Alt-BEAM Archive
Message #08939
To: beam@sgiblab.sgi.com
From: Timothy Flytcher flytch@hotmail.com
Date: Sun, 9 Jan 2000 02:33:45 -0500
Subject: RE: Pressure Sensors
> >
> >For example, a robot foot could be made from a assembly of two PCBs
> >separated by four CDR sensors, one at each corner. One PCB provides the
> >common contact for the sensors and the second PCB has 4 separate
contacts
> >for the other side of the sensors. Now with molded CDR sensors you
could
> >do anything.....
>
>
> Just a thought... It seems to me (all this talk has made my mind dwell on
> legs) that we use TWO types of sensors when we walk... one... a simple
> switch (tactile sense of touch) and two... our feedback of presser ... So
> wouldn't our bots also need two??? Well, need is not the right term...
maybe
> "better if"???
> Timothy...
> ______________________________________________________
>
8940 Sun, 09 Jan 2000 00:36:29 -0800 [alt-beam] Re: Pressure Sensors beam@sgiblab.sgi.com Bruce Robinson Timothy Flytcher wrote:
>
> Just a thought... It seems to me (all this talk has made my
> mind dwell on legs) that we use TWO types of sensors when we walk...
Well, actually ...
We also rely on proprioceptors that sense the position of our joints and
the extension of our muscles; stretch receptors that sense how much
tension is on each of our tendons; balance sensors that keep us upright;
and vision. People DO get by without balance sensors, or vision, or
proprioceptors, but missing even one of these makes it much more
difficult to walk.
But you're right ...
> wouldn't our bots also need two??? Well, need is not the right
> term... maybe "better if"???
Yes. Much better.
---- and ----
Jim Taylor wrote:
>
> When you think about it feedback of pressure isn't really
> important if you always extend your foot the same length
> or distance.
> ... A much more usefull sensor to consider would be a tilt
> sensor ...
Well ... how do you know when your balance is ABOUT to change? Pressure
sensors will tell you that ... tilt sensors won't. So if you rely only
on tilt sensors, you will be constantly recovering your balance (if
you're fast enough). Pressure sensors allow you to anticipate.
If biped walking were simple, Honda wouldn't have had to spend $200
million on their humanoid walker project. Of course, they went with
computers instead of analog technology, so that's set them way back :)
Bruce
8941 Sun, 09 Jan 2000 00:50:53 PST [alt-beam] Re: Pressure Sensors beam@sgiblab.sgi.com "Timothy Flytcher" But a tilt sensor only comes into play AFTER the robot has tilted....
Possibly fatally???
Timothy...
>When you think about it feedback of pressure isn't really important if you
>always extend your foot the same length or distance. Granted we use it to
>determain if we are planted on the ground firmly. However I don't think it
>has any use in a bot which can set the travel of it's legs.
> A much more usefull sensor to consider would be a tilt sensor to tell
>the bot if it has extended it's foot on something too high for it to walk
>over.
>
>
> > >
> > >For example, a robot foot could be made from a assembly of two PCBs
> > >separated by four CDR sensors, one at each corner. One PCB provides the
> > >common contact for the sensors and the second PCB has 4 separate
>contacts
> > >for the other side of the sensors. Now with molded CDR sensors you
>could
> > >do anything.....
> >
> >
> > Just a thought... It seems to me (all this talk has made my mind dwell
>on
> > legs) that we use TWO types of sensors when we walk... one... a simple
> > switch (tactile sense of touch) and two... our feedback of presser ...
>So
> > wouldn't our bots also need two??? Well, need is not the right term...
>maybe
> > "better if"???
> > Timothy...
> > __
______________________________________________________
8942 Sun, 09 Jan 2000 01:00:39 PST [alt-beam] Re: Pressure Sensors beam@sgiblab.sgi.com "Timothy Flytcher" You know Bruce, I have seen how the honda robot walks... Do we really walk
like that??? I mean it just looks so god awful silly... and ... unnatural...
I grant that it is smooth but there seems to be an ??? over-balanced look to
it... Is it just because it moves in slow motion??? It shifts all it's
weight from one foot to the other... as if it could just stop all motion at
any given instant...
Timothy...
>If biped walking were simple, Honda wouldn't have had to spend $200
>million on their humanoid walker project. Of course, they went with
>computers instead of analog technology, so that's set them way back :)
>
>Bruce
______________________________________________________
8943 Sun, 9 Jan 2000 10:04:22 +0100 [alt-beam] SV: photovore "Thomas Pilgaard" Except for connecting the leads on the motors wrong so i had a photophobi=
c
vore that turned away from the light and then connecting them wrong again=
to
have a variant photophobic vore that !backed! away from light mine worked
perfectly the first time i assembled it ;)
Happy botting and cheers
Thomas,
Denmark
> -----Oprindelig meddelelse-----
> Fra: owner-beam@sgiblab.sgi.com [mailto:owner-beam@sgiblab.sgi.com]P=E5
> vegne af David Perry
> Sendt: 09. januar 2000 02:25
> Til: beam@sgiblab.sgi.com
> Emne: Re: photovore
>
>
> ahhh, don't be so pessimistic, mine didn't work and i found out that th=
e
> lead had broken internally on one of the 0.22uf caps, i had to deconstr=
uct
> the whole thing to make it work.
> good luck making it,
>
> David Perry
>
>
> -----Original Message-----
> From: johannes urke
> To: beam@sgiblab.sgi.com
> Date: Sunday, 9 January 2000 7:27
> Subject: photovore
>
>
> >hey guys i finally started making a photopopper photovore and when i h=
ad
> >glued the transistors, 1381`s,the trimpot and the photodiodes together
> >(usind chiu`s tutorial of course)i found out that the caps i had
> were 2.2uf
> >not 0.22uf.
> >now ill solder together the stuff i can without them,
> >and when i get some caps there will be a mail with the subject: "why t=
he
> >#=A4@$ doesnt it work?" in your inbox so get ready to reply guys.
> >
> >______________________________________________________
> >
8944 Sun, 09 Jan 2000 01:06:28 PST [alt-beam] a link to honda's walking robot... beam@sgiblab.sgi.com "Timothy Flytcher" Here's the link ... Just incase anyone has not seen the honda robot ... it
is worth a look :)
Timothy...
http://incolor.inetnebr.com/bill_r/honda.htm
______________________________________________________
8945 Sun, 14 May 2000 12:24:10 -0500 [alt-beam] New Beam Page beam@sgiblab.sgi.com Sparky Hey Guys!
I finally have a web page to show off my walker.
(THANKS TO BRUCE !!! )
check it out and tell me what you think!
http://www3.telus.net/rfws/beam/sparky/index.html
-Sparky
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