JPH07284832A - Controlling method and device - Google Patents

Abstract

PURPOSE:To keep the controllability excellent even when the disturbance enters the object to be controlled with strong non-linearity. CONSTITUTION:A quantity of state estimating part 6a of a disturbance estimator 6 estimates the quantity of state as to the quantity of state (b) detected by a quantity of state detector 3 using a control model (f) to express the mutual relationship between the quantities of state (a), (b). A differentiator 6b of the disturbance estimator 6 outputs the difference between the quantity of state as estimated by the quantity of state estimating part 6a and the quantity of state (a) detected by the quantity of state detector 3 to a feed-back compensating controller 7 as the disturbance A. The feed-back compensating controller 7 obtains the feed-back compensation xFBC to cancel the change in the quantity of control (y) by the disturbance A. An adder 8 adds this feed-back compensation xFBC to the feed-back quantity of operation xFB from a feed-back controller 4, and to give the addition to the object 1 to be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus and a control method for controlling a controlled object having a strong non-linearity, such as a rolling mill for rolling a wide variety of rolled materials under various conditions.

[0002]

2. Description of the Related Art As a control target, there is one having a strong non-linearity such as a rolling mill for rolling a wide variety of rolled materials under various conditions. In such control of a control object having a strong non-linearity, setup control is performed to obtain an operating point of the controller such that the control object has a target value in a relatively stable steady state. In thermal power generators and plant control, it is called set point control.
The setup control is specifically described in “Theory and Practice of Sheet Rolling”, Japan Iron and Steel Institute, September 1, 1984, Item 289 to Item 292.

When the operating point is determined by the setup control system, a linear control model is created on the assumption that the fluctuation of the controlled object is within a range in which linear approximation can be performed in the vicinity of the operating point. , As a regulator problem that makes the deviation from the operating point to zero and a servo problem that follows the reference input, an optimal solution that minimizes fluctuations in input power and state is targeted for differential equations that represent system dynamics ( It has been attempted to realize a control system having desired control performance by performing feedback control according to a linear control theory for obtaining a feedback gain).

[0004]

However, when the operating point is significantly changed, such as when the rolling mill is accelerated or decelerated or when the rolling thickness is changed to change the target delivery side thickness and the target front tension during continuous rolling, When the rolling material has temperature fluctuations such as skid marks and the rolling load fluctuates or there is a disturbance in which the inlet plate thickness fluctuates, the control system that performs feedback control for the linear control model operates There is a problem that the linearity cannot be maintained near the point, the error between the actual control target and the linear control model becomes large, and the target control performance cannot be maintained.

The present invention has been made by paying attention to such a conventional problem, and provides a control device and a control method having excellent controllability even when a disturbance or the like enters a control object having a strong non-linearity. The purpose is to do.

As related prior arts, Japanese Patent Laid-Open Nos. 60-83720, 61-711117, 62-118913, and 1-20
Some are disclosed in Japanese Patent No. 2305.

[0007]

A control device for achieving the above object comprises a control amount detecting means for detecting a control amount which is an output from a control target, and a state amount detecting for detecting a state amount of the control target. Means, feedback operation amount calculation means for obtaining a feedback operation amount according to a deviation between the control amount detected by the control amount detection means and a predetermined target control amount, the operation amount given to the controlled object, and A first control model that represents a relationship between the state quantity of the controlled object, a deviation between the controlled variable and the target controlled variable, a disturbance with respect to the controlled object, and a feedback compensation amount that compensates for the feedback operation amount. And a control model storage unit that stores a second control model indicating the relationship between the control object and the first control model. The state quantity estimating means for estimating the state quantity, the difference between the state quantity detected by the state quantity detecting means and the state quantity estimated by the state quantity estimating means, and the difference of the control target Feedback compensation amount calculation means for obtaining the feedback compensation amount for the disturbance obtained by the disturbance estimation means such that the deviation becomes 0 using the disturbance estimation means for the disturbance and the second control model. And adding the feedback compensation amount calculated by the feedback compensation amount calculation unit to the feedback operation amount calculated by the feedback operation amount calculation unit, and adding the feedback compensation amount to the control target as the operation amount. And means.

Here, in addition to the state quantity used for determining the disturbance, the state quantity detecting means also has a state quantity that is uniquely determined with respect to the manipulated variable (hereinafter referred to as a specific state quantity). The manipulated variable of the first control model detected is the specific state quantity, and the state quantity estimating means displays the first control model indicating the relationship between the specific state quantity and another state quantity. Using the other state quantity with respect to the specific state quantity detected by the state quantity detection means, the disturbance estimation means, the other state quantity and the state quantity detected by the state quantity detection means You may make it obtain the difference with the said other state quantity estimated by the estimation means, and make this difference the said disturbance of the said control object.

The state quantity that is uniquely determined with respect to the manipulated variable is, for example, when the fluid to be controlled is a fluid flowing through a passage and a flow rate control valve that regulates the flow rate of this fluid, the valve opening as the manipulated variable. Of the actual valve opening (state quantity) when the degree is given to the flow rate control valve, it is not affected by the state quantities such as temperature and pressure of the fluid flowing through the flow path, and it is one-to-one correspondence with the manipulated variable. It is the state quantity determined by the correspondence relationship.

Further, another control device for achieving the above object is to provide a plurality of manipulated variables to a control object having a strong non-linearity to which a plurality of disturbances are input, and to output a plurality of output from the control object. In the control device for setting the control amount of each of the target values, a control amount detecting unit for detecting a plurality of the control amounts which are outputs from the control target, and at least one operation amount of the plurality of operation amounts. A specific state quantity having a unique relationship and a state quantity detection means for detecting some other state quantities, a plurality of the control quantities detected by the control quantity detection means, and a plurality of the control quantities. According to the deviation from the target control amount determined respectively, and at least one state amount among the plurality of state amounts detected by the state amount detecting means and the target state amount determined for the state amount. Depending on the deviation from Of the feedback control amount, a first control model representing the interrelationship of the plurality of state quantities of the controlled object, and a plurality of the control amounts and the respective target control amounts. Control model storage means for storing a plurality of second control models showing a relationship among a deviation, the plurality of disturbances, and a plurality of feedback compensation amounts for compensating for each of the plurality of feedback operation amounts; Using the control model of, one state quantity of the plurality of other state quantities,
State quantity estimating means for estimating from the state quantity including the specific state quantity detected by the state quantity detecting means excluding the one state quantity, the one state quantity and the state detected by the state quantity detecting means The difference with the one state quantity estimated by the quantity estimating means is obtained, and the difference is set as one specific disturbance among the plurality of disturbances, and the plurality of other states detected by the state quantity detecting means A plurality of the disturbance estimation means that obtains a disturbance other than the one specific disturbance among the plurality of disturbances from a state quantity other than the one state quantity among a plurality of quantities, and a plurality of the second control models. Feedback compensation amount calculation means for respectively obtaining feedback compensation amounts for each of the plurality of feedback operation amounts with respect to the plurality of disturbances obtained by the disturbance estimation means such that the deviations become 0 respectively; The feedback compensation amounts corresponding to the feedback compensation amounts determined by the feedback compensation amount computing unit are added to the feedback manipulation amounts determined by the work amount computing unit, respectively, and the feedback compensation amounts corresponding to the feedback compensation amounts are calculated. An operation amount adding means for giving the controlled object as an amount is provided.

Further, another control apparatus gives a plurality of manipulated variables to a control object having a strong non-linearity, which is input by a plurality of disturbances, and the control quantity which is an output from the control object becomes a target control quantity. In the control device for controlling as described above, a control amount detection unit that detects the control amount that is the output from the control target, a disturbance estimation unit that estimates a plurality of the disturbances from the state of the control target, and a plurality of manipulated variables. For each of them, a control model storage unit that stores a plurality of control models indicating the relationship between the deviation between the control amount and the target control amount and a plurality of the disturbances, and the disturbance detection using a plurality of the control models From a plurality of disturbances detected by the means, a plurality of manipulated variables such that the deviation between the controlled variable detected by the controlled variable sensing means and the target controlled variable is zero are obtained, and the plurality of manipulated variables are calculated. Give to controlled object And it is characterized in that it comprises an operation amount calculating means that.

[0012]

[Operation] For a controlled object having a strong non-linearity such as in the case of hot continuous rolling, the operating point is determined by the setup control system, and it is assumed that the fluctuation of the controlled object is within a range in which linear approximation can be performed near the operating point. Then, feedback control is performed using the linear control model. However, if disturbance or the like enters the controlled object, the linearity is not maintained near the operating point, and the error between the actual controlled object and the linear control model increases.

Therefore, in the present invention, focusing on the error between the actual controlled object and the control model, the state quantity of the actual controlled object and the state quantity obtained by the control model are compared, and the difference between the two state quantities is disturbed. As a result, the feedback control is supplemented by giving the controlled object an operation amount that cancels the influence of the disturbance on the control amount.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the control device of this embodiment is a control device for a continuous rolling mill.

The continuous rolling mill has a plurality of rolling mills arranged in series. I-th rolling mill 10i
Is a pair of rolls 11 and 12 provided so as to face each other in the vertical direction, a roll rotation drive device 14 for rotating the lower roll 12, and a roll reduction device 12 for moving the upper roll 11 in the vertical direction. Is configured.

The controller of the continuous rolling mill is the lower roll 1
2, a roll speed meter 25 that detects the rotation speed of the roll 2, a roll reduction position gauge 23 that detects the reduction position (position in the vertical direction) of the upper roll 11, and a delivery side plate that detects the thickness of the rolled material A on the delivery side of the rolling mill 10. Thickness gauge 21, front tension meter 2 for detecting the tension applied to rolled material A between one rolling mill and the next rolling mill
2. Detecting means such as a rolling load meter 24 for detecting the rolling load applied to the upper roll 11 when rolling the rolled material A. These detecting means are provided in each rolling mill.
In addition, in FIG. 1, in addition to the i-th rolling mill 10i and each detecting means for this rolling mill 10i, the exit side plate thickness gauge 21 (i- of the i-1th rolling mill 10 (i-1) is also used. 1) and the front tensiometer 22 (i-1) are drawn.

The control device of the present embodiment further includes a rolling mill 1.
0 and the rolled material A, a control model determiner 30 that determines a linear control model for a controlled object, a control model storage unit 35 that stores the linear control model determined by the control model determiner 30, and a control model storage unit The control gain calculator 50 for determining the gain for feedback control and the gain for feedback compensation control based on the linear control model stored in 35, and the feedback control gains calculated by the respective detection amounts and control gain calculator 50. Based on the feedback controller 60, the feedback controller 60 obtains a feedback reduction command value for the reduction device 13 and a feedback speed command value for the roll rotation drive device 14, and a disturbance estimator 4 for estimating the amount of disturbance with respect to the control target from each detected amount.
0, the disturbance estimated by the disturbance estimator 40 and the feedback compensation control gain calculated by the control gain calculator 50, based on the feedback compensation reduction command value for the reduction device 13 and the feedback compensation speed command for the roll rotation drive device 14. A feedback compensation controller 65 that obtains a value, a reduction command value adder 69 that adds the feedback reduction command value and the feedback compensation reduction command value and outputs this to the reduction device 13, a feedback speed command value, and a feedback compensation speed command. And a speed command value adder 63 for adding the value to the roll rotation driving device 14 and outputting the added value to the roll rotation driving device 14.

As shown in FIG. 2, the control model determiner 30 has a rolling model storage unit 31 for storing a rolling model to be controlled which has a strong non-linearity based on the rolling theory, the test of the rolling mill 10 and the like. There is. In this rolling model storage unit 31,
The linear control models in which the influence coefficients shown in (Equation 1) to (Equation 5) are undetermined are also stored. Note that (Equation 1) to (Equation 5) will be described later. Control model determiner 30
Further, in the steady state, the rolling position S of the upper roll 11 and the rolling position S of the upper roll 11 are set so that the outgoing side plate thickness h, the incoming side plate thickness H, the outgoing side plate speed v, the front tension t _f , the rear tension t _{b, and the} like become target values. A setup control unit 32 that defines an operating point such as the speed ωm;
The influence coefficient determination unit 33 determines the influence coefficient of the linear control model and determines the linear control model.

In the rolling mill 10, the disturbances for keeping the outgoing side plate thickness h and the forward tension t _f (hereinafter, these are control amounts) at the target values are the fluctuations of the incoming side plate thickness H and the rolling load P.
There are fluctuations in Therefore, as shown in FIG. 1, the disturbance estimator 40 has an entrance-side plate thickness disturbance estimator 41 and a rolling load disturbance estimator 45 in order to estimate these disturbances.

As shown in FIG. 3, the inlet side plate thickness disturbance estimating section 41 is an outlet side plate thickness gauge for the (i-1) th rolling mill (hereinafter referred to as the (i-1) th stand) 10 (i-1). 21 (i-1) output is stored in first-in first-out board thickness storage section 42
And the sampling time storage unit 43 for storing the sampling time of each detecting means, the i-1th stand 10 (i-1) and the i-th rolling mill (hereinafter referred to as the i-th stand) from the detected values. The moving distance estimating unit 44 that estimates the moving distance of the rolled material A between the i-th stand 10 (i-1) by estimating the speed of the rolled material A between 10i and 10i Then, it is determined whether or not the moving distance of the rolled material A reaches the distance between the i-1st stand 10 (i-1) and the i-th stand 10i. I-th stand 1 of the outgoing plate thickness Δh
The exit side plate thickness of the rolled material A portion reaching 0i is set to the i-th stand 1
It has a moving distance management unit 44a that outputs the input side plate thickness ΔH of 0i to the plate thickness storage unit 42.

As shown in FIG. 2, the rolling load disturbance estimating unit 45 estimates the rolling load for each detected value by using (Equation 3) and the rolling load estimating unit 46. Difference device 47 for obtaining a difference (= rolling load disturbance) between the estimated rolling load and the actual rolling load detected by the rolling load meter 24
And have.

The feedback controller 60 includes an integrator 61.
And a feedback control unit 62. Integrator 6
1 is the deviation Δ between the output of the outlet plate thickness gauge 21 and its target value.
h and the deviation Δ between the output of the front tension meter 22 and its target value
Integrate t _f . The feedback controller 62 includes a roll speed meter 25, a roll reduction position meter 23, and a front tensiometer 22.
i, the deviations Δv _R , ΔS, Δt _f , Δt _b between the respective outputs from the rear tension meter 22 (i-1) and the respective target values, and the output values from the integrator 61, the control gain calculator 50. The feedback speed control value and the feedback reduction command value are determined by multiplying the feedback control gain obtained in. Then, the feedback speed command value is given to the roll rotation driving device 14 via the speed command value adder 63, and the feedback reduction command value is given to the rolling down device 13 via the reduction command value adder 69 to obtain the control amount. The output side plate thickness and the forward tension are controlled to be constant.

By the way, since the rolling phenomenon has a strong non-linearity, when control is performed on the premise of a linear control object such as the modern control theory, first, in the steady state, the outlet plate thickness h,
The setup control unit 32 determines operating points such as the rolling position S of the upper roll 11 and the roll speed ωm so that the entrance side plate thickness H, the exit side plate speed v, the front tension t _f , the rear tension t _{b, and the} like become target values. To do. Next, the linear control model 35 represented by the following (Equation 1) to (Equation 5) is determined.

Here, in (Equation 1) to (Equation 5),
The superscript is an index indicating each rolling mill, and Δ represents the minute change amount from the value at the operating point. Also, S _P , ω _P
Represents a rolling position command and a roll speed command, respectively. Further, T _S and T _m represent time constants, and P _d , H, S _d , and ω _d are rolling load disturbance, inlet side plate thickness disturbance, rolling position fluctuation due to deviation of the rolling position zero point, roll due to roll eccentricity, etc. It represents the speed fluctuation. K is a spring constant when the controlled object is a spring system.

Specifically, (Equation 1) is a differential equation showing the relationship between the reduction position command value S _P for the reduction device 13 and the actual reduction position S.

[0026]

[Equation 1]

(Equation 2) is a differential equation showing the relationship between the roll speed command value ω _P for the roll rotation drive device 14 and the actual roll speed ω _m .

[0028]

[Equation 2]

(Equation 3) shows the relationship between the rolling load ΔP and each detected value. The value in parentheses by which each detected value is multiplied is an influence coefficient.

[0030]

[Equation 3]

(Equation 4) is a forward tension Δt _f which is a controlled variable.
And the respective detected values and the like are shown.

[0032]

[Equation 4]

[Mathematical formula-see original document] (Equation 5) shows the relationship between the outgoing side plate thickness Δh, which is a controlled variable, and each detected value. In addition, also in (Equation 4) and (Equation 5), the value in () is an influence coefficient.

[0034]

[Equation 5]

As described above, the rolling model storage unit 31 stores the linear control model in which the influence coefficient shown in (Equation 1) to (Equation 5) is not determined. For this reason,
Linear control model 35 represented by (Equation 1) to (Equation 5)
Is determined by determining an undetermined influence coefficient in the influence coefficient determination unit 33. For example, in (Equation 3),
The influence coefficient for a certain variable is obtained from the rolling load change when another variable is fixed at each operating point determined by the setup control unit 32 and a certain variable is slightly changed at that operating point.

The control gain calculator 50 determines the feedback control gain and the feedback compensation control gain using the linear control model 35. Here, with respect to the linear control model 35, assuming that the feedback control unit 65 is an integral compensation type optimum servo controller, the feedback control gain determination operation of the control gain calculator 50 will be described below.

The system matrix determination unit 51 of the control gain calculator 50 expresses the control model parameters of the linear control model 35 in a state space representation in order to apply the linear control theory, that is, develops into a system matrix.

The system matrix determination unit 51 first calculates the state vector, the input vector, the output vector, and the disturbance vector in the i-th stand by (Equation 6), (Equation 7), and (Equation 7), respectively.
It is defined as in (Equation 8) and (Equation 9).

[0039]

[Equation 6]

[0040]

[Equation 7]

[0041]

[Equation 8]

[0042]

[Equation 9]

The state equation of the state vector shown in (Equation 6) and the output equation of the output vector shown in (Equation 8) in the i-th stand are (Equation 10) and (Equation 1), respectively.
It can be expressed as 1).

[0044]

[Equation 10]

[0045]

[Equation 11]

However, in the above equation, A (i, i + 1), A
(i, i) and A (i, i-1) are 3 × 3 constant matrices in which the state vector of the i + 1, i, and i−1 stands influences the variation of the state vector of the i stand. B (i, i) is a 3 × 2 constant matrix in which the input vector of the i stand influences the fluctuation of the state vector of the i stand. E (i, i + 1) and E (i, i) are 3 × 4 constant matrices in which the disturbance vector of i + 1 and i stand influences the fluctuation of the state vector of i stand, respectively. C (i,
i) and C (i, i-1) are 2 ×, respectively, where the state vectors of the i and i-1 stands influence the output vector of the i stand.
3 constant matrix. F (i, i) is the disturbance vector of the i stand is i
A 2x4 constant matrix that affects the output vector of the stand.

Next, a reference input vector is defined as in (Equation 12) in order to perform follow-up control with respect to the output side plate thickness h and the forward tension t _{f which} are reference inputs.

[0048]

[Equation 12]

Then, as shown in (Equation 13), an error system (error system) which is the difference between the reference input vector and the output vector is introduced, and the error system of the i-th stand is incorporated into the state vector of the i-th stand. , Which is expressed as (Expression 14) as a state vector of the expansion system.

[0050]

[Equation 13]

[0051]

[Equation 14]

Here, the state equation of the state vector of the expanded system in the i-th stand shown in (Equation 14) is (Equation 1)
It can be expressed as 5).

[0053]

[Equation 15]

Further, the output equation of the expansion system of the i-th stand can be expressed as in (Equation 16).

[0055]

[Equation 16]

However, in (Equation 15) and (Equation 16), the newly introduced matrix is as shown in (Equation 17).

[0057]

[Equation 17]

From the above, the state equations and output equations of all stands can be expressed as (Equation 18) and (Equation 19), respectively.

[0059]

[Equation 18]

[0060]

[Formula 19]

However, in (Equation 18) and (Equation 19), n is the number of stands. xe is a 5n-dimensional state vector of the expansion system of all stands. u is a 2n-dimensional input vector of all stands. r is a 2n-dimensional reference input vector for all stands. w is a 4n-dimensional disturbance vector of all stands. y is a 2n-dimensional output vector of all stands. Ae
Is a 5n × 5n constant matrix in which the state vector influences the variation of the state vector. Be is a 5n × 2n constant matrix in which the input vector influences the fluctuation of the state vector. Ce
Is 2n × where the state vector affects the output vector
5n constant matrix. Ee is a 5n × 4n constant matrix in which the disturbance vector influences the fluctuation of the state vector. F is 2n where the disturbance vector affects the output vector of the i-stand.
× 4n constant matrix. G is a 5n × 2n constant matrix in which the reference vector influences the variation of the state vector.

For the above system, the evaluation function J is
It is shown as (Equation 20).

[0063]

[Equation 20]

However, Qe is a 5n × 5n diagonal matrix that gives a weight to the state quantity, and R is a 2n × 2n diagonal matrix that gives a weight to the input. These weight matrices are set by the weight matrix setting unit 52 of the control gain calculator 50.

State feedback U = -KX as input
Assuming that _e is given, the feedback gain K that minimizes the evaluation function J is calculated by the optimal regulator theory.
Can be asked. This feedback gain K
Is calculated by the feedback gain determination unit 53 of the control gain calculator 50 and sent to the feedback controller 60. Although the feedback controller 60 has been described as an integral compensation type optimum servo in the above, the present invention is not limited to this, and
It may be configured by a mold optimum servo, an optimum regulator, PID control, or the like.

Entry side plate thickness disturbance estimator 41 of the disturbance estimator 40
Then, from the i-th stand's outlet side plate thickness change Δh (i-1),
Estimate the entrance side plate thickness change ΔHi of the stand. The i-th stand 1 is stored in the thickness storage unit 42 of the entrance-side thickness disturbance estimator 41.
The output Δh (i-1) from the output side plate thickness gauge 21 (i-1) of 0 (i-1) is stored as first-in first-out. The moving distance estimating unit 44 includes a rolling position ΔS of the i-th stand and an i-th stand.
The front tension Δt _f of the stand, the front tension of the i−1 st stand, that is, the rear tension of the i th stand Δf _b , the roll speed ΔV _R of the i th stand, and the exit side plate thickness Δ of the i−1 st stand.
h (i-1) is input. The moving distance estimation unit 44 first
From these input values, the i-1 stand 10 (i-1) and the i-th stand
The speed V ₀ of the rolled material A with respect to the stand 10i is estimated.
The speed V ₀ of the rolled material A is determined by the roll speed V _R and the so-called advanced rate f, as shown in (Equation 21).

[0067]

[Equation 21]

Further, the advanced rate f is determined according to the detected values other than the roll speed V _R. Therefore, the advanced rate f is obtained from the other detected values, and the speed V ₀ of the rolled material A is estimated using (Equation 21). Next, the rolling material velocity V ₀ is multiplied by a certain period of time to obtain the moving distance of the rolling material A coming out from the (i-1) th stand 10 (i-1). In the moving distance management unit 44a,
It is determined whether or not the moving distance of the rolled material A reaches the distance between the i-1st stand 10 (i-1) and the i-th stand 10i.
Then, of the outgoing side plate thicknesses of the i-1th stand 10 (i-1) stored in the plate thickness storage unit 42, the outgoing side plate thickness Δh (i- (1) is set as the inlet side plate thickness disturbance ΔH of the i-th stand 10i and is output from the plate thickness storage unit 42 to the feedback compensation controller 65 and the rolling load disturbance estimator 45.

By the way, in the above, the moving speed of the rolled material A, the distance between the stands and the like were taken into consideration in estimating the entrance side plate thickness disturbance ΔHi of the i-th stand 10i. According to (Equation 22), the i-1 th
The entrance side plate thickness disturbance ΔH may be obtained from the time when the exit side plate thickness Δh (i-1) of the stand 10 (i-1) becomes the entrance side plate thickness ΔH of the i-th stand 10i, that is, the dead time.

[0070]

[Equation 22]

The rolling load disturbance estimating unit 45 estimates the rolling load disturbance Pd. The rolling load estimator 46 of the rolling load disturbance estimator 45 uses (equation 3) of the linear control model 35,
In this formula, the rolling position ΔS measured by the rolling position gauge 23,
The front tension Δt _f measured by the front tension meter 22i, the rear tension Δt _b measured by the rear tension meter (i-1th front tension meter) 22 (i-1), and the entrance side plate thickness disturbance estimation unit 41 The rolling load is estimated by substituting the obtained entrance side plate thickness ΔH. The difference unit 47 obtains the difference between the estimated rolling load and the actual rolling load measured by the rolling load meter 24, and outputs this as the rolling load disturbance ΔP _d to the feedback compensation controller 65. That is, that is, the rolling load disturbance estimator 45 sequentially calculates (Equation 23) obtained by modifying (Equation 3) to obtain the rolling load disturbance ΔP _d .

[0072]

[Equation 23]

The rolling load disturbance ΔP _d estimated by the rolling load disturbance estimating unit 45 is the original disturbance such as the rolling load fluctuation due to the temperature fluctuation of the rolled material A, or when the operator changes the target forward tension. Rolling load fluctuations such as

The feedback compensation controller 65 stabilizes the influence of the inlet side thickness disturbance ΔH from the sheet thickness disturbance estimator 41 and the rolling load disturbance ΔP _d from the rolling load disturbance estimator 45 on the outgoing side sheet thickness and the forward tension. The roll pressure reduction position command value and the roll speed command value that are canceled in the state are determined and given to the roll pressure reduction device 13 and the roll rotation drive device 14 via the adders 69 and 63, respectively. The roll control position command value and the roll speed command value that cancel the influences of the inlet side plate thickness disturbance and the rolling load disturbance on the outlet side plate thickness and the forward tension in a steady state are the linear control model 35.
It is decided based on.

A method of determining the roll pressure reduction position command and the roll speed command will be described below. In determining the roll reduction position command value that cancels the influence of the rolling load disturbance on the delivery side plate thickness in a steady state, the delivery side plate thickness deviation and the roll reduction command value that is the operation amount in (Equation 5) are unique. By paying attention to the term of the detected rolling position and the term of the rolling load disturbance, which are related to each other, as shown in (Equation 24), the delivery side plate thickness deviation = 0.

[0076]

[Equation 24]

Further, in determining the roll speed command value that cancels the influence of the rolling load disturbance on the forward tension in a steady state, the roll speed command value, which is the manipulated variable in (Equation 4), has a unique relationship. A sensed roll speed term,
Paying attention to the term of the detected rolling position and the term of the rolling load disturbance, which are uniquely related to the roll rolling command value which is the operation amount,
As shown in (Equation 25), the front tension deviation = 0.

[0078]

[Equation 25]

[Equation 24] and (Equation 2)
5) is solved for the detected rolling position and the detected roll speed as shown in (Equation 26) and (Equation 27), and the effects of the rolling load disturbance on the forward tension and the outlet side plate thickness are canceled in a steady state. Use the roll roll position command value and roll speed command value.

[0080]

[Equation 26]

[0081]

[Equation 27]

The value (feedback compensation control gain) multiplied by the rolling load disturbance ΔP _d in (Equation 26) and (Equation 27) is linearly controlled by the feedback compensation gain determination unit 54 in the control gain calculator 50. Determined using model 35.

Similarly, in the determination of the roll reduction position command value that cancels the influence of the inlet side plate thickness disturbance on the outlet side plate thickness in a steady state, as shown in (Formula 28), (Formula 5)
Is used to determine the roll reduction position at which the deviation of the plate thickness on the delivery side = 0.

[0084]

[Equation 28]

Further, even in the determination of the roll speed command value that cancels the influence of the entrance side plate thickness disturbance on the front tension in a steady state, the front tension is calculated using (Equation 4) as shown in (Equation 29). The roll roll down position where the deviation is 0 is calculated.

[0086]

[Equation 29]

The value (feedback compensation control gain) multiplied by the inlet side plate thickness disturbance ΔH of (Equation 28) and (Equation 29) is also linearly controlled by the feedback compensation gain determination unit 54 in the control gain calculator 50. Determined using model 35.

Therefore, the roll reduction position command value that cancels the influence of the rolling load disturbance and the inlet side plate thickness disturbance on the outlet side plate thickness and the front tension in a steady state is as shown in (Formula 30). ) Is added to the right side of (Equation 28).

[0089]

[Equation 30]

Further, the roll speed command value for canceling the influence of the rolling load disturbance and the inlet side plate thickness disturbance on the outlet side plate thickness and the front tension in a steady state is as shown in (Formula 31), (Formula 27) Is obtained by adding the right side of (Equation 29) to the right side of.

[0091]

[Equation 31]

The feedback compensation controller 65 is
The feedback compensation control gain described above is multiplied by the rolling load disturbance and the entrance side plate thickness disturbance to execute the calculations of (Equation 30) and (Equation 31).

The roll reduction position command value and the roll speed command value output from the feedback compensation controller 65 are the reduction command value adder 69 and the speed command value adder 6, respectively.
At 3, the roll reduction position command value and the roll speed command value output from the feedback controller 60 are added, and then sent to the roll reduction device 13 and the roll rotation drive device 14.

As described above, in this embodiment, even in the rolling phenomenon having a strong non-linearity, the clean controllability is compensated by the feedback control due to the disturbance and the like, and the feedforward control is compensated for. Therefore, even when the disturbance occurs. It is possible to prevent deterioration of control responsiveness. Further, in this embodiment,
The detector 21 required for feedback control and the detector 24 and control model 35 originally required for management of the rolling mill 10
Since the disturbance of the controlled object is estimated by using and, it is not necessary to purposely provide a special detector for grasping the disturbance, and the manufacturing cost can be suppressed.

By the way, the two disturbances, that is, the rolling load disturbance ΔP _d and the entrance side plate thickness disturbance ΔH are not mutually independent, but have mutual dependency. Thus, for example, the pressure command value S _p, rather than being determined only by the rolling load disturbance [Delta] P _d, is determined by the mutual rolling load disturbance [Delta] P _d and entrance side Atsugairan [Delta] H, also the speed command value V _p, ON It is not determined only by the side plate thickness disturbance ΔH, but by the rolling load disturbance ΔP _d and the entrance side plate thickness disturbance ΔH. In the present embodiment, the reduction command value S _p, which is two operation amounts.
And in determining the speed command value V _p , the relationship between the two manipulated variables S _p (= S) and V _p (= ω _m ) and the two ΔP _d and ΔH is shown (Equation 4), and one operation Since the two equations (Equation 5) showing the relationship between the quantity S _p and the two disturbances ΔP _d and ΔH are made simultaneous to obtain the two manipulated variables S _p and V _p ,
The value of each manipulated variable can be accurately obtained, and the controllability can be improved. In the present embodiment, the detected rolling reduction position is used to estimate the rolling load disturbance ΔP _d , but a rolling reduction command value that is an operation amount may be used.

Further, although the above embodiment is a control device for a rolling mill, the present invention is not limited to this, and may be applied to any control object having a strong nonlinearity. . The basic configuration of the control device for the general controlled object 1 having strong nonlinearity will be described below with reference to FIG.

This control device includes a controlled variable detector 2 for detecting a controlled variable y, which is an output from the controlled object 1, and a controlled object 1.
State quantity detector 3 for detecting the state quantities a and b, the control quantity y detected by the control quantity detector 2 and a predetermined target control quantity y.
It is detected by the feedback controller 4 which obtains the feedback manipulated variable x _FB according to the deviation Δy from ₀ , the control model storage unit 5 in which the linear control models f and g of the controlled object 1 are stored, and the state quantity detector 3. The disturbance estimator 6 that estimates the disturbance A of the controlled object 1 using the state quantities a and b and the deviation Δy is 0
Feedback compensation amount x for disturbance A such that
Feedback compensation controller 7 for _{obtaining FBC} and feedback manipulated variable x _FB obtained by feedback controller 4
And the feedback compensation amount x _FBC obtained by the feedback compensation controller 7 and the adder 8 which gives the sum to the controlled object 1. The control model storage unit 5 includes a first linear control model f representing the relationship between the state quantity a and the state quantity b of the controlled object 1 and a first linear control model f representing the relationship between the deviation Δy, the disturbance A, and the feedback compensation quantity x _FBC . 2 control model g
And are remembered. Further, the disturbance estimator 6 includes a state quantity estimation unit 6a that estimates the state quantity a _S for the state quantity b detected by the state quantity detector 3 using the first control model f,
It has a difference unit 6b which outputs the difference between the state quantity a _S estimated by the state quantity estimation unit 6a and the state quantity a detected by the state quantity detector 3 as the disturbance A to the feedback compensation controller 7. .

When controlling the controlled object 1 having strong non-linearity, first, the operating point is determined by the setup control system. The control model storage unit 5 stores the linear control models f and g created on the assumption that the variation of the controlled object 1 is within a range in which linear approximation can be performed near the operating point. The feedback controller 4 performs feedback control by linear control theory or the like that finds an optimum solution (feedback gain) that minimizes the fluctuation of the state. However, when the operating point changes drastically due to changes in the target control amount y ₀ , or when there is a disturbance, in a control system that performs feedback control on a linear control model, linearity near the operating point is used. Cannot be maintained, the error between the actual control target and the linear control model becomes large, and the target control performance cannot be maintained.

Therefore, here, the error between the actual controlled object 1 and the first linear control model f causes a large change in the operating point due to the change of the target controlled variable y _{0 or} the like as compared with the controlled object 1. Paying attention to the fact that it represents a general disturbance, the state quantity a of the actual controlled object 1 is compared with the state quantity a _S obtained by the linear control model f, and the difference between the two state quantities a and a _S A. Specifically, first, the state quantity estimating unit 6
At a, the state quantity a _S with respect to the state quantity b detected by the state quantity detector 3 is estimated using the first linear control model f stored in the control model storage unit 5. Then, the difference between the state quantity a _S and the state quantity b detected by the state quantity detector 3 is obtained by the difference device 6 b and is output to the feedback compensation controller 7 as the disturbance A. The feedback compensation controller 7 obtains a feedback compensation amount x _FBC that cancels the change in the control amount y due to the disturbance A, and supplies it to the controlled object 1 via the adder 8.

As described above, even in the case of the general controlled object 1 having a strong nonlinearity, in the present embodiment, the actual state quantity a of the controlled object 1 and the state quantity a obtained by the linear control model f are used. _Since the difference from _S is the disturbance A, an operation amount x that cancels the change in the control amount y due to the disturbance A is given to the controlled object 1 to supplement the feedback control.
Even if a disturbance or the like is input to the controlled object 1, deterioration of controllability can be prevented.

Here, the correspondence between this embodiment and the previous embodiment will be described. The controlled object 1 of this embodiment is the compressor 10 and the rolled material in the previous embodiment. Further, the control amount y of this embodiment is the delivery side plate thickness h of the previous embodiment, and the state amounts a and b of this embodiment are the rolling load P and the rolling position S of the previous embodiment, respectively. The operation amount x in this embodiment is the reduction command value S _P for the reduction device 13 in the previous embodiment.
Therefore, the control amount detector 2 of the present embodiment is the delivery side plate thickness gauge 21i of the previous embodiment, and the state amount detector 3 of the present embodiment is
The rolling load meter 24 and the rolling position gauge 23 of the previous embodiment.
Further, the feedback controller 4 of this embodiment includes the feedback controller 60 and the control gain calculator 5 of the previous embodiment.
0, which is the feedback compensation controller 7 of the present embodiment.
Are the feedback compensation controller 65 and the control gain calculator 50 of the previous embodiment.

In each of the above embodiments and the previous embodiments, the control model stored in the control model storage unit is linear, but the present invention is not limited to this. Instead, it may be a non-linear model. This is because even if a non-linear model is used, the error between the non-linear model and the actual controlled object eventually represents a disturbance for the feedback control system.

[0103]

According to the present invention, the difference between the actual state quantity of the controlled object and the state quantity obtained by the control model is taken as the disturbance to the controlled object, and the manipulated variable for canceling the change of the controlled quantity due to this disturbance is set. Since the feedback control is applied to the control target to supplement the control target, deterioration of controllability can be prevented even if disturbance or the like is input to the control target.

[Brief description of drawings]

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

FIG. 2 is a functional block diagram of a control model determiner, a control gain calculator, and a rolling load disturbance estimator according to an embodiment of the present invention.

FIG. 3 is a functional block diagram of an entrance-side plate thickness disturbance estimator of one embodiment according to the present invention.

FIG. 4 is a control block diagram of a control device according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Control object, 2 ... Control amount detector 2, 3 ... State amount detector, 10 ... Rolling machine, 11 ... Upper roll, 12 ... Lower roll, 13 ... Rolling down device, 14 ... Roll rotation drive device, 21
... Plate thickness gauge, 22 ... Tensiometer, 23 ... Rolling down position gauge, 24 ... Rolling load meter, 25 ... Roll speed meter, 30 ... Control model determiner, 35, 5 ... Control model storage section, 40 ... Disturbance estimator,
41 ... Entry side disturbance estimation unit, 45 ... Rolling load disturbance estimation unit, 4
6 ... Rolling load estimator 46, 47 ... Difference calculator 50 ... Control gain calculator 53 ... Feedback control gain determiner
54 ... Feedback compensation control gain determination unit 54, 6
0, 4 ... Feedback controller, 63, 8 ... Adder, 6
5, 7 ... Feedback compensation controller, 69, 8 ... Adder.

Claims (10)

[Claims] 1. A control device that applies a manipulated variable to a controlled object having a strong non-linearity and sets a controlled variable that is an output from the controlled object as a target value, wherein the controlled variable that is an output from the controlled object is A control amount detecting unit for detecting, a state amount detecting unit for detecting a state amount of the controlled object, and a feedback operation according to a deviation between the control amount detected by the control amount detecting unit and a predetermined target control amount. A feedback control input calculation unit for determining an amount, a first control model representing a relationship between the control input given to the control target, and the state amount of the control target, and the control control target and the target control control Control model storage means for storing a second control model showing a relationship between a deviation, a disturbance with respect to the controlled object, and a feedback compensation amount for compensating the feedback operation amount; Using a model, state quantity estimating means for estimating the state quantity of the controlled object with respect to the manipulated variable given to the controlled object, and the state quantity detected by the state quantity detecting means and estimated by the state quantity estimating means The disturbance estimation means for obtaining the difference between the state quantity and the disturbance estimation means for using the difference as the disturbance of the controlled object, and the disturbance estimation means for making the deviation zero by using the second control model. Feedback compensation amount calculation means for obtaining the feedback compensation amount with respect to the disturbance obtained in, and the feedback operation amount obtained by the feedback operation amount operation means to the feedback operation amount obtained by the feedback compensation amount operation means. In addition,
An operation amount adding means for giving this to the controlled object as the operation amount, a control device. 2. The state quantity detecting means detects, in addition to the state quantity used for determining the disturbance, a state quantity (hereinafter referred to as a specific state quantity) uniquely determined with respect to the manipulated variable. However, the operation amount of the first control model is the specific state amount, and the state amount estimating means uses the first control model indicating a relationship between the specific state amount and another state amount. And estimates the other state quantity with respect to the specific state quantity detected by the state quantity detection means, and the disturbance estimation means estimates the other state quantity and the state quantity estimated by the state quantity detection means. 2. The control device according to claim 1, wherein a difference from the other state quantity estimated by the means is obtained, and the difference is used as the disturbance of the control target. 3. The control target is a pair of rolls facing each other, a roll rotation drive means for rotating at least one roll of the pair of rolls, and the other roll so that the mutual interval of the pair of rolls can be changed. A rolling mill having a roll moving means for relatively moving the roll to one of the rolls, and a rolling material passing between the pair of rolls of the rolling mill, wherein the control amount is from the rolling mill. It is the plate thickness of the rolled material that has come out, the state quantity is a rolling load applied to the rolled material by the rolling mill, and the disturbance estimated by the disturbance estimation means is detected by the state quantity detection means. The difference between the rolling load and the rolling load estimated by the state amount estimating means is a rolling load disturbance, and the operation amount given to the control target is the roll moving means of the rolling mill. The control device according to claim 1 or 2, which is the position of the other roll that is output. 4. A control device in which a plurality of manipulated variables are applied to a controlled object having a strong non-linearity which is input by a plurality of disturbances, and a plurality of controlled variables which are outputs from the controlled object are respectively set to target values. , A control amount detection unit that detects a plurality of the control amounts that are outputs from the control target, a specific state amount that has a unique relationship with at least one of the plurality of operation amounts, and other Depending on the deviation between the state quantity detection means for detecting several state quantities and the plurality of control quantities detected by the control quantity detection means and the target control quantities respectively set for the plurality of control quantities. , And, in accordance with a deviation between at least one state quantity among the plurality of state quantities detected by the state quantity detecting means and a target state quantity defined for the state quantity, in the plurality of manipulated variables Calculate the feedback control amount A feedback manipulated variable calculation means, first indicating the interrelationship of the plurality of the state quantity of the controlled
Of the control model and the deviation between the plurality of control amounts and the respective target control amounts, the plurality of disturbances, and the plurality of feedback compensation amounts for compensating for each of the plurality of feedback operation amounts. A control model storage unit that stores a plurality of second control models, and one state quantity of the plurality of other state quantities excluding the one state quantity by using the first control model. A state quantity estimating means for estimating from a state quantity including the specific state quantity detected by the state quantity detecting means, the one state quantity detected by the state quantity detecting means and the state quantity estimating means estimated by the state quantity estimating means. A difference with one state quantity is obtained, and the difference is set as one specific disturbance among the plurality of disturbances, and the one state quantity among the plurality of other state quantities detected by the state quantity detecting means. From state quantities other than the above A plurality of disturbances obtained by the disturbance estimation means such that a plurality of the deviations are 0 by using a disturbance estimation means for obtaining a disturbance other than the one specific disturbance and a plurality of the second control models. Feedback compensation amount calculation means for respectively obtaining feedback compensation amounts for each of the plurality of feedback operation amounts with respect to the disturbance, and the feedback compensation amount calculation means for the plurality of feedback operation amounts obtained by the feedback operation amount calculation means. A plurality of feedback compensation amounts corresponding to each of the feedback compensation amounts obtained in step S3, and an operation amount adding means for giving the feedback compensation amounts to the control target as a plurality of the operation amounts. Control device. 5. The control target is a pair of rolls facing each other, a roll rotation driving means for rotating at least one roll of the pair of rolls, and the other roll so that the mutual interval of the pair of rolls can be changed. A rolling mill having a roll moving means for relatively moving the roll to one of the rolls, and a rolling material passing between the pair of rolls of the rolling mill, wherein the control amount is from the rolling mill. It is the plate thickness of the rolled material that has come out and the tension applied to the rolled material that has come out from the rolling mill, and the plurality of operation amounts are the position of the other roll that is output to the roll moving means. A rotation speed of the one roll output to the roll rotation driving means, the specific state amount is an actual position of the other roll, among the plurality of other state amounts, the one of the one State quantity is The rolling load applied to the rolled material by the rolling mill, the one specific disturbance estimated by the disturbance estimating means is estimated by the rolling load and the state amount estimating means detected by the state amount detecting means The difference between the rolling load is a rolling load disturbance, the disturbance other than the one specific disturbance estimated by the disturbance estimating means is the amount of change in the plate thickness of the rolled material entering the rolling mill, The control device according to claim 4, wherein the control device is a side plate thickness disturbance. 6. A control device for applying a plurality of manipulated variables to a controlled object having a strong non-linearity, which is input by a plurality of disturbances, and controlling the controlled variable which is an output from the controlled object to be a target controlled variable. , A control amount detection unit that detects the control amount that is the output from the control target, a disturbance estimation unit that estimates a plurality of the disturbances from the state of the control target, and a plurality of manipulated variables A control model storage unit that stores a plurality of control models showing the relationship between the deviation between the control amount and the target control amount and a plurality of the disturbances; and a plurality of the detection models detected by the disturbance detection unit using the plurality of control models. From the external disturbance, a plurality of manipulated variables are obtained such that the deviation between the controlled variable detected by the controlled variable sensing means and the target controlled variable is 0, and the manipulated variables are given to the controlled object. Computing means, A control device comprising: 7. The control target is a pair of rolls facing each other, roll rotation driving means for rotating at least one roll of the pair of rolls, and the other roll so that the mutual interval of the pair of rolls can be changed. A rolling mill having a roll moving means for relatively moving the roll to one of the rolls, and a rolling material passing between the pair of rolls of the rolling mill, wherein the control amount is from the rolling mill. It is the plate thickness of the rolled material that has come out, or the tension applied to the rolled material that has come out from the rolling mill, and the plurality of operation amounts are the position of the other roll output to the roll moving means. , The rotation speed of the one roll output to the roll rotation driving means, the plurality of disturbances is a rolling load disturbance that is a change amount of the rolling load, and a plate of the rolled material that enters the rolling mill. Thick Claim 6, characterized in that in the thickness at entrance side disturbance is of weight
The control device described. 8. A control model determining means for determining the control model using a model prepared in advance each time the target control amount changes and storing the control model in the control model storage means. The control device according to claim 1, 2, 3, 4, 5, 6 or 7. 9. A control method in which an operation amount is applied to a control object having a strong non-linearity, and the control amount output from the control object is controlled to a target value, the control amount is detected, and the control amount is controlled. A feedback control amount according to a deviation between the control amount and the target control amount with respect to the control amount, a first control model representing a relationship between the control amount given to the control target and the state amount of the control target, and A second relationship showing a relationship between a deviation between the control amount and the target control amount, a disturbance entering the control target, and a feedback compensation amount for compensating the feedback operation amount when the disturbance enters the control target. A control model is prepared in advance, and while using the first control model, the state quantity of the control target with respect to the operation amount given to the control target is estimated, while the state quantity of the control target is calculated. In fact Detecting, by obtaining a difference between the estimated the state quantity actually detected state quantity,
The difference is taken as the disturbance of the controlled object, the feedback compensation amount for the disturbance such that the deviation becomes 0 is obtained by using the second control model, and the feedback operation amount obtained is the same as A control method, wherein the calculated feedback compensation amount is added and the feedback compensation amount is given to the control target as the operation amount. 10. A control method in which a plurality of manipulated variables are given to a controlled object to which a plurality of disturbances are input and the controlled variable which is an output from the controlled object is controlled to be a target controlled variable. For each of the quantities, a plurality of control models indicating the relationship between the deviation of the control quantity and the target control quantity and the plurality of disturbances are prepared in advance, and the control quantity that is the output from the control target is While detecting, estimating a plurality of the disturbance from the state of the controlled object, using the plurality of control models, from the plurality of detected disturbances, the deviation between the detected control amount and the target control amount A control method, wherein a plurality of manipulated variables such that 0 becomes 0 and the plurality of manipulated variables are given to the controlled object.