Experimental Investigation and Semi-physical Modelling of the Influence of Rotational Speed on the Vertical Tyre Stiffness and Tyre Radii

Development and validation of vehicle dynamics controls and automated driving functions require real-time capable tyre models that are able to consider main influencing parameters at the tested operation condition accurately. In the presented study, experimental investigations with two types of tyres were conducted to quantify the effect of the tyre rotation on the vertical tyre stiffness, the unloaded, static and effective tyre radius. Based on the semi-physical handling tyre model TMeasy, an enhanced modelling approach is presented which is able to consider the rotational speed dependent tyre behaviour in an effective semi-physical and numerically efficient manner. The measurement results of the tyre testing series are analysed and the effects of the tyre rotation are identified. The tested tyres show a nearly linear rotational speed induced increase of the vertical stiffness and a non-linear increase of the unloaded radius. Finally, the performance of the presented enhanced semi-physical model for the vertical tyre force transmission and tyre radii is validated. The results are discussed and an outlook regarding further investigations is given.