毕业设计外文资料翻译

毕业设计外文资料翻译题目FIR数字滤波器多级输送带的连续称量学院机械学院济南大学毕业设计外文资料翻译专业机械设计制造及其自动化班级学生学号指导教师二〇一四年三月十五日Measurement40(2007)791–796Continuousweighingonamulti-stageconveyorbeltwithFIRfilterRyosukeTasaki,TakanoriYamazaki,HideoOhnishi,MasaakiKobayashi,ShigeruKurosuDepartmentofMechanicalEngineering,KyotoInstituteofTechnology,JapanDepartmentofMechanicalEngineering,OyamaNationalCollegeofTechnology,771Nakakuki,Oyama323-0806,JapanDepartmentofEngineering,ShinkoCo.,Ltd.,4219-71Takasai,Shimotsuma304-0031,JapanResearchInstitute,Crotech,JapanReceived13January2006;receivedinrevisedform23March2006;accepted11May济南大学毕业设计外文资料翻译2006Availableonline2June2006AbstractTodayhigherspeedofoperationandhighlyaccurateweighingofpackagesduringcrossingaconveyorbelthasbeengettingmoreimportantinthefoodanddistributionindustriesetc.Continuousweighingmeansthatmassesofdiscretepackagesonaconveyorbeltareautomaticallydeterminedinsequence.Makingtheproperuseofnewweighingscalecalledamulti-stageconveyorbeltscalewhichcanbecreatedsoastoadjusttheconveyorbeltlengthtotheproductlength,weproposeasimplifiedandeffectivemassestimationalgorithmunderpracticalvibrationmodes.Conveyorbeltscalesusuallyhavemaximumcapacitiesoflessthan80kgand140cm,andachievemeasuringratesof150packagesperminuteandmore.Theoutputsignalsfromtheconveyorbeltscalesarealwayscontaminatedwithnoisesduetovibrationsoftheconveyorbeltandtheproductinmotion.Inthispaperdigitalfilteroffinite-durationimpulseresponse(FEB)typeisdesignedtoprovideadequateaccuracy.Theexperimentalresultsonconveyorbeltscalessuggestthatthefilteringalgorithmproposedhereiseffectiveenoughtopracticalapplications.Aslongasspacesbetweensuccessiveproductsaresetwithinaspecifiedrange,theproductscanbeweighedcorrectlyevenifproductshavingdifferentlengthsaretransportedinrandommanner.Keywords:Massmeasurement;Continuousweighing;Conveyorbelt;FIRfilter*Correspondingauthor.Tel.:+81285202212;fax:+81285202884.E-mailaddresses:yama@oyama-ct.ac.jp(T.Yamazaki),oonishi@vibra.co.jp(H.Ohnishi),mkobayas@vibra.co.jp(M.Kobayashi),kurosu_shi@yahoo.co.jp(S.Kurosu).1Tel.:+81296432001;fax:+81296432130.2Tel./fax:+81296284476.0263-2241/$-seefrontmatte?r2006PublishedbyElsevierLtd.doi:10.1016/j.measurement.2006.05.010IntroductionConveyorbeltscalesamongthesearemostimportantfortheproductionofagreatvarietyofprepackagedproducts[1].Whenaproductisputonaconveyorbelt,ameasuredsignalfromtheconveyorbeltscaleisalwayscontaminatedbynoises.Sincethemeasuredsignalisusuallyinthelowerfrequencyrange,afilterwhichwilleffectivelycutdownnoisesatthehigh-frequencyendcanbeeasilydesigned.If,however,theproduct(likeacardboardboxandaparceletc.)hasalowfrequencycomponent,wherethenoiseintensityishigh,itispracticallyimpossibletoseparatethemeasuredsignalfromnoise.Therestillexistrealproblemsforwhichengineeringdevelopmentinnoise-filteringisneeded.Therecenttechniquesofdynamicmassmeasurementhavebeeninvestigatedtofindawaytoobtainmassoftheproductunderdynamicconditions.Thekeyideaofdynamic

济南大学毕业设计外文资料翻译measurementisthatwetakeintoconsiderationthevariousdynamicfactorsthataffectthemeasuredsignalintheinstrumenttoderiveanestimationalgorithm[2].Ono[3]proposedamethodthatdeterminesmassofdynamicmeasurementusingdynamicquantitiesofthesensingelementactuatedbygravitationalforce.Also,Lee[4]proposedthealgorithmofrecursiveleastsquaresregressionforthemeasuringsystemsimulatedasadynamicmodeltoobtainthemassbeingweighed.Successfuldynamicmassmeasurementdependsmainlyonamathematicalmodeltoachieveaccuratemeasurement.Buteventhesimplestructureofaconveyorbeltscalemakesitdifficulttoobtaintheexactmodel.Ontheotherhand,somefilteringtechniqueshavebeenappliedtoasignalprocessingfortheconveyorbeltscale[5].Inordertoreducetheinfluenceofdynamicsandtoimprovetheaccuracyofmassmeasurementwithoutlosingthequickness,wehaveproposedasimplifiedandeffectivealgorithmfordataprocessingunderpracticalconveyorbel'tsvibrations[6–9].BasicconfigurationOutlineofconveyorbeltscalesThefundamentalconfigurationoftheconveyorbeltscalesmayberepresentedschematicallyasshowninFig.1.Theloadreceivingelementisabeltconveyorsupportedbyaloadcellattheedgeoftheframe.ThedetectedsignalbytheloadcellissentintoaFIRdigitalfilterthroughaDCamplifier.Themassoftheproductcanbeestimatedasthemaximumvalueevaluatedfromthesmoothedsignal.Thesimulationsandtheexperimentsarecarriedoutunderthefollowingconditions:lengthofproduct:li=20–140cmlengthofthebeltconveyor:Lj(L1=40cm,L2=40cm,L3=60cm)massoftheproduct:mi=20–80kgdistancebetweenproducts:di=20–100cmconveyorbeltspeed:v=132m/minrequiredaccuracy:≤±0.7%samplingfrequency:fs=2000Hz(samplingperiod:Ts=0.5ms)

济南大学毕业设计外文资料翻译Thetotallengthofthemulti-stageconveyorisconsideredinthefollowingpatterns:L=L3(=60cm):forthesingle-stageconveyorbeltscale,L=L1+L2(=80cm):forthetwo-stageconveyorbeltscalel,L=L2+L3(=100cm):forthetwo-stageconveyorbeltscale2,L=L1+L2+L3(=140cm):forthethree-stageconveyorbeltscale.2.2.MinimumdistancebetweenproductsTheminimumdistancebetweenproductsmustbeexaminedcorrectlybythegeometricalconditions.Incaseofathree-stageconveyorbeltscale,lettheminimumtravellingdistancewhichisnecessaryforreachingthesteadystatevalueofanoutputsignalbeSandtheminimumdistancewhichisshorter,di-1ordi,bedS.ThehypotheticaltimechangesofaloadinginputcanbeshowninFig.2undertheconditionthatdS<L-li.Whentheproductmiistransportedontotheconveyorbeltscale,theminimumtravellingdistanceSisnecessaryformeasuringthemassofproductsaccurately.AscanbeseenfromFig.2,theminimumdistancedSbetweenproductscanbeexpressedby:2dS≤L-li+S(ds=min(di-1,di))(1)ByapplyingactualvaluesoftheproductlengthliandtheminimumdistanceS(=20cm)toInequality(1),theminimumdistancedSwithrespecttotheproductlengthlicanbeobtaineddiagrammaticallyasshowninFig.3.ItshouldbenotedthatdSissettobenotlessthan40cm.济南大学毕业设计外文资料翻译DesignofFIRfiltersThedesignofdigitalfiltersiswellestablishedandextensivelycoveredintheliterature.Therearetypicallytwokindsofdigitalfilters,i.e.infinite-durationimpulseresponse(IIR)typeandfinite-durationimpulseresponse(FIR)one.Aftertheproductpassesthroughtheconveyorbeltandtheloadinginputchangestozero,thetransientresponseinthefiltershouldbereturnedtotheinitialstatesofast[1—012].Forthisreason,FIRfiltercanbeconsideredtobeadequateforconveyorbeltscales.Now,weexplaintheprocedurefordesigningtheFIRfilter.WritingthenormalizedfrequencyasΩ=fT,wherefisthefrequency(Hz),andTisthesamplingperiod(s),thedesiredtransferfunctioncanbeexpressedbyThefilterHd(ejΩ)canbeeasilyobtainedbythewell-knownRemezalgorithm.Whentheloweredgefrequency(Ωs)ofthestopbandwidthischosenaslessthan0.05forthedesignofaFIRfilter,itbecomesgenerallyimpossibletodesignsincethenoiseattenuationeffectdecreasesrapidly,andthesamplingperiodTshouldbeadjustedthroughthedown-sampling.Thedatatobesmoothedareextractedateverydown-samplingperiodT(=nTm,inwhichnisaproperinteger)fromthemeasureddataateverysamplingperiodTm=0.5ms.Inourcase,ncanbechosenasn=4,6and8(correspondingtoT=2,3and4ms).ThegainplotofthefilterdesignedfortheorderM=42isshowninFig.4(a).Fig.4(b)showstheimpulseresponseobtainedforthedesignspecificationsthaΩtp=0.002andΩs=0.05.Also,Fig.5(a)showsthesimulationresultsobtainedafterfilteringtheoutputsignal.Itcanbeseenthatundesirablesignalsexistinginthehigh-frequencyrangecanbeeffectivelyeliminated,andbyincreasingTtheresponsecanbesmoothed.济南大学毕业设计外文资料翻译Next,Fig.5(b)showsanexampleofdiscretedatasmoothedforthedown-samplingperiodsisprocessedateverysamplingperiod(Tm=0.5ms).Aminorcontaminationofthesmoothedsignalbyhigh-frequencynoisebecomesseriousintheneighborhoodofmaximumpoint.ForthesamplingperiodT=4ms,theresultingfrequencyofthesampleddatecanbedeterminedhasaperiodicityoff=1/T=250Hz.Thenaturalfrequencyoftheconveyorbeltisinthevicinityof200Hz.Toreducetheeffectofnoiseasimplestfirst-orderlowpassfilter(cutoff-frequency10Hz)iscascadedwiththeFIRfilter.Technicalproblems4.1.Non-uniformlydistributedweightToillustrateanexampleofcrucialproblems,acombinedsetforthreeproductsinsequencepassesovertheconveyorbeltscaleundertheconditionthatli=100cm,mi=80kg,anddi=60cm.Fig.6(a)showstherealtimehistoryoftheoutputsignals.Thefirst,secondandthirdsignalsdenoteoutputsignalsfromconveyorbeltscaleL1,L2andL3theaddedsignaldenotesasumofoutputsignalsthatcorrespondstothemassofaproduct.Itis

济南大学毕业设计外文资料翻译clearthatanexactdeterminationofmassesisimpossible,becausethecurveshaveseveralpeakvalueslikeawindingpath.Thesimplestcauseofthecrookedcurvesisthatthebaseplateoftheproductisslightlycurved(oruneven)orthereexistsalittledifferenceinlevelbetweenthebackandforthconveyors.Thus,thesegeometricdeviationsdonotmaketheweightdistributeuniformly.Next,Fig.6(b)showstherealtimehistoryoftheoutputsignalsforonlyoneproductunderthesameconditionsasshowninFig.6(a).Itcanbeseenthatthemaximumvalueoftheaddedsignalindicatesroughlythemassoftheproduct(80kg).However,thisresponsecurveisnotthesmoothedtrapezoidalwaveasshowninFig.6(a),butthecurvesweepsfarandwide.Thisshapeexpressesthattheweightcannotbeauniformlydistributedload.Thus,whenthenextproductmovesontotheconveyorscalebeforethecurrentproducttobemeasuredhasmovedofftheconveyorbelt,theaddedsignalcanbecontaminatedbytheoutputsignalsofthenextproduct,andseveralpeakvaluescanbefoundontheaddedsignal.4.2.AllowablerangeforsearchingamaximumvalueThemassesofproductscanbeeasilyestimatedasthemaximumvaluesindurationsofthesmoothedsignalssuppliedfromtheconveyorbeltscales.However,therearesometimescrucialcasesthatmassescannotbedeterminedbythemaximumvaluesthatoccursinthestreamofoutputsignals.Firstly,letusconsiderthehypotheticalloadinginputprofilesthattheweightdistributesuniformlyontheconveyorbeltscale.ToinvestigatethetimeTMtoreachthemaximumvaluefortheconveyorbeltscales,thesimulationsarecarriedout.ThevariationofTMwithliisparticularlylinearandTMcanbeestimatedbyusingTм=ao+a1li[s](3)Next,wegiveabriefexplanationofanewmassestimationmethodforthemulti-stage

-8-济南大学毕业设计外文资料翻译conveyorbeltscaleandpointouttheproblemsinestimatingmasseswithhighaccuracy.Actually,sinceeachmassofaproductvariesaccordingtothewayhowitisloadedevenifthetotalmassofaproductissame,hencerangesofthemaximumtimefornonuniformlydistributedmassofaproductshouldbeinvestigated.Theresultsobtainedbysimulationssuggestthatthemaximumvalueisbelievedtobewithinanintervalof10msaroundtheidealmaximumvalueTM,andtheallowablerangecanbedefinedbyTb≤Tм±10ms(4)Thus,itcanbeseenthateventhoughtheoutputcurveshaveseveralpeakvalues,thequasi-maximumvaluesontheoutsideoftherangeTbproveunacceptableinthemass-measurement.ExperimentsToinvestigatetheaccuracyforthemulti-stageconveyorbeltscale,thefollowingconditionsfortheexperimentsareconsidered:20≤li≤130cm(at10cmintervals),20≤mi≤80kg(at20kgintervals)andd1=d2=40,50cm.Acombinedsetforthreeproductsinsequencepassesthroughontheconveyorbeltscalesundertheconditionthatli,mi,anddiareexactlythesame.Thenumberofmeasurementsforacombinedsetis7times,andthedataforeachmassmeasuredare21points.Theestimateofmass^mcanbeeasilyobtainedasthemaximumvalueevaluatedfromthecontinuousdataofthesmoothedsignal.Thenwecanobtainestimationerrorebymeansof济南大学毕业设计外文资料翻译wheremiisthetruemassofaproduct.Fig.7(a)–(d)showsthehistogramsofestimationerrorswithrespecttoli.Itcanbeseenfromthese-10--10-济南大学毕业设计外文资料翻译figuresthatthedispersionofestinationerrorsdecreaseslightlywiththelengthli.Table1showsthemeanestimationerrors_ewithrespecttothelengthofproductsliforthemulti-stageconveyorbeltscale.Allofexperimentaldataareconsideredtobelessthantherequiredaccuracy0.7%,buttherearesomeexceptions.Theexperimentaldataforasingle-stageshowthattheestimationerrorsforli=20cmarebiasedtopositivesideonthewhole.Theerrorsareconsideredtobeduetothetransientbehaviorsbecauseofimpulsiveinputloadingpatternsinmotion.Theresultsobtainedfromathree-stageconveyorbeltscaleincaseofli=90cmindicatethatthemeanerror_eisgreatlydependentonthedistancebetweenproductsdi.ThisisduetothefactthatthemeasurableconditionInequality(1)canbecriticallysatisfiedincasedi=40cmandthepositivesideofecanbegenerated.Itisclearfromthesefiguresthattheexperimentalresultsdonotsatisfythisrequirementatpresent.Thissuggeststhatthelengthofaproductlessthan20cmmayimposealimitontheobtainableerrorofourmethod.Ourcontinuousweighingbymulti-stageconveyorbeltscaleisconsidere‘d‘goodenough''intheindustry,regardlessofsomeexceptions.ConclusionsTosumupthemajorpointsofourworkareasfollows:Themeasurementmethodisestablishedforthemulti-stageconveyorbeltscalebyintroducingthedynamicmodeloftheproduct.-11-济南大学毕业设计外文资料翻译Sinceitisobviousthattheproduct-lengthsinmotiondirectlyaffecttheerrors,themulti-stageconveyorbeltscalerevealthattheupperlimitoftheproductisapproximately140cm.Apossibleextensiontosearchingamaximumvalueasanestimateofmassisproposed.Toavoidtakingaquasi-maximumpoint,theallowablerangetosearchamaximumisreasonablylimitedwithintherangepredictedonthebasisofidealuniformlydistributedweights.Theexperimentalresultsshowthattheaccuratemeasurementispossiblyimprovedbycontinuingevolutionoftechnology.AcknowledgementsTheauthorswouldliketothanktheSasakawaScientificResearchGrantforvaluablefinancialsupport.ReferencesR.Schwartz,Automaticweighing-principles,applicationsanddevelopments,ProceedingsofXVIIMEKOWorldCongress,Vienna(2000)259–267.T.Ono,Basicpointofdynamicmassmeasurement,ProceedingsofSICE(1999)43–44.T.Ono,Dynamicweighingofmass,Instr.Autom.12(2)(1984)35.W.G.Lee,etal.,Developmentofspeedandaccuracyformassmeasurementsincheckweighersandconveyorbeltscales,ProceedingsofISMFM(1994)2–328.K.Kameoka,etal.,Signalprocessingforcheckweigheir,ProceedingsofAPMF(1996)122–128.T.Yamazaki,etal.,Continuousmassmeasurementincheckweighersandconveyorbeltscales,ProceedingsofIMEKOTC3/TC5/TC20JointConference(2002)295–301.Y.Nodaetal.,Improvementofaccuracyforcontinuousmassmeasurementincheckweighers,Trans.SICE38(9)(2002)759–764.R.Tasakietal.,Continuousweighingbymulti-stageconveyorbeltscale,Trans.SICE39(11)(2003)1022–1028.R.Tasakietal.,ImprovedcontinuousweighingbymultistageconveyorBekscale,Trans.SICE40(12)(2004).M.Mitani,DigitalFilterDesign,Shoko-do(1987)86–96.M.Takebe,DesignofDigitalFilter,Tokai-UniversityPublications,1990,pp.70–76.S.Takahashi,etal.,DigitalFilter,Baifu-kan(1999)77–91.-12-济南大学毕业设计外文资料翻译Measurement40(2007)791–796FIR数字滤波器多级输送带的连续称量田崎亮介，山崎，孝典大西秀雄，小林正明，黑须茂机械工程系，京都工艺纤维大学，日本机械工程系，国立小山科技大学，中久喜771，小山323-0806，日本工程部，新光有限公司，高道祖4219-71，下妻市304-0031，日本研究所，小黑㈱，日本摘要今天更高的操作速度和高精度的称重包装对于一个交叉皮带输送机在食品行业等诸如此类的行业分布越来越重要。连续称重装置使大量的离散包装在传送带上自动有序的排列。一个新秤合理的制造使用称为多级输送机皮带秤可以以产品的长度来调整输送带长度，我们在实际振动模式下提出了一个简单而有效的质量估计算法。皮带秤一般都小于80公斤和140厘米长的最大容量，实现测量每分钟150包或者更多。从输出信号可以得出输送机皮带秤的污染是由于输送带的振动噪声和运动产品的噪声。在本文中，数字滤波器的有限脉冲响应(2月)类型目的是提供足够的精度。在传送带上的实验结果表明，该滤波算法对于实际应用是足够有效的。只要在连续空间内设置一个指定产品范围，产品重量可正确地表达即使产品在随机的运输方式上具有不同的长度。关键词：质量测量；连续称重；传送带；FIR滤波器1介绍输送机皮带秤主要应用于大量的预包装产品生产【1】。当一个产品放在传送带上，-13-济南大学毕业设计外文资料翻译被测信号来自于皮带秤的噪声污染。由于测得的信号通常是在低频范围内，在高频端可以很容易地设计一个过滤器将有效地减少噪声。如果，产品(如纸板箱、包等)具有低频率成分，其中噪声强度高，实际上它是从噪声中分离出来的不可测量的信号。存在的实际问题，就是噪音过滤工程开发所需要的实际问题。找到了一种新方法对动态质量测量的技术进行了研究，在动态条件下得到产品的质量。动态测量的关键思想是我们考虑影响测量信号，在仪器的各种动态因素推导出一种估计算法【2】。小野提出了一种利用传感元件驱动的引力来确定动态测量质量的动态数量【3】。同时，李提出了以递归最小二乘算法来测量系统的动态模型【4】，以获得质量称重测量系统的算法。动态质量测量的成功主要取决于数学模型来实现精确的测量。但即使是一个结构简单的皮带秤，也难以得到精确的模型。另一方面，一些过滤技术已被应用于输送机皮带秤的信号处理上【 5】。为了降低动力学的影响，并提高质量测量的精度，而不失去速度，根据实际传送带的振动我们提出了一种简化和有效的算法对数据进行处理。【6-9】。2、基本配置2.1输送皮带秤的轮廓该输送机皮带秤的基本结构可以如图1所示。载荷接收元件是通过一个在带式输送机框边上的测力传感器来支持。通过测力传感器检测到的信号通过一个直流放大器送入FIR数字滤波器。产品的质量可估计为从平滑的信号进行评估的最大值。图1.多级输送机皮带秤模拟仿真和实验进行的条件为：产品长度：li=20—140cm皮带输送机的长度：Lj(L1=40cm，L2=40cm，L3=60cm)产品的质量：mi=20–80kg产品之间的距离为：di=20—100cm-14-

济南大学毕业设计外文资料翻译输送带速度：v=132m/min精度要求：≤±0.7%采样频率：fs=2000Hz(采样周期：Ts=0.5ms)在以下模式下多级输送机的总长度被认为是：L=L3(=60cm)：对单级式输送机皮带秤，L=L1+L2(=80cm)：对于两级输送机皮带秤1，L=L2+L3(=100cm)：对于两级输送机皮带秤2，L=L1+L2+L3(=140cm)：对于三级输送机皮带秤2.2.产品之间的最小距离产品之间的最小距离必须由几何条件进行正确地检测。如果一个三级输送机皮带秤，使最小距离所需要达到的稳态值的输出信号为S和短距离最小值，di-1，di或者是ds。假设一个输入时间的变化可以显示为图2dS<L-li条件下。当产品mi被输送到输送皮带秤，最小行驶距离S用于测量产品的质量准确是必要的。从图2中可以看出，产品之间的最小距离Ds可以表示为：2dS≤L-li+S (ds=min(di-1,di))(1)应用产品长度的实际值li和最小距离S(=20cm)得到不等式(1)，最小距离Ds相对于产品长度li可以图解得到，如图3所示。应当指出的是Ds设定为不小于40-15-济南大学毕业设计外文资料翻译厘米图3.产品之间的最小距离FIR滤波器的设计在覆盖的文献中数字滤波器的设计已经非常成熟和广泛。通常有两种类型的数字滤波器，即无限脉冲响应型（IIR）另一种是有限脉冲响应型（FIR）。该产品通过传送带和加载输入变化到零后，在过滤器中的瞬态响应应快速返回到初始状态[10—12]。出于这个原因，FIR滤波器可以被认为是足够的输送带秤。现在，我们解释FIR滤波器的设计程序。记录的归一化频率为Ω=fT,，其中f是频率（Hz），T为采样周期（S），所需的传递函数可以表示为：Hd（ejΩ）=1通带（0≤Ω≤Ωp）Hd（ejΩ）=0阻带（Ωs≤Ω≤0.5）（2）该滤波器的Hd（ejΩ）可以很容易的由著名的雷米兹算法得到。当较低边缘频率Ωs的阻带宽度选择为小于0.05的一个FIR滤波器的设计，由于噪声衰减的影响迅速减小它通常就变成不可能的设计，并且采样周期T应通过下采样来调整。数据进行平滑处理在每个下采样周期T中提取（T=nTm，其中n是一个合适的整数）测得的数据，每一个采样周期Tm=0.5毫秒。在我们的例子中，n可以被选为n=4，6和8（对应于T=2，3和4毫秒）。该过滤器的设计为M=42的增益图显示为图4（a）。图4（b）显示了Ωp=0.002和Ωs=0.05设计规格的脉冲响应图。同时，图5（a）显示输出信号的滤波后获得的仿真结果。可以看出，在高频范围内存在的不良信号可以有效地消除，而通过增加T可以响应平滑。-16-济南大学毕业设计外文资料翻译图4.频率响应和脉冲响应图4.频率响应和脉冲响应接下来，图5（b）显示的是一个平滑离散数据的下采样周期的例子是在每个采样周期（Tm=0.5毫秒）上处理的。在最高值附近的高频噪声信号波形的轻微污染日益严重。对于采样周期T=4毫秒，由此产生的取样时间的频率就可以有一个周期性的F=1/T=250赫兹来确定。传送带的固有频率在200赫兹附近。为了减少噪声最简单的一种方法就是一阶低通滤波器（截止频率10Hz）与FIR滤波器的级联。图5.仿真结果图5.仿真结果技术问题-17-

济南大学毕业设计外文资料翻译4.1.重量的非均匀分布为了说明一个关键问题，一个用于三种产品序列并通过电子皮带秤的条件为li=100cm，mi=80kg，di=60cm。图6（a）显示输出信号的实时记录。第一，第二和第三信号表示从皮带秤L1输出的信号，L2和L3的附加信号的总和表示输出信号对应于一个产品的质量。很明显，群众的精确测定是不可能的，因为曲线有多个峰值像一条蜿蜒的小路。曲线弯曲的最简单原因是产品的底板稍弯曲（或不均匀）或存在来回传送带之间一点的水平差异。因此，这些几何偏差使重量非均匀分布接下来，图6（b）显示在相同条件下一个产品只有一个实时记录的输出信号，如图6（a）所示。可以看出，增加信号的最大值大致显示产品的质量（80公斤）。然而，这种响应曲线不是平滑的梯形波如图6（a），但曲线扫视远且宽广。这种形状表示重量不能均匀分布荷载。因此，当下一个产品进入皮带秤进行测量之前当前的产品已经移出了输送带，增加的信号可以通过下一个产品的输出信号污染，而多个峰值可以在增加的信号上发现。图6.输出信号的实验结果4.2.允许的范围内搜索最大值产品的质量可以很容易地估计为在从输送机皮带秤供给的平滑信号的持续时间的最大值。然而，有时会出现关键的案例，大部分是不能由输出信号的最大值确定的。首先，让我们假设输入配置文件的重量均匀分布在皮带秤上。调查时间Tm达到皮带秤的输送最大值，进行模拟。Tm与li的变化是线性的和Tm可估计通过使用公式：-18-济南大学毕业设计外文资料翻译Tм=ao+a1li[s](3)接下来，我们简要说明给一个新的多级输送机皮带秤的估计方法和指出在高精度估计方法上存在的问题。事实上，由于每个产品的质量不同即使它的总质量是相同的装入的方式也不同，因此最大时间范围的为非均匀