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Mavic Air 2 home point in vision mode

EvanAle

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Hello everyone,

I would like to share the following experience that I had recently flying my MA2 (using the UgCS app for DJI). I was inside a gorge without gps reception so I was flying in vision mode. Once the drone was at max alt ~30 m above ground it probably found gps signal and switched to gps mode. Considering that I was just hovering and not flying along a route, I decided to drain the battery until it starts rth. When rth (due to low battery) started, I noticed that the drone moved for approximately 50m off the take-off position. Then I took it hovering above me and set a new home-point and that's how I managed to land it where it took-off.
This experience makes me think the following:
- was there a spatial adjustment of the home point when the drone switched to gps mode? If yes, then why that happened?
- does this relate to the app or the drone software?
- how does the MA2 set the home point in vision mode? Is it with compass, speed and altitude?
I suppose that home-point is a critical parameter and it should not change from one mode to the other.
Did any of had a similar experience that you would like to share?

Thanks a lot and enjoy!
Evan
 
If you took off wuithout GPS then no home point was set. If you get a GPS lock is during the flight the home point is set to that, so it'll be wherever you are at that point.

how does the MA2 set the home point in vision mode?
It does not. There can't be any home point or RTH without GPS. If you consider it critical (rightly so) you never fly without GPS nor take off before the home point was set.
 
If you took off wuithout GPS then no home point was set. If you get a GPS lock is during the flight the home point is set to that, so it'll be wherever you are at that point.


It does not. There can't be any home point or RTH without GPS. If you consider it critical (rightly so) you never fly without GPS nor take off before the home point was set.
Hi,

Thanks for the feedback! Now it makes sense, because I flew it within a short radius from the take-off position. So, if the battery gets low in vision mode then the drone is going to land at the nearest location? In any case, I believe it would be a good thing to be able to set home in vision mode. That shouldn't be much of a struggle to implement..
 
In any case, I believe it would be a good thing to be able to set home in vision mode
How could it do that?
What references would it use and how would it work out where it was in relation to where the homepoint is.
For the drone GPS is the source of all that information and in "vision mode" is not GPS insufficient?
 
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...I believe it would be a good thing to be able to set home in vision mode. That shouldn't be much of a struggle to implement..
?

Here's a map covering the whole globe ... the HP is where the red cross is placed, I know exactly where it is.

1631565635913.png

The only problem now... is to get my drone to understand where it's present location is & in which direction it should fly in order to return home.
 
Welcome to the MavicPilots forum. Hopefully, the excellent advice the forum gave will keep you safe in the sky. Enjoy, and happy flying! ??
 
Hello everyone,

I would like to share the following experience that I had recently flying my MA2 (using the UgCS app for DJI). I was inside a gorge without gps reception so I was flying in vision mode. Once the drone was at max alt ~30 m above ground it probably found gps signal and switched to gps mode. Considering that I was just hovering and not flying along a route, I decided to drain the battery until it starts rth. When rth (due to low battery) started, I noticed that the drone moved for approximately 50m off the take-off position. Then I took it hovering above me and set a new home-point and that's how I managed to land it where it took-off.
This experience makes me think the following:
- was there a spatial adjustment of the home point when the drone switched to gps mode? If yes, then why that happened?
- does this relate to the app or the drone software?
- how does the MA2 set the home point in vision mode? Is it with compass, speed and altitude?
I suppose that home-point is a critical parameter and it should not change from one mode to the other.
Did any of had a similar experience that you would like to share?

Thanks a lot and enjoy!
Evan
Highly encourage you to learn more about your drone BEFORE flying it. Many, many YouTube video and other things to fully understand how the drone works.

Flying and NOT having GPS and being what seems to be a newbie is a dangerous combo. Never heard the term "vision mode" but guess that is same as ATTI - no GPS and flying by seat of pants. ATTI is not recommended for any beginner and esp around any kind of gorge or other place where very likely you'll lose the drone.

Taking the battery down to RTH level and not really having GPS / RTH is another recipe for a lost drone. Best when learning to fly - find a nice big wide open field / space that allows full GPS mode and practice A LOT there to see how the drone works. Far less chance to lose the drone than flying around or in a gorge / canyon / etc.

Learning to fly in ATTI mode should only be done once you are good with how the drone reacts under many different conditions WITH GPS. ATTI is very different and the drone can and will do a lot of weird things - as GPS is essential in keeping it stable under normal conditions. You won't have that with ATTI.

Learning to fly a drone is like learning to ride a bike / etc - one small step at a time. Trying to be a cowboy on first few flights will more than likely end with a crashed / lost drone. That is NO FUN.
 
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Highly encourage you to learn more about your drone BEFORE flying it. Many, many YouTube video and other things to fully understand how the drone works.

Flying and NOT having GPS and being what seems to be a newbie is a dangerous combo. Never heard the term "vision mode" but guess that is same as ATTI - no GPS and flying by seat of pants. ATTI is not recommended for any beginner and esp around any kind of gorge or other place where very likely you'll lose the drone.

Taking the battery down to RTH level and not really having GPS / RTH is another recipe for a lost drone. Best when learning to fly - find a nice big wide open field / space that allows full GPS mode and practice A LOT there to see how the drone works. Far less chance to lose the drone than flying around or in a gorge / canyon / etc.

Learning to fly in ATTI mode should only be done once you are good with how the drone reacts under many different conditions WITH GPS. ATTI is very different and the drone can and will do a lot of weird things - as GPS is essential in keeping it stable under normal conditions. You won't have that with ATTI.

Learning to fly a drone is like learning to ride a bike / etc - one small step at a time. Trying to be a cowboy on first few flights will more than likely end with a crashed / lost drone. That is NO FUN.
Darn right. I can't think of a more reckless way to fly a drone.
 
Highly encourage you to learn more about your drone BEFORE flying it. Many, many YouTube video and other things to fully understand how the drone works.
Never heard the term "vision mode" but guess that is same as ATTI - no GPS and flying by seat of pants.
May I recommend you follow your own advice and learn more about your drone before giving guess-based incorrect comments on something you don't know about?
 
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Kilrah - what is the vision system on an MA2?
 
The camera that looks down and allows for holding position/GPS-like control without GPS as long as you're below the max height it can work at. Every DJI aircraft since the Inspire 1 has it.
 
The camera that looks down and allows for holding position/GPS-like control without GPS as long as you're below the max height it can work at. Every DJI aircraft since the Inspire 1 has it.
You need to go back and reread the manual. The Air 2 vision system is much more than that.

Head to page 16 of the Mavic Air 2 User Manual ...

Capture.JPG
 
Hello everyone,

I would like to share the following experience that I had recently flying my MA2 (using the UgCS app for DJI). I was inside a gorge without gps reception so I was flying in vision mode. [snip]

Thanks a lot and enjoy!
Evan
As others have pointed out, your expectations of what your drone can do are a bit unrealistic. E.g., your understanding of how the drone knows where it is in space is limited. While the drone does have some level of internal inertial guidance, it depends on other systems to understand its current location in space. Its on-board vision systems only help it to avoid obstacles and locate itself in space above a fixed point when hovering (aka not moving). And the gimbaled camera - well, you are in charge of that positioning system.

Think of the downward vision system as it helps with hovering as a photo of the ground with a rock. The system detects a rock, and controls X,Y,Z to hold the drone over that rock. If you control the drone away from the rock, the drone does not record the direction or speed you sent the drone. So when it hovers the next time, it has to find something else to focus on: a plant, a different rock, etc. The front and rear vision systems are looking for obstacles. They do not record anything. They simply compare images from the cameras real time and detect size and shape changes and infer distance information: did that round thing get bigger and not move from the frame? Obstacle - swerve!

The only thing on the drone that can place the drone in 3D space we fly in is the global positioning system the drone uses - or global navigation satellite system (GNSS). When GPS is off, the drone is pretty dumb. When the GPS is on, the drone knows where it is within a couple of feet, so you can fly it 100 feet from where it recorded HOME, and then ask the drone to return. But the spot it returns to can be off a meter for lots of reasons.

It's all of these factors that underscore why the FAA is requiring drone pilots to learn before they fly. Follow the rules of a club if you are recreational, basically fly under supervision of that club; or learn the airspace regulations and things licensed private pilots need to know to fly safely around people and property by studying for the Part 107 license.
 
In the app Vision mode refers to the bottom camera and positioning, the rest is referred to as obstacle avoidance. The former is what was discussed and matters in the context of this thread.
Not the way I read it - and with the plethora of vision capabilities of the MA2 and MA2S it isn't surprising a novice believes the drone can do more than it can. That's still no excuse to not reading the manual and understanding limitations prior to flight.

But in that light I can also say DJI could do much better with their documentation. One issue that affected me was their Fly More combo with the Smart Controller doesn't even tell users which of the many apps installed is the correct one for the MA2 it came with. You have to divine which one to try to use. Eventually I found a reference to DJI Fly - the app running on the SC - in the Mavic Air 2 manual. Why would I be reading the drone manual to find the app I should use on the smart controller? It only makes sense when you consider a cell phone as the controller. Aka - lore.

Plus - you are totally missing the DJI text I posted above: helps the drone fly indoors and in other environments where GPS is unavailable. A green light for doing exactly what the OP did.
 
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Hello everyone,

First to clarify a few things:
- Being new to this forum does not mean that someone is a novice pilot. I built my first drone in 2013 so hold your horses before you give advice.
- Surely most of you are pro pilots, but some are just looking to justify their license or what

MA2 operates also in vision mode which is clarified on earlier comments for those who don't know.
As a matter of fact, engineers like me would think that there should be also a way to RTH even without gps. In fact this should not be a big deal for a company like DJI. If you have the know-how for obstacle avoidance, then reversing the route based on compass and speed data is easy.

Now I am going to write this code on a script and try to make some money instead of bras-de-fering online.

Cheers,
 
...As a matter of fact, engineers like me would think that there should be also a way to RTH even without gps. In fact this should not be a big deal for a company like DJI. If you have the know-how for obstacle avoidance, then reversing the route based on compass and speed data is easy.

Now I am going to write this code on a script and try to make some money instead of bras-de-fering online.

Cheers,
The only problem here is that of your 3 stated parameters (route, speed & compass) to be used to calculate a RTH route without GPS ... is that only 1 exists (gets logged) in reality.

- The route you think's can get reversed isn't logged without a proper GPS lock ...
- & it's equal with the speed data, nowhere to be found without GPS lock.
- So the only data you have & can work with is the IMU Yaw data that is started up by the compass direction at power on.

Unfortunately a bunch of different yaw directions will not alone get you back to the HP ...
 
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- Surely most of you are pro pilots, but some are just looking to justify their license or what
Very few here are pro pilots.
As a matter of fact, engineers like me would think that there should be also a way to RTH even without gps. In fact this should not be a big deal for a company like DJI.
It would be very rare that drone flyers would need to RTH in a GPS-denied environment.
So rare that it's not worth the development cost for a feature than almost no-one would ever use, particularly on a drone intended for the mass market..

Designing such a system would be an interesting intellectual challenge, but I can't imagine a situation where you would need it.
 
So rare that it's not worth the development cost for a feature than almost no-one would ever use
And while SLAM works great in closed environments of moderate sizes an aircraft with nothing but the ground to look at and at a distance too far to get much detail and a sensor that changes its view based on airftaft tilt isn't exactly as suitable, so it would most likely be too unreliable to be worth doing as well. No point doing that if it'd only be needed in a few % of cases where GPS isn't available, and it couldn't work in most of those either.
 
Very few here are pro pilots.

It would be very rare that drone flyers would need to RTH in a GPS-denied environment.
So rare that it's not worth the development cost for a feature than almost no-one would ever use, particularly on a drone intended for the mass market..

Designing such a system would be an interesting intellectual challenge, but I can't imagine a situation where you would need it.
Hi,
Thanks for your input on this matter. I totally agree with you but flying in remote narrow valleys or remote canyons for example, is quite a case where RTH is useful. Of course may not worth for the mass market but still I can see potential applications.
 
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