Centroidal momentum observer: Towards whole-body robust control of legged robots subject to uncertainties

Abstract

This paper aims to provide robust dynamic motion control and eliminate parameter uncertainty in single-legged robots with a centroidal momentum-based control algorithm. In order to ensure the continuity of the movement despite external disturbances, the disturbance observer (DOB), which is frequently used in the motion control literature, is used. A one-legged robot model was simulated using MSC ADAMS, and then a centroidal momentum-based control algorithm and Zero Moment Point (ZMP)-based control algorithm were developed. The performances of the controllers were tested in the simulation environment in line with three different scenarios, unknown load, external forces and external momentum disturbances. The controllers were evaluated by comparing the selected reference orbital positions with the center of mass (CoM) positions on the x and z axes and the ZMP positions on the x-axis. The simulation results satisfactorily validated the proposed centroidal momentum observer as it performed well in all tested conditions.