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Help: Odd flight behavior in Ground Station Mode

Discussion in 'Phantom 2 Vision + Discussion' started by yawnalot29, Sep 26, 2014.

  1. yawnalot29

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    Hi all,

    I am experiencing an odd flight behavior that I hope someone can shed some light on.

    I have a stock P2V+ w/ Flytrek Core installed using latest firmware and apps.

    While flying in GPS mode, it flights fine, no odd behavior.

    When in flying a mission in Ground Station mode, the P2V+ flights with its nose pointing about 20 degree to right. The flight path stay true to the path shown on ground station. The end result is a video always shooting 20 degree to right of the direction I am heading.

    I tried compass calibration, IMU calibration, adjust gain settings, but nothing seems to help.

    What I have not tried is re-orient the GPS unit or the IMU unit. I have not done so because everything is behaving as expected when not in ground station mission flying.

    I've only flown GPS mode (no ATTI or Manual).

    Any suggestion on how I can resolve this?


    Thanks
     
  2. ilovecoffee

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    That is unusual. The app does control orientation in regards to the next waypoint, at least that's what I suspected when looking at the code and now I can confirm because it is clearly able to fly in a certain direction not facing forward.

    Hopefully you figure it out. Good news for me though when I get a chance to modify the app to make the phantom face a certain direction to the next waypoint.
     
  3. AHill

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    You might try reloading the GS software, maybe when doing the last software upgrade it didn't save a good copy. One small glitch when saving it could cause a problem like that.
     
  4. yawnalot29

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    Basically just delete the apps and then re-install the app?
     
  5. yawnalot29

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    In the mean time, my P2V+ is flying "side way"..... annoying....
     
  6. AHill

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    Yes, it may not help but it could correct a fault if you have a bad copy of the software installed. It is just something to try and seems to be a likely cause since everything else works correctly. If it is not the cause of the problem it shouldn't add any new problems and it would eliminate the software as a possible cause. The software itself seems to be ok because I have not seen any other complaints about this particular problem. That was the only thing I could think of that you didn't indicate you had already tried.
     
  7. ilovecoffee

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    There is no way it would be caused by the software. You cannot download a "bad copy" because it would simply fail. My guess is compass.
     
  8. yawnalot29

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    I thought it might be compass and have calibrate it several times. Each time with same results. I event went as far as calibrating the compass in middle of a big grassy field away from all the structures and power line.

    What's odd is that under normal flight condition, it flies straight as an arrow. I can yaw to whichever direction I want, then push the right stick forward and it'll go in the direction where the nose (where the USB port for P2V+ is located) is pointing. I can then immediately initiate the GS mission (in mid air w/o landing), it would then turn/yaw and fly toward the direction of the first way point but at about 20 degree angle offset from the path it is heading.
     
  9. AHill

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    Did you try disconnecting Flytrex from GPS? It could be something in DJI GS software that is not compatible with the Flytrex system. If so I would notify Flytrex of the problem so they can correct it. There may not be enough people that have Flytrex and have also used GS with it for problem to be noticed yet.
     
  10. yawnalot29

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    Let me give that a try tomorrow.
     
  11. DrD

    DrD

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    Your ground station (Phantom's) flight behavior might be due to a computed true bearing being used between waypoints, while the Phantom uses a magnetic compass heading during flight. Could the difference you see be due to magnetic declination (variation)?

    -Dale-
     
  12. Panamon Creel

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    Hmmm interesting theory Dale but later firmware versions are supposed to have a table to correct for location specific declination, furthermore even if there is no correction the unit would not fly with the nose angled to the path instead it would likely just fly a path that is angled to the calculated path and correct after ( J-Hook).
    To me it sounds like as if it's flying with orientation lock on a path, is it a hidden feature unlocked? :p
     
  13. DrD

    DrD

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    Could the quad point on a magnetic compass course to the waypoint, but fly with a heading that is corrected to the true bearing by flying sideways by the difference? It would converge on the target waypoint, if it could be seen that closely. On the other hand, have others noticed the same thing, or is this unique to the op? I will try it myself, but I don't get as much opportunity as I would like to fly at all! I have flown a few missions,though, and I don't remember any noteworthy crab angles, but I'm still flying pretty close to the nest.

    -Dale-
     
  14. rrmccabe

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    So are you saying this tilt is similar to what you would get flying into a crosswind?
     
  15. Questa

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    Flying with course lock or home lock on?