Effect of the Dynamics of a Horizontally Wobbling Mass on Biped Walking Performance

TL;DR

This paper investigates how the horizontal wobbling of an upper body mass affects bipedal walking stability and energy efficiency using a passive dynamic model, revealing that certain wobbling behaviors enhance performance.

Contribution

It introduces a compass model with a horizontally oscillating wobbling mass, analyzing its impact on walking stability and energy efficiency, which is a novel approach.

Findings

Certain wobbling behaviors improve energy efficiency.

Wobbling mass movement opposes upper body motion, stabilizing gait.

Different limit cycles depend on spring constant values.

Abstract

We have developed biped robots with a passive dynamic walking mechanism. This study proposes a compass model with a wobbling mass connected to the upper body and oscillating in the horizontal direction to clarify the influence of the horizontal dynamics of the upper body on bipedal walking. The limit cycles of the model were numerically searched, and their stability and energy efficiency was investigated. Several qualitatively different limit cycles were obtained depending mainly on the spring constant that supports the wobbling mass. Specific types of solutions decreased the stability while reducing the risk of accidental falling and improving the energy efficiency. The obtained results were attributed to the wobbling mass moving in the opposite direction to the upper body, thereby preventing large changes in acceleration and deceleration while walking. The relationship between the locomotion of the proposed model and the actual biped robot and human gaits was investigated.