Design of Modular End-effector for Collaborative Robot based on Underactuated Mechanism

In this paper, we introduce end-effector adopting the modular finger module, which is the under-actuated system based on two four-bar link mechanism. The four fingers, excluding the thumb, consist of distal interphalangeal (DIP), proximal interphalangeal (PIP), metacarpophalangeal (MCP) joints. The thumb part consists of interphalangeal (IP), metacarpophalaneal (MCP), carpometacarpal (CMC) joint. The size of proposed modular end-effector similar to the average adult male's hand. Four fingers assemble on the palm of the end-effector, and those are arranged to parallel for the force balance during grasping objects. Each finger was modularized for easy replacement, and each one was actuated by one linear motor. The Thumb module has an extra motor for abduction/adduction. The finger module consists of the four links and three joints; MCP, PIP, DIP joint. The finger module is an under-actuated system based on the two four-bar linkage mechanism.