Alt-BEAM Archive

Message #06559



To: beam@sgiblab.sgi.com
From: JVernonM@aol.com
Date: Sat, 9 Oct 1999 16:16:17 EDT
Subject: [alt-beam] Re: Reversing walkers


In a message dated 10/9/99 4:02:08 PM Eastern Daylight Time,
jester96beam@iname.com writes:

> Ok, now I'm confused. What is so great about making a walker reverse if it
> bumps into something? No, it's not that obvious to me, since when it start
> going forward again, it would bump into the same thign.

I've asked myself the same question.

> Ian has a schematic of an "almost complete walker" that can reverse. Doe
it
> turn as it reverses or something?

I don't think so. You can make a 2 motor walker turn in reverse by making use
of an intentional imbalance, but it's tricky at best. If you noticed the
little walker Tilden built on the latest robot show, it reversed straight
back when hitting an object, but the reverse gate caused a slight drift to
the bots left. This would cause a walker to eventually get around something,
but again, it's hit and miss. My point was only that my customized toy walker
is as agile as the most complex two motor walker and it uses one motor.
Mechanics allow the thing to be as capable as a walker with twice the
actuators. Just food for thought.

> How would you make a 2 motor walker turn? I know you change the center of
> the leg's gate (or something like that) but what would the circuit be like
on
> a master/slave bicore walker to make it turn towards light?

It's very difficult, and usually only slightly effective.

> Another question - to make a walker solar powered, do you just use a PM1
SE
> and wire the output wires to the power leads of the walker?

Yes, basically that's it.



See ya,
Jim
http://www.geocities.com/SoHo/Exhibit/8281/beamart.html



6560 Sat, 09 Oct 1999 15:06:33 -0700 [alt-beam] Re: Reversing walkers beam@sgiblab.sgi.com Sean Rigter The moment the walker reverses is not synchronized with the forward leg motion
and as a result the some turning will generally occur while reversing before the
legs center themselves. Similarly when switching back to forward motion there is
a high probability that the first few steps randomly steer away from the original
path.

Saved by chaos!

regards

wilf

JVernonM@aol.com wrote:

> In a message dated 10/9/99 4:02:08 PM Eastern Daylight Time,
> jester96beam@iname.com writes:
>
> > Ok, now I'm confused. What is so great about making a walker reverse if it
> > bumps into something? No, it's not that obvious to me, since when it start
> > going forward again, it would bump into the same thign.
>
> I've asked myself the same question.
>
> > Ian has a schematic of an "almost complete walker" that can reverse. Doe
> it
> > turn as it reverses or something?
>
> I don't think so. You can make a 2 motor walker turn in reverse by making use
> of an intentional imbalance, but it's tricky at best. If you noticed the
> little walker Tilden built on the latest robot show, it reversed straight
> back when hitting an object, but the reverse gate caused a slight drift to
> the bots left. This would cause a walker to eventually get around something,
> but again, it's hit and miss. My point was only that my customized toy walker
> is as agile as the most complex two motor walker and it uses one motor.
> Mechanics allow the thing to be as capable as a walker with twice the
> actuators. Just food for thought.
>
> > How would you make a 2 motor walker turn? I know you change the center of
> > the leg's gate (or something like that) but what would the circuit be like
> on
> > a master/slave bicore walker to make it turn towards light?
>
> It's very difficult, and usually only slightly effective.
>
> > Another question - to make a walker solar powered, do you just use a PM1
> SE
> > and wire the output wires to the power leads of the walker?
>
> Yes, basically that's it.
>
>
> See ya,
> Jim
> http://www.geocities.com/SoHo/Exhibit/8281/beamart.html

Home