Abstract: Provided are a method of calculating repeatable runout (RRO) of a hard disk drive (HDD) in a frequency domain, a method of calculating a compensation value using the RRO calculating method, and recording media used therefore. The method of calculating RRO in a disk with a plurality of tracks includes: calculating first set of frequency coefficients for representing the RRO by analyzing a position error signal (PES), which is sampled in a target track, in a frequency domain while a head follows the target track; and calculating the RRO using the first set of frequency coefficients.

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.

Abstract: Provided are a method, apparatus, and storage medium for controlling a track seek servo in a disk drive. Thus, a transducer is moved to a target track using a transformed Proximate-Time Optimal Servo (PTOS) velocity trajectory in which an acceleration duration is symmetrical to a deceleration duration in a track seek mode.

Abstract: In a hard disk drive (HDD), biases are measured across all zones of a disk, and nonlinear bias components are extracted. Upon a change in operational condition of the HDD, biases are measured at two reference positions on the disk so as to estimate a corresponding change in a linear bias component across all zones of the disk. The bias at a given position of the disk is then calculated based on the estimated linear bias component and the extracted nonlinear bias component.

Abstract: There are provided a method and apparatus for high-speed compensating repeatable run-out in a hard disk drive. The method includes a) obtaining a value of a position error signal (PES) of the hard disk drive, the PES being a relative position signal of the head with respect to the center of the target track of the disk; b) determining whether the head is in the settling mode; c) if the head is in the settling mode, compensating the RRO error without feeding back the PES; and d) if the head is in the track-following mode, compensate the RRO error by feeding back the PES. Accordingly, an excessive RRO error is compensated. Even though the hard disk drive receives an external shock or is assembled in an offline servo writing manner, the performance of the hard disk drive does not deteriorate.

Abstract: An apparatus and method are provided for quickly and finely compensating for non-repeatable run out (NPRO) of a disc drive. The NPRO compensation control apparatus in a run out compensation apparatus of a system includes: a frequency estimator directly estimating a trigonometric function value of an NRRO frequency from a predetermined signal responding to the system using a correlation between a filter coefficient of a notch filter and a notch frequency; and an NRRO compensator canceling NRRO of the system using the trigonometric function value of the NRRO frequency estimated by the frequency estimator.

Abstract: A servo control device for a disk drive capable of effectively compensating for a low frequency disturbance incoming to the disk drive is provided. The servo control device includes: a state variable estimator calculating a position estimation error based on a control input for controlling motion of a head and a position error signal by using a predetermined state equation; an estimation filter calculating a disturbance estimation value from the position estimation error by using a mathematical relation between a disturbance and the position estimation error; and a subtractor subtracting the disturbance estimation value from the control input.

Abstract: Provided are a method, apparatus, and storage medium for controlling a track seek servo in a disk drive. Thus, a transducer is moved to a target track using a transformed Proximate-Time Optimal Servo (PTOS) velocity trajectory in which an acceleration duration is symmetrical to a deceleration duration in a track seek mode.

Abstract: A settling control method and apparatus perform an improved settling control regardless of a seek distance when a disc drive track seek control operation is performed. An adaptive settling control method used in controlling the track seek mode of the disc drive includes: controlling a head to converge into a target position and a target velocity along with an eigen vector by transiting an initial state of the head motion onto an eigen vector line of a system at the time transiting from an acceleration/deceleration control mode of the track seek mode to a settling control mode.

Abstract: In a hard disk drive (HDD), biases are measured across all zones of a disk, and nonlinear bias components are extracted. Upon a change in operational condition of the HDD, biases are measured at two reference positions on the disk so as to estimate a corresponding change in a linear bias component across all zones of the disk. The bias at a given position of the disk is then calculated based on the estimated linear bias component and the extracted nonlinear bias component.

Abstract: A method, an apparatus and a computer readable recording medium storing a program for correctly detecting a free fall by referring to an acceleration and an integration of the acceleration. The method includes sensing an acceleration of the mobile device; integrating the sensed acceleration with respect to time; and determining the free fall by comparing the result of the integrating with a predetermined area threshold.

Abstract: Provided are a method of calculating repeatable runout (RRO) of a hard disk drive (HDD) in a frequency domain, a method of calculating a compensation value using the RRO calculating method, and recording media used therefore. The method of calculating RRO in a disk with a plurality of tracks includes: calculating first set of frequency coefficients for representing the RRO by analyzing a position error signal (PES), which is sampled in a target track, in a frequency domain while a head follows the target track; and calculating the RRO using the first set of frequency coefficients.

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.

Abstract: A servo control device for a disk drive capable of effectively compensating for a low frequency disturbance incoming to the disk drive is provided. The servo control device includes: a state variable estimator calculating a position estimation error based on a control input for controlling motion of a head and a position error signal by using a predetermined state equation; an estimation filter calculating a disturbance estimation value from the position estimation error by using a mathematical relation between a disturbance and the position estimation error; and a subtractor subtracting the disturbance estimation value from the control input.

Abstract: Provided are a method of generating a current trajectory for seek control of a hard disc drive and a seek control system using the same, the method including setting a current trajectory from harmonics of a sinusoidal wave; calculating a power consumed by a target device to be controlled using the current trajectory; and determining coefficients of the harmonics so as to minimize the power consumed by the device.

Abstract: A settling control method and apparatus perform an improved settling control regardless of a seek distance when a disc drive track seek control operation is performed. An adaptive settling control method used in controlling the track seek mode of the disc drive includes: controlling a head to converge into a target position and a target velocity along with an eigen vector by transiting an initial state of the head motion onto an eigen vector line of a system at the time transiting from an acceleration/deceleration control mode of the track seek mode to a settling control mode.

Abstract: An apparatus and method are provided for quickly and finely compensating for non-repeatable run out (NPRO) of a disc drive. The NPRO compensation control apparatus in a run out compensation apparatus of a system includes: a frequency estimator directly estimating a trigonometric function value of an NRRO frequency from a predetermined signal responding to the system using a correlation between a filter coefficient of a notch filter and a notch frequency; and an NRRO compensator canceling NRRO of the system using the trigonometric function value of the NRRO frequency estimated by the frequency estimator.

Abstract: There are provided a method and apparatus for high-speed compensating repeatable run-out in a hard disk drive. The method includes a) obtaining a value of a position error signal (PES) of the hard disk drive, the PES being a relative position signal of the head with respect to the center of the target track of the disk; b) determining whether the head is in the settling mode; c) if the head is in the settling mode, compensating the RRO error without feeding back the PES; and d) if the head is in the track-following mode, compensate the RRO error by feeding back the PES. Accordingly, an excessive RRO error is compensated. Even though the hard disk drive receives an external shock or is assembled in an offline servo writing manner, the performance of the hard disk drive does not deteriorate.

Abstract: Provided are a method of generating a current trajectory for seek control of a hard disc drive and a seek control system using the same, the method including setting a current trajectory from harmonics of a sinusoidal wave; calculating a power consumed by a target device to be controlled using the current trajectory; and determining coefficients of the harmonics so as to minimize the power consumed by the device.

Abstract: A micro robot includes first and second masses, each having a first contact surface having a first frictional coefficient and a second contact surface having a second frictional coefficient and formed to be inclined by a predetermined angle with respect to the first contact surface, the first and second contact surfaces being formed at the lower portion of the mass corresponding to a surface of a target object, and an actuator provided between the first and second masses for periodically changing the distance between the first and second masses and enabling the first and second contact surfaces of the first and second masses to selectively contact the surface of the target object in synchronization with a periodic change in distance between the first and second masses.