Dexterous robotic hands are the key to enabling the use of robots in many applications, including service robotics, assistive robotics, and healthcare. These applications require the ability of robots to manipulate engineered objects designed for humans and require manipulation capabilities beyond pick-and-place tasks. A key to making robotic hands dexterous is to have fingers such that fingertip motion and forces are controllable, while ensuring that the fingers are compact and akin to the size of an average human, so that the hand can manipulate objects designed for humans. Although a wide range of hands have been proposed in the literature, there is no readily available robotic hand that is compact, dexterous, reliable, and cost-effective. Therefore, with a view towards building compact reliable dexterous robotic hands, in this paper we study the em fundamental problem of designing a robotic finger with abduction/adduction and flexion/extension capability and size similar to a human finger such that the fingertip motion and forces can be controlled.

We present a novel series-parallel 3-DoF finger mechanism with abduction/adduction as well as flexion/extension capability, for which we derive the position kinematics relations and the Jacobian. Thus, we can control the position and velocity of the fingertip as well as do force control (because of the closed-form Jacobian). To the best of our knowledge, this is the first 3-DoF finger with abduction/adduction as well as flexion/extension, where the kinematics is well understood.

Related Papers: