proposal 开题报告.docx

proposal 开题报告.docx

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proposal开题报告

High-performanceSmall-sizedHoppingRobot

forComplexTerrainDetecting

ThesisProposal

Candidate

JixueMo

Supervisor

Prof.BingLi

SchoolofMechanicalEngineeringandAutomation

HarbinInstituteofTechnology

June15th,2016

1.INTRODUCTION

Onground,animalsusedifferenttypesoflocomotionsuchaswalking,rolling,running,hoppingandcrawling.Mobilerobotsareusuallyconstructedwithwheelsorlegstomimicthelocomotionofanimals.Thereisavarietyoflocomotionformobilerobots.Thecommonlocomotiontypesformobilerobotsarewheels[1-3].Thewheelsaresimplesttechniquetoimplementmobilityinarobot.Thistacticisrobustandsimpleasitcanuseonlyoneactuatortodrivethewheels.Wheelslocomotionsystemeasilyfailedwhenfacingobstaclestoovercome.Theobstaclesizeof1.5timesthewheeldiametercanbeovercamebyusingwheelslocomotion[4].Thebodyhingesorexpandablewheelsdesignhasbeenproposedtoenabletherobottoovercomelargeobstacles[5].Tracksarealsousedbymobilerobotsthatdonotneedhighspeedandprecisemovementbutneedtotravelthroughroughterrain.Wheeledlocomotionislimitedtotheobstaclesizeascomparedtotherobotbodydimensions.Legslocomotioncanalsobeusedtomoveinunevenground.Thelegsofferimprovedgroundlocomotionwhichisadvantageousinroughterrain[6,7].Thelegslocomotiondesignsaremechanicallymoremultifacetedascomparedtowheelslocomotionandhavemoremovingparts.Thecombinationofwheelsandlegsiswhegslocomotionwhichisusedin[8-10].Legsrobotsarerestrictedbyobstaclesheight.Thelegsclimbingrobotsclimbgraduallyandarelimitedtorelativelysmoothground;itisthemaindrawbackofclimbingrobots.Groundobstaclescanbeovercamebyusingflyinglocomotion[11-14].Theflyinglocomotionismoreexpensive,ascomparedtoleggedorwheeledlocomotion.

Hoppingisfastestlocomotionongroundandusedbyvariousanimalstoreachathigherplace,overcomeobstacles,travelonroughgroundetc.[15-19].Variousanimalsalsousehoppinglocomotioninanyemergencysituationtosavethemselves;ashoppingprovidesrapideffectinaveryshorttime.Thecurrenthotissueistodevelophoppingrobots,becauseoftheirgreatmovingabilities.Theadoptionofhoppingtohandlelocomotiononroughground,allowstherobottoovercomeobstacleseveraltimeslargerthanitsownsize;whichwouldnotbepossiblewithawheeledorleggedlocomotion.Inhoping,steeringandhopangle

aremostimportantelements,becausethefunctionalitiesofsteeringandhopanglecontrolarenecessarytoachievethedesireddirectionanddistance.Tothebestofourknowledge,thereisnosuchfuelpoweredhoppingrobot,whichhasbothfunctionalities.Animalsusetheirlivesensorstoexploretheenvironmentandsurvival.Theresultinginformationisprocessedinthebrainandasoutput,anactionperformedbytheanimalinanymannertosurviveorexplore.Similarly,hoppingrobotscollectinformationofthesurroundings,usinginstalledsensors.Thecollectedinformationisprocessedintherobot’smicrocontrollerknownasbrainandasoutputresult;itsendsthesignalstoactuatorsanddevicesforperformingallottedtask.

Themainobjectiveofthisprojectistodesignakindofgas-fuelpoweredhoppingrobotwhichhaveexcellentjumpingabilityandcanabsorbthejerks,shocksandhighimpactforcesduringlanding.Thehoppingrobotcanadjustitsattitudewhilehoppingintheairsothattherobotcanlandwithoutdamagingitsinnercomponent.Lastbutnotleast,therobotissupposedtodoautomaticpathplanningandovercomelargeobstaclesefficiently.

2.LITERATUREREVIEW

2.1Hoppinglocomotion

Energysourcesusedinhoppingmechanismsaremainlyelectrical,pneumaticandcombustiveenergy.Mostelectrical-energy-basedhoppingmechanismsareactuatedbyDCmotors.Torealizeajump,acertainupwardvelocityistobeproducedinaveryshorttime,requiringtheactuatortopossesshighinstantaneouspoweraswellaspowertoweightratio.DCmotorsdonothavesuchability;hence,alargeamountofpotentialenergyneedstobestoredthroughtransmissionchainsinelasticelementswhichcanbereleasedquicklytorealizeajump.ThisapproachwasfoundintheuseofDCmotor-actuatedjumpingrobotswithgearedhoppingmechanisms,suchassix-bar[20]andfour-bar[22]linkagewithpotentialenergystorageelements,suchascoilspring[23],bendingspring[21],torsionspring[22],springhoopandcurvedbeam[33].Thejumpisrealizedthroughthesuddenreleaseofthestoredenergy,byuseoftriggermechanismssuchascam[22],singlewaybearing[24]andsegmentalgear[23],whicharealsopartofthetransmissionchains.

PneumaticenergyofcompressedairwasusedtoactuatethehoppingmechanismintheTITECHrescuerobot[27],whileabipedaljumpingandlandingrobot,Mowgli,wasdevelopedusingpneumaticartificialmuscles[28].Themaindrawbackofthistechniqueisthelowenergydensityofcompressedaircomparedtootherapproaches.

Amongthesourcesofenergycurrentlyusedinthesemechanisms,combustivefuelshavethehighestenergydensity,asshownin[34].Theyareofoneortwoordersofmagnitudehigherthaneventhemostadvancedelectricalbatteriesintermsofenergydensity[35].Anexampleoftheuseofcombustivefuelsinahopping-likemechanismisthedieselpilehammerinthebuildingconstructionindustry.Oncecompressed,amixturemadeofairanddieselignites,andtheheavypistonisdrivenupseveralmetershighwithouttheneedforanytransmission.

Duetotheuseofadirectdrivemechanism,ahoppingactuatorpoweredbycombustivefuelscanbesimple,structurallycompactandhasnoneedforanytransmissionsystems.Tothebestofourknowledge,onlySandiaLabinitiatedtheresearchonthehydrocarbonfuel-poweredhoppingmechanism[30]anddevelopedahighperformancewheeledhoppingvehicle[31],andthenanurbanhoppercapableofjumping7.5mhighwasdemonstratedbySandiaLabandBostonDynamics[32].ItwasrecentlyreportedBostonDynamicshasdevelopedtheSandFlea,whichcanjumpfrom1to8m,withgyrostabilization.Unfortunately,muchoftheperformancefiguresortechnicalspecificationwerenotwidelypublishedaboutthesefuel-poweredhoppingrobots,suchasstructuralandworkingparameters,innerstructure,andworkingcharacteristics.

2.2Hoppingrobot

Mobilegroundrobotscanmainlybecategorizedintotwokinds.Oneisthewheelorpedrailrobot,whichhasawideapplicationinthecurrentsociety,suchasexplosiveordnancedisposal（EOD）,firefightingandspaceexploration,etc.Theotheristhebioniccrawlingorwalkingrobot,suchassnakerobot,cricketrobot,etc.Thewheelrobothasthebestefficiencybuttheworstadaptability[25].Itcanonlymoveonrelativelyeventerrain,soitsrangeofmotion（ROM）willbeconstrainedseverelyinanunknown,ruggedterrain.Thepedrailmodehasgoodclimbingabilitybutitsefficiencyandflexibilityarelow,andcanonlyovercomesomespecificorsmall-scaleobstacles.Thecrawlingorwalkingrobothasgoodadaptabilitytoterrainbuttheworstefficiencyduetoitscomplicatedtransmissionmechanism,andcannotgetoverobstaclesseveraltimesitsowndimension.Sotheabovemobilerobotscannotmeettheneedsofovercominglargeobstaclesforavarietyofapplicationsfromcelestialbodyexplorationtosurveillanceandrescueoperation,etc.

Robotswithhoppingabilityprovideasolutiontotheproblem.Uptonow,researchershavedevelopedsomehoppingrobots[36-38].Papanikolopoulosetal.presentedminiaturejumpingrobotsforstair-climbing[26].Jumpingisachievedbyelectricallywinchingthesprintfootaroundthebodyandreleasingitsuddenly.Forcelestialexploration,Refs.[39-40]developedthreegenerationsofelectricallyactuatedhoppingrobots,whichreachedhoppingheightof1.2m.Themainproblemofthehoppingrobotactuatedelectricallyislowefficiencybecauseofmanytransmissionmechanismsandthelowenergydensityofbattery,whichwilldecreasethenavigationdura-

tionofrobotsandincreasethepollutionofwastebattery.Tsukagoshietal.presentedajumpingrescuerobotactuatedbycompressedair[41-42].Thisrescuerobotcanjumpover80cmobstaclesandismoreefficientthantheelectricallyactuatedrobot,butcompressedairisstilloflowenergydensity.FuelwastakenasenergysourcebyFisheretal.forhoppingrobotbecauseofitshighenergydensity,whichcanjumpwithaheightofmorethantentimesitsdimension[29],[33].

3.OBJECTIVES

Theobjectivesoftheprojectareto:

∙Designandmanufacturethegas-fuelpoweredactuatorandvalidateitsperformancebyexperiment.

∙Designthemainstructureofthehoppingrobot.Assemblethehoppingrobotwithitscomponentsandthevalidatedgas-fuelpoweredactuator.

∙DesignandmanufacturethecontrolPCBofthehoppingrobot.Realizeitsremotecontrolattitudeadjustingintheair.

∙Proposeeffectivecontrolstrategyandpathplanningalgorithm,realizetheautomationofthehoppingrobot.

4.METHODOLOGY

4.1Explosionmodelingofthecombustionchamber

Thesecondstageoftheexplosionisanadiabaticexpansionprocess,thegasofhightemperatureandhighpressureexpandtomakethecylinderworkssothatthecylindermovesupwards.Supposetheinstantaneouspressureduringtheexplosionprocessis

thevolumeofthecombustionchamberis

thentheequationofquasistaticadiabaticprocessofidealgasis

a——constant；

——adiabaticindexofidealgas，forpolyatomicgas，

；

Supposetheratioofinstantaneousvolume

toinitialvolume

is

then

Attheinitialmoment,

.Whenthecylindermovesupwardsandexhaustgasdischargefr