JP2009291809A - Diagnostic method of disturbance of dynamic process - Google Patents

Abstract

Kind Code: A1 To identify various disturbances causing a change in a process state quickly with a certain accuracy.
A disturbance generator 60 reads out a disturbance characteristic amount based on a state change amount, and outputs it to a computing unit 48 as an assumed disturbance. The calculation unit 48 calculates the simulation change amount and outputs the simulation change amount to the comparison calculation unit 62. The comparison calculation unit 62 compares the absolute value of the difference between the state change amount and the simulation change amount with a threshold value, and when the absolute value of the difference is equal to or less than the threshold value, displays the assumed disturbance as an actual disturbance. To the unit 52.
[Selection] Figure 1

Description

  The present invention is applied to a dynamic process based on a change in a process state that can occur in the dynamic process due to the disturbance when the disturbance is applied to a dynamic process such as a hot finish rolling process for a steel strip. The present invention relates to a disturbance diagnosis method for a dynamic process for identifying a disturbance.

  In a dynamic process such as a hot finish rolling process for a steel strip, there is a time delay from when a certain disturbance is applied until the process state changes due to the disturbance. In such a dynamic process, various automatic control methods aimed at quickly suppressing the influence of applied disturbances have been vigorously developed. For example, the quality produced through the dynamic process It has achieved great results in reducing variation in

  Recently, as a result of the application of the above-mentioned automatic control method to dynamic processes, the operator's work has shifted from focusing on the operation of the process equipment constituting the dynamic process to monitoring of these process equipment. Yes. By the way, in a dynamic process to which such a control method is applied, the influence of disturbance is quickly suppressed by automatic control. As a result, the operator cannot suddenly control unless the change in the internal state of the process equipment is detected. It will face a big danger such as. However, in many dynamic processes, the functions of various process devices have become sophisticated, complicated, and related to each other, so that the operator is in a steady state change or unsteady such as equipment failure. It is difficult to properly determine whether the state change is caused by a factor.

  For example, in the hot finish rolling process, advanced control by various computer systems and control systems is performed in order to meet the increasing demand for quality improvement of rolled products. Nevertheless, in the hot finish rolling process, it is not possible to completely prevent the occurrence of unstable operation and product defects. The causes of such problems can be classified into product materials, driver operation methods, rolling equipment, control systems, and the like. When operational instability or product failure occurs, determine whether the cause is a system failure or abnormal operation by the driver, and take measures to prevent recurrence according to the cause. I must take it.

However, when a detailed cause analysis for a defect must be performed, in many cases, it is necessary to analyze and judge by looking at an online analog chart that records changes in each process state. At that time, the analysis and judgment are mostly performed by an operator who is familiar with the target dynamic process based on intuition and past experience, and there are many causes and complicated relations. In some cases, it took a long time to analyze and judge. Moreover, since the analysis work depends on the ability of the individual worker, the analysis content may be biased depending on the knowledge and experience of the worker.
For example, Patent Document 1 discloses a finish rolling abnormality diagnosis device, and in this finish rolling abnormality diagnosis device, in order to deal with a problem of sheet thickness quality in a steel strip after rolling, among the above problems, An analysis according to the situation where a plate thickness quality abnormality occurs is performed using a known rule-based method, and thereby the cause of the plate thickness quality abnormality is estimated.
JP 2004-167704 A

However, since the finish rolling abnormality diagnosis device described in Patent Document 1 is only subject to analysis of sheet thickness quality abnormality, other quality abnormality and operational problems that require improvement even before the abnormality does not occur are dealt with. A possible method is not disclosed.
An object of the present invention is to provide a dynamic process disturbance diagnosis method that can quickly identify various disturbances that cause changes in the process state with a certain degree of accuracy in consideration of the above facts. .

  A disturbance diagnosis method for a dynamic process according to claim 1 of the present invention is a disturbance diagnosis method for estimating a disturbance applied to a dynamic process in which a change in a process state due to the disturbance appears with a time delay. Input the assumptions assumed in the disturbance assumption step into the disturbance assumption step that assumes the disturbance applied to the dynamic process and the disturbance state model that calculates the change of the process state based on the disturbance to obtain the simulation result A simulation step; and a comparison operation step for comparing a change in the process state due to the disturbance and the simulation result, and calculating a difference between the two, wherein the difference calculated in the comparison operation step is within a predetermined range. Until the disturbance assumption step is corrected, and the simulation step and the comparison operation step are corrected. Tsu Repeat-flops, and identifying the disturbance.

  A dynamic process disturbance diagnosis method according to claim 2 of the present invention is the dynamic process disturbance diagnosis method according to claim 1, wherein the dynamic process is a hot finish rolling process, and the finish entry temperature, roll Using the disturbance state model in which at least one of a gap and a mill speed is a disturbance and at least one of a looper angle, a plate thickness, a tension between stands, and a rolling load is a process state. To do.

According to the disturbance diagnosis method for a dynamic process according to the present invention described above, the disturbance assumed in the disturbance assumption step is corrected until the difference calculated in the comparison calculation step is within a predetermined range, and the simulation step and By identifying the disturbance by repeating the comparison operation step, when the disturbance is applied to the dynamic process to be diagnosed and the process state is changed by this disturbance, the cause of the process state change in the dynamic process is It is possible to quickly identify various disturbances with a certain accuracy.
As a result, for example, in the hot finish rolling process, it is possible to estimate the factors of operational fluctuations that require improvement, even if quality abnormalities and operational failures do not occur, and the factors can be estimated quickly. Such a malfunction state can be restored to a normal state at an early stage.

Hereinafter, a disturbance diagnosis method for a hot finish rolling process for a steel strip according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of a disturbance diagnosis device that performs disturbance diagnosis in a hot finish rolling process according to an embodiment of the present invention. Here, the hot finish rolling process to be diagnosed by the disturbance diagnosis device 10 is executed in the hot finish rolling mill 14 shown in FIG. The hot finish rolling mill 14 sequentially rolls the rolled material 12 heated to a predetermined finish entry side temperature by a plurality of rolling stands F1 to F7, and manufactures a hot rolled steel sheet as a final product from the rolled material 12. Is for. This hot finish rolling process is a dynamic process with a time delay from when a disturbance is applied to a predetermined operating factor in the process until a change in the process state caused by the disturbance appears.

  FIG. 3 schematically shows two rolling stands adjacent to each other in the hot finish rolling mill 14 shown in FIG. 2 and the configuration between these rolling stands. Here, the upstream rolling stand 18 is arranged at the (N−1) th (where N is a natural number selected from 2 to 7) along the conveying direction (arrow m direction) of the rolled material 12, and downstream. The rolling stand 20 on the side is assumed to be arranged Nth along the conveyance direction m. Further, the rolling stand 18 and the rolling stand 20 have basically the same configuration.

  The rolling stands 18 and 20 are provided with a pair of upper and lower work rolls 22 and 24 for pressing and holding the rolled material 12, and a pair of backup rolls 26 and 28 that press against the pair of work rolls 22 and 24 from above and below, respectively. Is provided. The rolling stands 18 and 20 include a work roll motor 30 that transmits torque to the pair of work rolls 22 and 24, respectively, and a motor control device 32 that controls driving of the work roll motor 30. The work roll motor 30 is connected to the pair of work rolls 22 and 24 via a torque transmission mechanism to transmit driving torque. The motor control device 32 controls the rotational speed and driving torque of the work roll motor 30, respectively. The rolling stands 18 and 20 are provided with a gap control device 34 above the backup roll 26, and the gap control device 34 detects a rolling load L applied to the rolled material 12 by the work rolls 22 and 24. A stand load meter and a gap gap meter for detecting the roll gap G between the pair of work rolls 22 are incorporated.

  The hot finish rolling mill 14 is provided with a looper mechanism 36 that adjusts the tension of the rolled material 12 by pressing a looper roll 38 against the rolled material 12 between the pair of rolling stands 18 and 20. The looper mechanism 36 is provided with a looper roll 38, a looper arm 40, a looper motor 42, and a motor control device 33. The base end side of the looper arm 40 is connected to the looper motor 42 and is supported by the looper motor 42 so as to be swingable. A looper roll 38 is rotatably attached to the distal end portion of the looper arm 40. The looper arm 40 presses the looper roll 38 against the rolling material 12 from the lower surface side with a pressing force according to the torque generated by the looper motor 42.

The hot finishing mill 14 sets command values for the motor control device 32 and the motor control device 33 for each rolling stand 18 and controls the work roll motor 30 and the looper motor 42 through the motor control devices 32 and 33. An angle control device 44 is provided.
The looper motor 42 includes a looper angle sensor that detects the angle of the looper arm 40 and a tension sensor (not shown) that detects the tension of the rolled material 12 (inter-stand tension T). This looper angle sensor outputs a detection signal corresponding to the looper angle θ which is the inclination angle of the looper arm 40 with respect to a predetermined reference direction (for example, the horizontal direction) to the tension / looper angle control device 44. A detection signal corresponding to the inter-tension T is output to the tension / looper angle controller 44.

  When the detection signals corresponding to the looper angle θ and the inter-stand tension T are input to the tension / looper angle control device 44, the looper angle θ and the inter-stand tension T are respectively set in advance based on the detection signals. The rotation speed of the work roll motor 30 and the torque of the looper motor 42 that maintain the target values are calculated, and set as command values in the motor control device 32 and the motor control device 33, respectively. The motor control device 32 and the motor control device 33 to which the command value is set execute control so that the rotation speed of the work roll motor 30 and the output torque of the looper motor 42 coincide with the command value.

  The disturbance diagnosis apparatus 10 is configured as a part of a control system (not shown) that controls the entire rolling equipment including the hot finish rolling mill 14, for example. As shown in the block diagram of FIG. 1, the disturbance diagnosis apparatus 10 includes a disturbance state model calculation unit 48, a disturbance data correction unit 50, and a result display unit 52. Here, in the disturbance data correction unit 50, a disturbance generator 60 and a comparison calculation unit 62 are realized in software or hardware.

In the hot finish rolling mill 14 according to this embodiment, at least the finish entry temperature of the rolled material 12, the roll gap and the roll speed of the pair of work rolls 22 that roll the rolled material 12, are operating factors for the hot finish rolling process. And at least a pair of rolling stands 18 and 20 adjacent to each other, a looper angle θ disposed between the pair of rolling stands 18 and 20, a sheet thickness P of the rolled material 12 fed from the pair of work rolls 22, and a pair of rolling stands 18 and 20. The rolling load L applied to the rolled material 12 by the inter-stand tension T and the work rolls 22 and 24 is a process state (output factor) in the hot finish rolling process.
When any disturbance DR (i) is applied to at least one selected from the operating factors, the process state changes to at least one process state (state change amount XD (i) ) May appear. Here, the symbol “i” indicates an index of the state quantity.

  As the feature amount of the process state, for example, in the case of the rolling load L from the work rolls 22 and 24, immediately after the front end portion of the rolled material 12 is bitten at the reduction position by the pair of work rolls 22 and 24. In the case of using the data and the looper angle θ in the rolling stand 18 (see FIG. 3), several seconds after the leading end of the rolled material 12 bites into the work rolls 22 and 24 of the downstream rolling stand 20. Use the minimum and maximum values in. Note that, for example, the looper angle θ is used as a parameter that represents the tension state and the doubled state of the tip end portion of the rolled material 12. If such a state can be appropriately expressed, other than the looper angle θ. May be used as a parameter, and other process states can be substituted with other processes as long as the state to be monitored can be appropriately represented.

  The hot finish rolling mill 14 includes a looper angle sensor that detects a looper angle θ, a tension sensor that detects an inter-stand tension T, and work rolls 22 and 24 as sensors for detecting changes in the process state. In addition to these sensors, a stand thickness sensor 54 for detecting the thickness P of the rolled material 12 fed from the work rolls 22 and 24 to the downstream side is provided. 3).

  Further, as shown in FIG. 1, the hot finish rolling mill 14 is provided with a state monitoring controller 56 for monitoring the process state as a part of the control system. Detection signals output from the looper angle sensor, tension sensor, stand load sensor, and plate thickness sensor 54 are input. The state monitoring controller 56 calculates the looper angle θ, the inter-stand tension T, the rolling load L, and the sheet thickness P for each predetermined calculation period based on the detection signals from the sensors, and calculates the calculated values for a predetermined sampling period. It is determined whether or not any of the looper angle θ, the inter-stand tension T, the rolling load L, and the plate thickness P has changed by comparing with one or a plurality of calculated values.

Next, a disturbance diagnosis method for the hot finish rolling process according to the present embodiment will be described based on the block diagram of FIG. 1 and the flowchart of FIG.
The state monitoring controller 56 of the hot finishing mill 14 determines whether or not any of the looper angle θ, the inter-stand tension T, the rolling load L, and the sheet thickness P has changed during the sampling period. At this time, if the state monitoring controller 56 determines that any of the looper angle θ, the inter-stand tension T, the rolling load L, and the plate thickness P has changed during the sampling period, the looper generated during the sampling period The change amount of the angle θ, the inter-stand tension T, the rolling load L, or the plate thickness P is output to the disturbance diagnosis apparatus 10 as the state change amount XD (i). Thereby, the disturbance diagnostic apparatus 10 of the hot finishing mill 14 starts execution of the control flow of the disturbance diagnostic method shown in FIG.

Note that the looper angle θ, inter-stand tension T, rolling load L, and plate thickness P are merely examples of quantitatively changing process states, as long as they can be quantitatively detected by various sensors. Other process states can also be determined by the state monitoring controller 56 as to whether or not a change has occurred.
In step S100, the disturbance diagnosis apparatus 10 inputs the state change amount XD (i) to the disturbance generator 60 and the addition point 58 in parallel. A simulation change amount XS (i), which is a simulation result for a process state change described later, is input to the addition point 58 together with the state change amount XD (i). The disturbance generator 60 also stores a state change amount XD (i) and a data table storing the disturbance attributes and feature amounts in the hot finish rolling process that is estimated to cause the state change amount XD (i). I have.

  At this time, for the disturbance attribute and feature amount estimated to be the cause of the state change amount XD (i), for example, a disturbance (actual disturbance) DR is actually applied to the hot finishing mill 14 and applied. The disturbance DR (i) attribute and amount are changed continuously or stepwise, and at that time, a change in the process state occurring in the hot finish rolling mill 14 (hot finish rolling process) is measured, and this process is performed. It can be obtained in advance by making the state change correspond to the disturbance DR (i).

  In step S102, the disturbance generator 60 uses the state change amount XD (i) as an index, reads out the feature quantity of the disturbance in the hot finishing rolling process from the data table, and uses the disturbance feature quantity as the assumed disturbance DV (i). To the disturbance state model calculation unit 48. The disturbance state model calculation unit 48 is obtained by, for example, a multiple regression equation obtained by multivariate multiple regression analysis based on data stored in the data table of the disturbance generator 60 or a neural network having a learning function. It is constructed by a neural network model, a dynamic simulator, etc.

  In step S104, the disturbance state model calculation unit 48 calculates (simulates) the simulation change amount XS (i) generated in the hot finish rolling process by inputting the assumed disturbance DV (i), and the simulation change amount XS (i ) Is output to the addition point 58. In step S106, the addition point 58 calculates the difference between the simulation change amount XS (i) and the state change amount XD (i), and outputs the difference D (i) to the comparison calculation unit 62 in the disturbance data correction unit 50. To do.

  In step S108, the comparison calculation unit 62 compares the absolute value of the difference D (i) with a preset threshold value S, and when the absolute value of the difference D (i) is equal to or smaller than the threshold value S (in step S108). In the case of YES), the control routine proceeds to step S110. In step S110, the comparison calculation unit 62 considers the assumed disturbance DV (i) output from the disturbance generator 60 as an actual disturbance DR (i) in the hot finish rolling process, and assumes the assumed disturbance DV (i). It outputs to the result display part 52. Thereby, the result display unit 52 displays on the screen that the assumed disturbance DV (i) is a disturbance generated in the hot finish rolling process at time (i).

  Further, the comparison calculation unit 62 compares the absolute value of the difference D (i) with a preset threshold value S, and if the absolute value of the difference D (i) is larger than the threshold value S (NO in step S108). In the case), the control routine proceeds to step S112. In step S <b> 112, the comparison operation unit 62 outputs the assumed disturbance DV (i) and the difference (i) output from the disturbance generator 60 last time to the disturbance generator 60.

In step S114, the disturbance generator 60 determines the sign (plus or minus) of the difference D (i), and executes a correction operation on the assumed disturbance DV (i) based on the sign. Specifically, the disturbance generator 60 adds a predetermined positive correction amount Vc to the assumed disturbance DV (i) if the sign is negative, and the assumed disturbance DV (if the sign is positive. The negative correction amount Vc is added to i), and the result is output to the disturbance state model calculation unit 48 again as a new assumed disturbance DV (i). As a result, the control routine returns to step S104.
The correction amount Vc, for example, reads the assumed disturbance DV ′ (i) increased by one step (when the sign is negative) in the data table with respect to the assumed disturbance DV (i) read from the previous data table, It is obtained by calculating {DV (i) −DV ′ (i)) / N.

  Here, N is a finite natural number, and by setting this N to a sufficiently large value, the correction amount Vc can be set to a sufficiently small value, and as a result, the finally obtained assumed disturbance DV (i) The error with respect to the actual disturbance DR (i) can be made sufficiently small. Similarly to the correction amount Vc, the threshold value S set in the comparison calculation unit 62 is corresponding to the corresponding state change amount XD (i) set in the data table and the state change amount XD (i). The difference from the state change amount XD ′ (i) increased or decreased by one step in the data table may be obtained by dividing by the natural number M.

In addition to the above, an assumed disturbance DV (i) that minimizes the absolute value of the difference D (i) may be found by a search method in the range of lower limit value ≦ assumed disturbance DV (i) ≦ upper limit value.
In the returned step S104, the disturbance state model calculation unit 48 calculates (recalculates) the simulation change amount XS (i) based on the assumed disturbance DV (i) re-input from the disturbance generator 60, and performs this recalculation. The simulated change amount XS (i) is output to the addition point 58. Also at the addition point 58, similarly to the previous time, the difference between the simulation change amount XS (i) and the state change amount XD (i) is calculated, and the difference D (i) is output to the comparison calculation unit 62. Thus, the above calculation by the disturbance state model calculation unit 48, the addition point 58, the comparison calculation unit 62, and the disturbance generator 60 is repeated until the absolute value of the difference D (i) becomes equal to or less than the threshold value S, and the difference D (i ) Is equal to or smaller than the threshold value S, the assumed disturbance DV (i) generated by the disturbance generator 60 is regarded as the actual disturbance DR (i) and displayed on the result display unit 52.

Next, the effect | action of the disturbance diagnostic method of the hot finishing rolling process which concerns on this embodiment is demonstrated concretely based on FIG. FIG. 2B schematically shows changes in the process state when disturbances are individually applied to the roll gaps G in the rolling stands F1 to F7. In FIG. 2B, X _{F1 to} X _F7 indicate changes in the process state respectively generated in the rolling stands _{F1 to F7} due to the disturbance applied individually to the rolling stands _{F1 to F7} .

On the other hand, FIG. 2C schematically shows changes in the process state when a disturbance is applied to the rolling stand F4 and the rolling stand F5. In this case, the hot finish rolling process has almost the same process state change X _C as the result of superimposing X _F4 and X _F5 appearing when disturbance is individually applied to the rolling stand F4 and the rolling stand F5. Appears. Therefore, in such a case, a change in the process state occurring in the hot finish rolling process is measured, and this change occurs in each of the rolling stands F1 to F7 due to the disturbance applied individually to each of the rolling stands F1 to F7. By comparing with the change in the process state, it is possible to accurately estimate the rolling stand F4 and the rolling stand F5 to which the disturbance is applied, and the attribute and feature amount of the disturbance.

FIG. 5 is a block diagram showing a configuration of a device controller that controls a specific control target in the hot finishing rolling mill according to the present embodiment.
The device controller 70 uses, for example, operation devices such as a heating device, a motor unit, and an actuator that operate the finish entry temperature of the rolled material 12, the roll gap and roll speed of the pair of work rolls 22 and 24, as the control target 72. The device controller 70 basically controls the control object 72 by known feedback control such as PID control and PD control so that the state quantity of the operation factor matches the target value SV.

  First, basic feedback control by the device controller 70 will be described. A state value target value SV is preset in the control object 72 by another controller, a higher-level process computer, or the like, and this target value SV is input to the device controller 70 through the first addition point 74. On the other hand, the control object 72 is provided with a sensor (not shown) for detecting the state quantity, and this sensor parallels the state quantity detection signal to another controller, a higher-level process computer, and the first addition point 74. Output to. The device controller 70 calculates a deviation E between the state value detection value PV and the target value SV in the control object 72 based on the detection signal from the sensor at every predetermined calculation cycle. An operation amount OV is determined with respect to, and the operation amount OV is output to the control object 72 through the second addition point 76.

Further, in the hot finish rolling mill 14, when disturbance is caused by the operating factor operated by the control object 72 and a change in the process state appears in the hot finish rolling process, the disturbance diagnosis device 10 is in the process state as described above. The disturbance DR (i) that caused the change is identified. This disturbance DR (i) is output to the second addition point 76. At the second addition point 76, the disturbance DR (i) is multiplied by a preset gain K, and the result K · DR (i) is added to the manipulated variable OV. Thereby, in the hot finish rolling process, the operation amount OV generated by the device controller 70 can be effectively corrected so that the change in the process state caused by the disturbance DR (i) is canceled out.
In the hot finish rolling process described above, for example, the state change amount XD of the process state is represented by the following equation (1).

  FIG. 6 shows the influence on the plate thickness P and the looper angle θ when a disturbance is applied to the finish entry temperature T in the hot finish rolling process for each rolling stand F1 to F7. In the hot finish rolling process, the influence on the sheet thickness P and the looper angle θ when a disturbance is applied to the rolling position (roll gap) of the work roll of the rolling stand F1 with respect to the rolled material is applied to each of the rolling stands F1 to F7. FIG. 8 shows the influence on the sheet thickness P and the looper angle θ when a disturbance is applied to the rolling position (roll gap) of the work roll of the rolling stand F2 in the hot finish rolling process. It is shown for each of the rolling stands F1 to F7.

  The following equation (2) indicates that the disturbances (ΔS1 to ΔS4) applied to the roll gaps shown in FIGS. 7 and 8 respectively have an influence on the plate thickness P (Δh1 to Δh7) and an influence on the looper angle θ ( An example of Δθ1 to Δθ6) is shown. As for the influence of other process states when a disturbance is applied to other operating factors, an arithmetic expression similar to equation (2) can be obtained by appropriately setting coefficients according to the attributes of the operating factors and the process states. Can be represented by:

  Moreover, when the state change amount of the process state when a disturbance is applied to the operating factor in the hot finish rolling process is XD, the disturbance that minimizes the evaluation function in the following (3) is calculated. It is possible to estimate the applied disturbance DR.

  Note that the calculation of the influence coefficient and the feature amount in the above equations (1) and (2) inevitably includes errors. Therefore, in determining the disturbance DR, a threshold value is set, and the influence of the error is evaluated by combining and evaluating the magnitude of the disturbance DR estimated in the above process and the appropriateness of the directionality between the state quantities. The final disturbance state can be accurately estimated by reducing.

It is a block diagram which shows the structure of the disturbance diagnostic apparatus which implements a disturbance diagnosis in the hot finishing rolling process which concerns on embodiment of this invention. (A) is a block diagram which shows typically the hot finishing rolling mill in which the hot finishing rolling process which concerns on embodiment of this invention is performed, (B) is a disturbance separately to the roll gap | interval in the rolling stands F1-F7, respectively. FIG. 6C is a characteristic diagram schematically showing a change in the process state when applying a pressure, and FIG. 6C is a characteristic diagram schematically showing a change in the process state when disturbance is applied to the rolling stand F4 and the rolling stand F5. FIG. 3 is a side view schematically showing two rolling stands adjacent to each other in the hot finish rolling mill shown in FIG. 2 and the configuration between these rolling stands. It is a flowchart for demonstrating the disturbance diagnostic method of the hot finishing rolling process which concerns on embodiment of this invention. It is a block diagram which shows the structure of the device controller which controls the specific control object in the hot finishing rolling mill which concerns on embodiment of this invention. It is a timing chart which shows the influence which it has on the plate | board thickness and looper angle when disturbance is applied to the finishing entry temperature in the hot finishing rolling process which concerns on embodiment of this invention. It is a timing chart which shows the influence which it has on the plate | board thickness and looper angle when disturbance is applied to the roll gap | interval of the work roll in the hot finishing rolling process which concerns on embodiment of this invention. It is a timing chart which shows the influence which it has on the plate | board thickness and looper angle when disturbance is applied to the roll gap | interval of the work roll in the hot finishing rolling process which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Disturbance diagnosis apparatus 12 Rolled material 14 Hot finishing rolling mill 18, 20 Rolling stand 22, 24 Work roll 26, 28 Backup roll 30 Work roll motor 32 Motor control apparatus 33 Motor control apparatus 34 Gap control apparatus 36 Looper mechanism 38 Looper roll 40 Looper arm 42 Looper motor 44 Tension / looper angle control device 48 Disturbance state model calculation unit 50 Disturbance data correction unit 52 Result display unit 54 Plate thickness sensor 56 State monitoring controller 58 Addition point 60 Disturbance generator 62 Comparison calculation unit 70 Device controller 72 Control target 74 First addition point 76 Second addition point DR Disturbance DV Assumed disturbance F1, F2, F3, F4, F5, F6, F7 Rolling stand XD State change amount XS Simulation change amount θ Looper angle

Claims (2)

A disturbance diagnosis method for estimating a disturbance applied to a dynamic process in which a change in a process state due to a disturbance appears with a time delay,
A disturbance assumption step assuming a disturbance applied to the dynamic process;
A simulation step of obtaining a simulation result by inputting the assumption assumed in the disturbance estimation step into a disturbance state model that calculates a change in process state based on the disturbance,
A comparison operation step for comparing the change in the process state due to the disturbance and the simulation result to calculate the difference between the two,
With
The disturbance calculated in the disturbance assumption step is corrected until the difference calculated in the comparison calculation step is within a predetermined range, and the disturbance is identified by repeating the simulation step and the comparison calculation step. Disturbance diagnosis method for dynamic processes. The dynamic process is a hot finish rolling process,
The disturbance state model in which at least one of finishing entry temperature, roll gap, and mill speed is a disturbance, and at least one of a looper angle, a plate thickness, a tension between stands, and a rolling load is a process state. The dynamic process disturbance diagnosis method according to claim 1, wherein:

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