JP2018091693A - Cylindrical surface inspection device and cylindrical surface inspection method - Google Patents

Abstract

The present invention provides a cylindrical surface inspection device and a cylindrical surface inspection method that can improve the detection accuracy of wrinkles generated in the axial direction of a cylinder in a label wrapped around the cylindrical surface of a cylindrical product. [Solution] The cylindrical surface inspection device includes: an illumination device that irradiates light to the cylindrical surface of a cylindrical product that rotates with the cylindrical shaft as the rotation axis so as to generate a bright line in the direction of the cylinder axis; and a cylindrical surface that rotates with the cylindrical shaft as the rotation axis. An imaging device that sequentially images a part of the cylindrical surface of a cylindrical product and images the entire circumference of the cylindrical surface, and multiple bright lines included in the cylindrical surface image obtained by combining the sequentially captured images of the cylindrical surface. A calculation unit that calculates the respective widths of the lines, and a calculation unit that determines where the labels wrapped around the cylindrical product are attached and where wrinkles have occurred in the direction of the cylinder axis based on changes in the width of the bright line over time. and a notification section that notifies that a defect exists on the cylindrical surface when a location where wrinkles are generated in the axial direction of the cylinder is determined. [Selection diagram] Figure 3

Description

  This case relates to a cylindrical surface inspection apparatus and a cylindrical surface inspection method.

  Inspection to detect the paper sheet formed on the paper using a plurality of imaging data where the location where the light is irradiated to the paper is picked up by a plurality of cameras and the brightness of the location is different due to the difference in shooting angle A technique is disclosed (for example, see Patent Document 1).

JP-A-2005-214734

  However, in the method disclosed in Patent Document 1, a normal bonding portion of a label wound around a cylindrical surface of a cylindrical product is mistakenly recognized as a defect (label wrinkle) generated in the cylindrical axis direction of the label, and a normal product is obtained. Nevertheless, it may be determined as a defective product.

  The present invention has been made in view of the above problems, and in a label wound around a cylindrical surface of a cylindrical product, a cylindrical surface inspection device and a cylindrical surface inspection capable of improving the detection accuracy of wrinkles generated in the cylindrical axis direction. It aims to provide a method.

  In one aspect, a cylindrical surface inspection device includes an illumination device that irradiates light so that a bright line is generated in a cylindrical axis direction on a cylindrical surface of a cylindrical product that rotates with a cylindrical axis as a rotation axis, and the bright line is included in an imaging range. An imaging device that sequentially images a part of the cylindrical surface of the cylindrical product that rotates with the cylindrical axis as a rotation axis, and sequentially captures a part of the cylindrical surface. For each of a plurality of bright lines included in a cylindrical surface image obtained by synthesizing the captured images, a calculation unit that calculates the width in the rotation direction of the cylindrical product, and the cylinder based on the temporal change of the width of the bright line A discriminating section for discriminating between a pasting portion of a label wound so as to cover the cylindrical surface of the product and a portion where wrinkles are generated in the cylindrical axis direction in the label, and wrinkles are generated in the cylindrical axis direction. Have If the position is determined, and a notification unit for notifying that there is a defect in the cylindrical surface.

  In one aspect, the cylindrical surface inspection method irradiates light so that a bright line is generated in the cylindrical axis direction on a cylindrical surface of a cylindrical product rotating with the cylindrical axis as a rotation axis, and the bright line is included in the imaging range. With this imaging device, a part of the cylindrical surface of the cylindrical product rotating around the cylindrical axis as a rotation axis is sequentially imaged, the entire circumference of the cylindrical surface is imaged, and a part of the cylindrical surface is sequentially imaged. For each of the plurality of bright lines included in the cylindrical surface image obtained by synthesizing the images, the width in the rotation direction of the cylindrical product is calculated, and the cylindrical surface of the cylindrical product is calculated based on the change over time of the width of the bright line. And a portion where wrinkles are generated in the cylindrical axis direction in the label, and a portion where wrinkles are generated in the cylindrical axis direction is determined. ,Previous Notifying that a defect exists in the cylindrical surface.

  In the label wound around the cylindrical surface of the cylindrical product, the detection accuracy of wrinkles generated in the cylindrical axis direction can be improved.

Fig.1 (a) and FIG.1 (b) are the figures for demonstrating the wrinkle which arises in the label of a cylindrical product. Fig.2 (a) and FIG.2 (b) are the figures for demonstrating the bonding location of the label of a cylindrical product. 3A is a top view of the cylindrical surface inspection apparatus, and FIG. 3B is a front view of the cylindrical surface inspection apparatus. FIG. 4A is a block diagram for explaining the hardware configuration of the control device, and FIG. 4B is a functional block diagram of the control device. FIG. 5A is a diagram illustrating an example of a cylindrical surface image synthesized by the synthesis unit, and FIG. 5B is a diagram illustrating an example of time-series data of the thickness of the bright line. FIG. 6A to FIG. 6D are diagrams showing the change with time of the thickness of the bright line at the portion where the vertical wrinkle is generated. Fig.7 (a)-FIG.7 (d) are figures which show the time-dependent change of the thickness of the bright line in the bonding location of a label. It is an example of the flowchart performed when a cylindrical surface inspection apparatus test | inspects a cylindrical product. FIG. 9A and FIG. 9B are diagrams illustrating examples of cylindrical surface images.

  Prior to the description of the embodiment, the wrinkles generated on the label of the cylindrical product and the bonding location of the label of the cylindrical product will be described with reference to FIGS. 1 (a) to 2 (b). 1 (a) and 2 (b) are side views of the cylindrical product, and FIGS. 1 (b) and 2 (b) are respectively A-A in FIGS. 1 (a) and 2 (b). It is sectional drawing.

  In the cylindrical product 70, when the label 71 is wound around the cylindrical surface of the cylindrical product main body 72, a stress is generated in a direction different from the winding direction of the label 71 for some reason, and the label 71 has convex and streak defects (wrinkles). ) May occur. For example, as shown in FIGS. 1A and 1B, a defect having a length L in the cylinder axis direction of 10 mm or more, a width W in the cylinder surface direction of 0.3 mm or more, and a height H of 30 μm or more. Wrinkles. In the following description, as shown in FIG. 1A, wrinkles generated in the cylindrical axis direction of the label 71 are referred to as “vertical wrinkles”.

  When light is applied to the cylindrical surface of the cylindrical product 70, the way in which the light irradiated onto the cylindrical surface is reflected differs between the portion where the vertical wrinkle is generated and the portion where the vertical wrinkle is generated. The width of the bright line generated on the surface changes. Therefore, it is conceivable to detect vertical wrinkles using the characteristic that the bright line width changes.

  However, since the manner in which the light irradiated onto the cylindrical surface is reflected also changes at the location where both ends of the label 71 wound around the product main body 72 overlap (the location where the label 71 is bonded: see FIG. 2B), the cylindrical surface changes. The width of the bright line generated on the surface changes. Therefore, if it is attempted to detect vertical wrinkles simply by using the characteristic that the bright line width changes, there is a possibility that the pasted portion of the label 71 shown in FIG. 2B is erroneously detected as vertical wrinkles. In the following embodiments, a cylindrical surface inspection apparatus and a cylindrical surface inspection method that can determine a position where vertical wrinkles are generated and a bonding position of the label 71 and improve the accuracy of detecting vertical wrinkles will be described.

  FIG. 3A and FIG. 3B are diagrams illustrating the overall configuration of the cylindrical surface inspection apparatus 100 according to the embodiment. FIG. 3A is a top view of the cylindrical surface inspection apparatus 100. FIG. 3B is a front view when the cylindrical surface inspection apparatus 100 is viewed from the direction of the arrow A in FIG.

  As illustrated in FIG. 3A, the cylindrical surface inspection device 100 includes a fixing unit 10, a rotation device 20, an illumination device 30, an imaging device 50, a control device 60, and the like. Any one bottom surface of the cylindrical product 70 to be inspected is fixed to the fixing portion 10. When a metal product is used as the cylindrical product 70, a magnet or the like can be used as the fixed portion 10. The cylindrical product 70 is not particularly limited as long as it is cylindrical. In the present embodiment, the cylindrical product 70 is a dry battery as an example.

  The rotating device 20 is a motor or the like, and rotates the fixing unit 10 in accordance with an instruction from the control device 60. Thereby, the cylindrical product 70 rotates about the cylindrical axis as a rotation axis.

  The illumination device 30 is disposed, for example, obliquely above the cylindrical product 70, and irradiates the cylindrical surface with light so that a bright line is generated in the cylindrical axis direction on the cylindrical surface of the cylindrical product 70.

  The imaging device 50 is disposed at a position where the bright line generated on the cylindrical surface by the illumination by the illumination device 30 can be imaged. That is, the imaging device 50 is arranged so that the bright line is included in the imaging range of the imaging device 50. The imaging device 50 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) camera, a CCD (Charge Coupled Device) camera, or the like. The imaging device 50 sequentially images a part of the cylindrical surface of the cylindrical product 70 sequentially from above according to the instruction of the control device 60, and images the entire circumference of the cylindrical surface.

  The image obtained by the imaging device 50 is sent to the control device 60. The control device 60 combines a plurality of images obtained by the imaging device 50, and inspects the label 71 of the cylindrical product 70 using the obtained composite image.

  FIG. 4A is a block diagram for explaining the hardware configuration of the control device 60. As illustrated in FIG. 4A, the control device 60 includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a storage device 103, an interface 104, and the like. Each of these devices is connected by a bus or the like. The CPU 101 is a central processing unit. The CPU 101 includes one or more cores. The RAM 102 is a volatile memory that temporarily stores programs executed by the CPU 101, data processed by the CPU 101, and the like. The storage device 103 is a nonvolatile storage device. As the storage device 103, for example, a ROM (Read Only Memory), a solid state drive (SSD) such as a flash memory, a hard disk driven by a hard disk drive, or the like can be used.

  FIG. 4B is a functional block diagram of the control device 60. When the CPU 101 executes the program stored in the storage device 103, as illustrated in FIG. 4B, in the control device 60, the storage unit 61, the synthesis unit 62, the calculation unit 63, the determination unit 65, and A notification unit 67 and the like are realized. Note that each unit of the control device 60 may be hardware such as a dedicated circuit.

  The storage unit 61 receives images (frames) sequentially acquired at a predetermined imaging interval (for example, 45 fps (frame per second) when imaging an AA battery that rotates once per second), and the cylindrical product The number of images corresponding to the entire circumference of 70 cylindrical surfaces is stored in association with the time data. If the imaging interval of the imaging device 50 when imaging an AA battery that rotates once per second is 45 fps, 45 images are stored in the storage unit 61 as images corresponding to the entire circumference of the cylindrical surface.

  The synthesizing unit 62 synthesizes the images of the entire circumference of the cylindrical surface of the cylindrical product 70 (hereinafter referred to as a cylindrical surface image) by joining the images stored in the storage unit 61 in time series. FIG. 5A shows an example of a cylindrical surface image of the cylindrical product 70 synthesized by the synthesis unit 62. In FIG. 5A, a solid line represents a bright line. A dotted line represents the boundary of the image. As shown in FIG. 5A, the cylindrical surface image of the cylindrical product 70 includes a plurality of bright lines.

  Returning to FIG. 4B, the calculating unit 63 records the thicknesses of the plurality of bright lines included in the cylindrical surface image of the cylindrical product 70 synthesized by the synthesizing unit 62 in order of time. Create series data. More specifically, the calculation unit 63 calculates the width of the bright line for each of the plurality of bright lines included in the cylindrical surface image. The width of the bright line is represented by, for example, the number of pixels (pixels). Then, the calculation unit 63 classifies the thickness of the bright line as “thick” when the width of the bright line is equal to or greater than a predetermined threshold, and sets the thickness of the bright line as “thin” when the width of the bright line is less than the predetermined threshold. Classify. Note that the predetermined threshold value may be appropriately determined based on the number of pixels of the image captured by the imaging device 50. Thereafter, the calculation unit 63 creates time-series data in which the thickness of the bright line is recorded in time order. FIG. 5B shows an example of time-series data of the thickness of the bright line created by the calculation unit 63 based on the composite image in FIG. As shown in FIG. 5B, the time series data of the bright line thickness records the bright line thickness along the time series.

  Returning to FIG. 4B, the determination unit 65 determines the bonding location of the label 71 and the location where the vertical wrinkle is generated based on the change over time of the thickness of the bright line recorded by the calculation unit 63. To do.

  Here, the principle of discriminating between the location where the label 71 is bonded and the location where the vertical wrinkles are generated in the present embodiment will be described with reference to FIGS. 6A to 6D and FIGS. 7 (d) is used for explanation. 6 (a) to 6 (d) are diagrams showing the change over time in the thickness of the bright line at the portion where the vertical wrinkles are generated, and the upper diagram shows a cross section of the cylindrical product 70, and The figure shows the side of the cylindrical product 70. FIG. 7A to FIG. 7D are diagrams showing the change over time of the thickness of the bright line at the location where the label 71 is bonded. The upper diagram shows a cross section of the cylindrical product 70, and the lower diagram is a cylinder. A side view of the product 70 is shown. In the lower diagrams of FIGS. 6A to 7D, white portions that are not hatched represent bright lines.

  As shown in FIG. 6A, the thickness of the bright line generated on the circumferential surface of the cylindrical product 70 by the light IL irradiated from the illumination device 30 is thin on a normal cylindrical surface.

  Here, as shown in FIG. 6B, when the cylindrical product 70 is rotated, the light IL is irradiated onto one inclined surface of the vertical wrinkle 73 (left side of the apex of the vertical wrinkle 73 on the paper surface). The reflected light diffuses and the bright line becomes thicker.

  Thereafter, the vertex of the vertical wrinkle 73 is moved by the rotation of the cylindrical product 70, and when the light IL is irradiated to the vertex of the vertical wrinkle 73 as shown in FIG. 6C, the thickness of the bright line is reduced again. Then, as shown in FIG. 6D, when the cylindrical product 70 is rotated, the other slope of the vertical wrinkle 73 (right side of the top of the vertical wrinkle 73 on the paper surface) is irradiated with the light IL. The reflected light diffuses again and the bright line becomes thicker. In this way, at the portion where the vertical wrinkle 73 is generated, the thickness of the bright line changes from “thick” → “thin” → “thick”.

  On the other hand, as shown in FIG. 7B, when the light IL is applied to the slope of the label 71 bonding portion (left side of the end portion 71 a of the label 71 on the paper surface) as shown in FIG. The reflected light of the light IL diffuses and the thickness of the bright line increases. Thereafter, the position of the end 71a is moved by the rotation of the cylindrical product 70, and as shown in FIG. 7C, when the light IL is applied to the end 71a, the thickness of the bright line becomes thinner again. Thereafter, the light IL is applied to the cylindrical surface of the cylindrical product 70 by the rotation of the cylindrical product 70. If vertical wrinkles are not generated, the bright line remains thin as shown in FIG. is there. Therefore, in the case where the label 71 is pasted, the thickness of the bright line changes from “thick” → “thin” → “thin”.

  From the above, the determination unit 65 can determine the location where the vertical wrinkle is generated and the location where the label 71 is pasted by the change in the thickness of the bright line over time. More specifically, when the thickness of the bright line changes from “thick” → “thin” → “thick”, the determination unit 65 determines that the vertical wrinkle is generated, and the bright line When the thickness of the label changes from “thick” → “thin” → “thin”, it is determined that the label 71 is to be attached.

  Returning to FIG. 4B, the notification unit 67 notifies the occurrence of vertical wrinkles (the presence of a defect on the cylindrical surface) when the determination unit 65 determines the location where the vertical wrinkles are generated. . For example, the notification unit 67 displays a message or symbol for notifying the occurrence of vertical wrinkles on a liquid crystal display or a printer connected to the control device 60. The notification unit 67 may output a warning sound for notifying occurrence of vertical wrinkles from a sound output device such as a speaker. Alternatively, the notification unit 67 may transmit an e-mail notifying the person in charge of the inspection of the occurrence of vertical wrinkles.

  FIG. 8 is an example of a flowchart executed when the cylindrical surface inspection apparatus 100 inspects the cylindrical product 70.

  As illustrated in FIG. 8, the storage unit 61 receives images sequentially acquired by the imaging device 50, and associates the number of images corresponding to the entire circumference of the cylindrical surface of the cylindrical product 70 (for example, 45) with time data. Save (step S11).

  Next, the synthesizing unit 62 synthesizes the cylindrical surface image of the cylindrical product 70 by joining the images stored in the storage unit 61 in time series (step S13).

  Next, the calculation unit 63 creates time-series data in which the thicknesses (thick and thin) of the plurality of bright lines included in the cylindrical surface image are recorded in order of time (step S15).

  Next, the determination unit 65 acquires one of the earliest time data from the time-series data of the thickness of the bright line (step S17).

  Next, the determination unit 65 determines whether or not the thickness of the acquired bright line is “thick” (step S19). When the thickness of the bright line is “thin” (step S19 / NO), the determination unit 65 determines whether or not all data included in the time-series data of the bright line thickness has been processed (step S23).

  When all the data has not been processed yet (step S23 / NO), the determination unit 65 returns to step S17 and acquires the next data from the time-series data of the thickness of the bright line.

  On the other hand, when the thickness of the bright line is “thick” (step S19 / YES), the determination unit 65 determines whether the thickness of the bright line has changed from “thick” → “thin” → “thick” ( Step S21). In step S <b> 21, it is determined whether the portion where the thickness of the bright line is thick is a portion where vertical wrinkles are generated or a portion where the label 71 is bonded. If the thickness of the bright line is “thick” in the last data of the time series data of the bright line thickness, the thickness of the bright line changes from “thick” → “thin” → “thick”. It may be determined using the last data, the first data, and the second data.

  For example, as shown in FIG. 9A, in the composite image SI1, the thickness of the bright line extending over the third and fourth images and the bright line included in the sixth image are “thick”. The thickness of the bright line between them is “thin”. In this case, since the thickness of the bright line changes from “thick” → “thin” → “thick”, the determination in step S21 is YES. Note that the thick bright line included in the 43rd image is due to the location where the label 71 is bonded.

  Returning to FIG. 8, when the thickness of the bright line is changed from “thick” → “thin” → “thick” (step S21 / YES), the corresponding part is determined to be a part where vertical wrinkles are generated. Therefore, the notification unit 67 notifies that vertical wrinkles have been detected (step S25), and ends the process of FIG.

  On the other hand, as shown in FIG. 9B, in the composite image SI2, the thickness of the bright line extending over the third and fourth images is “thick”, and the thickness of the other bright lines is “thin”. Yes. In this case, since the thickness of the bright line has not changed from “thick” → “thin” → “thick”, the determination in step S21 is NO.

  When the thickness of the bright line does not change from “thick” → “thin” → “thick” (step S21 / NO), the corresponding part is determined as the bonding part of the label 71. In this case, the determination unit 65 returns to step S17, and acquires data at the next time from the time-series data of the thickness of the bright line.

  By the way, when the determination at step S23 is YES while the determination at step S21 is not YES, no vertical wrinkle is generated in the label 71. In this case, the notification unit 67 notifies that there is no abnormality (step S27), and ends the process of FIG.

  As described above in detail, according to the present embodiment, the cylindrical surface inspection apparatus 100 irradiates the cylindrical surface of the cylindrical product 70 that rotates about the cylindrical axis with light so that a bright line is generated in the cylindrical axis direction. And an imaging device 50 that is arranged so as to include the bright line in the imaging range, sequentially images a part of the cylindrical surface of the cylindrical product 70 that rotates about the cylindrical axis, and images the entire circumference of the cylindrical surface. And a calculation unit 63 for calculating the width in the rotation direction of the cylindrical product 70 for each of the plurality of bright lines included in the cylindrical surface image obtained by combining images obtained by sequentially capturing a part of the cylindrical surface, and the width of the bright line A discriminating unit 65 for discriminating between a pasting portion of the label 71 wound so as to cover the cylindrical surface of the cylindrical product 70 and a portion where wrinkles are generated in the cylindrical axis direction in the label 71, , Cylindrical shaft If the locations wrinkled direction has occurred is determined, it includes a notifying unit 67 for notifying that there is a defect in the cylindrical surface. Based on the change over time in the thickness of the bright line, in order to discriminate between the location where the vertical wrinkle is generated and the location where the label 71 is bonded, the location where the label 71 is bonded is defined as a location where the vertical wrinkle occurs It is possible to suppress erroneous detection. Therefore, the detection accuracy of vertical wrinkles can be improved.

  Further, when the thickness of the bright line changes from “thick (bright line width ≧ threshold)” → “thin (bright line width <threshold)” → “thick (bright line width ≧ threshold)”, When it is determined that a vertical wrinkle has occurred, and the thickness of the bright line changes from “thick” → “thin” → “thin”, it is determined that the label 71 is to be attached. Thereby, since it can suppress misdetecting the bonding location of the label 71 as the location where the vertical wrinkle has generate | occur | produced, the detection accuracy of a vertical wrinkle can be improved.

  In the above embodiment, the time-series data of the bright line thickness in which the bright line thickness is expressed as “thick” and “thin” is created, but the present invention is not limited to this. The calculation unit 63 may create time series data of the thickness of the bright line in which the bright line whose width is equal to or greater than the threshold is represented by “1” and the bright line whose width is less than the threshold is represented by “0”.

  In the above-described embodiment, the imaging device 50 images one cylindrical product 70. However, light is irradiated so that bright lines are generated on the cylindrical surface, and a plurality of cylindrical products 70 that rotate in synchronization are simultaneously displayed. You may image. In this case, since the number of the imaging devices 50 can be suppressed, the cost can be reduced.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Fixing part 20 Rotating apparatus 30 Illuminating apparatus 50 Imaging apparatus 60 Control apparatus 61 Storage part 62 Composition part 63 Calculation part 65 Discriminating part 67 Notification part 70 Cylindrical product 71 Label 72 Product main body 100 Cylindrical surface inspection apparatus

Claims (3)

An illumination device that irradiates light so that a bright line is generated in the cylindrical axis direction on a cylindrical surface of a cylindrical product that rotates about the cylindrical axis
An imaging device that is arranged so as to include the bright line in an imaging range, sequentially images a part of the cylindrical surface of the cylindrical product that rotates around the cylindrical axis, and images the entire circumference of the cylindrical surface;
A calculation unit that calculates the width in the rotation direction of the cylindrical product for each of the plurality of bright lines included in the cylindrical surface image obtained by combining images obtained by sequentially capturing a part of the cylindrical surface,
Based on the change over time of the width of the bright line, it is determined whether the label is attached so as to cover the cylindrical surface of the cylindrical product, and where the wrinkles are generated in the cylindrical axis direction on the label. A discriminator to perform,
A notification unit for notifying that a defect is present in the cylindrical surface when a location where wrinkles are generated in the cylindrical axis direction is determined;
A cylindrical surface inspection apparatus comprising:   The discriminating unit discriminates that a wrinkle is generated in the cylindrical axis direction when the width of the bright line is changed to a predetermined threshold value or more, less than the predetermined threshold value, or more than the predetermined threshold value, The cylindrical surface inspection apparatus according to claim 1, wherein when the width of the bright line changes to a predetermined threshold value or more, less than the predetermined threshold value, and less than the predetermined threshold value, the cylindrical surface inspection apparatus determines that the label is attached. The cylindrical surface of the cylindrical product that rotates with the cylindrical axis as the rotation axis is irradiated with light so that a bright line is generated in the cylindrical axis direction.
With the imaging device arranged to include the bright line in the imaging range, sequentially image a part of the cylindrical surface of the cylindrical product rotating around the cylindrical axis as a rotation axis, and image the entire circumference of the cylindrical surface,
For each of a plurality of bright lines included in a cylindrical surface image obtained by combining images obtained by sequentially capturing a part of the cylindrical surface, calculate the width in the rotation direction of the cylindrical product,
Based on the change over time of the width of the bright line, it is determined whether the label is attached so as to cover the cylindrical surface of the cylindrical product, and where the wrinkles are generated in the cylindrical axis direction on the label. And
When it is determined where wrinkles are generated in the cylindrical axis direction, it notifies that there is a defect in the cylindrical surface,
A cylindrical surface inspection method.

Images