A Useful Tire Model for ATV Ride Performance on Rough Roads 2010-01-1922
Virtual prototyping has been widely used in the industry and academy as a system performance prediction tool before production. Particularly for the analysis of vehicle ride comfort, the quarter car model is popular since it requires only the essential and least amount of input data. However, the assumption of point contact between the tire and road may sometimes be misleading, especially in rough road applications or low pressure tires for all terrain vehicles (ATV).
To have a realistic prediction at the early design stage when little information is available, the quarter car model is modified in this research by allowing the tire to leave off the ground and considering variable tire patch contact. These features are important when designing ATVs used in versatile environments and with low pressure tires. Inclination of distributed tire springs and constant division road profile are implemented to facilitate fidelity and efficiency in simulation. Vehicle characteristics and simulation results are acquired and validated by experiments.
As road roughness increases, the detachability (the ability of the tire to separate from the terrain) and tire patch effects become significant. In particular, detachability is found important for low frequency and high amplitude road profiles whereas tire patch is significant for high frequency and small amplitude ones. Both features result in smaller optimal damping than that of the point contact model according to the conflict diagram. Tire patch variation is also investigated in the proposed model.