log file attached.....running AC3.3.1 on Pix, was in loiter then guided mode just hovering at 5m for a while, all good, then sent the land command thru GCS and it just accelerated wildly to the right eventually ramming into my car and then into the ground, GPS masts broken, broken arm and motor mount, and nice gash on my car's door....
what the heck is Err: 0-44 mean? never seen that before but it happned just before I issued the land cmd, I dont see any mechanical issues and thou it appears there is some EKF issue right after the Err: 0-44 I dont see any specific EKF error
Randy or Leornard? please help! thanks
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I noticed that thou honestly didnt think much of it as I thought GPS wasnt used during a LAND mode, only the althold controller is used or something like that....I dont even think land uses EKF as land is a failsafe mode for EKF...so i have no idea what could have gone so wrong during a land if it doesnt rely on any navigation?
GPS will be used on "land" mode if the FC has a lock.
From the wiki:
http://copter.ardupilot.com/wiki/land-mode/
If the GPS coords move there is no way to tell if they are accurate and valid or if the quad has moved. So some bad readings give a worse result than a failed gps with no lock.