Appointed-finite-time Control for Quadrotor UAVs with External Disturbances: An Adaptive Sliding Mode Observer based Approach

This work investigates the appointed-finite-time attitude tracking control problem for quadrotor unmanned aerial vehicles subject to external disturbances. More specifically, a terminal sliding mode based observer is designed firstly so that the external disturbances can be precisely estimated. Then, a novel appointed-finite-time controller is developed to realize the attitude tracking objective by the technique of adding a power integrator. The appointed-finite-time stability of the proposed observer and controller is proved by rigorous Lyapunov theory. Finally, numerical simulation results are presented to illustrate that the quadrotor can successfully accomplish the tracking task by utilizing the proposed controller.