Tyre modelling for motorcycle dynamics

A tyre model based on simplifying mechanical assumptions is derived, which is, however, qualitatively valid over the whole region of possible operating conditions up to saturation. A one-dimensional brush model on the two-parameter Pasternak foundation is used, which is sometimes called the enhanced string model. The analysis is limited to the behaviour under steady-state conditions and under slow variations in these conditions, for this case the model can be reduced to a point contact model. The inputs to the tyre model are the normal tyre deflection, the camber angle, the longitudinal and lateral slips and the normal spin. The resultant normal, lateral and longitudinal forces and the aligning moment are the outputs. A difference from previous studies is the way in which the first-order relaxation is modelled; the relaxation lengths depend on the state of motion.