Alt-BEAM Archive
Message #00846
To: beam@corp.sgi.com, "'Evaristo Westplate'" evaristo@qctechnology.nl
From: "van Zoelen, Bram SSI-TSEA-352" Bram.A.A.vanZoelen@is.shell.com
Date: Tue, 23 Feb 1999 12:35:38 +0100
Subject: [alt-beam] Re: Turning a 2 motor walker - brainstorm mail
So, let me respond to this.
> ----------
> From: Evaristo Westplate[SMTP:evaristo@qctechnology.nl]
> Reply To: Evaristo Westplate
> Sent: Tuesday, February 23, 1999 11:33 AM
> To: beam@corp.sgi.com
> Subject: Turning a 2 motor walker - brainstorm mail
>
> Hi,
>
> The last few days I have been thinking about how to make a two motor
> walker
>
---
Did you read the FAQ's?
---
> turn. Analyzing the walker, it seems impossible to make it turn left or
> right. Different gaits won't work (as far as I can see) and only effects
>
---
Different gaits will certainly work. Its possible to figure out a gait
patron that will turn the walker.
---
> speed and direction (forward/backwards). Turning the legs more CW (Clock
> Wise) then CCW (Counter CW) result in flipping the walker on its side. My
>
---
Not if you turn then not too far to one side. This can be done by some
restriction. There are several examples how to do this.
---
> conclusion is that it can't be done with two motors. Ofcourse you could
> spin one of the motors which will drag the walker in a circle (this was
> meantioned a while back on the list) but it will result quickly in a
> flipped walker (timberrrrrrrr).
>
---
If you contruct your walker en its legs right then this would be the most
effective and fastest way to turn. It require some enginering from your
side.
---
> How to make the walker turn. One motor is used for lift so it can't be
> used
> to turn it ( I have the walker configuration of Chiu-Yuan Fang in mind).
>
---
Why not?
How far you lift one leg determine where the leg will drop next time that
the walker gets a push. This can turn a walker.
---
---
> The other motor provides the push. Now if the legs could push more in one
> direction then an other direction, the walker would turn as it moves. Hmmm
>
> OK so lets look at three motors. Push, lift and turn. The third motor
> could
> be mounted in the waist and rotate the front left or right. The walker
> will
> probaly become a bit unstable will turning due to the shifted point of
> gravity. Are there people have have made these types of walkers? If so,
> how
> did it perform? Now if the legs could push more in one direction then an
> other direction. What if the push is done using two motors? One motor for
> the left side, the other for the right side. It could push more in one
> direction then the other direction. Did somebody try this?
>
---
I never made a 3 motor walker but when i think about it and when i read the
results they are far better suited for turning.
---
> Would like to hear your thoughts and ideas about it.
>
> See'ya
>
---
I only have one comment.
Excellent piece of work! your gizmo
Thanks for sharing it with us.
Bram
Robotic pages
http://www.xs4all.nl/~vsim
----
> Evaristo
>
> Gizmo homepage: http://www.crosswinds.net/amsterdam/~evaristo
>
------------------------------------------------------------------------
eGroup home: http://www.eGroups.com/list/alt-beam
Free Web-based e-mail groups by eGroups.com
Home