GPS, ATTI, OPTI Modes - what controls modes and are they controllable

[Dougcjohn]

Several threads indicate ATTI or OPTI mode and concern GPS kicks in while flying indoors. Is there a RC control I’ve overlooked that allows a controlled switch & hold of a non-GPS mode? Is it only gps signal that determines mode? What is difference or what controls which for ATTI or OPTI mode? Some say, use OPTI mode on indoors, how do you select these modes? Is there a mode for indoor flying... that forces the proper mode by turning off various sensors? Like an "airplane" mode for cell phones. Realize this is probably a bit naive to some, but when I feel I have a handle on it, another thread creates confusion.

 

[vashon100]

In addition to the manual, there's this link Expert World Travel that might help.

 

[Kilrah]

No. That's one of the main complaints about the Mavic, you cannot choose/force a simpler mode manually, it always decides by itself based on sensor availability and that isn't reliable in borderline conditions hence the recommendations not to fly indoors or with spotty GPS coverage.

 

[Lake_Flyer]

And that's why the Mavic is not the drone to start with. when you never flown a drone before and have no clue what you're doing. It's a robotic flying system that needs to be fully understood by the user.

 

[Dougcjohn]

And that's why the Mavic is not the drone to start with. when you never flown a drone before and have no clue what you're doing. It's a robotic flying system that needs to be fully understood by the user.

That has some merit, it certainly allows new flyers to fly safely and controllable, but they don't learn the foundation of all the flight dynamics. I lean more on the side of robotic electronics, overall more will join the hobby, learn & enjoy. But on your point and my question, I would like the ability to control and turn off SW to add to the abilities and controlabilty.

I understand the rotor flight concept, I've built & flown RC gas choppers and many low grade quads over the years... all lacked the electronics of modern quads. The early gyros were crude but exciting introduction. The guidance systems are the areas of question and SW controllability.

Everyone is confirming these are electronically controlled and no manual overrides. Makes indoor or darkness a little more challenging if sensors activate suddenly due to environment.

Various threads indicate this is a MP deficit, are the Phantom series different? Are the Yuneec series any different?

 

[Dougcjohn]

In addition to the manual, there's this link Expert World Travel that might help.

Thanks... great 2 articles. So isn't OPTI mode better than ATTI mode... it's using visual and barometric sensors where ATTI is barometric only for altitude. Is that correct? Then why does it always fail outside to ATTI mode instead of OPTI mode... it's bright enough for visual sensors?

 

[vashon100]

Thanks... great 2 articles. So isn't OPTI mode better than ATTI mode... it's using visual and barometric sensors where ATTI is barometric only for altitude. Is that correct? Then why does it always fail outside to ATTI mode instead of OPTI mode... it's bright enough for visual sensors?

Yes. Yes. Lighting and height limitations affect whether opti mode works. There is a list of other considerations in the opti article portion too.

 

[Xtreme Drone Pilot]

And that's why the Mavic is not the drone to start with.

No, it's exactly why Mavic is THE drone to start with. The last thing beginner needs is that ATTI switch. Mavic is the most idiot-proof drone on the planet.

 

[Kilrah]

Various threads indicate this is a MP deficit, are the Phantom series different?

Yes, Phantoms have manually selectable ATTI.

Thanks... great 2 articles. So isn't OPTI mode better than ATTI mode... it's using visual and barometric sensors where ATTI is barometric only for altitude. Is that correct? Then why does it always fail outside to ATTI mode instead of OPTI mode... it's bright enough for visual sensors?

OPTI only works when close (<13m at best) to ground, i.e. almost never when you're out flying.

No, it's exactly why Mavic is THE drone to start with. The last thing beginner needs is that ATTI switch. Mavic is the most idiot-proof drone on the planet.

Strongly disagree, yes for their first few flights auto is nice, but as soon as they manage that they should start training in ATTI mode for the day the aircraft falls back to it at the worst possible moment since that WILL happen. The Mavic doesn't let them do that, so people are untrained and that played a role in many lost aircraft scenarios posted here.

 

[Lon Denard]

Now this is very interesting. I happen to own a drone, 3DR Solo, that you can manually set the modes. It's instructive but in my opinion, dangerous. My advice for anyone that wants to least to fly "manual" is to get a small, inexpensive, non gps drone to play with. $1,000 be isn't a ton of money but it's too much for experimenting. The point of the Mavic, and other drones like it, is for the average smuck to be able to operate it. There are plenty of more advanced models to be had, if you're feeling froggy.

The one question I've had is the notion that it's "dangerous" for the drone to go from atti to gps. To me that's more safe and stable. I fly indoors a lot and I've never had any problems. In the past, with other drones, the problems start when you lose gps mode, not when you gain it. In fact, just today, I took off from inside my warehouse (opti), flew around inside (atti\opti) then out a door (gps) Flew outside for a few and then back in (opti until I landed). No problems.

 

[LivinLarge]

For those who started out on the earlier model Phantoms, it was important to learn to fly in ATTI mode, because if GPS was lost or the compass was confused, the drone would just fly away. The way to save it was to switch to ATTI mode (which ignores GPS and compass) just fly it back home. I have wished that there was a physical switch on the Mavic. I read that there is a hack that will allow changing the function of the Sport mode switch to ATTI instead.

 

[Kilrah]

In fact, just today, I took off from inside my warehouse (opti), flew around inside (atti\opti) then out a door (gps) Flew outside for a few and then back in (opti until I landed). No problems.

Great. Just be aware that there have been dozens of reports on here about either OPTI getting confused or GPS kicking in with a poor signal and the aircraft flying itself into a wall with no way to prevent it.
When it works it's nice, but the fact you have no way to force a known safe mode means that when it doesn't the brown stuff is guaranteed to hit the fan.

 

[Lon Denard]

Great. Just be aware that there have been dozens of reports on here about either OPTI getting confused or GPS kicking in with a poor signal and the aircraft flying itself into a wall with no way to prevent it.
When it works it's nice, but the fact you have no way to force a known safe mode means that when it doesn't the brown stuff is guaranteed to hit the fan.

Hey you could be right but I have done this at least 20+ times. It's actually my favorite way to launch. I honestly don't get how the drone "just flies into a wall" without any control input. It might not hover perfectly stable from gps to atti or opti. That I get. The wind speed was about 15 mph outside, so I had to be careful coming back in because the drone was fighting a cross wind to zero suddenly. What I don't get or have never seen or understood, is how a crash would occur if gps came on while you were indoors? Why would it suddenly fly into a wall with you having no control?

Maybe I'm missing something but I'm hearing you say. "I'm indoors hovering in opti mode, gps kicks in and my drone flies into a wall and I'm powerless to stop it."

 

[LivinLarge]

Hey you could be right but I have done this at least 20+ times. It's actually my favorite way to launch. I honestly don't get how the drone "just flies into a wall" without any control input. It might not hover perfectly stable from gps to atti or opti. That I get. The wind speed was about 15 mph outside, so I had to be careful coming back in because the drone was fighting a cross wind to zero suddenly. What I don't get or have never seen or understood, is how a crash would occur if gps came on while you were indoors? Why would it suddenly fly into a wall with you having no control?

Maybe I'm missing something but I'm hearing you say. "I'm indoors hovering in opti mode, gps kicks in and my drone flies into a wall and I'm powerless to stop it."

Even if you can receive GPS signals indoors, they may be very unreliable. It may be that the aircraft is trying to return to a previous GPS position that is outside that wall you hit and that return to position takes precedence over stick inputs.

 

[Lon Denard]

Even if you can receive GPS signals indoors, they may be very unreliable. It may be that the aircraft is trying to return to a previous GPS position that is outside that wall you hit and that return to position takes precedence over stick inputs.

Hmm.... Okay but why is it "trying to return to a previous GPS position"? I'm being honestly curious. I can't see the logic here. I've owned several drones of questionable GPS abilities, the Karma for example, I've never had one fly off because it gained GPS lock. I've had them try to take off after losing GPS. I'm being serious here, I fly this way all the time, >70% of my flights, if there's a legitimate problem, I want to hear it. If it's just a bunch of guys that are just blaming the drone for their mistakes or some old repaired glitch then not so much.

 

[LivinLarge]

Hmm.... Okay but why is it "trying to return to a previous GPS position"? I'm being honestly curious. I can't see the logic here. I've owned several drones of questionable GPS abilities, the Karma for example, I've never had one fly off because it gained GPS lock. I've had them try to take off after losing GPS. I'm being serious here, I fly this way all the time, >70% of my flights, if there's a legitimate problem, I want to hear it. If it's just a bunch of guys that are just blaming the drone for their mistakes or some old repaired glitch then not so much.

I have no real knowledge of how these algorithms work in the Mavic. I do know from several bad experiences with early Phantoms, that when GPS or compass was confused, the drone might just take off at full speed in some random direction, ignoring stick input, unless you were quick enough to switch into Atti mode.
I do know that GPS signals can bounce around indoors and give false positioning. One second, the drone thinks it is in position A, the next second, it thinks it has moved to position B even though you have given no stick input so it tries to return to position A. In GPS mode, it also uses the compass which may be unreliable indoors.
I have not tried flying indoors, so I am just guessing. It would be interesting to see flight logs from those who have had these problems. If the logs show positions outside the building or compass errors then that might explain the behavior.

 

[Lon Denard]

I have no real knowledge of how these algorithms work in the Mavic. I do know from several bad experiences with early Phantoms, that when GPS or compass was confused, the drone might just take off at full speed in some random direction, ignoring stick input, unless you were quick enough to switch into Atti mode.
I do know that GPS signals can bounce around indoors and give false positioning. One second, the drone thinks it is in position A, the next second, it thinks it has moved to position B even though you have given no stick input so it tries to return to position A. In GPS mode, it also uses the compass which may be unreliable indoors.
I have not tried flying indoors, so I am just guessing. It would be interesting to see flight logs from those who have had these problems. If the logs show positions outside the building or compass errors then that might explain the behavior.

Now this is what I like! Hypothesis based on reasoned conjecture and experience. I'm not aware of compass being unduly affected by merely being indoors but I could be wrong. The thing with GPS is intriguing. It's my experience that most modern drones ignore GPS when it is faulty or contradictory. Which is why the Mavic changes modes when it loses its GPS lock. I won't say conclusively that it wouldn't take off if it received confusing GPS data but considering that it uses two separate systems and typically locks in a dozen or more satellites, I find this hard to conceptualize. Obviously, a case can be made that this is a defect in some of the units. IE their processor went crazy when it received conflicting data. However, I don't see this as endemic of the entire product line as the unit is advertised to be safe to fly indoors. Some may remark that DJI doesn't care but I can assure you that they care very much if it can be shown that it might, during normal use, spontaneously fly into your child's face with sharp, spinning blades. Blind children make very unappealing spokesmodels.

 

[MAvic_South_Oz]

It's a robotic flying system that needs to be fully understood by the user.

Something I read on another thread n the past couple of months has stayed in my head . . . you are controlling a computer that is flying the Mavic . . . how true that is most of the time even while you are in charge of basic directional / speed controls.

 

[Lon Denard]

Something I read on another thread n the past couple of months has stayed in my head . . . you are controlling a computer that is flying the Mavic . . . how true that is most of the time even while you are in charge of basic directional / speed controls.

True but the same can be basically said about driving a car.

 

[MAvic_South_Oz]

True but the same can be basically said about driving a car.

I'm glad my vehicle doesn't return to home if getting low on fuel, or park if I get near the kerb