Abstract: Planetary rover exploration is an effective approach to expand the scope and depth of extraterrestrial detection. Targeting mobility failure risks induced by soft terrains on extraterrestrial bodies, this work elucidates the inherent relationship between soil mechanical properties and robotic trafficability. Experimental studies are conducted on the relationship between rover trafficability and soil mechanical properties, including in-situ Bevameter measurements and prototype mobility tests. Qualitative relationships are revealed between soil mechanical parameters (cohesive modulus, frictional modulus, compression index, shear modulus) and sinkage/slip ratio. Trafficability comparisons are made for granular simulants (coarse sand and fine sand on flat terrain). The results demonstrate that these mechanical parameters are critical factors influencing soil trafficability, and exhibit positive correlations with both bearing-shear resistance and trafficability. The study validates the effectiveness of sinkage/slip-ratio-based indirect assessment for identifying non-geometric hazards and preliminarily reveals intrinsic correlations between soil particle morphology/composition and trafficability.

Key words: mobile robot, trafficability, soil mechanical properties, sinkage, slip ratio