The relation between rolling resistance and tyre temperature in real driving scenarios

Sammanfattning: A large portion of the world’s total emissions is caused by the transport sector where rolling resistance is one of the contributing factors. The inner tyre temperature is a factor that greatly influences the rolling resistance. The effect of temperature and rolling resistance is often examined in standardised tests carried out in a lab environment. In this work, field tests were carried to find out typical operating temperatures in real driving scenarios. The field tests were carried out on one set of A-class tyres and one set of B-class tyres at different speeds: city-, small country road-, large country road- and motorway driving. Tests were performed in varying ambient temperatures and weather conditions. The results show that the rear inner tyre temperature varies between 11 to 36C in the spring around Linköping in Sweden. A brush model was also developed to see how accurately the rolling resistance could be predicted. With springs, dampers, and Coulomb friction elements the behaviour of rubber was captured. The final model contains five model parameters that were estimated by parameter fitting to measurement data, using optimisation. Measurements were carried out at a test rig that measures the forces acting on the tyre. The measurements were performed for both the A-class and B-class tyre at two different temperatures corresponding to the findings from the field tests. The results show that the developed model has a promising correlation with the measurements for all loads and speeds that were tested.