
MIT's Soft Robotic Fish Explores Reefs in Fiji - sohkamyung
https://spectrum.ieee.org/automaton/robotics/robotics-hardware/mit-soft-robotic-fish-explores-reefs-in-fiji
======
spraak
This is completely flippant to say, since I've never built anything like this
and don't understand the complexity behind it, but I'm surprised at how
awkwardly it looks swimming. It's clear to my eyes that it's not a real fish.

~~~
jonathanyc
I wonder if other fish will interpret it as injured and attempt to eat it :)

~~~
Mononokay
It's doubtful - it's swimming _more_ powerfully than other fish, not less.
It's why it looks so odd to humans - the tail strokes are far too heavy. Fish
have a lot more subtlety in their own.

~~~
harperlee
But the fact that it spends more energy, and it is less efficient, should be
interpreted as a sign that something is wrong, isn't it? The gestures are
powerful but the fish does not advance a lot.

Limping on one leg is a more extenuant exercise _precisely_ because you need
(and show) more power (and that is less sustainable). I don't think a lion
would see it as a warning signal!

~~~
ibnjmn
I know next to nothing about submarine dynamics, but I am an RC plane pilot,
and it looks to me like this fish swims in a constant stall. If it was a
plane, I'd be inclined to say that its center of gravity was too far back.

The video states that it can control its own bouyancy, yet it looks like it's
constantly fighting to swim level instead of sinking. If it could achieve a
neutral bouyancy then I bet it would glide along much more like a real fish.

------
tsaoyu
A short list of the other attempts on bio-inspired underwater robots:

* Fish [https://seagrant.mit.edu/publications/MITSG_00-4J.pdf](https://seagrant.mit.edu/publications/MITSG_00-4J.pdf) * Octopus [https://phys.org/news/2015-04-octopus-inspired-robotthe-fast...](https://phys.org/news/2015-04-octopus-inspired-robotthe-fastest-underwater-robot.html) * Snake [https://eelume.com/](https://eelume.com/) * Jellyfish [http://www.emdl.mse.vt.edu/projects/alex.html](http://www.emdl.mse.vt.edu/projects/alex.html) * Manta Ray [https://www.usnews.com/news/news/articles/2017-12-04/singapo...](https://www.usnews.com/news/news/articles/2017-12-04/singapore-researchers-underwater-robot-inspired-by-manta-ray)

------
hendler
There's lots of very interesting research in this area inspired by biology.
Check out
[http://www.people.fas.harvard.edu/~glauder/FishRoboticsLaude...](http://www.people.fas.harvard.edu/~glauder/FishRoboticsLauderHarvard.htm)

------
Rifu
It's a little amusing how the controller is a super nes controller

------
duck
The paper on this provides a lot of interesting insight:
[https://groups.csail.mit.edu/drl/wiki/images/a/a5/Hydraulic_...](https://groups.csail.mit.edu/drl/wiki/images/a/a5/Hydraulic_Autonomous_Soft_Fish-
RKatzschmann_AMarchese_DRus_Final_Submission.pdf)

~~~
blacksmith_tb
CSAIL has published some other papers[1] on the fish-bot which look
interesting, too.

1:
[http://groups.csail.mit.edu/drl/wiki/index.php?title=Soft_Ro...](http://groups.csail.mit.edu/drl/wiki/index.php?title=Soft_Robotics#Soft_Robotic_Fish)

------
ChristianGeek
The video mentions that the controller uses ultrasonic signals to communicate.
I wonder if those signals would disturb the other fish, negating the “neutral
observer” aspect of the project.

------
liminal
I like that it has a "fish-eye" camera in the front

------
evv
I hope larger fish don't get confused and attempt to eat these robots.

So I wonder what are the biggest predators that live near these reefs.. and
how they are able to identify prey.

~~~
caymanjim
Reefs attract some fairly large predators. Barracuda, various sharks, grouper,
moray eels, among others. All can get to well over a meter, or a couple meters
in some cases.

~~~
ed_balls
Sharks prefer colder waters. It's more likely destroyed by trigger fish.

------
hencoappel
They need to put as much stabilisation on that camera as they can.

Pretty cool otherwise.

------
saifs
That's pretty interesting

------
nkg
I want one.

