Humanoid eye robot with angle control and image registration

This paper presents a humanoid eye robot with five degrees of freedom, including independent horizontal rotation for each eyeball, one synchronous vertical rotation, and two vertical motions of the eyelids. Two cameras were implemented for target tracking. The color difference of the images received by the cameras was compared for precise image registration. The horizontal rotation of each eyeball was monitored by an angle gauge, and the control accuracy was investigated. Actual geometric measurement was conducted for calibrating the angle gauge. The gauge value was then compared with the image registration. The comparison result indicated that the image registration algorithm effectively promoted the horizontal angle accuracy by decreasing rotation error from more than 2 degrees to less than 0.5 degrees.