HOW TO: Calibrate IMU on Mavic Pro

[The Editor]

It's actually not recommended. Which is my point. If it asks, then, do it.... if it doesn't then don't


Sent from my iPhone using MavicPilots

This is DJI trying to filter out the idiot gene again since many will not calibrate their IMU correctly (let's face it a high proportion won't even read the manual)!
I have designed, built flown and crashed pretty much everything RC including years flying multirotors from both DJI and other manufactures - believe me there is nothing bad about calibrating an IMU (if done correctly) and there is no magic mumbo jumbo behind it.
It is simply!y a collection of sensitive mems gyros and 3 axis accelerometers which sense and feedback aircraft attitude in real time to the flight controller.

 

[Rick]

This is DJI trying to filter out the idiot gene again since many will not calibrate their IMU correctly (let's face it a high proportion won't even read the manual)!
I have designed, built flown and crashed pretty much everything RC including years flying multirotors from both DJI and other manufactures - believe me there is nothing bad about calibrating an IMU (if done correctly) and there is no magic mumbo jumbo behind it.
It is simply!y a collection of sensitive mems gyros and 3 axis accelerometers which sense and feedback aircraft attitude in real time to the flight controller.

Thanks for the reply. It seems whether DJI recommend it or not, it is best to do an IMU after delivery of your new product, in an environment free of interference and on a perfectly level surface. I am also inclined to take the advice of doing the same after new firmware has been installed.

 

[ovyyus]

What is the ideal temperature for performing an IMU calibration?

 

[The Editor]

What is the ideal temperature for performing an IMU calibration?

A cool environment (but not freezing).
The important thing is to try and do it on a cooled and freshly powered up aircraft before the IMU's have reached a warm state.
The mems gyros and accelerometers initialise quickly but for baseline purposes the solid state devices also take into account temperature of the device.
If it is done on a warm machine the IMU will take longer to initialise because if will wait for the sensors to warm.
30 minutes outside on a coolish/cold evening will be fine.
Then bring the Mavic inside and immediately calibrate the IMU (as soon as you turn it on and the gimbal has initialised)

Hope that helps.

 

[ovyyus]

Thanks, it helps. If calibration of the IMU causes temperature specific initialization, will a hot aircraft take longer to power up (needs time to cool down) when IMU calibration is performed at lower temps?

 

[The Editor]

Thanks, it helps. If calibration of the IMU causes temperature specific initialization, will a hot aircraft take longer to power up (needs time to cool down) when IMU calibration is performed at lower temps?

No - on all the aircraft I have built/flown, the converse is true. Once a 'cold' calibration is done you get quick initialisation times whether machine or ambient temp is high or low.

 

[ovyyus]

Thanks, much appreciated.

 

[Snow Bird 1]

Hi Guys; Do not have my Mavic yet, so this question is probably an easy one. I have read the manual(s), watched tutorials and just about every post, BUT... The DJI tutorial on calibrating the IMU states - do not use the combination stick control to start the motors after calibration - does the auto take off button first start the motors and then you lift off?? Hope so, otherwise.....

 

[msinger]

The DJI tutorial on calibrating the IMU states - do not use the combination stick control to start the motors after calibration

They must be referring to not doing a CSC prior to starting the IMU calibration (i.e. calibrate the IMU with the motors off). It's perfectly fine to start the motors with a CSC at anytime.

does the auto take off button first start the motors and then you lift off?

Yes.

 

[Snow Bird 1]

They must be referring to not doing a CSC prior to starting the IMU calibration (i.e. calibrate the IMU with the motors off). It's perfectly fine to start the motors with a CSC at anytime.


Yes.

Thanks for the "yes" - was a bit concerned I was missing something - does not state that anywhere I have seen.

Re: the CSC after IMU calibration - I watched the video again - states NOT to use the CSC after calibration - right at the end of the DJI tutorial.... Unless I am totally missing something. I await more info etc...

I am totally jealous of all the comments and discussions turning into "I got it; this happened; I flew it today, etc Oh well.... My time will come!

 

[Snow Bird 1]

I meant to add - I am sure it is meant to be only the first time starting the motors after IMU calibration.........

 

[msinger]

I am sure it is meant to be only the first time starting the motors after IMU calibration

It's fine to do a CSC at anytime -- except when the arms are folded and you're getting ready to do an IMU calibration. I understand it might be confusing the way it's presented, but that must be what they are trying to communicate.

 

[Rick]

It's not about anything technical as far as I have understood. It's a safety issue (a pretty basic one) that is there to inform you that if you start the drone's motors up while performing an IMU then you could damage the drone and possibly yourself. In the DJI video the blades are still attached to the drone. Other versions show the blades removed. With the blades removed there's less risk of injury in the event of an owner inadvertently starting the drone up while handling it. Not everything is in the manual, but the manual will probably be updated a couple more times as time goes on.

 

[Mr Spock]

Hello all i just got my Mavic pro and i am super excited! I had a P3A and an I1v2 before and i see the calibration on this bird is a totally different game . What are the typical IMU values for the Mavic pls?

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[Jeffdj]

I notice that the IMU readings in the DJI GoApp on my Mavic Pro showed yellow only on one of the IMU's. I did a calibration as per DJI video tutorial but after this the readings were the same ie one yellow dot on one IMU. The tutotrial shows two green dots on the MAVIC they were using, one for each IMU, this indicates excellent rather than good on both IMU's. How do I get my MaVIC to the same level of calibration? I have flown it many times and it performs really well. Should I not bother with this?

 

[kodiak1120]

I watched the video again - states NOT to use the CSC after calibration - right at the end of the DJI tutorial....

Unless they changed the video since this post was made, the video does NOT say not to use CSC AFTER the calibration... It says, "Make sure not to start the motors with the CSC." Although it is at the end of the video, its part of the "Notes" section regarding the IMU calibration process generally. I think they are saying to be careful not to accidentally start the props with the CSC during the calibation process, which would be bad for a number of reasons, no the least of which is that the arms are folded and your props would get damaged.

 

[mnobes.12]

I noticed in the video that the app states "dismount propellers..." but they show the props still attached to the A/C in the pictures and video. Any idea if props should be on or off?

 

[FeliPereira]

Follow the video. It is not difficult.

 

[mnobes.12]

Follow the video. It is not difficult.

Thanks for the sass pal, I was just trying to clarify if the props should or should not be removed based on what DJI says to do with their written instructions vs their visual instructions.

 

[FeliPereira]

Thanks for the sass pal, I was just trying to clarify if the props should or should not be removed based on what DJI says to do with their written instructions vs their visual instructions.

You can do it with or without the props. It will not interfere at all.