An Overview of Tire-Ground Contact Modeling Approaches for Surface Mobility Applications

Wheels and tires serve as the critical interface between vehicles and the ground, enabling traction, force transmission, and ultimately mobility. As planetary exploration systems adopt increasingly complex wheel and tire designs, look to explore increasingly extreme terrains, and adopt increasingly aggressive performance requirements, physics-based modeling has become essential for both designing these mechanisms and predicting performance under conditions that are difficult or impractical to replicate experimentally, such as reduced gravity. This paper provides a high-level overview of commonly used modeling approaches for simulating tireground interaction, including those currently employed or under development at NASA Glenn Research Center, NASA Johnson Space Center, and the Jet Propulsion Laboratory. The paper first categorizes modeling techniques based on their fidelity and underlying assumptions. It then discusses the applications, benefits, and limitations of each approach, highlighting current knowledge gaps and modeling challenges. Finally, the paper outlines ongoing and future work aimed at addressing these limitations, including initial results from automated soil preparation experiments that support the generation of consistent physical test data and the development of terramechanics simulations for evaluating and comparing model fidelity.