Disk drive adaptive resonance compensation method and apparatus

An adaptive system resonance compensation method comprising:

• detecting a frequency component affecting a servo control output in a disk drive/head during the manufacturing of a disk drive;
• calculating a first parameter value to determine a center frequency of a filter used for servo control so as to suppress the detected frequency component and storing said calculated parameter value in a nonvolatile memory device;
• and
• reading a second parameter value corresponding to a currently selected mode from said nonvolatile memory device every time said disk drive is turned on by a user and updating said second parameter value to determine said center frequency of said filter using the second parameter value.

An adaptive system resonance compensation apparatus used in a hard disk drive comprising:

• a servo control circuit performing servo control having a filter configured to compensate for a specific frequency component;
• a storage device for storing a frequency component affecting said servo control, said frequency component measured according to a mode selected during manufacturing of said disk drive;
• and
• a system controller reading a frequency component corresponding to a currently selected mode from said storage device each time said system is turned on by a user, said system controller configured to calculate a parameter value of said filter to suppress the read frequency component, said controller updating the parameter value of said filter to said calculated parameter value.

An adaptive system resonance compensation apparatus comprising:

• a servo control circuit controlling the position of an object to be controlled including a filter used to compensate for a specific frequency component;
• a storage device storing a parameter value of said filter calculated to suppress a frequency component affecting said position control, said parameter value measured according to a mode selected in a system during manufacturing of a disk drive;
• and
• a system controller reading a parameter value corresponding to a currently selected mode from said storage device each time the system is turned on by a user, said controller updating the parameter value of said filter to the read parameter value.

A disk drive comprising:

• at least one disk;
• at least one head positioned above said disk, said head configured to write or read information to or from the at least one disk;
• a servo controller controlling a position of said at least one head using a servo signal read from said head;
• a filter amplifying a frequency component corresponding to a parameter value to an initially set gain associated with said disk drive, said filter connected in parallel to an input terminal of said servo controller;
• a circuit for subtracting an output signal of said filter from a control signal output from the servo controller;
• an actuator moving said head using an output signal from said subtracter circuit;
• a storage device for storing a frequency component affecting a position control of said head measured according to a head selected in a manufacturing process;
• and
• a system controller reading a frequency component from said storage device corresponding to a selected head each time said disk drive is turned on by a user, said controller calculating a parameter value of said filter to suppress the read frequency component, said controller updating the parameter value of said filter to the calculated parameter value.

A disk drive comprising:

• at least one disk;
• at least one head configured to write or read information to or from the at least one disk;
• a servo controller controlling a position of said at least one head using a servo signal read from said head;
• a loop filter amplifying a frequency component corresponding to a parameter value to initially set a gain of said disk drive, said filter connected in parallel to an input terminal of said servo controller;
• a subtracter for subtracting an output signal of said filter from a control signal output from the servo controller;
• an actuator moving said head using an output signal of the subtracter;
• a storage device storing a parameter value of said loop filter to suppress a frequency component affecting an output from said servo controller measured during a manufacturing process of said disk drive;
• and
• a system controller reading a parameter value corresponding to a selected head from the storage device each time the disk drive is turned on by a user, said controller updating the parameter value of said filter to the read parameter value.