Study on applicability of RFT to traveling analysis of wheel with grousers: Comparison with DEM analysis as a virtual test

Abstract

We studied a method to calculate the traveling characteristics of small and lightweight rovers at low cost. Specifically, discrete element method (DEM) was considered as a high-cost and high-accuracy virtual test, and plate tests and traveling analyses of the wheel with grousers were performed. Meanwhile, we adopted resistive force theory (RFT) as a low-cost analysis method and confirmed its applicability to the traveling of wheels with grousers by comparing it with the results obtained by DEM analysis of a loose frictional soil. First, we determined the scale factor necessary for RFT calculation by DEM analysis of the plate penetration test. Then, DEM wheel models with three types of grouser were prepared, and we compared the drawbar-pull under several levels of slippage with the results obtained by RFT. Although RFT cannot sufficiently consider the influences of the shearing of the soil and of distance between grousers, it found that the effects of grousers can be examined at low cost by RFT.