Design and development of 6 DoFs detachable robotic head utilizing differential gear mechanism to imitate human head-waist motion

This paper proposed a design of a detachable robotic head that can imitate human motion in a remote environment. Firstly, the biomechanics of the human body parts related to human vision are studied: neck and waist. After that, the design parameters are extracted from the neck and waist as the design requirement. Then, the mechanical design of the detachable robotic head is split into three parts: neck, waist, and detachable mechanism. The gear differential mechanism is used further to develop the motion range of the proposed design. Consequently, a prototype is made from a 3d-printed part to test the functionality of the design. The evaluations are separated into three sections. First, the range of motion shows that the proposed design can guarantee the human motion range and provide more motion range in the remote environment. Secondly, the frequency response shows that the detachable head can handle the natural headshaking motion of the human at 1.5 Hz in horizontal and 2 Hz vertical head shaking. However, both do not reach the vigorous voluntary headshaking. Also, the maximum latency between the user and the robot is 25 ms, which is low enough for human perception. Last, the angular error between the user and the robot is tested in trackability. As a result, the error is less than 1.6 degrees, and this means the proposed design can imitate human head motion without feeling dislocated.