J2264_201401

__________________________________________________________________________________________________________________________________________SAETechnicalStandardsBoardRulesprovidethat:“ThisreportispublishedbySAEtoadvancethestateoftechnicalandengineeringsciences.Theuseofthisreportisentirelyvoluntary,anditsapplicabilityandsuitabilityforanyparticularuse,includinganypatentinfringementarisingtherefrom,isthesoleresponsibilityoftheuser.”SAEreviewseachtechnicalreportatleasteveryfiveyearsatwhichtimeitmayberevised,reaffirmed,stabilized,orcancelled.SAEinvitesyourwrittencommentsandsuggestions.Copyright©2014SAEInternationalAllrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofSAE.TOPLACEADOCUMENTORDER:Tel:[phone](insideUSAandCanada)Tel:[phone](outsideUSA)Fax:[phone]Email:[e-mail]:://°Ftesting,andupdatestodefinitionsandnomenclatureaimedatharmonizingthesequantitiesacrossrelatedSAEdocuments.FOREWORDElectricchassisrolldynamometersprovidethemeansforrapid,accurate,automaticadjustmentofdynamometerloadingtosimulatevehicleroadloadovertheentirespeedrangethroughwhichthevehicleistested.Precisecalibrationofchassisrolltorquemeasurementandspeedinstrumentation,accuratemeasurementofbaseinertia,andcontrolsemployingvalidalgorithmshaveresultedinaccuratedynamometerloadcoefficientmeasurementsusingcoastdowntechniqueswithoutrequiringonerouscomputationanddatamanipulationbyusers.Variabilityofeachdynamometerandbetweendynamometersislow,permittingloadcoefficientsobtainedononedynamometertobeusedonothersimilardynamometers.Toachievethisinterchangeabilityofloadingcoefficients,operationalfactorsarespecifiedwiththeobjectiveofkeepingtestvariabilityatthelowlevelsofthedynamometer.Thisprocedurewasoriginallydevelopedinconjunctionwiththeintroductionofthe1.219m(48in)diametersingle-rollelectricdynamometerforvehicleemissionsandfueleconomytesting,however,themethodologyisgenerictoanydynamometercapableofcarryingouttheroadloadderivationdescribed,regardlessofrollsize,geometry,orrollsurfaceroughnessandisintendedtoprovideastandardofbestpracticeforallvehicletestingrequiringaccurateroadloadsimulation.DownloadedfromSAEInternationalbyBeijingUnivofTechnology,Wednesday,August17,2016SAEINTERNATIONALJ2264RevisedJAN2014Page2of22TABLEOFCONTENTS1.SCOPE..........................................................................................................................................................21.1Purpose.........................................................................................................................................................22.REFERENCES..............................................................................................................................................32.1ApplicableDocuments..................................................................................................................................32.2RelatedPublications.....................................................................................................................................33.DEFINITIONS...............................................................................................................................................44.EQUIPMENT.................................................................................................................................................84.1Dynamometer................................................................................................................................................84.2RestraintSystem...........................................................................................................................................94.3AirCirculation/Cooling...................................................................................................................................95.COASTDOWNCOMPUTATIONS................................................................................................................95.1IntegrationforAnalytically-ObtainedValuesoft.......................................................................................105.2ExampleCalculationSequence..................................................................................................................106.ROADLOADDERIVATIONPROCEDURE................................................................................................136.1Summary........................................................