Intelligent transport systems -- Cooperative adaptive cruise control systems (CACC) -- Performance requirements and test procedures

Cooperative Adaptive Cruise Control (CACC) system is an expansion to existing Adaptive Cruise Control (ACC) control strategy by using wireless communication with preceding vehicles (V2V) and/or the infrastructure (I2V). Both multi vehicle V2V data and I2V infrastructure data are within the scope of this document. When V2V data is used CACC can enable shorter time gaps and more accurate gap control, which can help increase traffic throughput and reduce fuel consumption. It can also receive data from the infrastructure, such as recommended speed and time gap setting, to improve traffic flow and safety. This document addresses two types of Cooperative Adaptive Cruise Control (CACC): V2V, and I2V. Both types of CACC system require active sensing using for example radar, lidar, or camera systems. The combined V2V and I2V CACC is not addressed in this document. The following requirements are addressed in this document: — classification of the types of CACC; — definition of the performance requirements for each CACC type; — CACC state transitions diagram; — minimum set of wireless data requirements; — test procedures. CACC: — does only longitudinal vehicle speed control; — uses time gap control strategy similar to ACC; — has similar engagement criteria as ACC. Coordinated strategies to control groups of vehicles, such as platooning, in which vehicle controllers base their control actions on how they affect other vehicles, and may have a very short following clearance gap are not within the scope of this document. CACC system operates under driver responsibility and supervision. This document is applicable to motor vehicles including light vehicles and heavy vehicles.

Titre manque

General Information

Status
Published
Publication Date
17-Jan-2019
Current Stage
6060 - International Standard published
Start Date
08-Dec-2018
Completion Date
18-Jan-2019
Ref Project

Buy Standard

Standard
ISO 20035:2019 - Intelligent transport systems -- Cooperative adaptive cruise control systems (CACC) -- Performance requirements and test procedures
English language
16 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 20035
First edition
2019-01
Intelligent transport systems —
Cooperative adaptive cruise control
systems (CACC) — Performance
requirements and test procedures
Reference number
ISO 20035:2019(E)
ISO 2019
---------------------- Page: 1 ----------------------
ISO 20035:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 20035:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

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

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

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Symbols and abbreviated terms ........................................................................................................................................................... 3

5 Classification ............................................................................................................................................................................................................ 4

5.1 Type of CACC systems ....................................................................................................................................................................... 4

5.2 Curve capabilities ................................................................................................................................................................................. 4

5.3 Classes of on-board V2X devices ............................................................................................................................................. 4

6 Requirements .......................................................................................................................................................................................................... 5

6.1 V2V CACC ..................................................................................................................................................................................................... 5

6.1.1 V2V CACC response ....................................................................................................................................................... 5

6.1.2 Region of interest ............................................................................................................................................................ 5

6.1.3 Potential Vehicle of Interest (PVOI) ................................................................................................................. 5

6.1.4 State transition diagram ............................................................................................................................................ 6

6.1.5 Control operation strategy ...................................................................................................................................... 7

6.1.6 V2V CACC data requirements ............................................................................................................................... 9

6.2 I2V CACC ....................................................................................................................................................................................................10

6.2.1 Control Operation Strategy ..................................................................................................................................10

6.2.2 I2V CACC data requirements ..............................................................................................................................12

6.3 General operational control requirements ..................................................................................................................12

7 Performance evaluation test methods ........................................................................................................................................12

7.1 V2V CACC ..................................................................................................................................................................................................12

7.1.1 Communication range test ...................................................................................................................................12

7.1.2 Accuracy test (lane and range discrimination tests) .....................................................................12

7.1.3 V2V cooperative operating modes/states tests .................................................................................13

7.2 I2V CACC ....................................................................................................................................................................................................15

7.2.1 Set speed test ...................................................................................................................................................................15

7.2.2 Time fap test .....................................................................................................................................................................16

7.3 Test environment conditions ...................................................................................................................................................16

© ISO 2019 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 20035:2019(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).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

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.
iv © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 20035:2019(E)
Introduction

Cooperative Adaptive Cruise Control (CACC) system is an enhancement to the Adaptive Cruise

Control (ACC) system by the addition of wireless communication with preceding vehicles and/or the

infrastructure to augment the ACC active sensing capability. It uses active sensing data such as ranging

to forward vehicle, subject vehicle data, over the air data from other surrounding vehicles and from

infrastructure, and driver input to longitudinally control the vehicle via throttle and brake controls,

and to convey the appropriate CACC status information to the driver (see Figure 1).

Figure 1 — Functional CACC elements

ACC systems can be made cooperative by adding vehicle-vehicle (V2V) and/or infrastructure-vehicle

(I2V) communication capabilities and adjusting the performance of the system to make use of the

information received via the communication system, e.g. Dedicated Short Range Communication

System (DSRC) (see Figure 2).
Figure 2 — CACC additions to ACC
© ISO 2019 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 20035:2019(E)

The V2V communications can provide the ACC system with frequent updates about the speed,

acceleration and commands (throttle and brake) of multiple vehicles driving in the surrounding area of

the CACC-equipped vehicle. This enables the following performance improvements over ACC:

— higher-accuracy control of vehicle following gap, while maintaining smooth ride quality;

— significantly faster responses to speed changes by multiple forward vehicles, not only the vehicle

immediately ahead of the subject vehicle;

— shorter vehicle-following gap settings, without compromising safety or driver confidence and

comfort with the system.
These performance improvements produce the following benefits:

— increased driver confidence in the responsiveness of the system, leading to willingness to select

shorter gap settings and use ACC under a wider range of traffic conditions;

— fewer cut-ins at the shorter gaps may make ACC acceptable to a wider range of drivers;

— significant damping of traffic flow disturbances, improving traffic flow dynamics and thereby

reducing energy use and emissions;

— significant increase in the effective capacity (throughput) per lane of highway traffic.

The I2V communications can provide the ACC system with inputs from the local traffic management

system, which determines the recommended values for set speed and vehicle-following gap. These

can be used to enhance the effectiveness of traffic management strategies on limited access highways,

where it is possible to determine the speed and gap settings that are likely to maximize the effective

capacity of a bottleneck section. When the I2V CACC vehicles follow these recommended values, the

overall traffic flow capacity can be optimized with a minimum of active intervention by the vehicle

drivers (other than opting in to decide to follow the infrastructure-based guidance). This means that

the driver of the subject vehicle gains a smoother trip, with less acceleration and braking and lower

energy consumption, and the highway as a whole gains a higher effective capacity, reduced energy

consumption and pollution, and reduced traffic delays.
vi © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 20035:2019(E)
Intelligent transport systems — Cooperative adaptive
cruise control systems (CACC) — Performance
requirements and test procedures
1 Scope

Cooperative Adaptive Cruise Control (CACC) system is an expansion to existing Adaptive Cruise Control

(ACC) control strategy by using wireless communication with preceding vehicles (V2V) and/or the

infrastructure (I2V). Both multi vehicle V2V data and I2V infrastructure data are within the scope

of this document. When V2V data is used CACC can enable shorter time gaps and more accurate gap

control, which can help increase traffic throughput and reduce fuel consumption. It can also receive

data from the infrastructure, such as recommended speed and time gap setting, to improve traffic flow

and safety.

This document addresses two types of Cooperative Adaptive Cruise Control (CACC): V2V, and I2V.

Both types of CACC system require active sensing using for example radar, lidar, or camera systems.

The combined V2V and I2V CACC is not addressed in this document. The following requirements are

addressed in this document:
— classification of the types of CACC;
— definition of the performance requirements for each CACC type;
— CACC state transitions diagram;
— minimum set of wireless data requirements;
— test procedures.
CACC:
— does only longitudinal vehicle speed control;
— uses time gap control strategy similar to ACC;
— has similar engagement criteria as ACC.

Coordinated strategies to control groups of vehicles, such as platooning, in which vehicle controllers base

their control actions on how they affect other vehicles, and may have a very short following clearance

gap are not within the scope of this document. CACC system operates under driver responsibility and

supervision.

This document is applicable to motor vehicles including light vehicles and heavy vehicles.

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 15622, Intelligent transport systems — Adaptive cruise control systems — Performance requirements

and test procedures
© ISO 2019 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO 20035:2019(E)
3 Terms and definitions
For the purpose of this document, the following definitions apply.

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

— IEC Electropedia: available at https: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
active brake control

function which causes application of the brake(s), controlled by the CACC system not by the driver

3.2
Adaptive Cruise Control
ACC

enhancement to conventional cruise control systems [see Conventional Cruise Control (3.7)], which

allows the subject vehicle to follow a forward vehicle at an appropriate distance proportional to the

time gap set by the driver by controlling the engine and/or power train and potentially the brake

3.3
brake

part in which the forces opposing the movement of the vehicle develop and which may be a friction

brake (when the forces are generated by friction between two parts of the vehicle moving relatively to

one another); an electrical brake (when the forces are generated by electro-magnetic action between

two parts of the vehicle moving relatively but not in contact with one another); a fluid brake (when the

forces are generated by the action of a fluid situated between two parts of the vehicle moving relatively

to one another); or an engine brake (when the forces are derived from an artificial increase in the

braking action, transmitted to the wheels, of the engine)

Note 1 to entry: For the purposes of this document, transmission control devices are not considered as brakes.

[SOURCE: UN ECE Regulation 13-H:1998, 2.6]
3.4
CACC system states

operation modes of the system presented in this document as three system states as shown in 6.1.4 and

Figure 4
3.5
clearance

distance from the forward vehicle's trailing surface to the subject vehicle's leading surface

3.6
connected vehicle

any vehicle that has a V2X wireless communication system and broadcasts over the air standard

message protocol
3.7
conventional cruise control
system capable of controlling the speed of a vehicle as set by the driver
3.8
forward vehicle

vehicle in front of and moving in the same direction and travelling on the same roadway as the

subject vehicle
3.9
free-flowing traffic

smooth flowing and heavy traffic excluding stop and go and emergency braking situations

2 © ISO 2019 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 20035:2019(E)
3.10
heavy vehicle category

single vehicle or combination of vehicles defined as Category 1-2 or Category 2 in the United Nations

Economic and Social Council World Forum for Harmonization of Vehicle Regulations (WP.29) TRANS/

WP.29/1045
Note 1 to entry: A truck is in the heavy vehicle category.
3.11
Potential Vehicle of Interest
PVOI

connected vehicle that exists in the V2V CACC region of interest, communicates with the subject vehicle,

is of possible interest to the longitudinal control, and is not the target vehicle (TV)

3.12
region of interest
ROI
area where PVOI and TV may exist and affect CACC system control operations
3.13
set speed

desired travel speed, set by either the driver or by some control system that is external to the CACC

system and which is the maximum desired speed of the vehicle while under CACC control

3.14
stationary object
object in front of the subject vehicle which is stationary
3.15
steady state

condition whereby the value of the described parameter does not change with respect to time,

distance, etc.
3.16
subject vehicle

vehicle equipped with the system in question and related to the topic of discussion

3.17
target vehicle

vehicle that the subject vehicle follows which may or may not be equipped with a connected vehicle device

3.18
time gap
value calculated from vehicle speed v and clearance c by τ = c/v

Note 1 to entry: to entry: v is the subject vehicle speed and c the distance between the subject vehicle and the

forward vehicle.
4 Symbols and abbreviated terms
A utilised area, general for area
A illuminated surface
a maximum allowed lateral acceleration in curves
lateral_max
© ISO 2019 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO 20035:2019(E)

a minimum allowed longitudinal acceleration = Maximum allowed longitudinal deceleration

min
a maximum allowed longitudinal acceleration
max
a maximum allowed acceleration during curve test
test
a maximum possible deceleration capability during manual driving
vehicle_max
CTT coefficient for Test Target for infrared reflectors
c clearance, inter vehicle distance
PVOI Potential Vehicle of Interest
ROI region of interest
TV target vehicle
V2V vehicle to vehicle
v the true subject vehicle speed over ground
τ gap, time gap between vehicles
5 Classification
5.1 Type of CACC systems

Types of CACC are based on the type of the over the air data that may affect the longitudinal control of

the vehicle. Two types of CACC systems are addressed in this document: V2V and I2V.

Table 1 — CACC system types
CACC type Active sensing required Wireless communication Type of data affecting
requirement (for example: the longitudinal control
DSRC is low latency, and 4G
is higher latency)
V2V Yes Low latency is minimum V2V over the air data
requirement
I2V Yes Some data can be broad- I2V over the air data
cast using higher latency
as appropriate to message
urgency.
5.2 Curve capabilities

This document is applicable to CACC systems of different curve capabilities as specified in ISO 15622.

5.3 Classes of on-board V2X devices
Type A: OEM device that receives and processes vehicle CAN data.
Type B: OEM device that does not receive or process CAN data.
Type C: Non-OEM device that receives and processes CAN data.
Type D: Non OEM device that does not receive or process CAN data.
4 © ISO 2019 – All rights reserved
---------------------- Page: 10 ----------------------
ISO 20035:2019(E)
6 Requirements
6.1 V2V CACC
6.1.1 V2V CACC response

V2V CACC system reacts to V2V over the air data in addition to the active sensing data originated from

sensors such as radar or camera.
6.1.2 Region of interest

Region of interest (ROI) is defined for a straight road as in Figure 3. This ROI is 32 m wide and extends

from the driver position in the subject vehicle up to 250 m ahead of the subject vehicle and 100 m behind

the subject vehicle. The ROI in Figure 3 is illustrated for a straight road. For a curved road, the ROI is to

bend itself to follow the curvature of the road.
Figure 3 — V2V CACC region of interest
6.1.3 Potential Vehicle of Interest (PVOI)

PVOI is any connected vehicle that exists in the V2V CACC ROI, communicates with the subject vehicle,

is of possible interest to the longitudinal control, and is not the target vehicle (TV), e.g. a vehicle

that is predicted to merge into the subject vehicle’s lane (for illustration please refer to Figure 7).

Another example: a vehicle that is braking hard ahead of and in the same lane as the target vehicle (for

illustration, please refer to Figure 8). PVOI may have the potential to become a TV.

© ISO 2019 – All rights
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.