Method and apparatus compensating disturbance in state control device
AssigneeSamsung Electronics Co., Ltd.
InventorsSang-min Suh, Sang-eun Baek, Jun-seok Shim, Yong-kyu Byun
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Abstract
A method and system are disclosed for compensating disturbance applied to a plant, such as a HDD component, controlled by a state control device having an estimator & controller. The estimator & controller is adapted to generate a first control signal in response to a state signal indicating an estimated state of the plant. A second control signal is generated by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal. An overall control signal is generated in response to the second control signal and the control signal derived from the first control signal and applied to the plant.
Claims19
A track following control device of compensating a disturbance applied to a plant controlled by a state control device having an estimator & controller, the estimator & controller generating a first control signal in response to a state signal indicating an estimated state of the plant in a track following mode, the method comprising:
- generating a second control signal in a transfer function shaping controller by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal, wherein application of the transfer function H(s) reduces low frequency components in the disturbance having a frequency less than a cross-over frequency defined in frequency response characteristics of the plant;
- generating an overall control signal in response to the second control signal and the control signal derived from the first control signal;
- and
- applying the overall control signal to the plant.
A state control device adapted to the control of a plant, the plant receiving a disturbance, and the state control device comprising:
- a track following controller including an estimator & controller adapted to generate a first control signal in response to a state signal indicative an estimated state of the plant in a track following mode;
- a first adder adapted to add a reference signal to the first control signal;
- a transfer function shaping controller adapted to generate a second control signal by applying a transfer function H(s) to an output of the first adder to reduce low frequency components of the disturbance having a frequency less than a cross-over frequency defined in frequency response characteristics of the plant;
- and
- a second adder adapted to add the second control signal and the output of the first adder and generate an overall control signal provided to the plant.
A track following control device comprising:
- a head driving unit;
- a track following controller including an estimator & controller adapted to generate a first control signal in a track following mode and in response to a state signal indicating an estimating state for the head driving unit based, at least in part, on servo samples associated with a head of the head driving unit;
- a transfer function shaping controller adapted to generate a second control signal by applying a transfer function H(s) to a control signal derived from the first control signal to reduce low frequency components of the disturbance having a frequency less than a cross-over frequency defined in frequency response characteristics of the plant;
- and
- an adder adapted to provide the head driving unit with an overall control signal generated from the second control signal and the control signal derived from the first control signal.
A hard disk drive (HDD) unit comprising:
- a disk adapted to store information;
- a spindle motor adapted to rotate the disk;
- a head adapted to write information on the disk and reading information from the disk;
- a voice coil motor (VCM) driver adapted to drive a VCM, the VCM adapted to move the head across a surface of the disk;
- and
- a controller for adapted to control the VCM driver, the controller comprising a track following controller including an estimator & controller adapted to generate a first control signal in a track following mode and in response to a state signal associated with the VCM driver, and a transfer function shaping controller;
- wherein the controller is further adapted to control the VCM driver by generating a second control signal in the transfer function shaping controller by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal, wherein application of the transfer function H(s) reduces low frequency components of the disturbance having a frequency less than a cross-over frequency defined in frequency response characteristics of the plant.
A processor-readable recording medium having embodied thereon program code defining a method of compensating disturbance applied to a plant controlled by a state control device comprising a track following controller and a transfer function shaping controller, wherein the track following controller includes an estimator & controller that generates a first control signal in response to a state signal indicating an estimated state for the plant in a track following mode, the method comprising:
- generating a second control signal in the transfer function shaping controller by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal to reduce low frequency components of the disturbance having a frequency less than a cross-over frequency defined in frequency characteristics of the plant;
- and
- generating an overall control signal by adding the second control signal to the control signal derived from the first control signal and applying the overall control signal to the plant.
Dependencies are inferred from the claim text.