Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Horizon off alittle...

Discussion in 'Pro/Adv Discussion' started by meissner58, May 13, 2016.

  1. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    I was just curious if anyone notices my horizon being off alittle bit. Yesterday I noticed it so I recalibrated everything and I'm still seeing the slight tilt to the left. Is there any way of correcting this?

    Also uploaded this from IMovie to Utube in 4k but only showing 1440p. Is that all I will get out of Utube?
    Thanks for any help...
     
  2. RedHotPoker

    Joined:
    May 3, 2015
    Messages:
    3,972
    Likes Received:
    1,365
    Location:
    Edmonton Alberta
    If a cold IMU and gimbal calibration won't correct that very small out of level horizon, you can manually adjust it in the Go app.

    RedHotPoker
     
    meissner58 likes this.
  3. MikeyOnline

    Joined:
    Apr 22, 2016
    Messages:
    338
    Likes Received:
    116
    I've had no real success with either. My P3P does the same thing and I've done multiple IMU and gimbal calibrations. The problem with mine is that it's not consistent. It'll go from perfect to off a little, and back. If I adjust the gimbal with the -/+, it only makes it worse because correcting it when it's "bad" just makes it swing the other way at times (and worse). The one thing that seemed to help mine was doing the gimbal calibration while the AC was hovering. I did that and now mine is off, at most, less than half a degree.

    Mike
     
    meissner58 likes this.
  4. jonebk12

    Joined:
    Feb 6, 2016
    Messages:
    272
    Likes Received:
    96
    This seems to be a very common issue with the P3, and I think I've even seen P4 videos exhibiting the same problem. Both P3As that I've owned had the issue. I've scoured the internet and these forums and there's no consensus on either a cause or a solution. People like to jump in and say "IMU and gimbal cal," but those of us who have the issue know those don't really fix anything. Surely DJI knows about this problem and it seems like something they could pretty easily take care of with a firmware update. I'm not sure why they haven't. Maybe it's not actually that easy.
     
  5. BVC

    BVC

    Joined:
    Feb 21, 2015
    Messages:
    533
    Likes Received:
    182
    Location:
    Sacramento, CA / Dener, CO
    I only notice it when it's windy out..
     
  6. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    Kind of weird but I never had this problem before updating from 1.6 to 1.8..I've also heard of many people having same gimbal issue..when I went to calibrate it said everything was ok but I went ahead and did it anyways. It was originally off half degree. Now there at zero. It seemed to correct a "tiny" bit but still noticeable to me. I guess I'll wait and see if something from DJI comes out or someone has an easy solution. I guess I could manually move it but I'm going to give it a little more time ..until then I'll just keep sifting through posts. Thank u everyone for feedback.
     
  7. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    I've heard the term cold IMU. Does that mean throw in freezer for 5 mins then calibrate or does it simply mean making sure everything's cooled down, batteries , quad etc...
     
  8. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,537
    Likes Received:
    1,486
    Location:
    Sacramento CA
    A static horizon slant that doesn't change and is always the same angle can be fixed with a gimbal roll adjustment if a good IMU doesnt work.

    Here is my standard input to anyone who asks about drifting horizon issues.
    The dreaded horizon tilt

    .
     
    #8 Oso, May 13, 2016
    Last edited: May 13, 2016
  9. jonebk12

    Joined:
    Feb 6, 2016
    Messages:
    272
    Likes Received:
    96
    I actually did notice mine got worse when I updated to 1.8. Maybe 1.9 will be better...
     
  10. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,145
    Likes Received:
    1,662
    Location:
    San Francisco, CA
    Cold IMU means calibrating when aircraft is cold. Normally we keep the right screen open and aircraft sitting on leveled platform. Switch on the aircraft and the moment connection is established with RC/ Go App, start calibration by pressing the button.

    Most of the times, I have done it at ~50 -55 deg F and have come out good. Some keep it in fridge for "some time" and then do it. I never do that as always scared of condensation inside :)

    Minor roll adjustment can be done with Go App and major by aligning the motor shaft properly. But I have no idea for intermittent deviations.
     
    meissner58 likes this.
  11. matti

    Joined:
    Mar 15, 2016
    Messages:
    401
    Likes Received:
    62
    There are a lot of threads about tilted horizon here. I have tried some of them but I still have to a) Adjust Gimbal Roll or b) fix the horizon in post (shooting 4K helps because I output HD).

    I have saved some snippets as a memo:

    IMU and Gimbal calibration:

    Might fix tilted horizon. Make sure "Adjust Gimbal Roll" is 0° before calibrating.

    Cool the P3 (and battery?) for one hour in my refrigerator or other cool place followed by an immediate IMU calibration and gimbal auto calibration on a perfectly level surface on power-up as soon as the DJI GO app shows a live camera view from the P3 (which will be very foggy due to condensation on the cold camera lens).

    Gyroscope Mod 0.0-1.5, Acceleration (g) X, Y 0.00 Z -1.00 Mod 1.00 (0.98-1.02)




    If the horizon is still tilted you might try the following:

    Get airborne, climb to a height that gives you a clean horizon and then manually change the gimbal roll in the DJI GO app > Gimbal Param Settings > Adjust Gimbal Roll lets you adjust the horizon in 0.2 degree increments. You might make this a P3P shortcut to C1 and C2, then turn right thumbwheel.

    A poster has suggested tilting the camera straight down pointing at ground before starting the auto gimbal calibration.

    A poster has suggested doing the gimbal calibration while the AC is in the air on a calm day with little wind.

    A poster has suggested that if the AC takes off from an un level surface the horizon will be tilted.

    A poster has suggested that the camera is attached to the gimbal unit and secured by a small set screw. It is possible to loosen the screw and rotate the camera assembly slightly to correct the tilt.

    A poster has suggested doing IMU calibration (as above), but then adjusting gimbal roll with the grid on the camera to some level object, followed by gimbal calibration.

    Tilted Horizon issues on Phantom 3 pro
    Non-Level P3 Pro Camera Horizon FINALLY Resolved!
     
  12. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    I'm unsure about the fridge idea too haha. I suppose for a short time may not hurt. No different than me flying in 20 degree weather and coming into a 68 degree house and vice versa. I use a level app on my phone works great and used it before. Same spot too. I dunno, maybe I'll try the cold IMU idea. From what I hear alot of people do it. Thanks for insight.
     
  13. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    Very good info thank you! I'm at work , when I get home I will check this out. This is exactly the reason I spend many hours on this forum. To learn, grow and hopefully be the guy helping someone else.
     
  14. meissner58

    Joined:
    Mar 10, 2016
    Messages:
    210
    Likes Received:
    28
    Ok sounds great thank you..
     
  15. MikeyOnline

    Joined:
    Apr 22, 2016
    Messages:
    338
    Likes Received:
    116
    I'm sensing we need some sort of "IMU calibration dance". Put it in the fridge, take it out, face it north, start the IMU calibration, and do the dance (on a concrete or other non-flexible floor), and hope for the best. ;)

    I've tried every suggestion listed except the fridge: I have the same condensation concern. I may try putting it on an AC vent as that would be less cooling, but for me, the one thing that has worked the best was doing the gimbal calibration while hovering outside on a calm day. My horizon drifts. Sometimes it's level. Other times it's off a little. Before I did the gimbal cal in the air, it would be off as much as 1 degree. Now after the in-air gimbal calibration, it seems to only be off a fraction of a degree: most of the time either level or maybe at most a quarter of a degree.

    My 2 cents, YMMV, and all that.

    Mike
     
    meissner58 likes this.
  16. RedHotPoker

    Joined:
    May 3, 2015
    Messages:
    3,972
    Likes Received:
    1,365
    Location:
    Edmonton Alberta
    Placing the drone in the fridge for a mere fifteen minutes won't be enough time for a condensation concern. ;-) but don't chill the flight battery.
    When you are ready to do a cold IMU calibration, have the RC on and the app set to the calibration page. Place the flight battery in, turn on the drone, when the camera stops moving, then tap the calibration button. Do the gimbal right after. I usually step outside for my compass calibration next.

    Good luck you drone pilots. Get 'er done. Hahaha

    RedHotPoker
     
    meissner58 likes this.
  17. MikeyOnline

    Joined:
    Apr 22, 2016
    Messages:
    338
    Likes Received:
    116
    In preparing to set mine up for a cooldown in front of an A/C vent for a cold IMU calibration, I noticed something just now. With the table perfectly level, I can put my level on the tips of the props and that gives a different reading: table is level but the props are not. Same if I take the props off and use the tops of the motor hubs. Shouldn't we really be leveling the props or if the props are off: the motor hubs? I mean, how much tolerance is there in the legs and are they perfectly level with the craft? Logic tells me we should probably be leveling front prop to back prop (either on the left or right) and left prop to right prop (either on the front or back). At least, that's my logic: once you're in the air, the feet don't matter and what you really want is a level AC.

    Thoughts?

    Mike
     
    matti likes this.
  18. matti

    Joined:
    Mar 15, 2016
    Messages:
    401
    Likes Received:
    62
    hey where did you get the "face it north" voodoo?! i haven't tried the "or other non-flexible floor" either...

    last winter i did the AC cooling outside at about +2°C instead of putting it in the fridge ... i wonder if it would be best to do the actual IMU calibration outside, too?! ;-)
     
  19. RedHotPoker

    Joined:
    May 3, 2015
    Messages:
    3,972
    Likes Received:
    1,365
    Location:
    Edmonton Alberta
    Overthinking this a little bit aren't we? ;-)
    There is no such thing as a perfectly level surface. Perhaps only in outer space... Hahaha
    As flat as can be.

    RedHotPoker
     
    meissner58 likes this.
  20. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,537
    Likes Received:
    1,486
    Location:
    Sacramento CA
    See the link in post #8 above.