Passenger cars -- Simulation model classification

Voitures particulières -- Classification des modèles de simulation

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DRAFT INTERNATIONAL STANDARD
ISO/DIS 11010-1
ISO/TC 22/SC 33 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-09-10 2020-12-03
Passenger cars — Simulation model classification —
Part 1:
Vehicle dynamics
ICS: 43.100
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
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WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11010-1:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
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ISO/DIS 11010-1:2020(E)
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© ISO 2020

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ii © ISO 2020 – All rights reserved
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ISO/DIS 11010-1:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Model designation numbers ..................................................................................................................................................................... 3

4.1 Physical system ....................................................................................................................................................................................... 3

4.2 Controller ..................................................................................................................................................................................................... 3

5 Model classes ............................................................................................................................................................................................................ 5

5.1 General ........................................................................................................................................................................................................... 5

5.2 Vehicle / Body .......................................................................................................................................................................................... 6

5.3 Aerodynamics .......................................................................................................................................................................................... 9

5.4 Brake .............................................................................................................................................................................................................11

5.5 Powertrain ...............................................................................................................................................................................................16

5.6 Steering .......................................................................................................................................................................................................19

5.7 Suspension ...............................................................................................................................................................................................23

5.8 Tire .................................................................................................................................................................................................................27

5.9 Road surface ...........................................................................................................................................................................................30

6 Driving manoeuvres .......................................................................................................................................................................................32

6.1 Driving manoeuvre classes ........................................................................................................................................................32

6.2 Classification of standardized driving manoeuvres .............................................................................................32

7 Classification matrix ......................................................................................................................................................................................34

Bibliography .............................................................................................................................................................................................................................36

© ISO 2020 – All rights reserved iii
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ISO/DIS 11010-1:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,

Vehicle dynamics and chassis components.
A list of all parts in the ISO 11010 series can be found on the ISO website.
iv © ISO 2020 – All rights reserved
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ISO/DIS 11010-1:2020(E)
Introduction

This document was developed in response to worldwide demand for standardization of simulation

models and their requirements in specific application and driving manoeuvres as use cases. During

development and test of road vehicles the question arises, which models should to be used and how good

simulation models have to be for performing certain applications with related driving manoeuvers.

Without standardization, it is common practice that experts in different organizations develop their

own methods and processes to answer this question. When it comes to comparability and model

exchange between project partners, obstacles occur. Today, either the requirements for simulation

models have to be elaborately created and coordinated by experts, or there are major uncertainties in

implementation and quality.

The main purpose of this standard is to provide a framework that enables a systematic assignment

of certain application, driving manoeuvres to required simulation models and their elements and

characteristics. This document classifies the simulation models into certain model classes, their

designation number and related elements, characteristics and common modelling method. Assigning

models to classes related to specific application is the responsibility of the user or other regulations

and standards. The standard contains recommendations in the sense of an appropriate simulation

quality in terms of performance tests. The standard thus enables the user to specify the requirements

for the models with reference to the standard. The standard thus also creates the basis for model

recommendations relevant to vehicle dynamics with regard to Advanced Driver Assistance Systems

and Automated Driving (ADAS/AD).
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DRAFT INTERNATIONAL STANDARD ISO/DIS 11010-1:2020(E)
Passenger cars — Simulation model classification —
Part 1:
Vehicle dynamics
1 Scope

This document establishes a standard for the classification and application of modular simulation

models with regard to vehicle dynamics in context of global vehicle without human driver. With the

created framework a systematics was created, defining how the requirements of simulation models can

be defined for certain application and driving manoeuvres. Thus, allowing to specify the requirements

for simulation models for necessary applications and driving manoeuvres in a standardized way.

For this purpose, the proposed framework systematically divides the vehicle model into model classes and

all model classes into different model types, corresponding to different model characteristics and common

modelling methods. The vehicle dynamics manoeuvres were additionally structured and clustered. One

can assign the manoeuvers to the model classes and model types using an allocation and requirement

table. The standard thus also creates the basis for model recommendations relevant to vehicle dynamics

with regard to Advanced Driver Assistance Systems and Automated Driving (ADAS/AD).

The application of the framework and the specification of the model requirements are the responsibility

of the user or may be determined by other regulations and standards. The standard contains

recommendations for selectable model characteristics in terms of adequate simulation quality with

respect to performance tests and associated application patterns. With regard to functional testing, the

recommendations can be adapted accordingly.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 8855, Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 3833 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
Simulation model

calculation of the system state variables from equations in a mathematical model describing a vehicle

or vehicle sub-systems; the vehicle’s environment is only modelled as far as required, i.e. friction of

the road surface, wind etc. Models in this context are both, the unit under test (UuT) or models to

supplement or complete the simulation loop.
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ISO/DIS 11010-1:2020(E)
3.2
Model class
mathematical model from the vehicle or vehicle sub-systems
3.3
Model designation number

different gradations of model types and depths with associated model characteristics, represented

effects and minimal model inputs and outputs
3.4
Steady state model (physical models)

A steady state model is a model, which represents the definitions of steady state equilibrium mentioned

in ISO 8855 and therefore steady state. The model has to represent the transfer function between model

input and output for steady-state equilibrium. The model is not capable of representing the correct

time behaviour. Effects caused through small changes in time may be neglected. The model is usually

mathematically described by a gain.
3.5
First order model (physical models)

In addition to the steady state model, a first order model is capable of representing the transient

behaviour. The model is usually mathematically described by a differential equation with a first order

lag force element such as PT1 behaviour with a first order.
3.6
Second order model (physical models)

A second order model is defined by a second order force element such as PT2 behaviour with second

order. Due to its conjunct complex poles, a time variant input results in an oscillatory output.

3.7
Model-in-the-Loop
MiL

Testing method in which the controller is integrated as unit under test (UuT) with full-function

controller into the simulation model as a controller model
3.8
Software-in-the-Loop
SiL

Testing method in which the controller is integrated UuT with complete controller functionality into

the simulation model as a controller software function from the ECU
3.9
Processor-in-the-Loop
PiL

Testing method in which the controller with processor emulation is integrated into the simulation model

3.10
ECU-in-the-Loop
HiL

This is a hardware-in-the-loop test method in which the controller are integrated into the simulation

model as a real ECU. In this document it refers to controller primarily.
3.11
Open-loop control

An open-loop controller influences a system’s behaviour without a feedback loop for example based on

maps and is an electric device.
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ISO/DIS 11010-1:2020(E)
3.12
Principal logic closed-loop controller

A closed-loop controller influences a physical system’s behaviour with a feedback loop. For principal

logic, the controller is implemented in a fundamental way – e.g. with a PID controller – to demonstrate

the control logic.
3.13
Full-function controller (MiL/SiL)

For full-function (MiL/SiL), the controller is implemented as the full-function, but just regarding the

function control algorithm. The controller is either realized in MiL or SiL.
3.14
Full-function ECU (SiL/HiL)

For full-function ECU (SiL/HiL), the controller is implemented as the full-function ECU with the whole

software e.g. with function architecture such as Autosar for connecting the ECU to the vehicle on-board

network and not just the function control algorithm. The controller is either realized virtually via

emulation in SiL mode or physically in HiL mode.
3.15
eBooster

An eBooster is a electric brake booster – comprising a control unit, actuator and transmission

device – which has the ability to boost the brake force applied by the driver and to build up pressure

[20]
autonomously without driver actuation .
4 Model designation numbers

Each model class may consist of a physical system including hydraulics and pneumatics and a controller.

NOTE This segmentation can be extended to sensor and actuator.
4.1 Physical system

The model of a physical system shall have a model designation number out of Table 1 according to the

definitions in Chapter 3. The force element characteristic changes from level 0 – no model – to level 3

– second order model and within the sub-designation levels 1.x to 3.x. If a model requires a deeper sub-

categorization, the dot notation and a second digit starting from 1 shall be used.

NOTE The model designation number are valid for all vehicle sub-systems from chapter 5.1 except the

suspension model because its designation number 1 and 2 lack body masses. Nevertheless, the suspension model

designation numbers are reasonably adapted.
Table 1 — Model characteristic and designation number of a physical system
Force element characteristic Model designation number
None 0
Steady state model 1
First order model 2
Second order model 3
4.2 Controller

The controller model shall have a model designation number out of Table 2 according to the definitions

in Chapter 3. The model characteristics increases from level 0 – no model – to level 4 – HiL. For Level 2

and 3 a deeper subcategorization “3.x” is used.

The subcategorization “.x” of level 2 and 3 defines the range of subsets of the target software (see

figure 1), being included in the test bench. This depends on the scope of investigation, mostly in the

context of model-based testing. While level 1 and 2.1 controller models contain a simplified logic,

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ISO/DIS 11010-1:2020(E)

level 2.2 models map the target function (MiL) – that is the original control structure function and

application. Model level 2.3 (SiL) is based on the complied target code of the software. A level 3.1 model

is restricted to the application software (e.g. implementation of control functions and application

parameter) as well as the base software such as a virtual ECU. A level 3.2 model additionally includes

the emulation of the processor and the software is compiled for the target processor. Model 4 is the

typical HiL with hardware related software, communication and diagnosis.
Table 2 — Model characteristic and designation number of a controller
Model designation num-
Description
ber
None 0
Open-loop control 1
Principal logic closed-loop controller 2.1
Target function: Model-in-the-Loop (MiL) – Application Software Model only 2.2
Target software: Software-in-the-Loop (SiL) – Application Software only 2.3
Target software: Software-in-the-Loop (SiL) – Application + Base Software 3.1
Target software: Processor-in-the-Loop (PiL) 3.2
Target ECU: Hardware ECU (HiL) 4
Figure 1 — Subsets of a controller

Note Though it is possible to calculate the time response of communication by high level control models

only, low level models might be enabled by empirical latency time delays. E.g. also the performance of a closed-

loop controller (Level 2) might be significantly influenced by the latency time of sensor signals.

Compared to the model designation number of the physical system (see chapter 4.1), the designation

number of the controller is not mainly influenced by the driving manoeuvre, but by the scope of the

investigation. In pre-development stage, a simple principal logic might be sufficient to evaluate the

overall vehicle behaviour; for functional development and safeguarding, the original function should

be used. Some exemplary types of investigation concerning the choice of the controller designation

number are given in Table 3 as sample.
Table 3 — Examples for the selection of controller designation number.
Type of investigation Controller designation number
preliminary design physical system 0/1/2.1
Functional development (preliminary design) 2.2/2.3
Homologation 2.3/3.1/4
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ISO/DIS 11010-1:2020(E)
Table 3 (continued)
Type of investigation Controller designation number
Safeguarding of software implementation 2.3/3.1
Safeguarding of function including operation system 3.1/3.2/4
Systematic functional safeguarding in spite of a lack of a virtual con-
troller model
5 Model classes
5.1 General

The vehicle model is structured in the following model classes according to Figure 2: Vehicle / Body

(VH), Powertrain (PT), Brake (BR), Steering (ST), Suspension (SU), Aerodynamics (AE) and Tire (TI)

and the Road with Road Surface (RS) and Road Wind (RA). Some model classes consist only of a physical

system XXM, other as combination of a physical system XXM and a control system XXC. The models

refer to common vehicle systems as they are used in passenger cars today. The user can create model

prototypes of future systems accordingly.

Independent from the above-mentioned structure of the models, a controller is not necessarily mapped

to a single ECU. A ECU will likely hold more than one single controller. In addition, a controller algorithm

might be distributed over multiple ECU. This is of important role especially for higher model designation

numbers, where base software or other properties of the ECUs must be considered.

NOTE There might be differing allocations and interfaces defined in chapter 5. In this standard, the axial

rotation of wheels is calculated in the powertrain (PTM) and is passed to the Tire (TIM) and Brake (BRM).

Key
actor forces
signalbus
(bidirectional)
sensor kinematics
Figure 2 — Top-level model architecture
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ISO/DIS 11010-1:2020(E)

The control systems XXC are specific for their components XXM. Sometimes a “central controller”

coordinates the component specific controller. For ADAS a sensor-based environment detection and

track planning is necessary as well as a track control. The path control generates target values for the

component specific controllers; in longitudinal direction for the powertrain (PTC) and brake (BRC) and

in the lateral direction for the steering (STC). Due to the fact that the “central controller” is very specific

to the manufacturer it is not classified in this standard.

NOTE The “central controller” might be partitioned to separate control unit(s) or be added to the control

unit of the specific controller(s).

The capital letters in parenthesis are the model classes’ abbreviations. The selected designation number

of a model class shall be written in the following syntax:
M
C

The actual names resp. numbers shall replace the placeholders in angle brackets. For the

the specified abbreviation shall be used. The syntax looks like in the following examples:

STM2
PTM2 PTC4
BRM2.1 BRC3.1
NOTE This can be extended to sensor and actuator via the syntax:
S
A
5.2 Vehicle / Body

The model class “Vehicle” with the architecture in Figure 3 is actually targeted to describe the modelling

of vehicle body. However, depending on the designation number, it is possible that the vehicle body is

not isolated from the whole vehicle model. The higher the designation number, the better the vehicle

body can be isolated.

The model class Vehicle (VH) shall have a designation number of the physical system (VHM) in

accordance with Table 3.

The designation numbers for class Vehicle does not follow exactly the classification as

descripted in Table 1. Here the principle “Best Practice” applies. Thus, the models are clustered

into three groups:
VHM1: one body model

VHM2: Multi-Body Model splitted sprung mass, unsprung mass, rigid bodies and lock-up table for

suspension

VHM3: Multi-Body Model splitted sprung mass, unsprung mass, multi-body suspension

In the group VHM1 the tyre is lumped to the vehicle, while in the group VHM2 and VHM3, the vehicle

body can be isolated from suspension and tire. As example, the wide used single-track model belongs to

VHM1, and VHM3 has the 3D-vehicle body model with local stiffness/stiffness matrix in its scope.

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ISO/DIS 11010-1:2020(E)
Figure 3 — Vehicle architecture
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ISO/DIS 11010-1:2020(E)
8 © ISO 2020 – All rights reserved
Table 3 — Vehicle system
Common modelling methods / Minimal Minimal
Model type Model description Description Effects
typical application area model input model output
VHM 0 None
single mass, one dimen- Forces (braking,

VHM 1.1 Single mass 1-DoF starting, braking (ODE) differential equation (1-DoF) ax

sional accelerating)
Lateral dynamics model understeer-/over- (ODE ) dif ferent ia l equat ion /
VHM 1.2 Single track model steering angle ay, yaw
with constant velocity steer function test for controler
VHM1.2+ lateral load load transfer due

Single track model with lat- transfer due to ay, load to vehicle later- VHM1.2+ load dependant tyre forces

VHM 1.3 VHM 1.2 VHM 1.2, roll
eral load transfer dependent tyre model al acceleration due to roll
required tyre characteristics
VHM1.2+ longitudinal load transfer due
VHM1.2+ load dependant tyre forces

Single Track model with lon- load transfer due to ax, to vehicle longitu- VHM 1.1+ VHM

VHM 1.4 due to pitch/ function test with con- VHM 1.1+ VHM 1.2
gitudinal dynamics load dependent tyre dinal acceleration 1.2
troller (eg. ACC)
model required tyre characteristics
MBD mechanics

3D-model with rigid bodies 3D Model with rigid bod- (splited sprung- 3DModel with suspension + tyres/ func- forces moments Motion of bodies

VHM 2.1

and lock-up table suspension ies incl. wheel bounce mass, unsprung- tion and performance test of controller / aero and hard points

masses)
MBD mechanics

3D-model with rigid bodies 3D Model with rigid bod- (splited sprung- 3DModel with suspension + tyres/ func- forces moments Motion of bodies

VHM 3.1

and MBD suspension ies incl. wheel bounce mass, unsprung- tion and performance test of controller / aero and hard points

masses)
VHM 3.1. and global
3D-model with flexibel el- VHM 3.1+global stiffnesses lumped in
VHM 3.2 stiffnesses (torsional VHM 3.1 VHM 3.1 VHM 3.1
ements (global stiffnesses) concentrated spring-damper elements
stiffness, bending)

3D-Modell with flex bodies VHM 3.2 + local stiff- VHM 3.2 + local VHM 3.2 + parts flexible modelled or

VHM 3.3 VHM 3.2 VHM 3.2
(local stiffnesses) nesses deformation full flex-body (stiffness matrix)
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ISO/DIS 11010-1:2020(E)
5.3 Aerodynamics

The model class Aerodynamics (AE) with the architecture in Figure 4 shall have a model designation

number of the physical system (AEM) in accordance with Table 4. The modelling of aerodynamic effects

is divided into three sub-groups. Aerodynamic effects in the vehicle models discussed in this paper are

modelled by forces and sometimes moments. The first effect considered is in general the drag force,

see AEM 1.1. The next level is including vertical forces described by the sublevel AEM 1.2. In order to

include sidewind effects in the model sublevel AEM 1.3 is included.
Figure 4 — Aerodynamics architecture
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ISO/DIS 11010-1:2020(E)
10 © ISO 2020 – All rights reserved
Table 4 — Aerodynamics system
Common modelling
Minimal Minimal
Model type Model description Description Effects methods /
model input model output
typical application area
AEM 0 No Aerodynamics
only longitudinal Drag force from constant factor
AEM 1.1 Drag drag-forces vehicle velocity long. force
forces considered or curve.
vertical forces

aditionally front and which influence force from constant factor long. and vertical forc-

AEM 1.2 AEM 1.1 + vertical vehicle velocity
rear lift forces limit under-/over- or curve. es, pitch moment
steer balance.
forces and moments (or a
all three dimensions are sidewind sensi- vehicle and air ve- AEM 1.2 + yaw, roll
AEM 1.3 AEM 1.2 + sidewind pair of forces) from constant
considered. tivity locity moment
factor or fields
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ISO/DIS 11010-1:2020(E)
5.4 Brake

The model class Brake (BR) with the architecture in Figure 5 contains the brake controller (BRC) and

the physical system (BRM) is a s
...

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