Off-road motorcycle tyre force estimation

To improve the performance of off-road motorcycles, tyre contact forces need to be estimated. Differently to on-road motorcycle contact force estimators where the rider can be considered attached to the chassis, an off-road motorcycles estimator needs to model the rider dynamics, since driving in standing position provides significant isolation from motorcycle motion. In this article, we use a novel simple rider model to approximate the interaction with the motorcycle when no sensing on him is possible. In particular, the novelty is to keep the pitch angle of the rider constant by means of an active torque on the hip. A tyre force estimator is built using this rider model coupled to a five degree-of-freedom motorcycle, which is verified with a virtual experiment performed on Working Model 2D, showing promising results.