Control surfaces of aquatic vertebrates: active and passive design and function

Fish, Frank E.; Lauder, George V.

doi:10.1242/jeb.149617

Cited by 63 publications

(67 citation statements)

References 161 publications

(173 reference statements)

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“…4). During the second half of the half-cycle, there is the possibility for energy savings if swimming velocity can decrease owing to passive coasting, or minimal fin deflections for braking (Fish and Lauder, 2017). However, fin beats continued throughout the cycle and the increase just before the direction change may indicate active braking motions or preparation for the direction change and acceleration.…”

Section: Pectoral Fin Beat Frequencies and Behavior With Oscillatory mentioning

confidence: 99%

Energetics and behavior of coral reef fishes during oscillatory swimming in a simulated wave surge

Marcoux

Korsmeyer

2019

Journal of Experimental Biology

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Oxygen consumption rates were measured for coral reef fishes during swimming in a bidirectional, oscillatory pattern to simulate station-holding in wave-induced, shallow-water flows. For all species examined, increases in wave intensity, as simulated by increases in frequency and amplitude of oscillation, yielded increased metabolic rates and net costs of swimming (NCOS; swimming metabolic rate minus standard metabolic rate). Comparing species with different swimming modes, the caudal fin swimming Kuhlia spp. (Kuhliidae) and simultaneous pectoral-caudal fin swimming Amphiprion ocellaris (Pomacentridae) turned around to face the direction of swimming most of the time, whereas the median-paired fin (MPF) swimmers, the pectoral fin swimming Ctenochaetus strigosus (Acanthuridae) and dorsal-anal fin swimming Sufflamen bursa (Balistidae), more frequently swam in reverse for one half of the oscillation to avoid turning. Contrary to expectations, the body-caudal fin (BCF) swimming Kuhlia spp. had the lowest overall NCOS in the oscillatory swimming regime compared with the MPF swimmers. However, when examining the effect of increasing frequency of oscillation at similar average velocities, Kuhlia spp. showed a 24% increase in NCOS with a 50% increase in direction changes and accelerations. The two strict MPF swimmers had lower increases on average, suggestive of reduced added costs with increasing frequency of direction changes with this swimming mode. Further studies are needed on the costs of unsteady swimming to determine whether these differences can explain the observed prevalence of fishes using the MPF pectoral fin swimming mode in reef habitats exposed to high, wave-surge-induced water flows.

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Section: Pectoral Fin Beat Frequencies and Behavior With Oscillatory mentioning

confidence: 99%

Energetics and behavior of coral reef fishes during oscillatory swimming in a simulated wave surge

Marcoux

Korsmeyer

2019

Journal of Experimental Biology

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“…This suggests that the difference we observed between controller and propulsive flipper‐hydrofoils is driven largely by the proximal half and that the distal half has a similar function in both. The sharp decline in bone proportion at Strip 5 (Figure b) suggests a more flexible trailing edge at the tips of both flipper types, which might serve to improve hydrodynamic efficiency by modifying tip vortices (Fish & Lauder, ).…”

Section: Discussionmentioning

confidence: 99%

Flipper bone distribution reveals flexible trailing edge in underwater flying marine tetrapods

DeBlois

Motani

2019

Journal of Morphology

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Hydrofoil-shaped limbs (flipper-hydrofoils) have evolved independently several times in secondarily marine tetrapods and generally fall into two functional categories:(1) those that produce the majority of thrust during locomotion (propulsive flipperhydrofoils); (2) those used primarily to steer and resist destabilizing movements such as yaw, pitch, and roll (controller flipper-hydrofoils). The morphological differences between these two types have been poorly understood. Theoretical and experimental studies on engineered hydrofoils suggest that flapping hydrofoils with a flexible trailing edge are more efficient at producing thrust whereas hydrofoils used in steering and stabilization benefit from a more rigid one. To investigate whether the trailing edge is generally more flexible in propulsive flipper-hydrofoils, we compared the bone distribution along the chord in both flipper types. The propulsive flipperhydrofoil group consists of the forelimbs of Chelonioidea, Spheniscidae, and Otariidae. The controller flipper-hydrofoil group consists of the forelimbs of Cetacea. We quantified bone distribution from radiographs of species representing more than 50% of all extant genera for each clade. Our results show that the proportion of bone in both groups is similar along the leading edge (0-40% of the chord) but is significantly less along the trailing edge for propulsive flipper-hydrofoils (40-80% of the chord). Both flipper-hydrofoil types have little to no bony tissue along the very edge of the trailing edge (80-100% of the chord). This suggests a relatively flexible trailing edge for propulsive flipper-hydrofoils compared to controller flipper-hydrofoils in line with findings from prior studies. This study presents a morphological correlate for inferring flipper-hydrofoil function in extinct taxa and highlights the importance of a flexible trailing edge in the evolution of propulsive flipper-hydrofoils in marine tetrapods. K E Y W O R D S flexible trailing edge, flipper functional morphology, secondarily marine tetrapods

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“…The placement and the design of the surfaces should also be considered. The control of the surface by generating torques provides to the animal stability [12]. The forces used to control are shown in Figure 13.…”

Section: Underwatermentioning

confidence: 99%

A Design Methodology for Cuttlefish Shaped Amphibious Robot

Arslan¹,

Akça²

2019

European Journal of Science and Technology

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Most of the engineering problems can be easily solved by using biomimetic designs. Biomimetic is the process of imitating live animals to create new designs. For example, by mimicking the movements of a fish or snake, it is possible to transfer the desired swimming or crawling movements to a robot. This research is based on an amphibious robot where the propulsion system is imitated by a cuttlefish. In this study, to obtain the required sine wave motion for the cuttlefish's fin, crank-rocker mechanisms are used. Additionally, a circular slot mechanism was used to move these crank-rocker mechanism up and down as in the cuttlefish fins. Since the cuttlefish has two symmetrical wings, these crank-rocker and circular slot mechanisms are repeated symmetrically on both sides. Two separate servo motors (one on the right and one on the left) were used to control the angular position of the crankshafts in circular slots. These servo motors allow the fins to move up and down while the robot is in the water. They also serve to hold the wings at a fixed angle in terrestrial mode. In similar applied robotic researches, dozens of servo motors are used to obtain the required sine motion. This study proposes a propulsion system that can be operate with simple crank-rocker and circular slot mechanisms, instead of using too many servo motors that are expensive and constitutes control complexity. In this study, a design methodology is proposed for this new propulsion system. Various conditions have been considered in the design procedure. In the design criteria section, the required force and velocity, the capacity to overcome obstacles and the motion requirements has been considered for an amphibious robot. Furthermore, the requirements of a continuous movement for oscillating motion have been also considered. As a result of this study, minimum crank number and crank angles were obtained for the undulating motion. It has been also considered the necessary continuous balance condition, in order to make motion on land without tumbling. The calculation of the part lengths that meets the design criteria is described in the mechanism synthesis section.

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Control surfaces of aquatic vertebrates: active and passive design and function

Cited by 63 publications

References 161 publications

Energetics and behavior of coral reef fishes during oscillatory swimming in a simulated wave surge

Energetics and behavior of coral reef fishes during oscillatory swimming in a simulated wave surge

Flipper bone distribution reveals flexible trailing edge in underwater flying marine tetrapods

A Design Methodology for Cuttlefish Shaped Amphibious Robot

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