考虑足地作用的足式机器人环境表征与路径规划

足式机器人在行走过程中，足端与地面之间的相互作用影响机器人的地面通过情况。足地作用与地表的几何形状和地面的物理特性息息相关，因此仅基于几何特性地图进行路径规划难以满足野外环境下规避松软沙土等非几何危险的需求。针对该问题，考虑足地作用力学提出包含几何与物理特性的环境模型进行足式机器人路径规划。通过简化和统一软硬地面下的足地作用模型，提出表征地面法向松软特性和切向摩擦特性的参数化指标，结合几何特性构建更全面的环境模型。综合考虑影响机器人通过性的地面几何与物理特征，重构路径规划的优化目标，通过图搜索算法实现最优路径规划。以六足机器人Elspider为对象进行仿真和试验，验证了所提出的方法能够有效规避非几何危险，实现了更安全、通过性更强的路径规划。

Environmental Characterization and Path Planning for Legged Robots Considering Foot-terrain Interaction

During the walking of a legged robot, the interactions between its end of feet and the terrain strongly affect the traversability of the robot. Foot-terrain interaction is closely related to the geometry of the terrain surface and the physical characteristics of it. Therefore, path planning based on geometric map alone is difficult to meet the demand of avoiding non-geometric hazards such as soft sand in the wild. To solve this problem, an environment model including geometric and physical characteristics is proposed in consideration of foot-terrain interaction for path planning of legged robots. By simplifying and unifying the foot-terrain interaction model under soft and rigid terrain, parameterized indexes characterizing the normal softness and tangential friction characteristics of the terrain are proposed, and a more comprehensive environment model is constructed by combining geometric characteristics and the proposed physical characteristics. Comprehensively considering the ground geometric and physical characteristics affecting the robot's traversability, the optimization target of path planning is reconstructed and the optimal path is planned for legged robots with graph search algorithm. Simulation and experiments with the hexapod robot Elspider verified that the proposed method can effectively avoid non-geometric hazards and plan a safer and more reliable path to traverse.