JP2005241361A - Profile measuring method and profile measuring system for slab shape object to be measured - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a profile measuring method and profile measuring system for a slab shape object to be measured which makes it possible to measure angle of four corners of a slab shape object to be measured speedily and at a low cost. <P>SOLUTION: By using image input devices 30R and 30L put above a carrier line 14, edges 12R and 12L of a steel plate are detected. A photo switch 26 put above the carrier line 14 and lining in the direction crossing to the carrier direction detects the timing for responding to the edges 12F and 12B of the steel plate 10. From the timing when the photo switch 26 reacts and the position of the photo switch 26 and a carriage velocity of the steel plate 10, the positions of the edges 12F and 12B of the steel plate 10 are calculated. From each position of edges 12R, 12L, 12F and 12B of the steel plate 10, each angle θ1, θ2, θ3, θ4 of four corner of the steel plate 10 is calculated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plate-like object to be measured for measuring an intersection angle between an edge extending in the conveying direction of an object to be measured conveyed on a conveying line and an edge extending in a direction intersecting the conveying direction of the object to be measured. The present invention relates to a shape measuring method and a shape measuring apparatus.

In recent years, production lines for various products are highly automated and labor-saving, and raw materials supplied to the production lines are required to have high-precision dimensional shapes. When a rectangular plate such as a steel plate is supplied as a raw material to a highly automated / labor-saving production line, high-precision dimensional shapes are available for the width, length, strain, and corner angles of the four corners. Desired.
Therefore, when manufacturing a steel plate at an ironworks, the width, length, strain and angle of the four corners of the manufactured steel plate are strictly inspected, and the dimensional shape of the steel plate is maintained with high accuracy. For example, when measuring the angles of the four corners of a steel sheet, an operator enters the steel sheet production line, presses right angle skewers against the four corners of the steel sheet, and measures the angle of each corner of the steel sheet.

A method for measuring the inspection of the corner angles of the four corners of the steel sheet using a right angle skewer will be described below. As shown in FIG. 6, the right angle scorer 50 used for the measurement has a right triangle, the side 52a and the side 52b sandwich the right vertex 54a, and the vertex 54a and the vertex 54b sandwich the right side 52b. The length of the side 52b is L1. When measuring the angle of the corner 11 sandwiched between the edge 12a and the edge 12b of the steel plate 10 using the right angle skewer 50, first, the right angle skewer 50 is placed on the steel plate 10, and the side 52a of the right angle skewer 50 is placed. , Along the edge 12a of the steel plate 10, the apex 54a of the right angle skewer 50 is made to coincide with the corner 11 of the steel plate 10. Then, a line segment perpendicular to the side 52b of the right angle skewer 50 is drawn from the vertex 54b of the right angle skewer 50 to the edge 12b of the steel plate 10, and the distance L2 from the vertex 54b to the edge 12b in this line segment is measured. When the distance L2 is measured, the squareness α of the corner 11 is calculated using the following equation (1).
α = L2 / L1 × W (1)
W: Length of edge 12b (mm)
When the angle of the corner 11 of the steel plate 10 is 90 °, the value of the squareness α of the corner 11 is 0 mm. When the angle of the corner 11 is smaller than 90 °, the value of the square angle α of the corner 11 is a negative value. When the angle of the corner 11 is larger than 90 °, the square angle α of the corner 11 is a positive value.

Moreover, the angle of the corner of a steel plate is also measured using an automated measuring device. As an automated measuring apparatus, there is an apparatus that acquires image data of a steel plate using an image input device such as a CCD camera, analyzes the acquired image data, and measures a corner angle of the steel plate (for example, Patent Document 1). , See Non-Patent Document 1).
Japanese Patent Laid-Open No. 11-44516 Toru Yawaka, “Development of flat shape meter, automation of flat plate shape inspection”, Materials and Processes, Japan Iron and Steel Institute, 1995, Vol. 18, No. 5, p. 1162-1163

However, when an operator enters a production line for a plate-like object to be inspected and manually measures the angles of the four corners of the plate-like object, there are the following problems.
That is, when the worker manually measures the angles of the four corners of the plate-like object, it is necessary to temporarily stop the conveyance of the plate-like object in the production line. If the conveyance of the plate-like object is stopped in the production line, the production efficiency of the plate-like substance is lowered, which is not preferable.

In addition, the measurement accuracy is likely to vary depending on the skill level of the worker, and the corner angle of the manufactured plate-like object may not be maintained with high accuracy.
Further, when the plate-like product is in a high temperature state, such as a steel plate that has been subjected to the hot rolling process, it is necessary to carefully measure the angle of the corner of the steel plate by hand, resulting in poor work efficiency.
Furthermore, when measuring the angles of the four corners of the plate-like object using a measuring device including an image input device such as a CCD camera, there are the following problems.

  That is, since a measuring device including an image input device such as a CCD camera is used, high-accuracy image data is required to improve measurement accuracy. For this purpose, it is necessary to use an expensive CCD camera with a large number of pixels and a high resolution, and to acquire a large amount of image data. The acquired large amount of image data is analyzed using an arithmetic device having a high processing speed. Must be processed. Therefore, the cost of the CCD camera and the arithmetic unit increases, and it becomes difficult to measure the angles of the four corners of the plate-like object at a low cost.

In particular, in steelworks, steel sheets of various dimensions are manufactured, and these steel sheets are transported on the same manufacturing line. When measuring the angles of the four corners of the steel plate with a measuring device equipped with a CCD camera with high accuracy, if the position of the CCD camera was moved in correspondence with the dimensions of each steel plate, the conveying speed of the steel plate decreased, The manufacturing efficiency of the steel sheet is reduced. Therefore, in order to measure the angles of the four corners of all the steel plates with high accuracy without reducing the manufacturing efficiency of the steel plates, a large number of CCD cameras must be installed. It is difficult to measure the angle at a low cost.
The present invention has been made in order to eliminate the above-described problems of the prior art, and the object of the present invention is to be able to measure the angles of the four corners of a plate-like object to be measured quickly and at a low cost. It is providing the shape measuring method and shape measuring apparatus of a plate-shaped to-be-measured object.

  The present invention has the following configuration in order to solve the problem. The shape measuring method of a plate-like object to be measured according to the invention of claim 1 is a method for measuring the shape of a plate-like object to be measured conveyed on a conveying line, and is an image installed above the conveying line. Using the image data acquired by the input device, the position of the edge extending in the conveyance direction of the object to be measured is detected, and a plurality of lines arranged in the direction intersecting the conveyance direction of the object to be measured are installed above the conveyance line. Using the optical switch, the timing at which each of these optical switches reacts to the edge extending in the direction intersecting the transport direction of the object to be measured is detected, the timing at which each optical switch reacts, the position of each optical switch, The position of the edge extending in the direction intersecting the conveyance direction of the measured object is calculated from the conveyance speed of the measured object, and the detected position of the edge extending in the conveyance direction of the measured object and the calculated measured object How to transport And a position of the edge extending in a direction intersecting with, calculates the edge extending in the conveying direction of the object to be measured, the angle of intersection between the edge extending in a direction intersecting the transport direction of the object to be measured.

  According to the invention of claim 1, when measuring the angles of the four corners of the plate-like object to be measured, the position of the edge extending in the transport direction of the object to be measured is detected by an image input device such as a CCD camera, By improving the resolution of the image input device, the position of the edge extending in the conveyance direction of the object to be measured is detected with high accuracy. On the other hand, the position of the edge extending in the direction intersecting the conveyance direction of the measured object is detected by a plurality of optical switches, and each optical switch reacts to the edge extending in the direction intersecting the conveyance direction of the measured object. The timing can be detected accurately and easily, and the position of the edge extending in the direction intersecting the conveyance direction of the object to be measured is calculated with high accuracy. The intersection angle between these edges from the position of the edge that extends in the transport direction of the measured object detected with high accuracy and the position of the edge that extends in the direction intersecting the transport direction of the measured object calculated with high precision Can be calculated with high accuracy.

As the optical switch, for example, a laser reflection type optical switch can be used. When the laser beam is projected and the projected laser beam hits the edge of the object to be measured and is reflected, the reflected light is received. The presence of the edge of the measured object can be detected.
In addition, a laser transmission type optical switch can be used as the optical switch. The laser light is projected, and depending on whether the projected laser light is received without being scattered on the way, The presence of an edge can be detected. Since these optical switches only switch between an on state and an off state depending on whether or not laser light is received, it is extremely easy to accurately detect the timing at which the on state and the off state are switched.

  Since an optical switch is less expensive than a high-resolution image input apparatus, even if a plurality of optical switches are installed side by side in a direction crossing the conveyance direction of the conveyance line, the installation cost is low. Therefore, the necessary and sufficient number of optical switches can be installed at low cost corresponding to the dimensions of the object to be measured conveyed on the conveyance line, and the position of the edge extending in the direction intersecting the conveyance direction of the object to be measured is determined. It can be calculated with high accuracy.

An image input device that is more expensive than an optical switch is only used for detecting the position of an edge extending in the conveyance direction of the object to be measured, and the number of installed image input devices can be reduced. The cost of equipment required to measure the angles of the four corners is low.
When using the image input device to detect the position of the edge extending in the conveyance direction of the object to be measured, analyze the image data acquired by the image input device, change the brightness in the image data, change the shade of the color, etc. From the edges extending in the conveyance direction of the object to be measured, the positions of at least three points are specified, and the position of the object to be measured is determined from the positions of the points of the specified points using, for example, the least square method. The position of the edge extending in the transport direction is determined.

  In addition, when calculating the position of the edge extending in the direction intersecting the transport direction of the object to be measured, the measurement target is determined from the timing at which each optical switch reacts, the position of each optical switch, and the transport speed of the object to be measured. The positions of at least three or more points are calculated from the edges extending in the direction intersecting the object conveyance direction, and the measured object position is calculated from the calculated positions of the points using the least square method, for example. The position of the edge extending in the direction crossing the transport direction is determined. Therefore, in order to suppress the error of the position of the edge extending in the direction intersecting the transport direction of the measured object to be calculated, the number of optical switches that react to the edge extending in the direction intersecting the transport direction of the object to be measured is 3 It is preferable to use more than one.

A shape measuring method for a plate-like object to be measured according to the invention of claim 2 is the shape measuring method for a plate-like object to be measured according to claim 1, wherein the position of the image input device is measured above the transport line. The object is moved in a direction crossing the conveyance direction of the measurement object, and an edge extending in the conveyance direction of the measurement object is placed in the field of view of the image input apparatus.
According to the second aspect of the present invention, the position of the image input device moves above the transport line in a direction that intersects the transport direction of the object to be measured. It becomes possible to change. Therefore, it is possible to correspond to the measurement object of the measurement object of various dimensions conveyed through the conveyance line without increasing the number of installed image input devices, and the edge extending in the conveyance direction of each measurement object The position can be detected.
When objects to be measured of various dimensions are conveyed along the conveyance line, each object to be measured is suppressed in order to suppress errors in the position of the edge extending in the direction intersecting the calculated object conveyance direction. It is preferable to determine the number of optical switches so that the number of optical switches that react to the shortest edge among the edges extending in the direction intersecting with the transport direction is three or more.

A shape measuring apparatus for a plate-like object to be measured according to a third aspect of the invention is a measuring apparatus for measuring the shape of a plate-like object to be measured conveyed on a conveying line, and is installed above the conveying line. And an image input device that acquires image data of an edge extending in the transport direction of the measured object, and is installed above the transport line, aligned in a direction intersecting the transport direction of the measured object, and the transport direction of the measured object A plurality of optical switches that react to edges extending in a direction intersecting the line and the position of the edge extending in the conveyance direction of the measured object are detected from the image data acquired by the image input device, and intersect the conveyance direction of the measured object The position of the edge extending in the direction intersecting the conveyance direction of the object to be measured is calculated from the timing at which each of the optical switches reacts to the edge extending in the direction, the position of each optical switch, and the conveyance speed of the object to be measured. , Inspection An edge extending in the transport direction of the measured object from the position of the edge extending in the transport direction of the measured object and the position of the edge extending in the direction intersecting the calculated transport direction of the measured object; A calculation unit that calculates an intersection angle between the edge extending in the direction intersecting with the conveyance direction.
According to the invention of claim 3, the shape measuring method of the plate-like object to be measured according to claim 1 can be implemented.

A shape measuring apparatus for a plate-like object to be measured according to a fourth aspect of the invention is the shape measuring apparatus for a plate-like object to be measured according to claim 3, wherein the image input device is an object to be measured above the conveying line. It is configured to be movable in a direction that intersects the transport direction.
According to the invention of claim 4, the shape measuring method of the plate-like object to be measured according to claim 2 can be carried out.

  Since the present invention is a shape measuring method and a shape measuring apparatus for a plate-like object to be measured as described above, the plate-like object that can measure the corners of the four corners of the plate-like object at a low speed and at a low cost. There is an effect that it is possible to provide a shape measuring method and a shape measuring apparatus of a measurement object.

The best mode for carrying out the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, a shearing device 16 configured to be able to manufacture a steel plate 10 having a predetermined size by shearing a steel strip into a rectangle is installed on the upstream side of the conveying line 14 of the steel plate 10. . The shearing device 16 has the same configuration as that of the conventional one. The conveyance line 14 is formed from a base 18 and a plurality of conveyance rolls 20 supported by the base 18, and is configured to be able to convey the steel plate 10 exiting the shearing device 16 to the downstream side.

A gantry 22 is installed on the downstream side of the transfer line 14. The gantry 22 has two upper and lower arms 24U and 24D, and each of the arms 24U and 24D is positioned above the transfer line 14 across the transfer line 14 and orthogonal to the transfer direction of the transfer line 14.
A plurality of optical switches 26 forming a part of the shape measuring apparatus 1 are supported on the upper arm 24U side by side at equal intervals. Each optical switch 26 is a laser reflection type optical switch. Each optical switch 26 projects laser light from a light projecting unit (not shown) toward the lower conveyance line 14, and when the steel plate 10 is present on the conveyance line 14 immediately below the optical switch 26, the light projecting unit The laser light emitted from the light hits the steel plate 10 and is reflected, and the reflected laser light is received by the light receiving unit 28 of the optical switch 26. When the light receiving unit 28 receives the laser light, the optical switch 26 is turned on, and the light receiving unit 28 If the laser beam is not received, the optical switch 26 is turned off. The on / off state of the optical switch 26 is sent to an arithmetic unit 36 that forms part of the shape measuring apparatus 1.

Two image input devices 30R and 30L forming a part of the shape measuring device 1 are supported side by side on the lower arm 24D. Each image input device 30 is a CCD camera similar to a conventional one, and each image input device 30 captures the lower conveyance line 14 to acquire image data, and sends the acquired image data to the arithmetic device 36. It has become. A moving device 32 is installed at the end of the arm 24D, and the image input devices 30R and 30L can be moved along the arm 24D by the moving device 32, respectively.
3 is a front view of the shape measuring apparatus 1 as viewed from the downstream side, in which the illustration of the shearing device 16 is omitted. In FIG. 3, the image input device 30R is located on the right side, and the image input device. 30L is located on the left side.

A speedometer 34 is installed on the side of the gantry 22, detects the amount of rotation of the transport roll 20, calculates the transport speed of the steel plate 10 that passes under the arms 24 U and 24 D of the gantry 22, and calculates The conveyance speed of the steel plate 10 is sent to the calculation device 36.
The arithmetic device 36 is installed on the side of the gantry 22 and constitutes a part of the shape measuring device 1. The computing device 36 has a computing unit 38, and the computing unit 38 has programs P1, P2, P3, P4, and P5.
The program P1 controls the moving device 32, and determines the positions of the image input devices 30R and 30L so that the edges 12R and 12L extending in the transport direction of the steel plate 10 are in the visual fields of the image input devices 30R and 30L, respectively. It is a program. In FIG. 3, the edge 12R of the steel plate 10 is located on the right side, and the edge 12L of the steel plate 10 is located on the left side.

Specifically, when the program P1 analyzes the image data acquired by the image input device 30R and determines that the steel plate 10 is not present in the image data, the program P1 sets the image input device 30R in FIG. The position of the image input device 30R is controlled so that the edge 12R of the steel plate 10 enters the field of view of the image input device 30R.
When the program P1 analyzes the image data acquired by the image input device 30R and determines that the steel plate 10 exists in the image data but the edge 12R of the steel plate 10 does not exist, the moving device 32, the image input device 30R is moved to the right in FIG. 3, and the position of the image input device 30R is controlled so that the edge 12R of the steel plate 10 enters the field of view of the image input device 30R.

  Furthermore, when the program P1 analyzes the image data acquired by the image input device 30L and determines that the steel plate 10 is not present in the image data, the program P1 moves the image input device 30L to the right in FIG. When it is determined that the steel plate 10 exists in the image data of the image input device 30L but the edge 12L of the steel plate 10 does not exist, the image input device 30L is moved to the right of FIG. And the position of the image input device 30L is controlled so that the edge 12L of the steel plate 10 enters the field of view of the image input device 30L.

Note that when analyzing the image data from the image input devices 30R and 30L, the program P1 detects the presence of the steel plate 10 and the edges 12R and 12L of the steel plate 10 from changes in luminance and color tone in the image data. It has a configuration.
The program P2 is a program that analyzes image data from the image input devices 30R and 30L and calculates the positions of the edges 12R and 12L extending in the transport direction of the steel plate 10 on the transport line 14.
Specifically, the program P2 detects the positions of three or more points in each of the edges 12R and 12L from the change in brightness, the change in color tone, etc. in the image data, and the detected points in each point. Is calculated on the transport line 14 at a time, and a straight line is drawn by applying the least square method to the calculated position of each point, and these straight lines are defined as the edges 12R and 12L of the steel plate 10. have.

The program P3 transfers the steel plate 10 on the transfer line 14 from the installation position of each optical switch 26, the timing when each optical switch 26 is turned on and off, and the transfer speed of the steel plate 10 calculated by the speedometer 34. This is a program for detecting the positions of the edges 12F and 12B extending in the direction crossing the direction.
1 and 2, the edge 12F of the steel plate 10 is located on the downstream side, and the edge 12B of the steel plate 10 is located on the upstream side.
Specifically, the program P3 passes directly under each optical switch 26 from the timing at which each optical switch 26 switches between the on state and the off state and the conveyance speed of the steel plate 10 detected by the speedometer 34. The position of each point in the edge 12F or the edge 12B of the steel plate 10 occupies the time on the conveyance line 14 is calculated, and a straight line is drawn by applying the least square method to the calculated position of each point. The straight line is configured as an edge 12F or an edge 12B of the steel plate 10.

The program P4 is a program for calculating the corner angles of the four corners of the steel plate 10.
Specifically, the program P4 determines the distance between the edges 12R and 12F from the positions of the edges 12R and 12L of the steel plate 10 calculated by the program P2 and the positions of the edges 12F and 12B of the steel plate 10 detected by the program P3. Corner angle θ1, corner angle θ2 between edge 12L and edge 12F, corner angle θ3 between edge 12L and edge 12B, and corner angle θ4 between edge 12R and edge 12B, respectively. It has the composition to do.
The program P5 compares the installation positions of the optical switches 26 with the positions of the image input devices 30R and 30L, and when any one of the optical switches 26 is located immediately above the image input devices 30R and 30L, This is a program for stopping the operation of the optical switch 26.

The present embodiment is configured as described above, and the operation thereof will be described next.
The steel strip is supplied to the shearing device 16, and the shearing device 16 shears the steel strip into a rectangular steel plate 10 having a predetermined size. The steel plate 10 exiting the shearing device 16 is transported to the downstream side of the transport line 14, and the gantry It passes under 22 arms 24U, 24D. The conveyance speed of the steel plate 10 passing under the arms 24U and 24D is calculated by the speedometer 34, and the calculated conveyance speed of the steel plate 10 is sent to the arithmetic device 36.

  In the steel plate 10 transported along the transport line 14, the edges 12R and 12L extending in the transport direction of the steel plate 10 are edges in the longitudinal direction of the steel plate 10, and the direction in which the edges 12R and 12L extend is the transport direction of the steel plate 10. The direction is roughly the same. Further, in the steel plate 10, of the edges 12 </ b> F and 12 </ b> B extending in the direction intersecting the conveyance direction of the steel plate 10, the edge 12 </ b> F is located on the downstream side of the conveyance line 14 and the edge 12 </ b> B is located on the upstream side of the conveyance line 14. Yes.

The image input devices 30R and 30L supported on the arms 24D of the gantry 22 capture the image on the transport line 14, and the image data acquired by the image input devices 30R and 30L are sent to the arithmetic device 36, respectively.
In the arithmetic unit 36, the program P1 analyzes changes in luminance, changes in color tone, and the like in the image data sent from the image input devices 30R and 30L, and in the arm 24D by the moving unit 32 according to the analysis result. The positions of the image input devices 30R and 30L are adjusted, the edge 12R of the steel plate 10 is placed in the field of view of the image input device 30R, and the edge 12L of the steel plate 10 is placed in the field of view of the image input device 30L.

  In the arithmetic device 36, the program P2 analyzes the image data sent from the image input device 30R, detects the positions of three or more points in the edge 12R of the steel plate 10, and detects the detected points at each location. Is calculated on the transfer line 14 at a certain time, a straight line is drawn by applying the least square method to the calculated position of each point, and this straight line is defined as the edge 12R of the steel plate 10.

Similarly, the program P2 analyzes the image data sent from the image input device 30L, detects the positions of three or more points in the edge 12L of the steel plate 10, and conveys the detected points of each point. The position occupied at a certain time on the line 14 is calculated, a straight line is drawn by applying the least square method to the calculated position of each point, and this straight line is defined as the edge 12L of the steel plate 10.
On the arm 24 </ b> U of the gantry 22, a laser beam is projected from the light projecting portion of each optical switch 26 directly below. When the steel plate 10 does not exist on the conveyance line 14 directly below the optical switch 26, the laser light projected from the optical switch 26 goes straight as it is, and the optical switch 26 is in an off state. When the edge 12F of the steel plate 10 enters under the arm 24U, the laser beam strikes and reflects the edge 12F of the steel plate 10, and the reflected laser beam is received by the light receiving unit 28 of the optical switch 26 that projects the laser beam. The optical switch 26 that has received the laser light is switched from the off state to the on state.

Note that the optical switch 26 positioned immediately above the image input devices 30R and 30L is specified by the program P5, and the operation of the optical switch 26 positioned immediately above the image input devices 30R and 30L is stopped. Except for the optical switches 26 that have been deactivated by the program P5, the on / off state of each optical switch 26 is sent to the arithmetic unit 36.
In the arithmetic device 36, the program P3 uses each optical switch from the installation position of each optical switch 26, the timing at which each optical switch 26 switches from the OFF state to the ON state, and the conveyance speed of the steel plate 10 calculated by the speedometer 34. 26, a position occupied by each point in the edge 12F of the steel plate 10 that has passed directly below the position 26 on the transport line 14 is calculated, and the least square method is applied to the calculated position of each point. And this straight line is defined as an edge 12F of the steel plate 10.

When the edge 12B of the steel plate 10 exits from the bottom of the arm 24U to the downstream side of the conveying line 14, the steel plate 10 does not exist under each optical switch 26, and the optical switch 26 that has been in the ON state until then. Switches to the off state.
In the arithmetic device 36, the program P3 determines the optical switches based on the installation positions of the optical switches 26, the timing at which the optical switches 26 are switched from the on state to the off state, and the conveyance speed of the steel plate 10 calculated by the speedometer 34. 26, the position occupied by each point in the edge 12B of the steel plate 10 that has passed directly below the position on the transport line 14 is calculated, and the least square method is applied to the calculated position of each point. And this straight line is defined as an edge 12B of the steel plate 10.

When the positions of the edges 12R, 12L, 12F, and 12B of the steel plate 10 are detected by the programs P2 and P3, the program P4 is detected between the positions of the edges 12R, 12L, 12F, and 12B between the edges 12R and 12F. The corner angle θ1, the corner angle θ2 between the edge 12L and the edge 12F, the corner angle θ3 between the edge 12L and the edge 12B, and the corner angle θ4 between the edge 12R and the edge 12B are calculated, respectively. .
In the present embodiment, both the image input devices 30R and 30L can be moved along the arm 24D by the moving device 32, but one image input device is fixed and the other image input device moves along the arm 24D. Of course, it may be possible.

Next, the result of the verification test carried out using the shape measuring apparatus and the shape measuring method according to the present invention will be reported.
As an example of the invention, using the shape measuring apparatus and the shape measuring method having the above-described configuration, the angle of one corner of the four corners of each steel plate is determined for 10 steel plates conveyed on the transfer line. It was measured. In the shape measuring apparatus of the invention example, the number of optical switches is set to 16, the CCD camera forming one image input device is fixed, and only the CCD camera forming the other image input device is movable and fixed. The steel plate was transported so that an edge extending in the transport direction of the steel plate always entered the field of view of the CCD camera.

  Further, in the shape measuring apparatus of the comparative example, the all-optical switch of the shape measuring apparatus of the invention example is replaced with one CCD camera, and a total of three CCD cameras are provided. The configuration is such that the edge of the steel plate extending in the direction intersecting with is detected, and the other configuration is the same as that of the shape measuring apparatus of the invention example. And using the shape measuring apparatus of this comparative example, the angle of the corner of the same part as an invention example was measured with respect to ten steel plates measured by the invention example.

In measuring the corner angle of the steel sheet using the shape measuring apparatus of the comparative example, the same method as the shape measuring method of the invention example was used except for the following points. That is, from the image data acquired by the CCD camera replaced with the optical switch, the position occupied by three or more points on the edge of the steel plate extending in the direction intersecting the conveyance direction on the conveyance line is calculated and calculated. A straight line was drawn by applying the least square method to the position of each point, and this straight line was used as the edge of the steel plate extending in the direction intersecting the transport direction.
The number of pixels of each CCD camera included in the shape measuring apparatus of the invention example and the shape measuring apparatus of the comparative example is 480 × 512 (vertical × horizontal).

Furthermore, as an actual measurement value, the corner angle of each steel plate measured in the inventive example and the comparative example was directly measured using a right angle skewer.
The angle of the corner of the steel sheet measured in the inventive example and the comparative example is converted into a square angle α, the measurement result in the inventive example is shown in FIG. 4, and the measurement result in the comparative example is shown in FIG. The vertical axis in FIG. 4 represents the squareness α in the actual measurement value, and the horizontal axis represents the squareness α in the measurement value of the inventive example. Further, the vertical axis in FIG. 5 represents the squareness α in the actual measurement value, and the horizontal axis represents the squareness α in the measurement value of the comparative example.

If the perpendicularity α of the measured value in the inventive example and the perpendicularity α of the actually measured value match, the plots in FIG. 4 are on the same straight line, and the perpendicularity α of the measured value in the comparative example and the perpendicularity of the actually measured value. If the angle α coincides, the plots in FIG. 5 should be on the same straight line, and when the gap between the measured value perpendicularity α and the measured value perpendicularity α of the invention example increases, The plot in FIG. 5 is greatly scattered, and if the difference between the squareness α of the measured value of the comparative example and the squareness α of the actual measurement becomes large, the plot in FIG. 5 should be greatly scattered.
4 and 5, the standard deviation σ of each plot in FIG. 4 of the invention example is 1.8, and the standard deviation σ of each plot in FIG. 5 of the comparative example is 4.7. The dispersion degree of each plot in the comparative example is larger. Therefore, it can be seen that the measurement accuracy of the inventive example is superior to the measurement accuracy of the comparative example.

The following can be considered as the reason why the measurement accuracy of the inventive example is superior to the measurement accuracy of the comparative example.
In detecting the edge of the steel sheet extending in the direction intersecting the transport direction, in the invention example, the timing of switching between the ON state and the OFF state of the optical switch is used to detect the edge of the steel sheet extending in the direction intersecting the transport direction. The position of the point is calculated. In this case, the timing at which the optical switch is switched between the on state and the off state is detected with high accuracy, and the position of the edge of the steel sheet extending in the direction intersecting the transport direction is also detected with high accuracy.

  On the other hand, in the comparative example, the image data captured by the CCD camera is analyzed, and the position of the point in the edge of the steel plate extending in the direction intersecting the transport direction is calculated. In this case, the accuracy of the image data captured by the CCD camera depends on the resolution of the CCD camera, and the accuracy of the image data of the CCD camera having the number of pixels of 480 × 512 (vertical × horizontal) is not high, and intersects the transport direction. The error of the position of the edge of the steel plate extending in the direction also becomes large. Therefore, the invention example is superior in the detection accuracy of the edge of the steel plate extending in the direction intersecting the transport direction.

  In addition, in FIG. 4 of the invention example, the standard deviation σ is 1.8. When detecting the edge of the steel plate extending in the transport direction, the image data captured by the CCD camera is analyzed and the sensor is extended in the transport direction. This is because the position of the point in the edge of the steel plate is calculated, and this is because the calculated position includes an error. Therefore, in order to increase the measurement accuracy of the corner angle in the invention example, the number of pixels of the two CCD cameras included in the shape measuring apparatus of the invention example may be increased to improve the resolution of the CCD camera.

  On the other hand, in order to increase the corner angle measurement accuracy in the comparative example, the resolution of the three CCD cameras included in the shape measuring apparatus of the comparative example must be improved. That is, if the shape measuring apparatus of the invention includes two high-resolution CCD cameras, the measurement accuracy can be improved. However, in the shape measuring apparatus of the comparative example, a high-resolution CCD camera is used. Without providing three, the measurement accuracy cannot be increased.

It is a top view of a conveyance line provided with the shape measuring apparatus which concerns on this invention. It is a side view of a conveyance line provided with the shape measuring apparatus which concerns on this invention. It is the front view which looked at the shape measuring device concerning the present invention from the downstream. It is explanatory drawing of the measurement result of the example of an invention. It is explanatory drawing of the measurement result of a comparative example. It is explanatory drawing of the method of measuring the corner angle of a steel plate using a right angle skewer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shape measuring device 10 Steel plate 11 Steel plate corner 12a, 12b Steel plate edge 12R, 12L Edge of steel plate extending in conveyance direction 12F Edge of steel plate extending in direction intersecting conveyance direction 12B Extending in direction intersecting conveyance direction Edge of upstream side of steel plate 14 Conveying line 16 Shearing device 18 Base 20 Conveying roll 22 Base 24U, 24D Arm 26 Optical switch 28 Optical switch light receiving unit 30R, 30L Image input device 32 Moving device 34 Speedometer 36 Arithmetic device 38 Arithmetic Part 50 Right angle square 52a, 52b Right angle square side 54a, 54b Right angle square vertex P1, P2, P3, P4, P5 Program θ1, θ2, θ3, θ4 Corner angles of four corners of steel plate

Claims (4)

A method for measuring the shape of a plate-like object to be measured conveyed on a conveyance line,
Using the image data acquired by the image input device installed above the transport line, the position of the edge extending in the transport direction of the object to be measured is detected,
A plurality of optical switches that are installed above the conveyance line and arranged in a direction intersecting the conveyance direction of the object to be measured are used, and each of these optical switches is arranged on an edge extending in a direction intersecting the conveyance direction of the object to be measured. The timing of reaction is detected, and the position of the edge extending in the direction intersecting the transport direction of the measured object is calculated from the timing of each optical switch reacting, the position of each optical switch, and the transport speed of the measured object. And
An edge extending in the transport direction of the measured object from the detected position of the edge extending in the transport direction of the measured object and the position of the edge extending in the direction intersecting the calculated transport direction of the measured object; A method for measuring a shape of a plate-like object to be measured, wherein an intersection angle between an edge extending in a direction intersecting with an object conveyance direction is calculated.   The shape measurement method for a plate-like object to be measured according to claim 1, wherein the position of the image input device is moved above the transport line in a direction intersecting the transport direction of the object to be measured, and the field of view of the image input device A shape measuring method for a plate-like object to be measured, characterized in that an edge extending in the conveying direction of the object to be measured is put inside. A measuring device for measuring the shape of a plate-like object to be measured conveyed on a conveyance line,
An image input device that is installed above the transport line and acquires image data of an edge extending in the transport direction of the object to be measured;
A plurality of optical switches that are installed above the conveyance line, arranged in a direction intersecting the conveyance direction of the object to be measured, and reacting to an edge extending in a direction intersecting the conveyance direction of the object to be measured;
The position of the edge extending in the conveyance direction of the object to be measured is detected from the image data acquired by the image input device, the timing at which each of the plurality of optical switches reacts to the edge extending in the direction intersecting the conveyance direction of the object to be measured, From the position of the optical switch and the conveyance speed of the object to be measured, the position of the edge extending in the direction intersecting the conveyance direction of the object to be measured is calculated, and the position of the edge extending in the conveyance direction of the detected object to be measured; The intersection angle between the calculated edge position extending in the direction intersecting the conveyance direction of the measured object and the edge extending in the conveyance direction of the measurement object and the edge extending in the direction intersecting the conveyance direction of the measurement object An apparatus for calculating a shape of a plate-like object to be measured, comprising:   4. The shape measuring apparatus for a plate-like object to be measured according to claim 3, wherein the image input device is configured to be movable in a direction intersecting a conveying direction of the object to be measured above the conveying line. An apparatus for measuring the shape of a plate-like object to be measured.

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