Modeling and Hover Control of a Dual-Rotor Tail-Sitter Unmanned Aircraft

A tail-sitter unmanned aircraft is capable of transition between horizontal and vertical flight. This paper highlights topics of interest to developing a more accurate model to make the simulation results more reasonable. The modeling processes are presented in details. Aerodynamics of this unmanned aircraft is obtained by wind tunnel tests associated with aerodynamic estimation software. Characters of propeller slipstream are analyzed and the mathematical relationships among slipstream velocity, propeller speed, radial location and axial location of propeller plane are deduced from the experiment data. Besides, separate consideration of the propeller slipstream on wings and control surfaces gives better estimations on the dynamic pressure. Models of actuators and motors are also obtained through some tests to make the results reliable. Furthermore, a simple controller is designed to implement the hover attitude control.