JPS62276428A - Shape detector - Google Patents

Abstract

PURPOSE:To enhance a detection accuracy, in a shape detector applying external force to an object to be measured cyclically to detect the displacement quantity thereof, by calculating the S/N of the detected displacement quantity and control ling an external force applying means so as to make said S/N large. CONSTITUTION:External force is cyclically applied to an object 1 to be mea sured by an external force applying device 4a and the displacement detector signal detected by a displacement detector 4b is inputted to a displacement quantity detection part 100. First detection parts 5-7 detect the displacement quantity of the object 1 to be measured from the inputted detection signal and second detection parts 21-23 detect a noise component and a difference device 24 subtracts the above mentioned noise component from the above mentioned displacement quantity to output the subtracted value. An external force applying operator 27 operates a S/N ratio from the above mentioned displacement quantity and the noise component and an external force applying drive signal generator 28 is controlled so as to make the S/N large and the external force corresponding to the above mentioned S/N is applied to the object 1 to be measured.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention detects the shape (flatness) of a strip-shaped body such as a 3914 plate by knowing its tension distribution in the width direction. This invention relates to a detection device.

[Conventional technology]

In general, when cold rolling a strip, the shape (also called flatness) is important as well as the thickness accuracy. However, in cold rolling, high tension is applied during rolling, so
Due to the elastic elongation of the rolled material, that is, the strip, even if elongation or poor flatness occurs in the strip, the displacement (unevenness) will usually decrease or disappear and cannot be detected. .

Therefore, while it is not possible to directly detect the flatness defects of the strip under high tension as described above, it is especially possible to indirectly detect the shape by knowing the tension distribution in the width direction of the strip. It is well known as shown in Publication No. 53-17071.

In other words, the tension is weak in areas with poor flatness, so the shape can be determined from the tension distribution.

FIG. 3 is a block diagram showing an example of this type of conventional shape detection device.

Reference numeral 1 denotes an object to be measured, that is, a strip-shaped body, and 2 denotes a support roll, such as a deflector roll, for applying tension to the strip-shaped body 1. 3 is a rectangular wave oscillator as an example of a drive signal generator, and 3a is an amplifier.

Reference numeral 4 denotes a detection head, which is provided along the width direction of the strip-shaped body 1 and spaced apart from the surface of the strip-shaped body 1 at appropriate intervals by appropriate locking means. This detection head 4 has an external force application bag W, 4
a and a displacement detector 4b. The external force applying device 4a consists of an electromagnet in which an excitation coil B is provided on a magnetic pole A having a U-shaped cross section along the width direction of the strip 1, and the displacement detector 4b is attached to a basic portion C along the width direction of the strip 1. A plurality of cylinders of displacement measuring electrodes are provided facing the surface of the strip 1, and are provided integrally with the external force applying device 4a.

Note that the displacement detector 4b may be provided separately from the external force applying device 4a, and the external force applying device may be a device such as the one described above (not limited to an electromagnet, but capable of applying force without contact, such as compressed air). Any means may be used as long as it does not depart from the purpose of the present application. 4C is a displacement converter such as a capacitance-to-voltage converter.

9 is a signal processing circuit, and a polarity switch 5. It is composed of an integrating circuit 6° sample hold circuit 7 and a timing generating circuit 8 connected to each of the devices 5, 6° 7, and the timing generating circuit 8 is connected to each device 5, 6° 7 and the square wave oscillator 3. Each is connected. The signal processing circuit 9 is connected to a display device 11, such as a CRT monitor, via a display control device 10. Further, the signal processing circuit 9 can also be connected to the roll crown adjustment device 13 via the roll crown control circuit 12.

Next, the operation will be explained. First, the rectangular wave oscillator 3 generates a rectangular wave with a period Tc as a drive signal. Next, this drive signal is amplified in the amplifier 3a, and this amplified signal is applied as an external force to the surface of the strip 1 via the external force applying device 4a, thereby causing the strip 1 to generate a displacement P (x-t). The displacement P(x・L) generated on the surface of the strip 1 is detected as a capacitance by a displacement detection electrode provided in the displacement detector 4b, and the displacement is detected as a capacitance by a signal converter, that is, a capacitance-voltage converter. It is converted into a voltage signal by a displacement converter 4C. The plurality of displacement detection electrodes provided along the width direction of the strip 1 detect the displacement of each part of the strip 1 in the same way, and the signal is converted into a voltage signal by this detection. is input to the signal processing circuit 9. After the polarity of the displacement detection signal is switched by a polarity switch 5, it is manually inputted to an integrating circuit 6, where it is integrated for each rectangular wave period. This removes noise other than the tension signal,
Only the portion related to the tension of each part of the strip is calculated, and its integral value is input to the sample and hold circuit 7, where it is sampled and held. The timing generation circuit 8 controls each timing such as the polarity switching timing of the polarity switch 5, the recent timing of the integrating circuit 6, and the sample hold timing of the sample hold circuit 7, based on the reference signal from the square wave oscillator 3. do. Sample hold circuit 7
For example, the output of CR
It is displayed on a display device 11 such as a T-monitor, is provided for monitoring by an operator, and is also used as data for shape adjustment.

In addition, when performing automatic shape control of the object to be measured, that is, the strip-like object 1, the output of the sample hold circuit 7 is sent via an automatic control system, that is, a roll crown control circuit 12, separately from the display system.
The purpose can be achieved by providing input to the roll crown adjustment device 13.

In the above description, a case has been described in which a rectangular wave signal is used as the drive signal, but the drive signal is not limited to a rectangular wave signal, and signal waveforms such as an M-sequence signal, a random signal, or a sine wave signal may also be used. , and when these signal waveforms are employed, a multiplication circuit may be provided in place of the polarity switch 5 in the signal processing circuit 9.

Furthermore, to explain using a mathematical formula, in Fig. 3, T(x): Tension L per unit width at x 1 for the span between two rolls: A coefficient in the force balance, and considering the force balance for the band width (hereinafter simply referred to as plate width) ΔX, approximately Displacement P(x・t
) is represented by . Furthermore, assuming that Equation 11 is the displacement detection signal, the output C(x-nTc) of the sample-and-hold circuit 7 is expressed as follows.

Tc: Period of the rectangular wave n: Number of cycles of the rectangular wave Further, the external force f(t) per unit width is a rectangular wave with an amplitude a, and can be expressed as Tc.

Therefore, assuming that equation (3) is also the amount of electrical signal, the output value C (x-nTc) from the sample and hold circuit 7 is the above f
l), <2> and (3). Here (4
The second term in equation ) is the effect of disturbance, but it can be considered that if the rectangular wave period Tc becomes large, it becomes sufficiently smaller than the stationarity of the irregular vibration d(t) of the strip body 1, so the above (4) The equation is expressed as follows, and further, from this equation (5), the width direction coordinate
The tension per unit width T (x) at can be expressed as and the tension is measured.

Next, the content of (4) 2 above is realized. The signal waveforms of each signal processing section in the circuit of FIG. 3 will be explained with reference to FIG. 4.

(a) of FIG. 4 shows a rectangular wave signal generated by the rectangular wave signal generator 3, where n is a positive integer, ..., m
-2,..., m+l is the multi-value that n takes.

In FIG. 4, (bl is O of the period Tc by the external force applying device 4a.
The alternating current waveform of the displacement signal when the strip 1 is displaced by applied external forces of N and OFF is shown.

In Fig. 4, (C1) is the disturbance signal component at point ■ due to irregular vibrations of the band-shaped body, and the random noise signal due to this vibration is superimposed on the displacement signal in Fig. 4 (b) above. The signal has the waveform of (d) in FIG. 4, which is the signal waveform at point ■ indicating the output of the displacement converter 4c, and when the polarity of the input signal in (d) of FIG. 4 is switched, the output of the polarity switch 6 A signal (point ■ signal) with the waveform of (e) in FIG. When the signal (f) in FIG. 4 is sampled and held by the sample-hold circuit 7 at the point (n+1)Tc, the output of the sample-and-hold circuit 7 (g) in FIG. 4 is obtained.
A signal (◎ point signal) is obtained.

As is clear from the above equation (4) and the signal processing waveform in FIG. 4, the output (gl) of the shape detection device is obtained every rectangular wave period Tc.

[Problem that the invention seeks to solve]

Since the conventional shape detection device is configured as described above, the output response is determined by the rectangular wave period Tc for periodically applying an external force to the object to be measured, and by shortening the rectangular wave period Tc. The response must be fast, but
Due to the effect of removing noise caused by irregular vibrations of the object to be measured by increasing the rectangular wave period Tc, the lower limit of the period Tc is also limited, and there is a problem that the response cannot be made faster. 4) The ratio of the first and second terms in the equation is S/N
It can be expressed as a ratio (signal-to-noise ratio), and this S/
The magnitude of the N ratio is one of the main factors that influences the detection accuracy of the shape of the object to be measured, and generally the irregular vibration d(t) of the object to be measured is applied to the object to be measured. It is thought that the amplitude and frequency are determined by the magnitude of the tension applied to the object to be measured. Therefore, the S/N ratio of the output of the signal processing circuit changes depending on the value of the tension applied to the object to be measured. The S/N ratio is affected by the tension value applied to the measurement object, and even if the amount of disturbance due to irregular vibrations changes, there are problems in that it is not possible to ensure detection accuracy corresponding to the change.

This invention was made in order to solve the above-mentioned problems, and provides an output that removes noise caused by irregular vibrations of the object to be measured for each period smaller than one period of the periodic wave, resulting in high response. A shape detection device that can improve detection accuracy by measuring the noise level caused by irregular vibrations of the object to be measured and controlling the applied external force to ensure a sufficiently high displacement signal of the object to be measured. The purpose is to obtain.

[Means for solving problems]

The shape detection device according to the present invention detects the shape of the object to be measured by applying an external force to the object to be measured in each periodic first period, in which one period consists of a first period and a second period. In a shape detection device that detects the displacement of the body by a displacement detection means to generate a displacement detection signal, and outputs a shape signal indicating the shape of the measured object based on the displacement detection signal, A first integral amount of the absolute value of the displacement detection signal outputted by the first integral processing means and included in the displacement detection signal outputted by the second integral processing means for each period of at least one of the first and second periods. The difference means outputs a shape signal which is the difference between the noise component and the second integrated quantity of the noise component due to the irregular vibration of the measured object, and the applied external force calculation means outputs the shape signal which is the difference between
The S/N ratio is calculated from the integral amount, the external force to obtain the desired S/N ratio is calculated based on this S/N ratio, and the external force applying means applies an external force according to the calculation result to the measured object. and the timing generating means receives the first input from the external force applying means.
The operational timing of the first and second integral processing means and the difference means is controlled based on the reference signal indicating the second period.

[Effect]

In the shape detection device according to the present invention, the first integral amount output by the first integral processing means includes the integral amount due to the displacement signal component generated by the application of external force and the integral amount due to the noise component. The second integral amount of the noise component generated by the second integral processing means is subtracted from the first integral amount by the difference means (by this, the difference is caused by The integral amount of only the displacement signal component is output as a shape signal from the difference means twice per cycle, that is, every first and second period, and the ratio of the first and second integral amounts is approximately S/ Since the external force applying means applies an external force to the object to be measured in each first period according to the calculation result of the external force calculated by the applied external force calculation means based on this S/N ratio, the desired It is possible to obtain a S/N ratio and output a shape signal with a desired S/N ratio.

〔Example〕

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

In FIG. 1, the parts with the same symbols as those in FIG. It is a bypass filter that allows the Reference numeral 22 has the same configuration as the integration circuit 6, and is an integration circuit after the bypass filter 21. Reference numeral 23 has the same structure as the sample and hold circuit 7, and a sample and hold circuit after the integration circuit 22. Reference numeral 24 indicates a sample and hold circuit 7.23. Integrating circuit 6 held at
, 22, which calculates the difference between the two integral results. Further, 25 is a sample and hold circuit having the same configuration as the sample and hold circuit 7 connected between the output side of the subtractor 24 and the input side of the display control circuit 10 and/or the input side of the roll crown control device 12; This is a timing generation circuit, and a polarity switch 5. Integrating circuits 6, 22. A timing signal is generated for timing each operation of the sample and hold circuits 7, 23, 25 and the differentiator 24. Furthermore, 27 is an applied external force calculator for calculating the S/N ratio by manually re-outputting the sample and hold circuits 7 and 23, and calculating the required applied external force according to the amount of the disturbance signal; Reference numeral 28 denotes a rectangular wave generator as an example of a drive signal generator, which changes a rectangular wave signal (for example, its level) according to the calculation result of the applied external force calculation unit 27 and generates it in the amplifier 3a. The parts in double brackets 40.5 to 7 and 21 to 25 are each composed of a plurality of tubes (for example, each N tubes), and for example, each part is made up of a plurality of cylinders (for example, each number of cylinders is N), and for example, the number of cylinders is equal to the number of displacement detection electrodes and displacement detectors 4b in the head 4. (For example, each N number), if there are, they are connected correspondingly.

Figure 2 shows the signal waveforms of each part of the device shown in Figure 1,
The vertical axis represents the voltage value, and (a) to (e) in FIG. 2 are the same as (a) to (el) in FIG. 4.

Next, the operation of this embodiment will be explained. n is a positive integer and takes the value of m-2, . . . , m+l, . This external force f(t) causes the band-shaped body 1 to be displaced, resulting in the amount of displacement shown in the first term of equation (1) above.

On the other hand, irregular vibrations are occurring in the strip l, which is the source of the disturbance signal as shown in (C) in Figure 2, and naturally the applied external force r(
This irregular vibration d(t) is added to the displacement of the strip 1 due to
is superimposed, and this noise component is expressed as the second term in equation (1) above.

Displacement amount P (x-t
) is operated by the timing signal from the timing generation circuit 26 in the displacement converter 4C via the displacement detector 4b, and the polarity of the displacement detection signal at point 2 on the output side of the displacement converter 4c in FIG. The waveform of the displacement signal inverted by the anti-polarity switch 5 is 0, which is the output side of the polarity switch 5.
The point is indicated by (Q) in FIG. Also, the integration circuit 6
The integrated value is shown by (f) in FIG. (
At the time point n+1)Tc, the output of the integrating circuit 6 is sampled and held by the sample and hold circuit 7.

By repeating the above operation, the output side of the integrating circuit 6 is 0.
The signal at the point is T c/2, as shown in FIG. 2(f).
The integral value of the displacement amount P (x-t) of the above equation (1) is obtained for every T c/2, and the sample-hold circuit 7 receives Sl, N2 . The integral value of the displacement amount P (xt) of N3... is sampled and held.

On the other hand, the disturbance signal component at point ■ due to the irregular vibration of the strip 1 is between the rectangular waves nTc +
A case where the disturbance signals due to irregular vibration in □ are almost equal will be explained.

The disturbance signal component due to the irregular vibration of the band-shaped body 1 shown in FIG. 2(C) is input to a bypass filter 21 that passes only a frequency band sufficiently higher than the rectangular wave period Tc, and is extracted. The output of the bypass filter 21 is sent to the integrating circuit 22.
Only the disturbance signal due to the irregular vibration shown in FIG. 2(C) is integrated.

The signal at point 0, which is the output side of 22, is as shown in FIG. 2(g).

Then, the disturbance signal due to the integrated random vibration is (n+
1) At time Tc0, the sample and hold circuit 23 samples and holds, and as shown in FIG. 2(g), NO,
N2. For example, the integral value of the disturbance signal due to irregular vibration of N4 is (m-2)Tc, (m-1)Tc.

It can be obtained at the timing of mTc, (Sho+1)Tc.

A sample hold value S1. which is an integral value of the displacement amount already obtained. N2. N3... and sample hold value No. which is the integral value of the disturbance signal due to irregular vibration, N2. N4・
. (f) in FIG.
The signal waveform at point [F], which is the output side of the sample and hold circuit 25, is sampled and held every c/2 by the sample and hold circuit 25, and the signal waveform is CI, C2, C in (h) of FIG.
It is shown as 3... A signal that changes every Tc/2 from the sample and hold circuit 25 is applied to the display control circuit 10 to the display device 11, or is applied to the roll crown adjustment device 13 via the roll crown control device 12.

On the other hand, regarding the displacement detection signal at point 2 in FIG. 1, referring to the above equation (1), by increasing the external force f (t), the first term becomes large and the S/N ratio can be increased. Therefore, if the irregular vibration d (t) of the strip l is large, the disturbance signal shown in (C) in Fig. 2 will also be large and the second
Since the integral value of (g) in the figure also increases, the external force f (tl
The necessary S/N ratio can be secured by increasing the level of (false) in FIG. 2 and increasing the integral value of (f) in FIG.

The held value of the integral value of the disturbance signal due to irregular vibration is output from the sample hold circuit 23, and the ratio of this integral value to the output of the sample hold circuit 7, which is the output of the integral value of the displacement amount, is S/N. The applied external force calculator 27, which inputs these two signals from both sample and hold circuits 7.23, calculates the ratio of both human force signals and outputs the current S/N ratio. The external force f (t) necessary to ensure a suitable S/N ratio is calculated and instructed to the square wave generator 28 . Upon receiving this instruction, the rectangular wave generator 28 changes the level of the rectangular wave signal, for example, and applies a required external force f (t
) is added. In addition, the calculation for the external force applying device 4a can specifically calculate the current external force from the amount of displacement,
It can be calculated by functional calculation using the calculated S/N ratio and a desired S/N ratio set in advance, or it can be easily calculated by using a well-known interpolation formula or the like.

Note that the timing generation circuit 26 determines the polarity switching timing of the polarity switch 5, the reset timing of the integrating circuits 6 and 22, and the sample hold circuit 7°23.25 based on the reference signal from the square wave oscillator 28. Control each timing such as timing.

The irregular vibrations of the strip 1 are stationary over a relatively long period of time, and the tension T(x) applied to the strip 1 does not fluctuate rapidly, so the external force f (calculation of tl The period does not need to be every rectangular wave period Tc, and the external force applying device 4a applies external force f (t) every M-Tc which is longer than Tc.
All you have to do is do the calculation.

Here, M may be set depending on the irregular vibration and tension state of the belt-shaped body 1.

In addition, in the above embodiment, the disturbance signal due to the irregular vibration of the strip 1 was integrated only during the period when the external force f (t) was O, but the external force f (t) outputs an amplitude of a and the strip 1 is Similarly, the disturbance signal due to irregular vibrations may be integrated during the period of displacement, and the difference between the displacement amount and the integral value of the irregular vibrations during the same period may be determined.

Also, the applied external force calculator 27. Of course, a plurality of electromagnets (for example, N pieces) of the drive signal generator 28° amplifier 3a and the external force applying device 3a may be provided.

Further, in the above embodiments, a plurality of double parentheses are provided for each portion, but it is of course possible to use only one portion for each portion.

〔Effect of the invention〕

As described above, according to the present invention, the displacement of the object to be measured is detected, the polarity is switched every 1/2 Tc cycle, which is every half cycle of the drive signal, and the polarity is integrated every 1/2 Tc cycle. Then, the disturbance signal due to irregular vibration of the measured object is extracted every 1/2 Tc cycle, integrated, and then held to obtain the noise amount, and the displacement amount and the noise are By calculating the difference between the displacement amount and the noise amount, a displacement signal of the measured object from which irregular vibration noise of the measured object has been removed is obtained every 1/2 ・Tc period, and further, S/ By calculating the N ratio, the external force f ftl that should always ensure the expected S/N ratio is specified and the external force f (t) is applied, so the shape of the object to be measured is・
It is possible to obtain a Tc period, to detect a shape with a fast response speed, and to detect a shape with high accuracy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a shape detection device according to an embodiment of the present invention, Fig. 2 is a signal waveform diagram of signal processing of each part of the device in Fig. 1, and Fig. 3 is a block diagram showing a conventional shape detection device. 4 are signal waveform diagrams of signal processing of a conventional device. In the figure, 1 is a strip-shaped body, 4a is an external force applying device, 4b is a displacement detector, 4C is a displacement converter, 5 is a polarity switch, 6.
22 is an integration circuit, 7, 23, 25 is a sample and hold circuit, 21 is a bypass filter, 24 is a difference device, 26 is a timing generation circuit, 27 is an applied external force calculator, and 28 is a drive signal generator. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 2 (Go to Ko = b Fu →

Claims (1)

[Claims] One period for the object to be measured to which tension is applied is the first and second period.
and a displacement detection means for detecting the displacement of the object to be measured due to the application of an external force during each of the first periods and generating a displacement detection signal, and the displacement detection signal of the displacement detection means is In the shape detection device that outputs a shape signal indicating the shape of the object to be measured based on the shape, the absolute value of the displacement detection signal is determined for each of the first period and for each second period in which the external force is not applied to the object to be measured. and a first integral processing means that generates a first integral amount of noise components due to irregular vibrations of the object to be measured included in the displacement detection signal for each of at least one of the first and second periods. a second integral processing means for producing two integral quantities; a difference means for taking the difference between the first and second integral quantities and outputting the difference as the shape signal; and calculating an S/N from the first and second integral quantities. applied external force calculation means for calculating the external force to be applied to the object to be measured in order to obtain a desired S/N ratio based on the S/N ratio; an external force applying means that generates an external force in each of the first periods, the first and second integral processing means based on a reference signal indicating the first and second periods input from the external force applying means, 1. A shape detection device comprising: timing generation means for controlling operational timing of the difference means.