• Title/Summary/Keyword: Fish Locomotion

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Hydrodynamics Analysis of Fish Locomotion Using a Biomimetic Fish Robot (생체모사 물고기 로봇을 이용한 물고기 운동의 유체역학적 해석)

  • Han, Cheol-Heui;Lee, Seung-Hee;Shin, Chang-Rok;Park, Jong-Hyeon
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.435-440
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    • 2007
  • Fish-mimetic robots or fish-mimetic propulsors have been developed or under construction. A mechanical system cannot have the same functions as bio-organic systems. Thus, the hydrodynamic characteristics of fish locomotion should be well understood in order to develop and control a feasible intelligent fish-mimetic robot with its optimal motion pattern known. In this paper, a mackerel-mimetic robot fish is fabricated in order to understand the hydrodynamic characteristics of fish locomotion. A simplified unsteady flow theory is also applied to the hydrodynamic analysis of the motion of the anterior part of the robotic fish. The normal and axial forces of the fish are measured by changing the amplitude and frequencies of fanning motion. It is found that the present theoretical results agree with the measured data.

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A STUDY ABOUT FISH LOCOMOTION USING COMPUTATIONAL FLUID DYNAMICS (전산유체역학 기법을 이용한 물고기 유영에 관한 연구)

  • Kim, S.H.;Jung, Y.S.;Kwon, O.J.
    • Journal of computational fluids engineering
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    • v.19 no.2
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    • pp.99-107
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    • 2014
  • The aim of the present study is to investigate the flow interference between two adjacent undulating fish-like body, and its effect on the undulating propulsion. For this purpose, unsteady two dimensional incompressible flow calculations were conducted using an unstructured mesh flow solver, coupled with an overset mesh technique. To deal with mesh deformation due to fish locomotion, spring analogy is utilized. The fish body used in the simulation is constructed from the NACA0012 airfoil. The study indicates that the propulsion of undulating fish is proportional to frequency and wavelength of the midline oscillation when there is no adjacent fish. It also reveals that average thrust was increased when the vortex shedding from the tail was conserved well and pressure difference between upper and lower sides of the fish was magnified due to flow interference. From this study, which relative position and phase difference of locomotion between two fishes can generate maximum thrust was known among six different cases.

Propelling and Turning Motions of Fish for Virtual Aquarium (가상 수족관 물고기의 추진과 회전 유영 생성 방법)

  • Han, yoon-seok;Yoon, jae-hong;Kim, eun-seok
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.33-37
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    • 2008
  • The interaction between artificial fish and aquatic surroundings and the fish's realistic locomotion are very important elements to construct virtual aquariums. In general, the artificial fish in virtual aquariums used to be created by 3D modeling tools, and was repeatedly showing the simple and constant form of swimming. This paper will analyze the sorts of biological forms of fish-swimming and the propelling and turning characteristics. Then, we propose a method of the basic swimming and turning of artificial fish to generate various and natural-looking locomotion. It is possible to make a explorable virtual aquarium more immersive by using interactive interfaces together.

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Trajectory Tracking Control of a Fish-Mimetic Robot Using CPG (CPG 를 이용한 물고기 모사 로봇의 궤적 추종 제어)

  • Kim, Dong-Hee;Lee, Seung-Hee;Kwon, Jong-Hyun;Han, Cheol-Heui;Park, Jong-Hyeon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.870-875
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    • 2008
  • The main objective of this paper is to control a trajectory tracking of the fish-mimetic robot by CPG (Central Pattern Generator), which is biological approach. CPG is biological neural networks that generate rhythmic movements for locomotion of animals, such as walking, running, swimming and flying. Animals show marvelous ability of autonomous dynamic adaptation for an unsteady fluid dynamic environment or various environments. So, we propose the 3-DOF CPG controller to track the trajectory of the fish robot in plane motion. The conformity of the proposed control algorithm is validated by simulation for a fish robot model, which is made by a commercial dynamic package.

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MDOF Ionic-Polymer-Metal-Composite Actuators with Selectively Grown Multiple Electrodes (선택적으로 성장 시킨 다중 전극판을 갖는 다자유 IPMC 작동기)

  • Jeon, Jin-Han;Oh, Il-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.294-298
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    • 2008
  • The ionic polymer-metal composite actuators with selectively grown multiple electrodes were developed to mimic the swimming locomotion of a fish. The developed method is based on combining electroplating with the electroless chemical reduction using the patterned mask. The advantages of this fabrication method are that the initial compositing between the polymer and platinum particles can be assured by the chemical reduction method, and the thickness of each electrode can be controlled easily and rapidly by electroplating. By using the fabricated actuator with a multiple degree of freedom, the oscillatory wave of the flexible membrane actuator was generated and a twisting motion was also realized to verify the possibility of mimicking the fish-like locomotion. The frequency response function was analyzed to investigate the natural frequency and the damping factor by a mechanical shaker and direct electrical excitation through the swept-sine method. Present results show that this novel method can be a promising technique to easily pattern each of multiple electrodes and to implement the biomimetic motion of the polymer actuators with good mechanical bending performance.

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Expressing Techniques of Natural-Looking Fish Locomotion applied the Pendulum Concept (진자개념을 적용한 자연스러운 어류 움직임 표현 기법)

  • Yoo, Bong-Gil;Ryu, Nam-Hoon;Ban, Kyeong-Jin;Kim, Kyeong-Og;Oh, Kyeong-Sug;Lee, Hye-Mi;Kim, Eung-Kon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.4 no.2
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    • pp.108-115
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    • 2009
  • Thanks to the development of computer graphics, Animation can be easily accessed through movies or games. The users can meet various contents and are asking for high quality animations that resembles reality to a near perfection. The research is proceeded to observe the fish shapes and swimming movements through cyber aquariums, fish ecology museums and fish encyclopedias. The core of expressing undersea scenery is the natural and dynamic movements of the fish. In this thesis in order to achieve the natural shape of fish swimming, it is necessary to design a fish growth process system based on environmental factors and apply different standard points depending on the various swimming types of fish species to express the fish as near reality as possible. And by calculating the different swimming velocities of different standard points, a natural swimming shape will be achieved.

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Pivot Interpolation for Dynamic Locomotion Expression of Fishes (어류의 역동적 움직임 표현을 위한 기준점 적용 보간법)

  • Ryu, Nam-Hoon;Lee, Hye-Mi;Yoo, Bong-Gil;Kim, Eung-Kon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.5
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    • pp.415-420
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    • 2010
  • Due to the improvement in PC performance and the development of computer graphics technology, high quality computer animation in various industrials is on the rise. This study suggests pivot interpolation to realize the process of expressing dynamic and natural motion of fish, the key of expressing the ocean landscape through the morphing technique. By applying fish tail motion, this study solves unnatural speed of the previous morphing technique and realizes the realistic swimming way without simple motion.

Vibration Characteristics of Patterned IPMC Actuator (패턴된 IPMC 작동기의 진동특성)

  • Jeon, Jin-Han;Oh, Il-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.718-721
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    • 2007
  • The ionic-polymer-metal-composite actuators have the best merit for bio-mimetic locomotion because of their large bending performance. Especially, they have the advantage for mimicking a fish-like motion because IPMCs are useful to be actuated in water. So we have developed IPMC actuators with multiple electrodes for realization of biomimetic motion. This actuator is fabricated by combining electroless plating and electroplating techniques capable of patterning precisely and controlling a thickness of Pt electrode layer. The FRF analysis was conducted by a mechanical shaker and direct electrical excitation which is based on sweep sine wave function. From this result, the proper young‘s modulus of Platinum was investigated and applied on expecting the vibration characteristics of patterned IPMC actuator. The calculated maximum displacement of the patterned IPMC was 2.32mm under an applied 4mN/mm. The natural frequency was increased however displacement was decreased in according to increase a thickness of Pt.

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Fabrication of MDOF IPMC Actuators to Generate Undulatory Motion (파동형 움직임이 가능한 다자유 IPMC 구동기 제작)

  • Jeon, Jin-Han;Oh, Il-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.119-123
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    • 2006
  • The ionic-polymer-metal-composite actuators have the best merit for bio-mimetic locomotion because of their large bending performance. Especially, they have the advantage for mimicking a fish-like motion because IPMCs are useful to be actuated in water. So we have developed IPMC actuators with multiple electrodes for realization of biomimetic motion. Generally, the IPMC actuator has been fabricated in electroless plating technique, while it needs very long fabrication time and shows poor repeatability in the actuation performance owing to the variables in chemical fabrication process. Therefore, the novel fabrication methods were investigated by combining electroless plating and electroplating techniques capable of patterning precisely. On the whole, two different methods were compared and analyzed with similar thickness level of Platinum electrodes. Present results show that mixing chemical reduction and electroplating can be a promising candidate for electrode patterning.

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Anti-stress Effects of Natural Products from Jeju Island in Zebrafish (제브라피쉬에서의 제주도 천연추출물의 항스트레스 효과)

  • Lee, Jeongwon;Lee, Seungheon
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.85-85
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    • 2019
  • Objective: In this study, the anti-stress effects of extract of Hydrangeae Dulcis Folium (EHDF) or ethalonic extract of Opuntiaficus-indica (EOF) of natural extracts from Jeju Island were investigated. Methods: We performed measurement of whole-body cortisol level and behavioral experiments including the novel tank test (NTT) or the open field test (OFT) to assess stress responses in zebrafish. To induce physical stress, we used the net handling stress (NHS). Fish were treated with EOF or EHDF for 6 min before they were exposed to stress. And then, we sacrificed fish for collecting body fluid from whole-body or conducted behavioural tests, including novel tank test and open field test, were evaluated to observe anxiety-like behaviours and locomotion. We used the cortisol enzyme-linked immunoassay kit to measure the amount of cortisol in each zebrafish sample. Results: The results indicate that increased anxiety-like behaviours in novel tank test and open field test under stress were prevented by treatment with both EOF and EHDF (P < 0.05). Moreover, compared with the unstressed group, which was not treated with NHS, the whole-body cortisol level was significantly increased by treatment with NHS. Compared with the NHS-treated stressed control group, pre-treatment with each EHDF and EOF for 6 min significantly prevented the NHS-increased whole-body cortisol level (P < 0.05). Conclusions: In conclusion these results suggest that both EOF and EHDF pretreatment may prevent stress responses and that its mechanism of action may be related to its positive effects on cortisol release.

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