JPH0258775A - System for accelerating head driving motor - Google Patents

Abstract

PURPOSE:To prevent a temperature rise in a drive circuit by providing a means which calculates the speed change of an actuate motor at the time of acceleration from delaying time and the maximum speed. CONSTITUTION:An aimed position signal from a host device is inputted to a microprocessor 2, where the difference between the aimed position signal and the current position signal of a head obtained from a position detection circuit 9 is calculated, through an interface circuit 1. A calculated result of the microprocessor 2 is sent to a speed pattern generation circuit 3 as a positional difference signal and converted into a speed pattern signal. The speed pattern signal is sent to a differential amplifier 4. Then a position-speed conversion circuit 10 sends the difference between the speed pattern signal and a detected speed signal converted into a speed signal to an actuate motor drive circuit 5 as a speed difference signal and the circuit 5 drives a voice coil motor 8 by outputting the drive signal corresponding to the speed difference signal, so that a head 6 can be moved by means of arms 12a and 12b moving around a pivot 7. Therefore, the drive current can be reduced and a temperature rise in the drive circuit can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an acceleration drive system for an actuate motor, which is a technical field.

BACKGROUND ART Conventionally, acceleration driving of this type of head driving actuator is performed as follows. That is, when the amount of deviation between the current head position and the target position to which the head is about to move is obtained from the upper host device to which the magnetic storage device is connected, a predetermined speed pattern is generated from the CPU and fed back. The speed of the actuator I/motor is controlled so that the difference between the detected speed signal corresponding to the actual head speed and the speed tip turn signal is always canceled.

FIG. 2 shows an example of the waveform of the speed pattern in this case, where the speed pattern signal VTI generated by the CPU is indicated by the solid line h, and the actual head detected speed pattern signal ■S1
is indicated by a dotted line. This figure shows an example where the positional deviation amount (゛) is given so that the head reaches its maximum speed. Therefore, the speed pattern signal Vll generated from the CPU sharply increases from zero speed to the maximum speed. It is said to be a rising waveform pattern.

In the conventional actuator motor speed control method described above, during acceleration, the detected speed signal S1 is the speed control pattern signal V.
Until reaching T1, there is a delay time t as shown in FIG. This is due to the inertial weight of the head and actuator motor.

During this delay time t, the amount of deviation between the speed pattern signal and the detected speed signal is large, so a large current flows through the actuator motor. When the detected speed signal reaches the speed pattern signal, the current suddenly decreases. If the deviation amount is small and the maximum speed is not reached, as the detected speed signal approaches the speed pattern signal, deceleration begins, and the direction of current flow is rapidly reversed.

Therefore, during acceleration, in addition to the disadvantage that the temperature of the drive circuit of the actuate motor increases, immediately after the head speed reaches the maximum speed of the speed pattern signal, vibrations of the head and actuate motor occur, causing the head to move. The disadvantage is that the vibration noise generated inside becomes louder.

However, the present invention has been made to solve the drawbacks of the conventional ones, and its purpose is to suppress the temperature rise of the drive circuit by reducing the drive current as much as possible. The object of the present invention is to provide an acceleration drive method for a head drive motor that allows the acceleration of the head drive motor.

Another object of the present invention is to provide an acceleration drive method for a head drive motor that is capable of suppressing vibration by eliminating sudden changes in current when transitioning from acceleration operation to constant speed operation or deceleration operation. .

Structure of the Invention The acceleration drive method of the head drive motor according to the present invention uses two standard speed patterns that rise sharply from zero speed to maximum speed in order to measure the delay time of the head drive actuator motor during acceleration. a pre-stored storage means;
measuring means for measuring a delay time from when the actuate motor stops until it reaches the maximum speed when the actuate motor is driven using the reference speed pattern; and means for generating a speed pattern suitable for the actuator motor using the calculated speed change. The present invention is characterized in that the actuate motor is accelerated and driven using a speed pattern.

X-ri week Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. A target position signal sent from a host device (not shown) passes through an interface circuit 1 and is input to a microprocessor 2. The microprocessor 2 receives the current position signal of the head 6 obtained by the position detection circuit 9;
The speed pattern generation circuit 3 calculates the difference with the target position signal.
sends a position difference signal to. The speed pattern generation circuit 3 converts the position difference signal into a speed pattern signal and sends it to the differential amplifier 4.

The differential amplifier 4 detects the position of the head 6 by the position detection circuit 9, and then drives the actuator motor by using the difference between the detected speed signal converted into a speed signal by the position-velocity conversion circuit 10 and the speed pattern signal as a speed difference signal. Send to circuit 5. Actuate motor drive circuit 5 outputs a drive signal corresponding to the speed difference signal to drive voice coil motor 8, and moves head 6 via arms 12a and 12b centered on pivot 7. These operations are controlled by a series of programs stored in memory 1 as data in advance.

Next, the operation of the blocks in FIG. 1 will be explained in detail with reference to the waveforms of the velocity patterns in FIGS. 2 and 3.

The operation can be roughly divided into voice coil motor8. arm 12a,
12b, the pivot 7, and the head 6. The first speed operation is an initial operation for understanding the characteristics of the head 12b, the pivot 7, and the head 6, and the normal second speed operation is performed after the first speed operation is completed.

The first speed operation will be explained with reference to FIG.

The first speed operation is performed independently of the post device, and is an initial operation for determining the delay time t caused by the inertial weight of the head, actuate motor, etc.
This is performed in order to find the conditions of the speed pattern signal to be used in the subsequent second speed operation.

The microprocessor 2 outputs a reference speed pattern signal VT1 that rises steeply from zero speed to the maximum speed, and then outputs the detected speed signal VT1 obtained via the position-velocity conversion circuit 10.
S1 is taken in and VT1 and VS1 are compared. When VTl and VSl become equal, a delay time t is calculated, and the slope Δ■/Δt of the detected speed signal VS1 is calculated from this delay time t.

After that, the microprocessor 2 outputs the speed pattern signal VTI.
A deceleration pattern is output as shown in the figure, and the head 6 is stopped.

The reference speed pattern signal VTI is stored in the memory 11 in advance and speed profile data is used.

The first speed operation, which is the initial operation, is performed one or more times with the forward direction and reverse direction as one set. The aforementioned processes such as comparing VTl and vsi, calculating the time t at which VTl and VSl match, and calculating the slope Δ■/Δt of VSl can be easily realized by a combination of an A-D converter and a microprocessor. Therefore, the details will be omitted.

The second speed operation will be explained with reference to FIG.

After the first speed operation is completed, all movements of the head 6 are performed at the second speed operation. In the second speed operation, when accelerating from zero speed, the microprocessor 2 receives the speed data signal VT2 using the slope Δ■/Δt of the detected speed signal VS1 obtained in the first speed operation as an acceleration profile.
It is outputted from and applied to the differential amplifier 4.

By doing this, the difference between the speed pattern signal applied from the start of acceleration and the detected speed pattern signal becomes very small, so it is possible to drive the actuator motor with the minimum drive current, and it is also possible to drive the actuator motor at a constant speed or from acceleration to constant speed. It is possible to eliminate the sudden current thinning when deceleration starts. Therefore, it is possible to suppress the temperature rise and vibration of the drive circuit as much as possible.

The speed data signal VT1 used for the first speed operation is not limited to the data in the memory 11. Further, the comparison between the position signal and the target position signal and the output of the position difference signal are not limited to the use of the microprocessor 2. Second
After the speed operation is completed, the data signal VT2 becomes Δ as shown in FIG.
The present invention is not limited to a straight line pattern having a slope of (2)/Δt, and it is also possible to use a speed data signal obtained by modifying ΔV/Δt.

Note that in the above embodiment, during the first speed operation, a steeply falling speed pattern is not generated during deceleration;
The slope of the speed during deceleration may be calculated using this steeply falling speed pattern, and a deceleration speed pattern having this speed slope may be generated and applied during subsequent deceleration operations.

As described in detail, according to the present invention, the speed during acceleration determined by the physical weight of the actuate motor itself, the inertial weight of the mechanical system attached to the actuate motor such as the arm and head, and the frictional force is Since it is possible to find the slope 8■/Δt and determine the acceleration pattern of the speed pattern signal according to 8■/Δt, the difference between the speed pattern signal and the detected speed signal is made very small from the start of acceleration. This has the effect that the actuate motor can be driven at the maximum speed and slope with the minimum drive current. Therefore, the temperature rise of the actuator motor drive circuit is suppressed, there is no sudden change in current when changing from acceleration to constant speed or deceleration, and it is possible to suppress vibration and suppress vibration noise.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing an example of a speed pattern waveform during initial operation used in an embodiment of the present invention, and FIG. 3 is a diagram showing an example of a speed pattern waveform used in an embodiment of the present invention. 2 is a diagram showing an example of a speed pattern waveform during a speed operation of No. 2; FIG. Explanation of symbols of main parts 2...Microprocessor 3...Speed pattern generation circuit 4...Differential amplifier 5...Actuator drive circuit 6... ...
Head 8...Actuate motor 9...Position detection circuit 10...Position-speed conversion circuit

Claims (1)

[Claims] (1) In order to measure the delay time of the head drive actuator motor during acceleration, a storage means that stores in advance a reference speed pattern that rises sharply from zero speed to maximum speed, and a measuring means for measuring a delay time from when the actuate motor stops until it reaches the maximum speed when the actuate motor is driven; The actuator motor includes a calculation means for calculating a speed change during acceleration of the motor, and a means for generating a speed pattern suitable for the actuator motor using the calculated speed change. An acceleration drive method for a head drive motor, characterized in that the motor is accelerated.