自動(dòng)夾具中英文對照外文翻譯文獻(xiàn)

中英文對照外文翻譯文獻(xiàn)(文檔含英文原文和中文翻譯)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.自動(dòng)夾具在三維中的合成摘要夾具是一個(gè)安排在裝夾模塊中的位置，并進(jìn)行工件在一個(gè)以制造業(yè)為主的運(yùn)作。我們在這項(xiàng)工作中,考慮固定裝置與無摩擦點(diǎn)接觸，并給出了一個(gè)方案，為安置的接觸點(diǎn)上的非棱柱體三維工件。它是一個(gè)非確定性，勢場算法的接觸點(diǎn)安置。該方法提供了一個(gè)基本框架，為整合異構(gòu)高層次裝夾代理商通過一個(gè)界面基于區(qū)的吸引力和斥力就工件邊界。該算法可能會產(chǎn)生多余的固定裝置，并能增加部分的解決辦法，以形成完整的封閉裝置。導(dǎo)言夾具是一個(gè)安排的裝夾模塊中的位置，并舉行工件在一個(gè)以制造業(yè)為主的操作，如加工，裝配和檢驗(yàn)。裝夾是最重要的，以工業(yè)制造，并構(gòu)成的一個(gè)重要部分，所有的制造成本。因此，夾具設(shè)計(jì)自動(dòng)化是非常重要的。夾具設(shè)計(jì)涉及多種因素，例如，克制，決定性的位置，裝載和工具無障礙環(huán)境。高效的算法處理整個(gè)一系列的裝夾問題，為全面域工件尚不存在。最近，brost和彼得斯出版了一種算法[brost＆彼得斯1996]延伸早前經(jīng)典的工作brost和戈德堡[brost＆戈德堡，1994]，以三維域。這種算法，但需要縱向和橫向平面構(gòu)成相當(dāng)大一部分的工件邊界。它產(chǎn)生的所有可能的固定裝置，然后在利率，他們因此對某些衡量標(biāo)準(zhǔn)。這是在計(jì)算上昂貴的。Wagner等提出了一種算法，使用7個(gè)模塊的Struts安裝在一個(gè)盒子里，以夾具多面體[Wagner等，1995年]。這個(gè)算法是不全面的，在這個(gè)意義上講，它并不能有效地處理某些情況下，例如一個(gè)立方體的臉平行包裝盒。它也經(jīng)歷著從高計(jì)算復(fù)雜度。wallack和精明提出另一種方法，并有"列舉與匯率"的味道[wallack＆Canny，1996年]。它可以夾具棱柱工件與平面和圓柱垂直表面。龐塞提出了一種算法，利用曲率的影響，計(jì)算出固定裝置與四指為多面體零件[龐塞96]。在數(shù)量減少的接觸應(yīng)提供更好的復(fù)雜算法，但質(zhì)量的生產(chǎn)設(shè)備，似乎不亞于那些利用更多的接觸，并提供古典形式封閉。在這篇文章中我們提出了一種新的潛在場算法，有效地生產(chǎn)優(yōu)質(zhì)夾具設(shè)計(jì)。我們的算法工程任意工件，并提供便捷的普遍手段，代表不同的裝夾要求。這種算法是一種直接泛化的二維勢場裝夾算法penev和requicha[penev＆requicha1996]。我們認(rèn)為，固定裝置與無摩擦點(diǎn)接觸。它已證明七名接觸是必要的。[somoff，1900]，并有足夠的[markenscoff等人，1990年]固定任何工件在三維繼至少承諾的策略，過程夾具合成可分為三個(gè)階段-裝夾任務(wù)分析，接觸點(diǎn)安置以及夾具布局設(shè)計(jì)。在裝夾任務(wù)分析階段工件幾何和制造過程中分析，以確定各種參數(shù)的裝夾問題，如切削力，交通不便或禁止的領(lǐng)域，并找出特點(diǎn)，可用于申請裝夾裝置，例如機(jī)械平面，橫向和縱向表面，對平行表面，對垂直于表面，等等。圖1：接觸點(diǎn)安置在接觸點(diǎn)安置階段的一些聯(lián)絡(luò)點(diǎn)，是擺在工件邊界（圖1），因此由此產(chǎn)生的配置接觸滿足確定的限制因素，在分析階段，以及一些運(yùn)動(dòng)學(xué)要求必須得到滿足，任何夾具如完全克制。圖2：從接觸點(diǎn)配置，以夾具布局設(shè)計(jì)

在布局設(shè)計(jì)階段"水塔"的裝夾元件是建立并置于周圍工件等，以接觸的部分，在點(diǎn)位置計(jì)算，在接觸點(diǎn)安置階段。舉例來說，一個(gè)接觸點(diǎn)上，橫向工件表面（圖甲），可導(dǎo)致以實(shí)例化的額外開銷鉗說，接觸了工件在那個(gè)特定點(diǎn)（圖2B）條。這是一個(gè)以設(shè)計(jì)為功能的問題，制約了一套可裝夾單元及其參數(shù)。這實(shí)現(xiàn)了套聯(lián)絡(luò)點(diǎn)的功能規(guī)格及夾具布局是一個(gè)配置的部件。在本研究中，我們的重點(diǎn)聯(lián)系點(diǎn)安置，并把它納入其中部分和任務(wù)的分析。安排的接觸點(diǎn)必須滿足某些運(yùn)動(dòng)學(xué)條件，以一個(gè)基礎(chǔ)，有一個(gè)良好的夾具。特別是，它必須提供的封閉形式，確定位置，夾緊穩(wěn)定，脫離能力和裝載[Asada&By]。該算法采用離散化的工件邊界，類似的網(wǎng)格所使用的有限元分析。但是，不同于有限元分析，我們注意的是，對網(wǎng)格節(jié)點(diǎn)上，而不是放在網(wǎng)格元素。離散選擇為以下幾個(gè)原因：首先，我們可以處理工件任意幾何，只要把部分的邊界是一家集表面光滑，而我們知道如何主題詞。這項(xiàng)規(guī)定是滿意的所有表面用在現(xiàn)代CAD系統(tǒng)。其次，離散化是必要的，以避免昂貴的計(jì)算測曲線。第三，離散應(yīng)該不會大大影響結(jié)果，只要有多少離散候選地點(diǎn)就邊界要遠(yuǎn)遠(yuǎn)大于人數(shù)表面上。在我國實(shí)施離散邊界構(gòu)成的幾百點(diǎn)。實(shí)驗(yàn)證據(jù)表明，這是不夠現(xiàn)實(shí)的工件。我們引進(jìn)一個(gè)潛在場對工件邊界界定區(qū)的吸引與排斥，我們稱之為個(gè)P-區(qū)。接觸是仿照由于帶電粒子的這一舉動(dòng)對邊界驅(qū)動(dòng)這個(gè)潛在的領(lǐng)域。接觸也受到相互排斥的基礎(chǔ)上，之間的距離每兩個(gè)接觸，在扳手向量空間。該算法執(zhí)行了一系列的模擬時(shí)代。每一個(gè)劃時(shí)代的開始，以隨機(jī)配置，收益是通過一定數(shù)量的步驟，向低勢能和結(jié)束一場考驗(yàn)運(yùn)動(dòng)學(xué)條件（形成封閉）。該算法終止時(shí)，一個(gè)劃時(shí)代的產(chǎn)生令人滿意的配置。傳播接觸點(diǎn)上的邊界，我們模擬斥力之間相互對他們。強(qiáng)度斥力之間的兩個(gè)接觸點(diǎn)，取決于它們之間的距離及其相應(yīng)的扳手在扳手向量空間。我們的模擬收益，在有限的幾個(gè)步驟，或直至平衡是達(dá)成共識。由此產(chǎn)生的就業(yè)，應(yīng)該有很好的機(jī)會，導(dǎo)致一個(gè)好的夾具。這種隨機(jī)方法假定一套正元組的聯(lián)系點(diǎn)（對N大于3）表示，滿足運(yùn)動(dòng)學(xué)要求，有措施，都大于零，是比較大。這就是說，解空間非常大。雖然我們尚未能證明這一假設(shè)的數(shù)學(xué)，我們的實(shí)驗(yàn)已經(jīng)證實(shí)了它。此外，這項(xiàng)措施增加多少接觸點(diǎn)，例如，這是比較容易找到一個(gè)封閉的形式安排多于8分之7。概念斥力是必不可少的方法，因?yàn)檫@可以容易容納其他因素。我們可以把更多的斥力點(diǎn)就工件邊界，以代表故宮地區(qū)。我們還可以介紹中心的吸引力。這些對應(yīng)的地方被推薦人的分析階段可取配售聯(lián)系點(diǎn)，例如，基準(zhǔn)面表面。因此，我們提出一個(gè)勢場為代表一致異構(gòu)裝夾信息。地區(qū)斥力對應(yīng)地區(qū)的積極潛力。負(fù)電位，是與魅力。零電位對應(yīng)于中立地區(qū)。初始隨機(jī)抽選的聯(lián)系點(diǎn)，被視為微粒，正在吸引或擊退一個(gè)勢場，其中包括成對斥力。目標(biāo)體系的聯(lián)系點(diǎn)是為了最大限度地減少其總勢能。輸入輸入我們的算法包括CAD模型的工件邊界，以及一套堅(jiān)實(shí)的P-區(qū)。每個(gè)人P-區(qū)界定一個(gè)潛在場的影響區(qū)域與非零收費(fèi)。三離散工件邊界，第一步，我們的做法是把離散邊界的工件，因而創(chuàng)造候選人接觸點(diǎn)的位置，我們稱之為節(jié)點(diǎn)。離散化是做了引用標(biāo)準(zhǔn)工作面嵌入在幾何造型。離散是儲存在一個(gè)面向圖形數(shù)據(jù)結(jié)構(gòu)。每個(gè)節(jié)點(diǎn)的圖形對應(yīng)的一個(gè)節(jié)點(diǎn)上的網(wǎng)格。邊緣的圖形對應(yīng)邊的網(wǎng)格連接相鄰節(jié)點(diǎn)。在每個(gè)節(jié)點(diǎn)螺絲代表聯(lián)系點(diǎn)，是計(jì)算和儲存。螺絲釘是一個(gè)簡潔和方便的代表性表面正常位置的節(jié)點(diǎn)。它是用來在所有運(yùn)動(dòng)測試基于螺旋理論。離散工件邊界第一步，我們的做法是把離散邊界的工件，因而創(chuàng)造候選人接觸點(diǎn)的位置，我們稱之為節(jié)點(diǎn)。離散化，是做了，引用標(biāo)準(zhǔn)表面嵌入在幾何造型，我們使用。離散是儲存在一個(gè)面向圖形數(shù)據(jù)結(jié)構(gòu)。每個(gè)節(jié)點(diǎn)的圖形對應(yīng)的一個(gè)節(jié)點(diǎn)上的網(wǎng)格。邊緣的圖形對應(yīng)邊的網(wǎng)格連接相鄰節(jié)點(diǎn)。在每個(gè)節(jié)點(diǎn)螺絲代表聯(lián)系點(diǎn)，是計(jì)算和儲存。螺絲釘是一個(gè)簡潔和方便的代表性表面正常位置的節(jié)點(diǎn)。它是用來在所有運(yùn)動(dòng)測試基于螺旋理論。計(jì)算勢場聯(lián)系點(diǎn)，在我們的算法是受聯(lián)合行動(dòng)，由兩部分組成，形成了潛在的領(lǐng)域。背景勢場是其中的組成部分。這是產(chǎn)生由P區(qū)和不依賴于地理位置的聯(lián)系點(diǎn)。背景勢場的計(jì)算方法是只計(jì)算一次，在一開始的算法。另一部分是動(dòng)態(tài)的和，這是由于該斥力之間的接觸。動(dòng)態(tài)部分是計(jì)算機(jī)在每一個(gè)劃時(shí)代的。計(jì)算的背景勢場的收益如下：首先，我們找到所有的節(jié)點(diǎn)所在內(nèi)的P-區(qū)。我們履行會員分類每個(gè)節(jié)點(diǎn)對每個(gè)人P-區(qū)[tilove1980年]。如果節(jié)點(diǎn)內(nèi)一定的P-區(qū)，負(fù)責(zé)為P區(qū)，有助于節(jié)點(diǎn)的電荷。貢獻(xiàn)，可以是正面的還是負(fù)面的，這取決于該標(biāo)志區(qū)的電荷。經(jīng)過這個(gè)程序的節(jié)點(diǎn)進(jìn)行分類外，所有的P-區(qū)仍具有零收費(fèi)。如果一個(gè)節(jié)點(diǎn)米制內(nèi)的P-區(qū)Z1的，z2的...專用料ZK其負(fù)責(zé)厘米等于一筆收費(fèi)的那些人P-區(qū)：之后，負(fù)責(zé)該節(jié)點(diǎn)內(nèi)的P-特區(qū)，是我們評價(jià)我們開始通過計(jì)算潛在的所有節(jié)點(diǎn)。我們界定的潛在處于被控節(jié)點(diǎn)，初步等于它的電荷時(shí)=厘米。每個(gè)被控節(jié)點(diǎn)m的范圍內(nèi)負(fù)責(zé)厘米，我們演出廣度優(yōu)