Please select Into the mobile phone version | Continue to access the computer ver.
When and how to properly calibrate the IMU
744 16 2017-4-26
Uploading and Loding Picture ...(0/1)
o(^-^)o
Frenck
lvl.3
Flight distance : 142723 ft
Italy
Offline

Hello guys. I would like to know in what circumstances should I calibrate the IMU and how?
2017-4-26
Use props
DJI Mindy
Administrator
Flight distance : 7 ft
Offline

Hello, if the aircraft cannot hover or takes long time to preheat, you can try to do the IMU calibration.
Or the DJI GO app pops up the error message about IMU, please try to do the calibration.
Here is the video tutorial for your reference.
2017-4-26
Use props
Antonio76
Captain
Flight distance : 144403 ft
Denmark
Offline

DJI Mindy Posted at 2017-4-26 23:13
Hello, if the aircraft cannot hover or takes long time to preheat, you can try to do the IMU calibration.
Or the DJI GO app pops up the error message about IMU, please try to do the calibration.
Here is the video tutorial for your reference.

Hi Mindy, I've read that the surface on which you do this  must be horizontal... what is the maximum tolerance allowed?   30'? 0º? 1º? 2º?
2017-4-27
Use props
hallmark007
Captain
Flight distance : 5942287 ft
  • >>>
Ireland
Offline

IMU "Inertial measurement unit"

As far as I see it, IMU calibration on a level surface updates a table of values the flight controller software uses as a reference for a level stationary hover. From there the craft responds predictably to flight commands.  It also likely measures any sensor noise and thermal drift so that these technical imperfections are accounted for when using IMU sensor data in flight. - this is likely why there must be no vibrations during the calibration process.


Bad IMU calibration could cause drift and attitude issues as the flight controller fights to hold the craft in what it thinks is the correct attitude as opposed to the correct physical attitude.


The IMU usually has 2 types of sensors – angle and acceleration and in turn 3 sensors of each type measuring in the X,Y and Z axis. These sensors can, through vibration, aging, impact etc, drift in their response over time and thus an IMU calibration will establish a new reference for the IMU’s level/stationary state that the flight controller can work with to restore stable flight.


Think of calibration as the bringing back into line the measured craft attitude with the true physical craft attitude.


As to how often an IMU calibration is needed, First refer to your manual I wouldn’t like to say; certainly after any impact or if there are suspicions the craft can’t hover in a level attitude in a windless environment.
2017-4-27
Use props
Frenck
lvl.3
Flight distance : 142723 ft
Italy
Offline

DJI Mindy Posted at 2017-4-26 23:13
Hello, if the aircraft cannot hover or takes long time to preheat, you can try to do the IMU calibration.
Or the DJI GO app pops up the error message about IMU, please try to do the calibration.
Here is the video tutorial for your reference.

Can I IMU calibration be performed on the floor of the house? Do I have to be on a certain surface insulated from the ground?
2017-4-27
Use props
Frenck
lvl.3
Flight distance : 142723 ft
Italy
Offline

hallmark007 Posted at 2017-4-27 02:05
IMU "Inertial measurement unit"

As far as I see it, IMU calibration on a level surface updates a table of values the flight controller software uses as a reference for a level stationary hover. From there the craft responds predictably to flight commands.  It also likely measures any sensor noise and thermal drift so that these technical imperfections are accounted for when using IMU sensor data in flight. - this is likely why there must be no vibrations during the calibration process.

Can I IMU calibration be performed on the floor of the house? Do I have to be on a certain surface insulated from the ground?
2017-4-27
Use props
hallmark007
Captain
Flight distance : 5942287 ft
  • >>>
Ireland
Offline

Frenck Posted at 2017-4-27 04:16
Can I IMU calibration be performed on the floor of the house? Do I have to be on a certain surface insulated from the ground?

Yes it can,but not wise, for me if you have a table outside which you can level properly, use a sprit level to be sure, this for me would be your best option, or a table inside which is also level. Floors or ground are notoriously known for not being level.
2017-4-27
Use props
Frenck
lvl.3
Flight distance : 142723 ft
Italy
Offline

hallmark007 Posted at 2017-4-27 04:47
Yes it can,but not wise, for me if you have a table outside which you can level properly, use a sprit level to be sure, this for me would be your best option, or a table inside which is also level. Floors or ground are notoriously known for not being level.

It's hard to have a table with "spirit level"! Does the drone calibration system have any tolerances? Should I calibrate on a table outside a home? I've watched some videos and I noticed that the calibration is performed in a room on a normal table. Thanks for your answers.
2017-4-27
Use props
hallmark007
Captain
Flight distance : 5942287 ft
  • >>>
Ireland
Offline

Frenck Posted at 2017-4-27 05:20
It's hard to have a table with "spirit level"! Does the drone calibration system have any tolerances? Should I calibrate on a table outside a home? I've watched some videos and I noticed that the calibration is performed in a room on a normal table. Thanks for your answers.

Outside is best because this is where you will fly, so doing IMU at similar temperatures will insure warming up time will be less when starting your AC, You can always do this indoors I would recommend that you leave your AC outside or in a cold room for an hour , then do the IMU inside, but pay special attention to making sure that the surface you carry out IMU is level.
2017-4-27
Use props
marctronixx
Second Officer
Flight distance : 210118 ft
  • >>>
United States
Offline

Lots of opinions here.

it would be great if DJI could officially say one way or another.
2017-4-27
Use props
KM5RG-Robert
Captain
Flight distance : 2075213 ft
United States
Offline

Everything I've seen says the IMU should be cold (though I do not know how cold or if something is too cold but certainly well below room temp) and on a level surface (as level as you can get if you want a level horizon).
2017-4-27
Use props
Frenck
lvl.3
Flight distance : 142723 ft
Italy
Offline

hallmark007 Posted at 2017-4-27 05:38
Outside is best because this is where you will fly, so doing IMU at similar temperatures will insure warming up time will be less when starting your AC, You can always do this indoors I would recommend that you leave your AC outside or in a cold room for an hour , then do the IMU inside, but pay special attention to making sure that the surface you carry out IMU is level.

If I reset the factory settings, will the calibration of the "IMU" also be restored to the original factory conditions?
2017-4-27
Use props
betonven
lvl.3
United States
Offline

KM5RG-Robert Posted at 2017-4-27 05:54
Everything I've seen says the IMU should be cold (though I do not know how cold or if something is too cold but certainly well below room temp) and on a level surface (as level as you can get if you want a level horizon).

Well, in my experience you don't get a level horizon just by doing a perfectly leveled IMU calibration. You also need a gimbal that actually works properly (you know, the one that apparently most P4Ps do not have...)
2017-4-27
Use props
betonven
lvl.3
United States
Offline

Frenck Posted at 2017-4-27 05:20
It's hard to have a table with "spirit level"! Does the drone calibration system have any tolerances? Should I calibrate on a table outside a home? I've watched some videos and I noticed that the calibration is performed in a room on a normal table. Thanks for your answers.

It's not as hard as you think. I bought a sprit level for the occasion, it costed me something like 3$. You just place it on the table, and if you see it's not perfectly horizontal, you add a few papers under the legs in the proper side to get it where it should be.
2017-4-27
Use props
hallmark007
Captain
Flight distance : 5942287 ft
  • >>>
Ireland
Offline

Frenck Posted at 2017-4-27 06:13
If I reset the factory settings, will the calibration of the "IMU" also be restored to the original factory conditions?

First of all are you being prompted to do IMU and what do you think is the problem with your aircraft, there is a very simple way of checking if your IMU is ok.
2017-4-27
Use props
hallmark007
Captain
Flight distance : 5942287 ft
  • >>>
Ireland
Offline

marctronixx Posted at 2017-4-27 05:50
Lots of opinions here.

it would be great if DJI could officially say one way or another.

Doesn't seem to be that much fluctuation in opinions just yet.
2017-4-27
Use props
KM5RG-Robert
Captain
Flight distance : 2075213 ft
United States
Offline

Frenck Posted at 2017-4-27 06:13
If I reset the factory settings, will the calibration of the "IMU" also be restored to the original factory conditions?

I think not.
2017-4-27
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules