A school of robotic fish capable of coordinating their movements underwater – just like real fish – has been created by a team of engineers.
Harvard University experts created the fish-inspired bots to operate without any external control, mimicking the fish-bearing groups they display.
Fish ladders display complex, synchronized behaviors that help them find food, migrate and escape from predators without a single fish coordinating the movements.
The robotic fish can align their movements like a real school of fish, with no external control – the first time this complex behavior has been demonstrated in robots.
The team says that in the future, a swarm like artificial fish could be used to conduct environmental research and study in sensitive environments such as coral reefs.
These fish-inspired robots can synchronize their movements without external control
The fish-inspired school, called Blueswarm, operates in three-dimensional spaces such as air and water and uses blue LED lights and cameras for navigation.
‘Robots are often used in areas that are accessible or dangerous to humans, areas where intervention would not be possible,’ said first author Florian Berlinger.
‘In these situations, you have the advantage of having a highly automated, self-sufficient robot swarm.
‘Using comprehensible rules and 3D visual understanding, we were able to create a system that has a high degree of underwater independence and flexibility where things like GPS and WiFi are not accessible.’
Diverse blueswarm with real fish. They could one day be used to monitor changes in fragile ecosystems such as coral reefs
They were created in the laboratory of Radhika Nagpal, a pioneer in self-organizing systems at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS).
Previously, his team developed a 1,000 Kilobot robot sword and a termite-inspired robotic construction team – however they worked in a 2D space.
To overcome challenges found from working in 3D space, the team developed a vision-based coordination system in their fish robots based on blue LED lights.
Each underwater robot, called Bluebot, is equipped with two cameras and three LED lights – the cameras detect LEDs of neighboring Bluebots and use a custom algorithm to determine their speed, direction and head. .
Based on simple production and LED light detection, the researchers showed that the Blueswarm could exhibit complex self-organized behavior.
These behaviors included the gathering, scattering, and formation of circles, with ‘every Bluebot suddenly reacting to the roles of its neighbors,’ Berlinger said.
‘So if we want the robots to go together, each Bluebot will measure the position of each of its neighbors and move towards the center,’ he said.
‘If we want the robots to spread, the Bluebots will do the opposite. If we want them to swim like a ladder in a circle, they are programmed to follow lights directly in front of them in a clockwise direction. ‘
The fish-inspired school, called Blueswarm, works in three-dimensional areas such as air and water and uses blue LED lights and cameras for navigation.
The researchers also considered a simple survey mission with a red light in the tank.
Using the scattering algorithm, the Bluebots scatter out across the tank until one comes close enough to the light source to detect it.
As soon as the robot finds the light, its LEDs will start flashing, which will trigger the collection algorithm in the rest of the school.
From there, all the Bluebots go around the signal robot.
Key components of Bluebot include four oscillating fins that allow for energetic movements and two omnidirectional cameras that detect neighbors’ blue light.
‘Our results with Blueswarm represent an important milestone in the study of self-organized underwater aggregation behavior,’ Nagpal said.
Insights from this research will help us develop in the future small underwater flocks that can conduct environmental studies and study in high-visibility but fragile environments such as coral reefs.
This research is also a way to better understand fish schools, by reproducing their behavior synthetically. ‘
The research is published in Science Robotics.