KR100189546B1 - Compensation method for position error signal according to distorted components in magnetic disk driver of tracking operation - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

A magnetic disk drive recording apparatus for magnetic recording / reading of digital information, and more particularly, the head following a track following a head on another disk while the head tracks to read data from a specific track on one magnetic disk. The present invention relates to a method of compensating off-track when switching.

2. The technical problem to be solved by the invention

In general, a hard disk driver has a mechanical component and a circuit component, and among them, the response characteristics of the head switching are degraded due to a system error caused by the mechanical component.

3. Summary of Solution to Invention

In the magnetic disk drive recording apparatus for magnetic recording / reading of digital information, the track following head is switched to the head on another disk while the head tracks in order to read data from a specific track on one magnetic disk. It provides a more stable way to compensate when doing so.

4. Important uses of the invention

Compensation for off-track generation immediately after head switching during track tracking in a magnetic disk drive recording apparatus.

Description

Position error signal compensation method according to distortion component in track following in magnetic disk drive recording apparatus.

1 is a perspective view of a disk clamping device and a state in which a disk is fixed by the disk clamping device.

2 is a block diagram of a magnetic disk drive apparatus applied to the present invention.

3 is a flow chart of initialization control during power input according to the related art.

4 is a flow chart of initialization control at power input according to the present invention.

5 is a control flow diagram for detecting a RRO (Repeatable Run Out) component in a sector in a track according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive recording apparatus for magnetic recording / reading of digital information. In particular, the performance of a system is degraded due to a certain distortion component while the head tracks to read data from a specific track on a magnetic disk. It is about how to compensate.

Typically, a hard disc drive (HDD) is a system that combines a head disc assembly (HDA) made of mechanical components and a printed circuit board (PCB) made of circuit components. It is widely used as an auxiliary memory device of a computer system because it can magnetically write / read data on a magnetic disk to access a large amount of data at high speed. Such a magnetic disk drive is stored in tracks arranged concentrically on a rotating magnetic disk. These tracks are accessed by two magnetic heads for reading and writing data on two magnetic disks as shown in FIG.

The head is moved in the radial direction on the magnetic disk by control of a head position servo mechanism that can be selectively positioned on any selected track of the tracks. As such, to selectively position the head on a particular track, it is necessary to know the current head position relative to each track.

Servo information informing the position of the head relative to the tracks as described above is provided by using a particular servo pattern that is read on the magnetic disk by the head. This servo pattern is permanently recorded in advance on the magnetic disk when assembling the magnetic disk drive on the magnetic disk. At this time, each servo pattern includes track position information, track address, index information, and the like. Positioning on a specific track using this servo pattern is performed by two steps consisting of track seek and track folldwing. Track search is the step of moving the head from the current track to the desired track. Track tracking is a step of accurately following a track that has been searched, and keeps the head following the track's centerline for accurate reading and writing operations once the head is located on one track.

However, the assembling of the head disc assembly (HDA) consisting of the mechanical components in the hard disc drive (HDD) as described above is mainly performed by artificial manual work, and consists of the circuit components. The assembly of a printed circuit board (PCB) is mainly performed by automated equipment, so that the characteristics of the apparatus change. Therefore, the characteristics of the servo are changed due to the change of the mechanism, and normal control is impossible, so that an unstable state is maintained during track search and track tracking, and as a result, an error occurs during read / write.

For example, the flatness of the disk may be a defect in manufacturing or an error in assembling such as a screwing force of a screw of a clamp portion that fixes the disk at all times when the disk is mounted on the spindle motor, or a spacer that is inserted between the disk and the disk. When the head tracked or tracked on the disc, the RRO (Repeatable Run Out) component of a certain frequency occurred. Therefore, in order to solve the above problems, conventionally, the structure of the clamp is mechanically deformed or the screw fastening force of the screw is increased to increase the flatness. Although the method of filtering the distortion components of a certain frequency is used, there is a problem in filtering because the frequency of the generated distortion components occurs differently when using several disks.

Accordingly, an object of the present invention is to provide a method of detecting and compensating for a software during an initialization routine when distortion occurs due to an error in disk flatness when assembling a magnetic disk drive device.

In order to achieve the above object, the present invention provides a method for compensating a position error signal according to a distortion component during track tracking in a magnetic disk drive recording apparatus, wherein all variables necessary for system operation in a memory are performed by performing an initialization routine when power is turned on. Initializing all the parameters required for the system operation, unlatching the latched and located heads in the picking zone, and tracking the unlatched head from the outer track of the track to the inner track. By measuring the bias values of the tracks sequentially and storing them in a bias table for correction, the bias-calibration step and the scanning of the RRO component of a specific frequency type caused by the flatness error of the disk after the bias-calibration step are performed. And the inner track from the outer track after performing the scanning step. Acceleration component for correcting the acceleration component of the head movement that occurs when moving to a - characterized by performing the correction step.

Hereinafter, with reference to the accompanying drawings of the present invention will be described in detail.

FIG. 1 shows a disk clamping device and a state in which a disk is fixed by the disk clamping device (for example, in the case of a drive for mounting two disks), and shows two disks 10a and 10b as information storage media. In order to fix on the spindle motor 14, the spindle motor 14 forms a plurality of screw holes 16 in the rotor, ie the upper surface of the hub, to which the disks 10a and b are fitted. Compressing the disk (10a, b) is provided with a spacer (12) for maintaining the spacing and flatness between the disk (10a) and the disk (10b), and fitted to the hub of the spindle motor 14 It has a clamp 18 for. At this time, the clamp 18 forms a screw hole 20 coinciding with the screw hole 16 of the spindle motor 14 on the inner flat surface, and the bone-shaped disk having a gap with the flat surface on the outer circumference. The crimping portion 22 is formed. A disk support 24 having the same diameter as the spacer 12 is formed below the hub of the spindle motor.

2 is a block diagram of a magnetic disk drive device applied to the present invention, in which the disk 110 is rotated by a spindle motor 134. The head 112 is located on the corresponding one of the disks 110, from the E-block assembly 114 coupled with the rotary voice coil actuator 130 towards the disks 110. Corresponding to the elongated support arms, respectively. The preamplifier 116 preamplifies the signal picked up by one of the heads 112 and applies the analog read signal to the read / write channel circuit 118 during the read. The coded write data applied from the read / write channel circuit 118 is written onto the disc through the corresponding one of the heads 112. The read / write channel circuit 118 detects and decodes a data pulse from a read signal applied from the preamplifier 116 and applies it to the disk data controller (DDC) 120. The read / write channel circuit 118 applies the write data applied from the DDC 120. Decode and apply to preamplifier 116. The DDC 120 is controlled by the microcontroller 124 and writes data received from the host computer through the read / write channel circuit 118 and the preamplifier 116 onto the disc or reads data from the host. Send to a computer. The DDC 120 also interfaces the communication between the host computer and the microcontroller 124. The buffer RAM 122 temporarily stores data transmitted between the host computer, the microcontroller 124 and the read / write channel circuit 118. The microcontroller 126 controls the DDC 120 in response to a read or write command received from the host computer and controls track searching and track following. The ROM 126 stores a program executed by the microcontroller 124 and various setting values. The servo driver 128 generates a driving current for driving the actuator 130 by a signal for controlling the position of the heads 112 generated from the microcontroller 124 and applies it to the voice coil of the actuator 130. . The actuator 130 moves the heads 112 on the disks 110 corresponding to the direction and level of the driving current applied from the servo driver 128. The spindle motor driver 132 rotates the disks 110 by driving the spindle motor 134 according to a control value for the rotation control of the disks 110 generated from the microcontroller 124. The disk signal controller 136 generates various timing signals necessary for read / write, decodes the servo information, and applies it to the microcontroller 124.

3 is a conventional control flow chart when power is input. After power is input, all variables in the memory are initialized and the head is unlatched, and the bias-correction and acceleration components-from the outer track to the inner track are set. After performing the calibration, switch to standby.

4 is an initialization control flow chart when the power is input according to the present invention, performing an initialization routine when the power is turned on, initializing all variables necessary for system operation in a memory, and initializing all variables necessary for the system operation. Unlatching the latched head located in the parking zone, and track search operation of the unlatched head from the outer track of the track to the inner track so that the bias value of the track is sequentially measured and stored in the bias table for correction. After the bias-calibration step and the bias-calibration step, scanning the RRO component of a specific frequency type caused by the disc flatness error, and after performing the scanning step, the head is moved from the outer track to the inner track. Acceleration component-calibration stage that corrects the acceleration component of head movement that occurs when moving To be carried out.

5 is a control flow diagram for detecting a RRO component in a sector in a track according to the present invention, and entering the RRO component detection mode to move from the first sector to detect a current position error signal of the sector; Detecting whether the current position error signal value exceeds a preset limit position error signal value, and when the RRO component is detected in excess of the preset limit position error signal value, a position error signal is called out from the sector table. Calculating the bias, calculating the external bias, and detecting the current position error signal of the sector by a predetermined number of times, recalculating the external bias, and calculating the external bias again. Calculating the average value, storing the calculated average value of the external bias in a sector table, and then And the step of the mobile station characterized by the carrying.

Hereinafter, the flowcharts of FIGS. 4 and 5 will be described in detail with reference to the block diagram of FIG. 2 attached to the present invention.

When the power is input to perform the initialization routine, as shown in the flowchart of FIG. 4, when the power is turned on in step 410, the microcontroller 124 initializes all variables in the memory in step 420. Then, in step 430, the microcontroller 124 is latched to move the head to a predetermined track by unlatching the head 112 located in the parking zone. Then, in step 440, the microcontroller 124 tracks the unlatched head 112 from the track set track to the inner track, sequentially measuring the bias value of the track, and storing and correcting the bias value in the bias table. Perform a bias-calibration step. Then, in step 450, the microcontroller scans the RRO component of a specific frequency type caused by the flatness error of the disk after the bias-correction step.

In this case, the performing of the RRO component scanning will be described with reference to FIG. 5. First, from step 500 to step 504, the microcontroller 112 starts the current position error signal PES1 from the sector position of the preset zone. Move to the next zone as you sample the values. In operation 506, the microcontroller 112 detects whether the detected current position error signal PES2 is greater than a preset limit PES value. At this time, when the current position error signal PES2 is greater than a preset limit PES value, the microcontroller 112 recognizes that the RRO (Repeater Run Out) component has a specific frequency in step 508 and 510. Error signal PES2 is read from the table. In this case, in operation 510, the microcontroller 112 calculates an external bias value by adding the detected current position error signal PES1 and the position error signal PES2 of the current sector loaded from the table. Then, in step 512, the microcontroller 112 detects the external bias value until a predetermined number of times by operating a counter. Then, when the number of times the counter is set, the microcontroller 112 obtains the average value of the detected external bias value in step 514 and stores the new correction value in the current sector in step 516. Thereafter, in step 518, the microcontroller 112 moves the head to the next sector. At this time, when the moved sector is not the last sector, the external bias value of the always calculated sector is stored in a table and fed back in step 504 to detect the current position error signal of the next sector again, but the moved sector is the last one. In operation 528, the microcontroller 112 moves the zone. Then, in step 530, the microcontroller 112 feeds back to step 502 when the moved sector is not the last sector, and detects the current position error signal of a new sector in the next zone. At the last sector, it goes to standby to perform the next process.

After performing the RRO component detection step as described above, the acceleration component correction step (step 460 in FIG. 4) is performed to correct the acceleration component of the head movement generated when the head moves from the outer track to the inner track. End routine and go to standby.

As described above, the present invention provides a method of detecting and compensating for a software during an initialization routine when distortion occurs due to an error in the flatness of the disk when assembling the magnetic disk drive device. There is an advantage of lowering the work yield when writing, and an advantage of improving the reliability of the product.

Claims (2)

A method for compensating position error signals according to distortion components in track tracking in a magnetic disk drive recording apparatus, the method comprising: performing an initialization routine when a power is turned on to initialize all variables necessary for system operation in a memory; and After initializing all the variables, latching and latching the head located in the parking zone, and performing the track search operation of the unlatched head from the outer track of the track to the inner track, the bias value of the track is measured sequentially. A bias-calibration step of storing and calibrating in a table, scanning the RRO component of a specific frequency type caused by the flatness error of the disk after the bias-calibration step, and after performing the scanning step, Acceleration of Head Movement when Moving from Outer Track to Inner Track A method of compensating position error signal according to distortion component in track following in a magnetic disc drive recording apparatus, characterized in that it performs an acceleration component-calibration step of correcting a minute. The method of claim 1, wherein the scanning of the RRO component having a specific frequency type comprises: entering an RRO component detection mode and moving from the first sector of the first zone area to detect a current position error signal of the sector; Detecting whether the error signal value exceeds a preset limit position error signal value, and when the RRO component is detected in excess of the preset limit position error signal value, a position error signal is called out from the sector table. Calculating an external bias according to an equation; and calculating the external bias by detecting a current position error signal of the sector by a predetermined number of times after calculating the external bias, and calculating the external bias again; Calculating the average value and calculating the average value in the sector table. Position error signal compensating method according to the track following during the distortion component in the magnetic disk drive recording apparatus, characterized by carrying out the step of moving to the next area after armed. External bias = current position error signal + position error signal retrieved from sector table. … … (expression)