基于超聲波的非侵入式壓力測量方法研究.pdf

1、浙江大學博士學位論文基于超聲波的非侵入式壓力測量方法研究姓名：林韶峰申請學位級別：博士專業(yè)：控制科學與工程指導教師：張宏建20050501AbstractPressureisoneofthemostimportantparametersinmodernindustryInordertoensurethedevicesworkingproperlyandsafelyitisnecessarytomonitorandcontrolthepr

2、essureConventionalmethodsmostofthembelongingtotheinvasivemethodtomeasurethepressurerequiredrillingaholeinthewallofthedeviceswhichnotonlyinduceslocalstressconcentration，butalsobringsmanysafetyproblemsInthispaperanovelmeth

3、odtomeasurethepressurenoninvasivelybasedontheultrasoniciSpresentedWiththismethod，thepressurecanbegottenbymeasuringthetransittimedifierenceofultrasonicunderdifierentpressuresThemainresearchachievementjSshowedasfoIlows：1Ba

4、sedonthemodelofRayleighwavesmeasuringstressandthinfilmtheoryofvessels，withthesurfacestressasmiddlevariable，therelationshipbetweenthevelocitychangesandthepressureiSestablishedforthe10WandmiddlepressurevesselsorpipesConsid

5、eringvelocitycouldnotbemeasureddirectlytherelationshipbetweenthetransittimedifferenceandthepressureiSdeducedfartherandtheeffectofstraintothemeasurementresultsiSalsomodified2BecausetheRayleighwavessampledbytheADcardalways

6、containthecorrelativecolorednoise，thegeneralcorrelativetimeestimationmethodbasedontheCWTiSpresentedtocalculate山etransittimedifierenceunderdifferentpressuresAccordingtothismethod，theexperimentalsystemWasbuiltThestudieswer

7、edonewhentheRayleighwavepropagatedinthedirectionofaxisandcircumferenceofthevesselsTheexperimentalresultsshowthattheproposedmodelcouldpredicttherelationshipbetweenthetransittimedifierenceandthepressureaccuratelyandthemeth

8、odtomeasurepressureusingRayleighwaveisfeasible3T0solvetheproblemsexistingintheexperiment，suchas10wprecisionoftimemeasurement，longtimeneededtoealculatethetransittimedifferenceandhighcostoftheexperimentaldevices，anewmethod

9、waspresented，usingtheelectricalsignalfromthereceivertetriggerthetransmitterandthedevicewasmadeWiththisdevice，theprecisionoftimemeasurementwasimproved，butthecostofexperimentaldeviceswasreduced4Thea舵ctoftemperaturewasdiscu

10、ssedaccordingtosomephenomenaintheexperimentOnlyconsideringthemainaspectsofthetemperatureaffectingtheresults，themodelofthetransittimedifferenceandpressurewasmodifiedandaccordingtothisnewmodel，amethodwaspresentedtocorrectt

11、heerrorscausedbythetemperaturefluctuationTheexperimentalresultsshowthatthismethodCaneliminateorweakentheaffectoftemperatureeffectivelyKeyword：Pressuremeasurement，Noninvasive，Rayleighwaves，Acoustics，StressStrain，Delayesti