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The elastic contact influences on passive walking gaits

Published online by Cambridge University Press:  02 December 2010

Feng Qi
Affiliation:
School of Aerospace, Tsinghua University, Beijing, 100084, P.R. China
Tianshu Wang*
Affiliation:
School of Aerospace, Tsinghua University, Beijing, 100084, P.R. China
Junfeng Li
Affiliation:
Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P.R. China
*
*Corresponding author. E-mail: tswang@tsinghua.edu.cn

Summary

This paper presents a new planar passive dynamic model with contact between the feet and the ground. The Hertz contact law and the approximate Coulomb friction law were introduced into this human-like model. In contrast to McGeer's passive dynamic models, contact stiffness, contact damping, and coefficients of friction were added to characterize the walking model. Through numerical simulation, stable period-one gait and period-two gait cycles were found, and the contact forces were derived from the results. After investigating the effects of the contact parameters on walking gaits, we found that changes in contact stiffness led to changes in the global characteristics of the walking gait, but not in contact damping. The coefficients of friction related to whether the model could walk or not. For the simulation of the routes to chaos, we found that a small contact stiffness value will lead to a delayed point of bifurcation, meaning that a less rigid surface is easier for a passive model to walk on. The effects of contact damping and friction coefficients on routes to chaos were quite small.

Type
Articles
Copyright
Copyright © Cambridge University Press 2010

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