AN ANALYTICAL MODEL FOR THE PREDICTION OF TYRE ROAD FRICTION UNDER BRAKING AND CORNERING

In this paper, an analytical model for the prediction of friction between a pneumatic tyre and road surface is presented. The input data need are minimal, importantly, they can be determined or predicted by simple experiments and measurements. This feature drastically reduces the cost associated with the extensive experimentation which previously has been considered necessary. For a known wheel load and pressure distributions, the main inputs needed are: tyre stiffness, and either locked-wheel braking coefficient or maximum sideway force coefficient. The model predicts the longitudinal and lateral forces that act on the tyre, for a given percentage slip and orientation of the tyre relative to the road. The procedure for calculation of frictional (shear) forces is provided. The derivation of mathematical equations is given in an illustrative example, followed by validation of the model against measured data. Two options of computer program are given, to be used with equipment which can produce either locked-wheel Braking Force Coefficient (BFC), or maximum Sideway Force Coefficient (SFC).