Fixing DJI's Compass Problem

[Andy T]

I have a little more patience.
I think we tend to forget how high tech and cutting edge this hobby is.
With an RC airplane you move the control stick and it sends a command to the airplane and one of few control surfaces moves. PERIOD. That's all there is to it. The airplane control is low tech and piloting takes lots of skill.
I think most of us know but may not think about...
When you are hovering the Phantom the IMU keeps it level, constantly sensing any tilt and varies individual motor speeds to keep it level. The baro altimeter senses baro pressure and the motor speeds are adjusted to maintain a constant altitude. The magnetic field sensor provides heading and clockwise and counterclockwise motors are varied to hold heading. And then with six or more satellites in view the phantom uses GPS data to hold position by varying individual motor speed to tilt the phantom to counteract wind etc. Then when you want to move it your commands are combined with the above to move the craft in either normal flying, course lock, or home lock modes. There is a lot going on when you are zooming along in course lock while spinning it around in yaw. And now we are getting the GS capability, a quite a bit late, but initial reports are encouraging and it gives us a whole new capability. The fun never ends!!
So they blew it with the declination problem, maybe because that isn't a problem where they are located. It took the Drunken Sparrow to get things rolling but they are working on it. It is certainly slower than any of us would like. As many have explained, in concept there are a number of easy fixes, but in detail implementation they have to be careful depending on how they structured their software. My main complaint would be that they could have done a much better job of keeping us informed but there are language and a cultural differences for most of us.
That being said obviously each of us will decide if we want to stay in a cutting edge hobby ( I will because that's my nature ) and with every purchase we get to choose who we do business with. So with any future purchase we will compare capabilities, our experience, and costs, to make our decision. So DJI could have done better with fixes, but overall when I tell people about the capabilities of the Phantom, and even the problems we are working, IT BLOWS THEIR MINDS. Most people don't have hobbies that come even close to rivaling ours in capabilities and complexities.
I do understand that those of you who are using it for business purposes are bound to have a different, less tolerant, perspective.
My 2 cents worth.

Yeah and if you are buying the latest model then I suppose you are buying the Beta version. My Vision 2 was obsolete a week after I bought it when the Vision + came out. I was watching an Eric Cheng (DJIs photography expert) video last night where he was flying a vision + and it looked to me like it did the J hook and TBE and he didn't seem to mind.

 

[ToddSmi]

Just got a replacement Vision +, and after learning about this thread realized I have this 'magnetic declination' problem as well (TBE and J hook flying pattern that clears up after about 5 minutes of flight). My initial V+ model did not have this problem so for whatever reason it affects some models and not others in the same geographic location (13 degrees MD in my area). Interesting thread (special thanks to Ian Wood) - will be on the lookout for the new firmware update.

 

[robby666111]

There are a few reports of crabbing while using GS. So, it doesn't hook or TBE as it is always correcting it's position but the orientation of the Phantom may not be perfectly straight between waypoints. I don't have GS and so cannot neither confirm or deny.

Yes, crabbing would be an accurate term for what I see with GS. This unfortunately means the videos taken are off-center substantially.
Cheers
Rob

 

[apadua]

One more affected user. I'm in Sao Paulo, Brazil (-20.5 declination) and my first flight was a disaster. I wasn't aware of the issue and crashed into a tree. Broke two props.

Running v3.04.


Cheers.

 

[wharfbanger]

One more affected user. I'm in Auckland, NZ (19 declination).
Running v3.04.

 

[billyvid]

Hi
I am From South Africa. Having this problem as well. Spoke to supplier who reluctantly admitted to knowing about this bug.

 

[billyvid]

This my corresponce with DJI up to Now

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Daniel Huang (DJI)
Jun 26 16:19
Hi Billy,
If that's your problem,
We are releasing a firmware to address the magnetic declination problem soon. It's under beta test stage but the outcome is quite satisfying.
Best Regards


billy
Jun 26 15:16
Hi Daniel
I will try and video it this weekend when the weather is clear and there is as little wind as possible.
Should I upload video to YouTube and send you the link?
I believe people on the net have described this behaviour of the phantom 2. Believing it to be compass related.
Not taking into consideration hi declination areas. South Africa being one.
I have included some links describing exactly what I am experiencing.
Thank you in advance for taking time to assist me in solving this problem
Regards
Billy
http://www.rcgroups.com/forums/showthread.php?t=2175384
http://www.rcgroups.com/forums/showthread.php?t=2175384
http://www.ianwood.com/docs/dji-phantom ... nation.pdf
Attachment(s)
image003.jpg



Daniel Huang (DJI)
Jun 26 10:58
Dear Sir,
Could you video your problem for me?
Best Regards


Noreply
Jun 24 18:59
Products: Phantom 2 + H3-3D
Name: Billy van Zyl
Location: Africa
Email: [email protected] (mailto: [email protected])
Dealers: orms
Tel: 27415818903
Message: dji phantom 2 unstable in gps mode for the first few minutes of flight. Have done all necessary upgrades. Could it be because of hi declination in South Africa

This email is a service from DJI. Delivered by Zendesk.

 

[Andy T]

So who is going to be the first to test http://www.dji.com/info/releases/dj...or-phantom-2-vision-and-phantom-2-vision-plus on declination challenged birds ? I'm interested to know how the compass issue will affect the GS function?

I tried it twice and both time it started doing things that made no sense whatsoever so I aborted both times.. It just went up about 10 ft. or so and started doing kind of a TBE ridiculousness so I just parked it. I wasn't in a huge field to let it do it's thing so. whatever.. I'm sick of messing with it

 

[Lenny7118]

I'm not thanking anyone. There's no outrage and pressure to get the beta 3.05 released to the public and DJI can make their tweaks while it's released and being used by all of us that decide if we want to download it.
Oh I forgot , the beta testers got their Fix with getting the 3.05 firmware so they are flying straighter.

 

[RVN]

Add another to the list...I'm in Christchurch, New Zealand and I believe I'm experiencing the same problem. Veers violently to the left with TBE both of which seem to mellow over time.

 

[damoncooper]

Administrivia: This thread was started on 3/18/2014. That's over three months I've been following this thread. No update issued yet from DJI.

I will be evaluating all other (non-DJI) options when the time comes to replace or upgrade.

 

[droneranger]

Administrivia: This thread was started on 3/18/2014. That's over three months I've been following this thread. No update issued yet from DJI.

I will be evaluating all other (non-DJI) options when the time comes to replace or upgrade.

Right On!!

 

[HacKiwi]

Add another to the list...I'm in Christchurch, New Zealand and I believe I'm experiencing the same problem. Veers violently to the left with TBE both of which seem to mellow over time.

Me too. Been fighting TBE, J-Hook and left tracking for 2 months. Finally caved an rotated my compass today. Not advocating you try it (warranty / other issues) but it makes a big difference. Happy now but will be ecstatic when DJI finally roll out a fix.

 

[ianwood]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it. Hopefully the yaw instability is addressed as well. It's been a long haul but we're close enough to the goal to keep going. Hang in there.

 

[ElGuano]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it. Hopefully the yaw instability is addressed as well. It's been a long haul but we're close enough to the goal to keep going. Hang in there.

Another thought on timing--assuming this update is going out to P2, P2V and P2V+ (may maybe other FCs), DJI may want/need to coordinate the update to coincide with a scheduled release. I know this is going to be an unpopular statement to this audience, but if I was a PM I wouldn't consider the declination issue to be critical to the point of requiring an urgent hotfix (fatal bug, instacrash, bricking hardware), meaning that it would introduce additional complexities to release first and then merge the change (along with associated testing, etc.) into multiple codebases for multiple products on different timeframes.

Once the declination code is finalized, they may want to distribute to the different teams working on individual product updates so they can integrate and test accordingly. Chances are this is already being taken care of on the roadmap in the release management process, but the more products are involved, the more questions of inter-product timing come into play. OTOH, they may just want to get a fix out there urgently and put the matter to bed, which may impact the timeline of future scheduled updates (probably not a concern to this group, but it will be to the company).

Just idle speculation and potentially throwing fuel on the fire, but hopefully gives folks some insight into how timing of these things can shake out and why it sometimes comes off as unintuitive or recalcitrant...

 

[landonkk]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it. Hopefully the yaw instability is addressed as well. It's been a long haul but we're close enough to the goal to keep going. Hang in there.

Let's hope it is closer to being released for testing than when they said the exact same thing two weeks ago.

Reminder:

By Ianwood, Sun Jun 22, 2014 8:54 pm : "My thinking is if they don't cough something up by the end of next week, they'd better have a reason as to why. That seems reasonable."

2 days and counting.......

 

[Gutter1]

Ianwood...

I'm new to this forum, and late to this party, but felt I should chime in. I have the original Phantom 1, and a 6-month old Phantom 2 that I rarely fly because of these exact issues (TBE and drift.) Your PDF (awesome job btw) describes the symptoms perfectly. So please add me to the total # of pilots with the same Phantom 2 TBE and drift issues. (For the record, I'm in Philadelphia, and I'm meticulous in my flight prep and pre-flight check list. etc.) What I find odd: the old Phantom 1 flies true, and straight, in the same area and under the same conditions. In fact, the only reason I got the Phantom 2 was for the extended flight time... but it remains grounded because I can't trust it.

I applaud your efforts to get this fixed, and I admire the tack you've taken with DJI. (You've made a very compelling and comprehensive case). On behalf of all of us, thank you. Best I can tell, you're now under the impression that DJI's 3.5 update (the 2nd beta) solves 80% of the problem(s). Is this accurate? Or did I miss something?

Anyway, no matter what happens, you deserve a medal.

 

[droneranger]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it. Hopefully the yaw instability is addressed as well. It's been a long haul but we're close enough to the goal to keep going. Hang in there.

My fear here is that the 2nd beta will have a "wait time" at least as long as the first one. That places the release timeframe at least a month away, at a minimum. What I don't understand is, if as it appears from the beta testers, the fix has solved the majority of the issues we've been complaining about for so long with few, if any, negative impacts, why they don't release 3.05 NOW so that we can take advantage of the corrections? OK, so there is still a yaw problem. Deal with that in the next release.

Please understand that I feel Ianwood's contributions and leadership have been outstanding. We could not have a better advocate in dealing with DJI. I am just so tired of these seemingly endless delays in getting the fix out to the rest of us.

 

[BigBadFun]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it.

Hi Ian. Nice work.

Supposing initial flight tests on the 2nd beta indicate no major issues such as Phantom's falling out of the sky, and indeed drastically improve the performance of flight within areas of high MD - will you be able to open the beta immediately to those who would benefit from it, request it, accept all liability, and who have been following and contributing to this discussion?

As you know, a lot of us are feeling a little alienated and fear another round of public discussions over several weeks from existing beta testers about how it is 99% ready would really wind up the troops.

 

[damoncooper]

I have been told by DJI that the 2nd beta is going through final checks and should be sent to us for testing very soon. If that goes well, then it shouldn't be much longer before everyone has it.

Hi Ian. Nice work.

Supposing initial flight tests on the 2nd beta indicate no major issues such as Phantom's falling out of the sky, and indeed drastically improve the performance of flight within areas of high MD - will you be able to open the beta immediately to those who would benefit from it, request it, accept all liability, and who have been following and contributing to this discussion?

As you know, a lot of us are feeling a little alienated and fear another round of public discussions over several weeks from existing beta testers about how it is 99% ready would really wind up the troops.

I think that has to be DJI's call.