new infra red sensor that records accurate tyre carcass temperature has been developed by TPMS specialists BERU f1systems. For the first time, DigiTyre IR provides accurate temperature and pressure data unaffected by heat soak from the rim and brakes.
“Tyre temperature sensors are normally fitted to the rim as part of the valve,” says managing director John Bailey. “Heat soak from the rim and brakes distorts results from a traditional wheel sensor. Our system uses IR sensors to measure the inside temperature of the tyre itself, not air temperature. Engineers will now be able to correlate accurate tyre carcass temperature to wear, traction and loading.” The technology is being introduced in F1 in 2009
but like the firm's traditional pressure monitoring systems a derivative for commercial vehicles will also be available. In active dutry, information about the tyre carcass temperature could also help to identify tyre deflation issues quicker too. “There
a chain of events when a tyre deflates,” says Bailey. “If a tyre develops a puncture, tyre and air temperatures rise with a short lag between the two. Traditional systems only measure air temperature; our new system will receive data about changes to
the carcass temperature, so we could determine a puncture a little earlier.” This could improve decision making about the status of the tyres in emergency situations.
The system offers excellent resolution (0.25ºC) and accuracy (0.5ºC) across an extended temperature range (-40 ºC to 215ºC). The wheel sensor transmits pressure, air and tyre temperature at 1Hz, via antennae to the ECU. The system is also compatible with CAN bus, making its use in car, van and truck applications relevant.
The system is now being tested in F1 where tyre setup and pressure is essential to lap times and race success. For the development of military vehicles, the IR sensor will provide information on how tyre temperature affects tyre performance and wear.
