Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Design of a Mechanical Joint for Zero Moment Crane By Kriging

크리깅을 이용한 제로 모멘트 크레인에 적용되는 조인트의 설계

  • Received : 2009.12.24
  • Accepted : 2010.03.11
  • Published : 2010.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

This study focuses on the design of a mechanical joint for a zero moment crane (ZMC), which is a specialized loading/unloading system used in a mobile harbor (MH). The mechanical joint is based on the concept of zero moment point (ZMP), and it plays an important role in stabilizing a ZMC. For effective stabilization, it is necessary to ensure that the mechanical joint is robust to a wide variety of loads; further, the joint must allow the structures connected to it to perform rotational motion with two degrees of freedom By adopting a traditional design process, we designed a new mechanical joint; in this design, a universal joint is coupled with a spherical joint, and then, deformable rolling elements are incorporated. The rolling elements facilitate load distribution and help in decreasing power loss during loading/unloading. Because of the complexity of the proposed system, Kriging-based approximate optimization method is used for enhancing the optimization efficiency. In order to validate the design of the proposed mechanical joint, a structural analysis is performed, and a small-scale prototype is built.

본 논문에서는 모바일하버의 하역 시스템으로 특화되어 개발한 제로 모멘트 크레인에 적용되는 조인트를 설계하고자 한다. 해당 조인트는 제로 모멘트 포인트의 개념에 기반하여 제로 모멘트 크레인을 안정화시키는데 중요한 역할을 수행한다. 이 목적을 위해서는 크고 다양한 형태의 하중을 견딜 수 있으며, 또한 2 방향의 자유도를 허용할 수 있어야 한다. 통상적인 설계 과정을 거쳐, 유니버셜 조인트와 스피리컬 조인트를 결합한 후 가변형 구름 요소를 적용한 새 디자인을 제안하였다. 구름 요소는 하중을 분산시키며 하역 과정 동안의 동력 손실을 줄여준다. 시스템의 복잡성과 최적화 과정의 효율성을 고려하여, 크리깅 기반 근사 최적화 기법을 선정하였다. 설계된 조인트를 검증하기 위해, 구조 해석을 수행하고, 축소 시제품을 제작하였다.

Keywords

References

  1. Ju, B. H., 2008, “Reliability Based Design Optimization Using a Kriging Metamodel and a Moment Method,” Doctoral Thesis of KAIST.
  2. Lee, T. H., Jung J. J. Hwang, I. K. and Lee C. S., 2004, “Sensitivity Approach of Sequential Sampling for Kriging Model,” Trans. of the KSME(A), Vol. 28, No. 11, pp. 1760-1767 https://doi.org/10.3795/KSME-A.2004.28.11.1760
  3. Ka, J. D. and Kwon, J. H., 2004, “A Study on 2-D Airfoil Design Optimization by Kriging,” Trans. of the KSCFE, Vol. 9, No. 1, pp. 34-40
  4. http://www.ansys.com
  5. KR, 2009, “Rules and Guidance for the Classification of Steel Ships”
  6. Jang, C. S., Kim, Y. J., Kwak, D. O. and Boo, S. W., 2002, “Contact Analysis on a Horn-Holder Assembly for Wire Bonding,” Trans. Of the KSME(A), Vol. 26, No 10, pp. 2008-2017 https://doi.org/10.3795/KSME-A.2002.26.10.2008
  7. Lee, T. H., Kim, S. W. and Jung J. J., 2006, “Influence of Correlation Functions on Maximum Entropy Experimental Design,” Trans. of the KSME(A), Vol. 30, No. 7, pp. 787-793 https://doi.org/10.3795/KSME-A.2006.30.7.787
  8. Oh, S. H., 2005, “Optimal Design of Composite Structures using Efficient Metamodels,” Doctoral Thesis of KAIST
  9. Deb, K., Pratap, A., Agarwal, S. and Meyarivan, T., 2002, “A Fast and Elitist Multiobjective Genetic Algorithm: NSGA-II,” IEEE transactions on evolutionary computation, Vol.6, No.2, pp.182-197 https://doi.org/10.1109/4235.996017
  10. Kragelsky, V., 1996, “Friction, Wear, Lubrication,” 1st edition, Oxford, pp. 14-16
  11. Khonsari, M. M., 2001, “Applied Tribology,” John Wiley & Sons, Inc., pp.459-463