Modeling and Control of a Magnetic Rotor-Bearing System with Magnetic Coupling

This study deals with the modeling and nonlinear control of a magnetic rotor-bearing system. The system is taken from a high-speed spindle in a machine center. Instead of the commonly used uncoupled linear models, a magnetically coupled nonlinear model is considered here. A robust sliding mode controller is designed based on the coupled nonlinear model. It is found from numerical simulations that the closed-loop system not only achieves stabilization and high precision, but also is robust to parameter variations, impact loads, external disturbances and sensor noises.