> 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/4368.md). # 4368 - IMPROVING THE EXPANDING/CONTRACTING SPEED OF A PUSH-ROLLING ROVER ON LOOSE SURFACES WITH STEEP SLOPES {% hint style="info" %} Paper presented at ISTVS 2025 | 55th Conference of the International Society for Terrain-Vehicle Systems {% endhint %} **Authors:** *Daisuke Fujiwara, Hiroto Fujisawa, Tasuku Hoshino, Kojiro Iizuka* **Keywords:** Mobile robot; Push-rolling motion; Loose soil; Planetary explorations **Abstract:** The wheeled rover has played an important role in planetary or lunar exploration. The planet and moon surfaces are covered with granular materials, which causes the wheeled rover to get stuck. To suppress wheel slippage, the rover, which utilizes shear force beneath the anchored wheel, can effectively climb a loose surface with steep slopes. Previous studies have developed various types of push-rolling and wheel-walking rovers. Furthermore, our previous study developed a minimal configuration rover and confirmed that it can climb loose surfaces with steep slopes while suppressing slippage. During its movement, the rover changes its wheelbase length and moves its wheels using the resistance forces of the anchored wheels. However, the variable speed of the wheelbase length remains constant at 20 mm/s, and the effect of this speed on the rover’s traveling performance is still unclear. The traveling speed of the rover with small wheels tends to slow down; therefore, understanding the potential to improve its speed is important. The purpose of this paper is to validate the impact of the changing speed of the wheelbase length on the climbing ability. This paper presents a testbed rover that can change the speed of the expanding/contracting wheelbase length and performs the climbing experiment on loose soil with steep slopes. The experimental results suggested that driving performance was maintained even when the expanding/contracting speed increased three times faster than the conventional speed. --- # 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/4368.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.