Abstract
Coupled human balancing tasks, performed by a pair of artificial controllers and a pair of human subjects, have been studied by the present authors based on the coupled inverted pendula (CIP) model. On the contrary, in this paper, we examine another type of combination, the artificial controller and the human subject. We experimentally estimate Lyapunov and sub-Lyapunov exponents of balancing errors of the system of human subject and artificial controller, in which the human subject is in cooperation with the artificial controller having several different feedback gains. The result implies that the human subject seems to try to make the artificial controller minimally or neutrally stable.
