Studying Dynamical Principles of Human Locomotion using Inverse Optimal Control

Abstract

AbstractHuman movement, as for example human gait, can be considered as an optimal realization of some given task. However, the criterion for which the naturally performed human motion is optimal, is generally not known. In this article we formulate an inverse optimal control problem to study the relevance of four different optimization criteria in human locomotion. As a walking model we use an actuated three dimensional spring loaded inverted pendulum (3D‐SLIP), which is able to mirror the typical shape of the center of mass trajectory in human gait. Using a direct all‐at‐once approach, the weighting of the optimization criteria and the position of the footsteps are optimized in such a way, that the center of mass trajectory of the resulting optimal state fits real motion capture data as good as possible. Numerical experiments show, that whereas the so called capture point seems to have a great impact on human walking, minimization of the vertical center of mass movement does not show any relevance at all. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)