Real-Time Modeling of Soft Soil-Tire Interaction Using a Map-Based Approach

Accurate modeling of tire–terrain interaction represents a key aspect essential for assessing the performance of wheeled and tracked vehicles operating in off–road conditions, with direct applications in planetary exploration, agriculture, and military domains. Over the years, several families of models have been developed, including physical and semi–empirical approaches, capable of capturing detailed soft soil–tire interaction phenomena. However, their high computational cost restricts their use mainly to offline vehicle dynamics simulations. This limitation is particularly critical in real–time contexts, such as driving simulators, where computational efficiency and time constraints are essential. This paper introduces a novel contact model tailored for real–time simulation, based on precomputed force maps. These maps store tire forces and moments generated offline using a custom semi–empirical contact model. By systematically evaluating the original formulation across its independent variables, the maps provide comprehensive coverage of the expected operating conditions. The tabulated model is then integrated into a virtual quarter–car and benchmarked against the original semi–empirical approach. Numerical results show that the proposed map-based formulation preserves the accuracy of the semi–empirical model while drastically reducing computational effort, thereby enabling its use in real–time applications such as driving simulators for the safe and cost–effective training of military operators.