Samsung Electronics Co., Ltd.

Jun-Seok Shim

Sang-eun Baek

Chang-ik Kang

Sang-min Suh

Boldyrev Serguei

Yong-kyu Byun

Sung-Won Park

Cheol-soon Kim

Kyu-Nam Cho

Julian Stoev

Jae-min Ryu

You-jip Won

Hyung-kyu Jang

A method of detecting a free fall of a device includes measuring an acceleration of the device, calculating an integral of the acceleration, and determining whether the acceleration is periodic. If the acceleration is not periodic, the integral of the acceleration is compared with a first critical value to determine whether the device falls freely. If the acceleration is periodic, the integral of the acceleration is compared with a second critical value to determine whether the device falls freely. The first and second critical values are different. Since whether the device is periodically accelerated is considered, free fall of the device can be correctly detected, and thus malfunction of the device can be prevented. For example, an unnecessary protection operation for a hard disk drive of the device can be prevented, and thus a user can conveniently use the device.

Method of detecting free fall and apparatus to detect free fall using the method

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.

Method and apparatus compensating disturbance in state control device

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.

Bias calculation, bias compensation, and bias table editing methods for HDD, recording media storing computer programs for executing the same, and HDD using the same

A data input/output control method and apparatus in an input/output subsystem are provided. The data input/output control method, in a system for inputting/outputting data to/from a disk sector according to an input/output command provided from a disk driver, includes: extracting the input/output commands for inputting/outputting the data to/from disk sector from the disk driver and generating a set of input/output commands; analyzing the load feature of the input/output command based on the set of input/output commands; determining whether the load of the input/output command corresponds to a multimedia application; and controlling the data which is input/output to/from the disk to correspond to the multimedia application according to the determination result.

Input/output control method and apparatus of multimedia file

A speed control method of controlling a stepping motor to have a uniform instantaneous speed and an apparatus suitable for the same are provided. The stepping motor speed control method includes: calculating a repeated speed error for each phase while rotating a stepping motor at a constant speed and storing the calculated repeated speed error phase by phase; measuring a rotation speed of the stepping motor; sequentially and repeatedly reading the stored repeated speed errors phase by phase by synchronizing with the rotation of the stepping motor; and controlling the speed of the stepping motor with reference to the target speed, the measured speed and the repeated speed error for each phase. Accordingly, the stepping motor speed control apparatus rotates a stepping motor at a uniform instantaneous speed by controlling a rotation speed of the stepping motor phase by phase.

Stepping motor speed control method and apparatus suitable for the same

A method for writing a spiral reference servo signal suitable for a self-servo writing method in a hard disk drive includes writing a first reference pattern in an end direction of a spiral reference servo signal writing concentrically on the disk; writing a spiral reference servo signal on a current spiral track from a reference writing start position of the current spiral track; detecting a moving angle of a head to the first reference pattern, which corresponds to a distance from the reference writing start position to a reference writing end position of the spiral reference servo signal in the case that thermal expansion of the disk does not exist; compensating for a driving speed of the head with reference to the detected moving angle of the head; and writing the spiral reference servo signal on a next spiral track at a compensated driving speed of the head.

Method for writing spiral reference servo signal in hard disk drive and method for compensating for temperature

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.

Non-repeatable run out compensating apparatus and method and disc drive using the same

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.

Low frequency disturbance compensation control device and disk drive using the same

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.

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Seongnam-si, South Korea

Jun-Seok Shim