Reactive Support Polygon Adaptation for the Hybrid Legged-Wheeled CENTAURO Robot

Abstract

The need for robots operating in the real-world has sparked interest in hybrid locomotion that combines the versatile legged mobility with a simpler wheeled motion. The use of legged-wheeled robots in complex real-world scenarios requires controllers that will capitalise on this flexibility. In this work, a reactive control scheme that exploits wheels steering and robot articulated legs is proposed to continuously adjust the robot support polygon (SP) in response to unknown disturbances. The designed cartesian-space control is expressed in the joint-space to account for the hardware limits. To tackle the non-holonomy in the joint-space model, the linear velocity/acceleration-based model is developed for the general legged-wheeled platform and applied to resolve the SP adaptation of a platform with steerable wheels. The proposed control is experimentally verified on the CENTAURO robot, demonstrating the SP adjustment when external disturbances are applied.