JPH08320215A - Apparatus for measurement of steel sheet shape - Google Patents

Abstract

PURPOSE: To lessen the binary processing error owing to difference of the steel sheet temperature by obtaining a constant photoelectric element output signal even if the temperature of a steel sheet alters by measuring the temperature of the steel sheet by a radiation temperature gauge and controlling charge accumulating time for the photoelectric element, and then carrying out partial binary processing based on a peak holding treatment based on two-dimensional spatial differentiation. CONSTITUTION: A plurality of optical systems employing lens and groups of photoelectric elements 3 arranged in a line are installed in an upper part of a red heated steel sheet 1 and scanning is carried out by the groups of photoelectric elements 3 by receiving the driving signals P to move the steel sheet 1 forward in a prescribed distance by a scanning circuit 4. The groups of the photoelectric elements 3 generate an output proportional to the temperature of the steel sheet on a measurement line 3a. The temperature of the steel sheet at that time is measured by a radiation temperature gauge 14 and corresponding to the temperature of the steel sheet, the charge accumulating time for the groups of photoelectric elements 3 is controlled by an AGC circuit 15. For example, even though the output signal of the groups of photoelectric elements 3 increases proportionally to the temperature of the steel sheet in the case the temperature of the steel sheet changes from 700 deg.C to 900 deg.C, almost constant output signal can be obtained by controlling the charge accumulating time for the groups of the elements 3 corresponding to the temperature of the steel sheet.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention enables automatic and highly accurate measurement of crop shape, plate bending amount, and camber amount at the entrance side of a crop cutting shear facility at the tip and tail end of a steel plate. An object is to provide a steel plate shape measuring device.

[0002]

2. Description of the Related Art Deformation, plate bending, camber, etc., of the front and tail ends of a steel plate that occurs during hot rolling exerts an uneven load on the rolls in the subsequent rolling steps, which greatly affects the posture of the steel plate during rolling. And caused the generation of defective steel. In order to prevent this, conventionally, an operator visually observes the shape of the steel sheet and operates the front and rear ends of the steel sheet at appropriate positions on the front surface of the rolling mill to perform cutting, and also to approach guides and side guides. It was necessary to perform opening and closing operations and balance operation of the rolling load of the rolling mill.

For this reason, the amount of deformation, bending, and camber of the tip and tail of the steel sheet is automatically measured, and the deformed portion is cut to the required minimum, so that the roll is uneven in the subsequent rolling. It is necessary to prevent the excessive load from being applied, and to automatically control the opening and closing of the approach guides and side guides and the left-right reduction balance control of the rolling mill based on the amount of bending and camber of the steel plate and the length of the generated camber.

Therefore, the deformation of the front and tail ends of the steel plate, the amount of bending of the plate and the amount of camber are automatically detected, and the necessary minimum cutting of the deformed portion is performed to feed the steel plate to the next-stage rolling mill, and Opening of the approach guides and side guides is controlled according to the amount of bending, and left-right reduction control of the next-stage rolling mill is performed according to the amount of camber, with the expectation of preventing the occurrence of defective steel plates by improving the steel plate threadability. The following shape detectors have been proposed.

FIG. 9 shows a block diagram of a conventional device. As shown in the figure, the presence or absence of a steel plate on the measurement line 3a is detected using a plurality of photoelectric elements 3 in which the plate width of the red hot steel plate 1 that flows through the hot rolling process is lined up with the optical system using the lens 2. . The photoelectric element 3 generates an output proportional to the temperature of the steel plate,
A scanning circuit 4 receives the drive signal P generated every time the steel plate 1 advances in the detection area for a certain distance, scans the photoelectric element group 3a, and sends an output.

The output of the photoelectric element is amplified by the amplifier 5.
6 is a quantizing circuit for quantizing a steel plate image signal obtained in analog with multiple values, 7 is a memory for two-dimensionally storing the quantized steel plate image signal, and 8 is a steel plate image signal stored in the memory 7. , A two-dimensional differentiating circuit, and 9 locally divides the temperature steepness signal generated by the differentiating circuit 8 into almost equal levels, and performs leveling so that each locality has a predetermined value. A steepness leveling circuit, 10 is a peak hold circuit that scans a leveled temperature steepness signal in a specific direction, and 11 is a binary value that binarizes a steel plate image signal with a fixed threshold value obtained in advance. A digitizing circuit, 12 is a tip / tail edge shape measuring circuit that measures the shape of the tip / tail edge from the binarized steel plate image image, and 13 is a plate bend and camber from the similarly binarized steel plate image image. Plate bending to measure the amount
It consists of a camber measurement circuit.

[0007]

Since the conventional apparatus is configured in this way, when the temperature differs for each steel sheet,
For example, as shown in FIG.
When the temperature changes up to 200 ° C., the spectral radiance of the photoelectric element differs by about 160 times at a wavelength of 1 μm, so that the steel plate image cannot be binarized correctly and as shown in FIG. When there is a momentary change in lateral shake, there are drawbacks such as bending of the plate and an error when measuring the camber.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional ones. The temperature of the steel sheet is measured by a radiation thermometer, and the charge storage time of the photoelectric element is controlled based on the steel sheet temperature. By doing so, even if the steel plate temperature changes, an almost constant photoelectric element output signal is obtained, and then two-dimensional spatial differentiation processing, steel plate inclination calculation processing, peak hold processing based on steel sheet inclination, local concentration histogram processing By performing the local binarization process based on the density histogram, it is possible to reduce the binarization process error due to the steel plate temperature difference, and a plurality of linear photoelectric element groups are arranged in the traveling direction of the steel plate. By doing so, it is an object of the present invention to provide a highly accurate steel plate shape measuring device that is not affected by vertical vibration (lateral vibration) of the steel plate.

[0009]

An embodiment of the present invention will be described with reference to FIG. In FIG. 1, an optical system using a lens and a plurality of photoelectric element groups 3 arranged in a line are arranged above the red-hot steel plate 1 in the traveling direction of the steel plate, and the scanning circuit 4 advances the steel plate 1 by a certain distance. Drive signal P generated for each
In response to this, the photoelectric element group 3 is scanned. The photoelectric element group 3 generates an output proportional to the steel plate temperature on the measurement line 3a. At this time, the temperature of the steel plate is measured by the radiation thermometer 14, and the charge storage time of the photoelectric element group 3 is controlled in the AGC circuit 15 according to the steel plate temperature. FIG. 2 shows an example thereof. For example, when the steel plate temperature changes from 700 ° C. to 900 ° C., the output signal of the photoelectric element group 3 also increases in proportion to the steel plate temperature, but the charge accumulation time of the photoelectric element group 3 is controlled according to the steel plate temperature. As a result, a substantially constant output signal can be obtained even if the steel plate temperature changes.

This output signal is amplified by an amplifier 5, 6 is a quantizing circuit for quantizing the analog steel plate image signal in multi-values, and 7 is a predetermined quantized linear steel plate image signal. It is a memory that sequentially performs the matching process until the length is reached and stores the steel plate image signal as a two-dimensional image signal. Since the scattered light of the radiant light and the reflected light such as the transport rolls and the apron for preventing the steel plate from falling exist around the red hot steel plate, the spatial light difference filter of 8 emphasizes the light amount difference between the steel plate and the peripheral portion. FIG. 3 shows a 3 × 3 pixel spatial differentiation filter. For example, with respect to the center point E,
E = | (A + nB + C)-(G + nH + I) | + | (A
+ ND + G)-(C + nF + I) | As a result, the weight is multiplied by n in the vertical and horizontal directions to enhance the edge portion enhancement effect.

Further, since there are portions on the steel sheet having different brightness due to water riding, scales, etc., as a measure for avoiding this effect, the inclination of the steel sheet is obtained and peak hold processing is performed in parallel to reduce the brightness inside the steel sheet. Fill in. Reference numeral 16 is a circuit for calculating the inclination θ of the steel plate, and FIG. 4 shows an example of calculating the inclination θ of the steel plate. The root l of the steel sheet is subjected to Hough transform processing, and the inclination θ of the steel sheet is obtained from the coordinates P. P = X · cos
When θ + Y · sin θ is calculated, P is the distance from the coordinate origin, and θ is the inclination of the perpendicular line drawn from the coordinate origin to the straight line P. Further, as shown in FIG. 5, the peak hold circuit of 10 performs peak hold processing in parallel with the inclination θ of the steel plate.

A stable steel plate image can be obtained by the above-mentioned AGC circuit, differentiating circuit, steel plate inclination calculating circuit, and peak hold circuit, but when binarization is carried out with a fixed threshold value due to uneven temperature distribution of the steel plate, The shape cannot be reproduced accurately. Therefore, the steel plate image area stored in the memory 7 is divided into a plurality of areas as shown in FIG. 6, and the steepness smoothing circuit shown in FIG. 9 calculates the density histogram distribution for each of the areas a to h. A predetermined threshold value is obtained and binarized by the local binarization circuit 11 shown. Then, the shape is measured by the steel plate tip / tail end shape measuring circuit shown in FIG. 12, and the cutting positions of the tip and tail end portions of the steel plate are determined.

FIG. 7 shows a method of determining the cutting positions of the front and tail ends of the steel plate. (A) is an example of a steel plate shape called a fishtail, in which a point A corresponding to a valley portion of the steel plate is obtained, and a point B separated by a predetermined distance Δl is determined as a cutting position. Further, (b) is an example of a steel plate shape called a tongue, and a cutting position B point which is separated from the longest point A point of the steel plate by Δl is determined by calculating W ′ obtained by multiplying the width W of the steel plate by a coefficient k. .

Reference numeral 13 denotes the bending amount M and the bending occurrence length N of the front and rear ends of the steel plate shown in FIG.
This is a circuit for measuring the camber amount X and the camber generation length Y shown in (b). If the bending amount and the camber amount at the tip and tail of the steel sheet are measured using one line-shaped photoelectric element group, the measurement accuracy is obtained when the steel sheet swings in the direction perpendicular to the traveling direction (lateral shake). Will affect and cause an error. Therefore, as shown in FIG. 1, three line-shaped photoelectric element groups are arranged in the traveling direction of the steel sheet, and at the same time, the width direction edge position of the steel sheet and the plate width center position are set to S data.
1n, S2n, S3n, the distance between each photoelectric element group is L1,
L2, if the differential value of each position data twice and ^{Δ 2 Sn, Δ 2 Sn =} {(S1n-S2n) ÷ L1- (S2n
-S3n) ÷ L2} / {(L1 + L2) ÷ 2}, and the result of integrating Δ ² Sn is ΔSn, ΔSn
= ΔSn ₋₁ + Δ ² Sn ₋₁ × χ Here, χ is the sampling pitch of the data. Further, if Sn is the result of integrating ΔSn, Sn = Sn ₋₁ + ΔSn ₋₁
Even if the steel sheet swings in the direction perpendicular to the traveling direction by determining xχ, it is possible to stably measure the bending amount and the camber amount.

In the above embodiment, the hardware such as the differentiating circuit, the steepness leveling circuit, the peak hold circuit, and the binarization circuit has been described, but it may be executed by software by a computer capable of realizing the same function. Furthermore, A for controlling the charge storage time of the photoelectric element group with respect to changes in the steel plate temperature
Although the GC circuit has been described, the function of adjusting the amount of received light may be added by controlling the shutter speed or controlling the aperture of the optical system.

[0016]

As described above, according to the present invention, the temperature of the red-hot steel sheet is measured, the charge accumulation time of the photoelectric element group is controlled according to the steel sheet temperature, and the steel sheet image stored two-dimensionally Spatial differential filtering is performed to emphasize the edge of the steel sheet, the inclination of the steel sheet is obtained, peak hold processing is performed in parallel with the inclination, the steel sheet image is divided into multiple areas, and the density histogram is calculated for each area. The local binarization process is executed for each predetermined threshold value, a plurality of linear photoelectric element groups are arranged in the traveling direction of the steel sheet, and the steel sheet width direction edge position and the center position are calculated at the same time. By doing so, error signals due to changes in the steel plate temperature, uneven steel plate temperature distribution, water riding, scale and steel plate runout are removed, and binarization and the steel plate tip / tail end shape, bending amount and camber amount are obtained. A steel plate shape measuring device that is not affected by disturbances such as changes in steel plate temperature, uneven steel plate temperature distribution, scattered light, reflected light, water riding, scale, and steel plate runout that are unavoidable in hot rolling lines is obtained. The practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a device of the present invention.

FIG. 2 is a graph showing a comparison of photoelectric device group outputs with and without controlling the charge storage time with respect to changes in steel plate temperature.

FIG. 3 is a diagram showing a 3 × 3 spatial differentiation filter.

FIG. 4 is a diagram showing a tilt of a steel plate.

FIG. 5 is a diagram showing that the peak hold process is performed in parallel with the inclination of the steel plate.

FIG. 6 is a diagram showing that the steel plate image is divided into a plurality of areas.

FIG. 7A is a diagram showing how to obtain cutting positions of a steel plate tip / tail end portion of a fishtail shape and FIG. 7B is a tongue shape.

[FIG. 8] (a) of the steel plate shows the amount of bending and the amount of bending,
FIG. 6B is a diagram showing a camber amount and a camber occurrence position.

FIG. 9 is a block diagram showing a configuration of a conventional device.

FIG. 10 is a graph showing changes in wavelength and spectral radiance with respect to changes in steel plate temperature.

FIG. 11 is a diagram showing deflection in a direction perpendicular to the traveling direction of the steel sheet.

[Explanation of symbols]

 1: Red-hot steel plate 2: Optical system lens 3: Line-shaped optical element group 4: Scanning circuit 5: Amplifier 6: Quantization circuit 7: Memory circuit 8: Differentiation circuit 9: Steepness leveling circuit 10: Peak hold circuit 11 : Binarization circuit 12: Steel plate tip / tail end shape measuring circuit 13: Steel plate bending amount / camber amount measuring circuit 14: Radiation thermometer 15: AGC circuit 16: Steel plate inclination calculating circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Sugiyama 1-1-2 Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Electric Corporation Control Factory

Claims (1)

[Claims] 1. An image of an object to be measured is formed on a plurality of photoelectron groups arranged on a line for a steel sheet having red-hot self-luminous light during hot rolling, and an electrical property corresponding to the temperature of the object to be measured is formed. Detecting means for generating a signal, means for controlling the charge storage time of the detecting means according to the temperature of the object to be measured, and quantizing means for converting the detection signal obtained by the detecting means into a multi-valued signal,
Memory means for storing the multi-valued signal obtained by the quantizing means, means for two-dimensionally recognizing the memory by image processing, and two-dimensionally for the quantized signal processed two-dimensionally. Differentiating means for differentially differentiated, peak hold means for peak-holding the signal based on the differential signal level, and a density histogram is created in a plurality of local units,
A local binarization unit that obtains a threshold value for each local from the density histogram and binarizes the threshold value for each local, and the shape of the steel plate front end portion and tail end portion, the plate bending amount from the binarized signal,
A steel sheet shape measuring device comprising means for measuring the amount of camber.