2D omnidirectional navigation of a biped robot based on an egocentric orbit following

Abstract

This paper addresses an omnidirectional locomotion control to make a biped robot walk back and forth, turn to any direction, move sideways and carry out them seamlessly. This is achieved by integrating smooth-path-tracking and lateral walking controllers that have been proposed by the authors, which is not straightforward because the path tracking is designed to converge to a referential path while the lateral walking aims to go away from the path. It can be avoided by extending the path-tracking controller to consecutively redraw the orbit that passes the middle of the feet. The proposed controller is designed completely in the robot-centric frame, namely, all the references and the manipulated variables are represented from the robot's viewpoint so that the operator can issue the referential values in the first-person view. Additionally, as the robot is ruled by neither a plan of footsteps nor time-dependent trajectories, it can flexibly respond to various perturbations. The validity of the proposed controller is investigated through computer simulations and an application to navigation of the robot is also shown.