DETERMINATION OF FEEDBACK FOR HUMAN POSTURE CONTROL WITHOUT PHYSICAL INTERVENTION

Abstract

Abstract This paper is a study of a method to determine from external observations only, potential sets of feedback gains that can be used by humans to control their postural stance. These gains amplify sensor signals in order to produce torques at the joints. The method consists of modeling the human biped in two ways-as a one degree-of-freedom inverted pendulum with a vestibular estimator and as a two degree-of-freedom compound inverted pendulum for which the vestibular system is approximated. The feedback gains in these models are systematically changed until the computer simulated motion of the nonlinear model is close enough to observed human motion. Comparisons are made between these results and those of other experimental investigations. An analysis of minimal sets of gains and sensitivity of the gains to measurement errors in weights, lengths, and moment of inertia are discussed.