Stabilization of a magnetic levitation system by backstepping and high-gain observers

In this paper we consider stabilization control of a magnetic levitation system by a backstepping technique and high-gain observers. We first derive state feedback stabilizing laws by a backstepping technique. Then we design high-gain observers and construct output feedback stabilizing controllers based on the designed high-gain observers. We also obtain discrete-time output feedback controllers for the sampled-data magnetic levitation system by an emulation of continuous-time state feedback laws and the exact discretization of high-gain observers. We show the efficiency of the obtained controllers by experimental results.