Automotive safety system

Project definition

In this project we are working on a wireless vehicle to vehicle communication, which should improve the active safety on the roads. The main goal is to prevent the mass car accidents with the distributed warning system. For example if there is an obstacle on the road, the first vehicle which makes a special maneuver (hard breaking, fast trajectory change...) immediately starts to transmit a warning signal which is then distributed to other nearby vehicles and forwarded by them to cars a few kilometers ahead the obstacle. Every vehicle is a self-standing function unit. It measures its own position and compares it with position of other units in range. Then it decides which messages are important and if there is a related action for them. The functionality of the system is based on a quite large amount of wireless nodes.

The project is devided into three nain parts:

• communication protocol

communication is based on a research in this paper, a model was made and verified with the UPPAAL modeling and verification tool.

    finished (February 2006)

• hardware development

in current days we have two wireless T-Mote Sky modules and we have developed GPS/Acccelerometer boards. In further work we assume our own control unit especialy widening the system for CAN communication

    working on

• software development

the communication between GPS/Acc. board and T-mote Sky modules is being finished with a testing application.

    working on

Keywords:

• ad hoc, multi-hop networks
• wireless communication
• localisation, GPS, accelerometer, triangulation
• CAN

Time-schedule

February 2007

• communication GPS/Acc. board and T-Mote Sky
• App. documentation

March 2007

• App. documentation
• finishing electronic schema of Control Unit
• Layout
• documentation

April 2007

• HW Sample
• testing
• documentation
• completition

The Gant Diagram

Tasks

• GPS comm: GPS -> TMote
• Application to show GPS data transmission
• Acc comm: Acc -> TMote
• documentation
• Time schedule
• SAM7XC Startup Bundle price 270 euro (220 euro only evaluation board)

Tmote Sky serial communication

Defining the radio packet length

According to CC2420 datasheet, the 128 byte packet size data limit can be transmitted, therefore the max payload length of TOS_msg should be:

128 - 10 (TOS_msg header) - 2 (MAC footer) = 116 bytes.

The default value of TOSH_DATA_LENGTH is 28 bytes, can be changed in: $TOSDIR/moteiv/tos/lib/cc2420Radio/AM.h

• Some protocol specifications
• TmoteSky programming

Links

• PReVENT - European automotive industry activity - Homepage
• PReVENT - WillWarn - related work
• CAR 2 CAR
• Atmel AT91SAM7XC256 processor datasheet

• Cygwin Help