The DJI mini 2 is definitely having some serious IMU issues. The quadcopter constantly turns in different directions during straight flight in sport mode. And this is not visible in the flight logs. The copter thinks it is flying in a straight line. I used to think it was the wind, but no. The Mini 1 didn't have such problems. This entry is after the "standard" requested IMU and manual compass calibration. https://youtu.be/7meT9l5AvIg https://app.airdata.com/share/EzHsom

Hi Dryvise,

Not sure, but to me it looks like a compass 'error'.
At start the compass data about 140 degrees offset.

So my advice is to calibrate the compass.
Btw   switching ON the drone and moving around the drone at the same time doesn`t help the compass and imu initializing.

cheers
JJB

JJB* Posted at 12-5 07:58
Hi Dryvise,

Not sure, but to me it looks like a compass 'error'.

I calibrated the compass before flying

Dryvise Posted at 12-5 08:08
I calibrated the compass before flying

Oke,  do it again.
The two lines in my chart are offset at start, almost always a compass 'in error'.

JJB* Posted at 12-5 08:10
Oke,  do it again.
The two lines in my chart are offset at start, almost always a compass 'in error'.

Ok, now it's dark and I'll try tomorrow morning.
By the way, in the topic about the constant IMU calibration request, people also wrote about the absence of a straight flight.

Dryvise Posted at 12-5 08:25
Ok, now it's dark and I'll try tomorrow morning.
By the way, in the topic about the constant IMU calibration request, people also wrote about the absence of a straight flight.

It is difficult to see in your flightlog, if your M2 does fly staight or not.

Mayby find an free open area and fly 200 meters just with 100% forward input, in normal and sport mode.
Than you can see in charts if the drone is heading and flying straight or not.



cheers
JJB

JJB* Posted at 12-5 09:17
It is difficult to see in your flightlog, if your M2 does fly staight or not.

Mayby find an free open area and fly 200 meters just with 100% forward input, in normal and sport mode.

Check youtube video. There is flightmap and stick input. Only worward input hit.

Yet literally thousands of us are happily flying our Mini 2 with no issues whatsoever. I think it is incorrect for you to say "the mini 2 is definitely having some serious IMU issues". Nonsense. Perhaps it might be down to user error on your part, no?

djiuser_F8NERRlBIjoJ Posted at 12-5 12:03
Yet literally thousands of us are happily flying our Mini 2 with no issues whatsoever. I think it is incorrect for you to say "the mini 2 is definitely having some serious IMU issues". Nonsense. Perhaps it might be down to user error on your part, no?

of course it isn't a general problem. I am flying a M2P and bought a Mini 2 for a number of reasons. Don't get me wrong, it is not a replacement of my M2P.

My Mini2 is responding too like it should.

There could be individual cases where it goes wrong. Could be calibration, propellors, IMU, operator or it could just be an individual bad unit, but nothing wrong with the overall product.

Having same problem, if it's just compass then great no need to replace/return.

First flight was at night and it started a fast drift. Not trying that again (at night) would have been an easy crash.

djiuser_F8NERRlBIjoJ Posted at 12-5 12:03
Yet literally thousands of us are happily flying our Mini 2 with no issues whatsoever. I think it is incorrect for you to say "the mini 2 is definitely having some serious IMU issues". Nonsense. Perhaps it might be down to user error on your part, no?

Guys, today I made two more flights. I recorded all my actions on video. What can I do wrong here?
There is no way to get out of the city yet, but I have flown mini1 here many times and never had such problems (the last time was a few days ago).
https://app.airdata.com/share/rplYaN
https://app.airdata.com/share/RLOtbo

Hi,

Looking at your video, the blue line in the app are straight lines.

But when i look in my charts,  the heading of the drone change when you apply UP stick.

Did you already stock-calibrate your RC ?

The red move heading line is calculated using GPS data, as your see the Drone Heading line (heading data from the flightlog) and the red line are almost equal = drone flying straight line.

cheers
JJB

In my opinion there is some issue with the drone. It is turning with no input. Open the support case with DJI and send for the replacment. In the end of the day we pay lots of money for the drones and have somthing not working out of the box is toatly disapointing.

I have my one send for the replacment gimbal was tilting from the day one. Now I'm waiting for a new one.

We are not alone. Almost all Mini2 users on Russian-language for, including me, have this problem. In addition, unlike Mini1, the drone poorly holds the position (joysticks released) moves left/right up/down. As if trying to take the right position and misses it. Bottom camera is work properly (tested).

djiuser_F8NERRlBIjoJ Posted at 12-5 12:03
Yet literally thousands of us are happily flying our Mini 2 with no issues whatsoever. I think it is incorrect for you to say "the mini 2 is definitely having some serious IMU issues". Nonsense. Perhaps it might be down to user error on your part, no?

Maybe You just don't know, what it should be, and  You think it's okay or don't think that it's a problem. I had a Mini 1. He had no such problems: he flew straight, if he stopped and directed the camera to the object, he never turned away from the object. Mini 2 behaves as he wants.

With best regards Alexandr.

Going to return mine or at a minimum they should replace.

Tested today in open field with recal of both IMU and compass. Drifts more as you fly it. Gets so bad the gimbal is tilted sideway after a while and the drone drifts more an more.

There is a fault. They need to fix it.

If GPS gets interfered the drone can't maintain its position and will drift. You can get interferences from several sources.

It's  more noticeable on windy days, sometimes it happens, sometimes not. It  generally flights straight (GPS corrects the natural drift that all  airships have) but when having GPS interferences (high Kp factor, for  example) it will drift a bit and you'll have to correct that manually on  the controller.

On the other hand I've been hand  launching/catching the drone for several days and it maintains the spot perfectly (I would't land if on my hand otherways).

PD: Just once in 20 flight hours it drifted a few meters away right after takeoff, but I saw in the log that I was getting low GPS  warnings right after the take off, so entirely my fault as I should have waited a little bit more till all GPS were connected. I usually take of right after the home point is set, but that location had some tall buildings arround and only some GPS were connected when I took off.

It's not the kind of drifts that happens over time randomly.

It has a pattern. You go up high enough to see about 100+ feet, and tell it to fly forward. And you let the stick go and it tries to stop in will shift sideways 1-2 meter immediately to the right. Try it a few time and it starts tilting and do continually uncommanded sideway movement.

At a low altitude when the bottom sensor can see the ground it wouldn't do this. Only at high altitude. Something is defiantly wrong with the IMU in my opinion.

Huginn Kenningar Posted at 12-6 11:02
If GPS gets interfered the drone can't maintain its position and will drift. You can get interferences from several sources.

It's  more noticeable on windy days, sometimes it happens, sometimes not. It  generally flights straight (GPS corrects the natural drift that all  airships have) but when having GPS interferences (high Kp factor, for  example) it will drift a bit and you'll have to correct that manually on  the controller.

And not every flight? right?

Dryvise Posted at 12-6 12:14
And not every flight? right?

Just occasionally, my unit is flying straight most of the time.

For example when manually returning home I usually flight in straight line to me (from 2Km away sometimes) and only need to do little adjustments from time to time.

Huginn Kenningar Posted at 12-6 13:02
Just occasionally, my unit is flying straight most of the time.

For example when manually returning home I usually flight in straight line to me (from 2Km away sometimes) and only need to do little adjustments from time to time.

Yeah))

But I was advised by DJI technical support to send the drone to them in China.
Great update after mini 1)))
Apparently this is a hardware problem and not all drones are affected. I'm more and more inclined that the reason was the poor quality batch of IMU

SipSip Posted at 12-6 10:41
Going to return mine or at a minimum they should replace.

Tested today in open field with recal of both IMU and compass. Drifts more as you fly it. Gets so bad the gimbal is tilted sideway after a while and the drone drifts more an more.

Funny you mention this.
I have the same problem I have reported this here
https://forum.dji.com/forum.php? ... p;page=1#pid2356677

There is more and more people with some kind of issue now.

I'm just waiting for the replacement, lets hope it will be ok. if not I will send it back again this time for refund.

JJB* Posted at 12-5 07:58
Hi Dryvise,

Not sure, but to me it looks like a compass 'error'.

Thank you for the very important technical detail

Dryvise Posted at 12-5 08:25
Ok, now it's dark and I'll try tomorrow morning.
By the way, in the topic about the constant IMU calibration request, people also wrote about the absence of a straight flight.

I couldn't fly straight either, and I calibrated everything many times. Asked me to do the IMU before nearly every flight.

SipSip Posted at 12-6 11:19
It's not the kind of drifts that happens over time randomly.

It has a pattern. You go up high enough to see about 100+ feet, and tell it to fly forward. And you let the stick go and it tries to stop in will shift sideways 1-2 meter immediately to the right. Try it a few time and it starts tilting and do continually uncommanded sideway movement.

Perfectly described, yes I never noticed it happening near ground level!

Hello everyone!
Today there was a YAW movement when returning home.
I am uploading video and transcript from Air Data.
The same happens when driving in sport and normal modes.
Maybe this telemetry data gives more information to the technical support service.
All calibrations are performed (IMU, gimbal, compass), latest firmware.
https://app.airdata.com/share/YxQyDP

Dryvise Posted at 12-21 03:25
Hello everyone!
Today there was a YAW movement when returning home.
I am uploading video and transcript from Air Data.

Im not convinced its the craft snd not the gimbal.
Has anyone tried locking the gimbal in fpv and retrying? Thst should show whether the craft is yawing or the gimbal

Dryvise Posted at 12-21 03:25
Hello everyone!
Today there was a YAW movement when returning home.
I am uploading video and transcript from Air Data.

That's a misalignment between the gimball and the drone, the drone flies straight (you can see it in the log) but the camera isn't centered. The result is that you perceive that the drone is drifting or not flying straight, but it's just the camera pointing a little bit to one side or the other.

To fix it midflight you just need to leave the sticks and let the drone hover for itself for 5 secs or so. You'll notice the drone "moves" alone, but that's just the gimball automatically aligning again with the drone in the yaw axis.

I usually need to do it onece or twice per flight, the camera automatically recenters perfectly and then the mini 2 just flies perfectly straight... untill it misaligns again. Maybe the missalignmant happens to prevent the video from shaking in some situations, or maybe it's a bug, idk.

PS: The calibrations you must perform are IMU, gimball (in a perfectly leveled surface for better results), compass, and controller. And then just do the calibrations again when the software tell you to do it.

I just calibrated the IMU once, the compass once, the gimball twice and the controller once in 32 hours of flight or so.

Huginn Kenningar Posted at 12-21 06:14
That's a misalignment between the gimball and the drone, the drone flies straight (you can see it in the log) but the camera isn't centered. The result is that you perceive that the drone is drifting or not flying straight, but it's just the camera pointing a little bit to one side or the other.

To fix it midflight you just need to leave the sticks and let the drone hover for itself for 5 secs or so. You'll notice the drone "moves" alone, but that's just the gimball automatically aligning again with the drone in the yaw axis.

Thanks for the answer!
It seems to me that your statement is not entirely correct.
The Yaw angle of the camera is 35 °. The video shows that the deflection angle is clearly more than 35 ° and at some moments reaches almost 90 °. This means that in addition to the camera, the drone turns itself.
The opinion of the moderators (DJI representatives) on this matter is interesting.

Blithe74 Posted at 2020-12-6 07:37
We are not alone. Almost all Mini2 users on Russian-language for, including me, have this problem. In addition, unlike Mini1, the drone poorly holds the position (joysticks released) moves left/right up/down. As if trying to take the right position and misses it. Bottom camera is work properly (tested).

Maybe You just don't know, what it should be, and  You think it's okay or don't think that it's a problem. I had a Mini 1. He had no such problems: he flew straight, if he stopped and directed the camera to the object, he never turned away from the object. Mini 2 behaves as he wants.

привет.да как раз мы недавно обсуждали эту проблему в группе в вк