Driving Dynamics Modelling with Modelica - … Andreasson, Division of Vehicle Dynamics, KTH Driving DynamicsDriving Dynamics L Vehicle model Hierarchy flange_SW BGR flange_1 flange_3

Johan Andreasson, Division of Vehicle Dynamics, KTH Driving Dynamics

Driving Dynamics Driving Dynamics ModellingModellingwith with ModelicaModelica

Johan Andreasson, Division of Vehicle DynamicsJohan Andreasson, Division of Vehicle DynamicsRoyal Royal InstituteInstitute of Technology, Swedenof Technology, Sweden

Johan Andreasson, Division of Vehicle Dynamics, KTH Driving DynamicsDriving Dynamics

OutlineOutline

• Aim with the Car.mo library• From the top to the bottom!• Library contents• Examples• Related libraries• Future improvments


AimAim with the with the Car.moCar.mo librarylibrary

• Driving Dynamics evaluation– Critical maneouvres– Lateral performance – Longitudinal performance– Comfort– Etc.


From the From the toptop to the to the bottombottom!!

Focus on chassisFocus on chassis


A A carcar modelmodel

driver

power train

chassis trailer

environment


Chassis interfaceChassis interface

steeringflange

bodyframe

drive shafts

Tyre-roadinteraction as a field


Chassis Chassis modelmodel

flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam

front suspension

rear suspension

body

wheels


Suspension InterfaceSuspension Interface

nameleft

MacPherson connectionto body

(steeringflange)

wheelconnectors


Suspension Suspension modelmodel (MacPherson)(MacPherson)

frame_U

_1

fram

e_U

_2

frame_C

L

R

flange_SW

L

f_s=f(s)f_d=f(der(s))

forceTable_1f_s=f(s)

f_d=f(der(s))

forceTableA


forceTable_2

datasuspensionparameters

anti-roll linkage

MacPherson linkages

steering


frame_U

_1

fram

e_U

_2

frame_C

A

AL

f_s=f(s)f _d=f (der(s))

forceTable_1

f _s=f (s)f _d=f (der(s))

forceTable_2

f _s=f (s)f _d=f (der(s))

f orceTableA

data

Suspension Suspension modelmodel (MultiLink4)(MultiLink4)

suspensionparameters

anti-roll linkage

multi-links

struts


LinkageLinkage modelmodel (MacPherson)(MacPherson)

frame_C frame_U

frame_L12


forceTable

r=rCL1_scaled

lower

wish-bone(A-arm)

MacPherson strut


ComponentComponent modelmodel (MacPherson strut)(MacPherson strut)

frame_L1L2

frame_C

r=rUS - rUL1L2

lowerFrameTranslation

fram

e_W

prismatic=rCS - rUSlowerShape

cylinder

upperShape

cylinder

body

Shap

e

box

a b

C

Spherical1

r=rU

W -

rUL1

L2

oute

rFra

meT

rans

latio

n


forceTable

r=rCS

upperFrameTranslation


L

Vehicle model

HierarchyHierarchy


L

Vehicle model

HierarchyHierarchy

flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam

Chassis model


L

Vehicle model

HierarchyHierarchy

flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam

Chassis modelSuspension model

frame_U

_1

fram

e_U

_2

frame_C

L

R

flange_SW

L



f_d=f(der(s))

forceTableA


forceTable_2

data


L

Vehicle model

HierarchyHierarchy

flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam


frame_U

_1

fram

e_U

_2

frame_C

L

R

flange_SW

L



f_d=f(der(s))

forceTableA


forceTable_2

data

Linkage modelframe_C frame_U

frame_L12


forceTable

r=rCL1_scaled

lower


L

Vehicle model

HierarchyHierarchy

flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam


frame_U

_1

fram

e_U

_2

frame_C

L

R

flange_SW

L



f_d=f(der(s))

forceTableA


forceTable_2

data

Linkage modelframe_C frame_U

frame_L12


forceTable

r=rCL1_scaled

lower

frame_L1L2

frame_C

r=rUS - rUL1L2

lowerFrameTranslation

fram

e_W

prismatic=rCS - rUSlowerShape

cylinder

upperShape

cylinder

body

Shap

e

box

a b

C

Spherical1

r=rU

W -

rUL1

L2

oute

rFra

meT

rans

latio

n


forceTable

r=rCS

upperFrameTranslationComponent model


LibraryLibrary contentscontents


LibraryLibrary contentscontents

Vehicle models

Chassis models

Suspension models

Linkage models

Component models

Car.Examples

Car.Chassis

Car.Chassis.Suspensions

Car.Chassis.Components


UsageUsage


UsageUsage –– ExsistingExsisting examplesexamples

Library

Chassis

Library

Wheels

Library

Drivers

Library

Examples

Library

Utilities

Library

Environments


Example

MyCar

Model

UsageUsage –– OwnOwn modelsmodels

Library

Chassis

Library

Wheels

Library

Drivers

Library

Examples

Library

Utilities

Library

Environments


Example

MyCar

Model

UsageUsage –– With With otherother librarieslibraries

Library

Chassis

Library

Wheels

Library

Drivers

Library

Examples

Library

Utilities

Library

Environments

Library

PowerTrain

Library

PowerTrainHevLib

Library

PowerTrain?


ResultsResults??

UsageUsage –– VisualisedVisualised performanceperformance


UsageUsage -- Suspension Suspension mappingmapping


UsageUsage -- Comfort Comfort issuesissues


RelatedRelated librarieslibraries


PlanarMultiBody.moPlanarMultiBody.mo

flange_SW

BGR

flange_2 flange_4

flange_1 flange_3

y

x

y

x

Wheel_1

y

x

y

x

Whe

el_2

y

x

y

x

Wheel_3

y

x

y

x

Whe

el_4

freeMotion

frontSuspension

left

XYSuspension

rearSuspension

left

XYSuspension

twoD

2Thr

eeD

ground

xy

bodyFi

xed1

=0


Forces.moForces.mo

Library

Utilities

a b a b

a b a b a b

ElastoGap

Library

Examples

a b

ElastoGap3D


SummarySummary

– Chassis modelling– Driving dynamics simulation– Interfacing other Modelica libraries


FutureFuture ImprovementsImprovements


EvaluationEvaluation aidsaids

• Related models– Drivers- Automatic test rigs- ...

• Motion constraints– Constant speed maneouvres– Constant radius turns– ...


ExtendedExtended flexibilityflexibility

• With/without bushings• Linear/nonlinear spring-dampers• Swapping tyre models• 1D-2D-3D geometries and combinations



• Different models share same interface.– Model focus/viewpoint can be changed easilly!


flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam

Different Different modelsmodels shareshare same interfacesame interface


flange_SW

BGR

flange_1 flange_3

ground

xy

whe

el_2

wheel_1

wheel_3

whe

el_4

freeMotion

frontSuspension

left

MacPherson

rearSuspension

left

TwistBeam

flange_SW

BGR

flange_2 flange_4

flange_1 flange_3

y

x

y

x

Wheel_1

y

x

y

x

Whe

el_2

y

x

y

x

Wheel_3

y

x

y

x

Whe

el_4

freeMotion

frontSuspension

left

XYSuspension

rearSuspension

left

XYSuspension

twoD

2Thr

eeD

ground

xy

body

Fixe

d1=0

Different Different modelsmodels shareshare same interfacesame interface

planar



• Different models share same interface.– Model focus/viewpoint can be changed easilly!– Higher requirements on interfaces!


SuitableSuitable interfaces?interfaces?

four wheelsteering?

Activesuspension?



• Different models share same interface.– Model focus/viewpoint can be changed easilly!– Higher requirements on interfaces!– Over-all model structure that is suitable!


SuitableSuitable structurestructure

L?

X-by wire? Fuel cell technology?

Vehicle dynamicscontrol systems?

Energy management?



• Different models share same interface.– Model focus/viewpoint can be changed easilly!– Higher requirements on interfaces!– Over-all model structure that is suitable!– Sub-models must know their limitations!


ModelModel limitiationslimitiations!!

-15 -10 -5 0 5 10 15

4

2

0

-2

-4

kN

o

αv

α

y

Magic FormulaLinear model


AcknowledgementsAcknowledgements

• Dynasim AB• DLR


ContactContact

[email protected]

Documents

Driving Dynamics Modelling with Modelica - … Andreasson, Division of Vehicle Dynamics, KTH Driving DynamicsDriving Dynamics L Vehicle model Hierarchy flange_SW BGR flange_1 flange_3