Quantifying anthropomorphism of robot hands

In this paper a comparative analysis between the human and three robotic hands is conducted. A series of metrics are introduced to quantify anthropomorphism and assess robot's ability to mimic the human hand. In order to quantify anthropomorphism we choose to compare human and robot hands in two different levels: comparing finger phalanges workspaces and comparing workspaces of the fingers base frames. The final score of anthropomorphism uses a set of weighting factors that can be adjusted according to the specifications of each study, providing always a normalized score between 0 (non-anthropomorphic) and 1 (human-identical). The proposed methodology can be used in order to grade the human-likeness of existing and new robotic hands, as well as to provide specifications for the design of the next generation of anthropomorphic hands. Those hands can be used for human robot interaction applications, humanoids or even prostheses.