JP2013169570A - Tubular body inspection device and tubular body inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply inspect an inside of a tubular body without inhibiting a tube making process using a container.SOLUTION: A tubular body inspection device includes: an inspection probe which generates a plurality of annular beam images while moving along an axial direction of a tubular body; a probe drive device which controls a position of the inspection probe inside the tubular body; and an arithmetic processing device which conducts image processing on the annular beam images and determines whether a defect exists on an inner surface of the tubular body. The probe drive device includes: an inspection stem having a probe drive mechanism on which the inspection probe is mounted, which moves the inspection probe along the axial direction of the tubular body, and rotates the inspection probe around a center axis of the tubular body; and a fixing jig which has a fitting surface which can be fitted to a fitting part arranged on at least either one of the container and a member mounted on the container, and fixes the inspection stem on at least either one of the container and the member mounted on the container.

Description

  The present invention relates to a tubular body inspection device and a tubular body inspection method.

  As a method for producing a seamless steel pipe made of stainless steel or high alloy steel, which is difficult to hot-work, a pipe making process using a billet by a Eugene-Sejunel hot extrusion method is performed.

  FIG. 22 is a schematic view showing a processing mode in this pipe making method by Eugene-Sejunel hot extrusion. A liner holder 1001 is installed in the container 1000, and a tubular container liner 1003 is installed in the liner holder 1001. A die 1005 is attached to one end of the container 1000. Here, the die 1005 is housed in the die holder 1007 and supported by the die backer 1009 from the front in the extrusion direction.

  Further, a hollow billet B heated from the other end of the container 1000 is inserted, and the hollow billet B is pushed out by a stem 1013 in which the mandrel 1011 is housed, so that the annular gap located between the die 1005 and the mandrel 1011 is removed. A seamless steel pipe having an outer diameter corresponding to the inner diameter of the die 1005 and an inner diameter corresponding to the outer diameter of the mandrel 1011 will be extruded.

  If irregularities are generated on the inner surface of the container liner 1003 during the hot extrusion, the outer surface of the hot extruded product becomes an outer surface. In particular, in the Eugene Sejunel hot extrusion method, a vitreous material is used as the lubricant, but the glass scale 1015 generated by the deposition may become lumpy. These irregular wrinkles are wrinkles that are harmful in manufacturing, and are not preferable to occur during the manufacturing process. In addition, so-called scale unevenness and dirt (hereinafter also referred to as pattern-based wrinkles) occur during the manufacturing process, but when there are no irregularities, they become harmless defects that require follow-up observation. As described above, when manufacturing a tubular body such as a steel pipe, various defects such as uneven wrinkles and pattern-based wrinkles may occur. It is necessary to find and take countermeasures.

  As a method for inspecting the surface of the tubular body, there is an optical inspection in which a detection probe composed of optical means such as an imaging device or an illuminating device that images the entire inner surface of the tubular body is moved in the axial direction within the tubular body. It has been implemented. Various types of axial positioning means for moving the detection probe in the axial direction of the tubular body have been proposed for carrying out such an optical inspection.

  For example, in the following Patent Document 1, the inner peripheral surface of a steel pipe is optically photographed while being self-propelled in the axial direction of the pipe in a state of being disposed inside the steel pipe, the photographed image is processed, It describes an inspection device for inspecting the presence or absence of water. The inspection device comprising the illumination means and the imaging means is mounted on a carriage that is movable inside the steel pipe by wheels, is driven in the axial direction of the steel pipe, and is adjusted so that it is positioned at the center of the steel pipe by the lifting function of the carriage. It is possible.

  In addition, the inner surface inspection system described in Patent Document 2 below includes a laser-type slit light source, a slit prism, an imaging prism, an imaging unit, and the like as main components of the measurement system. It has components of a drive system including a rotational drive function for rotationally driving an integrally supported integrated frame with respect to the central axis of the tubular body, a linear movement mechanism for linearly moving in the axial direction of the tubular body, and the like. . In the system described in Patent Document 2, components of the measurement system are inserted into the tubular body by a linear movement mechanism, and the entire circumference of the inner surface of the tubular body is photographed by a rotational drive function.

JP-A-8-261947 JP 2009-216453 A

  However, when using the inspection apparatus described in Patent Document 1, it is necessary to insert a carriage on the inner surface of a high-temperature container liner in the course of the manufacturing process. However, it is difficult to insert such a carriage. Even if the cart is downsized, the region corresponding to the length of the cart becomes a dead zone in the inspection, and it is impossible to inspect the entire length of the container liner.

  Further, in the inner surface inspection system described in Patent Document 2, the drive system components are installed outside the container and the measurement system components are inserted. However, a stand for holding the drive system components is separately provided. There is a problem that it is necessary to install, and inspection cannot be easily performed due to installation location restrictions and installation time restrictions.

Therefore, the technology described in the above-mentioned patent document has a problem in that it cannot respond to a request for performing periodic flaw inspection during the manufacturing process that gives a basis for rational maintenance and countermeasure strategy of the inner surface of the container liner. there were.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to more easily inspect the inside of a tubular body without obstructing the pipe making process using a container. An object of the present invention is to provide a tubular body inspection device and a tubular body inspection method.

  In order to solve the above problems, according to a certain aspect of the present invention, in a pipe making process using a container, it is used for inspecting an inner surface of a container liner that is a tubular body attached to the inner surface of the container. The tubular body inspection apparatus is configured to irradiate an inner surface of the tubular body with an annular laser beam while moving along the axial direction of the tubular body, and the inner body irradiated with the annular laser beam. An inspection probe that generates a plurality of annular beam images that are captured images of the annular laser light on the inner surface by imaging the surface along the axial direction of the tubular body, and the inspection inside the tubular body Image processing is performed on the annular beam image generated by the probe driving device for controlling the position of the probe for inspection and the inspection probe to determine whether a defect exists on the inner surface of the tubular body. The probe driving device is mounted with the inspection probe, moves the inspection probe along the axial direction of the tubular body, and moves the inspection probe to the center of the tubular body. An inspection stem provided with a probe driving mechanism that rotates about an axis, and a fitting surface that can be fitted with a fitting portion provided on at least one of the container and a member attached to the container. And a tubular jig inspection apparatus having a fixing jig for fixing the inspection stem to at least one of the container and a member attached to the container.

  When the fixing jig is fitted to the fitting portion, the central axis of the inspection probe is coaxial with the central axis of the tubular body.

  The fixing jig includes one or a plurality of outer diameter adjusting members provided so as to be concentric with the central axis of the fixing jig, and each of the outer diameter adjusting members includes the fitting portion. It may have a fitting surface that can be fitted, and the outer diameter adjusting member may be detachable according to the size of the fitting portion.

  The probe driving device may be attached to a die holder, and the fixing jig may have a fitting surface that can be fitted to the die holder.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, in the pipe manufacturing process using a container, the inner surface of the container liner which is a tubular body attached to the inner surface of the said container is test | inspected. An annular laser beam is applied to the inner surface of the tubular body while moving along the axial direction of the tubular body, and the inner surface irradiated with the annular laser beam is imaged. Thus, an inspection probe that generates a plurality of annular beam images that are captured images of the annular laser light on the inner surface along the axial direction of the tubular body, and the position of the inspection probe inside the tubular body And a processing unit for performing image processing on the annular beam image generated by the inspection probe and determining whether a defect exists on the inner surface of the tubular body The probe driving device is mounted with the inspection probe, moves the inspection probe along the axial direction of the tubular body, and moves the inspection probe around the central axis of the tubular body. It has a fitting surface that can be fitted with a fitting portion provided on at least one of the inspection stem provided with a probe driving mechanism to be rotated and the container and a member attached to the container. A container liner mounted on the container using a tubular body inspection apparatus having a fixing jig for fixing the inspection stem to at least one of the container and a member mounted on the container The fixing jig has a fitting surface that can be fitted with a die holder for fixing the container liner to the container. Ri, at predetermined intervals, the fixing jig the testing stem is provided housed in said die holder, the tubular body inspection method for inspecting the inner surface of the container liner is provided.

  As described above, according to the present invention, the fixing jig of the probe driving device can be fitted to the fitting portion provided in at least one of the container and the member attached to the container. This fixing jig fixes the inspection stem to which the inspection probe is attached, so that the inside of the tubular body can be more easily made without hindering the pipe making process using the container. It becomes possible to inspect.

It is the block diagram which showed the structure of the tubular body inspection apparatus which concerns on the 1st Embodiment of this invention. It is explanatory drawing which showed an example of the whole structure of the probe for a test | inspection which concerns on the embodiment, and a probe drive device. It is explanatory drawing which showed an example of a structure of the test | inspection probe which concerns on the same embodiment. It is explanatory drawing which showed an example of a structure of the test | inspection probe which concerns on the same embodiment. It is explanatory drawing which showed an example of the whole structure of the probe drive device which concerns on the same embodiment. It is explanatory drawing for demonstrating the tubular body test | inspection method which concerns on the embodiment. It is the block diagram which showed the structure of the image process part with which the arithmetic processing apparatus which concerns on the same embodiment is provided. It is explanatory drawing which showed an example of the irradiation area | region of the annular beam which concerns on the embodiment. It is explanatory drawing for demonstrating the coordinate transformation process which concerns on the same embodiment. It is explanatory drawing which showed an example of the annular beam image which concerns on the same embodiment. It is explanatory drawing which showed an example of the fringe image frame at the time of sending which concerns on the embodiment. It is explanatory drawing which showed an example of the fringe image frame at the time of transmission concerning the embodiment. It is explanatory drawing for demonstrating the optical cutting line process which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the displacement amount of the optical cutting line which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the sum total of the luminance which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the number of pixels of the bright line based on the embodiment. It is explanatory drawing for demonstrating the optical cutting line process which concerns on the same embodiment. It is explanatory drawing which showed an example of distribution of the number of pixels of the bright line which concerns on the embodiment. It is explanatory drawing which showed the relationship between the displacement of an optical cutting line, and the height of a defect. It is explanatory drawing for demonstrating the approximate correction process of the optical cutting line which concerns on the same embodiment. It is explanatory drawing for demonstrating the complementation process of the depth image which concerns on the embodiment. It is explanatory drawing which showed an example of the depth image which concerns on the embodiment. It is explanatory drawing which showed an example of the brightness | luminance image which concerns on the same embodiment. It is explanatory drawing which showed an example of the logic table used by the defect detection process which concerns on the same embodiment. It is the block diagram which showed the hardware constitutions of the arithmetic processing unit which concerns on the same embodiment. It is explanatory drawing for demonstrating the pipe making method by the Eugene Sejunel hot extrusion method.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<Overall configuration of tubular body inspection device>
First, the overall configuration of the tubular body inspection apparatus 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory view showing a configuration of a tubular body inspection apparatus 10 according to the present embodiment.

  The tubular body inspection apparatus 10 according to the present embodiment is used when an inspection probe 100 (to be described later) is fed into the tubular body, and when the tubular body 1 is delivered from the inside of the tubular body. It is an apparatus that inspects whether or not surface defects (concave and flaws and pattern-type wrinkles) exist on the inner surface of the tubular body 1 by performing image processing on both sides and performing image processing on an image obtained as a result of the imaging.

  Here, the tubular body 1 according to the present embodiment is not particularly limited as long as the tubular body 1 has a hollow portion, but examples of the tubular body 1 include spiral steel pipes, ERW steel pipes, UO steel pipes, Examples include not only various steel pipes and pipes such as seamless steel pipes (seamless steel pipes), forged steel pipes, and TIG welded steel pipes, but also tubular materials such as cylinders and container liners used in the hot extrusion method.

  As shown in FIG. 1, the tubular body inspection apparatus 10 according to the present embodiment includes an inspection probe 100 that images the inner surface of the tubular body 1, and the movement and tube circumference of the inspection probe 100 along the tube axis direction. A probe driving device 200 that controls the rotation of a direction and an arithmetic processing device 300 that performs image processing on an image obtained as a result of imaging are provided.

  The inspection probe 100 is attached to a probe driving device 200 described later, and is fed into the hollow portion of the tubular body 1. The inspection probe 100 sequentially images the inner surface of the tubular body 1 along the axial direction while changing the position along the axial direction of the tubular body 1 and calculates a captured image obtained as a result of the imaging. This is an apparatus for outputting to the processing apparatus 300. The position of the inspection probe 100 along the axial direction is controlled by a probe driving device 200 described later, and a PLG signal is received from a PLG (Pulse Logic Generator: pulse type velocity detector) or the like as the inspection probe 100 moves. It is output to the arithmetic processing unit 300. In the inspection probe 100, the imaging timing of the tubular body 1 is controlled by the arithmetic processing unit 300.

  As described above, the inspection probe 100 according to the present embodiment images the inner surface of the tubular body 1 when being fed into the tubular body, and also when being sent out from the inside of the tubular body. The inner surface of the camera is imaged.

  The probe driving device 200 is a drive control device including an actuator that controls movement of the inspection probe 100 in the tube axis direction and rotation in the tubular body circumferential direction with the tube center axis direction as a rotation axis. The probe driving device 200 controls driving processing such as movement of the inspection probe 100 in the tube axis direction and rotation in the circumferential direction of the tubular body under the control of the arithmetic processing device 300, for example.

  More specifically, the probe driving device 200 feeds the inspection probe 100 into the tubular body, and when the inspection probe 100 finishes imaging the inner surface to be inspected, the probe driving device 200 feeds the inspection probe 100. To stop. Thereafter, the probe driving device 200 rotates the inspection probe 100 in the circumferential direction of the tubular body with the central axis of the inspection probe 100 as a rotation axis. Thereafter, the probe driving device 200 causes the inspection probe 100 to be sent out from the inside of the tubular body.

  The arithmetic processing device 300 uses the captured image generated by the tubular body imaging device 100 to generate a striped image frame, and performs image processing on the striped image frame, thereby existing on the inner surface of the tubular body 1. This is a device for detecting a possible defect.

  At this time, the arithmetic processing device 300 according to the present embodiment generates an image generated from the captured image captured at the time of transmission so as to eliminate the dead zone due to the connecting member that connects the laser light source and the imaging device in the inspection probe 100. Is used to complement the image generated from the captured image captured at the time of delivery. Thereby, even when there is a dead zone in the captured image captured at the time of sending or sending, the inner surface of the tubular body can be inspected over the entire periphery.

  Hereinafter, the inspection probe 100, the probe driving device 200, and the arithmetic processing device 300 according to the present embodiment will be described in detail with reference to the drawings. In the following description, a case where the probe driving device 200 to which the inspection probe 100 is attached is sent to the inner surface of the container liner 1 under the control of the arithmetic processing device 300 is taken as an example. To do.

<About inspection probe>
First, the inspection probe 100 according to the present embodiment will be described with reference to FIGS. 2, 3A, and 3B. FIG. 2 is an explanatory diagram showing an example of the entire configuration of the inspection probe and the probe driving apparatus according to the present embodiment. 3A and 3B are explanatory views showing an example of the configuration of the inspection probe according to the present embodiment.

  As shown in FIG. 2, the inspection probe 100 according to the present embodiment is attached to the distal end of an inspection stem included in a probe driving device 200 described later, and is inside the tubular body (in this example, a container liner) 1. To be sent to. The inspection probe 100 irradiates the inner surface of the container liner with an annular laser beam (hereinafter also referred to as an annular beam), and images the inner surface irradiated with the annular beam, thereby picking up an image of the annular beam. A plurality of annular beam images are generated along the axial direction of the tubular body.

  As shown in FIGS. 3A and 3B, the inspection probe 100 according to the present embodiment includes a laser beam irradiation device 110, a camera 120, and a holding substrate 131 to which the laser beam irradiation device 110 and the camera 120 are fixed. And a connecting member 133 which is a support for connecting the two holding substrates 131. In the inspection probe 100 according to the present embodiment, the laser light irradiation device 110 and the camera 120 include the central axis of the laser light irradiated from the laser light irradiation device 110 and the central axis (optical axis) of the camera 120. Are arranged so as to be coaxial.

  The laser beam irradiation device 110 is a device that irradiates an annular beam along the circumferential direction of the inner surface of the tubular body 1, and includes a laser light source 111 and a conical optical element 113, as shown in FIG. 3A. Also have.

  The laser light source 111 is a light source that oscillates laser light having a predetermined wavelength. As such a laser light source 111, it is possible to use, for example, a CW laser light source that continuously performs laser oscillation. The wavelength of the light oscillated by the laser light source 111 is preferably a wavelength belonging to the visible light band of about 400 nm to 800 nm, for example. The laser light source 111 oscillates laser light based on an irradiation timing control signal sent from the arithmetic processing device 300 described later.

  The conical optical element 113 is an optical element including a conical mirror or prism, and is installed so that the apex of the conical portion faces the laser light source 111. The spot-shaped laser light emitted from the laser light source 111 is reflected by the apex of the conical portion of the optical element 113, and a line beam is generated in a ring shape. Here, when the cone angle of the cone portion is 90 °, as shown in FIG. 3A, the annular beam is irradiated in a direction perpendicular to the laser incident direction from the laser light source 111.

  The camera 120 is mounted with an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The camera 120 images the reflected light of the annular beam irradiated perpendicularly to the inner surface of the tubular body 1 from the direction of the angle φ as shown in FIG.

  The focal length and angle of view of the lens mounted on the camera 120 and the distance between the laser light irradiation device 110 and the image sensor of the camera 120 are not particularly limited, but the inner surface of the tubular body 1 is irradiated. It is preferable to select such that an entire image of the annular beam can be captured. Further, the size and pixel size of the image sensor mounted on the camera 120 are not particularly limited, but it is preferable to use a large image sensor in consideration of the image quality, image resolution, and the like of the generated image. Further, from the viewpoint of image processing described below, the line width (line width) of the annular beam is preferably adjusted to be about 1 to 3 pixels on the image sensor.

  The laser beam irradiation device 110 and the camera 120 scan the inner surface of the tubular body 1 while moving in the axial direction so as to substantially coincide with the central axis of the tubular body 1 by a probe driving device 200 described later. Further, the arithmetic processing unit 300 described later outputs a trigger signal for imaging to the camera 120 every time the inspection probe 100 moves a predetermined distance in the axial direction. The movement distance in the axial direction of the laser beam irradiation device 110 and the camera 120 can be set as appropriate. For example, it is preferable to set the same as the pixel size of the image sensor provided in the camera 120. By matching the movement distance in the axial direction and the pixel size of the image sensor, the resolution in the vertical direction and the resolution in the horizontal direction can be matched in the captured image.

  Note that the angle φ shown in FIG. 2 can be set to an arbitrary value, but is preferably about 30 to 60 degrees, for example. If the angle is too large, the scattered light (reflected light) of the annular beam from the inner surface of the tubular body 1 becomes weak. This is because the amount of movement of the stripes in the image is reduced, and information on the depth of the concave portion (or the height of the convex portion) existing on the inner surface of the tubular body 1 is deteriorated.

  The laser beam irradiation device 110 and the camera 120 are each fixed to a holding substrate 131, and these two holding substrates 131 are connected by one or a plurality of connecting members 133. The inspection probe for imaging the inner surface of the tubular body 1 is formed by fixing the laser beam irradiation device 110 and the camera 120 by the holding substrate 131 and the connecting member 133.

  The materials for the holding substrate 131 and the connecting member 133 may be appropriately selected according to the heat resistance and strength required for the inspection probe 100. Further, the number of the connecting members 133 may be set as appropriate according to the strength required for the inspection probe 100, and may be one or plural.

  The thickness of the connecting member 133 (for example, the tube diameter in the case of the cylindrical connecting member 133) is such that the annular beam irradiation region (hereinafter also referred to as a beam irradiation region) has an annular beam or imaging field of view. It is set so as to be wider than a region shielded by 133 (hereinafter also referred to as a shield region).

  Here, when a plurality of connecting members 133 are provided, for example, as illustrated in FIG. 3B, it is preferable that the connecting members 133 are arranged at equal intervals along the circumferential direction of the holding substrate 131 as illustrated in FIG. 3B. When a plurality of connecting members 133 are installed, it is preferable to determine the number so that the shielding area is as narrow as possible.

  When the number of the connecting members 133 is one, for example, the connecting member 133 may be installed at any one position among the four connecting members shown in FIG. 3B.

  Here, the probe driving device 200 described later rotates the inspection probe 100 in the circumferential direction according to the number of the connecting members 133 when imaging of the surface of the tubular body at the time of feeding is completed. The magnitude of this rotation angle is such that when the reference line virtually set on the surface of the tubular body is taken as a reference, the shielding area caused by the arrangement of the connecting member 133 is different at the time of sending and at the time of sending. (In other words, the shielding area at the time of sending and the shielding area at the time of sending do not overlap). Specifically, when the number of connecting members 133 is one, the probe driving device 200 rotates the inspection probe 100 by 180 ° along the circumferential direction, for example. Further, when two connecting members 133 are installed at equal intervals, the probe driving device 200 rotates the inspection probe 100 by 90 ° in the circumferential direction, for example, and three connecting members 133 are installed at equal intervals. Is rotated by 60 ° in the circumferential direction, for example. Further, as shown in FIG. 3B, when four connecting members 133 are installed at equal intervals, the probe driving device 200 rotates the inspection probe 100 by, for example, 45 ° in the circumferential direction.

  In the following, specific configurations, set values, and the like are listed for each apparatus included in the inspection probe 100 according to the present embodiment. Such a configuration, set values, and the like are merely examples, and the inspection probe 100 according to the present invention is not limited to the following specific examples.

○ Tubular container liner: inner diameter 150-600mm, length 850mm
○ Laser beam irradiation device Irradiates laser beam with an output of 160 mW. The conical optical element 113 irradiates the inner surface of the tubular body as an 80 mW annular beam. The line beam width irradiated on the inner surface of the container liner is 0.30 mm. However, the line beam width in this case is defined as 13.5% from the peak intensity value.
○ Camera A CCD with 2330 pixels x 1750 pixels is mounted as an image sensor. The frame rate is 30 fps, the focal length of the lens is 1.8 mm, the angle of view is 180 °, the pixel size of the image to be captured is 0.5 mm × 0.5 mm, and the line beam width is a bright line of 1 to 3 pixels on the captured image. Filmed in width.
○ Separation distance between laser beam irradiation device and camera image sensor: approx. 250 mm
The camera 120 captures an image of the inner surface of the tubular body every 0.5 mm in the axial direction.

<About the probe driver>
Subsequently, the probe driving apparatus 200 according to the present embodiment will be described in detail with reference to FIGS. 2, 4, and 5. FIG. 4 is an explanatory diagram showing an example of the overall configuration of the probe driving apparatus according to the present embodiment. FIG. 5 is an explanatory diagram for explaining the tubular body inspection method according to the present embodiment.

  The probe driving apparatus 200 according to the present embodiment is equipped with the inspection probe 100 and controls the position of the inspection probe 100 inside the tubular body. As shown in FIG. 2, for example, the probe driving apparatus 200 has an inspection stem 201 to which the inspection probe 100 is attached and an inspection stem 201 to which the inspection probe 100 is attached attached to a container liner. A fixing jig 203 to be fixed to the die holder.

  Here, the case where the fixing jig 203 is fitted to the die holder will be described below. However, the fixing jig 203 may be fitted directly to the container or directly to the container liner. It may be fitted directly to both the container and the container liner. Further, the fixing jig 203 may be fitted to a member other than a die holder or a container liner mounted on the container.

  The inspection stem 201 according to the present embodiment includes, for example, two holding substrates 211a and 211b (hereinafter, the two holding substrates may be collectively referred to as the holding substrate 211), as shown in FIG. A linear guide 213 that is a connecting member for connecting the two holding substrates 211 and a ball screw shaft 215 are provided.

  Here, the inspection probe 100 is mounted on the substrate 211a of one of the two holding substrates 211 (the side located inside the tubular body when the inspection stem 201 is fed into the tubular body 1). Is done. Further, the ball screw shaft 215 is disposed so as to pass through the central axis of the inspection stem 201 so that the central axis of the inspection probe 100 and the central axis of the inspection stem 201 are coaxial. Yes. In addition, if it is possible to send and send the inspection stem 201 while maintaining the same axis as the tubular body 1, the inspection stem 201 is sent and sent using a known means other than the ball screw shaft. May be.

  2 and 4 illustrate the case where two linear guides 213 are provided, the number of linear guides 213 is not limited to two, and is required for the inspection stem 201. If the strength can be realized, the number may be one, or three or more.

  As the material of the holding substrate 211 and the linear guide 213, a known material can be used as long as it can realize the heat resistance against the internal temperature of the tubular body 1 and the strength required for the inspection stem 201. . Examples of such a material include metals such as stainless steel and aluminum.

  One of the two holding substrates 211 (the side located outside the tubular body when the inspection stem 201 is fed into the tubular body 1) has an axial direction coupled to the ball screw shaft 215. A scanning motor 217 is provided. This axial scanning motor 217 is an example of a probe driving mechanism. The power from the axial scanning motor 217 is transmitted to the ball screw shaft 215, and the entire inspection stem 201 with the inspection probe 100 attached thereto is sent into and out of the tubular body. It is converted into the action to do. The inspection probe 100 according to the present embodiment moves on the inner surface of the tubular body (for example, the container liner) 1 along the axial direction by the tube axis direction moving mechanism including the ball screw shaft 215 and the axial direction scanning motor 217. It becomes possible to do.

  Of the two holding substrates 211, a circumferential rotation motor 219 is disposed on the substrate 211a on which the inspection probe 100 is mounted. The circumferential direction rotation motor 219 is an example of a probe driving mechanism. The power from the circumferential rotation motor 219 is transmitted to the inspection probe 100 mounted on the holding substrate 211a by a power transmission mechanism (not shown) including, for example, a gear provided on the holding substrate 211a. . The inspection probe 100 can be rotated in the circumferential direction around the axial direction of the tubular body by the rotation mechanism including the circumferential direction rotation motor 219 and the power transmission mechanism.

  Here, the position where the circumferential direction rotation motor 219 is disposed is not limited to the example shown in FIG. 4, and any position can be used as long as power can be transmitted to the inspection probe 100. It is possible to arrange. In FIG. 4, only one circumferential rotation motor 219 is installed on the inspection stem 201. However, the number of circumferential rotation motors 219 is not limited to the example shown in FIG. A plurality of motors 219 may be provided on the inspection stem 201.

  The axial scanning motor 217 and the circumferential rotation motor 219 are driven based on control signals output from the arithmetic processing unit 300 described later. Therefore, the probe driving device 200 according to the present embodiment is driven under the control of the arithmetic processing device 300.

  In the pipe making process by the hot extrusion method described with reference to FIG. 22, the steel billet is manufactured by pushing out the hollow billet filled in the container liner to the die side. Waste such as a glass scale that causes the above is accumulated on the die side inside the container liner. Therefore, it is preferable that the inspection stem 201 according to the present embodiment has such a length that at least a half region located on the die side of the entire length of the container liner can be inspected. Further, the inspection stem 201 according to the present embodiment may have a length capable of inspecting the entire length of the container liner.

  The inspection stem 201 as described above is held so as to be coaxial with the central axis of the fixing jig 203 provided with the ball screw nut system 221. Further, the inspection stem 201 may not be attached to the fixing jig 203 by using the ball screw nut system 221, and the inspection stem 201 is smoothly fed into and sent out from the inside of the tubular body 1. If possible, it may be performed using a known means such as a ball bearing.

  The fixing jig 203 is a substantially circular member used for accommodating the inspection stem 201 on which the inspection probe 100 is mounted in the die holder. The central axis of the fixing jig 203 is the tubular body 1. It is designed to be coaxial with the central axis in the tube axis direction. As shown in FIGS. 2 and 4, the surface of the fixing jig 203 that contacts the die holder is a fitting surface that can be fitted to the die holder. Have the same mating surface. As a result, the inspection stem 201 with the inspection probe 100 attached can be easily attached to the die holder.

  Further, as illustrated in FIG. 2, the fixing jig 203 is firmly locked to the container liner by being held by the die holder and the die backer. Since the center axis of the inspection stem 201 is coaxial with the central axis of the fixing jig 203, the inspection probe 100 and the inspection probe 100 are inspected by attaching the fixing jig 203 to the die holder. The stem 201 is coaxial with the central axis of the tubular body 1 in the tube axis direction, and the installation position of the inspection probe 100 can be uniquely determined. As a result, when the inspection process is periodically performed in the pipe making process, it is possible to drastically reduce the measurement error caused by the displacement of the mounting position of the inspection probe 100, and more accurate inspection always under the same conditions. Can be performed.

  Here, as shown in the right side of FIG. 4, the fixing jig 203 is concentric with the main body 251 around the main body 251 and the main body 251 on which the inspection stem 201 is mounted. 1 or a plurality of outer diameter adjusting members 253a, 253b (hereinafter, the plurality of outer diameter adjusting members may be collectively referred to as an outer diameter adjusting member 253). May be. The main body 251 and each outer diameter adjusting member 253 have the same fitting surface as that of a die used in a normal pipe making process. Each outer diameter adjusting member 253 is formed to be detachable from the main body 251.

  By configuring the fixing jig 203 with two types of members, the main body 251 and the outer diameter adjusting member 253, the outer diameter adjusting member 253 can be adjusted to the inner diameter of the tubular body 1 to which the fixing jig 203 is mounted. By attaching or removing, the outer diameter of the fixing jig 203 can be easily adjusted. As a result, the fixing jig 203 can be easily attached to the tubular body 1 having various inner diameters.

  4 illustrates a case where two outer diameter adjusting members 253 are provided around the main body 251. However, the number of outer diameter adjusting members provided around the main body 251 is an example shown in the drawing. It is not necessarily limited to this, and may be determined as appropriate according to the range of the inner diameter of the tubular body 1 to which the probe driving device 200 is attached.

  In addition, when various signals (for example, control signals, image signals, etc.) are exchanged between the inspection probe 100 or the inspection stem 201 and the arithmetic processing unit 300 via the cable, the cable passes through the cable. These through holes may be formed in the main body 251 of the fixing jig 203. The formation position of the through hole is not particularly limited, but it is preferable to form the through hole at a position where the cable does not get in the way when the inspection stem 201 is sent and received.

  The probe driving apparatus 200 according to the present embodiment has been described in detail above with reference to FIGS. 2 and 4.

<About a tubular body inspection method using an inspection probe and a probe driving device>
Next, a tubular body inspection method using the inspection probe 100 and the probe driving device 200 according to the present embodiment will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining a tubular body inspection method using the inspection probe and the probe driving device according to the present embodiment.

  In the steel pipe manufacturing process by the hot extrusion method, when the extrusion process is completed and the steel pipe is manufactured, a part of the hollow billet remains in the container as a pressed residue. Therefore, every time the hollow billet filled in the container is almost pushed out, after cutting and separating the manufactured steel pipe and the pressed residue, the pressed residue is put together with the die holder in the state where the pressed residue is in close contact with the die. And take out the dice and separate them (see the upper part of FIG. 5). That is, every time a steel pipe is manufactured, an operation of changing the die is performed.

  Therefore, in order to monitor and inspect the surface state of the inner surface of the tubular body such as a container liner, the inspection according to the present embodiment is performed on the container liner after taking out the die and the die holder in close contact with each other at predetermined intervals. The probe 100 and the probe driving device 200 are mounted (see the lower diagram in FIG. 5). Here, the timing of mounting the inspection probe 100 and the probe driving device 200 may be determined according to a preset management standard or the like, for example, any timing such as “every 20 steel pipes are manufactured”. Can be set to

  Here, the inspection probe 100 and the probe driving device 200 are accommodated in the die holder, and prepared in advance as an inspection unit by fixing with a die backer, without interfering with the flow work in the steel pipe manufacturing process, The inspection probe 100 and the probe driving device 200 can be attached to the container liner.

  When the inspection of the surface of the tubular body using the inspection probe 100 and the probe driving device 200 (imaging processing of the surface of the tubular body) is completed, the inspection probe 100 and the probe driving device 200 are removed together with the die holder and the die backer. Then, the die is accommodated in the die holder, and the unit in which the die is fixed by the die backer is mounted again, so that the steel pipe manufacturing process can be easily resumed.

  By performing such a periodic inspection, it is possible to obtain information on changes in container liners over time and wrinkle occurrence information under the same inspection conditions (imaging conditions inside the tubular body). As a result, accurate container liner monitoring can be achieved.

  The tubular body inspection method using the inspection probe 100 and the probe driving device 200 according to the present embodiment has been described above with reference to FIG.

<Overall configuration of arithmetic processing unit>
Returning to FIG. 1 again, the overall configuration of the arithmetic processing unit 300 included in the tubular body inspection apparatus 10 according to the present embodiment will be described.

  For example, as illustrated in FIG. 1, the arithmetic processing device 300 according to the present embodiment mainly includes an imaging control unit 301, an image processing unit 303, a display control unit 305, and a storage unit 307.

  The imaging control unit 301 is realized by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a communication device, and the like. The imaging control unit 301 performs imaging control of the inspection object by the inspection probe 100 and the probe driving device 200 according to the present embodiment. More specifically, the imaging control unit 301 sends a control signal for starting oscillation of laser light to the laser light irradiation device 110 when imaging of the tubular body 1 is started.

  Further, when the imaging processing at a certain position along the tube axis direction is completed, the imaging control unit 301 sends a control signal to the probe driving device 200 (more specifically, the axial scanning motor 217), The inspection stem 201 to which the inspection probe 100 is attached is moved by a predetermined distance (for example, 0.5 mm).

  When the inspection probe 100 and the probe driving device 200 start imaging of the tubular body 1, PLG signals are periodically transmitted from the inspection probe 100 and / or the probe driving device 200 (for example, probe driving with the inspection probe 100 attached). Each time the apparatus 200 moves 0.5 mm, one pulse (PLG signal) is transmitted, but the imaging control unit 301 transmits a trigger signal for starting imaging to the camera 120 every time the PLG signal is acquired. .

  In addition, when the inspection stem 201 with the inspection probe 100 attached thereto is fed in for a predetermined distance, the imaging control unit 301 detects the probe driving device 200 (more specifically, the circumferential rotation motor 219). A control signal is sent out to rotate the inspection probe 100 by a predetermined angle. Thereafter, the imaging control unit 301 sends a control signal for starting imaging processing at the time of sending to the inspection probe 100.

  The image processing unit 303 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The image processing unit 303 generates a fringe image frame using imaging data acquired from the inspection probe 100 (more specifically, the camera 120 of the inspection probe 100). Thereafter, image processing as described below is performed on the generated fringe image frame to detect defects that may exist on the inner surface of the tubular body that is the measurement object. When the image processing unit 303 finishes the defect detection process on the inner surface of the tubular body 1, the image processing unit 303 transmits information about the obtained detection result to the display control unit 305.

  Further, in the image captured by the inspection probe 100 according to the present embodiment, as described above, there is a shielding region caused by the connecting member 133. Therefore, the image processing unit 303 according to the present embodiment supplements the image generated from the striped image frame captured at the time of sending using the image generated from the striped image frame captured at the time of sending, and there is no shielding area. After generating an image, a defect present on the inner surface is detected.

  The image processing unit 303 will be described in detail later again.

  The display control unit 305 is realized by, for example, a CPU, a ROM, a RAM, an output device, and the like. The display control unit 305 is provided outside the arithmetic processing device 300 or an output device such as a display provided in the arithmetic processing device 300, and the defect detection result of the tubular body 1 that is the inspection object transmitted from the image processing unit 303. Display control when displaying on the output device. Thereby, the user of the tubular body inspection apparatus 10 can grasp the detection results regarding various defects existing on the inner surface of the inspection object (tubular body 1) on the spot.

  The storage unit 307 is realized by, for example, a RAM or a storage device included in the arithmetic processing device 300 according to the present embodiment. In the storage unit 307, various parameters, processes in progress, or various databases and programs that need to be saved when the arithmetic processing apparatus 300 according to the present embodiment performs some processing, or various databases and programs are appropriately stored. To be recorded. The storage unit 307 can be freely read and written by the imaging control unit 301, the image processing unit 303, the display control unit 305, and the like.

<About the image processing unit>
Next, the image processing unit 303 included in the arithmetic processing apparatus 300 according to the present embodiment will be described in detail with reference to FIG. FIG. 6 is a block diagram illustrating a configuration of an image processing unit included in the arithmetic processing apparatus according to the present embodiment.

  As shown in FIG. 6, the image processing unit 303 according to the present embodiment includes an A / D conversion unit 351, an annular beam center calculation unit 353, a coordinate conversion unit 355, a fringe image frame generation unit 357, and an image. A calculation unit 359 and a defect detection unit 371 are mainly provided.

  The A / D conversion unit 351 is realized by, for example, a CPU, a ROM, a RAM, and the like. The A / D conversion unit 351 performs A / D conversion on the captured images output from the camera 120 at the time of sending and sending, and outputs them as digital multivalued image data (that is, an annular beam image). Such digital multivalued image data is stored in an image memory provided in the storage unit 307 or the like. By sequentially using these digital multi-value image data along the axial direction of the tubular body, a striped image frame as described later is formed.

  The annular beam image is an image of the annular beam irradiated on the inner surface of the tubular body at a certain position along the axial direction of the inner surface of the tubular body 1. The annular beam image is a grayscale image in which the portion irradiated with the annular beam is displayed in white and the other portions are displayed in black by appropriately setting the camera gain and the lens aperture in advance. Further, the unevenness superimposed on the circumference of the annular beam includes information on defects existing on the inner surface of the tubular body.

  Here, as schematically shown in FIG. 7, the annular beam image according to the present embodiment includes a beam irradiation region where the annular beam is irradiated on the inner surface, and a dead zone where the annular beam is shielded by the connecting member 133. There is a shielding area. Further, when switching from the sending state to the sending state, the inspection probe 100 rotates by a predetermined angle in the circumferential direction of the tubular body (in FIG. 7, it rotates 45 degrees clockwise), so Focusing on a certain reference point, the position of the shielding area is different between the sending time and the sending time.

  When the A / D conversion unit 351 generates the annular beam images at the time of sending and sending as shown in FIG. 7 based on the two types of captured images output from the camera 120, the A / D conversion unit 351 corresponds to each of the generated annular beam images. The data to be output is output to the annular beam center calculation unit 353 described later.

  The annular beam center calculation unit 353 is realized by, for example, a CPU, a ROM, a RAM, and the like. The annular beam center calculation unit 353 calculates the center of gravity position of the ring and the radius of the ring for each of the annular beam images output from the A / D conversion unit 351 at the time of transmission and at the time of transmission.

  Here, the method of calculating the center of gravity position and the radius of the ring is not particularly limited, and any known method can be used. Specific examples of the method for calculating the center of gravity position and radius of the ring include the following two methods, which can be used regardless of the presence or absence of a shielding region.

Extract any three points on the binarized annular beam image and calculate the center of gravity of the position coordinates of these three points. The distance between the obtained barycentric position and any one of the three points is the radius of the ring.
-Circle extraction by Hough transformation is performed, and the center of gravity and radius of the circle (that is, the annular beam) are calculated.

  When the annular beam center calculation unit 353 calculates the center of gravity position and radius of the ring for each of the annular beam images at the time of transmission and transmission, the annular beam center calculation unit 353 generates information on the center of gravity position and radius of the ring, respectively, and a coordinate conversion unit 355 described later. Output to.

  In addition, in this embodiment, although the case where the cross-sectional shape of the inner surface of the tubular body 1 is close to a perfect circle is described, it can be applied to any cross-sectional shape. For example, the cross-sectional shape is an ellipse or a rounded corner. It may be a rectangle or the like. The center of gravity in such a case can be obtained from the shape of the annular beam, and by using the average value of the maximum value and the minimum value of the distance to the obtained center of gravity as the radius, coordinate conversion described later is performed in the same procedure. Can be implemented.

  The coordinate conversion unit 355 is realized by a CPU, a ROM, a RAM, and the like, for example. The coordinate conversion unit 355 converts the coordinate system of the annular beam image based on the calculated gravity center position and the separation distance between the gravity center position and the irradiated portion of the annular beam. After that, the coordinate conversion unit 355 generates a light section image that represents the irradiated portion of the annular beam as a line segment developed in the circumferential direction of the tubular body.

By calculating the position of the center of gravity of the annular beam, the pixel position corresponding to the irradiation position of the annular beam can be represented by polar coordinates (r, θ) with the center of gravity position as the origin. As shown in FIG. 8, the coordinate conversion unit 355 provides an allowance of ± Δr in the radial direction for the radius r calculated by the annular beam center calculation unit 353 (that is, a range of r−Δr to r + Δr). ), Coordinate transformation is performed with 0 ° ≦ θ ≦ 360 °. In the present embodiment, the case where coordinate transformation is performed in the range of r−Δr to r + Δr in the radial direction has been described. However, the value of the margin Δr is a range including the irradiated portion of the annular beam and is in the plus direction. The value may be different in the minus direction. In such a case, for example, the range in which the coordinate conversion is performed can be expressed as r−Δr _{1 to} r + Δr ₂ . However, in the present embodiment, the following description will be given for the case where the same value Δr is used in the plus direction and the minus direction.

  By performing such coordinate conversion, as shown on the right side of FIG. 8, the radius direction has a height of 2Δr around the radius r, and the angle direction has a length of 360 °. A band-like image is extracted. As is clear from the above description, the extracted belt-like image includes a line segment (hereinafter also referred to as a light cutting line) in which the annular beam irradiated portion is developed in the circumferential direction of the tubular body. Further, by extracting a range of 2Δr with the radius r as the center in the radial direction, it is possible to extract the entire circumference of the annular beam including the irregularities even if irregularities exist around the circumference of the annular beam. It becomes. The band-like image obtained in this way is hereinafter referred to as a light section image.

  The magnitude of Δr can be determined by roughly calculating in advance the range of the height of the unevenness that can exist in the tubular body 1 based on past operation data and the like.

  Also, the coordinate conversion unit 355 converts the coordinates of the pixels included in the light section image into orthogonal coordinates (r cos θ, rsin θ) by using the coordinates (r, θ) of each pixel in the extracted light section image. . Here, since the coordinate value conversion performed by the coordinate conversion unit 355 is conversion from the polar coordinate system to the orthogonal coordinate system, the lattice point (that is, the center position of the pixel) in the polar coordinate system is always a lattice in the orthogonal coordinate system. It does not necessarily correspond to a point, and there also exists a thing corresponding to a non-grid point. Therefore, in order to interpolate the density (pixel value) of the non-grid points in the orthogonal coordinate system, the coordinate conversion unit 355 interpolates based on the density of other grid points located near the point of interest. It is preferable to implement the image interpolation method together.

  Such an image interpolation method is not particularly limited, and for example, a well-known image interpolation method described in “Shokudo Image Processing Handbook” or the like can be used. Examples of such an image interpolation method include a nearest neighbor method, a bi-linear interpolation method, and a cubic interpolation method. Of these methods, the former has a higher processing speed, and the latter has a higher quality result. Therefore, the coordinate conversion unit 355 may appropriately determine the type of image interpolation method to be used according to the amount of resources that can be used for processing, the processing time, and the like. In the specific example of the light section image shown in the present embodiment, the cubic interpolation method is applied as the image interpolation method.

  Here, when converting the coordinate system, the coordinate conversion unit 355 according to the present embodiment performs the conversion process using the reference point virtually set on the surface of the tubular body as a reference (processing start point). The position on the surface of the tubular body where the reference point is set is not particularly limited, and can be set at an arbitrary position. For example, in the example shown in FIG. 7, the reference point K is set in the 3 o'clock direction when the tubular body surface is viewed in the feeding direction. The reference point K is selected so as to be the same position between the annular beam images captured at each position in the tube axis direction.

  When the coordinates of the reference point K are specified on the annular beam image at the time of sending, the position of the reference point K in the annular beam image at the time of sending is rotated by a predetermined angle with the coordinates of the reference point K at the time of sending. Can be specified. That is, when the inspection probe 100 is rotated by + X degrees when the clockwise direction is the positive direction at the time of sending, the position of the reference point K at the time of sending is rotated by -X degrees, thereby The position of the reference point K can be specified.

  FIG. 9 schematically shows an annular beam image captured by the inspection probe 100 at the time of sending and sending. In the case of the example shown in FIG. 7, the inspection probe 100 generates an annular beam image at the time of transmission after being rotated 45 degrees clockwise. Here, since the laser irradiation device 110 and the camera 120 of the inspection probe 100 are integrally formed, the camera 120 also rotates in accordance with the rotation of the inspection probe 100. Accordingly, in the annular beam image shown in FIG. 9, the reference point K rotates 45 degrees counterclockwise.

  When the coordinate conversion unit 355 completes the coordinate conversion process based on the reference point K and the image interpolation process, the image data corresponding to the obtained light-cut image is stored in the image memory provided in the storage unit 307 or the like. It stores sequentially along the axial direction of the tubular body.

  The fringe image frame generation unit 357 is realized by, for example, a CPU, a ROM, a RAM, and the like. The fringe image frame generation unit 357 sequentially acquires the light section images stored along the axial direction of the tubular body from the image memory provided in the storage unit 307 and the like. Thereafter, the fringe image frame generation unit 357 sequentially arranges the acquired light-cut images along the axial direction of the tubular body, and generates a fringe image frame at the time of sending and a fringe image frame at the time of sending, respectively.

  The number of light section images constituting one striped image frame may be set as appropriate. For example, one striped image frame may be composed of 256 light section images. Each light section image exists at every imaging interval (for example, 0.5 mm interval) of the annular beam image as described above. Therefore, one striped image frame composed of 256 light section images based on the annular beam images taken at intervals of 0.5 mm is 128 mm (= 256) along the entire circumference of the inner surface of the tubular body. This corresponds to the result of imaging in a range of × 0.5 mm).

  FIG. 10 is an explanatory diagram schematically showing the in-strip stripe image frame generated in this way, and FIG. 11 schematically shows the in-strip stripe image frame generated in this way. It is explanatory drawing shown.

  The striped image frames generated by the striped image frame generation unit 357 at the time of sending and sending are shown in FIGS. 10 and 11 according to the number of connecting members 133 provided on the inspection probe 100. There will be a shielding area. Further, since the origin of the fringe image frames in the circumferential direction is coordinate-transformed starting from a common reference point K by the coordinate transformation unit 355, the reference points are equal to each other as shown in FIGS. K.

  When the fringe image frame generation unit 357 generates the fringe image frame at the time of sending and the stripe image frame at the time of sending, the fringe image frame is output to the image calculation unit 359 described later. Further, the fringe image frame generation unit 357 associates time information related to the date and time when the fringe image frame was generated with the data corresponding to each of the generated fringe image frames, and stores the data in the storage unit 307 or the like as history information. Good.

  The image calculation unit 359 is realized by, for example, a CPU, a ROM, a RAM, and the like. The image calculation unit 359 includes a depth image representing the uneven state of the inner surface of the tubular body, the tubular body based on the two types of striped image frames generated by the striped image frame generation unit 357 at the time of sending and sending. And a luminance image representing the distribution of the luminance of the annular beam on the inner surface. As shown in FIG. 6, the image calculation unit 359 includes a light section line processing unit 361, a depth image calculation unit 363, a luminance image calculation unit 365, a depth image complementing unit 367, and a luminance image complementing unit. 369.

  The light section line processing unit 361 is realized by, for example, a CPU, a ROM, a RAM, and the like. The light cutting line processing unit 361 has three types of light cutting line feature values regarding the amount of displacement of the light cutting line (bending degree of the bright line), the number of pixels of the bright line, and the sum of the luminance for each light cutting line included in the fringe image frame. Is calculated.

  Hereinafter, the processing performed by the light section line processing unit 361 and the calculated light section line feature amount will be described in detail with reference to FIGS.

  In the following description, it is assumed that there are N light cutting lines in one striped image frame, and the horizontal length of the striped image frame is M pixels. In addition, it is assumed that one light section image including one light section line is composed of vertical 2Δr pixels × horizontal M pixels.

Here, for convenience of explanation, it is assumed that the X axis is taken in the circumferential direction of the striped image frame and the Y axis is taken in the axial direction of the striped image frame, and the pixel position in the striped image frame is expressed by XY coordinates. In the following description, the position of the m-th pixel (1 ≦ m ≦ M) from the left side of the j (1 ≦ j ≦ N) th light section line existing in the fringe image frame (ie, represented by X _{j, m} ). The position).

When the light cutting line processing unit 361 first selects an X coordinate position (a position represented by X _{j, m} in this description) of a light cutting line to be focused (hereinafter also simply referred to as a line). As shown in FIG. 12, the distribution of pixel values (that is, the luminance value of the annular beam) associated with the pixel at the focused X coordinate position of the focused line is referred to. At this time, the light cutting line processing unit 361 does not perform the process described below for all the pixels at the X coordinate position in the light cutting image, but instead performs the reference position Y _s of the Y coordinate in the light cutting image. The processing described below is performed on pixels belonging to the range of W before and after (that is, pixels belonging to the range of Y _s −W to Y _s + W).

Here, the reference position Y _s Y-coordinate is the position in the axial direction specified in advance for j-th line of the light section image of the fringe image frame, for example by specifying the axial center of the light section image When the same margin value Δr is used in the plus direction and the minus direction as described above, it becomes equal to the radius r (that is, the position of the light cutting line) calculated by the annular beam center calculation unit. The parameter W defining a processing range based on the height range of the irregularities which may be present in the tubular body 1 in the past operation data, the Y coordinate in the light section images before and after W reference position Y _s A rough calculation may be performed in advance so that the range fits in the light-cut image, and the range may be determined as appropriate. If the value of the parameter W can be reduced, the processing load of the optical section line processing unit 361 described later can be reduced.

Light section line processor 361, first, from among the pixels included in the range of Y _s -W~Y _s + _W, the first threshold value for specifying the pixels corresponding to the light section line given as an example A pixel having a pixel value equal to or greater than the threshold Th is specified. In the example illustrated in FIG. 12, three pixels represented by Y _{j, k} , Y _{j, k + 1} , Y _{j, k + 2} have pixel values I _{j, k} , I _{j, k + 1} , I _j that are greater than or equal to the threshold Th. _{, K + 2} . Accordingly, the light section line processing unit 361 sets the number p _{j, m} = 3 obtained by adding pixels having pixel values equal to or greater than the predetermined threshold Th in the line width direction. The number p _{j, m} obtained by adding pixels having pixel values equal to or greater than the predetermined threshold Th in the line width direction is a value corresponding to the number of pixels of the bright line at the position (j, m). one of. The light section line processing unit 361 also performs information (Y _{j, k} , I _{j, k} ), (Y _{j, k + 1} , I _{j, k + 1} ), (Y _{j, k + 2} ) regarding the extracted pixels in the following processing. , I _{j, k + 2} ) (hereinafter, sometimes simply abbreviated as (Y, I)), further light section line feature quantities are calculated.

Further, the light section line processing unit 361 calculates the total sum K _{j, m} of the luminances of the extracted pixels using the parameters p _{j, m} and the information (Y, I) regarding the extracted pixels. In the case of the example illustrated in FIG. 12, the sum of the luminances calculated by the light section line processing unit 361 is K _{j, m} = I _{j, k} + I _{j, k + 1} + I _{j, k + 2} . This total luminance K _{j, m} is also one of the features of the light section line.

Further, the light section line processing unit 361 uses the information (Y, I) regarding the extracted pixel and the reference position Y _{s of the} Y coordinate, and the barycentric position Y _C (j, m) and a displacement amount Δd _{j, m} = Y _s −Y _C (j, m) of the center of gravity Y _C (j, m) from the reference position Y _s are calculated.

Here, the center-of-gravity position Y _C (j, m) is a value represented by the following expression 101, where A is a set of extracted pixels. Therefore, in the case of the example shown in FIG. 12, the center of gravity position Y _C (j, m) is a value represented by the following expression 101a.

Here, the position in the axial direction corresponding to the pixel is a value quantized by the movement width of the inspection probe 100 (for example, 0.5 mm). On the other hand, the centroid position Y _C (j, m) calculated by the calculation shown in the above equation 101 is a value calculated by using a numerical calculation called division. It can be a value smaller than (so-called quantization unit). Therefore, the displacement amount Δd _{j, m} calculated using the center-of-gravity position Y _C (j, m) is also a value that can have a value smaller than the movement width. The displacement amount Δd _{j, m} calculated in this way is also one of the light section line feature amounts.

  The light section line processing unit 361 calculates the above three types of feature amounts with respect to M elements included in each section line. As a result, as shown in FIGS. 13A to 13C, a two-dimensional array of M columns × N rows is generated with respect to the displacement Δd of the light section line, the luminance sum K, and the number of pixels p of the bright line.

  The light section line processing unit 361 according to the present embodiment performs a process of specifying the position of the shielding region in addition to the above three types of light section line feature values. Hereinafter, the process of specifying the position of the shielding area will be described in detail.

Since the annular laser beam is not imaged by the camera 120 in the shielding region by the connecting member 133, there is no bright line having a luminance higher than the predetermined threshold Th as schematically shown in FIG. Accordingly, in the process of calculating the light section line feature amount, the light section line feature amount p _{j, m} for the number of pixels of the bright line is zero in the shielding region.

Therefore, the light section line processing unit 361 according to the present embodiment specifies the circumferential coordinate (X coordinate) indicating the range of the shielding region by paying attention to the number of pixels of the bright line at each circumferential direction (X direction) position. . In the following, description will be given by taking as an example the case of calculating the start position X _s1s and the end position X _s1e of the shielding area present first from the left in the striped image frame image.

The optical cutting line processing unit 361, for each of the N optical cutting lines constituting the annular beam image at the time of sending, the X coordinate position X _{s1js at} which the shielding area starts and the X coordinate position at which the shielding area ends. X _s1je (j = 1 to N) is specified. Then, in consideration of the case where the start position and the end position of the shielding area are shifted due to the influence of vibration generated in the inspection probe 100, the N of the specified N shielding area start positions _Xs1js the minimum value with the _{X S1S,} the maximum value of the shielding area end position _{X S1je} and _{X S1e.}

Further, the start position X _s1js and the end position X _s1je of the first shielding area from the left in the j-th line can be specified as follows. Hereinafter, a method for specifying the start position X _s1js and the end position X _s1je of the shielding area will be described in detail with reference to FIG.

The light section line processing unit 361 pays attention to the pixel number p _{j, m} (m = 1 to M) of the bright line in each X coordinate of the jth light section line. Then, the light section line processing unit 361 determines whether or not an X position where p _{j, m} = 0 appears for the number of bright line pixels p _{j, m at} each X position. When there is an X position where p _{j, m} = 0, the optical section line processing unit 361 stores the coordinate X _m and continues the state in which p _{j, m} = 0 for the subsequent X coordinates. Count the number. Here, as schematically shown in FIG. 15, when the number of consecutive states in which p _{j, m} = 0 is equal to or greater than a predetermined threshold TH _s (for example, TH _s = 10), the optical cutting is performed. line processor 361, the X coordinate _{X m} which had been stored is specified as the start position _{X S1js} of the first shielding area from the left in the j-th line.

Also, in the state where the start position X _s1js of the shielding area is specified, it is assumed that an X coordinate X _n where p _{j, m} ≠ 0 appears while searching for the number of bright line pixels in the X direction. . In this case, the light section line processing unit 361 stores the coordinates _Xn and counts the number of consecutive states where p _{j, m} ≠ 0 for the subsequent X coordinates. Here, as schematically illustrated in FIG. 15, when the number of consecutive states in which p _{j, m} ≠ 0 is equal to or greater than a predetermined threshold TH _s (for example, TH _s = 10), the light is cut. The line processing unit 361 specifies the X position _immediately before the stored X coordinate X _n as the end position X _s1je of the first shielding region from the left in the j-th line. In the above description has shown the case with the threshold value TH _s used to identify the start position of the shielding region, and the threshold value TH _s used to identify an end position of the shielding region is the same value The two threshold values may be different from each other.

Further, another method for determining the start position X _s1s and the end position X _s1e of the shielding area may be as follows.
For each X coordinate of the light cutting line of the j-th line, while moving the coordinate position, predetermined left and right k pixels (for example, k = 3 etc.) of the number of bright line pixels p _{j, m} (m = 1 to M). Average values q _{j, m} (m = 1 to M) are sequentially obtained (moving average processing). Next, an X coordinate position at which the obtained average value q _{j, m} is less than a preset threshold A (for example, A = 0.5) is set as a start position X _s1s of the shielding area. In addition, an X _coordinate position where the start position X _s1s of the shielding area is specified and the obtained average value q _{j, m} is equal to or greater than a preset threshold A is defined as an end position X _s1e of the shielding area.

By performing the above processing for each optical cutting line with j = 1 to N, the optical cutting line processing unit 361 determines the start position X _s1s and the end position X _s1e of the first shielding region from the left. Can be determined. Further, the same processing is performed on the second and subsequent shielding areas from the left, whereby the start position and end position of the shielding area can be determined.

The light section line processing unit 361 uses the light section line feature amount Δd _{j, m} for the amount of displacement of the light section line in the shielding region and the light section line feature amount K _{j, m} for the sum of the luminances in the shielding region. Are each treated as zero.

Therefore, for example, for the first shielding region from the left _, a two-dimensional array of bright line pixels p _{j, m,} a two-dimensional array of bright line luminance sums K _{j, m} , and a bright line displacement amount Δd _{j, m} The two-dimensional arrays are as follows.

p _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )
K _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )
Δd _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )

  For example, the optical section line processing unit 361 performs the above-described processing on the fringe image frame corresponding to the annular beam image at the time of sending in which the four connecting members 133 are reflected as shown in FIG. By implementing, as shown in FIG. 10, the start position and the end position of each of the four shielding areas can be specified.

In addition, the light section line processing unit 361 calculates the light section line feature amount in the same manner for the striped image frame at the time of transmission illustrated in FIG. However, for the striped image frame at the time of transmission, the start position and end position of the shielding area need not be specified. Here, when an X position where the number of bright line pixels p _{j, m} = 0 appears in the striped image frame at the time of transmission, the light-section line processing unit 361 includes the total luminance K _{j, m} of the corresponding X position, and The displacement amount Δd _{j, m} of the bright line is treated as zero.

The light section line processing unit 361 outputs a feature amount related to the displacement amount Δd of the light section line among the calculated light section line feature amounts to the depth image calculation unit 363 described later. In addition, the light section line processing unit 361 outputs, to the brightness image calculation unit 365 (to be described later), among the calculated light section line feature amounts, the feature amount related to the luminance sum K and the number p of bright line pixels. Further, the light section line processing unit 361 displays information indicating the start position and end position of each shielding area existing in the striped image frame at the time of sending (for example, information indicating X _{s1s to} X _s4e in FIG. 10). This is output to a depth image complementing unit 367 and a luminance image complementing unit 369 described later.

  The depth image calculation unit 363 is realized by, for example, a CPU, a ROM, a RAM, and the like. The depth image calculation unit 363 uses the optical section line feature amount (particularly, the feature amount related to the displacement amount Δd) generated by the optical section line processing unit 361 for each of the feeding time and the sending time. A depth image representing the uneven state of the surface is calculated. Hereinafter, the depth image at the time of sending is also referred to as a depth image at the time of sending, and the depth image at the time of sending is also referred to as a depth image at the time of sending.

  Specifically, the depth image calculation unit 363 calculates the feature amount (two-dimensional array) regarding the displacement amount Δd as shown in FIG. 13A and the vertical component incident angle (angle φ in FIG. 2) of the annular beam. Using this, a depth image is calculated.

  First, the relationship between the height of the unevenness present on the inner surface of the tubular body and the amount of displacement Δd of the light cutting line will be described with reference to FIG. FIG. 16 is an explanatory diagram showing the relationship between the displacement of the optical cutting line and the height of the defect.

  In FIG. 16, the case where the dent exists in the inner surface of the tubular body 1 is shown typically. Here, the difference between the height of the surface position and the height of the bottom of the dent when there is no dent on the inner surface is represented by Δh. Paying attention to the case where the vertically incident annular beam reflects the surface, when there is no dent on the inner surface, the reflected light propagates as shown in the light ray A of FIG. 16, but there is a dent on the inner surface. In this case, the reflected light propagates like the light beam B in FIG. The deviation between the light beam A and the light beam B is observed as the displacement Δd of the light cutting line in this embodiment. Here, as is apparent from the geometrical positional relationship, the relationship Δd = Δh · sinφ is established between the displacement Δd of the light cutting line and the depth Δh of the recess.

  In addition, although the case where a dent exists in the inner surface of a tubular body was demonstrated in FIG. 16, even if it is a case where a convex part exists in the inner surface of a tubular body, the same relationship is materialized.

  The depth image calculation unit 363 uses the relationship as described above, and based on the feature amount related to the displacement Δd of the optical cutting line calculated by the optical cutting line processing unit 361, the amount related to the unevenness of the inner surface of the tubular body Δh is calculated.

  Here, the displacement amount Δd of the optical cutting line used for the calculation of the depth image is calculated based on the barycentric position of the optical cutting line as described above, and has a value smaller than the moving width. It is a possible value. Therefore, the depth image calculated by the depth image calculation unit 363 is an image in which unevenness is reproduced with a resolution finer than the pixel size of the image sensor.

  In addition, as shown in FIG. 17, distortion such as curvature occurs in the optical cutting line due to a change in the shape of the inner surface of the tubular body that is the object to be inspected and the camera scanning direction axis deviating from the center of the tubular body. There is a case. On the other hand, in the defect detection method according to the present embodiment, the unevenness superimposed on the light cutting line is information on the cross-sectional shape of the inner surface of the tubular body and the surface defect existing on the inner surface. Therefore, when the depth image calculation unit 363 calculates a depth image based on the displacement amount Δd of the light cutting line, the depth image calculation unit 363 performs distortion correction processing for each light cutting line, and the unevenness superimposed on the light cutting line. Only the information regarding may be extracted. By performing such a distortion correction process, even if the camera scanning direction axis does not exactly coincide with the central axis of the tubular body or the shape of the inner surface is not a circle, it exists on the inner surface. It is possible to obtain only the information on the uneven surface.

  As specific examples of such distortion correction processing, (i) a fitting process using a multidimensional function or various nonlinear functions, and a difference calculation between the obtained fitting curve and the observed light cutting line, ii) A process of applying a low-pass filter such as a floating filter or a median filter by using the fact that the information on the unevenness is a high-frequency component can be mentioned. By performing such a distortion correction process, it is possible to flatten the light section line while maintaining the information on the uneven surface existing on the inner surface.

  When the depth image calculation unit 363 calculates the depth image at the time of sending and the depth image at the time of sending, the information about the calculated images is output to the depth image complementing unit 367 described later.

  The luminance image calculation unit 365 is realized by a CPU, a ROM, a RAM, and the like, for example. The luminance image calculation unit 365 is based on the light cutting line feature amount generated by the light cutting line processing unit 361 (particularly, the feature amount relating to the luminance sum K and the number of pixels p of the bright line). A luminance image representing the luminance distribution of the annular beam on the inner surface of the tubular body is calculated. Hereinafter, the luminance image at the time of sending is also referred to as a luminance image at the time of sending, and the luminance image at the sending time is also referred to as a luminance image at the time of sending.

Specifically, the luminance image calculation unit 365 has a feature amount (two-dimensional array) related to the luminance sum K as shown in FIG. 13B and a feature amount related to the number of pixels p of bright lines as shown in FIG. 13C ( The average luminance K _AVE (j, m) = K _{j, m} / p _{j, m} (1 ≦ j ≦ N, 1 ≦ m ≦), which is the average value of the total luminance in the line width direction. M) is calculated. After that, the luminance image calculation unit 365 sets the data array composed of the calculated average luminance K _AVE (j, m) as the luminance image of the focused tubular body.

  When the luminance image calculation unit 365 calculates the transmission luminance image and the transmission luminance image, the luminance image calculation unit 365 outputs information regarding the calculated images to the luminance image complementing unit 369 described later.

  The depth image complementing unit 367 is realized by, for example, a CPU, a ROM, a RAM, and the like. The depth image complementing unit 367 performs a complementing process of the portion corresponding to the shielding area in the depth image using the depth image at the time of sending and the depth image at the time of sending calculated by the depth image calculating unit 363. .

  In the depth image at the time of sending and the depth image at the time of sending calculated by the depth image calculation unit 363, the portion corresponding to the shielding region by the connecting member 133 is a portion where there is no change in the pixel value. Therefore, it is impossible to obtain accurate knowledge about the uneven state of the inner surface of the tubular body. Therefore, the depth image complementing unit 367 performs processing for complementing the depth information of the shielding region using these two types of depth images.

  Hereinafter, with reference to FIGS. 10, 11, and 18, the interpolation process for the portion corresponding to the shielding region that exists first from the left in the depth image will be specifically described.

  In the inspection probe 100 according to the present embodiment, when the state is changed from the state in which the annular beam image at the time of feeding is taken to the state in which the annular beam image at the time of sending is switched, the entire inspection probe 100 is only a predetermined angle. Rotate. Further, in the inspection probe 100, as described above, the thickness and the arrangement position of the connecting member 133 are determined so that the beam irradiation region is wider than the shielding region.

  Due to the above settings, in the tubular body inspection apparatus 10 according to the present embodiment, as shown in the striped image frame of FIGS. The position will change. As is clear from FIG. 11, since the beam irradiation region is wider than the shielding region, the shielding region in one striped image frame (for example, the striped image frame at the time of sending) is the other striped image frame (for example, sending out). It is included in the non-shielding region in the time stripe image frame).

  Therefore, the depth image complementing unit 367 according to the present embodiment supplements the shielding area of the in-feed depth image by using the sending-out depth image, for example, as shown in FIG. A depth image in which there is no portion corresponding to is generated.

FIG. 18 schematically illustrates a process of complementing the shielding area that exists first from the left.
The start position X _s1s and the end position X _s1e of the shielding area in the image at the time of sending are specified by the light section line processing unit 361 and notified to the depth image complementing unit 367. Therefore, the depth image complementing unit 367 acquires depth information of a portion (X _{s1s to} X _s1e ) corresponding to the shielding area of the in-feed depth image with reference to the in-depth image, and sends in The acquired depth information is substituted into the portion corresponding to the occlusion area of the hour depth image.

  Here, as is clear from the operation of the inspection probe 100, the N-th light cutting line in the striped image frame at the time of sending is the same as the first light cutting line in the striped image frame at the time of sending. Corresponds to the position in the tube axis direction. Therefore, the depth image complementing unit 367 uses the depth image corresponding to the Nth line of the sending depth image when complementing the depth information corresponding to the first line of the sending depth image. Then, complement processing is performed. Similarly, the depth image complementation unit 367 corresponds to the (N + 1−j) line of the depth image at the time of transmission when complementing the depth information corresponding to the jth line of the depth image at the time of transmission. Complement processing is performed using the depth image.

  The depth image complementing unit 367 performs such a complementing process on the portion corresponding to the first line to the Nth line, so that the shielding region present first from the left in the depth image at the time of sending is obtained. Depth information can be complemented.

  In addition, the depth image complementing unit 367 applies the same complementing process to the portions corresponding to the second and subsequent occluded regions from the left, so that all the occluded regions existing in the in-feed depth image It is possible to supplement the depth information of the part corresponding to.

  When the depth image complementing unit 367 complements the depth information of the part corresponding to the shielding region by the complementing process as described above, the depth image complementing unit 367 outputs information regarding the depth image after complementing to the defect detecting unit 371 described later. . In addition, the depth image complementing unit 367 may store information regarding the depth image after complementing as history information in the storage unit 307 or the like in association with time information regarding the date and time when the information is calculated. Further, the depth image complementing unit 367 may output information on the complemented depth image to the display control unit 305 and output the information to the display unit (not shown).

  An example of the depth image complemented by the depth image complementing unit 367 is shown in FIG. 19A. FIG. 19A is an explanatory diagram showing an example of a depth image according to the embodiment. Note that the depth image illustrated in FIG. 19A is obtained by planarly developing the depth image generated from the fringe image frame in the circumferential direction, and shows a part of the generated depth image.

  In the depth image shown in FIG. 19A, the convex portion is displayed so that the luminance gradation is bright, and the concave portion is displayed so that the luminance gradation is dark. As is clear from FIG. 19A, it can be seen that there are portions displayed darker than the surroundings in the vicinity of the left end and in the substantially central portion of the drawing, and there are recesses in such portions. In the depth image shown in FIG. 19A, the shape of the gem clip (thickness 1 mm) attached to the object to be inspected is clearly reproduced.

  The luminance image complementing unit 369 is realized by, for example, a CPU, a ROM, a RAM, and the like. The luminance image complementing unit 369 uses the in-transmission luminance image and the in-transmission luminance image calculated by the luminance image calculation unit 365 to perform a complementing process for a portion corresponding to the shielding area in the luminance image.

  In the in-transmission luminance image and the in-transmission luminance image calculated by the luminance image calculation unit 365, the portion corresponding to the shielding region by the connecting member 133 has a pixel value of zero, and from this portion, the inner surface of the tubular body It is not possible to obtain accurate knowledge about the unevenness state. Therefore, the luminance image complementation unit 369 performs a process of complementing the luminance information of the shielding area using these two types of luminance images.

Here, the luminance image complementing unit 369 performs the transmission-time luminance image based on the start position X _s1s and the end position X _s1e of the shielding area in the image at the time of transmission in the same manner as the complement processing by the depth image complementing unit 365. Referring to, the luminance information of the portion (X _{s1s to} X _s1e ) corresponding to the shielding area of the luminance image at the time of sending is acquired, and the acquired luminance information is substituted into the portion corresponding to the shielding area of the luminance image at the time of sending. To do. At this time, the luminance image complementing unit 369 uses the luminance image corresponding to the (N + 1−j) th line of the sending luminance image in order to complement the luminance information corresponding to the jth line of the sending luminance image. To complete the supplementary processing.

  The luminance image complementing unit 369 applies the same complementing process to the portions corresponding to all the occluded regions present in the image, so that the luminances of the portions corresponding to all the occluded regions existing in the in-transmission luminance image are applied. Information can be supplemented.

  When the luminance image complementing unit 369 complements the luminance information of the portion corresponding to the shielding region by the complementing process as described above, the luminance image complementing unit 369 outputs information on the luminance image after complementing to the defect detection unit 371 described later. In addition, the luminance image complementing unit 369 may store the information regarding the luminance image after complementing as history information in the storage unit 307 or the like in association with time information regarding the date and time when the information is calculated. Further, the luminance image complementing unit 369 may output information on the luminance image after complementing to the display control unit 305 and output the information to the display unit (not shown).

  An example of the luminance image complemented by the luminance image complementing unit 369 is shown in FIG. 19B. FIG. 19B is an explanatory diagram showing an example of a luminance image according to the embodiment. Note that the luminance image shown in FIG. 19B is obtained by planarly developing the luminance image generated from the striped image frame in the circumferential direction, and shows a part of the generated luminance image.

  In the luminance image shown in FIG. 19B, the luminance gradation is changed according to the average luminance value (brightness and darkness). A portion displayed in black in FIG. 19B corresponds to a pattern defect corresponding to a so-called scale residue.

Returning to FIG. 6 again, the defect detection unit 371 according to the present embodiment will be described.
The defect detection unit 371 according to the present embodiment is realized by, for example, a CPU, a ROM, a RAM, and the like. The defect detection unit 371 detects a defect present on the inner surface of the tubular body based on the depth image complemented by the depth image complementing unit 367 and the luminance image supplemented by the luminance image complementing unit 369.

  The defect detection unit 371 extracts a defect part specifying function that specifies a defective part based on the depth image and the luminance image, a feature quantity extraction function that extracts a feature quantity related to the form and pixel value of the specified defect part, and A defect discrimination function for discriminating the type of defect, the degree of harmfulness, and the like based on the feature amount. Hereinafter, these functions will be briefly described.

Defect site identification function The defect detection unit 371 is a filter that obtains a linear sum of pixel values (values representing depth or luminance values) with peripheral pixels for each pixel of the acquired depth image and luminance image. Regions such as vertical line wrinkles, horizontal line wrinkles, and fine wrinkles are emphasized by the processing, and it is determined whether or not the obtained value is equal to or greater than a second threshold value for specifying a defect site. By performing such a filtering process and a determination process based on the filtering process result, the defect detection unit 371 can generate a binarized image for specifying a defective part. In such a binarized image, a pixel whose calculated value is less than the second threshold corresponds to a normal location (that is, pixel value of the binarized image = 0), and the calculated value is equal to or greater than the second threshold. The pixel in question corresponds to a defective portion (that is, the pixel value of the binarized image = 1). Furthermore, the defect detection unit 371 identifies each defective part by combining consecutively generated defect parts.

Feature Extraction Function When the defect detection unit 371 specifies a defect part in the depth image and the luminance image by the defect part specifying function, the defect detection unit 371 extracts a feature quantity related to the form and pixel value of the defect part for each specified defect part. Examples of the feature quantity related to the form of the defective part include the width of the defective part, the length of the defective part, the peripheral length of the defective part, the area of the defective part, and the area of the circumscribed rectangle of the defective part. In addition, as the feature amount related to the pixel value of the defective part, for the depth image, the maximum value, the minimum value, the average value, etc. of the depth of the defective part can be mentioned. Value, minimum value, average value, and the like.

Defect determination function When the defect detection unit 371 extracts the feature amount of each defective portion by the feature amount extraction function, the defect detection unit 371 determines the defect type, the degree of harm, and the like for each defective portion based on the extracted feature amount. The determination processing such as the type of defect and the degree of harmfulness based on the feature amount is performed using a logic table as shown in FIG. 20, for example. That is, the defect detection unit 371 determines the type of defect and the degree of harmfulness based on the determination condition represented by the logic table illustrated in FIG.

  As illustrated in FIG. 20, defect types (defects A1 to An) are described as vertical items in the logic table, and feature types (feature amounts B1) are used as horizontal items in the logic table. To feature quantity Bm). Also, in each cell of the table defined by the defect type and the feature amount, a discrimination conditional expression (conditional expression C11 to conditional expression Cnm) based on the size of the corresponding feature amount is described. Each row of such a logic table is a set, and becomes a determination condition for each type of defect. The determination process is performed in order from the type described in the top line, and ends when all the determination conditions described in any one line are satisfied.

  Such a logic table is obtained by a known method using a database constructed by a learning process in which past operation data and a result of specifying a defect type and a hazard level by an examiner based on the operation data are used as teacher data. It is possible to generate.

  The defect detection unit 371 specifies the type of defect and the degree of harm for each defective part detected in this way, and outputs the obtained detection result to the display control unit 305. Thereby, the information regarding the defect which exists in the inner surface of the tubular body which is a detection target will be output to a display part (not shown). In addition, the defect detection unit 371 may output the obtained detection result to an external device such as a manufacturing control process computer, or may create a product defect form using the obtained detection result. Good. In addition, the defect detection unit 371 may store information related to the detection result of the defective part in the storage unit 307 or the like as history information in association with time information related to the date and time when the information is calculated.

  In the above description, the case where the type of the defect and the harmfulness are determined using the logic table has been described. However, the method for determining the type of the defect and the harmfulness is not limited to the above example. For example, a discriminator such as a neural network or a support vector machine (SVM) is generated by learning processing using past operation data and a result of specifying a defect type and a hazard level by a tester based on the operation data as teacher data, Such a discriminator may be used for discriminating the type of defect and the degree of harm.

  The configuration of the image processing unit 303 included in the arithmetic processing device 300 according to the present embodiment has been described above in detail.

  In the above description, when the depth image calculation unit 363 calculates the depth image, the case where the approximate correction process such as the difference calculation process or the low-pass filter process is performed has been described. However, such an approximate correction process may be performed by the light cutting line processing unit 361 before the light cutting line processing unit 361 calculates the light cutting line feature amount.

In the above description, the portion corresponding to the shielding area of the depth image at the time of sending and the luminance image at the time of sending is complemented by using the portion corresponding to the beam irradiation area of the depth image at sending time and the luminance image at sending time. However, the reverse process can also be performed.
That is, the light section line processing unit 361 specifies the start position and the end position of the shielding area in the striped image frame at the time of transmission, paying attention to the striped image frame at the time of transmission. In addition, the depth image complementing unit 367 and the luminance image complementing unit 369 use the portion corresponding to the beam irradiation area of the in-feed depth image and the in-feed luminance image, and send out the depth image and send out. A portion corresponding to the occluded area of the temporal luminance image may be complemented.

  Heretofore, an example of the function of the arithmetic processing apparatus 300 according to the present embodiment has been shown. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. In addition, the CPU or the like may perform all functions of each component. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  A computer program for realizing each function of the arithmetic processing apparatus according to the present embodiment as described above can be produced and installed in a personal computer or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

  Heretofore, the configuration of the tubular body inspection apparatus 10 according to the present embodiment has been described in detail. By utilizing the tubular body inspection apparatus 10 according to the present embodiment, it becomes possible to inspect the inner surface of the tubular body over the entire circumference in the circumferential direction and over the entire length. It can be detected simultaneously with accuracy. In addition, since the tubular body inspection apparatus 10 according to the present embodiment enables easy and quick inspection even during the production process of the tubular body, the productivity and yield of tubular bodies such as steel pipes can be improved. Can greatly contribute to quality assurance.

(About hardware configuration)
Next, the hardware configuration of the arithmetic processing apparatus 300 according to the embodiment of the present invention will be described in detail with reference to FIG. FIG. 21 is a block diagram for explaining a hardware configuration of the arithmetic processing device 300 according to the embodiment of the present invention.

  The arithmetic processing device 300 mainly includes a CPU 901, a ROM 903, and a RAM 905. The arithmetic processing device 200 further includes a bus 907, an input device 909, an output device 911, a storage device 913, a drive 915, a connection port 917, and a communication device 919.

  The CPU 901 functions as an arithmetic processing device and a control device, and controls all or part of the operation in the arithmetic processing device 300 according to various programs recorded in the ROM 903, the RAM 905, the storage device 913, or the removable recording medium 921. The ROM 903 stores programs used by the CPU 901, calculation parameters, and the like. The RAM 905 primarily stores programs used by the CPU 901, parameters that change as appropriate during execution of the programs, and the like. These are connected to each other by a bus 907 constituted by an internal bus such as a CPU bus.

  The bus 907 is connected to an external bus such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge.

  The input device 909 is an operation unit operated by the user, such as a mouse, a keyboard, a touch panel, a button, a switch, and a lever. The input device 909 may be, for example, remote control means (so-called remote controller) using infrared rays or other radio waves, or may be an external connection device 923 such as a PDA corresponding to the operation of the arithmetic processing device 300. May be. Furthermore, the input device 909 includes, for example, an input control circuit that generates an input signal based on information input by a user using the operation unit and outputs the input signal to the CPU 901. The user of the arithmetic processing device 300 can input various data and instruct processing operations to the arithmetic processing device 300 by operating the input device 909.

  The output device 911 is configured by a device capable of visually or audibly notifying acquired information to the user. Such devices include display devices such as CRT display devices, liquid crystal display devices, plasma display devices, EL display devices and lamps, audio output devices such as speakers and headphones, printer devices, mobile phones, and facsimiles. The output device 911 outputs results obtained by various processes performed by the arithmetic processing device 300, for example. Specifically, the display device displays a result obtained by various processes performed by the arithmetic processing device 300 as text or an image. On the other hand, the audio output device converts an audio signal composed of reproduced audio data, acoustic data, and the like into an analog signal and outputs the analog signal.

  The storage device 913 is a data storage device configured as an example of a storage unit of the arithmetic processing device 300. The storage device 913 includes, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device. The storage device 913 stores programs executed by the CPU 901, various data, various data acquired from the outside, and the like.

  The drive 915 is a recording medium reader / writer, and is built in or externally attached to the arithmetic processing unit 300. The drive 915 reads information recorded on a removable recording medium 921 such as a mounted magnetic disk, optical disk, magneto-optical disk, or semiconductor memory, and outputs the information to the RAM 905. The drive 915 can also write a record on a removable recording medium 921 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. The removable recording medium 921 is, for example, a CD medium, a DVD medium, a Blu-ray medium, or the like. Further, the removable recording medium 921 may be a compact flash (registered trademark) (CompactFlash: CF), a flash memory, an SD memory card (Secure Digital memory card), or the like. Further, the removable recording medium 921 may be, for example, an IC card (Integrated Circuit card) on which a non-contact type IC chip is mounted, an electronic device, or the like.

  The connection port 917 is a port for directly connecting a device to the arithmetic processing device 300. Examples of the connection port 917 include a USB (Universal Serial Bus) port, an IEEE 1394 port, a SCSI (Small Computer System Interface) port, and an RS-232C port. By connecting the external connection device 923 to the connection port 917, the arithmetic processing device 300 acquires various data directly from the external connection device 923 or provides various data to the external connection device 923.

  The communication device 919 is a communication interface configured with, for example, a communication device for connecting to the communication network 925. The communication device 919 is, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB). The communication device 919 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various communication. The communication device 919 can transmit and receive signals and the like according to a predetermined protocol such as TCP / IP, for example, with the Internet and other communication devices. In addition, the communication network 925 connected to the communication device 919 is configured by a wired or wireless network, and may be, for example, the Internet, a home LAN, infrared communication, radio wave communication, satellite communication, or the like. .

  Heretofore, an example of the hardware configuration capable of realizing the functions of the arithmetic processing device 300 according to the embodiment of the present invention has been shown. Each component described above may be configured using a general-purpose member, or may be configured by hardware specialized for the function of each component. Therefore, it is possible to change the hardware configuration to be used as appropriate according to the technical level at the time of carrying out this embodiment.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Defect inspection apparatus 100 Inspection probe 200 Probe drive apparatus 300 Arithmetic processing apparatus 201 Inspection stem 203 Fixing jig 211 Holding substrate 213 Linear guide 215 Ball screw shaft 217 Axial scanning motor 219 Circumferential rotation motor 221 Ball screw Nut system 251 Main body 253 Outside diameter adjusting member

Claims (5)

In a pipe making process using a container, a tubular body inspection device used for inspecting the inner surface of a container liner which is a tubular body attached to the inner surface of the container,
While moving along the axial direction of the tubular body, the inner surface of the tubular body is irradiated with an annular laser beam, and the inner surface is imaged by irradiating the annular laser beam. An inspection probe for generating a plurality of annular beam images, which are captured images of the annular laser light, along the axial direction of the tubular body;
A probe driving device for controlling the position of the inspection probe inside the tubular body;
An arithmetic processing device that performs image processing on the annular beam image generated by the inspection probe and determines whether a defect exists on the inner surface of the tubular body;
With
The probe driving device includes:
An inspection provided with the probe for inspection, provided with a probe driving mechanism for moving the inspection probe along the axial direction of the tubular body and rotating the inspection probe about the central axis of the tubular body Stem for
It has a fitting surface that can be fitted with a fitting portion provided in at least one of the container and a member to be attached to the container, and the inspection stem is attached to the container and the container. A fixing jig for fixing to at least one of the member and
A tubular body inspection device characterized by comprising:   2. The tubular body inspection according to claim 1, wherein a center axis of the inspection probe is coaxial with a center axis of the tubular body by fitting the fixing jig with the fitting portion. apparatus. The fixing jig includes one or a plurality of outer diameter adjusting members provided so as to be concentric with the central axis of the fixing jig, and each of the outer diameter adjusting members includes the fitting portion. It has a mating surface that can be mated,
The tubular body inspection device according to claim 1, wherein the outer diameter adjusting member is detachable according to the size of the fitting portion. The probe driving device is mounted on a die holder,
The tubular body inspection apparatus according to any one of claims 1 to 3, wherein the fixing jig has a fitting surface that can be fitted to the die holder. In a pipe making process using a container, it is used for inspecting the inner surface of a container liner, which is a tubular body attached to the inner surface of the container, and while moving along the axial direction of the tubular body, the tubular body An annular beam image, which is an image of the annular laser beam on the inner surface, is obtained by irradiating the inner surface of the body with an annular laser beam and imaging the inner surface irradiated with the annular laser beam. A plurality of inspection probes generated along the axial direction of the tubular body, a probe driving device for controlling the position of the inspection probe inside the tubular body, and the annular beam image generated by the inspection probe An arithmetic processing unit that performs image processing on the inner surface of the tubular body and determines whether or not a defect exists on the inner surface of the tubular body, and the probe driving device includes the inspection probe. An inspection stem provided with a probe driving mechanism for moving the inspection probe along the axial direction of the tubular body and rotating the inspection probe about the central axis of the tubular body; and the container And a member to be fitted to the container, and a fitting surface that can be fitted to a fitting portion provided in at least one of the container and the member to be attached to the container, and the member for attaching the inspection stem to the container and the container Using a tubular body inspection device having a fixing jig that is fixed to at least one of the container, and inspecting the inner surface of the container liner attached to the container,
The fixing jig has a fitting surface that can be fitted with a die holder for fixing the container liner to the container,
The tubular body inspection method, wherein the fixing jig provided with the inspection stem is accommodated in the die holder and the inner surface of the container liner is inspected at predetermined intervals.