Observer-based super twisting design: A comparative study on quadrotor altitude control.

This paper addresses the design of a continuous super twisting control combined with a high-order sliding mode observer for a class of nonlinear systems. An analysis of closed-loop stability is provided by means of Lyapunov approach, where sufficient conditions are given to ensure the convergence and to select the gains of the proposed controller. Numerical simulation and experimental results illustrate the performance of the proposed control-observer scheme for controlling the altitude of a quad-rotor aircraft. Furthermore, a comparative study against similar approaches from literature is included for illustrating that proposed methodology requires less control effort while shows the best performance.