Litchi Mission Switch to ATTI mode mid mission - P3P

[joeruby]

OMG, now we get the full story.

"Calibration measures the magnetic fingerprint of the surrounding area and on your drone itself."
Posted in this thread.

Compass Calibration, A Complete Primer

UPDATED October 2018 Why Calibrate? Compass calibration is an essential part of flying. Bad compass data will cause a disagreement between the GPS and compass. Calibration corrects for magnetic deviation (NOT to be confused with declination) which is often responsible for generating bad compass...

phantompilots.com

I really appreciate you posting your findings, so few do.

A lot of us try hard to help others, when it gets figured out we all learn.

Thanks

Rod

Thanks Rod, and everyone else that helped. How dumb can I get. I (use too )know better. Thanks for the compass primer link. It is a very good refresher.

 

[RodPad]

Until I hung around here long enough, I did the compass dance anytime I flew in a different area. I was stuck on deviation concept I guess.

I had never thought the calibration of compass was for the Phantom's own structure.


Rod

 

[Capt KO]

FYI:
Maybe I have found the reason why those two Litchi missions, at the fly-in-get-together, failed in ATTI mode! The night before the fly-in, Charlie said to bring my fishing bomb drop attachment. So I bolted on my Gannet fishing bomb drop. It contains some electronics and a battery! (see link below) I simply bolted it on and went flying. Those first two missions failed in ATTI mode.

Now when I first got this device a year or more ago, I bolted it on, and I am sure I calibrated the compass and the IMU and the control sticks. Then went and did a number of tests. After many tests with the bomb drop device, I gained confidence that it did not affect anything. I flew with it for many flights for over a year. No problems. Then I took it off for the Winter, because Joyce was not going fishing this Winter. I am sure I calibrated the IMU and compass again several times during the long time it was off the AC. Now for this fly-in I simple bolted it back on and thought nothing about it. I had the two ATTI failures at the fly-in, and many more ATTI failures during the testing described above in this thread. Until I calibrated the IMU and compass with the unit back on the aircraft. Then the ATTI mode failures stoped!

Could this explain my problem and why it has been solved? In my mind it could be the culprit. Finally explained, and understood.

As always, constructive commence welcome.

See:

Drone Fishing - Phantom 3 Gannet ( Replaced by the Gannet X)

Phantom 3 - Gannet Bait Release (patented) Designed specifically for the DJI Phantom 3 (All models) Main features: Mounts to your drone in...

dronefishing.com

Thanks for the heads up. I use the gannet sport manual release. Going to try their new xsport model with electronic/manual combo release. Will watch for this problem, and if necessary, use your solution. Thanks

 

[joeruby]

Thanks for the heads up. I use the gannet sport manual release. Going to try their new xsport model with electronic/manual combo release. Will watch for this problem, and if necessary, use your solution. Thanks

Capt KO, don't wait for the ATTI mode to happen when you are not expecting it. Just calibrate your compass (and the IMU) when you install your device on your AC.

And calibrate again whe you take the device off of your AC.
Joe
KC7GHT