Control Strategy for Transition Flight of a Fixed-wing UAV

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 disturbances 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.

[1]  Eung-Tai Kim,et al.  Autopilot design of tilt-rotor UAV using particle swarm optimization method , 2007, 2007 International Conference on Control, Automation and Systems.

[2]  Kenzo Nonami,et al.  Prospect and Recent Research & Development for Civil Use Autonomous Unmanned Aircraft as UAV and MAV , 2007 .

[3]  Frank Wong,et al.  Transitions between level flight and hovering for a fixed-wing mini aerial vehicle , 2010, Proceedings of the 2010 American Control Conference.

[4]  Koji Muraoka,et al.  Quad Tilt Wing VTOL UAV: Aerodynamic Characteristics and Prototype Flight Test , 2009 .

[5]  Mahmut Faruk Aksit,et al.  Design and construction of a novel quad tilt-wing UAV , 2012 .

[6]  Stephen E. Dunagan,et al.  PRECISION AGRICULTURE AS A COMMERCIAL APPLICATION FOR SOLAR-POWERED UNMANNED AERIAL VEHICLES , 2002 .

[7]  D. Shim,et al.  Controller Synthesis and Application to Hover-to-Cruise Transition Flight of a Tail Sitter UAV , 2010 .

[8]  Kenji Uchiyama,et al.  Control Architecture for Transition between Level Flight and Hovering of Fixed-Wing UAV , 2012 .

[9]  Richard Gourdeau,et al.  Extended Kalman filter implementation for low-cost INS/GPS Integration in a Fast Prototyping Environment , 2005 .

[10]  C.D. Johnson.  A family of 'universal adaptive controllers' for linear and nonlinear plants , 1988, [1988] Proceedings. The Twentieth Southeastern Symposium on System Theory.

[11]  Kenji Uchiyama,et al.  Design of Nonlinear Attitude Control System for Spaceplane Using Disturbance-Accommodating Control , 2008 .

[12]  Atsushi Konno,et al.  A hovering control strategy for a tail-sitter VTOL UAV that increases stability against large disturbance , 2010, 2010 IEEE International Conference on Robotics and Automation.

[13]  R.H. Stone,et al.  Control architecture for a tail-sitter unmanned air vehicle , 2004, 2004 5th Asian Control Conference (IEEE Cat. No.04EX904).

[14]  Fei-Bin Hsiao,et al.  The Design of a Small UAV System as a Testbed for Formation Flight , 2011 .