Fully actuated robotic finger with joint-specific remote actuation design
Design of a Fully Actuated 4-DOF Robotic Finger With Joint-Specific Hybrid Remote Actuation
Robotics
Summary
Robotic fingers need to move precisely like human fingers to grasp objects well. This paper shows a new robotic finger with four joints that are each controlled independently using a mix of cables and linkages. The system keeps the cables from interfering with each other’s movements and makes sure the finger can apply forces at each joint. The authors tested it by measuring finger movements and forces, showing it can handle different objects with separate joint control.
What this means in practice
- •For robotic hand designers: Build robotic fingers that independently control finger joints for improved dexterity in manipulation tasks using hybrid remote actuation.
- •For prosthetic developers: Create prosthetic fingers capable of more natural, isolated joint movements by integrating joint-specific remote actuation to enhance user control.
Authors
Hyojae Kang, Hyun-mok Jung, Joonho Lee, Dongil Park, Hyunmin Do, Jongwoo Park, Jeongdo Ahn
Abstract
This paper presents a fully actuated 4-DOF robotic finger using a joint-specific hybrid remote-actuation architecture. The metacarpophalangeal (MCP) joint is driven by two coordinated rigid-link transmission sets, whereas the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints are independently actuated by closed-loop wire transmissions incorporating circular rolling-contact joints (RCJs). A larger transmission radius is used at the PIP joint than at the DIP joint. The RCJ wire geometry maintains the total wire-loop length during joint rotation, and the DIP wire routing is designed so that PIP motion does not affect its differential actuation for a fixed MCP configuration. The distal wire transmission, MCP linkage, and fingertip kinematics are analytically modeled. In experiments, the transmission behavior was quantitatively evaluated from the ball-screw displacements measured using ArUco-marker tracking. MCP actuation produced measurable displacements of the PIP and DIP transmission units, whereas isolated PIP and DIP actuation with the MCP fixed supported the intended mechanical decoupling between the distal transmissions. The mean peak fingertip forces under isolated MCP, PIP, and DIP actuation were 21.28 N, 9.22 N, and 5.75 N, respectively. The resulting finger postures were also examined using objects of different geometries and sizes.