Abstract:

Vehicular ad-hoc networks (VANETs) are presented as a new generation of networks oriented to improve the road traffic safety and driving comfort. In these networks the vehicles can share information to each other, or receive alerts from and send data to infrastructure nodes using wireless technology. Since most of data received in one car come from other cars, the main sources of information in VANETs are the vehicles. There exist many prototypes including sensors on board to get information coming from traffic signs, speed limits, motorway tolls or semaphores, that can be retransmitted to other vehicles. The integration of many different technologies in a unique VANET environment increases the complexity of these systems and thus the difficulty of learning.

For this reason, we present a system specially developed to reach the following objectives:
•Serve as a demonstration system of the integration of several technologies in a VANET environment
•Provide a learning platform to the engineering students in the area of wireless technologies.
•Broadcast to the open public the improvements provided by VANETs on the road traffic safety.
•Transmit to the students the relevance of road traffic safety and the possibility to apply their knowledge to save many human lives.

The system is composed of vehicles, road circuits and a background computer. The vehicles have been constructed using the educational Moway mini-robot, with the ability to track a black line, thus providing autonomous driving capability. The native functionality is governed by a main PIC microcontroller and a secondary microcontroller dedicated to control the wheels movements. The vehicle is completed with an additional specially designed PCB that includes an RFID reader and a Zigbee transceiver. The RFID antenna has been integrated in the own robotic vehicle. The system executions are performed on several test road circuits composed of roundabouts, crossroads, speed limitation signals, etc. The road circuits are printed on 150 x 90 centimetres paper size. The RFID tags are incorporated to the road circuit at significant locations, such as the approaching to crossroads or roundabouts, speed limitation signals or one-way roads. These tags are detected by the vehicles when they are passing over them. Finally, a computer is employed to simulate services usually provided by the public infrastructure and telecommunication operators, such as positioning system, road traffic alerts, etc. The computer is also employed to collect telemetry information from the vehicles.

From a learning point of view, the system offers the possibility to develop the following tasks:
•Design and printing of road scenarios of special interest, performed using any illustration, image processing or design software.
•Design of the protocol to be programmed in the vehicles, specifying the technologies involved. Objective: learning on wireless technologies.
•Codification of the protocol defined previously and downloading to every robot. Objective: learning on wireless technologies, low-level programming, and robotic applications.
•Design and implementation of the services provided by the infrastructure, using any programming language. Objective: learning on programming and data communication.
•Design and implementation of telemetry applications using any visual programming language. Objective: learning on visual programming, robotic applications, data communication over different interfaces.

Keywords:

Learning system, road traffic safety, wireless technology.