Integration of an Active Brake Pedal Simulator in the ... · Simon Rothfuss, Michael Flad, Sören Hohmann: Integration of an Active Brake Pedal Simulator in the CarMaker Environment

www.kit.edu

Karlsruhe Institute of Technology (KIT) / Institute of Control Systems (IRS)

KIT – University of the state of Baden-Württemberg and

National Laboratory of the Helmholtz Association

Integration of an Active Brake Pedal Simulator in the CarMaker Environment for Design and Evaluation of

Haptic Driver Assistance SystemsIPG apply & innovate 2014, September 23/24

Simon Rothfuss, Michael Flad, Sören Hohmann

Simon Rothfuss, Michael Flad, Sören Hohmann:

Integration of an Active Brake Pedal Simulator in the CarMaker Environment for

Design and Evaluation of Haptic Driver Assistance Systems

Research Fields of the IRS

2 09/24/2014

Automation

SolutionsCooperative

Assistance Systems

Alternative Energy

Storage Solutions

Haptic Cooperative

Advanced Driving Assistance System (ADAS)

Sources: http://people.tuke.sk/ivo.petras/RLD.gif

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Haptic Cooperative ADAS

Direct Perception

Direct Integration

Instant Communication

Intuitive Cooperative

System

3 09/24/2014

Source: http://commons.wikimedia.org/wiki/File:American_shepherd3.jpg




Cooperative ADAS Development

Cooperative ADAS development requires test environment

4 09/24/2014

HW-in-the-loop HumanVirtual Car

Simulation




Overview

5 09/24/2014

Brake Simulator

Mechanics

Electronics

Control

HiL Integration

Validation

Overview

Components

Overview

Concepts

Driving Simulator




Advanced Driving Simulator

6 09/24/2014

Steering

Wheel

Brake

Screen

Realtime

System

Sound

Sources: pk-soundandmusic.com/imagebase/7-1417505.gif

sensodrive.de/__we_thumbs__/1035_5_s-pr-wheelHT-1.jpg

autosieger.de/images/articles/continental_gaspedal_3.jpg

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...downloads/pdf/antrieb/de_5/gs_datenbl_apm_de.pdf

dspace.com/files/jpg2/px4_px10_px20-de-002_desktopversion_schraeg...

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Throttle




Overview

7 09/24/2014

Mechanics

Electronics

Control

HiL IntegrationDriving Simulator

Validation

Overview

Components

Overview

Concepts

Brake Simulator




Hybrid car characteristic

Requirements

Conventional pedal force characteristic

8 09/24/2014

Accuracy according perception

Short response time

Human perception

Nonlinear force characteristic

Nonlinear dynamic

Recuperation

only

Recuperation

&

Conventional

Brake




New Concept

Accuracy according perception

Short response time

9 09/24/2014

Basic concepts for pedal force simulator

Passive Active

New Concept:

Brake Feedback Force Generation by Electric Drive

Nonlinear force characteristic

Nonlinear dynamic

Requirements




Brake Pedal Simulator - Mechanics

10 09/24/2014

Synchronous

Motor

GearboxConnector

Torque SensorPedal




Brake Pedal Simulator - Mechanics

11 09/24/2014

Incremental

Encoder

SpringLimit

Stops




Electrical System

12 09/24/2014

CANInterface

DSP

Incremental

EncoderQEI

Torque

Sensor

CAN

BusPWM

Drive Control Unit

SM µCGateUnit

Converter QEI

Pedal Control Unit

/A D




Software Architecture

13 09/24/2014

Sensor

Input

Reference

Calculation

Control Algorithm

Failure

Detection

SystemSupervision

System State

Estimation

OutputEnable & Limit

Filtering

PWM SignalField-Oriented

ControlGate Signals

EmergencyStop

Pedal Control Unit (DSP)

Drive Control Unit (μC)




System Model – Mechanics

14 09/24/2014

MM Motor Torque

MF Spring Torque

MP Pedal Torque

MG Pedal Mass Torque

MRi Friction Torque

i Gear Ratio

φi Shaft Angle left/right side

JM/G Inertia of Motor/Gearbox

J1‘ Inertia of connecting elements left

J2 Inertia right

kDK Spring Constant of Torque Sensor & Connector

dDK Damping Rate




System Equations

Coupled nonlinear differential equations

with

Constraints

15 09/24/2014

1 1 1 2 1 2 1 1

2 1 2 1 2 2 2

2

2

2

( ) ( ) ( ) ( ) ( ) ( ) ( )

(

( )

( ) ( ) ( ) ( ) ( ) ( ) ( ) ...

( ( ))

)

) ( )(

DK DK M R

DK DK p R

G F

J t k t t d t t i M t M

J t k t t d t t M t M

M t

t

M

t

t

20 ( ) : Angle of Limit Stops

-120 ( ) 120 M

t

Nm i M t Nm

2

1 1' ( )M GJ J i J J





16 09/24/2014

Sensor

Input

Reference

Calculation

Control Algorithm

Failure

Detection

SystemSupervision

System State

Estimation

OutputEnable & Limit

Filtering

PWM SignalField-Oriented

ControlGate Signals

EmergencyStop

Pedal Control Unit

Drive Control Unit




PI-State Feedback Control

17 09/24/2014

MP Pedal torque

MS Reference torque

x System states

u Command input torque to motor

z Disturbances

V

System

Kx

u

--

z

x

MPMS

Kp

Kiʃ




System State Estimation

Measurement equation

Problem: Not all system states x and pedal torque MP can be measured

Use of Extended Kalmanfilter for estimation

Estimated quantities

System states

Pedal torque

18 09/24/2014

1 1 2 2ˆ ˆ ˆ ˆ( ) ( ) ( ) ( )

T

t t t t

1

2

1

2

2

2

( )( ) 0 0 1 0

( )( ) 0 0 0 1

( )( ) 0 0

( )Mes DK DK

tt

tt

tM t k k

t

PM̂




V

System

Kx

u

--

z

MS

Kp

Kiʃ

Kalman-

filter zk

y

PI-State Feedback Control

19 09/24/2014

Pedal torque, estimated

MS Command input torque

System states, estimated

zk Disturbances, known, used in Kalmanfilter

x̂

PM̂

PM̂

x̂




Deviations below human perception

Measurement Results

20 09/24/2014

Root-Mean-Square-Error < 12N




Summary – Brake Pedal Simulator

System control and state estimation designed

Simulator emulates arbitrary nonlinear force characteristics

Required accuracy of pedal force achieved

21 09/24/2014

Control AlgorithmSystem Model

V

System

Kx

u

-

y

-

z

Kalman-

filter

x'

MP'

MS

zk

Kp

Kiʃ

1 11

1 1 1 11 1

2 2

2 22 2

2 2 2 2

1

0 1 0 0

( ) ( )

( ) ( )...

( ) ( )0 0 0 1

( ) ( )( )

0 0 00

1

( )

0

0

DK DK DK DK

DK S FDK DK DK

M

t tk d d k d

J J J Jt td

t tdt

t tk g kk d d d

J J J J

J t

iJ

M

1 10

1

2 20

0 2 0 2

2 2

0 0 ( )

( )0 0 0

( ) ( ) ( )1 1

0

R

R

P g F

sign M

sign M

M t M M

J J




Overview

22 09/24/2014

Mechanics

Electronics

Control

Driving Simulator

Validation

Overview

Components

Overview

Concepts

Brake Simulator HiL Integration




Brake Pedal Simulator Integration

23 09/24/2014

CAN

Source: duden.de/_media_/small/P/PC-201100281327.jpg

dspace.com/files/jpg2/px4_px10_px20-de-002_desktopversion_schraeg...

..._refl_dp_300dpi_200x250mm_cmyk_081218.jpg

Brake Pedal

Simulator CarMaker




Integration Concepts

Concept 1

Brake pedal simulation in CarMaker

Feedback force command to

brake simulator

Pedal position used in

CarMaker

Complex brake pedal simulation

possible

Concept 2

Brake pedal characteristic

implemented on brake pedal

simulator

CarMaker selects characteristic

Pedal position returned to

CarMaker

Higher torque / time resolution

24 09/24/2014

Brake Pedal

Simulator

CAN

CarMaker




Conclusion

25 09/24/2014

Advanced Driving Simulator presented

Haptic interfaces available

Test bench for cooperative ADAS




Result

26 09/24/2014




27 09/24/2014

Thank you for your attention




Appendix

28 09/24/2014




Pedal Feedback Force Characteristic

29 09/24/2014

Real brake pedal force introduced

by braking system

Modelling with pedal force

characteristic

( ( ), ( )) ( ( ))

( ( ), ( ))

( ( ), ( ))

Pedal Static

Hysteresis

Damping

F s t s t F s t

F s t s t

F s t s t

( ): Pedal Travels t

( ( ))StaticF s t





30 09/24/2014

( ( )) ( ( ), ( ))Static HysteresisF s t F s t s t ( ( ))d s t





Idealized pedal force characteristic for 2 different pedal velocities

31 09/24/2014





32 09/24/2014

CAN Signal

Internal Signal

Sensor

Input

Reference

Calculation

Control

Algorithm

PWM

Signal

Emergency

Stop

Failure

Detection

System

Supervision

System State

Estimation

Output

Enable

& Limit

Field-

Oriented

Control

Gate

Signals

Filtering

Pedal Control Unit

Drive

Control

Unit




System Equations

Coupled differential equations

Friction model

33 09/24/2014

1 1 1 2 1 2 1 1

2 1 2 1 2 2 2

2 2

2

( )

( )

( ) ( ) ( ) ( ) ( ) ( ) ( )

( ) ( ) ( ) ( ) ( ) ( ) ( ) ...

( ( ()) ( ))

DK DK M R

DK DK p R

G F

J t k t t d t t i M t M

J t k

t

t t d t t M t M t

t M tM

0( ) ( )Ri i i Ri Ri iM sign M d




System Equations

34 09/24/2014

Coupled differnetial equations

Non-Linearities

Linearization through

2 2( ) ( )2

G P

lM m g sin t

2 2

2

( ) ( )2

( )

G P

O S

sinlM m g sin t

g g t

2 20 and

1 1 1 2 1 2 1 1

2 1 2 1 22 2 222

( ) ( ) ( ) ( ) ( ) ( ) ( )

( ) ( ) ( ) ( ) ( ) ( ( ( ))) ( )

DK DK M R

DK DK p GR F

J t k t t d t t iM t M

J t k t t d M t M MMt t




System Equations

35 09/24/2014

1 1 1 2 1 2 1 1

2 1 2 1 22 22 2 2

( ) ( ) ( ) ( ) ( ) ( ) ( )

( ) ( ) ( ) ( ) ( ) ( ( ( )) ( ) )

DK DK M R

DK DK p R G F

J t k t t d t t iM t M

J t k t t d M M Mt t t M

Coupled differnetial equations

Non-Linearities

Linearization through

2 2 2( ) ( ) ( )FM k a sin t cos t

2 2

0 2 2 2

( ) · · ( )

( ) ( )· ( )

F

F F

sin cosM k a t

M k t

2 2 and




Control Concepts Overview

36 09/24/2014

Compensator

DeadbeatController

SISO - Control H - Control

PI – State Feedback

Constant State Feedback

State Feedback Control




Control Implementation with additional Spring

37 09/24/2014

V

System

Kx

u

--

z

MS-MF

Kp

Kiʃ

Kalman-

filter zk

y

-MF

x̂

PM̂




Identification

38 09/24/2014




State Space Model for Kalmanfilter

39 09/24/2014

System equation

39

1 11

1 11 1 1 1

2 2

2 22 2

2 2 2 2 2

0 1 0 0 0

ˆ ˆ( ) ( )0

ˆ ˆ( ) ( )

ˆ ˆ( ) ( )0 0 0 1 0

( ) 1ˆ ˆ( ) ( )

ˆ ˆ( ) ( )

0 0 0 0 0

DK DK DK DK

DK S FDK DK DK

P P

t tk d d k d

t tJ J J J

t t

k g kk d d dt t

J J J J JM t M t

1

1 10

0 0 2 2 20

2

...

0 0

10

( ) ( )0 0

( ) ( )1

0

0 0

M R

g F R

Ji M t sign M

M M sign M

J




State Space Model for Kalmanfilter

40 09/24/2014

Measurement equation

1

12

22

2

ˆ ( )

ˆ ( )( ) 0 0 1 0 0

ˆ ( )( ) 0 0 0 1 0

( ) 0 0 0 ˆ ( )

ˆ ( )

Mes DK DK

P

t

tt

tt

M t k k t

M t




Kalmanfilter - Simulation

41 09/24/2014

Time [s]




Kalmanfilter - Simulation

42 09/24/2014

Time [s]




Kalmanfilter - Measurement

43 09/24/2014




Quelle:

http://www.kistler.co

m/medias/sys_mast

er/

celum_assets/88247

08071454_934-

073_web_6407_png

.jpg?2

Measurement Setup

44 09/24/2014

Pedal force sensor attached to pedal

Actuation via human foot

Hence, no possibility to apply velocity profiles

Record command input torque

Used pedal characteristics:

Documents

Integration of an Active Brake Pedal Simulator in the ... · Simon Rothfuss, Michael Flad, Sören Hohmann: Integration of an Active Brake Pedal Simulator in the CarMaker Environment