An effective method to identify thermodynamic tire characteristics through driving maneuvers

Abstract

The optimal tire temperature is a determining factor to get quick lap times in motorsport, because the tire rubber compound characteristics decay very rapidly outside a given temperature range. The characteristics of road car tires also vary with temperature, although such a variation is smaller than the one of racing cars; however, the performance of sport cars is still massively influenced by tire temperatures. The heat coming out of high performance driving is transferred in different ways throughout the tires, resulting in very big temperature variations within the tire parts. The tire surface in contact with the road can get warm very quickly because of friction energy in the contact patch, and can also cool down rapidly because of air convection and heat conduction into the track. On the other hand, the inner liner has much smaller and slower variations in temperature, partly because of the relatively low thermal conductivity of the rubber compound. These two spots where the tire temperature is usually detected have an influence on tire characteristics which are relevant for vehicle dynamics: the surface temperature correlates with grip, the inner liner temperature with cornering stiffness [1]. The measurement of these quantities requires additional (and reliable) sensors, setting a tough task.