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Wall climbing robot - the grippers don't touch the wall. — Parallax Forums

Wall climbing robot - the grippers don't touch the wall.

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-05-30 15:20
    That's very cool, and counterintuitive at first: i.e. air coming out of the cup creating suction. I guess Bernoulli was right again!

    -Phil
  • Martin_HMartin_H Posts: 4,051
    edited 2011-05-30 18:14
    They are very cool. I saw this earlier and posted a thread on it under the name non-contact Bernoulli Grippers which is quote a mouth full.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-05-30 19:02
    You know, if they made the umbilical a little stiffer then they wouldn't need the air flow or the wheels. Just use it as a stick puppet.

    Sorry, I think tethered robots are cheating.

    Edit: That came out harsher than I meant it. I do think it's a cool project. But it's kind of limited having to be connected to those hoses.
  • John R.John R. Posts: 1,376
    edited 2011-05-30 19:48
    Duane Degn wrote: »
    You know, if they made the umbilical a little stiffer then they wouldn't need the air flow or the wheels. Just use it as a stick puppet.

    Sorry, I think tethered robots are cheating.

    Edit: That came out harsher than I meant it. I do think it's a cool project. But it's kind of limited having to be connected to those hoses.

    Projects that push the envelope commonly "cheat" when compared to "conventional" technology. In this case, the object wasn't to build a wall climbing robot, but to see what it would take for this type of "suction" to work. The next phase would be working on making an air source small enough and powerful enough to work. Until you know how much air/pressure it takes, how can you start on this "next step". Tethering a robot as a starting point makes life a whole lot easier to prove concepts.

    I've seen tethers used for power, data gathering (sensors to monitor the "robots" performance), and control (where relatively powerful computers were used to prove a concept before developing an "embedded" solution).
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-05-30 20:22
    John, Yes, I can see tethers can be very useful. I admit I often have my robots on tethers (power & debug line) while testing my robots.

    I'm just a bit skeptical that the kind of air flow this robot will require can be self-contained. If they use compressed air or CO2, they will likely have icing problems. I hope they prove me wrong. As I said, my remarks (meant to be humorous) came across harsher than I intended.

    I do think this is a neat experiment.

    I was washing out some tubing the other day with water. I had a "T" valve in the line. I covered the side opening of the valve with my finger to make sure all the water went straight through the valve. When I decide it was time to let water out the side opening, I was surprised to find no water came out. Instead there was suction at the opening. I remembered in my chemistry classes we used water aspirators (I think that's what they were called) to create vacuums for our lab experiments. I had assumed it required special geometry to create the vacuum. The vacuum action of a simple "T" valve came as a surprise.

    I doubt if they used water instead of air the robot would work as well. It would be interesting to see though.
  • Martin_HMartin_H Posts: 4,051
    edited 2011-05-31 06:20
    Liquid nitrogen evaporating inside a pressure vessel could provide a source of gas for the grippers and power for pneumatics as well. The big issue would be the mass of the required heat sink and possible ice build up.
  • Dave HeinDave Hein Posts: 6,347
    edited 2011-05-31 09:23
    Before I looked at the link I wondered how it would get any traction to climb a wall. The "grippers" don't touch the wall, but the wheels do. This is an interesting technique, but it doesn't seem to be very efficient. I like the climbers that use molecular attraction to hang on the wall. The grippers can be easily pulled away perpendicular to the wall, but resist sliding down the wall.
  • Martin_HMartin_H Posts: 4,051
    edited 2011-05-31 10:29
    I was thinking that a hexapod using pneumatic limbs tipped with a friction pad and gripper pad would be a good one plus. That would provide motive power and gripping power using the same power source.
  • RavenkallenRavenkallen Posts: 1,057
    edited 2011-05-31 19:18
    That was really neat. I could see it being used in a lot of applications, especially military systems. If they could miniaturize the system they could have a real "Fly on the wall" drone. I still don't really get how pushing air out can create suction?
  • W9GFOW9GFO Posts: 4,010
    edited 2011-05-31 19:37
    I still don't really get how pushing air out can create suction?

    Try this simple experiment. Get a spool of thread and a piece of paper. Hold the paper to one end of the spool and try to blow the paper off by blowing through the spool.

    Rich H
  • RavenkallenRavenkallen Posts: 1,057
    edited 2011-05-31 20:05
    @w9gfo... I will have to give it a try:)
  • ScribblerKartScribblerKart Posts: 45
    edited 2011-06-07 08:27
    I think that's cool though there's a problem.... can't get the video! :blank: Dad says the computer I'm on blocks Youtube vids. :blank: (again...)
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