Design and grasping test of a rope-driven variable stiffness flexible robotic finger
GUO Shuyan
XU Yong
SUN Weijun
LIU Lingxiao
Abstract：[Objective]Inspired by the movement principle of human fingers,a cable-driven bionic flexible robotic finger was designed.To address the problem of improving the grasping capability of robotic hands,the stiffness of the finger's flexible joints was studied.[Methods]The main structure of the finger was designed,and the goal of variable stiffness was achieved by adjusting the stiffness of the flexible joints.On this basis,the stiffness model,kinematic model,fingertip trajectory model,and static model of the flexible joint during finger grasping were established,and the influence of the cross-section of the flexible joint on finger bending was analyzed.To meet the application requirements,thermoplastic polyurethane(TPU)was selected as the material for the flexible joints,and finite element simulation verification was performed.A test platform was built,and joint stiffness tests and finger bending tests were carried out.Finally,the fingertip trajectories under different joint stiffness configurations were compared.[Results]The results show that changes in joint stiffness significantly affect the bending mode of the finger;without modifying the finger structure,the bending mode can be changed only by adjusting the joint cross-section.It is found that the grasping performance of the finger can be improved without changing the finger structure and envelope range.The theoretical modeling and structural design of this flexible finger are reasonable,which provides beneficial reference for improving the grasping capability of robotic hands.
Keywords：Robot fingerRope-drivenFlexible jointStiffness difference
Publication Date：2025-12-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 152-160 )