Botoxicated! Can a Propeller balance a wine glass for 4 weeks? - Now with Pres

Hanno

Greetings!
I'm getting ready to install DanceBot into a public kiosk in the middle of Christchurch, NZ where it will balance a wine glass for 4 weeks.
I'm making slow progress to start selling this as a kit- let me know if you're interested... (Spin Debugger and ViewPort v4.1 are taking up a bunch of time, but are in last beta stages)
www.physicsroom.org.nz/kiosk/2008/montejo/
Hanno


Post Edited (Hanno) : 12/22/2008 11:56:11 PM GMT

ElectricAye

Personally, I'd rather see it try balancing the US budget.

It is looking mighty spiffy, though. Yet, I dare say that if it merely stands in one place and doesn't move around, a lot of people might just think it's glued to whatever you have its tires setting on. And they might think, therefore, that it is not a quasi-living thing, containing a little bit of your ghost in its machine. Maybe you could have it drive around so that people can really see what it's doing.
Or consider this: you have a board floating in a trough of very viscous fluid, like silicone oil. It moves to one end of the board, where it dwells and senses how much tilt is taking place, and when the tilt gets to a critical point, it drives itself to the opposite side of the board and makes the board level out (for a while) until that side sinks down below a critical point, etc. If the fluid is a bit sticky, like glycerol or hot fudge, it might even get really funny to watch it running that chocolate fudge sundae from one side to the other, two giant outstretched plastic tongues poised at each end, trying their best to lick off the cherry on top, but alas the endless frustration and futility of it all....

Ah, such is life....

SRLM

I assume that you will have a power cord running to the robot? 4 weeks on battery power and running two motors seems like a stretch. Still, I like it. And, as refinement of ElectricAye's idea, you might be able to do the same thing without a liquid. Perhaps a seesaw type, with the axle geared down to a heavy rotating disk that provides momentum: the same principle applies as with the thick fluid, without the mess.

ElectricAye

SRLM has a good idea about using the geared-down see-saw. You might even have the gear portion drive a fly wheel, and atop the flywheel is a minibot trying to keep atop the wheel and not get rolled off. It could be the high techy version of a log rolling contest, or some kind of dance, piezo sensors embedded in the plastic case in which it is housed, so that the harder the noses of the audience press against it, the faster it rolls around and around.

SRLM

Flywheel! That was the word I was looking for...

Ken Peterson

Seems to me like two-wheel balancing bots need a higher center of gravity than what you might have in the picture. You need a sufficient moment of inertia to balance the torque applied to the wheels. Perhaps if the wine glass is glued to the platform? I assume the wine glass will be filled.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Beau Schwabe

Hanno,

Neat idea!
...as far as "Can a Propeller balance·a wine glass for 4 weeks?" - I have no doubt that the Propeller could do it, however as it has been mentioned, the power required to manage·the unit for 4 weeks might be a difficult task.· That said, if the wheel diameter is increased so that you can move·the center of gravity "below" the wheel axis, it wouldn't require any power at all to balance the wine glass.· The only power required would be to move from one location to the next.· In this case under careful power management it could last 4 weeks but would depend on how often you wanted it to move.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

n45w73

How about a stack of batteries with a chocolate piece on top instead of a glass of wine !

It might solve your problems, the stack of batteries will give you power for a long time and will make the bot unstable.
And the chocolate will taste good after 4 weeks if it work !

Ken Peterson

Way to think outside the box, Beau!

n45W73: One could still use a wine glass on top of the battery, but it may have to be taped down

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Nick McClick

I think it's an art piece, the whole point is to transpose & contrast the machines vs. people with an endurance test previously only done by people. Maybe it's about how machines do things better than people, or how our original measures of people have now been replaced or augmented by technology.

That said, I would just lower the CG, add some wires to make it look like a robot & call it a day. Since the display will be static anyway, it's not really like anyone will be able to tell. And you'll still get your message across. Looks pretty cool, though!

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RiJoRi

Looks good, but it MUST dance about to get people's attention. Otherwise it's just a piece of metal standing there: a VERY expensive table! Red wine will add some interest and color; red water would also do. Even wilder would be layers of colored liquids -- I saw that in a photo book -- they used different liquids to get differently colored layers.

And, consider lighting the glass from the bottom for some drama.

--Rich

Hanno

Thanks for all the replies! Was away on a short trip to Lake Tekapo - far away from civilization, did manage to integrate OpenCV with ViewPort- more on that later...

No- it will not balance the budget. However, it does work- at least in my office, with it's current dimensions as pictured. Very stable, with or without wine. It uses a camera to keep track of where it is relative to a "Southern Cross" on the floor (I'm in the southern hemisphere). It is an art project, but also feasibility study of the DanceBot hardware. It's powered by a thin, flexible cable connected to a battery that's trickle charged. I considered solar/inductive but the project is complicated enough. Interesting ideas about different colored fluids, seesaw, flywheel!

It's not a static display- it will dance.
Hanno

SRLM

So, if it dances, are you going to program it not to run over it's own cable, or some sort of clever mechanical solution?

Hanno

The bot has big wheels, the cable is thin and strong. The Kiwi attitude sums it up nicely "She'll be alright...."
Hanno

Hanno

So far so good! After showing of the robot at the local robotics club, kiwibots.org Gaby (my sculptor friend) and I installed DanceBot into the display case last Friday in streaming rain. Some last minute adjustments and then we left DanceBot alone- to balance a filled champagne flute in a street kiosk for the next 4 weeks. Here's an article from the Press: www.stuff.co.nz/thepress/4801688a26834.html How long will it go???
Hanno

SRLM

You should put in a webcam on the display case (or around it) for those of use who can't make it to New Zealand (or at least some picture... [noparse]:)[/noparse].

Hanno

Got some photos, more on my website: mydancebot.com/kiosk
Going ok- had a problem with the wallwart transformer which blew out after 2 days, now replaced with a new one... Great attention getter- even in a busy city it attracts quite a few people...

ElectricAye

Just curious: If you drive the wheels in opposing directions, the robot will spin around. So how fast can you make it spin and remain stable with that glass on top?

pgbpsu

Hanno-

I know you've been busy with the debugger and many other things, but when you have a chance could you update us on how the exhibit went? I see around Christmas there was trouble with the power supply. Once that was solved did your robot, manage to stay on its feet?

Just curious,

pgb

Hanno

Hi pgb!
Thanks for asking! It was quite a challenge exhibiting a complex robot in a hot, public space. Did I mention that it was hot? On a few days the temperature outside the plexiglass greenhouse with halogen lights hit 35'C! I believe this caused an intermittent loose connection in one of the quadrature encoder connections. For a couple days we would find dancebot lying down looking quite sad with his champagne spilled on the floor- must have a had a rough night! (Since the encoder was only registering 1 part of the signal, the robot would get confused and finally run into a wall) Finally, I hooked up ViewPort's LSA to the bot and wiggled all the connections. It was easy to see that one of the traces fell out every now and then. Having found the fault it was easy to fix it. Now I know why they "bake test" electronic products. Other than that it went quite well, every time I checked on it there were a couple curious onlookers.
Hanno