Method of estimating a height of water in contact with a tire on a road

A device for estimating a height of water (hw) present on a wet ground of a road and in contact with a tread of a tire of a vehicle travelling on the wet ground, the device comprising:

• a tire, the tire having a tread that is equipped with one or more sensors each configured to measure a characteristic quantity of stresses experienced locally by the tread rolling on a ground;
• a transmitter for transmitting a signal corresponding to measurements of the characteristic quantity obtained by the one or more sensors;
• and
• a signal processing unit configured to extract, from the transmitted signal, a signal portion corresponding to a number or to a duration of passage of the one or more sensors in an area of contact of the tire rolling on the ground, wherein the signal processing unit is configured to execute a program for implementing a method of estimating a height of water (hw) present on a ground of a road based on the extracted signal portion, the method including:
• obtaining measurements of the characteristic quantity when the tire is rolling on the ground, the measurements being obtained from the one or more sensors;
• producing the signal corresponding to the measurements;
• extracting the portion of the signal relating to the passing of the one or more sensors into the apparent area of contact between the tire and the ground;
• determining an instantaneous value (ΔL) corresponding to a length of an indirect contact region of the apparent area of contact between the tread of the tire and the ground, based at least in part on the extracted portion of the signal;
• and
• estimating a height of water (hw) from a calculation that takes into account the determined instantaneous value.