月球车轮刺效应的理论分析与实验研究

Theoretical Analysis and Experimental Research on Wheel Lug Effect of Lunar Rover

轮地相互作用地面力学在星球车研究中有着重要意义,目前对于轮地作用中的轮刺效应研究尚不充分。基于Rankine被动土压力理论,分析轮刺与土壤作用的两种工作方式,推导了形成稳定剪切土环时轮刺高度与个数之间的关系式和保证连续剪切的轮刺倾斜角度计算公式。采用轮地相互作用测试系统对宽度为165mm,半径分别为135mm和157.35mm的月球车车轮,改变轮刺高度、个数和倾角进行实验,验证了理论分析结果,同时得到如下结论:增加轮刺高度可以提高车轮的牵引性能,轮刺高度为15mm时,比光滑车轮的最大牵引力提高达60%;增加轮刺个数有助于形成稳定的剪切土环;轮刺的倾斜角度可以减小车轮的振动幅度;车轮的牵引力随滑转率增加而增大,但最好将滑转率控制在0.4以下。研究成果为月球车轮刺设计和进行轮地作用力预测提供了依据,并可应用于类似的火星车和地面车辆等。

Wheel-soil interaction terramechanics is of great significance for the research of planetary rovers, yet the current research on wheel lug effect is insufficient. Based on the Rankine passive soil pressure theory, the two work modes of lugs are analyzed, formula for calculating the lug height and number to form continuous shearing soil loop, as well as that for determining inclination angle are deduced. Experiments were performed using wheel-soil interaction system and two wheels with height of 165mm, radius of 157.35mm and 135mm, respectively. The lug heigh, lug number and inclination angle were changed. Experimental data verified the theoretical results and some useful conclusions were obtained： increas- ing lug height can improve the traction performance, for example, the wheel with lugs of 15mm in height increased the drawbar pull by 60% ; increasing the number of lugs can be helpful for forming continuous shearing loop; the inclination of lugs can decrease the vibration amplitude of wheel; the drawbar pull increases with the slip ratio, but it is better to control it under 0.4. The researching results of this paper provide theory for lug design and force prediction, which can also be used for the similar Mars rover and terrestrial vehicle.