REGENSBURG, Germany—If research being carried out by Continental A.G. pans out, tires someday may be able to tell drivers not only when they need air, but also when they're worn out and/or need replacing or that the car is overloaded.
Drawing on resources of the company's wide-ranging vehicle dynamics businesses, researchers at Continental researching the feasibility of sensors built into tires that can deduce tread depth from gradual changes in tire rolling characteristics and as well as detect a vehicles' load by measuring tire deflection.
“It's not for nothing that legislators all over the world have defined a minimum tire tread depth for safe driving,” said Andreas Wolf, head of Conti's Body & Security business unit. “We...will, in future, be able to conveniently read tread depth electronically with the aid of sensors embedded in the tires.”
This new feature could be offered as early as 2017 on new car models equipped with direct tire pressure monitoring systems from Continental, Wolf said, which Conti calls electronic Tire Information System, or “eTIS.”
This new generation of tire sensors will be fitted directly underneath the tread of the tire, Conti said, where they can infer running characteristics from the variations in tire deformation. On-board software then can analyze the data and determine either the tread depth or vehicle load.
To determine tread depth, sensors monitor a tire's rolling characteristics over a longer period of time. The specifics of the tires' altered rolling characteristics are compared with the accumulated empirical data; if the tread is run down to below a tire-specific threshold value, the on-board electrical system signals that a tire change is due.
Conti stresses that drivers can monitor their treadwear through the tire-wear indicators that Conti molds into its tires. These small ridges between the tread grooves indicate that the recommended minimum allowable tread depth—3 millimeters in summer tires, 4 mm for winter tires—have been attained.
Regarding vehicle load, software developed by Continental can calculate load by detecting changes in tire rolling characteristics 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, Conti said.
Continental has been supplying tire pressure sensors since 2002 under its VDO brand, and more recently it has enhanced its offerings in this area with the development of the “Filling Assistant,” a system integrated at the original equipment level with the vehicle to help the driver fill his or her tires accurately without the use of a tire gauge.
This feature triggers the car's horn when the proper inflation pressure has been achieved. Nissan Motor Co. Ltd. has promoted this feature on several of its models.
Starting this November, TPMS will become mandatory for newly registered passenger cars in the European Union.