RTH w/ Precision Landing

[dbrockman2]

Hey everyone. Getting back in the swing of things after getting my MPP back from warranty repair (they replaced it actually). Today did about 40 mins of flying and both times I selected precision take off point and when I did RTH it was off by several feet. Like land on the roof and land in the tree, off. Ideas?

My old one would land back inside a chalk outline of itself.

 

[wytnyt]

theres several threads here explaining this but overall your drone doesnt have precision landing.

 

[dbrockman2]

My drone isn’t a M2. Its a MPP. It still gives me the option of precision landing whereas the M2s don’t.

 

[tcope]

First, I've never been sold that precision landing either 1) was accurate at all or 2) even exits. That is, I really don't think this ever worked as DJI said it would. How would anyone know if it worked or not? I think it did not work as intended and since no one could know, DJI never really fixed any issues with it.

You should never count on the Mavic landing within a foot or two of the take off point on RTH. You should _always_ allow as much room as possible, even 10-20' as a minimum. If you are at the RTH point I recommend taking control of the Mavic as soon as possible and land manually. I also _recommend_ that RTH only be used as a last resort (i.e. only when you lose contact with the Mavic). People will disagree with this, but they usually say that RTH works perfectly and they never have any problems..... but then we consistently see people posting here that have problems with it. RTH is good, I'm not saying that it is not. But only using it as a last resort avoids the problem that you mention.

As far as it landing a few feet away, this is a function of GPS (and perhaps precision landing) and a lot of things can affect GPS. You may find next that it is as accurate as it was before.

 

[dbrockman2]

Thanks for your reply! First off. I do a lot of manual return home flights but I also fly Part 121 and just like in the jet we check things and I always like to know something will work when I need it to. Plus the MPP just came back from repair so I was checking functionality and noticed it was different from pre-repair.

Also I thought that the precision landing took a photo of your landing point and after using GPS to get in the vicinity then it matches the photo up.

But maybe I’m wrong.

 

[Meta4]

Today did about 40 mins of flying and both times I selected precision take off point and when I did RTH it was off by several feet. Like land on the roof and land in the tree, off. Ideas?

There are a number of points for precision landing to work,.
Here's what the manual says:

Precision Landing performance is subject to the following conditions:
a. Home point is recorded upon take off, and cannot not be refreshed during flight.
b. Aircraft must take off vertically. Take off altitude must be greater than 10 meters.
c. Home point terrain features remain largely unchanged.
d. Home point terrain with no distinctive features will affect the performance.
e. Lighting conditions cannot be too light nor too dark.​

Failing to comply with B is a common cause of complaint about Precision Landing.
You have to allow the drone to capture an image from about 10 metres up.

 

[Prmath]

Besides enabling it in the app, there are a number of points for precision landing to work,.
Here's what the manual says:

Precision Landing performance is subject to the following conditions:
a. Home point is recorded upon take off, and cannot not be refreshed during flight.
b. Aircraft must take off vertically. Take off altitude must be greater than 10 meters.
c. Home point terrain features remain largely unchanged.
d. Home point terrain with no distinctive features will affect the performance.
e. Lighting conditions cannot be too light nor too dark.​

Failing to comply with B is a common cause of complaint about Precision Landing.
You have to allow the drone to capture an image from about 10 metres up.

Just wait a little bit for the software to be tweaked...... it’s already in the making for an upgrade.
Per tech support .......

 

[dbrockman2]

Just wait a little bit for the software to be tweaked...... it’s already in the making for an upgrade.
Per tech support .......

I guess that’s plausible. It worked with .300 then it failed before I could load .400 now its all wonky. They could have broke it with an update.

 

[53-63-6f-74-74]

Precision landings most definitely work and your mp should be landing within inches of its takeoff point. It works the same on the p4 that I've used for over two dozen pix4d missions. It lands on a target after mission completion. I would recommend using DJI Assistant to downgrade to a previous firmware and see if it helps, or perhaps reflash the current firmware. I haven't upgraded since 1.04.00.

 

[dbrockman2]

Precision landings most definitely work and your mp should be landing within inches of its takeoff point. It works the same on the p4 that I've used for over two dozen pix4d missions. It lands on a target after mission completion. I would recommend using DJI Assistant to downgrade to a previous firmware and see if it helps, or perhaps reflash the current firmware. I haven't upgraded since 1.04.00.

Ugh, Assistant. Okay. I’ll try it. My last experience with Assistant was less than exciting. Lol. Thanks for the suggestion.

 

[gnirtS]

A few things, what were ambient light levels like?
Was the take off area nice high contrast and textured?
Did you have the downward sensors all turned on?
Did the precision takeoff climb slowly to 20ft or so or now?
What was the GPS accuracy on takeoff?
Have you calibrated the sensors?

 

[dbrockman2]

A few things, what were ambient light levels like?
Was the take off area nice high contrast and textured?
Did you have the downward sensors all turned on?
Did the precision takeoff climb slowly to 20ft or so or now?
What was the GPS accuracy on takeoff?
Have you calibrated the sensors?

Thanks for your help.

Ambient light was great, it was approximately 3:30pm. T/O area was my driveway, same place I have launched and recovered several times with accuracy of a couple inches. It took off and slowly ascended to approx 20 feet. GPS was like 12-15 sats if I remember correctly.

I didn’t turn the sensors off but I didn’t check that. Where would I find that setting? How do I go about calibration?

Thank you again.

 

[gnirtS]

The sensors menu and Advanced Sensor in the same menu.
You can also try cleaning the bottom sensors.

Calibration it with DJI Assistant.

Do the .txt log files show any "precision landing" position corrections before touchdown at all?

 

[dbrockman2]

The sensors menu and Advanced Sensor in the same menu.
You can also try cleaning the bottom sensors.

Calibration it with DJI Assistant.

Do the .txt log files show any "precision landing" position corrections before touchdown at all?

I haven’t checked the logs but I will do that and get back to you.

 

[bushie]

I have a MP. Lastest firmware and software. Use RTH on most flights
Normally land within mm of the takeof point
Onlu exception if i takeof from an area with no contrast.

 

[EsiMavic]

RTH works well with me. I'll wait for a couple of seconds before I slammed the stick up.

 

[zosoaol]

Mine's been off since the last update as well. Interesting it comes down in the wrong spot now about 10-20 feet off but it's consistant. Also it does not correct mid flight any more when landing. Just comes straight down from where it starts to descend on return to home. Not a big problem but it would be nice to have it back.

 

[gnirtS]

Interesting - its doing the same as the M2 since the release then....

 

[gjmphoto]

I'm joining the bandwagon here too. I used to get PERFECT precision landings within an inch or two, but over my last two flights only (so, since the last update), I'm off by about 7 feet and I have to take over control to get it back to my pad. What's interesting is that I noticed that both times (and twice is not exactly a trend), the drone was off the left and further away from where it took off - but it was facing in opposite directions to the pad. In other words, it's as if the GPS read is wrong because it's deviating to a spot relative to the takeoff spot, not relative to the direction the MPP is facing.

 

[Prmath]

until DJI updates the Mav’s firmware, the Precision landing will be .......... “not so great”
The Go4 app or the Litchi app does not matter(I think) ‍