Belt conveyor scratch detection system and method for detecting scratch

Abstract

To provide a belt conveyor scratch detection system and a scratch detection method which can detect a large scratch efficiently.SOLUTION: A belt conveyor scratch detection system 100 includes: a rotatable belt 12 that is endlessly looped around a pully; an illumination unit 50 that irradiates the belt 12 with illumination light L; an imaging unit 20 that images an imaging region SR including a direct illumination region IR irradiated with the illumination light L and an indirect illumination region near the direct illumination region IR; and a control unit 40 that can acquire an image of the imaging region SR taken by the imaging unit 20. The control unit 40 generates a determination region in the direct illumination region of the image and detects a scratch of the belt 12 in a range of the determination region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a belt conveyor damage detection system and a damage detection method. [Background technology]

[0002] Conventionally, belt conveyors have been used as a means of transporting construction generated soil. The advantage of using belt conveyors to transport construction generated soil is that a constant amount of soil can be transported at all times. However, if the belt is scratched or damaged by soil, it may become difficult for the belt conveyor to operate.

[0003] When inspecting belts for damage by human eyes, there is a risk that the accuracy of detecting damage will vary depending on the skill of the worker performing the inspection. In addition, the belts of conveyor belts used in large-scale facilities are very long, so inspecting them by human eyes is time-consuming and laborious. For this reason, a damage detection system using sensors, etc. is required.

[0004] Examples of scratch detection systems include scratch detection systems that use an imaging device such as a camera, and scratch detection systems that use an optical sensor such as a laser sensor (for example, Patent Document 1). Conventionally, scratch detection systems that use an imaging device such as a camera irradiate light onto a belt using an illumination device such as an LED light, and detect the presence or absence of scratches in the area irradiated with the light. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-45206 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, a scratch detection system that detects scratches in a light-irradiated area may not be able to accurately detect large scratches that extend beyond the light-irradiated area because the range in which scratches can be detected is limited to the light-irradiated area. In addition, in order to expand the range in which scratches can be detected, it is necessary to add more lighting devices, which may increase the area occupied by the scratch detection system and the power consumption.

[0007] In consideration of the above circumstances, an object of the present invention is to provide a belt conveyor damage detection system and a damage detection method capable of efficiently detecting large damage. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. The belt conveyor damage detection system of the present invention comprises a belt that is endlessly wound and rotatable, an illumination unit that can irradiate illumination light onto the belt, an imaging unit that can capture an image of the imaging area including a direct illumination area irradiated by the illumination light and an indirect illumination area near the direct illumination area, and a control unit that can acquire an image of the imaging area captured by the imaging unit, wherein the control unit generates a judgment area in the indirect illumination area in the image and detects scratches on the belt within the range of the judgment area.

[0009] The scratch detection method of the present invention is a scratch detection method for detecting scratches on a rotatable belt that is endlessly wound, and includes the steps of obtaining an image of a shooting area including a direct lighting area in which the belt is irradiated with illumination light and an indirect lighting area adjacent to the direct lighting area, generating a judgment area in the indirect lighting area in the image, and detecting scratches on the belt within the range of the judgment area. Effect of the Invention

[0010] According to the belt conveyor damage detection system and the damage detection method of the present invention, it is possible to provide a belt conveyor damage detection system and a damage detection method capable of efficiently detecting large damage. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of the configuration of a belt conveyor damage detection system according to an embodiment of the present invention; [Diagram 2] 10 is a diagram showing a schematic diagram of a damage detection image in the belt conveyor damage detection system. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention will be described with reference to the drawings.

[0013] Fig. 1 is a diagram showing an example of the configuration of a belt conveyor damage detection system 100 according to this embodiment. Fig. 2 is a diagram showing a schematic diagram of a damage detection image in the belt conveyor damage detection system 100.

[0014] The belt conveyor damage detection system (damage detection system) 100 includes a transport unit 10, an imaging unit 20, a reading unit 30, a control unit 40, and an illumination unit 50. The scratch detection system 100 is a transport device capable of transporting an object such as soil or sand by a transport unit 10.

[0015] 1 and 2, in this embodiment, the vertical direction in the scratch detection system 100 is defined as the "upper-lower direction B," the vertical upward direction is defined as the "upper side B1" in the vertical direction B, and the vertical downward direction is defined as the "lower side B2" in the vertical direction B. In addition, among the horizontal directions perpendicular to the vertical direction B, the direction in which the conveying unit 10 mainly conveys the transported object is defined as the "conveying direction A," the direction in which the transported object is conveyed is defined as the "downstream side A2" in the conveying direction A, and the opposite direction is defined as the "upstream side A1" in the conveying direction A. In addition, the direction perpendicular to the vertical direction B and the conveying direction A is defined as the "width direction C," one side in the width direction C is defined as the "right side C2," and the other side is defined as the "left side C1" in the width direction C.

[0016] The transport unit 10 includes a pulley 11 and a belt 12. The transport unit 10 is a belt conveyor device capable of transporting objects such as soil and sand.

[0017] The pulley 11 is substantially cylindrical in shape and has a central axis O extending in the width direction C, and is a rotating member that is rotatable about the central axis O. The pulley 11 has a first pulley 11a and a second pulley 11b.

[0018] In the pulley 11, the first pulley 11a is provided on the downstream side A2 and is rotatable about a central axis O1, while the second pulley 11b is provided on the upstream side A1 and is rotatable about a central axis O2.

[0019] The belt 12 is a wide ring-shaped member that is endlessly wound around the first pulley 11a and the second pulley 11b. The belt 12 is made of rubber or the like and has flexibility. When the pulley 11 rotates, the belt 12 rotates while wound around the first pulley 11a and the second pulley 11b due to frictional force generated between the belt 12 and the pulley 11.

[0020] 1, when the first pulley 11a and the second pulley 11b are rotated in a rotational direction R, an upper B1 portion of the belt 12 wound around the first pulley 11a and the second pulley 11b moves from the upstream side A1 to the downstream side A2. Conversely, a lower B2 portion of the belt 12 moves from the downstream side A2 to the upstream side A1.

[0021] Therefore, when an object to be transported (e.g., soil and sand) is placed on the upper side B1 of the belt 12 on the upstream side A1 of the belt 12, the object to be transported can be moved from the upstream side A1 to the downstream side A2 by rotating the first pulley 11a and the second pulley 11b in the rotational direction R.

[0022] The pulley 11 is connected to a driving device (not shown) such as an electric motor, and rotates by driving the driving device. One of the first pulley 11a and the second pulley 11b is a driving pulley that actively rotates, and the other is a driven pulley that passively rotates.

[0023] For example, the first pulley 11a is a driving pulley rotated by a driving device, and the second pulley 11b is a driven pulley. In this case, the second pulley 11b does not need to be connected to a driving device such as an electric motor.

[0024] When the first pulley 11a is rotated in a rotation direction R1 by the driving device, the belt 12 rotates due to frictional force between the first pulley 11a and the second pulley 11b. At this time, the second pulley 11b passively rotates in a rotation direction R2 due to frictional force between the second pulley 11b and the belt 12 rotated by the first pulley 11a. The second pulley 11b may be a driving pulley and the first pulley 11a may be a driven pulley. The conveying unit 10 may have three or more pulleys. The pulley 11 may rotate in the opposite direction to the rotation direction R shown in FIG. 1.

[0025] The imaging unit 20 is an imaging device such as a camera capable of capturing images of the surroundings. As shown in Fig. 1, the imaging unit 20 is provided on the downstream side A2 of the conveying unit 10, and is capable of capturing images of the end of the belt 12 on the downstream side A2. Here, the end of the belt 12 on the downstream side A2 refers to the portion of the belt 12 that is looped around the first pulley 11a in the conveying unit 10.

[0026] The scratch detection system 100 may also include a plurality of imaging units 20. The scratch detection system 100 may include any number of imaging units 20 depending on the dimension in the width direction C of the belt 12 and the performance of the imaging units 20. For example, the scratch detection system 100 may include three imaging units 20.

[0027] Here, the belt 12 has a plurality of tags T. The plurality of tags T are embedded, for example, in the side surface of the belt 12 in the width direction C. In the example shown in Fig. 1, the belt 12 has a first tag T1, a second tag T2, a third tag T3, and a fourth tag T4. The number of tags T that the belt 12 has is not limited thereto, and may be three or less, or five or more.

[0028] The reading unit 30 is provided on the downstream side A2 of the transport unit 10. The reading unit 30 is a reading device capable of contactlessly reading predetermined information from the tag T. In this embodiment, the multiple tags T have position information (address information) of the tag T with respect to the belt 12.

[0029] For example, if the first tag T1 is provided at a predetermined position (address) on the belt 12, the first tag T1 has information about the address where the first tag T1 is provided. The reading unit 30 communicates with the first tag T1 by transmitting and receiving radio waves, and acquires the address information held by the first tag T1. The multiple tags T are, for example, RFID (Radio Frequency Identification) tags capable of wireless communication with the reading unit 30. Details of the acquisition of the address information by the reading unit 30 will be described later.

[0030] The control unit 40 is connected to the imaging unit 20 and the reading unit 30 wirelessly or via a wire, and can control the imaging unit 20 and the reading unit 30. The control unit 40 can acquire images captured by the imaging unit 20. The control unit 40 can also acquire information read by the reading unit 30 (e.g., address information of the tag T).

[0031] The control unit 40 is, for example, a program executable device (computer) equipped with a processor, a memory, a storage unit, and the like. Each function of the control unit 40 is realized by, for example, one or more processors such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) executing a program stored in a program memory. However, all or part of these functions may be realized by hardware (e.g., a circuit unit; circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). In addition, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), a RAM (Random Access Memory), or the like.

[0032] The control unit 40 may be connected to the transport unit 10 and the illumination unit 50 and be capable of controlling the transport unit 10 and the illumination unit 50.

[0033] The lighting unit 50 is provided on the downstream side A2 of the transport unit 10. The lighting unit 50 is a lighting device having an LED light or the like. The lighting unit 50 can irradiate the downstream side A2 of the belt 12 with illumination light L to illuminate the end of the belt 12 on the downstream side A2.

[0034] Next, a scratch detection method in the scratch detection system 100 will be described.

[0035] When the scratch detection system 100 is activated, first, the imaging unit 20 captures an image of the end portion of the downstream side A2 of the belt 12. Hereinafter, the range of the belt 12 captured by the imaging unit 20 is referred to as an imaging region SR.

[0036] At this time, the illumination unit 50 irradiates the downstream side A2 of the belt 12 with illumination light L. Therefore, the photographing area SR of the belt 12 photographed by the imaging unit 20 includes a direct illumination area IR irradiated with the illumination light L. In addition, the area of ​​the belt 12 near the direct illumination area IR is also indirectly illuminated by the illumination light L. Hereinafter, the area of ​​the belt 12 indirectly illuminated by the illumination light L will be referred to as the indirect illumination area. The photographing area SR photographed by the imaging unit 20 includes the direct illumination area IR irradiated with the illumination light L and the indirect illumination area indirectly illuminated by the illumination light L.

[0037] In addition, when the imaging unit 20 photographs the belt 12, the reading unit 30 acquires address information from the tag T. For example, the reading unit 30 acquires address information of the tag T provided within the range of the photographed photographed area SR or in the vicinity of the photographed area SR. In the example shown in FIG. 1, the imaging unit 20 photographs the vicinity of the position where the first tag T1 is provided on the belt 12. In addition, of the multiple tags T, the first tag T1 is located in the vicinity of the reading unit 30.

[0038] Therefore, when the imaging unit 20 captures an image of the vicinity of the position where the first tag T1 is provided on the belt 12, the reading unit 30 acquires the address information of the first tag T1. Hereinafter, the address information of the first tag T1 will be referred to as the first address, the address information of the second tag as the second address, the address information of the third tag as the third address, and the address information of the fourth tag as the fourth address. The reading unit 30 can read the address information of the tag T that is closest to the reading unit 30 among the multiple tags T.

[0039] Next, the control unit 40 acquires an image of the photographing region SR photographed by the imaging unit 20 from the imaging unit 20. The control unit 40 also acquires the address information acquired by the reading unit 30. The control unit 40 associates the image acquired from the imaging unit 20 with the address information acquired from the reading unit 30. Therefore, the user can know which range of the belt 12 is captured in the image photographed by the imaging unit 20.

[0040] 1, when the pulley 11 rotates in the rotation direction R, the belt 12 rotates, and the second tag T2 moves to the vicinity of the end of the downstream side A2 of the belt 12. At this time, the first tag T1 moves to the portion B2 below the belt 12.

[0041] When the second tag T2 moves to the end of the downstream side A2 of the belt 12, the second tag T2 approaches the reading unit 30 and is disposed in the vicinity of the reading unit 30. At this time, the reading unit 30 acquires the address information (second address) held by the second tag T2.

[0042] The imaging unit 20 also captures an image of the belt 12 in the vicinity of the second tag T2 as an imaging region SR. The control unit 40 then acquires the image captured by the imaging unit 20 and the address information (here, the second address) acquired by the reading unit 30, and associates the image with the address information. Therefore, the user can recognize that the image captured by the imaging unit 20 is an image of the second address on the belt 12.

[0043] In this way, the control unit 40 acquires and links the image captured by the imaging unit 20 with the address information acquired from the tag T by the reading unit 30, thereby enabling the user to understand which range of the belt 12 the photographed area SR indicated by the image corresponds to.

[0044] In the scratch detection system 100, the transport unit 10 is not stationary but is in a state where it can rotate and transport an object to be transported. The imaging unit 20 captures images of the rotating transport unit 10 continuously or at regular intervals, and transmits the captured images to the control unit 40. The reading unit 30 also acquires address information of a tag T located in the vicinity of the reading unit 30 on the rotating transport unit 10, and transmits the acquired address information to the control unit 40.

[0045] Therefore, even when the transport unit 10 is rotating, the control unit 40 can acquire and link the image acquired from the imaging unit 20 and the address information acquired from the reading unit 30 at any time.

[0046] Next, the control unit 40 performs a flaw detection operation on the image of the photographed region SR photographed by the imaging unit 20.

[0047] The control unit 40 detects scratches on the image of the photographing region SR photographed by the imaging unit 20, and generates a scratch detection image (image) PM shown in Fig. 2. In the photographing region SR shown in the scratch detection image PM, a scratch SC occurs on the surface of the belt 12. In the photographing region SR, the direct illumination region IR is located near the center in the vertical direction B. Note that the direct illumination region IR in the scratch detection image PM is not limited to being near the center in the vertical direction B, and may be located near the end of the upper side B1 or near the end of the lower side B2.

[0048] First, the control unit 40 generates a binary image from the grayscale image (raw image) captured by the imaging unit 20. Here, the binary image refers to an image in which the colors of the scratches and the background are separated into white and black. The control unit 40 generates the binary image by making the scratches SC white and the surface of the belt 12 where the scratches SC do not occur black. The control unit 40 may also generate the binary image by making the scratches SC black and the surface of the belt 12 where the scratches SC do not occur white.

[0049] At this time, the smallest unit of an image is a pixel. The control unit 40 can calculate the area of ​​the flaw SC by calculating the number of pixels in the portion (white portion) showing the flaw SC in the image.

[0050] The control unit 40 detects the flaw SC by generating a binary image. The control unit 40 also generates a determination area JR in the image captured by the imaging unit 20, detects the flaw SC within the range of the determination area JR, and generates a flaw detection image PM shown in FIG.

[0051] The determination area JR is an area located near the direct illumination area IR, and is generated in a range (indirect illumination area) of the belt 12 that is indirectly illuminated by the illumination light L. The determination area (indirect illumination area) JR is an area that is irradiated with a smaller amount of illumination light L than the direct illumination area IR.

[0052] In the flaw detection image PM, the determination region JR has a first determination region (first indirect lighting region) JR1 located above the direct lighting region IR at B1, and a second determination region (second indirect lighting region) JR2 located below the direct lighting region IR at B2. The determination region JR is located outside the range of the direct lighting region IR.

[0053] The control unit 40 detects a flaw SC2 located within the first determination region JR1 and a flaw SC3 located within the second determination region JR2. It is preferable that the control unit 40 is also capable of detecting a flaw SC1 located within the direct illumination region IR.

[0054] The control unit 40 can detect not only the scratch SC1 located in the direct illumination area IR, but also the scratches SC2 and SC3 located above B1 and below B2 of the direct illumination area IR. Since the scratch detection system 100 can detect scratches SC located outside the range of the direct illumination area IR, it can detect larger scratches compared to conventional scratch detection systems that can only detect scratches within the direct illumination area directly irradiated with illumination light. Furthermore, since the scratch detection system 100 is not limited to the direct illumination area IR in its range of detectable scratches SC, there is no need to add an illumination device, and scratch detection can be performed efficiently.

[0055] The control unit 40 may transmit the generated scratch detection image PM to a display device (not shown) such as a display. By displaying the image PM in which the scratch SC is detected on the display device, the user can easily grasp the size of the scratch SC that has occurred on the belt 12.

[0056] Moreover, the control unit 40 preferably generates an area (address area) in the scratch detection image PM that displays the acquired address information. By the control unit 40 generating an address area in the scratch detection image PM that indicates the address information corresponding to the scratch detection image PM and displaying the scratch detection image PM having the address area on a display device, the user can check the scratch detection image PM and grasp the address (position) where the scratch SC is present in the belt 12, and can quickly carry out repair work for the scratch SC.

[0057] The belt conveyor scratch detection system 100 and the scratch detection method of this embodiment include a conveyor unit 10 having a plurality of pulleys 11 (first pulley 11a and second pulley 11b) and a belt 12 that is endlessly wound around the plurality of pulleys 11 and can rotate, a lighting unit 50 that can irradiate the belt 12 with illumination light L, an imaging unit 20 that can capture an image of the imaging area SR including a direct illumination area IR irradiated with the illumination light L and an indirect illumination area near the direct illumination area IR, and a control unit 40 that can acquire an image of the imaging area SR captured by the imaging unit 20. The control unit 40 generates a determination area JR in the indirect illumination area in the image captured by the imaging unit 20, and detects scratches SC (SC2, SC3) of the belt 12 within the range of the determination area JR.

[0058] As a result, a belt conveyor scratch detection system and scratch detection method can be provided that can detect large scratches efficiently, compared to conventional scratch detection systems that can only detect scratches within a direct illumination area that is directly illuminated by illumination light.

[0059] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like within the scope of the present invention are also included. In addition, the components shown in the above-mentioned embodiment and the modified examples shown below can be appropriately combined to form a configuration.

[0060] (Variation 1) In the above embodiment, the imaging unit 20 captures an image and transmits it to the control unit 40, but the configuration of the imaging unit and the control unit is not limited to this. The imaging unit may capture a moving image and transmit the captured moving image to the control unit. In addition, the control unit may perform binarization on a predetermined frame (image) extracted from the acquired moving image to detect scratches. [Explanation of symbols]

[0061] 100 Belt conveyor damage detection system (Damage detection system) 10 Transport section 11 Pulley 11a First pulley 11b Second pulley 12 Belt 20 Imaging unit 30 Reading unit 40 Control section 50 Lighting Department T tag T1 First Tag T2 Second Tag T3 Third Tag T4 Fourth Tag L illumination light SR shooting area IR direct illumination area PM Scratch detection image (image) JR judgment area (indirect lighting area) JR1 First judgment area (first indirect lighting area) JR2 Second judgment area (second indirect lighting area) SC scar B Vertical direction B1 upper B2 Downward A Transport direction A1 Upstream A2 downstream side C Width direction C1 left C2 right side

Claims

1. A rotatable belt that is endlessly wound around the belt; an illumination unit capable of irradiating the belt with illumination light; an imaging unit capable of imaging an imaging area including a direct illumination area irradiated with the illumination light and an indirect illumination area adjacent to the direct illumination area; A control unit capable of acquiring an image of the photographing area photographed by the imaging unit; Equipped with The control unit is generating a judgment region in the indirect lighting region in the image; detecting a scratch on the belt within the range of the determination area; Belt conveyor damage detection system.

2. The control unit is generating a first determination area, which is the determination area, above the direct illumination area; generating a second determination area below the direct illumination area, the second determination area being the determination area; detecting a flaw in the belt in the first determination area and the second determination area; 2. The belt conveyor damage detection system according to claim 1.

3. The control unit detects scratches on the belt in the direct illumination area.

3. The belt conveyor damage detection system according to claim 2.

4. Further comprising a reading unit, the belt has a plurality of tags capable of wireless communication with the reader; The reading unit acquires address information corresponding to the photographing area from the tag, The control unit is Acquire the address information from the reading unit; Linking the image with the address information; The belt conveyor damage detection system according to any one of claims 1 to 3.

5. A method for detecting a defect in a rotatable belt that is endlessly wound, comprising the steps of: acquiring an image of a photographed area including a direct illumination area where the belt is irradiated with illumination light and an indirect illumination area adjacent to the direct illumination area; generating a judgment region in the indirect lighting region in the image; detecting a flaw in the belt within the determination area; Equipped with Flaw detection methods.

6. The determination region includes a first determination region generated above the direct illumination region and a second determination region generated below the direct illumination region. The flaw detection method according to claim 5 .

7. acquiring address information corresponding to the photographing area; A step of linking the image with the address information; Further comprising: The flaw detection method according to claim 5 or 6.

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