A new empirical 'exponential' tyre model

Abstract

In this paper, a new and simple formula is presented for empirical modelling of tyre force data. Based on exponential functions, it is capable of matching single slip data for lateral or longitudinal forces using three parameters, which can be computed in terms of stiffness, peak and saturated force values. Through a factorial study, the three parameters are also reformulated into functions of load and slip to provide full mapping of Fx and Fy across the range of longitudinal slip, lateral slip and vertical load. Significantly, the resulting model does not rely on a total slip calculation, so it retains a simple structure in force vs. slip or load derivatives. The new model is compared with two alternative simple tyre models and is shown to map forces generated from a reference Pacejka model. It is also used to fit measured tyre force data accurately.