Integral-backstepping-based Attitude Control for UAH with Immeasurable States

In this paper, a new control scheme is proposed for the attitude control of unmanned autonomous helicopter (UAH) with immeasurable states. For the design of the control scheme, the attitude model of UAH considering flapping dynamics which is used to illustrate the change of flapping angles is established firstly. However, it is unpractical to install a sensor on the rotor to measure the flapping angles in actual system. In order to get the flapping angles in real time, a high-gain observer is applied. Meanwhile, the integral-backstepping algorithm is adopted to design the controller. By using Lyapunov theory, the stability of the closed-loop system is illustrated. Besides, the effectiveness of the proposed method is verified by numerical simulations, compared with the results obtained by the linear extend state observer.