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372Vol.30No.4,pp.372377,2012PETMAN:AHumanoidRobotforTestingChemicalProtectiveClothingGabeNelson∗,AaronSaunders∗,NeilNeville∗,BenSwilling∗,JoeBondaryk∗,DevinBillings∗,ChrisLee∗,RobertPlayter∗andMarcRaibert∗∗BostonDynamics1.IntroductionPetmanisananthropomorphicrobotdesignedtotestchemicalprotectiveclothing(Fig.1).PetmanwilltestIndividualProtectiveEquipment(IPE)inanenvi-ronmentallycontrolledtestchamber,whereitwillbeexposedtochemicalagentsasitwalksanddoesbasiccalisthenics.Chemicalsensorsembeddedintheskinoftherobotwillmeasureif,whenandwherechemi-calagentsaredetectedwithinthesuit.Therobotwillperformitstestsinachamberundercontrolledtemper-atureandwindconditions.Atreadmillandturntableintegratedintothewindtunnelchamberallowforsus-tainedwalkingexperimentsthatcanbeorientedrela-tivetothewind.Petman’sskinistemperaturecon-trolledandevensweatsinordertosimulatephysiologicconditionswithinthesuit.Whentherobotisper-formingtests,aloosefittingIntelligentSafetyHarness(ISH)willbepresenttosupportorcatchandrestarttherobotshoulditlosebalanceorsufferamechani-calfailure.Theintegratedsystem:therobot,chamber,treadmill/turntable,ISHandelectrical,mechanicalandsoftwaresystemsfortestingIPEiscalledtheIndividualProtectiveEnsembleMannequinSystem(Fig.2)andisbeingbuiltbyateamoforganizations.†In2009whenwebeganthedesignofPetman,therewasnohumanoidrobotintheworldthatcouldmeettherequirementssetoutforthisprogram.PrevioussuittestingrobotssuchasPortonmanfromtheDefenseScienceandTechnologyLaboratoryusedexternalactu-ationorfixturestosupporttherobotduringexercises.Limitationsofthesesystemsincludealimitedrepertoireofbehaviorsorthecompromiseoftheprotectivesuit201242Petman,Humanoid,Mannequin,Dynamic,Pro-tectiveClothing∗78FourthAve.,Waltham,MA,02451USAFig.1ThePetmanrobotwalkingonatreadmillwheretheexternalfixtureattachestotherobot.Otherhumanoidrobotsfromtheresearchcommunityhavedemonstratedimpressivemovementwithoutexternalsupport.PerhapsPetman’snearestneighborsaretheHumanoidRobotProject’sHRPseriesofrobots[1]andthehydraulicallypoweredSarcosPrimushumanoid[2].ThekeychallengesincreatingPetmanweretobuildarobot,withhumananthropometry,thatcouldsimulta-neouslyachievehuman-likestrength,speedandmotion†MRIGlobal,BostonDynamics,MeasurementTechnologyNorthwest,SRD,OakRidgeNationalLab,Smith-Carter&HHI.JRSJVol.30No.4—38—May,2012PETMAN:AHumanoidRobotforTestingChemicalProtectiveClothing373Fig.2TheIndividualProtectiveEnsembleMannequinSystemwillbeusedtotestchemicalprotectiveclothing.ItiscomprisedofthePetmanrobot,theIntelligentSafetyHarness,acontainmentcham-berandwindtunnel,treadmillandturntable,andacontrolstationforpreparingandmonitoringtestswhilewearinghumanclothing,includingfootwear.Petmanachievescompact,highstrengthactuationusinghydraulics.Aninnovativeandtightlyintegratedmechanicaldesignachieveslargerangeofmotionatthejointswhilekeepingallmechanicalandelectricalsys-temswithintheenvelopeofanaveragemalesoldier†.Aflexibletetherthatenterstherobotattheanklesup-plieshydraulicandelectricalpower,cooledwater,andcommunicationswiththerobot.TodatePetmanhasdemonstrateddynamicallybalanced,heel-to-toewalk-ingatarangeofspeedsupto4.8[km/h](3[mph]).Us-ingmotionscriptingsoftwarewehavecreated,therobothasdemonstrated2hourendurancetestsinwhichitperformsprogrammedsequencesofmotionsincludingstand,squat,squatwhileturning,side-stepwitharmsraisedoverhead,andwalk.ThegoalofthisprogramwastodesignanddeliverPetmaninjust3shortyears.Akeychallengefac-inguswastodevelopcontrolsoftwarethatwouldallowabipedalrobottodynamicallybalancewithanatural,human-likegait.InordertomakeprogressonthiswhilePetmanwasbeingdesignedandbuilt,wequicklyde-velopedasimplebiped,calledthePetmanPrototype,earlyintheprogram.2.ThePETProtoRobotThePetmanPrototypebiped(PetProto)wasbuilt†Fig.1showsPetmaninalaboratorytestconfigurationpriortoupperbodyskinintegration.Fig.3PetProtowalkswithanaturalheel-to-toegait.PetProtowasbuiltquicklyusingBigDoghardwareinordertoacceleratecontroldevelopmentfromexistingBigDog[3]hardware.UsingBigDoglegsandelectronicsallowedustobuildthisrobotinfourmonths.PetProtohastwo,fivedegree-of-freedom(DoF)legs:theupper-mostDoFbeingabduc-tion/adductionatthehip,theremainingDoFsnom-inallymovingthelegparalleltothesagittalplane(Fig.3).PetProtoisabout1.5meterstall,withthehipsabout1meterabovetheground.Thehipshavea19[cm]lateralseparation,whichissimilartothatofahuman.WithPetProto,wewereabletodemonstrateady-namic,heel-to-toe,bipedalwalkinggait.Therobot,startingfromastand,wasabletowalkatvaryingspeedsashighas7.2[km/h](4.5[mph]).Bydesign,thecontroloftherobot’scadenceandsteplength,asafunc-tionofwalkingspeed,mimickedthatofahumanofsim-ilarsize.Additionally,theapproximately44[kg]robotwasabletocarryapayloadof40[kg].Whilewalking,itcouldregainitsbalancewhenpushedmoderatelyfromtheside,thoughdisturbancesthatcausedlargecross-overstepsbetweenthelegswerechallenging.PetProtowasalsoabletowalk,withoutcontrolmodifications,withvaryinghumanfootwear(fromslenderclimbingshoes—size10US,withamaximumwidthof9.5[cm]—tolargearmyboots),andwithahydraulictetherattachedtoonelegjustaboveth