Road loads prediction using LMS CDTire - LMS International

LMS CDTire applications (2005 software)Application areas:! Durability and reliability,! Ride comfort,! Handling (in special cases).Type of tires:! Radial [and diagonal]! Passenger cars, light trucks, vans, heavy on-road trucks.Limitations:! No large deformation of belt (belt → rim)! No motorcycle & scooter tires! “Smooth” tread (no lugs)© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 3

Digital Test Track: the main inputsRoad surfaceDriver modelVehicle modelTire© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 4

Digital Test Track: beyond “MBS handling models”Vehicle model! Rotating wheels! (Simple) powertrain for transientsRoad surface! Height = f(x,y)for different proving ground events,or public roads)! Slip/friction coefficientsTire model! Tire design (nominal geometry,stiffness, profile, ...)! Inflation pressure! Dynamics (speed-dependentdamping, ...)! ImbalanceDriver model! Path following© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 5

LMS Comfort and Durability Tire – Model Family OverviewCDTire 20! Rigid ring model! Long wavelength surfacesCDTire 30! Single flexible ring model! Short wavelength surfaces,lateral height profile constantppCDTire 40! Multiple flexible rings! Suited for• irregular road surfaceslike “Belgian Block” or• cleats with variable heightor arbitrary positionppRimRimppSubmodels can be switched online© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 6

Correct Simulation of Contact in Tire Patch2 separate contact areasCorrect Correct contact contact pressure pressure distribution distribution = correct correct spindle spindle forces forces and and moments moments© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 7

Application: Honda rear suspension test rigPublished as JSAE paper 20055277by H. Haga (in Japanese)• 2 Drums at same speed• Different cleats on the drum(s)• Full rear suspension (2 wheels)• Fixed at body attachment points• Measured forces and displacements• Multi body simulation with LMS DADS© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 8

Rear Suspension,Tire Parameters! Tire: Bridgestone 195/65 R15! Tests for parameter identification:! Performed by Bridgestone! With “Tire on Drum” type of setup! Parameter Identification! Performed by LMS with first (experimental) version ofLMS CDTire Parameter Identification software! Independent validation performed by Honda, Bridgestoneand LMS after the parameter identification© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 9

Rear suspension,Cleat Height 46mm (1)46 10 km/h Left46 10 km/h Right3.03.0Longitudinal Force, N2.01.00.0FX_MEASFX_SIM-1.00.0 0.1 0.2 0.3Time, sLongitudinal Force, N2.01.00.0FX_MEASFX_SIM-1.00.0 0.1 0.2 0.3Time, s46 mm! h = 46 mm! v = 10 km/h! both cleats in synch46 10 km/h Left46 10 km/h Right5.04.05.04.0MeasurementVertical Force, N3.02.01.0FZ_MEASFZ_SIMVertical Force, N3.02.01.0FZ_MEASFZ_SIMSimulation0.00.0 0.1 0.2 0.3Time, s0.00.0 0.1 0.2 0.3Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 10

Rear Suspension,Cleat Height 46mm (2)46 20 km/h Left46 20 km/h RightLongitudinal Force, N3.02.01.00.0FX_MEAS-1.0FX_SIM-2.00.0 0.1 0.2Time, sLongitudinal Force, N3.02.01.00.0FX_MEAS-1.0FX_SIM-2.00.0 0.1 0.2Time, s46 mm! h = 46 mm! v = 20 km/h! both cleats in synch46 20 km/h Left46 20 km/h Right5.04.05.04.0MeasurementVertical Force, N3.02.01.0FZ_MEASVertical Force, N3.02.01.0FZ_MEASSimulation0.0FZ_SIM0.0FZ_SIM-1.00.0 0.1 0.2Time, s-1.00.0 0.1 0.2Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 11

Rear Suspension,Cleat Height 36mm36 40 km/h Left36 40 km/h RightLongitudinal Force, N3.02.01.00.0FX_MEAS-1.0FX_SIM-2.00 0.05 0.1 0.15Time, sLongitudinal Force, N3.02.01.00.0FX_MEAS-1.0FX_SIM-2.00 0.05 0.1 0.15Time, s! h = 36 mm! v = 40 km/h! both cleatsin synch36 mm36 40 km/h Left36 40 km/h Right6.05.06.05.0MeasurementVertical Force, N4.03.02.0FZ_MEASVertical Force, N4.03.02.0FZ_MEASSimulation1.0FZ_SIM1.0FZ_SIM0.00 0.05 0.1 0.15Time, s0.00 0.05 0.1 0.15Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 12

Rear Suspension,Cleat Height 26mm26 40 km/h Left26 40 km/h RightLongitudinal Force, N2.01.51.00.50.0FX_MEAS-0.5FX_SIM-1.00 0.05 0.1 0.15Time, sLongitudinal Force, N2.01.51.00.50.0FX_MEAS-0.5FX_SIM-1.00 0.05 0.1 0.15Time, s! h = 26 mm! v = 10 km/h! both cleatsin synch26 mm26 40 km/h Left26 40 km/h RightVertical Force, N5.04.03.02.01.0FZ_MEASFZ_SIMVertical Force, N5.04.03.02.01.0FZ_MEASFZ_SIMMeasurementSimulation0.00 0.05 0.1 0.15Time, s0.00 0.05 0.1 0.15Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 13

Rear Suspension,Cleat: Semicircle 5mm0.5R5 40 km/h Left0.5R5 40 km/h Right5 mmLongitudinal Force, N0.30.0-0.3FX_MEASFX_SIM-0.50 0.05 0.1Time, sLongitudinal Force, N0.30.0-0.3FX_MEASFX_SIM-0.50 0.05 0.1Time, s! r = 5 mm! v = 20 km/h! both cleats in synchR5 40 km/h LeftR5 40 km/h Right3.03.0MeasurementVertical Force, N2.82.52.3FZ_MEASFZ_SIMVertical Force, N2.82.52.3FZ_MEASFZ_SIMSimulation2.00 0.05 0.1Time, s2.00 0.05 0.1Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 14

3D Cleat PassingF zzyxω Drumω Tire© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 15

3D cleat passing: case 1F zVertical Force, N80002.3 kN7000600050000.0 0.1 0.2 0.3Time, sMeasurementSimulation! Cleat:! Height: 10mm! Width: 25mm! Preload: 5.9 kN! Speed: 80 km/hF xLongitudinal Force, N200010002.2 kNMeasurementSimulation0.8 kN100050000-1000-500Lateral Force, NMeasurementSimulationF y-20000.0 0.1 0.2 0.3Time, s-10000.0 0.1 0.2 0.3Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 16

3D cleat passing: case 2F zVertical Force, N3.4 kN7000MeasurementSimulation600050004000300020000.0 0.1 0.2 0.3Time, s! Cleat:! Height: 10mm! Width: 25mm! Preload: 3.9 kN! Speed: 80 km/hF xLongitudinal Force, N10005000-50010001.6 kN MeasurementSimulation0.7 kNLateral Force, N5000-500MeasurementSimulationF y-10000.0 0.1 0.2 0.3Time, s-10000.0 0.1 0.2 0.3Time, s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 17

Sneak preview of SAE 2006 paper by Honda (H. Haga)LongitudinalForce at Front W heelM easurem entSimulationforce18 18.5 19 19.5 20! Full vehicle simulation! Using LMS Virtual.Lab and LMS CDTire! Curb height: 120 mm! Speed: approx. 20 km/h! Paper to be published at SAE WorldCongress, April 2006, Detroit! Related paper at JSAE Fall 2006forcetime (s)V erticalForce at Front W heelM easurem entSimulation18 18.5 19 19.5 20tim e (s)© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 18

Road Surfaces: Random and ParametricAlso available with Virtual.Labfor TNO TyreRandom surface! Grid size: 5mm * 5mm! Required for Belgian block, pave, etc.Parametric surface! Manual editing to include artificial obstacles! Used for curbstone crossing, twist ditch, etc.DaimlerChryslerVolkswagenBoth Both approaches can can be be combined in in a single single LMS LMS Road Road Surface Model Model© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 19

Features of Digital Road Surface Model (DRSM)! Model: z = f( x, y )! Typically delivered on grids with! 5mm by 5mm and! 10mm by 10mmhorizontal grid spacing! 5mm by 5mm: excellent accuracy for all durability events (e.g. curbs)© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 20

DRSM Process Overview: Patch Level and Global Level! Test track is split into “patches”4.0 – 4.5 m 2 m“Patch”Patch 4! Bulk of measurement is performed onpatch level with “Miniature ProjectionTechnique”! Patches are joined on global levelPatch 3Patch 2Patch 1© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 21

Measurement on Patch Level:Miniature Projection Technique (MPT)ProjectorCamera! Patented technology! Better accuracy than “pure”photogrammetry! System consists of projector andcamera! Multiple patterns are projectedfrom the same position onto thesame object! Pure measurement time perpatch: 45 – 60 s© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 22

Global Level: Joining the Patches! MPT: height inside of patch! Global level: correct “rigid body” position of patch! Patches are joined based on! Markers – separate “conventional surveying” process! Information from overlap areas! Preserves long wavelength content! prevents “drift”Overlap! Model: global x-y coordinate systemfor whole proving ground(up to 20 km by 20 km)© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 23

Benefits of LMS Digital Road Surface Model! Short wavelength features preserved: Good accuracy at impact events (curbs, potholes)! Long wavelength structure preserved: Good 0 – 25 Hz accuracy for handling, ride comfortand durability! High lateral resolution: High accuracy for lateral forces due to ruts, etc! Full track width: Assessment of repeatability enabled! Grey scale road texture: Helps defining friction values! Minimal blocking of proving ground for measurement! Long-term archiving Additional ASCII files for software independence© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 24

Road surface visualization! Standalone road surfaceviewer! Fixed (coarse) resolutionroad surface +vehicle animationworks todayin Virtual.Lab and MSC.ADAMS(see PSA animation earlier)! Dynamic (LOD) resolutionroad surface + vehicleplanned for animationsin Virtual.Lab© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 25

Identification of tire parametersLMS CDTire Parameter Identification! Software tool! For tire manufacturers, test houses,…“Finished” parameters available from! major tire manufacturers! LMS! [soon] others© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 26

LMS CDTire UsersSoftware! approx. 50 end users since 2002at:! Automotive OEMs• 6 in Europe• 4 in Japan! 4 Truck manufacturersProving ground modelsCustomers:! Germany: 4! Europe: (4 + ) 3! Japan: 4Repeat business2 customers! 3 Tire manufacturers! Consulting companies, labs, …Length:! Most longer than 1 km! Some 3 to 4 km range© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 27

The LMS CDTire team! Algorithms and software! Axel Gallrein! Andreas Janocha! & Virtual.Lab Motion team! Ride comfort applications! Valerio Cibrario! Paola Diglio! Ivan Bosmans! ….! Tire parameter identification! Riccardo Moeller! Road surface measurement & modeling! Thomas Langthaler! Others! Durability applications! Manfred Baecker! Riccardo Moeller! Thomas Langthaler! Reinhold Carmine! …! Product management and marketing! Hans van den Wijngaert! Volker Koettgen! Support! Team in Japan! Team in Kaiserslautern, Germany© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 28

One complete packageSoftwareParameters and modelspp! All submodels! CDT20! CDT30! CDT40! Software for! Tire! Road surface! 1 set of tire parameters! 1 road surface modelppRimRimpp! in! Virtual.Lab! MSC.ADAMS© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 29

LMS CDTire applications (Outlook for 2006/2007)Application areas:! Durability and reliability,! Ride comfort,! Handling (in special cases).Type of tires:! Radial [and diagonal]! Passenger cars, light trucks, vans, heavy on-road trucks.2006/07Limitations:! No large deformation of belt (belt → rim)! No motorcycle & scooter tires! “Smooth” tread (no lugs)© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 30

© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 3115 cm

LMS CDTire for large deformation (“misuse”) applicationsNew ElementsSide Wall HeightDistancemm?%?! Extension of CDTire! Validation program with major automotive OEM in 2006! Large set of physical tests planned (tire and full vehicle)! Availability to other users in 2007© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 32

LMS CDTire for motorcyclesProject withYamaha Motorsto developCDTire 40 formotorcycle tires© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 33

LMS CDTire for multi body simulation of motorcyclesCurrentCurrentofferingofferingforforCarCarandandTruckTruckLMS CDTire 20! Rigid ring model! Long wavelength surfaces! HandlingOfferingOfferingforforMotorcycleMotorcycle(2006/07)(2006/07)TNO Tyre for Motorcycle! Empirical model! HandlingppLMS CDTire 30! Single flexible ring model! Short wavelength surfaces,lateral height profile constant! Ride comfort! DurabilityppRimRimppLMS CDTire 40! Multiple flexible rings! Suited for• irregular road surfaceslike “Belgian Block” or• cleats with variable heightor arbitrary position! DurabilityLMS CDTire 40 for MC! Multiple flexible rings! Suited for• irregular road surfaceslike “Belgian Block” or• cleats with variable heightor arbitrary position! DurabilitySubmodelsSubmodelscancanbebeswitchedswitchedonlineonline© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 34

Relaxation length: Example of physical modeling in CDTireLMS CDTire! Physical model! Many feature direct outcome of physics,e.g. relaxation length (→ mass effect)ExampleSlip angleKinematical setupLateral forceresponse! Spindle fixed vertically! Constant velocity (30 km/h)! Camber angle 0°! 10° slip angle stepRelaxationlength > 0© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 35

Trucks! Cooperation with 2 major truck manufacturers! Cooperation with Fraunhofer LBF for tire testing! Tire parameter identification by LMS! Several truck manufacturers are already running simulationswith up to 30 tires on a vehicle© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 36

CDTire for virtual test rigs! Test rig designs! 4 poster (only vertical)! MAST under each wheel (6 degrees of freedom per wheel)! Flat tracks on MAST (rotating wheels on 1 to 6 DOF tables)! LMS Hybrid Road! Prediction of road loads based on predecessor vehicle! Objective! Determine road loads faster and cheaper as with proving ground testing! LMS CDTire will support separate MAST under each wheel by end of 2006© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 37

Hybrid road with CDTire: Chassis loads (longitudinal dynamics)Spindle force F x(rear left): range pairsPhysical test: sedan22%Physical tests: vans26%Accumulated damage100%Hybrid Road simulation: van! Base model: sedan, 5 seats! Variant: van, 7 seats! Physical validation tests with the van were performed as 4 separate repeats (shown)Difference between Hybrid Road simulation and average of 4 physical tests was26% in pseudo damage, or 5% in load amplitude!© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 38

Hybrid road with CDTire: Chassis loads (vertical dynamics)Spindle force F z(rear left): range pairsPhysical test: sedanHybrid Roadsimulation: vanAccumulated damage16%18%Physical tests: vans100%Same case as before.Now looking at vertical rather than longitudinal forces.Difference between Hybrid Road simulation and average of 4 physical tests was16% in pseudo damage, or 3.5% in load amplitude!© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 39

ConclusionsPassenger cars, SUVs, light trucks! At leading automotive manufactures, CDTire has become part of the standarddurability engineering process – after years of evaluations and process adaptations! CDTire is also used at many automotive manufacturers for ride comfort assessment! “Misuse” simulation is coming up!Trucks! CDTire works as is, but process integration will take some timeVirtual test rigs! CDTire is the key element for improving accuracy for longitudinal forcesMotorcycles! The all new CDT40-based model will give capabilities that the motorcycle communityhas asked for since a long time© LMS International 2006 – LMS Conference Europe 2006 ― CDTire 40

Thank you© LMS International 2006 – LMS Conference Europe 2006