AcomprehensivesurveyofaugmentedrealityassemblyresearchAbstractprovideaconciseoverviewofthetechnicalfeatures,characteristicsandbroadrangeofapplicationsofARbasedassemblysystemspublishedbetween1990and2015.Introduction1.traditionalcomputer-aidedassemblytechnology:requirtoidentifyconstraintinformationbetweenthematingparts;difficulttoforeseetheimpactofindividualmatingspecificationsonotheraspectsoftheassemblyprocess;lacksdirectinteractionbetweenusersandthecomponents.2.VRassemblysystem:lackingofrealisticexperience,decreasingthefidelityandcredibility;noteasytofullyandaccuratelymodelthereal-timeandactualworkingenvironments.3.ARassemblysystem:doesnotneedtheentirerealworldtobemodeled;enhancestheinteractionbetweenthesystemsandtheusers,manipulatetheobjectsnaturally.SixfunctionalmodulesofARassemblysystemThreemaincategoriesARassemblysystem120articles,39.47%116articles,38.16%68articles,22.37%ARmulti-mediaandinteractiveinstructionsDisadvantage:focussolelyonprovidingstep-basedinstructions,overlookinguser’sneedoftimelyguidanceinassemblyoperations;couldnotkeeptrackoftheassemblystatusinreal-timeandrecognizeerrorsandcompletionstates;whenassistingcomplexassemblyprocesses,time-consumingauthoringprocedures,integrationwithenterprisedata;theinteractionschememaydisturborinterruptuser’son-goingassemblytask.Target:detectingandrecognizingtheusers’actionsinordertoprovideanindustrialrobusthandsfreeinteraction.examinetheappropriatenessofARguidanceformorecomplex,multi-stepassemblytasks.Context-awarenessandauthoringARassemblysystemkeepstrackofthestatusofusersinreal-time,automaticallyrecognizingmanualerrorsandcompletionateachassemblystepanddisplayingmultimediainstructionscorrespondingtotherecognizedstates.ARassemblyauthoringsystemshavebeenenabledtocopewithmanualassemblyoperationsefficiently;Disadvantage:time-consumingtobuild‘‘adhoc’’systems.needmanualinput.Target:tobemoretask-adaptive,suiteforawiderangeofdifferenttasks.considertheimplementationissuesofsensors.becomesmartenoughtounderstandauser’sintentandgeneratetimelycontext-awareguidanceduringassemblyoperationswithoutmanualinput.EvaluationofARassemblyguidance1.Effectivenessevaluation:concernsthecapabilityofthesystemtoproduceadesiredresultforacertaintaskoractivity.2.Usabilityevaluation:involvesinvestigatingtheeaseofuseandlearnabilityoftheARassemblysystembasedonneedsanalysis,userinterviewsandexpertevaluations.Disadvantage:differentfactorsthatinfluencetheeffectivenessandusabilityofanARassemblysystemarestillobscure.suchasvariousinteractionmethods.designedonlyforaspecific‘‘adhoc’’assemblytask.Trend:evaluatingnovelARinterfaces,especiallyhowtheseinterfacescanimprovehumanresourcecapabilitiesandtheattendanthumanfactors.ARassemblytrainingResearchinthisareahaslargelyinvolvedproceduraltaskswhereauserfollowsvisualorothermulti-modalcuestoperformaseriesofsteps,withthefocusonmaximizingtheuser’sefficiencywhileusingtheARsystemDisadvantage:provideminimalfeedbackwhentheusersmakeamistake,whichisnotconducivetolearning.Target:theadaptivityofvariousmethodsanddifficultylevelsofassemblyoperationswouldbeexpectedtobeintegratedtotheARassemblytrainingsystem.handlecurrenttrendsofagileproductdevelopmentandmanufacturing.ARassemblyprocesssimulationandplanningmanyofthecurrentARassemblysimulationsystemsseemtobelimitedtotheinteractionbetweenvirtualobjects.ignoreanimportantissueofincorporatingrealobjectsintotheARenvironmenttoprovidethecorebenefitsofAR.suchashapticfeedback,naturalinteractionandbettermanipulationintuition.Hand-basedHCIhasbecomeapopularresearchtopicinARassemblysimulation.Disadvantage:theuserneedtoundertakespecificsimpleactionstoimplementtheinteractionwiththeARenvironment.theactionlackintuitiveness.onlyalimitedtypesofgestureshavebeenusedandthegesturesaredesignedbyresearchersforoptimalrecognitionratherthanfornaturalness.themappingsbetweengesturesandcommandstothecomputerareoftenarbitrary.assemblydesignandplanningTheimplementationofassemblydesignandplanningintheARenvironmentispromisingandagrowingnumberofresearchershavestudiedthisarea.Disadvantage:accuracyissue,intuitivenessanddependencyonCADsoftware.Target:toconstructanintegratedARassemblyplatformtomodeltheinteractionbetweenmatingcomponentsaccurately.toproposeaninformationmanagementmethodtoextractsinformationfromCADsystem,storesandreasonstheassemblyrelationsindependently.Marker-basedtrackingTheuseofmarkersisverycommoninARassemblybecauseitincreasestherobustnessandimprovesthecomputationefficiencyduetothestableandfastdetectionofmarkers.Disadvantage:sufferfrommarkerocclusion.industrialcomponentsaretoosmalltoattachmarkers.Sensor-basedtrackingThetrackingprincipleisbasedondifferenttypesofsensors.Visionbasedtrackingreliesoncomputervisiontechniques.Marker-lesstrackingbedeemedtobeadesirablesuccessorofmarkersrecently.Disadvantage:thetrade-offsbetweenthetrackingaccuracyandcomputationcostneedtobeconsideredcarefully.CollaborativeARinterfaceatechnologyaimmingatassemblydesigners,plannersaswellasoperatorscanparticipatetogethertofacilitatecommunicationbetweenthemduringassemblyprocess.Rana