中英文對(duì)照外文翻譯文獻(xiàn)(文檔含英文原文和中文翻譯)原文：Feature-BasedComponentModelsforVirtualPrototypingofHydraulicSystermAbstract:Thispaperproposesafeature-basedapproachforthevirtualprototypingofhydraulicsystems.Itpresentsaframeworkwhichallowsthedesignertodevelopavirtualhydraulicsystemprototypeinamoreintuitivemanner,i.e.throughassemblyofvirtualcomponentswithengineeringdata.Theapproachisbasedonidentifyingthedatarequiredforthedevelopmentofthevirtualprototypes,andseparatingtheinformationintobehaviour,structural,andproductattributes.Suitablerepresentationsoftheseattributesarepresented,andtheframeworkforthefeature-basedvirtualprototypingapproachisestablished,basedonthehierarchicalstructureofcomponentsinahydraulicsystem.Theproposedframeworknotonlyprovidesaprecisemodelofthehydraulicprototypebutalsooffersthepossibilityofdesigningvariationclassesofprototypeswhosemembersarederivedbychangingcertainvirtualcomponentswithdifferentfeatures.Keywords:Computer-aidedengineering;Fluidpowersystems;Virtualprototyping1.IntroductionHydraulicsystemdesigncanbeviewedasafunction-to-formtransformationprocessthatmapsanexplicitsetofrequirementsintoaphysicalrealisablefluidpowersystem.Theprocessinvolvesthreemainstages:thefunctionalspecificationstage,theconfigurationdesignstage,andtheprototypingstage.Theformatforthedescriptionofthedesignineachstageisdifferent.Thefunctionalspecificationstageconstitutestheinitialdesignwork.Theobjectiveistomapthedesignrequirements.Toachievethis,thedesignproblemsarespecifiedCorrespondenceandoffprintrequeststo:DrS.C.Fok,SchooolofMechanicalandProductionEngineering,NanyangTechnologicalUniversity,NanyangAvenue,Singapore639798.Thedesignermustidentifytheperformanceattributes,whichcanincludepressure,force,speed,andflowrate,withtherequiredpropertiessuchassize,cost,safetyandoperatingsequence.performancerequirementsforeachattribute.Inthisstage,thedesignisabstractedintermsoftheperformanceattributeswithassociatedvalues.Theobjectiveoftheconfigurationdesignstageistosynthesiseahydrauliccircuitthatperformstherequiredfunctionsconformingtotheperformancestandardswithindefinedconstraints.Atypicalhydraulicsystemismadeupofmanysubsystems.Thesmallestbuildingblockinasubsystemisthestandardhydrauliccomponent(suchasvalves,cylinders,pumps,etc.).Eachtypeofstandardcomponentservesaspecificelementalfunction.Thedesigneffortintheconfigurationdesignstageisfundamentallyasearchforasetofoptimalarrangementsofstandardcomponents(i.e.hydrauliccircuit)tofulfilthefunctionalrequirementsofthesystem.Basedonthisframework,thedesignerswouldnormallydecomposetheoverallsystemfunctionsintermsofsubfunctions.Thiswillpartitionthesearchspaceandconfinethesearchforsmallerhydraulicsubcircuitstoperformthesubfunctions.Computersareoftenusedtosupporttheconfigurationdesignprocess.Forexample,KotaandLeedevisedagraph-basedstrategytoautomatetheconfigurationofhydrauliccircuits.Afterthedevelopmentofthehydrauliccircuits,digitalsimulationtoolsareoftenusedtostudyandevaluatetheseconfigurations.Withthesetools,designerscancomparethebehaviourofdifferentcircuitsandalsoanalysetheeffectswhensubcircuitsarecombined.Intheconfigurationdesignstage,thedesignistraditionallyrepresentedasacircuitdrawingusingstandardiconstosymbolisethetypeofstandardcomponent.ThisisaformofdirectedgraphS(C,E)wherethecircuitScontainscomponentsCintheformofnodeswithrelationsbetweencomponentsdenotedbyedgesE.Theprototypingstageistheverificationphaseofthesystemdesignprocesswheretheproposedhydrauliccircuitfromtheconfigurationdesignstageisdevelopedandevaluated.Physicalprototypingaimstobuildaphysicalprototypeofthehydraulicsystem666S.C.Foketal.usingindustrialavailablecomponents.Theprocessofphysicalprototypinginvolvesthefollowing:Searchforappropriatestandardcomponentsfromdifferentmanufacturers.Pre-evaluationandselectionofcomponentsbasedonindividualcomponentcost,size,andspecification,andcompatibilityfactorsbetweencomponents.Procurementandassemblyoftheselectedcomponents.Testandevaluatethephysicalprototypebasedontheoverallsystemrequirements.Useothercomponentsorredesignthecircuit(orsubcircuits)ifnecessary.Besidesdynamics,thedevelopmentofthephysicalprototypemusttakeintoconsiderationotherfactorsincludingstructure,cost,andweight.Thedynamicsdataareusedtoconfirmthefluidpowersystembehaviourwhereasthegeometricinformationisusedtoexaminetheassemblyproperties.Thedevelopmentofthephysicalprototypewillprovidetheactualperformance,structure,andcostofthedesign.Themaindisadvantageofphysicalprototypingisthatitisverytediousandtimeconsumingtolookforasetofsuitablecombinationsofstandardcomponentsfromamongsomanymanufacturers.Althoughthebasicfunctionsofthesametypesofstandardcomponentfromdifferentmanufacturersdonotdiffer,theirdynamics,structuralandcostcharacteristicsmaynotbesimilar,becauseofdesignvariation.Hence,foragivenhydrauliccircuit,differentcombinationsofpartsfromdifferentmanufacturerscanhaveimplicationsontheresultingsystem,intermsofdynamics,structure,andcost.Valueengineeringcanbeusedatthisstagetoimprovethesystemdesignbyimprovingtheattributesatthecomponentlevel.Thisincludesmaximizingtheperformance-to-costratioandminimisingthesize-to-performanceratio.Virtualprototypingcanbeviewedasacomputer-aideddesignprocess,whichemploysmodellingandsimulatingtoolstoaddressthebroadissuesofphysicallayout,operationalconcept,functionalspecifications,anddynamicsanalysisundervariousoperatingenvironments.Themainadvantageofvirtualprototypingisthatahydraulicsystemprototypecanbeassembled,analysed,andmodifiedusingdigitalcomputerswithouttheneedforphysicalcomponents,thussavingleadtimeandcost.Themainrequirementofavirtualhydraulicsystemprototypeistoprovidethesameinformationasaphysicalprototypeforthedesignertomakedecisions.Toachievethis,thevirtualprototypemustprovidesuitableandcomprehensiverepresentationsofdifferentdata.Furthermore,transformationfromonerepresentationtoanothershouldproceedformally.Xiangetal.havereviewedthepastandcurrentcomputer-aideddesignandprototypingtoolsforfluidpowersystems.Theworkrevealedthatthecurrenttoolscouldnotprovideacompleterepresentationofthedesignabstractionsattheprototypingstagefordesignjudgement.Mostofthetoolsconcentrateonthedynamicsbehaviour.Vitalgeometricalandproductinformationthatrelatestothesystemprototypeconsiderationandevaluationisfrequentlymissing.Toadvancethedevelopmentofcomputer-aidedvirtualprototypingtoolsforfluidpowersystems,thereisaneedtoaddresstheformalrepresentationsofdifferentabstractionsofbehaviour,structural,andproductdataalongwiththeirintegration.Thispaperfocusesontheseissuesandproposestheformalismofaunifiedcomponentmodelandthetaxonomybasedonthefeature-basedapproach.InSection2,wediscussthefeature-basedapproachfocusingonthekeyinformationandtheirrepresentationsrequiredforhydraulicsystemprototyping.Section3presentsaformalismofthefeature-basedmodelandstructureforthedevelopmentofvirtualhydraulicsystemprototypes.Thestructureisillustratedwithanexample.FutureworkandconclusionsaregiveninSection4.2.Feature-BasedApproachFeaturescanbedefinedasinformationsetsthatrefertoaspectsofattributesthatcanbeusedinreasoningaboutthedesign,engineeringormanufacturingprocesses.TheconceptofusingfeaturestointegrateCAD/CAPP/CAMisnotnewandtherearemanypapersontheapplicationofthisapproachinCIM.Inalltheseapplications,thefeaturemodelisregardedasthebasiswhereasdesignbyfeaturesisthekeyfortheintegration.Todevelopafeaturemodel,therelevantinformationconcerningthedesignmustbeidentifiedandgroupedintosetsbasedonthenatureoftheinformation.Therelevantinformationshouldcontainsufficientknowledgeforactivitiessuchasdesign,analysis,test,documentation,inspection,andassembly,aswellassupportvariousadministrativeandlogisticfunctions.Designbyfeaturesistheprocessofbuildingamodelofthedesignusingfeaturesasprimitiveentities.Thefeaturemodelprovidesthestandardisationofrelevantdata.Throughthedesignbyfeaturesapproach,vitalknowledgeofthedesignwillbegeneratedandstored.Together,thefeaturemodelandthedesignbyfeaturesapproachwillprovidetheessentialinformation,whichcanbeused,notonlyforthesimultaneousconsiderationofmanydifferentconcernswiththedesign,butalsotointerfacethemanyactivitiesinthedesignrealisationprocess,includingthelifecyclesupportoperations.Themaindrawbackofthefeature-baseddesignapproachisthatthefeaturemodelshouldbeproperlydefined.Thiscanbedifficult,asfeaturesaresetsofknowledgethatareapplicationdependent.Theorganisationofthefeaturescanalsobeapplicationspecific.Non-trivialdata-managementproblemscouldariseifthefeaturemodelisnotproperlydefined.Toavoidtheseproblems,thetype,representationandstructureofthefeaturesshouldberesolvedpriortousingthefeature-baseddesignmethodology.Themainconcernwhendevelopingafeaturemodelisthatitisapplication-specific.Inthedomainofvirtualprototypingofhydraulicsystems,thedetailsoftheconstituentstandardcomponentsmustbeabletobeusedtodescribetheoverallsystem.Thecomponentfeaturesarebearersofknowledgeaboutthatpart.Tocreateasuitablefeaturemodelforhydraulicsystemdesignbasedontheassemblyofstandardcomponents,therelevantinformationassociatedwithvariousstandardcomponentsmustbeidentifiedandclassified.ThisdefinitionFeature-BasedComponentModels667ofthecomponentfeaturesetcanthenbeextendedtoencompassthesubsystemfeaturesetbasedonthehierarchicalstructurebetweenthecomponentsinthesubsystem.Inthesamemanner,ahierarchicalstructureforthehydraulicsystemfeaturerepresentationwouldevolvebyconsideringthesystemasahierarchyofsubsystems.Thenecessaryinformationrequiredforaproperdescriptionofthevirtualprototypemustbenolessthanthatderivedbythedesignerfromaphysicalprototypefordecisionmaking.Thesedatashouldgenerallyincludetheshape,weight,performanceproperties,cost,dimensions,functionalitydata,etc.Comparisonwiththephysicalprototypingprocess,theinformationrequiredforeachstandardcomponentcouldbeseparatedintothreedistinctgroups:behaviourattributes,structuralattributes,andproductattributes.2.1BehaviourAttributesThebehaviourofahydrauliccomponentcanbedefinedintermsofthedynamicscharacteristicsusedtosatisfythefunctionalrequirements.Considerahydrauliccylinderconnectedtoaload.Itsfunctionistotransmitaforcefromthestrokeofthepistontotheload.Themaximumforceitcantransmitcanbeusedtodefinethefunctionalityandthebehaviourrequirementscanbespecifiedintermsofthedesiredloadaccelerationcharacteristics.Henceforahydrauliccomponent,behaviourattributesexpressfunctionalityandcanbereflectedinthedynamicscharacteristics.Thedesignerisresponsiblefortheproperdefinitionoftheoverallsystembehaviourcharacteristicsintermsofthedesireddynamics.Astandardcomponentwillhaveitsownbehaviourandprovideaspecificfunction.Complexfunctionsthatcannotbeachievedbyasinglestandardcomponentarederivedusingacombinationofcomponents.Hence,thebehaviourofthestandardcomponentwillplayanimportantroleastheindividualbehavioursofcomponentstogetherwiththeirarrangementcanaltertheoverallsystemfunction.Thebehaviourofastandardcomponentcanbenonlinearandcanbedependentontheoperatingconditions.Whentwocomponentsarecombined,itispossiblethattheirbehaviourscaninteractandproduceundesiredorunintendedcharacteristics.Theseunwantedbehavioursareassumedtohavebeenresolvedduringtheconfigurationdesignstage.Thehydrauliccircuitusedintheprototypingstageisassumedtoberealisableandwithoutanyundesirableinteractingbehaviours.Thismeansthattheoutputbehaviourofacomponentwillprovidetheinputtothesubsequentcomponent.Therepresentationofbehavioursforhydraulicsystemshasbeenwidelyinvestigated.Theserepresentationsincludetransferfunctions,state-spaceandbondgraphs.Transferfunctions(forsingle-input–single-outputsystems)andstate-spaceequations(formultiple-input–multiple-outputsystems)arebasedontheapproximationofthedynamicsaboutanominaloperatingcondition.Thepowerbondgraphmodelisbasedonthecausaleffectsthatdescribetheenergytransformationsinthehydraulicsystem.Thisapproachisappealingforhydraulicsystemanalysis.Themaindisadvantageisthatthederivationofthedynamicsequationinabondgraphofacomplicatedfluidpowersystemcanbecomeverytedious.Asaresult,recentworkhasconcentratedontheusedofartificialintelligencetorepresentthenonlinearmappingbetweentheinputandoutputdata,whichcanbeobtainedviaexperimentalwork.Thesenonlinearmappingscanbeaccomplishedusingartificialneuralnetworks.Itisquitenaturalforahydraulicsystemdesignertouseinput–outputdatatodescribethebehaviourofahydrauliccomponent.Theconfigurationdesignofahydraulicsystemisoftenachievedthroughstepsoffunctiondecomposition.Todesignahydraulicsystem,thedesigneroftentriestodecomposethefunctionsandtheirrequirementsdowntothecomponentlevel.譯文：基于原型液壓系統(tǒng)特征的機(jī)構(gòu)模型摘要：本文為原型液壓系統(tǒng)的設(shè)計(jì)提出了一種基于特征的方法。它提出了一個(gè)框架,允許設(shè)計(jì)師以更加直覺(jué)的方式開(kāi)發(fā)一個(gè)真實(shí)液壓機(jī)構(gòu)原型，例如，通過(guò)真實(shí)的工程學(xué)數(shù)據(jù)進(jìn)行設(shè)計(jì)。這種方法是在真正原型數(shù)據(jù)的基礎(chǔ)上發(fā)展起來(lái)的，它可以分離信息入行為，結(jié)構(gòu)，和產(chǎn)品屬性。這些屬性被用適當(dāng)?shù)谋硎痉ㄌ岢?，并且框架為基于特點(diǎn)的真正原型的方法建立，根據(jù)組分等級(jí)結(jié)構(gòu)在一種液壓機(jī)構(gòu)。它所提出的框架不只是真實(shí)的液壓系統(tǒng)的一個(gè)精確模型，而且為設(shè)計(jì)成員提供了當(dāng)由于某些零件的一些特性改變導(dǎo)致系統(tǒng)改變而獲得一個(gè)新的液壓系統(tǒng)精確模型的可能性。關(guān)鍵詞:計(jì)算機(jī)輔助工程;液壓動(dòng)力系統(tǒng);真實(shí)樣機(jī)1.介紹液壓機(jī)構(gòu)設(shè)計(jì)可能被看作是一個(gè)為映射明確套要求入物理可實(shí)現(xiàn)的液壓能力系統(tǒng)的作用對(duì)形式變革過(guò)程。這個(gè)過(guò)程涉及三個(gè)主要階段:功能規(guī)劃階段，結(jié)構(gòu)設(shè)計(jì)階段，和樣機(jī)制造階段。描述各個(gè)設(shè)計(jì)階段的所用的格式是不同的。功能的規(guī)劃是所有設(shè)計(jì)中最初的工作。為了達(dá)到這個(gè)要求，設(shè)計(jì)問(wèn)題是以指定的書(shū)信和印成單行本發(fā)給新加坡南陽(yáng)大道南陽(yáng)技術(shù)大學(xué)機(jī)械和制造工程的DrS.C.Fok。明確地根據(jù)作用和表現(xiàn)。設(shè)計(jì)師必須確定產(chǎn)品的性能和屬性，其中包括壓力，強(qiáng)度，速度和流體速度，以及一些所必需的東西如尺寸大小，成本,安全要求和操作順序。其次，設(shè)計(jì)師必須敘述出各個(gè)特征的精確性能要求。在這個(gè)階段，設(shè)計(jì)以摘要的形式寫(xiě)出產(chǎn)品的相關(guān)性能要求。結(jié)構(gòu)設(shè)計(jì)階段的目標(biāo)是完成一個(gè)液壓系統(tǒng)回路。這個(gè)回路能完成系統(tǒng)設(shè)計(jì)參數(shù)規(guī)定的各個(gè)功能。一種典型的液壓機(jī)構(gòu)由許多子系統(tǒng)組成。組成子系統(tǒng)的最小模塊是標(biāo)準(zhǔn)液壓系統(tǒng)元件(譬如閥門(mén)，氣缸，液壓泵等。).每種液壓標(biāo)準(zhǔn)元件都有各自的特殊作用。結(jié)構(gòu)設(shè)計(jì)階段的任務(wù)就是從根本上找到一個(gè)基本液壓元件（例如液壓回路）的布置圖。這個(gè)基本的液壓回路能達(dá)到系統(tǒng)的各個(gè)功能要求。根據(jù)這個(gè)結(jié)構(gòu)，設(shè)計(jì)師通常把整個(gè)系統(tǒng)功能模塊分成一個(gè)個(gè)最基本的子函數(shù)。這樣就能隔開(kāi)搜索空間，通過(guò)搜索較小一級(jí)的液壓系統(tǒng)基本回路去實(shí)現(xiàn)各個(gè)子函數(shù)的功能要求。在外觀(guān)設(shè)計(jì)過(guò)程中計(jì)算機(jī)往往會(huì)發(fā)揮很大的作用。例如，Kota和Lee想出了一個(gè)基于圖表的液壓系統(tǒng)回路結(jié)構(gòu)的自動(dòng)設(shè)計(jì)方法。在液壓回路被發(fā)展以后，人們經(jīng)常被使用數(shù)字模擬實(shí)驗(yàn)工具來(lái)學(xué)習(xí)和評(píng)估這些結(jié)構(gòu)。通過(guò)這些工具，設(shè)計(jì)師能比較不同的電路塊的功能，并且能夠分析出這些功能塊結(jié)合后的效果。在結(jié)構(gòu)設(shè)計(jì)階段，傳統(tǒng)上設(shè)計(jì)往往用一張回路圖來(lái)代表標(biāo)準(zhǔn)元件。這里是被(C，E)包含結(jié)構(gòu)C的回路S以結(jié)的形式聯(lián)系組分之間由邊E表示的地方圖表的形式。樣機(jī)設(shè)計(jì)階段是結(jié)構(gòu)設(shè)計(jì)過(guò)程中提出的液壓回路的證明階段。通過(guò)這個(gè)階段能證明結(jié)構(gòu)設(shè)計(jì)中對(duì)回路的提出與評(píng)估是否正確。實(shí)際樣機(jī)的目的是建立液壓機(jī)構(gòu)666S的一個(gè)物理原型。使用工業(yè)可利用的零件。涉及真實(shí)樣機(jī)的過(guò)程以下:從不同的制造商手中尋找適當(dāng)?shù)臉?biāo)準(zhǔn)零件。零件的選擇和評(píng)估是建立在零件之間的成本，尺寸大小，規(guī)格和互換性等因素之上的。選擇的零件取得和裝配。根據(jù)整個(gè)系統(tǒng)要求測(cè)試和評(píng)估物理原型。使用其它零件或重新設(shè)計(jì)電路(或支電路)如果需要。除動(dòng)力學(xué)以外，物理原型的發(fā)展必須考慮到其它因素包括結(jié)構(gòu)，成本與重量。動(dòng)力學(xué)數(shù)據(jù)用來(lái)確認(rèn)液壓動(dòng)力系統(tǒng)的性能，但是幾何學(xué)信息用來(lái)系統(tǒng)的安裝性能。物理樣機(jī)的研制將提供設(shè)計(jì)產(chǎn)品的真實(shí)性能，結(jié)構(gòu)和設(shè)計(jì)成本。物理樣機(jī)的主要缺點(diǎn)是,它必須非常繁瑣和費(fèi)時(shí)地從在許多制造商手中尋找一套標(biāo)準(zhǔn)零件的適當(dāng)組合。由于設(shè)計(jì)的變化，從不同的制造商購(gòu)買(mǎi)的同樣類(lèi)型的標(biāo)準(zhǔn)零件的作用都不相同，他們的動(dòng)力學(xué)，結(jié)構(gòu)和費(fèi)用特征也不可能相似。因此，為同樣的一個(gè)液壓回路，選擇不同的制造商的標(biāo)準(zhǔn)零件去組裝，所完成的系統(tǒng)，最后在力學(xué)、結(jié)構(gòu)和產(chǎn)品的成本等方面也會(huì)不同。在這一過(guò)程中可以使用評(píng)估工程，通過(guò)在零件標(biāo)準(zhǔn)特性上的改變來(lái)改進(jìn)在這個(gè)情況下的系統(tǒng)設(shè)計(jì)。其中就包括最優(yōu)化的性?xún)r(jià)比率和對(duì)零件大小進(jìn)行最合理的設(shè)計(jì)。真正樣機(jī)設(shè)計(jì)過(guò)程可能被觀(guān)看作為一個(gè)計(jì)算機(jī)輔助設(shè)計(jì)過(guò)程，它可以使用模擬制造和模擬仿真工具來(lái)驗(yàn)證樣機(jī)的物理布局，操作，功能規(guī)格，以及在在各種各樣的操作環(huán)境下的力學(xué)分析。虛擬樣機(jī)的主要好處是,不需要實(shí)際零件，通過(guò)使用數(shù)字計(jì)算機(jī)就可以對(duì)一個(gè)液壓機(jī)構(gòu)原型進(jìn)行裝配和分解，因而大大的節(jié)省了時(shí)間和費(fèi)用。一個(gè)真正虛擬液壓機(jī)構(gòu)樣機(jī)的主要要求是，它必須能像真實(shí)的產(chǎn)品一樣，為設(shè)計(jì)者提供信息和幫助他們做出決定。為了達(dá)到這個(gè)要求，虛擬樣機(jī)必須提供另外