Patent attributes
Method of determining the footprint of a tire on the ground, using devices already installed in standard production tires. Since the frequency of the transmitter clock present in a wheel unit is perturbed by mechanical vibrations when the tire contacts the ground, the frequency variations of the reference clock are representative of the value of the footprint. The method therefore includes determining the footprint on the ground of a tire of a wheel by measuring continuously, as a function of time, a signal representative of the variations in frequency of the reference clock supplied at the output of the time control device; determining a time interval during which the frequency variations of the reference clock occur; and, on the basis of the rotation speed of the tire, deducing therefrom an angular range of contact (Θ) corresponding to the footprint between the ends representing the ground contact length of the tire.