Subject:
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RE: Antenna Bumpers/Insects
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 4 Dec 1998 16:48:23 GMT
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Original-From:
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Gary Kacmarcik (Exchange) <Garykac@Exchange.!ihatespam!MICROSOFT.com>
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Viewed:
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2765 times
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insects can indeed move backwards, although perhaps not in the way you're
imagining.
--- more info than you probably care to know about roaches ---
most hexapod robots hard-code a "tripod gait" on their robots, where the
first (prothoracic) and last (metathoracic) legs on one side are always in
sync with the middle (mesothoracic) leg on the other side. the gait is
quite stable, but it is far from the only gate used by real insects. for
example, when running roaches will use a gait where only 2 legs are on the
ground at a time. (and, their locomotion system is robust enough to adapt
when legs are missing.)
in addition, note that each of the three pairs of legs on a roach is quite
different in structure from the other legs (as opposed to the typical
hexapod robot which use the same leg structure for all 6 legs). very
roughly speaking, the metathoracic legs are larger and used for thrusting
forward, the mesothoracic legs are used to control direction, and the
prothoracic legs are smaller and are used for balance.
to move backwards (for example, when the roach detects something approaching
from the front), the roach will crouch backwards with the rear 2 sets of
legs while steering to the left or right with the middle legs (the front
legs don't seem to do much here). then the roach will push forward while
continuing the steering with the middle legs. this isn't "walking
backwards", but it is moving backwards to change direction.
(note: it's been a while since i've followed roach-research (it's not
terribly relevant to my current job), so it's quite possible that biologists
have figured out more details of cockroach locomotion than i'm aware of.
please consider the above comments to be a rough description, and don't make
any financial investments based on it. ^_^)
not surprisingly, this is somewhat off-topic. non-robotics-related
questions/comments should probably be taken off-line.
--- end of roach info ---
so, what's the point of all this? your robot hardware is going to be so
different from a real insect's "hardware", that it's not worth worrying too
much about differences in "software" (should i bring up "firmware" at this
point? ^_^).
techniques that serve the roach well may be worthless to a robot-builder
(and vice-versa). so, make your robot walk backwards if that solves the
problem at hand.
-gary "roach boy"
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Gary Kacmarcik
Natural Language Processing Group
Microsoft Research
garykac@microsoft.com
-----Original Message-----
From: Vaan, Howard [mailto:howard.vaan@csfp.co.uk]
Sent: Friday, December 04, 1998 4:57 AM
To: 'lego-robotics@crynwr.com'
Subject: Antenna Bumpers/Insects
I've just made a simple bot with the antenna-like config in the
Constructopedia + implemented the simple touch>stop motor algorithm.
One problem the robot has is with table/chair legs and the like - the bot
wanders straight into it and then can't escape because the antennae make it
continually steer back into it.
OK - I know plenty of ways to fix this, from a HW or SW point of view . . .
that's not the question.
How do real insects with long antenna manage this problem? Can they walk
backwards? I don't think so . . .
(We don't have many large roaches here in the UK that I can observe)
Cheers,
Howard
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Message has 1 Reply:
 | | Re: Antenna Bumpers/Insects
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| Hey, I vote that gait discussions are definitely *on* topic - a lot of my thought about LEGO robotics in the past has related to mobility! But on a different tangent - what would be needed to run a neural net on an RCX? What kind of processing model (...) (26 years ago, 5-Dec-98, to lugnet.robotics)
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