JP7286479B2 - Length measuring device - Google Patents

Description

Embodiments of the present invention relate to length measuring devices.

Conventionally, in the rolling process of a steel plate, which is a metal sheet, the edges on both sides of the rolled long steel plate in the direction orthogonal to the conveying direction (hereinafter referred to as the width direction) are imaged from above with two cameras, A length measuring device is known that measures the length of a steel plate in the width direction by extracting the edge of the steel plate from a captured image.

In this length measuring device, the actual width direction length of the steel plate can be calculated by grasping the correspondence relationship between the pixel address of the camera (the address indicating the position of the light receiving element) and the distance to the steel plate in advance. It was configured to

In this case, the two cameras are arranged side by side in the width direction of the steel plate. In the past, when a lift occurred from the carriage, lift correction was performed.

JP 2008-128756 A

As a result of this floating correction, the length of the steel plate in the width direction contained a certain amount of error. As the distance between the camera and the edge in the width direction of the steel plate to be conveyed increases, the error that occurs in the calculated length of the steel plate in the width direction tends to increase considerably. For example, if the distance between the camera and the edge is 1200 mm, the calculated steel plate length will have an error of up to 0.7 mm.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a length measuring apparatus capable of alleviating errors in the calculated length of an object to be measured.

A length measuring device according to an embodiment includes a first image sensor arranged at a position facing a measurement surface of a plate-shaped measurement object for detecting the position of an edge on one side of the measurement surface, and measuring the thickness of the measurement object. a second image sensor arranged at a position facing the one surface shown, an imaging direction substantially orthogonal to that of the first image sensor, and detecting the position of the edge on the one side, and arranged at a position facing the measurement surface of the measurement object; a third image sensor for detecting the position of the edge of the measurement surface opposite to the one side; A fourth image sensor arranged in an imaging direction substantially orthogonal to the third image sensor for detecting the position of the edge on the opposite side; and the one side detected by the first image sensor and the second image sensor. calculating the position of the edge on the one side of the object to be measured based on the position of the edge of the measurement object, and calculating the position of the edge on the opposite side detected by the third image sensor and the fourth image sensor; a calculation unit for calculating the position of the opposite edge of the object and calculating the length of the measurement object including the one edge and the opposite edge; the first image sensor and the third image; facing the sensor, provided farther from the first image sensor and the third image sensor than the second image sensor and the fourth image sensor, and emits light toward the first image sensor and the third image sensor A first light source and a second light source provided near the second image sensor for emitting light having a wavelength different from that of light emitted from the first light source toward one surface of the measurement object indicating the thickness. and a third light source that is provided near the fourth image sensor and emits light having a wavelength different from that of the light emitted from the first light source toward the other surface of the object to be measured that indicates the thickness; wherein the first image sensor and the third image sensor transmit light emitted by the first light source and block light emitted by the second light source and light emitted by the third light source. wherein the second image sensor receives light emitted from the second light source and reflected by the object to be measured, and the fourth image sensor receives light emitted by the third light source and reflected by the object to be measured. receive light.

FIG. 1 is a diagram showing an entire length measuring device according to an embodiment. FIG. 2 is an explanatory diagram showing the arrangement relationship of the length measuring devices. FIG. 3 is an explanatory diagram for calculating the edge on one side of the steel plate. FIG. 4 is a graph showing the relationship between the distance (Wds) from the camera to the edge of the steel plate and its error (ΔWds). FIG. 5 is an explanatory diagram for calculating the edge on the other side of the steel plate. FIG. 6 is a block diagram showing the hardware configuration of the arithmetic unit. FIG. 7 is a flow chart showing the length measurement process of the steel sheet in the width direction by the calculation unit 20 .

A length measuring device according to an embodiment will be described below with reference to the drawings. The invention is not limited by this embodiment.

FIG. 1 is an explanatory diagram of an embodiment in which a length measuring device is applied to conveying a steel plate and configured as a steel plate length measuring system.

The length measuring system 10 can be broadly divided into a steel plate conveying device 11 that conveys a long steel plate 2 (measurement object) that has been flattened by a rolling device (not shown), and a steel plate that is conveyed by the steel plate conveying device 11. 2 and performs lift correction of the conveyed steel plate 2 while measuring the length;

In the steel plate conveying device 11, a plurality of conveying rollers 1 rotating in the conveying direction (arrow Y2 direction) of the steel plate 2 are arranged in parallel at regular intervals. Each conveying roller 1 is rotated in the same direction by a power source (not shown) to convey the steel plate 2 in the conveying direction.

The length measuring device 13 includes a camera 3 (first image sensor), a camera 4 (second image sensor), a camera 5 (third image sensor), a camera 6 (fourth image sensor), a first light source 7, a second A light source 8 and a third light source 9 are provided. The camera 3 is installed above the steel plate 2, that is, at a position facing the upper surface 2-1 (measurement surface) of the steel plate 2. As shown in FIG. The camera 3 is an image sensor in which light receiving elements are arranged in a row in the width direction of the steel plate 2 (direction of arrow Y1). That is, the imaging direction of the camera 3 is the width direction of the steel plate 2 (that is, the arrow Y1 direction). The camera 3 takes an image of the upper surface of the steel plate 2 in the vertical direction from above to below. The camera 3 takes an image of the upper surface 2-1 of the steel plate 2 including the right edge 2R which is one edge. The camera 3 transmits video information indicating the captured image to the calculation unit 20, which will be described later. The camera 4 is installed at a position facing the side surface 2-2 (one surface showing the thickness) of the steel plate 2 including the right edge 2R, which is one edge of the steel plate 2. As shown in FIG. The camera 4 is an image sensor in which light receiving elements are arranged in a line in the thickness direction of the steel plate 2 (that is, the vertical direction (arrow Y3 direction)). That is, the imaging direction of the camera 4 is the thickness direction of the steel plate 2 (that is, the vertical direction (arrow Y3 direction)). That is, the camera 4 is located on the side of the right edge 2R side of the steel plate 2 and below the right edge 2R (opposite to the top surface 2-1), and images the steel plate 2 including the right edge 2R. . The camera 4 transmits video information indicating the captured image to the calculation unit 20, which will be described later.

The camera 5 is installed above the steel plate 2, that is, at a position facing the upper surface 2-1 (measurement surface) of the steel plate 2. As shown in FIG. The camera 5 is an image sensor in which light receiving elements are arranged in a row in the width direction of the steel plate 2 (direction of arrow Y1). That is, the imaging direction of the camera 5 is the width direction of the steel plate 2 (that is, the arrow Y1 direction). The camera 5 images the steel plate 2 in the vertical direction from above to below. The camera 5 images the steel plate 2 including the left edge 2L, which is the edge on the other side. The camera 5 transmits video information indicating the captured image to the calculation unit 20, which will be described later. The camera 6 is installed at a position facing the side surface 2-3 (the other side indicating the thickness) of the steel plate 2 including the left edge 2L, which is the edge on the opposite side of the steel plate 2. As shown in FIG. The camera 6 is an image sensor in which light receiving elements are arranged in a line in the thickness direction (that is, the vertical direction) of the steel plate 2 . That is, the imaging direction of the camera 6 is the thickness direction of the steel plate 2 (that is, the vertical direction (arrow Y3 direction)). That is, the camera 6 is located on the side of the left edge 2L of the steel plate 2 and below the left edge 2L (opposite direction to the top surface 2-1), and the top surface 2 of the steel plate 2 including the left edge 2L. -1 is imaged. The camera 6 transmits video information indicating the captured image to the calculation unit 20, which will be described later.

The first light source 7 is arranged vertically below the steel plate conveying device 11 and below (distantly) the cameras 4 and 6 . The first light source 7 includes a light source in which light emitting elements are arranged in a row in the width direction of the steel plate 2 on the upper surface. When the light source emits light, the first light source 7 emits light vertically upward from the lower side of the steel plate 2 . Light emitted from the first light source 7 and not blocked by the steel plate 2 is received by the cameras 3 and 5 . Also, the light emitted from the first light source 7 and blocked by the steel plate 2 is not received by the cameras 3 and 5 . That is, of the light receiving elements provided in camera 3 and camera 5 , the light receiving element facing steel plate 2 does not receive the light emitted from first light source 7 . That is, the video information output from the cameras 3 and 5 is a dark level signal corresponding to the width of the steel plate 2, and falls or rises at the positions of the right edge 2R and left edge 2L of the steel plate 2. FIG.

Here, by correlating (calibrating) the pixel addresses of the light-receiving elements with the scale of the steel plate 2 in the camera 3, the arithmetic unit 20, which will be described later, can calculate the steel plate from the rising and falling addresses of the light-receiving elements. 2's right edge 2R can be calculated.

Further, by correlating (calibrating) the pixel addresses of the light receiving elements with the scale of the steel plate 2 in the camera 5, the left edge 2L of the steel plate 2 is calculated from the rising and falling addresses of the light receiving elements. be able to. The cameras 3 and 5 transmit the information received by the light receiving elements (information about which light receiving elements have received light and which light receiving elements have not received light) as video information to the calculation unit 20, which will be described later. do.

The second light source 8 is installed on the right edge 2R side of the steel plate 2 being conveyed. The second light source 8 is provided with a light source in which light emitting elements are arranged in a line in the vertical direction. The second light source 8 emits light obliquely downward toward the side surface including the right edge 2R of the steel plate 2 . Light emitted from the second light source 8 and reflected by the side surface of the steel plate 2 is received by the camera 4 . On the other hand, the light emitted from the second light source 8 and not reflected by the side surface of the steel plate 2 is not received by the camera 4 .

The third light source 9 is installed on the left edge 2L side of the steel plate 2 being conveyed. The third light source 9 includes a light source in which light emitting elements are arranged in a line in the vertical direction. The third light source 9 emits light obliquely downward toward the side surface including the left edge 2L of the steel plate 2 . Light emitted from the third light source 9 and reflected by the side surface of the steel plate 2 is received by the camera 5 . On the other hand, the light emitted from the third light source 9 and not reflected by the side surface of the steel plate 2 is not received by the camera 5 .

The wavelengths of the light emitted from the second light source 8 and the third light source 9 are shorter than the wavelength of the light emitted from the first light source. A filter (not shown) for cutting short wavelength light emitted from the second light source 8 and the third light source 9 is attached to the camera 3 and the camera 5 in front of the image sensor. By doing so, the cameras 3 and 5 receive the light emitted from the first light source 7 but do not receive the light emitted from the second light source 8 and the third light source 9 .

The calculation unit 20 is configured as a so-called computer system, and includes a computer body including a CPU, ROM, RAM, external storage devices (SSD, hard disk, etc.), a display unit, a printer, and the like. The calculation unit 20 is electrically connected to the cameras 3, 4, 5, and 6 via a communication line P. As shown in FIG. The calculation unit 20 receives video information captured by the cameras 3 , 4 , 5 and 6 . The calculation unit 20 calculates the positional information of the right edge 2R and the left edge 2L of the steel plate 2 based on the video information, and calculates the length of the steel plate 2 in the width direction based on the positional information.

FIG. 2 is an explanatory diagram showing the arrangement relationship of the length measuring device 13. As shown in FIG. 2 is a view of the length measuring device 13 of FIG. 1 as seen from the downstream side in the conveying direction. In FIG. 2, the width direction (horizontal direction in FIG. 2) is defined as the x-axis coordinate, and the vertical direction (vertical direction in FIG. 2) is defined as the y-axis coordinate, centering on the origin (0, 0). The cameras 3 and 5 are arranged at the same height from the steel plate 2 above the steel plate 2 being conveyed. The distance between camera 3 and camera 5 is L. The origin exists at a position just below the midpoint between camera 3 and camera 5 (at a distance of L/2 from camera 3 and camera 5). The steel plate 2 is conveyed in the conveying direction with the intermediate point between the camera 3 and the camera 5 positioned substantially at the center of the steel plate 2 .

The camera 3 has a calibration position at a distance a from the camera 3 in the vertical direction. The camera 5 has a calibration position at a distance a from the camera 5 in the vertical direction. That is, the calibration position of camera 3 and the calibration position of camera 5 are at the same height in the vertical direction. The origin is a calibration position that is a distance a away from the midpoint between the cameras 3 and 5 in the vertical direction. Both the calibration position of the camera 3 and the calibration position of the camera 5 are located below the conveying position of the steel plate 2 . Note that the calibration position is the position at which the image captured by the camera is recognized.

The camera 4 is positioned outside the camera 3 in the width direction by a distance Ld and above the calibration position of the camera 3 . That is, the camera 4 is arranged below the steel plate 2 .

The camera 6 is positioned outside the camera 5 in the width direction by a distance Lw and above the calibration position of the camera 5 . That is, the camera 6 is arranged below the steel plate 2 .

The length W of the steel plate 2 in the width direction is set shorter than the distance L between the cameras 3 and 5 . The camera 3 is located on the widthwise outer side (on the right side in FIG. 2) of the position of the right edge 2R of the steel plate 2 by a distance Wds. In addition, the camera 5 is positioned widthwise outside (left side in FIG. 2) from the left edge 2L of the steel plate 2 by a distance Wws.

The calibrating position of the camera 4 is set at a vertically downward position of the camera 3 . That is, the camera 3 is arranged above the calibration position of the camera 4 on the vertical line. The calibration position of the camera 4 is located Wds apart from the right edge 2R of the steel plate 2 to the outside in the width direction.

Further, the calibration position of the camera 6 is set at a position vertically below the camera 5 . That is, the camera 5 is arranged above the calibration position of the camera 6 on the vertical line. The calibration position of the camera 6 is positioned Wws away from the left edge 2L of the steel plate 2 to the outside in the width direction.

Light emitted upward from the first light source 7 is received by the camera 3 or the camera 5 . Of the light emitted from the first light source 7, the camera 3 receives the light outside the light KR that has passed through the right edge 2R. In addition, the camera 5 receives the light outside the light KL that has passed through the left edge 2L, out of the light emitted from the first light source 7 . However, of the light emitted from the first light source 7 , the light inside the light KR and the light KL is blocked by the steel plate 2 and is not received by the camera 3 or the camera 5 .

The camera 4 receives the light SR reflected by the right edge 2R of the steel plate 2 among the light emitted obliquely downward from the second light source 8 . However, of the light emitted from the second light source 8 , the light that passes outside the right edge 2 R of the steel plate 2 (upper side in FIG. 2 ) is not reflected by the steel plate 2 and is not received by the camera 4 . In this case, the right edge 2R is located on the upper surface of the steel plate 2. As shown in FIG.

The camera 6 receives the light SL reflected by the left edge 2L of the steel plate 2 among the light emitted obliquely downward from the third light source 9 . However, of the light emitted from the third light source 9 , the light that passes outside the left edge 2 L of the steel plate 2 (upper side in FIG. 2 ) is not reflected by the steel plate 2 and is not received by the camera 6 . In this case, the left edge 2L is located on the upper surface of the steel plate 2. As shown in FIG.

Note that the steel plate 2 emits natural light (self-luminescence) by itself when it is at a high temperature. When the steel plate 2 emits light by itself, the cameras 3, 4, 5, and 6 can receive self-light from the steel plate 2 without the first light source 7, the second light source 8, and the third light source 9. , video information similar to the video information associated with receiving the light emitted by the first light source 7 , the second light source 8 , and the third light source 9 can be transmitted to the calculation unit 20 .

Next, the process of calculating the coordinates of the right edge 2R by the calculation unit 20 based on the video information accompanying the imaging by the cameras 3 and 4 will be described. FIG. 3 is an explanatory diagram for calculating the right edge 2R of the steel plate 2. FIG.

First, the position Pd of the camera 3 is the distance L/2 from the origin in the x-axis direction and the distance a in the y-axis direction from the origin, so the coordinate position of the camera 3 is Pd (L/2, a). Further, the camera 3 measures the right edge 2R of the steel plate 2 at the camera 3 calibration position Qd. The calibration position Qd of the camera 3 is Qd(L/2-Wdc, 0). Since the position Rd of the camera 4 is located on the x-axis separated by the distance L/2+Ld in the x-axis direction, the coordinate position of the camera 4 is Rd(L/2+Ld, 0). Also, the camera 4 measures the right edge 2R of the steel plate 2 at the calibration position Sd of the camera 4 . The calibration position Sd of the camera 4 is Sd(L/2, hd). Coordinates Ed (xd, yd ), let Xd be the distance on the x coordinate from the origin to the coordinate xd, and let Yd be the distance on the y coordinate from the origin to the coordinate yd.
(Number 1)
Yd−a=(Xd−L/2)·a/Wdc (1)
(Number 2)
Yd=(Xd−L/2−Ld)·hd/Ld (2)
becomes. Substituting equation (1) into equation (2), we get
(Number 3)
(Xd−L/2−Ld)·hd/Ld−a=(Xd−L/2)·a/Wdc (3)
becomes. Solving equation (3) for Xd, we get
(Number 4)
Xd=[(L/2+Ld)·hd/Ld+a−L/2·a/Wdc]/(hd/Ld−a/Wdc) (4)
becomes. The position of the distance Xd in the x-axis direction from the origin is the x-coordinate (xd) of the coordinates Ed (xd, yd). The distance Yd is obtained by substituting Xd obtained by the expression (4) into the expression (1) or (2). The position of the distance Yd in the y-axis direction from the origin is the y-coordinate (yd) of the coordinates Ed (xd, yd). Then, since Xd=L/2-Wds, substituting into equation (4) yields
(Number 5)
L/2-Wds=[(L/2+Ld).hd/Ld+a-L/2.a/Wdc]/(hd/Ld-a/Wdc) (5)
becomes. Solving this equation for Wds yields
(Number 6)
Wds=L/2-[(L/2+Ld).hd/Ld+a-L/2.a/Wdc]/(hd/Ld-a/Wdc) (6)
becomes. By the way, in equation (6), when Wdc contains error ΔWdc and hd contains error Δhd, expressing ΔWds, which is the error of Wds, is as follows:
(Number 7)
Wds+ΔWds=L/2−[(L/2+Ld)・(hd+Δhd)/Ld+a−L/2・a/(Wdc+ΔWdc)]/[hd/Ld−a/(Wdc+ΔWdc)] (7)
becomes. Solving this equation for ΔWds yields
(Number 8)
ΔWds=L/2−[(L/2+Ld)・(hd+Δhd)/Ld+a−L/2・a/(Wdc+ΔWdc)]/[hd/Ld−a/(Wdc+ΔWdc)]−Wds (8)
becomes. FIG. 4 shows the relationship between Wds and ΔWds when the errors ΔWdc and Δhd are used as parameters for this equation (8).

FIG. 4 is a graph showing the relationship between the distance (Wds) from the camera 3 to the right edge 2R of the steel plate 2 and the error (ΔWds) included in the distance (Wds). In this graph, for example, when ΔWdc and Δhd have an error of ±0.1 mm, and the distance between the camera 3 and the right edge 2R is 1200 mm, the error ΔWds is ±0.24 mm. That is, even if the distance (Wds) from the camera 3 to the right edge 2R of the steel plate 2 increases, the error ΔWds can be mitigated (reduced).

From now on, the process of calculating the coordinates of the left edge 2L by the calculation unit 20 based on the video information accompanying the imaging by the cameras 5 and 6 will be described. FIG. 5 is an explanatory diagram for calculating the left edge 2L of the steel plate 2. FIG.

First, the position Pw of the camera 5 is the coordinate position Pw (- L/2, a). Further, the camera 5 measures the left edge 2L of the steel plate 2 at the camera 5 calibration position Qw. The calibration position Qw of the camera 5 is Qw(-L/2+Wwc, 0). In addition, since the position Rw of the camera 6 is located on the x-axis separated by the distance L/2+Lw in the x-axis direction, the coordinate position Rw of the camera 6 is Rw (-L/2-Lw, 0). . Further, the camera 6 measures the right edge 2R of the steel plate 2 at the calibration position Sw of the camera 6 . The calibration position Sw of the camera 6 is Sw(-L/2, hw). Coordinates Ew (xw, yw ), let Xw be the distance on the x coordinate from the origin to the coordinate xw, and let Yw be the distance on the y coordinate from the origin to the coordinate yw.
(Number 9)
Yw−a=(Xw−L/2)·a/Wwc (9)
(Number 10)
Yw=(Xw−L/2−Lw)·hw/Lw (10)
becomes. Substituting equation (9) into equation (10), we get
(Number 11)
(Xw-L/2-Lw) hw/Lw-a=(Xw-L/2) a/Wwc (11)
becomes. Solving equation (11) for Xw, we get
(Number 12)
Xw=[(L/2+Lw)·hw/Lw+a−L/2·a/Wwc]/(hw/Lw−a/Wwc) (12)
becomes. The position of the distance Xw in the x-axis direction from the origin is the x-coordinate (xw) of the coordinates Ew (xw, yw). The distance Yw is obtained by substituting Xw obtained by the expression (12) into the expression (9) or (10). The position of the distance Yw in the y-axis direction from the origin is the y coordinate (yw) of the coordinate Ew (xw, yw). Then, since Xw=L/2-Wws, substituting into equation (12) yields
(Number 13)
L/2−Wws=[(L/2+Lw)·hw/Lw+a−L/2·a/Wwc]/(hw/Lw−a/Wwc) (13)
becomes. Solving this equation for Wws yields
(number 14)
Wws=L/2−[(L/2+Lw)·hw/Lw+a−L/2·a/Wwc]/(hw/Lw−a/Wwc) (14)
becomes. By the way, in equation (14), when Wwc contains an error ΔWwc and hw contains an error Δhw, expressing ΔWws, which is an error of Wws, is
(Number 15)
Wws+ΔWws=L/2−[(L/2+Lw)·(hw+Δhw)/Lw+a−L/2·a/(Wwc+ΔWwc)]/[hw/Lw−a/(Wwc+ΔWwc)] (15)
becomes. Solving this equation for ΔWws yields
(Number 16)
ΔWws=L/2−[(L/2+Lw)・(hw+Δhw)/Lw+a−L/2・a/(Wwc+ΔWwc)]/[hw/Lw−a/(Wwc+ΔWwc)]−Wws (16)
becomes. Regarding this formula (16), the relationship between Wws and ΔWws when the errors ΔWwc and Δhw are parameters is the same as the relationship between Wds and ΔWds shown in FIG. Even if the distance (Wws) to the point increases, the error ΔWws can be mitigated (reduced).

In addition, the length of the steel plate 2 in the width direction is W=Xd+Xw. Then, when Xd=Xw (that is, when Xd=Xw=W/2), the length values obtained by Equations (9) to (16) are the same as Equations (1) to (8). (1) to (8) (that is, the values of Equations (9) to (16) can be determined by Equations (1) to (8)). Then, the error ΔWds=ΔWws. Therefore, the error with respect to the length W of the steel plate 2 in the width direction is ΔWds+ΔWws=2ΔWds.

From here, the hardware of the calculation unit 20 will be described. FIG. 6 is a block diagram showing the hardware configuration of the computing unit 20. As shown in FIG. As shown in FIG. 6, the computing section 20 includes a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, a memory section 24, and the like. The CPU 21 is the main control entity. The ROM 22 stores various programs. The RAM 23 develops programs and various data. The memory unit 24 stores various programs. The CPU 21 , ROM 22 , RAM 23 and memory section 24 are connected to each other via a bus 25 . The CPU 21 , ROM 22 and RAM 23 constitute a control section 200 . That is, the control unit 200 executes the control processing of the calculation unit 20 described later by the CPU 21 operating according to the control program stored in the ROM 22 and the memory unit 24 and developed in the RAM 23 .

The RAM 23 includes a camera 3 information section 231 , a camera 4 information section 232 , a camera 5 information section 233 and a camera 6 information section 234 . The camera 3 information unit 231 stores video information received from the camera 3 based on light received by the camera 3 . The camera 4 information section 232 stores video information received from the camera 4 based on the light received by the camera 4 . The camera 5 information section 233 stores video information received from the camera 5 based on the light received by the camera 5 . Camera 6 information unit 234 stores video information received from camera 6 based on the light received by camera 6 .

The memory unit 24 is composed of a HDD (Hard Disc Drive), a flash memory, or the like, and maintains stored contents even when the power is turned off. The memory unit 24 has a control program unit 241 . A control program unit 241 stores a control program for controlling the arithmetic unit 20 .

The control unit 200 connects the operation unit 27 and the display unit 28 via the bus 25 and the controller 26 . The operation unit 27 is a keyboard. The display unit 28 displays information to the person who operates the calculation unit 20 .

Also, the control unit 200 is connected to a communication interface (I/F) 29 via a bus 25 . Communication interface 29 is connected to camera 3, camera 4, camera 5, and camera 6 via communication line P. FIG. Communication interface 29 receives video information received from cameras 3 , 4 , 5 and 6 .

Next, the control of the widthwise length calculation process of the steel plate 2 by the calculation unit 20 will be described. FIG. 7 is a flow chart showing the length measurement process of the steel sheet in the width direction by the calculation unit 20 . As shown in FIG. 7, the control unit 200 of the calculation unit 20 receives from the camera 3, the camera 4, the camera 5, and the camera 6, video information accompanying images captured by each camera (that is, video information based on light information) is received via the communication line P (S11).

Next, the control section 200 stores the video information received from each camera in the RAM 23 (S12). That is, the control section 200 stores the video information received from the camera 3 in the camera 3 information section 231 . Also, the control unit 200 stores the video information received from the camera 4 in the camera 4 information unit 232 . Also, the control unit 200 stores the video information received from the camera 5 in the camera 5 information unit 233 . Also, the control unit 200 stores the video information received from the camera 6 in the camera 6 information unit 234 .

Next, the control unit 200 calculates the xy coordinate position of the edge of the steel plate 2 based on the video information stored in the RAM 23 (S13). Specifically, based on the video information acquired from the camera 3 stored in the camera 3 information unit 231 and the video information acquired from the camera 4 stored in the camera 4 information unit 232, the control unit 200 The coordinates Ed (xd, yd) of the right edge 2R of the steel plate 2 are calculated using the above formulas (1) to (8). Further, the control unit 200 uses the above formula ( 9) Calculate the coordinates Ew (xw, yw) of the left edge 2L of the steel plate 2 using Equation (16). At that time, the error ΔWds included in the distance Wds used when calculating the coordinate xd and the error ΔWws included in the distance Wws used when calculating the coordinate xw are mitigated (the error is small). . Therefore, more accurate coordinates xd and xw can be calculated.

Next, the control unit 200 calculates the length of the steel plate 2 in the width direction based on the calculated coordinates Ed (xd, yd) and Ew (xw, yw) (S14). That is, the control unit 200 calculates the length of the steel plate 2 in the width direction by calculating the distance between the coordinate xd and the coordinate xw on the x-axis. Then, the control unit 200 ends the processing.

The length measuring device of such an embodiment detects the position of the right edge 2R on one side in the width direction of the plate-shaped steel plate 2 by means of an image sensor in which light receiving elements are arranged in a row in the width direction of the plate-like steel plate 2. A camera 4 for detecting the position of the right edge 2R of the steel plate 2 by means of a camera 3 and an image sensor in which light receiving elements are arranged in a row in the thickness direction of one side surface of the steel plate 2, and receiving light in the width direction of the steel plate 2. A camera 5 for detecting the position of the left edge 2L on the other side in the width direction of the steel plate 2 by an image sensor in which the elements are arranged in a row, and a light receiving element arranged in a row in the thickness direction of the side surface on the other side of the steel plate 2. The position of the right edge 2R of the steel plate 2 is calculated based on the positions of the right edge 2R detected by the camera 6 that detects the position of the left edge 2L of the steel plate 2 and the cameras 3 and 4 using the image sensor. , a calculation unit that calculates the position of the left edge 2L of the steel plate 2 based on the position of the left edge 2L detected by the cameras 5 and 6, and calculates the length of the steel plate 2 in the width direction. Therefore, it is possible to reduce the error when calculating the length of the steel plate 2 in the width direction.

A program to be executed by the length measuring system 10 (computing unit 20) of the present embodiment is a file in an installable format or an executable format and stored in a semiconductor memory device such as a CD-ROM, a USB memory, or a DVD (Digital Versatile Disk). ) or other computer-readable recording medium.

Alternatively, the program executed by the length measuring system 10 of this embodiment may be stored in a computer connected to a network such as the Internet, and may be provided by being downloaded via the network. Also, the program executed by the length measuring system 10 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

Further, the program of the length measuring system 10 of the present embodiment may be configured to be pre-installed in a ROM or the like and provided.

Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and its equivalents.

REFERENCE SIGNS LIST 1 transport roller 2 steel plate 2L left edge 2R right edge 3 camera (first image sensor)
4 Camera (second image sensor)
5 Camera (third image sensor)
6 Camera (4th image sensor)
7 first light source 8 second light source 9 third light source 10 measurement system 11 steel plate conveying device 13 measuring device 20 arithmetic unit 200 control unit 241 control program unit P communication line

Claims (5)

a first image sensor arranged at a position facing a measurement surface of a plate-shaped measurement object and detecting a position of an edge on one side of the measurement surface;
a second image sensor arranged at a position facing one surface showing the thickness of the object to be measured, having an imaging direction substantially orthogonal to the first image sensor, and detecting the position of the edge on the one side;
a third image sensor arranged at a position facing the measurement surface of the measurement object and detecting a position of an edge of the measurement surface opposite to the one side;
It is arranged at a position facing the other surface indicating the thickness opposite to the one surface indicating the thickness of the object to be measured, the imaging direction is substantially orthogonal to the third image sensor, and the position of the edge on the opposite side is detected. a fourth image sensor;
calculating the position of the one-side edge of the object to be measured based on the position of the one-side edge detected by the first image sensor and the second image sensor; calculating the position of the opposite edge of the object to be measured based on the position of the opposite edge detected by an image sensor, and calculating the length of the object to be measured including the one edge and the opposite edge; a calculation unit that calculates the
facing the first image sensor and the third image sensor and provided farther from the first image sensor and the third image sensor than the second image sensor and the fourth image sensor; a first light source that emits light toward the third image sensor;
a second light source that is provided near the second image sensor and emits light having a wavelength different from that of the light emitted from the first light source toward one surface of the object to be measured that indicates the thickness;
a third light source that is provided near the fourth image sensor and emits light having a wavelength different from that of the light emitted from the first light source toward the other surface showing the thickness of the object to be measured;
with
The first image sensor and the third image sensor include a filter that transmits light emitted by the first light source and blocks light emitted by the second light source and light emitted by the third light source, The second image sensor receives light emitted from the second light source and reflected by the measurement target, and the fourth image sensor receives light emitted from the third light source and reflected by the measurement target.
Length measuring device. The calculation unit calculates an intersection of a straight line connecting the position of the edge on the one side and the position of the first image sensor and a straight line connecting the position of the edge on the one side and the position of the second image sensor. to calculate the position of the edge on the one side, and a straight line connecting the position of the edge on the opposite side and the position of the third image sensor, and the position of the edge on the opposite side and the position of the fourth image sensor. Calculate the position of the opposite edge by calculating the intersection of the connecting straight lines;
A length measuring device according to claim 1. The angle of the second light source is adjusted so that the light emitted from the second light source is not received by the fourth image sensor, and the light emitted from the third light source is not received by the second image sensor. Adjusting the angle of the third light source,
The length measuring device according to claim 1 or 2 . The first image sensor, the second image sensor, the third image sensor, and the fourth image sensor receive self-luminescence emitted by the high-temperature measuring object.
4. Length measuring device according to any one of claims 1 to 3 . The position of the edge on one side and the edge on the opposite side are formed on the measurement surface of the object to be measured. The fourth image sensor is arranged on the side opposite to the measurement surface, and the fourth image sensor is arranged on the side opposite to the measurement surface of the object to be measured from the position of the opposite edge.
A length measuring device according to claim 4 .

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