> For the complete documentation index, see [llms.txt](https://2025.istvs.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://2025.istvs.org/submissions/papers/4217.md). # 4217 - A COMPUTATIONALLY EFFICIENT PLUG-IN FOR HIGH-FIDELITY OFF-ROAD VEHICLE DYNAMICS STUDIES ON DEFORMABLE TERRAINS {% hint style="info" %} Paper presented at ISTVS 2025 | 55th Conference of the International Society for Terrain-Vehicle Systems {% endhint %} **Authors:** *Amir Khosravian, Sadegh Yarmohammadisatri, Corina Sandu, Yinglong HE, Davide Tavernini* **Keywords:** Off-road mobility; Vehicle dynamics; Tire-terrain interaction; Deformable terrain modeling; Flexible tire modeling **Abstract:** Accurate simulation of off-road vehicle dynamics on deformable terrains remains computationally challenging despite advances in vehicle dynamics modeling. In this paper, we develop an efficient yet high-fidelity off-road simulation toolbox, which incorporates the Hybrid Soft Soil Tire Model (HSSTM), a semi-empirical, experimentally validated off-road tire model, and the widespread simulation platform IPG CarMaker. This integration enables high-fidelity simulations on deformable terrains and facilitates the development of off-road vehicle control algorithms for highly dynamic scenarios. The integrated tire-vehicle model provides a tool for simulating the ride, handling, and mobility of off-road vehicles. HSSTM models the tire as discretized lumped masses with Kelvin-Voigt elements on a 3D deformable terrain. Unlike rigid-ring models, HSSTM captures tire flexibility, which is crucial for simulating tire dynamics on medium-hard to rigid terrains. To enhance computational efficiency, we adopt a Dynamic Terrain Adaptation algorithm that models only a localized portion of the terrain around the vehicle, dynamically updating as the vehicle navigates. Simulations on non-deformable terrain demonstrate that HSSTM tire forces are in good agreement with existing on-road tire models (e.g., MF-Swift). Further, simulations on deformable terrains in longitudinal and lateral scenarios (including force coupling) confirm accurate off-road dynamics representation across various terrain types. The plug-in assesses contact patch pressure, normal and shear forces, elastic and plastic sinkage, and multi-pass effect. Finally, a sensitivity analysis across various simulations with different tire and terrain discretization levels evaluates the accuracy/efficiency trade-off of our plug-in. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://2025.istvs.org/submissions/papers/4217.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.