Compass calibration on a ship...

m00se · Aug 10, 2015

Kilrah said:
Well there still is an issue because an i1/p3 will not even let you start motors if the compass data is considered invalid, regardless of mode.

Envoyé de mon SM-G920F en utilisant Tapatalk

I had this problem when flying indoors a couple of months ago in one of the malls here, I had to make a big stack of wooden pallets to get me up far enough from the floor to arm....

Flying from a boat is riddled with problems, I'm not sure I would want to try it..... maybe with a 40 euro quad first to see what kind of panic situation it put me in

damoncooper · Aug 10, 2015

Careful with cruise ship launches. I saw someone was planning to do this several pages back.

My understanding is drones are forbidden on many cruise lines now. Check before you go.

damoncooper · Aug 10, 2015

lrwskyfilms said:
I've done a shoot on a catamaran which had a aluminum hull and steel railings, decks etc as well as steel containers on board. As stated above do your compass cal and IMU cal at known good locations, do not do these onboard.

On start up my MODS went from 1450/1550 to 2700/2900, only when I took off and hovered about 10ft from the craft did the MODS drop to about 1500. I took off and landed in GPS mode, with my finger on the ATTI switch.

Also as the CAT hit 30+knots I cancelled the 500mtrs distance settings, otherwise you'll have to hit dynamic home point frequently.

I flew around the craft in the same waters as other boats/ships, no interference from sonar/radar/comms etc and no picture break-up.

The hardest bit was doing 30+ knots across others waves, holding on, keeping balance, keeping LOS and trying to film/shoot made it somewhat exciting.

Home point! Yes hadn't thought of that but that's gotta be important

TobyInspire · Aug 10, 2015

I was also worried about taking of from a very rocky (but insanely beautiful) boat ride.

The immediate solution with no access to this useful forum:

Had a dingy take me to shore, then I calibrated, then left the unit on, another boat ride back, took off...
Worked, and for everyone concerned about battery life, I lost 6% on the P3P crappy battery.

On another note, I was reading about the new SMART RETURN HOME feature, in the water that would mean the Inspire would just "land" in the water???

- fast forward to 1:33

SultanGris · Aug 10, 2015

Yes, I try to avoid using any of the auto flight stuff. Tech isn't there yet, it has no idea what is in the flight path or landing zone. It may work ok in wide open flat empty fields but other than that it's a crap shoot unless you survey the area and adjust settings accordingly. I don't see how land at current location would ever end well. Plus it flies super slow in auto mode, it's much faster and easier to just fly yourself.

DavidB · Aug 15, 2015

Not sure if you still get a message about this belated "reply". I had a query about the GPS ATTI situation. I tried to land (hand catch) the I1 on the deck of a yacht under sail. Even though the yacht was only moving at around 4 knots I ended up crashing on the deck as the battery was getting low. I realised retrospectively that I should have switch to ATTI mode, as every time I centred to sticks, the I1 wanted to stop and stay at that point. In ATTI mode it would have still drifted for a while, at hopefully 4 knots. I was impressed by your landing. Was it is GPS or ATTI? Thanks

JayVapes · Aug 16, 2015

Smart home. Set to hover instead of land. Unless low battery kicks in then it will try and land

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southerndoug · May 30, 2016

Is anyone still on this thread or interested? I have noticed that with the latest firmware (1.8.01.00), the I1 will not arm/start the motors if the compass error kicks in due to interference. This may have been present in earlier firmware, I just haven't tried it until now. I have a need for take-off from a steel ships helideck. No compass calibration possible, and a long way from point of departure. I mean a LONG way. Magnetic declination and inclination will have changed hugely from our port of departure. I was planning to do the whole show in ATTI mode, but I can't even seem to spin the props up to get airborne. Any thoughts anyone? What would happen if I disconnect the compass board from the FC? Will I still get an error? Probably...

cycoptic · May 30, 2016

southerndoug said:
Is anyone still on this thread or interested? I have noticed that with the latest firmware (1.8.01.00), the I1 will not arm/start the motors if the compass error kicks in due to interference. This may have been present in earlier firmware, I just haven't tried it until now. I have a need for take-off from a steel ships helideck. No compass calibration possible, and a long way from point of departure. I mean a LONG way. Magnetic declination and inclination will have changed hugely from our port of departure. I was planning to do the whole show in ATTI mode, but I can't even seem to spin the props up to get airborne. Any thoughts anyone? What would happen if I disconnect the compass board from the FC? Will I still get an error? Probably...

Hi mate, i have been through this myself. Just grab one of the big plastic bins put your inspire on it and take off from there. This will give you enough space so the compass won't go haywire. you can land it on the deck but put it down fast so it doesn't get interference again. Don't bother trying a compass calculation out there it should lock in when your airborne. If the inspire won't play ball with the bin take it indoors and turn it on, maybe on top of a table, it should reset itself, then turn it off and try the bin again. I put some scrap wood on top of the bin also for the take off if there is any lying around. good luck

also if you are worried about the compass use attitude like you said, once your airborne

DavidB · May 30, 2016

I await your progress with interest. Another option is to try a hand launch. I have thought about hand catching and launching the I1 from a boat and developed the handle detailed at Hand Catching an Inspire. Making a Removable Grab Handle.

I would be in ATTI mode, so hopefully all should be well. Good luck.

southerndoug · May 30, 2016

Thanks for your replies guys. In answer to my own question, disabling the compass board by disconnecting it from the FC results in exactly the same problem. No motor arming possible. Cycoptic, thanks for your input... I'm interested to know how large the ship you launched from was, and that a plastic fish bin (?) was enough to deconflict the compass. I'll be on a 5000 tonne ship with steel everything. There's also a precedent set for operating off this ship using an inspire 1 in ATTI mode. Their report states:

"The day before departure a trial flight was undertaken on the ship. As expected the ship’s steel construction interfered with the compass and the drone’s safety arming checks prevented the motors starting up when placed on the deck. Further tests were undertaken in different areas of the ship to determine where this calibration issue would occur, and it appeared to encompass the entire ship, which was not unexpected.
At this point it was clear we would need to disable the compass sensor for initial arming, which was not as simple as flying in ‘non-GPS’ mode, as the drone still required a successful compass reading in this mode, even without GPS. Through further testing we discovered a workaround whereby we could manually disable the sensors, allowing us to successfully arm and takeoff in full manual mode."

But they don't elaborate on their "workaround". I've contacted him but he never got back to me.

southerndoug · May 30, 2016

DavidB said:
I await your progress with interest. Another option is to try a hand launch. I have thought about hand catching and launching the I1 from a boat and developed the handle detailed at Hand Catching an Inspire. Making a Removable Grab Handle.

I would be in ATTI mode, so hopefully all should be well. Good luck.

Yeah DavidB, thought about that and have ordered some grab handles off eBay to try. I may run into problems on the ship with OH&S issues, Risk Management etc. And it still may not be enough to get the I1 out of the magnetic interference "zone".

ianwood · May 31, 2016

Don't try to calibrate on a steel ship. That won't end well. Taking off, you need to get the Inspire as far away from the steel as possible. And even then, it may not work depending on the ship's magnetic field. Be prepared to fly in ATTI if it starts to get squirrelly.

cycoptic · May 31, 2016

View attachment 8694 Hi, i have flown off all steel ships and oil rigs before. The big rubbish bins that are around, sometimes they contain oil spill kits,sometimes just for rubbish. They are about waist high, this will stop the compass losing it.
I have done it of an esky, or cooler before too, you just need to get it off the metal.