Phantom 4 Advanced flyaway

[Meta4]

there is far and away enough data to show something bad was happening to this drone...now ignoring the messages makes more sense to me after hearing you say compass failure messages are not uncommon. That is where I would have said they were reckless..but if I saw compass messages routinely and never had a n incident I might ignore them too..but what if they are REAL? That drone was a goner.

I think you're reading a bit much between the lines.
There's nothing in the data that shows anything bad happening.
If there was we could lock on to it and maybe have an idea what the problem was.
The compass error messages in this case appear to have been false alarms and not related to anything.
The battery cells being 0.1v different isn't a big deal and doesn't indicate any serious issue.
There's definitely no correlation to any voltage spike - as there is no voltage spike.

 

[sar104]

I don’t put this person in that box of wreckless , they might have been, but not based on the post or the data, there is far and away enough data to show something bad was happening to this drone...now ignoring the messages makes more sense to me after hearing you say compass failure messages are not uncommon. That is where I would have said they were reckless..but if I saw compass messages routinely and never had a n incident I might ignore them too..but what if they are REAL? That drone was a goner.

The OP clarified that the flight was authorized, and so if that was the case then the pilot was not reckless - I made that point in an earlier post. In any case, reckless flying does not, usually, cause Phantoms to vanish in midair. Whether this was equipment failure or the pilot shut down the app, unplugged it from the RC or whatever, is not possible to discern from the data. Ignoring the compass errors was probably unwise, but it does not, on its own, account for the loss of the aircraft.

 

[Slickvolt]

No - I said that compass errors are relatively common. The FC is continually comparing the magnetometer data with the time-integrated rate gyro data. When they disagree it throws a compass error. The disagreement can be due to external or internal factors, such as a local field distortion or a bad compass calibration. Neither of those indicates a design fault.

Ah I see you may not be familiar with internal power spike effects. Every component has an acceptable power operating range, and depending on use of internal power conditioning every conditioner has power range tolerance. Exceed those ranges and conditioners shut down and components don’t get clean power, causin* all kinds of instability and internal component failures...I see evidence of that as well, or at least something asking for excessive instantaneous power draw

 

[sar104]

Ah I see you may not be familiar with internal power spike effects. Every component has an acceptable power operating range, and depending on use of internal power conditioning every conditioner has power range tolerance. Exceed those ranges and conditioners shut down and components don’t get clean power, causin* all kinds of instability and internal component failures...I see evidence of that as well, or at least something asking for excessive instantaneous power draw

You are going to have to point to the specific evidence, rather than just asserting that you see it, if you want to have that discussion. The device logs do not record current or power, only voltages, and those all appear to be within spec. What are you talking about?

 

[Slickvolt]

I think you're reading a bit much between the lines.
There's nothing in the data that shows anything bad happening.
If there was we could lock on to it and maybe have an idea what the problem was.
The compass error messages in this case appear to have been false alarms and not related to anything.
The battery cells being 0.1v different isn't a big deal and doesn't indicate any serious issue.
There's definitely no correlation to any voltage spike - as there is no voltage spike.

Ummmm yes there is a very obvious indication. When you see over spec cell deviation on the battery the reason is because an instantaneous demand for a lot of power draw was momentarily demanded. If you notice that cell deviation returns to normal every time, that occurs when the component or components requiring the overdraw no longer need that intense draw...something was really flipping out on that drone, maybe not just one thing...that is what the data doesn’t show..but it does show several over spec deviations during its flight..they were clearly over spec.

 

[sar104]

Ummmm yes there is a very obvious indication. When you see over spec cell deviation on the battery the reason is because an instantaneous demand for a lot of power draw was momentarily demanded. If you notice that cell deviation returns to normal every time, that occurs when the component or components requiring the overdraw no longer need that intense draw...something was really flipping out on that drone, maybe not just one thing...that is what the data doesn’t show..but it does show several over spec deviations during its flight..they were clearly over spec.

Perhaps you could state what the specification is for acceptable cell voltage deviation?

 

[Meta4]

Ummmm yes there is a very obvious indication. When you see over spec cell deviation on the battery the reason is because an instantaneous demand for a lot of power draw was momentarily demanded. If you notice that cell deviation returns to normal every time, that occurs when the component or components requiring the overdraw no longer need that intense draw...something was really flipping out on that drone, maybe not just one thing...that is what the data doesn’t show..but it does show several over spec deviations during its flight..they were clearly over spec.

If a 0.1V differential between cells causes serious issues, we'd see a lot more serious issues.
I look at a lot of these logs and that is nothing out of the ordinary.

 

[Slickvolt]

You are going to have to point to the specific evidence, rather than just asserting that you see it, if you want to have that discussion. The device logs do not record current or power, only voltages, and those all appear to be within spec. What are you talking about?

I did in another comment...the overspec cell deviations that kept occurring are just that..over spec power draws..over pec being the key engineering term..that’s why it gets flagged..it’s not suppose to do that. Something or somethings combined was demanding more instantaneous power than the battery was designed to provide..its that simple..and that translates to electronic instability in a ripple effect fashion...

 

[Slickvolt]

If a 0.1V differential between cells causes serious issues, we'd see a lot more serious issues.
I look at a lot of these logs and that is nothing out of the ordinary.

That .1v is more than a 100% increase from nominal....ooopsie

 

[sar104]

I did in another comment...the overspec cell deviations that kept occurring are just that..over spec power draws..over pec being the key engineering term..that’s why it gets flagged..it’s not suppose to do that. Something or somethings combined was demanding more instantaneous power than the battery was designed to provide..its that simple..and that translates to electronic instability in a ripple effect fashion...

Yes you keep asserting that the cell deviation is "over spec" but you haven't said what you think that the specification is. That makes it hard to discuss your hypothesis.

 

[sar104]

That .1v is more than a 100% increase from nominal....ooopsie

So you are saying that the nominal cell deviation specification is less than 0.05 V? Do you have a reference for that?

 

[Slickvolt]

The OP clarified that the flight was authorized, and so if that was the case then the pilot was not reckless - I made that point in an earlier post. In any case, reckless flying does not, usually, cause Phantoms to vanish in midair. Whether this was equipment failure or the pilot shut down the app, unplugged it from the RC or whatever, is not possible to discern from the data. Ignoring the compass errors was probably unwise, but it does not, on its own, account for the loss of the aircraft.

...and those aren’t the only failures the log shows...there is ample evidence for a hw, and or a sw error in the logs.

 

[With The Birds]

That .1v is more than a 100% increase from nominal....ooopsie

Are you saying a nominal cell deviation is 50mv?

 

[sar104]

...and those aren’t the only failures the log shows...there is ample evidence for a hw, and or a sw error in the logs.

Please - go ahead and point to the specific data that you think are that evidence.

 

[Slickvolt]

So you are saying that the nominal cell deviation specification is less than 0.05 V? Do you have a reference for that?

Look if you see nominal and happy. .02 to.08 range, then you see .11 is out of spec...it’s not rocket science there is as much as 100%increase in the deviation and as little as 30% on the deviations bringing it out fo spec...certainly 100% increase out of spec is NOT GOOD...NOT BY ANY STANDARD

 

[With The Birds]

So you are saying that the nominal cell deviation specification is less than 0.05 V? Do you have a reference for that?

With all your log snooping what do you see as a typical cell deviation for a seemingly good battery? I get suspicious of a pack that shows frequent 70mv+ deviations hiwever I have one pack that can be 120mv out on occasion that hasn’t failed me yet.

 

[Slickvolt]

Perhaps you could state what the specification is for acceptable cell voltage deviation?

Perhaps I don’t need to, as the system reported it as a fault...or did you forget already...you seem to like to argue with no point. It’s a reported failure by the system, and if you were honest you can compare the values throughout the flight and see it went over spec several times...or do you prefer mindless argument?

 

[Slickvolt]

With all your log snooping what do you see as a typical cell deviation for a seemingly good battery? I get suspicious of a pack that shows frequent 70mv+ deviations hiwever I have one pack that can be 120mv out on occasion that hasn’t failed me yet.

As it’s 1am and I’m lying in bed, I didn’t break out my calculator, but from recollection I saw a range of .02 to about .08 all within spec, no alarm. Initially there were higher draws, which makes sense, causing higher deviations, but I do recall a section where it seemed to level off at somewhere near .048, kind of a mid number in the range, so I would guess nominal deviation is probably around .05...I also noticed anywhere near .1 deviation was a reported failure...so about 100% increase in nominal yields an out of spec condition

 

[sar104]

Perhaps I don’t need to, as the system reported it as a fault...or did you forget already...you seem to like to argue with no point. It’s a reported failure by the system, and if you were honest you can compare the values throughout the flight and see it went over spec several times...or do you prefer mindless argument?

You mean the red numbers in the PhantomHelp data table? That's not a reported error - that's a PhantomHelp interpretation of the data. The FC did not record any errors.

 

[Slickvolt]

You mean the red numbers in the PhantomHelp data table? That's not a reported error - that's a PhantomHelp interpretation of the data. The FC did not record any errors.

So are you saying Phantomhelp based it’s reporting on a whim? You’re not even logical.