Algorithm for Turn Right or Left

[AdamKt1]

Its my first post in this forum...
I am a student of Computer science, I am required to write a thesis on AutoPilots.
I am trying to develop an algorithm for turning a model plane (SkyRaiderII) right or left by keeping in view the current & required LAT/LONs.
I need suggestions from all capable...
Adam Katana

[toxicmouse]

-find the bearing the aircraft has been flying on
-using the current location and the destination, find the required bearing.
-compare the bearings to find the required change.

is this what you are asking for?

[AdamKt1]

Yes, it is what I am after.
Next question is to keep the model plane leveled, do I have to use gyro.
If yes, what may be the most economical solution.
Thank you.

[toxicmouse]

gyros? maybe, i suppose it depends on your aircraft. i think that most people developing autopilots integrate gyros at some point. maybe you would get more specific answers if you got the details of some autopilots and compared them.

[danstrider]

The hardest part for you in this project is learning the appropriate aero stab & controls IMHO. A good place to start is to grab Aircraft Stability and Controls by Robert Nelson from your university's library. There are several better books about autopilot design, but that one came to mind first.

I suggest reading a few of these papers too. It isn't 100% exactly what you're after, but it'll give you a basis of the high-end of student project complexity. Some of the papers have much more detail about their autopilots; homemade is getting more rare:
http://art1.mae.ncsu.edu/twiki/bin/view/Main/CompetitionPapers

I suggest this one in particular because it goes through a homebuild autopilot with a wing leveler.
http://art1.mae.ncsu.edu/twiki/pub/Main/CompetitionPapers/AUVSI_2004_-_VCU.pdf

Several folks here will recommend the FMA CoPilot. It is a thermopile attitude leveler. That is to say, it looks at the horizon with four IR sensors and attempts to balance their values. If ground is a value of 99 and sky is a value of 0, the CoPilot will add aileron and elevator command so all the sensors give a value of 50. I have seen this work on a much more complicated basis too, so I think there is lots of potential. It would be an extremely easy system to have: gps for location and heading, copilot for wing leveling, and YOU control the rudder to steer the aircraft to null the heading error (cmd vs actual).
Here is the CoPilot:
http://www.fmadirect.com/Detail.htm?item=1768&section=29

Shoot me a PM with your email address if you'd like more suggestions based on the copilot solution.

Dan