> 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/0954.md). # 0954 - ENHANCING COMBINED SLIP MANOEUVRES IN HIGH CENTRE-OF-MASS OFF-ROAD VEHICLES USING A SEMI-ACTIVE SUSPENSION SYSTEM {% hint style="info" %} Paper presented at ISTVS 2025 | 55th Conference of the International Society for Terrain-Vehicle Systems {% endhint %} **Authors:** *Christos Kapareliotis, Schalk Els, Andries Peenze* **Keywords:** Semi-Active Suspension; Combined Slip; High centre-of-mass vehicle; Vehicle Model; Experimental testing **Abstract:** Emergency driving scenarios require combined slip, where tyres generate longitudinal and lateral forces to slow the vehicle while following a path. Stability systems e.g. as ABS brakes and Electronic Stability Control assist in regaining control after loss of stability. These systems do not actively prevent instability. ABS and ESC systems do not have direct rollover prevention which is necessary in vehicles with a high centre of mass. For off-road vehicles, this challenge is exaggerated by uneven terrain, loose soil, and rollover risk. Stability control systems struggle with unpredictable road inputs, often compromising handling. A preventative system is needed that manipulates load transfer to improve tyre contact before traction limits are exceeded and where the roll angle of the vehicle can be directly controlled. This study proposes using a semi-active suspension system to improve performance during combined slip manoeuvres. By adjusting suspension parameters, the system manipulates load transfer, and enhances overall traction limits, reducing instability and rollover risk while maintaining steering and braking. A vehicle, equipped with a controllable semi-active suspension system is used as a test platform. A high-fidelity model is used for design and optimization studies. Results are validated using experimental tests, with open-loop manoeuvres using brake and steering robots for repeatability and controlled assessment. Preliminary findings indicate that a semi-active suspension system enhances combined slip performance, reducing instability risks. While this research begins on paved surfaces, it provides a critical foundation for off-road applications, where terrain variability further challenges the vehicle’s stability. --- # 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/0954.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.