Mobility performance of a rigid wheel in low gravity environments

Effect of gravity on the mechanical properties of lunar regolith tested using a low gravity simulation device

“…k u was slightly reduced as the gravity decreased, but k c exhibited little variation. For fine-grained soils such as lunar regolith, previous studies have found that changes in gravity have little effect on cohesive behavior such as that expressed by k c , but do affect frictional behavior such as that expressed by k u (Kobayashi et al, 2010;Nakashima et al, 2011;Wong and Kobayashi, 2012).…”

“…Kobayashi et al investigated the influence of gravity on the mobility of wheeled rovers for lunar/planetary exploration missions. They performed model experiments for a soil-wheel system on an aircraft during variable gravity maneuvers (Kobayashi et al, 2010). Nakashima et al determined the effects of gravity on the angle of repose of sand pile particles by allowing dry sand to flow from a hopper during a parabolic airplane flight under simulated low-gravity conditions.…”

A tire model for vehicle motion analysis on dry sand

“…The grain size distribution is relatively narrow; grains ranging from 0.1 to 0.4 mm in diameter account for more than 95% of the sand [9]. The relative density for the test bed is about 25% near the sand surface, which converts to 1.40 g/cm 3 in bulk density.…”

Advantages of continuous excavation in lightweight planetary robotic operations

“…Short of testing on the surfaces of the Moon and Mars directly, reduced-gravity flights (Boles et al, 1997;Kobayashi et al, 2010) offer the testing environment that is most representative of the reduced gravity in planetary operations. In these tests, the regolith and robot are both subject to reduced g. Future research on lightweight excavation would benefit from testing in reduced-gravity flights.…”