LQR-Assisted Whole-Body Control of a Wheeled Bipedal Robot With Kinematic Loops

作者：Victor Klemm, Alessandro Morra, Lionel Gulich, Dominik Mannhart, David Rohr, Mina Kamel, Yvain de Viragh, Roland Siegwart · 发表于：IEEE Robotics and Automation Letters · 年份：2020 · DOI：10.1109/lra.2020.2979625 · 被引用次数：184 · 研究领域：Robotic Locomotion and Control、Control and Dynamics of Mobile Robots、Biomimetic flight and propulsion mechanisms

We present a hierarchical whole-body controller leveraging the full rigid body dynamics of the wheeled bipedal robot Ascento. We derive closed-form expressions for the dynamics of its kinematic loops in a way that readily generalizes to more complex systems. The rolling constraint is incorporated using a compact analytic solution based on rotation matrices. The non-minimum phase balancing dynamics are accounted for by including a linear-quadratic regulator as a motion task. Robustness when driving curves is increased by regulating the lean angle as a function of the zero-moment point. The proposed controller is computationally lightweight and significantly extends the rough-terrain capabilities and robustness of the system, as we demonstrate in several experiments.