Altitude control of an Unmanned Aircraft System using a Super-Twisting controller based on High Order Sliding Mode Observer

In this paper, the altitude tracking problem for an Unmanned Aircraft System (UAS) is considered under the assumption that the altitud velocity is unknown. Since in a practical implementation the employed sensors used to measure the altitude (Barometer and GPS) do not provide the altitude velocity. The proposed strategy was designed by using a Super-Twisting controller based on a High Order Sliding Mode Observer. A comprehensive stability analysis based on the Lyapunov Stability Theory guarantees the convergence of the tracking error in finite time. To demonstrate the performance of the proposed solution, a set of simulation results are presented.