Development of a Tyre and Vehicle Dynamics Model for Formula SAE 2015-01-0071
A broad spectrum of modelling techniques exists for predicting tyre performance and force characteristics under various operating conditions. These can range from purely theoretical models to semi-empirical fits of data collected from constrained or on-vehicle testing. This paper puts forward a combination of existing techniques for modelling the performance of a racing slick tyre using data obtained from constrained tyre testing with the aim of reducing computational expense and capturing salient differences in tyre behaviour under changes in inclination angle, pressure and normal load.
The force vs. slip data is non-dimensionalised and compressed such that a single characteristic curve taking into account the above parameters can be fitted and then expanded. Response surface modelling of the characteristic curve coefficients is also used to interpolate tyre performance between the test data points. These non- dimensional fits are then expanded for any combination of the input parameters that are fed into the model.
This information is then used to create simple steady-state vehicle models based on both constant radius and constant velocity constraints to investigate vehicle turn-in and limit performance. Additionally, this paper presents steady-state testing of a Formula SAE vehicle which attempts to validate model behaviour and reconcile differences between the data obtained from constrained testing and that obtained from the vehicle.