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Multiple Ping)))s — Parallax Forums

Multiple Ping)))s

TaishoTaisho Posts: 34
edited 2006-04-15 03:42 in BASIC Stamp
I searched but could not··find if mounting two pings (one looking forward and one backward) can be mounted to provide 360 degree coverage.

Thanks for any help....

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-04-14 14:24
    Hello,

    ·· One PING))) will not provide 180 degrees of coverage without panning it using the PING))) Mounting Bracket.· If you used two, front and back, then yes, you would have 360 degree coverage.· Just not all at once due to time it takes to pan.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • TaishoTaisho Posts: 34
    edited 2006-04-14 14:28
    I am going to mount them on swiveling brackets.· Thanks for the fast answer.· I am completely obsessed with this robot.
  • JonathanJonathan Posts: 1,023
    edited 2006-04-14 15:22
    Taisho,

    I don't know if you are planning on making your own swivel mount or are going to buy one, but here are some pictures and information about a 180 degree pan, 45 degree tilt sensor array that I made for the hydrogen powered robot using stuff you can get from a hardware store.

    http://madlabs.info/h2fcrp/h2fcrp_sensors.shtml

    Have fun!

    Jonathan

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-04-14 16:28
    Jonathan -

    Just out of nothing but curiosity, forgetting the CMUCam for a moment, what do you feel you're "gaining" by the 45 degree tilt as regards the two distance sensors?

    Will either of them accurately and repeatedly "edge detect" with such a tilt, as in detecting the impending edge of a table on which it's travelling?

    TIA

    Regards,

    Bruce Bates

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    Post Edited (Bruce Bates) : 4/14/2006 5:10:04 PM GMT
  • JonathanJonathan Posts: 1,023
    edited 2006-04-14 17:35
    Bruce,

    Between the ultrasonic and IR sensors we do get reliable edge detection. We found that the combination of the two sensor types was inportant for this, as surface texture and color can spoof one or the other, but we always seem to see a drop with one or the other. Not that I would allow the robot to depend on it over a significant drop. I haven't tried it yet, but I think you could also use it to determine if a slope in front of the bot is climbable.

    In more practical terms, since the sensor array is mounted so high, the pan allows us to detect objects at close range in front of the 'bot. It's not perfect, but we can pick up objects like a pencil or larger in front of the bot. However, the CMUcam was the main reason we went for the pan. And because it's cool to watch the sensor array pan and tilt :-0. And the fact that I enjoy building little bits of hardware like that smile.gif.

    Jonathan

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • SciTech02SciTech02 Posts: 154
    edited 2006-04-15 03:42
    I see what you're saying (About edge and surface problems).· What if you used multiple sensers?· (2 is the most practical, but you could use 4 or even 6)· That wouldn't be cheep, but it would account for edge and texture problems.··· -SciTech02.
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