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1、NonlinearDynamics(2005)40:21–34cSpringer2005FuzzyLogicControlofSeatVibrationsofaNon-LinearFullVehicleModelRAHMIGUCLUFacultyofMechanicalEngineering,YildizTechnicalUniversity,Besiktas,Istanbul,Turkey(e-mail:guclu@yildiz.edu.tr;fax:+90-212-2616659)(Received:12January2003;accepted:9September2004)Abstract.Inthispaper,thedynamicbehaviorofanon-lineareightdegreesoffreedomvehiclemodelhavingactivesuspensionsandafuzzylogic(FL)controlledpassengerseatisexamined.Thenon-linearityoccursduetodryfrictionontheda。
2、mpers.Threecasesofcontrolstrategiesaretakenintoaccount.Inthefirstcase,onlythepassengerseatiscontrolled.Inthesecondcase,onlythevehiclebodyiscontrolled.Inthethirdcase,boththevehiclebodyandthepassengerseatarefullycontrolledatthesametime.Thetimeresponsesofthenon-linearvehiclemodelduetoroaddisturbanceandthefrequencyresponsesareobtainedforeachcontrolstrategy.Attheend,theperformancesofthesestrategiesarecompared.Keywords:activesuspensions,FLcontrol,non-linearsystems,vehiclevibrationsNomenclaturea,b=dista。
3、ncesofaxletothecenterofgravityofthevehiclebodyc,d=distancesofunsprungmassestothecenterofgravityoftheaxlese,f=distancesofpassengerseattothecenterofgravityofthevehiclebodycsi=ithdampingcoefficientofsuspensioncs5=dampingcoefficientofpassengerseatf(Vri)=ithdryfrictionforceksi=ithspringconstantofsuspensionks5=springconstantofpassengerseatkti=ithstiffnesscoefficientoftiremi=ithmassofaxlem5=massofthepassengerxi=ithstatevariablezi(t)=ithroadexcitationIx7=massmomentofinertiaofthevehiclebodyforpitchmotionIx8。
4、=massmomentofinertiaofthevehiclebodyforrollmotionM=massofthevehiclebody1.IntroductionVehiclesuspensionservesthebasicfunctionofisolatingpassengersandthechassisfromtherough-nessoftheroadtoprovideamorecomfortableride.Duetodevelopmentsinthecontroltechnol-ogy,electronicallycontrolledsuspensionshavegainedmoreinterest.Thesesuspensionshaveactivecomponentscontrolledbyamicroprocessor.Byusingthisarrangement,significantachievementsinvehicleresponsecanbecarriedout.Selectionofthecontrolmethodisalsoimportantdur。
5、ingthedesignprocess.Inthisstudy,fuzzylogic(FL)controllersparalleltoMcPhersonstrut-typeinde-pendentsuspensionsareused.Themajoradvantagesofthiscontrolmethodareitssuccessandthe22R.Gucluabilityofusingthesetypesofcontrollersonvehicles.Tosimplifymodels,anumberofresearchersassumedvehiclemodelstobelinear.However,suchmodelscontainnon-linearitiesthatshouldbetakenintoaccount.Byincludingnon-linearitiessuchasdryfrictionondampers,theresultsbecomemorerealistic.Inthelastdecademanyresearchersappliedsomelinearand。
6、non-linearcontrolmethodstovehiclemodels.Becauseofsimplicity,quartercarmodelsweremostlypreferred.RedfieldandKarnopp[1]examinedtheoptimalperformancecomparisonsofvariablecomponentsuspensionsonaquartercarmodel.Yueetal.[2]appliedlinearquadraticregulator(LQR)andlinearquadraticGaussian(LQG)controllertoaquartercarmodel.LQRisalinearoptimalfullstatefeedbackcontrolmethodwiththeobjectiveofminimizingthequadraticperformanceindex.Alinearquadraticregulatorproblemissolvedwhichassumesthatallstatesareavailableforfe。
7、edback.However,thisisnotalwaysapplicablebecauseeitheritisnotpossibletosenseallthestatesorthemeasurementisverynoisy.AKalmanfiltercanbedesignedtoestimatetheunmeasuredstates.ThecombinationoftheLQRcontrollerandKalmanfilteriscalledalinearquadraticGaussiancontroller.LQGislessrobustthanaLQR.Therefore,LQGhasnoguaranteedstabilitymargins,buthasabetternoisesuppression.SteinandBallo[3]designedadriver’sseatforoff-roadvehicleswithactivesuspensions.Hac[4]appliedoptimallinearpreviewcontrolontheactivesuspensionsof。
8、aquartercarmodel.Rakhejaetal.[5]addedapassengerseatintheiranalysis.Apassengerseatsuspensionsystemwasdescribedbyageneralizedtwodegreesoffreedommodelandwithnon-linearitiessuchasshockabsorberdamp-ing,linkagefrictionandbumpstops.Sincethequartercarmodelisinsufficienttogiveinformationabouttheangularmotionsofavehicle,someresearchersusedmorecomplexmodelslikehalfandfullcarmodels.Thesemodelsgiveinformationaboutthepitch,rollandbouncemotionsofavehiclebody.CrollaandAbdelHady[6]comparedsomeactivesuspensioncont。
9、rollawsonafullcarmodel.Integratedorfilteredwhitenoisewastakenastheroadinput.Thesameresearchersappliedlinearoptimalcontrollawtoasimilarmodelin1992.Hrovat[7]comparedtheperformancesofactiveandpassivesuspensionsystemsonquarter,halfandfullcarmodelsusinglinearquadraticoptimalcon-trol.Dryfrictionondampersisoneofthemainfactorsaffectingridecomfort.Ongoodroadsurfacesandatlowvehiclespeeds,theeffectofroadinputcannotovercomedryfrictionforceand,there-fore,thesuspensionsarealmostlocked,whichisknownasBoulevardJe。
10、rk,andanuncomfortablevibrationmodebecomeseffectiveduetoreduceddegreesoffreedom[8].Someapplicationsusingnon-linearityonactivesuspensionswereachieved.Alleyneetal.[9]comparedslidingmodecon-trolledactivesuspensionswithPIDcontrolledactivesuspensionsforaquartercaractivesuspensionsystem.PIDcontrolisappliedasaconventionalmethod.Sincethiscontrolmethodcanbeappliedeasilyandwidelywellknown,ithasanimportantroleincontrolapplications.But,thismethodisnotinsensitivetoparameterchanges.Sincemodelsmighthaveuncertain。
本文标题:汽车论文翻译
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