scholarly journals Collective Response of Zebrafish Shoals to a Free-Swimming Robotic Fish

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e76123 ◽  
Author(s):  
Sachit Butail ◽  
Tiziana Bartolini ◽  
Maurizio Porfiri
Keyword(s):  
Robotic Fish ◽  
Free Swimming ◽  
Collective Response

Autonomous Charging for an Underwater Robotic Fish by Direct Contact

2016 ◽  
Author(s):  
Paul Phamduy ◽  
Jayhwan Cheong ◽  
Maurizio Porfiri
Keyword(s):  
Autonomous Navigation ◽  
Direct Contact ◽  
Autonomous Underwater Vehicles ◽  
Robotic Fish ◽  
Laboratory Research ◽  
Free Swimming ◽  
Charging Station ◽  
Battery Capacity ◽  
Series Of Experiments ◽  
Field Deployment

The operation of autonomous underwater vehicles is often hindered by their battery capacity, limiting the duration of its use. Here, we propose an integrated solution for autonomous charging of a robotic fish via direct contact through a novel claw mechanism for docking guidance. To assist the robotic fish in the docking process, the system incorporates a charging station designed with form-fit claws. A controller is designed to monitor the battery level of the robotic fish during free swimming and coordinate the docking process with respect to the maneuvers of both the robot and form-fit claws. Upon recognizing a low battery level, the controller commands the robotic fish to begin the docking process, and video feedback from an overhead camera is used to inform the autonomous navigation toward the charging station. After reaching a battery level threshold, the robotic fish is then released back in the water and returns to free swimming until the battery is discharged again. Through a series of experiments, we demonstrate the possibility of prolonged operation, consisting of repeated cycles of autonomous charging. Our proposed charging method enables prolonged autonomous swimming with minimal human supervision, opening the door for new, transformative applications of robotic fish in laboratory research and field deployment.

Dynamic Modeling of Robotic Fish With a Base-Actuated Flexible Tail

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Jianxun Wang ◽  
Philip K. McKinley ◽  
Xiaobo Tan
Keyword(s):  
Hydrodynamic Force ◽  
Beam Theory ◽  
Small Deformation ◽  
Robotic Fish ◽  
Free Swimming ◽  
Flexible Tail ◽  
In Series ◽  
Optimization And Control ◽  
And Control ◽  
Body Theory

In this paper, we develop a new dynamic model for a robotic fish propelled by a flexible tail actuated at the base. The tail is modeled by multiple rigid segments connected in series through rotational springs and dampers, and the hydrodynamic force on each segment is evaluated using Lighthill's large-amplitude elongated-body theory. For comparison, we also construct a model using linear beam theory to capture the beam dynamics. To assess the accuracy of the models, we conducted experiments with a free-swimming robotic fish. The results show that the two models have almost identical predictions when the tail undergoes small deformation, but only the proposed multisegment model matches the experimental measurement closely for all tail motions, demonstrating its promise in the optimization and control of tail-actuated robotic fish.

Collective Response of Zebrafish to a Mobile Robotic Fish

2013 ◽  
Author(s):  
Sachit Butail ◽  
Tiziana Bartolini ◽  
Maurizio Porfiri
Keyword(s):  
Visual Cues ◽  
Color Pattern ◽  
The Body ◽  
Robotic Fish ◽  
Steering Control ◽  
Trajectory Data ◽  
Experimental Conditions ◽  
Collective Response ◽  
Multi Target Tracking ◽  
Social Organism

We investigate the response of groups of zebrafish, a model social organism, to a free-swimming robotic fish. The robot has a body and tail section and moves forward by beating the tail. Steering control is achieved by offsetting the beating tail with respect to the body. The color pattern and shape of the robot are informed by visual cues known to be preferred by zebrafish. A real-time multi-target tracking algorithm uses position and velocity estimates to autonomously maneuver the robot in circular trajectories. Observables of collective behavior are computed from the fish trajectory data to measure cohesiveness, polarization, and speed of the zebrafish group in two different experimental conditions. We show that while fish are significantly less polarized in the presence of the robot with an accompanying change in average speed, there is no significant change in the degree of cohesion.

Design and characterization of a miniature free-swimming robotic fish based on multi-material 3D printing

2017 ◽  
Vol 1 (2) ◽  
pp. 209-223 ◽  
Author(s):  
Paul Phamduy ◽  
Miguel Angel Vazquez ◽  
Changsu Kim ◽  
Violet Mwaffo ◽  
Alessandro Rizzo ◽  
...  
Keyword(s):  
3D Printing ◽  
Robotic Fish ◽  
Free Swimming

scholarly journals On a Miniature Free-Swimming Robotic Fish with Multiple Sensors

10.5772/62887 ◽  
2016 ◽  
Vol 13 (2) ◽  
pp. 62 ◽  
Author(s):  
Junzhi Yu ◽  
Shifeng Chen ◽  
Zhengxing Wu ◽  
Weibing Wang
Keyword(s):  
Robotic Fish ◽  
Free Swimming ◽  
Multiple Sensors

The time course of calcium deposition in shells of the barnacle (Balanus amphititre amphititre) during cyprid-juvenile metamorphosis

1994 ◽  
Vol 52 ◽  
pp. 178-179
Author(s):  
Nancy R. Wallace ◽  
Craig C. Freudenrich ◽  
Karl Wilbur ◽  
Peter Ingram ◽  
Ann LeFurgey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Time Course ◽  
Vertical Plane ◽  
Mantle Cavity ◽  
Qualitative Assessment ◽  
Calcium Deposition ◽  
Free Swimming ◽  
Freeze Dried ◽  
Scanning Electron

The morphology of balanomorph barnacles during metamorphosis from the cyprid larval stage to the juvenile has been examined by light microscopy and scanning electron microscopy (SEM). The free-swimming cyprid attaches to a substrate, rotates 90° in the vertical plane, molts, and assumes the adult shape. The resulting metamorph is clad in soft cuticle and has an adult-like appearance with a mantle cavity, thorax with cirri, and incipient shell plates. At some time during the development from cyprid to juvenile, the barnacle begins to mineralize its shell, but it is not known whether calcification occurs before, during, or after ecdysis. To examine this issue, electron probe x-ray microanalysis (EPXMA) was used to detect calcium in cyprids and juveniles at various times during metamorphosis.Laboratory-raised, free-swimming cyprid larvae were allowed to settle on plastic coverslips in culture dishes of seawater. The cyprids were observed with a dissecting microscope, cryopreserved in liquid nitrogen-cooled liquid propane at various times (0-24 h) during metamorphosis, freeze dried, rotary carbon-coated, and examined with scanning electron microscopy (SEM). EPXMA dot maps were obtained in parallel for qualitative assessment of calcium and other elements in the carapace, wall, and opercular plates.

I3S Pattern as a mark-recapture tool to identify captured and free-swimming sea turtles: an assessment

2018 ◽  
Vol 589 ◽  
pp. 263-268 ◽  
Author(s):  
B Calmanovici ◽  
D Waayers ◽  
J Reisser ◽  
J Clifton ◽  
M Proietti
Keyword(s):  
Sea Turtles ◽  
Free Swimming ◽  
Mark Recapture

Understanding the Outcomes of Climate Change Campaigns in the Australian Environmental Movement

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robyn Gulliver ◽  
Kelly S. Fielding ◽  
Winnifred Louis
Keyword(s):  
Climate Change ◽  
Collective Action ◽  
Environmental Advocacy ◽  
Personal Support ◽  
Governmental Organizations ◽  
Collective Response ◽  
Non Governmental Organizations ◽  
Advocacy Network ◽  
Australian Climate

Climate change is a global problem requiring a collective response. Grassroots advocacy has been an important element in propelling this collective response, often through the mechanism of campaigns. However, it is not clear whether the climate change campaigns organized by the environmental advocacy groups are successful in achieving their goals, nor the degree to which other benefits may accrue to groups who run them. To investigate this further, we report a case study of the Australian climate change advocacy sector. Three methods were used to gather data to inform this case study: content analysis of climate change organizations’ websites, analysis of website text relating to campaign outcomes, and interviews with climate change campaigners. Findings demonstrate that climate change advocacy is diverse and achieving substantial successes such as the development of climate change-related legislation and divestment commitments from a range of organizations. The data also highlights additional benefits of campaigning such as gaining access to political power and increasing groups’ financial and volunteer resources. The successful outcomes of campaigns were influenced by the ability of groups to sustain strong personal support networks, use skills and resources available across the wider environmental advocacy network, and form consensus around shared strategic values. Communicating the successes of climate change advocacy could help mobilize collective action to address climate change. As such, this case study of the Australian climate change movement is relevant for both academics focusing on social movements and collective action and advocacy-focused practitioners, philanthropists, and non-governmental organizations.

Sign in / Sign up

Export Citation Format

Share Document