JPH06135609A - Strip tensile force controller - Google Patents

Abstract

PURPOSE:To obtain a stable strip tensile force controller having good responsiveness, which can eliminate mutual intervension between a tensile force control system and a dancer roll position control system. CONSTITUTION:A compensation calculating unit 14 for calculating the speed correction amount of bridle roll 2, 3 and the torque correction amount of a dancer roll 4 on the basis of the correction amount calculated by a tensile force correction amount calculating unit 14 from the difference between the detected value of a tensile force detecting unit 12 and the tensile force set value previously set and the correction amount calculated by a position correction amount calculating unit 11 from the difference between the detected value of a position detecting unit 10 and the position set value previously set is provided. Moreover, a non-linear compensation calculating unit to form the speed correction amount and the torque correction amount calculated by the compensation calcualting unit 14 into a non-line on the basis of a non-linear element by friction not to be ignored actually is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip tension control device for controlling the tension of a strip in a process line to be constant.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional strip tension control device. In the figure, 1 is a strip on the process line, and 2 and 3 are bridle rolls for feeding the strip 1. A dancer roll 4 is arranged between the bridle rolls 2 and 3 and applies a predetermined tension T to the strip 1. Reference numeral 5 is a dancer roll drive unit that controls the position P of the dancer roll 4, 6 is a dancer roll motor that rotates the dancer roll drive unit 5, and 7 is a torque control unit that controls the dancer roll motor 6. Reference numeral 8 is a bridle motor for rotating the bridle roll, and 9 is a speed control unit for controlling the bridle motor 8.

Further, 10 is a position detecting section for detecting the position P of the dancer roll 4, and 11 is a position P of the dancer roll 4 detected by this position detecting section 10 and a preset position of the dancer roll 4. The position correction amount calculation unit calculates a correction amount based on the difference from the set value P ^* and outputs the calculated correction amount to the speed control unit 9. Reference numeral 12 is a tension detecting section for detecting the tension T of the strip 1, and 13 is the tension T of the strip 1 detected by the tension detecting section 12 and a preset tension set value T ^{* of the} strip 1 ^.
It is a tension correction amount calculation unit that calculates a correction amount based on the difference between and and outputs it to the torque control unit 7.

Next, the operation will be described. In a process line such as a production line in the steel industry, in which a predetermined treatment is carried out while continuously feeding the strip 1, the value of the tension T of the strip 1 is extremely effective for the accuracy of the product sheet thickness and the uniform surface treatment. Have a big impact. Therefore, even if there are various disturbances, it is required to keep the tension T constant, and therefore, a dancer roll mechanism is installed to perform control for absorbing the change in the tension T. The tension control of the strip 1 will be described below.

The tension detector 12 constantly detects the tension T of the strip 1, and the difference between the detected value T and the preset tension set value T ^* of the strip 1 is applied to the tension correction amount calculator 13. Sent. The tension correction amount calculation unit 13 calculates a correction amount based on the difference between the detected tension value T of the strip 1 and the tension set value T ^*, and the calculated correction amount is calculated by the torque control unit 7.
Output to. The torque control unit 7 controls the rotation of the dancer roll motor 6 according to the input correction amount, and the dancer roll driving unit 5 adjusts the position P of the dancer roll 4 according to the rotation of the dancer roll motor 6 to remove the strip 1 from the strip 1. Control the tension T applied to.

On the other hand, the position detector 10 constantly detects the position P of the dancer roll 4, and the detected value P and the preset position set value P of the dancer roll 4 are set.
The difference from ^* is sent to the position correction amount calculation unit 11. The position correction amount calculation unit 11 calculates a correction amount based on the difference between the detected value P of the position of the dancer roll 4 and the position set value P ^*, and outputs it to the speed control unit 9. The torque control unit 7 controls the rotation of the bridle motor 8 according to the input correction amount,
Correct the rotation speed of the bridle roll 2. As a result, the rotation speed of the bridle roll 2 with respect to the adjacent bridle roll 3 is adjusted to an appropriate value, and the position P of the dancer roll 4 related to the loop length is set to the position set value P.
^* Returns to the vicinity and is controlled so that the position is stably maintained.

As described above, the conventional strip tension control device controls the tension T of the strip 1 by controlling the torque of the dancer roll 4, and the position of the dancer roll 4 deviated by the tension control controls the rotational speed of the bridle roll 2. To return to the set position.

As a document describing a technique related to such a conventional strip tension control device, there is, for example, JP-A-3-174916.

[0009]

Since the conventional strip tension control device is constructed as described above, the dancer roll 4 generated by the control of the tension T of the strip 1 performed by the torque control of the dancer roll 4 is described. It is necessary to restore the deviation from the position set value P ^{* of} P by the control of the rotation speed of the bridle roll 2, and the correction of the position P of the dancer roll 4 and the control of the tension T of the strip 1 are mutually opposite. There is a problem in that it is extremely difficult to obtain a strip tension control device having high responsiveness because of disturbance.

The present invention has been made to solve the above-mentioned problems, and has high responsiveness except for mutual interference between the strip tension control system and the dancer roll position control system, and The object is to obtain a stable strip tension control device.

[0011]

A strip tension control device according to a first aspect of the present invention calculates a tension correction amount calculation unit from a difference between a detection value of a tension detection unit and a preset tension set value. Based on the correction amount calculated by the position correction amount calculation unit from the difference between the detected correction amount and the detected value of the position detection unit and the preset position setting value, the speed correction amount of the bridle roll and the torque correction of the dancer roll are corrected. A compensation calculation unit for calculating the quantity is provided.

Further, in the strip tension control device according to the invention described in claim 2, the speed compensation amount and the torque compensation amount calculated by the compensation calculation unit are made non-linear based on a non-linear element such as friction. Is further added.

[0013]

According to the invention as set forth in claim 1,
Input the correction amount calculated by the tension correction amount calculation unit and the correction amount calculated by the position correction amount calculation unit, and based on them, determine the bridle speed correction amount and the dancer roll position control necessary for tension control. Mutual interference was compensated by calculating the speed correction amount of the bridle roll and the torque correction amount of the dancer roll in consideration of the necessary dancer roll torque correction amount, and outputting them to the speed control unit and the torque control unit. To realize a strip tension control device capable of tension control and position control.

Further, the non-linear compensation calculation unit in the invention according to claim 2 further nonlinearly corrects the speed correction amount and the torque correction amount calculated by the compensation calculation unit,
This makes it possible to compensate for non-negligible non-linear movements due to friction, etc., and enhances the responsiveness of tension control and position control.

[0015]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment in which the invention described in claim 1 is applied to a process line of the steel industry. In the figure, 1 is a strip, 2 and 3 are bridle rolls, 4 is a dancer roll, 5 is a dancer roll drive unit, 6 is a dancer roll motor, 7 is a torque control unit, 8 is a bridle motor, 9 is a speed control unit, 10 Is a position detection unit, 11 is a position correction amount calculation unit, 12 is a tension detection unit, 13
Is a tension correction amount calculation unit, which is the same as or equivalent to those of the related art denoted by the same reference numerals in FIG. 5, and therefore detailed description thereof is omitted.

Further, 14 receives the respective correction amounts calculated by the position correction amount calculation unit 11 and the tension correction amount calculation unit 13, and based on them, the dancer roll necessary for the position control of the dancer roll 4. A torque correction amount ΔQ of the dancer roll 4 in consideration of the torque correction amount and a speed correction amount ΔV of the bridle roll 2 in consideration of the bridle speed correction amount necessary for tension control are calculated, and these are calculated. It is a compensation calculation unit that outputs to the speed control unit 9.

Next, the operation will be described. Here, in the following description, in order to simplify the description, instead of the position P of the dancer roll 4, the change rate of the position P of the dancer roll 4 such as the moving speed of the dancer roll 4 is used, which is used as the dancer roll 4 The variable n is used as a control variable instead of the position variation, and is shown by the following equation.

[0018]

[Equation 1]

At this time, in the steady state, the relationship between the speed correction amount ΔV of the bridle roll 2 and the torque correction amount ΔQ of the dancer roll 4, the tension change amount ΔT of the strip 1 and the moving speed change amount Δn of the dancer roll 4 is as follows. It is expressed as.

[0020]

[Equation 2]

When the relationship of the equation (2) is summarized and displayed in the form of a matrix, the following equation is obtained.

[0022]

[Equation 3]

Therefore, the velocity correction amount of the bridle roll 2 obtained by the tension value control calculation in the tension correction amount calculation unit 13 is set to ΔV ^*, and the dancer roll position control calculation in the position correction amount calculation unit 11 is performed to obtain the dancer. When the torque correction amount of the roll 4 is ΔQ ^* , new speed correction amount ΔV and torque correction amount ΔQ that compensate for interference with other variables can be calculated by the following calculation. That is, the inverse matrix of the matrix showing the transfer function expressed by the equation (3) is expressed as follows.

[0024]

[Equation 4]

"D" in the above equation (4) is given by the following equation.

D = g ₁₁ · g ₂₂ −g ₁₂ · g ₂₁ (5)

The new correction criterion can be expressed by the following equation by using this inverse matrix [C].

[0028]

[Equation 5]

Next, by substituting the expressions (4) to (6) into the expression (3), the following expression is obtained.

[0030]

[Equation 6]

By rearranging this equation (7), the following equation is obtained.

[0032]

[Equation 7]

As can be seen from the equation (8), the speed correction amount ΔV ^* obtained by the tension control calculation gives
Only the tension value of the strip 1 changes by ΔT, and the torque correction amount ΔQ obtained by the dancer roll position control calculation
^{By *} , only the position P of the dancer roll 4 is changed by Δn, and the interference with other variables is compensated.

FIG. 2 shows the result of simulating the open loop transfer characteristic from the manipulated variable such as the speed reference and torque reference to the controlled variable such as tension and position in this embodiment. In the figure (a), the open loop characteristic T / Vr from the bridle speed to the strip tension and the open loop characteristic T / gr from the dancer roll driving torque to the strip tension are shown. In the figure (b), the bridle speed is shown. Shows the open loop characteristic P / Vr from to the dancer roll position and the open loop characteristic P / gr from the dancer roll drive torque to the dancer roll position. Here, as is apparent from FIG. 2, it is effective that the tension control is performed by the bridle speed reference and the position control of the dancer roll 4 is performed by the torque reference. Therefore, as in this embodiment, the position correction amount calculation unit 11 calculates the torque correction amount of the dancer roll 4 and the tension correction amount calculation unit 13 calculates the speed correction amount of the bridle roll 2 also from this point. That is valid.

Further, in the above explanation, for the sake of convenience of explanation, only the steady-state characteristic is focused, but in the equation (2), g ₁₁ , g ₁₂ ,
By using g ₂₁ and g ₂₂ which include appropriate dynamic characteristics, it is possible to suppress the transient disturbance that the tension control and the dancer roll position control exert on each other.

Example 2. Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing an embodiment of the invention described in claim 2, and the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof is omitted. In the figure, 15
Makes the torque correction amount ΔQ and the speed correction amount ΔV output from the compensation calculation unit 14 non-linear, thereby compensating for the non-negligible non-linear operation due to friction or the like, and the torque correction amount ΔQn of the new dancer roll 4 is compensated for. And the torque control unit 7 as the speed correction amount ΔVn of the bridle roll 2.
Alternatively, it is a non-linear compensation calculation unit that is supplied to the speed control unit 9.

Next, the operation will be described. Here, since the basic operation is the same as that of the first embodiment, the description will be focused on the operation of the above-mentioned nonlinear compensation calculation unit 15. The torque correction amount ΔQ of the dancer roll 4 and the speed correction amount ΔV of the bridle roll 2 calculated from the correction amounts calculated by the tension correction amount calculation unit 13 and the position correction amount calculation unit 11 in the compensation calculation unit 14 are torque control values. It is not directly input to the section 7 and the speed control section 9, but is once input to the nonlinear compensation calculation section 15. In response to this, the non-linear compensation calculation unit 15 determines whether the dancer roll 4 is subjected to static friction or dynamic friction, and applies a non-linear gain to the torque correction amount ΔQ and the speed correction amount ΔV to obtain them. Non-linearization of.

FIG. 4 is an explanatory diagram showing the characteristics of such a non-linear gain. In FIG. 4A, the change in gain applied to the torque correction amount ΔQ is shown, and in FIG. 4B, the speed correction is shown. The change in gain applied to the quantity ΔV is shown. 4A and 4B, the moving speed of the dancer roll 4 or the rotating speed of the dancer roll motor 6 is graduated. As shown in FIG. 4A, the non-linear compensation calculation unit 15 performs non-linear processing by applying a large gain to the torque correction amount ΔQ when the dancer roll 4 starts moving and a small gain when the dancer roll 4 starts moving. , And outputs it to the torque control unit 7 as a new torque correction amount ΔQn. Further, as shown in FIG. 4B, with respect to the speed correction amount ΔV, a small gain is applied when the dancer roll 4 starts moving, and a large gain is applied when the dancer roll 4 starts moving. It is output to the speed control unit 9 as a new speed correction amount ΔVn.

As described above, torque control is performed by nonlinearizing the torque correction amount ΔQ and the speed correction amount ΔV in which mutual interference is compensated so as to compensate for a non-linear operation such as friction that cannot be actually ignored. Section 7 and speed control section 9
We are supplying the optimum correction amount for. In addition to the friction, mechanical loss such as bearing loss can be considered as the non-linear operation that cannot be ignored in practice. Also,
The curve showing the characteristic of the non-linear gain in FIG. 4 is shown as an example, and the target dancer roll mechanism and GD
² (Moment of inertia), various changes depending on the motor.

Example 3. In addition, in the above-mentioned embodiment, the case where it is applied to the control of the strip tension in the process line in the steel industry has been described, but the looper of the process line having the similar structure, the device having the similar structure in the paper manufacturing line, etc. The same effect as the above embodiment can be obtained.

[0041]

As described above, according to the first aspect of the present invention, the compensation calculation unit is provided so as to compensate for the mutual interference between the tension control and the position control. The responsiveness can be arbitrarily increased without affecting the dancer roll position, and the responsiveness can be enhanced by ignoring the effect on the tension value from the viewpoint of the dancer roll position control system. Therefore, there is an effect that a strip tension control device can be obtained which is expected to absorb and control disturbance components that are significantly higher than those of conventional devices.

Further, according to the invention described in claim 2, since the non-linear compensation calculation unit is further provided to compensate for the non-negligible non-linear operation, the non-linear operation such as friction can be corrected more realistically. Therefore, there is also an effect that a stable control region can be further widened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an open loop characteristic of a dancer roll model in the above embodiment.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a characteristic of a non-linear gain in the embodiment.

FIG. 5 is a block diagram showing a conventional strip tension control device.

[Explanation of symbols]

 1 strip 2 bridle roll 3 bridle roll 4 dancer roll 10 position detection unit 11 position correction amount calculation unit 12 tension detection unit 13 tension correction amount calculation unit 14 compensation calculation unit 15 non-linear compensation calculation unit

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 8, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

Therefore, the velocity correction amount of the bridle roll 2 obtained by the tension value control calculation in the tension correction amount calculation unit 13 is set to ΔV ^*, and the dancer roll position control calculation in the position correction amount calculation unit 11 is performed. When the torque correction amount of 4 is ΔQ ^* , new speed correction amount ΔV and torque correction amount ΔQ that compensate for interference with other variables can be calculated by the following calculation. That is, the inverse matrix of the matrix showing the transfer function expressed by the equation (3) is expressed as follows.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

FIG. 2 shows the result of simulating the open loop transfer characteristic from the manipulated variable such as the speed reference and torque reference to the controlled variable such as tension and position in this embodiment. The open loop characteristic T / Vr from the bridle speed to the strip tension and the open loop characteristic T / qr from the dancer roll driving torque to the strip tension are shown in (a), and the bridle speed is shown in (b). Shows the open-loop characteristic P / Vr from the dancer roll position to the dancer roll position, and the open-loop characteristic P / qr from the dancer roll drive torque to the dancer roll position. Here, as is apparent from FIG. 2, it is effective that the tension control is performed by the bridle speed reference and the position control of the dancer roll 4 is performed by the torque reference. Therefore, as in this embodiment, the position correction amount calculation unit 11 calculates the torque correction amount of the dancer roll 4 and the tension correction amount calculation unit 13 calculates the speed correction amount of the bridle roll 2 also from this point. That is valid.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. A correction amount based on a tension detection unit for detecting a tension value of a strip between adjacent bridle rolls, and a difference between a detection value of the tension detection unit and a preset tension set value of the strip. A tension correction amount calculation unit for calculating, a position detection unit for detecting the position of the dancer roll arranged between the bridle rolls, a detection value of the position detection unit and a preset position setting value of the dancer roll Based on each correction amount calculated by the position correction amount calculation unit, the tension correction amount calculation unit and the position correction amount calculation unit, which calculates the correction amount based on the difference between
A strip tension control device comprising a compensation calculation unit that calculates a speed correction value of the bridle roll and a torque correction value of the dancer roll. 2. A non-linear compensation calculation unit for nonlinearizing the speed correction amount and the torque correction amount calculated by the compensation calculation unit based on a non-negligible non-linear element due to friction or the like. The strip tension control device according to claim 1.