Mechanical model building of bionic walking robot in motion with soft terrain

Bionic walking robots exhibit excellent mobility on rigid terrain.

however, their trafficability on soft terrain remains a significant challenge affecting their overall performance. To address this issue, we firstly developed a kinematic model of a bionic walking robot to derive the motion parameters between the footpad and soft terrain. Subsequently, a footpad-terrain interaction model was established to analyze the forces acting on the robot during its movement on soft terrain. An exemplar robot leg was built and three footpads at various walking speed were experimentally tested using a versatile single-legged test bench, various stages of footpad-terrain interactions were recorded and vertical force F₁ and horizontal force F₂ were measured. The results confirmed that the model could predict the forces with an accuracy greater than 90 %. The minimal differences observed between the experimental and model values suggest that the mechanical model is reliable for force analysis. Therefore, the mechanical model developed in the study could be further determine the forces exerted on the footpads at and defined moments and sinkage, and a layout foundation to understand the stability of walking robots.