| 主权项 |
1. A magnetic disk device, comprising:
a head that reads servo information on a disk; and a controller that performs position control for the head by using a high-order adaptive digital filter, the high-order adaptive digital filter including a first variable coefficient and a second variable coefficient based on positional error information generated from the servo information read by the head, the first variable coefficient being generated by adding the positional error information, a second value, and a fourth value, the second value being obtained by multiplying a first value by an adaptation coefficient, the first value being obtained from primary delay of the first variable coefficient, the fourth value being obtained by multiplying a third value by a first coefficient, the third value being obtained from secondary delay of the first variable coefficient, the second variable coefficient being generated by adding a fifth value, a seventh value, and an eighth value, the fifth value being obtained by multiplying the first variable coefficient by a second coefficient, the seventh value being obtained by multiplying the first value by a sixth value that is obtained by inverting the adaptation coefficient to negative, the eighth value being obtained by multiplying the third value by a third coefficient, the adaptation coefficient being generated based on the positional error information and the first variable coefficient transitioning with an elapsed time. |
