JPS6099414A - Control method of looper angle - Google Patents

Abstract

PURPOSE:To restrain the excessive quantity of a loop and the fluctuation of strip tension by estimating the changing quantity of a strip speed basing on the detecting value of a looper angle, etc. and controlling the roll speed of a mill stand when the looper angle is fluctuated by disturbance. CONSTITUTION:The angle or angular velocity of a looper 3 is detected when the looper 3 angle is changed by the change of the speed of a strip 4 caused by disturbance. Next, the changing quantity of strip 4 speed is estimated basing on the angle or angular velocity of looper 3 and a speed command value for a speed control device 5. The speed command value corresponding to that estimated value is inputted to the device 5 used for controlling the roll speeds of mill stands 1, 2. Thus the change of looper 3 angle caused by the disturbance is corrected by controlling the roll speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly applies to hot-rolling finishing mills, etc. by adjusting the angle of
It relates to a method for i'l fill.

Normally, the looper controls the length of the stroke between the stands, as well as the loop amount to maintain stable strip tension, and the louver angle (specifically, the arm angle of the looper) is controlled by the mill stand. Control is carried out by adjusting the speed of the vehicle at E)4. This control of the louver angle is configured as a PII) control system. Figure 1 is a block diagram of the conventional looper angle control system, and Figure 2 shows the characteristics of the open circuit transfer function of the entire control system. This is a graph showing. In Fig. 1, when the angle command value θref is set in the angle control system of the looper, it is added to the currently set louver angle θ, and proportional integral processing (transfer function: KP (1-1-1
/s-1)K1]: Proportionality coefficient, TL: Integral time +
S nila plus operator), differential processing (transfer function: 1
+ S TD , TII = differential time) and the following ('')
is input to the speed control device of the rolling mill stand with a transfer function Gn (s) expressed by the equation.

S'-+23ωn 0ωn 7' However, Kn gain constant ωSn: Natural frequency (rad/sec) From the speed control device, the roll speed control Hv of the mill stand
A signal corresponding to is output, and roll speed control is performed by adding the amount of influence on the strike IJ tube speed as a disturbance, for example, due to poor heat treatment, etc., and the amount of shadow W due to a change in the backward movement rate. As a result, the looper is rotated at an angular velocity P (=dθ/dL) by the transfer element (looper dynamics) of the transfer function GL (S), and the louver angle is set to θ via the integral element, and then the louver angle is set to θ again. control a1 to repeat the above process until it is added to θref and the two match;
1 is done.

The characteristics of the speed control device and looper as described above, that is, the phase and gain, are approximated by a second-order lag system, and each natural frequency (rad/sec) is ωn = 10 in the speed control device.
~20, and in the looper it is approximately ωL-5 to 30, so the open circuit transfer function G of the entire control system. Characteristics of (S),
That is, the gain curve is set as shown in FIG. Second
The graph in the figure shows the angular frequency ω (rad/sec) on the horizontal axis and the gain (dB) on the vertical axis. Breaking point frequency for such a control system to maintain stability]/'I"L
, ωn gain conditions are determined by equations (2) and (3), respectively, so Go(]/”rL)≧10 dB −124
Go (ωn)≦-10dB ・f31 intersection angle frequency ω
C is ωC#ωn·1/3, and is set to a value as shown in equation (4).

ωC≦3～6 (4) By the way, automatic plate thickness control (AGC) is performed in finishing mills, and for example, pressure loads naturally occur in areas where there are factors such as skid marks or other factors that change the plate thickness in the strip. It gets bigger and along with this the tip of the strip.

As the backward movement rate changes, the stripping speed instantaneously changes greatly, but the response of the looper angle control cannot follow this because the crossing angular frequency ωC is about 3 to 6 rad/sec, as mentioned above, and the stripping speed changes rapidly. Tension and looper amount change greatly. ]・If the lip tension changes, the strip thickness,
By changing the strip width, the strip thickness control ff1l 8M function cannot fully demonstrate its effect, and on the other hand, large fluctuations in the looper amount can cause operational troubles such as triple jamming and narrowing due to sideways strip slippage. is born.

The present invention has been made in view of the above circumstances, and when the strip speed changes due to disturbance, the change in strip speed is fixed using a simulator based on the roll speed command value, the looper angle, or the angular speed of the looper. A looper inputs a speed command value corresponding to the estimated value to a roll speed control device, controls the roll speed to stabilize the louver angle, and quickly responds to changes in strip speed caused by disturbances. The purpose is to provide an angle control method.

The looper angle control α11 method according to the present invention is a method in which the angle of the looper is controlled by adjusting the roll speed of a rolling mill stand with a speed control device. The angle or the angular velocity of the looper is detected, the amount of speed change of the rolled material is estimated based on the angle of the looper or the angular velocity of the looper, and the speed command value for the speed control device, and the speed command value corresponding to the estimated value is set as described above. Input the roll speed to the speed control device to correct the looper angle change due to disturbance;
It is characterized by a+l.

The present invention will be specifically explained below based on the drawings.

FIG. 3 is a schematic diagram showing the implementation state of the method of the present invention, in which 1 and 2 are two adjacent stands in a finishing mill;
3 indicates a looper, and 4 indicates a strip. The looper 3 is located between the stands 1 and 2 and presses the strip 4 passed from the direction of the white arrow upward from its lower surface side.
It is designed to provide the proper tension to the strip 4 and to ensure proper looping of the strip between the stands 1 and 2. The looper 3 is constructed by pivotally supporting a roll 3C at the upper end of an arm 3b which is pivotally supported on a support base 3a, and connecting the operating rod of a hydraulic cylinder 3d to the middle part of the arm 3b. , the arm 31J is set at a required angle by operating the hydraulic cylinder 3d.

5 is a speed control device for the finishing mill, which calculates the arm angle (hereinafter referred to as louver angle) θ based on the angle data input from the arm angle detector provided at the lower end of the arm 3b of the looper 3, and calculates a preset command value. Compared with θref, θre
Each motor control part IL of the mill stand is adjusted to match f.
12 to output a signal corresponding to the controlled amount. 6 is a simulator of the speed control device 5, 7 is a louver simulator, and each of these simulators 6.7
estimates the speed fluctuation of the strip due to disturbance while maintaining the looper angle stably, and inputs a signal corresponding to this estimated value to the speed control device 5 as a speed command value, thereby controlling the responsiveness of the looper. High.

It is designed to stabilize the looper angle and strip tension.

These control processes will be specifically explained below based on the block diagram shown in FIG. FIG. 4 is a block diagram showing the louver angle control system, where the louver angle command value θref
When the setting is input, the currently set looper angle θ
is added to the proportional integral (transfer function: KP (1+
1/sTL)) processing, differentiation (transfer function: l+5TD)
After processing, the estimated disturbance value ω is added to the transfer function l/G
n (0) through the transmission element and input as the speed command value X to the speed control device 5 and its simulator 6. The speed control device 5 with the transfer function Gn(S) expressed by the equation (1) outputs the speed control ffi■, and the disturbance ω
is added to perform roll speed control. As a result, the looper is rotated at an angular velocity P by the transfer element (louver dynamics) of the transfer function GL (S), and the looper angle is set to θ via the integral element (transfer function: 1/S).
This set value is used as feedback data again as θref.
and the above process is repeated.

On the other hand, from the simulator 6 for the speed control device 5 of the transfer function Crn\ (S), the estimated roll speed control amount
is output and added to the estimated disturbance value 0 years, which will be described later.
A value corresponding to the deviation Δθ* (= θ-θ Function GL”
(s) - Input to the simulator for the 1/S looper, from which the estimated value of the looper angle 0 years of the louver is output.

This louver angle estimated value θ′ is added to the looper angle setting value θ and amplified to g+ (θ−θX), and as described above, the difference between the roll speed control amount estimated value v tree and the disturbance estimated value ωY (
-g2 (θ-
After being amplified to the end of θ), the estimated disturbance value ω is outputted through an integral element (transfer function 1/S). This disturbance estimated value 0 is not only added to the roll speed control amount estimated value ■o which is the output of the roll speed control simulator, but also input to the transfer element of the transfer function 1/Gn (0), and its output is It is added to the output of the differential element described above, and is added to the speed command value X, which is sent to the roll speed control device ff15 as described above.
and is input to the simulator 6.

By using the simulator 6.7, strip speed fluctuations caused by disturbances are calculated accurately and quickly, and as a result of inputting this calculated value to the roll speed control device 5, the roll speed control system, in other words, the louver The responsiveness of the angle control system becomes faster, and excessive loop amounts and tension fluctuations can be quickly dealt with.

FIG. 5 is a block diagram showing another implementation state of the present invention, in which the integral element is removed from the louver simulator 7 shown in the block diagram shown in FIG. 4, and the transfer function G in the looper is
The angular velocity P that is the output of the transfer element (louver dynamics) of L (s) and the estimated angular velocity that is the output of the transfer element (element corresponding to louver dynamics) of the transfer function GL'' (S) in the looper simulation tough 2 years old and 2 years old.And this angular velocity difference (P-P
") is multiplied by the gain coefficient g1 and gl (P-p") is added to the difference (v2-ω") between the roll speed estimation control ffi yt and the disturbance estimated value ω7 (V tree-ω8+g1(P
-, P')), and the angular velocity difference (P-Pi) is multiplied by the gain coefficient -g2, gz (P P') is integrated, and the output, the estimated disturbance value 0, is given to the speed control device 5.
In addition to adding it to the estimated roll speed control amount ■2, which is the output of is added to the value subjected to proportional fraction processing and differentiation processing, and the speed control device 5 sets the roll speed command value x.
and input it to the simulator 6.

In such control, the angular velocity of the looper is used instead of the looper angle θ, and the same looper angle control can be performed as in the case where the looper angle θ is used (not shown in FIG. 4).

In the angle control process shown in FIGS. 4 and 5, the simulator 6.
The estimated looper angle θ1 and the estimated angle P” are calculated using 7.
and the estimated disturbance value 0 years old are given as follows. Now, the transfer function Gn (s) of the speed control device 5, the transfer function GL (s) of the looper dynamics, and the transfer function G,n j (s,) of the simulator 6゜7 corresponding to these.
, G, L (s) are equal, the looper angle θ
(S, ) Disturbance ω(S) Roll speed setting value x (s)
, estimated value θ* (S), ω”, (S
) The mutual relationships are as follows in the control method shown in Figure 4.
(51, ((i), (It can be expressed as equation 71.

θ (s) −1/s −GL (s) (X (S)
・Gn (s) −ω (S)) ... (5) θ'
(s) -1/5-GL, (s) Cx (s)・Gn
'(s) -ω' (S) 10g1 (θ (S) -〇O (S)))...(6
) ω (s) = gz (θ (S) −θ*(S)
l・1/S...(7) The looper angle deviation Δθ-θ'-θ is given by (5), (from equation 61 to equation (8) below.

Δθ (S) = 1/5-GL (s) (-ω” (
s)g+ Δθ0ω(S)) ... (8) ω of equation (8)" Substituting equation (7) into (S), Δθ (s)
-1/5-GL (s) (g2/s・Δθ (s)
g+ ・Δθ →−ω(S)) ・・・(9) ,,Δθ (S) s2+gl GL (,s) ・S+g2 ・'ct
(S)...θ0) Also, fil, 0 years old from formula 001 (S) s2-: + g+' ct, (s) ・s +g2 H
Gt, (s)...(11) On the other hand, in the control method shown in FIG. 5, the looper angle change rate P(S)', disturbance ω(S), roll speed setting value x(S), These estimated values P* by the simulator
The relationship between (s) and ω(S) is as follows (12), (13)
), ' given by equation (1, 4).

P (s) =GL (s)('x (s)Gn (s
)-ω(S)) ...(12) P\' (s)-GL (s)(x (s)Gn'(
s)−ω tree (s) +gr (P (s)=P″′(
s') ) ) ... (13) ω" (s) = gz
(P(s)-])*(s)1・1/S...
(14) Looper angular velocity deviation ΔP (s)=P" (s)-P
(s), ω" (s) is calculated from equations (12) to (14) in the same manner as described above, and becomes as shown in equations (15) and (16) below.

8P (s)=GL (s) (-ω' (s)gs
ΔP (s) +ω(S)) S・ω(S) ・GL (s) (1+g+-GL, (s)l s×g2-GL (s)
...(■5) ω' (S) (1+gr ・GL (S)) s0g2 ・GL (
S)...(16) Oo+, <11> formula or (15), (1
6) If the gains g+ and gz are appropriately selected from the formula, t
-■ becomes Δθ-0, θ* (S)-〇(S), ω
ω(S)−ω(S). g+ and gz can be calculated as follows.

For example, if GL(s)=KL/'(1+sTL) (where KL is a gain constant), then this becomes (10).

Substituting into equation (11), we get equations (17) and (18).

Δθ (S) S ・ω (S) TL−s3 →−s2+KL −g 1 ・s+g2
・Kl.

... (17) ω1 (S) ω (S) TL -s3+s2+KL 'g+ ・S+g2 ・K
L... (18) Similarly, substituting into equations (15) and (16) yields (19).

It becomes as shown in equation (20).

...(19) ω" (S) TL -s2+ (KL g+ →-1)・s+g2K
L... 20) Therefore, in order to make the response of ω* (S) given by equation (20) faster than the response of the control system, assuming TL<g2KL (taking gz sufficiently large), ( Equation 18) becomes a second-order delay element, and in the control method shown in FIG. 4, ωohm〒 Also, C″-, KL gI/2ω.

So, in order not to increase ζ−0,7,ω0 >i″L,
g2= (103~10') KL -... (21)
g+ = 1.4ω0 /KL = 1.4F "Seal U・
...(22).

In addition, in the control method shown in Fig. 5, ω0#press 1 and ζ#(KL gyu+1)/2ωn, so g+ and g2 are expressed as (23) in the same way as above.
, (24).

g2= (103~10') KL...(23)
g+ = 1.4 r shoulder (24) As described above, in the method of the present invention, when the louver angle is varied due to disturbance, the louver angle or louver angular velocity as well as the roll speed of the mill stand can be determined using a simulator. The amount of change in strip speed, which is a disturbance, is estimated based on the speed command value recorded on the control device, and this estimated value is input to the speed control device. The louver can quickly respond to changes in stripping speed without causing any changes in stripping rate, and excessive loop volume and tension fluctuations can be suppressed, so the present invention is useful for preventing operational troubles and improving product quality in factories. There are a lot of things to do.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a general looper angle control system, Fig. 2 is a graph showing the characteristics of the open circuit transfer function of the entire control system, and Fig. 3 is a diagram showing the implementation state of the method of the present invention. ,
FIG. 4 is a block diagram showing a control mode in the method of the present invention, and Section 5 is a block diagram showing another control mode in the method of the present invention. ■, 2... Bell stand 3... Louver 4... Hydraulic cylinder 5... Speed control device 6, 7... Simulator patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono 1 Figure! 2 Day 4 Figure 5

Claims (1)

[Claims] 1. What is the roll speed of the rolling mill stand? 1IIJ
Adjust the angle of the roots with the iD device a++J f
In the first method, when the looper angle changes due to a change in the rolling material speed due to a disturbance, the angle of the roots or the angular velocity of the looper is detected, and the angle of the looper or the angular velocity of the looper and the speed Mill fall are determined. The speed change amount of the rolled material is estimated based on the speed command value for the device, and the speed command value corresponding to the estimated value is manually inputted to the speed control device, and the roll speed is adjusted to correct the looper angle change due to taut. A rule characterized by controlling
t++J fac+method.