JPH02154379A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To perform an optimum head positioning control by providing a reading and sending means for reading a setting value of a parameter stored in a storage means in response to a request of an external interface and sending it out to the external interface. CONSTITUTION:The subject device is provided with the storage means 23a-23d for storing the setting value of the parameter relative to the head positioning control and the reading and sending means 26 and 27 for reading this stored setting value in response to the request of the external interface and sending out this read setting value to the external interface. Consequently, the setting state of the parameter can be monitored from the external interface, and in the case of compensating surplus head positioning, this can be perceived in advance to perform appropriate evasion work, or by knowing the secular change of a compensation parameter, the device can be checked. By this method, the optimum head positioning control can thus be performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk device used as an external storage device of a computer, for example, and in particular to a magnetic disk device that can set parameter values of a positioning mechanism in a predetermined procedure. The present invention relates to a magnetic disk device that allows set parameter values to be read from an external interface if the device is capable of doing so.

[Conventional technology]

In conventional magnetic disk drives, in order to position the magnetic head at high speed and with high precision, the parameter settings of the positioning servo mechanism, such as speed control and position control, can be automatically set in a predetermined procedure. In this way, a system was being introduced to set the optimum value for changes in the external environment and internal characteristics over time.

[Problem to be solved by the invention]

However, in conventional magnetic disk drives, even if they have the ability to automatically set the setting values of positioning mechanism parameters such as speed control and position control in a predetermined procedure, the set parameters cannot be set automatically. Since the values could not be read from the external interface, there was a problem in that if the external environment or internal characteristics changed significantly over time, unreasonable settings would be made, which would actually reduce the reliability of head positioning control.

This invention was made in order to solve the above-mentioned problems, and by making it possible to read the set parameter values from an external interface, it enables optimal head positioning control and improves reliability. The purpose is to obtain a high quality magnetic disk device.

[Means to solve the problem]

The magnetic disk drive according to the present invention includes a storage means (digital memory 23) for storing set values of parameters related to head positioning, and reads out the stored set values in response to a request from an external interface. The present invention is characterized in that it includes readout and output means (digital signal switching circuits 26 and 27) for transmitting the set value to the external interface.

[Effect]

In this magnetic disk device, storage means (digital
The memory 23) stores set values of parameters related to head positioning, and the reading/sending means 50 reads out the stored set values in response to a request from the external interface and sends the read set values to the external interface. do.

[Embodiments of the invention]

FIG. 1 is a schematic diagram of a magnetic disk device according to an embodiment of the present invention. In the figure, la to lc are magnetic disks for recording information, 2 (2a to 2g) are recording tracks on magnetic disk l, and 3 (33 to 3e) are for recording and reproducing information on magnetic disk 1. A magnetic head, especially 2 a
4. t: servo track, 3a is a servo head. 4 is a carriage for positioning the magnetic head 3; 5 (53 to 5c) is a head arm for supporting the magnetic head 3; 6 is a spindle motor for rotating the magnetic disk l; 7 is for driving the carriage 4. 8 is a magnetic circuit of the voice coil motor 7.

Carriage 4 above. The head arms 5a to 5c, the spindle motor 6, the voice coil motor 7, the magnetic circuit 8, and the like constitute a head positioning machine 4M30. 9 is a magnetic head! 10 is a head selection circuit for electrically selecting the magnetic head 3, 11 is a servo head amplifier for the servo head 3a, and 12 is a voice coil motor drive amplifier.

FIG. 2 shows speed control and position control in the magnetic disk device shown in FIG. In FIG. 2, reference numeral 13 indicates a position signal detection circuit that detects a position signal upon receiving the output of the amplifier 11 to the servo, 14 a speed signal detection circuit that differentiates the output of the position signal detection circuit 13 and detects a speed signal, and 15 16 is an A/D converter that converts the output of the position signal detection circuit 13 from analog to digital; and 16 is an A/D converter that converts the output of the speed signal detection circuit 4 from analog to digital. 17a is the input port of the microprocessor, 18
(18a, 18b) are switching circuits that switch between speed control and position control; 19 (19a to 19C) are digital variable resistors as parameter variable means; 20 (20a,
20b) is an operational amplifier, and 21 is a target speed generation circuit, the output of which is connected to one end of the switching circuit 18a.

In this case, the learning function section 17m of the microprocessor 17
The above parameters are set to optimal values according to a predetermined procedure. 22 is a position offset signal generation circuit that generates a position offset signal in accordance with head selection; 23 (2);
3a to 23d) are digital memories (storage means) that are connected and controlled by the output port 17b of the microprocessor 17 and store the set values of parameters related to head positioning control, and are connected to and controlled by the output port 17b of the microprocessor 17. It is connected to the circuit 22 and the like. 24a
24b is an ink-face receiver that receives a parameter designation signal; 24b is an interface receiver that receives a parameter read request signal; 25 is an interface receiver;
Driver, 26°27 is interface receiver 2
4a.

This is a digital signal switching circuit for outputting the contents of the digital memory 23 to the interface in response to a parameter designation and a read request from the digital memory 24b, and constitutes the reading/sending means 50.

Next, the operation of the digital memory in speed control of this embodiment will be explained. The switching circuit 18 in FIG. 2 shows a speed control state. Target speed generation port I! The output of 121 is sent to operational amplifier 2 via digital variable resistor 19a.
Applied to 0a. The sensitivity of the target speed is that variable resistor 1
Setting is possible by the position of 9a, and the control is performed by the output of digital memory 23a. The loop gain of this control is set by the digital variable resistor 19c. Control of the digital memory 23 is performed by the microprocessor output port 17b. The input port 17a of the microprocessor uses the A/D converter 16 to input the digital variable resistor amount etc. in speed control.
This is done by importing it into Therefore, the setting value of the digital variable resistor 19 can be grasped from the contents of the digital memory 23.

Next, the operation of the digital memory 23 in position control will be described. For position control, the switching circuit 18 is connected in a position opposite to that shown in FIG. Therefore, both the position signal from the position signal detection circuit 13 and the speed signal from the speed signal detection circuit 14 are applied to the operational amplifier 20a, and the digital resistor 19b mainly determines the damping characteristics of this control system. By the way, in position control, it is desirable to be able to compensate for the positional deviation characteristics of each magnetic head 3.

In this embodiment, this is achieved by the following method. In FIG. 1, the relative relationships between the magnetic heads 3a to 3e and the recording tracks 2a to 2e on the magnetic disks 1a to lc are different. In other words, the offset between the servo head 3a and the servo track 2a is relatively small, whereas the data heads 3b to 3e not only have a large offset with respect to the data tracks 2b to 2e, but also the offsets of the heads farther away from the servo head 3a are larger. big. In the figure, the offset of the magnetic helad 3e is the largest. In order to appropriately deal with the case where the offset amount differs from head to head, a reverse position offset signal generation circuit 22 is provided. This generation circuit 22
The output of the head selection circuit 10 is added to the head selection circuit 10, and an offset amount corresponding to the head can be generated. The amount can be grasped by the digital memory 23d.

Next, I will talk about the learning function. This magnetic disk drive has a learning control capability to set parameters related to speed control and position control to optimal values to maximize performance.

First, when the power is turned on, it is in a so-called cold start condition. Under this condition, the temperature of each component is low and the optimum parameters for speed control and position control are different from those under temperature saturated conditions.

Figure 3 shows the speed control profile. The speed of carriage 4 under temperature saturated conditions is profile 0.
-A-B-C, and the required time is T. However, at low temperatures, the mechanical load on the mechanical motion system increases because the temperature of the bearings of the carriage 4 is low, and when trying to give the same speed control profile, extra acceleration time is required, and the actual profile is 0-
It becomes like AI-81-C1, and the required time becomes Tl>T. One of the main performance characteristics of a magnetic disk drive is seek time, and lengthening the seek time is not desirable as it degrades performance. In this embodiment, the maximum speed was set high to compensate for the delay. That is, variable resistor 1
Change the setting value of 9b and create profile 0-A2-82-
I set it to C. In the learning process, the required seek time T is measured when the power is turned on, and the control parameters of the variable resistor 19b are set so that this value becomes a predetermined value.

Now, when a magnetic disk device is continuously operated, the temperature of each part reaches its upper limit, and the values of control parameters to be set become different from those when the power is turned on. Therefore, the required seek time is periodically measured and the control parameters are reset.

The reconfiguration algorithm is based on firmware installed in the microprocessor.

Next, the learning function in position control will be explained. In position control, the main objective is to ensure positioning accuracy. First, the variable resistor 19a is adjusted to reduce the transient state (so-called overshoot) after switching from speed control to position control and to shorten the setting time. Further, positioning accuracy is achieved by changing the loop gain of the control system by adjusting the variable resistor 19c. In FIG. 4, the horizontal axis indicates time t, and the vertical axis indicates the position signal. When switching from speed control to position control, the position signal is V
It is TH. In the case of the optimal value shown by the solid line, once −VTL~
Once within the range of +VTL, that condition is always maintained thereafter. In the inappropriate case shown by the broken line, an overshoot that becomes smaller than -VTL is seen again. During the overshoot period, positioning accuracy is not achieved, so a retriggerable timer called time interval (TR) is used to monitor the timing and delay the generation timing of the seek complete signal from TI to T2. is prevented. In the process of learning control, the seek complete signal is examined to find conditions under which a stable T1 time can be obtained.

In addition, finding an appropriate offset amount for each data point in position control is also one of the important functions of learning control.

Next, we will discuss the case where parameters to be read from the interface are specified. The parameters are designated by controlling the digital signal switching circuit 27 according to the content received by the interface/line receiver 24a. If a parameter reading request is further received by the interface receiver 24b, the switch of the digital signal switching circuit 27 is turned on and the output of the digital signal switching circuit 26 is transferred to the interface/line driver 24b.
Connect to 5. For example, when there is a request to read the loop gain parameter of the variable resistor 19c, the digital signal switching circuit 26 is connected to the rightmost contact.

Also, the digital memory 23 is the via of the variable resistor 19)
Appropriate hardware may be prepared depending on the number of devices. For example, in FIG. 2, the variable resistor 19 is 2 bits, so at least a 2-bit flip-flop is used.

Although one switching section of the digital signal switching circuit 27 is shown in the figure, it is actually matched to the number of bits of the digital memory 23. Similarly, the signal lines related to the microprocessor are also made up of a plurality of lines.

In the above explanation, the switch circuit has been realized mechanically, but it can actually be realized purely electronically. For example, the switching circuit 18 can be replaced with a FET analog switch, the variable resistor 19 can be replaced with a combination of a decoder and a FET analog switch, and the switching circuit 26 can be replaced with a multiplexer.

FIG. 5 shows an example of a variable resistor 19 using a weighted resistor. In FIG.
Analog switch 2, 3 (la to 3qd are weighted resistors, and the resistance value of resistor 3'la is 11th (-1)
When , the resistance 39b.

3 (jc, 3qd are r2J, r4J, r8J, respectively. 31 is a fixed input resistance, and the gain of the operational amplifier 28 is inversely proportional to (resistance value of resistor 31 + resistance value of resistor 3'i). 32 is The pull-up resistors 33 of the analog switches 29a to 29d are drive gates of the analog switch 29. When the input of the drive gate 33 is at a high level, the corresponding analog switches 29a to 29d are turned on.

The digital memory 23 consists of four memory flip-flops 343 to 34d, and launches the output of the microprocessor using a set clock.

The outputs of the flip-flops 343 to 34d are the drive gates 3
3 and drives weight resistors 3qa to 3qd. On the other hand, since the output of the digital memory 23 is connected to the digital signal switching circuit 26, it can be sent to the interface in response to a parameter reading request.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a storage means for storing set values of parameters related to head positioning control, a storage means for storing set values of parameters related to head positioning control, a storage means for reading out the stored set values in response to a request from an external interface, and an external Since the configuration is equipped with a reading and sending means for sending data to the interface, the setting status of the above parameters can be monitored from the external interface, and if excessive head positioning compensation is being performed, this can be detected in advance and appropriate measures can be taken. To provide a magnetic disk device with higher reliability by making it possible to perform avoidance work and inspecting the device by knowing secular changes in compensation parameters, thereby realizing optimal head positioning control. This has the effect of being able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of a control means of the magnetic disk device shown in FIG. 1, and FIG. Graph for explaining speed control in example, 4th
The figure is a diagram for explaining position control in this embodiment,
FIG. 5 is a block diagram showing an electrical configuration including the variable resistor shown in FIG. 2. Ia to IC...Magnetic disc, 2a to 2e...Recording track, 3a to 3e...Magnetic head, 4...Carriage, 7...Voice coil motor, 13...Position signal detection circuit , 14... Speed detection circuit, 17m... Learning function section, L9a-19c... Digital variable resistor,
22...Position offset signal generation circuit, 23a-23
c...Digital memory (storage means), 24a. 24b...interface receiver, 25...
Interface driver, 26.27... Digital signal switching circuit, 30... Head positioning mechanism, 40
. . . Control means, 50 . . . Reading and sending means. Agent Masuo Oiwa (and 2 others) Procedural amendment (voluntary) October 16, 1999 1. Case indication patent application No. 63-308057 3. Representative of the person making the amendment Moriya Shiki 5. A column for the subject claims and detailed description of the invention. G. Contents of amendment (1) The scope of claims will be amended as shown in the attached sheet. (2) "Switching circuit 27" on page 12, line 18 of the specification is corrected to "switching circuit 26." 2. A magnetic disk for recording claim information, a magnetic head for recording and reproducing information on this magnetic disk, a head positioning mechanism for driving this magnetic head, and a control for this head positioning mechanism. a control means for controlling the position of the magnetic head on the recording track after moving the magnetic head near the recording track on the magnetic disk at high speed while controlling the speed;
In a magnetic disk drive comprising a parameter variable means for changing parameters related to the control of the magnetic head, and a learning function unit capable of setting the parameters to optimal values in a predetermined procedure, The device is characterized by being provided with a storage means for storing, and a reading and sending means for reading out the setting values stored in the storage means in response to a request from the external interface, and sending out the read setting values to the external interface. magnetic disk device.

Claims (1)

[Claims] A magnetic disk for recording information, a magnetic head for recording and reproducing information on the magnetic disk, a head positioning mechanism for driving the magnetic head, and a magnetic disk for controlling the magnetic disk. a control means for controlling the position of the magnetic head on the recording track after moving the magnetic head near the recording track at high speed while controlling the speed;
In a magnetic disk drive that includes a parameter variable means that outputs parameters related to the control of the magnetic head, and a learning function section that can set the parameters to optimal values in a predetermined procedure, The device is characterized by being provided with a storage means for storing, and a reading and sending means for reading out the setting values stored in the storage means in response to a request from the external interface, and sending out the read setting values to the external interface. magnetic disk device.