Quadruped Capturability and Push Recovery via a Switched-Systems Characterization of Dynamic Balance

Hua Chen1; Zejun Hong1; Shunpeng Yang1; Patrick M. Wensing2; Wei Zhang1

2023

10.1109/TRO.2023.3240622

IEEE Transactions on Robotics   Impact Factor & Quartile

1941-0468

1941-0468

This article studies capturability and push recovery for quadruped locomotion. Despite the rich literature on capturability analysis and push recovery for legged robots, existing tools have been developed mainly with the requirement of reaching static or quasi-static balance following a push. In practice, this requirement commonly restricts capturability analysis to cases with simple dynamics and fails to encode the time dependence of capturable states for legged locomotion with time-based gaits. To address these issues, we apply switched systems to model quadruped locomotion and extend capturability notions through a novel specification of dynamic balance. We also provide an explicit model predictive control (EMPC) scheme to compute the dynamic balance and capturable tubes and offer a way of using the capturable tube to synthesize push recovery controllers. Such a generalization allows for a rigorous characterization of disturbance timing on the capturability of quadrupedal locomotion and opens the door of disturbance-timing-aware push recovery control strategies. Extensive simulation and hardware experiments illustrate the necessity of considering dynamic balance for quadrupedal push recovery, reveal how disturbance timing affects capturability, and demonstrate the significant improvement in disturbance rejection with the proposed strategy. Hardware experimental validations on a replica of the Mini Cheetah quadruped further verify that the proposed approach performs statistically better than the state-of-the-art baseline considered.

Capturability push recovery quadruped robot reachability switched systems

SCI

English

First

National Natural Science Foundation of China["62073159","62003155"] ; Shenzhen Science and Technology Program[JCYJ20200109141601708] ; Science, Technology and Innovation Commission of Shenzhen Municipality[ZDSYS20200811143601004]

Robotics

Robotics

WOS:000958803700001

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

IEEE

1.Shenzhen Key Laboratory of Biomimetic Robotics and Intelligent Systems, the Guangdong Provincial Key Laboratory of Human-Augmentation and Rehabilitation Robotics in Universities, and the Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, China
2.Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN, USA

Hua Chen,Zejun Hong,Shunpeng Yang,et al. Quadruped Capturability and Push Recovery via a Switched-Systems Characterization of Dynamic Balance[J]. IEEE Transactions on Robotics,2023,PP(99):1-20.

Hua Chen,Zejun Hong,Shunpeng Yang,Patrick M. Wensing,&Wei Zhang.(2023).Quadruped Capturability and Push Recovery via a Switched-Systems Characterization of Dynamic Balance.IEEE Transactions on Robotics,PP(99),1-20.

Hua Chen,et al."Quadruped Capturability and Push Recovery via a Switched-Systems Characterization of Dynamic Balance".IEEE Transactions on Robotics PP.99(2023):1-20.