SNU-Avatar Robot Hand: Dexterous Robot Hand with Prismatic Four-Bar Linkage for Versatile Daily Applications

This paper presents an innovative approach to designing a robot hand specifically tailored for the final round of the ANA Avatar XPRIZE Challenge, a teleoperation robot competition. The primary objective of the newly developed hand was to accurately depict teleoperation by replicating a person's remote actions, gestures, emotional expressions, and the ability to manipulate various objects commonly encountered in daily life, including tools. To accomplish the objective of enabling finger flexion-extension (FE) with a single linear actuating system, multiple 4-bar linkage mechanisms were employed to incorporate the FE joints. Additionally, to enable effortless grasping of objects with unknown shapes, compliance elements were implemented using adduction-abduction (AA) joints with timing belt pulley system and FE joint accompanying springs. As a result, a four-fingered hand boasting a total of eight degrees of freedom was developed, ensuring robust fingertip grip while minimizing the overall weight of the hand to preserve the payload capacity of the robot arm. This paper describes the hand's design process based on finger kinematic analysis. Finite Element Method (FEM) analysis results to assess the hand's ability to withstand disturbances and potential plastic deformation. Furthermore, taxonomy analysis derived from real gripping experiments.