Mavic Pro 2 Precision Landing

[gnirtS]

I just did some testing of this. Did 5 precision takeoff techniques and tested RTH and landing.

At times it was accurate to within inches, the worst i saw was maybe 1m or so off. This is far more accurate than you'd expect from GPS alone.
The drones behaviour is different - it doesn't reorientate itself to the same as it used to take off when it starts to descend.

Maybe i just got very lucky with a way better than average GDOP so i'll try again but if it was GPS only i wouldn't expect that accuracy level.

 

[networth]

DJI said, it can come with an update, so please chill.

 

[LivinLarge]

I hate to say it but those DJI reps are PR folks that don’t have any real insight in my experience of what is coming out of engineering.

Supposedly, he posted this after talking with the DJI engineers. Don't hold your breath waiting for this feature.

 

[gnirtS]

DJI said, it can come with an update, so please chill.

No they didn't. They didnt give any information either way.

 

[BlueBay]

I just did some testing of this. Did 5 precision takeoff techniques and tested RTH and landing.

At times it was accurate to within inches, the worst i saw was maybe 1m or so off. This is far more accurate than you'd expect from GPS alone.
The drones behaviour is different - it doesn't reorientate itself to the same as it used to take off when it starts to descend.

Maybe i just got very lucky with a way better than average GDOP so i'll try again but if it was GPS only i wouldn't expect that accuracy level.

Thanks for taking the time to test precision takeoff, RTH & landing. The insight is really valuable, the lack of reorientation is a mystery.

 

[gnirtS]

No reorientation makes sense - if theres no precision landing theres no point in doing it.
Im going to do some more tests now in case i got lucky with GPS geometry.
Currently im getting less accurate than precision landing but more accurate than GPS (substantially more).

Edit 1.5-2m out this flight. Not precise but better than GPS. Trees blocking some areas of horizon.

 

[Trees138]

I thought it was stated that downward sensors scanned the landing area to ensure it was safe. I did have my M2P refuse to set down because the landing area was not good enough (Tall weeds).

As I understand it, the precision landing feature that you all are familiar with would attempt to land the drone exactly where it took off from, including in the same orientation. This is my first drone, so I am blissfully ignorant.

Why is that so important? As long as it lands close to the home point, and in a safe location, what's the harm?

I'm not trying to be argumentative, I am trying to figure it out more my own information. Just genuinely asking questions.

 

[gnirtS]

Why is that so important? As long as it lands close to the home point, and in a safe location, what's the harm?

Because if you're unable to control the drone (RC issue, software issue) and its using GPS accuracy landing it could come down anywhere in a 5m radius.
Although the downward sensors detect large obstacles they dont see small rocks, long grass, weeds and other things that can easily damage the props or drone if it lands on them.
The mavic is so low to the ground even small bits of debris can cause damage.

My last flight for example it was off by roughly 2m. I had to manually take over as it was descending onto a clump of grass with some 8 inch weeds growing out of. This would have hit the props.

 

[Trees138]

I've not experienced that yet, although I have been manually landing for the most part. I'll see what I can get it to set down in at some point. Thank you for the insight. Is there a good known way to force that condition other than just using RTH? Can I just turn the RC off?

I'm sure the real solution for my questions is RTFM, lol.

 

[gnirtS]

Force what? If you want it to RTH then hit the RTH button. I'd never recommending turning the RC off.

 

[Trees138]

IME, requesting an action when all things are good can be different from an actual failure mode. But that is experience in a different sector, and I'm definitely unfamiliar with how drones work, I am still learning. I certainly wouldn't recommend turning of the controller either, but it's definitely an idea I'd discuss.

 

[LivinLarge]

I thought it was stated that downward sensors scanned the landing area to ensure it was safe. I did have my M2P refuse to set down because the landing area was not good enough (Tall weeds).

As I understand it, the precision landing feature that you all are familiar with would attempt to land the drone exactly where it took off from, including in the same orientation. This is my first drone, so I am blissfully ignorant.

Why is that so important? As long as it lands close to the home point, and in a safe location, what's the harm?

I'm not trying to be argumentative, I am trying to figure it out more my own information. Just genuinely asking questions.

I live in the mountains and often fly from the edge of a cliff or from the top of a rock on the riverbank. I sometimes have to hike along the river or trail a ways to keep the aircraft in sight as I fly. In the event of a disconnect, I am at the mercy of return to home accuracy. Precision landing is critical here as an error of even 1 meter could put it in the water or over the edge of a cliff.

 

[GringoLoco]

^ Yep, that's what I'm worried about. Just had my maiden voyage at a lake yesterday and went out of my way to set the RTH on a large clear patch of land well beyond the radius of typical GPS accuracy.

 

[Kingram]

^ Yep, that's what I'm worried about. Just had my maiden voyage at a lake yesterday and went out of my way to set the RTH on a large clear patch of land well beyond the radius of typical GPS accuracy.

A lake ? your braver then I am my maiden voyages are usually in a big open field so I can make sure the aircraft is operating properly before I venture out into the wild blue yonder.

 

[mcsenerd]

I just think that there are a lot of times where precision landing is useful and it's rather pointless to go through them all. The fact of the matter is that this was/is a feature almost throughout their product line and I don't think it's unnatural that folks just expected it to remain. More curious, is reading through the manual and it clearly states that all vision sensors are disabled during landing.

 

[LivinLarge]

Here are some of the places I fly from. It is difficult to find a decent flat spot to launch from, much less land. Precision landing is important if you lose RC connection. A miss by a few feet would mean total destruction.

 

[GringoLoco]

A lake ? your braver then I am my maiden voyages are usually in a big open field so I can make sure the aircraft is operating properly before I venture out into the wild blue yonder.

Not that brave, even doubled up on DJI refresh and State Farm insurance I was still trembling lol. My original plan was a local r/c field but it's in a state park and you have to jump through a ton of hoops to use it (join their club, take a class and test, $1M in liability insurance, etc). I live near farm country that's ideal to fly over but I was worried about pissing off landowners. First drone, I have the legal part down, still trying to figure out where it's socially acceptable to fly lol.

 

[gnirtS]

OK more tests, definitely only using GPS (must have got lucky earlier), Flights this evening in a less open area.
First time out by 5m or so, the second out by 3m. Manual intervention require on both to stop it hitting something.

As for "Vision systems are disabled", the original mavic did that. It means no OA.

 

[mreloc]

Wait... There's a setting for that with the Mavic 2?

I think he was referring to the original Mavic, which had the setting for battery drain down

 

[Kingram]

Precision landing solved.