Nonlinear control of a Magnetic Levitation System using feedback linearization

In this paper a nonlinear controller (NLC) is designed for a Magnetic Levitation System (MLS). The proposed NLC uses input-output feedback linearization using differential geometry in conjugation with a linear state feedback controller in outer loop to levitate a ferromagnetic ball. The electromagnetic force, which is a function of input magnetizing current and position of the ferromagnetic material to be levitated by the applied input force, is estimated using real-time experimental data. The results obtained show efficacy of the proposed NLC in comparison to a traditional PID controller.