ISO 10521-2:2006

Road vehicles — Road load — Part 2: Reproduction on chassis dynamometer

ISO 10521-2:2006 specifies methods of setting the target road load on chassis dynamometers for the purpose of a subsequent test, for example the fuel consumption test or the exhaust-emission measurement test. The road-load setting method on chassis dynamometers depends on the road-load measurement method, such as the coastdown method, the torquemeter method or the wind-tunnel and chassis-dynamometer method. ISO 10521-2:2006 gives detailed instructions on the methods of the chassis-dynamometer setting procedure for road-load value, obtained by the various measurement methods specified in ISO 10521-1:2006. ISO 10521-2:2006 is applicable to chassis dynamometers that can set road load at a minimum of three speed points, and to motor vehicles as defined in ISO 3833:1977 up to a gross vehicle mass of 3 500 kg.

Véhicules routiers — Résistance sur route — Partie 2: Reproduction sur banc dynamométrique

General Information

• Status: Published
• Publication Date: 01-Oct-2006
• ICS: 43.020 - Road vehicles in general
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 13-Dec-2020

Relations

• Revises: ISO 10521:1992 - Motor vehicle road load — Determination under reference atmospheric conditions and reproduction on chassis dynamometer
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10521-2
First edition
2006-10-01

Road vehicles — Road load —
Part 2:
Reproduction on chassis dynamometer
Véhicules routiers — Résistance sur route —
Partie 2: Reproduction sur banc dynamométrique




Reference number
ISO 10521-2:2006(E)
©
ISO 2006

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ISO 10521-2:2006(E)
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©  ISO 2006
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ii © ISO 2006 – All rights reserved

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ISO 10521-2:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Required overall measurement accuracy . 2
5 Preparation for chassis-dynamometer test . 3
5.1 Setting parameter . 3
5.2 Laboratory condition. 3
5.2.1 Roller. 3
5.2.2 Room temperature. 3
5.3 Preparation of chassis dynamometer. 3
5.3.1 Inertia-mass setting. 3
5.3.2 Preconditioning of chassis dynamometer . 3
5.4 Vehicle preparation. 3
5.4.1 Tyre-pressure adjustment. 3
5.4.2 Vehicle setting. 4
5.4.3 Vehicle preconditioning . 4
6 Load setting on the chassis dynamometer. 4
6.1 Chassis-dynamometer setting by coastdown method . 4
6.1.1 Load setting of chassis dynamometer . 4
6.2 Chassis-dynamometer setting using torquemeter method. 5
6.2.1 Load setting of chassis dynamometer . 6
Annex A (normative) Calculation of road load for the dynamometer test . 8
Annex B (normative) Adjustment of chassis-dynamometer setting load . 11

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ISO 10521-2:2006(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 10521-2 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 5, Engine
tests.
This first edition, together with ISO 10521-1, cancels and replaces ISO 10521:1992, which has been
technically revised.
ISO 10521 consists of the following parts, under the general title Road vehicles — Road load:
⎯ Part 1: Determination under reference atmospheric conditions
⎯ Part 2: Reproduction on chassis dynamometer
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ISO 10521-2:2006(E)
Introduction
This part of ISO 10521 has been prepared to reflect the state-of-the-art technique for the vehicle road-load
setting on chassis dynamometers. ISO10521-1 should be referred to for the basic road-load measurement
method. This part contains the following technical and editorial changes compared with ISO 10521:1992:
⎯ to simulate the road load on the chassis dynamometer precisely, the hydraulic absorber type
dynamometer is excluded;
⎯ only the chassis dynamometer of coefficient control is described in this part of ISO10521.

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INTERNATIONAL STANDARD ISO 10521-2:2006(E)

Road vehicles — Road load —
Part 2:
Reproduction on chassis dynamometer
1 Scope
This part of ISO 10521 specifies methods of setting the target road load on chassis dynamometers for the
purpose of a subsequent test, for example the fuel consumption test or the exhaust-emission measurement
test.
The road-load setting method on chassis dynamometers depends on the road-load measurement method,
such as the coastdown method, the torquemeter method or the wind-tunnel and chassis-dynamometer
method. This part of ISO 10521 gives detailed instructions on the methods of the chassis-dynamometer
setting procedure for road-load value, obtained by the various measurement methods specified in
ISO 10521-1.
This part of ISO 10521 is applicable to chassis dynamometers that can set road load at a minimum of three
speed points, and to motor vehicles as defined in ISO 3833 up to a gross vehicle mass of 3 500 kg.
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 3833, Road vehicles — Types — Terms and definitions
ISO 10521-1:2006, Road vehicles — Road load — Part 1: Determination under reference atmospheric
conditions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3833 and the following apply.
3.1
total resistance
total force-resisting movement of a vehicle movement, measured either by the coastdown method or by the
wind-tunnel and chassis-dynamometer method, including the friction forces in the drive train
3.2
running resistance
torque-resisting movement of a vehicle, measured by the torquemeter installed in the drive-train of a vehicle,
including the friction torque in the drive-train downstream of the torquemeter
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ISO 10521-2:2006(E)
3.3
road load
general meaning of force or torque which opposes the movement of a vehicle, including total resistance
and/or running resistance
3.4
reference speed
vehicle speed at which a chassis-dynamometer load is verified
NOTE Reference speeds may be continuous speed points covering the complete speed range.
3.5
target road load
road load to be reproduced on the chassis dynamometer
3.6
chassis-dynamometer setting load
load to be set on the power-absorption unit of the chassis dynamometer
3.7
simulated road load
road load to be calculated from measured coastdown data using the least-square regression
NOTE See Annex A for the calculation procedure.
3.8
speed range
range of speed of chassis-dynamometer roller between 15 km/h and maximum reference speed plus 10 km/h,
over which the coastdown test is conducted
3.9
chassis dynamometer of coefficient control
chassis dynamometer of which absorption characteristics are determined by giving coefficients of a road-load
approximation polynomial
3.10
chassis dynamometer of polygonal control
chassis dynamometer of which absorption characteristics are determined by giving load values at several
speed points
4 Required overall measurement accuracy
The required overall measurement accuracy shall be as follows:
a) chassis-dynamometer roller speed: ± 0,5 km/h or ± 1 %, whichever is greater;
b) chassis-dynamometer force:
Category 1 chassis dynamometer: ± 6 N, or
Category 2 chassis dynamometer: ± 10 N or ± 0,1 % of full scale, whichever is greater;
NOTE Category 2 chassis dynamometer usually has greater load capacity, e.g. 130 kW or more.
c) time: ± 50 ms or ± 0,1 %, whichever is greater;
d) wheel torque: ± 3 N⋅m or ± 0,5 %, whichever is greater;
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ISO 10521-2:2006(E)
e) atmospheric temperature: ± 1 K;
f) tyre pressure: ± 5 kPa.
5 Preparation for chassis-dynamometer test
5.1 Setting parameter
The following parameters shall be determined prior to the test, in accordance with the purpose of the
subsequent test:
a) target road load;
b) speed range;
c) reference speed.
5.2 Laboratory condition
5.2.1 Roller
The chassis-dynamometer roller shall be clean, dry and free from anything which might cause tyre slippage. In
the case of chassis dynamometers with multiple rollers, the chassis dynamometers shall be run in the same
coupled or uncoupled state as the subsequent emission test, fuel consumption test, etc., and the chassis-
dynamometer speed shall be measured from the roller coupled to the power-absorption unit.
5.2.2 Room temperature
The laboratory atmospheric temperature shall be within 293 K to 303 K as the standard condition, unless
otherwise required by the subsequent test.
5.3 Preparation of chassis dynamometer
5.3.1 Inertia-mass setting
Set the equivalent inertia mass of the chassis dynamometer in accordance with the vehicle mass or vehicle
mass category.
5.3.2 Preconditioning of chassis dynamometer
Precondition the chassis dynamometer in accordance with the dynamometer manufacturer’s
recommendations, or as appropriate, so that the friction loss of the chassis dynamometer can be stabilized.
5.4 Vehicle preparation
5.4.1 Tyre-pressure adjustment
The tyre pressure shall be adjusted to the recommended values for the test. These values shall correspond to
those recommended for the range of vehicle speeds encountered during the subsequent emission test, fuel
consumption test, etc., in conjunction with roller geometry of the chassis dyn
...