Departmental Papers (ESE)



We investigate the stability of a one degree of freedom mechanical spring-mass system modulated by a feed-forward "clock" that stiffens and relaxes a Hooke's law potential force according to a periodic rhythm. At the present early stage of inquiry, we offer sufficient conditions for local asymptotic stability of an isolated periodic orbit when there is no feedback to the clock at all but some viscous friction in the mechanism. We conjecture that, absent feedback, a lossless mechanical system cannot exhibit an asymptotically stable limit cycle in response to such rhythmic excitation.

Document Type

Conference Paper

Subject Area

GRASP, Kodlab

Date of this Version



n Systemics, Cybernetics and Informatics, 2000. Copyright 2000 IEEE. Reprinted from Proceedings of the 4th World Multiconference.

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NOTE: At the time of publication, author Daniel Koditschek was affiliated with the University of Michigan. Currently, he is a faculty member in the Department of Electrical and Systems Engineering at the University of Pennsylvania.


legged locomotion, coupled oscillators, clock driven system, CPG, feedforward control, biomechanics, spring-mass model



Date Posted: 02 June 2008

This document has been peer reviewed.