Please select Into the mobile phone version | Continue to access the computer ver.
Loss of altitude and Accuracy of telemetry
2208 19 2015-6-12
Uploading and Loding Picture ...(0/1)
o(^-^)o
Lonestar
lvl.1

United States
Offline

I'm starting to see errors in the telemetry showing the P3P much higher than it really is. I calibrate the compass prior to flight with each new location with no problems.

This morning, I'm hovering at 1.5 feet above the ground (directly over where I took off from) and the altitude is showing 15.1 feet. If I hover at 6 feet it shows 17 feet. If I let it sit stationary it will eventually start losing altitude and I will have to intervene.

When I start the props the home point is updated it shows 0.00 which is correct. Once airborne it will start increasing the altitude in the telemetry inaccurately.

Anyone experiencing this?

Is there something I can do to correct it?

Thanks!

Screen Capture.jpg
2015-6-12
Use props
dwcooze
lvl.1

Canada
Offline

I'm having a similar issue. Vertical climb and decent seem normal.
Try to hover around 15ft, 20ft and 8ft, and the P3P shows the last height from movement. As I leave the controls alone, to hover, it starts a slow incremental decent with no change in the recorded height.

At much higher heights it's too difficult to see if it is dropping slowly.
Next chance I have I will bring it somewhere where I can climb to 100 ft and leave it to hover. Then I will report back if I noticed a slow decent etc.

I've tried Calibrating the IMU, but that has made no difference at all.
2015-6-12
Use props
isaache
lvl.4
Spain
Offline

Hi,

Is the Visual Positioning System active in your P3? If so the P3 should be able to correctly hover when it is at or below 3 metres (in range of the ultrasound ranging system).

The Phantom 3 barometric altimeter drift is 1 centimetre per second, this figure provided by DJI is not likely to include atmospheric effects.

DJI states the altimeter error range of two metres (level of confidence unknown).

Isaac
2015-6-12
Use props
aburkefl
First Officer
Flight distance : 78612 ft
United States
Offline

Also, there you are - in the middle of the woods and 399 feet away from your Phantom!

I've tested stuff on mine with the Phantom sitting on the desk about 16 inches from the controller and have it tell me the Phantom to controller distance was 20 feet!
2015-6-12
Use props
Daninho
Second Officer

Germany
Offline

that is nothing, in the flight logs from one of my flights its said max height 230m but i never went above 30m. Definately strange bugs in the app and there was strange bug Error 63 aircraft cant take off please contact DJI but it was already in the air flying.
2015-6-12
Use props
Lonestar
lvl.1

United States
Offline

aburkefl@gmail. Posted at 2015-6-13 03:29
Also, there you are - in the middle of the woods and 399 feet away from your Phantom!

I've tested s ...

I am in the country yes. I am standing (with the controller in my hands) literally 5 feet of the Phantom at the time the photo was captured. I should have mentioned that in my original post. If you believe the telemetry its also showing 13 sats locked.

This anomaly has just started within the last two days. It doesn't matter where I am the telemetry starts giving erroneous data.  
2015-6-12
Use props
Lonestar
lvl.1

United States
Offline

isaache Posted at 2015-6-13 03:10
Hi,

Is the Visual Positioning System active in your P3? If so the P3 should be able to correctly ho ...

I appreciate the feedback. I have been flying by the GPS system and haven't used the VPS as of yet. It shows to be locked on to 13 satellites in the screen capture but I don't know what to believe. I'm wondering if the erroneous data is what's causing it to lose altitude by thinking it's at one altitude but the VPS sensors are telling it something else.

I'm just stumped by all of this.
2015-6-12
Use props
aburkefl
First Officer
Flight distance : 78612 ft
United States
Offline

Lonestar Posted at 2015-6-13 13:08
I appreciate the feedback. I have been flying by the GPS system and haven't used the VPS as of yet ...

At the time mine was giving erroneous readings I had the VPS disabled. I turned it off a couple of weeks ago and haven't turned it back on yet. I'm too nervous to fly too low at a decent speed and I don't have any location practical for flying indoors.

As for the satellite count, when I was testing, I placed the P3P as close to the window as I can. Wasn't sure if that would help any or not. I just wanted to see if I could "gather" enough satellites to make sure I could see everything there was to see without having to go outside in the heat. It seemed that 8 satellites was the "threshold" where I would start receiving the message "...safe to fly with GPS."

With the bird sitting by the window I think the max I ever saw was 9. I have no idea how many it sees outdoors! With the bright sun, even shading the Galaxy S5, that satellite number is *very* small and *very* difficult to see. Despite the tall trees (80 - 90 feet) around my property, I get a moderately quick GPS lock with both my quads (the other one is a Blade 350 QX3).
2015-6-13
Use props
mtnmaddman
Second Officer

United States
Offline

Lonestar Posted at 2015-6-13 13:08
I appreciate the feedback. I have been flying by the GPS system and haven't used the VPS as of yet ...

I live at 7000 ft. in the mountains I am getting an error message at start up sometimes (When it sits a while on before I start the motors )  that I have a barometric sensor problem and to contact dji if problem persists,  the motors wont start until I turn on and off the phantom, (that's what the error message says to do)  I have never thought to look at the app to see what it says my altitude is at that point, I just flew this morning and when I was landing I noticed my altitude said I was at 46 ft when it was level with my head. ( I had to restart it before I flew this morning, got error message) the barometric sensor does  an input to altitude I have not noticed the sinking problem, the fact that it said I was at 46 ft. when I was practically at ground level indicates that it was physically sinking during flight, unknown to me. but I am going to look a little closer at this. have you ever got the barometric sensor error message?  Try letting the phantom set a few minutes after everything is lit up except the motors and see if you get the error message that indicator may be drifting as it sets there not allowing the motors to start, yet if motors are lit and you take off it will of course not shut the motors off, but maybe cause these other altitude related anomalies,  I would say we either all have defective barometric sensors or there is another software bug for DJI to look at.
Please note this DJI
2015-6-13
Use props
venomx15301
lvl.4

United States
Offline

My first flight I took my P3P to like 4 feet and left it hover because my friend asked me a question. When I looked back it was like a foot off the ground. I never thought to see what the app was showing. My next trip out to fly I will keep track.
2015-6-13
Use props
mtnmaddman
Second Officer

United States
Offline

venomx15301 Posted at 2015-6-13 23:07
My first flight I took my P3P to like 4 feet and left it hover because my friend asked me a question ...

Let it set a few minutes with everything running except the motors  see if the drift in  the sensor shoots an error message and doesn't allow you to start the motors
2015-6-13
Use props
Lonestar
lvl.1

United States
Offline

mtnmaddman Posted at 2015-6-13 23:07
I live at 7000 ft. in the mountains I am getting an error message at start up sometimes (When it s ...

I've not received the barometric sensor error but I will bounce back and fourth between ATTI mode and then Safe to fly GPS . I've only had it for a week so I'm guessing that I'm still too new to it to know the differences yet. I'm flying very conservatively with it until I completely understand what to expect. I'm an amateur photographer and I bought this mainly for the camera to take my photography to the next level adding different perspective etc. With the erroneous readings I'm concerned about pushing my envelope until I get a feel for what's right and what's not.
2015-6-13
Use props
Lonestar
lvl.1

United States
Offline

mtnmaddman Posted at 2015-6-13 23:31
Let it set a few minutes with everything running except the motors  see if the drift in  the senso ...

I will give this a try as soon as the Thunderstorms pass. Houston is foretasted for rain for the next week. I guess I can try my indoor skills...lol
2015-6-13
Use props
Lonestar
lvl.1

United States
Offline

aburkefl@gmail. Posted at 2015-6-13 19:07
At the time mine was giving erroneous readings I had the VPS disabled. I turned it off a couple of ...

Reading through the threads here I'm wondering if the P3 series was rushed to the market just a bit before prime time. DJI won't be the first company to let their consumers be their beta testers but at the price point for this system and the potential for injury I would have thought that they would have been a little more conservative with their releases.  It's interesting how many people are seeing the same thing that I am, or haven't realized it until they looked for it. I don't know what it takes to escalate it as a bug that needs to be addressed by engineering.
2015-6-13
Use props
mtnmaddman
Second Officer

United States
Offline

Lonestar Posted at 2015-6-14 00:43
Reading through the threads here I'm wondering if the P3 series was rushed to the market just a bi ...

absolutely rushed to market Dji grew very fast whenever a company grows this fast it becomes cash flow hungry it needs to keep going ,producing and introducing new product fast. The lull by the high priced inspire slowed there roll they had to do something. I saw this coming, expect a phantom 4 and an inspire 2 in the future, some inspire owners aren't happy but my phantom 2 plus sits silent in the corner now, so will the inspire 1's when the 2's come out.  I am glad they introduced this, lets hope all the problems can be resolved so as we can buy, promote, and enjoy the rapid growth of this technology, Inspire owners don't feel bad I still want one, enjoy your Inspire until the technology compels you to buy something better.
2015-6-13
Use props
mtnmaddman
Second Officer

United States
Offline

Lonestar Posted at 2015-6-14 00:43
Reading through the threads here I'm wondering if the P3 series was rushed to the market just a bi ...

I totally agree lonestar this is a bug that likely is in the firmware I think I had the error on the previous ver. also I flew again this morning same results only worse when I landed the altimeter was at 56 ft altitude I could tell while descending that the alt. indicator was way off we need to draw the attention of dji to this problem this is even worse than the lagging video add 50 ft less altitude than what you are really at and lagging video together and you have a real situation that could be disastrous.  I can not believe all of these bugs what is going on are these bugs present in the inspire, if not why are they present in the p3 I don't get it.
2015-6-14
Use props
rhutty
lvl.3

United Kingdom
Offline

Here's a scary thought. If the altimeter is off, then, if you are descending at max and the altimeter shows no change. The motors will shut off. If you're 50 ft up, could be nasty.
RayH
2015-6-14
Use props
msjh
lvl.4

United Kingdom
Offline

Here's what I recorded

http://forum.dji.com/thread-31951-1-1.html
2015-9-28
Use props
capbat
Second Officer
Flight distance : 52726 ft
  • >>>
Canada
Offline

rhutty@gmail.co Posted at 2015-6-14 16:15
Here's a scary thought. If the altimeter is off, then, if you are descending at max and the altimete ...

Altimeter might be off but it would not prevent other accelerometers from recording a positive or negative vertical speed.
2015-9-28
Use props
office
lvl.1
Dominica
Offline

I am getting a similar problem. I pull my P# pro to around 6 ft, and it hoovers just near my head. Satellites locked, and they give it quite impressive position lock, much more precise than my old P2 had. but the fluid change of altitude is really a problem. If i let it hoover or slowly fly, but I don't touch altitude stick - it will go slowly down - WITHOUT reporting it on screen. Imagine if I fly over a lake or sea, and 100 meters from the shore it crashes in water! disaster!   (FPV image has a lag of about 1 second and sometimes image freezes, so i can't rely on vison too much either).

So, when i have to correct the height, it reacts fine and goes up. so i hoovered  again near my head. but after about 5 minutes - i noticed it reports... 18ft above ground. Well, I am only 5.6" tall, so i know it is a lie :-)
When it drops, it does not drop smoothly, but by about 1 ft drops, then it stays for a few moments, then it drops down again.

Is DJI EVER READING THIS FORUM?
What puzzles me is so many problems reported by users, and no answer from DJI. I hasd same bad experience with my 2 previous DJI drones. like support does not want to acknowledge and do anything about their buggy soft and other issues.

I have a job coming involving actually flying low over sea quite a bit, and i am afraid i will hit the water!
Any ideas?  any settings I can tweak through the app to keep it more aggressively up in the air?
2016-4-27
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules