Fixed time output feedback control for quadrotor unmanned aerial vehicle under disturbances

Abstract

This paper designs a fixed time output feedback trajectory tracking control scheme for quadrotor Unmanned Aerial Vehicle with unmeasurable velocity and external disturbances. Firstly, a fixed time extend state observer (ESO) is devised to accurately observe the unknown velocity and estimate unknown total disturbances within a fixed time. Especially, the convergence time of system is independent of system initial states. Secondly, considering control accuracy and convergence rate, robust fixed time controllers are respectively designed for position and attitude system. Thirdly, the tracking errors of controller is capable of converging to zero according to homogeneous theory and Lyapunov theory, and superior results can be achieved under the proposed control scheme. Finally, simulations and comparison studies are verified to demonstrate the effectiveness of the designed fixed time output feedback control scheme.