# Need the uav to perform a circle turn

I've got a project that will require my drone to perform a circle turn while the drone is always facing the tangent of the turning curve. Similiar to a car that is performing a frictionless banked turn. Just wondering which method should i use to achieve it, the throttle control can be ignored since i already have a pid on height control.

Any suggestions would be appreciated.

• Are you sure you want to achieve a target acceleration and not a target velocity? As per your description, if you let go of the sticks, the quadrotor will maintain constant speed. Is that what you want? Jan 14 '16 at 7:56
• Yes exactly, i need a it to make a circle turn, and the horizontal acceleration is used to encounter centripetal force Jan 14 '16 at 8:13
• I have never heard of a quadcopter controller following a circle this way. Anyway, it might be more complicated than you think, since in order to increase lateral acceleration you may need to increase both bank angle and thrust. Best of luck! Jan 14 '16 at 8:18
• Huh how would you finish a circle with the drone always facing to the tangent of the curve then? Jan 14 '16 at 8:19
• I You could look at the ArduCopter code. I think the way they do it (and I have done so as well in another project) is to build a potential field tangent to your desired circle and use it for reference orientation. There is an algorithm for a plane here: Beard, R., & McLain, T. (2012). Small unmanned aircraft: Theory and practice Jan 14 '16 at 8:28