

BugJuggler: plans for a 21 m tall robot that juggles cars - unwind
http://www.bugjuggler.com/

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chrisBob
We had a hydraulic accumulator in the machinery for making MDF at work, and it
scared the crap out of me. Priming it involved filling the reservoir with
roughly 10 standard high pressure nitrogen bottles, and then compressing that
further. The basic idea is that it is an air spring that you use to store
energy.

I am ok with sitting in the stands while cars fly through the air, but I am
not comfortable knowing that these three guys are going to make a big
breakthrough storing that much energy, in a very unstable form and then put it
near paying customers.

I have no problem believing that the first stage of the project can work, but
this is the sort of thing that won't scale that well.

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mikkom
Sounds safe.

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nodata
Hmph. Unless it can roller-skate too, I'm not interested.

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zardeh
As a reasonably proficient juggler and a less than reasonably proficient
roboticist:

The only functional juggling robot at any scale is housed inside a case and
doesn't use an arm, it can juggle at exactly one width, and doesn't use any
form of complex reverse kinematics.

There isn't any kind of "arm" on any scale that is currently capable of
juggling (that I've seen anyway). Some get close, but the only videos are of
slower forms where they get assistance from people or interact with people.

That also entirely ignores the physics of the situation. To get a 1000kg car
to move up the 8 or so meters from catch to head height, and then catch it
again, the forces are enormous. You'd need to apply nearly 80K newtons of
force over a second or so to slow the object down on the catch.

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abcd_f
Not built yet.

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unwind
True, I edited the title to make that clearer and less click-baity. Thanks.

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markild
Though an interesting concept, from an engineering perspective, this sounds
like a horribly bad idea.

Also, the project page doesn't seem to clearly get across how incredibly early
stage it is. Their 8ft small scale robot arm is still conceptual...

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jack-r-abbit
What a joke. Their "prototype" video even says "Robot arm imagery is computer
generated." How is that even a prototype?

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StavrosK
That "haptic interface" is never going to work. How can you juggle without
feeling your hands?

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tlb
It's extremely hard at human scale. I worked on building human-sized walking
robots, initially with hand controls, and I couldn't learn the eye-hand
coordination needed to make it balance. Juggling is similar to walking in
terms of speed and complexity of feedback.

However, the fact that it's so large means the time constants are longer. At
10x bigger than a human, each juggle should take sqrt(10) as long. So maybe
it's possible to do with entirely visual feedback.

