Wandering Off Course in Auto Mode

Log Analysis -- deprecated Copter Logs -- deprecated
1

I am running PixHawk with firmware version 3.04. In preparation for doing some mapping at an archaeological site, I have been flying a lot of autonomous test flights. The other day while engaged in my second autonomous flight of the day, the helicopter wandered off course. Fortunately I was able to put it in ALT-Hold and pull it back towards me. Can someone please look at the attached log & Flight Plan below and let me know if this was just a GPS glitch or a bigger problem? Thank you.

FLIGHT PLAN:
QGC WPL 110
0 1 0 16 0 0 0 0 34.201519 -118.225655 0.000000 1
1 0 3 206 7.280000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 1
2 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201533 -118.225772 12.192000 1
3 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201161 -118.225918 12.192000 1
4 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201149 -118.226035 12.192000 1
5 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201535 -118.225883 12.192000 1
6 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201538 -118.225995 12.192000 1
7 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201136 -118.226153 12.192000 1
8 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201124 -118.226271 12.192000 1
9 0 3 16 0.000000 0.000000 0.000000 0.000000 34.201541 -118.226106 12.192000 1
10 0 3 206 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 1
11 0 3 21 0.000000 0.000000 0.000000 0.000000 34.201519 -118.225655 0.000000 1

2

There are no obvious errors. It looks like you were having a GPS issue. Just before you took it out of Auto, your HDOP increased to over 3.0. Probably just random GPS wackiness, coupled with the fact you were operating near hills and mountains which could block the view of GPS satellites low on the horizon. Were it me I wouldn’t be overly concerned, beyond keeping an eye on it for a few more Auto flights.