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Issues with holding altitude...

Discussion in 'Pro/Adv Discussion' started by Kman, Jun 2, 2015.

  1. Kman

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    I've got almost 3 hours flight time with zero issues. I got my second battery today and wanted to run it down to 50% to make sure there is no issues with it.

    I did the auto take-off and immediately noticed something weird. Normally the P3 will rise and hover around 4 feet off the ground. This time it took off but only rose to 2 or 3 feet and then started slowly loosing altitude. I gave some stick input to raise the P3 and it went up. No fingers on the stick it slowly started going down and then after awhile it would raise up. I flew around with no issues but noticed the altitude was going up and down when it was hovering in place more than normal.

    I swapped out the battery for my old one and it did the same thing. Auto take off. Didn't rise like normal (a lot shorter) and then slowly started loosing altitude and then would over compensate and rise higher up.

    I've done an IMU Cal, Gimbal Cal, and Compass Cal since I installed the latest firmware. Any ideas? It was windy and colder than normal outside.
     
  2. Mako79

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    Is the Vision Positioning system on or disabled?
     
  3. Kman

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    Great point. This was my first flight with it disabled. Had 18 satellites at takeoff and during the flight.
     
  4. mconheady

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    mine does that too. It slowly sinks then almost when i get nervous that it will land it goes up a foot or two. VPS is on.
     
  5. leekiya

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    I have only ever used auto take off once, and it went up to about 2 mtrs then went back down to about 18" off the floor. Just figured it would be like that cos I have vps off, only ever tried it that once I prefer to fly it myself.
     
  6. TonG

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    My P3P shows more or less the same behavior with or without VPS.
    I did a lot of very low level atti-flying in my backyard just for the fun of flying and because of this behavior you have to be alert al the time.
     
  7. bbfpv

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    If it was windy, the barometer would be sensing a change in temps, which would cause it to bounce slightly. Ground effect would also cause it to move a little. It sounds like the bird is within the range of the stated hover accuracy, so I'm not sure why you'd be concerned. It's not like it's landing immediately after auto takeoff.
     
  8. craig4855

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    You must have the VP turned on, for the P3 to hover at 4', with auto takeoff
     
  9. RiskFactor

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    Noticed this same behavior with mine yesterday at the local park. Used auto-takeoff and just watched it. Rose to about 4', then gradually lost altitude to about 2 feet. It seemed to realize this and rose up slightly, but then sunk again. At one point it was hovering with landing gear only a few inches off the ground and was drifting away from me slightly by about 2'. No wind. VPS on.

    I also noticed some drift when flying indoors in my living room that required stick input to correct. Not sure my VPS unit is working as fully intended. Sonar seems to be working as it does try to correct altitude, but I do get some lateral movement. Is this normal? Everyone else see the same behavior?
     
  10. Kman

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    Interesting you guys are having similar issues. I plan on flying this afternoon and I'll do a flight with VPS on and one with it off again and see if I see a difference in altitude hold.
     
  11. JayB

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    I have VPS off, with auto takeoff it now only raises off the floor about a foot. I feel this has been since the latest app update, before,even with VPS off it went up to around 5 feet. I will try it with VPS on later to see if this effects it.
     
  12. Kman

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    Let me know what you find.
     
  13. JayB

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    Tested today and can confirm that with VPS off it only rises to around a foot and with VPS on it rises to around 4 feet and is more stable. I guess that shouldn't be a surprise as that is one of the things it is designed for, low flight stability.
     
  14. Kman

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    Awesome. Thanks for testing!
     
  15. VoicOfReason

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    I had this happen in tall grass. My guess is the wind was whipping the grass around and confusing the VPS.
     
    Bratinov likes this.
  16. Hasan Ahmad

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    This is a resulting of shift in light and temperature. Often at a time of sunrise or sunset. Happens to me only during those times
     
  17. Bratinov

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    Same here, sometimes it happens on a flat surfice, no more close flying over my head.
    Only happens after i did the firmware update.
     
  18. Ted Pretty

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    I've had issues as well, but after turning off VPS it is better...

    ...my main issue is wrong altitude readings. I land and it says 40' or 100'...always depending on how high I fly.

    Anyone experience altitude readings that are WAY off?