Passenger cars -- Vehicle dynamic simulation and validation -- Steady-state circular driving behaviour

ISO 19364:2016 specifies a method for comparing computer simulation results from a vehicle mathematical model to measured test data for an existing vehicle according to steady-state circular driving tests as specified in ISO 4138 or the Slowly Increasing Steer Test that is an alternative to ISO 4138. The comparison is made for the purpose of validating the simulation tool for this type of test when applied to variants of the tested vehicle. It is applicable to passenger cars as defined in ISO 3833. NOTE The Slowly Increasing Steer method is described in regulations such as USA FMVSS 126 "Federal Register Vol 72, No. 66, April 6, 2007" and UN/ECE Regulation No. 13-H, "Uniform provisions concerning the approval of passenger cars with regard to braking".

Voitures particulières -- Simulation et validation dynamique des véhicules -- Tenue de route en régime permanent sur trajectoire circulaire

General Information

Status
Published
Publication Date
04-Oct-2016
Current Stage
6060 - International Standard published
Start Date
27-Jul-2016
Completion Date
05-Oct-2016
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INTERNATIONAL ISO
STANDARD 19364
First edition
2016-10-01
Passenger cars — Vehicle dynamic
simulation and validation — Steady-
state circular driving behaviour
Voitures particulières — Simulation et validation dynamique des
véhicules — Tenue de route en régime permanent sur trajectoire
circulaire
Reference number
ISO 19364:2016(E)
ISO 2016
---------------------- Page: 1 ----------------------
ISO 19364:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 19364:2016(E)
Contents Page

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

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

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

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

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

4 Principle ........................................................................................................................................................................................................................ 2

5 Variables ....................................................................................................................................................................................................................... 2

6 Simulation tool requirements ................................................................................................................................................................ 2

6.1 General ........................................................................................................................................................................................................... 2

6.2 Mass and inertia ..................................................................................................................................................................................... 3

6.3 Tires .................................................................................................................................................................................................................. 3

6.4 Suspensions ............................................................................................................................................................................................... 3

6.5 Steering system ...................................................................................................................................................................................... 3

6.6 Aerodynamics .......................................................................................................................................................................................... 4

6.7 Brake system ............................................................................................................................................................................................. 4

6.8 Powertrain .................................................................................................................................................................................................. 4

6.9 Active controllers .................................................................................................................................................................................. 4

6.10 Data acquisition ..................................................................................................................................................................................... 4

6.11 Driver controls ........................................................................................................................................................................................ 4

7 Physical testing....................................................................................................................................................................................................... 4

7.1 General ........................................................................................................................................................................................................... 4

7.2 Test methods ............................................................................................................................................................................................. 5

7.2.1 Constant-radius ................................................................................................................................................................ 5

7.2.2 Constant speed .................................................................................................................................................................. 5

7.3 Documentation of limit condition .......................................................................................................................................... 5

7.4 Low-pass filtering of measured data .................................................................................................................................... 5

8 Simulation ................................................................................................................................................................................................................... 6

8.1 General ........................................................................................................................................................................................................... 6

8.2 Simulation procedure ......... ............................................................................................................................................................... 6

8.2.1 Direction of steer ............................................................................................................................................................. 6

8.2.2 Tests with steady-state conditions ................................................................................................................... 6

8.2.3 Tests with slowly changing conditions ......................................................................................................... 6

8.3 Data recording ......................................................................................................................................................................................... 6

8.3.1 General...................................................................................................................................................................................... 6

8.3.2 Tests with steady-state conditions ................................................................................................................... 6

8.3.3 Tests with slowly changing conditions ......................................................................................................... 7

9 Comparison between simulation and physical test results ..................................................................................... 7

9.1 General ........................................................................................................................................................................................................... 7

9.2 Calculation of boundary points................................................................................................................................................. 7

9.3 Tolerances for cross-plot boundary points..................................................................................................................... 9

9.4 Comparison of simulation cross plots with measured test data .................................................................. 9

10 Documentation ....................................................................................................................................................................................................... 9

Annex A (informative) Combined tolerance for normalized geometric profile ...................................................11

Bibliography .............................................................................................................................................................................................................................13

© ISO 2016 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 19364:2016(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 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.

The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 33, Vehicle

dynamics and chassis components.
iv © ISO 2016 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 19364:2016(E)
Introduction

The main purpose of this document is to provide a repeatable and discriminatory method for comparing

simulation results to measured test data from a physical vehicle for a specific type of test.

The dynamic behaviour of a road vehicle is a very important aspect of active vehicle safety. Any given

vehicle, together with its driver and the prevailing environment, constitutes a closed-loop system that

is unique. The task of evaluating the dynamic behaviour is therefore very difficult since the significant

interactions of these driver–vehicle–environment elements are each complex in themselves. A complete

and accurate description of the behaviour of the road vehicle should include information obtained from

a number of different tests.

Since this test method quantifies only one small part of the complete vehicle handling characteristics,

the validation method associated with this test can only be considered significant for a correspondingly

small part of the overall dynamic behaviour.
© ISO 2016 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 19364:2016(E)
Passenger cars — Vehicle dynamic simulation and
validation — Steady-state circular driving behaviour
1 Scope

This document specifies a method for comparing computer simulation results from a vehicle

mathematical model to measured test data for an existing vehicle according to steady-state circular

driving tests as specified in ISO 4138 or the Slowly Increasing Steer Test that is an alternative to

ISO 4138. The comparison is made for the purpose of validating the simulation tool for this type of test

when applied to variants of the tested vehicle.
It is applicable to passenger cars as defined in ISO 3833.

NOTE The Slowly Increasing Steer method is described in regulations such as USA FMVSS 126 “Federal

Register Vol 72, No. 66, April 6, 2007” and UN/ECE Regulation No. 13-H, “Uniform provisions concerning the

approval of passenger cars with regard to braking”.
2 Normative references

The following documents are referred to in 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 4138, Passenger cars — Steady-state circular driving behaviour — Open-loop test methods

ISO 15037-1, Road vehicles — Vehicle dynamics test methods — Part 1: General conditions for passenger cars

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1176, ISO 2416, ISO 3833,

ISO 8855 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 http://www.iso.org/obp
3.1
simulation

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

3.2
simulation tool

simulation environment including software, models, input data, and hardware case of hardware-in-the-

loop simulation
3.3
cross plot

plot where the horizontal axis shows values for a variable other than time (e.g. lateral acceleration)

© ISO 2016 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 19364:2016(E)
4 Principle

Open-loop test methods defined in ISO 4138 are used to determine the steady-state circular driving

behaviour of passenger cars as defined in ISO 3833.

The test characterizes vehicle-handling behaviour in steady-state conditions covering a range of

cornering conditions from straight-line up to limit conditions for steering control. Results are typically

reported by cross plotting steady-state measures of variables of interest against steady-state levels of

lateral acceleration, and possibly calculating characteristic values based on gradients of the plotted data.

Within this document, the purpose of the test is to demonstrate that a vehicle simulation tool can

predict the vehicle behaviour within specified tolerances. The vehicle simulation tool is used to simulate

a specific existing vehicle running through a steady-state test as specified in ISO 4138, or, alternatively,

a Slowly Increasing Steer Test used in stability control evaluation. Simulation results are used to define

graphical boundaries for overlaid cross-plots, and the data from physical testing are overlaid to see if

the measurements fall within the acceptable ranges.

NOTE This document may be used for several purposes. Depending on the purpose of the validation, only

parts of the validation requirements may be met.

The existing vehicle is physically tested at least three times to allow the test data to be compared with

the simulation results.
5 Variables
The following variables shall be compared:
— lateral acceleration;
— steering-wheel angle;
— sideslip angle;
— roll angle.

The steering-wheel torque shall also be compared if this document is used to validate a simulation

tool for the purpose of predicting steering torque during steady-state circular driving as defined in

ISO 4138.

Measurement requirements shall be taken from ISO 4138 and ISO 15037-1, unless noted otherwise.

For the purpose of this document, lateral acceleration should be measured directly by an inertial

measurement unit, rather than using the alternative calculation methods provided in ISO 4138.

6 Simulation tool requirements
6.1 General

The simulation tool used to predict behaviour of a vehicle of interest shall include a mathematical model

capable of calculating variables of interest for the test procedures being simulated. In this document,

the mathematical model is used to simulate a steady-state cornering manoeuvres (see 7.2) and provide

calculated values of the variables of interest from Clause 5.

The procedure for obtaining input data from experiments may differ for simulation tools, however, the

input data shall not be manipulated for better correlation. However, adaptation of input data to actual

testing conditions such as road friction should be allowed.

NOTE Active controllers and active intervention systems that prevent a steady-state condition from being

established are not relevant for the tests covered in this document.
2 © ISO 2016 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 19364:2016(E)
6.2 Mass and inertia

The mathematical model should include all masses, such as the chassis, engine, payloads, unsprung

masses, etc. The value of the mass and the location of the centre of mass are essential properties of the

vehicle for the tests covered in this document. On the other hand, moments and products of inertia have

no effect under steady-state conditions, when angular accelerations are negligible.

Vehicles with significant torsional frame compliance require a more detailed representation that

includes frame-twist effects that occur in extreme manoeuvres.
6.3 Tires

The vertical, lateral, and longitudinal forces and moments where each tire contacts the ground

provide the main actions on the vehicle. The fidelity of the prediction of vehicle movement depends

on the fidelity of the calculated tire forces and moments. Differences between the tire force and

moment measurements used for the model and those of used in vehicle testing can be expected due to

different wear and aging histories. Although difficult to account for these differences, it is important to

acknowledge and understand them.

Large lateral slip angles and inclination can occur under the conditions covered in this document.

Longitudinal slip ratios are usually limited to the amounts needed to generate longitudinal forces to

maintain a target speed in the test. The tire model shall cover the entire ranges of slip (lateral and

longitudinal), inclination angle relative to the ground, and load that occur in the tests being simulated.

The surface friction coefficient between the tire and ground is an important property for the limit

friction conditions that can be encountered in steady-state circular driving tests.

The simulated tests take place on a flat homogenous surface; detailed tire models that handle uneven

surfaces are not needed. If the test surface has inclination for water drainage, this should be included in

the simulation.

The simulated tests involve conditions that are intended to be steady-state; therefore, transient effects

in tire response (e.g. relaxation length) are not needed.
6.4 Suspensions

The properties of the suspensions that determine how the tire is geometrically located, oriented, and

loaded against the ground shall be represent
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 19364
ISO/TC 22/SC 33 Secretariat: DIN
Voting begins on: Voting terminates on:
2015-02-19 2015-05-19
Passenger cars — Vehicle dynamic simulation and
validation — Steady-state circular driving behaviour

Voitures particulières — Simulation et validation dynamique des véhicules — Tenue de route en régime

permanent sur trajectoire circulaire
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,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 19364:2014(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2014
---------------------- Page: 1 ----------------------
ISO/DIS 19364:2014(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2014

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 19364:2015(E)
© ISO 2013

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or

utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or

posting on the internet or an intranet, without prior written permission. Permission can be requested

from either ISO at the address below or ISO's member body in the country of the requester.

ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland.
Contents

This template allows you to work with default MS Word functions and styles. You can use these if you

want to maintain the Table Of Contents automatically and apply auto-numbering if this is your

preference. Delete this Table of Contents if not required.

Foreword .......................................................................................................................................................................... 5

Introduction..................................................................................................................................................................... 6

1 Scope ............................................................................................................................................................................... 7

2 Normative references ............................................................................................................................................... 7

3 Terms and definitions .............................................................................................................................................. 7

4 Principle ........................................................................................................................................................................ 8

5 Variables........................................................................................................................................................................ 8

6 Simulation Tool Requirements ............................................................................................................................. 8

6.1 General ...................................................................................................................................................................................... 8

6.2 Mass and inertia .................................................................................................................................................................... 9

6.3 Tires ........................................................................................................................................................................................... 9

6.4 Suspensions ............................................................................................................................................................................ 9

6.5 Steering system .................................................................................................................................................................. 10

6.6 Aerodynamics ..................................................................................................................................................................... 10

6.7 Brake system ....................................................................................................................................................................... 10

6.8 Powertrain ........................................................................................................................................................................... 10

2 © ISO 19364 – All rights reserved
---------------------- Page: 3 ----------------------
ISO 19364:2015 (E)

6.9 Active controllers .............................................................................................................................................................. 10

6.10 Data Acquisition .............................................................................................................................................................. 11

6.11 Driver controls ................................................................................................................................................................. 11

7 Physical Testing ....................................................................................................................................................... 11

7.1 General ................................................................................................................................................................................... 11

7.2 Test Methods ....................................................................................................................................................................... 11

7.2.1 Constant-radius ......................................................................................................................................................... 11

7.2.2 Constant speed ........................................................................................................................................................... 11

7.3 Documentation of limit condition .............................................................................................................................. 12

7.4 Low-pass filtering of measured data ......................................................................................................................... 12

8 Simulation .................................................................................................................................................................. 12

8.1 General ................................................................................................................................................................................... 12

8.2 Simulation Procedure ...................................................................................................................................................... 12

8.2.1 Direction of steer ...................................................................................................................................................... 12

8.2.2 Tests with steady state conditions .................................................................................................................... 12

8.2.3 Tests with slowly changing conditions ............................................................................................................ 13

8.3 Data recording .................................................................................................................................................................... 13

8.3.1 General .......................................................................................................................................................................... 13

8.3.2 Tests with steady state conditions .................................................................................................................... 13

8.3.3 Tests with slowly changing conditions ............................................................................................................ 13

9 Comparison between simulation and physical test results ..................................................................... 13

9.1 General ................................................................................................................................................................................... 13

9.2 Calculation of boundary points ................................................................................................................................... 14

9.3 Tolerances for cross-plot boundary points ............................................................................................................ 16

9.4 Comparison of simulation cross plots with measured test data ................................................................... 16

10 Documentation ...................................................................................................................................................... 16

Annex A (informative) Combined Tolerance for Normalized Geometric Profile ................................ 18

© ISO 19364 – All rights reserved 3
---------------------- Page: 4 ----------------------
ISO 19364:2015 (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. 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. 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 meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO's adherence to the WTO principles in the Technical

Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC22/SC9 which will be in 2015 TC22/SC33.

© ISO 19364 – All rights reserved 5
---------------------- Page: 5 ----------------------
ISO 19364:2015(E)
Introduction

The main purpose of this Standard is to provide repeatable and discriminatory test results.

The dynamic behaviour of a road vehicle is a very important aspect of active vehicle safety. Any given

vehicle, together with its driver and the prevailing environment, constitutes a closed-loop system that is

unique. The task of evaluating the dynamic behaviour is therefore very difficult since the significant

interaction of these driver-vehicle-environment elements are each complex in themselves. A complete

and accurate description of the behaviour of the road vehicle must necessarily involve information

obtained from a number of different tests.

Since this test method quantifies only one small part of the complete vehicle handling characteristics,

the results of these tests can only be considered significant for a correspondingly small part of the

overall dynamic behaviour.

Moreover, insufficient knowledge is available concerning the relationship between overall vehicle

dynamic properties and accident avoidance. A substantial amount of work is necessary to acquire

sufficient and reliable data on the correlation between accident avoidance and vehicle dynamic

properties in general and the results of these tests in particular. Consequently, any application of this

test method for regulation purposes will require proven correlation between test results and accident

statistics.
6 © ISO 19364 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 19364:2015 (E)
Passenger cars — Vehicle dynamic simulation and validation —
Steady-state circular driving behaviour
1 Scope

This International Standard specifies a method for comparing computer simulation results from a

vehicle mathematical model to measured test data for an existing vehicle according to steady-state

circular driving tests as specified in ISO 4138 or the Slowly Iincreasing Steer test that is an alternative

to ISO 4138. The comparison is made for the purpose of validating the simulation tool for this type of

test when applied to variants of the tested vehicle.
It is applicable to passenger cars as defined in ISO 3833.

NOTE The Slowly Increasing Steer method is described in regulations such as USA FMVSS 126 “Federal

Register Vol 72, No. 66, April 6, 2007” and UN/ECE Regulation No. 13-H, “Uniform provisions

concerning the approval of passenger cars with regard to braking.”
2 Normative references

The following referenced documents are indispensable for the application of this document. For these

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

ISO 1176, Road vehicles — Masses — Vocabulary and codes
ISO 2416, Passenger cars — Mass distribution
ISO 3833, Road vehicles — Types — Terms and definitions

ISO 4138, Passenger cars — Steady-state circular driving behaviour — Open-loop test methods

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

ISO 15037-1, Road vehicles — Vehicle dynamics test methods — Part 1: General conditions for passenger

cars
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1176, ISO 2416, ISO 3833,

ISO 8855 and the following apply.
3.1
simulation

calculation of motion variables of a vehicle from equations in a mathematical model of the vehicle

system
3.2
simulation tool

simulation environment including software, models, input data, and hardware in case of hardware in

the loop simulation
3.3
cross plot

plot where the horizontal axis shows values for a variable other than time (e.g., lateral acceleration)

© ISO 19364 – All rights reserved 7
---------------------- Page: 7 ----------------------
ISO 19364:2015(E)
4 Principle

Open-loop test methods defined in ISO 4138 are used to determine the steady-state circular driving

behaviour of passenger cars as defined in ISO 3833.

The test characterizes vehicle-handling behaviour in steady-state conditions covering a range of

cornering conditions from straight-line up to limit conditions for steering control. Results are typically

reported by cross plotting steady-state measures of variables of interest against steady-state levels of

lateral acceleration, and possibly calculating characteristic values based on gradients of the plotted

data.

Within this International Standard, the purpose of the test is to demonstrate that a vehicle simulation

tool can predict the vehicle behaviour within specified tolerances. The vehicle simulation tool is used to

simulate a specific existing vehicle running through a steady-state test as specified in ISO 4138, or,

alternatively, a Slowly Increasing Steer test used in stability control evaluation. Simulation results are

used to define graphical boundaries for overlaid cross-plots, and the data from physical testing are

overlaid to see if the measurements fall within the acceptable ranges.

NOTE This International Standard may be used for several purposes. Depending on the purpose of the

validation, only parts of the validation requirements may be met.

The existing vehicle is physically tested at least three times to allow the test data to be compared with

the simulation results.
5 Variables
The following variables shall be compared:
 Lateral acceleration
 Steering wheel angle
 Side slip angle
 Roll angle

The steering wheel torque shall also be compared if this International Standard is used to validate a

simulation tool for the purpose of predicting steering torque during steady-state circular driving as

defined in ISO 4138.

Measurement requirements shall be taken from ISO 4138 and ISO 15037-1 unless noted otherwise.

NOTE For the purpose of this International Standard, lateral acceleration should be measured directly

by an inertial measurement unit, rather than using the alternative calculation methods provided in ISO

4138.
6 Simulation Tool Requirements
6.1 General

The simulation tool used to predict behaviour of a vehicle of interest shall include a mathematical

model capable of calculating variables of interest for the test procedures being simulated. In this

8 © ISO 19364 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 19364:2015 (E)

International Standard, the mathematical model is used to simulate a steady-state cornering manoeuvre

(see 7.2) and provide calculated values of the variables of interest from Clause 5.

NOTE 1 Procedure for obtaining input data from experiments may differ for simulation tools, however,

the input data should not be manipulated for better correlation.

NOTE 2 Active controllers and active intervention systems that prevent a steady state condition

from being established are not relevant for the tests covered in this International Standard.

6.2 Mass and inertia

The mathematical model should include all masses, such as the chassis, engine, payloads, unsprung

masses, etc. The value of the mass and the location of the centre of mass are essential properties of the

vehicle for the tests covered in this International Standard. On the other hand, moments and products of

inertia have no effect under steady-state conditions, when angular accelerations are negligible.

Vehicles with significant torsional frame compliance require a more detailed representation that

includes frame-twist effects that occur in extreme manoeuvres.
6.3 Tires

The vertical, lateral, and longitudinal forces and moments where each tire contacts the ground provide

the main actions on the vehicle. The fidelity of the prediction of vehicle movement depends on the

fidelity of the calculated tire forces and moments.

Large lateral slip angles can occur under the conditions covered in this International Standard.

Longitudinal slip ratios are usually limited to the amounts needed to generate longitudinal forces to

maintain a target speed in the test. The tire model should cover the entire ranges of slip (lateral and

longitudinal), inclination angle relative to the ground, and load that occur in the tests being simulated.

The surface friction coefficient between the tire and ground is an important property for the limit

friction conditions that can be encountered in steady-state circular driving tests.

The simulated tests take place on a flat homogenous surface; detailed tire models that handle uneven

surfaces are not needed.

The simulated tests involve conditions that are intended to be steady state; therefore, transient effects

in tire response (e.g.,
...

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