IMU CAL

[cactus683]

Is an IMU cal needed after a firmware update?

 

[Egika]

No

 

[Robbyg]

No

Egika I would normally agree but after so many people had problems with .550 firmware and IMU calibration I would suggest that he calibrates it.

Rob

 

[Egika]

Sorry, maybe I am missing information.
do they have problems with the IMU current settings or with the calibration process?
Btw: how many are "so many"?

 

[Robbyg]

Sorry, maybe I am missing information.
do they have problems with the IMU current settings or with the calibration process?
Btw: how many are "so many"?

I have seen a few posts about the Mavic having problems after the .550 update, problems that went away after they did an IMU calibration. I was not really keeping track of how many but anything over three reports makes me take notice.
Before .550 I would have never recommended an IMU calibration. Who knows DJI might have sorted the problem with .600 but I would not take a chance until more people report in.

Rob

 

[SoapyGolem]

I have a question on a IMU, is it better to calibrate the drone as quickly as you can before heats up? or does it even matter? i been seeing people talking about this

 

[Mr Spock]

I have a question on a IMU, is it better to calibrate the drone as quickly as you can before heats up? or does it even matter? i been seeing people talking about this

yes and at the Phantom series i use to pop mine in the fridge before cali. Also leveled surface is needed. Cold cali will save u warm-up time at AC startup.

 

[Mr Spock]

I done an upgrade from .0300 to .0400 avoiding to go to .0600 by using the DJIGO4 app 3 second hold on the top right 3 lines of the menu. i never done an IMU cali in the Mavic Pro AC before but now i think is time to do so as my gimbal had issues with .0300 and it was knocking about in its chase during initialization and also had the gimbal twitching .0300 issue that looks like its gone with .0400. So in my case IMU cali or not?

 

[SoapyGolem]

they say its good to do a IMU cal after most updates, mine is still at .002. 004 max

 

[Rick]

Follow the DJI help videos to be sure you calibrate properly. There is nothing to fear in calibrating the IMU so long as you follow procedure. I don't understand why people are so reticent to calibrate the Mavic when there are so many posted issues of poor flight characteristics. (Statistically there are more people flying happily than those that are not, human nature will produce more posts of complaint than praise).
Why wouldn't you safeguard against a problem if you could, rather than trusting things are ok?

 

[Strafe1]

IMU calibration instruction has been varied. Most agree that only do it when prompted to, or when you have a problem that IMU calibration can fix. The HOW part is equally varied. The official DJI instruction vid says to dismount the props, yet the video is done with the props on. Notable gurus on this forum have even said that when you do calibrate, do so on a perfectly level surface, verified with a carpenters level even. The thing that is confusing, is that DJI says it can be done with props on OR off. But there is a difference in the Mavic orientation with the props on vs. off. If absolute level is important, than so to must be the prop placement. If it is not critical, then maybe the calibration is just relative to the Mavic itself, and not so much as the surface it's on (other than it be flat). I have had great success calibrating with props on, and others have had equal success with them off. It seems to not matter, nor does an absolute level surface then. Any thoughts?

 

[sdharris]

Only calibrate if it prompts on the app, and if you do, calibrate when cold and start as quickly as possible.

I had to calibrate mine due to a gimbal issue, which was not resolved but before sending it in for repair I powered it up a couple of times and the dreaded IMU warming up messages appeared, which had never appeared before the calibration. Leads me to believe it needs to be quite cold prior to calibration to avoid the delay in startup.

 

[Rick]

Here's how I do an IMU calibration.

Take the props off.

Put the Mavic in a cool/cold place for half an hour, but don't put it in the fridge. The reason to keep it cold is because it will take a shorter time for the IMU to boot up as it is temperature sensitive.

Find a relatively flat space (use a level by all means)

This space must be away from any forms of interference, say 10 to 15 feet away.
Examples of interference include your phone/tablet and the controller and take off your (smart) watch. Make sure there are no metal objects within the vicinity, including to think about hidden metal objects within floors and walls. Try to avoid areas carrying high wifi signals.
Retrieve the Mavic from your chosen cold place and start the IMU calibration as shown in countless videos online.

The DJI video is as good as any. The only anomaly I have is when the Mavic is positioned upright as it sits at a slight angle of around 10 degrees. Some suggest holding it up vertically, which I have tried before but don't bother now as the results seem the same, and leaving the Mavic alone seems better to me than trying to hold it and potentially inducing an inaccuracy with a trembling hand.

 

[Rnl]

Had my mavic since early February, all updates done, have not calibrated anything because I thought it would tell you if it needed. Have not had the first problem yet. ( YET)

 

[Rick]

Had my mavic since early February, all updates done, have not calibrated anything because I thought it would tell you if it needed. Have not had the first problem yet. ( YET)

If all your flights have been problem free and your calibration status is good then you're on the right path. Always check the calibration status before each flight.

 

[sekine12]

The surface doesn't have to be perfectly level, it just has to be flat. These calibration routines are designed with redundant opposite measurements in mind such that if the surface they're on isn't level it can see that during calibration and adjust. This is similar to how "smart-levels" are calibrated (carpenter's levels with digital readouts). You take one measurement, swap the tool end for end, and take the other measurement. If it sees +2% in one direction, and -2% when swapped end for end, you're good. If it sees +4% in one direction, and +0% (Level) in the other, it knows it's off by 2% and adjusts accordingly.

Edit: A great example of a calibration routine that does need a level surface is the Hubsan X4, you only calibrate in one position. You're telling the IMU "Gravity is perpendicular to the aircraft right now". The multi-position routine avoids that problem. I'd take the props off as instructed though...

 

[regdawg]

Had my mavic since early February, all updates done, have not calibrated anything because I thought it would tell you if it needed. Have not had the first problem yet. ( YET)

I'm with you. I got my Mavic 2 weeks ago. Upgraded firmware to .550 then .600. I've done the compass caliberation because the GO app told me to otherwise its never told me to caliberate the IMU and have not seen any warnings whatsoever. I've had about 6 flights so far (2 with .600).

 

[Flying Irish]

Have had my magic since November Every once in awhile I get a notice after starting blades not to move until IMU calibrates. Takes about 15 seconds. Is this the same calibration in this thread?

 

[Tomasz]

I started calibrating IMU after each firmware update since i had 3 incidents with sudden switch to ATTI, drift and lack of responsiveness after an update without cal. I am not sure that its related to lack of calibration but after doing IMU cal. the issue seem to be solved. Maybe there are some default IMU settings which are restored after each update, for 80% of mavics these are fine and no issues and for the rest you might have troubles and therefore mixed opinions are expressed here.