Dynamic Walking: Toward Agile and Efficient Bipedal Robots

TL;DR

This paper reviews the mathematical modeling, optimization, and control methods enabling agile and efficient dynamic walking in bipedal robots, highlighting recent advances and experimental validations.

Contribution

It provides a comprehensive overview of the end-to-end process for achieving dynamic walking, integrating models, gait generation, and real-time control on various platforms.

Findings

Successful implementation of dynamic walking in multiple robots

Models effectively capture essential walking behaviors

Experimental results demonstrate agility and efficiency

Abstract

Dynamic walking on bipedal robots has evolved from an idea in science fiction to a practical reality. This is due to continued progress in three key areas: a mathematical understanding of locomotion, the computational ability to encode this mathematics through optimization, and the hardware capable of realizing this understanding in practice. In this context, this review article outlines the end-to-end process of methods which have proven effective in the literature for achieving dynamic walking on bipedal robots. We begin by introducing mathematical models of locomotion, from reduced order models that capture essential walking behaviors to hybrid dynamical systems that encode the full order continuous dynamics along with discrete footstrike dynamics. These models form the basis for gait generation via (nonlinear) optimization problems. Finally, models and their generated gaits merge in the context of real-time control, wherein walking behaviors are translated to hardware. The concepts presented are illustrated throughout in simulation, and experimental instantiation on multiple walking platforms are highlighted to demonstrate the ability to realize dynamic walking on bipedal robots that is agile and efficient.