nigelwilkins Posted at 2015-12-30 15:04
It's not that I can't see a difference between  P-GPS and ATTI, I just haven't tested it yet.  It' ...

Hi Nigel,

I was lucky to have had only changing winds between 1 and 8 m/s in the back yard this afternoon without any rain.
So here are my "results" in vibration testing:
- new props or old props: no difference
- P-GPS or ATTI mode: no difference
BUT I witnessed the following:
Ground idle (after engine start) generally begins with low RPMs which then increase to higher values. Reaching this higher RPMs the vibration starts. (Similar to helicopter ground oscillation/resonance.)
By lowering the yaw gain from 100% to 80%, the time until reaching/entering higher RPMs gets longer (or maybe could be infinite). I even saw slight ground vibration eliminating itself at 80% yaw gain. Any higher value shortens the time until entering ground vibration (yaw axis shaking) and keeps it stronger/permanent. (Orientational ESC to IMU response.)
Then, when hovering, reduced pitch&roll gains of 90% helped to avoid  pitch&roll axis shaking (vibration/resonance) which gives the gear and gimbal a hard time additionally. (Attitudinal/positional ESC to IMU response in ATTI/P-GPS mode.)
Finally when climbing I noticed that also here a value of just 90% vertical gain reduced the fluctuating prop sound which came IMO with v1.5/1.6. (Collective/vertical ESC to IMU response. EDIT: or baro response).

In the end I tested groundspeed values against >7m/s headwinds: H/S > 10.x m/s. So reducing the gain for attitude (pitch&roll) does not seem to (significantly) reduce the A/Cs top speed capability.

My personal conclusion:
lowering the basic gains to e.g. pitch=90%, roll=90%, yaw=80% and vertical=90% seems to smoothen the ESC-to-IMU response reducing thereby the probability of oscillation/resonance.

Thanks to the people who first suggested changing those gains...

Greetings,
Claus

EDIT: now the question remains if and to what extent cold temperatures (battery protective thrust reduction) contribute to RPM fluctuation.

DJI-Ken Posted at 2015-12-30 16:31
If you cannot get rid of the vibrations with downgrading or lowering the gains, calibrating IMU, a ...

Hi Ken,

thanks for your prompt response.
As you can see in my post #201 everything seems to work fine for me by lowering all gains respectively.
So I have a great product, looking forward to new FWs and maybe new features.
In conclusion the FW updates v1.5/1.6 seem to have toughened the ESC response to IMU values.
It seems to be possible to circumvent or smoothen these tough reactions by reducing the basic gains of all axis. This eliminates the "new" and obvious tendency of oscillation/resonance as a result of "over reacting".  (Just my opinion)
Greetings,
Claus

vr-pilot Posted at 2015-12-31 01:51
Hi Ken,

thanks for your prompt response.

Ya I totally agree. Ever since I've been flying DJI products I always had lower gains. I'm not a speed racer and just really liked the docile mushy feeling, especially for getting smooth video footage.

vr-pilot Posted at 2015-12-30 17:25
Hi Nigel,

I was lucky to have had only changing winds between 1 and 8 m/s in the back yard this a ...

Excellent!, thanks for taking the time & effort...as always, there will likely be some fine tuning in different weather conditions, but it's certainly good enough to get good stable flight & sharp videos/photos.  Now I just need to test camera shutter speeds to see how long an exposure I can get without blur.

Good work.

DJI-Ken Posted at 2015-12-30 19:34
Ya I totally agree. Ever since I've been flying DJI products I always had lower gains. I'm not a s ...

For documentation purposes of what "increased RPM ground idle oscillation" looks like I made a little video during my tests of today. Reducing basic gain levels as described in my post #201 and #202 eliminates all vibrations to a satisfying degree.
Here is the video (with prop sound):
https://dl.dropboxusercontent.co ... 2013.58.16.mp4?dl=0
Greetings,
Claus

EDIT:
And one more of this afternoon showing the oscillation almost equally on all four arms  (with all basic gains at 100%):
https://dl.dropboxusercontent.co ... 2014.46.24.mp4?dl=0

vr-pilot Posted at 2015-12-31 05:11
For documentation purposes of what "increased RPM ground idle oscillation" looks like I made a litt ...

Really great news, thanks for posting it.

vr-pilot Posted at 2015-12-31 05:11
For documentation purposes of what "increased RPM ground idle oscillation" looks like I made a litt ...

but in both videos vibrating the drone,not?

First firmware update I have done as only just got phantom advanced. All went smoothly and phantom is flying fine no problems encountered.

Dan30 Posted at 2015-12-30 23:00
but in both videos vibrating the drone,not?

Exactly. This is the v1.6 state in ground idle when all basic gains are at 100% (default setting).
It is just to show the oscillation that came IMO with the new FW v1.5/1.6.
When I set the basic gains manually to pitch=90%, roll=90%, yaw=80% and vertical=90% (not shown in this video but see above post #201), I have no vibrations at all.
(My vibration problems were never as bad that they affected my videos, but the absorber/gimbal was on its limit, I think. For me it was just the vibration in the long term that caused some headache in regard to possible material fatigue...)

Greetings to Spain,
Claus

howieian Posted at 2015-12-31 06:05
First firmware update I have done as only just got phantom advanced. All went smoothly and phantom i ...

Exactly my circumstances and experience on the first four flights, then I tried a fifth flight :-(

vr-pilot thanks !! try tomorrow and see if those settings still vibrating drone. me neither affects to the videos but I have the fear that due to fatigue break and fall..

DJI-Ken Posted at 2015-12-30 23:34
If you have intermittent video, it's not a firmware issue but rather a device issue. you need to u ...

It's not device related. Tried on three 'approved' iPads/iPhones. As a number of issues are cropping up I'm now inclined towards a hardware and not a firmware issue.

One question, how it affects the lower values ​​in the phantom? less horizontal speed? it is safe to fly with these values? it could fly into the wind?, thanks! !!

DJI-Ken Posted at 2015-12-30 22:57
So you are saying that you had vibrations on 1.6, then downgraded to 1.5 and they went away ?
Just ...

Wasn't referring to vibrations, I was responding to issues with the firmware as per the thread title.

eldreds Posted at 2015-12-31 11:48
Wasn't referring to vibrations, I was responding to issues with the firmware as per the thread tit ...

Sorry, try a different device and also force quit all background running apps. Also slow down the transmission quality as well.

New update...I decided to take my chances and roll the dice by doing the firmware update to 1.6 on the replacement craft.

I first started by checking the current versions.  The craft was sitting at 1.4 so I decided I would start with the 1.5 fw.  It ran successfully into the craft.  I then ran the fw upgrade for the RC through the app.  That also completed successfully.  I started up the controller and the craft and checked to make sure everything was ok before continuing - There were no issues, I had a video feed from craft and I was good to go.  The app did tell me the craft FW was out of date so i decided to go ahead with the 1.6 FW update.  It also ran successfully into the craft.  I restarted everything, and i currently have no issues.  I have a video feed and all green for current FW and flying.  So it appears that the first P3P craft I bought was a bad seed, the replacement one works perfectly so far after all the upgrades.  Oh, and I almost forgot, I am still using my Samsung Galaxy Tab 4 7.0 even though it is not on the approved list.  I will post if I end up having any issues.  Thanks to all who provided input and advice.

DJI-Ken Posted at 2015-12-31 11:55
Sorry, try a different device and also force quit all background running apps. Also slow down the  ...

Teaching me to suck eggs, done all that already. Hardware problem. Taken back to retailer for refund/replacement.

Dan30 Posted at 2015-12-31 04:47
One question, how it affects the lower values ​​in the phantom? less horizontal speed? it is safe  ...

Hello Dan30,

as I said in my post #201:
"In the end I tested groundspeed values against >7m/s headwinds: H/S > 10.x m/s. So reducing the gain for attitude (pitch&roll) does not seem to (significantly) reduce the A/Cs top speed capability. "

In addition to that DJI-Ken said (see his Post #203) that he always had lower gains since he is flying DJI products. This would be especially good for getting smooth video footage.

So from his expertise and from my test yesterday IMO there should be no significant loss of performance using lower gains.
(With 90% for "roll&pitch" and for "vertical" the settings I use since yesterday are still 10% above DJI's minimum input values. 80% (lowest gain) for "yaw" should IMO be used to avoid ground idle oscillation.)

From what I have "learned" about the term "basic gains" yesterday is, that it does not seem to change the endvalues (range), but the ESC-interpretation method of inputs (IMU+baro stabilization "plus" stick inputs) from soft (80%) to hard (120%).
So the A/C will reach the same performance but it takes a longer time: it reacts more smoothly (slower!) than before. Maybe that is something you should keep in mind.
And like DJI-Ken also said in his post #203: he is not a speed racer. So basic gain settings like 120% will on one hand give you a highly responsive drone ("nervous"), but on the other hand the end speeds along its axes (performance) will not increase. (As far as I understand it)

Season's Greetings from Germany,
Claus

PP3-John Posted at 2015-12-31 12:18
New update...I decided to take my chances and roll the dice by doing the firmware update to 1.6 on t ...

Glad it's working for you. Just to let you and anyone else know, you can skip updates and go to the latest. The only one you cannot skip is 1.3 because it has an R/C firmware update. So you can go from 1.3 to 1.6 and it's fine.And glad it's working on your device, sometimes as the GO app needs more power after each update, your device may work but not after updating.

eldreds Posted at 2015-12-31 20:06
Teaching me to suck eggs, done all that already. Hardware problem. Taken back to retailer for refu ...

If you had the module 8 and 15 error and cannot get it to take and update after multiple upgrades/downgrades, then yes it's a hardware issue and needed to be repaired.

vr-pilot Posted at 2015-12-31 21:01
Hello Dan30,

as I said in my post #201:

Yes, explained well, for those without the vibration the stock settings are perfectly fine to fly with. I just prefer the lower gain settings to make it more docile and smoother video for my style of flying.
And lowering the basic gains only affects reaction time and not overall speed or degree of pitch/rollAnd thank you very much vr-pilot for contributing to this forum.

vr-pilot Posted at 2015-12-31 21:01
Hello Dan30,

as I said in my post #201:

vr-pilot thank you very much !! especially for explain everything 2 times ... Greetings and Happy New Year to all !!

Hi All,
Same here.
Brand new P3 Pro.
Upgraded to latest FW prior to flying and screen goes blank and app drops out, also gimbal goes to approx. 45-60 degrees or face down and does not move. When trying to record video on the floor it stops recording after 7-10 seconds. Have spent the last three days upgrading downgradind, swopping devices ( all apple and new) swopping memory cards, formatting etc etc, whatever is being said on the forums etc etc. FW upgrade and downdrade all show success in log but camera and app go blank. Deleted app and re-installed numerous times.
The firmware installs with no issues both ways up and down but still hangs.
The model flies hovers and all control surfaces work but then the screen goes blank and stops.
Looks like I will have to replace the P3 for a new one as this isn't device related but is either firmware or actual P3 Pro.
Have upgraded and downgraded and sometimes it seems to work, I take model and try to fly and it just hangs again or camera locks in a strange position. Both back buttons do not work either.
Shame as this model looks awesome but not going to risk it, I have 30 years in RC helis, planes and gliders and fully researched before I bought the P3Pro.
Will wait till I get a new one.
Thanks
Lucas

gbeck Posted at 2015-12-29 20:28
Oh really? How is that then? Me and many others have had major issues after updating with P3s that ...

The fact the not just my P3P,   but all the all those in the local group work fine,  proves without a shadow of a doubt that the firmware works fine,  no vibrations,  no crashes, no fly aways,  no large issues,  no small issues.  IT JUST WORKS.

However,  similar to my last recent test report,  if you bother to read it, yesterday we took three P3P's out with a total of 9 batteries,  3 each and flew them in all sorts of ways,  aircraft close together,  operators close together,  wide apart,  highest altitude,  low altitude.  mid altitude,  over water, over land,  over large metal factory buildings,  we spent time doing this in various locations until all the batteries were exhausted.  If there is some sort of tests you would like us to do with the exception of cold climate which we cannot do, we would be happy to attempt them and report back.

Keep in mind,  no IMU calibrations have ever been done on all the units at all since the firmware was installed on each of them.  All three units IMU check,  stated no calibration needed so none was done.   Two did not have compass calibrations either and have not been done since firmware installed either.   One seemed to need it,  but it turned out there was a piece of rebar buried under the soil right where he happened to put the P3P which caused the compass error,  so it was probably not needed either but was done.   Once again as always each aircraft was given a full pre-flight and safety inspection before any flights.

If you have issues,  then either your P3 is faulty  (get it fixed),  or you are fixing things are not broken (extremely likely IMU I betcha ;)  ) or flying in unsafe areas (also possible),  or you are not doing a full pre-flight inspection before every flight (most likely of all,  and I say that as three weeks ago we watched users at the local RC club,  and around only 10% of users we saw spent considerable time looking at their aircraft and equipment before flights,  while the rest spent little to no time at all checking their aircraft or equipment, they just flew).   After speaking with the organisers, they mentioned to us, in almost all cases,  incidents were caused by lack of pre-flight checks,  lack of maintenance,  or lack of experience.

So our collective conclusion is,  we believe many if not most issues are user faults, or procedural faults and its just easy to try to lay the blame elsewhere.,  DJI,  firmware etc.  Exempting of course those with genuine faulty aircraft,  or possibly temperature affects on the aircraft which we are unable to test in our climate.
keep in mind too as per my last report we did have issues getting a good zip extraction of the firmware.

Hallo i had a body vibration after upgrading firmware to 1.6. Before upgrading i haven't....
I downgraded to 1.5.30+ but the problem was not solved. I have a little video and the problem is the same inside, outside or with and without vps.
I had a problem only after i upgraded firmware.

Video vibration

Re-posted in "Phantom 3 Pro/Adv Battery Firmware v1.6.0040 Install Guide and Support Thread", can/will delete this one if so desired.

Had my Phantom 3 Pro stored since at least November due to it turning to just brown and gray out, but now that it's finally a winter wonderland and sunny tomorrow, I started prepping her for Saturday, see the firmware update, start at it and... failed with the screeching. Gone through every thread I could find, formatted card, tried another card, even tried the past 3 firmwares, all fail after a couple minutes, and there's no video signal now if I try to run it anyway. In the misc folder log file it's showing 15 and 08 as "device not detected", which I'm seeing people say they have to send back to DJI over... How on earth could firmware require being sent back for repairs? And how ungodly long is that going to take now that everyone who got a DJI product for Christmas probably crashed it on their first flight (or had the firmware updates brick it)? Ugh... With my luck the winter wonderland part of the year will be gone by the time it got back.

Partial log file, starting with this last latest version attempt, as far as I can tell:
[00014574]========== remo-con disconnect. boot(15) ============
[00014622]Packet [C:\P3X_FW_V01.06.0040.bin] detected, card sn [0x831d2a07].
[00014681]Packet upgrade start...

[00014737]Packet checking...
[00014787]Packet vlink 01.06.0040 <-> 01.05.0030.
[00014846]Record vlink 01.04.0010 <-> 01.03.0020 (flow = 0).
[00014897]Done.

[00014950]Version checking[1]...
[00027508][03 05][00] device not detected.
[00040059][03 06][00] device not detected.
[00040119][04 00][00] v1.41.0.0 -> v1.41.0.0
[00052676][11 00][00] device not detected.
[00065225][12 00][00] device not detected.
[00077774][12 01][00] device not detected.
[00090323][12 02][00] device not detected.
[00102893][12 03][00] device not detected.
[00115442][15 00][00] device not detected.
[00127989][17 00][00] device not detected.
[00140549][17 01][00] device not detected.
[00153110][19 00][00] device not detected.
[00153159][01 00][00] v1.26.4315 -> v1.26.4315
[00153290][01 01][00] v1.26.4315 -> v1.26.4315
[00165846][08 00][00] device not detected.
[00165922][09 00][00] v0.0.0.0 -> v2.13.0.0 need upgrade.
[00165977]Done.

[00168030]Waiting for user confirm...
[00178082]Timeout, start upgrade automatically.

[00178188]Firmware upgrading[1]...
[00178265][09 00] Firmware upgrade start...
[00231658][09 00] Firmware upgrade finished successfully.
[00231708]Done.

[00231762]Version checking[2]...
[00231856][03 05][00] v34.2.0.9 -> v34.2.0.9
[00231936][03 06][00] v2.4.10.7 -> v2.4.10.7
[00231995][04 00][00] v1.41.0.0 -> v1.41.0.0
[00232136][11 00][00] v1.7.15.1 -> v1.7.15.1
[00232255][12 00][00] v1.10.0.0 -> v1.10.0.0
[00232356][12 01][00] v1.10.0.0 -> v1.10.0.0
[00232456][12 02][00] v1.10.0.0 -> v1.10.0.0
[00232556][12 03][00] v1.10.0.0 -> v1.10.0.0
[00245105][15 00][00] device not detected.
[00245205][17 00][00] v1.1.1.7 -> v1.1.1.7
[00245369][17 01][00] v1.0.2.7 -> v1.0.2.7
[00245436][19 00][00] v1.0.8.96 -> v1.0.8.96
[00245485][01 00][00] v1.26.4315 -> v1.26.4315
[00245545][01 01][00] v1.26.4315 -> v1.26.4315
[00258100][08 00][00] device not detected.
[00258177][09 00][05] v2.13.0.0 -> v2.13.0.0
[00258232]Packet upgrade failed at version checking.



[00014481]========== remo-con disconnect. boot(15) ============
[00014540]Packet [C:\P3X_FW_V01.06.0040.bin] detected, card sn [0x831d2a07].
[00014592]Packet upgrade start...

[00014648]Packet checking...
[00014705]Packet vlink 01.06.0040 <-> 01.05.0030.
[00014756]Record vlink 01.04.0010 <-> 01.03.0020 (flow = 0).
[00014809]Done.

[00014860]Version checking[1]...
[00014961][03 05][00] v34.2.0.9 -> v34.2.0.9
[00015061][03 06][00] v2.4.10.7 -> v2.4.10.7
[00015118][04 00][00] v1.41.0.0 -> v1.41.0.0
[00015261][11 00][00] v1.7.15.1 -> v1.7.15.1
[00015371][12 00][00] v1.10.0.0 -> v1.10.0.0
[00015529][12 01][00] v1.10.0.0 -> v1.10.0.0
[00015654][12 02][00] v1.10.0.0 -> v1.10.0.0
[00015781][12 03][00] v1.10.0.0 -> v1.10.0.0
[00028423][15 00][00] device not detected.
[00028526][17 00][00] v1.1.1.7 -> v1.1.1.7
[00028686][17 01][00] v1.0.2.7 -> v1.0.2.7
[00028777][19 00][00] v1.0.8.96 -> v1.0.8.96
[00028831][01 00][00] v1.26.4315 -> v1.26.4315
[00028890][01 01][00] v1.26.4315 -> v1.26.4315
[00041444][08 00][00] device not detected.
[00041517][09 00][00] v2.13.0.0 -> v2.13.0.0
[00041577]Packet upgrade failed at version checking.

nicwilson Posted at 2016-1-2 09:48
The fact the not just my P3P,   but all the all those in the local group work fine,  proves without ...

sorry buddy, but I had a phantom that worked perfect and after updating began to vibrate, like my many other people , that you and your friends will fence it does not mean that the rest of the world will fence ...
that 10 minutes looking at the drone , is a nonsense , I revised it at home before each flight and not have to look so 10 min in the field..
your answer is a bit arrogant , probably many of them vibrating , care and review the phantom more than you and your friends.

guerinomaione@g Posted at 2016-1-2 08:37
Hallo i had a body vibration after upgrading firmware to 1.6. Before upgrading i haven't....
I down ...

Me too.
Donwgrade not helped.

guerinomaione@g Posted at 2016-1-2 07:37
Hallo i had a body vibration after upgrading firmware to 1.6. Before upgrading i haven't....
I down ...

Your short video actually shows the vibration (during stationary hovering) very good. It shows that absorber and gimbal have a hard time.

Have you tried these settings already?:
basic gains (inside the "DJI GO app"): pitch=90%, roll=90%, yaw=80%, vertical=90%
I have tested it (see my post #201) and for me it works great. In Post #218 you can find an explanation what it acutally does and DJI-Ken confirms that to be useful (for those with issues) in his post #221.

So maybe you can give it a try as long as experiencing the oscillation with the current FW.

Happy new year everybody,
Claus

vr-pilot Posted at 2016-1-2 15:33
Your short video actually shows the vibration (during stationary hovering) very good. It shows tha ...

Hi, thanks for your answere... I tried with values you said. It seems better but it is very very slow to response..

I think that Dji should solve that problem but....

Guerinomaione Posted at 2016-1-3 12:01
Hi, thanks for your answere... I tried with values you said. It seems better but it is very very s ...

That's odd, because I haven't really noticed much difference.  The way I understand it is the gains alter the drones response to outside influence, such as wind, rather than controller response.  Expo settings adjust controller response, no?  May try adjusting expo settings to get back what you feel you've lost.

nigelw Posted at 2016-1-3 13:31
That's odd, because I haven't really noticed much difference.  The way I understand it is the gain ...

Yes but dji should not create this problem. A lot of people have a problem with the new firmware and what does dji do for solving it?
Dji should be sure that the firmware releases...

Guerinomaione Posted at 2016-1-3 09:10
Yes but dji should not create this problem. A lot of people have a problem with the new firmware a ...

I posted my FW 1.6 vibration issue in the software update 1.5 and vibration thread. Looks like the next step is to lower the gains.

Guerinomaione Posted at 2016-1-3 14:10
Yes but dji should not create this problem. A lot of people have a problem with the new firmware a ...

Agreed, if they've introduced the problem they should identify & resolve it.  I have no way of knowing if mine will reoccur in different conditions.

nigelw Posted at 2016-1-3 15:29
Agreed, if they've introduced the problem they should identify & resolve it.  I have no way of kno ...

Hi Nigel,

today I made a short test flight under those (extreme) conditions:
carbon fibre reinforced props, changing winds between 7 and 10 m/s, -6°C (windchill/realfeel -16°C!).

As you know my "basic gain" settings are pitch=90%, roll=90%, yaw=80%, vertical=90%.

With windchill of -16°C and winds of up to 10m/s it was beyond DJI's recommendations to fly and I had to stop my short trip because it was after 15 minutes flight time impossible for me to move my fingers on the RC accordingly... (next time special gloves perhaps?)

Regarding vibrations while hovering and in flight/climb everything felt right (but frosty), only on ground at idle thrust the oscillation reoccurred after self-increasing RPMs (although yaw set to 80%).
This could be related to extreme temperatures of -6°C (felt like -16°C), intervened perhaps by the new v1.5/1.6 "cold battery protection by lowered thrust" programming.
The wind could play a role, and maybe even the carbon fibre reinforced props could be playing a part:
http://forum.dji.com/thread-24486-1-1.html
Next time I will make test flights with the standard white props again to rule out this (quote from the above mentioned thread, post #10)
"The (carbon fibre reinforced) props are stiffer than the stock ones and my initial flight testing seem to be more crisp actions to input." (quote end)
And more crisp actions to input could again contribute to oscillation/resonance.

I am actually not having an issue for the time being as for inflight lowered basic gains (like mentioned above) do the trick for me under currently low temperatures here.

Always happy landings,
Claus

vr-pilot Posted at 2016-1-3 21:21
Hi Nigel,

today I made a short test flight under those (extreme) conditions:

Thanks Claus

If it ever stops raining I'll be able to do more testing, but it looks like I'll be grounded for the next week.

I did have to replace one of the gimbal mounting/shock absorber rubbers after the last flight, I'm not sure if the vibration had anything to do with it or what their expected life expectancy is.  It would be a good idea to be extra vigilant when checking the aircraft for damage/loose screws etc.

vr-pilot Posted at 2016-1-3 22:21
Hi Nigel,

today I made a short test flight under those (extreme) conditions:

Hallo, my test have been made at 6-10°. Really it serena that the problem there is only at the takeoff. The vibration get less after 1 or 2 minutes.

Ps excuse me for my bad english, i hope you understand...

guerinomaione@g Posted at 2016-1-2 08:37
Hallo i had a body vibration after upgrading firmware to 1.6. Before upgrading i haven't....
I down ...

Same problem. With 1.5 there wasn't vibration, now upgraded to 1.6 and have vibration. I have done the cold IMU calibration etc.

Priidik Posted at 2016-1-4 17:44
Same problem. With 1.5 there wasn't vibration, now upgraded to 1.6 and have vibration. I have done ...

Should I upgrade to 1.6 ?

I haven't upgraded my Phantom before the day POI existed. Apart from some gimbal jitters everything works fine. Is it safe to upgrade to 1.6 for my P3P ?

Dan30 Posted at 2016-1-2 20:45
sorry buddy, but I had a phantom that worked perfect and after updating began to vibrate, like my  ...

Downgraded some of the phantoms in the group to the last firmware and we are still unable to find any issue at all,  so your thoughts about why this occurs is obviously misguided, care to think about any other variables?   you obviously are being narrow minded and laying the blame squarely in one place.   THAT is the issue IMHO,  and still think most issues are caused by the relentless need to keep calibrating the IMU and then without really doing it properly,  or even knowning the reason and theory behind what you are doing,  or temperature related as we never experience cold climate ever.