| Hello guys I experienced two different situations that I can't really explain and I was wondering if someone could help me understand what happened. 1) I was recording and moving forward but I couldn't descend the drone. When I stopped it, I was able to do so. The signal had 3 bars and the weather conditions were shiny and clear. I am not sure if it was a bag or a feature that OA has. (I was flying above the sea) 2) After automatic RTH the recording stopped. Usually, when I do RTH the recording continues. I am not sure if it had to do with the fact that I had a low battery percentage and the drone initiated and an automatic RTH. Thanks |
Drone did not descend and stopped recording
- Thread starter GiannisS
- Start date
With regards to 1) upload the txt flight log to either
a) here, as an attachment
b) DJI Flight Log Viewer | Phantom Help
c) Airdata.
With the phantomhelp page then copy and paste the resulting page's URL here. With Airdata you need to make the page public and post its URL here, I have forgotten how you do that,
Have a read of the Phnatomhelp site for instructions on how to get the txt flight log from the controller or phone etc..
If you are struggling to find the txt flight log tell us which controller you are using, what computer system ( Window/Mac/Linux ) you are using and if relevant what sort of phone ( Androis/IOS ) you are using..
The log might possibly tell us why the recording stopped.
a) here, as an attachment
b) DJI Flight Log Viewer | Phantom Help
c) Airdata.
With the phantomhelp page then copy and paste the resulting page's URL here. With Airdata you need to make the page public and post its URL here, I have forgotten how you do that,
Have a read of the Phnatomhelp site for instructions on how to get the txt flight log from the controller or phone etc..
If you are struggling to find the txt flight log tell us which controller you are using, what computer system ( Window/Mac/Linux ) you are using and if relevant what sort of phone ( Androis/IOS ) you are using..
The log might possibly tell us why the recording stopped.
Greetings from Birmingham Alabama USA, welcome to the forum! We look forward to hearing from you!
DJI Flight Log Viewer | Phantom Help
- Post your flight data to get help
- Go to DJI Flight Log Viewer | Phantom Help
- Follow the instructions there to upload your flight record from your phone or tablet.
- That will give you a detailed report on the flight data.
- Come back and post a link to the report it provides.
Upload and view DJI Phantom, Mavic, and Spark flight logs online
@Meta4 and/or @slup are great at offering explanations from the data.
HOW TO: Copy TXT flight logs from DJI RC remote controller
HOW TO: Copy TXT flight logs from DJI RC remote controller
@GFields @Yorkshire_Pud Hello Guys thank you both for your early response. So please find attached the two different flight logs.
1st issue regarding descending started happening approximately at 11:10 according to the flight log: DJI Flight Log Viewer - PhantomHelp.com
2nd issue regarding the stopped recording happened after 18:56.8
Thank you a lot for your help and looking forward to your updates.
1st issue regarding descending started happening approximately at 11:10 according to the flight log: DJI Flight Log Viewer - PhantomHelp.com
2nd issue regarding the stopped recording happened after 18:56.8
Thank you a lot for your help and looking forward to your updates.
There's nothing unusual in the data at that time.
Perhaps you mean for 10 seconds after 10:44.3.
Your flight data shows a fall in downlink quality at that time.
But the drone was 2.6 kilometres away at the time, in an urban area, so interference would have been a factor.
I can't see any indication that there is a problem with the drone.
The data indicates that the video was recording from 0:09.3 until 19:56.3, when the drone was 50 metres from home.
There is a message shortly after that said:
Aircraft storage full. Back up file and clear space (Code: 10062)
That explains why the video stopped.
Hello, thank you for your early response. I hope so, is my first drone and I am a bit worried it is faulty. However I am sure that I had to stop moving forward on air in order to lower the altitude because i tried 3 times and i couldnt . Hope as you said was the intereference of the signal. Do you think that i should replace it with a new one? The 14-day return period havent passed yet
Yeah but I wasn't using the aircraft's storage but instead an SD card at the time which I am sure had plenty of free space for it
There's no indication that there is anything wrong with the drone.
Interference at that distance over an urban area, particularly with the drone down low and close to the interference can cause glitches in the control signal.
Recording stopped when that message appeared.
I'd check the card and internal storage as the message says.
Sorry again for the disturbance guys i did a mistake in the timings for the descending issue. So it's not at 11:10 but between 10:44,7 and 10:49,3
Thanks again for your time !
Uuum I think there may have been a few moments when the drone paused its descent but at the moment I don't think you need be worried about them but I am going to sleep on this,
Attached are plots of the flight produced by CsvView ( CsvView Downloads ). You can see some minor 'platforms' in the descent when full elevator is given,
I am not sure if these are a consequnce of wind.
The set of three plots show
a) height vs horizontal speed,
b) throttle & elevator,
c) drone pitch & roll.
However the main reaosn fo my posting is to say I think you need to think about the way you are flying this.
You took off from somewhere that seems to be 350ft above sea level and maybe from the roof of a house which would add another 20 to 30ft to the AMSL.
Relative to the take off point the drone reached a maximum height when over the sea of 87ft.
Presumably, without getting its feet wet, the drone also reached -422ft whilst over the sea. In combination those two suggest that the previously mentioned high was more than 510ft AGL,
Additionally, your go home height was set to 394ft and the failsafe was set to RTH. A disconnection over the sea would have sent the drone up to somewhere between 700 and 800ft AGL,
Aside from possibly being into manned aircraft airspace and leaving your open to discussions with the authorities such heights could put the drone up into significant wind.
I am curious, how where you assessing that the drone was not descending, I think it must have been via the screen, at a distance of 8,000ft there is no way you could see the drone.
Assuming you were screen watching I am somewhat surprised you could see the pauses in descent, you must have good eyes..
Attached are plots of the flight produced by CsvView ( CsvView Downloads ). You can see some minor 'platforms' in the descent when full elevator is given,
I am not sure if these are a consequnce of wind.
The set of three plots show
a) height vs horizontal speed,
b) throttle & elevator,
c) drone pitch & roll.
However the main reaosn fo my posting is to say I think you need to think about the way you are flying this.
You took off from somewhere that seems to be 350ft above sea level and maybe from the roof of a house which would add another 20 to 30ft to the AMSL.
Relative to the take off point the drone reached a maximum height when over the sea of 87ft.
Presumably, without getting its feet wet, the drone also reached -422ft whilst over the sea. In combination those two suggest that the previously mentioned high was more than 510ft AGL,
Additionally, your go home height was set to 394ft and the failsafe was set to RTH. A disconnection over the sea would have sent the drone up to somewhere between 700 and 800ft AGL,
Aside from possibly being into manned aircraft airspace and leaving your open to discussions with the authorities such heights could put the drone up into significant wind.
I am curious, how where you assessing that the drone was not descending, I think it must have been via the screen, at a distance of 8,000ft there is no way you could see the drone.
Assuming you were screen watching I am somewhat surprised you could see the pauses in descent, you must have good eyes..
Attachments
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Hello @Yorkshire_Pud and thank you for answering my question. I saw the graphs and is clear I think in the first one (speed v elevation) the pause in its descent. You mentioned something about the wind but I am not sure how this can affect its descent movement (I am guessing you are referring to a potential signal loss from interference). But wouldn't that be indicated in a rudder map where all the response timings are mentioned? Is there any other potential reason that can justify its behavior? As long as the altitude is considered, generally, I don't have any issue with it cause I manage to keep it always under 120m (approx. 400ft.). Remember that we always talking about AGL which simply means to keep the altitude (approx. the distance between the point where the underneath sensors are located to the point on the ground where the drone flies at the time) lower than the aforementioned value. I always try to fall in line with what the current regulations state no matter how unclear are. Lastly, I would say that these are the benefits of a drone equipped with occusync 4 plus don't forget that the descending speed is written in big letters on the left-hand side of the screen.
Thank you a lot for your time spent on my question and your help of course!
Thank you a lot for your time spent on my question and your help of course!
I am not sure why you removed the attachments and/or did not provide links to Phantomhelp. People here want to help, but also want to learn. That continues after the OP questions have been answered.
Simply because they are not working anymore and they were reverted to the original website....
Let me start out by saying... it indeed was a couple abnormalities regarding how the drone obeyed commands for a descent, and it hadn't anything to do with control signal glitches... and it wasn't any faulty drone that caused it either.
The cause was likely wind related, together with how the firmware prioritized between holding the heading speed up, preventing side drift & at the same time slowing down the motor RPM to descend.
This unresponsiveness to descend only occurred when you commanded max heading speed with a full elevator stick input, together with a negative throttle input for a descent.
The windspeed from one of the occasions where this happened is shown below... the wind was coming in from south & the flight direction was in an nearly exact easterly direction, pretty much a precise side wind.
During this section the drone struggled to prevent a northerly drift & at the same time obey your command for max heading speed. The roll & pitch angle was nearly the same, about 20 degrees, this together made up a total tilt angle of 30 degrees... which is max for the mode you flew with.
The drone mostly managed to prevent a northerly drift & at the same time achieve those 12m/s (27mph) that is max for the mode. But here you also commanded max descend speed with a full negative throttle input... nothing happened here at all, the vertical speed stayed at 0m/s. So all became a prioritization game...
-allowing a descent without scarifying the heading speed = drone starts to drift north
-allowing a descent & preventing a northerly drift = the heading speed disappears
-allowing the commanded heading speed & preventing side drift = the motor RPM's can't be lowered to make descending possible.
DJI went with the last combination as a highest priority...
As soon as you let off from the elevator stick for full heading speed completely... other opportunities opened, which allowed the drone to direct the tilt angle directly into roll & by that prevent the drift easier & at the same time lower the RPM for a descent.
Here's the original .TXT log... upload it to either PhantomHelp or Airdata yourself for a quick overview.
I later found that OP asked same question in DJI forum with these, working, links:
1st : DJI Flight Log Viewer - PhantomHelp.com
2nd : DJI Flight Log Viewer - PhantomHelp.com
Hello, I just saw your message and I really appreciate all the time you spent on the provided explanation. However, today it did the exact same thing. When switched into cine mode the decent was disabled again when the moving forward stick was in command. I tried to switch it back to normal but nothing changed. Here you can find the flight log info for today:
(8m 7.6s -8m 26.4s)
Are you sure that it is not an issue from signal interferences? Someone else from a different forum gave me this explanation "Quadcopters always produce vertical thrust, in any flying conditions, without any vertical thrust it will become a falling brick.Flying with full forward stick (thus fwd speed) and full down stick will make the drone descend with a linear rate of descend value. In this fly situation, there are both a vertical and horizontal thrust component ; vertical force < mass of object = descending." But wouldn't there be any Dji software to prevent this effect? I really kinda losing it cause I am not really sure what's going on. This effect now is happening almost every time. Have you experienced something similar with your drones? Another explanation of mine is that when the signal is weak it tries to keep the altitude constant in order to avoid any potential loss. But again isn't something that make me feel better.
Thank you again for your help and looking forward to updates!
This thread might raise an interesting discussion of a seemingly very simple question, " how does a drone descend under control ? "
My initial thoughts were it slows the motors and that is true............but.....
If the motors slow their propellers produce less thrust, if the sum of the vertical components of the thrust from each propeller is less than the thrust needed to counter act gravity then the drone accelerates downwards.
It then occurred to me that in order for the drone to descend in a controlled manner at a specific speed the vertical components of the prop thrust and aerodynamic drag must be more or less equal to the force required to counter act gravity. Variations away from that 'balance' would result in an acceleration either upwards or downward.
Think of travelling in a lift, your apparent weight changes when the lift is accelerating, when the lift is travelling at a constant speed then your weight seems the same as normal.
This morning another variable entered my head but my physics is too rusty to work it out.
When the drone is descending it is losing gravitational potential energy, the question that came into my head was, "does this loss of potential energy have an effect on the required motor rpm ?".
A question for perhaps @sar104
With drones where the DAT can be read one can check the motor speeds during descent and they are slowed somewhat during a descent, I recollect checking this and in some cases the slowing struck me as quite significant and in others it struck me as fairly small (relatively speaking).
Unfortunately with the mini 4 pro's I think the DATs from both the screen device and the drone are encrypted.....that's a pity.
It might be interesting to perform some experiments in this area, I do not have a mini 4 pro so I can't do them.
My first suggestion would be to set the stick gains to what ever value, ( 0.5 ? ), gives a straight line response in the associated plots, I think that you can now do this in the fly app.
I would then make throttle-fully-closed descents at various CONSTANT elevator settings and hold the individual elevator settings for long enough for the drone to reach a steady horizontal speed, it would need a wind less day, if you get them there.
Process the flight logs with CsvView and look to see what the speed vs height plots or z vs h speed plots show.
I am just wondering if this behaviour starts at a certain speed.
It might also be interesting to see what happens whilst the drone is accelerating horizontally.
You can probably control acceleration by very careful movements of the elevator joystick but it might be an idea to check if it is possible to change the horizontal acceleration limits in the fly app. I have never looked into that so have no idea if there is such a feature even in the likes of Go & Go4.
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