ISO 15622:2018

INTERNATIONAL ISO
STANDARD 15622
Third edition
2018-09
Intelligent transport systems —
Adaptive cruise control systems —
Performance requirements and test
procedures
Systèmes intelligents de transports — Systèmes stabilisateurs de
vitesse adaptés — Exigences de performance et modes opératoires
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 4
5 Classification . 5
5.1 Type of ACC systems . 5
6 Requirements . 5
6.1 Basic control strategy . 5
6.2 Functionality . 6
6.2.1 Control modes . 6
6.2.2 Stationary or slow moving targets . 6
6.2.3 Following capability . 6
6.2.4 “Go” transition . 8
6.3 Basic driver interface and intervention capabilities . 9
6.3.1 Operation elements and system reactions . 9
6.3.2 Display elements .10
6.3.3 Symbols .10
6.4 Operational limits .10
6.5 Activation of brake lights .12
6.6 Failure reactions .12
7 Performance evaluation test methods .13
7.1 Environmental conditions .13
7.2 Test target specification .13
7.2.1 General.13
7.2.2 Infrared LIDAR .13
7.2.3 Millimetre wave RADAR .14
7.3 Automatic “Stop” capability test for FSRA-type only .14
7.3.1 Test target vehicle .14
7.3.2 Initial conditions .14
7.3.3 Test procedure .14
7.4 Target acquisition range test .15
7.5 Target discrimination test .15
7.5.1 General.15
7.5.2 Initial conditions .16
7.5.3 Test procedure .16
7.6 Curve capability test .16
7.6.1 General.16
7.6.2 Test field .17
7.6.3 Curve capability, target vehicle .17
7.6.4 Driving scenario .17
Annex A (normative) Technical information .19
Bibliography .24
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
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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).
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URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
This third edition of ISO 15622 cancels and replaces ISO 15622:2010 and ISO 22179:2009, which have
been technically revised.
The main changes compared to the previous editions are as follows:
— the third edition of ISO 15622 is extended with the performance requirements and test procedures
for full speed range adaptive cruise control systems formerly described in ISO 22179:2009 (with
minor changes);
— in-vehicle devices are allowed as a possible source for the acquisition of driver commands (set-
speed-advise);
— curve classification and related dependencies have been removed;
— automatic start from hold is no longer prohibited.
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 2018 – All rights reserved

Introduction
The main system function of Adaptive Cruise Control (ACC) is to control vehicle speed adaptively to
a forward vehicle by using information about: (1) distance to forward vehicles, (2) the motion of the
subject (ACC equipped) vehicle and (3) driver commands (see Figure 1). Based upon the information
acquired, the controller (identified as “ACC control strategy” in Figure 1) sends commands to actuators
for carrying out its longitudinal control strategy and it also sends status information to the driver.
Optionally, the driver may choose to have the ACC use set speed advice from in-vehicle devices.
Figure 1 — Functional ACC elements
The goal of ACC is a partial automation of the longitudinal vehicle control and the reduction of the
workload of the driver with the aim of supporting and relieving the driver in a convenient manner. The
generic ACC system comprehends two classes: Full Speed Range ACC (FSRA) and Limited Speed Range
ACC (LSRA).
This document can be used as a system level standard by other standards, which extend the ACC to
a more detailed standard, e.g. for specific detection and ranging sensor concepts or higher level of
functionality. Therefore, issues like specific requirements for the detection and ranging sensor function
and performance or communication links for co-operative solutions will not be considered here.
INTERNATIONAL STANDARD ISO 15622:2018(E)
Intelligent transport systems — Adaptive cruise control
systems — Performance requirements and test procedures
1 Scope
This document contains the basic control strategy, minimum functionality requirements, basic driver
interface elements, minimum requirements for diagnostics and reaction to failure, and performance
test procedures for Adaptive Cruise Control (ACC) systems.
ACC systems are realised as either Full Speed Range Adaptive Cruise Control (FSRA) systems or Limited
Speed Range Adaptive Cruise Control (LSRA) systems. LSRA systems are further distinguished into
two types, requiring manual or automatic clutch. Adaptive Cruise Control is fundamentally intended
to provide longitudinal control of equipped vehicles while travelling on highways (roads where non-
motorized vehicles and pedestrians are prohibited) under free-flowing and for FSRA-type systems
also for congested traffic conditions. ACC can be augmented with other capabilities, such as forward
obstacle warning. For FSRA-type systems the system will attempt to stop behind an already tracked
vehicle within its limited deceleration capabilities and will be able to start again after the driver has
input a request to the system to resume the journey from standstill. The system is not required to react
to stationary or slow moving objects
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 2575, Road vehicles — Symbols for controls, indicators and tell-tales
UN/ECE Regulation No. 13-H. Uniform provisions concerning the approval of passenger cars with
regard to braking
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1
active brake control
function that causes application of the brake(s), not applied by the driver, in this case controlled by the
ACC system
3.2
Adaptive Cruise Control
ACC
enhancement to conventional cruise control systems [see conventional cruise control (3.5)], which allows
the subject vehicle to follow a forward vehicle at an appropriate distance 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
Note 1 to entry: It can 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); an engine brake (when the forces are derived from an artificial increase in the braking action,
transmitted to the wheels, of the engine).
Note 2 to entry: Definition according to ECE-R 13-H, except for the purposes of this document, transmission
control devices are not considered as brakes.
3.4
clearance
distance from the forward vehicle's trailing surface to the subject vehicle's leading surface
3.5
conventional cruise control
system capable of controlling the speed of a vehicle as set by the driver
3.6
forward vehicle
vehicle in front of and moving in the same direction and travelling on the same roadway as the subject
vehicle (3.11)
3.7
free-flowing traffic
smooth-flowing and heavy traffic excluding stop and go and emergency braking situations
3.8
time gap
τ
time gap calculated as clearance, c, divided by vehicle speed v
Key
c clearance
v vehicle speed
NOTE τ = c/v.
Figure 2 — Time gap
3.9
set speed
desired travel speed, set either by the driver or by some control system that is external to the ACC system
Note 1 to entry: The set speed is the maximum desired speed of the vehicle while under ACC control.
3.10
steady state
condition whereby the value of the described parameter does not change with respect to time,
distance, etc.
2 © ISO 2018 – All rights reserved

3.11
subject vehicle
vehicle equipped with the ACC system in question and related to the topic of discussion
3.12
system states
one of several stages or phases of system operation
Note 1 to entry: See Figure 3.
3.12.1
ACC off state
phase in which direct access for activation of “ACC active state” is disabled
3.12.2
ACC stand-by state
phase in which there is no longitudinal control by ACC system and the system is ready for activation by
the driver
3.12.3
ACC active state
phase in which the system controls the speed and/or clearance
3.12.4
ACC speed control state
phase in which the system controls the speed according to the set speed
3.12.5
ACC following control sub-state
phase in which the system controls the clearance to the target vehicle according to the selected time gap
3.12.6
FSRA hold state
phase in which the system is active during standstill
Note 1 to entry: Applied for FSRA-type systems only.
3.13
target vehicle
vehicle that the subject vehicle follows
3.14
stationary object
object in front of the subject vehicle which is stationary
3.15
slow moving object
object in front of the subject vehicle which is moving with less than MAX [1,0 m/s, 10 % of subject
vehicle speed] in the direction of the centreline of the subject vehicle
3.16
Full Speed Range Adaptive Cruise Control
FSRA cruise control
class of adaptive cruise control systems (3.2), which allows the subject vehicle to follow a forward
vehicle at an appropriate distance by controlling the engine and/or power train and the brake down to
standstill
3.17
Limited Speed Range Adaptive Cruise Control
LSRA cruise control
class of adaptive cruise control systems (3.2), which allows the subject vehicle to follow a forward vehicle
at an appropriate distance by controlling the engine and/or power train and the brake above a certain
minimum velocity
3.18
in-vehicle device
manufacturer-integrated device that provides the ACC set-speed value without active communication
to external devices
4 Symbols and abbreviated terms
a maximum allowed lateral acceleration in curves
lateral_max
a longitudinal acceleration of the target vehicle at the automatic “stop” capability test
stopping
CTT Coefficient for Test Target for infrared reflectors
c clearance, inter vehicle distance
c minimum clearance under steady state conditions for all speeds (including hold state)
min
d distance, below which detection of a target vehicle is not required
d distance, below which neither distance measurement nor determination of relative speed
is required
d distance for measurement purposes
d maximum detection range on straight roads
max
R circle radius, curve radius
R minimum curve radius
min
RCS RADAR Cross Section
v the true subject vehicle speed over ground
v maximum speed on a curve for a given lateral acceleration a
circle lateral_max
v vehicle speed as it enters a curve of radius R
circle_start
v minimum operational speed
low
v maximum selectable set speed
set_max
v minimum selectable set speed
set_min
v vehicle speed of the target vehicle at the automatic “stop” capability test
stopping
v vehicle speed at the end of a test
vehicle_end
v maximum vehicle speed
vehicle_max
v vehicle speed at the start of a test
vehicle_start
τ gap, time gap between vehicles
4 © ISO 2018 – All rights reserved

τ (v) maximum possible steady-state time gap at a given speed v
max
τ maximum selectable time gap
max
τ minimum selectable time gap
min
5 Classification
5.1 Type of ACC systems
Different configurations of actuators for longitudinal control result in very different system behaviour.
Therefore, based on the two different ACC classes, three types of ACC systems are addressed in this
document.
Table 1 — Classification of ACC system types
Manual clutch operation
Type Operational speed range
required
FSRA No Full speed range
LSRA 1 Yes Minimum operational speed v_low
LSRA 2 No Minimum operational speed v_low
The deceleration capability of the ACC system shall be clearly stated in the vehicle owner's manual. All
types incorporate active brake control. In case of active brake intervention in vehicles with a clutch
pedal (type LSRA 1) the driver shall be informed clearly and early about a potential conflict between
brake and engine idle control, if the clutch cannot be disengaged automatically. A practicable and
unambiguous handing-over procedure shall be provided for the driver. See 6.3.1.
6 Requirements
6.1 Basic control strategy
ACC systems shall, as a minimum, provide the following control strategy and state transitions. The
following constitutes the fundamental behaviour of ACC systems.
— When the ACC is active, the vehicle speed shall be controlled automatically either to maintain a
clearance to a forward vehicle, or to maintain the set speed, whichever speed is lower. The change
between these two control modes is made automatically by the ACC system.
— The steady-state clearance may be either self-adjusting by the system or adjustable by the driver
(see 6.3.1).
— If there is more than one forward vehicle, the one to be followed shall be selected automatically
(see 6.2.3.3).
— Only for FSRA-type: The state shall change from following control to hold state within a time period
not to exceed 3 sec after the subject vehicle has come to a stop.
— Only for FSRA-type: In “Hold” state, automatic brake control shall be accomplished for keeping the
subject vehicle stationary.
— Only for LSRA-type: The transition from “ACC stand-by” to “ACC active” shall be inhibited if the subject
vehicle's speed is below a minimum operational speed, v . Additionally, if the vehicle's speed drops
low
below v while the system is in the “ACC active” state, automatic acceleration shall be inhibited.
low
Optionally, the ACC system may drop from “ACC active” to “ACC stand-by” (see 6.3.2 and 6.4).
NOTE * Manual transition describes a switch to enable/disable ACC function. Automatic switch off can be
forced by failure reaction.
Figure 3 — ACC states and transitions
6.2 Functionality
6.2.1 Control modes
The transition between the control modes (following controlled or speed controlled) shall be made
automatically.
6.2.2 Stationary or slow moving targets
Generally, it is not a requirement that an ACC system is designed to respond to the presence of stationary
or slow moving targets. If the system is designed not to respond to stationary targets the driver shall be
informed at least by a statement in the vehicle owner's manual.
Systems of FSRA-type will and systems of LSRA-type may attempt to stop behind an already tracked
and stopping vehicle within their limited deceleration capabilities.
6.2.3 Following capability
6.2.3.1 General
τ shall be the minimum selectable time gap for following control mode under steady-state conditions
min
for all speeds v. τ shall be greater than or equal to 0,8 s.
min
At least one time gap setting τ in the range of 1,5 s to 2,2 s shall be provided for speeds higher than 8 m/s.
Under steady-state conditions the minimum clearance shall be MAX(c , τ *v).
min min
Under transient conditions, the clearance may temporarily fall below the minimum clearance. If such a
situation occurs, the system
...