Method and system for estimating the interaction between tyre and road surface

A method for estimating an interaction between a tyre mounted on a first wheel (W1) of a vehicle, equipped with a command and control unit, and a road surface, wherein the method comprising:

• generating a detection request signal (RS) of the interaction between tyre and road surface by the command and control unit;
• and
• in response to the detection request signal (RS):
• applying a torque (Tr) to the first wheel (W1);
• estimating a current value of a first parameter (Uc) representative of a friction between the tyre mounted on the first wheel (W1) and the road surface;
• estimating a current value of a second parameter (λc) representative of a slip of the tyre mounted on the first wheel (W1) with respect to the road surface;
• and
• estimating an available friction coefficient (Ue) between the tyre and the road surface as a function of the current value of the first (Uc) and second parameter (λc),
• wherein applying the torque (Tr) is performed as a function of a mounting position (P) of the first wheel (W1) on the vehicle and as a consequence of the applying the torque (Tr), an axle of the vehicle to which belongs the first wheel (W1) is more unloaded with respect to remaining axles of the vehicle due to a redistribution of a total mass of the vehicle (1).

A system for estimating an interaction between a tyre mounted on a first wheel (W1) of a vehicle, equipped with a command and control unit, and a road surface, the system comprising:

• an actuation device operatively connected to the first wheel (W1) of the vehicle;
• and
• a processing unit operatively connected to the actuation device and in dialogue with the command and control unit, wherein the processing unit is programmed and configured for:
• in response to a detection request signal (RS) of the interaction between tyre and road surface generated by the command and control unit:
• commanding the actuation device for applying a torque (Tr) to the first wheel (W1);
• estimating a current value of a first parameter (Uc) representative of a friction between the tyre mounted on the first wheel (W1) and the road surface;
• estimating a current value of a second parameter (λc) representative of a slip of the tyre mounted on the first wheel (W1) with respect to the road surface;
• and
• estimating an available friction coefficient (Ue) between the tyre and the road surface as a function of the current value of the first (Uc) and second parameter (λc),
• wherein the processing unit is programmed and configured for commanding the actuation device for applying the torque (Tr) as a function of a mounting position (P) of the first wheel (W1) on the vehicle and as a consequence of the applying the torque (Tr), an axle of the vehicle to which belongs the first wheel (W1) is more unloaded with respect to remaining axles of the vehicle due to a redistribution of a total mass of the vehicle.