JPS62195747A - Tape carrying controller - Google Patents

Abstract

PURPOSE:To obtain a tape carrying controller keeping tightly a tape tension at a constant force even in the rapid operating state such as start/stop of a tape by adopting the constitution that the gain constant in a compensator is correctable in response to the gain change of the mechanism. CONSTITUTION:In the constitution of the speed control system, a speed error detector 34 compares a speed command 23 and a signal 17 representing a real tape speed are compared and an obtained speed error is outputted to speed controllers 26, 27. The control constant required for the motion control of the tape is calculated at each torque of reel by a reel load sensor 33 and the result is set to the speed controllers 26, 27. In the constitution of the tension control system, a tension error detector 28 compares a tension command 24 and a signal 18 representing a real tape tension and the obtained tension error is outputted to tension controllers 29, 30. The tension controller 29 decides a correction current outputted to a winding reel motor 1 to keep the tape tension to the object value and the tension controller 30 decides the correction current outputted to a supply reel motor 2 similarly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tape transfer control device, and more specifically, it is a reel-to-reel direct tape transfer control device without a buffer, which controls tape transfer between two reels. The present invention relates to a device for transferring magnetic tape from one reel to the other reel by controlling a motor.

[Conventional technology]

A conventional device of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 53-14430.
As stated in Publication No. 7, the beginning of the tape! This is a closed-loop control method that allows the tension to be maintained constant even in motion states such as starting or stopping.

[Problem that the invention seeks to solve]

However, in actual equipment, changes in the tape on reel 1-
Due to variations in components, the closed-loop control method described above cannot maintain the tension constant in a strict sense. For example, if the component variation error is large, - the loop gain value in the closed loop control method described above will be affected,
This also occurs with τ, which destabilizes the closed-loop control system.

It is an object of the present invention to provide a tape transfer control device which is a direct tape transfer device between the tapes and which can maintain the tape tension strictly constant even in sudden movement states such as starting and stopping the tape. It is.

More specifically, it is an object of the present invention to provide an apparatus that has a high tolerance for errors caused by variations in apparatus parts.

[Means for solving problems]

The above object is achieved by configuring the compensator so that the gain constant in the compensator can be corrected in response to changes in the gain of the mechanical section.

[For stoppers]

In rapid motion conditions such as starting and stopping the tape, the tape tension compensation is not affected by load changes, and the tape tension can be maintained at a strictly constant value.

〔Example〕

The effect of tension fluctuations that can be compensated for by closed-loop control techniques is
It can be determined from the total gain value and bandwidth of this control system, and there are limits to its compensation. The point of interest of the present invention is that the tension fluctuation is not compensated for afterwards, but is reduced during the process in which the tension fluctuation occurs.

Tape tension fluctuations tend to occur during tape starting and stopping motions where a large force is applied to the tape, causing vibrations according to the natural vibration mode of the mechanical part including the tape. Therefore, if the magnitude of the tape driving force related to this natural vibration mode is reduced, the generated vibrations will also be reduced. In the present invention, tape vibration is reduced by superimposing the tape vibration waveform on the tape driving force.

[Embodiments of the invention]

The tape transfer device is a direct reel-to-reel tape transfer device, and the radius value of each reel required for tape motion control can be determined by measuring the amount of tape transferred during one rotation of each reel shaft. can.

Because of this tape transfer amount of 811 in total, both reel
Use a tachometer and a fine tachometer. In addition, the inertia of the tape is 1l in total if the tape material constant is known.
It can be calculated using a calculation formula using the reel radius value.

An embodiment of the present invention will be described below with reference to FIG. The magnetic tape 5 is wound around a supply reel 4 and a take-up reel 3, and can be transferred from one reel to the other through a tension sensor 9, a magnetic head 6, and a speed meter 8 along the way. Two reels 3゜4 are connected to the shafts of each motor 1, 2, and each is equipped with a reel tachometer (not shown).
be combined. The reel radius can be measured using the reel tachometer speed and the tachometer 8. Detector 10.
1.1. ．． 12 are for generating pulse signals from a speed tachometer, an 8° reel tachometer, and a speed tachometer, respectively.

On the other hand, the detector 13 is for converting the tension value measured by the tension sensor 13 into an electrical signal. The controller 16 receives signals 17. from each of these sensors. ．． 18.1 n, 2
．． 0 is used to control the movement of the tape. The power amplifiers 14.15 also convert the motor operation signals 21.22 of the controller 16 into dryer drive signals.

In order to clarify the features of the present invention, the operation of the controller 16 will be explained using FIG. 2.

In the configuration of the speed control system, a speed error detector 34 compares a speed target value 23 with a signal 17 indicating the actual tape speed, and the obtained speed error is output to speed controllers 26 and 27. The speed controller 2nd determines the accelerating current of the take-up reel Ko-Yu 1 [
7 and 27 determine the acceleration current of the supply reel motor 2. Here, the control constants necessary for tape motion control are calculated by the reel load sensor 33 each time each reel rotates, and are set in the speed controllers 26 and 27. The control constant is the product of a constant that determines the bandwidth of the speed control system and a constant that corrects motor load changes.

Next, in the configuration of the tension control system, a tension error detector 28 compares the tension target value 24 with a signal 18 indicating the actual tape tension, and the obtained tension error is outputted to the tension controller 29, So.

The tension controller 29 determines the correction current to be output to the take-up reel motor 1 in order to maintain the tape tension at the target value, and the tension controller 30 similarly determines the correction current to be output to the supply reel motor 2. One of the features of the present invention is that the control constant of the tension controller 29.3(') constituting the closed loop control system can be adapted to changes in the load of the reel motor. This is a point set by the reel load sensor 33 that calculates the constant.

FIG. 3 is a detailed diagram of the controller 29, including the series compensator 3:
8 is a compensator that determines the answer of 1, 1 of the control system. -゛Meanwhile: The adaptive controller 39 is a controller for compensating for the influence of changes in the mechanical load, and receives constant updates from the reel load sensor 33.

Another feature of the present invention is that a force for suppressing tape vibration is devised and superimposed on the tape driving force for starting and stopping the tape. The cause of tape tension fluctuation is the tape driving force transmitted to the tape from the two reel motors.
For example, if there is an error due to component variations in the 1-herk constant of the motor, an error driving force is generated and tape tension fluctuation occurs.

FIG. 4 shows, as an example, the error driving force when the direction of the error driving force is positive and the tape tension between the reels increases. Figure 5 shows the tape tension waveform generated as a result of Figure 4 in tM.
This is a diagram obtained by adding 18+11. FIG. 6 is an example of the superimposed signal used to reduce the vibration of the tape created from FIG. 5. When the superimposed signal shown in FIG. 6 is added to the error driving force shown in FIG. 4, the superimposed signal has exactly the opposite phase to the tape tension waveform shown in FIG. 5, and thus reduces the magnitude of the tape tension waveform.

Next, we will show the results of calculation data based on the actual machine.

FIG. 7 shows a tape tension waveform (thick line) when using a superimposed signal, which is a feature of the present invention. In addition, in order to give an error driving force in the calculation, the two motor driving forces are set to 3 in advance.
The difference is about 0%. On the other hand, Fig. 8 shows the tape tension waveform (thick line) when the superimposed signal is not used.
Comparing the figures, the magnitude of the tape tension waveform is reduced to about -.

Moreover, the thin line in FIGS. 7 and 8 is the reel motor drive torque waveform, and in the acceleration section t,1, the deformation due to the addition of the superimposed signal can be seen. Furthermore, looking at the tape tension waveform in FIG. 8, the vibration waveform is repeated several times after the acceleration period ta, which is different from the vibration damping situation due to feedback compensation. As can be seen from the above, this method is different from feedback compensation in that it suppresses the tape vibrations that occur by superimposing another force on the tape drive force. Examples will be described below. FIG. 3 is a detailed diagram of the tension controller 29, and here shows an example in which it is used in conjunction with the first characteristic technique of the present invention. Since the basic principle is different from the first characteristic technique, the effect will be doubled if both are used together. A superimposed signal generator 40 receives the tension error signal 35 and generates a superimposed signal. In particular, a minus sign is set for the reel count on the take-up side. A plus sign is set for the reel motor on the supply side. The adaptive controller 41 is a controller for optimizing the superimposed signal with respect to the tape driving force, and corrects the influence of changes in mechanical load.

According to the device described above, the constant that determines the response of the tension control system can always be maintained at an optimal setting value without being affected by motor load changes that vary depending on the amount of tape wound on the reel. Therefore, the error correction ability of the tension control system is maintained at the set value, and the tension control system is stabilized. As a result, phenomena such as an increase in tape transient vibration that appears temporarily when the motor is under load, which is observed in the prior art, can be avoided.

In addition, when an error occurs in the tape drive force of the two reel motors due to component variations in the mechanism or control circuit, and a situation occurs where tape tension fluctuation occurs, the tape tension fluctuation occurs in the tape drive force. By adding a suppressing superimposed signal, tape tension fluctuations can be effectively reduced.

Further, since the two features of the present invention have different basic principles, it is possible to use both in combination, and great effects can be obtained.

〔Effect of the invention〕

As explained hereinabove, according to the present invention, the tape tension can be maintained constant even in rapid motion states such as starting and stopping the tape.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG.
3 is a detailed diagram of the tension controller in FIG. 2, FIGS. 4 to 6 are diagrams showing the relationship between the superimposed signal and the tape tension waveform, and FIGS. 7 and 8 The figure is a diagram showing calculation results for monitoring an actual machine. 3... Take-up reel, 4... Supply reel, 5...
Magnetic tape, 6...Magnetic head, 8...Speed tachometer, 9...Intermediate tension sensor, 1; 3...Detector, 1
((...controller, 26.27...speed controller, 29
．． 30... Tension controller, 33... Reel load sensor.

Claims (1)

[Claims] 1. The reels are driven by separate motors,
Transporting the tape from one reel past the read/write head to the other reel without buffering;
A direct reel-to-reel tape transfer device for maintaining proper tape transfer at a read/write head, the tape transfer control device having tape tension control means for reducing tape tension fluctuations that occur with tape movement. . A tape transport control device, characterized in that a control constant of a tension controller included in the tension control means is set so as to compensate for the influence of a motor load that changes as the tape is wound. 2. The tension control means is configured to apply a force to the tape driving force that is in opposite phase to the tape tension fluctuation waveform that occurs as the tape is interlocked and acts to reduce the magnitude of the tape tension fluctuation waveform. 13. A tape transfer control device according to claim 12, characterized in that the tape transfer control device is configured as follows.