Alt-BEAM Archive

Message #13611



To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Mon, 17 Apr 2000 22:21:46 -0700
Subject: Re: Try building a robot that tries to avoid getting stepped on.


"John A. deVries II" wrote:
>
> Was Mr. Robinson's challenge. Ben Hitchcock replied:
>
> >Female chickens will stoop down whenever a shadow falls over them, because
> >they think that a rooster is about to mate with them. A shadow cast by a
> >human works just as well as a rooster. I wonder just how 'sure' a robot
> >needs to be?
>
> His last sentence, I think, is a real clue to the situation.
> Wandering off thinking about various technologies is not necessarily
> the right place to start with this challenge.

For sure. Especially when the technology will set you back more than the
cost of a couple of robots.

> Firstly, there isn't a really good definition of "environment",
> "avoid", or, for that matter, "being stepped on".

I went for the unstructured approach :) It's not a formal contest, after
all. Yet.

> Well, what does that take? What behaviors are involved? The
> aggressive manner has been suggested but actually fails -- so
> what if someone gets lots of needles in their foot (silly person!)?
> They still have stepped on the robot.

I suppose if you included some slithery, twisty movement, it might
deflect the impact sufficiently to allow survival -- kinda like a
rattlesnake.

> I think that the behavior that best fits the situation would be for
> the robot simply to Not Be There when a foot comes down.

Certainly. Adding other strategies, such as a sudden loud noise that may
delay the footfall and provide a little more maneuvering time will help,
but not being there is the optimum.

> The truly bizarre imagination might think of "BEAMing" the robot
> (sorry, just couldn't avoid the pun) somewhere else ...

:)

> ... Generally speaking, the early warning method would cause the
> robot to flee from ANY change in its environment presuming it could
> figure out the direction of the change and this is pretty wasteful
> of energy.

There's also the probability that it will become overstimulated and lock
up, incapable of moving at all. Kind of like "Lobster".

> ... Using just a little bit of digital logic (rather similar to
> what I was talking about in that other huge note way back when)
> Jon was able to come up with a behavior that is very nearly a
> solution to Bruce's challenge...

So can we do it with Nv and Nu neurons? Better perhaps??

> So... with the addition of a single sensor and a teensy bit of digital
> logic the robot was enormously more "adept" than a simple photovore.

The simplicity of that single extra sensor is wonderful. Now I need to
go and improve on the digital logic :)


AND TurtleTek@aol.com wrote:

> ... What qualifies to me as a BEAM bot is a solar powered one...

This is something I noticed when I first joined the list. There are two
schools of BEAM, one oriented to solar applications (mostly wheeled or
fixed in place), and one oriented to walkers (mostly driven by
microcores, bicores, etc). Of course there's the whole spectrum in
between, and there are some people who have a foot in both camps.

For the record, I see BEAM as pertaining to Solar power AND/OR nervous
nets AND/OR other analog mechanisms, with room for a little assist from
CPU's where nothing else works. NOTE: "assist", not "replace".

Anyway, the challenge was for fun and mental stimulation, and so far it
seems to be accomplishing a bit of both.

Bruce



13612 Tue, 18 Apr 2000 15:55:19 +1000 idea... "leif_ 74"
> Lightning just struck my brain. (That must have hurt) - Hook
>
> I just got an idea. A cheap _simple_ infared beacon. There probably is an
> idea (or a million) like this, but I want to know how to do it. I know
your
> probably saying yeah, like what does this have to do with BEAM? I could
make
> a walker (based on a microcore) that tracks the beacon. It would function
> like a regular walker, except when you turned on the beacon (by flipping a
> switch) it would become beacon-tropic :) Input please. Thanks for
listening
> to my pathetic rambling,
> Eric
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>


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13613 Tue, 18 Apr 2000 16:56:14 +1000 [alt-beam] solarbotics solar panels? alt-beam@egroups.com Joe Tochka [SMTP:eyor@beld.net] Here is solarbotics' description of the SC2433 solarcell:
"
Solar Cell - SC2433 24x33mm Competition-grade Sunceram Solarcells producing
2.7 volts (open circuit) @ 16mA (short circuit)2.7 volts in noon sunlight.
Perfect for you ambitious Solaroller racers who want that extra edge in the
competition!
"
and here is the description of the sc2422:
"
Solar Cell - SC2422 24x22mm Standard Sunceram Solarcells producing 3.5
volts (open circuit) @ 6mA (short circuit) in noon sunlight.
"

Does the latter actually produce more voltage than the larger, first one?
because the second one is smaller and cheaper, but it says it produces .7
more volts.

Also, (no offense dave), does anyone know of anywhere else that I can buy
solarpanels from??
Thankyou very much.

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