Vibration analysis and optimal control for self servo track writer

Major vibration sources in self-servo track writing (SSTW) are identified and linear matrix inequality (LMI) approach is applied to design an H/sub 2/ controller for the SSTW. Experimental measurement of the position error signal (PES) is used to determine the spectrum of the PES. The identification of vibration sources is based primarily upon the spectral decomposition of the measured PES. Upon determining the vibration sources, an H/sub 2/ controller together with a feedforward compensator is designed via LMI approach to achieve an optimal error containment for error propagation in the SSTW. In addition, the error containing effectiveness of optimal H/sub 2/ control is compared with that of PID and PD feedback control in the SSTW with the feedforward error compensation. To our knowledge, no existing result involves the methodology proposed here in SSTW.