The Research about Containment the Radial Error Propagation in Self-Servowriting in Hard Disk

The process of self-servowriting and the problem that is critical to self-servowriting are discussed in the thesis. The errors coming from the last track can be inherited to next track when the R/W head writes servo information in self-servowriting process. This prevents servo information from being propagated to all tracks on the disk. This paper proposed a new method for error containment based on feedforward compensation. It adds a correction signal to the servo loop to eliminate the errors of last track. In order to resist to disturbance and noise and keep the robust of the close loop it uses Hinfin feedback control method. The whole self-servowriting process adapts this method is modeled. Then it´s effectiveness is proved in theory and in simulation test.