On show at the Frankfurt International Motor Show in September was what was described as “the second generation of tyre pressure control systems”, developed by Siemens VDO Automotive, in conjunction with Goodyear.

This unit is more than just a pressure sensor, as it can record mileage and tyre wear, moving one step further towards the “intelligent tyre”. The new sensors operate with an indirect power supply and allow electronic identification of the tyres, as they are embedded into the tyre carcass, rather than part of an external sensor fitted to the wheel.

As well as the sensor, the system incorporates an antenna in the tyre and a transmitter/receiver in the cabin. It is this latter unit that supplies the tyre with energy. Should there be a drop in pressure, the sophisticated software recognises this and sends a warning to the driver. Additionally, a chip in the tyre records the mileage and the distance that can be travelled without sufficient pressure.

The electronics are only a few square millimetres in size and they measure the tyre temperature and, with the aid of a micromechanical sensor, the air pressure in the tyre. The system evaluates additional information such as wheel speed, then the software calculates the nominal air pressure, notifying the driver if this falls below pre-determined levels. The driver can also request the current pressure or mileage of each tyre at any time.

Because the sensors are a permanent component of the tyre, data such as tyre type can be sent directly to the vehicle electronics, which is also helpful for the ABS and other chassis control systems. Another advantage is that the new system does not require a separate sensor to be fitted to the wheel and, if the tyre is changed from one wheel to another, there is no transfer of sensor needed.

Finally, the light weight of the sensor means that it has no adverse effect on tyre performance or vehicle handling.