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Structural optimization for flexure-based parallel mechanisms–Towards achieving optimal dynamic and stiffness properties




Flexure-based parallel mechanisms (FPMs) are a type of compliant mechanisms that consist of a rigid end-effector that is articulated by several parallel, flexible limbs (a.k.a. sub-chains). Existing design methods can enhance the FPMs’ dynamic and stiffness properties by conducting a size optimization on their sub-chains. A similar optimization process, however, was not performed for their sub-chains’ topology, and this may severely limit the benefits of a size optimization. Thus, this paper proposes to use a structural optimization approach to synthesize and optimize the topology, shape and size of the FPMs’ sub-chains. The benefits of this approach are demonstrated via the design and development of a planar X − Y − θz FPM. A prototype of this FPM was evaluated experimentally to have a large workspace of 1.2 mm × 1.2 mm × 6°, a fundamental natural frequency of 102 Hz, and stiffness ratios that are greater than 120. The achieved properties show significant improvement over existing 3-degrees-of-freedom compliant mechanisms that can deflect more than 0.5 mm and 0.5°. These compliant mechanisms typically have stiffness ratios that are less than 60 and a fundamental natural frequency that is less than 45 Hz.

Author(s): Lum, Guo Zhan and Teo, Tat Joo and Yeo, Song Huat and Yang, Guilin and Sitti, Metin
Journal: Precision Engineering
Volume: 42
Pages: 195--207
Year: 2015
Month: May
Day: 26
Publisher: Elsevier

Department(s): Physical Intelligence
Bibtex Type: Article (article)

DOI: 10.1016/j.precisioneng.2015.04.017


  title = {Structural optimization for flexure-based parallel mechanisms--Towards achieving optimal dynamic and stiffness properties},
  author = {Lum, Guo Zhan and Teo, Tat Joo and Yeo, Song Huat and Yang, Guilin and Sitti, Metin},
  journal = {Precision Engineering},
  volume = {42},
  pages = {195--207},
  publisher = {Elsevier},
  month = may,
  year = {2015},
  month_numeric = {5}