getrag driveline systems gmbhgetrag driveline systems gmbh vehicle dynamics expo 2005 “seven at...

> Seven at ONE blow <

GETRAG Driveline Systems GmbH

Vehicle Dynamics Expo 2005“Seven at ONE blow”

Michael HoeckManager Vehicle Dynamics

> Seven at ONE blow <17-May-05Dateiname

> Content <

• Introduction• Modular PTU• Control Strategy• Vehicle Instrumentation• Test Track• Test Programme• Vehicle Test Results

• Low-µ• High-µ

• How much Improvement does each System deliver?• Outlook


> Introduction <

Why Mini ?FWD with East-West EngineCooper S stands for „Freude am Fahren“ (Fun to drive)More power than suitable for FWD ( >160 HP )No AWD availablePackage VERY tight = 4WD Version is challengingBenchmark for Vehicle DynamicsObjective comparison of different driveline configurations in one vehicle

Influence on tractionInfluence on vehicle dynamicsHow much improvement does each system deliver?


> State of the Art Hang On East West Engine <> Modular PTU <

Hypoid Gear Set /„Power-Take-off Unit“ (PTU)

Hang-On-Coupling

PropshaftPTU with integratedCoupling


> Modular PTU <

PTUPTU

Hang-On & TRACKSTER TWINSTERHang-On Permanent AWD& TRACKSTER Front & Centre*

*no hardware available yet


> 7 Driveline Concepts in ONE Vehicle <

By the modular PTU the following driveline concepts can be investigated in ONE vehicle:

1. FWD2. FWD with TRACKSTER (electronic controlled front axle differential)3. RWD4. AWD (primarily FWD with hang on coupling to rear axle)5. AWD (hang on coupling to rear axle and TRACKSTER)6. AWD (primarily RWD with hang on coupling to front axle) 7. TWINSTER (primarily RWD with TWIN couplings to front axle (Active Yaw))


> Control Strategy <

• Bicycle Model • Calculation of theo. Yaw Speed• Comparison to Vehicle Yaw Speed• Coupling Selection• Coupling Activation

Lat.

Acc

elera

tion

Stee

ring

Angle

Thro

ttle P

os.

Engin

e To

rque

Whe

el sp

eeds

Long

. Acc

elera

tion

Yaw

Spee

d

TCS

Activ

e

ABS

Activ

e

ESP

Activ

e

ASR

Activ

e

Slip

Control

Lateral Dynamics

Control

Brak

e Ac

tive

Hand

brak

e Ac

tive

Longitudinal Dynamics

Control

CAN Bus Input Signals

Smart Actuator

Right Coupling

Smart Actuator

Left Coupling


> Vehicle Instrumentation <

DGPS Base Station

System Accuracy for Position: +/- 0.2 m

DGPS Sensor


> Test Track Low-µ <

Handling

Circular Track

Workshop

µ-split Hill

µ-Split Straight Line


> Test Track High-µ <

Vehicle Dynamics Area, Diameter: 300 mWet Handling Track, Length: 1.1 km


> Test Programme <

Coupling compatibility to other control systems

• Braking on • µ-high• µ-low• µ-split• µ-transition• Checkerboard

• Acceleration on• µ-split

• Lane Change with DSTC

Lateral dynamics

• Circle test• Steady state• Throttle off• Acceleration• Braking

• Lane Change • Slalom• Steer Step• Handling

Durability• Load cycle measurement

• Test track• Public roads

Traction and functionality

• Acceleration on• µ-high• µ-low• µ-split• µ-sprung• Checkerboard• µ-split grade


> Test Results on Low-µ <

Traction• Acceleration on

• Snow• Ice• Split-µ

Lateral Dynamics• Wide Open Throttle from Steady State Cornering

• Influence of Torque Distribution Control on Lateral Dynamics


> Test Procedure Straight Line Acceleration <

• Test procedure (closed loop test)

• The vehicle is accelerated straight line from still standing to max. speed

• The drivers target is to accelerate in a manner that bestacceleration behaviour is achieved

• Torque steering is compensated by counter steering


> Straight Line Acceleration on different Surfaces <

0,00

0,50

1,00

1,50

2,00

2,50

3,00

Acc

eler

atio

n m

/s²

Snow Ice µ-split

FWD

RWD

FWD&DSC

FWD&TRACKSTER

AWD Hang On

AWD Hang On&TRACKSTER

TWINSTER


> Test Procedure WOT from Steady State Cornering <

• Testprocedure (open loop test)

• Surface: packed snow

• The vehicle is accelerated up to 50 km/h steady state corneringspeed

• After reaching steady state speed a full throttle manoeuvre is done

• The driver does not change steering wheel and throttle position


> Wide Open Throttle from Steady State Cornering on Low-µ <

-100

-80

-60

-40

-20

0

20

40

60

80

100

120

140

m/s

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100Deg

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°/s

0

50

100

150

200

250

300

350

400

450

500%

0

50

100

150

200

250

300

350

400

450

500%

3.5 4.0 4.5 5.0 5.5 6.0 6.5

s

FWD

Yaw Speed decrease because of:• reduced sideforce capability on front wheels


-100

-80

-60

-40

-20

0

20

40

60

80

100

120

140

m/s

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100Deg

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°/s

0

50

100

150

200

250

300

350

400

450

500%

0

50

100

150

200

250

300

350

400

450

500%

7.0 7.5 8.0 8.5 9.0 9.5 10.0

s

RWD

Yaw Speed increase because of:• reduced sideforce capability on rear wheels




-100

-80

-60

-40

-20

0

20

40

60

80

100

120

140

m/s

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100Deg

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°/s

0

50

100

150

200

250

300

350

400

450

500%

0

50

100

150

200

250

300

350

400

450

500%

7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0

s

AWD Hang on to Rear

Slight Yaw Speed decrease because of:• controlled sideforce reduction on front wheels



TWINSTER

-100

-80

-60

-40

-20

0

20

40

60

80

100

120

140

m/s

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100Deg

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°/s

0

50

100

150

200

250

300

350

400

450

500%

0

50

100

150

200

250

300

350

400

450

500%

20.0 20.5 21.0 21.5 22.0 22.5 23.0

s

Slight Yaw Speed increase because of:• controlled sideforce reduction on rear wheels


> Comparison of Slip Angle and Yaw Speed <

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30°/s

3.5 4.0 4.5 5.0 5.5 6.0 6.5

s

FWD

TWINSTERAWDRWD

Wide Open Throttle from Steady State Cornering


> Influence of Torque Control on Vehicle Dynamics <

AWD Hang on to Rear% %° °/sm/s

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100Deg

500 50030 30

Change orque Control generates

Yaw Speed increase

Slip Angle increase

Torque l set up II

14025 25 450 450

120

20 20400 400100

15 1580

350 35010 10

60300 3005 5

40

250 2500 020

-5 -5 200 2000

-10 -10-20150 150

-15 -15-40 Contro100 100

-20 -20-60

50 50-25 -25-80

in T-100 -30 -30 0 0

9.5 10.0 10.5 11.0 11.5 12.0 12.5

s


> Test Results on High-µ <

Lateral Dynamics

• Steady State Cornering Self Steering Characteristic• Steer Step with Wide Open Throttle• Steer Step Input in Throttle Off• Yaw Damping with TRACKSTER Differential• Wet Handling


> Test Procedure Quasi Steady State Cornering <

• Test procedure (closed loop test)

• Surface: dry asphalt, 80 m circle radius

• The vehicle is accelerated with full throttle in 4th gear from very low speed to max cornering speed

• The drivers target is to hold the corner radius constant by adjusting the steering wheel angle

• Throttle position is not changed


> Steady State Cornering Self Steering Characteristic <

05

101520253035404550556065707580859095

100105110115120125

25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105

Vehicle Speed km/h

Stee

ring

Angl

e °

FWD

TWINSTERAWD&TRACKSTERFWD&TRACKSTERAWD

RWD


>Steady State Cornering Self Steering Characteristic <

05

101520253035404550556065707580859095

100105110115120125

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.510.0

FWD

TWINSTERAWD&TRACKSTERFWD&TRACKSTERAWD

RWD

Lateral Acceleration m/s²

Stee

ring

Angl

e °


> Test Procedure Steer Step Input WOT <

• Test procedure (open loop test)

• Surface: dry asphalt

• The vehicle is accelerated up to 60 km/h straight line steadystate speed

• The driver proceeds a full throttle with a steer step manoeuvre from 0° to 80° steering angle

• The steering wheel and throttle position is not changed


> Steer Step Input with Wide Open Throttle <

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10sm

-130 -110 -90 -70 -50 -30 -10 10

sm

0 20 40 60 80 100 120

RWD

FWD

FWD&TRACKSTERAWD

AWD&TRACKSTERTWIN

STER

Position x

Speed km/h

RWDFWD&TRACKSTERAWDAWD&TRACKSTERTWINSTER

FWD

Max. Cornering Speed

Pos i

tion

y

RWDOversteering!


> Steer Step Input with Wide Open Throttle <

-7.5

-5.0

-2.5

0.0

2.5

5.0°

-0.1 0.5 1.1 1.7 2.3 2.9 3.5

s

TWINSTER• best response• highest controlable slip angle

Time s

Slip

Ang

le °

RWD• extreme slip angle / oversteering

RWDFWD&TRACKSTERAWDAWD&TRACKSTERTWINSTER

FWD


> Test Procedure Steer Step Input in Throttle off <

• Test procedure (open loop test)

• Surface: dry asphalt

• The vehicle is accelerated up to 110 km/h straight line steady state speed in 3rd gear

• The driver proceeds a throttle off with a steer step manoeuvre from 0° to 80° steering angle

• The steering wheel and throttle position is not changed


> Steer Step Input in Throttle off <

-180

-170

-160

-150

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0sm

-150 -100 -50 0 50

sm

FWD&RWD • oversteering

RWDFWD&TRACKSTERTWINSTER

FWD

Position x

Posi

tion

y


> Yaw Damping with TRACKSTER Differential <

Open Differential DSC off

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150kmh

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5°

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100°

-5

0

5

10

15

20

25

30

35

40

45

50°/s

-200

-150

-100

-50

0

50

100

150%

0

50

100

150

200

250

300

350

400

450

500Nm

-0.5 2.5 5.5 8.5

s



0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150kmh

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5°

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100°

-5

0

5

10

15

20

25

30

35

40

45

50°/s

-200

-150

-100

-50

0

50

100

150%

0

50

100

150

200

250

300

350

400

450

500Nm

-1 2 5 8

s

TRACKSTER Differential DSC off



-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5°

-500

-250

0

250

500

750Nm

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100°

-5

0

5

10

15

20

25

30

35

40

45

50°/s

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750Nm

-0.5 2.5 5.5 8.5

s

Delta Torque Generates

Yaw Damping

Comparison Open and TRACKSTER Front Differential, DSC off

Slip Angle Reduction


> Wet Handling <

Test procedure (closed loop test)

• Surface: water sprayed asphalt

• The target is to drive 5 laps as fast as possible


> Lap Times Wet Handling <

40

42

44

46

48

50

52

54

56

58

60

FWD RWD FWD&TRACKSTER AWD AWD&TRACKSTER TWINSTER

Lap

Tim

e s

Track Length 1.1 km


>Section Speeds Wet Handling <

41

3

2

50

55

60

65

70

75

80

85

Spee

d [k

m/h

]

Section 1 Section 2 Section 3 Section 4

FWD RWD AWD FWD+T AWD+T TWINSTER


> How much Improvement does each System deliver? <

0

20

40

60

80

100Im

prov

emen

t %

Acc

el_h

igh_

µ

Acc

el_m

ed_µ

Acc

el_l

ow_µ

Acc

el_s

plit_

µ

SS

C_h

igh_

µ

SS

C_l

ow_µ

Thro

_off_

SS

C

SS

C_A

ccel

_hig

h_µ

SS

C_A

ccel

_low

_µ

FWD&TRACKSTER AWD AWD&TRACKSTER TWINSTER


>TRACKSTER <

• TRACKSTER provides all advantages of passive locking differentials by avoiding there disadvantages like• yaw moment build up when driving on split-µ at high speeds • understeering when cornering at low speeds• ABS / ESP interference

• Compared to open FWD• TRACKSTER improves traction on

• split-µ• when cornering• on inhomogeneous road surfaces• less improvements on homogeneous surfaces

• TRACKSTER improves lateral dynamics by• yaw damping • increasing cornering speed / lateral acceleration


> AWD “Hang on to Rear Axle” <

Compared to FWD

• “AWD Hang on coupling only” improves mainly traction and lateraldynamics on medium- and low-µ surfaces

• With the combination of AWD „Hang on“ & TRACKSTER all benefits of the active axle locking differential can be added


....and the winner is.......

• The TWINSTER showed the best performance of all tested systems:• Best cornering performance by Active Yaw function

• when cornering• lowest steering angle • highest Lateral Acceleration

• best handling performance• noticeable reduction of “steer in” understeering under acceleration

while cornering• Best Traction performance by

• using dynamical weight increase on the primarily driven axle during acceleration

• on split-µ the system acts like a combination of axle locking differential and hang on coupling


> Outlook <

TWINSTER and Hang on & TRACKSTER• Vehicles available for evaluation by OEMs• Refinement to utilize full potential of all concepts ongoing

• Control strategy with additional features• e.g. Network with ESP, suspension control etc.

• Affordable Active Yaw system (TWINSTER)

• Direct comparison of 7 drivelines in ONE vehicle

• All concepts are commercially available

• Distinction of individual brands possible with similar hardware

getrag driveline systems gmbhgetrag driveline systems gmbh vehicle dynamics expo 2005 “seven at...

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