声表面波陀螺效应检测技术的研究

论文题目：声表面波陀螺效应检测技术的研究专业：微电子学与固体电子学硕士生：魏星(签名)指导教师：刘骏跃(签名)摘要现阶段声表面波陀螺效应主要应用在SAW陀螺仪(角速度传感器)领域，但是还处于理论研究阶段。尽管英、美、日提出在SAW传播路径上用金属点阵的方法达到测量介质旋转角速度W的目的，但结果并不理想。本文以声光之间的联系作为理论基础，利用声光探测技术来检测声表面波陀螺效应。首先利用叉指换能器在一透明压电介质表面产生声表面波，当介质以一定的旋转角速度旋转时，介质将产生声表面波陀螺效应，这时如果一束光射入压电介质，将产生布拉格衍射现象，本文设计的系统方案就是通过检测布拉格衍射光夹角达到检测声表面波陀螺效应的目的。本文的设计方案主要对声光陀螺效应过程中产生的衍射光夹角角度的测量，由于衍射角度很小，所以采用精确度较高的线阵CCD作为测量器件，当两条衍射光照射在CCD上，形成两个光斑，CCD的光敏元产生光生电荷。因为CCD输出量为模拟信号，为了进行定位算法的处理，必需通过AD芯片把CCD输出的模拟信号转化成数字信号，再把经过AD转换后的数字信号输入到FPGA中进行算法和数据的处理。在这个过程中，采用Verilog语言实现三阈值二值化法光敏元定位算法，算出衍射光照在CCD上形成的两个光斑之间的距离，利用Verilog语言编写的乘法器和除法器实现夹角的计算。本文采用的CCD测量光夹角的结构，是一种应用前景很广阔的结构，它可用在声光陀螺仪上。经过进一步的完善，以实现对旋转物体自身旋转角速度的实时检测。关键词：声表面波；电荷耦合器件；FPGA；ADC研究类型：应用研究Subject:ResearchofSurfaceAcousticWaveGyroEffortDetectionTechnologySpecialty:MicroelectronicsandsoildstateelectronicsName:WeiXing(Signature)Instructorl:LiuJunyue(Signature)ABSTRACTInpresent,SAWgyroscopeeffectismainlyusedintheSAWgyroscope(angularvelocitysensor)field,butinthestageoftheoreticalresearch.AlthoughtheUnitedKingdom,theUnitedStatesandJapanraisedamethodthatmetallatticeisputonSAWpropagationpathtomeasuretheangularvelocityofrotationofthemedium,theresultisnotideal.Thispapertakesthecontactionbetweenthesoundandlightastheoreticalbasis,andusesacoustoopticdetectiontechnologytodetectthesurfaceacousticwavegyroscopiceffect..Usingtheinterdigitaltransducerproducesfirstlysurfaceacousticwaveinatransparentpiezoelectricmediumsurface.Whenthemediumtoacertainangularvelocityofrotation,themediumwillproducethesurfaceacousticwavegyroscopiceffect.Ifabeamoflightexposurestothepiezoelectricmediumbythis,themediumwillproduceaBraggdiffractionphenomenon.Inthispaper,thedesignofsystemsolutionsbydetectingtheBraggdiffractionoflightangleachievethepurposeofdetectionoftheSAWgyroscopiceffect.Theproposedprogramistomeasurethediffractedlightgeneratedangleintheprocessofthegyroscopiceffectofthesoundandlight,becausethediffractionangleisverysmall,sothehigherprecisionlinearCCDworkasameasuringdevice.WhenthetwodiffractionraysshineontheCCD,twospotsareformedontheCCDandphotosensitiveelementsproducelight-inducedcharge.CCDoutputisananalogsignal,inordertocarryouttheprocessingofthepositioningalgorithm,theCCDanalogoutputbytheADchipsignalfirstlyconvertsintodigitalsignal,andthenthedigitalsignalaftertheADconversioninputstotheFPGAforalgorithmsandprocessingthedata,inthisprocessVeriloglanguageisusedtoachievethephotosensitiveelementpositioningalgorithmofthethreethresholdvalue.andcalculatethedistancebetweenthediffractionlightspotformedontheCCD,andfinallythemultiplieranddividerrealizeinVeriloglanguageisusedtoachievethecalculationsbetweentheangle.Thestructureofmeasuringthelightangleinthispaperisaverybroadapplicationprospectsofthestructure,itcanbeusedinacousto-opticgyroscope,afterfurtherrefinement,itcanachievereal-timedetectionoftheangularvelocityoftherotatingobject.Keywords:SAW；CCD；FPGA；ADCThesis:ApplicationResearch目录I目录1绪论...............................................................................................................................11.1课题的研究背景.........................................................................................................11.2课题的国内外研究动态及发展趋势...........................................................................21.3课题的研究意义.........................................................................................................21.4课题的主要任务.........................................................................................................32SAW陀螺效应的声光检测理论和检测方案.....................................................................42.1SAW的陀螺效应.........................................................................................................42.2声光探测技术的基本理论..........................................................................................52.2.1声光效应“光栅衍射说”...................................................................................52.2.2声光效应的量子解释...........................................................................................62.2.3声光效应耦合理论...............................................................................................72.2.4声光布拉格衍射与声行波速度的关系................................................................92.3SAW陀螺效应声光检测方案研究............................................................................102.3.1SAW陀螺效应检测方案....................................................................................102.3.2SAW陀螺仪各个部分的设计.............................................................................112.4本章小结...................................................................................................................133CCD声光信号采集..........................................................................................................143.1检测布拉格衍射光夹角大小的光学原理.................................................................143.2光电采集系统的构造................................................................................................143.2.1CCD基本结构和工作原理...............................................................................