A Binocular Motor System Model and Its Application to Robot Eye Control

In this paper, we propose a binocular motor system model from the viewpoint of systems and control engineering based on the anatomic structure and physiological function of the brainstem.Using the model, a unified transfer function is obtained for the different dynamic characteristics of conjugate and vergence eye movements including smooth pursuit, optokinetic response (OKR) and vestibuloocular reflex (VOR). Pairs of symmetrical coordinate systems are introduced to describe the kinematic and dynamic characteristics of the binocular movement, and account for the symmetrical structures and functions of the pairs of organs in the oculomotor system. A robot-eye system with a control system similar to the model is described. The robot-eye system exhibits several characteristics specific to human-eye movement, including: (1) Two-eye-one-point. Both eyes move in tandem and have the same target point in the central pits. This characteristic is considered as a basic condition for structuring a stereo-image using the image signals from both eyes. (2) Moving together. That is to say, if one eye is shut or obstructed by an obstacle, the eye will follow the movement of the other eye so that it can find the target swiftly when the eye is opened or the obstacle is removed. (3) Blur-compensation. The binocular motor system and the robot-eye system have the ability to compensate for the blurs caused by rotational and translational head movement.