Wet road conditions are typical causes of road accidents. The drivers can easily choose a too high driving speed or try to perform highly dynamic maneuvers at such reduced road grip levels that can cause the saturation of tire forces. It can be surprising since drivers are usually experiencing dry road friction conditions and the humans' actual grip estimations are limited. An even more dangerous situation can occur in cases where the vehicle reaches such velocities that the removal of the water below the tire in the grooves is not possible anymore. In such conditions, the friction coefficient drops to near zero, and the car's loss of stability and control could be a likely result. This sudden reaction (or loss of response) of the vehicle can be fatal in real driving situations where there is no space for the car to slow down. For this reason, the prevention of such conditions is particularly important.

The driver can easily avoid risky situations with the reduction of vehicle speed. However, critical speed limits can significantly change with water depth, tire conditions, and vehicle parameters. Hence, it is challenging for the driver to estimate dangerous velocity limits from where aquaplaning onset. Therefore, an accurate warning signal from the vehicle dynamics states would be beneficial to motivate the driver to reduce speed.

Motivated by the above phenomenon   and aim,  we had  the honor  to cooperate with Professor Manfred Plöchl and his team Johannes Edelmann and   Andreas   Fichtinger,   from   TU   Wien   Institut für Mechanik und Mechatronik for the better understanding of the phenomenon and the practical   design   of   a   warning   system.   The   braking   platform of the ZalaZONE Automotive Proving ground provided an excellent platform for us to carry out our measurements. The aquaplaning basin with a variable water depth provided the possibility to analyze the hydroplaning situation with high water levels that often occurs in heavy rain and unfavorable road conditions. In comparison, the asphalt lane with sprinklers gave us the possibility to test conditions similar to the beginning of rain. See photos taken about the different scenarios below.

To properly understand and validate our concept, different test vehicles were used with all possible drivetrain concepts. As an essential factor, various tire types, sizes, and conditions were included in the measurements. The front-wheel-drive scenario was tested with a Skoda Octavia and the rear-wheel-drive with a BMW M2Competition parallel with a Porsche 911 (blue). Duplicated cars with rear-wheel-drive enhanced the testing of the robustness and validation of our findings. For evaluating hydroplaning behavior  with all-wheel-drive, another Porsche 911 (white) was used. All of our test vehicles were equipped with a high precision measurement system, for example, differential dual antenna   GNSS   system,   IMU,   optical   displacement   measurement   unit.Moreover,   all   the   vehicle   dynamics   signals   (wheel   speeds,   inertial measurement unit, steering angle, etc.) were available in all of our tests.

Our publication about the detailed results and the proposed methods for avoiding many of the accidents related to aquaplaning will be released soon (we will announce it on this platform too). Don't miss to read and cite it if you find it advantageous.

It was a genuine pleasure to work with Professor Plöchl and his team. We believe in the synergy of this research cooperation, and hope that we can proceed in this effective way in the future.

A special thanks goes to Inventure Automotive for supporting us in CAN data  acquisition. Last but not least, we want to thank the ZalaZONE Automotive Proving Ground for providing us this excellent platform for our tests. Without their support, this work would not have been possible.