Loop shaping based robust control of a magnetic bearing

H/sub infinity / robust control design of a magnetic bearing is considered. In particular, the design of a control system using the loop shaping design procedure (LSDP) is presented. After the introduction of the experimental machine and digital controller, model uncertainty and performance of the magnetic bearing are discussed. The performance and robust stability design objectives are specified as the requirements for particular closed loop transfer functions with the weighting functions. The frequency responses of these closed loop transfer functions are approximated by that of the open loop transfer function in a certain frequency band. Experimental results are presented to illustrate the robust stability and good performance of the designed control system.<>