An Adaptive Three-Fingered Prismatic Gripper With Passive Rotational Joints

In this letter, we present the design of an underactuated three-fingered robotic hand and evaluate its performance. The hand utilizes radially symmetric, prismatically actuated fingers controlled by a single actuator. Each finger consists of a single joint finger connected to the prismatic joint via a passive rotational joint perpendicular to the palm. The rotational joints allow the fingers to passively switch between spherical and cylindrical grasps while the finger joint allows the fingers to wrap about the grasped object. We compare the performance of this design to that of a concentric gripper with cylindrical fingers and two other underactuated hand designs using the YCB grasping benchmark. This evaluation shows that the three finger prismatic hand performs well especially when equipped with the single joint fingers in comparison to other designs.