International Automotive Congress 2009 · - scope: vehicle level, system level, component level ......

© ika 2009 · All rights reserved13/14 September 20099hr0120.pptx Slide No. 1

Institut für Kraftfahrzeuge

RWTH Aachen University

Standardised Determination of Comparable Parameters

for Vehicle

Shenyang, 13/14. September 2009

Univ.-Prof. Dr.-Ing. Stefan Gies

International Automotive Congress 2009


Contents

• Overview about vehicle benchmarking at ika

• Chassis benchmarking

• Further Steps

• Conclusion


Vehicle Benchmarking at ika

• Conduct comparable vehicle and component analyses- different vehicles and customers- scope: vehicle level, system level, component level

• Prerequisite for comparability: standardised analysisstandardised processes and parameters

• Installation of a vehicle properties data poolpossibility for the comparison of vehicle data

• Assessment of different engineering fields- body- driveline- electrics/electronics - chassis


Vehicle Benchmarking at ika

Core Competencies

prototyping

testingdefinition phase

studies & concepts

design

analysis of production costs

structural analysis

crash analysis

development of component tests

full vehicle crash tests

numerical

optimisation

market investigations

technology rating

simulation-based

concept definition

realisation of meas-

ures for pedestrian

protection

functional benchmarking

dimensioning

Analysis and Concept

Development of Body

Structures


Body Benchmarking

Overview: Analyses and Parameters

• Design benchmarking (DBM)

- determination of mass, dimensions, sheet thickness etc.

- determination of manufacturing and joining technologies etc.

• Functional benchmarking (FBM)

- determination of torsion and bending stiffnesses of bodies-in-white

- determination of global and local stiffnesses and strengths of

body components

- analysis of crash behaviour

(deformation, energy absorption, force-travel-characteristic)

455

735

1059

800816

840

1084


Body Benchmarking

Example: Torsional Stiffness

tors

ion

ala

ngle


Driveline Benchmarking


• Measurement of tractive resistances

- What is the vehicle’s power demand?

- How are the resistance components distributed?

- Are there any abnormal effects in contrast to competitors?

• Efficiency measurement of driveline components

- Which energy efficiency characteristic can be shown for the

driveline components?

- How is the distribution of the driveline losses on different

driveline components?

- How does the driveline efficiency compare to the competition?

0

20

40

60

80

100

120

0 20 40 60 80 100 120 140

time [s]

ve

loc

ity

[k

ph

]

V BMW [kph]

V VW [kph]

V Honda [kph]


Driveline Benchmarking

Example: Wheel Hub Benchmarking

• Measurement and Benchmarking

- Wheel hub losses

- Residual braking torque

- Influence on fuel consumption

Restbremsmoment

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200 1400 1600

Raddrehzahl [U/min]

Ve

rlu

stl

eis

tun

g [

kW

]

0

0.132

0.264

0.396

0.528

0.66

0.792

0.924

1.056

Kra

fts

toff

ve

rbra

uc

h [

l/h

]

Maximum

Minimum

Radlager

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 200 400 600 800 1000 1200 1400 1600

Raddrehzahl [U/min]

Ve

rlu

stl

eis

tun

g [

kW

]

0.000

0.026

0.053

0.079

0.106

0.132

0.158

0.185

0.211

0.238

0.264K

raft

sto

ffv

erb

rau

ch

[l/h

]Maximum

Minimum

wheel hub

po

wer

los

s [

kW

]

po

wer

los

s [

kW

]

fue

l co

ns

um

pti

on

[l/

h]

fue

l co

ns

um

pti

on

[l/

h]

residual braking torque

wheel speed [U/min] wheel speed [U/min]


Electrics/Electronics Benchmarking


• Electric Power Network Analysis

Powernet-Profiling© : Analysis of various power network properties

- Energy storage

- Energy generation

- Cable tree safeguarding

- Energy distribution and monitoring

• Electronic Architecture Analysis

- Electronic systems and control units

- System architectures

- Data buses (FlexRay, CAN, LIN, MOST, etc.):

Realization, Bus Type, Bus Loads, Sleep and wakeup procedures


Electrics/Electronics Benchmarking

Example: Electric Power Steering (EPS)

7.5 10 12.5 15 17.5t [s]

9

10

11

12

13

14

15

U [

V]

Battery Voltage

• Parking manoeuver with EPS (Imax 80A)

• Voltage drops with Umax 1.5V


Chassis Benchmarking


• Determination of inertia parametersmass, centre of gravity (CoG) position, mass moments of inertia (MoI)

• Suspension analysisK&C test rigSuspension design benchmarking

• Vehicle dynamics analysisvehicle dynamics characteristics (understeer gradient, roll gradient etc.)comfort characteristics (defined test surface, body acceleration / K-value)

• Tyre properties analysisdetermination of tyre parameters (MF-Tyre, Ftire, etc.)measurement of rolling resistance

• Determination of damper propertiesfor conventional and adaptive / semi-active dampers



Determination of Inertia Parameters

• Measurement of vehicle overall mass

in defined loading condition

• Center of gravity (CoG) position

in x, y and z axis

• Mass moments of inertia (MoI)

in x, y and z axis

• Employment of VIMM test bench

Vehicle Inertia Measurement Machine

1 – vehicle platform

2 – base

3 – hydraulic actuators

1

2

3



Suspension Function Analysis

• K&C test rig

- kinematics and compliance analysis

- toe and camber angle characteristics

- vertical spring characteristics

- roll spring characteristics

- roll centre height front and rear

- influence of longitudinal and lateral force

Spur über Radhub VA

-0,6

-0,4

-0,2

0,0

0,2

0,4

0,6

0,8

-120,0 -100,0 -80,0 -60,0 -40,0 -20,0 0,0 20,0 40,0 60,0 80,0

Sz [mm]

Sp

ur

[°]

Spur VA

Sturz über Radhubweg VA

-1,0

-0,5

0,0

0,5

1,0

1,5

-120,0 -100,0 -80,0 -60,0 -40,0 -20,0 0,0 20,0 40,0 60,0 80,0

Sz [mm]

Stu

rz [

°]

Sturz VA



Suspension Design Analysis

• Suspension design properties

- axle/suspension type

- spring and damper type

- types of control arms and bushings

(material, weights, measures)

- measurement of hard points



Vehicle Dynamics Analysis

• Instrumenting of the vehicle

strap down platform, velocity sensor,

steering robot, data acquisition

• Execution of track testing

standard manoeuvres

lateral and vertical dynamics

subjective assessment

• Vehicle dynamics characteristics

understeer gradient, roll gradient, etc.

• Comfort characteristics

body accelerations, K-value (VDI 2057)

• Acquisition of measurement data

for validation of simulation models



Tyre Properties Analysis

• Determination of tyre properties

execution of tyre measurements

• Fitting of tyre models

- MF-Tyre (vehicle dynamics, horizontal)

- Ftire (comfort / vertical dynamics)

• Rolling resistance measurement

determination of tyre rolling resistance

• Possible perspective:

Build-up of tire data pool

use of tyre parameter data for

vehicle dynamics simulation



Determination of Damper Properties

• Analysis of shock absorbers

on a servo-hydraulic test bench

• Determination of damper characteristics

- passive shock absorbers

- variable shock absorbers (e.g., CDC)



Example: Subjective Assessment

• Vertical Dynamics

4.6 Fahrkomfort

6,44

9,00

6,44

8,00

7,00

6,22

6,67

6,33

0

2

4

6

8

10

4.6.1 Federungskomfort

4.6.2 Schluckvermögen

4.6.3 Kanten-

empfindlichkeit

4.6.4 Anfedern / Kopieren

4.6.5 Aufbaudämpfung

4.6.6 Abrollkomfort

4.6.7 Lenkungs-

flattern / Unwucht-

empfindlichkeit

4.6.8 Lenkungsstößigkeit

Shimmy

tyre comfort

body damping

copiing

edge sensitivity

absorptiveness

vertical comfort

steering joltiness



Further Steps

• Standardised process of vehicle model generation and validation

Hard Points Tyre PropertiesCoG / MoI K&C

Damper

Properties

Vehicle

DynamicValidated full vehicle simulation model


Conclusion

• Standardised analysis of vehicles

- Top-down analysis from vehicle level over system level to the

component level

- Usage of standardised processes and evaluation of standardised

parameters results in comparability of different vehicle

• Data pool of all measured vehicles

- Information about the spreading of paramaters for the measured

vehicles (possibly seperated into the vehicle segments)

• Chassis benchmarking supplies required data for simulation

model generation

- Pool of validated simulation models for further simulative

investigations


Contact

Phone +49 241 80 25601

Fax +49 241 80 22147

Email [email protected]

Internet www.ika.rwth-aachen.de

Institut für Kraftfahrzeuge

RWTH Aachen University

Steinbachstraße 7

52074 Aachen

Germany

Univ.-Prof. Dr.-Ing. Stefan Gies

International Automotive Congress 2009 · - scope: vehicle level, system level, component level ......

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