Application of a terrain-deformation-based terramechanics model for wheel mobility modes: Driving, braking, and lateral slip

The development and operation of exploration rovers are essential for promoting lunar and planetary exploration. However, evaluating wheel and vehicle prototypes under conditions corresponding to extra-terrestrial gravity and soft terrain is challenging. Therefore, a systematic assessment of the vehicle mobility characteristics through numerical simulations is required. This study presents the application of a terrain-deformation-based terramechanics model to analyze wheel mobility modes, including driving, braking, and lateral slip behaviors. The proposed model considers the soil deformation effects on wheel–soil interactions, enabling more accurate predictions of trafficability under various wheel mobility conditions. To validate the model, numerical simulations were conducted and compared with single-wheel experimental results on deformable terrain. The comparison demonstrates that the proposed model effectively captures the influence of terrain deformation on wheel performance, particularly in the braking and lateral slip scenarios, and provides reasonable predictions of wheel mobility. Another notable feature of the proposed model is its ability to handle multiple mobility conditions using a single parameter set. Consequently, we successfully captured the transitional changes in wheel mobility modes from driving to braking, and vice versa, and analyzed the resulting traveling behavior.