以二级半转轮腿式月球车为研究对象,考虑月球车在松软月面上的下限问题,在轮腿的跨步杆两端各添加一个“足”,并设计出两种月球车轮腿足部构型方案,以增大足部与月壤间的有效接触面积和摩擦力。依据车辆地面力学基本理论,分析月球车的轮腿足瓣与月壤的相互作用力学特性,建立了月球车无轮刺足瓣与月壤的相互作用力学模型,在此基础上,分析了足瓣轮刺效应。提出月球车驱动性能的四个评价指标:足瓣沉陷指标、足部牵引性能指标、驱动电动机性能指标和爬坡性能指标,通过给定月壤特性参数、月球车载荷和滑转率,研究了足瓣的半径、宽度以及轮刺的高度和个数对挂钩牵引力、驱动力矩的影响。Matlab仿真表明,增大足瓣半径、宽度以及轮刺高度和个数均可以提高月球车的驱动性能,与增加足瓣宽度相比,增加足瓣半径效果更好。研究结果为后续的足部机构设计提供了理论参考。
Taking the wheel-legged lunar rover with double-half-revolution mechanism as the research object, feet are added on both ends of the striking rod with the consideration of lunar rover’s sinkage problem when walking on the loose lunar surface. Two kinds of foot configuration schemes have been designed, in order to increase the effective contact area and their friction between the foot and lunar soil. According to the basic theory of terrain mechanics, the mechanical properties between the foot and lunar soil are analyzed. The mathematical models between the foot without wheel thorn and lunar soil are built up, and the influences of foot configuration parameters with wheel thorns are analyzed. Four driving performance evaluation indexes are proposed, including foot sinkage index, foot traction performance index, driving motor performance index and climbing performance index. Through the given characteristic parameters of the lunar soil, the lunar rover load and slip rate, the influences of foot radius/width and wheel thorn height/ number on hook traction and driving torque are simulated by Matlab software. The results show that the increase of the foot radius, height and width as well as the number of the wheel thorns can improve the driving performance of the lunar rover. Compared with the foot width, the increase of foot radius is better. The results provide a theoretical basis for the subsequent foot configuration design.