Intelligent transportation systems - Adaptive cruise control systems - Performance requirements and test procedures
1 Scope
This standard specifies 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.
This standard applies to the performance test of ACC systems
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply. However, parties to agreements based on this specification are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 4782 Road vehicles - Controls, indicators and tell-tales - Vocabulary
UN ECE-R13-H Uniform provisions concerning the approval of passenger cars with regard to braking
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply:
3.1.1
active brake control
function which causes application of the brake(s), not applied by the driver, in this case controlled by the ACC system
3.1.2
adaptive cruise control(ACC)
enhancement to conventional cruise control systems(see 3.1.5 "conventional cruise control") which allows the subject vehicle to follow a forward vehicle at an appropriate distance by controlling the engine and/or power train and optionally the brake
3.1.3
brake
the process in which the forces (braking forces) opposing the movement or movement trend of the vehicle are produced, which is classified as followings:
friction brake: the forces are generated by friction between two parts of the vehicle moving relatively to one another;
electromagnetic brake: the forces are generated by electro-magnetic action between two parts of the vehicle moving relatively but not in contact with one another;
fluid brake: the forces are generated by the action of a fluid situated between two parts of the vehicle moving relatively to one another;
engine brake: the forces are generated by the braking action of the engine and transmitted to the wheels.
Note: For the purposes of this standard, transmission control devices are not considered as brakes.
3.1.4
clearance, c
distance from the forward vehicle's trailing surface to the subject vehicle's leading surface
3.1.5
conventional cruise control
system capable of controlling the speed of a vehicle as set by the driver
3.1.6
forward vehicle
vehicle in front of and moving in the same direction and travelling on the same roadway as the subject vehicle
3.1.7
free-flowing traffic
smooth flowing and heavy traffic, excluding stop-and-go and emergency braking situations
3.1.8
time gap, τ
time interval for travelling the clearance between consecutive vehicles
Note: The time gap (τ) is related to vehicle speed (v) and clearance (c), which is calculated by using the formula: τ = c/v, as shown in Figure 2.
Figure 2 Time gap
3.1.9
set speed
desired travel speed, set by either the driver or by some control system that is external to the ACC system, corresponding to the maximum desired speed of the vehicle while under ACC control
3.1.10
steady state
condition whereby the value of the described parameter does not change with respect to time, distance, etc.
Note: A circle can be described as a curve with a steady state radius. Similarly, a vehicle travelling at constant speed can be described as travelling at steady state speed.
3.1.11
subject vehicle
vehicle equipped with the ACC system in question and related to the topic of discussion
3.2 System states
For the purposes of this standard, the symbols listed in Table 1 apply.
Contents
Foreword I
Introduction II
1 Scope
2 Normative references
3 Terms, definitions and symbols
3.1 Terms and definitions
3.2 System states
4 Type and state of ACC Systems
4.1 Type of ACC systems
4.2 ACC System State
5 Performance requirements
5.1 Basic control strategy
5.2 Basic performance
5.3 Basic Human-Computer Interaction Function
5.4 Operational limits
5.5 Activation of brake lights (ACC Type 2 only)
5.6 Failure reactions
6 Performance evaluation test methods
6.1 Environmental conditions
6.2 Test target specification
6.3 Detection range test
6.4 Target discrimination test
6.5 Curve capability test
Annex A (Normative) Technical information
Bibliography
