METHOD FOR ESTIMATING THE EXTERNAL RADIUS OF A TYRE FITTED TO A WHEEL OF A MOTOR VEHICLE

A method for estimating the external radius Rof a tire fitted to a wheel of a motor vehicle, the wheel including a radial acceleration sensor. The method includes: acquiring, by the sensor, a signal S when the vehicle is in motion under non-steady-state conditions, detecting local extrema of the signal S which are respectively associated with phase values and with detection instants, determining a variation in frequency F′ of rotation of the wheel as a function of said phase values and of said detection instants, determining, for at least one detection instant, a discrepancy between the local extremum associated with said detection instant and a reference signal obtained by eliminating the fluctuations in the signal S, determining a value for the longitudinal acceleration Vof the vehicle as a function of the at least one discrepancy, estimating the external radius Ras a function of Vand F′.