System for controlling the stability of a vehicle using an algorithm comparing average slopes of variation of a parameter

摘要

System for controlling the stability of a vehicle, the system comprising means for imparting a longitudinal force on the tire and means for calculating the slip parameter G^Opt at each activation of the means for imparting a longitudinal force on the tire in the following manner: determining coefficients A_[avg/p] by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_i, G_i), so as to model a first curve of variation μ_i=f(G_i, A_[avg/p]) including the origin, and the pair or pairs (μ_i, G_i), in which μ_i is different from zero, determining an indicator of the average slope α₁ of the first variation curve, determining coefficients B_[avg/p] by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_i, G_i), so as to model a second variation curve, free not to pass through the origin, μ_i=f(G_i, B_[avg/p]) including the pair or pairs (μ_i, G_i), in which μ_i is different from zero, determining an indicator of the average slope α₂ of the second variation curve, as long as the difference between α₁ and α₂ is below a predetermined slope threshold, repeating the previous operations for each new acquisition of the pair of values (G_i, μ_i), as soon as the difference between α₁ and α₂ exceeds the predetermined slope threshold and determining a target slip G^Cavg using at least the last pair of values (G_i, μ_i).