Discrete Backstepping Control of Magnetic Levitation System with a Nonlinear State Estimator

In this paper a discrete robust controller is implemented for a magnetic levitation system. To circumvent the problem of discretizing the nonlinear model of magnetic levitation system, the paper uses much easier obtained Euler approximated model with sufficiently small sampling time. The magnetic levitation model has only position measurement available as the output, thus a Kreisselmeier filter is implemented to estimate the unmeasured state. A discrete backstepping controller is derived and implemented with magnetic levitation system with digital to analog and analog to digital conversion units. The efficacy of the proposed controller, when compared with continuous backstepping controller and PID controller, is illustrated via simulation.