JP3036323B2 - Rolling mill control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a rolling mill, and more particularly to priority control of sheet thickness and tension.

[0002]

2. Description of the Related Art In a rolling mill in which a plurality of rolling stands are continuously arranged, the thickness and tension of each stand are controlled in order to obtain a desired product quality. Usually, priority is given to the constant thickness control, and for example, when the control value becomes 70% or less of the set value, band control for giving priority to the tension with respect to the thickness is performed.

Each stand is provided with a roll driving device (electric motor) for controlling the roll peripheral speed and a roll-down device for controlling the roll gap. In cold rolling, the roll speed is changed to control the thickness, and the rolling position is changed to control the tension. The reverse operation is performed in hot rolling.

[0004] However, between the sheet thickness and the tension in the rolling phenomenon, there is mutual interference in which one change affects the other, which causes a reduction in control accuracy. Further, in the band tension control, the plate thickness during this period is sacrificed, and the product quality and the yield are reduced.

Recently, rolling control has been put to practical use in which the thickness and tension are simultaneously controlled by a multivariable control theory to eliminate mutual interference and improve control accuracy.

[0006]

In order to design a highly accurate DDC control system based on the multivariable control theory, a model that accurately grasps the dynamic characteristics of the rolling phenomenon is required. However, for example, if there is a composition abnormality or a shape defect in a part of the rolled material, it is difficult to accurately grasp the dynamic characteristics. In fact, Hill (Hi
In accordance with the approximation formula (11), the error between the predicted value and the actually measured value by the model is adjusted by an influence coefficient or the like. Moreover, since the rolling phenomenon has strong nonlinearity, an operating point is determined according to the rolling state, and a method of linearly approximating around the operating point is used.

For this reason, in the conventional multivariable control, when the thickness and the tension are simultaneously controlled, if the models and the influence coefficients are largely different, mutual interference cannot be eliminated in response to the change in the rolling phenomenon. There is a problem that the control accuracy is lower than that of the classical control with one input and one output.

Further, in the conventional multivariable control, there is no sufficient consideration for the difference in response time of the roll driving device or the pressing device, and there is a problem that a short-cycle control command cannot be sufficiently followed.

A first object of the present invention is to provide a high-precision and stable rolling control method and apparatus by simultaneously controlling the thickness and the tension while improving the control effects of the thickness control and the tension control. is there.

A second object of the present invention is to provide a rolling control method and apparatus which effectively utilizes the difference in response speed between actuators, eliminates interference due to rolling with high response, and improves control accuracy. is there.

A third object of the present invention is to provide priority control and non-interference control for simultaneous control of sheet thickness and tension irrespective of the difference between the rolling process to be applied, such as cold or hot, and the actuator used. Another object of the present invention is to provide a rolling control system that can be applied for general purposes.

[0012]

A first object of the present invention is to provide a method for controlling a rolling mill for simultaneously controlling the thickness and tension of a rolling mill.
This is achieved by giving priority to the thickness control when the deviation of the measured tension value from the target value is within a predetermined tension range (threshold value), and giving priority to the tension control when the deviation is outside the range. .

A second object of the present invention is to provide a method of controlling a rolling mill in which an actuator of a pressing device and a roll driving device are operated to simultaneously control a thickness and a tension. Is canceled by non-interference control by the actuator having the faster response speed.

A third object of the present invention is to provide a feedback control system for simultaneously controlling the measured thickness and tension so as to eliminate deviations from target values, and a non-interference control system for canceling interference due to thickness or tension control. And a rolling mill control device that includes a rolling-down device and a roll driving device that operate in accordance with control commands from these control systems, and that simultaneously controls a thickness and a tension. Control gain adjusting means for changing a corresponding control gain and a control gain corresponding to a tension deviation in accordance with a difference in an applied cold process or a hot process and / or a thickness priority or a tension priority control; The tension non-interference control gain corresponding to the sheet thickness deviation set in the control system and the sheet thickness non-interference control gain corresponding to the tension deviation are determined by the response of the pressing device and the roll driving device. It is achieved by providing a non-interference control gain adjustment means for adjusting in response to the time constant.

[0015]

The priority control of the present invention is realized by increasing one of the thickness control gain and the tension control gain with respect to the other, depending on whether or not the tension deviation is within a predetermined range. In particular, the tension range (threshold value) for switching the target of the priority control is determined for each stand and for each step (class) of the tension set value set according to the change of the operating point. As a result, a precise threshold value adapted to the operating point is set,
Since the optimum priority control is executed optimally for each rolling state, it is possible to improve both the accuracy of the sheet thickness and the tension due to the tension deviation. In addition, since the tension is constantly monitored to prevent the sudden change, a stable operation of the rolling mill becomes possible.

According to the non-interference control of the present invention, non-interference control by an actuator with a low response speed is performed in a phase-matched manner by an actuator with a high response speed. The effect of controlling the tension can be improved.

According to the control device of the rolling mill of the present invention, priority control of the sheet thickness or the tension is performed by a cold process in which the roll thickness is controlled by a roll driving device to reduce the thickness in a rolling device, and a hot process which is the reverse control. Applicable to both processes. Further, the execution device of the non-interference control can be applied to both the case where the response speed of the rolling-down device is fast and the case where the response of the roll drive device is fast, so that the construction and change of the rolling control system become easy. .

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a schematic configuration diagram of a rolling control system to which the present invention is applied. This control system is an optimal control system that changes the control gain of the DDC controller 5 online.

The set-up control system 4 calculates a set value for calculating a target value and a rolling condition of each stand according to the rolling schedule and an operating point and an influence coefficient according to the rolling state from the detecting device 3 based on the rolling model 6. It has means 4-1.

The rolling models are shown in (Equation 1) to (Equation 3).

[0022]

(Equation 1)

[0023]

(Equation 2)

[0024]

(Equation 3)

(Equation 1) showing the physical relationship of the rolling load is as follows:
In the Hill's approximation, the friction correction term is expressed by (Equation 2). The intersection of the rolling load curve of (Equation 1) and the gauge meter type of (Equation 3) is the operating point.

The setup control system 4 calculates the operating point by the load equation and the gauge meter equation under various rolling conditions by the Newton method or the like.

The DDC controller 5 calculates a deviation between a set value such as a target value or an operating point set by the setup control system 4 and an actually measured value from the detection device 3, and controls the deviation so that the deviation becomes zero. Calculate the command. The actuator 8 operates the rolling mill 1 according to the control command.

FIG. 1 is a schematic diagram of a rolling control device for controlling a rolling mill comprising a multi-stage stand according to an embodiment of the present invention. Each rolling stand has a thickness detector 3-1, a tension detector 3-2, a roll peripheral speed detector 3-3, a rolling position detector 3-4, a rolling load detector 3 as a detecting device 3.
5, a sheet speed detector 3-6 and the like are installed. The output side plate thickness hi, the rear tension τbi, the rolling position Si, the roll speed VRi-1, the rolling load Pi, and the like from these detectors are input to the setup control system 4, and the operating point, the influence coefficient, and the like according to the rolling state. Is changed.

The exit side thickness h of the rolled material by the thickness detector 3-1 and the rearward tension τb by the tension detector 3-2 are input to the feedback control unit 5-1. The control unit 5-1 includes:
Deviations between these input values and the target thickness values hs, τbs from the setup control system 4 are obtained, each deviation is multiplied by a control gain, integrated, and a control command is output. This control command includes a rolling-down command component and a speed command component.

The control gain (set value) set in the feedback control section 5-1 is calculated by a control model. That is, based on the rolling load equation for the minute change in which Taylor-expanded (Equation 1) near the operating point and the gage meter equation described for (Equation 3) in a deviation value system, the state quantity X and the manipulated variable U
When a relational expression of the control amount Y is obtained and expressed by a general expression, a state equation of (Formula 4) which is a control model is obtained.

[0031]

(Equation 4)

The control gain F of the feedback control system 5-1 can be calculated by discretizing the state equation (Equation 4) at a control cycle and obtaining a matrix element for each operating point. Although this calculation method solves the Riccati equation based on the discretized state equation, it is well known in “Automatic Control Handbook Part 1 (page 154)” edited by the Society of Automatic Engineers and is omitted.

The non-interference control unit 5-2 receives a control command based on a thickness deviation or a control command based on a tension deviation from the control unit 5-1 and multiplies each of these deviations by a non-interference control gain to obtain a rolling-down command component. Alternatively, a non-interference control command of a speed command component is output.

The control output unit 5-3 adds the control command of the feedback control unit 5-1 and the non-interference control command from the non-interference control unit 5-2 for each component, and the speed command Vp is added to the front stand (i- Roll drive device 8 which is the speed control device of 1)
Then, the rolling-down command Sp is output to the rolling-down device 9 which is the rolling-down position control device of the stand (i).

In FIG. 1, the roll driving device 8 is shown in the front stand i-1, and the pressing device 9 is shown for the own stand i. Actually , the roll driving device and the pressing device are arranged for each stand. Have been. In the hot rolling, the speed command Vp may be output to the roll drive device of the stand (i). The tension to be controlled is also the forward tension τf.
(Τbi = τf (i−1)).

FIG. 1 shows, as characteristic components of the present embodiment, a priority control determining unit 5 for simultaneously determining the priority of the thickness and the tension to be simultaneously controlled and determining the non-interference control to be executed accordingly.
-4, the control gain set value set by the setup control system 4 (usually at the time of coil change) is corrected by the adjustment coefficient from the priority control unit 5-4 to enable priority control, and the feedback control unit 5-1 and the non- A control gain calculator 5-5 for setting the interference controller 5-2 is provided.

FIG. 3 is a schematic diagram showing the details of the feedback control unit 5-1 and the non-interference control unit 5-2, showing only the speed command generation system. The speed control output calculation unit 5-1-1 includes:
The control gain Fhvi multiplied by the sheet thickness deviation △ hi as shown in (Equation 5) and the control gain Fτvi multiplied by the tension deviation △ τi as shown in (Equation 6) are used as a control gain calculating unit in accordance with the above calculation. 5-5. The former is set for the cold rolling, and the latter is set for the hot rolling.

[0038]

５Vhi = ∫Fhvi △△ hi (speed command for thickness control)

[0039]

△ Vτi = ∫Fτvi · △ τi (speed command for tension control) The speed non-interference control unit 5-2-1 is connected to the thickness non-interference control output calculation unit 5-2-11 and the tension non-interference control unit 5-2-11. Interference control output calculator 5-2
12 and a delay circuit 5-2-13, and is a non-interference control system configured when the response speed of the roll driving device 8 is faster as described later.

The arithmetic unit 5-2-11 performs cold rolling, and the control gain Fdhvi is set (Equation 7) while the feedback control system 5-1 is executing the tension priority control. Vdhi). The calculation unit 5-2-12 performs the control gain Fd during the hot-rolling and the execution of the thickness priority control.
τvi is set (Equation 8) and the tension non-interference control output (△ V
dτi).

[0041]

７Vdhi = Fdhvi · △ Sτi where ΔSτi: reduction command due to tension difference

[0042]

△ Vdτi = Fdτvi · △ Shi where: ΔShi: Reduction command due to plate thickness knitting difference This non-interference control output △ Vdhi or △ Vdτi is delayed by dead time Tdvi through dead time circuit 5-2-13. After that, the control command from the feedback control system 5-1 output to the roll driving device is subtracted.
The dead time Tdvi is calculated from the response time constant of the roll driving device 8 and the pressing device 9 and the dead time, so that the timing of non-interference control is adjusted to the phase in which interference occurs.

FIG. 4 is a schematic diagram showing only the rolling-down command generation system of the feedback control unit 5-1 and the non-interference control unit 5-2. The rolling position control output calculation unit 5-1-2 is multiplied by the control gain Fhsi multiplied by the plate thickness deviation △ hi as shown in (Equation 9) and the tension deviation △ τi as shown in (Equation 10). Control gain Fτsi is set. The former is set for hot rolling, and the latter is set for cold rolling.

[0044]

[Expression 9] △ Shi = △ Fhsi △△ hi (a reduction command for sheet thickness control)

[0045]

△ Sτi = ∫Fτsi · △ τi (Reduction command for tension control) The reduction non-interference control unit 5-2-2 is connected to the thickness non-interference control output calculation unit 5-2-21 and the tension non-interference control unit 5-2-21. Interference control output calculator 5-2
22 and a dead time circuit 5-2-23. As will be described later, this is a non-interference control system configured when the response speed of the screw down device 9 is faster.

The arithmetic unit 5-2-21 is a hot rolling, and the control gain Fdhsi is set (Equation 11) while the feedback control system 5-1 is executing the tension priority control. Sdhi). Arithmetic unit 5-2-22
Is the cold rolling, and the control gain F
dτsi is set and the tension non-interference control output (△ Sdτi) of (Equation 12) is generated and executed.

[0047]

１１Sdhi = Fdhsi · △ Vτi

[0048]

△ Sdτi = Fdτsi △△ Vhi This non-interference control output is delayed by the dead time Tdsi through the dead time circuit 5-2-23.

The configuration of each of the above-described non-interference control sections is such that the non-interference control gain is made valid (coefficient 1) or invalid (coefficient 0) by an adjustment coefficient output from the priority control section 5-4 described later. Is switched.

FIG. 5 is a functional block diagram showing the configurations of the priority control section 5-4 and the control gain calculation section 5-5. The priority control section 5-4 includes a thickness / tension priority control section 5-4-1 and a non-interference priority control section 5-4-2.

First, the plate thickness / tension priority control section 5-4-1 will be described. The threshold value setting means 21 is a back tension setting value τbrefi set by the setup control system 4 for each stand.
The threshold value is set with reference to a table (Table 1) that classifies in advance. The classification table stores the upper and lower limits of the rear tension set value τbrefi of each class and the threshold value (tension range) ± τbDij for the actually measured value τbi of the class. Note that the threshold value may be in a range of 0 to −τbDij.

[0052]

[Table 1]

Note that, instead of the tension deviation Δτi to be compared with the threshold value, a tension set value ratio (% Δτi = Δτi / τbrefi) may be used in order to easily grasp the characteristics.

The tension deviation value output means 22 outputs the set value τbref
The difference between i and the measured backward tension value τbi from the tension meter 3-2 is calculated, and a tension deviation Δτi from which noise components have been removed by filtering is output. The priority control determination means 23
It is determined whether or not the deviation △ τi is within a threshold value (tension range) ± τbDij. If it is within the range, a thickness priority signal is output, and if it is outside the range, a tension priority signal is output.

The control adjustment coefficient calculating means 24 determines an adjustment coefficient G for changing each control gain of the feedback control section 5-1 in order to execute the priority control of the plate thickness or the tension as follows. Output to the arithmetic unit 5-5.

The adjustment coefficient G is an eight coefficient corresponding to each control gain shown in FIGS. 3 and 4 and determined within the range of the threshold value (priority of thickness) and outside the range (priority of tension). Consists of
That is, Gvhi1, which adjusts the control gain Fhvi,
2, Gvτi1,2 for adjusting Fτvi, Gshi1,2 for adjusting Fhsi, and Gsτi1,2 for adjusting Fτsi. As for the suffix of the number attached to each coefficient, 1 indicates within the range and 2 indicates outside the range. Each of these adjustment coefficients is (Equation 1)
The relationship is defined in 3).

[0057]

Gsτi1 <Gsτi2 ... Relationship between tension adjustment coefficients for rolling control output Gvτi1 <Gvτi2 ... Relationship between tension adjustment coefficients for speed control output Gshi2 ≦ Gshi1 ... Relationship between plate thickness adjustment coefficients for reduction control output Gvhi2 ≦ Gvhi1 Thickness adjustment coefficient relationship In other words, the tension gain (Fτsi) relationship of the reduction control output and the tension gain (Fτvi) relationship of the speed control output are larger outside the range than within the range. Thickness gain (Fhsi) relation of reduction control output and thickness gain (Fhsi) of speed control output
hvi) The relationship is set so that the outside of the range is smaller than the inside of the range. As a result, the thickness priority control is performed within the range, and the tension priority control is performed outside the range. Incidentally, each adjustment coefficient in the case of cold rolling and in the case of hot rolling has a relationship shown in Table 2.

[0058]

[Table 2]

Further, each sheet thickness adjustment coefficient and the sheet thickness deviation △ hi are defined by a functional relationship of (Equation 14).

[0060]

(14) Gshi1,2 = fs (ｆhi) Gvhi
1,2 = fv (△ hi) or Gshi1,2 = fs (% △ hi) Gvhi1,2
= Fv (% △ hi) where% △ hi = △ hi / hrefi (href: set value) That is, the thickness adjusters Gshi1 and Gvhi1 within the range.
Increases the value in accordance with the thickness deviation to increase the gain of the thickness control. The same applies to the case outside the range.

FIG. 6 is a flowchart showing a processing procedure for the above-mentioned thickness / tension priority control. First, a tension threshold value ± τbDij corresponding to the set tension set value τbrefi
Is set (s101), and a deviation value △ τbi of the actually measured rear tension τbi is determined (s102). Next, the deviation value △
It is determined whether or not τbi is within the set threshold value ± τbDij (s103).

When it is within the range, the adjustment coefficient G is determined so as to give priority to the thickness control (s104). The control coefficient set value is multiplied by the adjustment coefficient G to obtain an online control gain (s106). For example, the adjustment coefficient G is determined so that the control gain (Fhvi) for controlling the plate thickness has a larger value than the control gain (Fτsi) for controlling the tension.

On the other hand, when the deviation value △ τbi is out of the range of the threshold value ± τbDij, priority is given to the tension control (Fτ
si> Fhvi) An adjustment coefficient is determined (s105).

Next, the non-interference priority control section 5-4-2 will be described. The non-interference control device determining means 24 compares the response time constants Tvi and Tsi of the roll drive device 8 and the pressure reduction device 9 and selects the device with the smaller time constant (higher response speed), and its non-interference adjustment coefficient. Output first name. Further, a response time constant Tvi of the roll driving device 8, a dead time Td1i,
Based on the response time constant Tsi and the dead time Td2i of the screw-down device 9, the dead time Tdi for adjusting the timing of the non-interference control to the interference phase is calculated by (Equation 15).
Since the response speed and dead time of the apparatus are determined when the system is designed or changed, the output from the means 24 can be determined in advance.

[0065]

## EQU15 ## Tdi = F (Tvi, Tsi) + │Td1i
−Td2i | The thickness non-interference control gain Fd in FIG.
hvi, Gd1 and Gd2 for adjusting each of the tension non-interference control gains Fdτvi, and the plate thickness non-interference control gain F in FIG.
dhsi and Gd3 for adjusting each of the tension non-interference control gains Fdτsi. The adjustment coefficient name output from the non-interference control device determining means 24 is determined by the relationship of (Equation 16).

[0066]

Tvi <Tsi → Gd1, Gd2 Tvi> Tsi → Gd3, Gd4 Normally, the response speed of the screw-down device 9 is fast at Tvi> Tsi, so that the plate thickness non-interference for calculating the non-interference control output to the screw-down device Control gain Fdhsi, tension non-interference control gain Fdτ
Gd3 and Gd4 for adjusting si are selected.

The non-interference adjustment coefficient determining means 25 comprises
In accordance with the name of the non-interference adjustment coefficient given from the above and the thickness control priority signal or the tension control priority signal from the priority control determination means 23, each non-interference adjustment coefficient is determined as in (Equation 17), and the control gain Output to the arithmetic unit 5-5.

[0068]

Gd1 = 0.0, Gd3 = 0.0 Gd2 = 1.0 (Tvi <Tsi), Gd4 = 1.0
(Tvi> Tsi) <Tension control priority> Gd2 = 0.0, Gd4 = 0.0 Gd1 = 1.0 (Tvi <Tsi), Gd3 = 1.0
(Tvi> Tsi) By the way, in the case where the reduction device 9 with the fast response executes the non-interference control, the tension non-interference control in the cold rolling is performed, so that Gd1 to Gd3 are all 0.0, and only the thickness of Gd4 is the thickness. It becomes 1.0 at the time of priority control and 0.0 at the time of tension priority control.

As described above, the non-interference priority control section 5-4-2
Determines the adjustment coefficient by which the non-interference control gain is multiplied so that the non-interference control is performed by the actuator having a fast response speed.

Next, the function of the control gain calculating means 5-5 will be described. The control gain calculating means 30 calculates the control gain set value (Frefi1,2) of the feedback control unit 5-1 by:
It is set from the setup control system 4. The control gain setting value is obtained by using the well-known Riccati equation for the state equation shown in (Equation 4) as described above. These control gain setting values are added to the adjustment coefficient calculating means 23.
The control gains shown in FIG. 3 and FIG.

[0071]

Fhvi = Fhvrefi1,2 Gvhi1,2 Fτvi = Fτvrefi1,2 Gvτi1,2 Fhsi = Fhsrefi1,2 Gshi1,2 Fτsi = Fτsrefi1,2 Gsτi1,2 With the numerical suffix, the sheet thickness priority control is indicated by 1 and the tension priority control is indicated by 2. According to the relationship of the adjustment factors shown in Table 2, Fτvi and Fhsi are zero in cold rolling, Fhvi> Fτsi when priority is given to thickness control, and Fhvi <Fτ when tension control is given priority.
si. Note that the control gain becomes zero in the cold state, and the control gain and the control system used in the hot state may be excluded from the design target when the construction system is determined.

The non-interference control gain calculating means 31 sets the non-interference control gain set value (Fdref
i) is set from the setup control system 4. As an example, the tension non-interference control gain in the case where the response of the reduction device is fast in cold rolling is shown in (Equation 19). The influence coefficients in the equation are given by the setup calculation. By multiplying these control gain setting values by the non-interference adjustment coefficient from the non-interference adjustment coefficient setting means 25, the respective non-interference control gains shown in FIGS. 3 and 4 are obtained as shown in (Equation 20).

[0073]

[Equation 19] Fdτsrefi = (Ki−∂Pi / ∂hi)
/ Ki where ∂Pi / ∂hi: Influence coefficient Ki: Roll spring constant

[0074]

## EQU20 ## Fdhvi = Fdhvrefi · Gd1 Fdτvi = Fdτvrefi · Gd2 Fdhsi = Fdhsrefi · Gd3 Fdτsi = Fdτsrefi · Gd4 FIG. 7 is a flowchart showing the procedure for determining the non-interference control gain described above. By the way, when the response speed of the reduction device 9 is faster in cold rolling (s201), Gd4 = 1.0 in (s202) during the thickness priority control (s204), so that the non-interference control gain Fdτsi = Fdτs
The refi is set (s206), and the tension non-interference control is performed by the screw-down device 9. On the other hand, when tension control is prioritized, Fd
Since τsi = 0, non-interference control is not performed.

The non-interference control gain calculating means 31 calculates the delay time Td ₁ i when the roll speed device is fast, based on the response time constant difference value Td from the non-interference control device determining means 25.
If, by calculating the delay time Td ₂ i where reduction device is high, set the decoupling control unit 5-2. This setting is performed at the time of system design or change. When the construction system is determined, non-interference control gains and control systems that are not used in some cases can be excluded from the design target.

FIGS. 8 and 9 show dynamic diagrams of the rolling system according to the present embodiment described above. FIG.
Is the response time of the rolling control unit shorter than the response time of the speed control unit,
This is the case during the thickness priority control. The system configuration of normal cold rolling uses a hydraulic pressure reduction device as a reduction control unit and a DC motor as a speed control unit, and corresponds to this case. In the figure, a thick solid line indicates priority control, a thin solid line indicates non-priority control in which simultaneous control is performed, and a dotted line indicates control that is not executed for reference.

FIG. 9 shows a case of the tension priority control in which the response time of the pressure reduction control unit is shorter than the response time of the speed control unit. This corresponds to the configuration of a normal hot rolling system.

According to the present embodiment, in the rolling control for simultaneously controlling the sheet thickness and the tension, if the actually measured tension deviation is within the range of the threshold value, the sheet thickness control gain is increased, and the range of the threshold value is increased. If it exceeds, the tension control gain is increased and priority control is performed. In addition, since the threshold value is set finely for each stand and for each step of the tension set value, precise priority control that follows the change of the operating point can be performed.

Therefore, the quality of the product is improved by increasing the control accuracy of the thickness and the tension together, and the operation of the rolling mill is quickly stabilized by controlling the response to the tension deviation with high response.

The effect (interference) on the tension of the rolled material caused by the thickness control command or the influence (interference) on the thickness of the rolled material caused by the tension control command is determined by using an actuator having a fast response. Non-interference control is performed in phase with an interference phenomenon caused by a slow actuator, so that interference can be eliminated in real time, and control accuracy of thickness or tension can be improved.

Further, since the rolling control device of this embodiment can be applied universally regardless of the differences in the system configuration such as the hot or cold rolling process and the performance of the actuator, it can be flexibly applied to the system construction and its change. Can respond.

Next, another embodiment of the present invention will be described. Although the feedback control system 5-1 in FIG. 1 shows only the control amount feedback control, it may be an optimal servo system to which state feedback control for controlling the state amount deviation of the rolling process is added. That is, the deviation between the actually measured values of the roll-down position Si by the roll-down position detector 3-4, the front stand roll speed VRi-1 and the rear tension τb by the roll peripheral speed detector 3-3, and the set-up values is obtained. A speed control command and a rolling-down control command for making the deviation zero are calculated, added to the above-described speed control command or the rolling-down control command of the control amount feedback control system, and output. It should be noted that the self-stand roll speed VRi and the forward tension τf may be used as the state quantities as in the case of the previous embodiment.

According to this, by the state feedback control with a fast response, the disturbance of the plate thickness and the tension is suppressed at a higher speed, and the effect of the priority control according to the present invention can be further enhanced.

As still another embodiment, there is a configuration in which a plate thickness value immediately below a roll is used as a control amount. The outgoing plate thickness hi, the incoming plate thickness Hi (outgoing plate thickness of the front stand), the incoming plate speed Vei, and the outgoing plate speed Voi of the plate thickness gauge 3-1 shown in FIG. The calculation of (Equation 21) is performed to calculate the plate thickness hmi immediately below the roll.

[0085]

Hmi = Vei · Hi / Voi A control command is calculated by obtaining a sheet thickness deviation △ hi from the hmi and a target value base hrefi from the setup system.

According to this, since there is no delay in the control until the rolled material moves from immediately below the roll to the exit thickness gauge 3-1, the effect of the priority control and the non-interference control according to the present invention can be further enhanced. .

As still another embodiment, the sheet thickness deviation Δhi
Alternatively, a non-interference control system in which the tension deviation △ τi is directly input can be configured. In this case, (Equation 7), (Equation 8) or (Equation 11) and (Equation 12) are modified as (Equation 22).

[0088]

(Equation 22)

According to this, since the integral calculation in the case of the control command is not performed, the change rate of the input signal is large, and the same effect can be obtained by increasing the non-interference control gain.

[0090]

According to the present invention, while simultaneously controlling the thickness and the tension, the thickness is preferentially controlled when the tension is within a predetermined range, and the tension is preferentially controlled when the tension is out of the predetermined range. By rapidly suppressing a sudden change in tension in the inside, there is an effect that stable operation is maintained, and control accuracy of both the plate thickness and the tension is increased, thereby improving the product quality.

According to the present invention, non-interference control is executed by using the actuator having the higher response speed in response to the priority control, so that interference by the slow actuator can be suppressed in real time, and the plate thickness and the tension can be reduced. This has the effect of improving the control accuracy of.

Further, according to the present invention, it is possible to provide a general-purpose control system in which a system can be easily constructed or changed even when a combination of a cold rolling process and a hot rolling process or an actuator is different.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a rolling control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a rolling control system to which the present invention is applied.

FIG. 3 is a functional block diagram showing details of a feedback control unit and a non-interference control unit in a roll speed control command system;

FIG. 4 is a functional block diagram showing details of a feedback control unit and a non-interference control unit for a rolling-down position control command system;

FIG. 5 is a functional block diagram illustrating details of a priority control unit and a control gain calculation unit;

FIG. 6 is a flowchart showing a processing procedure of a priority control unit and a control gain calculation unit.

FIG. 7 is a flowchart illustrating a processing procedure of a non-interference priority control unit.

FIG. 8 is a dynamic diagram of a rolling system during a thickness priority control according to the present embodiment.

FIG. 9 is a dynamic diagram of a rolling system during tension priority control according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... rolling mill, 2 ... control apparatus, 3 ... detection apparatus, 4 ... setup control means, 5 ... DDC controller, 5-1 ... feedback control part, 5-2 ... non-interference control part, 5-3 ...
Control output unit, 5-4: priority control unit, 5-5: control gain calculation means, 6: rolling model, 7: observation device, 8: roll drive device, 9: rolling device, 21: threshold value setting means, 23
... Priority control determination means, 24 ... Control adjustment coefficient calculation means, 2
5: non-interference control device, dead time determining means, 26: non-interference adjustment coefficient determining means.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Kashiwagi 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture Inside the Omika Plant, Hitachi, Ltd. (72) Inventor Hiroshi Saito 5-chome Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Omika Factory (72) Inventor Naoki Katayama 2-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture In-house Hitachi Information & Control Systems Co., Ltd. (72) Kenichi Yoshioka 5-chome, Omika-cho, Hitachi City, Ibaraki Prefecture 2-1 Hitachi Information & Control System Co., Ltd. (72) Inventor Kenji Nakatani 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Omika Plant (72) Inventor Takashige Watari, Hitachi City, Ibaraki Prefecture 5-2-1 Omikacho Hitachi Information & Control Systems Co., Ltd. (72) Inventor Takashi Okada Omika, Hitachi City, Ibaraki Prefecture 7-1-1 1-1 Hitachi Works, Ltd.Hitachi Research Laboratories (72) Inventor Jin Cheol Jae South Korea Goedong-dong, Gyeongbuk, No. 1 Pohang Integrated Steel Corporation (72) Inventor Park Shun Ki South Korea Gyeongbuk, Pohang No. 1 Goesong-dong, Pohang, Sogo Steel Co., Ltd. (72) Inventor Kim Young-Gyu No. 1 Goesong-dong, Pohang, Gyeongbuk, Republic of Korea Inside Pohang Sogo Steel Co., Ltd. (56) References JP-A-5-31517 ( JP, A) Japanese Patent Publication No. 2-32041 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B21B 37/16-37/20 B21B 37/52

Claims (23)

(57) [Claims] 1. A method for controlling a rolling mill in which a thickness and a tension are simultaneously controlled, wherein a deviation of a measured tension value from a target value falls within a predetermined tension range (threshold value). Wherein the tension control is prioritized when the tension is out of the predetermined tension range. 2. The method according to claim 1 , wherein the predetermined tension range (threshold value) is a target value of the tension.
A method for controlling a rolling mill, wherein the method is set for each step of a tension set value . 3. The sheet thickness control gain according to claim 1 , wherein the sheet thickness control gain is prioritized by a tension control gain.
Control method of a rolling mill, characterized by high relative emissions. 4. The method of claim 3, wherein the thickness control gain, the control method of a rolling mill to be set as a function of the deviation of the measured values of the thickness with respect to the target value of the plate thickness. 5. The rolling mill control method according to claim 1 , wherein the priority of the tension control is such that the tension control gain is higher than the thickness control gain. 6. The rolling mill control method according to claim 5 , wherein the tension control gain is set higher than a value in a case where the priority is given to the tension control. 7. An actuating device for a pressing device and a roll driving device.
Of the rolling mill that controls the plate thickness and tension simultaneously by operating the
In the control method, it is caused by controlling the thickness or tension.
Interference with plate tension or plate thickness
Canceling by non-interacting control by actuator
A method for controlling a rolling mill. 8. The non-interference control according to claim 7, wherein the response speed of the screw-down device is faster.
In the case, the thickness deviation of the measured value against the target value of the thickness or
A control command to the roll driving device based on the thickness deviation
And the non-interference reduction command multiplied by the tension non-interference control gain
Control method of rolling mill characterized by output to reduction device
Law. 9. The non-interference control according to claim 8, wherein the response speed of the screw-down device is faster.
In the case, the tension deviation of the measured value against the target value of the tension or
A control command to the roll drive device based on the tension deviation
And the non-interference reduction command multiplied by the thickness non-interference control gain
Control method of rolling mill characterized by output to reduction device
Law. 10. The non-interference control according to claim 7, 8 or 9, wherein the actuator has a low response speed.
Rolling that is performed in accordance with the phase of interference
Machine control method. 11. An actuating device for a pressing device and a roll driving device.
Rolling mill that simultaneously controls sheet thickness and tension by operating
In the control method, the tension deviation of the measured value from the target tension value is determined in advance.
When the thickness is within the specified tension range (threshold value),
Priority is given to tension control when it is out of the predetermined tension range.
Prior to priority control performed by an actuator with a slow response speed.
Activate with high response speed to avoid interference caused by priority control
Cancellation by non-interference control of the heater
A method for controlling a rolling mill. 12. The apparatus according to claim 11, wherein said roll driving device controls said thickness, and said pressing device controls said thickness.
In the case of cold rolling with tension control, priority is given to the above thickness control.
Sometimes, the control command value to the roll driving device is
Greater than the control command value for the
The tension non-interference control command value based on the control command value
Output to the pressure reduction device having a high response speed.
Rolling mill control method. 13. The apparatus according to claim 11, wherein said thickness control is performed by said pressing-down device, and said thickness is controlled by said roll driving device.
In the case of hot rolling in which the tension control is performed, priority is given to the tension control.
Sometimes, the control command value to the roll driving device is
Greater than the control command value for the
The thickness decoupling control command value based on the control command value to the braking system
Output to the pressure reduction device having a high response speed.
Rolling mill control method. 14. A method according to claim 11, wherein
There are, the roll drive device, before rolling machine is of the stand
Control method. 15. For each stand by setup calculation
The target values of the set thickness and back tension and their actual measured values or
And the roll drive and pressure to eliminate deviations from the estimate.
Operate the lower device to simultaneously control the thickness and tension of the rolled material.
In the method for controlling a rolling mill, the roll driving device having a large response time constant is mainly
Control is mainly performed by the screw down device having a small response time constant.
In the case of cold rolling in which force control is performed, a classification in which the target value of the back tension is classified according to its magnitude.
For a predetermined tension range (threshold value) predetermined for each
The tension deviation between the target value of the back tension and the measured value is the predetermined tension.
When within the force range, the sheet thickness control command value is
If it is out of the range, the tension control command value is
The priority control for increasing the thickness is performed.
The non-interference control command value multiplied by the control gain is
Non-determined based on the response time constant of
Non-priority control of tension is performed with a delay of the interference command dead time.
Subtracted from the running tension control command value
A method for controlling a rolling mill, comprising: 16. A detection device and a setup calculation
Set-up control means for setting target values, etc.
Control to eliminate the deviation between the target value and the measured value of tension and tension.
Feedback control means and a control finger from the control means.
Equipped with a roll-down device and a roll drive device that operate according to the order,
In a control device for a rolling mill, which simultaneously controls a thickness and a tension, a predetermined tension set in advance for each classification for dividing a target value of the tension.
For the force range (threshold value), the deviation of the tension is within the range.
The thickness control, when the tension deviation is out of the range.
In some cases, the feedback
Priority control means for determining the control gain of the
A control device for a rolling mill, comprising: 17. The apparatus according to claim 16, wherein said priority control means is provided from said setup control means.
The thickness control gain and tension control gain
So that one is higher than the other in response to the control
Control gain adjustment coefficient calculating means
Rolling mill control device. 18. The method according to claim 16, wherein the sheet thickness is controlled by the feedback control system.
Tension non-interference control means for canceling interference with tension
Or the interference with the thickness caused by tension control
Equipped with non-interference control means having thickness non-interference control means
A control device for a rolling mill. 19. The tension non-interference control means according to claim 18, wherein
And the tension non-driving set in each of the plate thickness non-interference control means.
The interference control gain and the thickness non-interference control gain,
And the response time constant of the roll drive
Equipped with non-interference control gain adjustment means to enable or disable
Control device for a rolling mill. 20. The non-interference control gain adjusting means according to claim 19 , wherein
The time constant is small and the feedback control means is
The thickness control by the roll drive device is executed with priority.
When the thickness non-interference control gain is enabled,
It is configured to execute tension non-interference control means.
And a control device for a rolling mill. 21. The method according to claim 18, 19 or 20.
The non-interference control means outputs the output of the
Delay that is delayed according to the difference in the response time constant of the roll drive device
A control device for a rolling mill, comprising rolling means. 22. The method according to claim 16, wherein
And each of the state variables of the rolling position, tension and roll speed
Between the set value and the measured value from the setup control means.
State quantity feedback means for controlling to eliminate deviation
And an optimal server together with the feedback control means.
A control device for a rolling mill, comprising a boss system. 23. Measured sheet thickness and tension and their target values
Control for simultaneous control to eliminate deviations
Means and tension or thickness by controlling the thickness or tension
Non-interference control means for controlling so as to cancel interference of
A pressure reduction device that operates in response to a control command from these control means.
And a roll drive unit, and a pressure to simultaneously control the thickness and tension
In the control device of the rolling mill, it corresponds to the thickness deviation set in the feedback control system.
Control gain corresponding to the tension deviation
Differences in the cold or hot process used and / or
Control gay that changes according to thickness priority or tension priority control
Thickness adjustment means and a thickness deviation set in the non-interference control system.
Tension non-interference control gain corresponding to, corresponding to tension deviation
The sheet thickness non-interference control gain is adjusted by the rolling device and the roll drive
Decoupling control gain adjusted according to the response time constant of the moving device
A control device for a rolling mill, comprising adjusting means.