Development and target following of vision-based autonomous robotic fish

Robotica ◽  
2009 ◽  
Vol 27 (7) ◽  
pp. 1075-1089 ◽  
Author(s):  
Yonghui Hu ◽  
Wei Zhao ◽  
Guangming Xie ◽  
Long Wang
Keyword(s):  
Visual Information ◽  
Fuzzy Logic Controller ◽  
Swimming Performance ◽  
Mean Shift ◽  
Digital Camera ◽  
Robotic Fish ◽  
Pectoral Fins ◽  
Underwater Image ◽  
Swimming Pattern ◽  
Camshift Algorithm

SUMMARYA novel ostraciiform swimming, vision-based autonomous robotic fish is developed in this paper. Its feasibility and capability are shown by implementing a dynamic target following task in a swimming pool. Inspired by boxfish that is highly stable and fairly maneuverable, the robotic fish is designed and constructed by locating multiple propulsors peripherally around a rigid body. Swimming locomotion of the robotic fish is achieved through harmonic oscillations of the tail and pectoral fins. The forces and moments acting on the fins and body are analyzed and the governing motion equations are derived. Through coordinating the movements of the propulsors, several typical swimming patters are empirical designed and realized. A digital camera is integrated in the robotic fish, and the visual information is processed with the embedded microcontroller. To treat the degradation of underwater image, a continuously adaptive mean shift (Camshift) algorithm is modified to keep visual lock on the moving target. A fuzzy logic controller is designed for motion regulation of a hybrid swimming pattern, which employs synchronized pectoral fins for thrust generation and tail fin for steering. A simple target following task is designed via an autonomous robotic fish swimming after a manually controlled robotic fish with fixed distance. The swimming performance of the robotic fish is tested and the effectiveness of the proposed target following method is verified experimentally.

A biomimetic cownose ray robot fish with oscillating and chordwise twisting flexible pectoral fins

2015 ◽  
Vol 42 (3) ◽  
pp. 214-221 ◽  
Author(s):  
Hongwei Ma ◽  
Yueri Cai ◽  
Yuliang Wang ◽  
Shusheng Bi ◽  
Zhao Gong
Keyword(s):  
Swimming Performance ◽  
Robotic Fish ◽  
Small Radius ◽  
Water Tank ◽  
Pectoral Fin ◽  
Content Type ◽  
Pectoral Fins ◽  
Propulsion Performance ◽  
Cownose Ray ◽  
And Control

Purpose The paper aims to develop a cownose ray-inspired robotic fish which can be propelled by oscillating and chordwise twisting pectoral fins. Design/methodology/approach The bionic pectoral fin which can simultaneously realize the combination of oscillating motion and chordwise twisting motion is designed based on analyzing the movement of cownose ray’s pectoral fins. The structural design and control system construction of the robotic fish are presented. Finally, a series of swimming experiments are carried out to verify the effectiveness of the design for the bionic pectoral fin. Findings The experimental results show that the deformation of the bionic pectoral fin can be well close to that of the cownose ray’s. The bionic pectoral fin can produce effective angle of attack, and the thrust generated can propel robotic fish effectively. Furthermore, the tests of swimming performance in the water tank show that the robotic fish can achieve a maximum forward speed of 0.43 m/s (0.94 times of body length per second) and an excellent turning maneuverability with a small radius. Originality/value The oscillating and pitching motion can be obtained simultaneously by the active control of chordwise twisting motion of the bionic pectoral fin, which can better imitate the movement of cownose ray’s pectoral fin. The designed bionic pectoral fin can provide an experimental platform for further study of the effect of the spanwise and chordwise flexibility on propulsion performance.

Design and Modeling of a Biomimetic Stingray-Like Robotic Fish

2014 ◽  
Vol 945-949 ◽  
pp. 1473-1477 ◽  
Author(s):  
Yang Wei Wang ◽  
Jin Bo Tan ◽  
Bao Tong Gu ◽  
Peng Fei Sang ◽  
Dong Biao Zhao
Keyword(s):  
Kinematic Analysis ◽  
Swimming Performance ◽  
Robotic Fish ◽  
Underwater Robot ◽  
Pectoral Fins

Freshwater stingrays employ enlarged undulating pectoral fins as their routine propulsion means. Their remarkable flexibility and maneuverability have provided many new inspirations for engineers. In this paper, a biomimetic stingray-like underwater robot was introduced. In order to investigate the mechanism of the undulatory propulsion, kinematic analysis and hydromechanics analysis were conducted. Lastly, underwater experiments were carried out to study the swimming performance of the robotic fish.

Design and Dynamic Modeling of a Flexible Feathering Joint for Robotic Fish Pectoral Fins

2014 ◽  
Author(s):  
Sanaz Bazaz Behbahani ◽  
Xiaobo Tan
Keyword(s):  
Dynamic Model ◽  
Robotic Fish ◽  
Power Stroke ◽  
Hydrodynamic Drag ◽  
Pectoral Fin ◽  
Flexible Joint ◽  
Blade Element Theory ◽  
Pectoral Fins ◽  
Flexible Part ◽  
Recovery Stroke

In this paper, we propose a novel design for a pectoral fin joint of a robotic fish. This joint uses a flexible part to enable the rowing pectoral fin to feather passively and thus reduce the hydrodynamic drag in the recovery stroke. On the other hand, a mechanical stopper allows the fin to maintain its motion prescribed by the servomotor in the power stroke. The design results in net thrust even when the fin is actuated symmetrically for the power and recovery strokes. A dynamic model for this joint and for a pectoral fin-actuated robotic fish involving such joints is presented. The pectoral fin is modeled as a rigid plate connected to the servo arm through a pair of torsional spring and damper that describes the flexible joint. The hydrodynamic force on the fin is evaluated with blade element theory, where all three components of the force are considered due to the feathering degree of freedom of the fin. Experimental results on robotic fish prototype are provided to support the effectiveness of the design and the presented dynamic model. We utilize three different joints (with different sizes and different flexible materials), produced with a multi-material 3D printer, and measure the feathering angles of the joints and the forward swimming velocities of the robotic fish. Good match between the model predictions and experimental data is achieved, and the advantage of the proposed flexible joint over a rigid joint, where the power and recovery strokes have to be actuated at different speeds to produce thrust, is demonstrated.

scholarly journals Relations between morphology, buoyancy and energetics of requiem sharks

2016 ◽  
Vol 3 (10) ◽  
pp. 160406 ◽  
Author(s):  
Gil Iosilevskii ◽  
Yannis P. Papastamatiou
Keyword(s):  
Body Temperature ◽  
Negative Selection ◽  
Swimming Performance ◽  
Ontogenetic Changes ◽  
Cost Of Transport ◽  
Pectoral Fins ◽  
Confined Spaces ◽  
Reef Sharks ◽  
The Cost ◽  
Derivatives Of

Sharks have a distinctive shape that remained practically unchanged through hundreds of millions of years of evolution. Nonetheless, there are variations of this shape that vary between and within species. We attempt to explain these variations by examining the partial derivatives of the cost of transport of a generic shark with respect to buoyancy, span and chord of its pectoral fins, length, girth and body temperature. Our analysis predicts an intricate relation between these parameters, suggesting that ectothermic species residing in cooler temperatures must either have longer pectoral fins and/or be more buoyant in order to maintain swimming performance. It also suggests that, in general, the buoyancy must increase with size, and therefore, there must be ontogenetic changes within a species, with individuals getting more buoyant as they grow. Pelagic species seem to have near optimally sized fins (which minimize the cost of transport), but the majority of reef sharks could have reduced the cost of transport by increasing the size of their fins. The fact that they do not implies negative selection, probably owing to decreased manoeuvrability in confined spaces (e.g. foraging on a reef).

Undulatory Swimming Performance and Body Stiffness Modulation in a Soft Robotic Fish-Inspired Physical Model

Soft Robotics ◽  
2017 ◽  
Vol 4 (3) ◽  
pp. 202-210 ◽  
Author(s):  
Ardian Jusufi ◽  
Daniel M. Vogt ◽  
Robert J. Wood ◽  
George V. Lauder
Keyword(s):  
Physical Model ◽  
Swimming Performance ◽  
Robotic Fish ◽  
Undulatory Swimming

Effect of Morphological Fin-Curl on the Swimming Performance and Station-Holding Ability of Juvenile Shovelnose Sturgeon

2016 ◽  
Vol 7 (1) ◽  
pp. 198-204 ◽  
Author(s):  
David Deslauriers ◽  
Ryan Johnston ◽  
Steven R. Chipps
Keyword(s):  
Swimming Speed ◽  
Early Onset ◽  
Positive Relationship ◽  
Swimming Performance ◽  
Fork Length ◽  
Critical Swimming Speed ◽  
Pectoral Fin ◽  
Speed Test ◽  
Shovelnose Sturgeon ◽  
Pectoral Fins

Abstract We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

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