Stair-Climbing Charts: On the Optimal Body Height for Quadruped Robots to Walk on Stairs

Quadruped robots have increasingly become one of the main choices when a mobile platform must be deployed to execute tasks in unstructured environments. Nowadays, their major applications are concentrated on monitoring and inspection inside industrial buildings, oil &gas platforms, and construction sites. In such environments, going up and down staircases are a common need and represent the most dangerous scenario where the robot locomotion is expected to be robust enough to prevent catastrophic damages in case of a fall. In this paper, we present a study on the robot’s body height to maximize feasible footholds when walking on stairs. As per study results, this paper introduces the Stair Climbing Charts (SCCs), which describe the best robot height to climb stairs according to the robot’s upper-leg length and lower-leg geometry, as well as the stair geometry (rise/go). Moreover, this paper presents a set of SCCs for various well-known quadruped robots, sold commercially or prototypes of academic research labs, and discusses the major differences between them.