Tuna-Inspired Experimental Platforms Exploring High-Performance Fish Swimming
White, Carl, Mechanical and Aerospace Engineering - School of Engineering and Applied Science, University of Virginia
Bart-Smith, Hilary, EN-Mech & Aero Engr Dept, University of Virginia
Autonomous underwater vehicles perform a growing variety of missions including exploration, surveillance, and defense. Their conventional designs feature rigid hulls and rotary propellers which contrast the flexible bodies and undulatory tails of fish. As a result, fish exhibit exceptional speed, efficiency, and maneuverability often surpassing that of conventional vehicles. This performance difference motivates the design of vehicles taking inspiration from biology. However, a significant gap in performance exists between such bio-inspired vehicles and the high-performance capabilities of fish. Bio-inspired vehicles typically focus on low-speed locomotion with low tail-beat frequencies. The few systems that do achieve high frequencies often remain limited to low speeds. Consequently, current robotic fish are unable to access the high-frequency, high-speed performance space of fish. Furthermore, the energetic costs of most robotic fish exceed those of fish by orders of magnitude while at a fraction of the speed.
Here we design and test robotic fish able to explore the high-performance space of fish with biologically realistic energy efficiencies. Our bio-inspired systems achieve this by modeling the morphology and kinematics of yellowfin tuna (Thunnus albacares), which are open-ocean swimmers with extraordinary speed and endurance. We present five generations of fish robots inspired by tuna and compare our results with data for tuna and a diversity of fish species. These Tunabots are research platforms that improve our understanding of high-performance fish swimming. The fifth generation, Tunabot Flex, demonstrates that body flexibility improves speed and efficiency. Our work provides a new baseline for the development of state-of-the-art underwater vehicles that aim to explore a fish-like, high-performance space and close the gap between robotic systems and fish swimming ability.
PHD (Doctor of Philosophy)
Tunabots, Tunabot Flex, Body Flexibility, Biomimicry, Bio-inspired engineering, Tuna, Swimming performance, Midline kinematics, Energetics, Cost of transport, Efficiency, Fin-fin interactions, Locomotion, Biolocomotion, Bio-inspired underwater vehicle, Autonomous underwater vehicle (AUV), High-performance, Fish robotics, Particle image velocimetry (PIV), Effective angle of attack, Strouhal number, Tail-beat frequency, Stride length, Head and tail-beat amplitudes, Dead-drag force and coefficient, Phase difference of caudal fin, Static thrust, Linear acceleration from rest
Office of Naval ResearchThe David and Lucile Packard FoundationHarvard University, Department of Organismic and Evolutionary Biology
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