Motion Control in Saccade and Smooth Pursuit for Bionic Eye Based on Three-dimensional Coordinates

Saccade and smooth pursuit are two important functions of human eye. In order to enable bionic eye to imitate the two functions, a control method that implements saccade and smooth pursuit based on the three-dimensional coordinates of target is proposed. An optimal observation position is defined for bionic eye based on three-dimensional coordinates. A kind of motion planning method with high accuracy is developed. The motion parameters of stepper motor consisting of angle acceleration and turning time are computed according to the position deviation, the target's angular velocity and the stepper motor's current angular velocity in motion planning. The motors are controlled with the motion parameters moving to given position with desired angular velocity in schedule time. The experimental results show that the bionic eye can move to optimal observation positions in 0.6 s from initial location and the accuracy of 3D coordinates is improved. In addition, the bionic eye can track a target within the error of less than 20 pixels based on three-dimensional coordinates. It is verified that saccade and smooth pursuit of bionic eye based on three-dimensional coordinates are feasible.