I just received my APM 2.5 and have yet to make an actual flight but have been familiarizing myself with it through the Flightgear simulator before throwing it into my Bixler.
I've been programming a simple mission with auto take-off, several waypoints, and ending with autoland. For some reason, after my last waypoint before it reaches the autoland point, APM is apparently commanding the plane to climb from the last waypoint of 40 meters all the way to 250 to 300 meters. Once it hits the autoland command point it starts a very long glide back down to the land which ends up being a very long distance away from where I want it to land. Any ideas? Is there a parameter that is set to do this?
Another issue with autoland is that APM locks in a trajectory that I do not intend. Although I plot a mission that allows a very generous straight approach to the autoland command point, in the sim it often makes a last moment crosstrack correction before hitting the autoland command point which frequently results in a water landing or into a barreling through a building (default runway is at SFO). If this were to happen in an actual flight, it could potentially mean a lost or damaged plane.
Is there a way to specify a landing heading that I am not seeing or is this just left to APM to decide?
Can you post your mission and your parameter file? A tlog would also be good.
The last minute crosstrack might indicate your WP_RADIUS is too small.
Thanks for the reply. I'll post them up after work this evening.
Edwards, see another post of mine and Andrew Tridgel replied to it, your case seems to be the same.
Autolanding has to be ensured by the user with appropriate approach waypoints with decreasing altitude and when the altitude is only few meters, only then Landing waypoint is set so that the plane does not glide much away from desired landing area.
Thanks for the replies and the video...I played with the sim a little more with the tweeks you recommended and things worked out better. I doubled the WP_radius to 60m (I'll go larger too and see what that does).
I followed Rana's recommendation of having the last few waypoints more closely spaced and incrementally lower. The last waypoint before the land command was 3m AGL and immediately next to the land command point. That seemed to do the trick.
Regardless, I think I have a bit more tinkering and reading to do before I feel confident in what ardupilot is doing before I send it up in my plane.