This repo contains a V2V communication protocol between autonomous RCs with a focus on platooning. The RCs' specs can be found here.

1. Installation

2. Get started

3. License

4. Requests

5. CID ranges

6. NTP

To install libcluon please refer to the installation guide Libcluon.

Clone the repo using:

git clone https://github.com/DIT168-V2V-responsibles/v2v-protocol.git

Make a build folder and navigate into it:

mkdir build
cd build

Run cmake to create the necessary build files:

cmake ..

Finally compile:

make

The protocol is licenced under GNU Lesser General Public License version 3.0. This is due to the incorporation of "libcluon" library as part of the project. Libcluon offers their software under LGPLv 3.0 licence and due to the copyleft nature, anyone who distribute its code or derivative works, are required to make the source available under the same terms. Libcluon library can be found here.

This section describes the protocol requests. Fields of requests and their types are denoted: Type field name.

This message is intended for the cars not leading other cars yet, to inform their presence on the network. The Announce Presence holds the IP of the car as a unique identification among all the cars that followers can connect to, if they choose to follow the car sending Announce Presence message. Moreover, the car also includes the id of the group in the message in order to inform the cars about the group number.

Fields

• string vehicleIp - IP of the car that sends the announce presence, used as a unique idetifier.
• string groupId - The project group number of the group that has the car.

This message is sent to the car that is about to be followed by another car that wants to initiate following. This message requires a response i.e. Follow Response.

This message is sent in response to a Follow Request. The message is used in combination with the Follow Request message to establish direct Car to Car communication.

This message is sent by a car to indicate that following must come to an end. Both the leading and the following vehicles are able to send this request. This message does not expect a response.

This message includes information about a leading vehicle and contains information relevant for a following car to be able to follow it. The LeaderStatus is sent in regular intervals of 125ms and does not expect a response.

Fields

• uint64_t timestamp - The time stamp (the time that the message has been sent) of the leading vehicle, represented as UNIX Epoch time in milliseconds.
• float speed - Current speed of the leading vehicle, the leading car should put its current Pedal Position Reading into this message field.
• float steeringAngle - Current steering angle of the leading vehicle, the leading car should put its current Ground Steering Reading into this message field.
• uint8_t distanceTraveled - The distance travelled since the last status update (according the odometer), represented in centimeters.

This message lets the leading car know that this follower is still following. The FollowerStatus is sent in regular intervals of 500ms and does not expect a response.

For the purposes of the DIT168 course, the OD4 session CIDs that the project groups are going to use are listed below.

The Announce Presence messages between the groups will be broadcast to an OD4 session with CID 250.

In order for a vehicle to send a meaningful timestamp to other vehicles, time.google.com shall be used as the NTP server for all vehicles.