Validation of ADAMSCar simulations and dynamic per

EXAMENSARBETE2005:069CIVMASTEROFSCIENCEPROGRAMMELuleåUniversityofTechnologyDepartmentofAppliedPhysicsandMechanicalEngineeringDivisionofComputerAidedDesign2005:069CIV•ISSN:1402-1617•ISRN:LTU-EX--05/69--SEValidationofADMS/Carsimulationsanddynamicperformanceinmulti-linksuspensionsMikaelNybackaEXAMENSARBETEValidationofADAMS/Carsimulationsanddynamicperformanceinmulti-linksuspensionsMikaelNybackaLuleºaUniversityofTechnologyDepartmentofAppliedPhysicsandMechanicalEngineeringDivisionofComputerAidedDesign2005-02-18iiABSTRACTDuetothehighcostsofdevelopingnewchassisandsuspensions,itisinterestingtoreducethecostswithtimee±cientMBA(MultibodySystemAnalysis)programslikeADAMS,DADS,Mechanica,etc.Inordertoreducedevelopingtime,hencecosts,thesimulationshavetobeasclosetherealityaspossible.Togetthere,students,thefutureinmechanicalengineering,havetolearnaboutconcurrentengineering,modeling,simulationanddistributedengineering.Moreover,thesisworkandresearchhavetobecarriedoutevenfurtherinthisareato¯ndnewapproachesandincreasetheknowledge.Thisthesisdesigns,simulatesandveri¯esthroughvehicletestinganewsuspensionforaracecar,whichimprovestheentryandexitintoturnswhilereducingundersteer.Toolstoenhancetheacceleration,analyzecontrolsystemsandbuildroaddata¯lesarepresentedinthisthesisforengineersandstudentsofthefuture.iiiivPREFACEThisreportisaresultofmythesisworktowardstheMasterofSciencedegreeinme-chanicalengineering,withaspecializationinComputerAidedEngineering.ThemasterthesishasbeenconductedattheDivisionofComputerAidedDesign,LuleºaUniversityofTechnology,duringthesecondhalfoftheyear2004.ThereportiswrittenwiththehelpofLATEX[1][2].ThisthesisworkhasgivenmeextensiveknowledgeaboutMBA1andhowitcouldbeim-plementedtothedevelopmentprocessinagoodway.Ithasalsoexpandedmyknowledgeofautomotiveengineering,especiallytheareaofautomotiveelectronics.JanvanDeventer,supervisoratLuleºaUniversityofTechnology-Iwanttothankyoufortheunquestionablehelpduringthewholethesiswork.Regardingelectronicsystemsandallthehelparoundthethesiswork.TobiasLarsson,examinatorandsupervisoratLuleºaUniversityofTechnology-Iwanttothankyouforyourfullsupportduringtheholethesiswork.RegardingADAMSsimu-lationsandallthehelparoundthethesiswork.HºakanFredriksson,studentLuleºaUniversityofTechnology-Thankyouforallthehelpwithmountingsensorsandreprogrammingthedatasystemofthecar.LLT,Localbusscompany-Forlendingthebussgaragetotestdrivein.IalsowanttothankmyfellowstudentsoftheformulaSAE2team2004and2005,fortheirassistancewiththeformulaSAEcar.LastbutnotleastIwanttothankmygirlfriend,familyandfriendsforbeingsosupportiveduringtheentirethesiswork.1MultibodySystemAnalysis2SocietyofAutomotiveEngineersvviCONTENTSChapter1:Introduction31.1Background..................................31.2Purpose....................................4Chapter2:Theory52.1Vehicledynamicexpressions.........................52.2Generalstatements..............................82.3Theoryandfactsaboutthenewsuspension................9Chapter3:Work153.1Buildingthemodel..............................153.2Reallifetesting................................183.3Preparatorywork...............................20Chapter4:Results23Chapter5:Discussionandconclusion255.1Results.....................................255.2Errorestimation...............................27Chapter6:Futurework296.1Electronicsandsystems...........................296.2Vehicledynamics...............................306.3Research....................................31AppendixA:AddedchassiscodeandTorsenpropertyfile33AppendixB:Results35AppendixC:Acquisitionprograminmatlabcode39AppendixD:Akimasplineandturboboostrepresentation41CHAPTER1IntroductionHowneartherealitycanyoucomewithADAMS/Carsimulations?Thatisonequestionamongothersthatispresentedinthisthesis.1.1BackgroundWithtoday'scomputersoftwareandhardwareitmightseemquitesimpletomodelandsimulateafullvehicleinthecomputer,however,howmuchreliancedoyouhaveintheresults?Istheresultreliableenoughsothatyoucanbuildyourcontrolsystembaseduponit?Thesearequestionsthathavetobeansweredandevaluatedbeforewecancontinuetheworkincon¯dencewiththesoftwaretools.Withthehelpofcar's,onboardmeasuringequipmentanddataloggingunitonecanperformvalidationsofsimulationprogramsversusreallifetesting.TheGPS1datafromthedataloggingcanbeusedtomodelreallifetracksliketesttracksorcircuits.Today'sautomotiveindustries,applyingmorecontrolsystemsonthecar'sinordertomakethemsaferandmorecomfortable.However,inordertomakethemevenmoresafeandcomfortableandinashorterdevelopingtime,thesystemshavetobeanalyzedanddesignedusingbothcontrolsystemdesignandMBA2software.1GlobalPositioningSystem2MultibodySystemAnalysis31.2PurposeThisthesisprojectoriginatedfromLuleºaUniversityofTechnology'sparticipationintheFormulaStudentcompetitioninBruntingthorpe,UnitedKingdom,2004.FormulaSAEstartedintheUSAintheearly80iesasancompetitionforstudentstocompeteinengineeringanddesign.Todaythecompetitionisglobalandeveryyearhundredsofuniversitiesenterinoneormoreofthethree¯nalsheldinAustralia,UnitedKingdomandUSA.Inordertoplacethecaratthetopinthe2005co