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

Due to the difficulty of manipulating muscle activation in live, freely swimming fish, a thorough examination of the body kinematics, propulsive performance, and muscle activity patterns in fish during undulatory swimming motion has not been conducted. We propose to use soft robotic model animals as experimental platforms to address biomechanics questions and acquire understanding into subcarangiform fish swimming behavior. We extend previous research on a bio-inspired soft robotic fish equipped with two pneumatic actuators and soft strain sensors to investigate swimming performance in undulation frequencies between 0.3 and 0.7 Hz and flow rates ranging from 0 to 20 cms in a recirculating flow tank. We demonstrate the potential of eutectic gallium–indium (eGaIn) sensors to measure the lateral deflection of a robotic fish in real time, a controller that is able to keep a constant undulatory amplitude in varying flow conditions, as well as using Particle Image Velocimetry (PIV) to characterizing swimming performance across a range of flow speeds and give a qualitative measurement of thrust force exerted by the physical platform without the need of externally attached force sensors. A detailed wake structure was then analyzed with Dynamic Mode Decomposition (DMD) to highlight different wave modes present in the robot’s swimming motion and provide insights into the efficiency of the robotic swimmer. In the future, we anticipate 3D-PIV with DMD serving as a global framework for comparing the performance of diverse bio-inspired swimming robots against a variety of swimming animals.

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Effect of body stiffness on the swimming performance of a robotic fish

Information Technology and Computer Application Engineering ◽

10.1201/b15936-180 ◽

2013 ◽

pp. 779-782

Keyword(s):

Swimming Performance ◽

Robotic Fish

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

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-11-2014-0426 ◽

2015 ◽

Vol 42 (3) ◽

pp. 214-221 ◽

Cited By ~ 8

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.

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Development and target following of vision-based autonomous robotic fish

Robotica ◽

10.1017/s0263574709005499 ◽

2009 ◽

Vol 27 (7) ◽

pp. 1075-1089 ◽

Cited By ~ 21

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.

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Nonlinear analysis of compliant robotic fish locomotion

Journal of Vibration and Control ◽

10.1177/1077546321997608 ◽

2021 ◽

pp. 107754632199760

Author(s):

Hongzhou Jiang ◽

Yanwen Liu

Keyword(s):

Swimming Performance ◽

Influence Factors ◽

Robotic Fish ◽

Transport Efficiency ◽

Fish Locomotion ◽

Resonant Effect ◽

Driving Torque ◽

Nonlinear Behaviors ◽

Body Theory ◽

Tail Beat

Compliant robotic fish can achieve a better swimming performance than rigid-bodied robotic fish. Therefore, this article investigates the swimming behavior of the compliant robotic fish based on a new swimming model that combines the large-amplitude elongated-body theory with decoupled natural orthogonal complement matrices. The simulation reveals that the multi-order resonances are generated in tail-beat amplitude, forward speed, stride length, and transport efficiency when the compliant robotic fish is driven at the corresponding frequency. Moreover, the resonant effects demonstrate the nonlinear behaviors as the driving torque increases. A control strategy for resonance utilization is presented to improve the performance capabilities. The potential influence factors for resonant effects are also discussed, showing that the tail-generated hydrodynamic force significantly impacts the resonant effect. These nonlinear characteristics can provide important guidelines for the motion control of the compliant robotic fish.

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A Study of the Planar Serial-Parallel Mechanism With Various Stiffness for a Biotic Compliant Fish

Volume 3A: Biomedical and Biotechnology Engineering ◽

10.1115/imece2013-62305 ◽

2013 ◽

Cited By ~ 1

Author(s):

Cui Zuo ◽

Jiang Hong-zhou

Keyword(s):

Simulation Model ◽

Strouhal Number ◽

Parallel Mechanism ◽

Swimming Performance ◽

Variable Stiffness ◽

The Body ◽

Robotic Fish ◽

Driving Frequency ◽

Parallel Mechanisms ◽

Forward Speed

Previous biological experiments show that the fish use their muscles to stiffen their bodies for improving the swimming performance. Inspired by that, we propose a planar model of oscillatory propulsor with variable stiffness using hyper redundant serial-parallel mechanisms to mimic a fish. Our goal in the paper is to identify the swimming characteristics with respect to the body stiffness. Moreover, a simulation model is presented and its results show that the swimming performance is largely dependent on the body stiffness and the driven frequency. Our primary conclusions include: 1) when the driven frequency is closed to the design frequency, the robotic fish with the calculated body stiffness has a super swimming performance. 2) Driven at the design frequency, the forward speed of robotic fish is linearly proportional to the driving frequency and the Strouhal number is consistent with the experiment results 0.25<St<0.35.

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Hydraulic geometry as a physical template for the River Continuum: application to optimal flows and longitudinal trends in salmonid habitat

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-020 ◽

2007 ◽

Vol 64 (5) ◽

pp. 755-767 ◽

Cited By ~ 47

Author(s):

Jordan S Rosenfeld ◽

John Post ◽

Geneva Robins ◽

Todd Hatfield

Keyword(s):

Life History ◽

Physical Model ◽

Swimming Performance ◽

Later Life ◽

Channel Structure ◽

Hydraulic Geometry ◽

River Continuum ◽

Life History Stages ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Small Streams

The River Continuum Concept lacks a quantitative physical model to represent downstream trends in habitat. We evaluate whether hydraulic geometry relationships can be used as a physical template to predict longitudinal trends in habitat availability and optimal flows for different life-history stages of rainbow trout (Oncorhynchus mykiss). Optimal flows based on hydraulic geometry indicate that (i) optimal flows are higher for larger fish, (ii) optimal flows proportionally increase as streams became smaller and decrease downstream, and (iii) maximum predicted habitat suitabilities for fry and juveniles are in small streams, and maximum suitabilities are displaced progressively downstream for later life-history stages. These patterns are an emergent property of downstream increases in channel depth and velocity and changes in habitat suitability curves associated with increased swimming performance of larger fish. Nonlinear downstream trends in habitat imply that fixed flow percentages recommended by the Tenant method may substantially underestimate optimal flows in small streams. Despite oversimplifying complex channel structure, hydraulic geometry relationships should serve as a useful physical model for testing downstream trends in habitat-related processes along the river continuum.

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Design of a Biomimetic Robotic Fish Controlled by a Touch Screen

Volume 2: Dynamic Modeling and Diagnostics in Biomedical Systems; Dynamics and Control of Wind Energy Systems; Vehicle Energy Management Optimization; Energy Storage, Optimization; Transportation and Grid Applications; Estimation and Identification Methods, Tracking, Detection, Alternative Propulsion Systems; Ground and Space Vehicle Dynamics; Intelligent Transportation Systems and Control; Energy Harvesting; Modeling and Control for Thermo-Fluid Applications, IC Engines, Manufacturing ◽

10.1115/dscc2014-5842 ◽

2014 ◽

Author(s):

Paul Phamduy ◽

Raymond Le Grand ◽

Maurizio Porfiri

Keyword(s):

Informal Learning ◽

Science Learning ◽

Swimming Performance ◽

Three Dimensional ◽

Touch Screen ◽

Robotic Fish ◽

Performance Tests ◽

Increasing Trend ◽

Biomimetic Robotic Fish ◽

Buoyancy Control

Biomimetic robotic fish exhibits have been an attraction for many visitors in informal learning settings. Although these exhibits are entertaining to the visitors, they generally lack interactive components to promote participants’ engagement. Interactivity in exhibits is an increasing trend in public educational venues, and is a crucial factor for promoting science learning among participants. In this work, we propose a novel platform for enhancing participant interaction through a robotic fish controlled by a touch screen device. Specifically, we develop and characterize a robotic fish based on a multi-link design with a pitch and buoyancy control system for three-dimensional biomimetic swimming. Performance tests are conducted to assess the robotic fish speed.

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