ABSTRACT
The resonant characteristics of mechanical systems deteriorate the required achievable positioning accuracy in nanopositioning control systems. Vibrations caused by the mechanical resonant modes arise from flow induced vibrations and seek control. The control performance for mass-produced consumer mechatronics such as Hard Disk Drives (HDD) has to be improved as parametric variations of the mechanical actuators are inevitable. HDDs are mass storage devices with a magnetic Read/Write (R/W) head flying above and reading/writing data on disks that are rotating at a high velocity. Due to the structural design in HDDs, there are situations where the R/W head contacts the disk surface as a result of a large shock or vibration, resulting in data damage or even breakage of the HDD in the worst case scenario. In the head-positioning system of HDDs, the head position is detected by discrete servo signals embedded in the disks.
