JPH06119731A - Position detecting system for control object and magnetic disk device - Google Patents

Abstract

PURPOSE:To shorten the calculation processing time for detecting a position of a magnetic head and to reduce the consumption of a data holding memory by calculating a digital value of 4-phase position signal and deciding the number of carry flags. CONSTITUTION:Information including the 4-phase position signal S regenerated from a magnetic disk 1 by using the magnetic head 8 is amplified by a read amplifier 7, and is inputted via a position detecting circuit 2 and an A/D converter 3 to a calculation processor 4, where calculation processing is performed to detect the present position. Then, a track-track distance is divided by 4, and at the time of position detecting in every 1/4 of the track, a digital value of a position signal detecting voltage 5 is calculated to decide the number of carry flags, so that a position of the magnetic head 8 in the 4-divided track- track distance can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of positioning a controlled object at a target position, and more particularly to a method of detecting a position during a positioning operation.

[0002]

2. Description of the Related Art A conventional magnetic head position detecting method in a magnetic disk device will be described with reference to the drawings.

FIG. 4 is a block diagram of a conventional magnetic disk device using a control target position detection method, FIG. 4A is a block diagram of a conventional magnetic disk device, and FIG. 4B is FIG.
FIG. 5A is an array diagram of four-phase position signals of the magnetic disk device of FIG. 5A, and FIG. 5 is a flow chart of a conventional method of calculating the position of a controlled object.

In FIG. 4, a magnetic head 8 is used to convert a magnetic signal into an electric signal from a magnetic disk 1 on which a four-phase position signal is recorded in advance. The signal including the converted four-phase position signal is amplified by the read amplifier 7 and becomes the read output 9. The read output 9 is converted into the position signal detection voltage 5 in the position detection circuit 2 and then A
It is input to the / D converter 3.

The position signal detection voltage 5 is converted into a position signal digital value 6 in the A / D converter 3 and then input to the arithmetic processing unit 4. In the arithmetic processing unit 4, the calculation unit 55 sequentially calculates and judges by the program shown in FIG.
The determination unit 56 makes a determination based on the result based on the position data held in advance, and detects the magnetic head position.

Next, the calculation unit 5 in the program shown in FIG.
5 and the determination unit 56 will be described in detail.

In the calculation section 55, first, a register for setting a position data table address (area / address on the program) prepared in advance in the data holding memory, which is determined by the calculation result, is cleared (initialized).

The third and fourth phases are transferred with the digital value 6 to the calculation register.

Then, the digital value 6 of the fourth phase is subtracted from the digital value 6 of the third phase.

It is judged whether or not the result is larger than zero, and if it is smaller, "1" is set in the odd / even track judgment register.
After adding, proceed to the next processing. At this time, if the result is greater than zero, nothing is done and the process proceeds to the next process.

Subsequently, the digital value 6 of the third phase is subtracted from the digital value 6 of the first phase.

Next, it is judged whether or not the result is larger than zero, and if it is smaller, "2" is added to the position table address setting register and then the process proceeds to the next processing. At this time, if the result is greater than zero, nothing is done and the process proceeds to the next process.

The digital value 6 of the fourth phase is subtracted from the digital value 6 of the first phase.

Then, it is judged whether or not the result is larger than zero, and if it is smaller, "4" is added to the position table address setting register and then the process proceeds to the next processing. At this time, if the result is greater than zero, nothing is done and the process proceeds to the next process.

Next, the judging section 56 judges whether the content of the odd / even track judging register is zero, and if it is zero, it is judged from the position table for the odd track indicated by the position table address setting register to zero. If not, the magnetic head position is detected by taking the position data from the even track position table. That is, the position table address is determined by the difference in the value of the position table address setting register, and the position determination is performed by taking the position data from each designated position table.

Note that ,,,, in FIG. 5 respectively represent: digital value of first phase: digital value of second phase: digital value of third phase: digital value of fourth phase

The separate processes A and B refer to processes (execution of calculation formulas) for performing fine position calculation (no judgment) provided for each odd or even track.

[0018]

In the above-mentioned conventional arithmetic processing method, since the calculation result of the digital value of the position signal is sequentially judged, the processing takes time and the processing is complicated, and the calculation is also complicated. Since the position data is held for each result, there is a drawback that the data holding memory is consumed extra.

An object of the present invention is to detect the magnetic head position by counting the number of carry signal (hereinafter referred to as carry) flags generated in the calculation result of the digital value of the position signal, and to detect the position of the magnetic head during the track positioning operation. When comparing the signal levels and detecting the current position, for the level comparison of the position signal,
It is an object of the present invention to provide a position detection method for a control target and a magnetic disk device that solve the above-mentioned drawbacks by using carry determination and shorten the position detection processing time.

[0020]

According to the position detecting method for control of the first aspect of the present invention, the present value is detected by comparing and judging the level of the position signal obtained as a result of the operation of the controlled object. In this case, the comparison / determination method is provided with an arithmetic processing method for determining / detecting the current position by using carry determination.

The magnetic disk drive of the second invention has means for positioning the controlled object to the target position by the position detection method for the controlled object of the first invention.

[0022]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a configuration diagram of a magnetic disk device using a position detection method of a controlled object according to an embodiment of the present invention.
1A is a configuration diagram of a magnetic disk device according to the present embodiment, FIG.
1B is an array diagram of four-phase position signals of the magnetic disk device of FIG. 1A, and FIG. 2 is a state of change in output voltage of the four-phase position signal when the magnetic head of the magnetic disk device of FIG. FIG. 3 is a flowchart of the arithmetic processing method of the position detection method of the controlled object of the present embodiment.

In FIG. 1A, information including a four-layer position signal reproduced from the magnetic disk 1 using the magnetic head 8 is amplified by the read-up 7, and the position detection circuit 2 and the A / D converter are amplified. After being input to the arithmetic processing unit 4 via 3, the arithmetic processing is performed to detect the current position.

Next, the position detection method of the controlled object and the operation of the magnetic disk device of this embodiment will be described in detail with reference to the drawings.

The four-phase position signals are recorded and arrayed on the magnetic disk 1, as shown in FIG. This is reproduced by using the magnetic head 8. The information 9 including the reproduced four-layer position signal is converted into a position signal detection voltage 5 in the position detection circuit 2 and then converted into a digital value 6 in the A / D converter 3.
Is input to the arithmetic processing unit 4.

Next, a method of detecting the position will be described with reference to FIGS. 2 and 3.

The position of the magnetic head and the position signal detection voltage are as shown in FIG. When the track-to-track division is divided into four, and the position is detected for each ¼ track, the digital value of the position signal detection voltage is calculated 36, 37 by the program shown in FIG. 3, and the number of carry flags is determined 35. Thus, the position of the magnetic head 8 between the four divided tracks is detected.

Below, a detailed explanation will be given of the calculation units 36 and 37 and the judgment unit 35 in the program shown in FIG.

In the calculation units 36 and 37, first, referring to FIG.
Figure 1 of (b) Phase 1 and 2 and Phase 3 and 4
The digital value 6 shown in (a) is transferred to the calculation register.

A carry flag and a register (carry counter) used for counting the number of carry flags generated in the calculation process are cleared (initialized).

Then, the digital value 6 of the first phase or the second phase of FIG. 1B is subtracted from the digital value 6 of the second phase or the first phase of FIG. 1B.

Then, if a carry is generated as a result of the calculation, "1" is added to the carry counter, and if it is not generated, "0" is added to proceed to the next process.

Next, the digital value 6 of the third phase of FIG. 1 (b) is subtracted from the digital value 6 of the second phase or the first phase of FIG. 1 (b).

If a carry is generated as a result of the calculation, "1" is added to the carry counter, and if it is not generated, "0" is added to proceed to the next process.

Then, the digital value 6 of the fourth phase in FIG. 1B is subtracted from the digital value 6 of the second phase or the first phase in FIG. 1B.

Then, if a carry is generated as a result of the calculation, "1" is added to the carry counter, and if it is not generated, "0" is added to proceed to the next process.

Next, in the judging section 35, "3" is subtracted from the carry counter, and if the result is zero, the processing proceeds to another processing 1.

If the result is not zero, "2" is subtracted from the carry counter in the next process, and if the result is zero, the process proceeds to another process 2. If the result is not zero,
In the next process, "1" is subtracted from the carry counter. If the result is zero, the process proceeds to another process 3, and if the result is not zero, the process proceeds to another process 4.

As described above, the position of the magnetic head shown in FIG. 2 is detected by the number of carries generated in the calculation process.

Note that ,, in FIG. 3 are the same as in the case of FIG. 5 in the section of the prior art: digital value of first phase: digital value of second phase: digital value of third phase : Indicates the digital value of the fourth phase.

Further, the separate processes 1 to 4 are processes (calculations) for performing fine position calculation (no judgment) provided for each odd or even track, as in the case described with reference to FIG. Execute the expression).

[0043]

As described above, according to the position detection method of the controlled object and the magnetic disk drive of the present invention, the magnetic head position is calculated by calculating the digital value of the 4-phase position signal and judging by the number of carry flags. There is an effect that it is possible to reduce the calculation processing time for detecting the error and to reduce the data holding memory consumption.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetic disk device using a control target position detection method according to an embodiment of the present invention. Figure 1 (a)
FIG. 1 is a configuration diagram of a magnetic disk device of this embodiment. Figure 1
FIG. 1B is an array diagram of four-phase position signals of the magnetic disk device of FIG.

FIG. 2 is a diagram showing a change in four-phase position signal output voltage and a magnetic head position when the magnetic head of the magnetic disk device of FIG. 1 is moved.

FIG. 3 is a flowchart of an arithmetic processing method of a position detection method of a controlled object of the present embodiment.

FIG. 4 is a block diagram of a magnetic disk device using a conventional control target position detection method. FIG. 4A is a block diagram of a conventional magnetic disk device. FIG. 4B is an array diagram of the four-phase position signals of the magnetic disk device of FIG.

FIG. 5 is a flowchart of a calculation processing method of a position detection method of a control target of a conventional example.

[Explanation of symbols]

 1 Magnetic Disk 2 Position Detection Circuit 3 A / D Converter 4 Arithmetic Processor 5 Position Signal Detection Voltage 6 4 Digital Values of 4 Phase Position Signal 7 Read Amplifier 8 Magnetic Head 9 Read Output

Claims (2)

[Claims] 1. When a current position value is detected by comparing / determining the level of a position signal obtained as a result of the operation of a controlled object, a carry signal determination is used as a comparison / determination method for the current position. A position detection method for control, comprising an arithmetic processing method for determining / detecting. 2. A magnetic disk drive comprising means for positioning the controlled object to a target position by the method for detecting the position of the controlled object according to claim 1.