Real-time brake torque estimation for internal com

MechanicalSystemsandSignalProcessingMechanicalSystemsandSignalProcessing22(2008)338–361Real-timebraketorqueestimationforinternalcombustionenginesJavierFrancoa,,MatthewA.Franchekb,KarolosGrigoriadisbaCumminsInc.,CumminsTechnicalCenter,1900McKinleyAvenue,Columbus,IN,47201,USAbDepartmentofMechanicalEngineering,UniversityofHouston,4800CalhounRoad,Houston,TX,77201,USAReceived30August2006;receivedinrevisedform2August2007;accepted4August2007Availableonline11August2007AbstractPresentedisareal-timeenginebraketorqueestimationmodelwheretheinstantaneousmeasuredenginespeedservesasthemodelinput.Themodeliscomprisedofnotchfiltersexecutedinthecrank-angledomaintoextractmeanenginespeedandthenthfrequencycomponentfromtheinstantaneousenginespeedsignalinreal-time.Herendenotesthenumberofenginecylinders.Moreover,theenginebraketorqueestimationisseparatedintotwoparts:steady-stateandtransient.Itwillbeshownthatthenthharmonic(inunitsofperiodsperenginecycle)ofenginespeedandmeanenginespeedaresufficienttoestimatetheenginebraketorque.Thesteady-stateportionofthemodelisdevelopedusingorthogonalleast-squaresestimationandresultsinamodelwith15regressorsforourparticularcase.Thetransientportionisidentifiedusingatimedomainidentificationmethod.Validationoftheenginebraketorquemodelisprovidedusingacomputationalenginemodelfora6-cylinderheavydutydieselengine.Transientenginespeedandtorqueconditionsinthepresenceofsensornoiseareevaluatedaswellascylinderpowerimbalancescenarios.r2007ElsevierLtd.Allrightsreserved.Keywords:Torqueestimation;Dieselengine;Internalcombustionengine;Crank-domainmodeling1.IntroductionForheavydutyapplications,manualtransmissionshavedominatedthemarketoverautomatictransmissionsduetotheirreliabilityandfueleconomy.However,onemaindrawbackofamanualtransmissionisthedriverinteraction.Today,advancementsinvehicletechnologieshaveenabledtheengineandtransmissiontobeelectronicallycoupledtothechassistherebyimprovingshiftqualityandfueleconomy.Thisworkismotivatedbyanewclassoftransmissionsforheavydutyapplications.Theautomatedmanualtransmission(AMT)automatesthestartingandgearshiftingprocesswhileretainingthehighreliabilityandefficiencyofthetraditionalmanualtransmission.Thegoaloftheautomationprocessistocompletetheshiftinminimaltimewithoutcausingshiftshock.ThusspeedandtorquecoordinationbetweentheengineandAMTisrequired.ARTICLEINPRESS:10.1016/j.ymssp.2007.08.002Correspondingauthor.E-mailaddress:[e-mail](J.Franco).ARTICLEINPRESSNomenclatureApistonpistonsurfacearea(m2)AMTautomatedmanualtransmissionBdviscousdampingvaluefortheharmonicdamper(Nms/rad)B1yB6viscousdampingforbearingandpistonrings(Nms/rad)ECMenginecontrolmoduleFRFfrequencyresponsefunctionG1(f)transferfunctionbetweenTssandTTransH(zy)discretenotchfilterHm(zy)cascadingdiscretenotchfilterIMEPindicatedmeaneffectivepressureJdequivalentinertiaofthedamperhousing(kgm2)Jfequivalentinertiaofthefloatinginertia(kgm2)Jfwequivalentinertiaoftheflywheel(kgm2)Jgequivalentinertiaofthegear-train(kgm2)Jtottotalinertiaincludingcrankshaftandreciprocatingassembly(kgm2)J1yJ6equivalentinertiaofeachcrankelement(kgm2)Kgspringstiffnessbetweenthedamperhousingandthegear-train(Nm/rad)Kg1springstiffnessbetweenthegear-trainandfirstelement(Nm/rad)K12springstiffnessbetweenthefirstandsecondelement(Nm/rad)K23Springstiffnessbetweenthesecondandthirdelement(Nm/rad)K34springstiffnessbetweenthethirdandfourthelement(Nm/rad)K45springstiffnessbetweenthefourthandfifthelement(Nm/rad)K56springstiffnessbetweenthefifthandsixthelement(Nm/rad)Kfwspringstiffnessbetweenthesixthelementandtheflywheel(Nm/rad)KmnotchfiltergainMmolecularweightofthegas(kmol)Meqequivalentmassofreciprocatingassembly(kg)M6amplitudeofthesixthcomponentoftheenginespeedsignal(rpm)M06M6compensatedduetochangesininertia.Mn6normalizationfactorforM6(rpm)Nmeanenginespeed(rpm)N*normalizationfactorforenginespeed(rpm)nnumberofcylindersN(n)symbolicindexN0(n)symbolicindexatidleconditionsOEMoriginalequipmentmanufacturerQnnetheatrelease(J)RPMrevolutionsperminuteTftorqueduetofrictionandpumpinglosses(Nm)Tinertiainertialtorque(Nm)Timindicatedtorqueforthemthcylinder(Nm)TLloadtorque(Nm)TEstimateLoadfinalloadtorqueestimate(Nm)¯Tlaverageengineload(Nm)T0mmasstorqueforatwolumpedmassmodel(Nm)Trmreciprocatingintertiatorqueforthemthcylinder(Nm)Tratedengineratedtorque(Nm)Tsssteady-statetorqueestimate(Nm)Ttranstransienttorqueestimate(Nm)J.Francoetal./MechanicalSystemsandSignalProcessing22(2008)338–361339Agearshiftconsistsofthreephases:(1)torquecontrolphase,(2)speedsynchronizationphase,and(3)torquetrackingphase(Fig.1)[1].Duringthetorquecontrolphase,theengineiscontrolleduntilzerobraketorqueisachieved.Onceachieved,theneutralgearisengageddecouplingtheenginefromthetransmission.Duringthedecoupledstagetheenginespeedissynchronizedtothetransmissionspeedwiththeproperconversionratioofthenewgear.OnceARTICLEINPRESSTDCtopdeadcenterVcylindervolume(m3)acrankradius(m)fkfunctionforthecrank-slidermechanismfssamplingfrequency(peri