Nonlinear control design and stability analysis of a small-scale unmanned helicopter

The main focus of this paper is to design nonlinear controllers and analyse stability for a miniature unmanned helicopter. Our work is to utilize nonlinear control methodology to command dynamics of unmanned helicopter which has been divided into slower translational dynamics (outer-loop) and faster orientation dynamics (inner-loop), thus exhibiting hierarchical structure. The attitude angles and position which separately belong to the inner-loop and the outer-loop can be independently controlled by backstepping control strategy. Stability analysis of the helicopter system including flapping dynamics has been presented after designing controllers.