ISO 22735:2021

INTERNATIONAL ISO
STANDARD 22735
First edition
2021-05
Road vehicles — Test method to
evaluate the performance of lane-
keeping assistance systems
Véhicules routiers — Méthode d'essai pour évaluer la performance
des systèmes d'aide au maintien de la trajectoire
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Variables . 2
4.1 Coordinate systems . 2
4.2 Lateral deviation from path (Y error) . 2
VUT
4.3 Variables to be measured . 3
5 Measuring equipment . 3
5.1 General . 3
5.2 Transducer installation. 3
5.3 Calibration . 3
5.4 Data processing . 4
6 Test conditions . 4
6.1 General . 4
6.2 Test data . 4
6.3 Test track . 4
6.3.1 General. 4
6.3.2 Lane marking . 4
6.4 Environmental conditions . 5
6.5 Test vehicle . 5
6.5.1 General condition . 5
6.5.2 LKAS settings . 5
6.5.3 Tyres . 5
6.5.4 Wheel alignment measurement . 6
6.5.5 Loading conditions . . 6
6.6 Vehicle preparation . 6
7 Test procedure . 7
7.1 Pre-test conditioning . 7
7.1.1 General. 7
7.1.2 Brakes conditioning . 7
7.1.3 Tyres conditioning . 8
7.1.4 System check . 8
7.2 Test scenarios . 8
7.3 Test execution .10
8 Performance metrics .11
8.1 General .11
8.2 Lateral speed of VUT during a test run (V ) and last lateral speed of VUT
latVUT
before line crossing (V ) .11
latVUT blc
8.3 Lane departure warning activation time during a test run (T ) and last lane
LDW
departure warning activation time before line crossing (T ) .11
LDW blc
8.4 LKAS activation time during a test run (T ) and last LKAS activation time before
LKAS
line crossing (T ) .11
LKAS blc
8.5 Time to line crossing during a test run (T ) and last T before line crossing
TLC TLC
(T ) .11
TLC blc
during a test run and last before crossing
8.6 Distance to line crossing (D ) D line (D ) .11
TLC TLC TLC blc
8.7 Maximum yaw velocity during a test run (Ψ̇ ) and last (Ψ̇ ) before line
VUT max VUT max
crossing (Ψ̇ ) .11
VUT max,blc
8.8 Maximum lateral acceleration during a test run (A ) and last (A )
latVUT max latVUT max
before line crossing (A ) .11
latVUT max,blc
8.9 Maximum steering torque during a test run (M ) and last (M ) before
VUT max VUT max
line crossing (M ) .12
VUT max,blc
Annex A (informative) Road markings .13
Annex B (informative) Test report .21
Bibliography .23
iv © ISO 2021 – All rights reserved

Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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electrotechnical standardization.
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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
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,
Vehicle dynamics and chassis components.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
Introduction
The main function of a lane keeping assistance system (LKAS) is to support the driver in keeping the
vehicle within the current lane. LKAS acquires information on the position of the vehicle within the
lane and, when required, sends commands to actuators to influence the lateral movement of the vehicle,
and in turn provides status information to the driver.
This document is intended to assess the complete performance of an LKAS fitted in a road vehicle:
— the capacity to keep the vehicle within the current lane during other situations not described in this
test method (more complex scenarios, other weather conditions);
— the capacity to avoid undesired lane change.
vi © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 22735:2021(E)
Road vehicles — Test method to evaluate the performance
...