Drone crash - what did I do?

[Turn11]

Recognition of difference between actual heading VS heading on display is the best defense.

IF one of the mode switches had been modified to ATTI would that have stopped the erratic behavior assuming fast recognition of problem and appropriate reaction?

 

[jeplane]

Where X = 50 km. Also note that not all M2s do this, for reasons I cannot explain.

It gets better!

I am the one who used my drone all over the US, without having to reset the compass ever! This lasted for 5-6 months.

Now that I have flown it in the Carribeans and Europe, it is asking to be reset pretty much all the time, since I continue to use it with hundreds or thousands of miles between flights...

How about that!!!

 

[sar104]

Recognition of difference between actual heading VS heading on display is the best defense.

IF one of the mode switches had been modified to ATTI would that have stopped the erratic behavior assuming fast recognition of problem and appropriate reaction?

Yes.

 

[Victorian Aerial Vision]

Mag interference can come from unlikely places. There are several (4) sports fields in the same complex near me that I sometimes take off from, in all but 1 I have no issues. The 1 field that causes me problems looks exactly the same as the others, light towers & a metal pipe fence at the perimeter. At the other fields I can take off anywhere in the field without an issue, this 1 field gives a mag interference error no matter where I try to take off from. The only thing I can figure is that this field has metal pipes underground for drainage or irrigation. It doesn't just affect the DJI products either, I had the same thing happen with my MI Drone.

Victorian Aerial Vision Videos

 

[Wazzo]

Iv'e had warning like this, if I have tried to take off from my car bonnet or car roof. So I respond by relocating the drone. Even picnic tables made of wood with metal frames can give similar warnings. I personally believe if this disorientation of the drone occurs DJI could have designed into the operating system to just let the drone hover and give you a pop up telling you why. This would allow you return your drone manually and deal with the problem at hand. Does anyone know, if this same out of control flight can occur if you fly near major metal objects after takeoff , or is it only during initial startup of the drone?
cheers Wazzo

 

[Meta4]

IDoes anyone know, if this same out of control flight can occur if you fly near major metal objects after takeoff , or is it only during initial startup of the drone?

Flying close enough to steel objects can cause wobbles in flight but move away from the steel object and there's no problem.
But starting the drone up in a magnetically dirty location causes the IMU to get a false sense of where north is and that can cause big problems.

 

[sar104]

Iv'e had warning like this, if I have tried to take off from my car bonnet or car roof. So I respond by relocating the drone. Even picnic tables made of wood with metal frames can give similar warnings. I personally believe if this disorientation of the drone occurs DJI could have designed into the operating system to just let the drone hover and give you a pop up telling you why. This would allow you return your drone manually and deal with the problem at hand. Does anyone know, if this same out of control flight can occur if you fly near major metal objects after takeoff , or is it only during initial startup of the drone?
cheers Wazzo

What you are asking for is the drone to switch to ATTI mode. That used to be the prompt response to these kinds of errors but recent firmware tries much harder to fix them in P-GPS and Mavics, of course, don't, by default, let you select ATTI with the mode switch.

As @Meta4 mentioned, while the commonest problem is incorrect yaw initialization at startup, flying close to large ferromagnetic objects can cause the problem during flight. For example:

Novice Mistake but got lucky!

I thought flying through an old steel bridge would make a good video. I should have realized the potential danger. Steel and radio signals don't mix well. Got lucky though. See video. Effects of steel on drone Control

mavicpilots.com

 

[PropSpin]

I knew someone would finally figure it out.

I actually happened across a group of people looking for "orbs" in Fredericksburg, VA near Hamilton's crossing (lots of civil war battles in the area) almost 20 years ago now. These orbs were supposedly balls of energy and they could be photographed, but not seen w/ the naked eye. If you had the right equipment, you could record audio of the voices of the long since departed according to these people. They said that they were not ghost hunting, mind you, in spite of the fact that they did most of their searching in places where there were lots of death had occurred in the past. Go figure. They related it all to quantum mechanics and also said that these orbs could drain the power from batteries. While we were talking, one of them snapped a photo and showed me the result in the camera's display. There certainly was something next to me that looked like a golf ball sized bubble. Not sure what to make of it all; I tried looking info up on the subject, but never really found anything.

 

[MAvic_South_Oz]

Wonder if there’s and affordable meter or such to check the mag interference? I carry an anemometer for wind speed...

I wonder if a normal compass would suffice ?
Bushwalking (hiking) during the past 25 years or so, we've experienced a few anomalies with compass readings in certain places.

Then again, I think when the little lady says "Home point set, check it on the map", I will simply check the direction of the mavic and the map arrow is the same, easiest all round.
Of course if getting a heads up about magnetic interference, you should move away and retry anyway.

 

[rcschreiner]

It looks like another case of magnetic interference at the takeoff location.View attachment 67446

Note that the yaw value is initialized at -116°. After takeoff, the yaw changes to -90° and forward elevator is applied, causing it to pitch forwards as expected. It should therefore move west, but it actually moves east.

View attachment 67447

That's reflected clearly in the GPS flight path, but note that the IMU initially thinks that it is moving west, based on its accelerometers and incorrect yaw value. It's probable that it was actually facing east. The mobile device DAT file contains the necessary magnetometer data to confirm that.

Dear Sar104

What software did you use for this analysis?
Thanks

 

[Starz]

Where X = 50 km. Also note that not all M2s do this, for reasons I cannot explain.

And remember, I have one of them. Still don’t know if I should feel special.
I’ll find the build date. Maybe they can be tracked by that?

Comes up as 7/19/18.

 

[sar104]

Dear Sar104

What software did you use for this analysis?
Thanks

The txt log conversion was done using TXTlogToCSVtool, and the data were plotted with Igor Pro.

 

[Lon Denard]

So ghosts cause this problem?

I get mag int notices to often in my opinion but I do the compass dance and keep it moving. I do agree that the M2P seems WAY more sensitive than the MP was. I think I calibrated my MP once in almost two years. I seem to calibrate the M2 as last once a month, sometimes more.

 

[sar104]

So ghosts cause this problem?

I get mag int notices to often in my opinion but I do the compass dance and keep it moving. I do agree that the M2P seems WAY more sensitive than the MP was. I think I calibrated my MP once in almost two years. I seem to calibrate the M2 as last once a month, sometimes more.

It's not that it's more sensitive - it's that the M2 firmware is programmed to request recalibration every 30 days or if it is further than 50 km from the previous flight.

 

[natbike]

It's not that it's more sensitive - it's that the M2 firmware is programmed to request recalibration every 30 days or if it is further than 50 km from the previous flight.

I have been keeping track and I haven't had to calibrate for 6 months. I use it mainly in the UK but have also flown in Portugal, France, and the US (California) in that time.

Is there any info I can provide to help someone ID why some don't seem to have this issue? I used to have to do the dance all the time with the Mavic Air. Now I simply move a few meters if I get a magnetic interference message.

 

[sar104]

I have been keeping track and I haven't had to calibrate for 6 months. I use it mainly in the UK but have also flown in Portugal, France, and the US (California) in that time.

Is there any info I can provide to help someone ID why some don't seem to have this issue? I used to have to do the dance all the time with the Mavic Air. Now I simply move a few meters if I get a magnetic interference message.

Sure - if you want to post a mobile device DAT file - that will include log entries on the recalibration status.

Mobile device DAT file: How to retrieve a V3.DAT from the tablet

 

[Lon Denard]

Sure - if you want to post a mobile device DAT file - that will include log entries on the recalibration status.

Mobile device DAT file: How to retrieve a V3.DAT from the tablet

I use the Smart Controller...would that be a similar file?

 

[Lon Denard]

It's not that it's more sensitive - it's that the M2 firmware is programmed to request recalibration every 30 days or if it is further than 50 km from the previous flight.

Hmmm...I'll have to look at that but I'll agree with you by default. I never tracked the frequency so I can't dispute your premise. Thanks for the reply.

 

[old man mavic]

guess i must be lucky my MPP has never been calibrated since i took it out of the box both the IMU or the compass.and i always check the status of the sensors in the app before i first fly at any location, so far no issues to report,that does not mean that one day i may have to do the calibration dance or reset the IMU

 

[hainerob]

What should a pilot do when they first notice this behaviour (The drone wandering off due to mag interference)? Full down?

Depends on your location.

I've only had this happen to me once, and my pre-programmed response to things being weird is to switch to sports mode and go Full UP. This got me well away from the car that was apparently causing interference, and gave my Mavic Pro time to gets its **** together, so I could then land in a controlled manner a few moments later.

Its much easier to control something in a large wide open space, and you will generally have more obstacles closer to the ground so up has always been a better option for me.