Patent ID: 7197380

Claim:
A vehicle stability control system in which a characteristic parameter Q of a functioning of a tire of the vehicle intended to roll on the ground varies as a function of a parameter P according to a certain law, an optimum value of the parameter P being imposed by a controller directly or indirectly, so as to act on at least one of elements chosen from a group comprising a rotation torque applied to the tire, a steering angle of the tire, a camber angle of the tire, and a vertical force applied to the tire, in which the controller comprises means for: determining coefficients A [avg/p] , by direct calculation or by a regression, from a sufficient number of pairs (P i , Q i ), so as to model a first variation curve Q i =f(P i , A [avg/p] ) including the origin, and the pair or pairs (Q i , P i ), in which Q i is different from zero, determining an indicator of an average slope α 1 of the first variation curve, determining coefficients B [avg/p] , by direct calculation or by a regression, from a sufficient number of pairs (Q i , P i ), so as to model a second variation curve Q i =f(P i , B [avg/p] ) including the pair or pairs (Q i , P i ), in which Q i is different from zero, determining an indicator of an average slope α 2 of the second variation curve, as long as the difference between α 1 and α 2 is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (P i , Q i ), if the difference between α 1 and α 2 exceeds the predetermined slope threshold, determining a target slip p Cavg using at least the last pair of values (P i , Q i ).