ISO 23375:2023

Intelligent transport systems — Collision evasive lateral manoeuvre systems (CELM) — Requirements and test procedures

This document specifies basic control strategies, minimum functional requirements, basic driver interface elements, and test procedures for verifying the system requirements for collision evasive lateral manoeuvre systems (CELM). A CELM is a safety system aimed at supporting the driver’s vehicle operation by avoiding collisions with objects in the forward path of the vehicle. When a collision is predicted, the CELM controls lateral movement of the vehicle by generating yaw moment. The lateral control manoeuvres can be performed automatically by CELM or can be initiated by the driver and supported by CELM. Specific methods for object detection and other environmental perception technologies are not described in this document. This document applies to light vehicles and heavy trucks. Vehicles equipped with trailers are not within the scope of this document.

Systèmes de transport intelligents — Systèmes de manœuvre latérale d'évitement de collision (CELM) — Exigences et procédures d'essai

General Information

• Status: Published
• Publication Date: 22-Feb-2023
• ICS: 03.220.20 - Road transport
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ISO/TC 204 - Intelligent transport systems
• Drafting Committee: ISO/TC 204/WG 14 - Vehicle/roadway warning and control systems
• Current Stage: 6060 - International Standard published
• Start Date: 23-Feb-2023
• Due Date: 01-Jan-2023
• Completion Date: 23-Feb-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23375
First edition
2023-02
Intelligent transport systems —
Collision evasive lateral manoeuvre
systems (CELM) — Requirements and
test procedures
Systèmes de transport intelligents — Systèmes de manœuvre latérale
d'évitement de collision (CELM) — Exigences et procédures d'essai
Reference number
ISO 23375:2023(E)
© ISO 2023
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ISO 23375:2023(E)
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© ISO 2023

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ISO 23375:2023(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

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

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

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

4 Symbols and abbreviated terms..........................................................................................................................................................2

4.1 Symbols ......................................................................................................................................................................................................... 2

4.2 Abbreviated terms .............................................................................................................................................................................. 3

5 System overview .................................................................................................................................................................................................. 3

5.1 General ........................................................................................................................................................................................................... 3

5.2 Classification ............................................................................................................................................................................................ 4

6 General functional requirements ...................................................................................................................................................... 4

6.1 Functional elements........................................................................................................................................................................... 4

6.2 State transition ....................................................................................................................................................................................... 4

6.2.1 Definition of states ........................................................................................................................................................... 5

6.2.2 Transition conditions ..................................................................................................................................................... 5

6.3 Response to failure during CELM active state ........................................................................................................... 6

6.4 Status indication ................................................................................................................................................................................... 6

6.4.1 Active state .............................................................................................................................................................................. 6

6.4.2 Optional warning ............................................................................................................................................................... 7

6.4.3 Failure .......................................................................................................................................................................................... 7

6.4.4 CELM switch on/off status ........................................................................................................................................ 7

6.5 Status symbols ........................................................................................................................................................................................ 7

6.6 Minimization of vehicle lateral movement by CELM ............................................................................................ 7

6.7 Driver override ....................................................................................................................................................................................... 7

6.8 User-adjustable intervention thresholds ........................................................................................................................ 7

6.9 Information to the user in the manual .............................................................................................................................. 7

7 Operating conditions and requirements for Type 1 systems ............................................................................... 7

7.1 General ........................................................................................................................................................................................................... 7

7.2 Object condition ...................................................................... ............................................................................................................... 8

7.2.1 Object type ............................................................................................................................................................................... 8

7.2.2 Amount of lateral offset ............................................................................................................................................... 8

7.3 Activation speed of subject vehicle ...................................................................................................................................... 9

7.4 Road condition ..................................................................................................................................................................................... 10

7.5 Operational limit ................................................................................................................................................................................ 10

7.5.1 Operation on roads with lane markings .................................................................................................... 10

7.5.2 Operation on roads without lane markings ............................................................................................ 11

8 Operating conditions and requirements for Type 2 systems ............................................................................12

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

8.2 Object condition ...................................................................... ............................................................................................................ 13

8.3 Activation speed of subject vehicle ................................................................................................................................... 13

8.4 Additional considerations for support beyond collision avoidance .....................................................13

9 Performance evaluation test methods ......................................................................................................................................13

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

9.2 Test conditions ..................................................................................................................................................................................... 13

9.2.1 Environmental conditions ...................................................................................................................................... 13

9.2.2 Test course conditions ................................................................................................................................................ 13

9.2.3 Test vehicle conditions ............................................................................................................................................... 14

9.2.4 Test system installation and configuration............................................................................................. 14

9.2.5 Data recording ................................................................................................................................................................... 14

9.2.6 Test target.............................................................................................................................................................................. 14

iii
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ISO 23375:2023(E)

9.3 Type 1 test procedures ................................................................................................................................................................. 15

9.3.1 Test case selection .......................................................................................................................................................... 15

9.3.2 Test parameters ............................................................................................................................................................... 15

9.3.3 Test target selection and positioning ............................................................................................................ 17

9.3.4 Test procedures ................................................................................................................................................................ 20

9.3.5 Pass criteria ......................................................................................................................................................................... 21

9.4 Type 2 test procedures ................................................................................................................................................................. 21

9.4.1 Test equipment .................................................................................................................................................................. 21

9.4.2 Trajectory and torque data .................................................................................................................................... 22

9.4.3 Test procedure...................................................................................................................................................................25

9.4.4 Pass criteria ......................................................................................................................................................................... 26

Annex A (informative) Examples of use cases for Type 1 systems....................................................................................27

Annex B (informative) Additional information for Type 2 testing ...................................................................................30

Bibliography .............................................................................................................................................................................................................................31

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ISO 23375:2023(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).

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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

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.

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.
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ISO 23375:2023(E)
Introduction

Reducing traffic fatalities, injuries and property damage caused by driver carelessness or unexpected

events is a global challenge.

To address this situation, automatic emergency braking (AEB) systems were introduced to mitigate

crash consequences through automatic deceleration by braking of the vehicle.

NOTE ISO 22839 and ISO 19237 are examples of related International Standards defining the minimum

performance requirements of such systems. The ISO 22733 series defines test procedures to evaluate the

performance level of such systems.

These AEB systems work effectively when there is a high probability of a collision, but their operation

can be limited, or they can potentially not work at all, when there is a low probability of a collision (e.g.

when the degree of overlap to the object is small). However, even in such scenarios, there are cases

where a collision can be avoided by system support, i.e. by a small amount of lateral movement.

This document defines functional requirements, minimum performance requirements and test

procedures to verify these requirements for collision avoidance systems using lateral movement of

the vehicle. The aim of this system is to avoid collisions occurring in the subject vehicle’s travelling

direction.
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INTERNATIONAL STANDARD ISO 23375:2023(E)
Intelligent transport systems — Collision evasive lateral
manoeuvre systems (CELM) — Requirements and test
procedures
1 Scope

This document specifies basic control strategies, minimum functional requirements, basic driver

interface elements, and test procedures for verifying the system requirements for collision evasive

lateral manoeuvre systems (CELM).

A CELM is a safety system aimed at supporting the driver’s vehicle operation by avoiding collisions

with objects in the forward path of the vehicle. When a collision is predicted, the CELM controls lateral

movement of the vehicle by generating yaw moment.

The lateral control manoeuvres can be performed automatically by CELM or can be initiated by the

driver and supported by CELM.

Specific methods for object detection and other environmental perception technologies are not

described in this document.
[1] [1]

This document applies to light vehicles and heavy trucks. Vehicles equipped with trailers are not

within the scope of this document.
2 Normative references

The following documents are referred to in the 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.

FMVSS 105, Hydraulic and Electric Brake Systems

ISO 19206-2, Road vehicles — Test devices for target vehicles, vulnerable road users and other objects, for

assessment of active safety functions — Part 2: Requirements for pedestrian targets

ISO 19206-3, Road vehicles — Test devices for target vehicles, vulnerable road users and other objects, for

assessment of active safety functions — Part 3: Requirements for passenger vehicle 3D targets

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
subject vehicle
vehicle equipped with a collision evasive lateral manoeuvre system (CELM)
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ISO 23375:2023(E)
3.2
object
obstacle that could represent a hazard if hit by the subject vehicle
3.3
lane marking

delineator, marking or Botts’ dot intentionally placed on the borderline of the lane

3.4
lane boundary
outer edge of the lane marking
Note 1 to entry: See 3.3.
3.5
system failure

inability of a system or system component to perform a required function within specified limits, which

is caused by mechanical or electronic malfunction
3.6
SV direction
direction of travel of SV used to predict a collision
3.7
time to collision
TTC

time that it will take a subject vehicle to collide with an object assuming constant relative velocity

3.8
critical approach

driving situation which leads to an imminent collision if no driver or system prevention reaction occurs

4 Symbols and abbreviated terms
4.1 Symbols
Symbols used in this document and their meanings are described in Table 1.
Table 1 — Symbols and meanings
Symbol Meaning Unit
V Speed of the SV. m/s
V Minimum SV speed for CELM operation. m/s
min
V Maximum SV speed for CELM operation. m/s
max
V The mean of lateral speed of the SV orthogonal m/s
svL
to the lane markings, i.e. the y-axis component of
vehicle motion when traveling parallel to the lane
markings (see 9.3.3.3 for details).
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ISO 23375:2023(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Meaning Unit
L Lateral distance between the outermost edge of m
the object and the extension of the side of the SV
closest to the object when measured parallel to
the SV (i.e. point at which the distance becomes
minimum).
A positive value refers to a situation where an
overlap exists between the SV and object.
A negative value refers to a situation where an
overlap does not exist between the SV and object.
See 7.2.2 for details.
L Distance between the edge of an object and the m
d_inner
inner edge of lane marking, when the object is
located inside the ego lane of the SV.
L Distance between the edge of an object and the m
d_outer
outer edge of lane marking, when the object is
located outside the ego lane of the SV.
L Minimum amount of lateral offset to which the m
ofst_min
system is designed to respond.
L Maximum amount of lateral offset to which the m
ofst_max
system is designed to respond.
x Minimum longitudinal distance for which the m
c_min
angle between the SV and an object must be con-
stant when the SV approaches a test target.
4.2 Abbreviated terms
AEB automatic emergency braking
CELM collision evasive lateral manoeuvre system
LDP lane departure prevention
TTC time to collision
GNSS Global Navigation Satellite System
5 System overview
5.1 General

The CELM detects objects in the front area in the current SV direction of travel.

The CELM determines objects as hazardous if they are predicted to be in the driving path of the SV and

a collision with the object is imminent.

The CELM activates actuators (e.g. steering, brake) to generate yaw moment in an attempt to avoid a

collision.

The CELM controls or supports the lateral movement of the SV in the direction which avoids the collision

in the best manner or which has been chosen by the driver.
The CELM may operate under conditions where AEB systems are activated.
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ISO 23375:2023(E)
5.2 Classification
CELMs are classified into two types as shown in Table 2.
Table 2 — Type classification
Types Initiation Description

Type 1 Automatic — The evasive manoeuvre is performed automatically by the system

(See Clause 7 for details).
— Amount of lateral movement is restricted.

Type 2 Driver trigger — The driver performs the evasive manoeuvre. The system supports

the driver (See Clause 8 for details).
— No restriction on the amount of lateral movement.
6 General functional requirements
6.1 Functional elements

The CELM shall be designed taking into consideration the functional elements shown in Figure 1.

Output to the brake actuator (e.g. activation of AEB systems) can potentially improve avoidance

performance. However, the implementation methods for such a combination are not described in this

document.
Key
common elements for both types
type specific elements
Figure 1 — Functional elements
6.2 State transition

A CELM shall operate according to the state transition diagram shown in Figure 2. Specific

implementation beyond what is illustrated in Figure 2 is left up to the manufacturer.

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ISO 23375:2023(E)

The transition diagram in Figure 2 is applicable to both Type 1 and 2 systems. However, conditions for

transition 3 and 4 are different.
Key
1 Ignition on 4 Driver override condition satisfied
and no system failure or evasive manoeuvre is completed
and CELM is switched on (optionally)
2 System failure 5 System failure
or ignition off or ignition off
or CELM is switched off (optionally) or CELM is switched off (optionally)
3 Type 1
— critical approach is predicted
— and V ≤ V ≤ V
min sv max
— and other criteria specified by manufacturer (optionally)
Type 2
— system predicts a critical approach to an object
— and the driver initiates an evasive manoeuvre
— and V ≤ V ≤ V
min sv max
— and other criteria specified by manufacturer (optionally)
Figure 2 — State transition diagram
6.2.1 Definition of states
6.2.1.1 CELM off state
State in which the CELM is not ready for activation.
6.2.1.2 CELM stand-by state
State in which the system is ready for activation.
6.2.1.3 CELM active state

State in which the system is activated. Operating conditions and requirements defined in Clause 7 (for

Type 1) or Clause 8 (for Type 2) and manufacturer-defined collision prediction conditions and minimum

functional requirements shall be satisfied.
6.2.2 Transition conditions
6.2.2.1 Transition from CELM off to CELM stand-by (key element 1 of Figure 2)

The system shall transition from CELM off state to CELM stand-by state with the conditions of ignition

on and no system failure. If the system is equipped with a CELM on/off switch, it shall transition from

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ISO 23375:2023(E)

CELM off state to CELM stand-by state with the conditions of ignition on, no system failure, and the

system has not been deactivated by the driver.
6.2.2.2 Transition from CELM stand-by to CELM off (key element 2 of Figure 2)

The system shall transition from CELM stand-by state to CELM off state with the conditions of system

failure or ignition off. If the system is equipped with a CELM on/off switch, it shall transition from CELM

stand-by state to CELM off state when the driver deactivates CELM with the switch.

6.2.2.3 Transition from CELM stand-by to CELM active (key element 3 of Figure 2)
6.2.2.3.1 Type 1 systems

The system shall transition from CELM stand-by to CELM active state when the system predicts a

collision, no driver avoidance operation is detected, and operating conditions and requirements defined

in Clause 7 are satisfied.
NOTE See Annex A for examples of use cases of Type 1 systems.
6.2.2.3.2 Type 2 systems

The system shall transition from CELM stand-by to CELM active state when the system predicts a

critical approach, the driver initiates an evasive manoeuvre, and operating conditions and requirements

defined in Clause 8 are satisfied.

6.2.2.4 Transition from CELM active to CELM stand-by state (key element 4 of Figure 2)

The system shall transition from CELM active state to CELM stand-by state when the evasive manoeuvre

is completed, or the driver overrides the system.
6.2.2.5 Transition from CELM active to CELM off (key element 5 of Figure 2)

The system shall transition from CELM active state to CELM off state with the conditions of system

failure or ignition off. If the system is equipped with a CELM on/off switch, it shall transition from CELM

active state to CELM off state. It is recommended for the transition to result in a gradual change of the

yaw moment control.
6.3 Response to failure during CELM active state

Occurrence of a system failure during CELM active state should not result in conditions uncontrollable

by the driver. Yaw moment control should fade out gradually.
6.4 Status indication
6.4.1 Active state

The system shall provide information to the driver when the system is in active state.

If the vehicle is equipped with AEB and/or lane departure prevention (LDP) systems, the display device

may be commonly used to indicate the active state of multiple systems.

The driver shall be provided with an indication of active state. Specific implementation of the indication

is left to the manufacturer.
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ISO 23375:2023(E)
6.4.2 Optional warning

When the system has detected probability of a collision exceeding the defined threshold, the CELM may

provide a driver with a warning to suggest evasive manoeuvres. If the vehicle is equipped with AEB

and/or LDP systems, the display device may be shared to provide this optional warning.

6.4.3 Failure

The driver shall be provided with an indication of system failure. Specific implementation of the

indication is left to the manufacturer.
6.4.4 CELM switch on/off status

If the system is equipped with a CELM on/off switch, it shall be possible for the driver to determine the

status of the switch (i.e. on or off) whenever needed.
6.5 Status symbols

Status symbols to indicate CELM function or malfunction may be specified by the manufacturer.

Standardized symbols in accordance with ISO 2575 may be used.
6.6 Minimization of vehicle lateral movement by CELM

Lateral movement should be limited so that the SV passes the object as close as possible while still

maintaining a sufficient clearance to reliably avoid a collision.
6.7 Driver override

The driver shall be provided with the means to override the system operation at any time. Such means

shall include steering wheel operation (e.g. towards the direction opposite to the evasive manoeuvre),

and optionally may include CELM off-switch operation if the vehicle is equipped with a CELM on/off

switch. When the system is either initiating, perform
...