Anthropomorphic joint mechanism with two degrees of freedom

We present a new 2-DOF anthropomorphic joint mechanism that makes it possible to mimic the human-like motion completely. The proposed joint, called double active universal joint (DAUJ), generates the 2-DOF motion free of rolling by the coupled motions of two independent motor-clutch pairs. Also, it has the advantage that the compliance of the mechanism can be easily controlled by modulating the engagement period of the magnetic clutch. The mechanism design and kinematics are described and two application examples, an in-pipe inspection robot and an anthropomorphic finger, are outlined. In addition, basic experiments are performed to confirm the effectiveness of the proposed mechanism