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US 7,609,474 B2Granted
Seek control method, seek control device and disk device
AssigneeFujitsu Limited
InventorKazuhiko Takaishi
Life of this patent
Estimating the term…
Abstract
A seek control device controls the seek of a plant to prevent the position shift due to an error between a model for generating seek current and a model of the plant. When the seek trajectory is provided by seek trajectory generation for controlling the seek of a plant, the frequency characteristic of a feed back loop is changed according to the seek time and the gain of the position shift component due to the shift of the actual plant and the model of the plant is increased, so as to suppress the position shift by the feed back loop. Dispersion of the seek time can be decreased, and an overrun or underrun can be prevented.
Claims16
A seek control method for seeking an object from a current position to a target position by an actuator, comprising the steps of:
- creating a seek trajectory signal according to said target position;
- creating a feedback control signal of said actuator from a position error between the current position of said object and said target position by a feedback loop;
- driving said actuator by said seek trajectory signal and said feedback control signal;
- determining a representative frequency to be suppressed at least according to seek time from said current position to said target position;
- and
- changing frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said determining step comprises a step of determining representative frequency to be suppressed from said seek time and a seek waveform of said seek trajectory signal, and a step of determining a frequency with which the power spectrum of said seek waveform becomes a maximum as said representative frequency.
4 more elements
A seek control method for seeking an object from a current position to a target position by an actuator, comprising the steps of:
- creating a seek trajectory signal according to said target position;
- creating a feedback control signal of said actuator from a position error between the current position of said object and said target position by a feedback loop;
- driving said actuator by said seek trajectory signal and said feedback control signal;
- determining a representative frequency to be suppressed at least according to seek time from said current position to said target position;
- and
- changing frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said creating step comprises a step of creating a feedback control signal of said actuator by observer control,
- and wherein said changing step further comprises a step of changing a disturbance estimation gain for said observer control according to said representative frequency.
5 more elements
A seek control device for seeking an object from a current position to a target position by an actuator, comprising:
- a trajectory block for supplying a seek trajectory signal according to said target position,
- a feedback loop for generating a feedback control signal of said actuator from position error between a current position of said object and said target position;
- a compute block for computing a drive value of said actuator by said seek trajectory signal and said feedback control signal;
- and
- a change block for determining a representative frequency to be suppressed at least according to the seek time from said current position to said target position, and changing the frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said change block determines the representative frequency to be suppressed from said seek time and a seek waveform of said seek trajectory signal,
- and wherein said change block determines a frequency with which the power spectrum of said seek waveform becomes the maximum as said representative frequency.
4 more elements
A seek control device for seeking an object from a current position to a target position by an actuator, comprising:
- a trajectory block for supplying a seek trajectory signal according to said target position,
- a feedback loop for generating a feedback control signal of said actuator from position error between a current position of said object and said target position;
- a compute block for computing a drive value of said actuator by said seek trajectory signal and said feedback control signal;
- and
- a change block for determining a representative frequency to be suppressed at least according to the seek time from said current position to said target position, and changing the frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said feedback loop comprises an observer control system, and
- wherein said change block changes a disturbance estimation gain for said observer control according to said representative frequency.
4 more elements
A disk device comprising:
- a head for at least reading data on a disk storage medium;
- an actuator for positioning said head to a predetermined position on said disk storage medium;
- and
- a control unit which comprises:
- a supply block for supplying a seek trajectory signal according to said target position;
- a feedback loop for generating a feedback control signal of said actuator from the position error between the current position of said object and said target position;
- and
- a compute block for computing a drive value of said actuator from said seek trajectory signal and said feedback control signal,
- wherein said control unit determines a representative frequency to be suppressed at least according to the seek time from said current position to said target position, and changes the frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said control unit determines the representative frequency to be suppressed from said seek time and a seek waveform of said seek trajectory signal, and
- wherein said control unit determines a frequency with which the power spectrum of said seek waveform becomes the maximum as said representative frequency.
8 more elements
A disk device comprising:
- a head for at least reading data on a disk storage medium;
- an actuator for positioning said head to a predetermined position on said disk storage medium;
- and
- a control unit which comprises:
- a supply block for supplying a seek trajectory signal according to said target position;
- a feedback loop for generating a feedback control signal of said actuator from the position error between the current position of said object and said target position;
- and
- a compute block for computing a drive value of said actuator from said seek trajectory signal and said feedback control signal,
- wherein said control unit determines a representative frequency to be suppressed at least according to the seek time from said current position to said target position, and changes the frequency characteristic of said feedback loop so as to suppress said representative frequency,
- wherein said feedback loop comprises an observer control system, and
- wherein said control unit changes a disturbance estimation gain for said observer control according to said representative frequency.
8 more elements
Dependencies are inferred from the claim text.