EMYS consists of three separate discs of which the upper and lower ones are movable. His eyes are located in the middle disc and can protrude about 10 cm.  The robots dimensions are shown in Fig. 1 and Fig. 2.


 Fig. 1 EMYS general dimensions.

Fig. 2 EMYS eye protrusion.

EMYS is mounted on a cross-shaped bracket (part no. 40009488), shown in Fig. 3. It is specifically designed to allow mounting EMYS on top of FLASH, but can also be used to mount the robot on a different chassis (using four ø7 holes), or even to attach the robot with clamps. The robot will stand on the mounting bracket even if it is not fastened in any way; however, rapid movements will cause him to tip over.

mounting bracket1
Fig. 3 
Mounting bracket dimensions.

EMYS joints

The head has 11 degrees of freedom. Each joint has its own unique number, shown in Fig. 4. The arrow directions correspond to increasing joint position values. All EMYS' joints are diven by one motor each, the only exception is the neck pitch joint (q1) which consists of two servos. For more information about EMYS' motors see Drive system and to learn how to control each joint check out Communication.  


Fig. 4 EMYS joint structure.

Joint limits

Joint Joint name   Higher limit   Lower limit 
q1  neck pitch (rotation) -20 [deg] 30 [deg]
q2  head yaw (rotation) -90 [deg] 90 [deg]
q3  head pitch (rotation) -6 [deg] 29 [deg]
q4   lower disc (rotation) -16 [deg] 5 [deg]
q5  upper disc (rotation) -7 [deg] 15 [deg]
q6  left eyelid (rotation) 0 [deg] 120 [deg]
q7   left eyebrow (rotation) -45 [deg] 45 [deg]
q8   left eye (translation) 0 [mm] 100 [mm] 
q9   right eyelid (rotation) 0 [deg] 120 [deg]
q10  right eyebrow (rotation) -45 [deg] 45 [deg]
q11  right eye (translation) 0 [mm]  100 [mm]


Starting position

The robot can be started in one of two positions (shown in Fig. 5). The straight starting position provides easier kinematics, while angled starting position enables the robot to raise his gaze higher.

side straight side angled 

Fig. 5 EMYS starting positions (left - straight, right - angled).



EMYS and FLASH are Open Source and distributed according to the GPL v2.0 © Rev. 0.8.0, 27.04.2016

FLASH Documentation