KR100635073B1 - Strip Tension Control Devices and Method of Continuous Processing Line by using Looper - Google Patents

Abstract

The present invention relates to a device and method for controlling tension of a steel sheet in a continuous process using a looper, and in particular, an apparatus for controlling the tension of a steel sheet by a looper used for storing the steel sheet in a cold rolling post-treatment process of a steel mill The present invention relates to a method of controlling tension.

Steel plate tension control device of the continuous process using the looper of the present invention comprises a comparator, a PI controller and an adder,

The comparator receives the input of the tension reference value (T _2ref ) set by the tension gauge tension meter 28 and the tension map of the line installed outside the looper No. 2, and outputs it to the PI controller.

The PI controller receives and amplifies the comparison error of the comparator, multiplies it by the adjustment gain, and outputs the multiplier to the adder installed at the input of the speed control reference value setter of each fixed helper roll driving motor.

The adder is configured to input the value received from the PI controller to the speed control reference value setter of the fixed helper roll driving motor in addition to the speed control reference value of the original fixed helper roll driving motor.

On the other hand, the steel sheet tension control method of the continuous process using the looper of the present invention

Measuring the tension value from the tension gauge tension meter 28 installed outside the looper 2;

Comparing the measured value with the tension reference value T _2ref set by the tension map of the line, calculating an error, and amplifying it;

Multiplying the amplified error by an adjustment gain value;

And adding the value as part of a speed control reference value of each fixed helper roll driving motor.

According to the present invention as described above, the tension disturbance is reduced, the response is improved, and the interference phenomenon between the tension control and other control, in particular, the interference phenomenon between the tension control and the carriage position control operated in the looper control, Due to the stability of the tension control system, it prevents the occurrence of scratches, buckles, etc., which has a very significant effect on operation and quality control.

Looper, tension, control

Description

Strip tension control devices and method of continuous processing line by using looper

1 is a block diagram of a control device used for looper control

2 is a configuration diagram of a looper including k fixed helpers with a drive motor attached thereto;

3 is a configuration diagram of the looper control equipment improved by the tension disturbance control method generated in the outer looper

Figure 4 is a comparison graph of the tension control performance before and after the implementation of the present invention

5 is a graph showing carriage position control performance expected after implementation of the present invention.

6 is a graph showing the carriage position control performance before implementation of the present invention;

<Description of Symbols for Major Parts of Drawings>

24, 31: Looper Carriage

18: tension controller (ATR) 19: speed controller

20: current controller 21: drive motor

25: moving roll 26: fixed roll

27: fixed roll drive motor 28: tension meter

29: current controller 30: speed controller

32: speed control reference value 33: tension feedback

34: Position difference between carriages 35: Inertia compensation control input

36: carriage position control input 37: inertia load inertia (GD2)

38: tension control device

The present invention relates to a device and method for controlling tension of a steel sheet in a continuous process using a looper, and in particular, an apparatus for controlling the tension of a steel sheet by a looper used for storing the steel sheet in a cold rolling post-treatment process of a steel mill The present invention relates to a method of controlling tension.

In general, in the continuous processing line of the cold rolling process, a looper is installed as a facility for storing steel sheets to continuously perform the main process, and during the time for processing on the entry side such as coil removal, reentry, coil welding, and welding mill passing Use the steel sheet in the looper or store the steel sheet in the looper. That is, a representative example of a cold rolling after-treatment process using a looper as described above may include a continuous annealing line (CAL), a continuous hot dip plating line (CGL), etc. In these processes, Tensioning and feeding at pre-designed line speeds may be necessary for temporary storage. At this time, the looper moves the carriage to store the steel plate or releases the stored steel plate while performing the work requiring the speed acceleration and deceleration of the line at the entry and exit side of the continuous line, so that the continuous processing of the main process is prevented.

The line driving equipment on the entry and exit side including the looper is composed of rolls of various sizes, some of which are driven by the drive by the rotational inertia, and some are driven purely by the tension of the steel sheet. In the case of the acceleration and deceleration of the vertical line of the continuous line and the exit line speed, the tension of the steel sheet must be worked for the roll inertia which is not necessary during the normal speed operation.

Since this tension disturbance is largely controlled by a tension control device such as a looper, the amount finally entering the main process section is only a fraction of the tension created at the outer edge of the looper. On the other hand, when the tension of the outer looper is excessively formed, such as the tension of the tension meter 28 TM2 of FIG. 1, it adversely affects an adjacent process.

That is, in the above-mentioned processes, problems in operation management and quality control may occur due to the excessive or excessive tension applied to the steel sheet, which is caused by the heat buckle in the continuous annealing line (CAL) and continuous molten plating line (CGL). Problems such as heat buckles and cooling buckles, width reduction and stretching may occur, and common problems of all lines include problems such as strip walking and scratches due to slip. May occur. Therefore, the control of the looper is an essential element in the continuous process line.

A conventional typical looper control system has a moving roll 25, a fixed roll 26, and a moving roll, which are helper rolls for winding and storing steel sheets, as shown in the configuration diagram of the control equipment used for the looper control of FIG. 1. 25 is composed of a looper carriage (24, 31) for conveying up and down, a drive motor (21), a drum (22), a fixed roll drive motor (27) for driving a fixed helper roll, a tension gauge (28), etc. have.

In the conventional looper control system, the control operation is generated by the drive motor 21 and the fixed roll drive motor 27, and control commands for the looper control system are performed by the tension controller 18 and the looper entry / exit speed control reference value 32. Feedforward control, electric tie control command for position difference between carriages 34 between a plurality of looper carriages, and the like are given as speed inputs or torque (current) control inputs, and various compensation controls are provided. The inputs are added to form a control system.

The adjustment value to be adjusted in this system in order to control the tension in accordance with the tension reference value given in the control system as shown in Figure 1 is the adjustment value of the tension controller 18, the position difference between the carriage 34, the carriage position control input ( 36 is an adjustment value of the inertia compensation control input 35 in the acceleration / deceleration section. In such a tension control system, the stability of the tension control system is determined according to the appropriateness of the adjustment value of the controller, and the instability of the tension control system may cause problems such as scratch, buckle, operation management, and quality control. do.

In the looper tension control system, the tension is mainly controlled by the drive control of the carriage. Here, the outermost looper from the main process is looper 1 on the entry, looper 2 on the exit, or looper 3 on the three. The following description will be based on the exit.

In this way, the largest tension disturbance is input to the outermost looper from the main process, but according to the conventional apparatus and method, there is a problem in that the tension disturbance becomes larger than necessary because the driving control ability of the carriage to offset it is extremely limited. One of the factors limiting the performance of the carriage drive control is that the reduction ratio of the drive motor is very large, which causes a problem in that the response is degraded.

In addition, there is a problem that an interference phenomenon between the tension control and other control, in particular, an interference phenomenon between the tension control and the carriage position control which is operated in the looper control occurs.

Therefore, problems such as scratch, buckle, operation management, quality control due to the instability of the tension control system as described above.

The present invention has been made to solve the above problems, in order to overcome the limitation of the tension control by the carriage drive control, the drive control by changing the speed control reference value of the fixed helper roll of the looper, and the influence of the control It is an object of the present invention to provide an apparatus and method for controlling tension of a steel sheet in a continuous process using a looper that can mitigate the tension transition phenomenon in a speed transition section of a line by maximally suppressing transmission to an adjacent carriage.

Steel plate tension control device of the continuous process using the looper of the present invention in order to achieve the above object is composed of a comparator, a PI controller and an adder, as shown in the block diagram of the looper control equipment of FIG.

The comparator receives the input of the tension reference value (T _2ref ) set by the tension gauge tension meter 28 and the tension map of the line installed outside the looper No. 2, and outputs it to the PI controller.

The PI controller receives and amplifies the comparison error of the comparator, multiplies it by the adjustment gain, and outputs the multiplier to the adder installed at the input of the speed control reference value setter of each fixed helper roll driving motor.

The adder is configured to input the value received from the PI controller to the speed control reference value setter of the fixed helper roll driving motor in addition to the speed control reference value of the original fixed helper roll driving motor.

On the other hand, the steel sheet tension control method of the continuous process using the looper of the present invention

Measuring the tension value from the tension gauge tension meter 28 installed outside the looper 2;

Comparing the measured value with the tension reference value T _2ref set by the tension map of the line, calculating an error, and amplifying it;

Multiplying the amplified error by an adjustment gain value;

And adding the value as part of a speed control reference value of each fixed helper roll driving motor.

On the other hand, the above-mentioned adjustment gain increases the speed compensation value for tension control at a constant interval from 0, so that the adjustment gain (G _k ) becomes 1 in the k-th final roll so as to control the tension in the drive motor of the i-th fixed helper roll. The adjustment gain G _i multiplied by the speed compensation value is determined as in Equation 1 below.

The operation of the control device and method of the present invention having the configuration as described above will be described.

First, a calculation process performed in the tension control device 38 for suppressing the tension disturbance formed on the outside of the outer looper, and the tension value of the line by measuring the tension value from the tension meter 28, which is a tension meter installed on the outside of the looper No. 2 _Compute the error by comparing the tension reference value (T _2ref ) set by the step, and amplify the error using the PI controller, and multiply the adjustment gain to give the speed correction value differently according to the position of the fixed helper roll. It is a process to add as a part of the speed control reference value of each fixed helper roll drive motor.

Here, the adjustment gain is determined differently depending on the position of the fixed helper roll, which is to suppress the transmission of the influence of the control to the adjacent looper as much as possible. The principle is as follows.

FIG. 2 is a configuration diagram of a looper including k fixed helpers with a drive motor, wherein a speed compensation value for tension control is fixed at a predetermined interval from 0 when k fixed helper rolls are driven by a drive motor inside the looper. In order to cushion the influence of the tension fluctuation by this control in the final loop, the adjustment gain _Gk becomes 1 in the final roll. That is, the adjustment gain at this time may always be expressed as in Equation 1 above.

In order to evaluate the performance of the controller proposed in the present invention, numerical results of the tension control using a known looper control system are shown. As shown in the comparison graph of the tension control performance before and after the implementation of the present invention of FIG. In the case of the present invention (dotted line), it can be seen that the deviation of the tension control is reduced by about 25% with respect to the reference value 900 kg.

Meanwhile, FIG. 5 is a graph showing the carriage position control performance expected after the implementation of the present invention, and FIG. 6 is a graph showing the carriage position control performance before the implementation of the present invention. When the carriage position is controlled stably in the conventional order, in the conventional method, carriage 3 has changed its position for tension control, but maintains the state without significantly seeing the effect of the tension control. Therefore, it is judged that it is advantageous from the control point of view to maintain the fixed position order in the position operation of the looper carriage.

According to the present invention as described above, the tension disturbance is reduced, the response is improved, and the interference phenomenon between the tension control and other control, in particular, the interference phenomenon between the tension control and the carriage position control operated in the looper control, Due to the stability of the tension control system, it prevents the occurrence of scratches, buckles, etc., which has a very significant effect on operation and quality control.

Claims (3)

In the steel plate tension control device of the continuous process, comprising a comparator, a PI controller and an adder, The comparator receives the input of the tension reference value (T _2ref ) set by the tension gauge tension meter 28 and the tension map of the line installed outside the looper No. 2, and outputs it to the PI controller. The PI controller receives and amplifies the comparison error of the comparator, multiplies it by the adjustment gain, and outputs the multiplier to the adder installed at the input of the speed control reference value setter of each fixed helper roll driving motor. The adder is configured to input the value received from the PI controller to the speed control reference value setter of the fixed helper roll drive motor in addition to the speed control reference value of the original fixed helper roll drive motor. Tension control device. In the steel sheet tension control method of the continuous process, the step of measuring the tension value from the tension gauge tension meter 28 installed outside the looper No. 2, Comparing the measured value with the tension reference value T _2ref set by the tension map of the line, calculating an error, and amplifying it; Multiplying the amplified error by an adjustment gain value; And adding the value as a part of a speed control reference value of each fixed helper roll driving motor. The i-th fixed helper roll according to claim 2, wherein the adjustment gain increases the speed compensation value for tension control from 0 to a predetermined interval so that the adjustment gain G _k becomes 1 in the kth final roll. The adjustment gain (G _i ) is multiplied by the speed correction value for the tension control to the drive motor of the steel sheet tension control method of a continuous process using a looper, characterized in that determined by the following equation (1 ). [Equation 1]

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