Hi guys

Upon cycling a new battery I've notice that if I leave the craft hovering after a short while it shows a negative altitude as per the pic below,is this normal?

I also get altitude drops at height

So I've run a cycle on the next battery and this time just left it idling to see what would happen, so it hasn't taken off just been left running,

And now this has happened

Is my craft broken?

It's still running now and the altitude is now at -1.2m and still going down

So I've hovered in atti mode and it won't hold altitude not sure if it's the carpet, however when I hover say 0.3m off the floor it's registering so silly height

Is this done by the barometer or the vps?

so annoyed

Tried on laminate and it won't hold altitude at all

rliamharpurb Posted at 2016-6-19 23:21
Tried on laminate and it won't hold altitude at all

VPS doesn't work just anywhere.
It needs ... Operating Environment        Surface with clear pattern and adequate lighting (Lux > 15)
'

Ok but that doesn't explain why in the first photo outside I have an altitude reading of -1.1m when I'm clearly Atleast 1m high, nor does it explain why when left idling on a surface and not taking off the altitude reading goes from 0m down to -2.2m?

Any ideas?

I have a video and it you watch when I throttle up the craft sinks but the altitude continues to go up?

Here's a link to the video I can't embed it for some reason

https://vimeo.com/171296973

Might I add when flying at height I do have altitude drop occasionally when flying forward or stopping but it can be counteracted by throttling up however I'm pretty sure that the craft should be able to hover stably at low heights

Liam

Bunp any dji reps advise? Bump

Hi Liam,

Try to keep an eye on this thread, too: http://forum.dji.com/forum.php?m ... D368%26typeid%3D368

Sorry if I can't be of further help. More experienced members will chip in I'm sure.

By the way what's your app version and FW statuses?

rliamharpurb Posted at 2016-6-19 21:14
so annoyed

Ячто то не пойму Фантомы 4 что такие глючные ?

Lates app version and iOS

Latest firmware version

Don't really want to send away as this is already the second craft I've had but if it isn't right guess I'll have too

Its been quiet here from the dji mods. They might reply as soon as the weekend is over and back to their office.

rliamharpurb Posted at 2016-6-19 23:49
Ok but that doesn't explain why in the first photo outside I have an altitude reading of -1.1m when  ...

Your posts are unclear.
If you leave your Phantom idling on the ground, it builds up heat which will affect the barometer's ability to give an accurate height reading.
As for your firsy photo, I don't know where you took off from.
Is the Phantom above or below the launch point?
Does your altitude reading at launch show zero?
If your barometer is showing inaccuracy, recalibrate the IMU indoors on a level surface.

The phantom I the first pic is above the launch point, I have taken off however you can see that the reading is inaccurate

At launch is says zero

And I have tried the IMU calibration twice,

Liam

How can my phantom take off then decide it is minus one meter?

Does the drone fly normally, other than this?

Hello rliamharpurb, I'd suggest you to calibrate the IMU and the sensing system. If it is possible, test it in different areas.

Ensure that you are running the latest Firmware and perform a complete calibration of everything. If you are unsure as how to do this check the Tutorial section and Youtube Tutorials are very helpful as well. Follow your Tutorials one step at a time. I doubt that there is a problem other than some fine tuning.

Hi guys thanks the replies and advice,

After the latest firmware updates I did recalibrate everything that was possible, I even done the cold IMU calibration using air con

However I will try this all again and see how it hovers over a different surface such as rock in a differ be location and update this weekend as we are forcast rain all week

Again thanks for the replies,

And yes the drone performs awesomely other then this but I'm just a bit concerned as to why I get a negative altitude reading if I hover then go up and back down

Liam

I see the last post is 2016. Have all these issues been resolved?
We have just painstakingly programmed slow, low-flying (2,6m above ground) tracks for a client. Both the Inspire 2 and Phantom 3A deviated by as much as 2 meters which is totally unacceptable. We used both the latest versions of DJI mission controller as well as Litchi. Litchi was better but still not consistent over three days. Are we doing something wrong or is this technology being over-sold to the public?
We have used the Phantom for some years doing video work with no problem but this application needs a great deal of autonomous flying. It is in a private game farm, so totally legal.
Kind regards,
Jan.

I'm not aware that the P3A is capable of flying a set distance above the ground.  It can hover very accurately (within half a foot or so in free space) at very low altitudes with VPS enabled, but if you fly horizontally and the elevation of the terrain below the AC varies, obviously the distance between the ground and the AC is going to vary as well.  

https://www.dji.com/phantom-3-adv/info#specs

jansime Posted at 2018-6-18 03:40
I see the last post is 2016. Have all these issues been resolved?
We have just painstakingly programmed slow, low-flying (2,6m above ground) tracks for a client. Both the Inspire 2 and Phantom 3A deviated by as much as 2 meters which is totally unacceptable. We used both the latest versions of DJI mission controller as well as Litchi. Litchi was better but still not consistent over three days. Are we doing something wrong or is this technology being over-sold to the public?
We have used the Phantom for some years doing video work with no problem but this application needs a great deal of autonomous flying. It is in a private game farm, so totally legal.

I can tell you that (some of?) the P4 Pro's have the same behavior even on latest release, worst just after start, they seem to settle when it warm up.

What i can suggest trying is to let them hover for a few minutes at around 2 meters and watch, my guess is that you will see they  yo-yo some and give some strange altitude readings.
After a few minutes (4-5) it should stabilize, then set it down and perhaps cut the motors to have the altitude reset and then take off again immediately.

Notice the reply above i think was meant for you.