Patent ID: 7515375

Claim:
A positioning control device for positioning a head of a disk device in a target position, comprising: a control unit which calculates a control amount of a positioning control and outputs said control amount to a drive unit of said disk device for driving said head; and a storage unit which continues to hold a variable value, which is used to calculate said control amount prior to the start of said calculation of said control amount, following said calculation of said control amount, wherein said control unit re-executes calculation of said control amount using said variable value stored in said storage unit during said calculation of said control amount, following said calculation of said control amount, said control unit has a first calculation unit and second calculation unit, said first calculation unit executes said calculation of said control amount and said second calculation unit executes determination processing relating to a positioning control state, and said determination processing relating to the position control state determines whether or not said calculation of said control amount performed by said first calculation unit is correct, and when said second calculation unit determines that said calculation of said control amount performed by said first calculation unit is not correct, said second calculation unit corrects an input value of said calculation of said control amount inputted to said second calculation unit.