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Subject: 
Re: an idea, can someone tell me if this is possible/been done before/etc?
Newsgroups: 
lugnet.robotics
Date: 
Wed, 3 Dec 2003 00:55:44 GMT
Viewed: 
1444 times
  
In lugnet.robotics, Jim Choate <ravage@einstein.ssz.com> wrote:
On Tue, 2 Dec 2003, Kevin L. Clague wrote:

Please explain what you mean by legs having symmetry and it is silly not to
use that here.  I'm not often called silly with regard to my LEGO models.

Symmetry is when something 'balances', it's a kind of equilibrium. Let's
look at a six legged walker for a moment and see what sort of symmetry it
has.

First off we have six legs and many of them (at least three in the right
location) must stay on the ground while the others move. If not we don't
have -dynamic- balance, the thing falls over. This is called the 'triangle
gate' and is the bedrock of 6-legged designs in general. 8-legged designs
tend toward 4-way gate. Which brings up a big advantage of 8-legged. If
you lose a leg then you can probably work out a gate. If a 6-legged one
loses a leg it's in a heap of trouble.

True.


The fact that one set moves in alternation with another set is the other
sort of symmetry that a walker has. That symmetry is what allows it to
move. It's worth noting here that this sort of symmetry is -not- a
requirement for motion. It quite possible to build walkers that don't have
legged symmetry. Most animals when moving over rough ground give up a lot
of gate symmetry.

I didn't call -you- silly. Might want to re-read that. And if you're
claiming to never had a silly or stupid idea....

I was just picking on you since you've spent your day publicly humiliating
people (dripping with sarcasm :^)

I have plenty of silly and/or stupid ideas.....  Some of them lead to really
great ideas.


Every day I think I haven't made a mistake, I've found my first of at least
two. I've accepted the fact that the 2nd law of thermo means that every
idea I or anyone else has will be flawed.

No doubt.  Flaws are a reality.


It is my understanding that using LEGO, dynamic balance has only been
acheived by Steve Hassenplug's LegWay and models similar to it.

Um, all I can say is that is wrong. I've seen bipeds as well as 4/6/8
leggers have both dynamic balance. -Any- model that moves and doesn't fall
over or fail in some other way has dynamic balance. If it will stand up
while standing still then it has static balance.

My fault.  I didn't really know the definition.  All my successful walkers have
dynamic balance.  It is built into the walking mechanism.

Steve's two wheeled vehicle is self balancing like a Segway (I thought this is
what you meant.)  Ignorance showing here.


I'm not familiar with Mr. Hassenplug's bot's however.

I understand.  I am also an engineer. Notice that very few of my robots have
decorative parts.

I'm a physicist, not an engineer. $$$ makes me do engineering ;)

I'm happy they pay me to be an engineer because I'm not a very good physicist
;^)


Blockage is not something I've studied at all.

I probably spend 75% of my design time figuring out how my 'stuff' (not just
robots) will/can fail. I tend to put it in the boundary conditions and
then bang on it really hard. If I run out of ideas, I can try to find
small kids to talk to about it or let them bang on it ;) When I used to
work in a science museum that part was easy, just take whatever in on Sat.
and put it on the exhibit floor. If it lasts all day it's done.

Nothing more stressful than showing it to others.

I often evoke the first rule of frisbee:  "never say anything more predictive
than watch this!"

At work my job is to make other peoples computer designs fail.  It makes my
brain tired after a while.

Lately I've been trying to make walkers that have something other than two
groups of feet that are 180 degrees out of phase.

If you are interested my walkers are here:

http://www.kclague.net

Do you have a web page I can look at.  I'd bet you've got some very interesting
robots.

Kevin



Message has 1 Reply:
  Re: an idea, can someone tell me if this is possible/been done before/etc?
 
(...) There's no fault involved from my perspective. The idea is to have fun. You can't do that without some sort of risk (at least I've never experienced 'fun' without some risk). The problem comes when people mix emotion/ego with curiosity. Very (...) (21 years ago, 3-Dec-03, to lugnet.robotics)

Message is in Reply To:
  Re: an idea, can someone tell me if this is possible/been done before/etc?
 
(...) Symmetry is when something 'balances', it's a kind of equilibrium. Let's look at a six legged walker for a moment and see what sort of symmetry it has. First off we have six legs and many of them (at least three in the right location) must (...) (21 years ago, 3-Dec-03, to lugnet.robotics)

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