questions on phantom3 pro failsafe

[cheddarman]

So WHAT COUNTRY ARE YOU IN, WHERE ARE YOU mj2019??

 

[mj2019]

Armenia

 

[cheddarman]

Umm, I think it highly possible that someone is deliberately jamming the GPS for some reason or other. Have a walk around the buildings with your Garmin, see if you can narrow it down.
I don't know what the laws are there but maybe involve the police, in most countries it is illegal to block GPS.

 

[mj2019]

well first as this strange problem with gps appeared from no where it just disappeared for now!!! at least i performed two successive flights in same area with no glitch!! ill continue to search for recent changes, thats a key to know what caused this, now let me ask those questions knowing the answers will let us make a better decision in case we faced such a scenario

suppose in gps mode or rth the barometer starts giving very high altitude what will the drone do??or it gives numbers that vary by 100s of foot , will the FC neglect that?? and continue rth?? the compass error in rth will cause a fly away right, or some thing else, like quiting to other modes?? in case of gps loss in rth what will the p3 do?? and in case it was to land will it quit land and go back to rth on its own in case gps signal regained?? in case of gps signal loss does the p3 rely on accelerometer to calculate ground speed , in my case i swear the drone was flying at 100 miles when i lost the gps signal but it was only displaying the heading speed as 2m\s??

 

[Meta4]

suppose in gps mode or rth the barometer starts giving very high altitude what will the drone do??or it gives numbers that vary by 100s of foot , will the FC neglect that?? and continue rth?? the compass error in rth will cause a fly away right, or some thing else, like quiting to other modes?? in case of gps loss in rth what will the p3 do?? and in case it was to land will it quit land and go back to rth on its own in case gps signal regained?? in case of gps signal loss does the p3 rely on accelerometer to calculate ground speed , in my case i swear the drone was flying at 100 miles when i lost the gps signal but it was only displaying the heading speed as 2m\s??

The barometer is usually very reliable and shouldn't start giving incorrect readings.
A compass error isn't a fault in the compass - it's the compass warning of magnetic interference at an unsuitable launch point.
If your drone flies normally, its compass is properly calibrated and should continue to fly normally.
RTH cannot function without GPS.
If GPS is lost while in GPS, the drone would drift in atti mode, but still be fully controllable if you manually fly it.

 

[cheddarman]

Very valid point there from Meta4 - "If GPS is lost while in GPS mode, the drone would drift in ATTI mode, but still be fully controllable if you manually fly it".
In our countries our licence to fly specifies that the drone should ALWAY be visible to the pilot! Loss of GPS, drone goes into ATTI mode and you manually fly it home.

 

[mj2019]

yeh, i know that,i fully understand pgps and atti, but would like to know answers for all worst scenarios i supposed , just in case! cause we diy or semi diy guys in quads are not familiar with having a platform with no configurator, although dji made things simple by there ready to use solutions on p3 family, but they never published what will happen in details if some thing goes wrong and of course no full parameters set ,... so am sure we will pass by some one with those details known to him, its good to know..

 

[Deleted member 62848]

yeh, i know that,i fully understand pgps and atti, but would like to know answers for all worst scenarios i supposed , just in case! cause we diy or semi diy guys in quads are not familiar with having a platform with no configurator, although dji made things simple by there ready to use solutions on p3 family, but they never published what will happen in details if some thing goes wrong and of course no full parameters set ,... so am sure we will pass by some one with those details known to him, its good to know..

Unfortunately there's no book on this,,phantoms are strange as in not one fix will fix another,,everyone of them reacts differently in bad situations, dji dont know what would happen either ,pretty untested in this area but they indeed should as it's their product,,

 

[cheddarman]

I guess it would be impossible to cover every possible scenario in a book but if you look back through this and the DJI forum you find answers to just about everything!
There are thousands of drone pilots out there and every time one of them encounters a problem, like you, they come on a forum for answers.
Good luck mj2019.

 

[mj2019]

hi guys though this thread was over a while ago, ifaced a problem iwould like to share with guys here, a week ago i was flying a 3pro filming a birthday on one of my 3pro set every thing was fine, as the battery is old i always keep an eve on its level display in ther go app, it was some 30% it gave red battery levels at 3.3v and a land , i usually in such cases give throttle in such cases to avoid landing and after a min usually the warning goes away , but this time i was lucky only at 2m over grass the quad turned dead and felt to the ground, what am sure of is that the battery turned off in air. luckly no damage , the audience didnt notice i plugged another bat and flew testing it to 18 min hover for testing no problem, i pluged another bat and continued filming...
now in a course of maybe 3000 p3pro flights this happened to me once earlier on a cold day butnow temp is too fine, accidentally yester day i noticed what caused me to write this whole story!! i earlier marked the battery that i had a fallen turned off phantom last winter while in flight and i also marked the battery of last week fallen phantom, while i was arranging my room i just noticed that both batteries are not like other dji ones , both have chinese writing on them !!!
so if some one can help in this, are those batteries not dji original so at a certain voltage they shutdown ???
by theway dose the p3 dji original battery smart circuit shutdown ata certain voltage to protect the batteries??
has anyone had such an accident??
am on fw 1.9.

 

[Meta4]

i just noticed that both batteries are not like other dji ones , both have chinese writing on them !!!
so if some one can help in this, are those batteries not dji original so at a certain voltage they shutdown ???

That battery looks like a genuine one.
It's not unusual for batteries made by a Chinese company to have Chinese text.

but this time i was lucky only at 2m over grass the quad turned dead and felt to the ground, what am sure of is that the battery turned off in air.

Old batteries don't last forever and gradually lose capacity.
It could be that the battery is on its last legs and not safe to fly with.
To check your battery and get an idea of how healthy it is (or isn't) ...

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.

Check the data in the battery cell voltage columns and see what's showing at the end of the flight.
Your battery needs to have cell voltages of >3.2 volts.
When the cell voltage reaches 3.2 volts, that's critical low voltage time.

 

[mj2019]

i know that lipos age and will perform poorer, the numbers underload like 3.3will quikly rise if load is released when the drone lands, what am after is the answer to the question that when the smart battery shuts down ???
am sure its not the lipos, they can still squeeze even if at 3.0v under load we see that on our quads , it is eaither the battery board shuts down or the main drone power board or esc shuts down or all of the above????and at what value does that happen??

 

[Meta4]

i know that lipos age and will perform poorer, the numbers underload like 3.3will quikly rise if load is released when the drone lands, what am after is the answer to the question that when the smart battery shuts down ???
am sure its not the lipos, they can still squeeze even if at 3.0v under load we see that on our quads , it is eaither the battery board shuts down or the main drone power board or esc shuts down or all of the above????and at what value does that happen??

If you are seeing 3.0 volts under load, it sounds the battery is past its use-by date.

 

[mj2019]

If you are seeing 3.0 volts under load, it sounds the battery is past its use-by date.

i dont care for this value on that battery what i need is the value that oncesmart battery or p3 power boardwill not accept, am planning to test a diy lithuim ion on the p3 , li ions can still give power to 3.0v , thats why am asking for that critical value?? and as an info that may help others