www.opel.com

HiL simulation of closed-loop-driving

maneuvers to predict the handling

performance of passenger cars

Dr.-Ing. Michael Kochem, Dr.-Ing. Henning Holzmann

GME Vehicle Simulation

September 16th, 2010

Agenda

September 16th, 2010 Dr.-Ing. Michael Kochem2

• Motivation

• Road-Lab-Math (RLM) Strategy

• Closed-Loop-Driving Maneuvers

• Simulation Environment

• Driver Model (IPGDriver)

• Validation of Closed-Loop-Driving Maneuvers

• Prediction of Handling Performance Ratings

• Conclusions

3

Is it possible to predict an automotive journal`s

handling score based on simulation results?

Question:

• How subjective/objective are the magazine’s handling scores?

• How does the simulation of closed-loop maneuvers reflect reality?

September 16th, 2010 Dr.-Ing. Michael Kochem

4

Road – Lab – Math (RLM) Strategy

Architecture Development

System Integration

Parameter Optimization

SiL - Simulation(Math)

Controller Application

Random Testing

Validation

Driving Test(Road)

Performance Check

Diagnosis

Failsafe

HiL - Simulation(Lab)

September 16th, 2010 Dr.-Ing. Michael Kochem

5

Closed-Loop-Driving Maneuvers

• Slalom (18m)

• ISO Lane Change

• VDA Double Lane Change

• Double Lane Change on wet surface

• Constant radius, constant speed

• Driving maneuvers with a driver in the loop

• Basic maneuvers to evaluate the handling performance of a vehicle

(e.g. used by auto motor und sport magazine in their Mastertest):

• Intensive dialogue with journalists and testers how these maneuvers are driven

• Boundary conditions and evaluation criteria are important

© auto motor und sport, 2009

September 16th, 2010 Dr.-Ing. Michael Kochem

6

Slalom (18m)

• Driver strategy:

• as fast as possible

• soft steering to reduce ESC intervention

• speed increase in 1-2 kph steps up to the limit

• ESC is active

• Pylon hit makes test invalid, slight pylon shift is allowed

• Objective evaluation: average speed (180m/time)

• Subjective evaluation: vehicle controllability, ESC interventions, steering effort

September 16th, 2010 Dr.-Ing. Michael Kochem

7

VDA Double Lane Change

• ESC is active and inactive (if switchable)

• Pylon hit makes test invalid, slight pylon shift is allowed

• Objective evaluation: entrance and exit speed

• Subjective evaluation: controllability, rollover stability, steering effort

• Driver strategy:

• free rolling after throttle off according to VDA definition (ISO 3888-2)

• rapid steering to provoke ESC intervention and/or instability

• speed increase in 1-2 kph steps up to the limit

September 16th, 2010 Dr.-Ing. Michael Kochem

CompilerLinker

ComponentModels

ManeuverDefinitions

ANSI-C

Suspension Simulation

Kinematic

Analysis

Compliance

Analysis

Virtual Vehicle

Chart

Characteristic

Plots

Data

Processing

BodyTopology

SuspensionTopology

Tire Data

BodyGeometry

Road Data

SuspensionGeometry

ASCII

Equationsof motion

Builder

ADAMSMesaverde

VehicleSimulation

Handling

Analysis

Ride

Analysis

Virtual Vehicle

Chart

Characteristic

Plots

HyperWorks

MotionView

CarMaker

Simulink Pro

SiL-/HiLSimulation

Data

ProcessingRoll-over

Analysis

Ground

Clearance

Compliance

Analysis

Simulation Environment

8 September 16th, 2010 Dr.-Ing. Michael Kochem

9

Hardware-in-the-Loop Simulation (HiL)

Simulation

Results

VV Chart

Simulink-based

Vehicle ModelAxle-Model

ABS/ESP ECU

1

1

IVCS

IVCS

[man_mcp]

man_mcp

ESP / ABS / TCS

Demux

1

1

IVCS

[man_mcp]

man_mcp

CDC

Demux

CDC ECU

1

1

IVCS

[man_mcp]

man_mcp

AWD ECU Hardware-in-the-Loop

Simulation (HiL)

Integration of

Vehicle Model

and real ECUs

September 16th, 2010 Dr.-Ing. Michael Kochem

10

Driver Model (IPGDriver)

Main applications of the IPGDriver

Control strategies and handling of active systems• Improvements of the longitudinal and lateral controllers

-- for driving at the limit, but also -- for driving slowly (standstill) or driving in small curves

• Getting a realistic behavior in all kinds of real driving situations and with all kinds of active systems like ABS, ESP, AFS …

Additional inputs• Speed profile

• traffic signs (speed limit, stop signs etc.)

• Speed correction due to banking curves

• Speed correction due to uphill & downhill

Driving vehicles with driving assistance systems• Backwards driving for parking assistance systems

• Steering with steering torque • active steering systems

• lane keeping assistance systems & collision avoidance

• parking assistance

September 16th, 2010 Dr.-Ing. Michael Kochem

11

Driver Model (IPGDriver)

Important feature: Driver adaptation

September 16th, 2010 Dr.-Ing. Michael Kochem

12

Validation of Closed-Loop Maneuvers

• Measurements at Opel Test Center Pferdsfeld, Germany

• Test Vehicle: Opel Insignia Sports Tourer 2,0 CDTI

• Standard measurement equipment:

• steering wheel angle, accelerations (lat., long.), yaw rate, vehicle speed,

status flags via CAN

• iMAR inertial measurement platform

• external light barriers for speed measurement

September 16th, 2010 Dr.-Ing. Michael Kochem

13

Validation of VDA Double Lane Change

Animation of the maneuver

Max. measured speed: 70 kph

Simulated speed: 70 kph

ams measurement: 70 kph

September 16th, 2010 Dr.-Ing. Michael Kochem

15 16 17 18 19 20-8

-6

-4

-2

0

2

4

Time [s]

Ro

ll A

ng

le [

°]

Measurement 68km/h

Measurement 70km/h

CarMaker

14

15 16 17 18 19 20-300

-200

-100

0

100

200

300

Time [s]

Ste

eri

ng

Wh

eel A

ng

le [

°]

Measurement 68km/h

Measurement 70km/h

CarMaker

15 16 17 18 19 20-15

-10

-5

0

5

10

15

Time [s]

Late

ral A

ccele

rati

on

[m

/s2]

Measurement 68km/h

Measurement 70km/h

CarMaker

15 16 17 18 19 20-60

-40

-20

0

20

40

60

Time [s]

Yaw

Rate

[°/

s]

Measurement 68km/h

Measurement 70km/h

CarMaker

Validation of VDA Double Lane Change

September 16th, 2010 Dr.-Ing. Michael Kochem

15

Validation of Slalom (18m)

Animation of the maneuver

Max. measured speed: 62 kph

Simulated speed: 62 kph

ams measurement: 63 kph

September 16th, 2010 Dr.-Ing. Michael Kochem

16

Validation of Slalom (18m)

12 14 16 18 20 22 24 26 28-200

-150

-100

-50

0

50

100

150

200

Time [s]

Ste

eri

ng

Wh

eel A

ng

le [

°]

Measurement

Special Measurement

CarMaker

12 14 16 18 20 22 24 26 28-15

-10

-5

0

5

10

15

Time [s]

Late

ral A

ccele

rati

on

[m

/s2]

Measurement

Special Measurement

CarMaker

12 14 16 18 20 22 24 26 28-40

-30

-20

-10

0

10

20

30

40

50

Time [s]

Yaw

Rate

[°/

s]

Measurement

Special Measurement

CarMaker

12 14 16 18 20 22 24 26 28-6

-4

-2

0

2

4

Time [s]

Ro

ll A

ng

le [

°]

Measurement

Special Measurement

CarMaker

September 16th, 2010 Dr.-Ing. Michael Kochem

17

Prediction of Handling Performance Ratings

September 16th, 2010 Dr.-Ing. Michael Kochem

18

Conclusions

• Based on GM’s Road-Lab-Math Strategy, an integrated simulation

environment was set up to simulate closed-loop-driving maneuvers

• Simulation environment allows precise predictions of the results of

relevant test maneuvers (IPGDriver is doing an excellent job!)

• Differences in simulation/test results are marginal, even

compared to automotive journal’s measurements

• Journal’s handling scores are based on objective measurements

in combination with subjective evaluation

• Prediction of the objective part is possible

• Subjective evaluation may vary the total score slightly

• Continued cooperation with IPG to improve the steering behavior

of the IPGDriver

September 16th, 2010 Dr.-Ing. Michael Kochem

19 September 16th, 2010 Dr.-Ing. Michael Kochem