Researchers create robotic fish that use implicit coordination to navigate

Date:19 January 2021 Author: Kyro Mitchell

If you’ve ever watched a school of fish swimming around, you would have noticed that they are extremely coordinated, to the point that it appears as though they’re all using the same brain to get around. This extreme coordination is actually a phenomenon called ‘implicit coordination‘ and happens when an individual fish makes decisions based on what their neighbour is doing.

Attempting to replicate implicit coordination in robotics has always been a goal for engineers around the world. Now, it looks as though a team of researchers from the Harvard John A Paulson School of Engineering and Applied Sciences and the Wyss Institute for biologically Inspired Engineering, have finally managed to crack the code and developed a set of robots that are able to synchronise their movements like a real school of fish would, without external control.

Researchers say this time implicit coordination has been demonstrated in underwater robots. Previous robotic swarms operated in two-dimensional space, three-dimensional spaces, however, like air and water, pose significant challenges to sensing exact location and direction.

To overcome these challenges, the researchers developed a vision-based coordination system in their fish robots based on blue LED lights. Each underwater robot, called a Bluebot, is equipped with two cameras and three LED lights. The on-board fish-lens cameras detect the LEDs of neighbouring Bluebots and use a custom algorithm to determine their distance, direction and heading.

Based on the simple production and detection of LED light, the researchers demonstrated that the Blueswarm could exhibit complex self-organised behaviours, including aggregation, dispersion and circle formation.

According to Florian Berlinger, author of the paper, “If we want the robots to aggregate, then each Bluebot will calculate the position of each of its neighbours and move towards the centre. If we want the robots to disperse, the Bluebots do the opposite. If we want them to swim as a school in a circle, they are programmed to follow lights directly in front of them in a clockwise direction.”

Researchers believe the Blueswarm robots could be used in search and rescue situations in areas that are inaccessible or dangerous to humans.

Take a look at the robotic fish below:



Picture: Self-organising Systems Research Group

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