A Method for Traction Ability Research of a Rover Wheel on Mixed Planet Terrain with Movable Stones

The mixed terrains of terramechanics research are mainly composed of static stones and loose soil. The movement behavior of stones is often ignored while analyzing the influence of the wheel’s traction performance caused by mixed terrain. When a wheel is in contact with the movable stone and with the loose soil at the same time, the residual soil model, therefore, is proposed to simulate the change of the contact force between the wheel and the remaining loose soil caused by the failure of the loose soil in the area covered by stone. The plastic homogeneous soil mechanics model is proposed based on the soil’s mechanical properties. It is used for simulating the reaction force provided by soil to the moving stones. These mechanical models are compiled into the simulation programs, which are called by Adams to calculate the contact forces and moments of the planetary rover’s wheels in the mixed terrain with the movable stone and loose soil. Carrying out soil bin tests under the same experimental conditions, the comparative analysis of the simulation and experiment for a wheel in contact with 4 types of stones shows that the comparison results are in good agreement, which can verify the effectiveness of the proposed models to an extent.