Analysis of lunar rover wheel slippage based on discrete element method

Preventing wheel slippage is crucial for ensuring safe and prolonged operation of the rovers on the lunar surface. Therefore, investigating the mechanism of wheel slippage during lunar traversal is of significant importance. Inspired by the wheels of the Yutu and Yutu-2 lunar rovers, a three-dimensional discrete element method (DEM) model was established to analyze wheel-soil interactions. To simulate the mechanical properties of the lunar soil, a three-dimensional lunar soil contact model, taking into account particle rotational resistance and van der Waals forces, was utilized. Comparative analysis was conducted to examine surface soil damage and sub-surface particle movement under different slip conditions, thereby exploring the impact of wheel slippage on the wheel-soil interaction process and elucidating the underlying mechanisms. Experimental results indicate that wheel slippage alters the magnitude and direction of sub-surface lunar soil particle movements, affecting the interaction forces between the wheel and the soil. Within certain limits, increased slippage can enhance wheel traversal capability; however, excessive slippage leading to significant sinking can diminish traversal performance.