Subject:
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Re: an idea, can someone tell me if this is possible/been done before/etc?
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Newsgroups:
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lugnet.robotics
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Date:
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Thu, 4 Dec 2003 19:39:39 GMT
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Viewed:
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1273 times
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In lugnet.robotics, Paul Kleniewski wrote:
>
> "Kevin L. Clague" <kevin_clague@yahoo.com> wrote in message news:HpAAsB.1Kpo@lugnet.com...
>
> > The foot on the obstacle is not in the air but on the ground. If you mean that
> > one foot is on the obstacle and the other can't reach the ground, I see your
> > point. I was hoping to add a suspension to Quad242 to make it handle a certain
> > level of uneveness.
>
> hmm
> my english is not very well so i'm explaining in weak way
>
> let's say your q242 is walking on a flat surface
> everything is quite well
>
> now ahead q242 there is one stair
> (it has appropriate size and so on)
> i can imagine
> q242 raises its leg
> moves it over the step
> and settle down
> but this time leg stops on the step (which is higher than the ground level)
>
> if foot will have mechanism described in former post
> q242 will not try to push leg to the ground level
> so leg will stay at the higher level (on the stair)
> in this case q242 body will stay flat
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.
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.
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?
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 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.
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?
>
> next leg will "walk" over the stair and will be set on the ground level
unless there is another step :^)
>
> 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.
>
> if this description is not undestandable
> i'll build such a mechnism to show what i meant to say :))))
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).
>
> one word summary:
> foot mechnism hovever pneumatic works as a touch sensor
Got that part.
Thank goodness you can speak english, because I can't speak polish.
>
> br
> pixel
Regards,
Kevin
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Message has 1 Reply:
 | | Re: WWW spider
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| "Kevin L. Clague" <kevin_clague@yahoo.com> wrote in message news:HpDyM3.A0z@lugnet.com... (...) yes i tried some sequensers during weekend and i'm on the way to create this functionality i hope it will work :))) (...) i think this could be done by (...) (21 years ago, 8-Dec-03, to lugnet.robotics)
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