The close cooperation between electronics and tyre developers at Continental, the international automotive supplier, continues to bear fruit. Future tyre pressure sensors, for instance, will be able to detect when a tyre change is necessary due to insufficient tread depth.
Explaining the importance of regular tread depth monitoring, Andreas Wolf, head of the Body & Security business unit, points out, “It’s not for nothing that legislators all over the world have defined a minimum tyre tread depth for safe driving. We are delighted that we will, in future, be able to conveniently read tread depth electronically with the aid of sensors embedded in the tyres.” Intelligent software makes the new feature possible. The software deduces tread depth from gradual changes in tyre rolling characteristics. The in-tyre pressure sensor infers running characteristics from the variations in tyre deformation. The new feature is tentatively slated to be available as of 2017 in new vehicle models equipped with direct tyre pressure monitoring systems (TPMS) from Continental (electronic tyre Information System, eTIS).
Tread Depth Detection
For this completely new type of electronic tread depth detection, Continental engineers draw on a tyre’s gradually changing rolling characteristics over a longer period of time. Tyre and electronics developers conducted an intensive series of tests that allowed the basic data to be fed into the electronics of future vehicles. The specifics of the tyres’ altered rolling characteristics are compared with the accumulated empirical data. If the tread is run down to below a tyre-specific threshold value, the on-board electrical system signals that a tyre change is due. If so desired, the vehicle’s telematics module is even capable of informing the local auto service center. It goes without saying that people will still be able to check for themselves when the recommended or legally required minimum tread depth has been reached. For this purpose, the tyre has wet-TWI (tread wear indicators). These are small ridges between the tread grooves that indicate that the brand manufacturers recommended minimum allowable tread depth (3 millimeters in summer tyres, 4 mm for winter tyres) have been attained.
Intelligent Tyres
With the introduction of the first tyre pressure sensors from Continental in 2002, the most important link between the vehicle and the road became intelligent. Since then, tyre pressure sensors have been able to provide tyre-by-tyre information about the current tyre pressure and conveniently warn drivers if tyre pressure is too low. As of November 2014, a tyre pressure monitoring system will become mandatory for newly registered passenger cars (Vehicle class M1) in the European Union. Tyre sensors can help ensure optimum inflation pressure; this extends the life of a tyre, reduces fuel consumption and, consequently, lowers CO2 emissions. Continental relies on these direct measuring systems with precise pressure display. With these, a sensor reads the tyre pressure either at the valve or directly under the tyre tread. If a second set of tyres needs to be equipped with sensors, Continental already supplies the corresponding retrofit sensors under the VDO brand.
Future Tyre Sensors
Continental is working with car makers all over the world to further expand the range of features that in-tyre pressure sensors can provide. Every tyre loses air slowly but surely. The tyre pressure sensor ensures that drivers are informed of tyre pressure loss at an early stage. Therefore they do not run the risk of driving with one or more dangerously under-inflated tyres. Initial car models equipped with intelligent sensors from Continental automatically signal when a tyre being inflated has attained the required tyre pressure. The Filling Assistant is a big help when inflating tyres and guarantees the right tyre pressure even when non-calibrated filling stations are used. Rolling resistance is reduced as a result and the tyres perform at their maximum capability in terms of safety and comfort.
Load Detection
Another feature about to be produced is load detection. Here, the vehicle uses software developed by Continental to specifically detect whether the maximum permissible load has been exceeded. This is very handy when setting off on vacation, for example. The electronics quickly detect a change in rolling characteristics due to excessive load and inform the driver of the respective axle load. Future driver assistance systems will use the load information to adjust their functions to the respective vehicle weight. Over the long term, this makes automated driving features safer still and even more convenient.
