MAVIC PRO Start Up Time

[kmaluo]

Sensor drift varies with temperature.

This gets mapped during the calibration, given the IMU will heat up during the rather long calibration process the FC can learn how the sensors behave over a significant temperature range, and it then wants to be in that range for flying. If the IMU is initially colder the FC will wait until it gets back in the known range through the heat generated by the electronics around before it lets you go.

So is calibrating in an abnormal temperature for that location not a bad thing?

 

[Kilrah]

Well we know how it compensates for that if the environment is colder but not how it behaves the other way or if it even matters. The internals may warm up enough during a calibration for it not to be an issue, say if it always heats up the sensors to 60°C during cal it's highly unlikely you'll fly in >60°C temps. Or the temp coefficients it learns can be used to extrapolate on the warm side better than on the cold side, who knows.

What we know is that colder temps cause a warmup delay, and that we've never seen anyone have an "IMU too warm" message.

 

[TheLightSpeed!]

I also come from being a DJI beta tester and have good relationships with both DJI R&D and Edward Windham at DJI - this is all well documented over on Inspire Pilots where I am a Moderator. With over 6,600 posts and nearly 4,000 'likes' I have clearly managed to advice and help just a few people with issues and problems with their DJI machines
Notable Members | DJI Inspire Forum
Although I am NDA'd with DJI so am somewhat shackled in what I can and can't say you will also see that I knew far more about the release of the Inspire2 than most people, either in the press or on any PooTube site.
I was one of the first individuals to advise against calibrating their compass before every flight or even when moving location (again this is well documented over on Inspirepilots and goes back over two years ago).
I explained the reasoning and theory behind it and eventually DJI agreed with my method and reasoning and indeed they actually now advocate not calibrating all the time now - a 180 degree change from their previous advice.
I also hold a degree in electronics engineering and have commercial certification from the CAA for SUAS operations.
Do I understand these machines? - Yes I do.
So I feel it a little presumptuous of you to say I come from lesser technology, however, if you prefer to find your answers in the manuals of DJI that is of course your prerogative. Sometimes however, real world experience has and can provide the answers where a manual is lacking.
I will try and help people wherever I can, whether they wish to listen is of course their desicision

Well if you're in tight with DJI you should have advised them differently on the final manual editing. Regardless of your credentials, there's no where it says to do it. So while you may be the expert on the topic your beef isn't with me, it's with DJI.

Also, do you understand what it does and how? Sure I'm sure we all do. However DJI has issued more information saying not to do it , than to the opposite.


Sent from my iPhone using MavicPilots

 

[Mako79]

Dji dont know crap. No where in any of their manuals do they suggest calibration in a cool room nor do they mention that you shouldnt let the mc warm up.

You should also consider this. Where is Shenzen and what is the current climate there? Do they adjust the temps according to what country the mavics are going to? Do they calibrate after a firmware update? How does the imu handle rough shipping? Have you seen what a stuck imu does?

You should redo an IMU calibration to readjust to your current climate. If calibrated correctly, you should get correct altitude readings (no negative altitudes). Its not hard and its very quick. Just make sure you remove your gimbal clamp.

 

[barefootFPV]

Just want to weigh in with personal experience. My Mavic was flying weird out of the box (unstable, tons of drift, rolling shutter). However, the Go app reported all sensors in calibration range (IMU reported .13 bias).

I posted on the DJI forum about it and Ken responded recommending an IMU calibration. Sure enough, that did the trick.

From my experience building multimotors, the IMU (gyroscope) is the MOST important sensor and a little bit of bias can cause a lot of error.

I'd calibrate according to the video msinger posted if you're having issues.

Sent from my Nexus 6P using MavicPilots mobile app

 

[MavicMinh]

I ve been flying DJI since their Wookong fw was 0.4.xxx It was something like 5 years ago. I can confirm that IMU calibration is how rebooting for PCs. It does fix things