Study on hard rock particle size division based on Mars rover traction performance

基于火星车牵引性能的石块粒径划分研究

Received: 16 September 2022

Abstract

To simplify the dynamic solution of the contact between the rigid wheel of Mars rover and the spherical hard stone on the mixed terrain, a model for hard stone particle size division based on the traction performance of Mars rover is proposed. On the mixed terrain of hard rock and soft soil, the movement of hard rock will affect the traction performance of the rigid wheels of Mars rover. According to the different effects of the hard stones on the traction performance of rigid wheels, stones are divided into three types. The static sinkage of rigid wheels is calculated according to the Bekker bearing model, and the calculation formula of sliding sinkage of rigid wheels and hard stone sinkage is proposed. The type of hard stones is determined by comparing the sinkage of hard stones and rigid wheels. Finally, three kinds of hard stones with slip ratios of 0.2, 0.5, and 0.7 were substituted into the single wheel simulation platform and the soil trough experiment platform for simulation and experiment. The results show that on mixed terrain, the error of simulation and experimental results of fixed hard stones under three slip rates is below 5.4%, the error of drawbar pull in simulation and experimental results of movable hard stones is above 126%, and the error of simulation and experimental results of scattered small hard stones is below 2%, which verifies the effectiveness of the hard stone particle size division model.

摘要

针对简化火星车刚轮与球形石块在混合地形上接触的动力学求解问题, 提出了一种基于火星车牵引性能的石块粒径划分模型。石块-软土混合地形上, 石块受载沉陷, 其运动状态会影响火星车刚轮的牵引性能。依据石块对刚轮牵引性能的影响效果不同, 将石块划分为3种类型。根据Bekker承压模型计算刚轮静沉陷, 提出刚轮滑动沉陷计算公式和石块沉陷计算公式, 根据石块和刚轮沉陷量确定石块类型。最后将滑转率为0.2, 0.5, 0.7时的3种石块分别代入单轮仿真平台和土槽实验平台进行仿真和实验。结果显示: 混合地形上, 3种滑转率下的固定石块的仿真和实验结果误差小于5.4%, 可移动石块的仿真和实验结果中的挂钩牵引力误差超过126%, 散布小石块仿真和实验结果误差小于2%, 验证了石块粒径划分模型的有效性。