Magnetic Bearing Measurement Configurations and Associated Robustness and Performance Limitations

Abstract

We obtain bounds on achievable sensitivity and complementary sensitivity reduction for a magnetic bearing system in three measurement configurations. We use the sensitivity reduction bounds to deduce achievable robustness and performance limits for each system configuration. We then show how these limits vary with varying magnetic bearing physical dimensions and other parameter values as well as varying closed-loop system bandwidth and controller relative degree. Using all of this information, we derive guidelines for designing magnetic bearing systems and their controllers, for each measurement configuration considered, for greatest achievable robustness and performance.