An overconstrained robotic leg with coaxial quasi-direct drives for omni-directional ground mobility

Abstract

Planar mechanisms dominate modern designs of legged robots with remote actuator placement for robust agility in ground mobility. This paper presents the novel design of an overconstrained robotic leg driven by two coaxially arranged quasi-direct actuators, capable of omni-directional ground locomotion. We investigated the design, modeling, and optimization of a robotic leg module based on the Bennett linkage, which is an overconstrained 4textit{R} linkage often exhibited with three-dimensional motion and unparalleled joint axes. We further explored the reconfigurable design using this Bennett leg module, resulting in a large class of overconstrained robots as a potential direction for novel designs of legged robots.