Constrained magnetic levitation control

Authors:	Kamenský Martin, Slovak Technical University, Slovakia (Slovak Republic) Huba Mikuláš, Slovak Technical University, Slovakia (Slovak Republic)
Topic:	2.3 Non-Linear Control Systems
Session:	Nonlinear Controller Design
Keywords:	magnetic bearings, minimum-time pole assignment control, saturation control, nonlinear control systems

Abstract

This paper shows that the highly nonlinear, unstable and fast system of magnetic levitation can be simply controlled by invariant sets based controller generalizing the pole assignment method for constrained systems. This can be reliably tuned by a modification of the well-known step-response based method by Ziegler and Nichols. As all unstable systems, it is tuned in an iterative manner: In the first phase a stabilizing controller is used to measure the static input-output characteristic and to bring the system to a reference starting position for further dynamic experiments, which can be later evaluated to improve the controller structure and tuning.