ISO 22179:2009

INTERNATIONAL ISO
STANDARD 22179
First edition
2009-09-01
Intelligent transport systems — Full
speed range adaptive cruise control
(FSRA) systems — Performance
requirements and test procedures
Systèmes intelligents de transport — Systèmes de commande de
croisière adaptatifs à la gamme entière de vitesse (FSRA) — Exigences
de performance et méthodes d'essai

Reference number
©
ISO 2009
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ii © ISO 2009 – 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 .3
5 Classification .4
6 Requirements.5
6.1 Basic control strategy.5
6.2 Functionality .5
6.3 Basic driver interface and intervention capabilities .9
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
7.3 Automatic “stop” capability test.14
7.4 Target acquisition range test .15
7.5 Target discrimination test.16
7.6 Curve capability test .18
Annex A (normative) Technical information .21
Bibliography.27

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 22179 was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
iv © ISO 2009 – All rights reserved

Introduction
The main system function of full speed range adaptive cruise control (FSRA) is to control vehicle speed
adaptively to a forward vehicle by using information about:
a) distance to forward vehicles,
b) the motion of the subject (FSRA equipped) vehicle, and
c) driver commands (see Figure 1).
Based upon the information acquired, the controller (identified as “FSRA control strategy” in Figure 1) sends
commands to actuators that carry out its longitudinal control strategy, and sends status information to the
driver.
Subject vehicle
Acquisition of
motion determination
driver commands
FSR A
Detection and ranging
of forward vehicles
control strategy
Actuators for
Driver information
longitudinal control
Environment Vehic le Dr iver
Figure 1 — Functional FSRA elements
The goal of FSRA is partial automation of longitudinal vehicle control to reduce drivers’ workload.
This International Standard may be used as a system level standard by other standards, which extend FSRA
to a more detailed standard, e.g. for specific detection and ranging-sensor concepts or higher levels of
functionality. Issues such as specific requirements for the detection and ranging sensor function and
performance or communication links for co-operative solutions are not considered in this International
Standard.
INTERNATIONAL STANDARD ISO 22179:2009(E)

Intelligent transport systems — Full speed range adaptive
cruise control (FSRA) systems — Performance requirements
and test procedures
1 Scope
This International Standard 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 full speed range adaptive cruise control (FSRA) systems. FSRA 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 congested traffic conditions. FSRA provides
support within the speed domain of standstill up to the designed maximum speed of the system. 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 {in accordance with ISO 15622 [adaptive
cruise control (ACC)]}.
2 Normative references
The following referenced documents are indispensable for the application 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
1)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
active brake control
function that causes application of the brake(s), not applied by the driver, in this case controlled by the FSRA
system
3.2
adaptive cruise control
ACC
enhancement to conventional cruise control systems (see 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

1) Definitions are in accordance with the glossary of ISO/TC 204/WG 14.
EXAMPLE Brakes can be of the following types: a friction brake (where forces are generated by friction between two
parts of the vehicle moving relatively to one another); an electrical brake (where forces are generated by electromagnetic
action between two parts of the vehicle moving relatively but not in contact with one another); a fluid brake (where 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 (where forces are derived from an artificial increase in the braking action of the engine, transmitted to the
wheels).
NOTE Definition adapted from ECE-R 13-H, except that for the purposes of this International Standard, 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
3.7
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
NOTE See Figure 2.
c
v
Key
c clearance
v vehicle speed
τ = c/v
NOTE
Figure 2 — Time gap
3.9
set speed
desired travel speed, set by either the driver or by some control system that is external to the FSRA system
NOTE The set speed is the maximum desired speed of the vehicle while under FSRA control.
3.10
steady state
condition whereby the value of the described parameter does not change with respect to time, distance, etc.
3.11
subject vehicle
vehicle equipped with the FSRA system in question and related to the topic of discussion
2 © ISO 2009 – All rights reserved

3.12
system state
one of several stages or phases of system operation
NOTE See Figure 3.
3.12.1
FSRA off state
direct access for activation of FSRA active state (3.12.3) is disabled
3.12.2
FSRA stand-by state
state in which there is no longitudinal control by FSRA system and the system is ready for activation by the
driver
3.12.3
FSRA active state
state in which the system controls speed and/or clearance
3.12.4
FSRA hold state
state in which the system is active during subject vehicle standstill
3.12.5
FSRA speed control state
state in which the system controls the speed according to the set speed
3.12.6
FSRA following control state
state in which the system controls the clearance to the target vehicle according to the selected time gap
3.13
stationary object
stationary object in front of the subject vehicle
3.14
slow moving object
object in front of the subject vehicle that is moving with less than MAX [1 m/s, 10 % of subject vehicle speed]
in the direction of the centreline of the subject vehicle
3.15
target vehicle
vehicle that the subject vehicle follows
3.16
full speed range adaptive cruise control
enhancement to 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
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
LIDAR light detection and ranging
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 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 time gap between vehicles
τ maximum selectable time gap
max
τ (v) maximum possible steady-state time gap at a given speed v
max
τ minimum selectable time gap
min
5 Classification
This International Standard permits FSRA systems of different curve capabilities as specified in Table 1.
Table 1 — FSRA performance classifications
Dimensions in meters
Performance Class Curve radius capability
Reserved for ACC ISO 15622,
I
not applicable for FSRA
II W 500
III W 250
IV W 125
4 © ISO 2009 – All rights reserved

6 Requirements
6.1 Basic control strategy
FSRA
speed
a
activate
FSRA on
control
FSRA FSRA
FSRA
FSRA
off
stand-by active
hold
a
FSRA
FSRA of f
de-activat e
following
control
a
FSRA of f
System states are indicated by the text contained in ellipses.
NOTE Manual transition describes a switch to enable/disable FSRA function. Automatic switch-off can be forced by
failure reaction.
a
This is manual and/or automatic after self-test.
Figure 3 — FSRA states and transitions
FSRA systems shall, as a minimum, provide the following control strategy and state transitions. The following
constitutes the fundamental behaviour of FSRA systems.
a) When the FSRA 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 FSRA system.
b) The steady-state clearance may be either self adjusting by the system or adjustable by the driver
(see 6.3.1).
c) If there is more than one forward vehicle the one to be followed shall be selected automatically
(see 6.2.3.3).
d) The state shall change from following control to hold state within a time period not to exceed 3 s after the
subject vehicle has come to a stop.
e) In the “hold” state, the automatic brake control shall be used for keeping the subject vehicle stationary.
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
The system will attempt to stop behind an already tracked and stopping vehicle within its limited deceleration
capabilities. It is optional to design FSRA systems to respond to the presence of stationary or slow moving
targets. If a given implementation is not intended to respond to stationary or slow moving targets, the driver
shall be informed at least by a statement in the vehicle owner's manual.
6.2.3 Following capability
τ shall be the minimum selectable time gap for following control mode under steady-state conditions for
min
all speeds v. τ shall be greater than or equal to 1 s.
min
c shall be the minimum clearance for following control mode under steady-state conditions for all speeds
min
v (including hold state). c shall be greater than or equal to 2 m.

min
Under steady state conditions the minimum clearance shall be MAX (c , τ ¥ v). Under transient conditions,

min min
the clearance may temporarily fall below the minimum clearance. If such a situation occurs, the system shall
adjust the clearance to attain the desired clearance.
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.
As a minimum requirement, the system shall be able, starting from steady state following, to stop behind a
gradually stopping vehicle which is decelerating with a at a speed below v (see the test

stopping stopping
procedure given in 7.3.2).
v = 10 m/s
stopping
a = 2,5 m/s
stopping
6.2.3.1 The FSRA shall have detection range, target discrimination and curve capabilities as specified
below.
6.2.3.2 Detection range on straight roads (performance classes II, III and IV).
If a forward vehicle is present within the distance range d to d , the FSRA system shall measure the range
1 max
between the forward and subject vehicles (see Figure 4). Within this range, the forward vehicle shall be
detected within a lateral area of at least the subject vehicle width.
d = τ (v ) ¥ v
max max set_max set_max
If a forward vehicle is present within the distance range d to d , the FSRA system shall detect the presence of
0 1
the vehicle but is not required to measure the range to the vehicle nor the relative speed between the forward
and subject vehicles.
d = 4 [m]
If a forward vehicle is present at a distance less than d , the FSRA system is not required to detect the
presence of the vehicle.
d = 2 [m]
6 © ISO 2009 – All rights reserved

d d
d 2
0 max
bc
a
Key
1 subject vehicle
2 forward vehicle
a Detection is not required.
b Detection of vehicles required.
c Determination of range required.
Figure 4 — Zones of detection
6.2.3.3 Target discrimination
If there is more than one forward vehicle on straight roads and for performance classes II, III and IV also in
steady state curves, the forward vehicle (refer to Figure 5) in the subject vehicle's path shall be selected for
FSRA control in typical FSRA situations as represented by the test scenario (see 7.5 Target discrimination
test).
Figure 5 — Target discrimination
6.2.3.4 Curve capability (performance classes II, III and IV)
The FSRA system shall enable steady state vehicle following with a time gap of τ (v ), on straight roads
max circle
(classes II, III and IV) and curves with a radius down to R = 500 m (classes II, III and IV) and
min,II
R = 250 m (classes III and IV) and R = 125 m (class IV). Therefore the system shall be capable of
min,III min,IV
following a forward vehicle with the steady state time gap τ (v ), if the forward vehicle cruises on a
max circle
constant curve radius R with a constant speed v .
min circle
va= *R
circle lateral_max min
where
τ (v) is the maximum possible steady state time gap while driving with a speed v on a straight;
max
a is the design lateral acceleration for curves on highways.
lateral_max
The values to use are
a = 2,0 m/s , and
lateral_max,II
a = 2,3 m/s , and
lateral_max,III
a = 2,3 m/s .
lateral_max,IV
The values for a are derived from average driver behaviour in curves (95 % of drivers) {see Figure 6

lateral_max
and Reference [3]}.
Key
a
1 maximum value Class IV.
b
2 95 % zone Class III.
c
Class II.
X subject vehicle speed (km/h)
Y lateral acceleration (m/s )
Figure 6 — Lateral acceleration of the average driver
8 © ISO 2009 – All rights reserved

6.2.4 “Go” transition (driver-initiated “go”)
The transition from hold to following control or speed control shall not be enabled without a driver’s request.
6.3 Basic driver interface and intervention capabilities
6.3.1 Operation elements and system reactions
6.3.1.1 FSRA systems shall provide a means for the driver to select a desired set speed.
6.3.1.2 In the FSRA following control and FSRA speed control states, braking by the driver shall
deactivate the FSRA function, at least if the driver initiated brake force demand is higher than the FSRA
initiated brake force. In the FSRA hold state, it is not mandatory that braking by the driver deactivates the
FSRA system [leading to FSRA standby state (see Figure 3)].
6.3.1.3 The FSRA system shall not lead to a significant transient reduction of braking response to the
driver's braking input (se
...