
How Cockroaches Crash into Walls and Keep Going - IntronExon
https://www.nytimes.com/2018/02/13/science/cockroaches-crash-robots.html?rref=collection%2Fsectioncollection%2Ftechnology
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taneq
"How cockroaches crash into walls and keep going"

Well, being 20mm long and weighing a couple of grams probably helps. And the
"robot cockroach" looks almost nothing like a real cockroach, it's just a
scaled down version of RHEX.

Also, the video of the cockroach doesn't show it crashing into the wall. It
shows it running towards the wall, adjusting its body posture and stride even
before its antennae make contact, slowing abruptly (watch the curved antenna
bend forward under the deceleration), then stepping up onto the wall. It's
categorically _not_ showing what the text describes. Maybe they have other
videos?

~~~
Maken
The original article [1] does include a video of cockroaches running into the
wall without even trying to avoid it, which is somewhat funny.

[1]
[http://rsif.royalsocietypublishing.org/content/15/139/201706...](http://rsif.royalsocietypublishing.org/content/15/139/20170664.figures-
only)

~~~
taneq
Ah, thanks for that! The link to the paper in TFA came up as a 403 when I
looked yesterday.

This is a much more interesting video. It looks like (1) the cockroaches
head/eyes are robust enough to just take the hit, which is interesting - I
always wondered how robust insect eyes were compared with mammalian eyes which
are obviously very delicate, and (2) the kinematics of the head/thorax flick
the thorax upwards on impact. There's a lot of this kind of 'physical
intelligence' built into animals' bodies, and it's a fascinating field of
study - witness the recent finding that flamingos on one leg are statically
stable:
[https://www.theatlantic.com/science/archive/2017/05/flamingo...](https://www.theatlantic.com/science/archive/2017/05/flamingos-
one-leg/527781/)

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YeGoblynQueenne
>> It turns out the cautious approach wasn’t necessary. The roaches that ran
headlong into the wall could make the upward shift just as quickly — in about
75 milliseconds — the researchers found.

The opposite is also true though- the dumb, headlong-crash approach isn't
necessary either, since it's not faster than the cautious approach.

I think what the article is really saying is that, absent a method to make the
cautious approach available, then the dumb approach is good enough.

However, the cautious approach might be evidence of a capacity for more
complex behaviours when necessary, the absence of which can significantly
hinder the animal's (or, indeed, the robot's) versatility in other situations,
besides climbing a wall quickly.

In other words, maybe cockroaches are hard to hit not because they can run
headlong at a wall without slowing down but because they have the choice of
not doing so when needed.

Which in turn means that robots that can only scale a wall by running blindly
at it will still not be as good as cockroaches in tasks other than climbing
walls.

~~~
YouAreGreat
The head-first strategy may allow for higher speed _before_ the transition.
From the journal article:

> Head-first impact is the primary (approx. 80%) transition strategy and often
> occurs at higher wall-approach speeds

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PhantomGremlin
No comments?

I sure don't miss NYC cockroaches. They're seriously tough mother fuckers.
Whack them with a shoe sole and they usually shrug it off and barely break
stride.

The real problem with apartments in cities is that your neighbors' roaches
become your roaches. No way to keep them from moving from apartment to
apartment via cracks in the walls. I don't know how you prevent something like
that? I'm now in a single family detached house in suburbia. That has its own
problems, but roach infestations aren't among them.

~~~
goldenkey
I used to live in a connected house in Brooklyn. In fact, the whole
neighborhood is streets of ten to twenty all-brick, connected houses. So if
even one person had a roach problem, it could migrate a couple houses down.
Having cats would definitely help.

One time, our neighbors decided to move and had moving sales. Well, apparently
their house was so decrepit and disgusting, the stove just covered in food and
soot, roaches roaming freely everywhere. We had seen a roach or two in our
house, a waterbug maybe, but were surprised that we hadn't seen more
considering how close it all was. I guess the brick/cement walls were tight?

I grew up in that house for 20 years, so I'm partial to having fond memories
despite my mother always complaining about how its' too little square feet and
too many steps. We were robbed when I was little, I have no recollection
except lucid and possibly ~fake~ dreams. My parents responded by putting
wrought iron bars on all the windows. Smart move. In fact I was often afraid
of being mugged since I had to get on the bus to goto Brooklyn Tech at around
5am when it was dark. But I survived. Used to carry bear-grade pepper spray
and a nice sized SpiderCo Civilian defense knife. Never had to use them
thankfully.

We had a basement that we finished nicely, so it was 3 decent sized floors -
but so many, so many steps, two long flights. My parents still live in that
house but want to move. I believe they purchased it nearly 35 years ago for
close to $150k. Now it's worth $800k. And its' not a mansion, brownstone, or
anything fancy. That's NYC / Brooklyn for you ;-)

~~~
mfoy_
I feel like if I carried a knife I'd just be that more likely to cut myself on
it, or have it taken and used against me...

~~~
goldenkey
Don't carry a weapon if you are not prepared to use it. Very important dogma.

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sibylsyndrome
Neat! I recently attended a talk by Jayaram about his work with cockroaches:
it's fascinating stuff, especially on a mechanical level.

As someone else mentioned, size and weight are huge factors in kinetic design.
Very roughly: when you're smaller than the dimensions of a mouse, you can
crash into things and count on passive mechanisms to recover. The relative
impact of crashes increases as you scale up, and so it becomes more worthwhile
to have a neurological mechanism that can sense obstacles beforehand and come
up with other ways to avoid them. Timing these neural signals also becomes an
issue that scales with size. So cockroaches and other small animals can use
very different movement-control mechanisms than we do, and the same scaling
principle would apply to cockroach- or human-sized robots.

For the cockroach in the first video, it's definitely sensing the wall and
preparing itself to change trajectory. But cockroaches who just crash into
walls and flail blindly to recover don't actually do worse than those who take
the time and energy to anticipate the walls. This is because they're at the
right size and material composition so that the crash doesn't debilitate them.

And yes -- there are many, many more videos that Jayaram took as part of his
work. Unfortunately I can't find any wall-crashing videos, but there are some
squeezing videos here: [http://www.pnas.org/content/113/8/E950/tab-figures-
data](http://www.pnas.org/content/113/8/E950/tab-figures-data)

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warent
I'm not a roboticist nor do I hold a PhD, but the robot cockroach wasn't
compelling to me at all. The cockroach very clearly elevates its posture as it
approaches the wall. The robot just brute-forces contact until its legs manage
to catch hold. Really no similarity at least from the videos.

That being said, the study is still very interesting!

~~~
khrm
They showed only one version of cockroach. Not one which crashes.

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anirudt
According to me, the antennae of the cockroach play a vital role in sensing
the obstacle ahead; but the work seems to make no use of this fact. There
needs to be some use of the frontal information in making the guided decision,
prior to struggling to climb the wall like the robot does.

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tonydiv
I'm already scared of Boston Dynamics. Once their bots start to look like
cockroaches, I'll never sleep the same.

~~~
dguaraglia
Meh. Nothing grosses me out as much as an actual cockroach. I consider myself
a pretty rational and relatively brave person, but every time I see one way up
on a wall I retreat to a different room in the off-chance that it decides to
jump and fly straight into me (which has happened before.)

~~~
goldenkey
Roaches are pretty harmless other than being disgusting looking.

