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Professional Normal IMU and compass vaLues

Discussion in 'Phantom 3 Help' started by The Phantom, Aug 2, 2015.

  1. The Phantom

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    Wich are the normal IMU and compass values, or where can i find this information?
    I´ve been searching for this info online but didn't find it, and the P3 manual doesn't mention this .

    Thanks in advance.
     
  2. doctordrone

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    I'm sure there's a better answer, but I believe "normal" numbers are whatever shows up when you calibrate as directed... In a electromagnetic neutral and perfectly flat spot.
     
  3. timmer

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    Should be this:

    Gyroscope Mod around 0.00
    Acceleration Mod around 1.00
    Compass Mod 1400-1600
     
  4. The Phantom

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    Thanks, but is there a lower and a higher limit that is acceptable? For example you say the Gyroscope mod is around 0.00, so what is the lowest acceptable number and the highest acceptable number?

    I know that the P2 had those kind of between this and that number that was considered normal and acceptable.

    I would´t count on that at all times, i feel safer to manually be able to look at the numbers and see that they are within acceptable limits.
    Who knows if a calibration has been done with interferences even though you think that it has been done without any interferences, for example.
     
  5. ucla996

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    Where can I find these values? I have the P3P.
     
  6. Dronason

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    Capture.PNG
    In the settings, MC settings / Advance settings / Sensors
     
  7. Dronason

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    You can ask the app to check if a cal is required or not.
    For Gyroscope the P3 should not a touched and the value should be max ±0.01. There is no reason it is higher.
    The accelerometer are matter of how leveled is the surface you place the P3 during calibration. Again, it is expect 0.00 ±0.01 for X and Y and 1.00 ±0.01 for Z.
    The most critical is the compas as it should be made really out of any magnetic interference. But it is not part of the IMU calibration.

    All values in this panel are live and you can play with the drone turn it, tilt it ... to check if the sensors are operating correctly.
     
  8. The Phantom

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    I feel as the app always says that calibration is not required, the app has not told me even once to do a cal. So can the app be trusted at all times when it says a cal is not needed?

    How critical is the absence of magnetic interferences, i mean is it okay to have a belt buckle made of metall or the keys in your pocket when you do the calibration?
     
  9. Dronason

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    At least for compas it says often but also this can be trust only in the way that if it says it, don't try to fly, try to understand why (what is in the underground, what is nearby, ...).
    If it don't says it, that doesn't mean there will be no issue. For the imu if it says do it, then for sure do it. I would redo if it is more than ±0.01 out of normal value.

    With the compas, a key or small items are not too critical. IMO the best is to do one time a good calibration where you take care to have nothing metallic in the surrounding and in a remote area. Then when it complain about compass interference, check if by just putting the P3 on a plastic box it goes away. There would be some metal in the underground. When it will be 30' high, in the air, it will be again in the same environment as the calibration. Just take care when you land as the compas can be affected again at ground level. Hand catching will avoid issue with that.
    That's my point of view.
     
  10. The Phantom

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    Thanks for the explanation. What about a belt buckle made of metall, since when i calibrate the drone its very near the waist area and a belt buckle is much bigger than a key. So would that influence the calibration?
    Its good to know if i need to take my belt off every time i calibrate?
     
  11. Dronason

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    First question is if it is magnetic at all.
    Then distance also matter.
    So if it can be magnetized, remove it or try to keep some distance when the bird is rotated.
    IMO better to take a little more time to do a good calibration and keep it for long time (if you don't fly at a completely different location) than doing often a quick but poor calibration