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3-D Underactuated Bipedal Walking via H-LIP Based Gait Synthesis and Stepping Stabilization

Xiong, Xiaobin and Ames, Aaron (2022) 3-D Underactuated Bipedal Walking via H-LIP Based Gait Synthesis and Stepping Stabilization. IEEE Transactions on Robotics . ISSN 1552-3098. doi:10.1109/tro.2022.3150219. (In Press)

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In this article, we holistically present a hybrid-linear inverted pendulum (H-LIP) based approach for synthesizing and stabilizing 3-D foot-underactuated bipedal walking, with an emphasis on thorough hardware realization. The H-LIP is proposed to capture the essential components of the underactuated and actuated part of the robotic walking. The robot walking gait is then directly synthesized based on the H-LIP. We comprehensively characterize the periodic orbits of the H-LIP and provably derive the stepping stabilization via its step-to-step (S2S) dynamics, which is then utilized to approximate the S2S dynamics of the horizontal state of the center of mass of the robotic walking. The approximation facilities a H-LIP based stepping controller to provide desired step sizes to stabilize the robotic walking. By realizing the desired step sizes, the robot achieves dynamic and stable walking. The approach is fully evaluated in both simulation and experiment on the 3-D underactuated bipedal robot Cassie, which demonstrates dynamic walking behaviors with both high versatility and robustness.

Item Type:Article
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URLURL TypeDescription video
Xiong, Xiaobin0000-0002-6275-3900
Ames, Aaron0000-0003-0848-3177
Additional Information:© 2022 IEEE. Manuscript received October 29, 2021; accepted January 24, 2022. This article was recommended for publication by Associate Editor O. Stasse and Editor E. Yoshida upon evaluation of the reviewers’ comments. This work was supported by Amazon Fellowship in AI and NSF under Grants 1924526 and 1923239.
Funding AgencyGrant Number
Amazon AI4Science FellowshipUNSPECIFIED
Subject Keywords:Bipedal walking, foot-underactuation, hybrid-linear inverted pendulum (LIP), step-to-step (S2S) dynamics, stepping stabilization
Record Number:CaltechAUTHORS:20220307-188394000
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113764
Deposited By: George Porter
Deposited On:08 Mar 2022 15:58
Last Modified:08 Mar 2022 15:58

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