Abstract
In a primate oculomotor system, a part of the central nervous system (e. g., superior colliculus and reticular formation) generates velocity command and position command separately in each of the horizontal and vertical directions regardless of the initial eye position.
While in the peripheral muscle and eye ball system, strong position dependent mechanical interactions are expected to exist among the six extraocular muscle forces.
A special controller which virtually decouples the interactions and computes an appropriate motor signal for each muscle would be necessary between the central nervous system (CNS) and the final motor system, otherwise the eye could be rotated in an unintended orientation.
This paper discusses the functional structure of such kind of decoupling controller on a simulated and simplified oculomotor system, in which an eye ball is rotated in three directions (horizontal, vertical and tortional) by a pair of thin wire and a DC motor for each direction.
A decoupling control scheme has been proposed which enables the CNS to control the rotation of the eye ball in any direction by monitoring the temporary eye position and velocity, as if the mechanical system comprised three separate linear systems.
Feasibility of the control scheme has been demonstrated via computer simulations of the system and the controller, and also via a real time control experiment on a hardware oculomotor system model with rotations about two axes (horizontal and vertical) by two DC motors.
Finally, an evaluation has been given on the applicability of the control scheme to the human oculomotor control system.
