Subject:
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Re: WWW spider
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Newsgroups:
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lugnet.robotics
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Date:
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Mon, 8 Dec 2003 11:14:45 GMT
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Viewed:
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1320 times
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"Kevin L. Clague" <kevin_clague@yahoo.com> wrote in message news:HpDyM3.A0z@lugnet.com...
> Yes, I understand that you would have the downward pressure of the step move
> stop the leg movement by cutting off pressure to the piston(s) driving the foot
> down. Once this pressure is cut off by the switch, presumably the other legs
> continue with the sequence.
yes
i tried some sequensers during weekend
and i'm on the way to create this functionality
i hope it will work :)))
> Eventually the sequence gets back to the foot that is on the step and the foot
> does not move (because the switch, acting as a touch sensor) still has the
> pressure turned off). It seems like the leg never starts moving again.
i think this could be done by the mechanism which could work as "clear" method
so let's say at the end of the sequence there will be a step called clear
and this step will set/reset some of the "dead" states
pistons which will akt as clear
should be connected to valves not in the same way as "normal" pistons
i assume "normal" piston is connected to valve let's say 1:1
so if the piston moves in or out the valve is moved from one end to the other end
but the clear should work in the way which would move the valve to the only one direction
when clear piston gets back it doesn't move the valve
of course the meaning of "clear" depends on you
> How do we tell the difference between the switch/pressure sensor being flipped
> because of premature end of step and flipped because it is on the floor?
in these terms i think there is no difference between
"on the step" and "on the ground"
> I'm interested in your idea, but I'm not sure how to use it. It may be me
> because I've not progressed from simple sequencers to complete pneumatic state
> machines that change state because of external inputs as well as current state.
> Quad242 plus the polarity reversers can do this if you consider the positioning
> of the polarity reversers' handles as inputs.
i thought about the sequencer as about electronic machine :)
> I suppose that if you combined the switch that is affected by weight bearing or
> not in series with a switch that tells you if the leg is completely extended or
> not, you could tell if the leg hit the ground prematurely.
yeah!!!
it's something like this
> Do you really want to leg to freeze once we detect this situation? This is
> certainly not what my dog would do. He'd extend the leg and keep going. It
> must be something special about the WWW spider that its trying to keep the body
> at the same altitude no matter what the terrain?
no no no
WWW spider has nothing to it
it was just the idea to put additional elements into the circuit
which could "inform" the system there were some changes in the environment
"to inform" means to robot "do something extraordinary"
something different that the primary sequence
and get back to the original sequence if the cause will disappear
> > when whole q242 step procedure will be finished
> > (all legs will finish its cycle)
> > q242 will start next cycle with the first leg
> > (this leg stays on the stair)
> > foot mechanism will raise such leg from its state
>
> This is the part where I get confused... If the incomplete leg extension
> detecter (pneumatic switch) cuts off the pressure to make the leg freeze, how do
> we undo this the second time around? It seems like simply cutting off the
> pressure is not the right way to use your pneumatic switch/touch sensor.
see clear description :)
> I think I understand your idea, I'm just curious how it fits in the big picture
> (remember I'm trying not to have the RCX control articulation).
sure!!! i know
the same is with my new hexapod
i want to do all movements from one motor which will rotate in one direction only :)
br
pixel
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Message has 1 Reply:
 | | Re: WWW spider
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| (...) Good luck! I look forward to it. (...) Hmmmmm.... I wondered if you might be thinking of this. A common method used in the past was to use a central pneumatic timer circuit that control the muscle pistons and make them move. This is what Doug (...) (21 years ago, 8-Dec-03, to lugnet.robotics)
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