Attitude control of a quad-rotor using speed sensing in brushless DC motors

Recently, the research in the area of autonomous miniature flying robots is growing thanks to the development of new configurations and prototypes of Unmanned Aerial Vehicles (UAV). In this paper, we introduce the problem of attitude and altitude control of a mini-quadrotor UAV in hovering-mode to indoor and outdoor applications. Therefore, we have implemented a control strategy based on speed sensing in each brushless motors. As result, the miniature aerial vehicle has a good and robust stabilization on the horizontal plane. This paper also describes a control strategy to stabilize the quad-rotor using a control algorithm based on PD controller as well as the speed sensing scheme. Finally, the experimental results of speed sensing control for stabilizing the quad-rotor at hover are presented.