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Subject: 
Re: Seeking Strategies on Humanoid Robots/Walkers
Newsgroups: 
lugnet.robotics
Date: 
Mon, 4 Jan 1999 22:43:42 GMT
Viewed: 
1867 times
  
My untested theory for the balance issue involves a Lego Gyroscope to maintain
the balance. I have yet to complete the design of the Gyro, but I will.. If the
Gyro were small and light, you would need a high rate of speed (20k+RPM?) to
maintain the balance on s <24" model with a weight of under 5 pounds. Sorry I'm
no physicist, this is conjecture and a bit of my own horribly unscientific
expirementation. With a lower RPM the Gyroscope itself would likely weigh approx
25% of the total wieght of the model in order to maintain the balance. I have
also hesrd conjecture about a dual gyroscopice method, involving seperate
unrelated Gyros operating in planes which would intersect at 90 degrees. The
dual Gyro method varies from using a verticle/horizonta pair to using a pair
offset from vert/horiz by 45degrees such as \ /
I have not had time or parts to test these effectively. Altough I intend to
attempt a lightweight higspeed Gyro soon.

Another idea I had (totaly untested involved a body which had approx 1/3 of it's
weight ditrbuted to be outside the legs and invoolved a moving belt with a
weight which would shift from from side to side, creating a balance..this has a
LOT of problems.
My third I dea is a wieghted pendulum which is controled by the drive motors to
shift it's weight to the outside of the leg which is down, thus counterbalancing
the body dynamically (kinda the why us humans do when we shift our torso to
balance on one foot).  I believe that we use slighter, less noticed motions when
we walk.  This is a hypothesis on my part based on watching my children as they
try to learn how to walk...

Personally I think that for a robotic implementation the weighted Gyro spinning
perpendicular to the legs (paralell to the line of motion) will likely be the
answer. This would require either a large torso or large hips.

I have messed with this quietly, in my spare time for 2 years. I have not found
a single static weight model which survived my series of tests.

Just my 32 cents.(1)

Andrew Phelps wrote:

Well, that is the million dollar question, so to speak :)

There really is no predetermined requirement that says the figure HAS to be
humanoid, so I suppose a four or six legged creature (or even a creature
with no legs) would work just as well, and could even be a more traditional
"rover" or other wheeled vehicle, but it would be very cool to do a
humanoid.  Thus the original subject of this thread, to which no one has yet
posted.  Am I to assume then that no one on this list has done this ?  Let
us call it a challenge then, to see if it CAN be done !  In theory, you
should be able to weight it correctly such that it will walk on 2 legs, but
theory is always so abstract...

Andy
RIT
This sounds very cool - but ... how will you stop it from falling over?

Cheers,

Ben.

--
Did you check the web site first?: http://www.crynwr.com/lego-robotics

--
Technical Support requests should be sent to support@opendisc.com
Joe Greene
Technical Support
OpenDisc Systems, Inc.
Boulder, Colorado, 80301-2442 USA
303-546-0460
Joe_Greene@OpenDisc.Com

(1) I know it should have been 2 cents..but once I started it just kept spewing
out.



Message is in Reply To:
  RE: Seeking Strategies on Humanoid Robots/Walkers
 
Well, that is the million dollar question, so to speak :) There really is no predetermined requirement that says the figure HAS to be humanoid, so I suppose a four or six legged creature (or even a creature with no legs) would work just as well, and (...) (25 years ago, 2-Jan-99, to lugnet.robotics)

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