JPS62212009A - Method for controlling tension between stands of continuous rolling mill - Google Patents

Abstract

PURPOSE:To eliminate the instability of responses and to stably control tensions by estimating a state amount and controlling tensions, excluding the influence of a detector. CONSTITUTION:A speed target value correcting amount VR of a mill speed controller and a current target value correcting amount GR of a looper torque controller are denoted as manipulated variables and respective deviations DELTAV, DELTAdelta, DELTAg, DELTAN, and DELTAtheta from a mill speed deviation detecting value, a deviation detecting value for a tension between stands, a looper torque deviation detecting value, a looper angle speed detecting value, and a looper angle deviation detecting value are denoted as quantities of state. An arithmetic unit estimates thereof, performs integrations by a proportional action of the proportional gain (f) and the integral gain K, and corrects the VR and GR.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method for controlling the looper angle of a looper between stands of a continuous rolling mill and the tension between the stands to desired values.

[Conventional technology]

The basic configuration of the looper and a block diagram of the control device that controls it are shown in FIG. are in contact.

In the conventional technology, mill speed [V], tension between stands [σ]
, looper torque [g], looper angular velocity [N], and louver angle [θ] are detected by detectors 11.12°13.14.15, and these detected values Vm, crm, gm, Nm, 0
Each deviation ΔVm, Δ from the start of control characterized by m
σm・6gm, ΔNm, ΔOrn, the speed target value correction amount [VR] of the mill speed control device, the current target value correction amount [GRl] of the looper torque control device so that the quadratic time integral type evaluation function of The inter-stand tension detection value [σm] and the looper angle detection value [θm] are operated in proportion to the amount, and the detected value of the looper angle [θm] and each target value [σref] are output.
Deviation [Δσref ] from [θref ], [Δθre
f ] to perform an integral operation to correct the speed target value correction amount and the current target value correction amount (Japanese Patent Publication No. 59-4
4129) (Japanese Patent Application Laid-Open No. 59-118213).

[Problem that the invention seeks to solve]

In conventional techniques, no particular consideration is given to the detector, but in order to achieve fast response, it is necessary to also consider the dynamic characteristics of the detector. The looper system is required to have extremely fast response, and in order to achieve this, the dynamic characteristics of the detector must be taken into account. The response of the inter-stand tension detection value becomes unstable.

In this invention, the state! , 1 detection amount ΔVm, Δσm, 6gm,
ΔV, Δσ from ΔNm, ΔOm and manipulated variables VR, GR
, Δg, ΔN, and Δθ, and control is performed by excluding the influence of the detector, assuming that there is no apparent ball detector, to eliminate response instability and perform stable tension control. shall be.

[Means for solving problems]

The present invention uses a looper control system as a looper system in a narrow sense as a two-man, two-output, five-dimensional multivariable control system, and the manipulated variables are the current target value correction amount of the looper torque control device and the speed target value correction of the mill speed control device. It is the amount. In addition, the state quantities are the mill speed, tension between stands, Φ looper torque, 0 looper angular velocity, and looper angle estimated from the operation amount, mill speed detection value, inter-stand tension detection value, looper torque detection value, looper angular velocity detection value, and looper angle detection value. This is the deviation from the start of each control. The outputs are the inter-stand tension deviation and looper angle deviation estimated previously. Necessary calculations are performed on these state quantities and outputs.

A broad-sense looper system is set in which the detected values of each state quantity in the narrow-sense looper system are state quantities and outputs, and the state quantities in the narrow-sense looper system are estimated from the manipulated variables and the outputs of the broad-sense looper system. do.

Next, the manipulated variable is corrected in accordance with the state quantity estimated in the looper system in the narrow sense, and the manipulated variable is corrected in accordance with the deviation between the output target value and the output in the looper system in the narrow sense from the start of control. The configuration is configured to correct this.

[Effect]

FIG. 1 is a control block diagram showing the configuration of a looper control system according to the present invention. In FIG. 1, the value at the start of control is used as a reference value, and is expressed as a deviation.

here.

Mill speed control device speed target value correction amount: [VR] Looper torque control device current target value correction amount = [GRl Mill speed deviation detection value [ΔVml Inter-stand tension deviation detection value [Δσm] Looper torque deviation detection value [Δgml Looper angular velocity detection value [ΔNml Looper angle deviation detection value [ΔOm] From, each state quantity [ΔV], [Δσ], [Δg], [ΔN].

[Δθ] is estimated by the arithmetic unit 2 using the method described later, and the proportional operation of the proportional gain f and the integral gain K
An integral operation is performed, and the speed target value correction amount [V R1 current target value correction amount [, GR] is corrected by the method described later.

Next, the operation of the continuous rolling mill looper control device of the present invention constructed as described above will be explained.

The looper dynamic characteristic model of a continuous rolling mill is a nonlinear model, but when it is expanded by Taylor in the vicinity of a steady state, the controlled object including the detector is expressed as a linear state equation as follows:
It becomes like the expression,■expression.

i; λi + 100 U ... (Di engineering Cx
...■ However, i: time differential d x / d t x, u, y: respectively below ■, ■, vector λ shown in formula 6, 100, C: (IOXIO), (10X2), (5X10) is a constant matrix, where t represents the transpose.

x=(ΔV, ΔVm, Δσ, Δσm, Δg.

Δgm, AN, ΔNm, Aθ, Δθm)1...■ u= (VR, GR)' = (
JV = (ΔVm, Δσm, 4gm,
ΔNm.

60m) t...■
The state quantities ΔV, Δσ, Δg, ΔN, and Δθ are estimated by the following method. However, "-" indicates an estimated value.

H and G are (5×5) constant matrices, and H is given so that it does not have a common eigenvalue with λ.

It is assumed that Ma=L1轡+L2Y, -(6) constitutes Ma.

The estimated value W of a five-dimensional vector (w=Tma; T: (5×10) constant matrix) is obtained from equation 0.

w=Hw+Gy+T#″Hau − (7) However, T is selected so that the following equation 0 holds true.

Tλ~HT=GC...■ At this time, from the formula ■■■■ w-Tx=H (w-Tx) ・-C9), so that all uniqueness of H has a negative or negative real part. The word asymptotes to Tx. Then, if T is chosen so that (from equation 0...(10)), then i can be specified.

When the looper system is newly expressed by a state equation using the obtained estimated value, the results are as shown in equations (12) and (13).

1=Ax+B*u...-(1
2) y=cx...(1
3) However, x and y are vectors shown in equations (14) and (15), and A, B, and C are (5X 5) and (5X2)
, (2×5) constant matrix.

x= (V, cr, g, N, θ)t − (14
)y=(σ, θ)t...(15)
The purpose of the looper control is to suppress fluctuations and deviations of the inter-stand tension and the looper height with respect to the target values, and if the control method of the integral type control system is used, the manipulated variable can be configured using the following equation.

u=-R'B" P21f (y-yR)dt-R-
1B” P22x −・−(1B)
Here, R: (2X2) positive value matrix yR: l standard value vector of output vector P21, P22: constant matrices (5X2) and (5X5), respectively, and the Riccati equation shown in the following equation (17). It is a submatrix of solution P.

A and B in equation (17) are constant matrices of (7X7) and (7X2) shown in the following equations (1B) and (19), and Q
is a (7×7) positive value matrix.

FIG. 1 is a block diagram of the above equation (16). Note that in the above configuration, control is performed using estimated values for all elements of the state vector and output vector, but
There are also detectors that do not affect controllability. Therefore, there is no need to distinguish between detected values and estimated values;
The proportional action and integral action in the figure may be performed directly on these detected values, and it is not necessary to use all detected values when estimating the state quantity, and the mill speed, looper torque, and looper angular velocity are Optional.

〔Example〕

Control is performed according to the control system configuration block shown in Fig. 1, and the inter-stand tension target value is adjusted in steps to IKgf/mrn'.
Figure 4 shows the response when the response is changed from 2Kgf/mm'' to 2Kgf/mm. .

Although the response was unstable, the method of the present invention can realize a fast and stable response.

〔Effect of the invention〕

In a looper tension control system that requires extremely fast response, this system eliminates the effects of the detection delay of detectors and achieves fast and stable response with a small number of detectors by estimating the state quantity. and the thickness of the rolled material,
It greatly contributes to quality improvement, such as improving plate width accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
Figure 3 is a block diagram showing the configuration of a conventional control method, Figure 3 is a graph showing the response of the conventional method when a looper angular velocity detector is considered, and Figure 4 is a graph showing the response of the control system according to the present invention. be. 1... Rolled material 2.3... Rolling mill stand 4... Looper 11... Mill speed detector 12... Inter-stand tension detector 13... Looper torque detector 14... Looper Angular velocity detector 15... Looper angle detector 21... Mill speed control device 22... Looper torque control device 31... Arithmetic device 41... Inter-stand tension generation mechanism 51-52... Integrator 32 ...Arithmetic device

Claims (1)

[Claims] 1. A tension control device consisting of a looper torque control device and a mill speed control device disposed between stands of a continuous rolling mill to control the looper angle and inter-stand tension to predetermined values. A method for controlling tension between stands of a continuous rolling mill, characterized in that looper torque and mill speed are simultaneously controlled by including the following steps (a) and (b). (a) The speed target value correction amount of the mill speed control device and the current target value correction amount of the looper torque control device are used as manipulated variables, and each of the mill speed, tension between stands, looper torque, looper angular velocity, and looper angle is adjusted from the start of control. A narrow-sense looper system is set in which the deviation is the state quantity and the deviation from the start of control of each of the tension between stands and the looper angle is set as the output, and the detected value of each state quantity in the narrow-sense looper system is set as the state. A looper system in a broad sense is set as a quantity and output, and a state quantity in the looper system in a narrow sense is estimated from the manipulated variable and the output of the looper system in a narrow sense. (b) Correct the manipulated variable in accordance with the state quantity estimated in the looper system in the narrow sense, and correct the manipulated variable in accordance with the deviation between the output target value and the output in the looper system in the narrow sense from the start of control. do.