RTH precision landing almost into trees !

[compuad77]

Hello,
Does anyone know what would cause a bird to almost go into trees while searching for a precision landing ?
I calibrated compass before flight, set home point. Took off and flew 10 minutes with no problem. Once I activated RTH, bird came back flawlessly, started a normal descent on it's own. But once it descended and came to nearly 80 ft. it started searching for the precision landing spot it then almost drifted 40 feet into the trees. I corrected, cancelled RTH and landed, but it was close. Had 18 good satellites, 60% battery, no wind, no other detectable issues.

 

[jaysrmc]

The home point must have some sort of pattern that the bottom camera can match up when it tries to land.. Sometimes this happens when you take off from green grass with no pattern, it is looking for the pattern. I use a landing pad because I have had it move around a bit looking for the spot.

 

[compuad77]

The home point must have some sort of pattern that the bottom camera can match up when it tries to land.. Sometimes this happens when you take off from green grass with no pattern, it is looking for the pattern. I use a landing pad because I have had it move around a bit looking for the spot.

It Took off of a Landing Pad with a BIG H, white on black ! Other suggestions ?

 

[Gizmo]

The manual states that you are supposed to hover at 10m for 10 seconds for the drone to aquire precision landing, did you do that?

 

[Mike4884]

The manual states that you are supposed to hover at 10m for 10 seconds for the drone to aquire precision landing, did you do that?

Yup this is what most people do not realize ... it has to be done to get precision landing

 

[compuad77]

Yup this is what most people do not realize ... it has to be done to get precision landing

I believe you nailed it. I looked at the video and it was hovering about 6-8 seconds before I moved it upon take off.

Interestingly enough I got a reply from DJI support today, thinking the problem would be with the VPS system after they reviewed the video and data logs. They didn't mention the 10 seconds hovering required at take off ??

Either way, thank you very much !

 

[msinger]

They didn't mention the 10 seconds hovering required at take off ??

They didn't mention it because there is no such requirement.

Per the Mavic manual, here's what you must do:

 

[Mike4884]

What i do is raise to about 30 feet let it hover for a few seconds....then im off.... u will not get Precision landing if you just launch and take off right away....works every single time for me!

 

[hoggdoc]

They didn't mention it because there is no such requirement.

Per the Mavic manual, here's what you must do:

View attachment 33426

Question for you. When I use the auto take off feature there is a check box asking if I want to use Precision Landing. If that is checked doesn't the Mavic know exactly what it has to do to accomplish a precision landing.

The reason I ask is I have never gotten my Mavic Pro to make what I would call a precision landing even when using a "commercial landing pad well marked" . I have tried recalibrating the compass, no difference. Then I went through the IMU calibration, no difference. What am I missing?

 

[Kilrah]

The option will make it go to the right height at the right speed but it won't prevent you from flying away too quickly.

 

[hoggdoc]

The option will make it go to the right height at the right speed but it won't prevent you from flying away too quickly.

So how long does it need to hover at that position?

 

[Kilrah]

Many mention 10 seconds, not sure on what basis. Would need to be tested, haven't done it myself since I don't care for the function in the first place.

 

[kidroc]

also if the AC was at 80m still then i have seen this happen as the AC comes down when it hits around 43m mark it should still moving to the right spot..

 

[dennyc39]

I ike to put something contrasty on the ground close to the takeoff point so the visual system can easily recognize it. Often I use my hat. It doesn't have to be directly on the point, just nearby and within the field of view and visible from 10m up or so. Be careful it's not something that will get moved by the downwash from the props. Also be sure you have 10 or more GPS birds.

This seems to eliminate most of the confusion that may be caused by undistinctive surfaces like grass or gravel.

 

[Wanbli]

I have a "similar" problem. The Mavic Pro will return to the home point at the set altitude nearly exact. It says it's landing, the drone turns to align with it's original take-off position, but it WILL NOT BEGIN LANDING, it just hovers there! If I initiate the landing by pulling down the left stick, it comes down, but if I let the stick go it stops. If I pull it down again, it decends until I release it again, then hovers, very odd! Another oddity is on take-off I ascend to 30' and hover for 30 seconds, but the drone keeps climbing after I release the stick for a few feet, then descends a couple feet.
I have reflashed the firmware to a "beta" (.0241) provided by DJI and the stepped back up to .0500, but no change. All calibrations have been completed (multiple times), and I do use a landing pad. Any help will be appriecated...