Designing a backstepping nonlinear controller for controlling six-blade vertical flight with new structure

Quadrators have become one of the most widely used UAV (Unmanned Aerial Vehicle) robots due to their simple mechanical structure and high maneuverability. But due to their low cargo capacity, they are limited in some applications. In the model of this research, to increase the cargo capacity of the drone, two coaxial propellers with constant speed and opposite direction of rotation have been added to the center of the quadrator. The drone dynamic modeling has been done by Newton - Euler method and the obtained equations are non-linear, under-excited, coupled and unstable. To control the vertical flight, the backstepping control method which has a high ability to control nonlinear systems, has been used. The control system and the drone have been simulated in MATLAB software and the simulation results show that the designed controller displays a desirable behavior in vertical flight controlling.