Method for determining the thickness of a motor vehicle tire

A method for determining the thickness of a tire of a motor vehicle, the motor vehicle being equipped with a tire pressure monitoring system comprising a tire pressure monitoring receiver connected to at least one tire pressure monitoring sensor placed at a level of a tire of the vehicle,

• each tire pressure monitoring sensor being positioned in contact with an internal wall of the tire so as to be able to measure a variation in the radial acceleration when the tread facing which the tire pressure monitoring sensor is positioned is brought into contact with the ground, the method comprising:
• at least two successive reference times are determined as a function of the variation with respect to time of the radial acceleration experienced by the tire pressure monitoring sensor,
• at least one instant of passage of a half-deflection angle is determined as a function of the variation with respect to time of the radial acceleration experienced by the tire pressure monitoring sensor, and of at least one reference time,
• the half-deflection angle is determined as a function of the instant of passage of the half-deflection angle and of the at least two successive reference times, then
• the value of a mean external radius, which radius is estimated in a range of angular positions, is determined as a function of a value for the speed or the acceleration of the vehicle, of the half-deflection angle and of the at least two successive reference times,
• a value of a mean internal radius, which radius is estimated in a range of angular positions, is determined as a function of the measurement of the radial acceleration and of the angular position of the tire pressure monitoring sensor, then
• the thickness of the tire is determined as being a difference between the mean external radius and the mean internal radius.