Alt-BEAM Archive

Message #04896



To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter Wilf.Rigter@powertech.bc.ca
Date: Sat, 26 Jun 1999 23:09:42 -0700
Subject: [alt-beam] Re: Feed Back


Hi James,

Although "fight or flight" sounds a bit high on the evolutionary curve
(ouch!) for BEAM bots, nevertheless changing feedback from positive to
negative can change behaviour ie phototropic to photophobic which =
could be
a form of fight or flight if bots carried light beacons. I am =
experimenting
with feedforward systems in the form of coupled oscillators which cause =
a
number of motors to react in a wavelike motion for undulating snake =
bots.
The motion of these can be a gentle ripple or can be strong whipping =
and
curling when "overstimulated". There is no adrenaline, emotion, or =
resonance
but there is a kind of electronic afterburner (figuratively speaking) =
that
can give the bot some extra kick when it is in a bind. As for =
"cornered
with an opposing bot staring it down" well ...... Anyway you did give =
me
some ideas and with evolutionary pressure on beam designers from all =
sides,
every year BEAM bots had better start giving double performance with =
half
the parts count or they will be left in the dust.=20

regards=20

Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493=20
fax: (604)590-3411

> -----Original Message-----
> From: James Wilson [SMTP:jameswilson1@home.com]
> Sent: Saturday, June 26, 1999 8:33 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: Feed Back
>=20
> I like the unpredictability of the positive feed back loop created. =
The
> question is could you create a situation where the feed back goes =
super
> critical i.e. hits resonance and in a mathematical sense blows up! =
Could
> this be used as an adrenaline gland for the bot? What actually =
happens to
> the current flowing will it hit resonance could with the proper =
amount of
> damping create the flight part of fight or flight instinct? Could it
> create
> the fight part of the instinct if say it were literally in a corner =
and an
> opposing bot were staring it down? I wish I had the expertise and =
the
> time
> to follow through with the appropriate experiments. But I know some =
one
> who
> does...Wilf? does this interest you?
>=20
> Jamws Wilson :-))
> ----- Original Message -----
> From: Bruce Robinson
> To: ; James Wilson
> Sent: Saturday, June 26, 1999 7:57 PM
> Subject: Re: Feed Back
>=20
>=20
> > James Wilson wrote:
> >
> > We use IR. detectors to make our bots photo tropic right? And we =
tend
> > to use visible light emitting diode to indicate the direction of =
the
> > light source for our own amusement. So what if we positioned an IR
> > emitter @ 90=B0 to the receiver and place a first surface mirror
> > (polished metal) at 45=B0 between the two and wired it to a) =
Positively
> > feed back into itself or
> > b) Negatively feed back into itself
>=20
> I think you might create a robot that either try to run toward =
itself,
> or try to run away from itself (kind of like my dog during a
> thunderstorm -- she just runs). That is, if you attached the mirrors =
to
> the robot.
>=20
> Now, what if you attach the mirrors to walls and obstacles? Or even =
more
> interesting, what if you make a bunch of these and attach outward =
facing
> mirrors to the 'bots themselves? Robot pinball!
>=20
> Seriously, with some fine tuning it would be an interesting way to
> create a collision-avoidance system.
>=20
> Take care, and above all else, have fun,
> Bruce

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