In the simulation of the dynamic response of a vehicle, the accuracy of the predictions strongly depends on the tyre properties. Even though tyre forces generated by a real tyre are nonlinear, there is a linear region where the slip and slip angle are low. Most normal driving is done in this region. This paper will present a new analytical tyre model capable of simulating pure cornering, pure braking, and combined braking/cornering in this region. The dynamic properties of the tyre are analytically derived as functions of the slip, slip angle, normal force, and road friction coefficient. For the combined braking/cornering condition, the unique function which effectively determines the trade-off between longitudinal force and cornering force is derived. The proposed tyre model can be analytically linearised about a given operating point; thus, it can be very useful for designing controllers and observers for use in vehicle dynamic control systems. (Author/publisher)
Abstract