$H_{\infty}$ Control of a Dual Motor Bearingless Machine

It is beneficial to use model-based control approaches for the position control of high-speed machines with a magnetically levitated rotor system, as the system inherently involves multiple inputs and outputs. There is always uncertainty in the model parameters, and thus, a robust control approach is a preferable choice. In this paper, an $H_{\infty}$ loop-shaping method for bearingless machine control synthesis is studied and compared with the widely used PID control approach. System identification experiments are conducted to validate the results and the controller performance in the prototype system.