عنوان مقاله [English]
Nowadays, vertical take-off and landing (VTOL) unmanned aerial vehicles (UAVs) are used in wide range of applications. Because of the high maneuverability, hovering at a stationary point and simple configuration, they are widely considered. This alongside with their extreme nonlinearities and under actuating control system raises the importance of the control of flight. In this paper, the effect of using stabilizing mechanisms in trajectory tracking of quad-rotor unmanned aerial vehicles under wind gust disturbance is studied. Two innovative mechanisms are introduced and simulated in this study. The first one is a spherical pendulum stabilizer and the second one is a cross stabilizer. Also appropriate controller is designed for each stabilizer mechanism. The performances of the systems are investigated in the presence of disturbing forces. The results show that instead of using complicated nonlinear control methods, the proposed stabilizer mechanisms yields a desired performance. Acceptable trajectory tracking shows the successful effectiveness of the presented stabilizers.