No abstract

An improved finite-time control technique for an uncrewed aerial (UA) quadcopter subjected to nonlinear uncertainties and disturbances is proposed in this paper. Firstly, high order sliding mode observer (HOSOM) is developed to estimate system states, nonlinear uncertainties and disturbances in the system. The estimated system states are then used to design an improved non-singular fast terminal sliding mode control scheme with an improved exponential term added to the sliding surface. The overall system stability under the proposed control scheme is investigated using the Lyapunov stability theory. Finally, numerical simulations show that the proposed control scheme offers a comprehensive solution to the trajectory tracking problem for a UA quadcopter.