magnetic shielding

[Ralph thompson]

If you're filming indoors & had to launch a drone (M2P in my case) off a reinforced concrete floor (most certainly full of reinforcing bars), could you avoid compass interference by laying an insulating fabric, Faraday blocking material under the drone? Has anyone tried this? Seen on amazon

Earthing Grounding EMI RFID RF EMF Shielding Electrically Conductive Fabric Magnetic Radiation Blocking Faraday39"x43" : Amazon.ca: Home

Earthing Grounding EMI RFID RF EMF Shielding Electrically Conductive Fabric Magnetic Radiation Blocking Faraday39"x43" : Amazon.ca: Home

www.amazon.ca

Or would just launching of a 2 foot high wooden or plastic table be equally effective?

 

[Rich QR]

If you're filming indoors & had to launch a drone (M2P in my case) off a reinforced concrete floor (most certainly full of reinforcing bars), could you avoid compass interference by laying an insulating fabric, Faraday blocking material under the drone? Has anyone tried this? Seen on amazon

Earthing Grounding EMI RFID RF EMF Shielding Electrically Conductive Fabric Magnetic Radiation Blocking Faraday39"x43" : Amazon.ca: Home

Earthing Grounding EMI RFID RF EMF Shielding Electrically Conductive Fabric Magnetic Radiation Blocking Faraday39"x43" : Amazon.ca: Home

www.amazon.ca

Or would just launching of a 2 foot high wooden or plastic table be equally effective?

That blocks electric fields. Any conductor will block electric fields. But the problem is magnetic fields. Electricity and magnetism are certainly related, but they are not the same thing.

The usual way to block a magnetic field is with large amounts of steel. But that's not totally effective. The real challenge would be to block the undesired magnetic fields while allowing the Earth's weak magnetic field to get to the drone's compass!

Fortunately, for indoor flying when GPS is not available, the magnetic compass isn't so critical to drone flight.

See Can You Block a Magnetic Field? - Bunting Europe

 

[Ralph thompson]

Thanks Rich, so maybe just launching from a 2 or 3' high plastic or wooden table (alloy screws) would be sufficient to separate the drone from the metal bars? The issue in my mind is avoiding the drone getting in the air, away from the metal rebars and then having a compass/IMU discrepancy.

 

[Rich QR]

Thanks Rich, so maybe just launching from a 2 or 3' high plastic or wooden table (alloy screws) would be sufficient to separate the drone from the metal bars? The issue in my mind is avoiding the drone getting in the air, away from the metal rebars and then having a compass/IMU discrepancy.

A compass/IMU discrepancy isn't a problem in itself; the problem is if the IMU disagrees with the GPS notion of direction. If the GPS says you're drifting south, the computer has to use the IMU's heading to figure out whether to fix the southward drift by sending the drone forward, backwards, right, left, or something in between. If it gets this too far wrong, it will send the drone in the wrong direction, resulting in the GPS saying you're going further south, commanding a further incorrect correction, and quickly causing the drone to speed off wildly.

But this won't happen if you're flying indoors, because you won't have GPS to tell you you're drifting off. The visual sensors tell the drone directly whether it's drifting foreward, backward, left, or right, so the correction can be made without needing a correct heading from the IMU.

Now, about your question regarding how much distance between the bars and the drone is needed (assuming you're using GPS), it depends on the magnetic field strength of the bars. The best way to know whether you've got it right is to check your heading on the map, compared to the actual direction you see the drone pointing. It doesn't have to be perfect, but if you're within 10-20 degrees or so of the correct heading, you should be safe to fly.

 

[Ralph thompson]

I have to turn off all the visual sensors because we need to go up to about 40' altitude. Already done a test run and the visual sensors limit the altitude to about 20'.
My thought was that climbing up from a strong magnetic interference (rebars) to a weaker interference would cause the compass to swing around and confuse the controller. I understood that a compass change without an IMU angular acceleration would confuse the controller. Elevating the drone on a table should reduce that possibility. But I think your saying if the heading indication in the Go4 app is correct (attitude indicator) by confirming with a map & maybe iPhone compass then it should be OK.

 

[Phantomrain.org]

If possible Launch outside , get GPS lock and fly it into the building where you need to film.

Phantomrain.org
Gear to fly your Mavic 2 in the Rain

 

[Ralph thompson]

It would be possible to launch outside and fly in, I guess the benefit is that u know the compass is good.

 

[Meta4]

maybe just launching from a 2 or 3' high plastic or wooden table (alloy screws) would be sufficient to separate the drone from the metal bars?

That should be fine.
You can't stop magnetic fields with insulation, but distance separating works.

 

[Ralph thompson]

Thanks Meta4

 

[Mosherf]

Will turning the RC switch to ATTI mode and flying completely manually make the app not ask for calibration?
What about warping the hole body of the drone with tin foil?

 

[Meta4]

Will turning the RC switch to ATTI mode and flying completely manually make the app not ask for calibration?
What about warping the hole body of the drone with tin foil?

No ... if the compass detects an abnormal magnetic field, it will give the badly worded warning asking for an unnecesary compass recalibration.
You can only avoid the warning by avoiding the situation that causes it.
And if you want to fly safely, you should pay attention to the warning and stop looking for a way to stop it and do exactly what it's warning you not to do.

 

[Mosherf]

No ... if the compass detects an abnormal magnetic field, it will give the badly worded warning asking for an unnecesary compass recalibration.
You can only avoid the warning by avoiding the situation that causes it.
And if you want to fly safely, you should pay attention to the warning and stop looking for a way to stop it and do exactly what it's warning you not to do.

No need of preaching please. Where all grown up people here and I'm aware of the risks.

 

[Meta4]

No need of preaching please. Where all grown up people here and I'm aware of the risks.

Clearly you are not if you just want to go ahead with this.
You need to find a way to do whatever it is you are trying to achieve without landing on the steel roof.
Why do you think you need to land on the roof?

 

[Ralph thompson]

In my opinion, if you have a good idea where the magnetic disruption is coming from, it’s best to keep the greatest distance possible before starting up the drone. I’ve read that this is an inverse square law, so I’m hoping that just elevating the drone on a high table (with no metal parts) should be sufficient (as discussed above). Thanks for all the inputs.

 

[Cymruflyer]

No need of preaching please. Where all grown up people here and I'm aware of the risks.

I did not read into that Meta4 post, any preaching at all. It was a straight concise response to correct what you were suggesting that the OP might try. He was saying don't bother adding further complications with tin foil and simply do what the drone is telling you and help remove the problem by flying from outside in or moving the drone away from the magnetic or metal source, for best flying and control results. I think you misunderstood the way it was worded.

 

[Tiger64]

Is hand launching an option for you? The rebar isnt a problem when landing.
I sometimes handlaunch when terrain isnt suitable

 

[Ralph thompson]

It is a good suggestion but since I’m going to be lugging a lot of camera gear anyway, I will have a tall sturdy tripod. I have just made a simple, plywood platform with a quick release plate attached and can launch from that. Sort of the same thing and will land on the floor to be safe. Thanks for yr suggestion.