KR101668343B1

KR101668343B1 - Hydraulic reduction control device, adjustment method and control program of hydraulic reduction control device

Info

Publication number: KR101668343B1
Application number: KR1020150094134A
Authority: KR
Inventors: 사토시 핫토리; 다츠야 가와사키; 슈고 혼다
Original assignee: 가부시키가이샤 히타치세이사쿠쇼
Priority date: 2014-08-19
Filing date: 2015-07-01
Publication date: 2016-10-28
Also published as: JP2016045526A; KR20160022238A; JP6308914B2; CN106180213B; TW201607741A; CN106180213A

Abstract

In the hydraulic pressure reduction control device, the adjustment value for adjusting the control gain of the hydraulic cylinder on the down-side and the open-side is obtained with high accuracy.
A hydraulic pressure reduction control apparatus for controlling a position of a piston of a hydraulic cylinder that adjusts an interval between work rolls of a rolling mill, comprising: a measured value acquiring section for acquiring an actual value of a position of a piston in the hydraulic cylinder; And a control gain adjusting section for adjusting the control gain when the oil pressure control section for controlling the oil inflow amount controls the oil inflow amount to the hydraulic cylinder based on the command value of the position of the piston and the actual value of the position of the piston, A control signal for vibrating the position command value is output to the hydraulic control unit and the control gain is adjusted in the case of moving the position of the piston of the hydraulic cylinder in the direction to narrow the distance between the work rolls and in the direction to widen the gap between the work rolls To be determined based on the actual value of the adjustment signal It is gong.

Description

TECHNICAL FIELD [0001] The present invention relates to a hydraulic pressure reduction control device, a hydraulic pressure reduction control device, and a hydraulic pressure reduction control device,

The present invention relates to a hydraulic pressure reduction control device, an adjustment method and control program for a hydraulic pressure reduction control device, and more particularly to an automatic adjustment method of a hydraulic pressure reduction control device for controlling the vertical work roll interval of a rolling mill.

In the rolling mill, automatic control such as tension control, which is indispensable for the plate thickness control and the stability of the operation directly connected to the product quality of the pressurized steel, is performed. The overall configuration of a general rolling mill and a hydraulic pressure reduction control device is shown in Fig. As shown in Fig. 17, the working roll speed of the rolling mill and the upper and lower work roll intervals are used as the operation end (operation end) of automatic control of the rolling mill. The work roll speed is controlled by a dedicated roll speed control device. The upper and lower work roll intervals are controlled by a dedicated hydraulic pressure reduction control device.

The hydraulic pressure reduction control device (2) for controlling the work roll interval controls the roll gap by adjusting the position of the piston in the hydraulic cylinder (11) by adjusting the hydraulic pressure. Therefore, the hydraulic pressure reduction control device 2 determines that the position actual value detected by the position detector 13 for detecting the piston position of the hydraulic cylinder 11 in the position control loop is equal to or larger than the position actual value detected from the rolling mill control device 3 And controls the hydraulic pressure adjusting device 12 for adjusting the hydraulic pressure applied to the hydraulic cylinder 11 so as to coincide with the output position command value. The control response in the hydraulic pressure reduction control device 2 is determined by the control gain indicated by " G " in the hydraulic pressure reduction control device 2 of Fig. The position control response of the hydraulic pressure reduction control device 2 changes depending on the external conditions such as the oil column length of the hydraulic cylinder 11 and the oil temperature used for generation of the hydraulic pressure.

If the hydraulic pressure reduction control device 2 can not exhibit a sufficient position control response, the plate thickness accuracy, which is important in the quality of the pressure-sensitive material rolled by the rolling mill, is deteriorated. In addition, vibration may occur in the hydraulic cylinder, and the quality of the surface of the pressure-sensitive expanding member may deteriorate.

Therefore, at the trial run adjustment of the rolling mill, adjustment of the hydraulic pressure reduction control apparatus is sufficiently performed by taking the step response and frequency response of the position control loop (see, for example, Patent Document 1). The adjustment operation by this frequency response requires a long time for adjustment because there is a need to connect a detector called FFT (Fast Fourier Transform) analyzer to the hydraulic pressure reduction control device. Therefore, conventionally, when an abnormality has occurred after adjustment at the time of trial drive adjustment, only the control gain G is reduced. Therefore, there is a problem in that the response of the hydraulic pressure reduction control device adjusted at the trial drive adjustment can not be maintained.

Japanese Patent Application Laid-Open No. 2009-282609

The hydraulic cylinder in the rolling mill is usually provided on the lower side of the rolling mill and is configured to adjust the piston position of the cylinder in the direction of reducing the work roll distance by pushing the work roll by applying hydraulic pressure from the lower side. On the other hand, the push-down side is always in a state in which a constant hydraulic pressure is applied, and a reaction force of a rolling load is applied to the push-down side, It is possible to move the push-down cylinder up and down by breaking the balance between the push-down side and the push-up side. That is, in the hydraulic cylinder, the hydraulic pressure on the push-up side is adjusted by the hydraulic pressure regulating device.

As described above, the push-down cylinder operates by a balance between the push-up side and the push-down side, and the hydraulic pressure drop control device changes the piston pressure of the cylinder by changing the hydraulic pressure on the push-up side. Therefore, the operation response differs depending on the sum of the machine weight and the rolling reaction force, which is the force applied to the push-down side. As a result, the response on the down-ward side becomes different from that on the open side, and a phenomenon occurs in which the push-down position performance does not follow the command value.

In order to solve such a problem, control for changing the gain of the position control loop (hereinafter referred to as " differential pressure compensation ") is performed on the down-pressure side and the open side in the push-down position control device. On the other hand, in the technique disclosed in Patent Document 1, the differential pressure compensation is not considered.

By using the above-described step-shaped waveform as an input signal, it is possible to adjust the respective gains on the down-side, the open-side, and the like. However, in a measurement method using a step response with a large deviation during measurement, it is difficult to make sufficient adjustment, and a calculated value from the mechanical structure is set. Therefore, there are many cases in which the computed value is not matched with the actual operating state of the hydraulic pressure reduction control device, and the control response is different between the down-pressure side and the open side. In this case, even if the roll gap is manipulated by the plate thickness control, the waveform of the command value differs from that of the actual value, thereby deteriorating the plate thickness control accuracy.

An object of the present invention is to obtain an adjustment value for adjusting the control gain of the hydraulic cylinder on the down-side and the open-side with high accuracy in the hydraulic pressure reduction control device.

One aspect of the present invention is a hydraulic pressure reduction control apparatus for controlling a position of a piston of a hydraulic cylinder that adjusts a gap between work rolls of a rolling mill, the hydraulic pressure reduction control apparatus comprising: an actual value acquiring section that acquires an actual value of a position of a piston in the hydraulic cylinder; And a control gain adjusting section for adjusting the control gain when the oil pressure control section for controlling the oil inflow amount to the hydraulic cylinder controls the oil inflow amount to the hydraulic cylinder based on the command value of the position of the piston and the actual value of the position of the piston And a control signal for vibrating the position command value at a predetermined frequency is output to the hydraulic control unit and the position of the piston of the hydraulic cylinder is moved in a direction to narrow the gap between the work rolls and in a direction to widen the gap between the work rolls The differential pressure compensation value for adjusting the control gain in the case of moving is determined based on the measured value for the adjustment signal Characterized in that the decision over.

By using the present invention, an adjustment value for adjusting the control gain of the hydraulic cylinder on the down-side and on the open-side can be obtained with high accuracy in the hydraulic pressure reduction control device.

1 is a block diagram showing an entire automatic adjustment of a hydraulic pressure reduction control device according to an embodiment of the present invention.
2 is a block diagram showing the entire control of the rolling mill according to the embodiment of the present invention.
3 is a view showing an example of operation of the rolling mill according to the embodiment of the present invention.
4 is a flowchart showing the role reorganization processing operation according to the embodiment of the present invention.
5 is a view showing a configuration of a hydraulic cylinder according to an embodiment of the present invention.
6 is a diagram showing the relationship between the open-side correction gain and the downside correction gain according to another embodiment of the present invention.
7 is a block diagram showing a functional configuration of a control gain adjusting device according to an embodiment of the present invention.
8 is a view showing an adjustment method by measuring the frequency response of the hydraulic pressure reduction control device according to the embodiment of the present invention.
9 is a diagram showing an example in which the differential pressure compensation gain is improper in the adjustment method by measuring the frequency response of the hydraulic pressure reduction control device according to the embodiment of the present invention.
10 is a flowchart showing an adjusting operation of the hydraulic pressure reduction control device by the frequency response measurement according to the embodiment of the present invention.
11 is a diagram showing an input waveform in the response measurement method using the simplified input waveform according to the embodiment of the present invention.
12 is a diagram showing an example of a case where the differential pressure compensation gain is appropriate or inappropriate in the response measurement method using the simple input waveform according to the embodiment of the present invention.
13 is a flowchart showing an adjustment operation of the hydraulic pressure reduction control apparatus based on the simple input waveform according to the embodiment of the present invention.
Fig. 14 is a flowchart showing the timing of response adjustment in the simple input waveform according to the embodiment of the present invention. Fig.
15 is a flowchart showing an adjustment operation of the differential pressure compensation gain according to the embodiment of the present invention.
16 is a block diagram showing the hardware configuration of the control apparatus according to the embodiment of the present invention.
17 is a block diagram showing the entire automatic adjustment of the hydraulic pressure reduction control device related to the related art.

In this embodiment, a single stand mill including a single mill stand 1, a left reel 101 and a right reel 102 as shown in Fig. 1 is taken as an example of an adjustment method of the hydraulic pressure reduction control device 2 .

The single stand rolling mill includes a single rolling mill stand and left and right reels 101 and 102 for unwinding or winding the rolled coiled material in the form of coils on the left and right sides of the rolling mill stand. When the rolling direction is the rightward direction, the rolled material is rolled off from the left reel 101, rolled in the mill stand 1, and then wound on the right reel 102.

The rolled material rolled up on the right reel 102 is unwound from the right reel 102 in the rolling direction in the left direction and is rolled again in the rolling stand 1, And wound around the left reel 101. [ This process is carried out until the prescribed product specification is satisfied for each pressurized steel product, thereby producing a pressurized steel product which becomes a product.

The rolling mill stand 1 is constituted by a plurality of rolls. The rolling pressure applied to the pressurized steel strip from the upper and lower work rolls 104, which sandwich the pressurized strip 103 from above and below, and the rolling pressure applied to the pressurized steel strip by the motor driving the left- The rolled material is pressed and extended by the applied tensile force so that rolling is performed.

An outline of the control method of the rolling mill is shown in Fig. The plate thickness precision in the longitudinal direction (rolling direction) is the most important in the rolled products produced by rolling mills. As shown in Fig. 2, on the left and right of the rolling mill stand 1, there are provided an inlet-side plate thickness meter 111 and an outlet-side plate thickness meter 112. The outputs of the input side thickness gauge 111 and the output side thickness gauge 112 are fed to the FF AGC 116 and the FB AGC 117 in the rolling mill control device 3 Respectively. The FF AGC 116 and the FB AGC 117 modify the position command value output from the rolling mill control unit 118 in the rolling mill control apparatus 3 on the basis of the input thickness of the pressurized steel strip. By such control, the work roll interval (roll gap) is controlled, and the plate thickness accuracy in the longitudinal direction is maintained.

The rolling operation is performed such that the rolling mill controller 118 rotates the left reel 101, the right reel 102 and the rolling mill control unit 113 for the left reel control unit 114, the right reel control unit 115 and the mill speed control unit 113, And outputting a signal for controlling the roll speed of the stand 1. The rolling mill control unit 118 operates the rolling mill stand 1 in accordance with various commands inputted by the operator of the rolling mill operating the operation board 110. [

Fig. 3 shows an operation example of the rolling mill. As shown in Fig. 3, in the present embodiment, the operation mode of the rolling mill is selected in the operation mode selection SW 150 provided in the rolling mill controller 3. In this embodiment, as the operation mode, there are a normal "rolling" operation, a "stop operation" for stopping the rolling operation, and a "roll reorganization". The " roll re-formation " is a mode in which rolls are exchanged regularly or when roll surface conditions deteriorate remarkably because the work rolls, intermediate rolls, backup rolls, etc. are worn by the rolling operation.

When " roll reorganization " is selected, the rolling mill controller 118 stops the rolling mill and opens the rolling mill. In this state, the operator carries out roll replacement (exchange of work roll, intermediate roll and backup roll as necessary). Thereafter, the operator presses the " zero point adjustment process start " SW, and the rolling machine controller 118 performs the zero point adjustment process. Each roll has different roll diameters because the surface is abraded by rolling and the surface is polished and used again. Therefore, the combination of the roll diameters before and after the roll reformation is different.

Although the position of the piston in the hydraulic cylinder 11 can be measured by the position detector 13, the size of the roll gap varies depending on the combination of the roll diameters, even at the same position. Therefore, It is necessary to match with some reference value. Normally, the roll down is closed, and the piston position where the rolling load becomes, for example, 5000 kN is defined as roll gap = 0, and the zero point adjustment processing is performed.

Referring to FIG. 4, the zero point adjustment process according to this embodiment will be described. In the zero point adjustment processing (S401), the process of tightening the pressure until the upper and lower work rolls touch (S402, S403), and thereafter the roll is revolved (the rolled material is driven at a low speed (Roll gap zero adjustment) (S407) in which the roll gap is set to 0 in the state that the rolling load becomes 5000 kN (S404) ) Is executed. Thereafter, the roll is released to stop the roll revolution (S408), and the zero point adjustment processing is terminated.

When the "rolling" mode in which the rolling operation is carried out, the operator operates the rolling operation of the rolling machine by using the SW of "rolling", "acceleration", "holding" and "stop" do. This SW is provided in the rolling mill control device 3 in the same manner as the operation mode selection SW 150. As shown in Fig. 3, by selecting " rotary ", the rolling mill accelerates to the rotary speed and operates at the speed. Next, "acceleration" is selected to accelerate the rolling speed. Then, when "keep" is selected, the operation continues at the rolling speed at that point. In this state, rolling is performed. Thereafter, the "rolling" is selected so that the rolling speed is decelerated to the deceleration speed, and the "stop" is selected, so that the rolling speed becomes zero and the rolling mill can be stopped.

As described above, since the rolling mill controlling apparatus 3 receives the command from the operator of the rolling mill and operates the rolling mill, it is possible to recognize what state the rolling mill is in (whether it is being rolled or undergoing roll reorganization) Do. Therefore, in the control system of the rolling mill according to the present embodiment, it is possible to change the method of adjusting the hydraulic pressure reduction control device according to the state of the rolling mill.

Fig. 5 shows details of the hydraulic cylinder 11. Fig. As shown in Fig. 5, in the hydraulic cylinder 11, the back pressure side and the down pressure side are balanced in a minute state. On the back pressure side, a constant fixed pressure is always applied, and a reaction force of the rolling load of the rolling mill is applied. The hydraulic pressure applied from the hydraulic pressure generator 14 is adjusted by the hydraulic pressure regulator 12 on the down-pressure side.

The hydraulic pressure reduction control device 2 operates the hydraulic pressure regulator 12 so as to increase the oil inflow amount to the hydraulic cylinder 11 so that the hydraulic pressure on the downside side is larger than the back pressure side. On the other hand, in the case of opening, the hydraulic pressure regulator 12 is operated so that the oil pressure on the down-side is made smaller than the oil pressure on the back-pressure side. Therefore, the pressure on the down-pressure side required for pressing down or opening changes due to the sum of the rolling load and the fixing pressure of the rolling mill, which is the pressure applied to the back pressure side, and the control response changes.

If the control response differs between the down-pressure side and the open-side, the differential pressure compensation gain is set such that the control response is made equal because the control such as AGC is adversely affected. For example, when the rolling load is large and the downside is difficult to operate, the differential pressure compensation gain on the downside is increased and the differential pressure compensation gain on the open side is reduced. That is, the downside correction gain and the open side correction gain as shown in FIG. 6 are set. This differential pressure compensation gain is used as the differential pressure compensation value.

In the hydraulic pressure reduction control device 2, a position deviation which is a difference between a position actual value detected by the position detector 13 and a position command value outputted from the rolling mill control device 3 is multiplied by a control gain G and a differential pressure compensation By integrating the gain (G _diff ), the control output to the hydraulic pressure regulator is determined. Here, " position deviation = position command value-position actual value ". The differential pressure compensation gain G _diff is determined on the basis of the position deviation by the differential pressure compensation gain setting section 21. The differential pressure compensation gain setting section 21 determines whether to use the downward correction gain or the open-side correction gain according to the sign of positional deviation.

6 is a graph showing changes in the values of the open side correction gain and the downside correction gain according to the values of the rolling load, and the bottom of Fig. 6 is a table showing values actually set. 6, the differential pressure compensation gain is a set of values of the open side correction gain and the downside correction gain, respectively.

Since the responsiveness to the position command value is adjusted by the control gain G, the differential pressure compensation gain (G _diff ) is a coefficient for adjusting the difference in responsiveness between the down-side and the open-side. To maintain the overall responsiveness adjusted by the control gain G, the set of the open-side correction gain and the down-side correction gain is set so that the product of the down-side correction gain and the open-side correction gain becomes 1 do.

For example, assuming that the larger piston position of the cylinder is on the downside and the smaller is on the open side, the differential pressure compensation gain setting section 21 operates on the open side when the positional deviation is on the minus side, Select the gain. On the other hand, in the case of the positive side, since it operates on the down side, the downside correction gain is selected.

Since the correction gain on the down-side and the open-side also changes depending on the outside temperature or the piston position of the hydraulic cylinder 11, when the difference between the down and open sides is large and the difference is large, it is necessary to change the control correction gain . Since it is necessary to measure the response on the down-sizing side and the open side, it is confirmed by using the step input. However, in the step waveform, even if there is a difference in the response on the down-pressure-side open side, it is often not apparent as a clear response, so adjustment is difficult.

When the step input is used, in the adjustment of the control correction gain, the rise time of the waveform is measured with respect to the down-side and the open-side, and when the difference is large, the control correction gain on the down- . As a result, since the control response also changes, it is necessary to measure the frequency response again, which requires time for adjustment.

The adjustment of the hydraulic pressure reduction control device is performed by using the control gain adjusting device 4 as shown in Fig. The measurement method setting device 404 receives an instruction as to how to measure from the adjustment method selection device 6 according to the state of the rolling mill, and selects a measurement method. Then, the measurement method setting device 404 notifies the signal generation device 401 of the determined measurement method. As a result, the signal generator 401 generates an input waveform according to the measurement method.

The measurement method setting apparatus 404 notifies the signal analyzing apparatus 402 of how to interpret the input signal and the output signal. The control gain changing device 403 adjusts the control gain based on the analysis result in the signal analyzing device 402 and notifies the hydraulic pressure reduction control device.

As an adjustment method of the hydraulic pressure reduction control device selected by the adjustment method selection device 6 described above, there are two types of methods in this embodiment, namely, measurement by frequency response and simple input waveform. Hereinafter, a description will be given of " adjustment method 1 " by measuring the frequency response and " adjustment method 2 " by the simple input waveform.

First, the adjustment method 1 will be described with reference to FIG. 8 is a sweep frequency waveform outputted by the signal generating apparatus 401 when adjustment of the adjustment method 1 is carried out. 8 is a board diagram of a response waveform to the input waveform at the upper end, that is, a waveform of the waveform of the detection signal by the position detector 13. Fig. In the adjustment method 1, the control gain is adjusted so that the phase margin is better than the target phase margin at the target frequency set for each mechanical device of the rolling mill.

For example, when the board diagram of the frequency response in the case of the control gain A is indicated by the dashed line at the bottom of Fig. 8, the " target phase margin " In this case, assuming that the hydraulic pressure reduction control device 2 has a large control gain and a control gain B, and a board line like the solid line is obtained, since the target phase margin is satisfied at the "target frequency" The control device 2 selects the control gain B. [

The "target frequency" refers to a frequency corresponding to the maximum change frequency that can be thought of as the change frequency of the control signal when the hydraulic pressure reduction control device 2 controls the hydraulic pressure adjustment device 12 Frequency. The above-mentioned " target phase margin " is a value indicative of the followability required for the measured value of the maximum change frequency of the control signal described above, and is, for example, -90 degrees. The reason why the " target frequency " is set to a frequency corresponding to the maximum frequency of change is that in the feedback control, the followability generally becomes worse as the frequency becomes larger.

As shown in the upper part of Fig. 8, a sinusoidal wave whose frequency changes is used as the input waveform. The signal generating apparatus 401 also inputs a reverse waveform obtained by inverting the amplitude of the waveform shown in the upper part of Fig. Since the net waveform and the reverse waveform are sinusoidal waves, the hydraulic pressure reduction control device is divided into a frequency band that operates in the downward direction and a frequency band that operates in the open side. Therefore, when the control response of the hydraulic pressure reduction is different between the down-pressure side and the open-side, as shown in Fig. 9A, the case of inputting the net waveform and the case of inverting the sign of the amplitude as shown in Fig. , The frequency response is different.

9 (a) and 9 (b), it can be seen that the phase delay is different in the frequency measurement result in the state where the control response on the down-side and the open side are different from each other, and in the portion surrounded by the broken line. Whether the result of the control on the down-side or the control on the open side can be judged on the basis of the frequency based on the input waveform shown at the top of Fig. 8 at the position of the horizontal axis of the board diagram. Therefore, if the phase delay is different from that of the forward and reverse waveforms, it is possible to determine whether the value of the differential pressure compensation gain set is shifted to the down-side or the open-side.

9 (a) and 9 (b), the graphs in the case where the gains on the down-sizing side and the open side are in an ideal state are indicated by broken lines. The graph of the ideal value can be obtained, for example, by taking an average value of each graph shown by a solid line in Figs. 9 (a) and 9 (b). The shift amount of the down-side correction gain and the open-side correction gain can be obtained from the difference between the solid line graph and the broken line graph.

Therefore, the signal analyzing apparatus 402 adjusts the differential pressure compensation gain by changing the differential pressure compensation gain set on the basis of the smoothing amount of the down-side correction gain and the open-side correction gain obtained by calculation.

Next, the processing when the adjustment of the adjustment method 1 is automatically performed will be described with reference to FIG. In the example of Fig. 10, a case where the input signal frequency at the phase delay of -90 degrees is adjusted to be the set frequency is considered. 10, first, the control gain adjustment device 4 measures the frequency response using appropriate control gain = X and control gain = Y (S1001, S1002).

After performing the processes of S1001 and S1002, the control gain adjustment device 4 checks the measurement result (S1003), and adjusts the frequency of the -90 ° phase delay (-90 degrees in the control gain X and the control gain Y XR and YR). Then, the control gain adjustment device 4 changes the control gain from the gain setting (X, Y) and the target frequency (xref) to x by linear approximation according to the following equation (1) (S1004). Then, the control gain adjustment device 4 again measures the frequency response using the sweep waveform (S1005).

After performing the processing of S1005, the control gain adjustment device 4 checks the result (S1006). If it is not the set frequency (S1007 / NO), the current control gain x and the current control gain The frequency (xR) of the phase delay is replaced by Y and YR, respectively, and the control gain is changed again (S1004 and S1005).

On the other hand, if it is determined in step S1006 that the set frequency is set (YES in step S1007), the control gain adjustment device 4 performs the adjustment operation of the differential pressure compensation gain. The adjustment operation of the differential pressure compensation gain will be described in detail later.

As described above, in the adjustment of the adjustment method 1 according to the present embodiment, the control gain adjustment device 4 repeats the control gain change and the frequency response measurement, thereby achieving the control in which the frequency of -90 degrees phase delay can be set as the target frequency The gain (x) is set as the control gain setting value. It is desirable to provide an allowable range for the target frequency, and to make a result check OK when the -90 degree phase delay frequency is within a certain range.

Further, after the control gain adjustment is appropriately performed, the differential pressure compensation gain set without shifting to the down-side correction gain and the open-side correction gain is selected by repeating the change of the differential pressure compensation gain set and the frequency response measurement. Ideally, it is preferable to select a differential pressure compensation gain set in which the forward waveform is input when the forward waveform is input and the reverse waveform is input when the reverse waveform is input. However, it is preferable to provide a certain allowable range, The check may be made when the amount of deviation of the open side correction gain is within a predetermined range.

In the case of performing the adjustment by the frequency response measurement, since it is necessary to input the sweep waveform as shown in the upper part of Fig. 8, there is a problem that it takes time for one measurement. As the sweep waveform, for example, frequency components from 1 Hz to 50 Hz need to be included, and a measurement time of about 30 seconds is required for one sweep. Therefore, in the case where the roll re-formation is carried out during the rolling operation due to the time taken for the measurement, the adjustment method related to the adjustment method 1 can not be used when the measurement can not be performed for a long time in order to resume the rolling operation as soon as possible.

Next, the adjustment method 2 will be described with reference to Fig. In order to confirm the frequency response in a short time and set the control gain, it is necessary to perform quick measurement at the target frequency. Therefore, in the adjustment method 2, the signal generating device 401 outputs a waveform composed of a single frequency component, and performs adjustment based on the response signal.

11 is a diagram showing a frequency component of 25 Hz as an example of a waveform outputted by the signal generating apparatus 401 when adjustment of adjustment method 2 is carried out. 11 shows the output waveform of the signal generator 401 and the output of the actual value of the position detector 13 with respect to the output waveform of the signal generator 401 at a frequency lower than the actual 10 Hz in order to explain the principle of the adjustment method 2. [ Fig.

As shown in Fig. 11, in the adjustment method 2, the signal generating apparatus 401 increases the waveform consisting only of the target frequency from the amplitude 0 to the set maximum amplitude, attenuates the amplitude to zero after reaching the predetermined maximum amplitude value And the measurement is terminated. The reason for this waveform is that when the target frequency component is added at the set maximum amplitude, the rolling machine machine or the roll may be damaged. That is, by using the waveform as shown in the upper part of Fig. 11, damage to the rolling machine machine or the roll can be avoided.

As shown in the lower part of Fig. 11, by comparing the input waveform and the output waveform, it is possible to easily measure the magnitude of amplitude and the phase delay in the case of a single frequency component. As for the value of the phase delay, a correlation coefficient is obtained by shifting the input waveform and the output waveform by a minimum sampling resolution, and a value which shifts the input waveform and the output waveform when the correlation coefficient becomes minimum is used. In this case, since the phase difference at the target frequency can be predicted from the measurement result of the frequency response measurement, that is, the measurement result of the adjustment method 1, the input waveform and the output waveform are shifted before and after the prediction shift, It is possible.

When the waveform shown in the upper part of FIG. 11 is used as the input waveform for measurement, it is possible to perform the measurement once in about 5 seconds. Since the FFT calculation is required for measuring the frequency response, a large calculation time is required. However, since only the correlation coefficient is taken in the measurement in the simple waveform, the calculation amount can be reduced and the control gain adjustment device 4 ) Can also be processed quickly.

12A and 12B show a method of adjusting the differential pressure compensation gain of the hydraulic pressure reduction control device when a simple input waveform is used. If there is no difference in the response of the hydraulic pressure reduction control on the down-pressure side and the open-side, as shown in Fig. 12 (a), the actual waveform is evenly distributed on the downside and the open side. On the other hand, when the response on the downward side is better than that on the open side, for example, as shown in Fig. 12 (b), the center of vibration of the input waveform is biased downward.

From this, it is possible to adjust the differential pressure compensation gain if it is possible to determine in which direction the output waveform of the position actual value has shifted in the case of inputting the simple measurement waveform as the position command value. (Hereinafter referred to as " response difference index ") (P _INDEX ) for determining whether the deviation is shifted to one of the values fb ( i) can be used. Here, n is the total number of each value constituting the output waveform.

12A, when there is no difference in the responses of the hydraulic pressure reduction control on the down-pressure side and the open-side, and the actual waveform is uniformly distributed on the down-side and the open-side, the determination index P _INDEX is It becomes zero or close to zero. On the other hand, when the distribution is biased downward as shown in Fig. 12 (b), the determination index P _INDEX becomes a positive value. Conversely, when the distribution is shifted toward the open side, the determination index (P _INDEX ) becomes a negative value.

Therefore, when the determination index (P _INDEX ) obtained by the calculation of the above expression (2) is positive based on the output waveform, the signal analyzing apparatus 402 determines that the downward correction gain is smaller than the current differential pressure compensation gain set , And a set with a larger open-side correction gain is selected. On the other hand, when the determination index P _INDEX is negative, the signal analyzing apparatus 402 selects a set whose downside correction gain is larger than the current set of differential pressure compensation gain, and whose open side correction gain is small.

Next, the processing when the adjustment of the adjustment method 2 is automatically performed will be described with reference to FIG. As shown in Fig. 13, first, the control gain adjustment device 4 measures the frequency response using appropriate control gain = X and control gain = Y (S1301, S1302).

After performing the processes of S1301 and S1302, the control gain adjustment device 4 checks the measurement results (S1303) and sets the phase delay values (XD and YD) in the control gain (X) and the control gain (Y) . The control gain adjustment device 4 sets the gain setting value x at which the phase delay value is -90 degrees based on the gain setting (X, Y) and the phase delay value (XD, YD) Is approximated by linear approximation using the equation (3) in (S1304). Further, " xref " in the expression (3) is the phase delay value of the target, that is, -90 degrees.

Then, the control gain adjustment device 4 performs the response measurement with the simplified waveform again using the control gain set value (x) obtained in S1304 (S1305). After performing the process of S1305, the control gain adjustment device 4 checks the result (S1306), obtains the phase delay value xD in the control gain x, and determines whether the phase delay value xD is If the phase delay of -90 DEG is not satisfied (NO in S1307), the current control gain x and the phase delay value xD are replaced by Y and YR, respectively, and the control gain is changed again to perform the measurement (S1304, S1305).

On the other hand, if it is determined in step S1306 that the phase delay value xD satisfies the phase delay of -90 degrees (YES in step S1307), then the control gain adjustment device 4 performs the adjustment operation of the differential pressure compensation gain (S1308). The adjustment operation of the differential pressure compensation gain will be described in detail later.

In the state where the rolling mill is stopped, the above-described measurement of the frequency response and the response adjustment by the simple input waveform are possible, but when the rolling mill is in the operating state, the measurement input waveform shown in FIG. It is not possible to give to the push-down control device because of deterioration of plate thickness accuracy or disturbance of operation.

Fig. 14 is a flowchart showing an example of the timing for performing the adjustment by the adjustment method 2, and shows a case where the adjustment is performed in the roll exchange and roll gap adjustment processing described in Fig. As shown in Fig. 14, steps S1401 to S1407 are executed in the same manner as S401 to S407 in Fig. After executing the roll gap zero point adjustment processing, the adjustment by the above-described adjustment method 2 is executed (S1408). Thereafter, similarly to S408 of Fig. 4, the roll is opened to stop the roll revolution (S1409), thereby completing the zero point adjustment processing.

After completion of the roll gap zero point adjustment after the roll reorganization, since the condition for applying the load to the rolling mill and determining the reference value of the roll down position is established, the measurement can be performed under a constant condition every time the roll reorganization is performed. Therefore, by performing the adjustment by the adjustment method 2 at this timing, it is possible to efficiently operate the apparatus.

In order to carry out the adjustment of the adjustment method 2, at least a frequency for generating a waveform as shown in Fig. 11, that is, information of the target frequency is required. This information is stored in advance in the storage medium installed in the signal generating apparatus 401 by the operator, and the signal generating apparatus 401 generates and outputs a waveform as shown in Fig. 11 based on the information .

Next, the adjustment operation of the differential pressure compensation gain according to the present embodiment will be described with reference to Fig. As shown in FIG. 13, when the adjustment of the differential pressure compensation gain is started, first, the control gain adjustment device 4 uses the appropriate differential pressure compensation gain set = X and differential pressure compensation gain set = Y to measure the frequency response (S1501, S1502).

In the process of S1501 and S1502, the control gain adjustment device 4 uses the output waveform shown in the upper part of Fig. 8 when the adjustment method 1 is being adjusted, and when the adjustment method 2 is being adjusted, The output waveform is used.

After performing the processes of S1501 and S1502, the control gain adjustment device 4 checks the measurement results (S1503) and determines whether the pressure reduction gain set X and the differential pressure compensation gain set Y are in the down- Side control gain. At this time, in the case of the adjustment method 2, the above-described response difference index is acquired.

Then, the control gain adjustment device 4 calculates the differential pressure compensation gain set x (x) in which the control gain is not shifted based on the differential pressure compensation gain set (X, Y) and the deviation of the control gain on the down- (S1504). In S1504, the control gain adjustment device 4 performs linear approximation similarly to the above-described equations (1) and (2), and sets the differential pressure compensation gain set closest to the result to the following equation From the table.

Then, the control gain adjustment device 4 performs the response measurement again using the differential pressure compensation gain set x obtained in S1504 (S1505). After performing the processing of S1505, the control gain adjustment device 4 checks the result (S1506), obtains the deviation of the control gains on the down and open sides in the differential pressure compensation gain set x, If the result is out of the permissible range (S1507 / NO), the current differential pressure compensation gain set x is replaced with Y, and the differential pressure compensation gain set is changed again to perform the measurement (S1504, S1505). On the other hand, if the check result in S1506 is within the allowable range (YES in S1507), the control gain adjustment device 4 ends the process.

The operation of this embodiment will be described with reference to Fig. The rolling machine condition determination device 5 determines the state of the rolling machine based on the information of the rolling condition, the roll reformed condition, and the operation stop status from the rolling mill controller 3. The adjustment method selection device 6 selects the adjustment method 2 when the roll is in roll-rest state, and the adjustment method 1 when it is in the operation stop state based on a result of the determination by the rolling-stock machine discrimination device 5.

The adjustment method selection device 6 selects a table (hereinafter referred to as an adjustment method selection table) indicating the correspondence between the determination result by the rolling machine condition determination device 5 and the adjustment method to be selected accordingly to the internal storage medium And selects the adjustment method corresponding to the determination result by the rolling-stock set discriminating apparatus 5 based on the table.

The control gain adjustment device (4) performs the response adjustment according to the adjustment method selected by the adjustment method selection device (6). 7, the measurement method setting device 404 generates an input signal to the signal generating device 401 based on the selection information of the adjustment methods 1 and 2 from the adjustment method selection device 6, For the signal analyzing apparatus 402, a timing for receiving the input signal and the output signal and a method of analyzing the signal are set.

In the signal analyzing apparatus 402, signal processing such as FFT or pattern matching is performed according to each of the adjustment methods 1 and 2 to determine whether or not the control gain is suitable, and how the control gain is changed is determined by a control gain changing device 403. The control gain changing device 403 changes the control gain G and the differential pressure compensation gain G _diff of the hydraulic pressure reduction control device on the basis of the signal inputted from the signal analyzing device 402. [ With such a process, it is possible to adjust the hydraulic pressure reduction control device by selecting the optimum adjustment method according to the state of the rolling mill, and it becomes possible to use the hydraulic pressure reduction control device in the optimum state at all times.

Here, the hydraulic pressure reduction control device 2, the rolling mill control device 3, the control gain adjustment device 4, the rolling mill condition determination device 5 and the adjustment method selection device 6 (hereinafter, Will be described with reference to Fig. 16. Fig. 16 is a block diagram showing the hardware configuration of the control apparatus according to the present embodiment. As shown in Fig. 16, the control apparatus according to the present embodiment has the same configuration as an information processing terminal such as a general server or a PC (Personal Computer).

That is, the control apparatus according to the present embodiment includes a CPU (Central Processing Unit) 201, a RAM (Random Access Memory) 202, a ROM (Read Only Memory) 203, a HDD (Hard Disk Drive) And an I / F 205 are connected via a bus 208. An LCD (Liquid Crystal Display) 206 and an operation unit 207 are connected to the I / F 205.

The CPU 201 is an operation means and controls the operation of the entire control device. The RAM 202 is a volatile storage medium capable of high-speed reading and writing of information, and is used as a work area when the CPU 201 processes information. The ROM 203 is a read-only nonvolatile storage medium, and stores programs such as firmware.

The HDD 204 is a non-volatile storage medium capable of reading and writing information, and stores an OS (Operating System), various control programs, applications, programs, and the like. The I / F 205 controls the bus 208 by connecting various hardware or a network. The LCD 206 is a visual user interface for the user to check the status of the control device. The operation unit 207 is a user interface for a user such as a keyboard or a mouse to input information to the control device.

In such a hardware configuration, a program stored in a recording medium such as the ROM 203 or the HDD 204 or an optical disk, not shown, is read into the RAM 202 and operated under the control of the CPU 201, . The function of the control apparatus according to the present embodiment is realized by a combination of hardware and software configured in this manner.

1 may be configured as a single apparatus having the configuration shown in Fig. 16, and in the information processing apparatus having one configuration shown in Fig. 16, the control apparatus shown in Fig. 1 It is also possible to realize a plurality of functions of each control device.

1, the apparatus for controlling the hydraulic pressure regulator 12 is described as a hydraulic pressure reduction control device 2 in a narrow sense. However, the hydraulic pressure reduction control device 2 may be configured to control the hydraulic pressure regulator 12 The rolling mill control apparatus 3, the control gain adjusting apparatus 4, the rolling mill condition determining apparatus 5 and the adjusting method selecting apparatus 6 function in conjunction with each other as described above. That is, as a whole of such a device, a hydraulic pressure reduction control device in a broad sense is constituted. In this case, the control gain adjustment device 4 functions as the actual value acquisition portion, the control gain adjustment portion, and the operation state determination result acquisition portion. Further, the hydraulic pressure reduction control device 2 functions as a hydraulic pressure control section.

As described above, according to the control gain adjusting device 4 for adjusting the control gain of the hydraulic pressure reduction control device 2 according to the present embodiment, as shown in Fig. 11, The control signal for oscillating the position command value is outputted and the control gain is adjusted based on the measured value for the adjustment signal. At this time, the differential pressure compensation gain is determined on the basis of the deviation of the center of vibration in the amplitude of the measured value.

With this processing, it is possible to perform high-precision adjustment with little adjustment error due to deviation during measurement. In the hydraulic pressure reduction control device, the adjustment value for adjusting the control gain of the hydraulic cylinder on the down- It is possible to acquire it with high accuracy.

1, the hydraulic pressure reduction control device 2, the rolling mill control device 3, the control gain adjustment device 4, the rolling mill condition determination device 5, and the adjustment method selection device 6, However, as described above, such a device cooperates to control the rolling mill. That is, the control system of the rolling mill is constituted by interlocking these devices.

Further, in the above embodiment, as a condition for carrying out the adjustment of the adjustment method 2, the roll reorganization state has been described as an example. In addition, it is possible to consider conditions under which adjustment of adjustment method 2 should be performed. For example, it is possible to change the roll shift position, to change the pressure-applying member, to change the rolling condition, to adjust the pass line of the rolling stand 1, and the like.

The roll shift position change is a case where the rolls are shifted in the direction of the rotation axis of the roll. In this case, since the load applied to the work roll 104 is changed, the control response to the control gain also changes. When the roll shift position is changed, the rolling operation is stopped. Therefore, when the roll shift position is changed, it is suitable as a case of adjusting the adjustment method 2.

The change of the pressurized sheet is a case where the material to be rolled by the work roll 104 is changed. Also in this case, it is conceivable that the load applied to the work roll 104 is changed by changing the material. Further, when changing the pressure-sensitive expanding member, the rolling operation is stopped. Therefore, even when the pressure-sensitive expanding member is changed, it is suitable as a case of adjusting the adjusting method 2.

The change of the rolling conditions refers to a case in which the conditions for changing the load applied to the work roll 104, such as the thickness for rolling the rolled material, are changed. Also in this case, since the rolling operation is stopped in order to maintain the plate thickness precision and the surface quality of the rolled product, the adjustment method 2 is suitable even when the rolling conditions are changed.

The pass line adjustment of the rolling mill stands 1 means that the rolling mill stand 1 is moved to the position of the left roll 101 and the right reel 102 so that the work roll 104 rolls the rolled- The position where the support member 104 is supported is adjusted. In this case also, it can be considered that the load applied to the work roll 104 is changed. The adjustment of the rolling mill stands 1 is also suitable for adjustment of the adjustment method 2 even when the rolling stand 1 is adjusted because the rolling operation is stopped.

As described above, the adjustment by the adjustment method 2 is not particularly suitable for stopping the operation of the rolling mill completely, but it is particularly suitable for changing the execution condition of the rolling operation after stopping the rolling operation once and resuming rolling again . That is, the adjustment method selecting device 6 is configured such that the state of the rolling mill judged by the rolling mill condition determining device 5 is a state in which, when the rolling operation is temporarily stopped so as to change the execution condition of the rolling operation, It is preferable to select the adjustment method according to the method 2.

When the condition for performing the adjustment of the adjustment method 2 is extended in this way, the adjustment method selection table stored in the adjustment method selection device 6 is changed to the roll shift position, And the correspondence relationship between the adjustment method 2 and the state of the pass line adjustment of the rolling mill stand 1 is stored and the rolling mill status determination device 5 determines whether or not the rolling mill position change, It is possible to determine the state of the pass line adjustment of the stand 1 or the like.

15, a method of adjusting a differential pressure compensation gain set by inputting a measurement waveform is described. However, a measurement waveform is input to check the result, and if the response measurement result is within an allowable range It is possible to terminate the process without performing the adjustment and to make the adjustment when the allowable range is exceeded. With this processing, the unnecessary processing can be omitted, and the adjustment operation can be terminated more quickly.

1: Rolling mill stand
2: Hydraulic pressure reduction control device
3: Rolling mill controller
4: Control gain adjustment device
5: Rolling machine condition determining device
6: Selection of adjustment method
21: Differential compensation gain setting device
11: Hydraulic cylinder
12: Hydraulic regulator
13: Position detector
14: Hydraulic generator
101: Left reel
102: Right reel
103: Pressure tightening material
104: work roll
110: operator panel
111: Inboard thickness meter
112: Exit plate thickness meter
113: Mill speed controller
114: Left reel control device
115: Right reel control device
116: FF AGC
117: FB AGC
118:
150: Operation mode selection SW
201: CPU
202: RAM
203: ROM
204: HDD
205: I / F
206: LCD
207:
208: bus
401: Signal generator
402: Signal analyzer
403: Control gain change device
404: Measuring method setting device

Claims

A hydraulic pressure reduction control device for controlling a position of a piston of a hydraulic cylinder for adjusting an interval between working rolls of a rolling mill,
An actual value acquiring section that acquires an actual value of the position of the piston in the hydraulic cylinder;
Wherein a control gain for controlling an oil inflow amount to the hydraulic cylinder is controlled based on an instruction value of the position of the piston and an actual value of the position of the piston, And an adjustment unit,
Wherein the control gain adjusting section comprises:
Outputting an adjustment signal for vibrating the position command value at a stored frequency to the hydraulic control unit and adjusting the control gain on the basis of the actual value for the adjustment signal and the adjustment signal,
A differential pressure compensation value for adjusting the control gain in the case where the position of the piston of the hydraulic cylinder is moved in a direction to narrow the gap between the work rolls and in a direction to widen the gap between the work rolls is set to an amplitude of the actual value Based on a deviation of the center of the oscillation of the adjustment signal in the first direction,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in a direction to narrow the gap between the work rolls, The control gain is determined so as to be larger than the control gain when the control gain is moved in a direction to narrow the gap between the work rolls,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in the direction of widening the gap between the work rolls, And the control gain for moving the work roll in the direction of increasing the gap between the work rolls is larger than the control gain when the work roll is moved in the direction for widening the gap between the work rolls.

The method according to claim 1,
Wherein the control gain adjusting section outputs, as the adjusting signal, a signal that gradually increases from an amplitude zero at the stored frequency and gradually attenuates to an amplitude zero after reaching a predetermined amplitude, .

The method according to claim 1,
Wherein the control gain adjusting section outputs the adjustment signal based on a plurality of different frequencies to the hydraulic control section and acquires a value based on an average value of the measured values for the adjustment signal as a determination index based on the frequency of the adjustment signal And the hydraulic pressure reduction control device.

The method according to claim 1,
The differential pressure compensation value is a coefficient multiplying the control gain in each case when the position of the piston of the hydraulic cylinder is moved in a direction to narrow the gap between the work rolls and in a direction to widen the gap between the work rolls,
Wherein the control gain adjustment section determines the differential pressure compensation value such that a product of a coefficient when the work roll is moved in a direction to narrow the gap between the work rolls and a coefficient when moving the work roll in a direction to widen the gap is 1 Hydraulic pressure reduction control device.

The method according to claim 1,
Wherein the control gain adjusting section comprises:
As the adjustment method for adjusting the control gain, a plurality of adjustment methods can be executed,
When the result of the determination of the operating state of the rolling mill indicates that the rolling mill is in a predetermined state when the control gain is adjusted, the adjusting signal, in which the position command value oscillates at the stored frequency, And outputs it to the control unit.

6. The method of claim 5,
The control gain adjusting section is in a state different from the case where the judgment result of the operating state of the rolling mill is different from the case of outputting the adjusting signal for vibrating the position command value to the hydraulic control section when the control gain is adjusted And outputting two signals whose amplitudes are inverted to the hydraulic control unit respectively as adjustment signals using the sweep frequency waveform, and adjusting the control gain based on the actual values of the two signals having the inverted amplitudes And the hydraulic pressure reduction control device.

An actual value of the position of the piston in the hydraulic cylinder is obtained by a control gain of the hydraulic pressure reduction control device which controls the oil pressure of the hydraulic cylinder for adjusting the interval between the working rolls of the rolling machine by adjusting the oil inflow amount to the hydraulic cylinder , An instruction value of the position of the piston and an actual value of the position of the piston,
An adjustment signal for vibrating the position command value at a stored frequency is outputted to the hydraulic control unit,
Acquires the measured value for the adjustment signal,
A differential pressure compensation value for adjusting the control gain in the case where the position of the piston of the hydraulic cylinder is moved in a direction to narrow the gap between the work rolls and in a direction to widen the gap between the work rolls is set to an amplitude of the actual value Based on a deviation of the center of the oscillation of the adjustment signal in the first direction,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in a direction to narrow the gap between the work rolls, The control gain is determined so as to be larger than the control gain when the control gain is moved in a direction to narrow the gap between the work rolls,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in the direction of widening the gap between the work rolls, The control gain of the hydraulic pressure reduction control device is determined so that the control gain becomes larger with respect to the control gain when the control gain is increased in the direction to widen the gap between the work rolls.

An actual value of the position of the piston in the hydraulic cylinder is obtained by a control gain of the hydraulic pressure reduction control device which controls the oil pressure of the hydraulic cylinder for adjusting the interval between the working rolls of the rolling machine by adjusting the oil inflow amount to the hydraulic cylinder A command value of the position of the piston and an actual value of the position of the piston,
Outputting an adjustment signal for vibrating the position command value at a stored frequency to the hydraulic control unit;
Acquiring the measured value for the adjustment signal;
A differential pressure compensation value for adjusting the control gain in the case where the position of the piston of the hydraulic cylinder is moved in a direction to narrow the gap between the work rolls and in a direction to widen the gap between the work rolls is set to an amplitude of the actual value Based on the deviation of the center of gravity of the vibration of the adjustment signal,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in a direction to narrow the gap between the work rolls, The control gain is determined so as to be larger than the control gain when the control gain is moved in a direction to narrow the gap between the work rolls,
When the center of the distribution of the amplitudes of the measured values deviates the position of the piston of the hydraulic cylinder from the center of the distribution of the amplitudes of the adjustment signals in the direction of widening the gap between the work rolls, And the control gain of the hydraulic pressure reduction control device is determined so as to be larger than the control gain when the control gain when moving in the direction of increasing the distance between the work rolls is increased. The medium.