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 means of 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 comparison between a value representative of a rate of the torque (Tr′) and a respective predetermined limit value (Tr′ref).

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
• 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 (W1) wheel 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 also programmed and configured for receiving as input a value representative of a rate of the torque (Tr′), and for commanding the actuation device for applying the torque (Tr) as a function of a comparison between the value representative of the rate of the torque (Tr′) and a respective limit value (Tr′ref).