Hi folks,

I was wondering what would happen in the following case:
• Spark has GPS lock and records home point successfully before takeoff
• While in the air, it loses quality GPS signal and enters OPTI mode (which actually does happen)

Will it still be able to return to home point?
If not, doesn't this make flying dangerous as in case of GPS signal loss, we are going down? In that case, RTH is good only in cases of RC connection loss?

Regards

Hello there, sparky can't go homepoint coordinates without seeing "current position" via the GPS. Actually ı guess no drone could do that. And yes it is always dangerous to fly in ATTI mode cause fly aways most of the time.

Hi,

How should the drone come back to a home point, if it doesn't even know where it is heading after an IMU failure?
In almost all the cases with the Spark flyaways it is technically not a loss of GPS reception, but an IMU problem, which results in all sorts of error messages like compass errors, GPS signal losses, yaw errors and so on. DJI should really correct this annoying problem.

If you want to do some ATTI mode training yourself and see how Sparky behaves then, see this thread.

Cheers,
Wolferl

Wolferl Posted at 2-1 04:45
Hi,

How should the drone come back to a home point, if it doesn't even know where it is heading after an IMU failure?

Does this mean that if I lose RC connection somehow, and the aircraft loses GPS signal, there is no way for it to come back?

that is correct.

mertsendag Posted at 2-1 05:13
Does this mean that if I lose RC connection somehow, and the aircraft loses GPS signal, there is no way for it to come back?

Exactly.
If you lose GPS reception/fix -> you're screwed.
If you get compass errors -> you're screwed.
If you get yaw errors -> you're screwed.

If any of that happens, you'll need to pilot your Spark home in ATTI mode. That's why I think everybody should be able to that.


Cheers,
Wolferl

no It can't go back to home point if it doesn't know where it is. If you doesn't have gps the drone doesn't know where it is.

mertsendag Posted at 2-1 05:13
Does this mean that if I lose RC connection somehow, and the aircraft loses GPS signal, there is no way for it to come back?

On it's own, no way....
Reasonable skilled pilot should be able to bring it back with ease.

mertsendag Posted at 2-1 05:13
Does this mean that if I lose RC connection somehow, and the aircraft loses GPS signal, there is no way for it to come back?

That's why you should keep your drone within your line of sight.

eYeSkYeYe Posted at 2-1 06:50
On it's own, no way....
Reasonable skilled pilot should be able to bring it back with ease.

How so? If aircraft disconnects (no RC) and loses GPS it is technically impossible to move it in any direction

Lysak2003 Posted at 2-1 06:56
That's why you should keep your drone within your line of sight.

Again, if aircraft disconnects (no RC) and loses GPS it will be impossible to move it in any direction even if you see it

mertsendag Posted at 2-1 07:26
How so? If aircraft disconnects (no RC) and loses GPS it is technically impossible to move it in any direction

Yep, you have the point....
In my experience, full connection loss is very rare though.... And even so, you are usually able to restore it pretty quickly. Than usually video link restores and it's just GPS that takes ages to get proper fix.

mertsendag Posted at 2-1 07:26
How so? If aircraft disconnects (no RC) and loses GPS it is technically impossible to move it in any direction

it will be a sad situation

Good tips to consider when flying with a bad GPS signal. This has happened to me multiple times.

darkfull1 Posted at 2-1 06:36
no It can't go back to home point if it doesn't know where it is. If you doesn't have gps the drone doesn't know where it is.

hi,

Not completely right. Most of the time GPS signals are OK but not used by the drone due to some other erorrs! (yaw, imu, speed calculation)

So the attitude indicator and compass does indicate the drone heading, so in ATTI you can use this to find your way manual back home.

Only with a 'good' compass error it is not possible to fly back (if out of sight) cause the GO 4 app screen will not give the correct information.

See this flight ; yaw errors so into ATTI mode, but GPS signals are OK (LAT LON data available).

cheers
JJB

mertsendag Posted at 2-1 07:26
Again, if aircraft disconnects (no RC) and loses GPS it will be impossible to move it in any direction even if you see it

nope, see #15

mertsendag Posted at 2-1 05:13
Does this mean that if I lose RC connection somehow, and the aircraft loses GPS signal, there is no way for it to come back?

If you can't see your Spark, this would be correct. Even if you can see it, some training may be necessary before you can successfully guide it home.

If the RC loses connection by the spark flying out of range, or if the RC battery dies or even if you point the  antennas down to the ground by mistake the  Spark will RTH as long as it does NOT lose GPS. Maybe you knew this but just wanted to be sure.  

JJB* Posted at 2-1 12:27
hi,

Not completely right. Most of the time GPS signals are OK but not used by the drone due to some other erorrs! (yaw, imu, speed calculation)

Would be good if the drone could use these data. Fortunately (or not)  in my country you are required by law to always keep your drone in the line of sight shouldn't be a problem if I loose gps. Plus I'm kind of use to ATTI mode since I fly racing drones that don't have gps.

Aircraft have flight recorders, and you can store a lot in a 120 gig sD card so I bet the major OEMS are already working on it.   The big problem in the countryside is chop shops using jammers.  If you lose contact with your drone in the same location you should repot it to the police.