Seems like this has been less discussed here in RCI and hence adding my part.
You can use KK board from hobbyking to stabilize fixed wing airplanes and to add auto leveling to them. this is done by flashing the KK board with a firmware called openaero
more info here:
http://www.rcgroups.com/forums/showthread.php?t=1708175a few terms to know:
Stabilization:
Uses gyros in the board to maintain the aircraft in the direction you want it to go and removed the disturbances caused by wind.
This does not put your plane back to normal position when you leave the controls.
especially useful for aerobatic pilots who want their planes to be on their rails while doing maneuvers.
lets say when you put your plane in a knife edge and leave it, the board will automatically give rudder input to maintain the level,
But, when you put the plane in a nose dive, it will maintain the axis(Lock) and will hit the ground in a straight path, it will not recover and put your plane and avoid a crash.
Auto leveling:
same as all the aspects of stabilization plus the plane will recover from bank and pitch and will level itself when the control inputs are removed.
ie, when you take your hands off the sticks, it will come to normal level, much like dihedral but in a better way.
this takes the use of inbuilt accelerometer and measure the change in bank and pitch and will correct it when the inputs are removed.
this also limits the bank and pitch of the plane to certain degree set by user(30 degree by default)
Limitations:
>This does not have any auto-landing function or any crash avoidance system, it simply levels the plane like a dihedral.
>All the autoleveling and stabilization depends on a perfect air frame, a sloppy servo link can spoil the performance and this doesnt mean that the openaero can still save this.
>This can be used on both flying wings and conventional air frames.
>Setting the horizon AKA calibration plays a vital role in auto leveling. if you calibrate wrongly, it will maintain that level and you will feel like the plane is banking on one side even with leveling.
>default values given in the PID tuning is good for skysurfer and bixler airframes and should be good for other planes too in the same wingspan however should be tuned for best performance.
Now lets get down on how to do it:
you need ,
4 channel electric airplane(not sure of their performance in nitros and 3 channel rudder only gliders)
KK board( v 5.5, KK 2.0 LCD board, KK 2.1 LCD board whatever)
USBASP
follow the instruction given in rcg link given and download the lazyzero software from here
http://lazyzero.de/kkflashtool. once installed you will have a window that has options to select the type of board and firmware and usbasp type.
more info on this video here:
(though there are countless videos available online, this is one good resource to count on!!)
Enjoy and ask any questions if you have any.
Ashok.P