SU1148728A1 - Method of determining moment of giving control signal to mechanism operating synchronously with material movement - Google Patents

Abstract

1. METHOD FOR DETERMINING .MOMENTA control signal to the mechanism .RAVOTAKMTSY accord with movement of the material, advantageously mechanism downmix shaping roller coiler plate rolling mill at which the control signal is supplied to the mechanism at a time defined by the time of passage over the sensor material presence checkpoint on the material being moved, taken as the reference point of the base section 4 a, and the length of the base segment, the length of the base segment being equal to or more than twice About the product of the maximum rewinding speed of the material by the maximum response time of the mechanism, characterized in that, in order to improve the accuracy of determining the mechanism response time when the material transfer speed changes, the baseline measurement result is doubled from the moment of reference of the base segment for the fixed time , then the result is summed up with the current value of the length of the material being moved and a control signal is sent to me Khanizm, when the result of summation is equal to the value of the base segment. 2. The method according to p. 1; deception with the fact that, in order to expand technological capabilities by reducing the length of the base segment, they take a fixed time, which is n times less than the response time of the mechanism, and cleverly within a fixed time4; The result of measurement of material relocation is measured on n, and the length of the base segment is assumed to be equal to or greater than the product of the maximum speed of material movement by ot the sum of the maximum response time of the mechanism and the fixed time.

Description

The invention relates to rolling production and can be used for automatic control of mechanisms, in particular, when mixing the forming rollers of a hot rolling mill winder at the end of winding a strip into a roll J, automatic dimensional cutting on flying scissors, pulsed cutting of ingots in a continuous steel casting production line. and etc.

A known sensing system for measuring cut, containing rollers driven by a moving material, a tachogenerator coupled to the rollers, measuring the speed of movement, an analog integrator, a summing amplifier and a comparator, made on operational amplifiers, an output amplifier and a relay, giving the command to activate the mechanism .

The system implements a method for determining the moment of supplying a control signal to mechanisms that operate consistently with the movement of a material, at which a movement of a material is measured by integrating speed at a basic segment equal to a given length of the material being cut, adding it to a displacement proportional to the instantaneous speed. length, and the proportionality coefficient of the second term is assumed to be equal to the response time of mechanism L.

The disadvantage of this method is low accuracy, since the response time is determined by the instantaneous speed value, while measurement errors of the movement speed or pulsation of the tachogenerator voltage can cause the comparator to fail to work in time, and the accuracy of the analog integrator cannot provide the required accuracy with a long cut length.

A known method for determining the beginning of the cycle of machines for cutting continuously moving material in which the control signal at the beginning of the cycle is fed ahead of the cut time 2J.

 The disadvantage of this method is the large error in determining the moment of supplying the control signal when changing the speed of movement of the material in the base sections. In this case, the error

the measurement is proportional to both the change in speed and the time of movement of the material in the base segment.

The aim of the invention is to improve the accuracy of determining the moment of operation of the mechanism when changing the speed of movement of the material.

The goal is achieved

5 by the fact that, according to the method for determining the moment of supplying the control signal to the mechanism that operates consistently with the movement of the material, it is advantageous for the mixing mechanism

0 forming rollers of a winder of a sheet rolling mill, in which a control signal is fed to the mechanism at a time determined by the moment of passage in front of the sensor

5 of the presence of a reference point material on the material being moved, taken as the reference point of the baseline, and the length of the baseline, the length of the baseline being equal to or more than twice the maximum movement speed of the material for the maximum response time of the mechanism, from the time the baseline is counted double the measurement result moving the material for a fixed time equal to the response time of the mechanism, then summarize the result obtained with the current value of g ins material transported and supplied the control signal to the mechanism, when the result of summation is equal to the base segment. i

In order to expand technological capabilities by reducing the length of the base segment, a fixed time is applied, n times less than the response time of the mechanism,

0 and for a fixed time multiplied by n the result of measuring the displacement of the material, and the length of the base segment is taken equal to

5 maximum material transfer speed for the sum of the maximum response time of the mechanism and a fixed time.

3The measurement of the doubled displacement of the material at the beginning of the base segment in a time equal to the response time of the mechanism makes it possible to take into account the length of the passage of the material in anticipation of the supply of a control signal to the mechanism. The measurement of directly moving the material instead of the moving time ensures that the measurement result is independent of the change in the velocity of movement throughout the entire base segment, with the exception of the initial segment. This makes it possible to increase the accuracy of the reference of a given length of the material being moved, especially in cases where the latter is much longer than the cut-off path, for example, when the counting time for the baseline passage is much higher than the response time of the mechanism.

Measuring the increased movement in time, n times shorter than the response time of the mechanism, allows to take into account the lead path on a smaller path and shorten the length of the base segment (in the limit by half).

FIG. 1 shows a block diagram of a device implementing this method; FIG. 2 and 3 are graphs of the dependence of the amount of movement of the material on the time of movement.

The device contains a pulse sensor 1 articulated with the upper shaft of the lower roller 2, coiler 3, lane 4, strip presence sensor 5, time relay 6, keys 7 and 8, circuit OR 9, counter 10, code comparison node 11, setpoint 12 , actuator 13.

The outputs of the sensor 1 pulses are connected to the first inputs of keys 7 and 8, the second input of key 7 through time relay 6 and the second input of key 8 are directly connected to the output of sensor 5 for the presence of a strip, the outputs of keys 7 and 8 are connected to the counter 10, the second the input of which is connected to the output of the sensor 5 for the presence of a strip, and the output to the first input of the node 11 of the code comparison, the second input of the node 11 is connected to the setting device 12, the output of the node 11 is connected to the actuator 13

The method is carried out /, as follows.

On the baseline segment 085 (in Fig. T, the segment from the sensor 5 is

48728 4

the strips to the bottom of the rollers 2) track the movement of the strip by means of a pulse sensor 1 coupled to the shaft of the driving roller 2. Sensor sequences 1 receive two pulse sequences with equal frequencies fj and fj. The frequency pulses fj are phase shifted relative to the frequency pulses fj. The number of pulses coming from sensor 1 is proportional to the angle of rotation of the pull pulleys and the movement of the strip, which is rolled by the pull pulleys without slipping.

15 When the end of the strip starts at the base segment (point 0 in Fig. T), the signal from sensor 5 opens key 8, relays 6 and counter 10 are triggered. Relay 6 is time for a time t, equal to the response time of the converting rollers 13 , holds open the key 7. Through the public keys 7 and 8 frequencies

5 fo 1 arrive at the circuit OR 9. At the output of the circuit OR 9, the total frequency f (+ f equal to twice the frequency f is obtained. This frequency is fed to the input of the counter 10.

Q In FIG. 2 shows the dependence of 1 displacement of the end of the strip on time and the dependence of 2 reference points of the path by the counter 10 on time. During time t, the end of the strip passes the path Sj, and the counter counts twice

Il (

path s.

At time t, a time relay 6 closes the key 7 and, thus, blocks the frequency fg. Thereafter

counter 10 continues to count

frequency pulses f. Next, the number from the output of the counter 10 is fed to the input of the code comparison node 11, to the second input of which from the unit 12 a number equal to the length of the base segment OSg in frequency pulses f4 is supplied, and the length of the base segment is determined by

SB 2V,

{

Max

where,; (x - maximum speed

band travel / t, - response time me

Khanizma.

At the time point ta, when the numbers coincide (specified and counted by counter 10), the control signal to the actuator 13 converges the forming rollers, which are reduced after the mechanism tI, is removed from the output of the code comparison node 11.

At the moment the mechanism triggers, the end of the material is at the reference mark (Fig. 2, point K). When changing the speed of the strip (on the graph is shown by the dashed line), for example, decreasing it from time t2, when the end of the strip passed the 0-82 segment (n, Dg known), equal to half of the base segment ((b from the known) The trigger signal for the mechanism is triggered at the time t when the result of the summation of the path becomes equal to the length of the non-baseline segment 0-S g (). The mechanism 13 is triggered at the moment of time The end of the band 4 is at the distance of the measurement error & S from the contact, roll mark.

The error is, AS - u, V t (where bV is the change in speed;

t. - time of operation of the mechanism.

As can be seen, when using the known method, when changing the speed of movement, the error is obtained more than the error of the proposed method by

fs. (t2 - t,) - proportional to the difference between the time of movement of the strip and the response time of the mechanism. In order to reduce the length of the base segment, a fixed time interval t ,, is set in times smaller than the response time of the mechanism t ..

During the time t, set by the time relay 6 (FIG. 1), through the public key 7, a frequency, n times greater than the frequency, is applied to the OR 9 circuit from the sensor 1

f.

FIG. 3 shows the dependence

1 moves the end of the strip 4 and the dependency 2 counts the track by the counter 1t3 from the time. In time t | the end of the strip passes the path Sj, and the counter

THEN counts the path longer than S in (n + 1) times. The control signal to the actuator 13 is removed from the code comparison node 11 at that moment (t2 in FIG. 3), when the counter 10 counts a number equal to the length of the base segment OSr, and the length of the base segment is set in this case based on the Sg condition. t,)

tde - maximum speed

the movement of the strip, t is the response time of the mechanism;

I.i:

1 p

At the same time, at the moment of supplying the control signal, the end of the strip is at such a distance from tons of the necessary rollers, the passage of which requires time t ,.

The use of the proposed method for determining the time of filing. the equalizing signal to the mechanism, which operates in coordination with the movement of the material, will improve the accuracy of obtaining a given length of material at the moment the mechanism triggers (the length of the cut part

0 rolled products in the measuring cut systems, the position of the end of the strip under the control in the winder control system, etc.) when the movement speed changes.

5 The use of the proposed method also makes it possible to reduce the length of the baseline measuring segment by K times (1 K 2), which is especially important in those cases where, for technological reasons, it is not possible to display the base segment of a large length. For example, the distance from the last stand of a wide-strip hot rolling mill to the

5 rollers is L, - 100 m. Mac -. the maximum rolling speed V 25 m / s, the response time of the mechanism for lowering the forming rollers t | 3 sec. The length of the base segment is required.

2V-t, 50

l to

7

TO

those. K must be greater than 1.5.

FIG.

Si

Claims (2)

1. METHOD OF DEFINITION THE TIME OF THE SUPPLY OF THE CONTROL SIGNAL TO THE MECHANISM OPERATING IN ACCORDANCE WITH THE MOVEMENT OF THE MATERIAL, mainly the mechanism of converting the forming rollers of the sheet rolling mill, in which the control signal is supplied to the mechanism at a time determined by the moment of passage of the material the reference segment, and the length of the base segment, and the length of the base segment is equal to or greater than twice the product of the maximum the speed of movement of the material for the maximum response time of the mechanism, characterized in that, in order to increase the accuracy of determining the moment of operation of the mechanism when the speed of movement of the material changes, from the moment of counting the base segment, double the result of measuring the movement of the material for a fixed time equal to the response time of the mechanism, then summarize the result with the current value of the length of the transported material and submit a control signal to the mechanism when the result of the summation equal to the size of the base segment. 2. The method according to p. 1; characterized in that, in order to expand technological capabilities by reducing the length of the base segment, take a fixed time, η times less than the response time of the mechanism, and for a fixed time multiplied by η the result of measuring the movement of the material, and the length of the base segment is taken equal to or greater than the product the maximum speed of movement of the material in the amount of the maximum response time of the mechanism and a fixed time. 148728