Résumé
IEEE Robotics and Automation Letters 2021 (Presented at IROS 2021) 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.