Session: MR-03-01 - Compliant Mechanisms (A. Midha Symposium)

Paper Number: 89856

89856 - Design and Modeling of a New Variable Stiffness Robotic Finger Based on Reconfigurable Beam Property Change for Flexible Grasping 

Flexible grippers can provide fine grasping and manipulation to various objects and environment interactions. However, most current mechanisms can not change the stiffness in a short time, which limits the application scenario of the flexible grippers. This paper presents a novel variable stiffness robotic finger that can adapt to soft and rigid gripping objects by continuously changing its stiffness over a wide range in a short period of time. The principle is to change the second area moment of inertia of the finger by changing the filling ratio of the cavity between two parallel beams. A complete theoretical stiffness model is developed and compared with the finite element analysis (FEA) model. Effects of multiple design parameters on finger stiffness performance are compared and analyzed, and the accuracy of the theoretical model is verified, with a maximum error of less than 6.5\%. The performance of the finger is further evaluated through an experimental prototype, which proved that the finger can safely perform a wide range of daily object-grasping tasks with adaptable compliance. The proposed stiffness-varying mechanism can adjust stiffness in a short time with a very large ratio (around 1:37). The design provides a new direction in developing variable-stiffness robotic grippers for flexible grasping.

Presenting Author: Wei Xu Purdue University

Presenting Author Biography: Wei Xu is a Ph.D. student in Purdue Polytechnic Institute at Purdue University and working with Prof. Dongming Gan. His research interests are robotics, deep learning, and mechanical design. Prior to Purdue, he completed his M.S. in Khoury College of Computer Sciences at Northeastern University. Previously, he received his B.Eng. and M.S. in the Department of Process Equipment and Control Engineering at Tianjin University, China.

Authors:

Wei Xu Purdue University
Jiaming Fu Purdue University
Dongming Gan Purdue University