P4 Pro fell down from the blue sky :) Flight log interpretation help needed

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Hi Fellows,
I am wondering if you could help me with analysis of a log file from P4Pro that has fallen down. I am analysing it using CsvView, however I fing it a bit difficult to figure it out. Is it a lost propeller? Navigation system error? Magnetic issue? No idea!
The bird has some navigation system issues, but I have no idea why.
Thank you in advance.
Here is a link to the dat file of this **** flight easyupload.io
Cheers,
Łukasz
 
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Meta4

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Hi Fellows,
I am wondering if you could help me with analysis of a log file from P4Pro that has fallen down. I am analysing it using CsvView, however I fing it a bit difficult to figure it out. Is it a lost propeller? Navigation system error? Magnetic issue? No idea!
The bird has some navigation system issues, but I have no idea why.
Thank you in advance.
Here is a link to the dat file of this **** flight easyupload.io
Cheers,
Łukasz
Post the .txt file and I'll have a look
 
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guys, are files you are reffering to in a location dji\dji.go.v4\FlightRecord on a device I used to fly with?
The newest files are from 2019
 

BudWalker

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Hi Fellows,
I am wondering if you could help me with analysis of a log file from P4Pro that has fallen down. I am analysing it using CsvView, however I fing it a bit difficult to figure it out. Is it a lost propeller? Navigation system error? Magnetic issue? No idea!
The bird has some navigation system issues, but I have no idea why.
Thank you in advance.
Here is a link to the dat file of this **** flight easyupload.io
Cheers,
Łukasz
Looks to me like the righttBack propeller went missing. At time 447 secs the time integrated gyro data shows the P4P began to tumble by rolling CW, pitching up end over end, and rotating CW about the z axis. These are all consistent with the rightBack losing propulsion. Also, the right back was being commanded 100%. The motor current data shows that the rightBack was drawing close to 0.0 amps indicating there was no propeller
1589329968903.png
 
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@BudWalker, thank you. Actually I drew the same conclusions (lost right back propeller in flight) before posting my question, however I was looking for a confirmation and judgement if it was not due to FC/compass mallfunction. This drone sometimes tends to lose GPS connection especially during heavy winds opposite to flight direction, I cannot actually determine why.

BTW, I am using a lot your applications for data logs analysis, great job, many thanks :)
 

BudWalker

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...This drone sometimes tends to lose GPS connection especially during heavy winds opposite to flight direction, I cannot actually determine why.
....
Is it a decreasing number of sats? Or, is it a decrease in navHealth (aka gpsLevel)? The latter can be caused by other factors besides a loss of sats.
 
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BudWalker

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navHealth parameter is dropping.
The FC derives location by fusing GPS, IMU and magnetometer data. NavHealth is a measure of the confidence that the FC has in the results of that computation. Quite often a drop in navHealth happens because the IMU or magnetometer data are incorrect, not because of problems with the GPS data.

Flying into a headwind can result in high tilt angles. If the direction of flight is aligned to the geomagnetic field, i.e. magnetic north or south, then compass heading can be difficult to compute. This is because the X axis magnetometer will be more orthogonal to the geomagnetic field at the higher tilt angles.

It's also possible the cause is something else.
 
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The FC derives location by fusing GPS
Actually I came across a discussion on dji forum where you took part and explained in detail how flight data is derived from set of sensors and how a navhealth can be behaving in case of f.i. not properly calibrated magnetometers. Very usefult and substantive one. I realized how a compass calibration affected by additional factors can impact a drone behaviour. In a log I attached, like 15 seconds before it began rolling, navhealth went south. are you able to assess what was the reason of it?
Best regards,
Łukasz
 

BudWalker

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Actually I came across a discussion on dji forum where you took part and explained in detail how flight data is derived from set of sensors and how a navhealth can be behaving in case of f.i. not properly calibrated magnetometers. Very usefult and substantive one. I realized how a compass calibration affected by additional factors can impact a drone behaviour. In a log I attached, like 15 seconds before it began rolling, navhealth went south. are you able to assess what was the reason of it?
Best regards,
Łukasz
I don't see a link to the uploaded .DAT. Am I missing something?
 

BudWalker

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OK, I get it. The .DAT in your original post also contained an example of the navHealth problem you were describing. There were other parts of this flight where a Yaw/magYaw separation caused problems. They just weren't bad enough to cause the FC to set navHealth to 0. I like to look at IMUEX:err that will sometimes show problems the FC sees but doesn't decrease navHealth.
1589552995051.png

These seem to be associated with the higher pitch angles. There also seems to be some correlation with Yaw as well. I'm gonna ask @sar104 to take a look. The analysis software he uses can better tease out the relation between attitude and the Yaw/magYaw separation. Have you calibrated the compass?
 
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captainmilehigh

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Gotta say, this forum is full of some properly helpful & clever people sometimes......

Yep. They are a whole lot smarter than me. But, that's what it's all

about..........helping each other with issues and questions.

Many of us would be grounded if the help wasn't here.

To all those that step in and help............THANKS !
 
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Had a similar problem last September.
 

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Will buy for parts ;)

And yes, regarding of a support level here - chapeau bas!!!
I am trying to contribute here as per my capabilities, however level of knowlegde of a lot of folks here is simply stunning!
 
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You have my Sympathy if nothing else, It looks to me like the P3 Series had far fewer problems, the best Drone, in my opinion, is the P3A it never lets me down, and its dirt cheap second hand... I have had x3 1 STD 2ADV and Never ever did any fly away or crash, except at my doing not the Drone... I flew into a Hill, Yet it Still FLYS hardly any damage... also got a TELLO for indoor fun and high PICS of close things... I love em all thank you America for inventing them!
 
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See my post about inspecting the inside of your prop hub.

Prop Check
 
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