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) and maintaining a second wheel (W2) of the vehicle, distinct from the first wheel, in free rolling onto the road surface;
• 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 (Ac) 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 (Ac),
• wherein the current value of the second parameter (Ac) is estimated as a function of a speed (Vx1) of the first wheel (W1) and of a speed (Vx2) of the second wheel (W2) of the vehicle.

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, wherein the system comprises:

• an actuation device operatively connected to the first wheel (W1) of the vehicle and to a second wheel (W2) of the vehicle distinct from the first wheel (W1);
• 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) and maintaining the second wheel (W2) in free rolling onto the road surface;
• 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 (Ac) 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 (Ac),
• wherein the processing unit is programmed and configured for receiving as input a speed (Vx1) of the first wheel (W1) and a speed (Vx2) of the second wheel (W2), and for estimating the current value of the second parameter (Ac) as a function of the speed (Vx1, Vx2) of the first (W1) and second wheel (W2).