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Hello all,

Today I tried to do something that I've never done before, the autotakeoff.
I had set the takeoff parameters as follows:

Minimum pitch 20 degrees(I have an airspeed sensor)

Autotakeoff altitude: 30 meter
0 m/s gps speed
0 seconds delay
15 accell throttle arming

0seconds delay.

I have a Bixler with the prop on its back so I don't need anything else that the accel check before arming the throttle.

So far so good.

So I threw it in auto mode. Immediately after the throw the throttle armed and engine revved up to max throttle. It pitched up and took off.
But after a few meters in flight the airplane started to bank right. It continued to climb but at the same time it continued banking to the right making a circle until it hit takeoff alt.
It stabilized and just "sat" there for a while. It took course for the first waypoint, but it stayed at takeoff alt for about 20 seconds. Then it throttled up, took off to waypoint 1 altitude at 100 meters and it continued its mission "like a boss".

It flew very well for the rest of the mission.

When I look at the log just now, I see that nav_roll during takeoff is limited to 5 degrees until it reaches takeoff alt. But roll never reaches the attitude the nav_roll controller is asking for. during the rest of the mission everything seems fine.

Looks like something is wrong with the autotakeoff coding.?

It is worth noting that the wind was very strong and turbulent today.

2013-08-16 14-41 92.log

autotakeoff.png