Nonlinear control of a magnetic levitation system

The feedback linearization control approach for a highly nonlinear, magnetic levitation application is presented. Regulation performance has been compared to that achievable by a linear state feedback. In addition, practical issues concerning feedback requirement, computational demands, and robustness with respect to changes in model parameter are discussed. It is concluded that the nonlinear approach yields better performance than the linear state feedback approach, especially in the area of reduced sensitivity to parameter changes. The feedback requirement is not significantly more demanding than the demands of any linear state feedback controller, and the control computations should be easily accomplished by microcontrollers operating at even moderate speeds