ISO 12021:2010
(Main)Road vehicles — Sensitivity to lateral wind — Open-loop test method using wind generator input
Road vehicles — Sensitivity to lateral wind — Open-loop test method using wind generator input
ISO 12021:2011 specifies an open-loop test method to determine the sensitivity to lateral wind of a vehicle by means of a wind generator. It applies to passenger cars as defined in ISO 3833, passenger car-trailer combinations and light trucks. Its applicability to motorcycles is yet to be investigated. The test conditions specified in this test method are not representative of real driving conditions but are useful to obtain measures of vehicle dynamic response to lateral wind.
Véhicules routiers — Sensibilité au vent latéral — Méthode en boucle ouverte avec génération de vent
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 12021
First edition
2010-12-01
Road vehicles — Sensitivity to lateral
wind — Open-loop test method using
wind generator input
Véhicules routiers — Sensibilité au vent latéral — Méthode en boucle
ouverte avec génération de vent
Reference number
ISO 12021:2010(E)
©
ISO 2010
---------------------- Page: 1 ----------------------
ISO 12021:2010(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2010
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing 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 2010 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 12021:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Principle .1
5 Reference system.2
6 Variables.2
7 Measuring equipment .2
7.1 Description.2
7.2 Transducer installation.3
7.3 Data processing.3
8 Test conditions .3
8.1 General .3
8.2 Test track.4
8.3 Weather conditions .4
8.4 Test vehicle .4
8.5 Vehicle loading conditions.4
9 Wind generators .5
10 Test procedure.5
10.1 Warm-up .5
10.2 Test speed.5
10.3 Steering .5
10.4 Number of test runs .5
10.5 Measuring points of lateral position using the dye-trail method .5
10.6 Data excluded from the computation method.6
11 Data analysis.6
11.1 General .6
11.2 Yaw velocity and lateral acceleration.7
11.3 Lateral deviation.8
12 Data presentation .8
Annex A (informative) Test report — General data .9
Annex B (normative) Test report — Presentation of results.12
Bibliography.14
© ISO 2010 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 12021:2010(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 12021 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 9, Vehicle
dynamics and road-holding ability.
This first edition of ISO 12021 cancels and replaces ISO 12021-1:1996, which has been technically revised.
iv © ISO 2010 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 12021:2010(E)
Introduction
The main purpose of this International 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.
© ISO 2010 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 12021:2010(E)
Road vehicles — Sensitivity to lateral wind — Open-loop test
method using wind generator input
1 Scope
This International Standard specifies an open-loop test method to determine the sensitivity to lateral wind of a
vehicle by means of a wind generator. It applies to passenger cars as defined in ISO 3833, passenger car-
trailer combinations and light trucks. Its applicability to motorcycles is yet to be investigated.
The test conditions specified in this test method are not representative of real driving conditions but are useful
to obtain measures of vehicle dynamic response to lateral wind.
NOTE The test conditions in this test method do not simulate natural wind conditions. However, the wind velocity
proposed here is representative of fairly severe wind conditions occurring naturally.
2 Normative references
The following referenced documents are indispensable for the application 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 1176:1990, Road vehicles — Masses — Vocabulary and codes
ISO 8855, Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary
ISO 15037-1:2006, 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 8855 apply.
4 Principle
The purpose of this test method is to determine vehicle sensitivity to lateral wind by which the vehicle motion
is disturbed. This method requires the measurement of vehicle behaviour under a lateral wind condition. The
vehicle behaviour can be characterized by several measures.
In this test method the vehicle is initially driven along a straight path and its response to a crosswind input of a
wind generator is then measured. The steering-wheel is held fixed during most of the test.
Two methods for finding the lateral deviation are proposed:
⎯ a direct method by means of direct measurement or with a dye-trail left on the road surface, and
⎯ an indirect method by means of a computation from on-board-measured vehicle motions.
© ISO 2010 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 12021:2010(E)
5 Reference system
The reference system specified in ISO 15037-1 shall apply.
6 Variables
The following variables corresponding to the terms and definitions of ISO 8855 shall be measured:
&
a) yaw velocity, ψ ;
b) lateral acceleration, a ;
Y
c) steering-wheel angle, δ ;
H
d) longitudinal velocity, v .
X
Measuring the following additional variables is optional:
⎯ lateral deviation, γ;
⎯ roll angle, ϕ;
⎯ sideslip angle, β;
⎯ lateral velocity, v .
Y
The variables listed in this clause are not intended to comprise a complete list.
7 Measuring equipment
7.1 Description
The variables selected from the list in Clause 6 shall be measured by means of appropriate transducers. Their
time histories shall be recorded on a multi-channel recorder having a time base. This is not obligatory for
lateral deviation, which can be measured directly after the test has been completed.
The typical operating ranges of the variables and recommended maximum errors of the combined transducers
and the recording system are shown in Table 1.
2 © ISO 2010 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 12021:2010(E)
Table 1 — Typical operating ranges of the variables and recommended maximum errors of
transducers and recording system
Recommended maximum error of the combined
Variable Range of variable
transducers and recording system
Yaw velocity −10°/s to +10°/s ±0,1°/s
2 2 2
Lateral acceleration −5 m/s to +5 m/s ±0,05 m/s
a
Steering-wheel angle −30° to +30° ±1°, but resolution < 0,3°
Longitudinal velocity 0 m/s to 40 m/s ±0,4 m/s
Lateral deviation 5 m ±0,02 m
Roll angle −10° to +10° ±0,1°
Sideslip angle −5° to +5° ±0,2°
Lateral velocity −10 m/s to +10 m/s ±0,2 m/s
NOTE Transducers for some of the listed variables are not widely available and are not in general use. Many such instruments are
developed by users. If any system error exceeds the recommended maximum value, this and the actual maximum error shall be stated
in the test report (see Annex A).
a
Assuming a conventional steering system.
7.2 Transducer installation
7.2.1 General
Subclause 4.2 of ISO 15037-1:2006 shall apply.
7.2.2 Lateral deviation
The lateral deviation may be measured either by direct measurement using appropriate instrumentation or by
means of a dye-trail, or by means of a computational method (see 11.3.3). The dye-trail shall be made on the
test track by means of a water jet. The water outlet should be 0,02 m above the track surface. An elastic tube
may be used to extend this outlet.
The water jet should be positioned as close as possible to the z-axis of the intermediate axis system. If this is
not the case, a correction can be applied to achieve values within the tolerance for lateral acceleration.
7.3 Data processing
The recording system and data processing requirements contained in 4.3 of ISO 15037-1:2006 shall apply.
8 Test conditions
8.1 General
The test conditions specified in 5.1 of ISO 15037-1:2006 and the conditions of 8.2 and 8.3 in this International
Standard shall apply. Any deviations shall be specified in the test report (see Annex A), including individual
diagrams for the presentation of results (see Annex B).
© ISO 2010 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 12021:2010(E)
8.2 Test track
All tests shall be carried out on a uniform hard road surface which is free of contaminants. The gradient, as
measured over the full width of the track in the lateral direction and over a distance of at least 50 m in the
longitudinal direction, shall be <2,5 %.
It is recommended that the track have either a smooth surface (asphalt or concrete) or a high-friction surface.
The test surfa
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.