22 SERVO 09.2016
SWAGBOT DOWN UNDER
In order to tackle the hills, dales, fields, cliffs, rivers, swamps,
crocodiles, platypuses, echidnas, koalas, quolls, emus, kangaroos,
wallabies, wombats, and dingoes (just to name a few common
obstacles in Australia), researchers from the Australian Centre for
Field Robotics at the University of Sydney led by Dr. Salah Sukkarieh
have designed and tested an all-terrain robot called SwagBot that’s
designed to be able to drive over almost anything while helping
humans manage their ranchland.
SwagBot is designed to “work in highly undulating terrain for
the purposes of supporting farmers in grazing livestock operations,”
according to Dr. Sukkarieh. The robot is electric with a rugged
waterproof chassis that can deal with almost anything Australia can
throw at it. It’s not autonomous yet, however. It just uses vision right
now to see the animals, but the researchers are working on figuring
out what kinds of sensing systems they’ll need to do a variety of
different activities.
Image courtesy of Australian Centre for Field Robotics.
STIMULATING SALAMANDERS
EPFL’s Pleurobot not only looks like a real
salamander — but more importantly — it moves just
like a real salamander. EPFL has spent years trying to
make sure that the way Pleurobot moves is as close to
the way that a real salamander does as possible.
In a recently published paper in the Royal Society
journal Interface, EPFL researchers describe how
they’ve combined “high speed cineradiography,
optimization, dynamic scaling, three-dimensional
printing, high-end servomotors, and a tailored dry-suit” to refine their robot to accurately capture the
degrees of freedom, range of motion, and gait
behaviors of the real animal.
Why so much focus on the humble salamander?
Primarily, it’s because they’re cute, but there are also a variety
of much “less” important considerations that make
salamanders interesting to study. They’re relatively primitive
quadrupeds making them simpler to study and model, but
they also represent a sort of transitional animal between fish
that swim and quadrupeds that walk which (evolutionarily
speaking) is an interesting place to be.
If you behead a salamander and then stimulate its spinal
cord, what’s left of it will start to walk. Stimulate it more, and
it’ll walk faster, and if you keep going, your headless zombie
electrosalamander will transition into a swimming gait.
(Brains are overrated.)
What’s even more fascinating is that the multimodal
nature of the salamander — its ability to both swim in the
water and walk on land — lies entirely in its musculoskeletal
structure and nervous system.
The reason this is important — besides the obvious
application of raising an army of the dead — is because
robots (most robots, anyway) spend way too much of their
brainpower trying to just keep from falling over. Shifting all of
that to an intelligently designed structure with low-level
control could be advantageous to walking robots —
multimodal or otherwise. Of course, a robot that so closely
replicates a biological system in biomechanics and neural
control could be a fun thing for salamander-ologists to play
with too.
Pleurobot is what’s called an anchor model of a
salamander, meaning that it’s “a realistic model fixed firmly or
grounded in the morphology and physiology of an animal.”
Doing this with a real robot as opposed to just simulation is
critical because it’s simply not possible to accurately simulate
everything in software the way that physical things interact
with the world around them.
