自动夹具中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)AUTOMATICFIXTURESYNTHESISIN3DKamenPenevProgrammableAutomationLaboratoryComputerScienceDepartmentandInstituteforRoboticsandIntelligentSystemsUniversityofSouthernCaliforniaLosAngeles,CA90089-0781 AristidesA.G.RequichaProgrammableAutomationLaboratoryComputerScienceDepartmentandInstituteforRoboticsandIntelligentSystemsUniversityofSouthernCaliforniaLosAngeles,CA90089-0781AbstractAfixtureisanarrangementoffixturingmodulesthatlocateandholdaworkpartduringamanufacturingoperation.Inthisworkwe.considerfixtureswithfrictionlesspointcontactsandpresentamethodforplacementofcontactpointsonanon-prismatic3Dworkpart.Itisanon-deterministic,potentialfieldalgorithmforcontactpointplacement.Themethodprovidesabasicframeworkfortheintegrationofheterogeneoushigh-levelfixturingagentsthroughaninterfacebasedonzonesofattractionandrepulsionontheworkpartboundary.Thealgorithmmayproduceredundantfixtures,andcanaugmentpartialsolutionstocompleteformclosurefixtures.1.IntroductionAfixtureisanarrangementoffixturingmodulesthatlocateandholdaworkpartduringamanufacturingoperation,suchasmachining,assemblyandinspection.Fixturingisofessentialimportancetoindustrialmanufacturingandconstitutesasignificantpartofallmanufacturingcosts.Therefore,fixturedesignautomationisveryimportant.Fixturedesigninvolvesagreatvarietyofconsiderations,suchasrestraint,deterministiclocation,loadability,andtoolaccessibility.Efficientalgorithmsthataddressthewholerangeoffixturingissuesforacomprehensivedomainofworkpartsdonotyetexist.Recently,BrostandPeterspublishedanalgorithm[Brost&Peters1996]thatextendstheearlierclassicworkofBrostandGoldberg[Brost&Goldberg,1994]tothe3Ddomain.Thisalgorithm,however,requiresverticalandhorizontalplanarsurfacestoconstituteasubstantialpartoftheworkpartboundary.Itgeneratesallpossiblefixturesandthenratesthemaccordinglytocertainmetrics.Thisiscomputationallyexpensive.Wagneretalpresentedanalgorithmthatusessevenmodularstrutsmountedinaboxtofixturepolyhedra[Wagneretal1995].Thisalgorithmisnotcompleteinthesensethatitcannoteffectivelyhandlecertaincases,suchasacubewithfacesparalleltothebox.Italsosuffersfromhighcomputationalcomplexity.WallackandCannysuggestedanothermethodwithan“enumerate-and-rate”flavor[Wallack&Canny1996].Itcanfixtureprismaticworkpartswithplanarandcylindricalverticalsurfaces.Ponceproposedanalgorithmthatutilizescurvatureeffectstocomputefixtureswithfourfingersforpolyhedralparts[Ponce96].Thereducednumberofcontactsshouldprovideforbettercomplexityofthisalgorithm,butthequalityoftheproducedfixturesseemstobeinferiortotheonesthatutilizemorecontactsandprovideclassicalformclosure.Inthispaperwepresentanewpotential-fieldalgorithmthatefficientlyproducesqualityfixturedesigns.Ouralgorithmworksforarbitraryworkpartsandprovidesconvenientuniversalmeansforrepresentingvariousfixturingrequirements.Thisalgorithmisadirectgeneralizationofthe2DpotentialfieldfixturingalgorithmofPenevandRequicha[Penev&Requicha1996].Weconsiderfixtureswithfrictionlesspointcontacts.Ithasbeenproventhatsevencontactsarenecessary.[Somoff,1900]andsufficient[Markenscoffetal,1990]toimmobilizeanyworkpartin3DFollowingaleast-commitmentstrategy,theprocessoffixturesynthesismaybeseparatedintothreestages–fixturingtaskanalysis,contactpointplacement,andfixturelayoutdesign.Inthefixturingtaskanalysisphasetheworkpartgeometryandmanufacturingprocessareanalyzedtoidentifyvariousparametersofthefixturingproblem,suchascuttingforces,inaccessibleorforbiddenareas,andalsotofindfeaturesthatmaybeusefulforapplyingfixturingdevices,suchasmachinedflatsurfaces,horizontalandverticalsurfaces,pairsofparallelsurfaces,pairsofperpendicularsurfaces,etc.FigureSEQFigure\*ARABIC1:ContactpointplacementInthecontactpointplacementphaseanumberofcontactpointsareplacedontheworkpartboundary(REF_Ref346884946Figure1),sothattheresultingconfigurationofcontactssatisfiestheconstraintsidentifiedintheanalysisphaseaswellascertainkinematicrequirementsthatmustbesatisfiedbyanyfixture,suchastotalrestraint.FigureSEQFigure\*ARABIC2:FromcontactpointconfigurationtofixturelayoutdesignInthelayoutdesignphase“towers”offixturingcomponentsarebuiltandplacedaroundtheworkpartsoastocontactthepartatthepointlocationscomputedinthecontactpointplacementphase.Forexample,acontactpointonahorizontalworkpartsurface(REF_Ref346884976Figure2a)mayleadtotheinstantiationofanoverheadclampthatcontactstheworkpartatthatparticularpoint(REF_Ref346884976Figure2b).Thisisadesign-for-functionproblemconstrainedbythesetofavailablefixturingmodulesandtheirparameters.Thesetofcontactpointsarethefunctionalspecificationandthefixturelayoutisaconfigurationofcomponentsthatachievesit.Inthisresearchwefocusoncontactpointplacementanditsintegrationwithpartandtaskanalysis.Anarrangementofcontactpointsmustsatisfycertainkinematicconditionsinordertobeabasisforagoodfixture.Inparticular,itmustprovideformclosure,deterministiclocation,clampingstability,detachabilityandloadability[Asada&By].Thealgorithmusesadiscretizationoftheworkpartboundary,similartothemeshesusedinFEA.However,unlikeFEA,ourattentionisonthemeshnodes,ratherthanonthemeshelements.Discretizationwaschosenforthefollowingreasons:First,wecanhandleworkpartswitharbitrarygeometry,aslongasthepart’sboundaryisacollectionofsmoothsurfaceswhichweknowhowtomesh.ThisrequirementissatisfiedbyallsurfacesusedinmodernCADsystems.Second,discretizationisnecessaryinordertoavoidanexpensivecomputationofgeodesiccurves.Third,discretizationshouldnotsignificantlyaffecttheresults,aslongasthenumberofdiscretecandidatelocationsontheboundaryismuchlargerthanthenumberofsurfaces.Inourimplementationthediscretizedboundaryconsistsofseveralhundredpointsonly.Experimentalevidenceindicatesthatthisissufficientforrealisticworkparts.Weintroduceapotentialfieldontheworkpartboundarydefinedbyzonesofattractionandrepulsion,whichwecallP-zones.Thecontactsaremodeledaschargedparticlesthatmoveontheboundarydrivenbythispotentialfield.Thecontactsarealsosubjecttomutualrepulsionbasedonthedistancebetweeneachtwocontactsinthewrenchvectorspace.Thealgorithmexecutesaseriesofsimulationepochs.Eachepochstartswitharandomconfiguration,proceedsthroughacertainnumberofstepstowardlowerpotentialenergyandendswithatestforkinematicconditions(formclosure).Thealgorithmterminateswhenanepochproducessatisfactoryconfiguration.Tospreadthecontactpointsontheboundarywesimulaterepulsionbetweeneachpairofthem.Theintensityofrepulsionbetweentwocontactpointsdependsonthedistancebetweentheircorrespondingwrenchesinthewrenchvectorspace.Oursimulationproceedsinalimitednumberofstepsoruntilequilibriumisreached.Theresultingplacementshouldhaveagoodchanceofleadingtoagoodfixture.Sucharandomizedmethodassumesthatthesetofn-tuplesofcontactpoints(forngreaterthanthree)thatsatisfythekinematicrequirementshasmeasuregreaterthanzeroandisrelativelylarge.Thatis,thesolutionspaceislarge.Althoughwehavenotbeenabletoprovethishypothesismathematically,ourexperimentshaveconfirmedit.Moreover,themeasureincreaseswiththenumberofcontactpoints,e.g.itiseasiertofindaformclosurearrangementwitheightpointsthanwithseven.Thenotionofrepulsionisessentialinourmethodasitallowsotherconsiderationstobeaccommodatedeasily.Wecanputadditionalrepulsionspotsontheworkpartboundarytorepresentforbiddenregions.Wecanalsointroducecentersofattraction.Thesecorrespondtoareasthatwererecommendedbytheanalysisphaseasdesirableforplacingcontactpoints,e.g.datumsurfaces.Thus,weproposeapotentialfieldforuniformlyrepresentingheterogeneousfixturinginformation.Regionsofrepulsioncorrespondtoareaswithpositivepotential.Negativepotentialisassociatedwithattraction.Zeropotentialcorrespondstoneutralareas.Theinitialrandomlyselectedcontactpointsareregardedasparticlesthatarebeingattractedorrepelledbyapotentialfieldthatincludesapairwiserepulsion.Thegoalofthesystemofcontactpointsistominimizeitstotalpotentialenergy.2TheInputTheinputtoouralgorithmconsistsofCADmodelsoftheworkpartboundaryandasetofsolidP-zones.EachP-zonedefinesapotential-fieldinfluencingregionwithnon-zerocharge.3DiscretizingtheWorkpartBoundaryThefirststepinourmethodistodiscretizetheboundaryoftheworkpart,thuscreatingthecandidatecontactpointlocationswhichwecallnodes.Discretizationisdonebyinvokingastandardfaceterembeddedinthegeometricmodelerweuse.Thediscretizationisstoredinanorientedgraphdatastructure.Eachnodeofthegraphcorrespondstoanodeonthemesh.Theedgesofthegraphcorrespondtoedgesofthemeshconnectingneighboringnodes.Ateachnodethescrewrepresentingthepointcontactiscomputedandstored.Ascrewisaconciseandconvenientrepresentationofthesurfacenormalandthelocationofthenode.Itisusedinallkinematictestsbasedonscrewtheory.4ComputingthePotentialFieldThecontactpointsinouralgorithmaresubjecttothecombinedactionoftwocomponentsformingthepotentialfield.Thebackgroundpotentialfieldisoneofthesecomponents.ItisgeneratedbytheP-zonesanddoesnotdependonthelocationofthecontactpoints.Thebackgroundpotentialfieldiscomputedonlyonce,inthebeginningofthealgorithm.Theothercomponentisdynamicandisduetotherepulsionbetweenthecontacts.Thedynamiccomponentiscomputedateachepoch.Thecomputationofthebackgroundpotentialfieldproceedsasfollows:First,wefindallnodesthatlieinsideP-zones.WeperformmembershipclassificationofeachnodeagainsteachP-zone[Tilove1980].IfthenodeisinsideacertainP-zone,thechargeoftheP-zonecontributestothenode’scharge.Thecontributionmaybepositiveornegative,dependingonthesignofthezone’scharge.AfterthisprocedurethenodesthatclassifyoutsideallP-zonesremainwithzerocharge.IfanodemclassifiesinsideP-zonesz1,z2...zkitschargeCmequalsthesumofthechargesofthoseP-zones:AfterthechargeofthenodesinsideP-zonesisevaluatedweproceedbycomputingthepotentialofallnodes.WedefinethepotentialatachargednodetobeinitiallyequaltoitschargePm=Cm.ForeachchargednodemwithchargeCmweperformabreadth-firsttraversalofitsneighborsupdatingtheirpotentialaccordingtotheformula：Hered(m,n)isthedistancebetweennodesm(thechargednode)andn,andd0isaconstantcalleddistanceofinfluence.Thedistancebetweentwonodesisdefinedasthenumberofedgesontheshortestpathbetweenthemonthemeshboundaryapproximation(REF_Ref347639717Figure3).FigureSEQFigure\*ARABIC3:DistancebetweentwonodesonthemeshAssumingthemeshsatisfiescertaincommonqualityrequirements,thisdistanceapproximatesquitewelltheactualgeodesicdistancebetweentwopointsontheobject’sboundary.Thebreadth-firsttraversalgoesonlyd0nodesdeep.Thusachargednodecausesupdatesofthepotentialonlyinitsd0-neighborhood.Forexample,ifthethreedarknodesinREF_Ref347639655Figure4havecharge100andd0=3thepotentialinthispartofthemeshwillbeasshownbythenumbersnexttoeachnode.FigureSEQFigure\*ARABIC4:PotentialfieldgeneratedbythreechargednodesThedynamicpotentialrepresentsrepulsionbetweenthecontactpoints.Therepulsionbetweentwocontactsdependsonhowdistanttheircorrespondingscrewsareas6-dimensionalvectors:Hereisasmallnumbertoavoiddivisionbyzero,isascalingfactorthatmakesthedynamicpotentialcompatiblewiththebackgroundcomponent,and(m,n)istheEuclideandistancebetweenthescrewsatnodesmandn.Therationalebehindrepulsionbasedonscrew-distanceisthefollowing:AnecessaryandsufficientconditionforformclosureisthatthesetofcontactscrewspositivelyspanstheentireR6[Wagneretal.1995].Asthecontactscrewsrepeleachother,theywilltendtodistributeregularlyinthespace,thusincreasingthepossibilityofformclosure.5EpochsEachepochstartswitharandominitialplacementofcontactpoints.Thenthesecontactpointsaresubjectedtothecombinedforcesduetothebackgroundpotentialfieldandtherepulsionbetweenthecontactpointsthemselves.Thealgorithmproceedsinaniterativefashion.First,thedynamiccomponentoftheaggregatedpotentialfieldiscomputedaccordinglyto(3).Thedynamicpotentialiscomputedonlyatthecontactsandtheirimmediateneighbors.Afterthecombinedpotentialiscomputed,eachcontactismovedtotheneighbornodewiththelowestpotential.Thusastepiscompleted.Ifthenumberofstepshasreachedacertainlimit,ornocontactwasmoved(i.e.equilibriumhasbeenreached),theepochiscompleted.Throughoutthisprocessspecialattentionispaidtonodesthatlieonedgesandverticesoftheworkpart.Thesenodesdonothaveascrewassociatedwiththemasthereisnonormaldefinedthere.Therefore,theycannotbeapossiblecontactlocation.Instead,theyservemerelyastransitnodesinthesimulation.Thisisachievedbyalwaysconsideringtheneighborsofsuchanodewheneverthenodeitselfisaddressed.Thenetresultofanepochisthattheinitiallyrandomconfigurationtransformsintoonethathasmoreregulardistributionofcontactscrewsinthescrewvectorspace,whileatthesametimekeepingawayfromrepulsionzonesandprovidingcontactsinsideattractionzones.6TestInthetestphasewecheckwhethertheplacementofcontactpointsprovidesformclosure.ThisisdoneusingthemethodofChouetal.[Chouetal.19??]Ittestswhetherthereexistsanon-zeromotionscrewthatcomplieswiththeconstraintsimposedbythecontactwrenches:Theexistenceofsistestedusinglinearprogrammingtechniques.Ifnosuchmotionexiststhearrangementofcontactsprovidesformclosure.Ifthetestsucceedsthealgorithmterminates.Otherwiseanewepochisinitiated.IfthetestfailsandacertainnumberofgenerationshavebeentriedweincreasethenumberofcontactpointsC.IncreasingCimprovestheprobabilityofendingupwithaformclosureconfigurationaswellashavingmorecontactsinP-zonesofattraction.Thealgorithmensuresthatnotwocontactpointsareplacedonthesamemeshnode.Therefore,intheextremecasetherearethreecontactsoneachface.Suchaplacementobviouslyimmobilizesanypolyhedralpart.Hencethecompletenessofthealgorithm(atleastforpolyhedralparts).Afteraredundantform-closureconfigurationiscomputed,thealgorithmcanremovetheextracontactsintheorderofdecreasingbackgroundpotential,i.e.startingwiththeonesinP-zonesofhighestrepulsion.Redundantfixturesaresometimespreferred,astheyminimizepartdeflectionandvibration.Thesystemcanoperatewithorwithoutredundancyreduction.Thedecisionmightbeguidedbytheanalysisphasebasedonthegeometricshapeofthepartandthemagnitudeoftheexternalforces,orahumanoperatormayallowredundancymanuallyandevenforceitbysettingtheinitialnumberofcontactstobemorethanthetheoreticalminimum(7in3D).Itispossibleforthekinematictesttosucceed,butthepotentialatsomecontactstobehigh.Thiscanhappenifacontactistrappedinalocalminimumofthepotentialfieldwherethepotentialishigh.Tohandlesuchsituationsweintroduceathresholdparametercalledmaximumallowablepotential.Arrangementswithpotentialatanycontacthigherthanthethresholdarediscarded.Thisnewtestmayleadtosituationsinwhichthealgorithmdoesnotterminatebecausenofixtureexistswithsufficientlysmallpotential.(Imaginetheextremeexamplethattheentireworkpartboundaryisaforbiddenregion.)Therefore,welimitthenumberofepochstoensuretermination.Inthecaseofsuchterminationthealgorithmoutputsthesolutionwiththelowestmaximumpotential.7.DiscussionTheproposedalgorithmsolvestheessentialprobleminfixturedesign–placingcontactpointsontheworkpartthatprovideformclosure.Itcanbeincorporatedinacompletefixturedesignsystemthatprovidesmodulesforfixturingtaskanalysisandlayoutdesign.Thealgorithmprovidesasimple,butpowerfulinterfacetothefixturingtaskanalysismodulesbasedonzonesofattractionandrepulsion.Admittedly,noteverycontactconfigurationcanbeimplementedbyacertainfixturingtoolkitinthelayoutdesignphase.Itmaybenecessarytoinvokethecontactplacementalgorithmseveraltimesuntilafeasibleconfigurationisproduced.7.1FixturingTaskAnalysisVariousfixturingheuristicsandrequirementscanbeexpressedintermsofzonesofhigherattractionorrepulsion.Forexample,attractionzonesmaybeusedtorepresent:datumsurfacesmachinedsurfacessurfaceswith“good”orientationareaswithgoodaccessibilityareasthatneedadditionalsupporttopreventdeflectionanddeformationRepulsionzonescanrepresent:inaccessibleareasforbiddenareasduetotoolaccessibilityrequirementssurfaceswithpoororientationcastsurfacessensitivesurfacesthatarevulnerabletoscratchingetc.AnimportantopenproblemishowtoassignnumericalvaluestotheP-zonepotential.Onepossibilityistoclassifytheconstraintsintoasmallnumberofcategories,e.g.“strongrepulsion”,“repulsion”,“neutral”,“attraction”,“strongattraction”.Allconstraintswithinthesamecategoryareassignedthesamepotential.Whilesuchaschemedoesnotreflectsubtledifferencesinprioritiesofthefixturingconstraints,itwillprobablycapturethemostimportantones.7.2FixtureCompletionAnimportantpropertyofthealgorithmisthatitallowspartialfixturestobeinput.Partialfixturesmaybeproducedbyotherfixturingagents,humansorcomputerprograms,whoplacecertainfixelstheyknowarenecessaryandhandtheworkovertoouralgorithmforcompletion.Thealgorithmthenplacesadditionalcontactssothatformclosureisachieved.Werepresentthepartialfixtureasfixedcontactswhichparticipateinthemutualrepulsionwiththefreecontacts,butarenotallowedtomove.Inthislight,thealgorithmmaybeviewedasafixturecompletionengine7.3Non-determinismandRedundancy.Duetotherandomnessoftheinitialplacementineachgeneration,thealgorithmisnon-deterministic,i.e.itcanproducedifferentsolutionsgiventhesameinput.Thisisdesirableasacontactpointconfigurationmayberejectedbythelayoutdesignmoduleandthealgorithmwillhavetoproduceanothersolution.Thealgorithmmayproduceredundantfixturesincertaincases.Redundantfixtureshavedrawbacksaswellasadvantagesovertheminimalones.Certainly,theyimpairloadabilityandwastecomponents.However,theymayalsominimizepartdeflectionanddeformation.Inpractice,humandesignersoftenproduceredundantfixtures.7.4EfficiencyTherunningtimeofthealgorithmdoesnotdependdirectlyonthecomplexityoftheworkpartboundary.Asimplecuboidandacomplexcurvedworkpartwillbediscretizedwithacomparablenumberofmeshnodes.Thisdecisionisbasedontheintuitiveassumptionthatafewhundredevenlydistributednodesontheboundaryprovideasufficientbasisforfixturabilityofanysolidobject.自动夹具在三维中的合成摘要夹具是一个安排在装夹模块中的位置，并进行工件在一个以制造业为主的运作。我们在这项工作中,考虑固定装置与无摩擦点接触，并给出了一个方案，为安置的接触点上的非棱柱体三维工件。它是一个非确定性，势场算法的接触点安置。该方法提供了一个基本框架，为整合异构高层次装夹代理商通过一个界面基于区的吸引力和斥力就工件边界。该算法可能会产生多余的固定装置，并能增加部分的解决办法，以形成完整的封闭装置。导言夹具是一个安排的装夹模块中的位置，并举行工件在一个以制造业为主的操作，如加工，装配和检验。装夹是最重要的，以工业制造，并构成的一个重要部分，所有的制造成本。因此，夹具设计自动化是非常重要的。夹具设计涉及多种因素，例如，克制，决定性的位置，装载和工具无障碍环境。高效的算法处理整个一系列的装夹问题，为全面域工件尚不存在。最近，brost和彼得斯出版了一种算法[brost＆彼得斯1996]延伸早前经典的工作brost和戈德堡[brost＆戈德堡，1994]，以三维域。这种算法，但需要纵向和横向平面构成相当大一部分的工件边界。它产生的所有可能的固定装置，然后在利率，他们因此对某些衡量标准。这是在计算上昂贵的。Wagner等提出了一种算法，使用7个模块的Struts安装在一个盒子里，以夹具多面体[Wagner等，1995年]。这个算法是不全面的，在这个意义上讲，它并不能有效地处理某些情况下，例如一个立方体的脸平行包装盒。它也经历着从高计算复杂度。wallack和精明提出另一种方法，并有"列举与汇率"的味道[wallack＆Canny，1996年]。它可以夹具棱柱工件与平面和圆柱垂直表面。庞塞提出了一种算法，利用曲率的影响，计算出固定装置与四指为多面体零件[庞塞96]。在数量减少的接触应提供更好的复杂算法，但质量的生产设备，似乎不亚于那些利用更多的接触，并提供古典形式封闭。在这篇文章中我们提出了一种新的潜在场算法，有效地生产优质夹具设计。我们的算法工程任意工件，并提供便捷的普遍手段，代表不同的装夹要求。这种算法是一种直接泛化的二维势场装夹算法penev和requicha[penev＆requicha1996]。我们认为，固定装置与无摩擦点接触。它已证明七名接触是必要的。[somoff，1900]，并有足够的[markenscoff等人，1990年]固定任何工件在三维继至少承诺的策略，过程夹具合成可分为三个阶段-装夹任务分析，接触点安置以及夹具布局设计。在装夹任务分析阶段工件几何和制造过程中分析，以确定各种参数的装夹问题，如切削力，交通不便或禁止的领域，并找出特点，可用于申请装夹装置，例如机械平面，横向和纵向表面，对平行表面，对垂直于表面，等等。图1：接触点安置在接触点安置阶段的一些联络点，是摆在工件边界（图1），因此由此产生的配置接触满足确定的限制因素，在分析阶段，以及一些运动学要求必须得到满足，任何夹具如完全克制。图2：从接触点配置，以夹具布局设计

在布局设计阶段"水塔"的装夹元件是建立并置于周围工件等，以接触的部分，在点位置计算，在接触点安置阶段。举例来说，一个接触点上，横向工件表面（图甲），可导致以实例化的额外开销钳说，接触了工件在那个特定点（图2B）条。这是一个以设计为功能的问题，制约了一套可装夹单元及其参数。这实现了套联络点的功能规格及夹具布局是一个配置的部件。在本研究中，我们的重点联系点安置，并把它纳入其中部分和任务的分析。安排的接触点必须满足某些运动学条件，以一个基础，有一个良好的夹具。特别是，它必须提供的封闭形式，确定位置，夹紧稳定，脱离能力和装载[Asada&By]。该算法采用离散化的工件边界，类似的网格所使用的有限元分析。但是，不同于有限元分析，我们注意的是，对网格节点上，而不是放在网格元素。离散选择为以下几个原因：首先，我们可以处理工件任意几何，只要把部分的边界是一家集表面光滑，而我们知道如何主题词。这项规定是满意的所有表面用在现代CAD系统。其次，离散化是必要的，以避免昂贵的计算测曲线。第三，离散应该不会大大影响结果，只要有多少离散候选地点就边界要远远大于人数表面上。在我国实施离散边界构成的几百点。实验证据表明，这是不够现实的工件。我们引进一个潜在场对工件边界界定区的吸引与排斥，我们称之为个P-区。接触是仿照由于带电粒子的这一举动对边界驱动这个潜在的领域。接触也受到相互排斥的基础上，之间的距离每两个接触，在扳手向量空间。该算法执行了一系列的模拟时代。每一个划时代的开始，以随机配置，收益是通过一定数量的步骤，向低势能和结束一场考验运动学条件（形成封闭）。该算法终止时，一个划时代的产生令人满意的配置。传播接触点上的边界，我们模拟斥力之间相互对他们。强度斥力之间的两个接触点，取决于它们之间的距离及其相应的扳手在扳手向量空间。我们的模拟收益，在有限的几个步骤，或直至平衡是达成共识。由此产生的就业，应该有很好的机会，导致一个好的夹具。这种随机方法假定一套正元组的联系点（对N大于3）表示，满足运动学要求，有措施，都大于零，是比较大。这就是说，解空间非常大。虽然我们尚未能证明这一假设的数学，我们的实验已经证实了它。此外，这项措施增加多少接触点，例如，这是比较容易找到一个封闭的形式安排多于8分之7。概念斥力是必不可少的方法，因为这可以容易容纳其他因素。我们可以把更多的斥力点就工件边界，以代表故宫地区。我们还可以介绍中心的吸引力。这些对应的地方被推荐人的分析阶段可取配售联系点，例如，基准面表面。因此，我们提出一个势场为代表一致异构装夹信息。地区斥力对应地区的积极潜力。负电位，是与魅力。零电位对应于中立地区。初始随机抽选的联系点，被视为微粒，正在吸引或击退一个势场，其中包括成对斥力。目标体系的联系点是为了最大限度地减少其总势能。输入输入我们的算法包括CAD模型的工件边界，以及一套坚实的P-区。每个人P-区界定一个潜在场的影响区域与非零收费。三离散工件边界，第一步，我们的做法是把离散边界的工件，因而创造候选人接触点的位置，我们称之为节点。离散化是做了引用标准工作面嵌入在几何造型。离散是储存在一个面向图形数据结构。每个节点的图形对应的一个节点上的网格。边缘的图形对应边的网格连接相邻节点。在每个节点螺丝代表联系点，是计算和储存。螺丝钉是一个简洁和方便的代表性表面正常位置的节点。它是用来在所有运动测试基于螺旋理论。离散工件边界第一步，我们的做法是把离散边界的工件，因而创造候选人接触点的位置，我们称之为节点。离散化，是做了，引用标准表面嵌入在几何造型，我们使用。离散是储存在一个面向图形数据结构。每个节点的图形对应的一个节点上的网格。边缘的图形对应边的网格连接相邻节点。在每个节点螺丝代表联系点，是计算和储存。螺丝钉是一个简洁和方便的代表性表面正常位置的节点。它是用来在所有运动测试基于螺旋理论。计算势场联系点，在我们的算法是受联合行动，由两部分组成，形成了潜在的领域。背景势场是其中的组成部分。这是产生由P区和不依赖于地理位置的联系点。背景势场的计算方法是只计算一次，在一开始的算法。另一部分是动态的和，这是由于该斥力之间的接触。动态部分是计算机在每一个划时代的。计算的背景势场的收益如下：首先，我们找到所有的节点所在内的P-区。我们履行会员分类每个节点对每个人P-区[tilove1980年]。如果节点内一定的P-区，负责为P区，有助于节点的电荷。贡献，可以是正面的还是负面的，这取决于该标志区的电荷。经过这个程序的节点进行分类外，所有的P-区仍具有零收费。如果一个节点米制内的P-区Z1的，z2的...专用料ZK其负责厘米等于一笔收费的那些人P-区：之后，负责该节点内的P-特区，是我们评价我们开始通过计算潜在的所有节点。我们界定的潜在处于被控节点，初步等于它的电荷时=厘米。每个被控节点m的范围内负责厘米，我们演出广度优