毕业论文英文文献及翻译 Novel Optical Sensor for Precise Tilt Angle Measurement(一种精确测量倾斜角度的光学传感器)

毕业设计说明书英文文献及中文翻译学生姓名：学号：学院：信息与通信工程学院专业：通信工程指导教师：**大学英文文献原文及翻译第17页共17页NovelOpticalSensorforPreciseTiltAngleMeasurementABSTRACTAnovelopticalsensor,whichcanmeasureinclinationangleortiltangleoftwoaxessimultaneouslyandprecisely,isintroduced.Thissensorisbasedontheprincipleoflaserinterferencesoithasveryhighaccuracy.Aprototypesensorisdesigned,builtandevaluatedtodemonstratethenovelconcept.Itisanoptoelectronicsensor.Therearenomovingpartsinthesensor.Afluidhorizontalthatisabsolutelyperpendiculartothetrueverticalprovidesthereferenceplane.Theanglebetweenthesensorandtheabsolutehorizonchangeswiththeinclinationoftheobjectbeingmeasured.Thesechangesarereflectedinthewayoffringepattern’scentrepositionshift.Differentinterferencepatternscentrelocationsaregeneratedwhentiltanglevaried.Theinterferencefringepatternarerecordedandprocessedtotranslateintothetiltanglesoftwoaxes,horizontalandvertical.Theaccuracycanreachashighas+/-1arcsecondwiththemeasurementrangeof700arcsecondswhen1024by1024pixelsimagesensorisutilized.Keywords:tiltanglesensor,inclinometers,laserinterferenceI.INTRODUCTIONThereareseveralkindsofcommercialsensorfortiltanglemeasurement,whichareavailableinthemarket.Someknownastiltanglesensor,someareknownasinclinometers.Theybaseondifferentworkingprinciples.Electrolyticliquid[1],capacitance[2]andpendulum[3]arethethreemainworkingprinciplesthatmosttiltanglesensororinclinometerusuallybaseon.Hereweproposeanovelopticalmethodandbuildupanoptoelectronicsensorwithlaser,opticalcomponentsandimagesensor.Itcandoprecisetiltanglemeasurementsimultaneously.Thereisnomechanicalmovementpart.Theworkingprincipleisbasedonopticalinterferometry.Coherentlaserisusedasthelightingsource.Itwillgothroughaliquidoilbox,whichisbuiltbyaglasscontainerfilledwithliquidoil.Afluidhorizontalthatisabsolutelyperpendiculartothetrueverticalprovidesthereferenceplane.Whenlaserbeampassthroughtheoilboxtwobeamsarereflectedbackbysurfaceoftheliquidandcontainerglass.Interferencefringesareformedwiththesetwobeams.Thefringepatternswillshiftincorrespondingtothechangesofthetiltangles.Thefringepatternsiscapturedandprocessedtogivethetiltangleinformation.Opticalworkingprinciplemakesitinsensitivetomagneticfield.Thesensorcanmeasuretwoaxesinclinationanglesimultaneously.Afluidhorizontalmakesurethereferenceplaneisanabsolutehorizontalplane.Highsensitiveopticalinterferencemeasurementprincipleassuresthehighaccuracy.Aprototypeofthemethodhasbeenbuiltupandevaluated.Experimentalresultsshowthetiltanglechangesrelativetosealevelcanbedetectedattheaccuracyof+-1arcsecondwithinthemeasurementrangeof700arcseconds.II.PRINCIPLEFigure1illustratestheschematicdiagramofworkingprinciple.PointOisthefocalpointofbeamexpandinglens.PointOcanbeconsideredasapointlightsource.Itemitssphericalwave-front.Liquidoilsurfacewillalwaysmaintainhorizontallyduetothegravityforceoftheearth.Theoilsurfaceisusedasthereferenceplane.Thecontainerismadeofglass.Itsbottomsurfacewillinclinetogetherwiththetargetobjectwhenthesensorisplacedonthetarget.Thelightfromoilsurfaceandglasssurfacewillinterferencetoformcircularfringespattern(seeFig.4).Theinclineanglecanbemeasuredwiththecentrepositionchangesofcircularfringes.PisthemirrorimageofOagainsttoglass-airsurfaceandQisthemirrorimageofOagainsttooil-airsurface.Theoil-airsurfacerepresentsthehorizontalplane.WhentheglasssurfacepositionedparallelwithoilsurfacethePandQareinthesamelineperpendicularwithoilsurface.Thislineisalsotheopticalaxisoftheopticalsystem.Thefringesarecircularfringeswithcommoncenter.Whentheoilboxisinclinedtheglasssurfacehasatiltangleaagainsttotheoilsurface.（1）wherenistherefractionindexofglass.Whenthetiltangleistiny,theaboveequationcanbesimplifiedas（2）Wecanobtainthefollowingequationfromand（3）whereristhecenterpositionofcircularfringes.Disthedistanceofthereceivingscreentotheglasssurfaceofoilbox.histhethicknessofglassandoil.nistherefractionindexofglassandoil(hereweassumetheglassandoilhavesameindexsincetheyareveryclose).AssumethatsothathisnegligiblerelativetoD.(4)Fromequation(4)n,Dandharefixedoncethesetupisassembled.Let,calledsystemconstant.Thissystemparametercanbeobtainedthroughcalibrationprocess.Henceequation(4)canbewrittenas（5）wherercanbecalculatedwithimageprocessingtechniqueandhencedothetiltangle.Fig.1SchematicdiagramofmeasurementprincipleIII.DESCRIPTIONOFSENSORFigure2showsthedetaillayoutoftheopticalheadofthesensor.Itincludeslaser1,beamexpander2,beamsplitter3,mirror4andliquidoilbox5.Apointlightsourceemitssphericalwave-front.Thisbeamgoesthroughtheoilbox.Itisreflectedbytheglasssurfaceandoilsurfacerespectively.Thesetwowave-frontsmeettogetheragainaftertheypassdifferentopticalpaths.Ifthecoherentlengthofthepointlightsourceislongerthantheopticalpathdifference,thesetwobeamswillinterfereandformcircularfringes.Whenonesurfacetiltsthecenterofthecircularfringeswillshiftaccordingly.Whentheopticalpathchanges,thefringeswillbegeneratedorabsorbedaccordingly.Onefringechangeoccursincorrespondingtoopticalpathdifference,whereisthewavelengthofthelightsource.Fig.2LayoutofopticalsensorheadAsillustratedinFigure2,thelaser1emitsalaserbeam.Thislaserbeamisexpandedbyabeamexpander2toformasphericalwave-frontbeam.Subsequentlythisbeamgoesthroughtheliquidoilbox5perpendicularly.Thereflectionsoccurinthesurfacesformedbymediaslayerswithdifferentrefractionindexes.Thereflectionratioisdeterminedbytheformulawhenincidentdirectionisperpendicularlytothereflectionplan（6）Whereandrepresentthediffractionindexofthetwomedias.Thecloserthetworeflectionindexesthelesslightreflected.Whenequalstothereisnoreflectionoccurringatthissurface.Whilebuildingthesensoroneofthemostimportantrequirementsistomakesurethatthecentersofallopticalcomponentsarepositionedonthesameline,e.g.theopticalaxis.Duetomechanicaltoleranceandthepreciserequirementsofthesensorhead,afinetuneonthealignmentoftheopticalheadisnecessarytomakesurethesensorcanworkwell.Themethodbeginswithaligningthelasertoenablethelaserbeamparalleltothebaseplatethatalltheopticalcomponentswillbemountedon.Subsequentlyinstallthebeamsplitter.Thedirectionoflaserbeamwillbechangebyarightangleandincidenttotheliquidoilbox.Adjustthebeamsplitteruntilthelaserbeamincidenttotheliquidoilboxperpendicular.Installbeamexpandertoconverttheparallelbeamintoasphericallaserbeam.Alignthebeamexpanderaxiswiththesystemopticalaxis.Thereflectedwavefrontscomingfromglasssurfaceandoilsurfacewillgothroughbeamsplitterandchangeitsdirectionatrightanglebymirrortoentercamera.Thealignmentofcameramakesensurethelaserbeamtobeimagedatthecenteroftheimagingplane.Thatis,theimagingaxisisnormaltotheimagingplane.Furthermore,themethodneedstofurtheraligntheliquidoilboxwiththethreescrews10mountedintheoilboxtoensuretiltanglewithinthemeasurementrange.Apatternwithcircularfringeswillappear.Adjustthescrew10untilthecenterofthefringepatternpositionedinthecenterofimagesensorasillustratedinFigure4A.Fig.3SchematicdiagramofoilboxFigure3showsthedetailsofliquidoilbox.Thefirstsurfaceisformedbyair-glass,calledair-glasssurface;thereflectionratioisabout3%sincetherefractionindexofairis1andtheglassweusedisaround1.4.Thesecondsurfaceisformedbyglass-oil,calledglass-oilsurface.Thereisalmostnoreflectioninthissurfacesincewechooseproperoilwiththecloserefractionindexwiththeglass.Thethirdsurfaceisconstructedbytheoilandair.Sothereflectionratioisaboutthesameasthefirstsurface.Thetworeflectedwavefrontsbythefirstglass-airsurfaceandthethirdoil-airsurfacewillmeettogetherandinterferenceeachothertoformapatternwithcircularinterferencefringesasillustratedinFigure4.Whentheglasssurfaceisparallelwithoilsurfacethecenterwillbepositionedintheopticalaxis(Fig.4A).Thepositionofcenterofthecircularfringeswillshiftwhenthetiltanglevaries(Fig.4B).Fig.4AInterferencefringepatterns(centerposition,nontilted)Fig.4BInterferencefringepatterns(sideposition,tiltedangle)IV.CALIBRATIONItisvitalforcalibrationofthesensortoensureanaccurateandreliablemeasurement.Apropercalibrationmakessurethatthecenterofthecircularfringesispositionedinthecenterportionoftheimagesensorwhenthesensorisplacedhorizontally.Thepurposesofthecalibrationarenotonlyobtainingsystemconstanthofequation(6)butalsocorrectingerrorscausedbyopticalaberration.Theconceptofcalibrationistoputoursensorandthebenchmarksensorontothesameplatethenchangethetiltanglesoftheplatetorecordthereadingsofoursensorandthebenchmarksensors.Figure5showsschematicdiagramofourcalibrationworkstationforthecalibrationofthesensor.Theworkstationconsistsofaflatplatesupportedatthreepointsandtwohighaccuratesingleaxistiltanglesensorswithaccuracyashighas1arcsecond.Thetwosensorsarepositionedatarightangle,oneisalongwithx-axistomonitorthechangeinxdirectionandtheotherisalongwithy-axistomonitorthechangeinydirection.Fig.5SchematicdiagramofcalibrationplatformTheplateissupportedatthreepointswiththreescrews.Itiseasytochangethetiltangleoftheplatebyadjustingthethreescrews.Ouropticalsensorheadisplacedinthecenteroftheplateandalignedwithxandyaxisofthestation.First,adjustthebaseplateuntilthereadingsofthesensorequalto0tolettheworkstationplateisparalleltothesealevel.Second,mountouropticalsensorthatneedstobecalibratedontotheplate.Alignthexandyaxiswiththebenchmarksenor.Third,adjustthelevelofliquidoilboxwiththethreescrewsonthecoveroftheliquidoilboxuntilthecentercircularfringesmovetothecenteroftheimagesensor.Thisadjustcanmakesurethepropermeasurementrange.Forth,changedifferenttiltanglesbymeansofadjustingthedifferentheightsofscrew.Recordthereadingsofthebenchmarksensorandcalculatethetiltanglesoftwoaxeswithoursensor.Thereadingsshouldcoverthewholemeasurementrange.Calibrationcoefficientcanbeobtainedwiththiscalibrationdata.Afterinputthecalibrationcoefficientintosoftwareapplicationprogram,thecalibrationprocessisover.Fig.6AshowsthecalibrationlineinXaxis.Fig.6BshowsthecalibrationlineinYaxis.Fig.6AMeasurementresultsofXaxisFig.6BMeasurementresultsofYaxisV.CONLUSIONAnovelopticalsensorwasinvented.Aprototypehasbeenbuiltupandevaluated.Accuracyof+-1arcsecondwithinthemeasurementrangeof700arcsecondshasbeenachieved.Itcanmeasureinclinationangleortiltangleoftwoaxessimultaneouslyandprecisely.Thissensorisbasedontheprincipleoflaserinterference.Ithasthefollowingmainadvantagescomparewithotherinclinometers.(1)Highaccurate.Itisopticalinterferenceprinciplebasedsensor.Anyvariationlessthan,e.g.0.3microninopticalpathwillcausethemovementofinterferencefringepattern.Thistinychangeisdetectedandconvertedtotiltangle.(2)Insensitivetomagneticenvironment.(3)Optoelectronicsensor,nomechanicalmovingparts.(4)Twoaxesanglesmeasurementatthesametime.REFERENCES[1]Olson,JackR.,“Electrolytictiltsensorandmethodformanufacturingsame”,USpatent,US6802132B1,2004[2]Urano,Mitsuhiro,“Capacitancetypeliquidsensor”,PatentEP1515117A1,2005[3]Zabler,Erich,“Tiltsensor”,PatentEP0768513A2,1997**大学英文文献原文及翻译一种精确测量倾斜角度的光学传感器摘要本文主要介绍了一种新型光学传感器，它可以同时准确地测量倾斜角或两轴倾斜角度。这种传感器是基于激光干涉原理，因此具有很高的精度。设计制作了一个传感器的模型来论证这个新的方法，这是一个光电传感器,传感器中没有移动的部分。由正交于铅垂面的流动水平面提供参考面。传感器和绝对水平面之间的角度随着被测量的物体倾斜而改变，这些变化反映在条纹图案的中心位置的转移方式。不同的干涉条纹的中心位置随倾斜角的变化而改变。干涉条纹图案进行记录和处理，转化为两轴、水平和垂直倾斜角度。当使用1024*1024像素的传感器时，测量范围为700弧秒，其精度可高达+/-1弧秒。关键词：倾斜角度传感器，倾斜仪，激光干涉I介绍市场上目前有几种类型的商业倾斜角度测量传感器。有些是角度传感器，有些是倾斜仪，它们的工作原理不同。电解液体、电容和钟摆是现在大多数倾斜角度传感器和倾斜仪的三个主要工作原理。在这里，我们提出了一种新的光学方法，建立了一个用激光、光学元件和图像传感器的光电传感器，它可以同时做精确的倾斜角度测量，不需要进行机械的移动，其工作原理是基于光学干涉，相干激光作为光源。光线通过一个装满液态油的玻璃油盒。由正交于铅垂面的流动水平面提供参考面。当激光束穿过油箱有两束光线反射回来，一束是液体的表面产生的，另一束是容器玻璃产生的，干涉条纹就是由这两条光线形成的，条纹图案将随着倾斜角度的变化产生相应的变化，条纹图案采集和处理后将反映倾斜角度信息，光学工作原理使它不受磁场的影响。该传感器可以同时测量两轴倾角。流动的水平面确保了参考面是一个绝对的水平面。高灵敏度光学干涉测量原理，保证了较高的精度。II原理图1说明了工作原理示意图，O点是光线扩大镜头的焦点，O点可以看作是点光源，它发出球面波。由于地球重力的影响，液体油面始终保持水平，因此用油面作为参考平面。该容器是玻璃材料的。当传感器被放在目标表面时，其底部表面将连同目标对象一起倾斜。图1测量原理工作示意图从油面和玻璃表面射出的光将干涉形成圆形图案（见图4）。倾斜角度可以通过圆形图案中心位置的改变测量得出。P是点O在玻璃和空间之间形成的镜像，点Q则是点O在油和空气之间形成的镜像，油—空气平面代表了水平面。当使玻璃面平行油面，点P和点Q在垂直于油面的同一条线上，这条线也是光学系统的轴线。边缘与共同中心圆形边缘。当油箱倾斜玻璃表面有一对以油面的倾斜角，这是同心圆图案。当油盒倾斜时，玻璃面相对于油面有个倾斜角。（1）其中n是玻璃的折射率。当倾斜角度很小，上面的方程可以简化为 （2）我们可以从和得到以下方程：（3）其中是圆条纹中心的位置，

D是接收屏幕到油箱玻璃表面的距离，H是玻璃和油的厚度，

n是玻璃和油折射率（因为玻璃和油的折射率非常接近，这里假设它们相等）。

假设折射率nD远远大于h，因此相对于来说h可以忽略不计。(4)从方程（4）可知，一旦装置安装好后，n,d,h是固定的。令,为系统常量，系统参数可以通过校验过程获得。因此方程(4)可以写成（5）其中可以通过图像处理技术计算出,由此可以得出值。III.传感器的描述图2显示了传感器的光学头部详细布局。它包括激光1，扩束2，光束分离器3，平面镜4和液体油盒5。一个点光源发出球面波，这束光线穿过油箱。这束光线分别被玻璃表面和油的表面反射，两束不同路线的光将再次相遇再次相聚。如果点光源相干长度大于长的光程差，这两束光线将产生干涉形成环形条纹。当一个表面发生倾斜，圆形条纹中心将相应地转变。当光学路径变化，条纹将相应的出现或者被吸收。条纹变化发生在一个相对应的光程差，其中为光源的波长。图2光学传感器布局如图2所示，激光发射激光束1。激光束通过扩束2被扩大，形成一个球形波前束，随后这束光线垂直穿过液