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SAE J2735-Draft-Rev29 [issued: 12-11-08]
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292 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
Annex I Cooperative Cruse Control (CCC) Use and Operation
1. Introduction
The Cooperative Cruise Control Message Set provides a mechanism for vehicles to effectively
communicate relevant information to each other, and operate as a coherent group. Vehicles will
communicate internally within the team in order to maintain group cohesion, operational safety, and
maximize individual and team mobility. The vehicle team will be able to communicate as a collective with
other vehicle teams, individual vehicles, and roadside infrastructure devices.
The goal in developing this message set is to standardize the process for communication within a
cooperative vehicle system, which is independent of the level of functional autonomy of the vehicle. The
message set is not meant to replace existing sensors and equipment on vehicles; rather, to enhance existing
sensor systems with information not directly acquired through intrinsic capabilities, enabling the formation
of a cooperative vehicle system.
In essence, the message set enables an adaptive cruise control capability, which utilizes low latency
communications in conjunction with vehicle sensors and controls. Data formatting follows the SAE J2735
message set. By utilizing this message set, the vehicle following distance can be dynamically managed in
cooperation with a driver. While it is not envisioned that full control of the vehicle is managed, the throttle
and brake may be may be utilized similar to current cruise control implementations, as well as audible and
visual warnings to the driver. A mechanism for providing active and automatic brake control may be
required for controlling the shorter following distances envisioned during cooperative cruise control
operations. Alterations to the preset driving condition will alert the driver while automatically ensuring a
safe following distance.
This message set is not meant to define such a system and set limits such as safe following distance, as
these are beyond the scope of the cooperative cruise control message set. System-related design concepts
should be considered in the development of the message set, where operational requirements and
implementation are left to vehicle OEMs, and the driver.
2. Operational Concept
The following section provides a definition for the operational concept of teaming operations, and more
specifically cruise control operations enhanced with low latent communications.
Team:
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Finite number of vehicles.
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Possessing DSRC communications.
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Traveling in same direction.
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Consecutively traveling in the same lane.
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Vehicles shall be of compatible Vehicle Type as defined by the FHWA Office of Highway
Policy Information. The J2735 Vehicle Type data representation will be used.
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Any single vehicle shall not be a member of more than one team concurrently.
Cooperative Cruise Control
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Adaptive cruise control mechanism or operation.
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Enhanced via low latent vehicle-to-vehicle and vehicle-to-infrastructure communications.