High-payload and self-adaptive robotic hand with 1-degree-of-freedom translation/rotation switching mechanism

This study proposes a novel robotic hand that can achieve self-adaptive grasping and a large payload (over 20 kg) with a single actuator. Accordingly, two novel mechanisms, an actuation system with self-motion switching and a self-adaptive finger with a self-locking mechanism, are installed in a 1-degree-of-freedom robotic hand. The actuation system switches the output motion from translational to rotational according to the applied external load. The finger is bent by inserting a flexible shaft inside it. Its bending posture can conform to the shape of the object owing to the flexible shaft, and the posture is fixed by a self-locking mechanism, which can be released by the rotational motion of the actuation system. This study presents a mechanical analysis of these mechanisms to achieve the desired behavior. The analysis was validated experimentally, and a robotic hand with these mechanisms were evaluated using grasping tests.