ISO 4272:2022

INTERNATIONAL ISO
STANDARD 4272
First edition
2022-09
Intelligent transport systems —
Truck platooning systems (TPS)
— Functional and operational
requirements
Systèmes de transport intelligents — Systèmes de convois de camions
(TPS) — Exigences fonctionnelles et opérationnelles
Reference number
© ISO 2022
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ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.4
4.1 Abbreviated terms . 4
5 Types of truck platooning systems .4
5.1 Top-down-managed platooning . 4
5.1.1 LV-managed platooning. 4
5.1.2 BO- and LV-managed platooning . 5
5.2 Peer-to-peer platooning . 5
6 Types of truck platoon formation . 5
6.1 Overview . 5
6.2 Formation on the motorway . 5
6.2.1 General . 5
6.2.2 Ad-hoc platoon formation on the motorway . 5
6.2.3 Planned platoon formation on the motorway . 5
6.3 Formation at the staging area . 6
6.3.1 Ad-hoc platoon formation at the staging area . 6
6.3.2 Planned platoon formation at the staging area . 6
7 Operation state diagram . 6
7.1 General . 6
7.2 Operation state diagram of platooning operations . 6
8 Platooning operation control function (POCF) . 7
8.1 General . 7
8.2 Join . 7
8.3 Leave . 8
8.4 Operation . 9
8.4.1 Join operation . 9
8.4.2 Leave operation . 10
8.5 Requirements . 10
8.5.1 Join requirements . 10
8.5.2 Leave requirements . 11
9 Platooning manoeuvre control function (PMCF) .11
9.1 General . 11
9.2 Longitudinal control . 11
9.3 Lateral control . 14
9.4 Longitudinal control operations . 15
9.4.1 Join manoeuvre .15
9.4.2 Cruising operation .15
9.4.3 Leave manoeuvre . 15
9.4.4 Cut-in operation . .15
9.4.5 Cut-out operation . 16
9.5 Lateral control operations . 16
9.5.1 Cruising (in-lane) operation . 16
9.5.2 Lane change operation . 16
9.6 Longitudinal control requirements . 17
9.6.1 Join manoeuvre requirements . 17
9.6.2 Cruising requirements . 17
9.6.3 Leave manoeuvre requirements . 17
iii
9.6.4 Cut-in requirements. 18
9.6.5 Cut-out requirements . 18
9.7 Lateral control requirements . 18
9.7.1 Cruising requirements . 18
9.7.2 Lane change requirements . 18
10 Communication data (V2V/V2I) .19
10.1 General . 19
10.2 Requirements of communication . 19
10.3 Communication data . 19
10.3.1 General . 19
10.3.2 Communication data for PMM . 19
10.3.3 Communication data for PCM . 22
11 Functional evaluation test method .23
11.1 Evaluation test conditions . 23
11.2 Evaluation test method .23
11.2.1 General .23
11.2.2 Join evaluation test .23
11.2.3 Leave evaluation test . 26
11.2.4 Cruising evaluation test . 27
11.2.5 Cut-in evaluation test .28
11.2.6 Cut-out evaluation test .30
Annex A (informative) Use cases of POCF .32
Annex B (informative) Use cases of PMCF .37
Bibliography .42
iv
Foreword
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This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
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v
Introduction
A truck platoon is a vehicle string in which multiple vehicles are driving under coordinated longitudinal
and possible lateral control.
Truck platooning is beneficial for the transportation industry because it can improve the operational
efficiency of motorway transportation, improve safety and reduce the energy consumption of truck
operation, as well as improving drivers' working environment and reducing workload. In addition,
truck platooning improves the road capacity and efficiency for overall traffic.
The truck platooning system consists of a platooning control system and optionally a back office (BO)
as shown in Figure 1. Information from the back office can be helpful and effective for planning platoon
operations.
The platooning control system controls the processes by which vehicles join or leave the platoon
and the manoeuvring of the platoon under coordinated longitudinal vehicle control strategies such
as cooperative adaptive cruise control (CACC). Each vehicle has vehicle-to-vehicle (V2V) over-the-
air communication to exchange information with the other vehicles in the platoon and recognizes
its participation in a platoon. Each vehicle controls its own motions in a platoon based on the data
obtained from sensors such as radar, lidar and camera, and the data received from the over-the-air
communication.
The truck platooning system may include a back office infrastructure system to support the platooning
control system. BO functions can include platooning demand matching, and platooning formation and
operation management. Platooning demand matching covers forming requests, matching requests,
route management and charge/payment of platoon from operators such as shippers and fleet operators.
Platooning formation and operation management may issue notifications about the acceptance/refusal
of platooning requests, truck sequence in platoon, route selection/permission/recommendation, and
geographical limitations on the platooning.
The platooning operational control function controls changes in the membership of platoon; the
platooning manoeuvre control function controls interactions within the platoon.
This document provides the common base needed for platooning system development. It also supports
market introduction of the platooning system and assists in accelerating the deployment of truck
platooning.
vi
Key
a
1 back office Join.
b
2 platoon (steady state) Leave.
c
3 platooning control system Vehicle to infrastructure (V2I) communication.
d
4 platooning manoeuvre control function Vehicle to vehicle (V2V) communication.
5 platooning operation control function
Figure 1 — Overall architecture of the truck platooning system (TPS)
vii
INTERNATIONAL STANDARD ISO 4272:2022(E)
Intelligent transport systems — Truck platooning systems
(TPS) — Functional and operational requirements
1 Scope
This document defines the terms and definitions related to truck platooning systems (TPS), and the
mode transitions in the platooning control system (PCS). The PCS is comprised of two main functions:
the platooning operation control function (POCF) and the platooning manoeuvre control function
(PMCF).
This document specifies:
— POCF and PMCF governing how vehicles join and leave platoons;
— PMCF governing longitudinal and lateral control of each vehicle;
NOTE PMCF makes reference to current International Standards, such as ISO 20035, ISO 11270 and
ISO 21717, where appropriate.
— functional evaluation test methods for POCF and PMCF.
This document also describes:
— the data to be communicated for POCF and PMCF in vehicle to vehicle (V2V) messages and optionally
in vehicle to infrastructure (V2I) messages, including local roadside and broader network and cloud;
— strategies for forming platoons, such as ad-hoc or planned formation, and types of truck platooning
systems, such as top-down management and peer-to-peer.
This document covers:
— platooning of heavy goods vehicles of multiple brands and fleets, operated by on-board drivers.
Light trucks, buses and passenger cars are excluded;
— level 1 and 2 driving automation systems, which provide driver support and operate under the
continuous supervision of the drivers.
The functions and operations of the back office (BO) are out of 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.
ISO 21202, Intelligent transport systems — Partially automated lane change systems (PALS) — Functional/
operational requirements and test procedures
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
platoon
vehicle formation with a common platoon ID and sequence of participants
3.2
platooning
operation of a platoon in which multiple vehicles are driving under coordinated longitudinal control
and possibly lateral control
Note 1 to entry: Each vehicle uses forward-vehicle detection by on-board sensors and vehicle to vehicle (V2V)
over-the-air communication to exchange information needed to execute the coordinated longitudinal control
with the other vehicles in the platoon (see Figure 2).
Key
Key
a
Vehicle to vehicle (V2V) communication. 3 following vehicle (FV)
1 potential leading vehicle (PLV) 4 potential following vehicle (PFV)
2 leading vehicle (LV) 5 other vehicle (OV)
Figure 2 — Platooning formation
3.3
leading vehicle
first vehicle in a platoon
3.4
following vehicle
vehicle operating in a platoon behind the leading vehicle and connected using vehicle to vehicle
communication
3.5
other vehicle
vehicle that does not participate in the platoon but can potentially affect platoon operations, by
performing emergency braking or a cut-in manoeuvre, for example
3.6
potential leading vehicle
vehicle that is not currently in a platoon but is in a position enabling it to potentially become the leading
vehicle in the future or a former leading vehicle after leaving the platoon
3.7
potential following vehicle
vehicle that is not currently in a platoon but is in a position enabling it to potentially become the
following vehicle in the future or a former following vehicle after leaving the platoon
3.8
join
transition by which one or more vehicle(s) become(s) member(s) of a platoon
3.9
leave
transition by which one or more vehicle(s) separate(s) from its current platoon
3.10
platooning control system
system for operating the platooning operation control function and the platooning manoeuvre control
function in a platoon, including the potential leading vehicle and potential following vehicle
3.11
platooning operation control function
function to manage the transitions of vehicles in and out of platoon membership
3.12
platoon management message
vehicle to vehicle communication or vehicle to infrastructure communication message that transmits
information relevant to the platooning operation control function
3.13
platooning manoeuvre control function
function to manage the continuous operations of platoon vehicles, including responses to situations
such as cut-in and cut-out
3.14
platoon control message
vehicle to vehicle communication message that transmits information relevant to the platooning
manoeuvre control function
3.15
vehicle to infrastructure communication
communication between vehicle and devices such as a roadside unit of infrastructure or mobile phone
base station, but excluding vehicles
3.16
back office
infrastructure system to support platoon operation, such as platoon planning and demand matching to
start the platoon, and route management and the charge/payment process from the operators, such as
shippers and fleet operators
3.17
time gap
time needed to travel a distance equal to the clearance gap between the rear surface of the preceding
vehicle and the forward surface of the following vehicle at the current vehicle speed
Note 1 to entry: This value is calculated as c/v , where v is the vehicle speed of the following vehicle and c is the
clearance between the head of the following vehicle and the tail of the leading vehicle.
3.18
heavy goods vehicle
truck with a gross combination mass (GCM) over 3 500 kg. which is considered as a vehicle according to
categories N2 and N3 of WP.29 TRANS/WP.29/78/Rev.6
Note 1 to entry: See Reference [14].
4 Symbols and abbreviated terms
4.1 Abbreviated terms
ACC adaptive cruise control
BO back office
CC cruise control
CACC cooperative adaptive cruise control
FV following vehicle
GCM gross combination mass
LKAS lane keeping assistance systems
LV leading vehicle
OV other vehicle
PADS partially automated in-lane driving systems
PALS partially automated lane change systems
PCM platoon control message
PCS platooning control system
PFV potential following vehicle
PLV potential leading vehicle
PMCF platooning manoeuvre control function
PMM platoon management message
POCF platooning operation control function
V2I vehicle to infrastructure/infrastructure to vehicle
V2V vehicle to vehicle
5 Types of truck platooning systems
5.1 Top-down-managed platooning
The top-down managed platooning type is managed by the LV via V2V communication or optionally
is managed by the BO via V2I communication to optimize platoon operations and recommend vehicle
sequence, platooning speed, time gap, etc.
5.1.1 LV-managed platooning
The LV-managed platooning type is managed by the LV. The LV or its driver selects the speed and
maximum number of vehicles in the platoon. The LV or its driver may inform the FV drivers about the
recommended minimum time gap for FVs.
POCF such as "join" and "leave" may be triggered by FV drivers. Final permission to join is provided by
the LV.
5.1.2 BO- and LV-managed platooning
The BO and LV perform the platoon management. Under management by the BO, the LV or its driver
selects the speed and number of vehicles in the platoon. The LV or its driver may inform the FV drivers
about the recommended minimum time gap for FVs and may make lane changing decisions under the
management by the BO.
POCF such as "join" and "leave" may be triggered by FV drivers. Final permission to join is provided by
the LV based on BO planning. The LV or BO may provide instructions for the "leave" operation.
5.2 Peer-to-peer platooning
Peer-to-peer platooning management operates based on peer-to-peer relationships among all of the
vehicles in a platoon. All vehicles have equal status and none of them are governing other vehicles. All
FVs individually control their speed (and optionally steering) to follow the LV or preceding FV and all
drivers may choose their preferred gap settings.
6 Types of truck platoon formation
6.1 Overview
When a platoon is formed, different locations and types of formation are applied based on one of the
strategies described in the following subclauses.
Platoon formation is the process in which it is determined if vehicles may become part of a platoon.
Platoon formation is the coordination of candidate vehicles which form the platoon in a defined
structure.
Platoon formation may be done on the motorway during driving or at the staging area before entering
the motorway.
Platoon formation may be done on an ad-hoc basis (that is, not planned) or planned in advance.
Platoon formation is completed to become a cruising operation after the join manoeuvre.
6.2 Formation on the motorway
6.2.1 General
In case of formation on the motorway, V2V and optionally V2I are used to search for other candidate
vehicles.
6.2.2 Ad-hoc platoon formation on the motorway
Any vehicle or platoon which is capable of platooning searches for other similarly capable vehicles or
platoons via V2V communications, and starts the join operation to form a new platoon. Optionally, V2I
communications may be used to identify the availability of other eligible vehicles to join the ad-hoc
platoon within the available effective communication range. The communication range covers the same
motorway as well as the access ramps and at the interchanges.
6.2.3 Planned platoon formation on the motorway
In case of planned formation on the motorway, the BO coordinates potential platooning participants via
V2I communication and manages speeds and routes to the meeting point of vehicles.
Platoon candidates (PLV and PFV) communicate with each other via V2V communications and join the
platoon on the motorway.
Platoon candidates can receive instructions from the BO via V2I communications for platoon formation
to allow the start of the "join" procedure with the platoon.
6.3 Formation at the staging area
6.3.1 Ad-hoc platoon formation at the staging area
Any vehicle or platoon which is capable of platooning searches for other similarly capable vehicles or
platoons via V2V and optionally V2I communications within the available communication range and
an ad-hoc platoon "join" operation is started at the staging area before entering the motorway. Each
vehicle may start in sequence of platoon when they enter the motorway, or may move to the staging
area in advance and park in sequence of platoon before entering motorway.
6.3.2 Planned platoon formation at the staging area
In case of planned formation at the staging area, the BO coordinates potential platooning participants
via V2I communication.
Platoon candidates can receive instructions from the BO for platoon formation to allow the start of the
"join" procedure with the platoon at the staging area.
Platoon candidates communicate via V2V communications and the "join" operation is implemented at
the staging area.
Platoon formation may be achieved and completed at the staging area before initiating the drive.
Vehicles can configure the sequence in platoon at the staging area based on the instructions from the
BO.
7 Operation state diagram
7.1 General
The truck platooning system is under operation when the PCS turns on (PCS ON). When the vehicle
turns on the PCS, the "join" operation can be implemented as a POCF. After the "join" manoeuvre is
completed, the platooning state is implemented and continues under various manoeuvre controls.
When the "leave" notification is transmitted, the "leave" operation is implemented and the vehicle
leaves the platoon and turns off the PCS (PCS OFF).
7.2 Operation state diagram of platooning operations
A state diagram of platooning operations is shown in Figure 3.
POCF and PMCF operations are described in Clauses 8 and 9.
a
Join complete.
b
Leave notification.
c
Leave complete.
Figure 3 — Operation state diagram
8 Platooning operation control function (POCF)
8.1 General
In the PCS, there are two modes of transition: "join" and "leave". Both transition modes are operated by
the POCF which controls the change in membership status of the platoon.
8.2 Join
In the platooning operation, a platoon ID is provided for a new platoon and a sequential number of
participant vehicles are confirmed to be a platoon. Joins may be achieved between any combination of
individual vehicles and platoons in the leading and following positions. The join transition can be made
within a lane during driving or at a staging area, such as a parking site.
Normally, the PLV becomes LV and the PFV becomes FV in a platoon. In some situations, V2V
communication and/or V2I communication with BO may adjust the sequence of PLV and PFV to make a
suitable platoon during this transition.
Use case examples of "join" transitions are shown in Annex A.
The typical operation flow of "join" transitions is shown in Figure 4.
— Join request: Request for platoon formation or addition to an existing platoon.
— Join response: Response to the request for platoon formation or addition to the existing platoon.
— Dotted boxes and lines represent the optional operations and information flows.
Figure 4 — Typical operation flow diagram of the "join" transition
8.3 Leave
In the platooning operation, the most basic "leave" transition is achieved when the LV and FV(s) separate
from each other and become PLV and PFV. In multiple-vehicle platoons, any individual vehicle or group
of vehicles may leave. The leave transition can be made while driving or at a staging area, such as a
parking site.
Use case examples of "leave" transitions are shown in Annex A.
The typical operation flow of "leave" transitions is shown in Figure 5.
— Leave instruction: Instruction to leave the platoon or of platoon dissolution.
— Leave notification: Notification of intention to leave the platoon.
— Dotted boxes and lines represent the optional operations and information flows.
Figure 5 — Typical operation flow diagram of leave
8.4 Operation
8.4.1 Join operation
The "join" operation is achieved when PFV searches PLV or LV to form a platoon and finally the PLV
becomes LV and the PFV becomes FV in a platoon. A "join" operation may also be achieved between any
combination of individual vehicles and platoons in the leading or following positions.
The "join" operation may also be achieved based on information such as a formation plan provided
from BO or it may be achieved by ad-hoc actions of the PLV and PFV and their drivers. The following
steps describe the "join" operation.
1) A PFV which intends to join and to become a platoon member transmits "join request" to the PLV
(or LV if the platoon already exists). In case of formation on the motorway, the PFV is travelling in
the same direction on the same motorway and is behind the PLV or LV.
2) The PLV or LV which receives the "join request" judges whether the PFV is eligible to join (i.e.
platoon has not reached its maximum size and PFV is properly equipped).
3) If the PFV is eligible to join, the PLV or LV transmits "join response: yes" to the PFV.
4) When the PFV receives "join response: yes", it starts the join manoeuvre to the PLV or last FV in
existing platoon and becomes a platoon member.
5) If the PFV is not eligible to join, "join response: yes" is not transmitted and “join response: no” is
transmitted by the PLV, LV or last FV. In this case, the PFV is not accepted to join and does not start
the join manoeuvre.
6) If the PLV or LV refuses to accept a join request from an eligible PFV based on reasons such as the
PLV or LV is leaving motorway soon, the PLV or LV transmits "join response: no" to notify the PFV
that the join is not possible.
7) After completion of the join manoeuvre, the PFV notifies the PLV or LV of the join completion and
the PLV or LV may also inform the BO of the join completion.
8.4.2 Leave operation
The "leave" operation is achieved when the LV and FV separate from each other and become PLV and
PFV. In platoons with three or more vehicles, any individual vehicle or group of vehicles can leave and
becomes a PLV, PFV or a shorter platoon. The following steps describe the "leave" operation.
1) The FV which intends to leave from a platoon transmits "leave notification" to the LV.
2) After the transmission of "leave notification", the FV starts the leave manoeuvre and separates
from a platoon, becoming a PFV.
3) When the FV needs to be separated from a top-down managed platoon, "leave instructions" may be
sent from the LV to FV, or from the BO to LV and/or FV.
4) When the FV or LV receives "leave instructions" or the FV intends to leave a top-down managed
platoon, the FV transmits "leave notification" and starts the leave manoeuvre.
5) After completion of the leave manoeuvre, when the LV receives a "leave completion" notification
from the FV of a top-down managed platoon, it may inform the BO of the leave completion.
8.5 Requirements
8.5.1 Join requirements
8.5.1.1 General
The following are the requirements for the vehicles in the join process.
8.5.1.2 Join request
1) A vehicle that intends to join with another vehicle or another platoon shall transmit a "join request".
2) In the case of a top-down managed platooning type, the "join request" shall contain vehicle
performance information, which is described in 10.3.1, about the vehicle(s) that intend(s) to join.
8.5.1.3 Join response
1) The vehicle or platoon which accepts the join request shall transmit "join response: yes". In case of
refusal to accept a join request, "join response: no" shall be transmitted.
2) The "join response" shall contain "platoon management information" which is needed to operate
platooning.
NOTE "Platoon management information" includes platoon ID, maximum number of vehicles in the
platoon, vehicle sequence in platoon, etc. See 10.3.1.
3) The "join response" shall contain the vehicle performance information of the platoon member
which is just in front of the joined vehicle.
8.5.1.4 Join completion
After completion of the "join" manoeuvre, the new FV or LV of the platoon may report the join completion
to the BO.
8.5.2 Leave requirements
8.5.2.1 General
The following are the requirements for the vehicles in the leave process.
8.5.2.2 Leave notification
1) A platoon member or a part of platoon who intend(s) to leave the platoon shall transmit "leave
notification". "Leave notification" may be initiated automatically by the driver’s take-over of
manual driving operation or may also be initiated by another driver action (e.g. platooning mode
on/off switch).
2) The driver or PCS of the vehicle that intends to leave may implement the leave operation in the
following situations. However, the specific periods and distances mentioned below are not specified
in this document.
— OV cut-in situation continues longer than a certain time.
— The distance to the preceding vehicle in the platoon becomes longer than a certain distance.
— V2V communication with preceding platoon member is interrupted for longer than a certain
time.
— The intended destination of the vehicle is approaching.
— The driver prefers to drive separately for any other reason.
8.5.2.3 Leave instruction
1) In case of top-down managed platooning type, the LV or BO may instruct platoon member(s) to
leave.
2) A platoon member who receives a "leave instruction" shall transmit "leave notification" and
perform the leave manoeuvre.
8.5.2.4 Leave completion
1) After the completion of the leave operation, in the case of top-down managed platooning type, the
PFV or PLV of the platoon shall report the leave completion to the LV or BO that issued the leave
instruction.
2) The PFV or PLV of a platoon which completed the leave operation shall delete their platoon
management information. If a platoon remains after the LV, FV or a part of platoon leaves, members
of the platoon that completed the leave operation and/or remain shall update all or part of their
platoon management information and share it.
9 Platooning manoeuvre control function (PMCF)
9.1 General
In the PCS, longitudinal control and optionally lateral control are applied to the platoon and its vehicles
to manage the platooning by platooning manoeuvre control function (PMCF).
9.2 Longitudinal control
A vehicle which receives “join response: yes” in POCF starts the join manoeuvre and completes the
formation of platoon. The LV or its driver controls its speed based on the traffic and road conditions
and maintaining separation from vehicles ahead of it.
When a platoon is driving in-lane, CACC is used to control the distances between vehicles. CACC control
may be the constant time gap with respect to speed (time-gap-based control; ISO 20035) or may be the
constant clearance with respect to speed (clearance-based control).
When an OV cuts in front of the FV, the FV should increase its following distance to maintain an
appropriate gap behind the OV. In this case, FV CACC mode makes a transition from close-follow mode
to CACC follow mode, or suspends CACC control with reference to the preceding LV or FV in the platoon,
and needs to change to ACC mode behind the OV.
NOTE The definition of an appropriate gap is left for manufactures and/or operators of platoon.
If an FV in a platoon is temporarily in ACC mode due to the OV in front, when the OV departs the lane of
the platoon, the FV needs to resume CACC control operation and starts CACC close-follow. In this case,
the FV increases speed to catch up with the preceding vehicle or communicates with the LV to request
it to reduce its speed so that the gap can be reduced.
The vehicle which transmits “leave notification” starts the leave manoeuvre and separates from the
platoon.
Use case examples of longitudinal control are shown in Annex B.
The typical operation flow of longitudinal manoeuvre control such as cut-in and cut-out is shown in
Figure 6.
— Dotted box and line represent the optional operation and information flow
Figure 6 — Typical operation flow diagram of longitudinal manoeuvre control
9.3 Lateral control
When a platoon is driving in lane, the drivers may steer the vehicles manually or lateral control system
may be used to maintain the in-lane position of each vehicle.
Vehicles in a platoon may use lane-keeping assistance system (LKAS) to stay in-lane.
Vehicles in a platoon may perform the lane change manually or may use PALS to change the lane. It
is recommended that the last vehicle in the platoon be the first to change lane to block the lane from
vehicles overtaking from behind, so that the rest of the platoon can complete the lane cha
...