Flight Control of Tilt-rotor UAV with Time-varying Constraints

This paper proposes a flight control strategy for the tilt-rotor UAV (TUAV) in the presence of aerodynamic disturbances and state constraints. Considering the flapping motion and rotor-wing aerodynamic disturbance, the TUAV is modeled in this paper. Then, a disturbance observer is introduced to estimate the aerodynamic disturbances, enhancing the robustness of the system. Furthermore, a safe flight controller is designed based on the timevarying barrier Lyapunov function (BLF) to address the state constraints. The bounded convergences of the closed-loop error signals are ensured by Lyapunov stability theory. The simulation results verify that the proposed control algorithm can effectively ensure that the TUAV keeps the flight state in the safe range.