www.opel.com

Generic Modeling and Control of an Electromechanical

Power Steering System for Virtual Prototypes

GENERIC EPS MODEL

Adam Opel AG, Control Systems & Brake CAE

Karlsruhe, Apply & Innovate, 20 September 2016

Dipl.-Ing. Roman Mannale,

Volker Ewald, Dr.-Ing. Markus Bauer

1. Introduction

2. EPS tool chain

3. Generic EPS model

4. Summary

AGENDA

3

VARIANT DIVERSITY

4

0

50

100

150

200

250

300

350

400

450

Senator

Astra

ABS, ESC, AWD, CDC

ABS & ESC

Chassis & ADAS

ABS

1984 1994 2004 2014

Increasing development, tuning and validation effort

ROAD LAB MATH STRATEGY (RLM)

5

Model/Software

in the loop simulation (MiL/SiL)

• Architecture development

• System integration

• Parameter optimization

Hardware

in the loop simulation (HiL)

• Diagnosis

• Failsafe

• Performance

LAB

Test drives

• System tuning

• Random testing

• Validation

ROAD

Ressource optimized development & validation

MATH

11

11

11

11

00

1/z

1/z

1/z

11

Straßenanregung MatCarAdam Opel AG

? ? ?

Manöver

IVCSIVCS

[BLS]

[man_mcp]man_mcp

[gas_gear_clutch]gas_gear_clutch

[stwhl_ang]stwhl_ang

1EngRngSt_value1

ESP / ABS / TCS

Demux

CDC

Control Systems Master Model (CSMM)

Multi Body Simulation (MBS)Master Model

SIMULATION TOOL CHAIN OVERVIEW

6

AxleFull vehicle

SiL

HiL

DiL

CarMaker (CM)vehicle infofiles

ComponentDatabase

ASCII

(CM-Infofile)

Parameters

ComponentData

Measurements

Design Data CSMM

Component Models CM-Models

Simulink Models

S-functions

c-Code

© fkfs.de

MASTER MODEL APPROACH

7User 1 User 2 User n

Master Model Master Model Master Model

Library 1

Library m

RLM EXAMPLES

8

Architecture phase Prototype phase Tuning & Validation

Develop Test

MiL SiL

HiL

Vehicle ROAD

LAB

MATH

Mule

Elimination

ESC

Homologation

RLM TOOL CHAIN FOR EPS SYSTEMS

9

Support all development phases

Develop Test

Architecture phase Prototype phase Tuning & Validation

MiL SiL

HiL

Vehicle ROAD

LAB

MATH

Generic EPS

model (MiL)

Supplier EPS

model (SiL)

Power pack

bench (HiL)

EPS system

bench (HiL)

Virtual steering test bench

EPS TOOL CHAIN APPLICATIONS

10

Analysis

Architecture

phase

Prototype

phase

Tuning &

Validation

Steering lever arm

Wheel

Tie rod

Torsion bar

E-Motor

Tasks

• Design of the steering system

• Define requirements for suppliers

• Predict the interaction with chassis components

• Sensitivity analysis

EPS TOOL CHAIN APPLICATIONS

11

Analysis

Tuning &

Validation

Tasks

• Detailed analysis of the interaction with chassis components

Dampers

Bushes

Mounting …

• ECU functional testing

Architecture

phase

Prototype

phase

EPS TOOL CHAIN APPLICATIONS

12

Analysis

Tuning &

Validation

Tasks

• ECU testing

Functional testing

Performance testing according to internal spec.

Pre-calibration of control functions

Architecture

phase

Prototype

phase

Power pack

bench (HiL)

EPS system

bench (HiL)

RLM TOOL CHAIN FOR EPS SYSTEMS

13

Develop Test

Architecture phase Prototype phase Tuning & Validation

MiL SiL

HiL

Vehicle ROAD

LAB

MATH

Generic EPS

model (MiL)

Supplier EPS

model (SiL)

Power pack

bench (HiL)

EPS system

bench (HiL)

Virtual steering test bench

VIRTUAL STEERING TEST BENCH

14

Automatic

identification

Model parameters

Measurement data

(from MBS or real system)

Validation

Validated

steering model

Measurement data

(from MBS or real system),

steering model

Analysis

Controlability, observability,

modal/stability/sensitivity analysis

Steering model

Virtual steering

test bench

EPS model B

EPS model AEPS model C

EPS model D

One tool for all models

(Opel/Supplier)

RLM TOOL CHAIN FOR EPS SYSTEMS

15

Develop Test

Architecture phase Prototype phase Tuning & Validation

MiL SiL

HiL

Vehicle ROAD

LAB

MATH

Generic EPS

model (MiL)

Supplier EPS

model (SiL)

Power pack

bench (HiL)

EPS system

bench (HiL)

Virtual steering test bench

GENERIC EPS MODEL COMPONENTS

• Controller model

• Reference model for target behaviour

• Model based approach: Internal Model Control

• Motor model

• Mechanical steering model

16

Non-linear

friction

Non-linear

friction

2 degrees

of freedom

REQUIREMENTS FOR GENERIC EPS MODEL

• Model in the loop Available for early development

• Modular concept

• Cover all basic EPS functions

• Physically-based self-adjusting controller setup

17

Generic EPS

model

Vehicle parametersEPS target values

18

F(s) GR(s)

GM(s)

-

u

yd

d

Filter Controller System

Model

Disturbances

Model error

G (s)

GR(s) = 1/GM(s)

INTERNAL MODEL CONTROL APPROACH

Controller parameters reflect physical parameters of the system

-

GENERIC EPS MODEL OVERVIEW

19

Generate reference

intermediate shaft

angular speed

Steering wheel

torque

Observers

Friction

compensator

Model (IMC)

Disturbance

compensator

Controller

(IMC)

Mech. system

GENERIC EPS REFERENCE GENERATION

20

Reference

intermediate shaft

angular speed

Steering wheel

torque

Stationary model

- Define desired

steering support (Boost Curve)

Dynamic model

- Ideal dynamic reference behaviour

- Tunable damping

GENERIC EPS EXAMPLE RESULT

• Test run:

• 100 km/h

• Slowly increase steering wheel angle (quasi stationary)

• Two vehicle models:

• Middle class

• Compact class

21

Lateral vehicle acceleration

Steering

wheel

torque

Middle class

Target behaviour

Compact class

Two vehicles classes, similar

steering wheel torque

SUMMARY

• RLM strategy for ressource optimized development & validation• Model/software in the loop (Math)

• Hardware in the loop (Lab)

• Test drives (Road)

• EPS tool chain as one part of RLM covers all development phases• Architecture phase

• Prototype phase

• Tuning & Validation

• Generic EPS model allows early analysis & system understanding • Available for early development (MiL)

• Modular concept

• Covers all basic EPS functions

• Physically-based self-adjusting controller setup

22

Roman Mannale

THANK YOU