范围内，截面面积和相对介电常数的变化与电容量变化成线性关系。不象电位器，变极距型电容传感器有无限的分辨率，这最适合测量微小的位移增量的位移。电感式传感器电感可以通过改变电感电路的阻抗来调节。电容式和电感式传感器的测量技术：a）用差分式电容或电感作为交流电桥；b）用交流电位计电路做动态测量；c）用直流电路为电容器提供正比于容值变化的电压；d）采用调频法，C或者L随着振荡电路频率的变化而改变。电容式和电感式传感器的一些重要特性如下：i)分辨率无限— 10精选文库ii）精确到满量程的±0.1%iii）位移范围从25*10-6m到10-3miv）上升时间小于50us典型的被测量是位移、压力、振动量、声音和液位。线性调压器压电式传感器电磁式传感器热电式传感器光电管机械式传感器及敏感元件在今天的信息时代里，信息产业包括信息采集、传输、处理三部分，即传感技术、通信技术、计算机技术。现代的计算机技术和通信技术由于超大规模集成电路的飞速发展，而已经充分发达后，不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高，还要求其成本低廉且使用方便。显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。世界许多发达国家都在加快对传感器新技术的研究与开发，并且都已取得极大的突破。如今传感器新技术的发展，主要有以下几个方面：利用物理现象、化学反应、生物效应作为传感器原理，所以研究发现新现象与新效应是传感器技术发展的重要工作，是研究开发新型传感器的基础。日本夏普公司利用超导技术研制成功高温超导磁性传感器，是传感器技术的重大突破，其灵敏度高，仅次于超导量子干涉器件。它的制造工艺远比超导量子干涉器件简单。可用于磁成像技术，有广泛推广价值。利用抗体和抗原在电极表面上相遇复合时，会引起电极电位的变化，利用这一现象可制出免疫传感器。用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。如用肝炎病毒抗体可检查某人是否患有肝炎，起到快速、准确作用。美国加州大学巳研制出这类传感器。传感器材料是传感器技术的重要基础，由于材料科学进步，人们可制造出各种新型传感器。例如用高分子聚合物薄膜制成温度传感器；光导纤维能制成压力、流量、温度、位移等多种传感器；用陶瓷制成压力传感器。高分子聚合物能随周围环境的相对湿度大小成比例地吸附和释放水分子。高分子电介常数小，水分子能提高聚合物的介电常数。将高分子电介质做成电容器，测定电容容量的变化，即可得出相对湿度。利用这个原理制成等离子聚合法聚苯乙烯薄膜温度传感器，其有以下特点：测湿范围宽；温度范围宽，