Observer based Appointed-finite-time Nonsingular Sliding Mode based Disturbance Attenuation Control for Quadrotor UAV

This work investigates the appointed-finite-time trajectory tracking control problem for quadrotor unmanned aerial vehicles subject to external disturbances. More specifically, two nonsingular terminal sliding mode manifolds are first designed so that the singularity problem is settled. Furthermore, the appointed-finite-time stability of the proposed manifolds is proved by rigorous Lyapunov theory. Then, two novel sliding mode based appointed-finite-time controllers are developed to realize the trajectory tracking objective. The undesired chattering is alleviated by discontinuous control structure. Finally, numerical simulation results are presented to illustrate that the quadrotor can successfully accomplish the tracking task by utilizing the proposed controllers.