Dynamic Walking on Compliant and Uneven Terrain using DCM and Passivity-based Whole-body Control

Abstract

This paper presents a complete trajectory generation and control approach for achieving a robust dynamic walking gait for humanoid robots over compliant and uneven terrain. The work uses the concept of Divergent Component of Motion (DCM) for generating the center of mass (CoM) trajectory, and Cartesian polynomial trajectories for the feet. These reference trajectories are tracked by a passivity-based whole-body controller, which computes the joint torques for commanding our torque-controlled humanoid robot TORO. We provide the implementation details regarding the trajectory generation and control that help preventing discontinuities in the commanded joint torques, which facilitates precise trajectory tracking and robust locomotion. We present extensive experimental results of TORO walking over rough terrain, grass, and, to the best of our knowledge, the first report of a humanoid robot walking over a soft gym mattress.