Method for determining the coefficient of adhesion between tyre and road

The force between tire and road is calculated using two groups of parameters. One group concerns conditions of the vehicle and of the surroundings and these values are provided by sensors. The other group involves fixed values concerning the tire properties, which are fed in initially. The parameters are used in a learning cycle to predict the limiting friction value that is fed to an ABS or ESP system as an initial value. The first group of parameters includes ambient temperature, road surface properties, road condition, speed, actual tire pressure, wheel loading and instantaneous tire profile. The other group of parameters concerns tire composition, tire profile, tire contour and construction, nominal air pressure. Some of the first group of parameters can be determined in steps, e.g. dry, wet, icy road surface. Some parameters can be provided by telemetry between groups of vehicles in a dynamic network.