Design of a Single Cam Single Actuator Multiloop Eyeball Mechanism

This paper reports design and implementation of a multiloop robotic eyeball mechanism that enables synchronously rotating two eyeballs using a single actuator. Our optimally designed eyeball mechanism can help in implementing light weight, agile and energy efficient robotic heads. To the best of our knowledge, no existing eyeball mechanism is able to synchronously rotate two eyeballs using a single actuator. This work demonstrates use of a multiloop mechanism for reducing the number of required actuators and hence reducing the overall power consumption. Our eyeball mechanism incorporates an optimally designed 4-PS (prismatic-spherical) plus 1-P (passive support) construct. This partially passive construct comprises of a double-dwell end-cam plus a 4-follower arrangement. The cam-follower arrangement also augments a control strategy for synchronously rotating eyeballs and irides. We also present a methodology for determining the position kinematics of this 4-degree of freedom robotic eyeball mechanism.