Surface inspection device, surface inspection method and control device

Abstract

To provide a surface inspection device, a surface inspection method and a program that can speedily detect foreign matter and a flaw on a surface of a cylindrical object.SOLUTION: A surface inspection device 1 comprises: a camera 21 which is arranged facing a surface of a cylindrical object, and images the surface of the cylindrical object; a rod-like member 23 which is arranged extending along an axis of the cylindrical object, and supports the camera 21; a head mechanism 24 which supports the rod-like member 23, and translates the camera 21 along the axis of the cylindrical object and also rotates the camera 21 on a center axis of the cylindrical object; and a control unit which is connected to the camera 21 and head mechanism 24, and controls operations of the camera 21 and head mechanism 24.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a surface inspection device, a surface inspection method, and Control device Regarding. [Background technology]

[0002] There is known a steel pipe inner surface inspection device for inspecting whether there is a foreign object or a flaw on the inner surface of a steel pipe. For example, Patent Document 1 discloses an inspection device configured to guide an image of the inner surface of a steel pipe to a light field camera using a conical prism or a conical mirror. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-9894 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inspection device of Patent Document 1 uses a conical prism or a conical mirror, so the imaging range is narrow and the number of images taken is inevitably large, resulting in the problem that it takes a long time to detect foreign objects and scratches. In addition, the inspection device of Patent Document 1 exclusively images the inner surface of the steel pipe, so there is also the problem that it cannot be applied to detect foreign objects and scratches on the outer surface of the steel pipe. Such problems are not limited to the case of inspecting steel pipes, but also exist when inspecting cylindrical objects other than steel pipes.

[0005] The present invention has been made based on the above background, and provides a surface inspection device, a surface inspection method, and Control device The purpose is to provide. [Means for solving the problem]

[0006] In order to achieve the above object, a surface inspection apparatus according to a first aspect of the present invention comprises: Towards the surface of a cylindrical object To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple A camera and a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; Equipped with.

[0007] before One or more of the elongated members are provided to support the plurality of cameras, The control unit may control the operation of the cameras and the head mechanism so as to rotate each camera around the central axis of the cylindrical object after the camera located most base end reaches the other axial end of the cylindrical object.

[0008] the control unit controls operation of each camera and the head mechanism so that, when the head mechanism translates from one end to the other end in the axial direction of the cylindrical object, each camera captures an image of a first imaging area set for each camera, and, when the head mechanism translates from the other end to the one end in the axial direction of the cylindrical object, each camera captures an image of a second imaging area set for each camera; Each of the first imaging areas extends in an axial direction of the cylindrical object and is set at intervals in a circumferential direction of the cylindrical object; Each of the second imaging areas may extend in the axial direction of the cylindrical object and may be set to be sandwiched between two adjacent first imaging areas.

[0009] The cameras may be aligned in the axial direction of the head mechanism, and two adjacent cameras may be disposed at equal intervals in the circumferential direction of the head mechanism.

[0010] The elongated member supports each camera individually; Each elongated member may be formed so that its tip end is thinner than its base end so as not to interfere with the camera that is not supported by the elongated member.

[0011] In order to achieve the above object, a surface inspection apparatus according to a second aspect of the present invention comprises: A camera disposed facing a surface of a cylindrical object and capturing an image of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; Equipped with the head mechanism supports the camera so as to be movable in a radial direction of the head mechanism; The control unit controls the operation of the head mechanism to adjust the position of the camera in a radial direction of the head mechanism in accordance with a radial size of the cylindrical object. do .

[0012] In order to achieve the above object, a surface inspection apparatus according to a third aspect of the present invention comprises: A camera disposed facing a surface of a cylindrical object and capturing an image of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; A conveying unit that conveys the cylindrical object; a support mechanism that supports the head mechanism so as to be movable in a conveying direction of the cylindrical object, When the control unit detects that the cylindrical object has been transported by the transport unit, the control unit controls an operation of the support mechanism so that the movement of the head mechanism follows the transport of the cylindrical object by the transport unit. do .

[0013] In order to achieve the above object, the present invention 4 The surface inspection device according to the above aspect is Towards the surface of a cylindrical object To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple A camera and a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member and translates the camera in an axial direction of the cylindrical object; a rotating stand on which the cylindrical object is placed and which rotates the cylindrical object around a central axis of the cylindrical object; a control unit connected to the camera, the head mechanism, and the rotating frame, for controlling operations of the camera, the head mechanism, and the rotating frame so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the cylindrical object around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; Equipped with.

[0014] In order to achieve the above object, the present invention 5 The surface inspection method according to the aspect of the present invention comprises: A surface inspection method performed by a surface inspection device, comprising: provided in the surface inspection device, and directed toward the surface of the cylindrical object To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple a step of causing a camera to capture an image of a surface of the cylindrical object while translating the camera from one end to the other end in an axial direction of the cylindrical object; After the camera reaches the other axial end of the cylindrical object, rotating the camera around a central axis of the cylindrical object; a step of causing the camera to capture an image of a surface of the cylindrical object while translating the camera rotated in the rotating step from the other end to one end in the axial direction of the cylindrical object; Includes.

[0015] In order to achieve the above object, the present invention 6 The surface inspection method according to the aspect of the present invention comprises: A surface inspection method performed by a surface inspection device, comprising: provided in the surface inspection device, and directed toward the surface of the cylindrical object To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple a step of causing a camera to capture an image of a surface of the cylindrical object while translating the camera from one end to the other end in an axial direction of the cylindrical object; After the camera reaches the other axial end of the cylindrical object, rotating the cylindrical object around a central axis of the cylindrical object; a step of causing the camera to capture an image of a surface of the cylindrical object while translating the camera from the other end to one end in the axial direction of the cylindrical object rotated by the rotating step; Includes.

[0016] In order to achieve the above object, the present invention 7 Pertaining to the viewpoint Control device teeth, A control device for controlling a surface inspection device, The above A surface inspection device is provided, and the surface of the cylindrical object is To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple a means for causing a camera to capture an image of a surface of the cylindrical object while translating the camera from one end to the other end in an axial direction of the cylindrical object; and , a means for rotating the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object; and , a means for causing the camera to capture an image of the surface of the cylindrical object while translating the camera rotated by the rotating means from the other end to one end in the axial direction of the cylindrical object; and , Equipped with do.

[0017] In order to achieve the above object, the present invention 8 Pertaining to the viewpoint Control device teeth, A control device for controlling a surface inspection device, The above A surface inspection device is provided, and the surface of the cylindrical object is To face in different directions a surface of the cylindrical object; Different areas of To capture Multiple a means for causing a camera to capture an image of a surface of the cylindrical object while translating the camera from one end to the other end in an axial direction of the cylindrical object; and , means for rotating the cylindrical object about a central axis of the cylindrical object after the camera has reached the other axial end of the cylindrical object; and , a means for causing the camera to capture an image of the surface of the cylindrical object while translating the camera from the other end to one end in the axial direction of the cylindrical object rotated by the rotating means; and , Equipped with do. Effect of the Invention

[0018] According to the present invention, a surface inspection device and a surface inspection method capable of quickly detecting foreign matter and scratches on the surface of a cylindrical object, Control device can be provided. [Brief description of the drawings]

[0019] [Figure 1] 1 is a perspective view showing a configuration of a surface inspection device according to an embodiment of the present invention. [Diagram 2] 1 is a perspective view showing a configuration of an inspection head according to an embodiment of the present invention. [Diagram 3]3 is a perspective view showing a state in which the inspection head 2A in FIG. 2 has an expanded diameter. [Figure 4] 1A to 1C are diagrams each showing a procedure for translation and rotation of a camera unit according to an embodiment of the present invention. [Diagram 5] 4A and 4B are plan views showing the camera arrangement when the inspection head according to the embodiment of the present invention is lowered and raised. [Figure 6] 4A to 4C are vertical cross-sectional views showing image capturing areas when a camera according to an embodiment of the present invention is used during descent and ascent. [Figure 7] 2 is a block diagram showing a hardware configuration of a control unit according to the embodiment of the present invention. FIG. [Figure 8] 2 is a block diagram showing a hardware configuration of a control device according to an embodiment of the present invention. FIG. [Figure 9] FIG. 2A is a block diagram showing the hardware configuration of an image processing device according to an embodiment of the present invention, and FIG. 2B is a diagram showing an example of a data table of an image data storage unit according to an embodiment of the present invention. [Figure 10] 4 is a flowchart showing a flow of an imaging process according to the embodiment of the present invention. [Figure 11] 4 is a flowchart showing a flow of a surface inspection process according to the embodiment of the present invention. [Figure 12] FIG. 1 is a front view showing the configuration of a surface inspection device according to a first modified example of the present invention. [Figure 13] FIG. 11 is a front view showing the configuration of a surface inspection device according to a second modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A surface inspection apparatus, a surface inspection method, and a program according to embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

[0021] A surface inspection device is a device that captures an image of the inner or outer surface of a cylindrical object and detects the presence or absence of foreign objects or scratches on the inner or outer surface of the cylindrical object based on the image obtained by imaging. Damage is, for example, chipping or burrs (protrusions) that occur when cutting a steel pipe. Cylindrical objects include not only hollow materials having a cavity, but also solid materials that do not have a cavity. Below, an example of detecting the presence or absence of foreign objects or scratches on the inner surface of a steel pipe, which is an example of a cylindrical object, is described.

[0022] 1 is a perspective view showing the configuration of a surface inspection device 1 according to an embodiment. The surface inspection device 1 includes a camera unit 2 that moves inside the steel pipe in the axial direction of the steel pipe while following the steel pipe being transported and captures an image of the entire inner circumference of the steel pipe, a transport unit 3 that transports the steel pipe to be imaged by the camera unit 2, and a control unit (not shown) that controls the operation of the camera unit 2 and the transport unit 3. The camera unit 2 and the transport unit 3 are each connected to the control unit so as to be able to communicate with each other.

[0023] The axial direction of the steel pipe is the axial direction in which the central axis of the steel pipe extends. The steel pipe is transported horizontally by the transport unit 3 with its axial direction facing the up-down direction. In the following, an orthogonal coordinate system is used in which the direction perpendicular to the transport direction of the steel pipe and extending on the horizontal plane is the X-axis direction, the transport direction of the steel pipe is the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis directions (the up-down direction) is the Z-axis direction.

[0024] The camera unit 2 includes an inspection head 2A that is inserted into the inside of the steel pipe and captures an image of the entire inner circumference of the steel pipe, and a support mechanism 2B that supports the inspection head 2A so that it can move up and down and in the conveying direction of the steel pipe. The inspection head 2A includes a plurality of cameras 21, a plurality of lights 22 provided on each camera 21, a plurality of rod-shaped members 23 that extend in the axial direction of the steel pipe and support the sets of the cameras 21 and the lights 22 at their tips, and a head mechanism 24 to which the base ends of the rod-shaped members 23 are connected and which moves each rod-shaped member 23 in the radial direction of the inspection head 2A and rotates each rod-shaped member 23 around the central axis of the inspection head 2A.

[0025] FIG. 2 is a perspective view showing the configuration of an inspection head 2A according to an embodiment, and FIG. 3 is a perspective view showing the inspection head 2A of FIG. 2 in an expanded diameter state. The cameras 21 are arranged in different directions toward the inner surface of the steel pipe and at equal intervals in the circumferential direction. The cameras 21 are arranged side by side in the axial direction of the inspection head 2A so as to make the diameter of the tip side of the inspection head 2A as small as possible. It is preferable that the cameras 21 adjacent to each other are arranged at equal intervals in the axial direction as well. In this case, the cameras 21 are arranged in a spiral shape around the central axis of the inspection head 2A.

[0026] The camera 21 is a camera that moves axially inside the steel pipe and captures images of an assigned area of ​​the inner surface of the steel pipe at a sampling period set by the user while being in close proximity to the inner surface of the steel pipe. The distance between the camera 21 and the inner surface of the steel pipe is, for example, about 30 mm. In order to reduce blind spots even on an uneven surface, the camera 21 is preferably equipped with a wide-angle lens with a deep depth of field, such as a fisheye lens. In addition, since the camera 21 captures images while moving, it is preferable that the camera 21 be a high FPS (Frames Per Second) and global shutter camera.

[0027] The lights 22 are attached to each camera 21, and illuminate the dark inner surface of the steel pipe with light to brighten it. The lights 22 are, for example, small LEDs formed in a square frame shape, and are arranged so as to surround the camera 21.

[0028] The rod-shaped member 23 is a long member extending in a fixed direction and supporting each camera 21 at its tip. The rod-shaped member 23 is formed so that the diameter of the tip is smaller than the diameter of the base end so as not to interfere with other cameras 21 that it does not support.

[0029] The head mechanism 24 comprises an expansion / contraction mechanism 24A that supports each rod-shaped member 23 so that they extend parallel to one another downward and moves each rod-shaped member 23 in the radial direction of the inspection head 2A by the same distance as each other, a rotation mechanism 24B that is arranged above the expansion / contraction mechanism 24A and rotates the expansion / contraction mechanism 24A around the central axis of the inspection head 2A, and a connecting member 24C that connects the expansion / contraction mechanism 24A and the rotation mechanism 24B.

[0030] The expansion / contraction mechanism 24A includes a plate-like member 24a and a plurality of actuators 24b that are radially arranged on the upper surface of the plate-like member 24a and move each of the rod-like members 23 in the radial direction of the inspection head 2A while supporting each of the rod-like members 23. The actuators 24b are connected to a single servo motor, and the rotation of the servo motor simultaneously moves each of the rod-like members 23 in the radial direction of the inspection head 2A.

[0031] The plate-shaped member 24a has a disk-shaped center and a plurality of radiating portions extending radially from the center. A main shaft member 24c extending downward along the central axis of the inspection head 2A is provided on the bottom surface of the plate-shaped member 24a.

[0032] Both ends of a plurality of connecting arms 24d are connected to each of the rod-shaped members 23 and the main shaft member 24c so as to be rotatable around an axis perpendicular to the axial direction of the rod-shaped members 23 and the main shaft member 24c. Therefore, when each of the rod-shaped members 23 moves so as to expand in the radial direction, the end of the connecting arm 24d connected to the rod-shaped member 23 rotates from the state shown in Fig. 2 around the rotation axis of the end of the connecting arm 24d connected to the main shaft member 24c, and moves in a direction away from the main shaft member 24c as shown in Fig. 3. Since each of the rod-shaped members 23 and the main shaft member 24c are constantly connected to the connecting arm 24d in this way, bending and vibration on the tip side of the rod-shaped member 23 are suppressed, and shaking of the camera 21 during movement can be suppressed.

[0033] The rotation mechanism 24B includes a support member 24e supported by the support mechanism 2B, and an actuator 24f disposed below the support member 24e and supported rotatably around the central axis of the inspection head 2A relative to the support member 24e. The support member 24e includes a plate-like member on which the actuator 24f is supported, and a pair of side members provided on both sides of the plate-like member to reinforce the plate-like member. The actuator 24f includes one servo motor, and the rotation of the servo motor rotates each rod-like member 23 around the central axis of the inspection head 2A.

[0034] The connecting member 24C comprises a plurality of first columnar members 24g extending upward from the upper surface of the plate-shaped member 24a of the expansion / contraction mechanism 24A, a first disk member 24h supported from below by the first columnar members 24g, a plurality of second columnar members 24i extending upward from the upper surface of the first disk member 24h, and a second disk member 24j supported from below by the second columnar members 24i.

[0035] Returning to Fig. 1, the support mechanism 2B comprises a stand 25 installed on the floor surface, a carriage 26 supported movably in the transport direction (Y-axis direction) of the steel pipe relative to the stand 25 and supporting the inspection head 2A movably in the up-down direction (Z-axis direction), and a tracking camera 27 attached to the carriage 26. The support mechanism 2B is provided with two servo motors, each of which moves the carriage 26 in the transport direction (±Y directions) relative to the stand 25 and moves the inspection head 2A in the up-down direction (±Z directions) relative to the carriage 26.

[0036] The tracking camera 27 is different from the camera 21 and is a camera that detects the position of the steel pipe transported by the transport unit 3. The tracking camera 27 is connected to a control unit, and the control unit controls the inspection head 2A to follow the steel pipe based on the image captured by the tracking camera 27. The above is the configuration of the camera unit 2.

[0037] The transport unit 3 is disposed between the conveyors transporting the steel pipes in the production line, receives the steel pipes on the upstream side, and delivers them to a sorting device of the production line installed downstream. The transport unit 3 is disposed to extend in the transport direction of the steel pipes (Y-axis direction), and includes a pair of transport conveyors 31 that move the steel pipes placed on the belt, a pair of columnar members 32 that respectively support each of the transport conveyors 31, and an expansion / contraction mechanism 33 that is installed on the floor surface and movably supports each columnar member 32 so as to adjust the distance between the pair of transport conveyors 31 in the X-axis direction.

[0038] The transport conveyor 31 is equipped with a servo motor that rotates the belt that transports the steel pipes.

[0039] The expansion / contraction mechanism 33 includes a plate-like member 33a, a pair of rails 33b that are installed on the upper surface of the plate-like member 33a so as to extend in the X-axis direction and support each of the columnar members 32 so that they can run, and an actuator 33c that moves the two corresponding columnar members 32 of each transport conveyor 31 in the X-axis direction. The actuator 33c includes one servo motor that moves the two corresponding columnar members 32 of each transport conveyor 31 closer to or farther away from each other.

[0040] The expansion / contraction mechanism 33 moves the pair of transport conveyors 31 in directions (±X directions) that move them away from or towards each other, so that the inspection head 2A can penetrate through the inside of the steel pipe without interfering with the transport unit 3 even when a steel pipe is placed on the transport conveyor 31. This allows the camera 21 located at the most base end side to capture an image of the lower end of the inner surface of the steel pipe. The above is the configuration of the transport unit 3.

[0041] Next, the procedure of the operation of the camera unit 2 according to the embodiment will be described with reference to Figs. 4 to 6. In Fig. 4, the configuration of the inspection head 2A is illustrated in a simplified manner for ease of understanding. In the following, it is assumed that the camera unit 2 detects the presence of a steel pipe being transported and moves in the +Y direction following the steel pipe. In the following, it is assumed that the inspection head 2A is provided with a total of five cameras 21 in order to capture an image of the entire inner circumference of the steel pipe.

[0042] First, the radial position of each camera 21 of the inspection head 2A is adjusted by the expansion / contraction mechanism 33 to match the inner diameter of the steel pipe. Next, as shown in FIG. 4(a), the inspection head 2A moves downward at a constant speed so as to pass through the inside of the steel pipe, and uses the five cameras 21 to sequentially capture images of the inner surface of the steel pipe in the axial direction. The arrangement of the five cameras 21 in the inspection head 2A is as shown in the camera arrangement during descent in FIG. 5. The dotted lines in FIG. 5 indicate the area captured by each camera 21. The cameras 21 extend vertically while being spaced apart from each other in the circumferential direction of the inner surface of the steel pipe, and sequentially capture images of the imaging area (first imaging area) during descent that is individually assigned to each camera 21. When the most proximal camera 21 reaches the lower end of the inner surface of the steel pipe, the inspection head 2A stops descending and capturing images.

[0043] Next, as shown in FIG. 4(b), the inspection head 2A rotates by a rotation angle θ set around the central axis of the inspection head 2A so that each camera 21 changes its orientation from the imaging area during descent to the imaging area during ascent (second imaging area). When the inspection head 2A is rotated, as shown in FIG. 5, the posture of each camera 21 changes from the posture for imaging the imaging area during descent to the posture for imaging the imaging area during ascent. The imaging area during ascent is sandwiched between two adjacent imaging areas during descent, and the entire surface of the inner surface of the steel pipe is included in either the imaging area during ascent or the imaging area during descent. In the case of five cameras 21, the cameras 21 are arranged at equal intervals around the circumference of the inspection head 2A at an angle of 72°, so the rotation angle θ is 36°.

[0044] Next, as shown in Fig. 4(c), the inspection head 2A is moved upward at a constant speed, and the five cameras 21 sequentially capture images of the inner surface of the steel pipe in the axial direction. The ascending speed of the inspection head 2A is preferably the same as the descending speed. Next, the inspection head 2A stops ascending and capturing images when the camera 21 at the most distal end has completely removed itself from the inner surface of the steel pipe. This completes the capturing of images of the entire inner surface of the steel pipe.

[0045] The imaging of the imaging areas by each camera 21 will be described in more detail. Fig. 6 is a vertical cross-sectional view showing the imaging areas by one camera 21 according to the embodiment when descending and ascending. Numbers 1, 2, ... indicate the order in which images are captured in each imaging area.

[0046] As shown in FIG. 6, when the inspection head 2A descends, the camera 21 sequentially captures the imaging area during descent such that adjacent images among the sequentially captured images partially overlap each other. After the inspection head 2A rotates around the central axis, the camera 21 sequentially captures the imaging area during ascent at the same pitch as the imaging during descent. As shown in FIG. 6, the imaging areas per imaging are vertically overlapped. The imaging area during ascent is disposed adjacent to the imaging area during descent. The imaging area during ascent and the imaging area during descent may partially overlap each other. Note that the cameras 21 are disposed offset from each other in the axial direction of the inspection head 2A, so that the positions of the images captured by the cameras 21 at the same timing in the Z-axis direction do not match.

[0047] By adjusting the imaging sampling period and the descent speed of the inspection head 2A, the inner surface of the steel pipe is imaged at a fine pitch so that the same spot on the inner surface of the steel pipe can be imaged from multiple camera positions. By obtaining multiple images of the same spot on the inner surface of the steel pipe at different angles, blind spots can be reduced even when there are irregularities such as threads on the inner surface of the steel pipe, so that foreign objects and scratches can be imaged without missing any. The above is the procedure for the operation of the camera unit 2.

[0048] 7 is a block diagram showing a hardware configuration of a control unit 4 according to an embodiment. The control unit 4 includes a control panel 4A and an image processing device 200. The control panel 4A is a device that controls each part of the surface inspection device 1. The image processing device 200 is a device that processes an image of the inner surface of the steel pipe captured by the camera 21 and detects whether or not there is a foreign object or a scratch on the inner surface of the steel pipe. The image processing device 200 is, for example, a general-purpose computer.

[0049] An image processing device 200, a plurality of lights 22, a tracking camera 27, and a plurality of servo motors 28 are communicatively connected to the control panel 4A, and a plurality of cameras 21 are communicatively connected to the image processing device 200.

[0050] The control panel 4A includes a touch panel 41, a plurality of servo amplifiers 42, a tracking controller 43, a lighting controller 44, a storage device 45, and a control device 100. The touch panel 41, the servo amplifiers 42, the tracking controller 43, the lighting controller 44, and the storage device 45 are each connected to the control device 100 so as to be able to communicate with each other.

[0051] The touch panel 41 displays an operation screen that accepts user operations, and supplies an operation signal corresponding to the position on the operation screen where the measurer makes a touch operation to the control device 100. The touch panel 41 is an example of an operation section and display section of the control panel 4A, and accepts user instructions regarding manual operation of each servo motor 28, selection of steel pipe to be inspected, and image processing settings. In addition, when an abnormality occurs, a message to that effect is displayed.

[0052] Each servo amplifier 42 is connected to each servo motor 28, and adjusts the voltage and frequency of the power input from a power source (not shown) based on a control signal from the control device 100, and outputs the adjusted power to each servo motor 28.

[0053] The tracking controller 43 is connected to the tracking camera 27 and controls the operation of the tracking camera 27 based on a control signal from the control device 100 .

[0054] The lighting controller 44 is connected to each lighting 22 and controls the operation of each lighting 22 based on a control signal from the control device 100.

[0055] The storage device 45 is a device that stores image data of foreign objects or scratches detected on the inner surface of the steel pipe by the image processing device 200, and is, for example, a hard disk drive.

[0056] The control device 100 is a device that controls each part of the control panel 4A, and is, for example, a PLC (Programmable Logic Controller). The above is the hardware configuration of the control unit 4.

[0057] 8 is a block diagram showing a hardware configuration of a control device 100 according to an embodiment. The control device 100 includes a communication unit 110, a storage unit 120, and a control unit 130. The units of the control device 100 are connected to each other via an internal bus (not shown).

[0058] The communication unit 110 is, for example, an interface that can be connected to a communication network such as the Internet and various peripheral devices (for example, a servo amplifier 42 and a tracking controller 43).

[0059] The storage unit 120 includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), and a flash memory. The storage unit 120 stores programs executed by the control unit 130 and various data. The storage unit 120 stores, for example, information regarding the initial position of the inspection head 2A and the rotation angle θ during rotation. The initial position of the inspection head 2A is the position of the inspection head 2A in the Y-axis direction and the Z-axis direction at the time when the inspection head 2A starts to follow the steel pipe, and the rotation position around the central axis of the inspection head 2A. The storage unit 120 also stores the correspondence between the type of steel pipe, the movement amount of the camera 21 in the Z-axis direction, the movement amount of the camera 21 in the radial direction, the sampling period of the image capture, the interval in the X-axis direction of the pair of transport conveyors 31, and the transport speed. The storage unit 120 also temporarily stores various information and functions as a work memory for the control unit 130 to execute processing.

[0060] The control unit 130 includes a processor and controls each unit of the control device 100. The processor is, for example, a CPU (Central Processing Unit). The control unit 130 executes the program stored in the storage unit 120 to perform the imaging process of FIG. 10. The control unit 130 functionally includes a detection unit 131, a motor control unit 132, and an imaging control unit 133.

[0061] The detection unit 131 controls the operation of the tracking controller 43 and detects the position of the steel pipe being transported by the transport unit 3 based on the image captured by the tracking camera 27 .

[0062] The motor control unit 132 controls each servo amplifier 42 to control the operation of each servo motor 28 provided in the expansion / contraction mechanism 24A and rotation mechanism 24B of the inspection head 2A, the cart 26 of the support mechanism 2B, and the conveying conveyor 31 and expansion / contraction mechanism 33 of the conveying unit 3.

[0063] Specifically, the servo motor 28 of the expansion / contraction mechanism 24A is rotated so as to move the camera 21 in the radial direction of the inspection head 2A in accordance with the known inner diameter of the steel pipe, and the servo motor 28 of the expansion / contraction mechanism 33 is rotated so as to adjust the interval between the pair of transport conveyors 31 in accordance with the known outer diameter of the steel pipe. Next, the servo motor 28 of the pair of transport conveyors 31 is rotated so as to transport the steel pipe at a constant speed.

[0064] Next, when the steel pipe transported by the transport unit 3 reaches the initial position of the inspection head 2A, the inspection head 2A is moved in the +Y direction at a constant speed to follow the steel pipe, and the servo motor 28 of the carriage 26 of the support mechanism 2B is rotated to lower the inspection head 2A in the -Z direction toward the steel pipe. Next, the inspection head 2A is moved downward in accordance with the known length of the steel pipe, and when the camera 21 located at the most proximal end side reaches the lower end of the steel pipe, the servo motor 28 of the rotation mechanism 24B is rotated so that the inspection head 2A rotates by the rotation angle θ around the central axis.

[0065] Next, while moving the inspection head 2A in the +Y direction at a constant speed, the inspection head 2A is raised toward the steel pipe, and when the inspection head 2A is pulled out of the steel pipe, the servo motor 28 of the cart 26 is rotated so that the inspection head 2A returns to its initial position. Next, while keeping the inspection head 2A returning to its initial position, the servo motor 28 of the rotation mechanism 24B is rotated so that the inspection head 2A rotates by -θ around the central axis.

[0066] The imaging control section 133 controls the lighting controller 44 and the image processing device 200, so that when the inspection head 2A starts to descend, the camera 21 captures an image of the inner surface of the steel pipe and emits light from the lighting 22 until the inspection head 2A stops. Also, when the inspection head 2A starts to rise, the camera 21 captures an image of the inner surface of the steel pipe and emits light from the lighting 22 until the inspection head 2A stops. The above is the hardware configuration of the control device 100 according to the embodiment.

[0067] 9(a) is a block diagram showing a hardware configuration of an image processing device 200 according to an embodiment. The image processing device 200 includes a communication unit 210, a storage unit 220, and a control unit 230. The units of the image processing device 200 are connected to each other via an internal bus (not shown).

[0068] The communication unit 210 is an interface that can be connected to a communication network such as the Internet, the camera 21, and the control device 100, for example.

[0069] The storage unit 220 includes, for example, a RAM, a ROM, and a flash memory. The storage unit 220 stores programs executed by the control unit 230 and various data. The storage unit 220 stores, for example, information related to a brightness threshold value used to determine foreign matter or scratches. The storage unit 220 also temporarily stores various information and functions as a work memory for the control unit 230 to execute processing. The storage unit 220 further includes an image data storage unit 221.

[0070] FIG. 9(b) is a diagram showing an example of a data table of the image data storage unit 221 according to the embodiment. The image data storage unit 221 stores image data obtained by imaging of each camera 21 in association with information on a steel pipe ID (Identification), a camera ID, and position information. The steel pipe ID is a unique identification number assigned to each steel pipe, and the camera ID is a unique identification number assigned to each camera 21. The position information is position information of the imaging location set based on the position of the camera 21 at the time of imaging. The position of the camera 21 is expressed, for example, by angles r1, r2, ... around the central axis of the inspection head 2A and Z coordinate values ​​z1, z2, ... which are the axial position of the inspection head 2A. The angles r1, r2, ... are, for example, angles between a reference line extending in the +X direction from the central axis of the inspection head 2A and the optical axis of the camera 21.

[0071] The control unit 230 includes a processor and controls each unit of the image processing device 200. The processor is, for example, a CPU. The control unit 230 executes the program stored in the storage unit 220 to perform the surface inspection process of FIG. 11. The control unit 230 functionally includes an acquisition unit 231, an image processing unit 232, a determination unit 233, and an output unit 234.

[0072] The acquisition unit 231 acquires image data of the inner surface of the steel pipe captured by each camera 21, and stores the image data in the image data storage unit 221. Acquisition by the acquisition unit 231 also includes reading out image data stored in the image data storage unit 221.

[0073] The image processing unit 232 executes a process for canceling horizontal stripes that originate from irregularities such as screw threads in the image acquired by the acquisition unit 231 .

[0074] When the determination unit 233 detects a pixel having a luminance equal to or greater than the luminance threshold in the image processed by the image processing unit 232, it determines that a foreign object or a scratch is present in the area corresponding to the pixel. The luminance threshold is set by the user in consideration of the illuminance of the lighting 22 and the size, shape, and material of the steel pipe.

[0075] The output unit 234 stores in the storage device 45 the data of the image in which the determination unit 233 has determined that a foreign substance or a scratch is present, and outputs a control signal to the control device 100 indicating that a foreign substance or a scratch has been detected. When the control device 100 receives the control signal indicating that a foreign substance or a scratch has been detected, it outputs a control signal to a dispensing device (not shown) installed downstream of the surface inspection device 1 in the production line, for example, to request dispensing.

[0076] The image processing unit 232 and the determination unit 233 execute a series of processes independently of the processing of the acquisition unit 231. In other words, rather than the acquisition unit 231, image processing unit 232, and determination unit 233 executing a series of processes for each image and repeating this series of processes for the number of images, the acquisition unit 231 first acquires all images consecutively, and the image processing unit 232 and determination unit 233 execute a series of processes in the order of the images acquired. Furthermore, the image processing unit 232 and determination unit 233 execute a series of processes in parallel for each camera 21 on the images captured by each camera 21. These processing procedures can reduce the time required to detect foreign objects and scratches for each steel pipe to be inspected. The hardware configuration of the image processing device 200 has been described above.

[0077] (Image capture processing) With reference to Fig. 10, the flow of the imaging process executed by the control unit 130 of the control device 100 according to the embodiment will be described. The imaging process is a process in which the inspection head 2A images the entire inner circumference of the steel pipe. The imaging process starts when a start instruction from the user is received, and ends when a stop instruction from the user is received. The user specifies the type of steel pipe when inputting the instruction, and the control unit 130 reads from the memory unit 120 the movement amount of the camera 21 in the Z-axis direction, the movement amount of the camera 21 in the radial direction, the imaging sampling period, the distance in the X-axis direction between the pair of transport conveyors 31, and the transport speed, which correspond to the type of steel pipe.

[0078] First, the motor control unit 132 sets the positions of the inspection head 2A in the Y-axis direction and the Z-axis direction and the position around the central axis of the head mechanism 24 to initial positions, and performs initial settings according to the size of the steel pipe (step S11). Specifically, the operation of the servo motor 28 of the expansion / contraction mechanism 24A is controlled to adjust the radial position of each camera 21, and the servo motor 28 of the expansion / contraction mechanism 33 is controlled to adjust the interval between the pair of transport conveyors 31.

[0079] Next, the motor control unit 132 constantly operates the pair of transfer conveyors 31 after the gap adjustment, and starts the transfer of the steel pipes supplied from the production line (step S12).

[0080] Next, the detection unit 131 determines whether or not a steel pipe is detected at the initial position of the inspection head 2A (step S13). If it is determined that a steel pipe is detected (step S13; Yes), the process proceeds to step S14. On the other hand, if it is determined that a steel pipe is not detected (step S13; No), the process waits until a steel pipe is detected.

[0081] If the result of the process in step S13 is Yes, the motor control unit 132 controls the servo motor 28 to move the carriage 26 of the support mechanism 2B in the +Y direction, thereby causing the inspection head 2A to start following the steel pipe (step S14).

[0082] Next, the motor control unit 132 controls the servo motor 28 provided on the carriage 26 of the support mechanism 2B to lower the inspection head 2A, which started tracking in the processing of step S14, in the -Z direction toward the inside of the steel pipe (step S15). In parallel with the processing of step S15, the imaging control unit 133 outputs a control signal to each camera 21 to start imaging the inner surface of the steel pipe at a sampling period set by the user, and sequentially stores the obtained image data in the storage unit 220 of the image processing device 200 in association with the steel pipe ID, camera ID, and position information.

[0083] The sampling period is such that images obtained at two adjacent times partially overlap in the Z-axis direction. An image capturing half of the inner surface of the steel pipe is obtained by the processing of step S15. The descent of the inspection head 2A and the capturing of images by each camera 21 are continued until the camera 21 located at the most base end reaches the lower end inside the steel pipe.

[0084] Next, the motor control unit 132 controls the servo motor 28 of the rotation mechanism 24B to rotate the inspection head 2A around the central axis by a rotation angle θ (step S16). In the case where there are five cameras 21, the rotation angle θ is 36°.

[0085] Next, the motor control unit 132 controls the servo motor 28 provided on the carriage 26 of the support mechanism 2B to raise the inspection head 2A rotated in the processing of step S16 (step S17). In parallel with the processing of step S17, the imaging control unit 133 outputs a control signal to each camera 21 to resume imaging of the inner surface of the steel pipe at a sampling period set by the user, and sequentially stores the obtained image data in the storage unit 220 of the image processing device 200 in association with the steel pipe ID, camera ID and position information. By the processing of step S17, an image of the remaining half of the area of ​​the inner surface of the steel pipe is obtained. This is continued until the camera 21 located at the most tip side exits from inside the steel pipe.

[0086] Next, the motor control unit 132 controls the servo motor 28, which moves the cart 26 of the support mechanism 2B, to return the inspection head 2A that has come out from inside the steel pipe to its initial position, and also controls the servo motor 28 of the rotation mechanism 24B to rotate the inspection head 2A by -θ around the central axis (step S18), and returns the processing to step S13. The above is the flow of the imaging process.

[0087] (Surface inspection processing) The flow of the surface inspection process executed by the image processing device 200 according to the embodiment will be described below with reference to Fig. 11. The surface inspection process is a process for inspecting whether there are foreign objects or scratches on the inner surface of the steel pipe based on an image of the entire inner circumference of the steel pipe obtained by the imaging process. The surface inspection process starts when the image processing device 200 acquires image data from the camera 21, and is executed in parallel for each image acquired by each camera 21.

[0088] First, the acquisition unit 231 acquires image data of the inner surface of the steel pipe stored in the storage unit 220 (step S21).

[0089] Next, the image processing unit 232 executes image processing for canceling horizontal stripes resulting from irregularities such as threads in the image acquired in step S21 (step S22).

[0090] Next, the determination unit 233 determines whether or not a pixel having a luminance equal to or greater than the luminance threshold stored in the storage unit 220 exists in the image that has been subjected to image processing in step S22 (step S23). If it is determined that a pixel having a luminance equal to or greater than the luminance threshold exists (step S23; Yes), the process proceeds to step S24. On the other hand, if it is determined that a pixel having a luminance equal to or greater than the luminance threshold does not exist (step S23; No), the process proceeds to step S25.

[0091] If the result of the process in step S23 is Yes, the output unit 234 stores image data containing pixels with a brightness equal to or greater than the threshold in the memory device 45 of the control panel 4A, and outputs a control signal to the control device 100 to the effect that a foreign object or scratch has been detected (step S24). The control device 100 outputs a control signal to a removal device located downstream of the surface inspection device 1 in the production line, requesting removal. Upon receiving this control signal, the removal device removes the steel pipe in which a foreign object or scratch has been detected from the production line as the steel pipe passes through the removal device.

[0092] If step S23 is No or after the process of step S24 is completed, the acquisition unit 231 judges whether acquisition of all images stored in the storage unit 220 has been completed (step S25). If it is judged that acquisition of all images has been completed (step S25; Yes), the process ends. On the other hand, if it is judged that acquisition of all images has not been completed (step S25; No), the process returns to step S21. The above is the flow of the surface inspection process.

[0093] As described above, the surface inspection device 1 according to the embodiment includes a plurality of cameras 21, a plurality of rod-shaped members 23 supporting each camera 21, a head mechanism 24 supporting each rod-shaped member 23, translating each camera 21 in the axial direction of the steel pipe and rotating each camera 21 around the central axis of the steel pipe, and a control unit 4 connected to each camera 21 and the head mechanism 24 to control the operation of each camera 21 and the head mechanism 24. Therefore, by controlling each camera 21 to photograph different areas on the outward and return paths when reciprocating inside the steel pipe, it is possible to efficiently photograph the entire inner circumference of the steel pipe even with a small number of cameras 21, and as a result, it is possible to quickly detect foreign objects and scratches on the inner surface of the steel pipe. In addition, since the number of cameras 21 can be reduced, the inspection head 2A including the cameras 21 can be configured compactly.

[0094] The present invention is not limited to the above-described embodiment, and the following modifications are possible.

[0095] (Modification) In the above embodiment, five cameras 21 are used in the inspection head 2A, but the present invention is not limited to this. The number of cameras 21 may be in the range of 1 to 4, or may be 6 or more, taking into consideration the size of the inner diameter of the steel pipe and the detection accuracy of foreign objects and scratches. If the number of cameras 21 does not correspond to the size of the inner diameter of the steel pipe and the entire inner surface of the steel pipe cannot be photographed in one reciprocation, it is advisable to increase the number of reciprocations to two or more, and photograph a different area on each reciprocation.

[0096] In the above embodiment, the cameras 21 are arranged so as to face outward toward the inner surface of the steel pipe, but the present invention is not limited to this. For example, the cameras 21 may be arranged so as to face inward toward the outer surface of the steel pipe.

[0097] In the above embodiment, the lighting 22 is attached to the camera 21, but the present invention is not limited to this. For example, the lighting 22 may be attached to the rod-shaped member 23 or the head mechanism 24. The number of lighting devices 22 does not necessarily need to correspond to the number of cameras 21, and can be changed as appropriate.

[0098] In the above embodiment, each camera 21 is attached to a corresponding individual rod-shaped member 23, but the present invention is not limited to this. The shape and number of long members are arbitrary as long as they extend in the axial direction of the steel pipe and all of the cameras 21 can be inserted into the inner surface of the steel pipe. For example, the long members are not limited to rod-shaped members, and may be cylindrical bodies having a space inside. Furthermore, the number of rod-shaped members or cylindrical bodies is not limited to five, and each camera 21 may be attached to one rod-shaped member or cylindrical body so as to be movable radially.

[0099] In the above embodiment, the servo motor 28 realizes translational movement of the inspection head 2A in the transport direction, the vertical direction, and the radial direction, but the present invention is not limited to this. For example, the servo motor 28 may be replaced with a linear motor.

[0100] In the above embodiment, the connecting member 24C that connects the expansion / contraction mechanism 24A and the rotation mechanism 24B is composed of a disk member and a rod-shaped member, but the present invention is not limited to this. For example, the connecting member 24C may have any shape as long as it can connect the expansion / contraction mechanism 24A and the rotation mechanism 24B. In addition, as long as it can connect the expansion / contraction mechanism 24A and the rotation mechanism 24B, it is optional whether or not to provide the connecting member 24C between the expansion / contraction mechanism 24A and the rotation mechanism 24B.

[0101] In the above embodiment, each camera 21 is configured to be movable in the radial direction by the expansion / contraction mechanism 24A, but the present invention is not limited to this. If the diameter of the steel pipe to be measured is constant, the expansion / contraction mechanism 24A may be omitted. For example, one or more cameras 21 may be fixed to one long member.

[0102] In the above embodiment, the cart 26 is installed on the stand 25, but the present invention is not limited to this. For example, the cart 26 may be installed so as to be able to run on a pair of rails that extend in the conveying direction and are installed on the floor surface.

[0103] In the above embodiment, the inspection head 2A is supported by the support mechanism 2B so as to be movable in the vertical direction and the transport direction, but the present invention is not limited to this. For example, the inspection head 2A may be supported by a robot arm.

[0104] In the above embodiment, the axial direction of the inspection head 2A is arranged in the vertical direction, but the present invention is not limited to this. The orientation of the inspection head 2A can be set appropriately according to the posture of the steel pipe to be measured. For example, when the axial direction of the steel pipe is arranged on a horizontal plane, the axial direction of the inspection head 2A may be arranged horizontally.

[0105] In the above embodiment, the descent of the inspection head 2A is stopped when the most proximal camera 21 reaches the lower end of the steel pipe, and the ascent of the inspection head 2A is stopped when the most distal camera 21 exits from inside the steel pipe, but the present invention is not limited to this. As long as the most proximal camera 21 can photograph the lower end of the steel pipe and the most distal camera 21 can photograph the upper end of the steel pipe, the timing for stopping the inspection head 2A is arbitrary. For example, the descent of the inspection head 2A may be stopped when the most proximal camera 21 exits downward from inside the steel pipe.

[0106] In the above embodiment, the imaging by the camera 21 is stopped at the same timing as the movement of the inspection head 2A in the Z-axis direction is stopped, but the present invention is not limited to this. The imaging by the camera 21 may be stopped after a certain time has elapsed after the movement of the inspection head 2A in the Z-axis direction is stopped.

[0107] In the above embodiment, the inspection head 2A follows the steel pipe being transported, but the present invention is not limited to this. For example, the inspection head 2A may be supported on a stand installed on the floor surface and configured to inspect a stationary steel pipe. In this case, the steel pipe traveling down the production line may be grasped by a pair of arms, placed directly below the inspection head 2A, and returned to the production line when the inspection is completed.

[0108] In the above embodiment, the cameras 21 are rotated around the central axis of the steel pipe by the inspection head 2A, but the present invention is not limited to this. For example, as shown in Fig. 12, a rotating stand 5 may be provided instead of the transport unit 3, and the steel pipe placed on the rotating stand 5 may be rotated around the central axis of the steel pipe. In this case, the rotation mechanism 24B may be omitted in the camera unit 2.

[0109] The rotating stand 5 includes a stand body 51 installed on the floor surface, and a rotating stage 52 supported by the stand body 51 and rotating the steel pipe with the steel pipe placed thereon. The rotating stage 52 includes a rotating member 53 on which the steel pipe is placed, and a fixed member 54 that rotatably supports the rotating member 53. The rotating member 53 and the fixed member 54 are each provided with through holes 53a, 54a through which the camera 21 and the rod-shaped member 23 can pass, respectively. The control unit 4 may control the rotation of the rotating stage 52 so that the steel pipe rotates by the set rotation angle θ around the central axis of the inspection head 2A after the lowest camera 21 reaches the lower end of the steel pipe.

[0110] In the above embodiment, the cameras 21 are moved in the axial direction of the steel pipe by the inspection head 2A, but the present invention is not limited to this. For example, as shown in Fig. 13, a telescopic stand 6 may be provided instead of the transport unit 3, and the steel pipe placed on the telescopic stand 6 may be moved in the axial direction of the steel pipe. In this case, the configuration for vertically moving the head mechanism 2A in the camera unit 2 may be omitted.

[0111] The telescopic stand 6 includes a stand body 61 installed on the floor surface, a telescopic mechanism 62 supported by the stand body 61 and extending in the longitudinal direction, and a table 63 supported by the telescopic mechanism 62 on which the steel pipe is placed. The telescopic mechanism 62 includes a telescopic rod 62a extending in the longitudinal direction, and a hydraulic cylinder 62b attached to the telescopic rod 62a and operating to extend and retract the telescopic rod 62a in the longitudinal direction. The table 63 is provided with a through hole 63a through which the camera 21 and the rod-shaped member 23 can pass. The control unit 4 moves the telescopic mechanism 62 upward until the lowest camera 21 reaches the lower end of the steel pipe, and after the rotation mechanism 24B rotates by the rotation angle θ, moves the telescopic mechanism 62 downward until the lowest camera 21 comes out of the upper end of the steel pipe.

[0112] In the above modification, the rotating stand 5 for rotating the steel pipe around its central axis and the telescopic stand 6 for moving the steel pipe in its axial direction are separate devices, but the present invention is not limited to this. For example, the steel pipe may be supported by a stand that can rotate the steel pipe around its central axis and move the steel pipe in its axial direction in response to a control signal from the control unit 4.

[0113] In the above embodiment, it is determined that a foreign object or a scratch is detected when there is a pixel with a luminance equal to or greater than the luminance threshold value, but the present invention is not limited to this. For example, it may be determined that a foreign object or a scratch is detected when the luminance is within a certain range defined by an upper limit and a lower limit.

[0114] In the above embodiment, various data are stored in the storage units 120 and 220 of the control device 100 and the image processing device 200, but the present invention is not limited to this. For example, all or part of the various data may be stored in an external control device or computer via a communication network steel pipe.

[0115] In the above embodiment, the control device 100 and the image processing device 200 operate based on the programs stored in the storage units 120 and 220, respectively, but the present invention is not limited to this. For example, the functional configuration realized by the programs may be realized by hardware.

[0116] In the above embodiment, the control device 100 is a PLC and the image processing device 200 is a general-purpose computer, but the present invention is not limited to this. For example, the control device 100 and the image processing device 200 may be realized by a dedicated system or a computer provided on a cloud. Moreover, the control device 100 and the image processing device 200 may be realized by one computer.

[0117] In the above embodiment, the processing performed by the control device 100 and the image processing device 200 was realized by devices having the above-mentioned physical configuration executing programs stored in the memory units 120, 220, but the present invention may also be realized as a program or as a storage medium on which the program is recorded.

[0118] In addition, a program for executing the above-mentioned processing operations may be stored and distributed on a non-transitory computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disk Read-Only Memory), a DVD (Digital Versatile Disk), or an MO (Magneto-Optical Disk), and the program may be installed on a computer to configure an apparatus that executes the above-mentioned processing operations.

[0119] In the above embodiment, the steel pipe is the object of inspection, but the present invention is not limited to this. For example, a cylindrical workpiece other than a steel pipe may be the object of inspection. In addition, the object of inspection is not limited to a workpiece, and for example, the surface of another cylindrical object may be inspected. The cylindrical object includes not only a cylindrical body with a circular cross section, but also a cylindrical body with an elliptical cross section and a cylindrical body with a polygonal cross section, for example, a rectangular cylindrical body. In addition, the cylindrical object also includes an object in which a part of the cylindrical body is cut out by a slit or an opening. The object in which the cylindrical body is cut out includes, for example, an object with a C-shaped cross section, a U-shaped cross section, or a U-shaped cross section.

[0120] The above-mentioned embodiments are merely examples, and the present invention is not limited to these, and various embodiments are possible without departing from the spirit of the invention described in the claims. The components described in each embodiment and modification can be freely combined. In addition, inventions equivalent to the inventions described in the claims are also included in the present invention. [Explanation of symbols]

[0121] 1 Surface inspection equipment 2 Camera unit 2A Inspection Head 2B Support mechanism 3. Transport unit 4. Control Unit 4A Control Panel 5 Rotating stand 6 Telescopic stand 21 Camera 22 Lighting 23 Rod-shaped member 24 Head mechanism 24A Expansion mechanism 24B Rotation mechanism 24C Connection parts 24a Plate-shaped member 24b, 24f Actuator 24c Main shaft member 24d connecting arm 24e Support member 24g First columnar member 24h First disc component 24i Second columnar member 24j Second disc member 25 Mount 26 Trolley 27 Tracking Camera 28 Servo motor 31 Transport Conveyor 32 Columnar member 33 Expansion / contraction mechanism 33a Plate-shaped member 33b Rail 33c Actuator 41 Touch Panel 42 Servo amplifier 43 Tracking Controller 44 Lighting Controller 45 Storage device 51,61 Stand body 52 Rotating Stage 53 Rotating parts 53a,54a,63a through hole 54 Fixing member 62 Telescopic mechanism 62a Telescopic rod 62b Hydraulic cylinder 63 Table 100 Control device 110 Communications Department 120 Storage section 130 Control section 131 Detection unit 132 Motor control unit 133 Imaging control section 200 Image processing device 210 Communications Department 220 Storage section 221 Image data storage unit 230 Control Unit 231 Acquisition Department 232 Image Processing Unit 233 Judgment section 234 Output section

Claims

1. A plurality of cameras are arranged to face in different directions toward a surface of a cylindrical object, the cameras capturing images of different areas of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; A surface inspection device comprising:

2. The elongated member is provided in one or more to support the plurality of cameras, the control unit controls the operation of the cameras and the head mechanism so as to rotate each camera around the central axis of the cylindrical object after the camera arranged at the most proximal end side reaches the other end in the axial direction of the cylindrical object. The surface inspection apparatus according to claim 1 .

3. the control unit controls operation of each camera and the head mechanism so that, when the head mechanism translates from one end to the other end in the axial direction of the cylindrical object, each camera images a first imaging area set for the camera, and, when the head mechanism translates from the other end to the one end in the axial direction of the cylindrical object, each camera images a second imaging area set for the camera; Each of the first imaging areas extends in an axial direction of the cylindrical object and is set at intervals in a circumferential direction of the cylindrical object; Each of the second imaging areas extends in an axial direction of the cylindrical object and is set to be sandwiched between two adjacent first imaging areas. The surface inspection apparatus according to claim 2.

4. The cameras are arranged in an axial direction of the head mechanism, and two adjacent cameras are arranged at equal intervals in a circumferential direction of the head mechanism.

4. A surface inspection apparatus according to claim 2 or 3.

5. The elongated member supports each camera individually; Each of the elongated members has a tip end thinner than a base end so as not to interfere with the camera that is not supported by the elongated member. The surface inspection apparatus according to claim 4.

6. A camera disposed facing a surface of a cylindrical object and capturing an image of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; Equipped with the head mechanism supports the camera so as to be movable in a radial direction of the head mechanism; the control unit controls an operation of the head mechanism to adjust a position of the camera in a radial direction of the head mechanism in accordance with a radial size of the cylindrical object. Surface inspection equipment.

7. A camera disposed facing a surface of a cylindrical object and capturing an image of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member, translates the camera in an axial direction of the cylindrical object, and rotates the camera about a central axis of the cylindrical object; a control unit connected to the camera and the head mechanism, for controlling the operation of the camera and the head mechanism so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; A conveying unit that conveys the cylindrical object; a support mechanism that supports the head mechanism so as to be movable in a conveying direction of the cylindrical object, when the control unit detects that the cylindrical object has been transported by the transport unit, the control unit controls an operation of the support mechanism so that the movement of the head mechanism follows the transport of the cylindrical object by the transport unit. Surface inspection equipment.

8. A plurality of cameras are arranged to face in different directions toward a surface of a cylindrical object, the cameras capturing images of different areas of the surface of the cylindrical object; a long member disposed to extend in an axial direction of the cylindrical object and supporting the camera; a head mechanism that supports the elongated member and translates the camera in an axial direction of the cylindrical object; a rotating stand on which the cylindrical object is placed and which rotates the cylindrical object around a central axis of the cylindrical object; a control unit connected to the camera, the head mechanism, and the rotating frame, for controlling operations of the camera, the head mechanism, and the rotating frame so as to cause the camera to capture an image of the surface of the cylindrical object while translating the camera from one axial end of the cylindrical object to the other axial end, rotate the cylindrical object around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object, and cause the camera to capture an image of the surface of the cylindrical object while translating the camera from the other axial end to one end of the cylindrical object; A surface inspection device comprising:

9. A surface inspection method performed by a surface inspection device, comprising: a step of causing a plurality of cameras provided in the surface inspection device, arranged so as to face in different directions toward the surface of a cylindrical object, and imaging different areas of the surface of the cylindrical object, to image the surface of the cylindrical object while translating the cameras from one end to the other end in the axial direction of the cylindrical object; After the camera reaches the other axial end of the cylindrical object, rotating the camera around a central axis of the cylindrical object; a step of causing the camera rotated in the rotating step to translate from the other end to one end in the axial direction of the cylindrical object while causing the camera to capture an image of the surface of the cylindrical object; A surface inspection method comprising:

10. A surface inspection method performed by a surface inspection device, comprising: a step of causing a plurality of cameras provided in the surface inspection device, arranged so as to face in different directions toward the surface of a cylindrical object, and imaging different areas of the surface of the cylindrical object, to image the surface of the cylindrical object while translating the cameras from one end to the other end in the axial direction of the cylindrical object; After the camera reaches the other axial end of the cylindrical object, rotating the cylindrical object around a central axis of the cylindrical object; a step of causing the camera to capture an image of a surface of the cylindrical object while translating the camera from the other end to one end in an axial direction of the cylindrical object rotated by the rotating step; A surface inspection method comprising:

11. A control device for controlling a surface inspection device, comprising: a means for causing a plurality of cameras provided in the surface inspection device, the cameras being arranged to face in different directions toward the surface of a cylindrical object and capturing images of different areas of the surface of the cylindrical object, to capture images of the surface of the cylindrical object while translating the cameras from one end to the other end in the axial direction of the cylindrical object; a means for rotating the camera around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object; a means for causing the camera to capture an image of a surface of the cylindrical object while translating the camera rotated by the rotating means from the other end to one end in the axial direction of the cylindrical object; A control device comprising:

12. A control device for controlling a surface inspection device, comprising: a means for causing a plurality of cameras provided in the surface inspection device, the cameras being arranged to face in different directions toward the surface of a cylindrical object and capturing images of different areas of the surface of the cylindrical object, to capture images of the surface of the cylindrical object while translating the cameras from one end to the other end in the axial direction of the cylindrical object; a means for rotating the cylindrical object around a central axis of the cylindrical object after the camera reaches the other axial end of the cylindrical object; a means for causing the camera to capture an image of a surface of the cylindrical object while translating the camera from the other end to one end in the axial direction of the cylindrical object rotated by the rotating means; A control device comprising:

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