30m-60m Altitude gain over a 15min mission flight time

[Meta4]

Just tried the same mission at 15m indicated on the controller, the error on landing was 8m, so much less than the automatic mode but still well over what I thought the GPS altitude could maintain given it was locating 17 satellites at any one time.

If you just fly manually across the property, does it still show a significant altitude error?
I'm trying to eliminate something about the waypoint flights as that could affect all 5 drones.

 

[WaitaDroneOperator]

Thanks I thought I had read elsewhere that the GPS altitude was used initially but I didn't know it was only for 20ft before the baro input took over. Cheers

 

[Meta4]

Thanks I thought I had read elsewhere that the GPS altitude was used initially but I didn't know it was only for 20ft before the baro input took over. Cheers

GPS is not used for altitude data.
GPS is for horizontal position data.
The drone has low range downward facing sensors that give additional (and more accurate height information at low altitudes.
The data from those was how I could tell that the issue was with the barometric sensor altitudes shown in your flight data.

I believe that such a big error affecting all 5 drones makes it look more like some outside influence causing the issue rather than an actual problem with each drone.
I would really like to know if the altitude data shows the same error when you aren't flying a waypoint mission.
It's likely to be very useful in identifying the source of the issue.

 

[boblui]

Looks like there is some problem with the barometer. Similar problems have been reported before resulting in the craft not being able to hold altitude. In a recent extreme case, the craft skyrocketed to the outer space all by itself after takeoff.

while barometer error is an easy conclusion, the fact that it occurred on all of your 5 drones make this highly unlikely. Can you confirm that pls ?

 

[WaitaDroneOperator]

If you just fly manually across the property, does it still show a significant altitude error?
I'm trying to eliminate something about the waypoint flights as that could affect all 5 drones.

HI Meta, it showed about an 8metre error in manual flight flying the same path at the indicated 15m on the controller vs 43m error when left to fly the mission on its own.

 

[Meta4]

HI Meta, it showed about an 8metre error in manual flight flying the same path at the indicated 15m on the controller vs 43m error when left to fly the mission on its own.

That's a pretty good hint that the issue has something to do with the waypoint mission rather than a fault in 5 drones.
A small difference is common with barometric sensor data over the time of a flight.
Can you post flight data from a non-waypoint flight as it might help shed more light on the issue?

 

[boblui]

May be you can post the .DAT flight log files which contains the raw sensor data . It will help to identify what individual sensor saw in the process including the accelerometer, GPS and barometer. I doubt if the drift in altitude has anything to do with the mode of flying, ie waypoint or manual. The 8m vs 43m difference you saw could just be random variation unless the results are repeatable.

Method to get the .DAT file in the controller : How to retrieve a V3.DAT from the tablet

 

[surfbird]

Any update on this?

 

[WaitaDroneOperator]

Hi guys, no, no update, unfortunately 3 of the 5 drones have crashed from batteries overheating and stopping dead in the sky... DJI have asked for all the drones and batteries back as they hadn't heard of this occurring before. Sounds like we were sold a dead bunch of drones to be honest.

 

[Not A Speck Of Cereal]

*ouch*

Good luck with that.

Chris

 

[ZUCSTA]

Your flight data confirms that there is a problem as you described.
Having an issue with one drone would be believable.
But having the same issue with 5 drones is baffling.

The issue has nothing to do with your downward facing sensors.
Your data shows that they are working properly.
It's the altitude data from the barometric sensor in the IMU that's the problem.
And wind has no effect on altitude measurement.

Normally recalibrating the IMU would be the thing to do to sort out altitude issues, and I'd recommend trying that first.
But as all 5 are showing the same issue and the error is greater than usually seen, I suspect something else is at play.

I'm wondering what would cause the same problem for 5 drones.
Have the drones been modified in some way?

We have the same problem with 45 MP2Es .Pea size Altitude monitor apparently seems faulty .If only DJI Would be honest about it so we can fly with confidence. It's been a sad sticking point with DJI TECH that they don't come to the party to resolve a widespread issue

 

[Meta4]

We have the same problem with 45 MP2Es .Pea size Altitude monitor apparently seems faulty .If only DJI Would be honest about it so we can fly with confidence. It's been a sad sticking point with DJI TECH that they don't come to the party to resolve a widespread issue

I've never heard of the issue affecting DJI's consumer models, but now a second one complaining of issues with multiple enterprise models ??
I would have guessed the used the same sensors but maybe not.

 

[ZUCSTA]

I've never heard of the issue affecting DJI's consumer models, but now a second one complaining of issues with multiple enterprise models ??
I would have guessed the used the same sensors but maybe not.

Happens with Mp2 Z& P

 

[ZUCSTA]

Hi all

Just wondering if anyone else has this issue with their mavic enterprise? We have 5 for use over a vineyard (flat land) and after a 15 minute mission all 5 seem to gain 30 - 60m in altitude by the time they have finished the run.
Is there any way to improve the accuracy so it can maintain the 15m programmed altitude? Worried given we have high tension power lines nearby.
RegardsView attachment 123556

Got a reply from DJI , let me know if you still have issues and what part of the globe your at .

 

[ZUCSTA]

Altitude is barometer driven above 20 or so feet altitude.
GPS is position in 2 dimensions as looking at a map.

Can you expand on the altitude part ?
Have the ear of DJI Global safety and they say no-one has come forward with these problems before. Hard to believe since I have had these issues since early 2019.

 

[Meta4]

Can you expand on the altitude part ?

Flight altitude comes from the barometric sensor, just as it is in real planes.
The VPS sensors also provide more accurate height measurement but only have a limited short range.

Have the ear of DJI Global safety and they say no-one has come forward with these problems before. Hard to believe since I have had these issues since early 2019.

The initial poster never came back with data necessary to properly understand what their problem was or let someone identify the issue and find a solution.
It might have been equipment issues, but that's unlikely to have affected five different drones.
Or it could have been a misunderstanding in operation of the drones, which seems more likely.

His and yours are the only reports of this that I've seen and you haven't given any information to help understand what your issue is or if it's even similar to his.

Are you able to describe the problem you have observed and provide some flight data to show what's going on.

 

[ZUCSTA]

Flight altitude comes from the barometric sensor, just as it is in real planes.
The VPS sensors also provide more accurate height measurement but only have a limited short range.

The initial poster never came back with data necessary to properly understand what their problem was or let someone identify the issue and find a solution.
It might have been equipment issues, but that's unlikely to have affected five different drones.
Or it could have been a misunderstanding in operation of the drones, which seems more likely.

His and yours are the only reports of this that I've seen and you haven't given any information to help understand what your issue is or if it's even similar to his.

Are you able to describe the problem you have observed and provide some flight data to show what's going on.

He has another thread with flight data posted.
I have tried flying both in calm and slight wind and have had problems over over height and under height of up to 30+m.
Have tried all the suggested fixes. RECAL., IMU ,COMPASS ,uninstall reinstall app and firmware. It goes away for a flight or 2 but comes back again.
I have had 2 MP2E replaced 1 for a GPS Failure and another with a terminal battery failure Without the battery overheating.
I have seen dozens of posts here and on DJI Hubs about this ,my first time experiencing thus was over 18 months ago with the V1 then V2 and once again I find nearly a whole fleet (85%) with issues. Now comes the time consuming task of sending flight data off weeding out the pilot error ones and legitimate ones. Will try keep you updated .I use my MP1 for all my height crucial work now ,Dual compasses seem to keep it trouble free.

 

[SkyeHigh]

Flight altitude comes from the barometric sensor, just as it is in real planes.
The VPS sensors also provide more accurate height measurement but only have a limited short range.

The initial poster never came back with data necessary to properly understand what their problem was or let someone identify the issue and find a solution.
It might have been equipment issues, but that's unlikely to have affected five different drones.
Or it could have been a misunderstanding in operation of the drones, which seems more likely.

His and yours are the only reports of this that I've seen and you haven't given any information to help understand what your issue is or if it's even similar to his.

Are you able to describe the problem you have observed and provide some flight data to show what's going on.

DJI have been using the Bosch BME barometric pressure range of sensors for a long time as have I (for none drone use) but have never heard of them failing or losing accuracy among the electronics community.

Curious to see how it shows in the logs.

 

[Meta4]

He has another thread with flight data posted.

I read that data and asked him to post data from a freehand flight to compare.
I wanted to eliminate possible problems in his waypoint programming.
He never came back with it.

Dual compasses seem to keep it trouble free.

That is just coincidence.
The compass is completely independent of anything related to altitude.

 

[3Greens]

Hello all,

I have 2 Aircraft, a Mavic Pro and a Mavic Enterprise Dual, I also have the exact same issue with the Enterprise Dual where the altitude is displayed inaccurately.
I believe this is a software issue because it’s only started since the latest update to the Smart Controller/Aircraft.
Sometime ago I had a issue with the Smart Controller where the compass was constantly incorrect, it went to Holland at DJI’s request and came back with a note saying “please wait for new software” I did and the compass error is now cured, I think this is a similar situation all over again.
The Mavic Pro does not suffer any issues and lands accurately from where it took off as does the Enterprise Dual however when the E.D. lands it will be displaying a minus figure.

As DJI may say - please wait for new software.

Regards.