Alt-BEAM Archive
Message #08395
To: beam@sgiblab.sgi.com
From: owner-beam@sgiblab.sgi.com [mailto:owner-beam@sgiblab.sgi.com]On
Date: Sat, 18 Dec 1999 16:24:38 -0500
Subject: Re: Bi ped
Hi
> yeah, you are going to need *at least* 10 motors to
> make a biped walker that can actually walk.
I'm watching a movie of a 4 motor biped walker walking fine right now so it
isn't "required" but if you want more maneuverability to turn and stuff your
going to need more.
> Say you want the bot to lift one leg while standing.
> You are going to have to shift the center of gravity
> 'COG' over the foot that is still planted on the
> ground. This is where your original pic that you
> posted fails. you have no DOF to accomplish this
> shift.
Um, no. Not from what I see. I have a side-to-side motor in each ankle. Just
turn that and raise the opposite leg and it will rest one leg. Then you are
able to lift the leg and move it around. Keeping the balance using the ankle
motor and hip motors of course.
> You are also going to need an impact cusioning motion at
> the knees for the leg as it plants, or your bots steps
> are going to be so sudden and jarring that it's going
> to bounce itself right onto it's back.
Maybe a couple springs in the heal?
> Now in order to stop it has to be able to shift the
> COG slightly back in order to slow down and counteract
> the forward momentum.. all while still shifting side
> to side and taking steps.
Yikes, well I've got some work cut out on the programming sensor electronics
side =)
> Now all this has to be done while dynamically keeping
> track of the balance of the bot, or it's going to fall
> over all the time. And you plan on doing this with a
> *Basic Stamp*???
That was my first thought. I'm going to give it a try.
> I dunno.. I don't want to rant about this too much..
> Honda has done an amazing thing with thier humanoid
> bot, in that it walks fairly closely to how a human
> walks..
Anyone got a million dollars for me to spend? I'm working more in the $100
range.
> The MIT little dinosaur bot can't even walk yet as far
> as I know.. all it can do is stand itself up from a
> crouch and then go back to a crouch. And they seemed
> pretty ecstatic about it....
That things pretty complex. Their other biped bots and do flips and stuff on
the other hand. Pretty cool!
> IMHO, you'd be better off spending your energy
> elsewhere.. There are plenty of exciting things to do
> in hobbyist robotics research.. Let the big
> orginazitions throw money at making bipedal walkers..
Your probably right but I'd like to at least give it a try. If I can at
least get it to stand up and balance I'll be happy.
Thanks for the info. You gave me lots of ideas.
Laterz
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