Parametric Uncertainty Identification and Model Reduction for Dual-Stage Robust H2 Track-following Control Synthesis

This paper presents a systematic method for identifying parameters and parametric uncertainty for a set of dual-stage hard disk drives. A modal analysis technique is selected to extract parameters from a batch of frequency response data. Next, an optimal model truncation methodology is presented to eliminate redundant modes from each multiple-input-multiple-output system model. Finally, principle component analysis is employed to obtain a low-order, minimally conservative approximation of uncertain parameters. The result is a reduced order state space model and parameter uncertainty set to be used in robust H2 control synthesis for a track-following servo.