JPH05296729A - Breadth measurement method for steel plate - Google Patents

Abstract

PURPOSE:To measure the breadth of a steel plate in such a way as generating no error, even when the steel plate gives a vibration in a vertical direction, by laying a plurality of linear sensors along the breadthwise direction of the steel plate for detecting the breadthwise ends thereof, and calculating the breadth of the steel plate on the basis of values detected with the sensors. CONSTITUTION:Two linear array type cameras 12 and 22 are fixed above a traveling steel plate 3 along the breadthwise direction thereof. The cameras 12 and 22 detect both ends of the steel plate 3 with the breadthwise direction thereof taken as one dimension, and are used as the one-dimensional position sensors with horizontal scanning for the breadthwise direction. A white lower illuminant 4 is installed under the cameras 12 and 22 in such a way as sandwiching the steel plate 3, thereby ensuring the easier detection of the breadthwise ends of the steel plate 3. Values detected with the two fixed cameras 12 and 22 are inputted to a computer, and the two-dimensional coordinates of the cross section of the steel plate 3, or the breadth of the steel plate 3 can be calculated by an operation expression or the like in the computer. According to this construction, a less measurement error occurs, even when the steel plate 3 vertically vibrates at the time of measurement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously measuring the width dimension of a steel sheet passing through a continuous processing line in a non-contact manner.

[0002]

2. Description of the Related Art As a method for continuously measuring the width dimension of a steel sheet when it is passed through a continuous processing line, the following method using a two-dimensional camera using a CCD image sensor has been conventionally used. It was done.

The dimension in the width direction is directly measured from the area of the measured object image occupying the imaging plane. The position of the camera is moved so that the area of the measured object image in the imaging plane is always constant (for example, the camera position is set so that 50% of the imaged area is always the area of the measured object image). The distance in the width direction of the steel plate is calculated from the camera position.

[0004]

However, in any of the measuring methods using the above-described two-dimensional camera, there is a problem that a measurement error occurs when the steel sheet as the object to be measured vibrates in the vertical direction. was there. In addition, in the above method, the camera etc. can be moved in order to appropriately change the camera position, but due to this moving type, the members supporting the camera etc. are worn out due to aging and a failure may occur. However, there has been a problem that the slippage of the moving member deteriorates and an error occurs in the measured value.

The present invention was devised in view of the above problems, and it is an object of the present invention to provide a method for measuring the width of a steel sheet in which the above measurement error does not occur.

[0006]

Therefore, in the method for measuring the width of a steel sheet according to the present invention, the width direction of the steel sheet is set to one dimension, and a plurality of linear sensors for detecting both ends thereof are fixed along the width direction of the steel sheet. The width of the steel sheet is calculated based on the detection value from each linear sensor.

In the method of the present invention, the steel plate width is calculated from the linear sensor detection value, for example, as follows.

In FIG. 1, two linear sensors 1 and 2 each having a lens system for detecting both end portions of the steel plate in the width direction are passed over the steel plate 3 and fixed along the width direction. One configuration example is shown, and for convenience of plate width calculation, the plate width direction of the steel plate 3 is set as an x coordinate and the plate thickness direction is set as ay coordinate. 1 in the figure
Reference numerals 0 and 20 denote image pickup lenses, and 11 and 12 denote image pickup plates. Also,
(X ₁ , y ₁ ) and (x ₂ , y ₂ ) are both end positions in the steel sheet width direction,
x _A and x _B are the respective widthwise positions of the sensors 1 and 2, y _L
The height position of the sensors 1 and 2 from the sheet passing plane y _0, y _f is the lens focal length, x _A1, x _B1, respectively (x _1, y ₁₎ and the line connecting the lens focus imaging plate 11 and 21 The distance between the point that hits the point and the center of the sensor, x _A2 and x _B2 are (x ₂ , y ₂ ) respectively
And the line that connects the lens focus to the image pickup plates 11 and 21,
The distance to the center of the sensor is shown.

From the positional relationship shown in the figure, the positions (x ₁ , y ₁ ) (x ₂ , y ₂ ) of both ends of the steel plate 3 can be expressed as follows.

[0010]

[Equation 1]

[0011]

[Equation 2]

[0012]

[Equation 3]

[0013]

[Equation 4]

From the above formula, the plate width W of the steel plate 3 can be calculated by the following formula.

[0015]

[Equation 5]

[0016]

FIG. 2 shows an example of an apparatus configuration capable of carrying out the method of the present invention.

As shown in the figure, in this embodiment, two linear ray cameras 12 and 22 are fixedly installed on the upper surface of the steel plate 3 to be passed along the width direction thereof. The linear ray cameras 12, 22 detect both ends of the steel plate 3 with the width direction of the steel plate 1 as one dimension, and are used as one-dimensional position sensors in the plate width direction by horizontal scanning.

Further, in this embodiment, the lower light source 4 for white light is installed below the linear ray cameras 12 and 22 with the steel plate 3 sandwiched therebetween to make it easier to detect both ends of the steel plate 3 in the width direction.

Although not shown, in this embodiment, a computer for calculating the width dimension of the steel sheet 3 from the one-dimensional detection values of the cameras 12 and 22 is provided by using, for example, the above mathematical formula.

With the above apparatus configuration, the detected values from the two fixed linear ray cameras 12, 22 are input to the computer, and the computer calculates the two-dimensional coordinates of the cross section of the steel plate 3 according to the above-mentioned equations. The width dimension of the steel plate 3 can be calculated.

[0021]

As described above, the steel sheet width measuring method according to the present invention calculates the width dimension of the steel sheet based on the one-dimensional data in the width direction detected by the plurality of linear sensors. Even if the steel plate vibrates in the vertical direction during the measurement, the measurement error is less likely to occur. In addition, since the sensor that detects both ends of the steel plate is a fixed type,
Naturally, the measurement error due to the conventional mobile type does not occur.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for calculating a steel plate width dimension from a detection value of a linear sensor.

FIG. 2 is a perspective view showing an example of a device configuration that can carry out the method of the present invention.

[Explanation of symbols]

 1, 2 Linear sensor 3 Steel plate 4 Lower light source 12, 22 Linear ray type camera

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Ishigaki 4-2-12 Nihombashi Muromachi, Chuo-ku, Tokyo Taihei Kogyo Co., Ltd. (72) Inventor Shinichi Shimizu 4-2-1-12 Nihombashi Muromachi, Chuo-ku, Tokyo Taihei Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A width direction of a steel sheet is defined as one dimension, and a plurality of linear sensors for detecting both ends of the steel sheet are fixedly arranged along the width direction of the steel sheet, and the linear sensors are detected based on detection values from the respective linear sensors. A method for measuring the width of a steel plate, which comprises calculating the width of the steel plate.