Continental has introduced a solution that allows road conditions to be classified with regard to tire/road friction. A specific situation called aquaplaning is extremely dangerous for manually driven vehicles as well as automated ones. Technology company Continental has now begun to develop new sensor-based concepts to warn the driver in the event of imminent loss of friction.
When there is a thick layer of water on the road, the water pressure between the tire footprint and the road surface can make the front wheels float. Braking and steering are no longer possible, and the driver loses control of the vehicle.
The system under development is all encompassing – tires, tire-sensors, cameras, algorithms, brake actuation, and the human-machine interface.
Continental’s developers are focused on predicting and managing the risk of aquaplaning. The objective is to detect a possible front-wheels floating situation as early as possible in order to trigger an early warning to the driver. Utilizing signals from surround view cameras and tire-mounted eTIS (electronic-Tire Information System) sensors, an early warning concerning the approaching aquaplaning situation is provided to the driver. Continental is also working on the control and stabilization of vehicles in aquaplaning situations, such as torque vectoring by individual wheel braking.
Aquaplaning conditions can also occur unexpectedly with no opportunity for advance warning. In such cases, the potential risk to other vehicles on the road can be mitigated by early communication via V2X technology and eHorizon, facilitating a network of solidarity where one vehicle acts as a safety sensor for all other vehicles and not just those in its direct vicinity. eHorizon can provide this information to vehicles that could potentially be affected, so they are able to adjust their driving functions to the aquaplaning conditions.
In addition to image information, Continental uses information from tires to detect the risk of aquaplaning. In this concept, signals from Continental’s eTIS sensors, mounted on the tire’s inner liner, are computed. “We use the accelerometer signal from the electronic-Tire Information System to look for a specific signal pattern”, said Andreas Wolf, head of Continental’s Body & Security business unit. A tire model processes the incoming radial acceleration of the part of the tire that is in contact with the road. For wet roads – when enough water is transported out of the tire tread to ensure an appropriate grip – the signal shows a distinct pattern. As soon as a wedge of water begins to form in front of the tire footprint region and there is excessive water on the road, the acceleration signal begins to oscillate in a characteristic way, indicating an early risk of aquaplaning. Since the eTIS sensors can also detect the remaining tire tread depth, a safe speed for a given wet road condition can be calculated and communicated to the driver.
Testing has shown that future aquaplaning assistance will also have the potential to intervene in an actual aquaplaning situation by applying the rear brakes in a controlled way to establish a degree of “torque vectoring” in order to maintain vehicle maneuverability within physical limits.