JP3093741B2 - Magnetic tape running control method and control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic tape running control method and control apparatus.

[0002]

2. Description of the Related Art There is known a magnetic tape device in which a file reel and a machine reel are driven by a file reel motor and a machine reel motor, and a magnetic tape runs between the file reel and the machine reel.

A driver and a DAC are sequentially connected to the file reel motor and the machine reel motor, respectively. Both DACs are connected to one CPU.

[0004] The CPU theoretically calculates the value of the current flowing through both motors, converts the calculation result into an analog signal by each DAC, and then flows the current according to the theoretical value to each motor via a driver. .

[0005]

However, due to variations in torque constants between the file reel motor and the machine reel motor, errors in drivers and DACs, friction, and the like, the torque generated between the file reel motor and the machine reel motor is different. Occurs. If there is a difference between the generated torques of the two motors, it will adversely affect the speed control of the magnetic tape.

If the motors, drivers, DACs, and the like are strictly selected from the beginning and manufactured, there is no difference in the generated torque between the two motors.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape traveling control method and a control apparatus in which the accuracy of speed control of a magnetic tape is improved by eliminating the difference in generated torque between a file reel motor and a machine reel motor at low cost. I will provide a.

[0008]

In order to achieve this object, according to the present invention, the drive of a file reel motor and a machine reel motor is controlled so as to correct the difference in generated torque between the file reel motor and the machine reel motor. Is what you do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic tape device to which a magnetic tape traveling control device according to the present invention is applied.

This magnetic tape device has a file reel 1
A machine reel 4, a magnetic tape 2 running between the file reel 1 and the machine reel 4, a file reel motor 6 for driving the file reel 1, and a machine reel motor 7 for driving the machine reel 4. ing.

A file reel motor 6, a driver 8, and a DAC 10 are sequentially connected to the file reel 1. On the other hand, a machine reel motor 7, a driver 9, and a DAC 11 are sequentially connected to the machine reel 4. A CPU 12 as a calculation unit and a drive control unit is connected to both DACs 10 and 11.

The CPU 12 has a function of calculating a ratio between the torques generated by the file reel motor 6 and the machine reel motor 7 as calculation means.

The ratio of the torque generated between the file reel motor 6 and the machine reel motor 7 is equal to the ratio of the amount of current flowing through the file reel motor 6 and the machine reel motor 7. Therefore, the CPU 12 reads the values from the DACs 10 and 11 to measure the current flowing through the file reel motor 6 and the machine reel motor 7.

The difference between the torque generated between the machine reel motor 7 and the file reel motor 6 is corrected by setting the current value of the machine reel motor 6 to the theoretical value and changing the amount of current of the file reel motor 6. ing.

The value of the current flowing through the machine reel motor 7 is
The value is the same as the theoretical value B obtained by theoretical calculation as flowing to the machine reel motor 7. On the other hand, the current flowing through the file reel motor 6 is a value A different from the theoretical value of the file reel motor 6.

The CPU 12 is set to calculate the current amount ratio A / B. This ratio A / B becomes the torque ratio.

Further, the CPU 12 calculates a control current value D which is actually supplied to the file reel motor 6 by multiplying the torque ratio A / B by a theoretical value C of the file reel motor 6 as drive control means. The setting is made so as to instruct the DAC 10 to flow the current value D to the file reel motor 6.

A memory 13 is connected to the CPU 12 as storage means. This memory 13 stores the CPU 12
The torque ratio A / B calculated in step (1) is received from the CPU 12 and stored.

The file reel motor 6 is provided with a file tach sensor 3 which detects the rotation speed and notifies the CPU 12 of the rotation speed. The machine reel motor 7 is provided with a machine tach sensor 5 that detects the rotation speed and notifies the CPU 12 of the rotation speed.

The timing at which the CPU 12 controls the speed of the magnetic tape 2 is when a signal from the file tach sensor 3 disposed on the file reel motor 6 interrupts the CPU 12. That is, when an interrupt signal is input from the file tacho sensor 3, the CPU 12 reads the torque ratio A / B from the memory 13 and calculates the control current value D flowing to the file reel motor 6.

In the magnetic tape device configured as described above, control is performed so as to correct the difference in the torque generated between the file reel motor 6 and the machine reel motor 7 as follows.

The steps from the calculation of the ratio of the generated torque difference between the file reel motor 6 and the machine reel motor 7 to the storage of the calculation result will be described with reference to FIGS.

First, as shown in step 201 of FIG. 2, the magnetic tape 2 is inserted into the magnetic tape device shown in FIG. The magnetic tape 2 has its BOT (Beginning).
Of Tape) is prevented from moving by F / W control, that is, by gradually changing the current flowing through the file reel motor 6. The current value at the time of the stoppage is a value A different from the theoretical value as described later.

In this state, as shown in step 202, the CPU 12 reads the values from the DACs 10 and 11 to measure the current flowing through the file reel motor 6 and the machine reel motor 7.

The value of the current flowing through the machine reel motor 7 is
The value is the same as the theoretical value B obtained by theoretical calculation so as to flow through the machine reel motor 7. File reel motor 6
Is a value A different from the theoretical value of the file reel motor 6 itself.

Next, as shown in step 203, the CP
U12 calculates A / B. A / B is the torque ratio.

Next, as shown in step 204, the CP
U12 stores the calculated torque ratio A / B in the memory 13
To save.

Based on the torque ratio A / B calculated in this manner, the file reel motor 6 and the machine reel motor 7
The speed control of the magnetic tape 2 for correcting the difference between the generated torque and that of the magnetic tape 2 will be described with reference to FIGS.

Now, as shown in step 301 of FIG.
An interrupt signal from the file tach sensor 3 is
When the process is started, the speed of the magnetic tape 2 and the amount of the magnetic tape 2 wound on the file reel motor 6 and the machine reel motor 7 are detected by a known method.

Next, as shown in step 302, the file reel motor 6 and the machine reel motor 6 are determined based on the speed of the magnetic tape 2 and the amounts of the magnetic tape 2 wound on the file reel motor 6 and the machine reel motor 7. 7 is theoretically calculated to obtain a theoretical value. The theoretical value of the file reel motor 6 is C.

Next, as shown in step 303, the torque ratio A / B is read from the memory 13, and the value D obtained by multiplying the torque ratio A / B by the theoretical value C of the file reel motor 6 is the theoretical value. Instead of C, the theoretical value of the file reel motor 6 is used.

Next, as shown in step 304, the control current value D of the file reel motor 6 is written into the DAC 10. As a result, the current amount of the control current value D is changed by the file reel motor 6.

As described above, based on the value D obtained by multiplying the ratio A / B of the torque generated between the file reel motor 6 and the machine reel motor 7 by the theoretical value C of the file reel motor 6, the file reel motor 6 The control current amount is changed, whereby the difference in the generated torque with the machine reel motor 7 is corrected, and the accuracy of the speed control of the magnetic tape 2 is improved.

The present invention is not limited to the above-described embodiment, and various modifications can be made.

For example, in the above-described embodiment, the current value of the machine reel motor 6 is set to the theoretical value, and the generated torque is balanced by changing the amount of current flowing to the file reel motor 7, but the present invention is not limited to this. Without
The current value of the file reel motor 6 is set to the theoretical value,
The amount of current flowing through the machine reel motor 7 may be changed.

In the above-described embodiment, the ratio of the value of the current flowing through the file reel motor 6 to the machine reel motor 7 is used as the torque ratio. However, the present invention is not limited to this. The torque ratio may be obtained by detecting.

In the above-described embodiment, the torque ratio A / B is stored in the memory 13. However, the present invention is not limited to this, and the processing may be performed only by the CPU 12 without providing the memory 13.

[0039]

As described above, according to the present invention, the difference in torque generated between the file reel motor and the machine reel motor can be corrected, so that the accuracy of the speed control of the magnetic tape can be improved.

Further, since the allowable range of the difference between the torque generated between the file reel motor and the machine reel motor can be expanded, the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic tape device to which an embodiment of a magnetic tape traveling control device of the present invention is applied.

FIG. 2 is a flowchart showing a procedure for calculating a generated torque ratio in the magnetic tape device of FIG. 1;

FIG. 3 is a flowchart showing a procedure for calculating a control current value of a file reel motor in the magnetic tape device of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 file reel 2 magnetic tape 3 file tach sensor 4 machine reel 5 machine tach sensor 6 file reel motor 7 machine reel motor 8 driver 9 driver 10 DAC 11 DAC 12 CPU (calculation means, drive control means) 13 memory (storage means)

Claims (6)

(57) [Claims] 1. A magnetic tape running control method for a magnetic tape device in which a file reel and a machine reel are driven by a file reel motor and a machine reel motor to run a magnetic tape between the file reel and the machine reel. Generation of file reel motor and machine reel motor
The drive of the file reel motor or the machine reel motor is controlled so as to determine the ratio of torque and to correct the difference in the generated torque between the file reel motor and the machine reel motor using the torque ratio. And a magnetic tape running control method. 2. A method for controlling the driving of the file reel motor and the machine reel motor so as to correct the difference in generated torque between the file reel motor and the machine reel motor. 2. The magnetic tape running control method according to claim 1, wherein a current of an amount corresponding to a theoretical value is supplied to one of the motors, and a current supplied to the other motor is changed. 3. A magnetic tape travel control device in a magnetic tape device for driving a file reel and a machine reel by a file reel motor and a machine reel motor to travel a magnetic tape between the file reel and the machine reel. Calculating means for calculating the ratio of the generated torque between the file reel motor and the machine reel motor; and correcting the difference in the generated torque between the file reel motor and the machine reel motor using the torque ratio obtained by the calculating means. A magnetic tape characterized by comprising drive control means for supplying a current of an amount corresponding to a theoretical value to one of a file reel motor or a machine reel motor and changing the amount of current supplied to the other motor. Travel control device. 4. The magnetic tape running control device according to claim 3, further comprising storage means for storing the torque ratio obtained by the calculation means. 5. The magnetic tape running device according to claim 3, wherein the calculating means is set so that a ratio of a current value flowing through the file reel motor to a machine reel motor is used as a torque ratio. Control device. 6. The drive control means passes a current according to the theoretical value of one of the file reel motor and the machine reel motor to the other motor, and multiplies the theoretical value of the motor by the torque ratio to the other motor. The magnetic tape running control device according to any one of claims 3 to 5, wherein the current is set so as to flow an amount of the current value obtained by the operation.