JP2019138755A - Tube traveling device - Google Patents

Abstract

To provide a tube traveling device capable of imaging an inner pipe wall surface of a pipe with a small clear image of distortion when inspecting the inside of the pipe by traveling the tube traveling device in the pipe.SOLUTION: A tube traveling device 1 includes a first imaging unit 13 for imaging a region in front of the tube traveling device 1, a second imaging unit 16 for imaging a tube wall surface of the side of the tube traveling device 1, a first image acquisition unit 52 for acquiring an image captured by the first imaging unit 13 while the tube traveling device 1 is in progress inside the pipe, a seam detection unit 53 for detecting the seam of the pipe based on the image acquired by the first image acquisition unit 52, a posture control unit 54 for controlling the posture of the second imaging unit 16 with respect to the seam detected by the seam detection unit 53, and a second image acquisition unit 55 for acquiring an image of the tube wall including a seam across the circumferential direction of the pipe and starting the imaging of the tube wall surface by the second imaging unit 16 in a position controlled by the posture control unit 54.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an in-pipe travel device that travels inside a pipe such as a water pipe or a gas pipe.

  2. Description of the Related Art In recent years, an in-pipe travel device that travels in a pipe as a device for investigating the laying state of a hollow tubular member (hereinafter referred to as a pipe) such as a water pipe or a gas pipe or observing and inspecting the internal state of the pipe. Has been developed.

  The in-pipe travel device receives drive control from an external control device so that it can travel freely inside the pipe according to the situation, or travels inside the pipe autonomously by a control device built in itself. Can do.

  When in-pipe inspection is performed by such an in-pipe travel device, a camera is usually mounted on the in-pipe travel device, and an image inside the pipe taken by the camera is used. Therefore, in order to enable efficient and highly accurate inspection using a large number of images taken while the in-pipe traveling device travels in the pipe, it is desired to obtain an image suitable for the inspection.

  For example, Patent Document 1 (Japanese Patent No. 4515787) discloses a technique for creating a development view of a pipe tub based on video data obtained by photographing the inner wall surface of the pipe tub and obtaining three-dimensional data using the development view. It is disclosed.

  In the technique of Patent Document 1, the side image is developed by obtaining the side image and the front image including the extraction point of the three-dimensional data obtained by photographing the wall surface of the pipe with the video camera mainly composed of the omnidirectional sensor. The same feature points of the developed image and the developed image obtained by developing the front image are associated with each other, and three-dimensional data is calculated from the positional deviation of the associated identical feature points.

Japanese Patent No. 4515787

  In general, defects such as fine scratches and deterioration tend to occur at the joints of pipes such as welded portions of tubes, flange-type or screw-in type joints, and plug-in type joints. Therefore, when inspecting a pipe joint using an in-pipe travel device that runs in the pipe, it is necessary to acquire a clear image with little distortion.

  On the other hand, the technique disclosed in Patent Document 1 uses an omnidirectional sensor composed of a main reflecting mirror facing forward and a sub-reflecting mirror facing a predetermined distance from the main reflecting mirror, The visible range is from the maximum shooting angle of about 115 degrees to the minimum shooting angle of about 30 degrees with respect to the optical axis of the video camera. A front image with an inclined angle of view within the range is also captured at the same time.

  For this reason, in the technique of Patent Document 1, when trying to inspect the joint of a pipe, there is a high possibility that fine scratches or deterioration occurring at the joint of the pipe are distorted and imaged. There is a possibility that it may be overlooked or the degree of deterioration cannot be judged correctly.

  The present invention has been made in view of the above circumstances, and when a pipe traveling device is run in a pipe to inspect the inside of the pipe, the pipe wall surface inside the pipe can be captured with a clear image with little distortion. It is an object to provide an in-pipe traveling apparatus.

  An in-pipe travel apparatus according to an aspect of the present invention is an in-pipe travel apparatus that travels inside a pipe, and includes a first imaging unit that images a region in front of the in-pipe travel apparatus inside the pipe, A second imaging unit for imaging the side wall surface of the pipe traveling device inside the pipe, and an image captured by the first imaging unit while the pipe traveling device is traveling inside the pipe A first image acquisition unit that acquires the joint, a seam detection unit that detects a joint of the piping based on the image acquired by the first image acquisition unit, and the second for the seam detected by the seam detection unit An attitude control unit that controls the attitude of the imaging unit; and imaging of the tube wall surface by the second imaging unit in an attitude controlled by the attitude control unit; and an image of the tube wall surface including the seam Comprising a second image acquisition unit that acquires over the circumferential direction of the tube, the.

  According to the present invention, when the in-pipe travel device is run in a pipe to inspect the inside of the pipe, the pipe wall surface inside the pipe can be captured with a clear image with little distortion.

Explanatory drawing which shows the in-pipe traveling apparatus of one Embodiment of this invention. Block diagram showing the control system of the in-pipe travel device Flow chart showing in-pipe inspection process Flow chart showing joint detection processing Explanatory drawing which shows the image in each position of the in-pipe traveling apparatus in piping Explanatory drawing showing the detection results of pipe joints Explanatory drawing which shows the movement to the target position of an in-pipe travel apparatus Explanatory drawing which shows the movement to the target position by image information Explanatory drawing showing attitude control in the yaw angle direction of the in-pipe travel device Explanatory drawing which shows the method of detecting the shift | offset | difference of the yaw angle direction of an in-pipe traveling apparatus. Explanatory drawing which shows the other method of detecting the shift | offset | difference of the yaw angle direction of an in-pipe traveling apparatus. Explanatory drawing showing attitude control in the pitch angle direction of the in-pipe travel device Explanatory drawing which shows the image of the pipe wall surface in each rotation position of the in-pipe travel device Explanatory drawing showing generation of unfolded composite image

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each drawing used in the following description is shown schematically, and in order to show each component in a size that can be recognized on the drawing, the dimensional relationship and scale of each member are made different for each component. May be shown. Therefore, the present invention is only in the illustrated form with respect to the quantity of each component described in each drawing, the shape of each component, the size ratio of each component, the relative positional relationship of each component, etc. It is not limited.

  The in-pipe travel apparatus 1 shown in FIG. 1 is used for investigating the laying state of the pipe 100 or observing and inspecting the internal state of the pipe 100 by running inside the pipe 100 such as a water pipe or a gas pipe. Device.

  In the present embodiment, the in-pipe traveling device 1 will be described by taking an example of a configuration that autonomously travels inside the pipe 100, but is connected to an external device (not shown) via a cable, and between the external devices. You may drive | work in piping, transmitting / receiving various signals.

  For this reason, the in-pipe traveling apparatus 1 of the present embodiment includes a plurality of wheels 11 in the main body 10, and the plurality of wheels 11 are pressed against the pipe wall surface inside the pipe 100 with a predetermined urging force. Drive on. In the present embodiment, a total of four wheels 11 are arranged in the same plane, two at each of the opposing portions of the main body 10.

  Here, when the traveling direction of the in-pipe traveling apparatus 1 is indicated by an arrow F in FIG. 1, the front end portion along the traveling direction F of the main body portion 10 is referred to as a “front end portion”. Further, in the direction along the traveling direction F, an end portion of the main body 10 opposite to the “front end portion” is referred to as a “rear end portion”. And the side with respect to the direction along the advancing direction F of the main-body part 10 shall be called "side part."

  In the present embodiment, the in-pipe traveling apparatus 1 includes, as four wheels 11, a pair of wheels 11 </ b> F provided on both side portions on the front end side of the main body 10 and both side portions on the rear end side of the main body 10. And a pair of wheels 11R.

  The pair of wheels 11F on the front end side of the main body 10 is provided as a traveling and steering wheel that receives driving force from a motor or the like, and the pair of wheels 11R on the rear end side of the main body 10 does not receive driving force. It is provided as a driven wheel that rotates.

  That is, the wheel 11F is rotated forward and backward by the traveling motor 20 (see FIG. 2) in the direction of the arrow R1 around the rotation shaft 11a serving as the rotation center, and the in-pipe traveling device 1 is moved in the longitudinal axis direction (the traveling direction F in the traveling direction F). (Adjacent direction) can be moved forward and backward as appropriate at a predetermined timing.

  The wheel 11F is rotated forward and backward by the steering motor 21 (see FIG. 2) in the direction of the arrow R2 around the stroke shaft 11b to steer the in-pipe travel device 1 that is moving forward and backward in the pipe 100 and travel in the pipe. The apparatus 1 can be appropriately moved at a predetermined timing along the circumferential direction of the pipe 100.

  Further, the wheels 11F and 11R are supported so as to be able to advance and retract in the direction of the stroke shaft 11b, and can be moved forward and backward in the direction of the tube wall surface. The forward and backward movement of the wheels 11F and 11R in the direction of the tube wall surface is performed by a wheel stroke actuator 22 (see FIG. 2) such as a pneumatic cylinder or a linear solenoid, and the wheels 11F and 11R are moved to the tube wall surface inside the pipe 100. It is pressed with a predetermined urging force.

  As will be described later, the wheel stroke actuator 22 adjusts the advance and retreat amounts of the wheels 11F and 11R in the direction of the stroke axis 11b, and the posture (pitch angle) of the in-pipe travel device 1 in the pipe 100 is controlled.

  The in-pipe travel device 1 includes a first observation unit 12 for observing the front of the in-pipe travel device 1 in the pipe, and a second observation unit for observing the side of the in-pipe travel device 1 in the pipe. 15.

  The first observation unit 12 is provided at the front end portion of the main body unit 10, and a first imaging unit 13 for imaging a region in the pipe in front of the in-pipe traveling device 1 and the main body unit 10 toward the front. It has the 1st illumination unit 14 for irradiating illumination light.

  The second observation unit 15 is fixedly provided on the side of the main body unit 10. The second observation unit 15 includes a second imaging unit 16 for imaging the side tube wall surface of the in-pipe traveling device 1 and a second imaging unit for irradiating illumination light from the main body unit 10 toward the side. An illumination unit 17 is provided.

  Each of the first imaging unit 13 and the second imaging unit 16 is not shown in the figure, but includes a plurality of objective optical lens groups that form an optical image (subject image) of the subject, and the optics formed by the objective optical lens group. An imaging unit that converts an image into an electronic image signal, an imaging drive circuit that drives the imaging device, and an image processing circuit that performs various image processing on image signals output from the imaging device is there.

  The configuration of the first and second imaging units 13 and 16 themselves is the same as that of an imaging unit applied to an imaging apparatus or the like that has been generally put into practical use. Omitted. The first imaging unit 13 and the second imaging unit 16 may be similar units. However, the second imaging unit 16 has a relative angle of view as compared with the first imaging unit 13. Even if it becomes narrow, it is desirable to increase the resolution.

  Each of the first lighting unit 14 and the second lighting unit 17 is a constituent unit having a light emitting source such as an LED (light emitting diode) and an illumination driving circuit for driving the light emitting source, for example. The configuration is the same as that of a general lighting unit. Therefore, detailed illustration and description thereof will be omitted.

  Note that the first and second illumination units 14 and 17 are not necessarily included in the first and second observation units 12 and 15, but may be arranged at different locations to irradiate the subject with illumination light. good.

  Further, in the present embodiment, the second observation unit 15 including the second imaging unit 16 is configured to be fixed at one place on the side portion of the main body unit 10. For this reason, as will be described later, in order for the second imaging unit 16 to capture an image of the tube wall surface in the circumferential direction, the main body 10 needs to be rotated in the circumferential direction in the tube.

  However, the present invention is not limited to this, and the second imaging unit 16 itself is configured to be rotatable around the axis of the main body 10 as indicated by a dashed arrow R3 in FIG. You may do it.

  When the second imaging unit 16 itself is configured to be rotatable, the second imaging unit 16 interferes with not only the side part of the main body part 10 but also the first imaging unit 13 on the front end side of the main body part 10. You may make it provide in the site | part which does not carry out, or the rear-end part side of the main-body part 10. FIG.

  Further, the second imaging unit 16 is configured to be disposed in a circumferential direction at a plurality of locations on the side portion of the main body 10, and a plurality of images in the circumferential direction in the pipe are obtained without rotating the main body 10. You may do it.

  Next, the control system of the in-pipe traveling apparatus 1 will be described. As shown in FIG. 2, in the control system of the in-pipe traveling device 1, the first observation unit 12 (the first imaging unit 13 and the first illumination unit 14) and the second observation unit are mainly controlled by the control device 50. 15 (second imaging unit 16 and second illumination unit 17), a traveling motor 20 that rotationally drives the wheel 11F, a steering motor 21 that steering-drives the wheel 11F, and the forward and backward movement of the wheels 11F and 11R in the stroke axis 11b direction. A wheel stroke actuator 22 that varies the amount is controlled.

  In addition, although the control apparatus 50 shall be incorporated in the main-body part 10 in this embodiment, you may make it provide separately in the exterior of the in-pipe traveling apparatus 1. FIG. In FIG. 2, only the main components related to the present invention are shown, and other parts not related to the present invention are not shown.

  Further, in the present embodiment, the two wheels 11F are configured to be individually driven for each wheel by one traveling motor 20, but may be configured to divide and transmit the driving force to each wheel. The wheel 11R may not be a driven wheel that rotates without receiving a driving force, and all the wheels 11F and 11R may be driven individually. Furthermore, it is good also as a structure by which all the wheels 11F and 11R are steered.

  The control device 50 is mainly configured by a single computer having a CPU, a ROM, and a RAM, or a computer system in which a plurality of computers are connected via a network, and includes an input / output interface circuit, a drive circuit, a power supply circuit, and the like. . The control device 50 is not limited to a computer system, and may be configured by hardware such as an FPGA or an ASIC.

  The in-pipe travel device 1 controlled by the control device 50 takes an image of the inside of the pipe with the first image pickup unit 13 and the second image pickup unit 16, and a pipe seam, for example, a pipe, where defects such as scratches are likely to occur. Collect data for inspection of welded parts with pipes, flange-type and screw-in type joints, and plug-in type joints.

  In the inspection of the joint of the pipe, the control device 50 detects the joint of the pipe such as the welded part or the joint from the image in the traveling direction imaged by the first imaging unit 13, and performs the second imaging for the detected seam. While controlling the posture of the unit 16 during imaging, an image of the wall surface including the seam is acquired in the circumferential direction.

  Therefore, the control device 50 includes a drive control unit 51, a first image acquisition unit 52, a joint detection unit 53, an attitude control unit 54, and a second image acquisition unit 55 as main function units. Details of each functional unit will be described below.

  The drive control unit 51 drives the wheel stroke actuator 22 to project the wheels 11F and 11R in the direction of the stroke shaft 11b, and presses the wheels 11F and 11R against the pipe wall surface of the pipe 100 with a predetermined urging force. And the drive control part 51 drives the motor 20 for a driving | running | working in the state which pressed the wheels 11F and 11R to the pipe wall surface of the piping 100, rotates the wheel 11F, and runs the in-pipe running apparatus 1 along the longitudinal axis direction of a pipe line. And run.

  Further, the drive control unit 51 drives the steering motor 21 as necessary to rotate the wheel 11F in the direction of the arrow R2 around the stroke shaft 11b. As a result, the in-pipe travel device 1 can smoothly pass through a bent portion or the like that bends at a predetermined angle with respect to the traveling direction, and the circumferential posture of the in-pipe travel device 1 in the pipe can be controlled.

  The first image acquisition unit 52 acquires an image obtained by capturing an area in a tube in front of the in-pipe travel device 1 by the first imaging unit 13 while the in-pipe travel device 1 is traveling in the pipe 100. That is, the first image acquisition unit 52 images a predetermined area in front of the in-pipe traveling device 1 with the first imaging unit 13 while illuminating the front of the in-pipe traveling device 1 with the first lighting unit 14. A front image (live view image) while driving is acquired.

  The joint detection unit 53 analyzes the live view image of the front area imaged by the first imaging unit 13 and detects the joints such as a welded part and a joint part of the pipe. In the present embodiment, the seam detection unit 53 detects a seam from an image obtained by imaging the inside of the pipe by image recognition using machine learning, pattern matching, or the like.

  For example, the joint detection unit 53 extracts feature amounts by supervised deep learning (deep learning) using a multilayer neural network, and determines the presence or absence of a joint in the pipe. As a network model, a convolutional neural network, which is a type of forward-propagation neural network that is not fully connected, is used, and the position and size of pipe joints, reliability of detection results, etc. by learning using this convolutional neural network Get the data.

  When the joint detection unit 53 detects a pipe joint, the posture control unit 54 instructs the drive control unit 51 to move the in-pipe travel device 1 to the target position. The target position is a position suitable for imaging by the second imaging unit 16, and can be determined from the position of the in-pipe traveling device 1 in the piping, the image data of the second imaging unit 16, and the like, as will be described later. .

  Then, when the in-pipe traveling device 1 moves to the target position, the posture control unit 54 makes the second imaging unit 16 and the pipe wall surface to be imaged face each other in order to obtain a clear seam image with little distortion. The posture of the in-pipe traveling apparatus 1 is controlled. In this embodiment, the attitude control of the in-pipe traveling apparatus 1 is control of a yaw angle and a pitch angle described below.

  Generally, the joint which joins a pipe | tube and a pipe | tube is provided in the cross section orthogonal to the longitudinal axis direction (direction along the advancing direction F of the in-pipe travel apparatus 1) of piping. In the following, for the sake of convenience, a cross section perpendicular to the longitudinal axis direction at the joint of the pipe is referred to as a “joining plane”, and the second imaging unit 16 and the pipe wall surface (curved surface) to be imaged face each other. Description will be made assuming that the joining plane and the imaging surface of the second imaging unit 16 are substantially orthogonal.

  The posture control of the in-pipe travel device 1 is mainly executed by correcting the yaw angle by setting the angle of deviation from the state in which the joining plane of the pipe and the imaging surface of the second imaging unit 16 are orthogonal to each other as the “yaw angle”. Is done. In the case of a straight pipe, the control of the yaw angle can be said to be control for correcting the direction of the in-pipe traveling apparatus 1 so that the optical axis of the imaging optical system of the second imaging unit 16 is substantially orthogonal to the longitudinal axis direction of the pipe. .

  Further, in the present embodiment, the attitude control unit 54 sets the angle of deviation from a state in which the joint plane of the piping and the vertical scanning direction of the imaging surface of the second imaging unit 16 are parallel as the “pitch angle”. Control to correct this pitch angle is added. This is because, in this embodiment, the in-pipe travel device 1 is rotated in the circumferential direction to acquire an image including the joint of the pipe in the circumferential direction, and control of the pitch angle may be omitted depending on conditions. Is possible.

  When the posture of the in-pipe traveling device 1 is controlled by the posture control unit 54 and the second image acquisition unit 55 is in a posture that faces the joint of the pipe, the second image acquisition unit 55 uses the second image acquisition unit 16. Start imaging the tube wall.

  Then, the second image acquisition unit 55 instructs the drive control unit 51 to image the tube wall surface with the second imaging unit 16 while rotating the in-pipe travel device 1 around the longitudinal axis along the traveling direction, An image including the seam is acquired over the circumferential direction of the pipe.

  Next, the inspection in the pipe by the above-described in-pipe traveling apparatus 1 will be described with reference to the flowcharts of FIGS. 3 and 4. The flowchart of FIG. 3 shows the in-pipe inspection process executed by the control device 50, and the flowchart of FIG. 4 shows the joint detection process in the in-pipe inspection process of FIG.

  The in-pipe inspection process in FIG. 3 is executed after the in-pipe travel device 1 is arranged inside the pipe to be inspected by the user (user). In this process, in the first step S1, the control device 50 drives the wheel stroke actuator 22 via the drive control unit 51 to bring the wheels 11F and 11R into contact with the pipe wall surface of the pipe 100 with a predetermined urging force. In this state, the traveling motor 20 is driven to rotate the wheel 11F around the rotation shaft 11a. As a result, the in-pipe travel device 1 travels in the pipe along the longitudinal axis direction of the pipe line.

  Next, it progresses to step S2, and the control apparatus 50 acquires the live view image of the front area | region where the in-pipe traveling apparatus 1 is drive | working the inside of a pipe | tube via the 1st image acquisition part 52. FIG. Specifically, as shown in FIG. 5, the first image acquisition unit 52 drives the first lighting unit 14 while the in-pipe travel device 1 is traveling in the pipe 100 from the position P1 toward the position P2. Then, while illuminating the traveling direction, the first imaging unit 13 is driven to image the front area in the tube, and the live view images G1 and G2 during traveling are acquired.

  In step S3, the seam detection unit 53 of the control device 50 analyzes the live view image in the pipe to determine whether or not there is a pipe seam, and detects the seam. FIG. 5 shows an example in which the joint JT of the pipe is not detected from the image G1 at the position P1, but the joint JT is detected from the image G2 at the position P2.

  Specifically, the detection of the joint of the pipe is executed by the joint detection process of FIG. Here, the joint detection process of FIG. 4 will be described. FIG. 4 shows an example of joint detection processing using a convolutional neural network.

  The joint detection unit 53 reads the live view image data in the traveling direction of the in-pipe traveling device 1 in the first step S11. In step S12, a data set of learning data generated in advance by supervised learning is read.

  Thereafter, the process proceeds from step S12 to step S13, in which learning data is read into a convolutional neural network, an inference operation is performed, and a feature amount of the seam is extracted from the live view image in the pipe to recognize the presence or absence of the seam. In step S14, the data obtained by the recognition process using the convolutional neural network is output.

  For example, as shown in FIG. 6, when the joint JT of the pipe is detected in the region GA of the live view image G2 by the image recognition process using the convolutional neural network, the joint detection unit 53 detects the detection size (in the region GA). Data such as width, height), detection position Jc (center coordinates of the area GA), detection reliability (probability of detection result), and the like are output.

  The data output in the joint detection process of FIG. 4 is referred to in the in-pipe inspection process of FIG. In step S4 of the in-pipe inspection process, the joint detection unit 53 determines the presence / absence of a pipe joint from the data output in the joint detection process.

  If there is no seam, the control device 50 determines that it is not necessary to record an image, and jumps from step S4 to step S8. In step S8, the control device 50 determines whether or not to end the inspection range by reaching the end position of the inspection range. If the end position of the inspection range has not been reached, the control device 50 returns to step S1 from step S8. The traveling is continued, and the inspection is terminated when reaching the end position of the inspection range.

  On the other hand, in step S4, for example, when the joint JT is detected from the image G2 acquired at the position P2 in FIG. 5, the process proceeds from step S4 to step S5. In step S5, the drive control unit 51 moves the in-pipe travel device 1 to a target position P3 in the vicinity of the joint JT of the pipe 100 as shown in FIG.

  The target position P3 is a position suitable for imaging by the second imaging unit 16, and uses the image data of the pipe wall surface in the pipe 100 imaged by the first imaging unit 13 and the data of the size and position of the seam. Can be estimated.

  For example, when the position of the joint JT is in the straight pipe portion, the distance to the joint JT can be estimated from the size of the pipe diameter, the angle of view of the first imaging unit 13, and the size of the joint JT. The in-pipe travel device 1 is moved to the target position P3 based on the information.

  Further, as shown in FIG. 8, the in-pipe traveling device 1 is moved forward while confirming the position of the joint JT based on the information of the image GH of the tube wall surface imaged by the second imaging unit 16, and the joint JT is displayed in the image GH. The in-pipe traveling apparatus 1 may be stopped with the position near the center of the target position P3. Furthermore, the target position P3 may be estimated based on the relationship between the laying piping drawing and the self-position of the in-pipe travel device 1 or the like.

  After that, when the in-pipe travel device 1 moves to the target position P, the process proceeds from step S5 to step S6, and the control device 50 causes the posture of the second imaging unit 16 at the time of imaging to be a posture facing the joint JT. The posture of the in-pipe traveling apparatus 1 is controlled via the posture control unit 54. In the present embodiment, the attitude control unit 54 performs yaw angle control and pitch angle control as attitude control of the in-pipe traveling apparatus 1.

  The attitude control unit 54 drives the steering motor 21 and the traveling motor 20 via the drive control unit 51 to control the yaw angle of the in-pipe traveling device 1, and advances and retracts the in-pipe traveling device 1 while changing the direction of the wheels 11F. Let

  As a result, as shown in FIG. 9, the in-pipe travel device 1 rotates in the direction of the arrow Ry to change the orientation of the in-pipe travel device 1 with respect to the major axis direction of the pipe 100, and the imaging surface of the second imaging unit 16 is changed. The deviation in the yaw angle direction is corrected so as to be substantially orthogonal to the joining plane of the pipe 100.

  The deviation in the yaw angle direction of the in-pipe traveling device 1 is provided with two distance measuring sensors 18 and 19 on the side of the in-pipe traveling device 1 with the second imaging unit 16 interposed therebetween, as shown in FIG. These distance measuring sensors 18 and 19 can be used for detection.

  The distance measuring sensors 18 and 19 measure the distance from the tube wall surface on both sides of the second imaging unit 16 along the forward direction of the in-pipe traveling apparatus 1. Based on the difference, the attitude of the in-pipe travel device 1 in the yaw angle direction is controlled.

  That is, when the yaw angle of the in-pipe traveling device 1 is shifted from the joint plane of the joint JT of the pipe 100 (when the yaw angle is not 0), the distances from the distance measuring sensors 18 and 19 to the pipe wall surface are different. Therefore, the output ratio of the distance measuring sensors 18 and 19 does not become 1.0. Therefore, the deviation of the yaw angle can be corrected by adjusting the direction of the in-pipe traveling apparatus 1 so that the output ratio of the distance measuring sensors 18 and 19 is equivalent to 1.0.

  Further, the deviation in the yaw angle direction of the in-pipe traveling device 1 can also be detected using an image of the tube wall surface imaged by the second imaging unit 16. When using an image of the tube wall surface, the deviation of the yaw angle is detected from the relationship of the luminance distribution due to the light distribution of the illumination in the image.

  That is, as shown in FIG. 11, an image G3 of the tube wall surface imaged in a state where the yaw angle of the in-pipe traveling device 1 is shifted has a luminance value close to the tube wall surface in the horizontal scanning direction across the joint JT. On the other hand, the luminance value on the side far from the tube wall surface becomes relatively small. For example, when the tube wall surface is imaged by the second imaging unit 16 in the posture of FIG. 10, the luminance distribution of the image G3 is as shown in FIG. 11 because the distance sensor 19 side is closer to the tube wall surface than the distance sensor 18 side. The brighter you go to the right. Therefore, the deviation of the yaw angle can be corrected by adjusting the direction of the in-pipe traveling device 1 so that the luminance distribution in the horizontal scanning direction of the image G3 is constant over the entire screen.

  Further, the posture control unit 54 corrects the pitch angle of the in-pipe traveling device 1 based on the inclination of the seam in the image of the tube wall surface imaged by the second imaging unit 16. As shown in FIG. 12, when the in-pipe traveling device 1 is tilted with respect to the longitudinal axis of the pipe 100, the joint JT of the pipe 100 is in the captured image G4r of the second imaging unit 16 with respect to the vertical scanning line. It is projected in a tilted state.

  Therefore, the posture control unit 54 drives the wheel stroke actuator 22 via the drive control unit 51 as a control of the pitch angle of the in-pipe travel device 1, and the joint JT of the pipe 100 is substantially parallel to the vertical scanning line. The stroke of the wheels 11F and 11R in the tube wall direction is adjusted so that the image G4 is obtained.

  In the present embodiment, the second imaging unit 16 is adjusted so as to face the pipe wall surface by controlling the posture of the in-pipe traveling apparatus 1, but the second imaging unit 16 itself is adjusted to the in-pipe traveling apparatus 1. The posture of the second imaging unit 16 may be directly controlled so that it can swing three-dimensionally with respect to the main body unit 10.

  After executing the posture control of the in-pipe travel device 1, the process proceeds from step S6 to step S7, and the second image acquisition unit 55 of the control device 50 starts imaging the tube wall surface by the second imaging unit 16, Acquire images across the circumference of the pipe.

  In the present embodiment, as shown in FIG. 13, the second imaging unit 16 images the pipe wall surface including the joint JT while rotating the in-pipe traveling apparatus 1 in the pipe 100 in the circumferential direction. At this time, the second image acquisition unit 55 determines the shutter speed and frame rate of the second imaging unit 16 from the rotational speed in the circumferential direction in the pipe of the in-pipe travel device 1 and the angle of view of the second imaging unit 16. Appropriately set and acquire a plurality of still image groups or moving images at predetermined intervals.

  For example, in FIG. 13, when the position of the in-pipe traveling device 1 when the second imaging unit 16 faces the pipe wall surface by posture control is K1, the second image acquisition unit 55 is the second at the position K1. The imaging unit 16 starts imaging, and an image GK1 of the tube wall surface including the partial seam JT1 is acquired.

  Next, the second image acquisition unit 55 drives the steering motor 21 via the drive control unit 51, rotates the wheel 11F from the position K1 about the stroke axis 11b, and then travels. The motor 20 is driven to rotate the in-pipe travel device 1 by a predetermined angle in the circumferential direction in the pipe 100 and stop (position K2). The second image acquisition unit 55 acquires an image GK2 including the joint JT2 imaged by the second imaging unit 16 at the position K2.

  Further, the second image acquisition unit 55 rotates the in-pipe travel device 1 from the position K2 to the positions K3, K4,..., And acquires images GK3, GK4,. When the in-pipe travel device 1 returns to the initial position K1, the second image acquisition unit 55 completes the acquisition of the image for one round in the pipe, and records and stores the acquired data.

  At this time, the second image acquisition unit 55 sets the rotation angle of the in-pipe traveling device 1 in consideration of the inner diameter of the pipe 100, the angle of view of the second imaging unit 16, and the like, as shown by a broken line in FIG. The positions of the images GK1, GK2, GK3, GK4,... Are overlapped. This is because the positions of the images are aligned when generating a developed combined image for inspection, which will be described later.

  When the second imaging unit 16 is configured to be rotatable around the axis of the main body 10 of the in-pipe travel apparatus 1 (see FIG. 1; the broken arrow R3), the attitude of the in-pipe travel apparatus 1 is controlled. Then, after the second imaging unit 16 is directly opposed to the tube wall surface, the second imaging unit 16 is rotated via an actuator (not shown) to image the tube wall surface at each position. Thereby, the image similar to image GK1, GK2, GK3, GK4, ... can be acquired for every position.

  On the other hand, when the second imaging units 16 are arranged in the circumferential direction at a plurality of locations on the side of the main body 10 of the in-pipe travel device 1, the arrangement intervals of the plurality of second imaging units 16 and the respective imaging units are arranged. Set the angle of view appropriately. Then, with the plurality of second imaging units 16 facing the tube wall surface, each unit images the tube wall surface simultaneously or sequentially, so that images similar to the images GK1, GK2, GK3, GK4,. Can be acquired.

  Thereafter, the control device 50 determines whether or not the inspection is finished in step S8. When the in-pipe traveling apparatus 1 has not reached the end position of the inspection range, the process returns from step S8 to step S1 to continue traveling in the pipe. When the in-pipe travel apparatus 1 has reached the end position of the inspection range, the inspection by this processing is terminated. .

  An image for inspection is generated from the image of the wall surface in the pipe 100 acquired by the above inspection. The inspection image may be generated in the control device 50 mounted on the in-pipe traveling apparatus 1 or may be generated by an external device by transmitting data from the control device 50 to the outside. .

  In this case, as the image for inspection, an image that is easy to view without the influence of distortion or the like is desired. Therefore, as shown in FIG. 14, one developed composite image GKe is generated from the plurality of acquired image groups GK1, GK2, GK3, GK4,.

  When generating this developed composite image, for example, when the in-pipe travel device 1 travels in a vertical pipe, it is difficult to keep the in-pipe travel device 1 itself in a constant posture, and the in-pipe travel device 1 is acquired while rotating. There is a possibility that a positional deviation occurs between the image data.

  Therefore, the positions of the images GK1, GK2, GK3, GK4,... Are aligned and then combined to generate one developed composite image GKe. In the developed composite image GKe, a joint JTe that is developed in a plane by connecting the circumferential seams JT1, JT2, JT3, JT4,. The

  For example, block matching that searches for matching points between images by evaluating the correlation of a predetermined region, or singular point matching that searches for matching points between images using singular points extracted from images. Etc. can be used.

  By outputting the generated developed composite image as a developed view, it is possible to easily detect defects such as scratches by facilitating visual inspection by an operator.

  Further, in the inspection system including the in-pipe traveling device 1, for example, the presence or absence of defects such as scratches may be automatically determined by an image recognition technique such as deep learning.

  In that case, the degree of degradation of the scratches may be classified and displayed by color, or the part having the scratches may be displayed in association with the installed piping drawing.

  Further, the work of the next process may be appropriately determined on the inspection system side according to the level of deterioration. For example, if the degree of deterioration is clearly large, the operation is shifted to a repair operation, and if the degree of deterioration is not clear, the operation is transferred to a detailed inspection such as an X-ray inspection.

  As described above, according to the present embodiment, when in-pipe inspection is performed by the in-pipe travel device 1, the control device 50 analyzes the image in the pipe imaged by the first imaging unit 13 to analyze the pipe seam. The presence or absence of is determined.

  When the joint of the pipe is detected, the control device 50 controls the yaw angle and pitch angle of the in-pipe traveling apparatus 1 and controls the posture so that the imaging surface of the second imaging unit 16 faces the joint of the pipe. And the pipe wall surface is imaged by the second imaging unit 16 while rotating the in-pipe travel device 1 in the circumferential direction in the pipe, and an image of the pipe wall surface is acquired over the circumferential direction of the pipe.

  As a result, the pipe wall surface inside the pipe can be picked up with a clear image with little distortion, and defects such as fine scratches and deterioration occurring at the joints of the pipe can be surely found.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be implemented without departing from the spirit of the invention. In addition, each processing sequence described in the above-described embodiment can allow a procedure to be changed as long as it does not contradict its nature.

  Therefore, the order of the processing steps is different each time the processing sequence is executed, for example, each time the order of processing steps is changed, multiple processing steps are executed simultaneously, or a series of processing sequences are executed. Anyway. Further, it goes without saying that in each step constituting these operation flows, portions that do not affect the essence of the invention can be omitted as appropriate.

  Of the technologies described here, many of the controls and functions mainly described in the flowchart can be set by a software program, and the above-described controls and functions can be performed by a computer reading and executing the software program. Can be realized.

  The software program is a computer program product in advance in the product manufacturing process, such as the storage medium or storage unit, specifically, a portable medium such as a flexible disk CD-ROM or a non-volatile memory, a hard disk volatile memory, or the like. Electronic data that is stored or recorded in whole or in part on a storage medium.

  Apart from this, it can be distributed or provided at the time of product shipment or via a portable medium or a communication line. Even after the product has been shipped, the user can download and install the software program on the computer via the communication network or the Internet, or install the software program on the computer from the storage medium. Can be.

DESCRIPTION OF SYMBOLS 1 ... Pipe travel apparatus 10 ... Main-body part 11, 11F, 11R ... Wheel 11a ... Rotating shaft 11b ... Stroke shaft 12 ... 1st observation part 13 ... 1st imaging unit 14 ... 1st illumination unit 15 ... 2nd Observation unit 16 ... second imaging unit 17 ... second illumination unit 18, 19 ... ranging sensor 20 ... traveling motor 21 ... steering motor 22 ... wheel stroke actuator 50 ... control device 51 ... drive control unit 52 ... 1st image acquisition part 53 ... Seam detection part 54 ... Attitude control part 55 ... 2nd image acquisition part 100 ... Piping

Claims (9)

An in-pipe travel device that travels inside a pipe,
A first imaging unit for imaging a region in front of the in-pipe travel device inside the pipe;
A second imaging unit for imaging a side wall surface of the in-pipe travel device inside the pipe;
A first image acquisition unit that acquires an image captured by the first imaging unit while the in-pipe traveling device is traveling in the pipe;
A seam detection unit for detecting a seam of the pipe based on the image acquired by the first image acquisition unit;
A posture control unit that controls the posture of the second imaging unit with respect to the joint detected by the joint detection unit;
A second image in which imaging of the tube wall surface by the second imaging unit is started in a posture controlled by the posture control unit, and an image of the tube wall surface including the seam is acquired in the circumferential direction of the pipe. An acquisition unit;
An in-pipe travel apparatus comprising: The in-pipe travel apparatus according to claim 1, wherein the joint detection unit detects the joint of the pipe by deep learning of a multilayer neural network from the image acquired by the first image acquisition unit. The in-pipe traveling apparatus according to claim 1, wherein the attitude control unit controls the attitude of the in-pipe traveling apparatus so that the tube wall surface and the second imaging unit face each other. The posture control unit controls the posture of the in-pipe travel device based on a difference in distance from the tube wall surface on both sides of the second imaging unit along the forward direction of the in-pipe travel device. The in-pipe traveling device according to claim 3. The in-pipe travel apparatus according to claim 3, wherein the attitude control unit controls the attitude of the in-pipe travel apparatus based on a luminance distribution of an image captured by the second imaging unit. The second imaging unit is fixedly provided on a side portion of the in-pipe traveling device,
The second image acquisition unit acquires the image of the pipe wall surface including the seam in the circumferential direction of the pipe by rotating the in-pipe travel device in the circumferential direction inside the pipe. The in-pipe traveling apparatus according to claim 1, wherein The second imaging unit is provided to be rotatable in a circumferential direction of the pipe,
The said 2nd image acquisition part acquires the image of the said tube wall surface containing the said seam over the circumferential direction of the said piping by rotating the said 2nd imaging unit. The in-pipe traveling apparatus as described. The second imaging unit is provided along the circumferential direction of the pipe at a plurality of locations of the in-pipe travel device,
The said 2nd image acquisition part acquires the image of the said pipe wall surface containing the said seam over the circumferential direction of the said piping with the said 2nd imaging unit of several places. In-pipe travel device. The second image acquisition unit acquires a plurality of images of the pipe wall surface including the seam in the circumferential direction of the pipe so as to overlap each other, and develops a single sheet by aligning positions between the images. The in-pipe traveling apparatus according to claim 1, wherein a composite image can be generated.