JPH04103085A - Positioning control device for disk device - Google Patents

Abstract

PURPOSE:To attain an accurate temperature compensation for each control means with a single device by providing a temperature compensation means in the outside of device for compensating the temperature in accordance with the measuring result of temperature variation inside of one device among plural disk devices, and controlling the positioning of each head on the plural disk devices with compensating the temperature by this temperature compensation means. CONSTITUTION:1st temperature measurement means 3, 4 measuring the temperature variation inside of one device among the plural disk devices 5 and the temperature compensation means 2 which is located at the outside of disk device 5, for compensating the temperature in accordance with the measuring result of the 1st temperature measurement means 3, 4 are provided. Also the control means 21 which are respectively arranged to the plural disk devices 5 and subjected to temperature compensation by the temperature compensation means 2, for controlling the positioning of each head 9, 10 on the plural disk devices 5 are provided. By this arrangement, the temperature compensation means for preparing each disk device are not required, and the accurate positioning control can be made with almost exactly correcting an offtrack of the had in accordance with the information of temperature compensation.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a head positioning control device, particularly a head positioning control device using temperature correction, and performs temperature correction to each control means of a plurality of disk devices with high precision using one device. A positioning control device for a disk device that controls the position of a plurality of disk devices each having a disk and a head for performing recording or reproduction processing on the disk in a housing, the plurality of disk devices having the following object: a first temperature measuring means for measuring a temperature change inside one of the devices; and a temperature correcting means located outside the disk device and correcting the temperature based on the measurement result of the first temperature measuring means. and disposed in each of the plurality of disk devices,
The temperature is corrected by the temperature correction means, and a control means is provided for controlling the positioning of each head of the plurality of disk devices.

[Industrial application field]

The present invention relates to a head positioning control device, and more particularly to a head positioning control device using temperature correction.

With the recent demand for higher density recording and higher speed on disks, highly accurate positioning of the head is required.

However, it is necessary to eliminate various off-track factors, and it is necessary to correct off-track caused by expansion and contraction of the disk due to temperature changes.

[Conventional technology]

In hard disk drives and the like in which the disk and head are sealed in a housing, the main causes of off-track are expansion and contraction of the disk due to temperature changes, thermal eccentricity, distortion of mechanical parts, and changes in the characteristics of vibration isolation members. Hard disk drives and the like have a sealed structure to prevent external dust from entering. This is because heat generated by a spindle motor that rotates the disk at high speed, a voice coil motor (VCM) that moves the head, and a power amplifier for recording and reproducing the head causes an increase in the temperature inside the device. On the other hand, as shown in Japanese Patent Application Laid-open No. 3379/1981, a positioning control device has been proposed that performs temperature compensation using a temperature detection means for detecting the ambient temperature of the disk device and a temperature correction means.

[Invention or problem to be solved]

However, the positioning control device disclosed in Japanese Unexamined Patent Application Publication No. 3379/1986 is provided with temperature correction means for each disk device. Therefore, in a storage device or the like in which a plurality of disk devices of the same size are housed in j lockers, it is necessary to provide a plurality of temperature correction means, resulting in the problem of an increase in the size and cost of the device.

In addition, there is a slight temperature difference between the atmosphere of the disk device and the disk, and there is also the problem that temperature correction cannot be performed sufficiently.

Therefore, the following means was provided for the purpose of performing temperature correction to each control means of a plurality of disk devices with high precision using three devices.

[Means to solve the problem]

In view of the above-mentioned problems, the present invention provides a positioning control device for a disk device that controls the position of a plurality of disk devices each having a disk and a head for recording or reproducing the disk in a housing, the device comprising: a first temperature measuring means for measuring a temperature change inside one of the plurality of disk apparatuses; and a first temperature measuring means located outside the disk apparatus and performing temperature correction based on the measurement result of the first temperature measuring means. and a control means that is disposed in each of the plurality of disk drives, performs temperature correction by the temperature correction means, and corrects the positioning of each head of the plurality of disk drives.

[Effect]

The present invention uses one temperature correction means to transmit temperature correction information to each control means of a plurality of disk devices.
In a storage device that accommodates a plurality of disk devices, there is no need to provide a temperature correction means for each disk device, and it is possible to avoid increasing the size and cost of the storage device. Further, the first temperature measuring means can accurately measure the temperature force on the disk, etc., and the temperature correcting means can perform substantially accurate temperature correction based on the measurement results. Therefore, in accordance with the temperature correction information, the control means can perform highly accurate positioning control by substantially accurately correcting the off-track of the head due to expansion and contraction of the disk or the like.

〔Example〕

FIG. 1 is a system diagram of a positioning control device according to an embodiment of the present invention. Based on the measurement results of the temperature measurement circuit 3 and the temperature sensor 4, the first controller 2 performs temperature correction on a second controller 21, which will be described later, and is installed in a plurality of disk drives 5.

A feature of the positioning control device according to the present invention is that a single device, that is, the first controller 2, measures the temperature correction amount of the drive current flowing to the plurality of disk devices 5. This is because if a correction device is provided for each disk device in a storage device that accommodates a plurality of disk devices of the same size, the cost will increase. Applicable to all disk devices, including not only magnetic disk devices but also optical disk devices, where the disk and head are housed in a housing, and where it is difficult to control the highly accurate positioning of the head due to expansion and contraction of the disk due to temperature changes. can.

The temperature sensor 4 is placed in a reference disk device 5a among the plurality of disk devices 5, and the temperature information measured by the temperature sensor 4 is encoded by the temperature measurement circuit 3 and sent to the first controller 2. .

Based on this temperature information, the first controller 2 transmits a temperature correction signal regarding the drive current output for each disk device to a second controller 21 (not shown) built in each disk device 5. The temperature sensor 4 is used to measure the temperature of a disk (not shown) of a reference disk device 5a. This is to control head positioning in consideration of expansion and contraction of the magnetic disk due to temperature changes. If it is difficult to directly measure the temperature of the disk, the temperature near the disk may be measured using the temperature sensor 4, and the measured temperature may be converted to the temperature of the disk.

For example, the temperature relationship between the disk and the inside of the casing is determined in advance, the temperature of the atmosphere is measured with the temperature sensor 4, and the calculation means for converting the measured temperature into the temperature of the disk is connected to the temperature measurement circuit 3 or the first It may be configured to be provided in the controller 2.

The first controller 2 can also be connected to an external computer or the like via the first interface 1. This also allows the positioning control to be corrected by an external computer.

FIG. 2 shows a control system diagram of the disk device of the present invention. The temperature correction signal from the first controller 2 is transmitted from the second interface 22 to the second controller 21 in each disk device 5.

Each disk device 5 is provided with a disk 8, a head 9, and an IO. Note that a servo surface servo method may be used for head positioning control, and 9 may be a data head and 10 may be a servo head.

The second controller 21 includes a servo system control circuit 18 and a data head 9 that performs recording or reproduction processing on the disk 7.
a read/write control circuit 19 that controls the disk 7;
The motor control circuit 20 that controls the rotation speed of the spindle motor 8 that rotates the motor will be summarized. A control signal from the first controller 2 transmitted from the second interface 22 controls the control circuit 18 of the servo system.

The second controller 21 has a second interface 2
Upon receiving the correction signal related to the drive current output from the first controller 2 transmitted from the first controller 2, the first controller 2 transmits a command to correct the predetermined drive current to the MPU 17. MPU! 7
Based on the command, the drive current applied to the drive coil in the actuator Il is corrected via the D/A converter 16 and the amplifier 12. The actuator 11 uses this drive current to rotate the head 9 and IO in the radial direction of the disk 7, thereby positioning them on a predetermined track.

On the other hand, the second controller 21 can receive the position information signal of the servo head IO from the MPU+7. The position information of the servo head 10 is amplified by the amplifier 13 and then sent to the servo demodulator 1.
4 and is demodulated by the MPU 17 via the A/D converter 15.
is transmitted to.

The positioning control method performed by the second controller 21 will be described below with reference to FIGS. 2 to 4.

FIG. 3 is a flowchart of positioning control using the control constant correction method of the present invention. First, step 301 determines whether there is a temperature change. Whether or not there is a temperature change is indicated by a temperature measurement circuit 3, which will be described later. If there is a temperature change, step 302 changes the control constants. Here, the control constants specifically refer to track spacing, force constant,
Represents the resistance value etc. of VCM. These are step 30 described below.
7 serves as an index for determining the output of the drive current. Next, it is determined whether it is step 303 or time Tk. This control employs a feedback control method that performs continuous control at fixed time intervals. Therefore, it is determined whether a predetermined time interval has been reached. If it is determined that time Tk has elapsed, step 304 detects the current position of the servo head IO. This is to calculate the drive current for positioning the head to the target position. From the result of step 304, step 305 and step 3
06, step 307 outputs the drive current. Step 30
5 calculates the control current. The control current is a current that is passed through the drive coil in order to move the servo head 10 from the current position to the target position without considering expansion and contraction of the disk 7 due to temperature changes. In response, step 306 calculates a correction current. The correction current is a current for correcting the control current in consideration of expansion and contraction of the disk 7 due to temperature changes. The correction current is closely related to the step 1020 control constant.

As the track distance increases, the moving distance of the heads 9 and 10 increases, so the drive current must be increased.
The amount of increase in this current varies depending on the drive current creation method. For example, in the PID control method in which a drive current is created by writing and adding an appropriate coefficient to the position/position integral/velocity, 3
If the track spacing increases by 3%, the drive current must be increased by 3%, and this amount becomes the correction current.

The force constant represents the magnitude of the force generated when a current flows, and when B1 is the force constant, F is the force, and U is the driving current, it is as follows.

F=B 1 u This force constant depends on the temperature, so for example, the force constant or 3
When the drive current increases by 1/1.03=0.970
It has to be multiplied by nine. The correction current in this case is -(1-0,9709)u of the drive current = -0,0291
It becomes u.

The resistance value of the VCM varies depending on the configuration of the amplifier through which the current flows. If it is an amplifier or a voltage source, the drive current will change according to Ohm's law as the resistance of the VCM changes. Therefore, if the resistance changes by 3%, the drive current must be increased by 3%.

Based on the calculation results of steps 105 and 106, step 1
07 calculates the drive current. The drive current is a current flowing through the drive coil of the actuator 11 that rotates the head 9 and IO. This makes it possible to control the positioning of the head with high precision even if the disk 7 expands or contracts due to temperature changes.

Note that if there is no temperature change, the control constant is not changed, and the correction current and drive current are calculated based on the previous control constant.

FIG. 4 shows a flowchart for controlling a plurality of disk devices. In step 401, a reference temperature is first measured. For example, a common temperature before driving each disk device 5 is selected. Subsequently, after driving, step 402 determines whether there is a temperature change in each disk device. If it is determined that there is a temperature change, the temperature of each disk device 5 is estimated in step 403, and the temperature information is notified to each disk device 5 in step 404.

〔Effect of the invention〕

As described above, according to the present invention, temperature correction for positioning control of each head of a plurality of disk devices can be performed with high precision using one device.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a positioning control device according to an embodiment of the present invention, FIG. 2 is a control system diagram of a disk device, FIG. 3 is a flowchart of positioning control using the control constant correction method of the present invention, and FIG. 4 is a disk drive control system diagram. It is a flowchart for controlling a plurality of devices. In the figure, l is the first interface, 2 is ! Controller 1 (disk controller) 3 is a temperature measurement circuit, 4 is a temperature sensor, 5 is a disk device, 5a is a reference disk device, 7 is a disk, 8 is a spindle motor, 9 is a data head, 10 is a servo head, 11 is an actuator, 12.13 is an amplifier, 14 is a servo demodulator, 15 is an A/D converter, 16 is a D/A converter, and 17 is an MPU. 18 is a servo system control circuit, 19 is a read/write control circuit, 20 is a spindle motor rotation speed control circuit, and 21 is a second
controller, 22 indicates a second interface. "#: Systematic diagram of a positioning control device piece according to an embodiment of the present invention. Flow chart 1 for installing a plurality of disk devices on the side Φ11.

Claims (3)

[Claims] (1) The positions of the heads (9, 10) of a plurality of disk devices (5) that have a disk (7) and heads (9, 10) that perform recording or playback processing on the disk (7) in a housing. A positioning control device for a disk device to be controlled, comprising: a first temperature measuring means (3, 4) for measuring a temperature change inside one of the plurality of disk devices (5); temperature correction means (2) that is located outside of the first temperature measurement means (3, 4) and performs temperature correction based on the measurement results of the first temperature measurement means (3, 4);
5), a control means (21) is provided, the temperature is corrected by the temperature correction means (2), and the control means (21) controls the positioning of each head (9, 10) of the plurality of disk devices (5). Disk device positioning control device featuring features. (2) At least one of the first temperature measuring means is disposed inside and/or outside of the housing.
2. The positioning control device for a disk drive according to claim 1, further comprising: second temperature measuring means; and calculating means for converting the temperature measured by the second temperature measuring means into the temperature of the disk. (3) The positioning control device for a disk drive according to claim 2, wherein the calculation means and the control means are integrated processing means.