Prediction of stable walking for a toy that cannot stand.
Previous experiments [M. J. Coleman and A. Ruina, Phys. Rev. Lett. 80, 3658 (1998)] showed that a gravity-powered toy with no control and that has no statically stable near-standing configurations can walk stably. We show here that a simple rigid-body statically unstable mathematical model based loosely on the physical toy can predict stable limit-cycle walking motions. These calculations add to the repertoire of rigid-body mechanism behaviors as well as further implicating passive dynamics as a possible contributor to stability of animal motions.
Coleman
M J
MJ
Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, New York 14853-7501, USA. mjc23@cornell.edu
Garcia
M
M
Mombaur
K
K
Ruina
A
A
D000818:Animals; D001696:Biomechanical Phenomena; D005684:Gait / Q000502:physiology*; D006112:Gravitation; D006801:Humans; D008953:Models, Anatomic; D009038:Motion; D010988:Play and Playthings; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D016138:Walking / Q000502:physiology*