A Whole-Body Disturbance Rejection Control Framework for Dynamic Motions in Legged Robots

TL;DR

This paper introduces a novel whole-body disturbance rejection control framework for legged robots that improves robustness against external disturbances and model uncertainties, demonstrated through simulations and real-world experiments.

Contribution

It proposes a new disturbance estimator combining adaptive control and ESO, integrated into a comprehensive whole-body control framework for legged robots.

Findings

Effective disturbance compensation in simulations

Enhanced robustness demonstrated in quadruped experiments

Potential for adaptation to complex terrains

Abstract

This letter presents a control framework for legged robots that enables self-perception and resistance to external disturbances and model uncertainties. First, a novel disturbance estimator is proposed, integrating adaptive control and extended state observers (ESO) to estimate external disturbances and model uncertainties. This estimator is embedded within the whole-body control framework to compensate for disturbances in the legged system. Second, a comprehensive whole-body disturbance rejection control framework (WB-DRC) is introduced, accounting for the robot's full-body dynamics. Compared to previous whole-body control frameworks, WB-DRC effectively handles external disturbances and model uncertainties, with the potential to adapt to complex terrain. Third, simulations of both biped and quadruped robots are conducted in the Gazebo simulator to demonstrate the effectiveness and versatility of WB-DRC. Finally, extensive experimental trials on the quadruped robot validate the robustness and stability of the robot system using WB-DRC under various disturbance conditions.