Humanoid Loco-Manipulations Pattern Generation and Stabilization Control

TL;DR

This paper presents a novel control strategy for humanoid robots that enables stable loco-manipulation by accounting for external forces during movement, demonstrated through simulation and real-world experiments.

Contribution

It introduces a new bipedal control approach that integrates external force effects into trajectory planning and stabilization for humanoid loco-manipulation.

Findings

Effective in simulation and real robot experiments

Improves stability during object manipulation while walking

Successfully compensates for external contact forces

Abstract

In order for a humanoid robot to perform loco-manipulation such as moving an object while walking, it is necessary to account for sustained or alternating external forces other than ground-feet reaction, resulting from humanoid-object contact interactions. In this letter, we propose a bipedal control strategy for humanoid loco-manipulation that can cope with such external forces. First, the basic formulas of the bipedal dynamics, i.e., linear inverted pendulum mode and divergent component of motion, are derived, taking into account the effects of external manipulation forces. Then, we propose a pattern generator to plan center of mass trajectories consistent with the reference trajectory of the manipulation forces, and a stabilizer to compensate for the error between desired and actual manipulation forces. The effectiveness of our controller is assessed both in simulation and loco-manipulation experiments with real humanoid robots.