Resources Contact Us Home
Method and apparatus for real-time filtering of a position error signal for a disk drive servo system

Image Number 6 for United States Patent #5995317.

A method and apparatus for real-time filtering of a position error signal in a servo system of a disk drive. Pre-calculated periodic components of the position error signal (PES) are used as future values in a real-time filter, preferably a real-time recursive median filter. This minimizes the amount of time-lag between obtaining the raw PES measurement from the disk surface and the providing the corresponding filtered PES output. This reduced time-lag minimizes the effect on the phase margin (PM) and results in improved servo stability. The invention can be used not only in servo systems in disk drives, but also in servo systems of other mechanical moving storage devices and in servo systems of rotating mechanical machinery in general, where the signal to be filtered may be a position error, velocity error, acceleration error, and the like.

  Recently Added Patents
Image forming apparatus, control method, and storage medium
Electrowetting display devices with a reflective plate structure
Battery terminal with current sensor
DL control channel structure enhancement
Device and method for generating soft tissue contrast images
Aromatic amine derivative, organic electroluminescent element employing the same, and process for producing aromatic amine derivative
Wireless device and communication control method
  Randomly Featured Patents
Mechanism for removing a hinge-positioner fixture from an automobile body
Space for aggregates which are arranged in the engine space of a motor vehicle
Material independent optical profilometer
Crossbow with bowstring redirection
Apparatus and method for amplifying a magnetic beam
Voice activated, voice responsive product locator system, including product location method utilizing product bar code and product-situated, location-identifying bar code
Fabrication method for vertical electronic circuit package and system
Vacuum check valve
Retractable lens system and method of retracting a retractable lens system
Method and system for monitoring use of digital works