Model identification and loop-shaping based controller design for VTOL UAV

In the past, we used the traditional PID controller in the attitude loop, the controller is stable but the performance is not very good. So we tried to design the controller in a more systematic approach. The simulation results show that the angular rate controllers designed by model identification and loop-shaping method have better performance than the controllers designed by PID method, mainly in the following areas: (1) better time domain response: less overshoot, shorter rise time, etc.; (2) More intuitive to design the controllers according to the Bode diagram, achieving good gain margin, phase margin and bandwidth; (3) This method allows us to analyze the signal response in different frequency bands, and design a more robust controller, which can suppress noise interference effectively.