车辆系统动力学外文论文课件Design of an Optimal Fuzzy Controller

WelcometoMyPresentationJacky20101108DesignofanOptimalFuzzyControllerforAntilockBrakingSystemsAuthor：AhmadMirzaei,MehdiMoallem,SeniorMember,IEEE,BehzadMirzaeianDehkordi,andB.Fahimi,SeniorMember,IEEEJournal：IEEETRANSACTIONSONVEHICULARTECHNOLOGY,VOL.55,NO.6,NOVEMBER2006Preview：TheReasonforABSBrakingforcelessthanvvv-v=vWheelslipandwheeldecelerationWheelwilllockupLateralstabilityWheeltraceforceVehiclestabilityVehiclesteerabilityPassengersafetyStoppingdistance•ABSmustprovidethebrakingforce（thevalueoftheλthatgivesthepeakvalueofμ）toavoidlockup,providingadequatevehiclestability,steerability,andpassengersafetyandreducingvehiclestoppingdistance.Coefficientoffrictionµversuswheelslipλ0.000.200.400.600.801.001.2000.20.40.60.81WheelSlipCoefficientoffriction（µ）LateralLongitudinalBestareaforbraking•Maintainingadequatevehiclestability&steerability•Reducingthevehiclestoppingdistance•IncreasingwheeltractionforceinthedesireddirectionTheFunctionofABSMaximumdecelerationLateralstability•Uptonow,variouscontroltechniquesthatmaintainthewheelsliptoadesiredlevelhavebeendeveloped.•SomeoftheapproachesthatwereproposedinthedesignofABScontrollerconsistofslidingmode,fuzzy,fuzzy-neural,fuzzy-slidingmode,andfuzzy-neuralslidingmode.CurrentSituationofABSMainGoalofthisPaperAnoptimalfuzzycontrollerisproposedforABS.HydraulicsystemBrakesystemVehicledynamicSensors（）wvV&aOptimalfuzzycontrollerBlockdiagramoftheproposedABS.•Theinputvariablestothecontrollerarewheelspeedandvehicleacceleration.•AlltheparametersofmembershipfunctionsandrulesofthefuzzysystemthatareTakagi–Sugeno–Kang(TSK)typeareoptimizedusinggeneticalgorithms•Inordertoobtaintheoptimumvalueinashortertimeandwiderregion,theerror-basedoptimizationapproachisused.•Suspensionandsteeringsystemdynamicsarenotconsidered.RequiresofthecontrollerRotationaldynamicsofі-thwheelJwω˙wi=Tei−Tbisign(ωwi)+RwFti−Twi−BwωwiVehicleDynamicsLinearvehicledynamics4.tii=1MVFF•Theenginetorqueattheithwheelisassumedtobezeroduringbraking,andthemomentofinertiaofrotatingpartsreferredatthewheelisconsideredtobeconstant.•TorqueduetowheelfrictionTwandforceduetovehiclefrictionFvaredescribedasfollows:Twi=RwBrNviFv=Fa+BrNv•TiretractionforceisafunctionofnormalforceFt=μNvBrakeHydraulicSystemDynamicsHydraulicsystemdynamicsfortheithwheelcylindercanbemodeledasfollows:12fbi1dipbi2dibilow22CP=ACP-P-ACP-P（）（）ThecoefficientsCd1iandCd2iarethecontrolinputs,whichcantakethevalues0or1,dependingonthecorrespondingvalvebeingopenorclosed.Cfisthecoefficientoftheflowandthetimederivativefunctionofhydraulicpressure.•TheTSKfuzzysystemisconstructedbythefollowingrulesDesigningFuzzyController11:,...,,lllnnRifxisBxisBthen011...llllnnyCCxCxwheretheBliisarefuzzysets,l=1,2,...,M,andtheCliisareconstants.Givenaninputx=(x1,...,xn)T∈U⊂Rn,theoutputf(x)∈V⊂RoftheTSKfuzzysystemiscomputedastheweightedaverageoftheyls()liiBx1111()()()nMlliilinMliiliyBxfxBxWhereisthevalueofthemembershipfunctionoftheithinputforantecedentofthelthrule.Fuzzyrulesiswrittensothatthewheelslipforanyroadismaintainedatthevalueofslipthatgivesthepeakvalueofthelongitudinalcoefficientoffrictionandmaximizesvehicledeceleration.Inordertoachievethebestgoal,afuzzycontrollerisdesignedwiththreeinputs:slipλ,differenceofslipdλ,anddifferenceofaccelerationdav,withsevenfuzzyrules.TheoutputofthecontrollersetsthebrakepressureInaddition,theparametersoftheconsequencesofrules,forachromosome,areobtainedusingaparallelgeneticalgorithmbyoptimizingthefollowingobjectivefunctionλopt(t)istheoptimalwheelslipunderdifferentroadconditions,andtsimisthesimulationtimeforobtainingthecomponentsofthefuzzysystem.20(())[()()]simtobjopttFttt•Theperformanceoftheproposedcontrolleristestedonthevehiclemodelwitheffectofdynamicloadtransferfromthereartothefrontaxle,withthehydraulicbrakesystem,fordifferentroadconditions.•Itisassumedthatthevehicleismovingat30m/s.Theroadsurfacechangesfromdryasphalttoicyasphaltafter30mandthenchangesfromicyasphalttodryasphaltafter30m.SimulationResultsPlotsofroadconditions,vehicleandwheelspeeds,wheelslip,braketorque,andvehiclepositionwithoutversuswiththehybridcontrollerHybridcontroller.PIcontrollerFuzzylogiccontrollerItisassumedthatthevehicleismovingat30m/sandiceisonbetween14and26mofthedryasphaltroad.ThevibrationsaremuchlessthanthatofthefuzzylogicandPIcontroller,sothevehiclehasadequatelateralstabilityandgoodsteerability.Inthecaseoftheproposedcontrollercomparedtofuzzy-logicandPIcontroller,theslipiskeptatverysmallvalueatslowvehiclespeedsothatthevehiclehasadequatelateralstabilityandgoodsteerability.•Inthispaper,anoptimizedfuzzycontrollerisproposedforABS.•Theinputvariablestothecontrollerarewheelspeedandvehicleacceleration.•Simulationresultsshowverygoodperformanceofthecontrollerfordifferentroadconditions.Conclusion