Disturbance Observer Based Attitude Control for a Three-Degree-of-Freedom Laboratory Helicopter

This paper deals with the attitude control design problem based on Generalized Proportional Integral (GPI) approach and a disturbance observer (DO) for pitch and rolling channels of a three-degree-of-freedom (3-DOF) laboratory helicopter. In the attitude control design, both of the channels are considered as linear systems. The GPI control laws based on integral reconstructions are developed to avoid the use of derivative operators, which can inhibit effects of measurement noise and time delay. The GPI control scheme based on DO can reject the effect of external disturbance. The control performance of the closed-loop control system under the designed controller is shown better than the traditional PID controller. Simulation results are given to show the effectiveness of the proposed GPI controller with the unknown external disturbance.