Adaptive vibration control for servo systems in data storage devices

In a data storage device having a medium mounted for movement relative to an access element, and a servo system for controlling the position of the access element with respect to the medium, a method for reducing the effect, on a position signal in the servo system, of a vibration, comprising:

• using a first corrective filter to reduce the effect of the vibration on the position signal by enhancing a control signal to the access element at a peak frequency of the vibration;
• repeatedly engaging the first corrective filter, including repeatedly accessing a filter state vector as initial filter conditions as the first corrective filter is repeatedly engaged;
• and
• refreshing the filter state vector periodically with corresponding outputs from the first corrective filter, or with quieting values.

A data storage device, comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling a position of the access element with respect to the medium;
• a system for reducing the effect of a vibration on a position signal in the servo system, including
• a detector for detecting, during operation of the data storage device, a frequency of the vibration of the medium.

A data storage device, comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling the position of the access element with respect to the medium;
• and
• a system for reducing the effect, on a position signal in the servo system, of a vibration from a source external to the data storage device, including
• means for detecting, during operation of the data storage device, a frequency of vibration of the medium, and
• a first corrective filter for reducing the effect of the vibration on the position signal.

A data storage device comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling the position of the access element with respect to the medium;
• and
• a system for reducing the effect, on a position signal in the servo system, of a vibration, including
• a first corrective filter to reduce the effect of the vibration on the position signal by enhancing a control signal to the access element at a peak frequency of the vibration;
• means for repeatedly engaging the first corrective filter, including means for repeatedly accessing a filter state vector as initial filter conditions as the first corrective filter is repeatedly engaged;
• and
• means for refreshing the filter state vector periodically with corresponding outputs from the first corrective filter, or with quieting values.

In a data storage device having a medium mounted for movement relative to an access element, and a servo system for controlling the position of the access element with respect to the medium, a method for reducing the effect, on a position signal in the servo system, of a vibration from a source external to the data storage device, comprising:

• detecting, during operation of the data storage device, a frequency of vibration of the medium;
• responsive to said detecting, modifying positioning of the access element relative to the medium to force the access element to more closely track movement of the medium;
• and
• wherein said modifying includes using a first corrective filter to reduce the effect of the vibration on the position signal.

In a data storage device having a medium mounted for movement relative to an access element, and a servo system for controlling the position of the access element with respect to the medium, a method for reducing the effect, on a position signal in the servo system of a vibration, comprising:

• detecting, during operation of the data storage device, a frequency of vibration of the medium;
• responsive to said detecting, modifying positioning of the access element relative to the medium to force the access element to more closely track movement of the medium;
• wherein said modifying includes:
• using a first corrective filter to reduce the effect of the vibration on the position signal by enhancing a control signal to the access element at a peak frequency of the vibration;
• repeatedly engaging the first corrective filter, including repeatedly accessing a filter state vector as initial filter conditions as the first corrective filter is repeatedly engaged;
• and
• refreshing the filter state vector periodically with corresponding outputs from the first corrective filter, or with quieting values.

A data storage device, comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling a position of the access element with respect to the medium;
• a system for reducing the effect of a vibration on a position signal in the servo system, including
• a detector for detecting, during operation of the data storage device, a frequency of the vibration of the medium;
• and
• wherein the servo system includes means for modifying positioning of the access element relative to the medium responsive to said detecting a vibration, to force the access element to more closely track movement of the medium.

A data storage device, comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling the position of the access element with respect to the medium;
• and
• a system for reducing the effect, on a position signal in the servo system, of a vibration from a source external to the data storage device, including
• means for detecting, during operation of the data storage device, a frequency of vibration of the medium;
• responsive to said detecting, means for modifying positioning of the access element relative to the medium to force the access element to more closely track movement of the medium;
• and
• wherein the means for modifying includes a first corrective filter for reducing the affect of the vibration on the position signal.

A data storage device comprising:

• a medium mounted for movement relative to an access element;
• a servo system for controlling the position of the access element with respect to the medium;
• and
• a system for reducing the effect, on a position signal in the servo system, of a vibration, including:
• means for detecting, during operation of the data storage device, a frequency of vibration of the medium;
• means for modifying positioning of the access element relative to the medium responsive to said detecting to force the access element to more closely track movement of the medium;
• and
• wherein the means for modifying includes:
• a first corrective filter to reduce the effect of the vibration on the position signal by enhancing a control signal to the access element at a peek frequency of the vibration;
• means for repeatedly engaging the first corrective filter including means for repeatedly accessing a filter state vector as initial filter conditions as the first corrective filter is repeatedly engaged;
• and
• means for refreshing the filter state vector periodically with corresponding outputs from the first corrective filter, or with quieting values.