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. 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 traffic conditions. ACC can be augmented with other capabilities, such as forward obstacle warning.

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.

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 Electro Technical Commission (IEC) on all matters of Electro Technical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC 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.

This second edition cancels and replaces the first edition (ISO 15622:2002) which has been technically revised.

The main system function of Adaptive Cruise Control is to control vehicle speed adaptively to a forward vehicle by using information about:

(1) Ranging to forward vehicles,

(2) The motion of the subject (ACC equipped) vehicle and

(3) Driver commands. 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.

This International Standard 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.

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 Adaptive Cruise Control (ACC) systems. 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 traffic conditions. ACC can be augmented with other capabilities, such as forward obstacle warning.
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 & 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.
4. active brake control: Function that causes application of the brake(s), not applied by the driver, in this case controlled by the ACC system
5. Adaptive Cruise Control: Enhancement to conventional cruise control systems, 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
6. 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: Adapted from UN ECE Regulation No. 13-H:1998.

Note 3 to entry: For the purposes of this International Standard, transmission control devices are not considered as brakes.

1. Clearance: Distance from the forward vehicle’s trailing surface to the subject vehicle’s leading surface
2. Conventional Cruise Control: System capable of controlling the speed of a vehicle as set by the driver
3. forward vehicle: Vehicle in front of and moving in the same direction and travelling on the same roadway as the subject vehicle.
4. Free-Flowing traffic: Smooth-flowing and heavy traffic excluding stop and go and emergency braking situations
5. Time Gap: DEPRECATED: τ value calculated from vehicle speed v and clearance c by: τ = c/vimg_1
6. 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.
7. Steady State: Condition whereby the value of the described parameter does not change with respect to time, distance, etc.
8. Subject Vehicle: Vehicle equipped with the system in question and related to the topic of discussion:
9. ACC System States: For the purposes of this International Standard, three system states are distinguished.
10. ACC Off State: State in which direct access for activation of “ACC active state” is disabled:
11. ACC Stand-by State: State in which there is no longitudinal control by ACC system and the system is ready for activation by the driver
12. ACC Active State: State in which the system controls speed and/or clearance
13. ACC Speed Control Sub-State: State in which the system controls the speed according to the set speed.
14. ACC Following Control Sub-State: State in which the system controls the clearance to the target vehicle according to the selected time gap
15. Target Vehicle: Vehicle that the subject vehicle follows.
16. Stationary Object: Object in front of the subject vehicle which is stationary.

Organisation need to define: 

1. Basic Control Strategy
2. Functionality (Control Model, Speed of Subject Vehicle, Stationery Target)
3. Detection Range
4. Target Discrimination
5. Curve Capability
6. Basic Driver Interface &
7. Activation of Break Light
8. Interval Operation limit
9. Failure reaction
10. Performance Evaluation Test Method
11. Annexure: A: Technical Information
12. Lidar, Coefficient of Test Target
13. Definition of RCS of Corner Tube Type Test Target
14. Following Capability