Robotics

Unleash the Kraken! Robot octopus learning to swim

A prototype octopus robot uses its flexible tentacles to scull through the water
A prototype octopus robot uses its flexible tentacles to scull through the water
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A cross-section shows the components of the OCTOPUS Project's latest artificial tentacle
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A cross-section shows the components of the OCTOPUS Project's latest artificial tentacle
A soft artificial tentacle can grasp underwater
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A soft artificial tentacle can grasp underwater
The FORTH team is exploring various forms of underwater locomotion using a prototype robot octopus with both soft and rigid tentacles
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The FORTH team is exploring various forms of underwater locomotion using a prototype robot octopus with both soft and rigid tentacles
The FORTH team created a computer simulation which accounts for fluid drag
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The FORTH team created a computer simulation which accounts for fluid drag
This prototype robot octopus flutters its rigid tentacles to achieve smooth one-directional locomotion
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This prototype robot octopus flutters its rigid tentacles to achieve smooth one-directional locomotion
The FORTH team's simulations mirrored the experimental results
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The FORTH team's simulations mirrored the experimental results
A prototype octopus robot uses its flexible tentacles to scull through the water
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A prototype octopus robot uses its flexible tentacles to scull through the water

The octopus is a natural escape artist. It can squeeze its soft body into impossibly tight spaces and often baffles aquarium workers with its ability to break out of tanks. These abilities could be very useful in an underwater robot, which is why the OCTOPUS Project, a consortium of European robotics labs, is attempting to reverse engineer it in all its tentacled glory. Now researchers from the Foundation for Research and Technology (FORTH), in Hellas, Greece are learning how the robot might use its tentacles to swim.

Back in 2011 we got a glimpse of the project's first stab at an artificial tentacle, which could have far-reaching implications for soft-bodied robots of the future. However, it's when you combine multiple tentacles that you can begin to explore how they help the octopus propels itself underwater. The FORTH team – Michael Sfakiotakis, Asimina Kazakidi, Nikolaos Pateromichelakis, and Dimitris P. Tsakiris – are experimenting with various methods of sculling.

Most of the time an octopus crawls to get around, but they swim quickly to avoid predation using a built-in water jet. Added propulsion comes from undulating all eight tentacles in unison, but the researchers have found that the robot can also move quite smoothly by fluttering its arms independently (something the real animal does not do).

Besides creating a dynamic simulation (which takes fluid drag into account), they also experimented with an actual prototype. You can see how these strategies affect locomotion in the following video:

Octopus-inspired Eight-arm Robotic Swimming by Sculling

This work was presented at the IEEE International Conference on Robotics and Automation (ICRA) 2013 last month. Moving forward, the team plans to experiment with other gaits and will add a stretchy webbing around the base of the tentacles to see how these affect its swimming. Eventually, the robot will be given a pump jet motor to simulate how a real octopus expels water.

Assuming all goes swimmingly, the OCTOPUS Project hopes to "open up new scenarios for marine exploration and underwater rescue," though admittedly that still seems a little far off.

Source: OCTOPUS Project via IEEE Spectrum

2 comments
Taryn East
I'd be curious to see what would happen if they put the robot into a tank with a real octopus - if it could pick up the "independent motion" movement from the robot.
dalroth5
Well, the thing is that according to the keepers of the New England Aquarium, octopuses tend to eat one another: http://www.loe.org/shows/segments.html?programID=11-P13-00046&segmentID=6 so my guess would be that if they tried that experiment then the real octopus would dismember the robot...