Applied Sciences (Mar 2024)

Design and Analysis of a Novel Variable Stiffness Joint Based on Leaf Springs

  • Caidong Wang,
  • Yafeng Gao,
  • Yapeng Xu,
  • Xinjie Wang,
  • Liangwen Wang

DOI
https://doi.org/10.3390/app14072685
Journal volume & issue
Vol. 14, no. 7
p. 2685

Abstract

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In response to challenges like the complexity and limited scalability of existing variable stiffness joints, a novel variable stiffness joint, based on leaf spring elements, is introduced in this paper. The joint stiffness can be adjusted in real time by changing the effective length of the leaf spring via the use of an Archimedean spiral groove. The stiffness adjustment range and load capacity of the joint can be defined by manually configuring the number of springs involved during offline joint operations. A stiffness model for the joint is established based on the cantilever beam theory of material mechanics. The coupled effects of the design parameters of the variable stiffness mechanism on joint stiffness, elastic torque, and stiffness adjustment resistance torque are analyzed. A dynamic model for the joint is developed, while a PID controller is designed for simulation purposes. The motion characteristics of the joint are analyzed, confirming that this approach has certain advantages in terms of stiffness adjustment speed and accuracy.

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