简介:Thisarticlepresentsanovelimageinterpolationbasedonrationalfractalfunction.Therationalfunctionhasasimpleandexplicitexpression.Atthesametime,thefractalinterpolationsurfacecanbedefinedbyproperparameters.Inthispaper,weusedthemethodof‘coveringblanket’combinedwithmulti-scaleanalysis;thethresholdisselectedbasedonthemulti-scaleanalysis.Selectingdifferentparametersintherationalfunctionmodel,thetextureregionsandsmoothregionsareinterpolatedbyrationalfractalinterpolationandrationalinterpolationrespectively.Experimentalresultsonbenchmarktestimagesdemonstratethattheproposedmethodachievesverycompetitiveperformancecomparedwiththestate-of-the-artinterpolationalgorithms,especiallyinimagedetailsandtexturefeatures.
简介:Wepresentthesolidmodeleditdistance(SMED),apowerfulandflexibleparadigmforexploitingshapesimilaritiesamongstCADmodels.ItisdesignedtomeasurethemagnitudeofdistortionsbetweentwoCADmodelsinboundaryrepresentation(B-rep).Wegivetheformaldefinitionbyanalogywithgrapheditdistance,oneofthemostpopulargraphmatchingmethods.Toavoidtheexpensivecomputationalcostpotentiallycausedbyexactcomputation,anapproximateprocedurebasedonthealignmentoflocalstructuresetsisprovidedinaddition.Inordertoverifytheflexibility,wemakeintensiveinvestigationsonthreetypicalapplicationsinmanufacturingindustry,anddescribehowourmethodcanbeadaptedtomeetthevariousrequirements.Furthermore,amultilevelmethodisproposedtomakefurtherimprovementsofthepresentedalgorithmonbotheffectivenessandefficiency,inwhichthemodelsarehierarchicallysegmentedintotheconfigurationsoffeatures.ExperimentresultsshowthatSMEDservesasareasonablemeasurementofshapesimilarityforCADmodels,andtheproposedapproachprovidesremarkableperformanceonareal-worldCADmodeldatabase.
简介:Inordertoreducenursingintensityandimprovefreedomoftheelderlyandthedisabled,amulti-functionnursingwheelchairwhichcanswitchchairtobedandrealizemanykindsofposturetransformationisdesigned.Thispaperintroducesthemechanicalstructuredesign(positionadjustmentmechanismandvariablewheelbasemechanism)andcontroldesignofposturetransformationunitofmultifunctionalnursingwheelchair.
简介:Motioncontrolcanbeconsideredasthesynergisticcollaborationofmechanicalandelectricalengineering,computerscienceandinformationtechnologytoapplyacontrolledforcetoachieveusefulmotioninfluidorsoiledelectromechanicalsystems.Withthedevelopmentofcomputer,electronics,andautomaticcontroltheory,motioncontrolcomestoanewstage.Greatapplicationsarebasedonthecharacteristics,stemmingfromadvantagesofelectronicsandmoderncontroltechnologyachievements,havingaverygoodloadmatchingproperty.Currently,microprocessor-basedcontrollersareinvariablyusedinmostapplicationsofdriveelectronics.Theobjectofthisworkistodesignapositioncontrolmechanismsystem,whichcanbeusedintestsectionoflowspeedwindtunnel.Systemloadspecificationsandperformancerequirementsaregiven.Acomprehensivestudyofmathematicalmodelingofthemechanismcomponentsisgiven.Procedureforselectionofvariouscomponentswithoptimumparametersisdiscussed.Afterselectionandcalculationofsystemparameterstomeettheperformancerequirements,aPIDcontrolmethodisadopted.
简介:Inthepreprocessingphase,theglobalterrainmodelispartitionedintoblockswiththeirfeaturepointsbeingpickedouttogenerateTINmodelforeachterrainblock,thenthemulti-resolutionmodelsofterrainorganizedintheformofquad-treeiscreatedbottom-up.Cracksbetweenterrainblocksareavoidedbyinsertingverticestoformcommonboundaries.Atrun-time,aview-dependentLODalgorithmisusedtocontroltheloadingandunloadingoftheproperblocksbyanadditionalsynchronousthread.ToeliminatetheartifactscreatedbyLODtransitions,geomorphingisusedinreal-time.TheserenderingstrategiesincreasethethroughputofGPUandavoidimbalanceofloadamongCPU,GPUandDiskI/O.Experimentalresultsshowthatthesystemcanperformvisuallysmoothrenderingoflarge-scaleterrainsceneswithfinequalityatanaveragerateof80fps.
简介:Themechanicalstructureaswellastheschematicorganizationhasbeendesignedtoachievelowerlimbrehabilitationtrainingfunction;Solidworkshasbeenusedtomodeltherobot.Andtherobothasbeenoptimizedbythemeansofhuman-interferenceengineering.TheprimarycomponentsoftherobothavebeenanalyzedbyAnsysworkbench.
简介:Simulationandrenderingoflarge-scalenaturalenvironments,especiallytheocean,hasalwaysbeenoneofthehotissuesincomputergraphics,whichcanproviderealismforvariousapplicationssuchascomputergame,movieandmilitaryusage.Simulationofoceanenvironmentisoftenlackofrealismforreal-timeapplicationduetoitscomplexityofdynamicwaves.Inthispaper,amethodbasedonFFTWavemodelisproposedtosolvethisproblem,whichcanalsosimulatetheoceanopticpropertywithatmospherescattering.Furthermore,ourmethodhasalotofadvantagesincludingglobaloceandatasetsupport,real-time,dynamicreflectionofocean,thefoamonthewave,smoothtransitionfromdeepoceantoseacoast,etc.Theexperimentalresultsdemonstratetherealismandeffectivenessofourapproach.
简介:Theefficientandreliablehumancentereddesignofproductsandprocessesisamajorgoalinmanufacturingindustriesfornumeroushumanfactorsmustbetakenintoaccountduringtheentirelifecycleofproducts.Amulti-agentsintelligentdesignsystemispresentedformanufacturingprocesssimulationandproducts’ergonomicanalysis.Invirtualdesignenvironment,thevirtualhumanwithhigh-levelintelligenceperformstasks’operationautonomouslyandshowsoptimumpostureconfigurationwithergonomicassessmentresultsinrealtime.Thefunctionsarerealizedbyintelligentagentsarchitecturebasedonamodernapproachderivedfromfuzzymulti-objectsdecision-makingtheory.Acasestudyispresentedtodemonstratethefeasibilityofthesuggestedmethodology.
简介:Pathplanningin3Dgeometryspaceisusedtofindanoptimalpathintherestrictedenvironment,accordingtoacertainevaluationcriteria.Tosolvetheproblemoflongsearchingtimeandslowsolvingspeedin3Dpathplanning,amodifiedantcolonyoptimizationisproposedinthispaper.Firstly,thegridmethodforenvironmentmodelingisadopted.Heuristicinformationisconnectedwiththeplanningspace.Asemi-iterativeglobalpheromoneupdatemechanismisproposed.Secondly,theoptimalantsmutatethepathstoimprovethediversityofthealgorithmafteradefinediterativenumber.Thirdly,co-evolutionaryalgorithmisused.Finally,thesimulationresultshowstheeffectivenessoftheproposedalgorithminsolvingtheproblemof3Dpipepathplanning.
简介:Accordingtothestudyonseat-backcurvesaboutdifferentpeople,themethodthatusingtwoarc-shapedroofstogivebacksupportingforceofthehumanbodyisproposed.Throughacleverdesignapplicationofpiezoelectricsensor,microcontroller,motors,andarc-shapedroofsformaclosedloopcontrolsystem.Throughthedesignofhorizontalandverticaladjustmentmechanism,aflexibleandadaptivemulti-dimensionalbackcanreducetheharmtohumanspinewhichcausedbypoorpostureandsedentarylifestyle.ModelbuildingandstressanalysisaredonebyInventorsoftwaretoverifythemechanismofstrength.