Abstract
Disk Drives are widely spread as data storage devices, and recently a demand for large capacity and down-sizing has been increased. In order to meet this demand, head positioning control technique, as one of techniques for achieving high recording density, is expected to improve the head positioning accuracy by reducing tracking error which is caused by disturbance such as bias-force and vibration.
In this paper, we discuss a head positioning control system with a disturbance observer which reduces influence of the disturbance. The control system using a disturbance observer, which has high-pass filter characteristics between disturbance and controlled variable, can achieve high performance of disturbance suppression characteristics.
We confirmed that the head positioning control system using disturbance observer can reduce tracking error caused by vibration through experiments. Still more, we confirmed that the disturbance compensation system using a disturbance compensation table can reduce the variance of switching condition from seeking mode to following mode and is useful to improve settling accuracy.
