Discussion on validity of lugged wheel model and evaluation method

Soft soil covers planetary surfaces, so the wheel of a planetary rover easily slips and gets stuck. In order to prevent increase in the slip and getting stuck, the wheel can have lugs that have a shape of a paddle to improve the wheel force. There have been some studies about the influence of the lugs. However, design method of an effective lug has not been studied well yet. Since terramechanics-based wheel models have been considered with a flat wheel surface, those models based on terramechanics are not applicable to the lugged wheel. In this research, in order to establish the design method of the effective lugs, a lugged wheel model was discussed and proposed regarding the variation of the shear characteristics. The variation of shear characteristics is indicated by a shear deformation modulus. The lugged wheel model is based on the shear deformation modulus varied by the lug design. In this paper, the simulation was performed to verify the validity of the lugged wheel model, and it was confirmed that the model could formulate the performance of the wheel traversability. Moreover, the wheel experimental device was described to understand the traversability of the lugged wheel. The evaluation method of the proposed lugged shear deformation model was also considered.