Adaptive robust output feedback control of a magnetic levitation system by k-filter approach

This work proposes an adaptive robust output feedback controller for position-tracking problem of a magnetic levitation system with a current feedback power amplifier. The controller is designed by a backstepping procedure with robustifying modification of the k-filter approach. The boundedness and guaranteed transient performance of the error signals are achieved by the nonlinear damping terms. And the ultimate position-tracking error is reduced by the adaptive laws. Experimental results are included to show the excellent control performance of the designed controller.