1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 14512:1999 ICS 43.
2、100 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Passenger cars Straight-ahead braking on surfaces with split coefficient of friction Open-loop test methodThis British Standard, having been prepared under the direction of the Engineering Sector Committee, was published unde
3、r the authority of the Standards Committee and comes into effect on 15 February 2000 BSI 02-2000 ISBN 0 580 35812 7 BS ISO 14512:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO 14512:1999 and implements it as the UK nati
4、onal standard. The UK participation in its preparation was entrusted to Technical Committee AUE/15, Safety related to vehicles, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or p
5、roposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement in
6、ternational publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all t
7、he necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title
8、page, pages ii to iv, pages 1 to 11 and back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.A Referencenumbe r ISO14512:1999(E) INTERNATIONAL STANDARD ISO 14512 Firstedition 19991215 PassengercarsStraightaheadbraking onsurfaceswithsplitcoeffici
9、entof frictionOpenlooptestmethod VoituresparticuliresFreinageenlignedroitesursurfacecoefficients dadhrencediffrentsMthodedessaienboucleouverteISO14512:1999(E) ii Contents 1Scop e1 2Normativereference s1 3Terms,definitionsandsymbol s.1 4Principl e2 5Apparatu s.3 6Parameterstobedetermine d.3 7Testcond
10、ition s4 8Testmethod 5 9Dataevaluatio n6 10Testrepor t8 AnnexA (normative) TestreportGeneraldat a9 AnnexB (normative) Presentationofresult s.11 ISO14512:1999(E) iii Foreword ISO (the InternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).Thework
11、ofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaisonwithISO,alsotakepartinthew
12、ork.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtoth ememberb
13、odiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. InternationalStandardISO 14512waspreparedbyTechnicalCommitteeISO/TC 22, Roadvehicles ,Subcommittee SC9, Vehicledynamicsandroadholdingability . AnnexesAandBformanormativepartofthisInternatio
14、nalStandard.ISO14512:1999(E) iv Introduction Thedynamicbehaviourofaroadvehicleisamostimportantaspectofactivevehiclesafety.Anygivenvehicle, togetherwithitsdriverandtheprevailingenvironment,constitutes aclosedloop systemwhichisunique.Thetask ofevaluatingthedynamicbehaviouristhereforeverydifficult,sinc
15、esignificantinteractio nofthesedrivervehicle roadelementsareeachcomplexinthemselves.Adescriptionofthebehaviouro ftheroadvehiclemustinevitably involveinformationobtainedfromanumberoftestsofdifferenttypes. Since this testmethodquantifiesonlyonesmallpartofthecompletehandlingcharacteristics,theresultsof
16、thistest canonlybeconsideredsignificantforacorrespondinglysmallpartoftheoveralldynamicbehaviour. Moreover,insufficientknowledgeisavailabletocorrelat eoverallvehicledynamicpropertieswithaccident prevention.A largeamountofworkisnecessarytoacquiresufficientandreliabledataonthecorrelationbetween acciden
17、tpreventionandvehicledynamicpropertiesingeneralandtheresultsofthistestinparticular. Therefore,it isnotpossibletousethismethodandtestresultsforregulationpurposes.INTERNATIONALSTANDARD ISO14512:1999(E) 1 PassengercarsStraightaheadbrakingonsurfaceswithsplit coefficientoffrictionOpenlooptestmethod 1Scop
18、e ThisInternationalStandarddescribesanopenlooptestmethodfordeterminingvehiclereactionsduringastraight linebrakingmanoeuvreonasurfacehavingasplitcoefficientoffriction. ItappliestopassengercarsasdefinedinISO3833. ThemethodisvalidforallbrakingeffortsuptofullABSoperatio n for vehicles so equipped, or ju
19、st up to the locking limitofthewheelsonthehighfrictionsurfaceforvehicleswithoutABS. 2Normativereferences The following normative documents contain provisions which,throughreferenceinthistext,constituteprovisionsofthis InternationalStandard.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyo
20、 f these publications do notapply.However,partiestoagreementsbasedonthisInternationalStandar dareencouragedtoinvestigatethe possibilityofapplyingthemostrecenteditionsofth enormativedocumentsindicatedbelow.Forundatedreferences, thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIE
21、Cmaintainregistersof currentlyvalidInternationalStandards. ISO611:1994, RoadvehiclesBrakingofautomotivevehiclesandtheirtrailersVocabulary . ISO1176:1990, RoadvehiclesMassesVocabularyandcodes . ISO3833:1977, RoadvehiclesTypesTermsanddefinitions . ISO8855:1991, RoadvehiclesVehicledynamicsandroadholdin
22、gabilityVocabulary . ISO150371:1998, RoadvehiclesVehicledynamicstestmethodsPart1:Generalconditionsforpassenger cars. 3Terms,definitionsandsymbols 3.1Termsanddefinitions ForthepurposesofthisInternationalStandard,thetermsanddefinitionsgiveninISO611andISO8855apply. 3.2Symbols ForthepurposesofthisIntern
23、ationalStandard,thesymbolsgiveninTable1apply.ISO14512:1999(E) 2 Table1Symbolsforparameters Symbol Parameter a X Longitudinalacceleration a Y Lateralacceleration F p Brakepedalforce a M H Steeringwheeltorque p B Pressureatmastercylinderoutput b s B Brakingdistance v X Longitudinalvelocity v Y Lateral
24、velocity b Sideslipangle d H Steeringwheelangle a y Yawangle y or d dt y Yawvelocity yor d dt 2 2 y Yawacceleration w 1 , w 2 , w 3 , w 4 Wheelrotationspeed a Controlparametersofhandlingmanoeuvre. b Vehiclereaction(see9.2.1) 4Principle The objective of thistestmethodistodeterminetheeffectsoncourseho
25、ldinganddirectionalbehaviourofavehicle producedbyabrakingmanoeuvreonastraightawayhavingalowcoefficientoffrictionononeside. Testresultsarestronglyinfluencedbyfrictioncoefficientsaswellasth edifferenceinfrictionbetweentheleftand rightsideofthecourse.Othertesttracksurfac echaracteristics(roughness,iceo
26、rsyntheticmaterials);whichare notquantifiedbythefrictioncoefficientalone,exertanimportantinfluenceo nthetestresults.Forthisreason,itis notpossibletodescribethesurfaceconditionsinareproducibleway.Alargedifferenceintheleftandrightside frictionconditionsisdesirableandaninterpretationofthetestresultsiso
27、nlyusefuli na comparison,forinstance witha“referencevehicle“usedinthesametest. Theinitialconditionforthetestisdrivinginastraightlineatconstantvelocity.Thepositiono f the steering wheel and acceleratorareheldassteadyaspossibleintheinitialstate.Th e steering wheel continues to be held fixed after the
28、brakingmanoeuvreisinitiated.Duringthetest,theoperatingfunctionsandvehicleresponses aremeasuredand recorded.Characteristicvaluesaredeterminedfromthemeasuredsignals. Thevariablesofmotionusedtodescribetheeffecto fbrakingoncourseholdinganddirectionalbehaviourofthe vehiclerelatetotheintermediateaxissyste
29、m X, Y, Z(seeISO8855). Thelocationoftheor iginoftheveh icleaxissystem(X V , Y V , Z V ),beingthereferencepoint,isindependentofthe loadingcondition.Itisfixedinthelongitudinalplaneofsymmetrya thalfwheelbaseandatthesameheightabove thegroundasthecentreofgravityofthevehicleatcompletevehiclekerbmass(seeIS
30、O1176). ISO14512:1999(E) 3 5Apparatus Themeasuringequipment,thetransducerinstallationandthedataprocessingshallbeinaccordancewith ISO150371. 6Parameterstobedetermined TheparametersthatshallbedeterminedforcompliancewiththisInternationalStandardaswellasparameters whicharerecommendedtobedeterminedaregiv
31、eninTabl e 2.Typicaloperatingrangesoftheparameterstobe determinedforthisInternationalStandardareshowninTabl e3.Foroperatingrangesforthedeterminationof parametersnotgiveninTable3,seeISO150371. Table2Parameterstobedetermined Parameter Required Recommended Longitudinalvelocity X Yawvelocity X Brakepeda
32、lactuation X Brakepedalforce a X Pressureatmastercylinderoutput a X Steeringwheelangle X Longitudinalacceleration X Lateralacceleration X Brakingdistance X Lateralvelocity X Sideslipangle X Yawangle X Steeringwheeltorque X Wheelrotationspeed X a Oneortheothershallbedetermined . Table3Typicaloperatin
33、grangesandrecommendedmaximumerrors Parameter Typicaloperatingrange Recommendedmaximumerrors ofthecombinedtransducerand recordersystem Steeringwheelangle -180to +180 1 Lateralacceleration -10m/s 2 to +10m/s 2 0,1m/s 2 Longitudinalacceleration -10m/s 2 to +10m/s 2 0,1m/s 2 Brakepressure 0kPato25 000kP
34、a(0barto250bar) 200kPa( 2bar) Brakepedalforce 0Nto2 000N 20N Brakingdistance 0mto200m 1m Rotationalvelocityofwheels 0s -1 to20s -1 0,2s -1 Steeringwheeltorque -20Nmto +20Nm 0,1Nm Brakepedalactuation Forinstance,astoplightswitchifmechanically actuatedbyabrakepedal. Transducersformeasuringsomeofthelis
35、tedvariablesarenotwidelyavailableandarenotingeneraluse. Manysuch instrumentsaredevelopedbyusers.Ifanysyste merrorexceedsthereco mmendedmaximumvalues,thisan dtheactual maximumerrorshallbestatedinthetestreport(seegeneraldata,annexA).ISO14512:1999(E) 4 7Testconditions 7.1General Limitsandspecifications
36、fortheambientandvehicletestconditionsestablishedin7.2to7.4shallbemaintained duringthetest.Anydeviationsshallbeshowninth etestreport(seeannex A)includingtheindividualdiagramsof thepresentationofresults(seeannexB). NOTE Theambienttemperaturemayinfluenceboththeroadfrictionandthetyrecharacteristics.Ther
37、eforethetests shouldbecarriedoutunderstableambienttemperatureconditions. Comparativestudiesshallbeconductedonsurfaceswiththesam efrictioncoefficient.Itisrecommendedtocarry outreferencemeasurementswithasecondvehicle. Thecoefficientsoffrictionhaveaverylargeinfluenceonmeasuringresults.Sincethecoefficie
38、ntsoffriction, especiallyonnaturalicesurfaces,canchangeconsiderablywithinashorttime(temperature,insulation,humidity, polishingeffectetc.),itisrecommendedtoregularlycheckthecoefficientsoffriction. OnepossiblewayofdetectingchangesincoefficientsoffrictionistoperformanABScontrolle d braking manoeuvre wi
39、thareferencevehicleandtocomparethedecelerationvalues.Togetagoodrepeatabilitythespeedshal lnot exceed50km/h. 7.2Testtrack Alltestsshallbecarriedoutonalevel,clean,uniformhardsurface.Theslopeshallnotexceed2, 5 %lengthwise and1%across.Thedifferenceincoefficientoffriction, m,betweenhigh mandlow mshouldbe
40、atleast0,5. Fortesttracksurfaceshavingalowcoefficientoffriction, m,polishedartificialandnaturalice,or lubricantwetted plasticsheeting,basalt,marble,stainlesssteelandothersurfaceswithcoefficientsoffrictionsimilartoice,are recommended.However,itisnecessarytotakeintoaccountthatthesesubstitutematerialsm
41、ayhaveaslip characteristicwhichdiffersfromthatofnaturalice. Ifalubricantisused,itshallbeevenlyredistributedaftereverytestrun. Thelow msectionshouldbeatleast5 0 mlongandsufficientlywid e to enable undisturbed measurement recording, even if large yaw angles occur, as wellasthedeterminingofareferenceco
42、efficientoffriction(forinstance,byABS brakingmanoeuvres)withall4wheels(onlow m).Thisreferencecoefficientoffrictiononly approximates the actual coefficientoffrictionandisdependentonqualityoftheABScontrol. Ashigh m surfaceadryroadtoppingofasphalt,concreteorsomeothersurfacehavingahighcoefficientoffrict
43、ion andsufficientwidthisrecommended.Ifalubricantisused,wettingofthehigh msurfaceshallbeavoided.If necessary,itshallberegularlycleaned. 7.3Windvelocity Thewindvelocityshallnotexceed5m/sandshallberecordedinthetestreport(annexA). 7.4Testvehicle 7.4.1Tyres ThetyreconditionsshallbeinaccordancewithISO150371:1998,5.4.2. 7.4.2Operatingcomponents OperatingcomponentsshallbeasspecifiedinISO150371:1998,5.4.3. 7.4.3 Brakesystemanddrivetrain Forstandardtestconditions,adjustmentandconditionofthe drivetra in(espec iallythed ifferentials,c lutches, lock
