JPS62114171A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To solve a pin neck and to obtain a smooth speed instruction signal by obtaining a scheduled acceleration signal comparatively simply based on a stepwise speed instruction signal outputted in response to a remaining cylinder quantity. CONSTITUTION:When a controller 1 receives an object cylinder quantity, a difference between the object cylinder and the existing cylinder is set to a remaining cylinder counter (not shown) built therein. A speed pattern generator of the controller 1 sends the stepwise speed instruction signal 17 in digital quantity to a D/A converter depending on the remaining cylinder quantity. The converter 3 converts the signal 17 into an analog signal 18. When the access mechanism starts seeking at first, a cylinder pulse 19 is generated from a position detector 8 every time a servo head crosses the cylinder. When the controller 1 receives the cylinder pulse 19, the content of the remaining cylinder counte is decremented by 1 and the speed instruction signal is outputted according to the cylinder quantity.

Description

Detailed Description of the Invention [Field of Application of the Invention] +5 The present invention relates to a magnetic disk device, and particularly to a speed control circuit W8 of an access mechanism suitable for high-speed, high-precision access.

[Background of the invention]

To control the speed of the positioning mechanism in conventional magnetic disk drives, the speed of the access mechanism is predetermined stepwise for each remaining cylinder up to the target cylinder, and then the speed of the carriage carriage on which the head is mounted is determined in advance. The speed signals were synthesized and used as a speed command signal. However, with this method, it is not possible to produce five consecutive step-like speed signals, and the carriage actuator.

A certain voice coil motor has large acceleration fluctuations.

resulting in mechanical resonance.

There was a drawback that the positioning accuracy deteriorated.

Therefore, the speed, speed, and high precision access mechanism.

Prior art for control (Japanese Unexamined Patent Publication No. 177571/1983)
.

In this case, the ROM (lj-do) is stored in advance for each remaining cylinder.

Staircase speed recorded in (Only Memory) etc.

Continuously changes from the acceleration command signal and scheduled acceleration.

It would be beneficial to provide a smooth speed command signal that would

For example, FIG. 2 is a speed control block diagram showing a conventional technique, in which step-like speeds and accelerations are generated for each remaining cylinder by a speed control generator and an acceleration pattern generator in the controller 1, respectively. Each pattern is converted from digital to analog quantity via D/A comparator 2.5.

, and the output of acceleration is configured with an integrator.

The output signal (smooth) is passed through the smoother circuit 4.

(the signal) is combined with the speed signal and used as the speed signal command.

do.

In the above configuration, there is a D/A comparator for speed and acceleration.

- It is necessary to provide the data 5 and 2 respectively. D/A.

Voice coil motor controller including converter.

In order to convert the rollers into LSi, K will do as much as possible.

Reduce the number of bin necks and high density.

It is important to resolve the problems that impede progress. .

[Purpose of the invention]

The purpose of the present invention is to convert one D/A converter from a stepped speed command signal recorded in advance in a ROM etc. for each remaining cylinder and a planned acceleration and K created using the speed command signal. It is possible to solve the bottle neck problem and the packaging density problem, and provide a smooth speed command signal.

[Summary of the invention]

The speed command for speed control is determined stepwise according to the acceleration capability of the access mechanism. - On the one hand, K to make the stepwise speed command a smooth curve.

requires a planned acceleration. Said speed, acceleration.

Each of the 5 units has a D/A converter to convert the degree from digital to analog quantity. deer.

However, there is a close relationship between the speed and acceleration.

A simple bar that uses its velocity signal to aim acceleration.

This is the result of focusing on the fact that it can be configured using software.

It was. The present invention uses the output of the velocity pattern generator.

using a predetermined acceleration pattern.

The hardware circuit to create and the drive for this circuit.

Includes timing control signals and analog switches.

It is characterized by having the following features:

[Embodiment of the invention] 15 Examples of the present invention are shown in FIGS. 1, 5, and 4.

This will be explained using FIG.

FIG. 1 shows a block diagram of speed control in an access mechanism of a magnetic disk device.

Read/write head of magnetic disk device and 5.

The servo head and the servo head are mounted on a carriage and are moved by a voice coil motor 7. Here, the read/write head.

The servo head and carriage together are called an access mechanism. Below, move from the current cylinder to the next target cylinder 5 (
Regarding speed control during seek).

I will explain.

Controller 1 receives the target signal from the host system.

When it receives the amount of data, it is built into the controller 1.

cylinders remaining counter (not shown).

, the difference between the target cylinder and the current cylinder (moving cylinder).

number of cylinders).

By the speed pattern generator of controller 1.

A stepped speed command signal depending on the amount of remaining cylinders.

17 in digital quantity 1)/A converter 5 K send.

1°D/A:Y inverter 5 converts digital signal 17 into 7 analog signal 18.

When the access mechanism first starts a seek operation, the position detector 8 and the track crossing detector generate a cylinder pulse 19 that is generated every time the servo head crosses a cylinder.The controller 1 receives this cylinder pulse 19.・When the remaining cylinders are taken, the content of the remaining cylinder counter is decremented by 1. and a speed command signal ・ is output depending on the amount of remaining cylinders. 5
Figure 3 shows the output signals of the main blocks, and will be explained below using Figures 1 and 5.

I will clarify.

The speed is controlled based on the amount of remaining cylinders.

At a certain point in time, the expected acceleration signal 21 is a servo.

as a function of the position where the head is positioned.

Acceleration generator (1) 11, acceleration generator υ) 12, hole opening.

The signals are generated by the control switches 15, 14 and the control signals 22, 25.

live. Note that the feed forward circuit 15 is as follows.

It provides a highly accurate smoother (consisting of a product and a 5-divider) output with a small speed deviation, and allows the speed command to be followed accurately.

The smoother circuit 4 receives the planned acceleration signal 21, performs integration for each cylinder pulse 19, and absorbs speed changes between cylinders, and the stepped speed command signal 1B is as follows:
This results in a smooth speed command signal 20.

This speed command signal 20 is transmitted to the error amplifier 5 and the error amplifier 5.

The access mechanism is driven by a voice coil motor 7° via a power amplifier 6. Here, the output of the power amplifier and
The output of the position detector 8 is used to detect the speed.

9 to detect the speed. Its detection speed.

is input to the position before the error amplifier 5 to calculate the speed.

constitutes feedback.

FIG. 4 shows a specific circuit configuration of the present invention.

Figure 5 is for controlling analog switches 15 and 14.

A time chart of control signals 22 and 25 is shown. .

The main parts of this circuit are the acceleration generator (1) 11;

degree generator (2) 12, analog switch 15, 1
4. Control.

The signals 22 and 25 are configured. Here, the acceleration generator,
.

(1) 11, acceleration generator (2) 12 is arithmetic intensifier 24
, resistance 2, operational amplifier 25, resistance ratio 1. Constructed by 几4.

When the controller 1 detects point A, the control signal 22 is set to a low level until the acceleration generator (2) 12 outputs the signal, and the gain at this time becomes ('+%)·Vi.

Therefore, to adjust the gain, you can easily change Vi, R1, and R4 in nine easy steps. 5 On the other hand, if controller 1 detects point B.

Move from speed control to position control. Control at this point.

The signal 22 is set to high level, and the control signal 25 is turned on.

Pressure level.

At this time, the acceleration generator (1) 11 is connected to the signal line 21.
° is output, and the gain is (1+ /B,,) x (D/
A Compa.

- output potential of the motor 5). Therefore, said acceleration.

Change the resistors R1 and R2 in the same way as the frequency generator 0).

This makes it possible to adjust the gain.

As described above, according to this embodiment, the planned acceleration signal can be obtained relatively easily based on the step-like speed command signal output according to the % remaining series and 5 degrees, and as a result, a smooth speed command can be obtained. It is possible to generate a signal.

Therefore, when converting the control circuit of a voice coil motor with a built-in D/A:1 inverter 5 into an LSi (remove the controller 1) according to the present invention, problems such as an increase in the number of bins, a mounting area, and It is possible to solve problems such as an increase in the amount of noise, and prevent abnormal vibrations of the access mechanism.

〔Effect of the invention〕

According to the present invention, the pin neck is solved and cleared.

Faster, because you can get a kana speed command.

It is possible to control the speed of the access mechanism with high precision.

It became Noh. 10

[Brief explanation of drawings]

FIG. 1 is a diagram of speed control according to an embodiment of the present invention. The lock diagram, Figure 2, is a block diagram of conventional speed control. Figure 5 shows the output signals of the main blocks. Figure 4 is a circuit diagram of an acceleration generator, etc.
The figure is a timing diagram of control signals. DESCRIPTION OF SYMBOLS 1... Controller, 4... Smoother circuit, 5... Air amplifier, 6... Power amplifier, 8... 7... Voice coil motor, 8... Position detector, 9... Speed detector, 22, 25... control signal. 24, 25... operational amplifier.
5 Figure 1 Figure 2 Mouth Figure 3 Figure 4 Figure 5 71 B L

Claims (1)

[Claims] 1. In a magnetic disk device in which a read/write head and a servo head are positioned on a target cylinder using a track servo method to read and write data, a predetermined speed pattern is generated using the output of a speed pattern generator. a hardware circuit that creates an acceleration pattern;
Equipped with a control signal and an analog switch to control the drive timing of the hardware circuit, it can smoothly operate at high speeds.
A magnetic disk device characterized by highly accurate speed control.