Title: Passivity Based Whole-body Control for Quadrupedal Locomotion on Challenging Terrain,
Abstract: We present a passivity-based Whole-Body Control approach for quadruped robots
that achieves dynamic locomotion while compliantly balancing the robot's trunk.
We formulate the motion tracking as a Quadratic Program that takes into account
the full robot rigid body dynamics, the actuation limit, the joint limits and
the contact interaction. We analyze the controller robustness against
inaccurate friction coefficient estimates and unstable footholds, as well as
its capability to redistribute the load as a consequence of enforcing actuation
limits. Additionally, we present some practical implementation details gained
from the experience with the real platform. Extensive experimental trials on
the 90 Kg Hydraulically actuated Quadruped robot validate the capabilities of
this controller under various terrain conditions and gaits. The proposed
approach is expedient for accurate execution of high dynamic motions with
respect to the current state of the art.