Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
권호 표지
DOI QR코드

DOI QR Code

Design and Manufacturing of Robotic Dolphin with Variable Stiffness Mechanism

가변강성 메커니즘을 적용한 로봇 돌고래 설계 및 제작

  • Park, Yong-Jai (Department of Mechatronics Engineering, Kangwon National University)
  • 박용재 (강원대학교 메카트로닉스공학과)
  • Received : 2020.02.25
  • Accepted : 2020.05.08
  • Published : 2020.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

Bio-inspired underwater robots have been studied to improve the dynamic performance of fins, such as swimming speed and efficiency, which is the most basic performance. Among them, bio-inspired soft robots with a compliant tail fin can have high degrees of freedom. On the other hand, to improve the driving efficiency of the compliant fins, the stiffness of the tail fin should be changed with the driving frequency. Therefore, a new type of variable stiffness mechanism has been developed and verified. This study, which was inspired by the anatomy of a real dolphin, assessed a process of designing and manufacturing a robotic dolphin with a variable stiffness mechanism. By mimicking the vertebrae of a dolphin, the variable stiffness driving part was manufactured using subtractive and additive manufacturing. A driving tendon was placed considering the location of the tendon in the actual dolphin, and the additional tendon was installed to change its stiffness. A robotic dolphin was designed and manufactured in a streamlined shape, and the swimming speed was measured by varying the stiffness. When the stiffness of the tail fin was varied at the same driving frequency, the swimming speed and thrust changed by approximately 1.24 and 1.5 times, respectively.

수중 로봇의 가장 기본 성능이라 할 수 있는 동적 성능인 유영속도와 동적 효율 향상을 위해 수중생물을 모사한 로봇들이 주로 연구되고 있다. 그중에서 생체모사 소프트 로봇은 유연한 꼬리지느러미를 적용함으로써 높은 자유도를 구현할 수 있다. 다만, 유연한 구동부의 효율을 높이기 위해서는 구동 주파수에 맞추어 꼬리지느러미의 강성이 바뀌어야 한다. 따라서, 연구를 통해 새로운 형태의 가변강성 메커니즘을 구현하고, 이를 연구 과정에서 검증하였다. 본 연구에서는 실제 돌고래의 해부도에서 영감을 얻어, 가변강성 메커니즘을 적용한 돌고래 로봇을 새로이 설계하고 제작하는 과정을 기술하였다. 실제 돌고래의 척추 모양을 모사하여, 절삭과 적층형 공정으로 가변강성 구동부를 제작하였다. 로봇 돌고래를 구동하기 위한 텐던도 실제 돌고래의 텐던 위치를 고려하여 배치하였으며, 추가로 강성 변화를 위한 텐던을 설치하였다. 돌고래의 유선형 외형을 모사하여 로봇 돌고래를 제작하였고, 강성 변화에 따른 로봇 돌고래의 유영속도를 측정하였다. 동일한 구동 주파수에 꼬리지느러미 구동부의 강성을 변화시켰을 때, 로봇 돌고래의 유영속도의 차이가 약 1.24배, 추력으로는 약 1.5배 변화하였다.

Keywords

References

  1. A. Raj, A. Thakur, "Fish-inspired robots: design, sensing, actuation, and autonomy-a review of research", Bioinspiration & Biomimetics, Vol.11, No.3, p.031001, Apr. 2016. DOI: https://doi.org/10.1088/1748-3190/11/3/031001
  2. D. S. Barrett, Propulsive efficiency of a flexible hull underwater vehicle, Ph.D.'s thesis, MIT, Cambridge, MA, USA, 1996.
  3. H. Morikawa, S. Nakao, S.-I. Kobayashi, H. Wada, "Experimental study on oscillating wing for propulsor with bending mechanism modeled on caudal muscle-skeletal structure of tuna", JSME International Journal Series C Mechanical Systems, Machine Elements and Manufacturing, Vol.44, No.4, pp.1117-1124, Sep. 2001. DOI: https://doi.org/10.1299/jsmec.44.1117
  4. D. T. Roper, S. Sharma, R. Sutton, P. Culverhouse, "A review of developments towards biologically inspired propulsion systems for autonomous underwater vehicles", Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, Vol.225, No.2, pp.77-96, May 2011. DOI: https://doi.org/10.1177/1475090210397438
  5. J. Liang, T. Wang, L. Wen, "Development of a two-joint robotic fish for real-world exploration", Journal of Field Robotics, Vol.28, No.1, pp.70-79, Jan. 2011. DOI: https://doi.org/10.1002/rob.20363
  6. W.-S. Chu, K.-T. Lee, S.-H. Song, M.-W. Han, J.-Y. Lee, H.-S. Kim, M.-S. Kim, Y.-J. Park, K.-J. Cho, S.-H. Ahn, "Review of biomimetic underwater robots using smart actuators", International Journal of Precision Engineering and Manufacturing, Vol.13, No.7, pp.1281-1292, 2012. DOI: https://doi.org/10.1007/s12541-012-0171-7
  7. C. J. Esposito, J. L. Tangorra, B. E. Flammang, G. V. Lauder, "A robotic fish caudal fin: effects of stiffness and motor program on locomotor performance", Journal of Experimental Biology, Vol.215, No.1, pp.56-67, Jan. 2012. DOI: https://doi.org/10.1242/jeb.062711
  8. A. Jusufi, D. M. Vogt, R. J. Wood, G. V. Lauder, "Undulatory Swimming Performance and Body Stiffness Modulation in a Soft Robotic Fish-Inspired Physical Model", Soft Robotics, Vol.4, No.3, pp.202-210, May 2017. DOI: https://doi.org/10.1089/soro.2016.0053
  9. P. V. y Alvarado, K. Youcef-Toumi, "Design of Machines With Compliant Bodies for Biomimetic Locomotion in Liquid Environments", Journal of Dynamic System, Measurement, and Control, Vol.128, No.1, pp.3-13, Mar. 2006. DOI: https://doi.org/10.1115/1.2168476
  10. P. V. y Alvarado, K. Youcef-Toumi, "Performance of Machines with Flexible Bodies Designed for Biomimetic Locomotion in Liquid Environments", in Proceedings of the 2005 IEEE International Conference on Robotics and Automation, IEEE, Barcelona, Spain, pp.3324-3329, April 2005. DOI: https://doi.org/10.1109/ROBOT.2005.1570623
  11. B. Epps, P. Valdivia y Alvarado, K. Youcef-Toumi, A. Techet, "Swimming performance of a biomimetic compliant fish-like robot", Experiments in Fluids, Vol.47, No.6, pp.927-939, Dec. 2009. DOI: https://doi.org/10.1007/s00348-009-0684-8
  12. H. El Daou, T. Salumae, A. Ristolainen, G. Toming, M. Listak, M. Kruusmaa, "A bio-mimetic design and control of a fish-like robot using compliant structures", in 2011 15th International Conference on Advanced Robotics, IEEE, Tallinn, Estonia, pp.563-568, June 2011. DOI: https://doi.org/10.1109/ICAR.2011.6088645
  13. K. H. Low, C. W. Chong, "Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin", Bioinspiration & Biomimetics, Vol.5, No.4, p.046002, Dec. 2010. DOI: https://doi.org/10.1088/1748-3182/5/4/046002
  14. R. Fan, J. Yu, L. Wang, G. Xie, Y. Fang, Y. Hu, "Optimized design and implementation of biomimetic robotic dolphin", 2005 IEEE International Conference on Robotics and Biomimetics (ROBIO), IEEE, Shatin, China, pp.484-489, July 2005. DOI: https://doi.org/10.1109/ROBIO.2005.246315
  15. I. Yamamoto, Y. Terada, T. Nagamatu, Y. Imaizumi, "Propulsion system with flexible/rigid oscillating fin", IEEE Journal of Oceanic Engineering, Vol.20, No.1, pp.23-30, Jan. 1995. DOI: https://doi.org/10.1109/48.380249
  16. B. Ahlborn, S. Chapman, R. Stafford, R. Harper, "Experimental simulation of the thrust phases of fast-start swimming of fish", Journal of Experimental Biology, Vol.200, No.17, pp.2301-2312, Sep. 1997. https://doi.org/10.1242/jeb.200.17.2301
  17. S. B. Behbahani, X. Tan, "Design and dynamic modeling of electrorheological fluid-based variable-stiffness fin for robotic fish", Smart Materials and Structures, Vol.26, No.8, p.085014, Jul. 2017. DOI: https://doi.org/10.1088/1361-665X/aa7238
  18. Y.-J. Park, U. Jeong, J. Lee, S.-R. Kwon, H.-Y. Kim, K.-J. Cho, "Kinematic Condition for Maximizing the Thrust of a Robotic Fish Using a Compliant Caudal Fin", IEEE Transactions on Robotics, Vol.28, No.6, pp.1216-1227, Dec. 2012. DOI: https://doi.org/10.1109/TRO.2012.2205490
  19. T. M. Huh, Y.-J. Park, K.-J. Cho, "Design and analysis of a stiffness adjustable structure using an endoskeleton", International Journal of Precision Engineering and Manufacturing, Vol.13, No.7, pp.1255-1258, Jul. 2012. DOI: https://doi.org/10.1007/s12541-012-0168-2
  20. Y.-J. Park, T. M. Huh, D. Park, K.-J. Cho, "Design of a variable-stiffness flapping mechanism for maximizing the thrust of a bio-inspired underwater robot", Bioinspiration & Biomimetics, Vol.9, No.3, p.036002, Sep. 2014. DOI: https://doi.org/10.1088/1748-3182/9/3/036002
  21. Y.-J. Park, Maximizing the thrust of a bio-inspired robotic fish with compliance, Ph.D.'s thesis, Seoul National University, Seoul, Korea, pp.4-88, 2013.
  22. Y.-J. Park, D. Park, K.-J. Cho, "Design and manufacturing a robotic dolphin to increase dynamic performance", in 2013 10th International Conference on Ubiquitous Robots and Ambient Intelligence (URAI), IEEE, Jeju, Korea, pp.76-77, Nov. 2013. DOI: https://doi.org/10.1109/URAI.2013.6677475