Influence of Objective Tire Characteristics on Vehicle Dynamics of Battery Electric SUVs with Focus on Low Rolling Resistance Tires
Authors:   Technische Universität Dresden, Institute of Automotive Engineering Dresden, Chair of Automotive Engineering, GERMANY, Birnbaum Florian , Winkler Tobias ,   Audi AG, GERMANY, Niessen Bart ,   Audi AG, GERMANY, Petry Frank ,   Goodyear S.A., LUXEMBOURG, Prokop Günther ,   Technische Universität Dresden, Institute of Automotive Engineering Dresden, Chair of Automotive Engineering, GERMANY
Published: March 2022

"Regarding the continually growing registrations of electric vehicles as well as the increasing popularity of Sport Utility Vehicles (SUVs), new tradeoffs between objective tire characteristics will dominate future vehicle developments. In this context, tire properties defining vehicle dynamics, ride comfort and efficiency have to be mentioned. On the one hand, SUVs appear to be a suitable vehicle concepts for electrification due to the high mass and volume for the required high capacity battery. On the other hand, the resultant higher weight and the requirement for efficiency enhancement lead to additional intensification of the aforementioned tradeoffs. In consequence, low-rolling resistance tires are essential to extend the electric range respectively a reduction of CO2-emissions for vehicles with conventional combustion engine. In order to reach an increase in efficiency, a comprehensive understanding of interaction between tire properties and their influence on vehicle behavior is inevitable. Therefore, this paper aims on the effect analysis of tire properties on vehicle dynamics under particular consideration of reducing rolling resistance. For this reason, the interaction between particular objective tire characteristics and their influence on objective vehicle criteria are investigated. For this purpose, specific tires are used for this analysis, which differ primarily in construction and material design. In spite of limitations concerning dimensions, the considered tires spread in relevant objective tire characteristics equivalent to tires of different rim dimensions. Based on the methodology for objective analysis of vehicle dynamics on component and full vehicle level, objective tire characteristics of the prototypes are discussed. The main tradeoffs, which occur during an optimization of the rolling resistance, are shown and described. To analyze the interdependencies between tire properties and vehicle dynamics, objective vehicle measurements are performed with an electrical vehicle and all previously analyzed tires. Furthermore, the interactions between tire and component level are investigated by aid of a virtual environment. In this connection, a nonlinear two track model with full axle kinematics and compliance, a dynamic steering and a nonlinear tire model is utilized. In conclusion, the tire and vehicle model is validated and the methodology of early and later stages of the tire development are correlated. Finally, the objective vehicle behavior is related to tire characteristics such as cornering stiffness, lateral relaxation length and grip level. With respect to this analysis, recommendations for further planned investigations and for design targets for vehicle concepts are derived."