Hexapod robots have attracted attention for their excellent terrain adaptabilities. When a robot walks on soft soil, dynamic subsidence and slippage greatly reduce its walking performance. The influence of foot’s shape is usually ignored or simply studied without considering the multibody dynamics of the robot. This study is focused on the influence of the foot shape on the walking performance of a robot by coupling the sinkage with multibody dynamics. A composite contact model based on the Bekker, spring-damping, and Janosi-Hanamoto models was used to model the interaction of the robot and soft soil. Non-uniform rational B-spline (NURBS) surface and mesh were used to describe the geometries of foot and soft soil, respectively. The influences of three foot shapes on the sinkage and walking stability of the robot were analyzed by comparsion. The improved X-shaped foot reduced the robot’s sinkage and improved its walking stability.

六足机器人以其出色的地形适应性吸引了人们的注意。当机器人在柔软的土壤上行走时，动态沉降和滑动会大大降低其行走性能。通常忽略或简单地研究脚的形状的影响，而不考虑机器人的多体动力学。这项研究的重点是通过将下沉与多体动力学耦合在一起，来研究脚的形状对机器人步行性能的影响。基于Bekker模型，弹簧阻尼模型和Janosi-Hanamoto模型的复合接触模型用于对机器人与软土的相互作用进行建模。非均匀有理B样条（NURBS）曲面和网格分别用于描述脚和软土的几何形状。比较分析了三足形状对机器人下沉和行走稳定性的影响。