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  1. robdigphot

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    I am experiencing an altitude drop of about 2 metres on my P4 after it has slowed to a hover. This did not happen on my P3P . I have calibrated the compass and the IMU's . Has anybody got any ideas on how to solve this? Check out the end of this video clip to see the issue
     
    #1 robdigphot, Mar 23, 2016
    Last edited: Mar 23, 2016
  2. flpholt

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    don't have one but have seen alot of people having this issue nothing you can due
     
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  3. Mako79

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    Maybe there is a bug in the sonar/VPS. The VPS on the P4 is now 10m vs 3m on the P3. Try turning it off and see if it drops altitude.

    Another thing that affects altitude is the heat inside the Phantoms. The IMU has altimeter/barometer which works by measuring pressure. I know heat affects pressure and this may lead to inaccuracies.
    Check your altitude readings and see if they get worse the longer you fly.
     
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  4. Marc Hufnagel

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    I see the drop too, something about 6-8 feet I'd say.
     
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  5. G-K

    G-K

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    I have the same issue. It is worse when flying in Sport Mode. You can also follow the link below and see who else has that issue...

    Altitude drops during flight...
     
    robdigphot likes this.
  6. Tripc

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    I think when you fly and come to a stop. The air brakes actually lift the quad up a little and then it settles back to original height. I'm thinking.
     
  7. M Evans

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    I had a drop too but fixed it with an IMU calibration
     
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  8. crashburn

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    Common problem, I've tried cold imu, gains, etc, nothing works. Perhaps a new firmware update? Was filming a peach orchard very low, and every hover was a problem with dropping into the trees.
     
  9. G-K

    G-K

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    Proper IMU calibration has solved the issue...
     
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  10. Troyboy

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    What's a proper Imu calibration, please specify? Thanks
     
  11. crashburn

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    Proper imu calibration, I assume, is to cool the P4 in a refrigerator for a while, then place it in a perfectly level spot, confirmed with a level, then calibrated in a very still and calm environment. Tried imu calibration couple of times, didn't work for me. Neither did calibrating the camera sensors using Assistant 2. Neither did playing with gains, sensitivities, etc. The P4 still drops during hover after cruising, in any mode. At least for me. Doesn't happen on any of my 3 Inspires or my Matrice. Hopefully a firmware fix.
     
  12. Mako79

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    Placing it in a refrigerator may be the issue. You are calibrating the altimeter/barometer when you are doing an IMU calibration and as far as i know, temperatures affect the barometer readings.
    Try doing an IMU early in the mornings when the ambient temps are just cool. Make sure you haven't flown the phantom for an hour or so. Also try doing the IMU calibration immediately the moment you turn on your phantom.
     
  13. crashburn

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    Done it that way also, didn't work.
     
  14. richardseguro

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    Agree with you. Anywhere between 4-8 from my end
     
  15. Dronetwinkies

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    Yup i am now experiencing this too with my P4, dropping between 2-6 ft
     
  16. Steven Mckelvie

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    I had the same dropping issue with my new P4. I contacted who I bought it from and they say I'm the only one in nz having the issue. I have sent it back to them. They also say they spoke with Dji and there is no major problem like this known. Yeah right!! How come there a threads like this then?
     
  17. Steven Mckelvie

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    Mine was only dropping when stopping from forward flight. Flying backwards or left/right no drop.
     
    KevMo Photog likes this.
  18. Stealthmatt

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    I have not seen this issue with my first or second phantom 4.

    Everyone who says "hopefully this will be fixed by a phantom 4 firmware" is wrong. If they do "fix it" then all the other people who don't have a problem will then have an issue.

    Take it back and get a replacement. Don't wait for a firmware update because it likely will only marginally fix the issue if at all.
     
  19. chris digata

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    are people only having this problem at low altitude? are the all in hot places? at what batt temp? is it a VPS problem due to more sensitive sensors
    ive seen the odd drop now and then but only at low height due to VPS adjustment
     
  20. Archer911

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    Having the same problem here.