Bionic Walking Foot and Mechanical Performance on Soil

The surface structure of the Chinese mitten crab dactylopodite was investigated. The results indicated that the Chinese mitten crab dactylopodite has grooves with variable section structure on the surface of dactylopodite for achieving good traveling behavior on soft terrain. Surface structure plays a key role in the walking performance of the leg mechanism. Based on the bionics coupling theory, three bionic walking feet with different section shapes, including circular (Bio 1), circular with grooves (Bio 2), hexagon (Bio 3) and a cylinder foot used for comparison on the aluminum alloy, were designed and fabricated successfully. Meanwhile, comparative experiments on intrusion, extraction and propulsion for walking feet were conducted on different soil. Experimental results show that a bionic walking foot reduced the energy consumption of insertion and extraction, which topped out to 93.95% and 92.78% of cylinder foot, and Bio 2 behaves better. Propulsion is closely correlated with intrusion depth; therefore, compared with cylinder foot, the sinkage of a bionic walking foot helps to achieve a larger propulsion force with the same pressure. Furthermore, the proper depth in balancing the sinkage and propulsion was discussed, which enables us to optimize the structure and performance of a walking foot