Tires have a limited capacity to evacuate water. When this is exceeded, the dreaded aquaplaning or hydroplaning appears. German and Italian engineers are working on a system, AIS, that makes it easier to drive in excess water and maintain control.
The aquaplaning or hydroplaning it is a phenomenon by which a vehicle can temporarily float on water. It occurs when the dislodging capacity of the tires has been exceeded and you are driving faster than the circumstances allow safely.
Several factors influence:
how much water accumulates on the asphalt drainage capacity (emptying) of the road tire condition (basically tread depth) driving speed
Therefore, all the water that the asphalt does not dislodge by itself will have to be evacuated by the tires. The moment there is more water between the asphalt and the tire than can be dislodged, hydroplaning will occur. This is, the car will temporarily not obey our orders.
Hydroplaning mainly affects the front wheels, since the rear wheels can go through asphalt with less water
We can preventively reduce the appearance of this phenomenon adapting the speed to the circumstances (It is always recommended), and keeping in mind how the wheels are. If they are new, they will release 5 liters / second at 100 km / hour. With a 3 mm groove, at 90 km / h, the risk of hydroplaning is very high.
Tire manufacturers have long been perfecting their products to improve water evacuation, either by optimizing their groove channels (the tread) or by spinning fine with the compound to repel more water. Nevertheless, a system is being tested that goes beyond.
Easyrain, a company based in Italy, is working with Bosch and Italdesign to design and produce a system that removes water before the tires roll over. This is also done with water, launching a jet in the opposite direction to the march to open a hole, as Moses did with the waters of the sea in the book of Exodus, but without divine intervention.
The basic components of the AIS system (from anti-aquaplaning system) are a pair of water injectors placed under the bumper, a pipeline to a pump, and a water collector that is refilled behind a front wheel. No deposit required. The electronic management decides when the pump has to work so as not to waste energy unnecessarily.
Easyrain and its partners have been working for a few years now, but for the first time we can see the result in a real car, an Audi A6. In this video provided by the manufacturer we can see at different camera speeds what happens when a curve is attacked with water with AIS and without AIS.
In the example shown in the video you can see how with a layer of 7 mm of water and a speed of 95 km / h it is enough for the A6 to lose the trajectory requested by the steering wheel and tend to understeer. Your tires momentarily lose contact with the ground without AIS. With AIS, the effect is much less pronounced.
In the development, technologies available now or soon are being taken into account, such as V2X communication by 5G (launching warnings to other vehicles, or knowing in advance where the system has to act by prior warning), sensors installed on the wheels themselves and integration with assistance to the driver (ADAS).
Every year, as a result of hydroplaning there are tens of thousands of road accidents. In the tests carried out by Easyrain it is verified that the Audi A6 35% more effective in a straight line and 30% more effective in a curve (when the rear wheels don’t benefit as much from the front wheels).
We do not know when the AIS system will become a commercial reality, if it will be a factory integrated solution (OEM) or if it can be installed in any vehicle through kits or through the skill of mechanics. Of course, massing the AIS will considerably reduce the problems associated with rain, always within what physics allows.
If the tires lose contact with the asphalt, we don’t care if we have ESP and all the associated alphabet soup
In the meantime, it must be taken into account that a tire with a 3 mm groove dislodges half the water at 70 km / h than a new tire, and that when it rushes to the witnesses (1.6 mm, the legal minimum) from 50 km / h it is very easy to hydroplan in the rain. Controlling it requires cold blood (gentle use of the steering wheel and brake), skill, having practiced it before, and of course … luck.