Fixed-Time Tracking Control Scheme for a Quadrotor with Time-Varying External Disturbances

To solve the tracking issue of a quadrotor unmanned aerial vehicle (UAV) with time-varying external disturbances, this paper presents the control method utilizing the fixed-time approach. First of all, the fixed-time disturbance observer (FxTDO) is designed to estimate external disturbance, the estimated time of disturbance is independent of initial condition and can be strictly guaranteed to be within a fixed upper bound. Secondly, a fixed-time sliding mode controller (FTSMC) is proposed for quadrotor. The fixed-time characteristics of the UAV closed-loop system is verified via the Lyapunov criterion. Finally, simulation cases and actual flight experiments illustrate the superiority and effectiveness of the constructed control strategy,