JP6681173B2 - Pipeline facility inspection aircraft and pipeline facility inspection system using the same - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a pipeline facility inspection flying body for flying an image in a pipeline facility such as a sewer pipeline to acquire an image and grasping the state of the inner surface of the pipeline facility, and a pipeline facility inspection system using the same. .

  At present, as a typical pipeline facility, there is a problem of deterioration of sewer pipelines. As aging progresses, abnormalities such as cracking, damage, and corrosion will occur. As a result, the function of separating the liquid inside the pipe from the outside of the pipe and lowering it will be reduced, and earth and sand will enter the pipe from the outside of the pipe and create a void in the ground, which may cause a road collapse accident. is there.

  Therefore, it is necessary to have a technology to understand the abnormality of the sewerage pipe due to aging. In order to meet such needs, for example, Patent Document 1 describes a technique of running a small self-propelled vehicle equipped with a television camera in a sewer pipe to monitor the state inside the pipe.

JP, 9-226570, A

  In Patent Document 1, an image is acquired by a TV camera of a self-propelled vehicle placed in the sewer pipe, but a person enters the sewer pipe in advance and receives the self-propelled vehicle from the ground to enter the sewer pipe Installation work is required. Since the sewage pipeline may be filled with toxic gases such as hydrogen sulfide, it is necessary to measure the concentrations of hydrogen sulfide and oxygen before people enter. If the environment is inappropriate for humans to work in the sewer pipeline, work to blow air from the ground into the sewer pipeline for ventilation is added.

  Further, when capturing an image of a sewer pipe, it is required that an image capturing device does not collide with the inner surface of the pipe and a stable image is captured.

  The present invention has been made in view of these problems, and an object of the present invention is to eliminate the need for workers to be present in the pipeline when inspecting the pipeline facility, and to stabilize the captured image in the pipeline. The purpose of the present invention is to provide a pipeline facility inspection vehicle that can be acquired by using the above and a pipeline facility inspection system using the same.

The pipeline facility inspection vehicle of the present invention is provided with an image capturing unit for capturing an image of the inside of the pipeline, an irradiating unit for irradiating light into the pipeline, the image capturing unit and the irradiating unit, and flying in the pipeline. A flying body, a distance sensor arranged on the flying body, for measuring a distance between the conduit and the flying body in the conduit, and a distance sensor arranged on the flying body and based on a measurement value of the distance sensor. And a flight control means for controlling the flight direction of the flying body in the pipeline , the distance sensor being disposed on the upper surface of the flying body, and the vertical line between the pipeline and the flying body in the pipeline. An upper distance sensor that measures an upward distance, and a distance between the pipeline and the flight body in the pipeline, which are arranged on at least two side surfaces of the flight body, in a direction perpendicular to the traveling direction of the flight body. a lateral distance sensors for measuring the Rukoto that having a characterized.

  ADVANTAGE OF THE INVENTION According to this invention, when inspecting a pipeline facility, it is not necessary for a worker to be present in the pipeline, and a pipeline facility inspection vehicle capable of stably acquiring a captured image in the pipeline and the same are provided. It is possible to provide a pipeline facility inspection system using.

1 is a side view and a top view of a pipeline facility inspection vehicle according to an embodiment of the present invention. FIG. 2 is a configuration diagram showing a pipeline facility inspection system using the pipeline facility inspection vehicle shown in FIG. 1. It is a radial cross-sectional schematic diagram at the time of the pipeline facility inspection flying body which concerns on one Example of this invention flying in the sewer installed horizontally. FIG. 3 is an axial cross-sectional view of a state in which a pipeline facility inspection vehicle according to an embodiment of the present invention is flying in a horizontally installed sewer pipe, as viewed from vertically above. An axial cross section of a state in which a lateral distance sensor of a pipeline facility inspection air vehicle according to an embodiment of the present invention is installed so as to measure a distance in a direction that is not at right angles to a traveling direction from vertical information. It is a figure. With respect to the angular deviation between the flight direction of the pipeline facility inspection air vehicle and the axial direction of the pipeline facility according to one embodiment of the present invention, the sum of the measured values of two distance sensors that measure distances in mutually opposite directions and It is a schematic diagram which shows the relationship of. FIG. 3 is an axial cross-sectional view of a state in which a pipeline facility inspection vehicle according to an embodiment of the present invention is flying in a horizontally installed sewer pipe, as viewed from vertically above. FIG. 1 is an axial cross-sectional view of a flying vehicle for inspecting a pipeline facility according to an embodiment of the present invention, which has a gentle curvature and is flying in a horizontally installed sewer pipe, as viewed from vertically above. It is a schematic diagram at the time of measuring measured value x3 and x4 with a downward distance sensor. FIG. 6 is a schematic diagram in the case where there are three distance sensors provided in a horizontal direction and a direction below the horizontal direction.

  The pipeline facility inspection vehicle of the present invention is an aircraft that flies in a pipeline facility and is used for inspection of cracks and cracks. Pipeline facilities include, for example, sewer pipes, gas pipes, tunnels, collecting pipes, water pipes whose contents have been replaced with gas, steam pipes, oil pipes, siding pipes, discharge pipes, manholes, etc., with particular restrictions. Not something that is done.

  Hereinafter, as a specific example, an embodiment in the case of targeting a sewer pipe will be described with reference to the drawings.

  FIG. 1 is a side view and a top view of a pipeline facility inspection vehicle 10 according to an embodiment of the present invention. In the pipeline facility inspection aircraft 10, a propeller 18, an imaging unit 20, an irradiation unit 22, an upper distance sensor 12, a lateral distance sensor 14, and a flight control unit 24 are arranged in a main body 30 of the aircraft. Although a motor, a battery, etc. are required for actual flight, it is assumed that both are provided in the flying body 30. Furthermore, in order to inspect the sewer pipe, a wireless transmission device 35 that wirelessly transmits the image captured by the image capturing means 20, a battery that drives them, and the like are also required, but these are also included in the aircraft body 30. To do.

  The pipeline facility inspection vehicle 10 rotates the propeller 18 to fly inside the sewer pipe. The irradiation means 22 irradiates the inner surface of the sewer pipe with light, and the imaging means 20 images the inner surface of the sewer pipe. The pipeline facility inspection vehicle 10 advances with the side provided with the imaging means 20 as the front. When the wall surface, the ceiling, or the bottom of the sewer pipe is photographed in more detail, the image pickup means 20 may be installed so as to be able to photograph a direction perpendicular to the traveling direction of the pipeline facility inspection vehicle 10. In order to prevent the pipeline facility inspection vehicle 10 from colliding with the ceiling, wall surface, bottom surface and water surface of the sewer pipe when moving, the vertical movement of the pipeline facility inspection vehicle 10 is controlled by controlling the rotation speed of the propeller 18. It moves back and forth, left and right, and rotates. Specifically, the measured values of the upper distance sensor 12 and the lateral distance sensor 14 are given to the flight control means 24 (for example, a microcomputer) in the flying body 30, and the output calculated by the flight control means 24 is supplied to each propeller 18. It controls movement and rotation by giving it to the motor that is the power source of. The rotation referred to here means that only the direction of the flight vehicle 10 is changed without changing the position of the pipeline facility inspection flight vehicle 10.

  The lateral distance sensor 14 is a sensor that measures the distance between the sewer pipe and the flying body 10 in the sewer pipe, and the flying body 30 is capable of measuring the distance in a direction perpendicular to the traveling direction of the flying body 10. It is installed on both sides of each (see Fig. 1). Both of them are preferably installed in a direction in which a distance perpendicular to the traveling direction is measured, but the direction to be measured need not be parallel to the traveling direction.

  The upper distance sensor 12 is a sensor that measures the distance between the sewer pipe and the flying body 10 in the sewer pipe, and is installed on the upper surface of the flying body 30 so as to measure the vertically upward distance. It should be noted that a plurality of different upper distance sensors 12 that measure the distance in the upward direction from the horizontal may be installed. An alternative is possible by incorporating in the flight control means 24 an algorithm for calculating the distance from the vertically upward direction based on the measured values of the plurality of upward distance sensors 12.

  Further, instead of the upper distance sensor 12, a lower distance sensor that measures a vertically downward distance between the sewer pipe and the flying body 10 may be provided. If there is a place where water drips from the ceiling of the sewer pipe, water may drop on the pipeline facility inspection vehicle 10 as well. When the upper distance sensor 12 is exposed to water droplets from the ceiling of the sewer pipe and the measurement accuracy decreases or measurement becomes impossible, a lower distance sensor is provided instead of the upper distance sensor 12 to measure the distance from the ceiling. You may estimate. For example, when the sewer pipe on which the pipeline facility inspection vehicle 10 flies is a circular pipe and the inner diameter 2r is known, the upper distance can be obtained by subtracting the lower distance from 2r. However, since the sewage normally flows through the sewer pipe and the water level changes depending on the location of the sewer pipe, the estimation accuracy of the upward distance is low.

  As the distance sensors 12 and 14 described above, it is desirable to use an ultrasonic sensor or an infrared sensor that is inexpensive, lightweight, and has low power consumption, but other than these, it is possible to realize inexpensive, lightweight, and low power consumption, and Any sensor may be used as long as it can output the distance. It is desirable to be able to measure the distance to solids such as the ceiling and wall surfaces in the sewer pipeline facility, but the ceiling and wall surfaces of the sewer pipe are often wet due to condensation and inflow water, so the distance to the liquid can also be measured. Is desirable.

  The propeller 18 has four propellers in FIG. 1, but is not limited to this, and may have six, eight, or two in the case of a contra-rotating propeller.

  The pipeline facility inspection vehicle 10 may be any device that is called a drone or UAV (Unmanned Aerial Vehicles, unmanned aerial vehicle), a small helicopter, or a balloon or an airship that can float and move in the air.

  The image capturing means 20 may be either a camera for capturing a still image or a video camera for capturing a moving image, but it is desirable that the image capturing means 20 be configured with equipment capable of capturing a moving image. It is even more desirable to be able to mount an infrared camera capable of photographing wavelengths in the near infrared, infrared, and far infrared regions, which have longer wavelengths than visible light. Since the infrared camera can detect the difference in temperature, it is possible to obtain information useful for detecting unknown water flowing from the outside of the sewer pipe based on the imaging result. Furthermore, it is more desirable if a stereo camera can be used as the image pickup means 20.

  As the irradiation means 22, it is desirable to reduce the weight of the battery to be loaded as much as possible, and therefore, an LED is mentioned, but the irradiation means 22 is not particularly limited. It is desirable to use a white light source because the operator may need to visually check the image. In order to measure the wet state of the wall surface of the sewer pipe 16 by using an image, a plurality of light sources having different light wavelengths may be alternately used for irradiation. For example, there is a method of using a white light source and a red light source. Since red light is easily absorbed by water, the image taken by the white light source and the image taken by the red light source are subjected to image processing, and the difference between the obtained images is evaluated, whereby the inner surface of the sewer pipe 16 gets wet. The state of can be detected. As a result, for example, unknown water flowing into the sewer pipe 16 can be identified.

  FIG. 2 is a diagram schematically showing a pipeline facility inspection system using the pipeline facility inspection vehicle 10 shown in FIG. The pipeline facility inspection vehicle 10 flies in the sewer pipe 16. A wireless transmission device 35 that wirelessly transmits the image captured by the image capturing unit 20 is arranged in the pipeline facility inspection vehicle 10. The image captured by the flying body 10 is transmitted and received from the wireless transmission device to the antenna 32 hung from the ground on the manhole 31 and the transmission / reception device 33 connected thereto, and displayed on the display device 34 on the ground. On the display device 34, a worker on the ground can confirm the photographed image at the same time as the photographing.

  In general, the sewer pipe 16 is arranged substantially parallel to the ground and is connected to the manhole 31 at a right angle. Therefore, even if a high-frequency radio wave with high straightness is sent to the sewer pipe 16 via the manhole 31, the radio wave may be greatly attenuated at the bent portion connected from the manhole 31 to the sewer pipe 16, and the radio wave may not reach easily. On the other hand, by arranging the antenna 32 in the manhole 31, it becomes easier for the radio wave to be transmitted through the sewer pipe 16 even if it is a high-frequency radio wave having a high straight traveling property, and it is possible to more stably communicate with the aircraft 10. You can

  The antenna 32 is formed by coating a conductor with a resin, and has a property that it can be wound into a cable shape, which is preferable for working. In FIG. 2, the antenna 32 is arranged in each of the manhole 31 on the entrance side and the manhole 31 on the exit side, but it may be arranged only on the entrance side or only on the exit side.

  The display device 34 is not particularly limited, and may be, for example, a stationary PC monitor such as a liquid crystal display, a plasma display, or a cathode ray tube, a commercial monitor, or a mobile device such as a smartphone or a tablet.

  FIG. 3 is a schematic cross-sectional view in the radial direction when the pipeline facility inspection vehicle 10 is flying inside the sewer pipe 16 installed in the horizontal direction. Sewage 26 flows through the sewer pipe 16. The upper distance sensor 12 measures the distance y from the ceiling of the sewer pipe 16, and the two lateral distance sensors 14 provided measure the distances x1 and x2 from the wall surface of the sewer pipe 16. ing. In this figure, the traveling direction is the other side of the drawing, and the pipeline facility inspection vehicle 10 is shown rearward. In the inspection work, it is desirable that the pipeline facility inspection vehicle 10 can fly in the axial direction in the sewer pipe 16 while keeping the distance y, the distance x1, and the distance x2 constant without colliding with the wall surface. .

  In this case, different distance sensors in three directions will be provided, but if the distance y to the ceiling and the distances x1 and x2 to the wall surface can be calculated, a larger number of distance sensors will be used as described above. You may prepare. However, an increase in the number of distance sensors leads to an increase in cost, weight, and power consumption, so a distance sensor with at most 10 directions is sufficient.

  FIG. 4 is an axial cross-sectional view of a state where the pipeline facility inspection vehicle 10 is flying in a pipeline facility installed in a horizontal direction, as viewed from above in the vertical direction. Of these, (a) is a desirable state in which the pipeline facility inspection vehicle 10 is flying in the axial direction. (b) is an unfavorable state where the flight direction of the pipeline facility inspection vehicle 10 is tilted to the right with respect to the axial direction, and (c) is the reverse, the flight direction of the pipeline facility inspection vehicle 10 is relative to the axial direction. Shows an unfavorable state of being tilted to the left. If it can fly in the state of (a), the pipeline facility inspection vehicle 10 does not collide with the wall surface and can capture an image in a fixed direction that is easy to analyze. In the case of (b) and (c), the image is difficult to analyze and there is a risk that the pipeline facility inspection vehicle 10 collides with the wall surface. Therefore, in the case of the states (b) and (c), it is necessary to rotate the pipeline facility inspection vehicle 10 and control it to the state (a). In the cases (b) and (c), the sum of the distance x1 and the distance x2 is longer than that in the case (a). The difference between the traveling direction of the pipeline facility inspection vehicle 10 and the axial direction of the sewer pipe 16 is defined as an angle deviation θ.

  FIG. 6 is a graph schematically showing the relationship between the angle deviation θ and the values of x1 + x2. When x1 + x2 has a minimum value, the angle deviation θ becomes 0. By utilizing this relationship and controlling the rotation of the pipeline facility inspection vehicle 10 so that the value of x1 + x2 becomes the minimum value, it is possible to fly while maintaining the flight direction of FIG. 4 (a). Become.

  As shown in FIG. 5, even if the measurement directions of the two lateral distance sensors 14 are not at right angles to the traveling direction, they are installed at the same angle with respect to the lateral sides of the pipeline facility inspection vehicle 10. In this case, the measured distances x6 and x7 may be used instead of x1 and x2 described above.

  However, as shown in FIG. 3, when the sewer pipe 16 is a circular pipe, flight control is performed only under the condition that x1 + x2 is made small, and when x1 + x2 approaches 0, it moves to the ceiling or the bottom and collides. The possibility arises. That is, it is necessary to control the rotation of the pipeline facility inspection vehicle 10 under the condition that the value of the distance y from the ceiling of the sewer pipe 16 is constant. This also applies to oval tubes. On the other hand, even if the sewer pipe is a rectangular pipe, it is desirable to control the rotation of the pipeline facility inspection vehicle 10 under the condition that the value of the distance y is constant. The flight control means 24 is provided with an algorithm for rotating x1 + x2 to a minimum value under the condition that the value of the distance y is constant (the distance y is half the inner diameter 2r).

  In the above, the example in which the value of x1 + x2 is the minimum has been described, but the calculation formula is not limited to this, and the value of the index obtained by inputting x1 and x2 may satisfy the target range. For example, the condition may be such that the value of k1 · x1 + k2 · x2 multiplied by the coefficient is the minimum, or the value of 1 / (x1 + x2) is the maximum. Alternatively, the condition may be that x1 is maintained within the target range and x2 is maintained within the target range. In any case, the value of the index obtained by inputting x1 and x2 may be a minimum value, a maximum value, or a value within a predetermined target range.

  The pipeline facility inspection air vehicle 10 may perform movement in the traveling direction and rotation at the same time, or may perform rotation based on a distance measurement value with respect to the wall surface at every movement of a certain distance or a certain time. Alternatively, if the distance measurement value to the wall surface is a value within a predetermined range, the rotation control may be performed when the measured value is outside the range without rotating.

  However, even if the vehicle spins and rotates as described above, the distance from the wall surface may not be constant and may change as shown in FIG. 7, depending on the state of the airflow in the sewer pipe 16. When flying in this manner, the captured image becomes difficult to analyze, and the pipeline facility inspection vehicle 10 may come into contact with or collide with the wall surface. Therefore, the flight control means 24 is provided with an algorithm for moving in the left-right direction so that the value of the lateral distance sensor 14 in at least one direction in the horizontal direction maintains a preset value. By using this algorithm, it is possible to avoid contact and collision with the wall surface, and it is possible to fly while maintaining a constant distance to the wall surface on the side provided with the lateral distance sensor 14. This makes it possible to avoid contact and collision with the wall surface. Further, it becomes possible to facilitate the processing of the image photographed by the image pickup means 20 provided in the front. For example, if the sewer pipe on which the pipeline facility inspection vehicle 10 flies is a circular pipe and the inner diameter 2r is known, x1 = x2 = r and y = r are set so that the pipeline facility inspection vehicle 10 is at the center of the pipe. Can fly. The image captured by the image capturing means 20 provided in the front is centered at a distant place, and the wall surface and the ceiling near the pipeline facility inspection aircraft 10 are reflected in the periphery. When this image is processed and converted into an image in which the wall surface side is directly viewed, which is called a development view, geometric conversion becomes easy when the image pickup means 20 is located at the center of the tube.

  Alternatively, the flight control means 24 is provided with an algorithm for moving in the horizontal direction so that the ratio of the measurement values of the two distance sensors that measure the distances in the opposite directions in the horizontal direction maintains a preset value. By providing this algorithm, it is possible to avoid contact and collision with the wall surface, and it is possible to fly while maintaining a constant distance ratio with the wall surface on the side where the lateral distance sensor 14 is provided. This makes it possible to avoid contact and collision with the wall surface. When the ratio of the measured values of the two distance sensors is made equal, the pipeline facility inspection air vehicle 10 can travel in the center of the pipe, and as described above, the processing of the image captured by the image capturing means 20 provided in the front is performed. It will be easy.

  When the sewage pipe is a straight pipe without any bends, a stable image can be obtained by flying while maintaining the state of FIG. 4 (a). However, in reality, not only straight pipes but curved pipes also exist. FIG. 8 is an axial cross-sectional view of a state where the pipeline facility inspection vehicle 10 is flying in a pipeline facility having a gentle curvature, as viewed from above in the vertical direction. As described above, by keeping the value of the distance y constant and flying by rotating so that the value of x1 + x2 becomes small, even a curved pipe having a gentle curvature can be used from (a) to (b) (c). ) (d) can achieve the desired flight.

  As described in the first embodiment, in the sewer pipe where there is a place where water drips from the ceiling, water droplets may also splash on the pipeline facility inspection vehicle 10. If the measurement accuracy decreases or measurement becomes impossible when water droplets are applied to the upper distance sensor 12 from above, a lower distance sensor should be provided instead of the upper distance sensor 12 and subtract from the inner diameter 2r of the sewer pipe 16. It is also good to estimate the distance to the ceiling. However, sewage normally flows to the bottom of the sewer pipe 16, and there is a high possibility that an error will occur in the estimated value of the distance to the ceiling.

  FIG. 9 shows a schematic diagram in the case where the measured values x3 and x4 are found by the lower distance sensor, which does not cause a problem even if water drops are applied if they are directed not horizontally downward but horizontally and downward. There are two relative positions of the circular tube having the inner diameter 2r with respect to the measured values x3 and x4 of the two distance sensors. On the other hand, FIG. 10 shows a schematic diagram in the case where there are three distance sensors provided in the horizontal direction and in a direction downward from the horizontal direction. When there are measured values x3, x4, and x5 of the three distance sensors, the estimated relative position to the circular tube is uniquely determined. Using the result, the distance to the ceiling can be accurately estimated based on the geometrical relationship.

  The sewage pipe 16 has a large amount of inflow water from the mounting pipe depending on the location, and the water level relative to the cross section of the pipe may become high. Pipeline facility inspection If the flying vehicle 10 flies by controlling the vertical position so that the upward distance maintains a value within a preset range, it may be submerged at a high water level. Occurs. If it is submerged in water, flight and image acquisition will become impossible, and the risk of failure increases, so it is desirable not to proceed to locations with high water levels. Therefore, it is desirable to provide a distance sensor that measures the distance in the downward direction, particularly the distance to the water surface. When the distance becomes smaller than a preset value, the flight control means 24 may be provided with an algorithm for stopping or moving in the direction opposite to the traveling direction. This makes it possible to prevent the failure of the pipeline facility inspection vehicle 10 due to submersion in water.

10 ... Pipe facility inspection air vehicle 12 ... Upper distance sensor 14 ... Side distance sensor 16 ... Sewer pipe 18 ... Propeller 20 ... Imaging means 22 ... Irradiation means 24 ... Flight control means 26 ... Sewage 30 ... Aircraft body 31 ... Manhole 32 ... Antenna 33 ... Transceiver 34 ... Display 35 ... Wireless transmission device

Claims (7)

Imaging means for imaging the inside of the pipeline,
Irradiation means for irradiating light into the pipeline,
An aircraft body that arranges the image pickup unit and the irradiation unit and flies in a pipeline,
A distance sensor that is arranged on the flight body, and measures a distance between the pipeline and the flight body in the pipeline,
Flight control means arranged on the aircraft body and controlling the flight direction of the aircraft body in the pipeline based on the measurement value of the distance sensor,
Equipped with
The distance sensor is
An upper distance sensor that is arranged on the upper surface of the aircraft body and that measures a vertically upward distance between the pipeline and the flight vehicle in the pipeline,
A lateral distance sensor that is disposed on at least two side surfaces of the aircraft body and that measures a distance between a pipeline and a flight vehicle in the pipeline in a direction perpendicular to a traveling direction of the flight vehicle;
Conduit facility inspection flying body which is characterized in Rukoto to have a. The flight control means according to claim 1 ,
Measured with the upper distance sensor, keeping the distance between the pipeline and the flight object in the pipeline to half the inner diameter of the pipeline,
A pipeline facility inspection vehicle, wherein the flight direction of the aircraft is controlled so that the total distance between the pipeline and the flight vehicle in the pipeline measured by the lateral distance sensor has a minimum value. The distance sensor according to claim 1 or 2 ,
A pipeline facility inspection aircraft, further comprising a downward distance sensor arranged on a lower surface of the aircraft body to measure a vertically downward distance between a water surface in the pipeline and the aircraft. The pipeline facility inspection vehicle according to any one of claims 1 to 3 , wherein the distance sensor is an ultrasonic sensor or an infrared sensor. In any one of claims 1 to 4, the image of the captured conduit in said IMAGING means, conduit facility inspection aircraft, characterized by arranging the wireless transmission apparatus to the flying body to be transmitted wirelessly . The pipeline facility inspection vehicle according to any one of claims 1 to 5 , wherein the pipeline is a sewer pipeline. A pipeline facility inspection vehicle according to any one of claims 1 to 6 ,
A transmitter / receiver that is placed on the ground and wirelessly receives an image taken by the duct facility inspection air vehicle via an antenna hung from the ground into a manhole,
A display device connected to the transmission / reception device for displaying a captured image;
A system for inspecting pipeline facilities, characterized by comprising:

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