1. OCAU Merchandise is available! Check out our 20th Anniversary Mugs, Classic Logo Shirts and much more! Discussion in this thread.
    Dismiss Notice

Insect style robot flies and walks

Discussion in 'Science' started by Fortigurn, Oct 19, 2007.

  1. hlokk

    hlokk Member

    Joined:
    Jul 18, 2003
    Messages:
    5,221
    Location:
    WA
    Actually, whegs have a better rough surface climbing ability. A spiked wheel could at best climb a step of the same height as its radius (minus half the thickness of the spikes). Passively compliant whegs can climb something 150% of its radius (i.e. 3/4 of the diameter). Thats assuming you can get a grip. If the spikes couldnt lever the wheel, then you would have to rely on good ol fashioned friction. A round object such as a pebble would also prove less of a problem for a whegs than a wheel as the geometry of the object can pass inside the wheel (i.e. closer to the hub than 1 radius). So on a rounded object, the whegs would have better grip (due to the tangent of where it contacts).
    Wheels tend to be more efficient, however, a wheel slipping is burning up energy doing nothing. For rough terrain mobility, whegs are better than similarily sized wheels, spikes or not.


    So they should just wait until every single possible piece of technology has been developed before announcing it? Most things can be miniaturised given research and development. They've just shown the basics can be done. Other people can then add any other features. Did they say it can actually DO these things they're promising, or did they say it COULD do these things given more development?
     
  2. OP
    OP
    Fortigurn

    Fortigurn Member

    Joined:
    Jun 27, 2001
    Messages:
    13,353
    Location:
    taipei.tw
    Well let's wait and see.

    See hlokk.

    Oh sorry, I see now you were only referring to the prop. My mistake.

    Well maybe you could offer it as a suggestion. :)

    I think they've done a very good job. They've shown a working model of the basic mechanism they set out to create, and the rest is just fine detail.
     
  3. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    That fine detail is a huge engineering effort itself with a lot more challenges.

    Yes they've got an interesting solution to part of the problem but making it autonomous or semi-autonomous is itself a much harder problem which will take up space , weight and power.

    GPS only solves part of the problem and it's localisation is quite limited then we've got the fact that GPS data is useless without a map. Sensors such as accelerometers , CCD's , not only take up weight for the things themselves but the processing and/or transmitting power also takes up weight itself.

    What they've essentially got is an RC airplane with folding wings and whegs. It's an interesting solution to the mobility problem but the rest is much more difficult.
     
  4. dohzer

    dohzer Member

    Joined:
    Jan 5, 2002
    Messages:
    5,479
    Why would it need a map? It could just use several points to help locate, say, its "base" and "mission area".
    Or it could use GPS to return the location of an IED.
     
  5. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    How would it know about obstacles? and how to avoid them? When you begin to add sensors and processing or transmitting power to make use of them you need to add power storage as well , that'll add to the weight.

    These things are designed for a 1 mile range though , so GPS might not even be needed other solutions might be appropriate.
     
  6. dohzer

    dohzer Member

    Joined:
    Jan 5, 2002
    Messages:
    5,479
    GPS has many other uses other than obstacle avoidance.
    We used it on our UAV so it could record its current location, overall path taken, to help plan its future path and for other things such as timing.
     
  7. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    If you don't use it with a map :) then you need more sensors to handle obstacle avoidance.
     
  8. dohzer

    dohzer Member

    Joined:
    Jan 5, 2002
    Messages:
    5,479
    You'd need sensors anyway.
    How does a map tell you about a truck or a temporary structure?
    Or random trees, etc.
     
  9. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    That depends upon the detail and the recency of the map.
     
  10. dohzer

    dohzer Member

    Joined:
    Jan 5, 2002
    Messages:
    5,479
    It sure does....
     
  11. OP
    OP
    Fortigurn

    Fortigurn Member

    Joined:
    Jun 27, 2001
    Messages:
    13,353
    Location:
    taipei.tw
    These days a GPS unit complete with maps can fit on a CF card. But it doesn't even necessarily need onboard GPS. It only needs a radio transmitter. All the complex data and processing can be carried out elsewhere and transmitted back to the device.

    I have noticed that CCDs these days can be made extremely small and efficient.
     
  12. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    When you are talking a target weight of 450grams including payload, weight rapidly becomes an issue.

    You not only need to take into account the weight of the payload but the batteries to power that.
     
  13. OP
    OP
    Fortigurn

    Fortigurn Member

    Joined:
    Jun 27, 2001
    Messages:
    13,353
    Location:
    taipei.tw
    Certainly, but as I pointed out not everything needs to be on the device itself.n And I didn't see anything in the article or video which requires a target weight of 450 grams including payload.
     
  14. Ze.

    Ze. Member

    Joined:
    Sep 13, 2003
    Messages:
    7,869
    Location:
    Newcastle, NSW
    Try going to the researchers labs and reading the papers on it.
     
  15. Vow

    Vow Member

    Joined:
    Aug 23, 2001
    Messages:
    629
    Location:
    Melbourne
    No, it pretty much has to be self-sufficient. What happens if it goes behind a hill? It's frequency gets jammed? Radio fails? Oh and the GPS receiver definitely has to be on the unit, no use having it back at base. :lol:
     
  16. OP
    OP
    Fortigurn

    Fortigurn Member

    Joined:
    Jun 27, 2001
    Messages:
    13,353
    Location:
    taipei.tw
    Thanks. From that information it's clear that they already have a radio transceiver and a camera on the device. It's only designed for short range work, so I don't think it needs to be massively equipped. They seem pretty happy with it so far.

    This is what they want from it:

    This is what they're currently getting from it:

    So in other words, it already has almost everything it needs, and it's already doing the reconnaissance job they want from it.

    According to the research papers, it only has to be 'semi-autonomous'.

    If it goes behind a hill, so what? If its frequency gets jammed or if the radio fails then it's useless anyway, because it won't be able to use GPS or communicate with the headquarters.

    Well of course, no one has said otherwise. But since they already have a radio transceiver on the device, I don't think it's unrealistic to suggest they keep it there.
     

Share This Page

Advertisement: