Sudden height increase! What's going on?

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Today i was going for a flight like normal, on a beach close by,
If been there often with my p4, an like always did the checks, hovering nearby en testing all the controls, then i swiched to sport mode, and pushed up at my controller.
As always my height is at max 100m, but this time it went farther up by itself, till 180m! I released the stick at approx 100m but it still climed, even when i was trying to lower it. It was a scary moment till it finally responded to desent.
(I also got a warning at 90m; propulsion output limited, aircraft mobilty has been lowered, after that no respond to get it down untill 180m).

I didnt feel save anymore to fly nearby the water so i put it back in normal mode and flew a litle away above a other field and pressed RTH, wich is always set at 60m.

Now it starts to climb till 60 i thought, but it went up till 110m and didnt respond anymore till suddenly it stopped and i could manually get it down.

Tryed testing RTH one more time and same thing happend!

I am not feeling safe anymore to fly with it.
Had all the updates and stuff.
Did the compass calibration like normal.
And the settings in the app still says 100m max height and 60m RTH

What now? Does anyone had a same experience?

Is it best to send it in, or should i upload the file here so somebody can see what happend?

Sorry for the long post;)
Greetz marcel

Sent from my SM-G920F using PhantomPilots mobile app
 
Last edited:
I would try again another day before you send it back. Maybe it was just a sudden change of atmospheric pressure that influenced the barometric altimeter inside the P4.
 
Propulsion auto-limit was added to firmware to prevent sudden battery shutdown following high voltage consumption and heat.


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I would try again another day before you send it back. Maybe it was just a sudden change of atmospheric pressure that influenced the barometric altimeter inside the P4.

If that were the case why would telemetry report a higher altitude?
Whatever OP was seeing, is whatever the P4 thinks it is at.

In other words, even if the sensors are wrong, and cause the P4 to think it is at altitude say of 120m when in reality it is at 90m, the algorithm of the IMU should make it go back to the height it was or to the max, which means it would have forced it down and not up.

This looks to me more like a problem, and I would send it back. Definitely also post your log files so people can chime in and analyze.


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If that were the case why would telemetry report a higher altitude?
Whatever OP was seeing, is whatever the P4 thinks it is at.

In other words, even if the sensors are wrong, and cause the P4 to think it is at altitude say of 120m when in reality it is at 90m, the algorithm of the IMU should make it go back to the height it was or to the max, which means it would have forced it down and not up.

This looks to me more like a problem, and I would send it back. Definitely also post your log files so people can chime in and analyze.


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Good reasoning, but there could be more parameters involved than just one wrong sensor. Maybe quickly changing barometric conditions due to temperature shifts being close to the sea and because of that conflicting altitude data between GPS and the barometer.

When you are right, it indicates a bug in the firmware itself, and that should affect all P4 drones running the same version. This is unlikely because in that case there should be many more reports.

I would test the drone once more, on a different day, on a different location, before starting to panic and running to the post office to send it back.
 
Good reasoning, but there could be more parameters involved than just one wrong sensor. Maybe quickly changing barometric conditions due to temperature shifts being close to the sea and because of that conflicting altitude data between GPS and the barometer.

When you are right, it indicates a bug in the firmware itself, and that should affect all P4 drones running the same version. This is unlikely because in that case there should be many more reports.

I would test the drone once more, on a different day, on a different location, before starting to panic and running to the post office to send it back.

GPS does not carry altitude data. Regardless of how many sensors are involved, the altitude reported is the one used by the phantom.
And, it cannot be a bug in the firmware because everyone would have been reporting this.
So my conclusion is that there is something wrong with the phantom, or the controller.
If OP does not want to return the phantom, then IMHO, the only thing to try is reinstall the firmware and recalibrate everything.




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I'm gonna reinstall en callibrate again like suggested, en try it on a wide open field later.
also i will upload the flight tonight from yesterday, so somebody could check it out.
It was on a "beach" of a lake (not sea) where i already flown for like 10 hours there minimum on many trips, im no expert but that doesnt feel like a atmosphere problem;)
Hope its a simple problem, last time i had almost sent it in with a gimbal problem, and after posting on this forum and using the reply's i had it solved! Got a love a big community;)


Sent from my SM-G920F using PhantomPilots mobile app
 
Have you recently installed any accessories, like a gimbal guard?
Nope, i know what you mean, i had bought one a few months back but i think its not a good product cause of yoyo effect;)
But it was just a normal flight like always so it scared the #$# out of me! thought it went bezerk and gonna be a fly away, and if i cant retrive it because of the lake then i would really had a problem with trying to get a free replacement[emoji6]

So back tot fields for some tests i guess

Sent from my SM-G920F using PhantomPilots mobile app
 
Today i was going for a flight like normal, on a beach close by,
If been there often with my p4, an like always did the checks, hovering nearby en testing all the controls, then i swiched to sport mode, and pushed up at my controller.
As always my height is at max 100m, but this time it went farther up by itself, till 180m! I released the stick at approx 100m but it still climed, even when i was trying to lower it. It was a scary moment till it finally responded to desent.
(I also got a warning at 90m; propulsion output limited, aircraft mobilty has been lowered, after that no respond to get it down untill 180m).

I didnt feel save anymore to fly nearby the water so i put it back in normal mode and flew a litle away above a other field and pressed RTH, wich is always set at 60m.

Now it starts to climb till 60 i thought, but it went up till 110m and didnt respond anymore till suddenly it stopped and i could manually get it down.

Tryed testing RTH one more time and same thing happend!

I am not feeling safe anymore to fly with it.
Had all the updates and stuff.
Did the compass calibration like normal.
And the settings in the app still says 100m max height and 60m RTH

What now? Does anyone had a same experience?

Is it best to send it in, or should i upload the file here so somebody can see what happend?

Sorry for the long post;)
Greetz marcel

Sent from my SM-G920F using PhantomPilots mobile app
Re-calibrate your VPS sensors using the DJI Software
Assistant. If it fails repeatedly try another computer screen.
 
GPS does not carry altitude data. Regardless of how many sensors are involved, the altitude reported is the one used by the phantom.
And, it cannot be a bug in the firmware because everyone would have been reporting this.
So my conclusion is that there is something wrong with the phantom, or the controller.
If OP does not want to return the phantom, then IMHO, the only thing to try is reinstall the firmware and recalibrate everything.




Sent from my iPad using PhantomPilots
From wikipedia:
GPS satellites broadcast signals from space, and each GPS receiver uses these signals to calculate its three-dimensional location (latitude, longitude, and altitude) and the current time.

I'm not sure the P4 uses this data, but why shouldn't it within a certain threshhold compared to the barometric data?

There maybe something wrong with the Phantom, but no product advanced like this is without bugs. It is quite possible that a unique set of circumstances led to this behavior, and it should be tested in a different environment to be able to determine the cause of that problem.
 
Test in a new location like a field to make sure your RTH is functioning properly.

I suspect sudden change in barometric pressure caused the sudden change in altitude. The air currents over a hot sandy beach are different from the air currents over cool/cold water these differences can cause "thermal turbulance" and or sudden changes in altitude.
 
Ok, so i tested it after vps and imu calibration.
Flew low and high, short and far, p en s mode, and tryed a bunch of manouvres and modes....(and RTH low, mid and high)
The result is that after the calibrations it works almost perfect again!
I say almost, cause now it takes more time to warm the craft up and the gimbal is moving till its ready to fly, and when im getting it to land (even in p mode) the drone wobbles a little (never seen it before) so even if i think it was good, i think its wise do calibrate vps again.
Maybe it wasn't so perfectly done[emoji6]

After work i will still try to find the time to upload the data of the scary flight, cause i still really would like to now what happend and if it can happen again due to problems with my bird or something.


Sent from my SM-G920F using PhantomPilots mobile app
 
I say almost, cause now it takes more time to warm the craft up and the gimbal is moving till its ready to fly, and when im getting it to land (even in p mode) the drone wobbles a little (never seen it before) so even if i think it was good, i think its wise do calibrate vps again.
Do a cold IMU calibration and it will shorten the warm up time. There are many threads on this subject.
 
It's not possible to turn off VPS in DJI GO.
 
It's not possible to turn off VPS in DJI GO.

I assume you're referring to Vision Positioning System? I ask because I'm considering a P4. As with the P3A & P3P you can enable or disable the VP. So why the difference between the P3's & the P4?


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