Alt-BEAM Archive

Message #02279



To: beam@corp.sgi.com
From: Terry Newton wtnewton@nc5.infi.net
Date: Tue, 13 Apr 1999 12:43:17
Subject: [alt-beam] Re: CPU again? (was Beam genome)


At 07:46 PM 4/12/99 -0700, Bob Shannon wrote:

>[snip]
>I beleive that BEAM construction and design methods will advance
>robotics, but
>I cannot accept the idea that Tilden's BEAM approach will ever comppete
>with CPU
>based robotics. The difficulty is designing and evolving a hardwired
>controller
>can only be justifiable if the end result is sufficiently superior to a
>CPU based
>design.

Practically speaking, true... but how pray tell would one program
a Symet that works better than a real one? I look at like this: if
the robot only needs a handful of fixed responses (or even one) then
no cpu is needed or desired. This covers most beam robots. A middle
ground is when the fixed responses needed would require lots of
circuitry, then it is convenient to replace many chips with one
cpu chip. Then there are things like reenforcement learning, mapping
etc that can only be (practically) achieved by using a cpu. Unless
you want to lug around dozens of chips. Some advanced stuff can be
hardwired but be prepared to lower your standards! I still want
to try a static ram hardwired RL brain though... my experiments
indicate that a 16 memory brain (4 address lines, two feelers,
left > right and right > left light) with very simple learning
rules works darn near as good as 64 memories with every trick
I know to throw at it. Would take about 6 chips. If I built it,
the only reason I could use to justify why I didn't use a cpu
would be "it's a learning machine that doesn't use a cpu".
Hmmm... I detect some macho-ism there. BUT someone else could
easily justify hardwiring because for them getting the necessary
programming equipment and knowledge would be much more expensive
than a half dozen stock chips. Unfortunately, since I did happen
to take the time to be able to do that stuff I do not have that
reason. It's hard to motivate myself to make a simple hardwired
net when I know I can program a single chip to do magnitudes more.

Whew! there I said it. I think... In short, if you solder, keep
soldering there's nothing wrong with it. If you want more than simple
responses, learn how to use micropower cpu's, it ain't that bad.

>This simply is not the case at all, a CPU can do everything a microcore
>can do,
>and then some. The first 'living machine', will have a CPU. Probalby
>more of
>them than the original Walkman has transistors.

:) that ought to draw some arrows... I am not convinced of this.
Actually computers are too sequential and deterministic to achieve
the necessary decoupling from reality to become "alive" in any normal
sense of the word. Some sort of quantum arctitecture will be needed.
However simulating life is good enough for me, cpu's can do that.

Defending the microcore and (hardwired) neural nets in general...
there are things going on in there that cannot be adequately simulated,
and if quantum-(un)determinate noise influenced the neuron threshholds,
you'd have the basic mechanism by which quantum consciousness could
arise, at least to the complexity the architecture can support.
Do you know what your coupled bicores are thinking about?

>But there is more behind the lack of science here. Without measurments,
>we cannot
>test the basic concept behind BEAM at all. Just how does it compare to
>implementing
>a stim/response based network with a CPU?

Depends on the test! In a static non-changing environment then a
hardwired network (be it real electronics or hard-coded cpu responses)
just about always does better. In a variable environment then some
kind of adaptability will increase the score. Imagine this... what
if a robot gets hung up in a way that would require an opposite motion
to free itself. A hard-wired robot would never know to try another move,
but a learning robot would notice that the move isn't working and would
try other moves until something worked. However in a race the hardwired
(or hard-coded) 'bot wins every time.

>(No, a stimuli/response system running on a CPU is not "BEAM", just ask
>a lawyer.)

Cool. We can sell it :)

>[snip]
>
>If we want to evolve a living machine, we need to adopt a standard
>platform.
>
>I think something along the lines of Terry Newton's PIC BOT II is a good
>starting
>point. Rather than have many people investing many hours into learning
>how to
>free form the same six transistors, we should invest time into
>developing new sets of behaviors for a standard platform.

Uh oh... I feel a layout coming on...

>Of course we would also have to have competitions, to test which sets of
>behaviors were superior to other sets. Identical platforms with
>different behavior sets could be placed into an arena (not a park) and
>observed. Simple timed trials common in animal behavior experiments
>could be used similar to the firefighting contests.

I've gotten a couple requests for kits, if I could sell at least a
dozen or so it would pay for the circuit boards and development.
The programming port would double as an external sensor port for
user-defined tasks (already is just haven't done anything with it:)

>Has any BEAM design ever entered one of those? How did it do? How
>would we know?

Well... I don't think my poparound picbot would do so well either
unless it had a battery and big motors.

There's room for both, it all depends on what you want your
robot to do, and whether you prefer solder or code. Using a
pic or other cpu is a design decision that is getting harder
to ignore all the time. They're out there. While not required
or for everyone, it should come as no surprise to see them
being used in robot designs once considered "beam". Cpus just
got good enough to use in tiny low powered robots.

Once a critical threshhold of users is reached the heckling
will die down. There should Always be access to traditional
beam designs for newcomers and those who wish not to program,
but once people start using cpus and stuff they'll need a place
to talk about it. Although some argue that this is off-topic for
this list, there is no other place one can go on the internet for
robotics that emphisise efficient, solar powered small practical
autonomous robots. The newsgroups are a joke. People trying to
run Linux on their robots... sheez. I much prefer it here
where a bug can be just a bug.

Terry Newton


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