JP2008309709A - Visual inspection device of long article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection device of a long article capable of substantially uniforming the brightness of irradiated radiation in the view from an imaging device side in the width direction of the long article when the irradiated radiation formed by radiating linear light to the outer peripheral surface of the long article having a substantially circular cross section is imaged by the imaging device. <P>SOLUTION: One irradiated radiation L is formed on the outer peripheral surface of a hose H by the linear light of a plurality of irradiation devices 10, each imaging device 50 is arranged in a substantial center of the circumferential direction of the hose H with respect to two adjacent optional irradiation devices 10 of the circumferential direction of the hose H of respective irradiation devices 10. Therefore, the brightness of the irradiated radiation L in the view from each imaging device 50 side can be substantially uniformed in the width direction of the hose H, and the light sensitivity adjustment of each imaging device 50 can be performed easily and appropriately. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a long object appearance inspection apparatus for inspecting the appearance of, for example, a hose or an electric wire.

In general, this type of long object appearance inspection apparatus is provided with a moving mechanism for moving a long plate-like object in the longitudinal direction, and a linear mechanism that is provided above the elongated object and is directed toward the upper surface of the elongated object. An irradiation device that irradiates light and an imaging device that is provided above the long object and that captures the irradiation light that is formed by irradiating the upper surface of the long object with the linear light, and is long based on imaging data from the imaging device. What inspected the upper surface of a scale is known (for example, refer patent document 1).
JP-A-6-281593

  By the way, in the appearance inspection apparatus, since the upper surface of the long object is flat, linear light is irradiated substantially uniformly over the width direction of the long object, and the luminance of the irradiation line is long. It is possible to easily and appropriately adjust the light sensitivity of the imaging device that images the irradiation line.

  However, as shown in FIG. 13, when the appearance inspection of the long object 100 having a circular cross section is performed, the brightness of the irradiation line is remarkably different between the range A immediately below the irradiation device 110 and the other range B. When the light sensitivity of the imaging device 120 is adjusted to the range A, the irradiation line of the range B becomes dark on the imaging data, and when the light sensitivity of the imaging device 120 is adjusted to the range B, the irradiation light of the range A becomes bright on the imaging data. Too much. That is, there is a problem in that the light sensitivity of the imaging device 120 cannot be adjusted appropriately.

  On the other hand, although it is conceivable to adjust the light sensitivity of the imaging device 120 for each pixel, there is a problem that the light sensitivity adjustment of the imaging device 120 becomes complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to image an irradiation line formed by irradiating linear light on the outer peripheral surface of a long object having a substantially circular cross section with an imaging device. In this case, an object of the present invention is to provide a long object visual inspection apparatus capable of making the luminance of the irradiation line viewed from the imaging apparatus side substantially uniform over the width direction of the long object.

  In order to achieve the above-mentioned object, the present invention is provided with a moving mechanism for moving a long object having a substantially circular cross section in the axial direction and a circumferential direction of the long object. A plurality of irradiation devices that irradiate the surface with linear light, and an imaging device that images a single irradiation line formed by irradiating the outer surface of the long object with the linear light of each irradiation device. In an appearance inspection apparatus for a long object that inspects an outer peripheral surface of a long object based on imaging data obtained by the apparatus, the imaging apparatus is replaced with any two irradiation apparatuses adjacent to each other in the circumferential direction of the long object. On the other hand, it arrange | positions in the approximate center of the circumferential direction of a long thing.

  Thereby, one irradiation line is formed by the linear light of a plurality of irradiation devices on the outer peripheral surface of the long object, and the image pickup device is an arbitrary two of the irradiation devices adjacent to each other in the circumferential direction of the long object. Since it is arrange | positioned in the approximate center of the circumferential direction of a long thing with respect to the irradiation apparatus, the brightness | luminance of the irradiation line seen from the imaging device side can be made substantially uniform over the width direction of a long thing.

  According to the present invention, when an imaging device captures an irradiation line formed by irradiating linear light on the outer peripheral surface of a long object having a substantially circular cross section, the luminance of the irradiation line viewed from the imaging device side is long. Since it can be made substantially uniform over the width direction of the object, the photosensitivity adjustment of the image pickup apparatus can be performed easily and appropriately.

  FIG. 1 to FIG. 12 show an embodiment of the present invention. FIG. 1 is a perspective view of an essential part of an appearance inspection apparatus for a long object, and FIG. 2 is a side view of an essential part of the appearance inspection apparatus for a long object. 3 is a cross-sectional view taken along line AA in FIG. 2, FIG. 4 is a perspective view of the main part of the hose, FIG. 5 is an example of imaging data, FIG. 6 is a partially enlarged view of FIG. Is an example of position data in the height direction subjected to subtraction processing, FIG. 9 is an example of an inspection image, FIG. 10 is a perspective view of a main part of a hose, FIG. 11 is an example of imaging data, and FIG. It is.

  This long object visual inspection apparatus includes a plurality of irradiation devices 10 capable of irradiating linear light S toward the outer peripheral surface of a hose H as a long object having a substantially circular cross section, and the hose H in the axial direction thereof. The moving mechanism 20 to be moved, the first guide mechanism 30 and the second guide mechanism 40 for guiding the hose H, and the irradiation light L formed by irradiating the outer surface of the hose H with the linear light S of each irradiation device 10. Are provided with a plurality of imaging devices 50 capable of imaging from a direction forming a predetermined angle α (approximately 30 ° in the present embodiment) with the light surface of the linear light S. The hose H is formed by vulcanizing a cloth member (not shown) wound around the outer peripheral surface in a spiral manner and removing the cloth member after vulcanization. SP (or convex part) is formed. Here, the linear light S is light that becomes linear on the irradiation object.

  The linear light S emitted from each irradiation device 10 is composed of red laser light, and the linear light S is irradiated linearly on the outer peripheral surface of the hose H. In the present embodiment, four irradiation devices 10 are provided, and each irradiation device 10 is disposed at a position shifted from each other by approximately 90 ° in the circumferential direction of the hose H. Moreover, each irradiation apparatus 10 is arrange | positioned so that the optical surface of the linear light S may cross | intersect the axial direction of the hose H substantially perpendicularly. The linear light S irradiated from each irradiation device 10 is connected to each other in the circumferential direction of the hose H, and one irradiation line L that goes around the hose H is formed on the outer peripheral surface of the hose H by the linear light of each irradiation device 10. Is done.

  The moving mechanism 20 includes a pair of upper and lower belt conveyors 21. The hose H is sandwiched between the belt conveyors 21, and the hoses H can be moved in the axial direction by rotating the belt conveyors 21.

  The first guide mechanism 30 has four guide members 31, and each guide member 31 is disposed at a position shifted by approximately 90 ° in the circumferential direction of the hose H. Each guide member 31 is disposed upstream of the irradiation line L in the moving direction of the hose H, and each guide member 31 is pressed against the outer peripheral surface of the hose H by an air cylinder (not shown). The surface of each guide member 31 pressed against the hose H is made of a low friction coefficient material having a friction coefficient with the outer peripheral surface of the hose H of 0.12 or less, and is formed to extend in the axial direction of the hose H. Examples of the low friction coefficient material include silicon, fluororesin, and ultrahigh molecular weight polyethylene having a molecular weight of 1 million or more. An auxiliary guide mechanism 32 for guiding the hose H to the first guide mechanism 30 is provided upstream of the first guide mechanism 30 in the conveying direction of the hose H.

  The second guide mechanism 40 has four guide members 41, and each guide member 41 is arranged at a position shifted by approximately 90 ° in the circumferential direction of the hose H. Each guide member 41 is disposed downstream of the irradiation line L in the moving direction of the hose H, and each guide member 41 is pressed against the outer peripheral surface of the hose H by an air cylinder (not shown). The surface of each guide member 41 pressed against the hose H is made of a low friction coefficient material having a friction coefficient with the outer peripheral surface of the hose H of 0.12 or less, and is formed to extend in the axial direction of the hose H. Examples of the low friction coefficient material include silicon, fluororesin, and ultrahigh molecular weight polyethylene having a molecular weight of 1 million or more.

  Each imaging device 50 has a plurality of pixels in the X-axis direction (direction according to the width direction of the hose H) and a plurality of pixels in the Y-axis direction (direction according to the height direction of the hose H) orthogonal to the X-axis. A three-dimensional imaging device. In the present embodiment, four image pickup devices 50 are provided, and each image pickup device 50 is disposed at a position displaced by approximately 90 ° in the circumferential direction of the hose H. Further, the imaging devices 50 are alternately arranged in the circumferential direction of the irradiation devices 10 and the hose H, and the imaging devices 50 are arranged at positions shifted from the irradiation devices 10 and the circumferential direction of the hose H by about 45 °. Yes. That is, each imaging device 50 is arranged at the approximate center in the circumferential direction of the hose H with respect to any two irradiation devices 10 adjacent to each other in the circumferential direction of the hose H. Each imaging device 50 is provided with a known light sensitivity adjustment function for adjusting the light sensitivity, and the light sensitivity adjustment function adjusts the light sensitivity of the entire image in a plurality of stages, not for each pixel.

  A method for inspecting the appearance of the hose H in the appearance inspection apparatus for a long object configured as described above will be described with reference to FIGS.

  First, in a state where the guide members 31 and 41 of the guide mechanisms 30 and 40 are pressed against the outer peripheral surface of the hose H by the air cylinder, the hose H is moved in the axial direction by the moving mechanism 20, and each irradiation device 10 The linear light S is irradiated toward the outer peripheral surface of the hose H. Next, when the hose H reaches a predetermined speed, each imaging device 50 images the irradiation line L on the outer peripheral surface of the hose H every predetermined time. In the following, one of the imaging devices 50 will be described, but the same processing is performed for the other imaging devices 50 as well.

  Subsequently, the height direction (Y-axis) of the irradiation line L corresponding to each position in the width direction (position of each pixel in the X direction) of the hose H from each image data (for example, see FIG. 5) imaged by the imaging device 50. Direction) position data is extracted. For example, 68.2 is extracted as position data in the height direction at the fifteenth pixel position from the left in the X-axis direction (X15 in FIG. 6). FIG. 5 shows imaging data obtained by imaging the irradiation line L in FIG. 4, and a concave wound K is formed on the irradiation line L in FIG. 4.

  Subsequently, position data in the height direction corresponding to each position in the width direction is subtracted by reference data (see FIG. 7) provided for each position in the width direction, and position data in the height direction ( (See FIG. 8). The reference data is numerical data provided for each position in the width direction according to the outer peripheral surface shape of the hose H.

  Subsequently, the inspection position image (see FIG. 9) is created by arranging the position data in the height direction of each imaged data subjected to the subtraction processing in the order of image capturing based on a predetermined color tone standard. As the predetermined color tone reference, for example, a reference that darkens the color as the numerical value of the position data in the height direction is smaller is used. Next, the presence / absence of an abnormality on the created inspection image is determined based on a predetermined determination criterion.

  On the other hand, luminance data of the irradiation line L corresponding to each width direction position (position of each pixel in the X-axis direction) of the hose H is extracted from each imaging data (see, for example, FIG. 11) captured by the imaging device 50. Note that FIG. 11 shows image data obtained by imaging the irradiation line L in FIG. 10, and a foreign matter D having a lighter color than the outer peripheral surface of the hose H is attached to the outer peripheral surface of the hose H shown in FIG. 10.

  Next, the luminance data of each imaging data is arranged in the order of imaging based on a predetermined color tone standard to create a luminance inspection image (see FIG. 12). As the predetermined color tone standard, for example, a standard that darkens the color as the numerical value of the luminance data is smaller is used. Next, the presence / absence of an abnormality on the created luminance inspection image is determined based on a predetermined determination criterion.

  Here, on the outer peripheral surface of the hose H, one irradiation line L is formed by the linear light of the plurality of irradiation devices 10, and each imaging device 50 is adjacent to the irradiation device 10 in the circumferential direction of the hose H. Since the two irradiation devices 10 are arranged at substantially the center in the circumferential direction of the hose H, the luminance of the irradiation line L viewed from the imaging device 50 side is made substantially uniform over the width direction of the hose H. be able to.

  Thus, according to this embodiment, when each imaging device 50 images the irradiation line L formed by irradiating the outer circumferential surface of the hose H having a substantially circular cross section with the linear light, from each imaging device 50 side. Since the brightness of the viewed irradiation line L can be made substantially uniform across the width direction of the hose H, the light sensitivity of each imaging device 50 can be adjusted easily and appropriately.

  That is, when the brightness of the irradiation line L as viewed from the side of each imaging device 50 is remarkably different in the width direction of the hose H and the light sensitivity adjustment of each imaging device 50 cannot be performed appropriately, the imaging data of FIG. Since the position of the irradiation line L in the height direction cannot be accurately extracted, this hinders the appearance inspection of the hose H. Further, when the brightness of the irradiation line L as viewed from the side of each imaging device 50 is significantly different across the width direction of the hose H, the imaging data of FIG. 11 is used unless the light sensitivity adjustment of each imaging device 50 is performed for each pixel. In this case, the change in the luminance of the irradiation line L due to the difference in the color of the outer peripheral surface of the hose H cannot be accurately extracted, which hinders the appearance inspection of the hose H. On the other hand, in this embodiment, the brightness of the irradiation line L viewed from each imaging device 50 side can be made substantially uniform over the width direction of the hose H, and the light sensitivity of each imaging device 50 can be easily adjusted. Since it can be performed appropriately, it is extremely advantageous in accurately performing the appearance inspection of the hose H.

  Moreover, since each imaging device 50 is provided by the same number as each irradiation device 10, and each imaging device 50 is alternately arranged in the circumferential direction of each irradiation device 10 and the hose H, the outer peripheral surface of the hose H is set to the entire circumference. Can be inspected at once.

  In this embodiment, the hose H that is vulcanized in a state where the cloth member is spirally wound around the outer peripheral surface is shown. However, the outer surface is coated with a resin and vulcanized. In addition to the hose H, it is also possible to perform an appearance inspection of an electric wire, a metal pipe, a non-metallic pipe, a rod-shaped material, and the like having a substantially circular cross section.

  In the present embodiment, four irradiation devices 10 are shown. However, two or three irradiation devices 10 can be provided, and five or more irradiation devices 10 can be provided. .

The principal part perspective view of the external appearance inspection apparatus of the elongate object which shows one Embodiment of this invention Side view of the main part of an appearance inspection device for long objects AA line sectional view in FIG. Perspective view of main part of hose Example of imaging data Partial enlarged view of FIG. Example of reference data Example of position data in the height direction after subtraction processing Example of inspection image Perspective view of main part of hose Example of imaging data Example of luminance test image Side view of the main part of a conventional long-size visual inspection device

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Irradiation device, 20 ... Movement mechanism, 21 ... Conveyor belt, 30 ... 1st guide mechanism, 31 ... Guide member, 32 ... Auxiliary guide mechanism, 40 ... 2nd guide mechanism, 41 ... Guide member, 50 ... Imaging device, H: Hose, S: Linear light, L: Irradiation beam, SP: Spiral recess, K ... Scratch, D ... Foreign matter.

Claims (2)

A moving mechanism that moves a long object having a substantially circular cross section in the axial direction, and a plurality of elements that are provided at intervals in the circumferential direction of the long object, and each irradiates linear light toward the outer peripheral surface of the long object And an imaging device for imaging one irradiation line formed by irradiating the linear light of each irradiation device on the outer peripheral surface of the long object, and the outer periphery of the long object based on the imaging data by the imaging device In the appearance inspection device for long objects that inspect the surface,
The external appearance of the long object characterized in that the imaging device is arranged at substantially the center in the circumferential direction of the long object with respect to any two irradiation apparatuses adjacent to each other in the circumferential direction of the long object. Inspection device. Provide the same number of imaging devices as each irradiation device,
2. The long object visual inspection apparatus according to claim 1, wherein the imaging devices are alternately arranged in a circumferential direction of each irradiation device and the long object.

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