Posts tagged "communication"

Communication Emergence in a Fleet of Connected and Autonomous Vehicles

IRIT , Toulouse University


Intelligent Transport System, Distributed optimization, Multi-Agent System, Referential Frame Transformation

Recent advancements to improve road traffic have led to the emergence of Intelligent Transport Systems (ITS). Vehicles can replace the human driver in specific context thanks to the ever-increasing number of smart devices, and they gradually become autonomous. As an autonomous entity, a vehicle behaves according to its perceptions provided by embedded sensors. Not only it can see, but it also has access to other vehicles perceptions through communications. There is a necessity for a CAV to perform social interaction and social signaling. The range of potential interlocutors is wide: vehicles, of course, but also other road users: pedestrians, motorcycles, cyclists, electric scooters and if we think ahead, robots. The overall objective is to provide CAVs with social skills making possible cooperative behavior.

The first addressed lock is the transformation of referential frame. A CAV referential frame refers to its environment self-representation. Usually, an autonomous entity uses itself as a reference point. Position, distance, vectors, etc. are calculated from it. This leads to a possible incomprehension between CAVs and the missuses of a critical information. To counter it, we have proposed a solution enabling CAV to understand information from different referential frame.

The second lock concerns the communication optimization in a fleet of CAVs. With the continuously increasing number of vehicles and smart devices, the number of sensed data become huge. Sharing the integrality of these data can cause issues like delays, errors, and bottleneck. Obviously, not everything is useful to share, and we have proposed a solution to optimize which information is shared based on its usefulness.

Figure 1: « A fleet of autonomous and connected vehicles. »

Scientific goals

- Enabling the use of an information from different referential frames

- Addressing the high dynamicity of the ITS

- Optimizing the communication volume and efficiency


Dynamic Collection of Cooperative Awareness Messages for Collision Avoidance with Vulnerable Road Users

IRIT – Toulouse University                                         


V2X Communication architectures, vulnerable road users safety, cooperative awareness messages.

With the evolution of Intelligent Transportation System (ITS), vehicles are capable of performing intelligent decisions and cooperative communications with other road users to exchange data and expand their environmental awareness. This communication is introduced as vehicle-to-everything (V2X) where vehicles exchange cooperative awareness messages « CAM » that includes important information (eg: position, speed, heading angle, vehicle type…). The generation rules of the CAM messages are defined by the ETSI standard and they are implemented in the facilities layer of each vehicle. The frequency of sending CAMs is between 10 and 1 Hz. However, we found out that following the standard, vehicles must generate a CAM if any change in their behavior is detected. This can lead to overloading the network if the number of road users is high, and might not be necessary if a vehicle has no.

Scientific goal

The aim of this work is to design a novel  neighboring mechanism to enhance the current version of the standard. Through a centralized server with a global vision of the network, the vehicles will be able to efficiently adapt the frequency of sending CAM messages using the information of surrounding neighbors received from the edge-server. Our mechanism is extended to support vulnerable road users (pedestrians, cyclists…) where reducing their transmission frequency undoubtedly helps in saving energy on their connected devices.


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