Alt-BEAM Archive

Message #08342



To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Fri, 17 Dec 1999 20:23:28 -0800
Subject: [alt-beam] Re: Bi ped


Ian wrote:
>
> Hi again, I'm in the design phase of a new walker
> I have planned. It's going to be a biped walker
> (see attachment) ...
>
> ... I am sort of leaning towards a BS2 for control
> and adding BEAM in for some stuff. Not sure what yet.

Hi, Ian.

Think about stability, from the ground up. Doesn't matter if you're
talking about static or dynamic stability.

The feet have to conform to the surface as they come down. Spring loaded
feet won't be enough, but you might want some very slight spring motion
between the foot servo arm and the foot itself. Consider sensors that
detect when one edge of a foot is about to touch down, and then use them
to control the angle of the foot. You could use Nv/Nu circuits to do
that, just as the human body takes care of such things at the spinal
level. Your control system might anticipate the angle and adjust the
foot accordingly, but I promise, you'll need that final feedback for
fine-tuning.

To some extent, you may be able to carry this idea up to the next level
of joint. Beam sub-systems, controlled or over-ridden by a high level
controller.

BTW, in your walking experiments, have you tried to keep your ankles
absolutely stiff in the fore-and-aft orientation? Your design only
allows side-to-side motion -- pretty hard to mimic on a human ankle. Try
it. It sure ain't easy.

Bruce



8343 Fri, 17 Dec 1999 23:13:17 -0500 [alt-beam] Re: BEAM Flocking (HPV) "Richard Caudle" > And then there's another question, that i always ask myself: What's the
> point? Okay, so say we get a flock up and running, with everyone
> supporting eachother, no one dying. So what? Wow we'll get to look at
> it. WE need a purpose! What are they doing?
>
> So, that's my whole 2 cents.
>
> -Kyle


A fair question and one that has been asked me by countless people who view
my work.

It's a developmental step. The flocking behavior is the first in a series
of steps toward a "useful" BEAM robot. When we get them to interact, then
we can get them to perform tasks. Clean the floor is one thing that
springs to mind. Imagine a herd of these critters sweeping your kitchen
floor, or picking up your LEGOs! Self-cleaning house, anyone?

Richard


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