Is estimation of Floquet multipliers of human walking valid?

Author

Ahn, Jeongseob ; Hogan, Neville

Author_Institution

Mech. Eng., Massachusetts Inst. of Technol., Cambridge, MA, USA

fYear

2014

fDate

25-27 April 2014

Firstpage

1

Lastpage

2

Abstract

The Floquet multiplier has been widely used to assess orbital stability of human walking. Floquet introduced it to quantify the stability of periodic motion of deterministic linear systems, but human walking involves highly nonlinear dynamics and inevitable noise. This preliminary study addresses the validity of Floquet multiplier estimation of a nonlinear system with stochastic noise. Noise was added to a simplified but nonlinear model of human walking so that the variability of model walking was comparable to that of human walking. Results show that linear regression yields a biased measure of the Floquet multiplier though its accuracy improves with a sufficient number of strides.

Keywords

differential equations; estimation theory; gait analysis; noise; nonlinear dynamical systems; physiological models; regression analysis; stochastic processes; Floquet multiplier accuracy; Floquet multiplier estimation; deterministic linear system; human walking estimation; human walking variability; linear regression; model walking variability; nonlinear dynamics; nonlinear human walking model; nonlinear system; orbital stability assessment; periodic motion stability quantification; stochastic noise; stride number; Estimation; Legged locomotion; Limit-cycles; Noise; Stability criteria; Stochastic processes; Floquet multiplier; linear regression; rhythmic movement; stability; stochastic noise; walking model;

fLanguage

English

Publisher

ieee

Conference_Titel

Bioengineering Conference (NEBEC), 2014 40th Annual Northeast

Conference_Location

Boston, MA

Type

conf

DOI

10.1109/NEBEC.2014.6972705

Filename

6972705