Attitude Control for Unmmaned Helicopter Based on Flap Angle Control

Abstract

Stabilizer (Fly-bar) makes the efficiency and performance of an unmanned helicopter worse but it is very reliable mechanical feedback to enhance its maneuverability and safety. In this paper, a design method for attitude control of the unmanned helicopter with stabilizer was proposed. Flapping motion of the rotor blades and stabilizer blades was considered for precise modelling of horizontal motion of the unmanned helicopter and dynamic inversion method was adopted to design the attitude controller. The attitude control system includes an observer to estimate the flap angle of the stabilizer blades. Utilizing flapping motion characteristics of both blades, the flap angle controller was designed. It was clarified that the stabilizer blade may resonate when the band limitation is not applied for control due to the small lock number of the stabilizer blade. Results of numerical simulations revealed that the proposed attitude controller functions properly by bandwidth limitation to control.