Well yesterday i maidened my Maxi Swift with my APM. It flew fine in Manual Mode and then when i went to auto it seemed to go in the direction of the first waypoint but continued on doing circles and getting further away until i could no longer see it! Luckily i had fitted a cheap android phone with the wheres my droid app which allowed me to pinpoint it 1.5km's away. There was no damage but the only reason it stopped was i had set the default altitude to 50M and it ran into a hill which was 50M above where i launched.
I have attached the google earth log and parameters below. I know there is probably something obvious wrong but im not sure what it is? Any help appreciated?!
NOTE: 07/11/2011 09:15:38 Plane: Wing Crash
Have you tuned the PIDs as per the manual by setting up four waypoints in a perfect square?
Its likely that your PIDs weren't sufficient enough to fight the wind and judging by the elongated part of the "circles" moving to the north east, my guess is the wind was originally coming from the south west during your flight.
No i just tried a basic triangle with 2 waypoints and it made no effort to head in the direction of the second one. There was little to no wind i could not even tell which direction it was coming from!
The Red section above is Auto and the Green is RTL but there is no apparant difference between them?
There seems to be something fundamentally wrong with it but im not sure where to look?
Well, I think you should start by following the excellent tutorial on PID tuning first, which includes flying in FBW modes first, then graduating to full AUTO modes later. Do this in a very close proximity so if the plane starts to take off in another direction you can switch it to manual and recover without a problem.
I spent several weeks doing this myself on a much simpler airframe than yours, and I continue to work on it regularly, including in a simulator.
Ardupilot is like a child, you need to invest a lot of time educating it and giving it the tools to tackle the world on its own before you ever let it leave your house on its own. Even then its bound to make a few mistakes along the way and if you don't continue to keep a close eye on it at all times, don't be surprised if it shows up on your doorstep drunk and with a police escort. ;)