JPH03184614A - Shape controller of rolling mill - Google Patents

Abstract

PURPOSE:To eliminate useless time and to execute the control of high speed response and high accuracy by constituting an overall control system having a form obtained by combining a feedback control system and a feed forward control system. CONSTITUTION:A deviation to a target value of an elongation percentage of the delivery is given to a control output arithmetic circuit 7 from a comparator 6. A comparator 11 compares an output signal of an elongation percentage mode expanding circuit 10 and an output signal of a target shape setting circuit 5 of a feedback control system, and inputs it deviation to a control output arithmetic circuit 7 of the feedback control system. The control output arithmetic circuit 7 operates a controlled variable against the respective deviations, executes weighting of the respective controlled variables because the controlled variable derived from the feedback control system and the controlled variable derived from the feed forward control system are brought to mutual interference, respectively and determines a final controlled variable. An actuator driving device 8 controls an actuator of a rolling mill 1 in accordance with the final controlled variable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to improvement of a shape control device for a rolling mill.

[Conventional technology]

FIG. 2 shows the configuration of a conventional shape control device for a rolling mill. In this figure, (1) is a rolling mill, (2) is a steel plate that is rolled by the rolling mill in the direction of arrow (A), and (3) is installed on the exit side of the rolling mill to detect the elongation rate of the steel plate. (4) is a mode expansion arithmetic circuit that expands the signal from the shape meter into a normalized orthogonal function; (51 is a target that sets a target elongation rate and emits a signal corresponding to it; The shape setting circuit (6) is a comparator that compares the output signal of the mode expansion calculation circuit (4) and the output signal of the target shape setting circuit (5) and outputs the difference as the shape mode deviation ΔAi. It is.

(7) is a control output calculation circuit that receives the shape mode deviation as input, and calculates and outputs the control amount Δ[Jj of the actuator of the rolling mill (1) according to the following equation.

ΔAi = (p)XΔ[Jj, °, ΔUj= (p)−'
-' is obtained, and the actuator control amount ΔUj is calculated by multiplying this by the shape mode deviation ΔAi output from the comparator (6). (8) is an actuator drive device that controls the actuator of the rolling mill (1) according to the output of the control output calculation circuit, and together with the above-mentioned devices constitutes a feedback type control system.
This is to control the shape of the .

[Problem to be solved by the invention]

The shape control device of a conventional rolling mill is configured as described above.
Since the control system uses a feedback method, there is dead time in the control system, and high-speed response control cannot be achieved unless this time is compensated for using the Smith method or the like. Furthermore, there is also a drawback that the control accuracy is not constant because the dead time changes depending on the rolling speed and the like.

This invention was made to solve the above-mentioned problems, and aims to provide a shape control device for a rolling mill that can eliminate waste time in the control system.

[Means for Solving the Problems] A shape control device for a rolling mill according to the present invention is provided with a feedforward control system in addition to a feedback control system, and a shape meter is also provided on the inlet side of the rolling mill. The output signal is compared with the output signal of the target shape setting circuit of the feedback control system, and the deviation is input to the control output calculation circuit of the feedback control system, and the actuator drive device is adjusted based on the deviation of the control system. It was made to work.

[For production]

According to this invention, the elongation rate of the steel plate on the entrance side of the rolling mill is detected by the entrance side profile meter, and by comparing this with the signal of the target shape setting circuit, the extent of the shape defect on the entrance side is known, and The actuator of the rolling mill is controlled to correct the defective shape, and feedforward control is used to eliminate wasted time in the control system.
High-speed response and high accuracy can be achieved.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

In this figure, (9) is a shape meter installed at the entrance side of the rolling mill, which detects the elongation rate of the steel plate and issues a signal accordingly;
00) is an elongation rate mode expansion circuit that performs high-speed calculations and is equipped with a data shift register that modally expands the signal from the profile meter (9) and tracks its value to just below the rolling mill (1). A comparator compares the output signal of the elongation rate mode expansion circuit 00) with the output signal of the target shape setting circuit (phrase) of the feedback control system, and inputs the deviation to the control output calculation circuit (7) of the feedback control system. A feedforward control system is constructed.The rest of the configuration is the same as that of the conventional device, so corresponding parts are designated by the same reference numerals and a description thereof will be omitted.

In such a configuration, the deviation of the elongation rate on the outlet side from the target value is given from the comparator (6) to the control output calculation circuit (7), and the deviation from the target value of the elongation rate on the inlet side is given to the comparator (I+ ) to the control output calculation circuit (7).

The control output calculation circuit (7) calculates the control amount ΔUj for each deviation as described above, but the control amount obtained from the feedback control system and the control amount obtained from the feedforward control system are mutually exclusive. Since there is interference, each control amount is weighted to determine the final control amount. Actuator drive device (a is the rolling mill (according to the final control amount)
As a result of controlling the actuator in 1), a comprehensive system that combines a feedback control system and a feedforward control system is obtained! It operates as a II control system, with no wasted time, high-speed response, and high accuracy. This is particularly effective for controlling reversible rolling mills.

〔Effect of the invention〕

As described above, according to the present invention, a comprehensive control system is constructed in which a feedback control system and a feedforward control system are combined, so that wasted time is eliminated and high-speed response and high-precision control are possible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a conventional shape control device for a rolling mill. In the figure, (1) is a rolling mill, (31 (91 is a shape meter, (
4) αω is a mode expansion calculation circuit, (51 is a target shape setting circuit, (6) and (11) are comparators, (7) is a control output calculation circuit, and (8) is an actuator drive device. , the same reference numerals indicate corresponding parts, respectively.

Claims (1)

[Claims] The elongation rate of the steel plate is measured at the exit side of the rolling mill, and the rolling mill is controlled based on the deviation from the target elongation rate. A device is installed to measure the elongation rate, and the deviation between the elongation rate on the entry side and the target elongation rate is calculated, and the rolling mill is controlled based on this deviation and the deviation on the exit side. A shape control device for a rolling mill, characterized in that it also performs system control.