The magnetic bearing-rotor system has the ability to support objects by electromagnetic forces without mechanical contact and lubrication process. These represent typical products of mechatronics in the sense that together with mechanical components they include electronic elements such as sensors, power amplifiers, a controller and an amount of software that determines their intelligent operation. In this book, the equations of motion of a rigid unbalanced asymmetrical rotor supported by magnetic bearings are derived via energy method, and transformed to a state-space form for optimal and robust control against the sensor noise and imbalance of the rotor. The system was controlled using the active control theories. The control characteristics were compared, and the validity of the theories were verified by experiment. The results displayed in this book are likely to contribute to a better design of unbalanced asymmetric rotors supported in magnetic bearing-rotor system.