The Research on the Effects of Motion Parameter on Adhesive Ability of a Lunar Crater Exploration Rover Wheel Based on DEM Simulation

Lunar soil sampling is the premise of the analysis of lunar soil and the study of lunar environment and evolutional history. Because of the restrictions of the sampling method, the size of drillers, the drilling pressure and the output power of driller, the traditional digging and vertical drilling methods can only acquire the samples from lunar surface to 3 meters deep. In order to acquire deeper samples based on the existing technical methods, a new exploration concept in which a driller fixed on the rover takes a horizontal drilling and sampling at the cross section of a crater after cleaning the surface chaotic soil was proposed in this paper. When drilling horizontally, the maximum drilling pressure is limited by the low adhesive ability between wheels and sandy road. For the purpose of making sure enough drilling pressure, study was carried out in this paper to improve the adhesive ability of wheel by modifying the surface of wheel. A new kind of wheel with micro convex structures was proved to be more adhesive and stable during horizontal drilling by comparing with the existing wheel structures, such as the wheel with thorns or the wheel with discontinuous rims. The motion parameter of wheel has a significant influence on the driving property of wheel. In order to research the effects of motion parameter on adhesive ability of wheel, the process that wheels move on sandy road was simulated using a DEM software EDEM, the simulation results show that though the adhesive ability of wheel with convex structures will decrease with the increase of tangential velocity slightly, its adhesive ability is much higher than the adhesive ability of normal wheel.