Discrete element method analysis of single wheel performance for a small lunar rover on sloped terrain

Abstract

The purpose of this study is to analyze the performance of a lugged wheel for a lunar micro rover on sloped terrain by a 2D discrete element method (DEM), which was initially developed for horizontal terrain. To confirm the applicability of DEM for sloped terrain locomotion, the relationships of slope angle with slip, wheel sinkage and wheel torque obtained by DEM, were compared with experimental results measured using a slope test bed consisting of a soil bin filled with lunar regolith simulant. Among the lug parameters investigated, a lugged wheel with rim diameter of 250 mm, width of 100 mm, lug height of 10 mm, lug thickness of 5 mm, and total lug number of 18 was found, on average, to perform excellently in terms of metrics, such as slope angle for 20% slip, power number for self-propelled point, power number for 15-degree-slope and power number for 20% slip. The estimation of wheel performance over sloped lunar terrain showed an increase in wheel slip, and the possibility exists that the selected lugged wheel will not be able to move up a slope steeper than 20 degrees.

Discrete element method simulations of Mars Exploration Rover wheel performance

“…Interest is increasing in the use of DEM models to improve the physical representation of off-road vehicle mobility in conditions where classical terramechanics models have difficulty (Li et al, 2012;Lichtenheldt and Schäfer, 2013;Nakashima et al, 2010;Smith and Peng, 2013;Smith et al, 2014;Wang et al, 2011). These studies have demonstrated that even 2-D DEM simulations with relatively simple particle geometries can provide useful qualitative representations of off-road vehicle mobility.…”

Space Robotics

“…The empirical method uses a practical measurement of soil strength with a specialized apparatus, such as a cone index (CI) [67], which is often used for an in situ prediction of vehicle traversability. The numerical method includes the finite-element method and discrete-element method that simulate soil deformation and vehicle-terrain interaction behavior with computer technology [72][73][74].…”

Micromechanical Behavior of DNA‐1A Lunar Regolith Simulant in Comparison to Ottawa Sand

“…There is particular interest in the study of the behavior of the lunar regolith at low effective stresses, but such experiments are difficult to be performed in the laboratory due to the effect of terrestrial gravity and the models used should be scaled for Moon's gravitational acceleration (Cafaro et al, 2018;Hasan & Alshibli, 2010;Sture et al, 1998). Hence, cost-effective numerical modeling tools such as the discrete element method (DEM; after Cundall & Strack, 1979) have been implemented for the simulation of the lunar regolith and its interactions with rover vehicles (Knuth et al, 2012;Li et al, 2010;Nakashima et al, 2010Nakashima et al, , 2011Sullivan et al, 2011) and retaining structures (Jiang et al, 2016).…”