JP2012237680A - Device and method for inspecting coated state, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for inspecting a coated state capable of processing at a high speed without complicating a device, and preventing the occurrence of erroneous recognition due to disturbance light.SOLUTION: A device 1 for inspecting a coated state includes: illumination devices 2 which are installed, in the proximity of an imaging device 3, above a work-piece W on which a sealing agent S is coated; the imaging device 3 which images the sealing agent S and the work-piece W in each of a lighting-on state and a lighting-off state of the illumination devices 2; and a processing device 4 which performs image inspection for whether or not the sealing agent S is normally coated. In an image generation unit 5-1, a brightness value of each image imaged by the imaging device 3 in the lighting-on state and the lighting-off state of the illumination devices 2 is subtracted, so that an inspection image is generated from which influence of the disturbance light is removed. An image determination unit 5-2 determines from the inspection image whether or not the coated state of the sealing agent S is normal.

Description

  The present invention relates to an application state inspection apparatus, method, and program for inspecting the application state of an application.

  Conventionally, in the assembly of machines that have a drive unit and require lubricating oil, oil leakage from the joint part is prevented by applying a liquid substance called a sealant made of silicone to the joint part of the machine part. Techniques for preventing it are widely used. As problems that occur in this method, oil leakage due to the cutting of the sealant, contamination of foreign matter into the drive unit due to scattering, and the like can be considered.

  In general, a dye is mixed with the sealant to cause a color difference between the work surface to be coated and inspected that it is properly applied by visual or image processing methods. . However, the inspection by image processing has a problem that it is easily affected by ambient light such as room lighting.

  For example, Patent Document 1 proposes a method of capturing an image so that uniform light is irradiated only to a limited inspection region by using illumination that can change the irradiation direction and irradiation luminance. . In Patent Document 2, there is a method of taking an image by irradiating a light having a wavelength band having a large absorbance to an application, and selectively transmitting only the light in the wavelength band toward an imaging device such as a camera. Proposed.

JP-A-10-170242 Japanese Patent Laid-Open No. 2002-45766

  However, in the method of Patent Document 1, an illumination light source having a drive unit is required, the inspection apparatus is complicated, and depending on the size and shape of the inspection target, it is necessary to perform imaging a plurality of times while changing irradiation conditions. There was a problem that the inspection took time.

  In addition, the method of Patent Document 2 requires a monochromatic light source suitable for the light absorption characteristics of the sealant and a filter that selectively transmits the wavelength band thereof, making the entire apparatus expensive, and the light absorption characteristics depend on the components of the sealant. Therefore, there has been a problem that it cannot cope with the change of the component of the sealant.

  The present invention has been made in view of the above-described circumstances, and can be processed at high speed without complicating the apparatus, such as requiring illumination having a drive unit, and is not erroneously recognized due to ambient light. An object of the present invention is to provide an application state inspection apparatus and method, and a program capable of preventing the occurrence.

In order to solve the above-described problem, in the present invention, as a first solving means related to the application state inspection device, there is provided an application state inspection device that inspects the application state of the application material applied to the workpiece, Illuminating means for illuminating the workpiece coated with coating, imaging means for imaging the workpiece coated with the coating material in each of the lighting state / extinguishing state of the illuminating means, and the lighting means in the lighting state of the lighting means Subtracting means for subtracting the extinguished image captured by the imaging means from the lighting image captured by the imaging means and outputting the inspection image while the illumination means is extinguished, and the inspection image output from the subtracting means And determining means for determining whether the application state of the applied material applied to the workpiece is normal or abnormal.
Further, as a second solving means related to the application state inspection apparatus, the determination means extracts the application locus of the application object from the inspection image output from the subtraction means, and applies the extracted application object. Comparing the trajectory with an allowable area centered on a predetermined reference trajectory, and determining that the application trajectory is normal when the application trajectory of the application is within the allowable area; When the application locus is not within the allowable area, it is determined that the application locus is abnormal.
Further, as a third solving means relating to the application state inspection apparatus, an area of a whiteout region having a luminance value greater than or equal to a predetermined value is calculated from an extinguished image captured by the imaging means when the illumination means is extinguished. When the area of the flying region is not within the predetermined value, the imaging unit takes an image with the illumination unit turned off until the area of the whiteout region is within the predetermined value while gradually shortening the exposure time. It is further characterized by further comprising an imaging control means for repeating the above.
Further, as a fourth solving means related to the application state inspection apparatus, predetermined from an unlit image captured by the imaging unit when the lighting unit is unlit and a lighting image captured by the imaging unit when the lighting unit is lit. When the area of the whiteout region having the above luminance value is calculated, and the area of the whiteout region is not within the predetermined value, the exposure area is gradually shortened, and the area of the whiteout region is the predetermined value. Until the illumination means turns on, the imaging means shoots with the illumination means turned off, the imaging means shoots with the illumination means turned on, and each photographed image and the previously taken off image and lighting It is further characterized by further comprising a photographing control means for repeating the synthesis with the image.
On the other hand, in the present invention, as a means for solving the application state inspection method, the application state inspection method for inspecting the application state of the application applied to the workpiece, the illumination of the workpiece on which the application is applied In a state where the application is applied, the first imaging step of imaging the workpiece on which the application is applied, and the application is applied in a state where the illumination is turned on on the workpiece on which the application is applied. A second imaging step of imaging the workpiece, and a subtraction step of subtracting the extinguished image captured in the first imaging step from the lighting image captured in the second imaging step and outputting an inspection image And a determination step of determining whether the application state of the application applied to the workpiece is normal or abnormal based on the inspection image.
Furthermore, in the present invention, as a solving means related to the application state inspection program, there is provided an application state inspection program for inspecting the application state of the applied material applied to the work, wherein the work to which the applied material is applied is illuminated. In a state where the application is applied, the first imaging process for imaging the workpiece on which the application is applied, and the application is applied in a state where the illumination is turned on on the workpiece on which the application is applied. A second imaging process for imaging the workpiece, and a subtraction process for subtracting the unlit image captured in the first imaging process from the lit image captured in the second imaging process to output an inspection image And a determination process for determining whether the application state of the application applied to the workpiece is normal or abnormal based on the inspection image.

  According to the present invention, it is possible to perform high-speed processing without complicating the apparatus, for example, by requiring illumination having a drive unit, and it is possible to prevent erroneous recognition due to ambient light.

It is the schematic which shows the structure of the application state inspection apparatus 1 by 1st Embodiment of this invention. It is a flowchart for demonstrating operation | movement of the application state inspection apparatus 1 by this 1st Embodiment. It is a figure which shows an example of the light extinction image image | photographed with the application | coating state test | inspection apparatus 1 by this 1st Embodiment. It is a figure which shows an example of the lighting image image | photographed with the application | coating state test | inspection apparatus 1 by this 1st Embodiment. It is a figure which shows an example of the test | inspection image obtained with the application state test | inspection apparatus 1 by this 1st Embodiment. It is a flowchart which shows the modification of operation | movement of the application | coating state inspection apparatus 1 by this 1st Embodiment. It is a flowchart for demonstrating operation | movement of the application | coating state test | inspection apparatus 1 by this 2nd Embodiment. It is a flowchart for demonstrating operation | movement of the application state inspection apparatus 1 by this 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration of a coating state inspection apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 1, the application state inspection apparatus 1 in the first embodiment is for inspecting the application state of a sealing agent (application material) S applied to a workpiece W, and the sealing agent S is applied thereto. In order to keep the brightness of the side surface above the workpiece W constant, the illuminating device 2 installed in the vicinity of the imaging device 3, and the sealing agent S and An image pickup device 3 that picks up an image of the workpiece W and a processing device 4 that is connected to the image pickup device 3 and performs an image inspection to check whether the sealant S is normally applied are provided.

  The processing device 4 includes an inspection unit 5 and a storage unit 6. The inspection unit 5 determines whether or not the application of the sealant S is normal from the photographed image, and includes an image generation unit 5-1 and an image determination unit 5-2. The image generation unit 5-1 uses disturbance light by subtracting the luminance value of each image based on each image captured by the imaging device 3 when the lighting device 2 is turned on / off. An inspection image from which the influence of the above is removed is generated.

  The image determination unit 5-2 extracts the application region to which the sealant S is applied from the inspection image from which the influence of disturbance light has been removed, and compares the extracted region with the application region extracted from the reference image previously captured with the normal workpiece W. Thus, it is determined whether or not the application state of the sealant S is normal. Alternatively, the application region is extracted from the inspection image from which the influence of disturbance light has been removed, the center line of the extracted application region is extracted as the application locus, and the application locus is the center line of the application region extracted from the reference image. By comparing, it is determined whether or not the application state of the sealant S is normal.

  The storage unit 6 includes, for example, an HDD (Hard Disk Drive), and stores, as a reference image 7, an application region and a reference trajectory extracted from a photographed image of the workpiece W to which the sealant S has been normally applied in advance.

  FIG. 2 is a flowchart for explaining the operation (inspection operation) of the application state inspection apparatus 1 according to the first embodiment. Moreover, FIG. 3 is a figure which shows an example of the light extinction image image | photographed with the application | coating state inspection apparatus 1 by this 1st Embodiment. FIG. 4 is a diagram illustrating an example of a lighting image photographed by the application state inspection apparatus 1 according to the first embodiment. FIG. 5 is a diagram illustrating an example of an inspection image obtained by the application state inspection apparatus 1 according to the first embodiment.

  First, the illumination by the illuminating device 2 is turned off, and the imaging device 3 captures an extinguishing image (see FIG. 3) of the workpiece W coated with the sealing agent S (step S1). As shown in FIG. 3, the unlit image has gloss due to disturbance light.

  Next, the illumination by the illuminating device 2 is turned on, and the imaging device 3 captures a lighting image (see FIG. 4) of the workpiece W coated with the sealant S (step S2). As shown in FIG. 4, the lighting image has gloss due to illumination in addition to disturbance light.

  Next, the image generation unit 5-1 subtracts the luminance value of each pixel of the unlit image from the luminance value of each pixel of the lit image to obtain an inspection image (see FIG. 5) (step S3). As a result, as shown in FIG. 5, the gloss caused by the disturbance light is removed from the inspection image.

  Next, in the image determination unit 5-2, the color component of the sealant S is extracted from the inspection image, and binarization processing is performed. The application region where the sealant S is applied and the non-application region where the sealant S is not applied (Step S4).

  Next, in the image determination unit 5-2, the application region divided in step S4 is compared with the application region stored in the storage unit 6 as the reference image 7, and whether or not the sealant S is normally applied. Is determined (step S5). Specifically, the areas of the mismatched areas are determined by overlapping the application areas, the distance between the outline and center line of the application areas is measured, or the geometric inconsistency of the application areas is calculated. Whether or not the sealing agent S is normally applied is determined according to the size of the area, distance, or degree of mismatch.

  FIG. 6 is a flowchart showing a modification of the operation (inspection operation) of the application state inspection apparatus 1 according to the first embodiment. The flowchart shown in FIG. 2 determines whether or not the sealant S is normally applied by comparing the application region extracted from the inspection image with the application region stored as the reference image 7. . On the other hand, in the flowchart shown in FIG. 6, the coating locus that is the center line of the application region extracted from the inspection image is extracted, and compared with the application locus stored as the reference image 7, the sealant S is normal. It is determined whether or not it is applied.

  First, similarly to the flowchart shown in FIG. 2, the unlit image of the workpiece W coated with the sealant S is captured (step S1), the lit image of the workpiece W is photographed (step S2), and the unlit image is subtracted from the lit image. (Step S3) and extraction of the application area (Step S4) are sequentially performed.

  Next, in the image determination unit 5-2, the center line of the application area of the sealant S is extracted as an application locus of the sealant S (step S11). As a method for extracting the center line of the application region, a center line extraction method known as general image processing can be used.

  Next, the image determination unit 5-2 compares the application trajectory that is the center line of the application region with the reference trajectory of the sealant S that is acquired from an image captured in advance with a normal workpiece W and stored in the storage unit 6. When the positional deviation of the application locus of the sealant S is within the allowable range, it is determined to be normal, and when it exceeds the allowable range, it is determined to be abnormal (step S12).

  More specifically, an allowable area is generated by expanding a reference trajectory of the sealant S obtained from an image photographed in advance with a normal workpiece W by a predetermined allowable error, and the allowable area and the application trajectory of the inspection target are generated. When the application locus of the inspection object is all included in the allowable area, the positional deviation of the sealant S is within the allowable range, so that it is determined to be normal. If there is a location that is not included in the allowable region in the trajectory, it is determined that the position of the sealant S does not match (it is considered that the positional deviation exceeds the allowable error), and is determined to be abnormal.

  Next, it is determined whether or not the determination result in step S12 is normal (step S13). If it is normal (YES in step S13), it is determined that it is normal (step S14). On the other hand, if it is not normal (NO in step S13), it is determined that it is abnormal (step S15), the user is notified of the abnormality, and the target workpiece W is paid out (step S16).

  According to the first embodiment described above, the illumination is arranged so that the relative position with respect to the workpiece is constant, the image is taken twice in the state where the illumination is turned off and the state where the illumination is turned on, and Since the luminance value of the image taken in the off state is subtracted from the luminance value for inspection, the influence of ambient light has been removed, so no illumination with a drive unit is required, and the entire device Can be made simple, and since it is only necessary to subtract the luminance value of each pixel, processing can be performed at high speed.

  Further, according to the first embodiment, even if the glossy state generated by the work surface that is a metal or the surface of the sealing agent that is piled up is greatly changed by the position / illuminance of the ambient light, the ambient light Therefore, it is possible to prevent the occurrence of erroneous recognition due to ambient light, since an image that is almost the same as that obtained by shooting under constant conditions can be obtained.

  Further, according to the modification of the first embodiment, the application locus of the photographed sealant S is compared with the allowable region generated by expanding the reference locus, and whether or not all of the allowable regions are included. Since the determination is made, it is possible to easily detect the displacement of the sealant S even when the part shape is changed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
When the intensity of disturbance light is particularly strong, a “whiteout” phenomenon occurs in which the direct reflection of disturbance light exceeds the imaging range of the imaging device 3, and information necessary for inspection may be lost. Therefore, in the second embodiment, there is no overexposure by performing a function of automatically adjusting the exposure time of the imaging device 3 when the overexposure is detected or by changing the exposure time stepwise. It can be combined with a function for obtaining an image. In addition, since the structure of the application | coating state inspection apparatus 1 is the same as that of FIG. 1, description is abbreviate | omitted.

  FIG. 7 is a flowchart for explaining the operation of the application state inspection apparatus 1 according to the second embodiment. First, the workpiece W is photographed in a state where the illumination by the illumination device 2 is turned off, and the obtained image is set as an extinguished image (see FIG. 3) (step S20). Next, a whiteout area is calculated (step S21), and it is determined whether the whiteout area is within a predetermined value (step S22). If the whiteout area is not within a predetermined value (step S22). (NO in S22), the exposure time is set short (step S23), and the extinguished image is taken again in step S20. Thereafter, until the overexposure area falls within a predetermined value, the exposure time is set to be shortened stepwise in step S23, and the shooting of the extinguished image is repeated.

  Then, when the whiteout area is within a predetermined value in the extinguished image (YES in step S22), the work W is photographed with the illumination by the illumination device 2 turned on, and the obtained image is turned on (see FIG. 4). (Step S24). Next, the image generation unit 5-1 subtracts the luminance value of each pixel of the unlit image from the luminance value of each pixel of the lit image to obtain an inspection image (see FIG. 5) (step S25).

  Accordingly, it is possible to exclude the influence of the gloss generated on the surface of the sealant S due to the reflection of light (a gloss region corresponding to the gloss can be included in the application region of the sealant S). For this reason, it becomes possible to improve the inspection accuracy. Further, in order to eliminate the influence of gloss generated on the surface of the sealant S by image processing, an illumination light source equipped with a driving unit as in the past, a monochromatic light source or the like is not required, and the apparatus is simplified and the cost is reduced. It can be realized.

  Next, in the image determination unit 5-2, the color component of the sealant S is extracted from the inspection image, the binarization process is performed, and the application area where the sealant S is applied is extracted (step S26). It is determined whether or not the sealing agent S is normally applied by comparing the application region of the sealing agent S with the application region of the sealing agent S acquired from a reference image previously captured with a normal workpiece W (step S1). S27).

  For the determination, a method similar to step S5 in FIG. 2 or steps S11 and S12 in FIG. 6 can be used. In other words, it is determined from the area of the mismatched area by overlapping the application areas extracted from each of the captured image and the reference image, or the distance between the outline and center line of the application area is measured, and the geometric area is measured. A general image processing technique such as calculating the degree of inconsistency can be used.

  According to the second embodiment described above, when whiteout is detected, an image without whiteout can be obtained by changing the exposure time of the imaging device 3 in stages, and the whiteout due to ambient light can be obtained. Can prevent erroneous recognition.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
In the second embodiment described above, when the exposure time is shortened, it is conceivable that a “blackout” phenomenon occurs in which the amount of light in a portion where no disturbance light is directly reflected is insufficient. Therefore, in the third embodiment, the turn-off image and the turn-on image are taken until the whiteout area becomes a predetermined value or less while the exposure time is shortened step by step, and the taken image (the turn-off image and the turn-on image) is immediately before By combining these images with HDR (High Dynamic Range) synthesis or the like, “blackout” is prevented. In addition, since the structure of the application | coating state inspection apparatus 1 is the same as that of FIG. 1, description is abbreviate | omitted.

  FIG. 8 is a flowchart for explaining the operation of the application state inspection apparatus 1 according to the third embodiment. First, the workpiece W is photographed in a state where the illumination by the illumination device 2 is turned off, and the obtained image is set as an extinguished image (see FIG. 3) (step S30). Next, the workpiece W is photographed in a state where the illumination by the illumination device 2 is turned on, and the obtained image is set as a turned-on image (see FIG. 4) (step S31).

  Next, the whiteout areas of the unlit image and the lighted image are respectively calculated (step S32), and it is determined whether or not each of the whiteout areas is within a predetermined value (step S33). If the overexposure area is not within the predetermined value (NO in step S33), the exposure time is set short (step S34), the extinguished image is captured (step S35), and the lit image is captured (step S36). Then, the photographed unlit image and lit image are combined with the immediately preceding image (here, the unlit image and lit image obtained in S31 in step S30) (step S37).

  Then, it is determined again whether or not the area of the whiteout of the unlit image and the lit image is within a predetermined value (step S33). Thereafter, until the overexposure area falls within the predetermined value, the exposure time is set to be shortened stepwise in step S34, the extinction image is captured (step S35), the lit image is captured (step S36), and the extinction image and the lit image are displayed. And the previous image (step S37) are repeated.

  When the area of whiteout of the unlit image and the lit image falls within a predetermined value (YES in step S33), the image generation unit 5-1 subtracts the luminance value of each pixel of the unlit image from the luminance value of each pixel of the lit image. Then, an inspection image (see FIG. 5) is obtained (step S38). Next, as in steps S26 and S27 in FIG. 7, the image determination unit 5-2 extracts an application region to which the sealing agent S has been applied (step S39), and whether the sealing agent S has been normally applied. It is determined whether or not (step S40).

  According to the third embodiment described above, when the whiteout of the extinguished image and the lit image is detected, the extinguishing time of the imaging device 3 is changed stepwise to capture the extinguished image and the lit image, and synthesized with the previous image. By doing so, it is possible to obtain an image without whiteout and blackout.

  It should be noted that the modification of the first embodiment described above can be applied to the second and third embodiments described above. That is, the processing of step S27 in FIG. 7 and step S40 in FIG. 8 can be changed to the processing of steps S11 to S16 in FIG.

  Further, the series of processing in the first to third embodiments described above uses a general image processing method, and therefore can be easily implemented and processed at high speed.

  In the first to third embodiments described above, the illumination device 2 and the imaging device are used in order to prevent the gloss generated when the light of the installed illumination device 2 is directly reflected on the workpiece W surface or the sealant S. It is conceivable to install a polarizer in front of each of the three. Even in this case, since the gloss due to the direct reflection of disturbance light cannot be removed, the methods according to the first to third embodiments described above are effective.

  In addition, even in general image processing / image inspection, not limited to the inspection of the sealant S, in the case where it is desired to obtain an image in a constant state regardless of the influence of ambient light, the first to third described above. The method according to the embodiment can be applied.

  Further, the method is not limited to the sealant S, and this method can be applied to a process of inspecting that the application state is appropriate even for a general application.

DESCRIPTION OF SYMBOLS 1 Application | coating state inspection apparatus 2 Illumination apparatus 3 Imaging apparatus 4 Processing apparatus 5 Inspection part 5-1 Image generation part 5-2 Image determination part 6 Memory | storage device 7 Reference | standard image S Seal agent (application | coating material)
W Work

Claims (6)

An application state inspection device for inspecting the application state of a coating applied to a workpiece,
Illuminating means for illuminating the workpiece coated with the coating material;
Imaging means for imaging the workpiece coated with the coating in each of the lighting state and the extinguishing state of the illumination means;
Subtracting means for subtracting the unlit image captured by the imaging means in the unlit state of the illuminating means from the lit image taken by the imaging means in the lit state of the illuminating means, and outputting an inspection image;
And a determination unit that determines whether the application state of the application applied to the workpiece is normal or abnormal based on the inspection image output from the subtraction unit. Condition inspection device. The determination means includes
The application trajectory of the application is extracted from the inspection image output from the subtracting means, the extracted application trajectory of the application is compared with an allowable area centered on a predetermined reference trajectory, and the application It is determined that the application trajectory is normal when the application trajectory is within the allowable area, and the application trajectory is abnormal when the application trajectory is not within the allowable area. The coating state inspection apparatus according to claim 1, wherein   When an area of a whiteout region having a luminance value greater than or equal to a predetermined value is calculated from a non-lighted image captured by the imaging unit in a state where the lighting unit is off, and the area of the whiteout region is not within a predetermined value, stepwise The imaging control unit according to claim 1, further comprising: an imaging control unit that repeats imaging in the unlit state of the illumination unit by the imaging unit until the area of the whiteout region is within the predetermined value while shortening the exposure time. The application state inspection device according to claim 1 or 2.   An area of a whiteout region having a brightness value greater than or equal to a predetermined value is calculated from the unlit image captured by the imaging unit when the lighting unit is off and the lighting image captured by the imaging unit when the lighting unit is on. When the area of the whiteout region is not within the predetermined value, the illumination unit is turned off by the imaging unit until the area of the whiteout region is within the predetermined value while gradually shortening the exposure time. And a shooting control unit that repeats shooting with the imaging unit in a lighting state of the illumination unit, and synthesis of each shot image with the previously taken off image and lighting image. The coating state inspection apparatus according to claim 1 or 2. An application state inspection method for inspecting the application state of a coating applied to a workpiece,
A first imaging step of imaging the workpiece coated with the coating material in a state where illumination is turned off with respect to the workpiece coated with the coating material;
A second imaging step of imaging the workpiece coated with the coating in a state where illumination is lit on the workpiece coated with the coating;
A subtraction step of subtracting the extinguishing image captured in the first imaging step from the lighting image captured in the second imaging step and outputting an inspection image;
And a determination step of determining whether the application state of the applied material applied to the workpiece is normal or abnormal based on the inspection image. An application state inspection program for inspecting the application state of a coating applied to a workpiece,
A first imaging process for imaging the workpiece coated with the coating in a state where illumination is turned off with respect to the workpiece coated with the coating;
A second imaging process for imaging the workpiece coated with the coating in a state where illumination is turned on the workpiece coated with the coating;
A subtraction process for subtracting the extinguished image captured in the first imaging process from the lighting image captured in the second imaging process and outputting an inspection image;
An application state inspection program that causes a computer to execute a determination process for determining whether the application state of the application applied to the workpiece is normal or abnormal based on the inspection image.

Images