EMC Shielding for ArduCopter3.0

Dale Brown September 21, 2015 at 9:15pm

I know this is an old post but thought it might fit

I am currently building a Tarot 680 Pro (modified slightly). I'm getting ready to build my production one now and want to take careful consideration for shielding. Shielding only where absolutely necessary for weight considerations but get the most accurate GPS data I can. I do plan to use this one for precision mapping applications so precise is the word.

My basic layout is my GPSs (2 3DR Ublox) are 120mm from center of top deck and 160mm in height. My pixhawk will be mounted under bottom deck near front edge mounted upside down (damn df13 connectors on top). My cameras, radios (433 mhz, 900 mhz & 2.4ghz) antennas all are below deck, above deck is my GPS antennas and batteries. The batteries I plan different configurations but all stacked on top deck in proximity to GPS antennas. The 120mm and 160mm mentioned is from center point and surface of top deck. In theory in this configuration a battery 4s - 6s could be as close as 100mm - 120mm from GPS antennas. What do you all think?

What is truly necessary to shield for GPS (and video) to protect them?

Will it hurt if I shield with mu metal (maybe something better now) between the pixhawk and batteries? This would put the Pixhawk itself below the shielding.

Dave July 22, 2013 at 8:08pm

This was my first attempt at using MU Metal to shield ESC wires and a UBEC. The UBEC has a buzzer on it that would cause the mag to shoot up. It worked well but took up too much space. It would be a tedious process to use smaller tubes lined with MU. Another option is to just lay the cables over a flat piece and tape them down.

Jiro Hattori July 1, 2013 at 2:43am

In my understanding is something like:

1) Shielding all magnetic field sources, such as ESCs, power distribution board, wrings and Lipo.

or

2) Protecting APM from artificial magnetic field. The copter is pitch and roll, so that the magnetic shielding also considering like GPS ground plain.

Euan Ramsay July 1, 2013 at 2:12am

Re: Earth...I thought the field ran from poles, so the magnetic lines are parrallel to the core...so as long as you don't mumetal *vertically*, you should be ok? So *horizontal* blocking (ie blocking fields directly below it) should be ok?

Caveat: I failed physics at school :-)

Jiro Hattori July 1, 2013 at 1:49am

Please make sure not to shielding magnetic field from Earth:-)

Euan Ramsay July 1, 2013 at 1:30am

Can I just go on record in saying that - if I was newb to quads (and I still am, I guess), or specifically APM, that the whole compassmot procedure & inteference mitigation is far too complex for a usability point of view.

I understand the whole compassmot thing is new, but we need a better process than this, surely? How about a preset program/button in MP, which does a precise compassmot test? I've done repeated compassmot calibration on the same airframe, and the results vary considerably, which I can only attribute to the calibration procedure.

Knowing what I know now about APM and what is needed to get good flight in 3.0.x, I would have bitten the bullet and got a Naza instead even at the extra cost. Naza has it's own problems of course, but it doesn't involve moongel, mumetal, spinning up props to 100% on the ground, etc etc.

Sorry - bit of a rant there. I still love my APM, but if I was new to APM and 3.0.x, I might not be so favourable.

Euan Ramsay July 1, 2013 at 1:19am

Got mine on order. Can't wait...got 148% compassmot, and while loiter/RTL works, I'm not happy that they have reached the same quality as in 2.9.1.

Dave June 30, 2013 at 2:14pm

Thanks, I will get a shipment of Mu Metal early next week. I'm only at 60% mag interference so hopefully a little will go a long way.

Jiro Hattori June 29, 2013 at 10:19pm

Here is my setup.

Dave June 29, 2013 at 9:28pm

Are you mounting the MU directly under the APM or around it?

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EMC Shielding for ArduCopter3.0

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