Control Strategy for Transition Flight of a Fixed-wing UAV

Ryota HATORI, Satoshi KONO, Kenji UCHIYAMA
2014 TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES AEROSPACE TECHNOLOGY JAPAN  
We propose a control system for a small fixed-wing unmanned aerial vehicle (UAV) transitioning from level flight to hovering without switching the controller gains and dynamical model. The proposed system is divided into translational and rotational control systems. Nonlinear equations of motion are linearized using a dynamic inversion method in the flight control system design. A robust rotational motion controller is employed because the attitude of the UAV is significantly affected by
more » ... ances such as wind. During the rotational controller design, the quaternion system was employed in place of an Euler angle to express the attitude angle of the UAV. This method enables the successive elimination of nonlinear terms through nonlinear state feedback because it is not necessary to select a typical equilibrium point. The unknown parameters of the nonlinear equations and the velocity of the UAV are estimated by an observer that is based on the disturbanceaccommodating control (DAC) method, and an extended Kalman filter, respectively. We have confirmed the effectiveness of the proposed flight control system through numerical simulations and experiments.
doi:10.2322/tastj.12.a99 fatcat:vr7h4ebhjvevfktnmiuhumeh2q