Design and Control of a Novel Coaxial Tilt-Rotor UAV

In this article, the design and control of a new coaxial tilt-rotor unmanned aerial vehicle (CTRUAV) are presented. The CTRUAV is an electric-powered unmanned aerial vehicle with a special configuration, which is composed of two pairs of tiltable coaxial rotors and a rear rotor. A CTRUAV prototype has been designed by 3-D computer-aided design software and constructed according to the designing scheme. The dynamic model of a CTRUAV is derived by utilizing the Euler-Lagrange equation, which considers the special features of the coaxial rotors and air drag forces on the CTRUAV. An adaptive controller is developed to realize motion control for the CTRUAV. The adaptive controller includes two subcontrollers: an inner-loop attitude controller and an outer-loop velocity controller. The stability of the resulting closed-loop CTRUAV system is analyzed via the Lyapunov method. Finally, several simulations and real experimental tests are implemented to validate the effectiveness of the developed CTRUAV system.