Experiments on the H∞ disturbance attenuation control of a magnetic suspension system

An H^∞ disturbance attenuation controller is experimentally demonstrated on a magnetic suspension system with a flexible beam. The apparatus utilized is a simplified model of magnetic bearings with an elastic rotor. A simple mathematical model of the apparatus is derived by taking all the disturbances into consideration. An H^∞ disturbance attenuation control problem where the augmented plant is constructed with a frequency weighting function is set up. An iterative computing environment, MATLAB, is then employed to calculate the central controller. Finally, the controller is implemented using a digital signal processor, μPD77230, with 12-b A/D and D/A converters. Experimental results show that the designed system is robustly stable against various parameter changes and uncertainties