Who can provide here a clear explanation of the compass use?
The only useful function I see is the orientation in the display when it is no longer visible (e.g. behind a tree :-)). Everything else should be able with GPS.
Since I am not using RTH, I would not care whether it comes back sideways, backwards or whatever, the main thing should be that it comes back.
With the MP I can still understand the orientation on the return flight, but not with the Mini.
DJI could provide clarity here ...

Hi DaMa,

DJI drones needs a working drone compass and GPS signals to fly in a stabilized GPS mode.
With large compass errors drone will change mode into ATTI.

When in a stabilized hover (out of vision range) the position is disturbed GPS data is used to recognize this and compass data is needed to know to wich motors more/less power is given to bring craft back in the position before the disturbance.

cheers
JJB

If compass heading and gps disagree your craft will dump gps for compass because you can fly without gps but not without compass .

hallmark007 Posted at 3-7 05:46
If compass heading and gps disagree your craft will dump gps for compass because you can fly without gps but not without compass .

Thank you both (hellmark007 and JBL*), the general explanation is already known.
I am flying helicopters without sensors (only gyro for stern). So for me flying is not a problem without sensors, compass and GPS.
My question was in the direction of the obviously occurring flight maneuvers without the pilot doing anything - actually only possible through wind if there is no software error.
The stabilization of the copter is also manual not a problem... As long as the copter is in sight, I don't care if the compass or GPS fails. Only the engines should still be running ... The copter just mustn't make his own way!
Perhaps the question has to be little more specific: What triggers what and what is the consequence?Maybe I want to know too much... In all the logs you can only see the action but not the cause ...

DaMa Posted at 3-7 08:55
Thank you both (hellmark007 and JBL*), the general explanation is already known.
I am flying helicopters without sensors (only gyro for stern). So for me flying is not a problem without sensors, compass and GPS.
My question was in the direction of the obviously occurring flight maneuvers without the pilot doing anything - actually only possible through wind if there is no software error.

I think it does need to be a bit more specific, post anything on this forum that seems out of context has a habit of being attacked, there are many good well explained articles that explain clearly the whole relationship between IMU MAGNETOMETERS COMPASS ACCELEROMETERS AND GPS and how it all works, and in some drones they’re small changes so I can’t say for certain that mini operates exactly same as inspire or phantom but principle will be the same, so articles explain what you are looking for really well.

hallmark007 Posted at 3-7 09:16
I think it does need to be a bit more specific, post anything on this forum that seems out of context has a habit of being attacked, there are many good well explained articles that explain clearly the whole relationship between IMU MAGNETOMETERS COMPASS ACCELEROMETERS AND GPS and how it all works, and in some drones they’re small changes so I can’t say for certain that mini operates exactly same as inspire or phantom but principle will be the same, so articles explain what you are looking for really well.

I'm not sure I understood that correctly. It shouldn't be an atakke on anything or anyone.
Ultimately, I am concerned with the following: It seems as if there are uncontrolled flight maneuvers without pilot intervention. All we know there are interferences, magnetism or something like that. Basically nothing tangible, as it can happen anytime, anywhere. In my opinion, there should be no such things, it would be too dangerous.
By the way, my DJI toys have always done what I wanted them to do.
Let's forget that, I think the answer I would like to have can only be given from DJI.

Cheers

Hello and good day DaMa. Thank you for reaching out and for the inquiry. The compass on the drone determines direction, aircraft  orientation and heading while the Inertial Measurement Unit or IMU determines or senses attitude of the said drone. Both supply data to the flight controller which enables it to balance thrust from each motor/ESC combination for the desired flight mode know which direction it is facing or travelling. Thank you.

DaMa Posted at 3-7 09:48
I'm not sure I understood that correctly. It shouldn't be an atakke on anything or anyone.
Ultimately, I am concerned with the following: It seems as if there are uncontrolled flight maneuvers without pilot intervention. All we know there are interferences, magnetism or something like that. Basically nothing tangible, as it can happen anytime, anywhere. In my opinion, there should be no such things, it would be too dangerous.
By the way, my DJI toys have always done what I wanted them to do.

Well if it’s mini your referring to I’m not sure some funny things happening with voluntary descent, apart from that I’m not aware of anything, regarding conflict between compass IMU and gps  and TBE well dji craft are set up to manage compass interference by dropping gps in favour of compass it takes some seconds to materialize and can be quicker depending on the force of interference..

DJI Stephen Posted at 3-7 09:48
Hello and good day DaMa. Thank you for reaching out and for the inquiry. The compass on the drone determines direction, aircraft  orientation and heading while the Inertial Measurement Unit or IMU determines or senses attitude of the said drone. Both supply data to the flight controller which enables it to balance thrust from each motor/ESC combination for the desired flight mode know which direction it is facing or travelling. Thank you.

Thanks DJI Stephen,
that is also my idea of the system. This is also confirmed by my MPs and the MM. :-)
My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?
The Kopter has to stop, tip over or land or engines off, but never fly on!
Are there real flyaways or are they pilot mistakes?
Difficult question, I know ...

DaMa Posted at 3-7 10:10
Thanks DJI Stephen,
that is also my idea of the system. This is also confirmed by my MPs and the MM. :-)
My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?

I'm afraid that there are flyaways. Most of them becase of flying in more crowded area (with more possible interference than modeler's airfield)...

DaMa Posted at 3-7 10:10
Thanks DJI Stephen,
that is also my idea of the system. This is also confirmed by my MPs and the MM. :-)
My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?

My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?
No.
Interference (if strong enough) might swamp the control signal which would initiate RTH.
But it won't cause the drone to fly away or crash.

Are there real flyaways or are they pilot mistakes?
Difficult question, I know ...
There are uncommon hardware errors which can cause uncontrollable flight.
But analysing flight data shows most incidents called "flyaways" in this forum are operator error.
Flyaway means I-lost-my-drone-and-don't understand-why.

virtual Posted at 3-7 10:32
I'm afraid that there are flyaways. Most of them becase of flying in more crowded area (with more possible interference than modeler's airfield)...

Sorry but this is not correct at all.

I am led to believe the compass in RTH is used just at the beginning, to orientate the drone for better return camera view. Once the RTH trip is ongoing you can freely rotate the drone and it will keep coming every which way you head it.

m80116 Posted at 3-7 15:23
I am led to believe the compass in RTH is used just at the beginning, to orientate the drone for better return camera view. Once the RTH trip is ongoing you can freely rotate the drone and it will keep coming every which way you head it.

The compass is used continually through RTH and normal flight to maintain the drone's heading.

The new Skydio 2 has no compass - interesting concept. But I have to admit those ex-MITers know a thing or two about drones having been doing it for quite awhile. Quite honestly I wouldn't be surprised to see dji follow suit in the future. How many incidents are related to compass issues saying taking off from a dirty magnetized area?

RickyinCO Posted at 3-7 15:52
The new Skydio 2 has no compass - interesting concept. But I have to admit those ex-MITers know a thing or two about drones having been doing it for quite awhile. Quite honestly I wouldn't be surprised to see dji follow suit in the future. How many incidents are related to compass issues saying taking off from a dirty magnetized area?

Do you know what they are using instead of compass?

Radio signal from R.C.?
Visual orientation?
Leap in using dual GPS antennas - very short distance apart?

Labroides Posted at 3-7 14:57
Sorry but this is not correct at all.

Right or not (I also tend to "not correct at all"), such answers (from "virtual") lead to general confusion and DJI does not try to invalidate this.

m80116 Posted at 3-7 15:23
I am led to believe the compass in RTH is used just at the beginning, to orientate the drone for better return camera view. Once the RTH trip is ongoing you can freely rotate the drone and it will keep coming every which way you head it.

Is that so?
Can't remember that I triggered an RTH with my DJI copters. Surely many have already done so – then the copter responds to stick movements?
I have done RTHs with my QX350, because there is no image transmission and orientation (no display). Can't remember the RTH was controllable... The weather here is crap ...

RickyinCO Posted at 3-7 15:52
The new Skydio 2 has no compass - interesting concept. But I have to admit those ex-MITers know a thing or two about drones having been doing it for quite awhile. Quite honestly I wouldn't be surprised to see dji follow suit in the future. How many incidents are related to compass issues saying taking off from a dirty magnetized area?

A good question. That prompted me to write "hocus pocus" here in the forum.

DaMa Posted at 3-8 00:05
Is that so?
Can't remember that I triggered an RTH with my DJI copters. Surely many have already done so – then the copter responds to stick movements?
I have done RTHs with my QX350, because there is no image transmission and orientation (no display). Can't remember the RTH was controllable... The weather here is crap ...

Yes... actually you can even speed up the return giving forward stick control, you can decide to stop the altitude climb and the drone will come at that specific height, you can freely rotate the drone 360° during return and it will keep moving towards you.
That's why I am led to believe it uses gyros/acc. Furthermore the return path between two points at least 20 meters apart should produce a quite reliable heading, so I find it quite realistic during that scenario the compass not being used except for adjusting the initial heading.

m80116 Posted at 3-8 03:46
Yes... actually you can even speed up the return giving forward stick control, you can decide to stop the altitude climb and the drone will come at that specific height, you can freely rotate the drone 360° during return and it will keep moving towards you.
That's why I am led to believe it uses gyros/acc. Furthermore the return path between two points at least 20 meters apart should produce a quite reliable heading, so I find it quite realistic during that scenario the compass not being used except for adjusting the initial heading.

Interesting, then the compass would ultimately only be responsible for the display. With two GPS coordinates, the compass is not necessary even for the initial heading.

Labroides Posted at 3-7 14:57
Sorry but this is not correct at all.

Q: "My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?"
A: "I'm afraid that there are flyaways."

What is incorrect at all? There are uncommanded descents and there are midflight flyaways or uncontrollable flight maneuvers (not only because of wind). And there's no bulletproof failsave system in case of fused electronics (due to pilots error) to stop the drone from flying away...

DaMa Posted at 3-7 10:10
Thanks DJI Stephen,
that is also my idea of the system. This is also confirmed by my MPs and the MM. :-)
My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?

You are very much welcome DaMa. Environment factors can contribute to drone flyaways as well. Interference from different sources can affect the performance of the drone and can lead to an unwanted incident and can damage the said drone. Always please prepare a preflight checklist for a safe and happy flight always. In addition I will post an official DJI Tutorial Video on DJI Safety Tips Preflight Checklist and Flight Environment Selection. Thank you and please be safe always.

virtual Posted at 3-8 11:11
Q: "My question: can interferences, magnetism, radio waves, WLAN or similar trigger uncontrollable flight maneuvers (without the pilot intervening)?"
A: "I'm afraid that there are flyaways."

What is incorrect at all?
I already explained that above:  https://forum.dji.com/forum.php? ... =210307&pid=2100966
Interference won't cause your drone to fly away or crash.

There are uncommanded descents and there are midflight flyaways or uncontrollable flight maneuvers (not only because of wind).
Since 2015 the DJI Go app has given us recorded flight data that allows us to investigate the cause of flight incidents.
Being able to see this, it's clear that drones don't just fly away and most incidents reported as a "flyaway" are caused by poor understanding and poor piloting.
Some are genuine hardware issues, but those are quite rare.

And there's no bulletproof failsave system in case of fused electronics  (due to pilots error) to stop the drone from flying away...
RTH isn't magic but it's very reliable.
The RTH problems I see are problems where the pilot doesn't understand how RTH works and what it can and can't do.

I've analysed the data from hundreds of incidents and I still haven't seen a genuine flyaway.
What are "fused electronics"?  I've never heard of that.

DJI Stephen Posted at 3-8 12:44
You are very much welcome DaMa. Environment factors can contribute to drone flyaways as well. Interference from different sources can affect the performance of the drone and can lead to an unwanted incident and can damage the said drone. Always please prepare a preflight checklist for a safe and happy flight always. In addition I will post an official DJI Tutorial Video on DJI Safety Tips Preflight Checklist and Flight Environment Selection. Thank you and please be safe always.

https://www.youtube.com/watch?v=w6Zf90zR378

Dear DJI Stephen,
thanks for the clear answer ...

Labroides Posted at 3-8 15:16
What is incorrect at all?
I already explained that above:  https://forum.dji.com/forum.php? ... =210307&pid=2100966
Interference won't cause your drone to fly away or crash.

I agree with you. I also see that interference etc. can affect sensors and radio waves. I do not see a "takeover" of the aircraft by inerferences & Co. Exclude faulty hardware or software ...
My recommendation for everyone who starts with this nice hobby: buy a small copter or helicopter for the inside and practice steering ... there can always be bad weather.
Think the copters in the photo are not a competitor to DJI... should be OK, the green-black one can be flown without any sensors.. I think Tello is too big for small rooms to begin with – for the Garden great.

DaMa Posted at 3-7 23:44
Right or not (I also tend to "not correct at all"), such answers (from "virtual") lead to general confusion and DJI does not try to invalidate this.

To make it clear - I like my Mini, I'm just trying to be realistic and I do not feel that all crashes are pure pilots errors of irresponsible and unconscious users. Plus I don't feel that drones electronics are bulletproof, actually I believe that it can be improved in many ways (and user experience shared on forum can help).
Who can You blame if beginner doesn't recognize compass interference on his cheap selfie drone? If beginner reads on screen "fly with caution" and drone crashes at full speed immediately after take-off with no stick input? You say "kopter has to stop" but Mini can fly away when error occurs, that's the fact.

virtual Posted at 3-9 04:24
To make it clear - I like my Mini, I'm just trying to be realistic and I do not feel that all crashes are pure pilots errors of irresponsible and unconscious users. Plus I don't feel that drones electronics are bulletproof, actually I believe that it can be improved in many ways (and user experience shared on forum can help).
Who can You blame if beginner doesn't recognize compass interference on his cheap selfie drone? If beginner reads on screen "fly with caution" and drone crashes at full speed immediately after take-off with no stick input? You say "kopter has to stop" but Mini can fly away when error occurs, that's the fact.

Is a difficult issue since it is a question of liability. Care refresh and no one asks ... and everyone is happy. The warranty case may also include liability.

DaMa Posted at 3-8 22:33
Dear DJI Stephen,
thanks for the clear answer ...

You are very much welcome DaMa. If you have any other inquiries or concerns with DJI. Please feel free to post it here at DJI Forum. We are all here to help and support you.