Automatica, Vol.50, No.2, 519-529, 2014
Potential and optimal control of human head movement using Tait-Bryan parametrization
Human head movement can be looked at, as a rotational dynamics on the space SO(3) with constraints that have to do with the axis of rotation. Typically the axis vector, after a suitable scaling, is assumed to lie in a surface called Donders' surface. Various descriptions of Donders' surface are in the literature and in this paper we assume that the surface is described by a quadratic form. We propose a Tait-Bryan parametrization of SO(3), that is new in the head movement literature, and describe Donders' constraint in these parameters. Assuming that the head is a perfect sphere with its mass distributed uniformly and rotating about its own center, head movement models are constructed using classical mechanics. A new potential control method is described to regulate the head to a desired final orientation. Optimal head movement trajectories are constructed using a pseudospectral method, where the goal is to minimize a quadratic cost function on the energy of the applied control torques. The model trajectories are compared with measured trajectories of human head movement. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Head movement;Donders' surface;Tait-Bryan parametrization;Euler Lagrange's equation;Potential control;Optimal control