AVL List GmbH (Headquarters)

Frontloaded e-AWD development

with automated system

optimizationEAWD19 - Electrification and All-wheel Drive Congress

Graz / Spielberg May 9. – 10. 5. 2019

Joachim ECKER

Mario OSWALD

Market Situation & ChallengeElectric vehicles worldwide sales

Source: https://about.bnef.com/blog/cumulative-global-ev-sales-hit-4-million/https://www.best-selling-cars.com/global/2018-full-year-international-worldwide-car-sales-and-global-market-analysis/

Performance

Efficiency

Offroad

capability

Driveability

Vehicle Dynamics

& Stability

NVH

1. Customer demands on electric vehicleWhich are the main electrification related vehicle attributes

Customer requirements

2. Electric vehicle development requirementsThe customer defines the main requirements

High acceleration level and vmax

High range, short charging time

High pulling force,

big ground clearance

Jerkless

accelerating

High cornering ability & traction

Low interior noise level

Vehicledevelopment requirements

3. Electric Vehicle SpecificationThe vehicle requirements set the vehicle specifications

Low vehicle mass,

high motor power

High battery capacity

Off-road tire,

high ride height

Driveability Calibration

Performance tire,

low ride height

Insulation measures

Vehiclespecification

Customer’s demands

Vehicle requirements

4. Powertrain System RequirementsThe vehicle specification set the powertrain requirements

Powertrain topology

E Machine type

Control strategy

Torque filter definition

Gear ratio

E machines power

& torque

Powertrainrequirements

Customer’s demands

Vehicle requirements

Vehicle specification

Syste

m level

Veh

icle

level

4. Powertrain System requirementsGoal of frontloaded development is to gain powertrain requirements

Customer Requirement Specification

Virtual Concept DefinitionProcess

Benchmarking:

• Competitive analysis

• Highlights & weaknesses

• Deep dive

Vehicles:

• Tesla Model X

• Jaguar I Pace

Vehicle Simulation

• Vehicle simulation and virtual calibration

• Simultaneous vehicle attribute assessment

Improvements

• Long. torque split

• Torque vectoring

• Slip control

• Regenerative braking

• Efficiency strategy

Output:E-AWD Powertrain according customer’s demands

Benchmarking Target Setting Simulation Improvements

Target Setting

Translating customers vision into technical requirements:

• Performance

• Efficiency

• Handling

• AWD / Off-road

• Driveability

Definition of E-AWD vehicle

attributes

AVL VSM

AVL-DRIVE

PERFORMANCE EFFICIENCY CONTROL SYSTEMOFF-ROAD / AWD

3

4

5

6

7

8

9

10

0-100[s]

max.Accerelation

[m/s²]

max.Speed[kph]

Range[km]

Real Worlddriving

consumption[kWh/100km]

ChargingEfficiency

[%]

Gradeability dirt[%]

Control qualityHDC[DR]

Pulling Forcegravel

[N]

Brake in a turn[DR]

Acceleration µ-split

[m/s²]

TorqueInterventionCornering

[DR]

Att

ribute

Rating

[DR] … AVL-DRIVE Rating

Benchmarking on Vehicle level

516

3.6

245

467

92

85

55

30.6

8.5

5)* no f unction available

12150

14920

4.8

2007.21

21.2

8

8.5

8

3.6

3.3

50

The I-Pace outperforms the Tesla in Offroad capability

Tesla: Very good slip control conservative in stability interventions

Jaguar: Very harmonic control systemTesla Model X outstanding performance

The Model X is the more efficient vehicle in terms of consumption and charging

5

8.8

PERFORMANCE EFFICIENCY CONTROL SYSTEMOFF-ROAD / AWD

3

4

5

6

7

8

9

10

0-100[s]

max.Accerelation

[m/s²]

max.Speed[kph]

Range[km]

Real Worlddriving

consumption[kWh/100km]

ChargingEfficiency

[%]

Gradeabilitydirt[%]

Control qualityHDC[DR]

Pulling Forcegravel

[N]

Brake in a turn[DR]

Acceleration µ-split

[m/s²]

TorqueInterventionCornering

[DR]

Att

ribute

Rating

[DR] … AVL-DRIVE Rating

BenchmarkingOffroad / AWD

8.5

5)* no f unction available

What causes the results and what are findings for the target

setting?

Let’s have a deeper look

Excellent performance level

Very good wheel slip control

Limited off-road capability

Inert on-road agility

Very restrictive cornering stability control

Very balanced over all attributes

Good total control system characteristic

Satisfying off-road capability (HDC, Hill hold)

Good on road handling balance

Model X

I pace

E-AWD related vehicle criteriaBenchmark Vehicles Overview

E-AWD related criteria

3

4

5

6

7

8

9

10

Pullin

g F

orc

e g

ravel

[N]

Gra

dabilty

dirt

[%]

Low

speed

Contr

ola

bility [

DR

]

Accle

ration level µ-

split

[m/s

²]

Decele

ration µ

-split

[m/s

²]

avera

ge w

heel slip

level µ-l

ow

launch [

%]

Unders

teer

[DR

]

Bra

ke in a

Turn

Sta

bilty

[D

R]

Max.

late

ral

Accele

ration [

m/s

²]

Turn

In A

gility ]

DR]

Att

ribute

Rating

What are the right system elements?

E/E components Inverter

Charger

TyreOff-road capability

Resistance / Grip

AerodynamicsDrag

Rideheight

BodyWeight

Geometry

Electric machines Induction / PSM type

Power

Powertrain Controls

E-AWD torque split

Slip control

Regenerative braking

Operation strategy

Battery Cell technology

Capacity

Size and weight

Voltage

Performance

High Moderate

Engaging Relaxed

Handling

High Low

Energy Efficiency

Translating customers vision into technical requirements down to a very detailed level

Competitor vehicles

High Low

Further attributes:

NVH, Driveability

Vehicle positioning

new e-AWD vehicle

Control System

Among the best Average

Offroade-AWD

Among the best Average

Objective targets upper target band

Objective targets minimum target band

Off-road capability:

Acceptable allover off-road capability

Good low speed controllability

Very good µ-split acceleration level

Performance

Performance level close to Model X

Very good overall traction

Handling

Low understeer

Good oversteer stability

Acceptable turning agilty

Target SettingE-AWD related vehicle criteria

3

4

5

6

7

8

9

10

Pullin

g F

orc

e g

ravel

[N]

Gra

dabilty

dirt

[%]

Low

speed

Contr

ola

bility [

DR]

Accle

ration level µ-

split

[m/s

²]

Decele

ration µ

-split

[m/s

²]

avera

ge w

heel slip

level µ-l

ow

launch

[%]

Unders

teer

[DR]

Bra

ke in a

Turn

Sta

bilty

[D

R]

Max. la

tera

lAccele

ration [

m/s

²]

Turn

In A

gility ]

DR]

Att

ribute

Rating

Set Up of Virtual Calibration Toolchain

Automatized Optimization Toolchain

AVL Cameo:DOE approachcalibration parameter variation

AVL VSM:Vehicle dynamic simulation +e-AWD controller model embedded

AVL-DRIVE™:Objective evaluation of driving attributes

E-AWD Functions

Function Torque split Slip ControlTorque vectoring

Mechanical equivalent

Center Differential E-LSD(electronic-limited slip differential)

TV-Differential

Description

Torque split between front and rear axle to maximize

traction and vehicle dynamics

Axle / wheel selective torque reduction in case of the spinning

wheels

Torque split between left and right side to generate

a yaw moment

E-AWD Functions Definition

Virtual Calibration and Optimization

AWD CONTROLS parameter

variation

SIMULATION vehicle, driver, road

SPECIFIC MANEUVERS

Traction, Gradeability, Pulling force

ATTRIBUTES ASSESSMENT

Offroad, Handling, Performance, WLTP

Optimization

Capability of vehicle dynamic calibration

Obj. Evaluation

DoE variation

Simulation

Benchmarking & competitor analysis Optimized AWD characteristic

DoE-based calibrationclosed- loop optimization

Target definition by KPIs Optimized AWD function parameter-set

Methodology for DOE optimization of AWD to achieve targets

Target Area

18% gradient µ-split

KPI Target value

max. long acc. > n [m/s²]

wheel slip level n-nn [%]

….

Optimization Result Video e-AWD

AVL VSM

Optimization Result Video Torque Vectoring – ISO T2 Lane Change

AVL VSM

Optimized results:

Target band could be met for all criteria

Very good on road handling due to torque vectoring

Good Performance due to low vehicle weight

Results of automated optimization E-AWD related vehicle criteria

3

4

5

6

7

8

9

10Pullin

g F

orc

e g

ravel

[N]

Gra

dabilty

dirt

[%]

Low

speed

Contr

ola

bility [

DR]

Accle

ration level µ-

split

[m/s

²]

Decele

ration µ

-split

[m/s

²]

avera

ge w

heel slip

level µ-l

ow

launch

[%]

Unders

teer

[DR]

Bra

ke in a

Turn

Sta

bilty

[D

R]

Max. la

tera

lAccele

ration [

m/s

²]

Turn

In A

gility ]

DR]

Att

ribute

Rating

Optimization Result Video Nürburgring Nordschleife

AVL VSM

www.avl.com

Thank You