Optimal Energy Consumption and Recovery

Based on a system network

Virtual Development Platform for Project

OpEneR: Optimal Energy Management & Recovery

Dr. Stephen Jones, AVL List GmbH, System Simulation

Jochen Steinmann, Robert Bosch GmbH, Chassis Systems Control

“apply & innovate 2012" - IPG Technology

Conference, September 18-19, 2012, Karlsruhe

OpEneR Project Introduction

OpEneR 3008 FEV Prototype

Development of Operational Control Strategies

Energy Manager Development

Optimal Speed Profile

Optimal Route Selection

Braking System & ESP®hev Co-Simulation

Contents

OpEneR will develop driving strategies and

driver assistance systems that increase the

efficiency, driving range, and safety of electric

vehicles.

This is to be achieved by merging data from

on-board and off-board sources. A particular

focus will lie on an optimal cooperation

between the electric drivetrain and the

regenerative braking system, supported by

data from radar, video, satellite navigation,

car-to-infrastructure and car-to-car systems.

Overall project budget: 7.7 Million €

EU OpEneR Project, Aim & Project Partners

3008 Hybrid4 3008 OpEneR

3008 FEV E-4WD Concept Derivation

Baseline vehicle is 3008 Hybrid4, transformed into Fully Electric 4WD vehicle.

Front conventional internal combustion engine replaced with 2nd e-Machine.

New larger battery package fitted.

Bosch ESP®hev w/ vacuum booster is replaced by Advanced Regenerative

Braking System ESP®hev + iBooster.

Accessories adapted (Heating, Cooling, Charging device, Cockpit HMI).

e-4WD gives better traction, perfect synchronisation front & rear e-machines.

20 % grade slope,

ice and snow mix

Flat surface, scraped ice

OpEneR 3008 4WD Performance

Ultrasonic

sensors Long range

radar

Multi purpose

camera

Components

Night Vision

camera

Mid range

radar rear

Mid range

radar plus

Long range

radar

Multi purpose

camera

2x Mid range

radar rear

Near Field

camera

OpEneR

ADAS in OpEneR Level 2

Functions

Traffic Sign, Object, Lane and Light

Vision

Eco ACC w/ Stop & Go

Blind Spot Detection

Lane Change Assist

Rear Cross Traffic Alert

Software Development Process – Technology Levels

Level 0 Level 1 Level 2 Level 3

Sensing Traffic & Environment Conditions

Weather Cond.

Traffic Jams

Road Works

3D Road … OpE

neR

Vehic

le D

evelo

pm

ent

Simulation toolchain development for simultaneous engineering

Integration of Complex Subsystems

Powertrain, Subsystems … Car2x … … ESP®hev, iBooster

… Satellite Navigation

… Radar, Video

…

Energy Manager Development Process

Co-Simulation Toolchain Overview

Co-simulation toolchain for

supporting complex vehicle

& powertrain development

process.

Use of appropriate

simulation tools for each

specialised application.

Integration of tools by

defining & setting-up

standard interfaces.

Enhanced MiL & SiL

platform, extendable to

Real Time HiL & Testbed

with AVL InMotion.

Parallelization of testing &

software validation.

AVL

CRUISE IPG CARMAKER

MATLAB

SIMULINK

AVL

CAMEO

S Y S T E M CTM

1D Powertrain System Simulation

OpEneR AVL CRUISE Powertrain Simulation

Twin axle e-drive powertrain & battery model.

Pre-defined performance simulation tasks.

Standard drive cycles e.g. NEDC, Real World.

Concept simulation & initial operational

system calibration.

Optimum torque split for efficient electrical traction & regeneration.

Potential of front-rear torque distribution control algorithm.

Optimal Torque Distribution

E-Machines have complex

efficiency characteristics.

Operate E-machines more

efficiently with optimal front-rear

torque split.

Offline CRUISE calculation of

efficient torque split map.

Efficiency improvement with

optimal torque distribution of up

to 5 to 6%, suggested in AVL

CRUISE simulated drive cycles.

Concept Simulation Using AVL Cruise

Assessment of e-machine and battery characteristics

(independent of topology)

Definition of concept vehicle targets

Concept analysis using various drive cycle / performance criteria

Battery characteristics

e-machine characteristics

AVL Cruise simulation with selected components to verify

vehicle targets

0 100 200 300 400 500

50

60

70

80

90

100

Distance in m

Vel

ocity

in k

m/h

Speed Profile Human Driver

Speed Profile Optimized

ΔE = -25.3%

T =

28

.7s

T =

22

.5s

E =

97

.0W

h

E =

77

.4W

h

ΔT = -6.2s

Optimal SpeedProfile

Human Driver

Optimized Short Term Speed Profile

System must support driver,

via Cockpit HMI, to drive safe

& efficient speed profile.

Example of optimal speed

profile when approaching 50

kph speed limit.

Higher initial regenerative

braking in order to reduce

energy losses at high vehicle

speeds, initially 100 kph.

Reduced braking rate in

second phase for increased

regeneration.

Model & Sub-system Interface Definition

Vehicle

Testtrack

Sub-systems

HEVC_M1b/CALCULATION/EMM_PMU/VEH_ON

Printed 20-Dec- 2006 18:04:34

VEH_ON

en: Entry_VEH_ON();

du: During_VEH_ON()

du: F_Traction_Driver();

en = Entry_VEH_ON function

du = During_VEH_ON function

du = F_Traction_Driver function

ENG_OFF

ENG_STOPENG_START

ENG_RUN

OffC = ENG_StopC function

OffC = ENG_OffC function

runC = ENG_RunC function

startC = ENG_StartC function

Parameters for the HEV System are optimised, for each cycle; the parameters and maps

are inputvalues depending on the Course signal. The internal structure of the Statemachine

is not changed / varied.

[ ENG_OffC() ]

[ ENG_StartC() ]

2

[ ENG_RunC() ]

1

[ ENG_StopC() ]

[ ENG_RunC() ]Controller

Environment

Driver model

Sensors

Powertrain

Navigation

HMI Simulink model with CRUISE & SystemC

model interfaces:

Info. exchange between various subsystems.

Incorporation of temporal behavior.

Signal exchange between sim. tools.

Consistency of signal features

Interface definition.

Simulink as Main Simulation Integration Tool:

IPG CarMaker for Simulink

PowerTrain .Misc

2

Sync_Out

1

PowerTrain

Brake

System

Brake.IF.In5

VhclCtrl .PT

4

VhclCtrl .Brake3

VhclCtrl .Steering2

Sync_In1

Various Complex Matlab Simulink® sub-

system models:

Robert Bosch ESP®hev hydraulic model

Robert Bosch ESP®hev software

ACC

Car2X emulator

Other OpEneR subsystem models

More suitable environment for complex

OpEneR software development.

Fully functional CRUISE powertrain &

CarMaker vehicle dynamics model.

Direct integration of developed

software, via autocoding to prototype

vehicle control unit.

CarMaker

for

Simulink

Navigation in the Loop:

On-line & offline data

transfer from navigation

system to the simulation

tool-chain.

Electronic horizon.

Virtualization of maps.

Most Probable Path (MPP).

Real-world road

characteristics:

Speed Limits

Curvature Information

Traffic signs

ADAS RP - NAVTEQ

Optimal Real Time Route Selection

Optimal

Route Selection

Instantaneous Information

via Cockpit HMI

Macroscopic method developed to find

energy optimal path from various

alternative route possibilities.

Diverse traffic conditions are

implemented on route using co-simulation

tool-chain and off-board c2x information.

Allows on-line energy optimal route

selection based on the real-time road

conditions, 3D road topology and vehicle

state (e.g. Battery SOC).

Non-optimal

Route Selection

ΔE = -10.3%

E =

1.9

8 k

Wh

E =

1.7

9 k

Wh

PATH 2

PATH 1

T =

45

4s

T =

27

2s

ΔT = 182s

Optimal route selection improves energy

consumption by around 10%, compared to

Stop & Go traffic condition.

Online route optimization is realized according

to RT energy consumption prediction for EV.

Optimal Real Time Route Selection

0 0.5 1 1.5 2 2.5 3 3.50

20

40

60

80

Distance [km]

Vehicle Velocities

Ve

loci

ty in

km

/h

Path 1

Path 2

0 0.5 1 1.5 2 2.5 3 3.598.5

99

99.5

100

Distance in km

Battery State of Charge

SO

C in

%

Path 1

Path 2

A B C

DE

I N

J O N

1. Basic Regenerative Braking System

Constant deceleration with constant brake

pedal position (equal to today’s pedal feel) • Complete recuperation no deceleration change

= "Blending" between regenerative and hydraulic

torque Bra

ke

to

rqu

e

Speed

Hydraulic brake torque

Regenerative brake torque

Bra

ke

to

rqu

e

Bra

ke

to

rqu

e

Generator characteristic

Deceleration changes with constant brake

pedal position

low recuperation low deceleration change

high recuperation high deceleration change

2. Cooperative Regenerative Braking System

De

ce

lera

tio

n

Regenerative brake torque

Hydraulic brake torque

De

ce

lera

tio

n

Speed

De

ce

lera

tio

n

Speed

Regenerative brake torque

Types of Regenerative Braking

Regenerative Braking System

Project benefits

Recuperation with high comfort &

efficiency

Amplified 4 wheel back-up mode

iBooster

Vacuum independent electro-mechanical

actuation

Pedal feel adaptable by software

Full regenerative braking with ESP®hev

ESP®hev

Rear axle hydraulically decoupled from

actuation for regenerative brake and

additional functions

Based on well known components

Technical characteristics

Regenerative Braking System

Example for torque blending with ESP®hev

BlendingActive (*)

BrakeLightSwitch (*)

pAccumulator (bar)

pSensePiston (bar)

sPushrod (mm)

MbRegenMax (Nm)

FrictionTorque (Nm)

RegenTorque (Nm)

VehicleTarget (Nm)

vVehicle (km/h)

#A_L (ms2)

#pVL (Bar)

0 - 1 [0.1/div]

0 - 1 [0.1/div]

-100 - 400 [50/div]

-90.5 - 209 [30/div]

-60.2 - 140 [20/div]

-5e+003 - 5e+003 [1e+003/div]

-5e+003 - 5e+003 [1e+003/div]

-5e+003 - 5e+003 [1e+003/div]

-5e+003 - 5e+003 [1e+003/div]

0 - 360 [36/div]

-46.3 - 5.25 [5.16/div]

-100 - 400 [50/div]velocity

Brake torque

Generator torque

Friction torque

Pedal stroke

P sense piston

P_FL

deceleration

50 bar

1000 Nm

t = 6.4 s

Result:

Constant

deceleration

during blending

between electric

and hydraulic

braking

Regenerative Braking System

ESP®hev Simulation

Cruise - CarMaker - Matlab Simulink

VehicleControl

Sync _In

DrivMan .In

Sync _Out

VhclCtrl .Steering

VhclCtrl .Brake

VhclCtrl .PT

Brake.IF .In

Vehicle

Sync _In

VhclCtrl .Steering

VhclCtrl .Brake

VhclCtrl .PT

Brake.IF .In

Brake.IF .Out.PT

Sync _Out

PowerTrain.Misc

Brake.IF .Out.Brk

ESP DrivMan

Sync _In

Ambient.Misc

Sync _Out

DrivMan .OutCM_LAST

Sync _In

PowerTrain.Misc

Sync _Out

CM _FIRST

Sync _In

Sync _Out

Ambient.Misc

Interfaces of a Generic ESP®hev simulation model are defined

The model is integrated into the simulation tool-chain

ESP®hev Simulation

Cruise - CarMaker - Matlab Simulink

Co-Simulated Recuperation on µ-split Road

0 200 400 600 800 1000 12000

20

40

60

80

100

120

140

Distance [m]

Velo

cit

y [

km

/h]

100 m.

Braking

Acceleration Cruise Recup.

300 m.

Co-Simulated Recuperation on µ-split Road

100 m.

Braking

Acceleration Cruise Recup.

300 m.

0 200 400 600 800 1000 12000

0.2

0.4

0.6

0.8

1

X: 402.8

Y: 0

Distance [m]

Recuperation Flag

Brake Pedal Travel

Co-Simulated Recuperation on µ-split Road

100 m.

Braking

Acceleration Cruise Recup.

300 m.

0 200 400 600 800 1000 12000

0.2

0.4

0.6

0.8

1

Distance [m]

Mechanical Brake Torque

Regenerative Brake Torque

Total Torque

Normalized Mech. Brake Torque FL/FR [Nm]

Co-Simulated Recuperation on µ-split Road

Thanks for your kind attention