ULTASONICRANGINGINAIRGERUDASHEVSKIANDAAGORBATOVUDC534,3219531710837ONEOFTHEMOSTIMPORTANTPROBLEMSININSTRUMENTATIONTECHNOLOGYISTHEREMOTE,CONTACTLESSMEASUREMENTOFDISTANCESINTHEORDEROF02TO10MINAIRSUCHAPROBLEMOCCURS,FORINSTANCE,WHENMEASURINGTHERELATIVETHREEDIMENSIONALPOSITIONOFSEPARATEMACHINEMEMBERSORSTRUCTURALUNITSINTERESTINGPOSSIBILITIESFORITSSOLUTIONAREOPENEDUPBYUTILIZINGULTRASONICVIBRATIONSASANINFORMATIONCARRIERTHEPHYSICALPROPERTIESOFAIR,INWHICHTHEMEASUREMENTSAREMADE,PERMITVIBRATIONSTOBEEMPLOYEDATFREQUENCIESUPTO500KHZFORDISTANCESUPTO05MBETWEENAMEMBERANDTHETRANSDUCER,ORUPTO60KHZWHENRANGINGONOBSTACLESLOCATEDATDISTANCESUPTO10MTHEPROBLEMOFMEASURINGDISTANCESINAIRISSOMEWHATDIFFERENTFROMOTHERPROBLEMSINTHEAPPLICATIONOFULTRASOUNDALTHOUGHTHEPOSSIBILITYOFUSINGACOUSTICRANGINGFORTHISPURPOSEHASBEENKNOWNFORALONGTIME,ANDATFIRSTGLANCEAPPEARSVERYSIMPLE,NEVERTHELESSATTHEPRESENTTIMETHEREAREONLYASMALLNUMBEROFDEVELOPMENTSUSINGTHISMETHODTHATARESUITABLEFORPRACTICALPURPOSESTHEMAINDIFFICULTYHEREISINPROVIDINGARELIABLEACOUSTICTHREEDIMENSIONALCONTACTWITHTHETESTOBJECTDURINGSEVERECHANGESINTHEAIRSCHARACTERISTICPRACTICALLYALLACOUSTICARRANGEMENTSPRESENTLYKNOWNFORCHECKINGDISTANCESUSEAMETHODOFMEASURINGTHEPROPAGATIONTIMEFORCERTAININFORMATIONSAMPLESFROMTHERADIATORTOTHEREFLECTINGMEMBERANDBACKTHEUNMODULATEDACOUSTICULTRASONICVIBRATIONSRADIATEDBYATRANSDUCERARENOTINTHEMSELVESASOURCEOFINFORMATIONINORDERTOTRANSMITSOMEINFORMATIONALCOMMUNICATIONTHATCANTHENBESELECTEDATTHERECEIVINGENDAFTERREFLECTIONFROMTHETESTMEMBER,THERADIATEDVIBRATIONSMUSTBEMODULATEDINTHISCASETHEULTRASONICVIBRATIONSARETHECARRIEROFTHEINFORMATIONWHICHLIESINTHEMODULATIONSIGNAL,IE,THEYARETHEMEANSFORESTABLISHINGTHESPATIALCONTACTBETWEENTHEMEASURINGINSTRUMENTANDTHEOBJECTBEINGMEASUREDTHISCONCLUSION,HOWEVER,DOESNOTMEANTHATTHEANALYSISANDSELECTIONOF241DLTGEPRADPARAMETERSFORTHECARRIERVIBRATIONSISOFMINORIMPORTANCEONTHECONTRARY,THEFREQUENCYOFTHECARRIERVIBRATIONSISLINKEDINAVERYCLOSEMANNERWITHTHECODINGMETHODFORTHEINFORMATIONALCOMMUNICATION,WITHTHEPASSBANDOFTHERECEIVINGANDRADIATINGELEMENTSINTHEAPPARATUS,WITHTHESPATIALCHARACTERISTICSOFTHEULTRASONICCOMMUNICATIONCHANNEL,ANDWITHTHEMEASURINGACCURACYLETUSDWELLONTHEQUESTIONSOFGENERALIMPORTANCEFORULTRASONICRANGINGINAIR,NAMELYONTHECHOICEOFACARRIERFREQUENCYANDTHEAMOUNTOFACOUSTICPOWERRECEIVEDANANALYSISSHOWSTHATWITHCONICALDIRECTIVITYDIAGRAMSFORTHERADIATORANDRECEIVER,ANDASSUMINGTHATTHEDISTANCEBETWEENRADIATORANDRECEIVERISSUBSTANTIALLYSMALLERTHANTHEDISTANCETOTHEOBSTACLE,THEAMOUNTOFACOUSTICPOWERARRIVINGATTHERECEIVINGAREAPRFORTHECASEOFREFLECTIONFROMANIDEALPLANESURFACELOCATEDATRIGHTANGLESTOTHEACOUSTICAXISOFTHETRANSDUCERCOMESTOWHEREPRADISTHEAMOUNTOFACOUSTICPOWERRADIATED,BISTHEABSORPTIONCOEFFICIENTFORAPLANEWAVEINTHEMEDIUM,LISTHEDISTANCEBETWEENTHEELECTROACOUSTICTRANSDUCERANDTHETESTMEMBER,DISTHEDIAMETEROFTHERADIATORRECEIVER,ASSUMINGTHEYAREEQUAL,ANDCISTHEANGLEOFTHEDIRECTIVITYDIAGRAMFORTHEELECTROACOUSTICTRANSDUCERINTHERADIATORSIN21DJWBOTHINEQ1ANDBELOW,THEABSORPTIONCOEFFICIENTISDEPENDENTONTHEAMPLITUDEANDNOTONTHEINTENSITYASINSOMEWORKS1,ANDTHEREFOREWETHINKITNECESSARYTOSTRESSTHISDIFFERENCEINTHEVARIOUSPROBLEMSOFSOUNDRANGINGONTHETESTMEMBERSOFMACHINESANDSTRUCTURES,THERELATIONSHIPBETWEENTHESIGNALATTENUATIONSDUETOTHEABSORPTIONOFAPLANEWAVEANDDUETOTHEGEOMETRICALPROPERTIESOFTHESOUNDBEAMARE,ASARULE,QUITEDIFFERENTITMUSTBEPOINTEDOUTTHATTHECHOICEOFTHEGEOMETRICALPARAMETERSFORTHEBEAMINSPECIFICPRACTICALCASESISDICTATEDBYTHESHAPEOFTHEREFLECTINGSURFACEANDITSSPATIALDISTORTIONRELATIVETOSOMEAVERAGEPOSITIONLETUSCONSIDERINMOREDETAILTHERELATIONSHIPBETWEENTHEGEOMETRICANDTHEPOWERPARAMETERSOFACOUSTICBEAMSFORTHEMOSTCOMMONCASESOFRANGINGONPLANEANDCYLINDRICALSTRUCTURALMEMBERSITISWELLKNOWNTHATTHEDIRECTIONALCHARACTERISTICWOFACIRCULARPISTONVIBRATINGINANINFINITEBAFFLEISAFUNCTIONOFTHERATIOOFTHEPISTONSDIAMETERTOTHEWAVELENGTHD/ASFOUNDFROMTHEFOLLOWINGEXPRESSION2WHEREJLISABESSELFUNCTIONOFTHEFIRSTORDERANDISTHEANGLEBETWEENANORMALTOTHEPISTONANDALINEPROJECTEDFROMTHECENTEROFTHEPISTONTOTHEPOINTOFOBSERVATIONRADIATIONFROMEQ2ITISREADILYFOUNDTHATATWOTOONEREDUCTIONINTHESENSITIVITYOFARADIATORWITHRESPECTTOSOUNDPRESSUREWILLOCCURATTHEANGLE（3）FORANGLES20EQ3CANBESIMPLIFIEDTO（4）D760RCSI50FDC7605WHERECISTHEVELOCITYOFSOUNDINTHEMEDIMAAANDFISTHEFREQUENCYOFTHERADIATEDVIBRATIONSITFOLLOWSFROMEQ4THATWHENRADIATINGINTOAIRWHEREC330M/SEC,THENECESSARYDIAMETEROFTHERADIATORFORASPEDFIEDANGLEOFTHEDIRECTIVITYDIAGRAMATTHE05LEVELOFPRESSURETAKENWITHRESPECTTOTHEAXISCANBEFOUNDTOBE（5）WHEREDISINCM,FISINKHZ,ANDISINDEGREESOFANGLECURVESARESHOWNINFIG1PLOTTEDFROMEQ5FORSIXANGLESOFARADIATORSDIRECTIVITYDIAGRAMTHEDIRECTIVITYDIAGRMNEEDEDFORARADIATORISDICTATEDBYTHEMAXIMUMDISTANCETOBEMEASUREDANDBYTHESPATIALDISPOSITIONOFTHETESTMEMBERRELATIVETOTHEOTHERSTRUCTURALMEMBERSINORDERTOAVOIDTHEINCIDENCEOFSIGNALSREFLECTEDFROMADJACENTMEMBERSONTOTHEACOUSTICRECEIVER,ITISNECESSARYTOPROVIDEASMALLANGLEOFDIVERGENCEFORTHESOUNDBEAMAND,ASFARASPOSSIBLE,ASMALLDIAMETERRADIATORTHESETWOREQUIREMENTSAREMUTUALLYINCONSISTENTSINCEFORAGIVENRADIATIONFREQUENCYAREDUCTIONOFTHEBEAMSDIVERGENCEANGLEREQUIRESANINCRE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āo)準(zhǔn)的聲音數(shù)額的選擇。（1）在PRAD輻射聲功率，B是平面波在介質(zhì)中吸收系數(shù)為，L是聲電傳感器和測試箱之間的距離，D是散熱器（接收）的直徑，C是的電聲換能器的散熱器方向性圖的角度。241DLTGEPRAD在均衡器（1）及以下，和作品1一樣，吸收系數(shù)依賴于振幅和而不是強(qiáng)度，因此，我們認(rèn)為有必要強(qiáng)調(diào)這種差異。圖1圖2SIN21DJW圖3在聲音的各種問題上，包括成員測試設(shè)備和結(jié)構(gòu)的關(guān)系，由于信號衰減吸收的平面和適當(dāng)?shù)膸缀涡再|(zhì)的聲束是，作為一項(xiàng)規(guī)則，一定是相差甚遠(yuǎn)的需要指出的是，選擇的實(shí)際情況中光束具體的幾何參數(shù)，是基于形狀的反射面和空間的一些失真相對平均排布。讓我們考慮一下更詳細(xì)的幾何關(guān)系和聲束的動力參數(shù)這個最常見包括平面和圓柱結(jié)構(gòu)的成員情況。眾所周知，定向特性瓦的一個圓形活塞振動無限擋板是一個活塞比例函數(shù),D/為下列表達(dá)式基礎(chǔ)（2）從均衡器（2）中很容易發(fā)現(xiàn)，在減少兩到一個敏感性散熱器方面,聲壓級角度將會引起注意。（3）表1F0KHZ102030405060801001502003005000DB/M05071215226354691640對角可以簡化為20EQ（3）（4）其中C是中期聲速,F是輻射震動的頻率它遵循均衡器（4），當(dāng)輻射到空中，其中C300米/秒，在05級的D760ARCSIN50FDC7605壓力面，散熱器為采取的軸的直徑用于指定角度的方向性圖上是必要的（5）其中D是厘米，KHZ是千赫，是度角。在圖1中顯示的曲線圖是均衡器（5）中6個角度散熱器的方向性圖。事實(shí)上，直徑的“超聲波降解標(biāo)本”現(xiàn)場控制的兩個變量，即直徑的散熱器和發(fā)散角的聲音束一般情況下，最小直徑的“超聲波降解標(biāo)本”在現(xiàn)場飛機(jī)表面處理，通常傾向于散熱器的軸心。（6）L是測試表面最小的距離。對應(yīng)的散熱器直徑（7）（7）作為從均衡器（6）及（7），“聲振”現(xiàn)場最小直徑，最高要求散熱器直徑距離不得少于2自然的，以短距離的障礙的大小，“聲振“表面的更少。其中D是厘米，KHZ的在千赫，是度角讓我們考慮在半徑為R的中聲波測距的情況。問題是在X和Y中坐標(biāo)軸上衡