Highly unstable after switching modes

[SimonMW]

Just experienced this today. I've only had the Inspire about a week, but have been flying without issue. Today I took it over to a mates to give him a demo. It was a nice open area so I decided to fly in ATTI mode for a change. All was absolutely fine.

After a while I decided to switch back to GPS mode, and then things started to go funny. The Inspire started performing some really funky movements and wouldn't hold position in a hover at all. I managed to land it (like an idiot I forgot to simply switch back to ATTI mode), but it was hairy for a bit.

My IMU is calibrated and I calibrate my compass in each new location. When I turned the Inspire off and then powered it back on again it all worked perfectly in GPS mode.

I haven't had a chance to test more, and will do when the batteries are charged. However, has anyone else come across this? Is there a possible bug that occurs switching from ATTI mode to GPS mid flight?

 

[sirnikolas]

Have you updated to the latest firmware?
Sounds like you've got the gps bug FW.

 

[SimonMW]

Firmware is the latest version. It was the first thing I did when I bought it was to upgrade to firmware 1.2.1.03.

 

[The Editor]

and I calibrate my compass in each new location.

And there is your problem!
There is absolutely no need to do a compass calibration in each new location. When you switched from Atti to GPS you no doubt had a skewed compass calibration which is why the AC acted the way it did.

 

[huppe]

To be honest I haven't calibrated my compass since last FW upgrade.I always check my app and when it tells compass is normal I will skip the"dance".

 

[SimonMW]

And there is your problem!
There is absolutely no need to do a compass calibration in each new location. When you switched from Atti to GPS you no doubt had a skewed compass calibration which is why the AC acted the way it did.

DJI suggest that it should be calibrated in each new location, is this wrong? I've read many threads where flyaways have been attributed to people not calibrating on a new day and new location.

However, I'm not sure why switching from ATTI to GPS should have this effect. When I shut down the craft and turned it back on again it was fine once again. Surely if the compass cal was out it would have continued to behave in a whacky way? Remember I started off in GPS mode, which flew fine, switched to ATTI mode, which flew fine, then back to GPS, which is when it went all weird.

 

[huppe]

DJI tells more fairytales.I can tell that I didn't have any fly away after they solved the ATTI problem.I trust on my app.Have been all around my place as far as 160 km.Didn't do the "dance" and it was fine.As Editor says there is no need to calibrate every time

 

[pgale]

Ed, I'm also curious why you say don't do a compass calibration in each new location when DJI explicitly say to do so. Do you have any inside information on this?

 

[The Editor]

Ed, I'm also curious why you say don't do a compass calibration in each new location when DJI explicitly say to do so. Do you have any inside information on this?

Have a look here (post number 83) - http://www.inspirepilots.com/threads/epic-2-mile-fly-away.3157/page-5

 

[BroxAg]

I'm also with pgale on this. Dji says to do a compass cal on every new location and gives no reference to distance from previous location, yet the editor is hell bent only doing a compass cal if you have moved thousands of miles. Could you please clarify where this info has come from and why we should take your word over dji as at the end of they day dji are the ones covering the warranty rather than your self mr editor

 

[The Editor]

I'm also with pgale on this. Dji says to do a compass cal on every new location and gives no reference to distance from previous location, yet the editor is hell bent only doing a compass cal if you have moved thousands of miles. Could you please clarify where this info has come from and why we should take your word over dji as at the end of they day dji are the ones covering the warranty rather than your self mr editor

Never a truer word spoken - I will not be replacing your Inspire when it all goes horribly wrong (by you constantly calibrating your compass )

Please feel free to follow whatever advice you feel is right for you.

 

[BroxAg]

And once aging the Ed makes reference to his way being the only 'correct' way, all the while failing to answer the original question of where he had gained this info from.

 

[The Editor]

And once aging the Ed makes reference to his way being the only 'correct' way, all the while failing to answer the original question of where he had gained this info from.

Ryan,

Thank you for your comment. I notice you have joined the forum today and feel it necessary to attack me within the 3 messages you have posted to date.
In no way do I attest that 'My way' is 'The Only way'.....
Of the handful of posts I have made on this forum I would hope that I have been able to help a few fellow Inspire owners out when things haven't gone as they have expected or they have needed help or advice with their Inspire. I would think my 'votes' or likes would reflect that.

I do have an NDA in place with DJI which precludes me from divulging as much information as I may like to however, what I would say is in the 20+ years of designing, building and flying RC aircraft, I have picked up a little bit of experience along the way. Most lately in the design, build and implementation of multirotor platforms across various FC's and firmwares. There are not many problems or idiosyncrasy's or failures that I have not come across in my time both on the ground and in the air. My 'info' is gained from many stick hours and thus far, a faultless flight record with mutirotors.

As I have said before, you are a free agent and as such are not bound by my advice, recommendations or experience. You are free to fly and calibrate as you see fit.

Thank you for your contribution to InspirePilots.com

 

[BroxAg]

All I am trying to do mr editor is clarify the source of your information for the benifit of myself and others. The manual written by dji who is the manufacturer of the craft states that a compass calibration should be done at every new location and yet in your link to post 85 above you state that compass calibration only needs to be done after a change in location of 1000's of miles. If Infact this is the case then why has dji not written it in the manual this way and how are you privilege to Information that we are somehow not? moreover what other information is in the dji manual that we should not be listening to? I'm not in any way attacking you I'm just struggling to understand (and I'm sure others are too) justification on your information given.
I may not have a long history with rc craft however I do come from an agricultural background specializing in surveying and gps control of large gear and we calibrate every morning and sometimes twice a day as the earth shifts in its axis and our accuracy starts to wain.

 

[huppe]

And once aging the Ed makes reference to his way being the only 'correct' way, all the while failing to answer the original question of where he had gained this info from.

Common BroxAg this is not the way to work here at this forum.The Editor could be right or wrong.You can agree or dissagree,but try to keep it clean.I can tell that my only experience according to the oiginal question was when I did a not needed calibration.My dealer is also clear on this,it is not needed every new day or location.DJI will tell you because it´s there for warranty reasons.They also told in the manual that there is a ground station.Feel free to calibrate if you want,but please after joining today don´t attack someone who is putting more time and energie on this forum then anybody else.
GPS measuring is something completly different I know,I work with Trimble equipment too,but a TomTom doesn´t need a calibration everyday too.

 

[BroxAg]

And there is your problem!
There is absolutely no need to do a compass calibration in each new location. When you switched from Atti to GPS you no doubt had a skewed compass calibration which is why the AC acted the way it did.



In a previous post above the Ed is stating that doing a compass calibration in a new location as per the manual is the cause of this persons problem.
I'm not trying to get anyone's back up huppe, the what I am trying to do is get to the bottom of a seemingly massive problem! Do we follow the manual as dji states and adhere to the conditions of warranty? Or do we take it on our own backs to decide when we should do a calibration? The editor has been asked serval times including once in this thread where he has got his information from but hasn't yet come up with a solid answer?
As for your reference to Tom tom, yes you are correct they don't need calibrating, however accuracy on a Tom tom is +/- 5m-ish. Not the sort of acuracy I would rely on for my I1

 

[PB30X]

For sake of argument. The question of compass calibration should be clearly stated and rewritten as it should and has already been done..... BUT!!!! Clearly people are finding out like myself that it does not have to be done continually.. That being said, like the Editor I agree 200% through experience with other AC's that it does in fact at times make matters worse.. I've experienced this first hand several occasions with owning a Phantom but have yet to encounter compass issues with the Inspire.. Does this mean it is correct, well NO PROBLEMS YET!!! one for the record.. Now beings you followed the manual word for word does that mean DJI is fully accountable and is legally documented?? Allot of questions, and I truly believe DJI will not answer them directly "FACT"... Allot of variables... We are here to help one another, but for someone to come here and flex artificial intelligence without the thought maybe we learned the easy way, or the hard way to fly our TOYS.. To think DJI, or any one person is far more intelligent than the engineers that design these AC's be my guest and spill the beans.. Cuz like anyone, we are here to either learn or help. Either way, not everything is as simple as it may seem. I will and will continue to fly my crafts to the best of my knowledge, and still manage to learn a few tips and tricks... Just my .02... Good Job Editor! For those who live by the book, have at it, much to learn[emoji6]!!! Fly Safe!!

 

[huppe]

And there is your problem!
There is absolutely no need to do a compass calibration in each new location. When you switched from Atti to GPS you no doubt had a skewed compass calibration which is why the AC acted the way it did.



In a previous post above the Ed is stating that doing a compass calibration in a new location as per the manual is the cause of this persons problem.
I'm not trying to get anyone's back up huppe, the what I am trying to do is get to the bottom of a seemingly massive problem! Do we follow the manual as dji states and adhere to the conditions of warranty? Or do we take it on our own backs to decide when we should do a calibration? The editor has been asked serval times including once in this thread where he has got his information from but hasn't yet come up with a solid answer?
As for your reference to Tom tom, yes you are correct they don't need calibrating, however accuracy on a Tom tom is +/- 5m-ish. Not the sort of acuracy I would rely on for my I1

Well the accuracy on the Inspire is not that good.Try a RTH and you will see what the accuracy is.Probably about 5 mtr from the start point.I told you I work with Trimble measuring equipment and yes there I need 1cm in height and position.But in countless occasions I lose signals due to houses and trees.
What I try to say that the Editor is giving a probable solution based on his experience.There is no need to say The Ed is once again pushing his advice.DJI has not proven to me to be customer friendly.Feel free to follow there advice.The Original poster has done all the given advices from the manual and he did have a problem so something was wrong.Nothing wrong if you try to follow some advice from very experienced pilots and see if it works.
So let´s get over this and let´s hope the wheather will improve here and I will post some positive threads about a great flight I did have that day

 

[Frank508]

The Editor is correct on this. The compass calibration is to correct for magnetic declination or variation (we call it variation here in the US.)

This Wikipedia page explains it, and puts into perspective this distance you would need to move to require a calibration.

http://en.wikipedia.org/wiki/Magnetic_declination

The DJI manual could be a lot clearer about this, so it is entirely reasonable that there is a lot of confusion.

I'm new to this forum, but I've been reading a lot of posts to educate myself, and your going to have a lot more success following The Editor's advice that you will ignoring it.

 

[SimonMW]

Some useful information. Although I would presume that you have to be sure of a "good" calibration in order to be confident of taking the I1 out without doing further calibrations? For example yesterday I flew her, and it didn't occur to me that there was a huge fence (possibly electrified) nearby, which I would presume could affect the calibration quite heavily?