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Yaw Drift after IMU Advanced Calibration

Discussion in 'Phantom 2 Vision + Discussion' started by Cytranic, Jan 6, 2015.

  1. Cytranic

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    I posted a thread the other day about Yaw drift... Whatever I do I cannot get it to stop drifting when I yaw in GPS mode. I've calibrated the compass, I've degaussed the compass, I"ve done advanced calibration 20 miles from society. The craft never flies as well as it did out of the box.

    Out of the box I could yaw in 10mph without any drift. Now after messing with the IMU it seems I always drift to the right when the craft is facing forward in GPS mode... If I go to atti mode, the drift is ALOT less.

    When I yaw in GPS mode, it drift 10 feet away, then it seems GPS kicks in and it starts to fly home.... It seems yawing is disabling the gps.. I can fly the craft around in GPS mode by yawing to the left and right. As soon as I stop yawing, about 3 seconds later the craft starts to fly back to the last GPS spot...

    Another issue I see is when I yaw, and I try to fight the drift, the craft actually WANTS to go into the direction of the drift... Like its fighting my stick movement... 2 seconds later GPS seems to kick in and it flies back..

    Its very annoying... I have video out of the box yawing while it holds its position... Anyone have a fix for this?
     
  2. DrJoe

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    That's a known issue, usually fixed with a compass calibration (you should do one after IMU calibrations). If the compass calibration doesn't do it, redo the IMU, then do a compass calibration.
     
  3. Cytranic

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    I've done the IMU calibration every which way. Including the way described at least 5 times. Same issue, drifts to the left side. I've done the Advanced IMU and compass calibration at least 10 times total. I"ve done them in my house, in my yard, 20 miles out in the Everglades , I didnt have cell phone service. I've had no belt on, no keys in my pocket. I've brought my laptop out into the everglades and leveled a piece of board with a bubble level, set the craft on the perfectly level block andthen did the IMU calibration, then compass calibration. Aside from renting Apples 50 million dollar anti-electromagnetic iphone design room, I've done everything possible to eliminate interference, and to ensure I've calibrated correctly.

    The craft would spin on a dime in 10 MPH winds before, now it swings 20 foot from its original gps position, then slowly moved back.. Its like the GPS is lagged or disabled on the yaw after whatever updates I applied.

    I've read many other threads, some people have seen the issue out of the box, others report it happened after the update.

    Is there a way to do a factory reset like it was out of the box?
     
  4. Cytranic

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    Anyone fix this? I dont want to let this thread die!
     
  5. crash1sttime

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    If the craft is in warranty I would consider sending it back to the seller.

    Just a thought, has this unit been crashed, it may be the naza unit has come loose from the board inside and is sat at an angle.
     
  6. mede8er

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    Same thing happened to me a couple weeks ago....big swing to the left under yaw...
     
  7. Cytranic

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    I found the fix. It basically involves placing the craft in the same exact spot, and same orientation for each IMU calibration. The main goal is to find the direction and calibrate the IMU to get a forward or backwards drift. From there you need to shim up the craft opposite of the drift with a few sheetsof paper. The IMU on V3's are super sensitive to being level. Mine took 10 sheets of paper, and over 20 tries to get it right.but now I can yaw on a dime, even in the wind... I'm so happy..

    You can read all my findings on DJI's forums. http://forum.dji.com/forum.php?mod=view ... =#pid28399
     
  8. EMCSQUAR

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    You might also want to reload the default settings and then redoing all your calibrations. I've had to do this on Phantoms before.
     
  9. Cytranic

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    EMCSquar, I saw your posts on youtube. I did do default settings. In the end, shimming with paper and 20+ IMU calibrations later I'm fixed.... I'm not touching IMU until I start drifting again.