> 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/0375.md). # 0375 - A GENERAL MODEL TO APPROXIMATE THE SLIPPAGE CURVE FOR APPLICATIONS FROM ANALYSIS OF THE TIRE AND SOIL CONTRIBUTIONS TO LONGITUDINAL SLIPPAGE {% hint style="info" %} Paper presented at ISTVS 2025 | 55th Conference of the International Society for Terrain-Vehicle Systems {% endhint %} **Authors:** *Vladimir Vantsevich, Jesse Paldan, Jordan Whitson, David Gorsich, Lee Moradi* **Keywords:** Off-road mobility; Soil characterization; Tires **Abstract:** The traction-longitudinal slippage curve characterizes the interaction of a driving wheel and deformable terrain and has important considerations affecting the performance of the wheel and of the vehicle. Knowledge of the slippage is crucial to off-road vehicle mobility and energy efficiency assessment and wheel control applications. To be able to analyze and compare the efficiency of different tires on the same terrain, or a tire on different terrains, the tire slippage should be split into two components to determine contributions of the tire and soil to the tire traction characteristic. A new exponential formulation of the longitudinal slippage was previously derived for this application. Many analytically-inspired-empirical based math models exist to describe slippage curves, which are validated, recommended, and being used in software products to approximate tire-terrain performance. To use these models in research with split tire and soil contributions would require rigorous research effort on re-deriving equations for each model because each is based on different mathematical theory and statistical constraints; such effort may not lead to a positive result. As an alternative approach, the analytical split traction-slippage curve is proposed as a general model to approximate other formulations of the slippage curve which can then be split into separate tire and soil slippage curves. Computational simulations of other slippage models are performed and their resulting curves are fit to the new exponential function to analyze the effectiveness of the split slippage model to approximate other models of traction-slippage curves and soil characterization. Using the split traction model, equations are derived to quantify tire and soil contributions the slip power losses. --- # 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/0375.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.