Bionic design of a anti-sinking walking wheel for micro tillers and wheel-soil interaction model

The existing wheels exhibit suboptimal performance when traversing the paddy fields. This study aims to develop a wheel suitable for the paddy fields. Firstly, an analysis was conducted into the morphological alterations and patterns of the webbed foot, leveraging the kinematic characteristics of mallards. Secondly, a walking wheel featuring anti-sinking and high-traction attributes was conceptualized and designed. Concurrently, a model elucidating the relationship between the contact area and the leg-foot angle variation was formulated. Subsequently, a series of field trials about the walking wheel and the paddy wheel were measured. Within the range of the slip ratio from 0 to 0.47, the drawbar pull, driving torque and sinkage of the walking wheel gradually increase, and the traction efficiency initially ascended and subsequently tapered off. In the paddy field and wetland, in comparison to the paddy wheel, the drawbar pull was augmented by 97.29 % and 51.65 % respectively. These findings validate the superior traction and traversal capabilities of the walking wheel. Finally, a terramechanics model delineating the relationship between the drawbar pull and slip ratio variation was established. This model holds the potential to furnish theoretical and technical underpinnings for augmenting the traction performance of walking wheels.