Theoretical and experimental research on lugged wheel performance for wheel mobile robot on loose sand

Based on limit equilibrium theory, the theory research was carried out to analyze the deformation of the loose sand and the contact force between lugs and loose sand. And then the theory model for matching reasonably the lug spacing and height was established. Meanwhile, the effect analysis of lug parameters on motion performance, namely traction performance and steering maneuverability of lugged wheel, was conducted in loose sand bin. All tests were done at a free wheel sinkage and 0 to 60% slip in a single-wheel test bed. Through the qualitative analysis and comparisons of motion performance between smooth wheel and the wheels with different lugs, the results showed that lug height and slip significantly influence the motion performance than lug spacing. In contrast, the effect degree of lug parameter on traction performance and steering maneuverability is opposite. Applying the evaluation indexes of motion performance to analyze the experimental data, the results indicted that the preferable lug parameters for the experimental smooth wheel with 135 mm radius are 15° lug spacing, 15mm lug height, which is consistent with theory result derived from matching reasonably the lug spacing and height, the optimum value of wheel slip is 13% from the perspective of saving energy to the similar loose sand in the experiment.