Extended position error signal linearization and normalization
AssigneeSeagate Technology LLC
InventorsMark Lowell Elliot, Alexei Hiram Sacks, Duc Tien Phan
Life of this patent
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Abstract
A method of producing a position error signal includes storing a normal position error value generated from a normal servo field and a quadrature position error value generated from a quadrature servo field, where the normal servo field is ninety degrees out of phase from the quadrature servo field. A position error numerator is created by arithmetically combining the normal position error value and the quadrature position error value. A position error denominator is created based on the normal position error value and the quadrature position error value. The position error signal is produced by dividing the position error numerator by the position error denominator.
Claims17
A method of producing a position error value indicative of a transducer head's position over a recording medium, the method comprising:
- storing a normal position error value generated from a normal servo field located on the recording medium and a quadrature position error value generated from a quadrature servo field located on the recording medium, the normal servo field being ninety degrees out of phase from the quadrature servo field;
- creating a position error numerator by arithmetically combining the normal position error value and the quadrature position error value;
- creating a position error denominator based on the normal position error value and the quadrature position error value;
- and
- dividing the position error numerator by the position error denominator to produce the position error value.
A servo system in a disc drive, the servo system for positioning a head relative to a medium, the servo system comprising:
- hold circuits capable of storing a normal position error value and a quadrature position error value read from the medium by the head;
- and
- combinatorial logic coupled to the hold circuits and capable of:
- combining the normal position error value and the quadrature position error value to form a first position error numerator;
- creating a position error denominator based on the normal position error value and the quadrature position error value;
- and
- dividing the first position error numerator by the position error denominator to produce a first position error value.
Dependencies are inferred from the claim text.