sam028

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Incorrect behavior with INS13
« on: October 28, 2017, 05:31:58 pm »
Hello,

I'm trying the PositionHold mode so to do this I change my setup from Complementary to INS13.
But while the copter is flying very well in Complementary mode it's completely crazy with INS13, I barely can't take off (and destroyed a couple of props).
What could be wrong? The mags have been calibrated and are all "green".
I'm using a Revo board with an additional GY-511 mag and a N8N GPS (GPS on a 10 cm mast, GY-511 just above the Revo).

Thanks,
Sam

f5soh

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Re: Incorrect behavior with INS13
« Reply #1 on: October 28, 2017, 07:52:57 pm »
Hi,

Mags will be green in Attitude > Mag tab (this mean each Mag is correctly calibrated) and the three bars still at 0 while moving the frame, this will made sure the AuxMag orientation is correct.
Set Mag usage to AuxOnly.

Be sure the Mag alarm in SystemHealth still ok while applying power. Should be the case while using AuxMag, away from strong currents).

Take a look at video:



sam028

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Re: Incorrect behavior with INS13
« Reply #2 on: October 28, 2017, 09:00:44 pm »
Thanks for the answers.
I searched before posting and the only thing which was not done like your description is the "Mag usage to AuxOnly", I used "Both".
The auxiliary mag is not that far from strong current but on a ZMR250 it's tricky to be very far away. If needed I'll put the GPS somewhere else and will the GPS mast for the aux. mag.
I'll try and will update the thead.

Sam

f5soh

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Re: Incorrect behavior with INS13
« Reply #3 on: October 28, 2017, 09:21:43 pm »
You may need at least a mast around 8cm long for a 250 sized frame.

Take care about power wires, you can twist wires and remove loops for reduced magnetic fields.

sam028

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Re: Incorrect behavior with INS13
« Reply #4 on: November 15, 2017, 05:58:08 pm »
So after a bunch of changes (new radio, SBUS receiver, calibrating the T° with the freezer trick, ...) it's much better with INS13 in stabilized modes.
It still have the "Toilet Bowl effect" but it's clearly because of the aux mag becoming red during the flight (I'll try again to fix the aux mag on the GPS mast).

Re: Incorrect behavior with INS13
« Reply #5 on: November 16, 2017, 10:58:02 am »
Hi,

I had the same problem. I solved it by using only one mag, the external one on the GPS receiver. There is a second mag in the Revo.

In the settings, select external instead of both and see if it solves your problem.

Laurent

sam028

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Re: Incorrect behavior with INS13
« Reply #6 on: November 16, 2017, 07:06:29 pm »
Yes, thank you, I followed @f5soh advice and check other posts but my AuxMag seems to close from the motors which makes it go red in flight.

Hi,

I had the same problem. I solved it by using only one mag, the external one on the GPS receiver. There is a second mag in the Revo.

In the settings, select external instead of both and see if it solves your problem.

Laurent

Re: Incorrect behavior with INS13
« Reply #7 on: November 16, 2017, 09:40:40 pm »
High current wires (battery to PDB to ESC to motors) too close to aux mag is one cause, but another you didn't mention is that all these high current wires must be twisted.

jdl

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Re: Incorrect behavior with INS13
« Reply #8 on: November 17, 2017, 11:58:39 am »
Hi, sam028,

I'd like to share some photos of one of my ZMR250 builds, they may be helpful to you...
All GPS / INS13 functionality works fine, no toilet bowls, no oscillations.

I use this frame for short to mid-range fpv and sometimes have to rely on RTB if signal is bad/lost. PositionHold, AutoLand are ok.

Completely solved the problems with INS13 / AuxMag on my ZMR250 frame by carefully twisting ALL high current wires. TheOtherCliff and f5soh already pointed that.

Furthermore, I've mounted the battery plug, primary power wires to the PDB, current sensor, BECs, Filters, LED driver, etc. between the bottom two carbon-fibre plates of the frame. Just used additional 5mm & 8mm spacers (this build has 3mm motor arms) to reach 8mm separation between the bottom plates.

AuxMag is integrated with GPS module (Beitian BN-880) that is placed farthest possible from motors and their wirings (on the top of the HD camera heatsink / mounting plate). I found that using GPS mast is not necessary for this particular build. Just had to calibrate the AuxMag for each type/size of battery I use due to its proximity to the AuxMag sensor. No such a problem to upload specific AuxMag calibrations when changing battery type, as the PID settings and FlightBattery settings should also be changed in this case.

Completely reworking already built frame is painful process so you may just try to twist the motor-to-ESC wires and the ESC-to-PDB wires, not touching the frame structure. If you put the AuxMag sensor on a mast, it should be sufficient.

You may submit some photos of your build here, this may help someone to give you more precise guidelines.

sam028

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Re: Incorrect behavior with INS13
« Reply #9 on: November 17, 2017, 07:45:22 pm »
It's much better now with the AuxMag on the GPS mast, it doesn't seems to move more 1 meter or so (better than two days ago when it ended in a window and broker its glass :)).
In my case PDB to ESC are not twisted (the PDB is below just like @jdl), only ESC to motors, I'll do this too.
As I'm sure you won't laugh (or very silently) I'm attaching a couple of links for the pics (without the FPV system, without shrinking tubes for GPS/AuxMag cables, ...) https://www.screencast.com/t/xIjts22eul and https://www.screencast.com/t/VkA9Oddj4BP (original images seems o be too heavy for the forum).

But I may have a bad Revo board: it seems I have to calibrate the gyro after each battery pack, if not I have something like this:
 http://www.screencast.com/t/GHPqXoeNF (quad landed, not moving at all). I'll confirm after more tests but it seems I have the same behavior after few minutes of flight (after having calibrated the gyros before taking off), see http://www.screencast.com/t/CDohAcdP12c . And of course the PFD goes crazy.

Thanks for the information and the pics, to be continued!

f5soh

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Re: Incorrect behavior with INS13
« Reply #10 on: November 17, 2017, 08:07:39 pm »
Quote
But I may have a bad Revo board: it seems I have to calibrate the gyro after each battery pack, if not I have something like this:

Try Thermal calibration, you have clearly a thermal drift issue with Gyros and also Barometer.

Please add some bumpers to the bottom side :)

sam028

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Re: Incorrect behavior with INS13
« Reply #11 on: November 17, 2017, 10:50:06 pm »
Quote
But I may have a bad Revo board: it seems I have to calibrate the gyro after each battery pack, if not I have something like this:

Try Thermal calibration, you have clearly a thermal drift issue with Gyros and also Barometer.

Please add some bumpers to the bottom side :)

Already done: thermal calibration from -16° Celsius to +20°C in a black bag with no light during calibration.
I'll get another Revo board sooner or later so I'll then see if my current board has a problem or not. Very smooth flights then gyros gets crazy, a bad board make sense IMHO.

edit: bumpers were there on day 1 but went off one by one after few emergency "landings" (more controlled crashes or uncontrolled crashes 8)).
« Last Edit: November 17, 2017, 10:53:07 pm by sam028 »

f5soh

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Re: Incorrect behavior with INS13
« Reply #12 on: November 17, 2017, 10:57:30 pm »
This big drift with both sensors is strange. Is the flying temperature inside -16° Celsius to +20°C range ?

Be sure the thermal calibration is done correctly, don't move board and protect from light while calibrating.

sam028

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Re: Incorrect behavior with INS13
« Reply #13 on: November 18, 2017, 01:44:38 pm »
This big drift with both sensors is strange. Is the flying temperature inside -16° Celsius to +20°C range ?
Yes, around 12°C.

Quote from: f5soh
Be sure the thermal calibration is done correctly, don't move board and protect from light while calibrating.
This is what I've done, no lights and no movement and a large sampled range: https://www.screencast.com/t/Ynulo8yDJCTL .
I'll do more tests, I'll try to find the correlation between the crazy gyros and "something".

f5soh

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Re: Incorrect behavior with INS13
« Reply #14 on: November 18, 2017, 02:07:54 pm »
Can you post your config file ?
File > Export UAV Settings