Disturbance Observer based Fixed-time Control Method for Carrier-based UAV

Carrier-based unmanned aerial vehicle (UAV) can significantly enhance operational range and reconnaissance-strike capabilities through coordination with aircraft carriers. However, due to the short landing time and environmental disturbances, the design requirements for the landing control system are critical. This paper proposes a disturbance observer based fixed-time convergence landing control method, which can guarantee that the landing trajectory tracking error converges within a prespecified time, regardless of the initial state. The disturbance observer can estimate the environmental disturbances, thereby enhancing the robustness of the landing controller. The stability and fixed-time convergence capability of this method are proven by the Lyapunov stability theorem. Furthermore, an automatic carrier landing system is established, and numerical simulation experiments are conducted. The simulation results reveal that the designed disturbance observer can effectively estimate the state error caused by the disturbance. Additionally, the proposed method achieves faster error convergence speed and higher landing control accuracy compared to the traditional PID method, thereby improving the flight performance of the carrier-based UAV.