A Fixed-time Disturbance Estimator of Aerial Transportation Systems With Unmodeled Dynamics

This paper proposes a fixed-time disturbance estimator for aerial transportation systems, to deal with uncertainties such as unmodeled dynamics and unknown disturbances. The observer is designed based on the original nonlinear dynamics of the aerial transportation system without linearization. A lumped disturbance term is introduced, which can be compensated by applying the proposed observer. The estimation error system is fixed-time stable, and the boundary of the convergence time is also given. The stability is proven rigorously and the effectiveness of the observer is verified through numerical simulation.