Journal of the Korean Society for Aeronautical & Space Sciences (한국항공우주학회지)

The Korean Society for Aeronautical and Space Sciences (한국항공우주학회)
권호 표지
DOI QR코드

DOI QR Code

Design of Bi-stable Mechanism Using Cylindrical Permanent Magnets

원통형 영구자석을 이용한 쌍안정 장치 설계

  • Received : 2020.01.14
  • Accepted : 2020.04.20
  • Published : 2020.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

Bi-stable mechanism is a system that has two different stable equilibrium positions within its range of motion. It has an ability to stay in two different positions without external power input and despite small disturbances. One of the most bi-stable applied mechanism is a morphing system, such as deployable structures, switch systems, and robot grippers. However, due to the complexity of mechanism and limitation of structure configuration, it is difficult to apply on a morphing system with rotating link mechanism. In this paper, an implementation method of rotational bi-stable mechanism using cylindrical permanent magnets is proposed. The magnetic field and the magnetic force were calculated from electromagnet model of the cylindrical permanent magnet. Based on the model, the force relation between two links containing the cylindrical permanent magnets was estimated. An array of cylindrical permanent magnets was selected for symmetric bi-stability, and an experiment on the link structure with the proposed bi-stable mechanism was performed to investigate the stability against a external torque.

쌍안정 장치는 서로 다른 두 가지 상태에서 안정성을 갖는 시스템이며, 구동에 있어 에너지 효율 측면에서 이득을 얻을 수 있다. 이러한 쌍안정 장치는 다양한 방법을 통해 구현되며, 전개형 구조물, 스위치 시스템 그리고 파지 로봇 등, 주된 동작이 두 종류로 구분되는 모핑 시스템에 적용될 수 있다. 하지만 기존 장치들의 복잡성과 구조적 제한 때문에, 링크 구조물처럼 회전하는 구조를 포함하는 모핑 시스템을 구현하는 것은 어려움이 존재한다. 본 연구에서는 원통형 영구자석을 이용하여 회전운동에 있어 쌍안정성을 갖는 장치를 구현하는 방법이 제안된다. 원통형 영구자석의 전자석 모델을 도입하여 자기장과 자기력을 도출했으며, 이를 이용하여 원통형 영구자석을 포함하는 두 링크 사이의 힘 관계를 추정했다. 대칭 쌍안정성을 위한 원통형 영구자석의 배열을 선정했으며, 제안하는 쌍안정 장치를 회전 조인트로 연결된 링크 구조물에 적용하여 외부 토크에 대한 안정성을 실험을 통해 확인하였다.

Keywords

References

  1. Hyer, M. W., "Some Observations on the Cured Shape of Thin Unsymmetric Laminates," Journal of Composite Materials, Vol. 15, No. 2, 1981, pp. 175-194. https://doi.org/10.1177/002199838101500207
  2. Kim, S. W., Koh, J. S., Lee, J. G., Ryu, J., Cho, M., and Cho, K. J., "Flytrap-inspired Robot using Structurally Integrated Actuation based on Bistability and a Developable Surface," Bioinspired & Biomimetics, Vol. 9, No. 3, 2014, 036004. https://doi.org/10.1088/1748-3182/9/3/036004
  3. Schultz, M. R., "A Concept for Airfoil-like Active Bistable Twisting Structures," Journal of Intelligent Material Systems and Structures, Vol. 19, No. 2, 2008, pp. 157-169. https://doi.org/10.1177/1045389X06073988
  4. Daynes, S., Weaver, P. M., and Potter, K. D., "Aeroelastic Study of Bistable Composite Airfoils," Journal of Aircraft, Vol. 46, No. 6, 2009, pp. 2169-2173. https://doi.org/10.2514/1.44287
  5. Arrieta, A. F., Bilgen, O., Friswell, M. I., and Ermanni, P., "Modelling and Configuration Control of Wing-shaped Bi-stable Piezoelectric Composites under Aerodynamic Loads," Aerospace Science and Technology, Vol. 29, No. 1, 2013, pp. 453-461. https://doi.org/10.1016/j.ast.2013.05.004
  6. Chen, G., Aten, Q. T., Zirbel, S., Jensen, B. D., and Howell, L. L., "A Tristable Mechanism Configuration Employing Orthogonal Compliant Mechanisms," Journal of Mechanisms and Robotics, Vol. 2, No. 1, 2010, 014501. https://doi.org/10.1115/1.4000529
  7. Zirbel, S. A., Tolman, K. A., Trease, B. P., and Howell, L. L., "Bistable Mechanisms for Sapce Applications," PLOS ONE, Vol. 11, No. 12, 2016, e0168218. https://doi.org/10.1371/journal.pone.0168218
  8. Suh, J. E., Jeong, S. Y., and Han, J. H., "A Two-dimensional Modular Deployable Truss Structure with Bistability," Journal of Intelligent Material Systems and Structures, Vol. 30, No. 3, 2019, pp. 335-350. https://doi.org/10.1177/1045389X18810806
  9. Rodriguez, A. R., "Morphing Aircraft Technology Survey," 45th AIAA Aerospace Sciences Meeting and Exhibit, January 2007, 1258.
  10. Kang, W. R., Kim, E. H., Jeong, M. S., and Lee, I., "Morphing Wing Mechanism Using an SMA Wire Actuator," International Journal of Aeronautical and Space Sciences, Vol. 13, No. 1, 2012, pp. 58-63. https://doi.org/10.5139/IJASS.2012.13.1.58
  11. Sofla, A. Y. N., Meguid, S. A., Tan, K. T., and Yeo, W. K., "Shape Morphing of Aircraft Wing: Status and Challenges," Materials & Design, Vol. 31, No. 3, 2010, pp. 1284-1292. https://doi.org/10.1016/j.matdes.2009.09.011