Differential flatness based hybrid PID/LQR flight controller for complex trajectory tracking in quadcopter UAVs

In this paper, we present a differential flatness based hybrid flight controller for the quadcopter UAV. The combination of conventional PID based controller with the full state feedback based LQR controller results in the proposed hybrid controller. The performance of the resulting controller is further enhanced by using differential flatness based feedforward control. The UAV with a hybrid flight controller is considered as the balance between stability and maneuverability, which makes it suitable for complex trajectory following applications. The dynamic model and the flight controller has been verified by means of numerical simulations for flight conditions involving complex maneuvers.