ISO 13674-1:2010

INTERNATIONAL ISO
STANDARD 13674-1
Second edition
2010-05-15
Road vehicles — Test method for the
quantification of on-centre handling —
Part 1:
Weave test
Véhicules routiers — Méthode d'essai pour la quantification
du centrage —
Partie 1: Essai en petite sinusoïde au volant

Reference number
©
ISO 2010
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ii © ISO 2010 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms, definitions and symbols .1
4 Principle.2
5 Variables.2
5.1 Reference system.2
5.2 Variables to be measured.2
6 Measuring equipment .3
6.1 Description.3
6.2 Transducer installations.3
6.3 Data processing.3
7 Test conditions .3
7.1 General .3
7.2 Test track.4
7.3 Wind velocity .4
7.4 Test vehicle .4
8 Procedure.5
8.1 Warm-up .5
8.2 Initial driving condition.5
8.3 Weave test procedure .5
9 Data evaluation and presentation of results.6
9.1 General .6
9.2 Time histories .6
9.3 Calculated lateral acceleration.6
9.4 Characteristic values .6
Bibliography.9

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
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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 13674-1 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 9, Vehicle
dynamics and road-holding ability.
This second edition cancels and replaces the first edition (ISO 13674-1:2003), which has been technically
revised.
ISO 13674 consists of the following parts, under the general title Road vehicles — Test method for the
quantification of on-centre handling:
⎯ Part 1: Weave test
⎯ Part 2: Transition test
iv © ISO 2010 – All rights reserved

Introduction
The main purpose of this part of ISO 13674 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 necessarily involves 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.

INTERNATIONAL STANDARD ISO 13674-1:2010(E)

Road vehicles — Test method for the quantification
of on-centre handling —
Part 1:
Weave test
1 Scope
This part of ISO 13674 specifies a test schedule that addresses a particular aspect of the on-centre handling
characteristics of a vehicle: the weave test. It is applicable to passenger cars in accordance with ISO 3833,
and to light trucks.
NOTE The manoeuvre specified in this test method is not representative of real driving conditions but is useful for
obtaining measures of vehicle on-centre handling behaviour in response to a specific type of steering input under closely
controlled test conditions. Other aspects of on-centre handling are addressed in the companion ISO/TS 20119 and
ISO 13674-2.
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, Road vehicles — Masses — Vocabulary and codes
ISO 2416, Passenger cars — Mass distribution
ISO 3833, Road vehicles — Types — Terms and definitions
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, definitions and symbols
For the purposes of this document, the terms, definitions and symbols given in ISO 1176, ISO 2416, ISO 3833,
ISO 8855 and the following apply.
3.1
on-centre handling
description of the steering “feel” and precision of a vehicle during nominally straight-line driving and in
negotiating large radius bends at high speeds but low lateral accelerations
3.2
ordinate deadband
vertical width of the hysteresis loops at abscissa zero
3.3
abscissa deadband
horizontal width of the hysteresis loops at ordinate zero
3.4
gradient
ratio of change in the ordinate with respect to a unit change in the abscissa, evaluated on each side of the
hysteresis loop
4 Principle
On-centre handling represents that part of the straight-line directional stability characteristics of the vehicle
existing at lateral acceleration levels, typically no greater than 1 m/s . On-centre handling is concerned
primarily with features that directly influence the driver's steering input, such as steering system and tyre
characteristics. Thus, test schedules for the evaluation of on-centre handling behaviour seek to minimize other
factors that influence the wider aspects of straight-line directional stability, such as disturbance inputs due to
ambient winds and road irregularities.
This part of ISO 13674 defines a test schedule that involves driving the vehicle in a nominally straight line at a
constant forward speed. During the test, driver inputs and vehicle responses are measured and recorded.
From the recorded signals, characteristic values are calculated.
5 Variables
5.1 Reference system
The variables of motion used to describe vehicle behaviour in a test-specific driving situation relate to the
intermediate axis system (X, Y, Z) (see ISO 8855).
The location of the origin of the vehicle axis system (X , Y , Z ) is the reference point and therefore should
V V V
be independent of the loading condition. The origin is therefore fixed in the longitudinal plane of symmetry at
half-wheelbase and at the same height above the ground as the centre of gravity of the vehicle at complete
vehicle kerb mass (see ISO 1176).
5.2 Variables to be measured
When using this test method, the following variables shall be measured:
⎯ steering-wheel angle, δ ;
H
⎯ steering-wheel torque, M ;
H
dψ
⎯ yaw velocity, ;
dt
⎯ longitudinal velocity, v .
X
The following variables should be measured:
⎯ lateral acceleration, a ;
Y
dδ
H
⎯ steering-wheel angular velocity, .
dt
See ISO 8855.
2 © ISO 2010 – All rights reserved

6 Measuring equipment
6.1 Description
All variables shall be measured by means of appropriate transducers and their time histories shall be recorded
by a multi-channel recording system. Typical operating ranges and recommended maximum errors of the
combined transducer and recording system are shown in Table 1.
Table 1 — Variables, typical operating ranges and recommended maximum errors
Recommended maximum error
a
Variable Typical operating range
b
of combined system
Steering-wheel angle ± 50° ± 0,1°
Steering-wheel torque ± 0,1 N ⋅ m ± 0,1 N ⋅ m
Yaw velocity ± 10 °/s ± 0,1 °/s
Longitudinal velocity 0 m/s to 50 m/s ± 0,5 m/s
2 2
Lateral acceleration ± 5 m/s ± 0,1 m/s
Steering-wheel angular velocity ± 100 °/s ± 1 °/s
Transducers for measuring 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 st
...