An adapted Burckhardt tire model for off-road vehicle applications

To develop a synthesis model combining simplicity and accuracy, we have designed a new tire model for off-road applications. This article describes the scientific approach we followed to achieve this result. This work adapts the Burckhardt tire model for off-road conditions, analyzing its shape coefficients and proposing an estimation methodology for model parameters. A virtual flat-trac using the Chrono Simulator is developed for data acquisition, leading to a linearized off-road tire model. This is a crucial step, enabling us to design control laws that are robust to variations in the tire-ground interaction.

Off-road vehicle mobility is a real challenge in many areas such as agriculture, military, or construction machinery. The introduction of autonomous vehicles in these fields requires more advanced control algorithms. Furthermore, the deformable nature of the terrain has a significant impact on vehicle behavior. In this context, a lot of research has been conducted to describe the wheel-ground interaction phenomena. Among the most significant factors, traction force, lateral force, and wheel sinkage are crucial aspects in the study of vehicle mobility. One of the most used approaches is based on the Bekker-Wong description. However, due to the mathematical complexity of this model, this approach is rather intended for vehicle simulation. Since the design of control laws requires less complex models, this paper proposes a method based on a road tire model structure adapted to deformable surfaces. This modification is based on the original Burckhardt tire model with a modified structure and estimated parameters. Furthermore, the parameter identification is performed by simulating a realistic virtual test bench allowing the data collection for the parameter estimation process. Finally, the obtained results show the applicability of the proposed method through a new tire model called the Adapted Burchardt Tire Model (ABTM).