

Robot needs 50 tries to learn how to flip pancakes. - spif
http://www.wired.com/gadgetlab/2010/07/robot-learns-to-flip-pancakes/

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iandanforth
Two interesting things to notice from the video:

1\. In the failure trials the robot does not move its arm toward the object as
it falls. This is distinctly inhuman! When we initiate a motor program we are
constantly checking our prediction for the behavior of both our body and
external objects against reality and then updating that program in real time.
This bot apparently updates its program only after each trial.

2\. The robot moves back to its standard starting position after each
successful trial. This demonstrates the specificity of the motor pattern it's
developed. Due to time pressure and the complexity of variations we deal with
it is usually advantageous to learn a generalized pattern rather than a single
pattern that works for a constrained set of starting conditions.

As a side note on the difficulty of this task, I agree with sukuriant that the
paucity of the information the robot has, especially lack of fine grained
touch, is a huge impediment. Secondly recall that in the human brain about 50%
of the neurons live in the cerebellum which is strongly implicated in storing
and updating fine grained motor patterns. (Gross patterns and intentions being
initiated in the motor cortex).

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Retric
Watch a professional basketball payer shoot freethrows and you see an attempt
to replicate initial conditions. It’s actually fairly normal when someone is
trying to be precise, ex: Darts, billiards, tennis etc.

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spif
Interesting how the failures make it look eerily human. And it seems to me
while watching that the robot becomes frustrated when failing. I know it's me
projecting that, seems interesting to apply that to human interaction though.
How much is projection and how much is real empathy.

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wlievens
If you haven't yet, read up on the concept of the "Uncanny Valley". It's
relevant to what you express here.

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ehsanul
What I find particularly interesting is the sort of "superstition" many of
these kinds of robots show. What I'm referring to in this case is how, after
50 tries, the robot arm here moves to its right before every flip attempt. I
believe the same thing shows up with solutions from genetic algorithms and
neural networks.

Seems like there is always some non-negligible probability that within the
factors any learning robot takes into account as part of its success is a
factor which is actually totally irrelevant. That's probably somewhat how our
own brains operate as well.

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chaosmachine
Perhaps running the learning process multiple times and averaging(?) the
results would eliminate irrelevant motions. Or perhaps the irrelevant parts
are critical to the rest of the movements, and removing them would break
things.

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sesqu
If the motions are truly irrelevant, then yes, they would disappear. But they
could disappear as a function of the number of trials, so anything that still
persists after 50 trials would take a long time to get rid of.

It is general a hard problem in adaptive learning algorithms that they only
produce results. You can't tell the superstition from the intuition.

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johnfn
What's interesting to me is that the robot has a little pan wobble at the end
of the flip. I wonder if that has some sort of advantageous effect on the
outcome of a flip? Or maybe the robot is just 'superstitious' because it had a
more successful run once when it added the wobble.

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Terretta
From the Vimeo description:

> _"After 50 trials, the robot learns that the first part of the task requires
> a stiff behavior to throw the pancake in the air, while the second part
> requires the hand to be compliant in order to catch the pancake without
> having it bounced off the pan."_

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sukuriant
The associated article seems to think that 50 steps is a long amount of time
for learning this article. I would argue that 50 steps is nearly no time at
all. Even though a human being may take less attempts to learn, 1) we are
likely taking input from more senses than the robot is about what's occurring
(we sense by stereoscopic sight, feel, etc. The robot may not sense by all of
these.) 2) can apply knowledge from other domains in solving this problem (if
memory serves me, this is part of the Holy Grail for artificial intelligence)
3) may make multiple attempts in our own minds before attempting to perform
the activity physically again.

While I'm primarily experienced in Genetic Algorithms and NNs (so not re-
enforcement learning, so much), 50 steps (or generations in a non-steady-state
GA) is a very short amount of time, and so learning to properly coordinate
multiple degrees of freedom into a successful activity in only 50 steps is, to
me, pretty impressive.

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sprout
I'd say it's pretty impressive even for a human.

We also have the advantage of having some 'physics simulation' software if you
will that lets us do some runs in our head before doing it physically.

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electromagnetic
Our biology is designed to anticipate gravity. Regardless of athletic training
the average person is capable of adeptly throwing and catching a ball.

I work in construction and I regularly throw and catch objects like rolls of
tape - duct tape sized rolls - 18V drills, levels, etc. but it's only when we
throw something light (IE that air-resistance has an effect) and then you
start getting screwed up. We don't expect things to slow down dramatically
when it's thrown or falls.

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ezy
I realize this isn't exactly the point of the whole exercise, but a stiff
pancake that easily slides onto the pan is kind of cheating. :-)

A deformable pancake would make the experiment batter.

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hugh3
If that was a pun, it was awful. If it was a Freudian slip, it was epic.

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msg
You seem to have very high standards for puns, and very low standards for
Freudian slips.

Here is the epic pun you are looking for:

<http://puzzlet.org/personal/wiki.php/KnockKnock/SoThisGuy>

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plusbryan
I'm pretty sure it would take me about as long to master...

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alain94040
Especially if you are blindfolded. Which are the conditions for the robot, I
believe.

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tassl
Even though it doesn't use any learning process, I think that you might find
this video interesting:

<http://video.google.com/videoplay?docid=3757897210640719617#>

The control uses the dynamics of the robot to optimize a trajectory to
increase the weight that the robot can lift.

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Tichy
Next: try pancakes of varying shapes and sizes. I have a suspicion they might
struggle with their approach.

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bfung
Or how about something more challenging... toss the pancake higher, or make
the pancake rotate more rotations when tossed =P

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chengas123
I'm curious if anyone knows why it sounded like there was a jet engine in the
background throughout the video? Was it just a bad recording or was there some
reason why the room had to have a crazy amount of ventilation?

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Spark23
Has anybody found a better link, describing more technical details?

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Lagged2Death
"Artificial pancake." You know, as opposed to the ones that grow on trees.
Great.

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hackermom
"WITH THIS ROBOT, HE PLANS TO ENSLAVE THE WORLD!" _dramatic choir_

Sarcasm aside, I'm sure stressed-out mothers and financiers alike rejoice...

