Spark compass error - flew off full speed

[Northwood Mediaworks]

When you do the calibration, move the aircraft to a large natural open space way from all structures, take off your Apple/Android watch, have someone else hold your mobile device (if possible) and call out the procedure as prompted on your mobile device during the process from as far away as possible, all other BT/Wifi devices off, and some will even suggest if you have any change in your pockets, or have a metal belt buckle, remove those too. (if your pants fall down without a belt on then pick a more private lcoation) Give the change to your helper as a tip.

 

[irvine]

Hi all I find once the imu is calibrated all I concentrate on is the compass calibration. As mentioned if the compass calibration is green then it's fine see video. I noticed knowone mentioned the satalites the more you have the better the GPS is. Good luck Irvine

When you do the calibration, move the aircraft to a large natural open space way from all structures, take off your Apple/Android watch, have someone else hold your mobile device (if possible) and call out the procedure as prompted on your mobile device during the process from as far away as possible, all other BT/Wifi devices off, and some will even suggest if you have any change in your pockets, or have a metal belt buckle, remove those too. (if your pants fall down without a belt on then pick a more private lcoation) Give the change to your helper as a tip.

 

[Deleted member 15525]

I had many compass errors in spark and phantom 3 but never flew out of control .. it just makes you control it gps isn’t accurate or to be trusted .byt the sticks always controlled it.

Just had a compass error Friday flying near the metal girders of bridges ... still brought her home and once I was further away from structure the error went away

 

[Deleted member 15525]

There’s also a power plant near by, an incinerator that creates electricity, and boats with radar up and down the river... pick the interference source lol... Mavic 2 had no issues but Sparky got temperamental ..., between the bridges lol

I think the train bridge was with Mavic 2

Snow one is with spark.

I almost lost my phantom by that train bridge . I got some kind of time out error and rth did not initiate for a few minutes I also started running closer to the bridge lol Kept recording the entire time.

 

[windryder]

This has happened many many times myself included. At first, the "experts" said it was pilot error! Or that we didn't follow the long list before take off! Then they said that in ATTI mode it would not fly away at full speed, that the wind would push it away and that it could be manually flown back to home! When this happened to me there was no response when I tried to fly it back! Dead stick no control, and it took off fast with no or very little wind! This has to be a firmware or onboard sensor problem that is causing this problem. DJI refuses to look into this problem or even acknowledge that there is a problem. Seems the spark isn't a priority to them.

 

[BudWalker]

The single most effective means to prevent a launch time fly away is to check the red triangle heading indicator in the map display.

If it doesn't agree with the actual AC heading then erratic flight and possible fly away is likely. This method is more robust and accurate than any of the other methods seen in this thread. It's really unfortunate that DJI doesn't put this in any documentation.

There are a few other points about compass calibration that should be mentioned.

1) The idea that a fly away can be caused by moving away from the calibration location is simply not true. A calibration can only determine and compensate for the magnetic properties of the AC. It's mathematically impossible to obtain the data necessary to compensate for magnetic effects external to the AC.

2) It's not necessary to calibrate at a new location. But, it also doesn't increase the risk of getting a flawed calibration. A geomagnetic field distorted enough to produce a flawed calibration will cause the calibration attempt to be rejected with the "interference detected, move to another location" message being issued.

3) No amount of compass calibration at any location will prevent these fly aways. The only fix is to move the AC to a better location.

@dingodar the reason that the AC flies away at high speed is because it doesn't know which wat it's pointed. It's constantly making corrections to it's position. To do this it has to know it's heading. If the heading is wrong any attempted correction will produce a larger position error. Then the next correction has to be larger. This repeats with each correction being larger than the previous.

If you want to know more about a particular fly away the best way is to look at the .DAT log file for that incident. Look here to see how to retrieve that .DAT.

 

[chits]

I travelled from the USA to the UK and did not calibrate my compass or IM Never had any trouble with compass.

 

[wsalopek]

1) Compass calibration is NOT about changing locations...the only thing that changes is the direction to magnetic north (the magnetic declination), and since Spark knows where it is (via the GPS of course), it automatically compensates for changes in magnetic declination.

2) So we are saying that switching to ATTI mode will stop a flyaway? Of course it will drift with the wind, but it won't be flying in some direction at full throttle / bank angle, correct?

3) Yes it's a good question...when the Spark's internal sensors are showing as unreliable...why wouldn't the Spark revert automatically to ATTI mode, instead of activating a full throttle fly away?

4) Also...on my other drones, I have a kill switch (or arm/disarm), so I can hit it if the drone starts flying away...be nice to have that on the Spark.

5) @BudWalker...good tip about simply comparing the arrow on the Spark's screen with your surroundings.

 

[Rnagade05]

I must say, I agree with compass re-calibration should not be performed routinely (such as location change).
However with that said, it would be a good idea to re-calibrate the compass with a major location change.
IE West coast to East coast USA, Etc...
But with even that said, I saw no issues with a 1,000mi change in location...two separate years.

So if I’m from MI and vacation in Az should I re calibrate when first flying in AZ?

 

[DameEdnaBrown]

My spark had compass error and said to land immediately. It went into Atti mode and gunned its engines and flew a couple thousand feet away in seconds!
Return to home would not work!!
There were error messages blocking my screen and I had no video or a clue where it went to. Finally I noticed the distance and altitude starting working and I brought it back using that. When it reached two hundred feet away the low battery kicked in, and the return to home activated.
My question is why does it gun it engines full blast and run off when there are errors?
This is the third time it has happened.

Also My Sons Spark had a similar experience - his Spark ramped the speed up full blast when a compass error occurred over water. Luckily he was able to recover by using the distance meter.

Is the max full speed ahead when errors occur - a normal phenomenon for the sparks?

There is a either a bug in DJI GO4 or bad design

 

[wsalopek]

So if I’m from MI and vacation in Az should I re calibrate when first flying in AZ?

There are different opinions, but the answer is mostly no. Calibration only has to do with the magnetic field that the drone itself is producing, which doesn't change from location to location.

 

[BudWalker]

1) Compass calibration is NOT about changing locations...the only thing that changes is the direction to magnetic north (the magnetic declination), and since Spark knows where it is (via the GPS of course), it automatically compensates for changes in magnetic declination.

2) So we are saying that switching to ATTI mode will stop a flyaway? Of course it will drift with the wind, but it won't be flying in some direction at full throttle / bank angle, correct?

3) Yes it's a good question...when the Spark's internal sensors are showing as unreliable...why wouldn't the Spark revert automatically to ATTI mode, instead of activating a full throttle fly away?

4) Also...on my other drones, I have a kill switch (or arm/disarm), so I can hit it if the drone starts flying away...be nice to have that on the Spark.

5) @BudWalker...good tip about simply comparing the arrow on the Spark's screen with your surroundings.

3) Yes it's a good question...when the Spark's internal sensors are showing as unreliable...why wouldn't the Spark revert automatically to ATTI mode, instead of activating a full throttle fly away?

Usually the "internal sensors" aren't showing as unreliable. All the FC knows is that Yaw (computed mostly from accelerometer and gyro data) doesn't agree with magYaw (computed just from magnetometer data). The FC can't know which is correct. It used to be that this was enough reason to switch to ATTI. When the Mavic was introduced the strategy became to remain in GPS+ATTI and attempt to reconcile the Yaw/magYaw separation by rotating the AC while holding Yaw constant until magYaw agreed with the constant Yaw value. Sometimes this works, sometimes not. I suspect the Spark does this now and that's why you see fly aways.

 

[Spark 317]

All the FC knows is that Yaw

The FC can't know which is correct.

What is FC?

I didn't see it on the AACU = Acronyms & Abbreviations Commonly Used list.

 

[Roy Rogers]

My spark had compass error and said to land immediately. It went into Atti mode and gunned its engines and flew a couple thousand feet away in seconds!
Return to home would not work!!
There were error messages blocking my screen and I had no video or a clue where it went to. Finally I noticed the distance and altitude starting working and I brought it back using that. When it reached two hundred feet away the low battery kicked in, and the return to home activated.
My question is why does it gun it engines full blast and run off when there are errors?
This is the third time it has happened.

Also My Sons Spark had a similar experience - his Spark ramped the speed up full blast when a compass error occurred over water. Luckily he was able to recover by using the distance meter.

Is the max full speed ahead when errors occur - a normal phenomenon for the sparks?

I have only had one compass error while flying . it happened while doing an inspection of a huge metal tank . The manual says to not calibrate within 5ft of metal , so I'm thinking flying >then 5ft is safe . I was flighting 10ft off the tank looking down a 5ft pipe I got " Compass Error with in a second I knew why so I flew straight up and that fixed it . I didn't get any fly away though.

 

[BudWalker]

What is FC?

I didn't see it on the AACU = Acronyms & Abbreviations Commonly Used list.

Sorry. Flight Controller.

 

[Spark 317]

Sorry. Flight Controller.

That's cool. I learn something everyday.

 

[Andre Levite]

That's cool. I learn something everyday.

FC = RC ?

 

[Spark 317]

FC = RC ?

That's what I thought, but could be referring to the Sparks on board "Flight Controller" (firmware).

 

[Simk1n]

Lets say you calibrate near metal vs calibrate way out in the field, as long as the calibration is done, does it matter? I tried calibrating my Air and was a few meters away from my car but had errors, had to move even more away but it turned out fine. Would the calibration be "better" if I was even longer away from my car?

 

[xtro83]

Compass Calibration Guide

Why Calibrate? A good compass calibration is important to ensure a safe, controlled flight. Warning Signs The Spark can only detect when the compass is providing extremely poor (implausible) data. This typically occurs if you place it near a strong magnetic field. It will flash red and yellow...

sparkpilots.com