JP7436403B2 - measurement system - Google Patents

Description

The present invention relates to a measurement system for measuring and maintaining power transmission and distribution equipment.

BACKGROUND ART Conventionally, regarding the maintenance of a steel tower on which power transmission lines are stretched, a method has been known in which the displacement of the steel tower is measured using an image of the steel tower taken by a camera and a structural model (Patent Document 1). However, this method could not accurately measure the inclination of steel towers and the slackness of electric wires, which are important items for ensuring the safety of power transmission and distribution equipment.

Therefore, an imaging system is known that uses a camera mounted on a flight device to image a vertically elongated structure (Patent Document 2). Furthermore, a drone that can easily, safely, and quickly measure the shape of a monitored object from various directions is also known (Patent Document 3). In the maintenance work of steel towers, it is effective to measure the shape of the object using a flying object such as a drone that can measure from various directions and to check for abnormalities (Patent Documents 1 and 2).

Japanese Patent Application Publication No. 2003-148916 Patent Application No. 2019-51729 Patent Application No. 2015-202854

However, data measured by drones has errors in the vertical direction, making it impossible to accurately determine the inclination of the tower. Furthermore, since steel towers are often installed on sloped ground, detecting abnormalities in the tilt of a steel tower requires understanding the topographical conditions, which is costly. Therefore, there is a need for a simple and highly accurate means of detecting abnormalities in power transmission and distribution equipment, such as tower inclination.

The present invention has been made in view of the above problems, and its purpose is to provide a high-precision measurement system that utilizes drones to measure the inclination of steel towers or the slackness of electric wires in measurement and maintenance work for power transmission and distribution equipment. Our goal is to provide the following.

The present invention that solves the above problems is a measurement system that measures the inclination of a steel tower or the sag of a wire as data for measuring and maintaining a steel tower in power transmission and distribution equipment or a wire stretched on a steel tower, The measurement data generation unit includes a drone control unit that flies a drone equipped with a camera along the electric wire, and a measurement data generation unit that calculates the shape of the electric wire or the steel tower from the image data of the electric wire acquired by the drone. The shape of the electric wire or steel tower is determined from the difference in image data of the electric wire over time.

According to the present invention, it is possible to provide a highly accurate measurement system that utilizes a drone to measure the inclination of a steel tower or the slackness of electric wires in measurement and maintenance work for power transmission and distribution equipment.

Using the measurement system according to the first embodiment of the present invention (abbreviated as "the system of the first embodiment"; the same shall apply hereinafter), the shape of the electric wire stretched on a steel tower inclined in the direction perpendicular to the track is measured. (a) Parallel to the track They are a directional side view and (b) a top view. They are (a) a side view in a direction parallel to the track, and (b) a plan view, in which the shape of an electric wire stretched on a steel tower tilted in a direction parallel to the track is measured by the system of Example 2. They are (a) a side view in a direction parallel to the track, and (b) a plan view, in which the shape of electric wires strung on steel towers whose installation topography has changed is measured by the system of Example 3. FIG. 4 is a side view in the parallel direction of the track, in which the shape of electric wires strung on steel towers erected on various terrains is measured by the system of Example 4, and (a) a diagram illustrating protrusions on the ground surface; and (b) ) is a diagram illustrating depressions on the ground surface. FIG. 7A is a side view in a direction parallel to the track, (b) a plan view, and a front view in a direction parallel to the track, which are measured by the system of Example 5 to estimate the inclination of a steel tower tilted in a direction perpendicular to the track. FIG. 12 is a perspective view showing an overview of a measurement method for measuring the shape of an electric wire using the system of Example 6. FIG. 7 is a perspective view showing an overview of a measurement method for measuring the shape of an electric wire using the system of Example 7; FIG. 7 is an explanatory diagram of the relationship with unmanned traffic management (UTM) in the system of Example 8. FIG. 9 is an explanatory diagram of the relationship with UTM in the system of Example 9. FIG. 7 is an explanatory diagram of a wire management application/module in the system of Example 10. It is a system of Example 11, and is a functional block diagram of estimation and prediction by the electric wire inspection management application/module of FIG. 10. FIG. 7 is a schematic explanatory diagram of measuring the shape of electric wires strung on steel towers standing on various terrains using the system of Example 12, and shows (a) a perspective view before tilting occurs, and (b) a perspective view after tilting occurs. It is. 12(a) and 12(b), the contours of the main parts of the tower are extracted in order to detect the inclination of the tower. (a) A perspective view before the inclination occurs, (b) A perspective view after the inclination occurs, and ( c) It is a perspective view superimposing the before and after occurrence of inclination. 13 is a functional block diagram for explaining estimation and prediction operations in the system of Example 13. FIG.

The embodiment of the present invention is based on measurement results obtained by measuring the three-dimensional shape and changes in the three-dimensional shape of electric wires strung between steel towers using a drone or the like, as will be described later with reference to FIG. 1. The objective is to understand and predict the current state of power transmission towers, inclinations of power transmission towers, damage and sagging of power lines, topographical changes in towers, and interference with trees. To acquire the three-dimensional shape, 3D synthesis from multiple two-dimensional images or direct three-dimensional point cloud acquisition using LiDAR (Light Detection And Ranging) can be used.

The shape of the electric wire can be understood by regressing to a catenary line, parabola, etc., or by parametrizing it using a triangle formed by three points consisting of the positions of both ends of the fixed electric wire and the lowest point of the electric wire. By acquiring three-dimensional image data of electric wires spanning at least three adjacent steel towers, two triangles made up of the three points described above can be obtained. The inclination of the steel tower can be determined from the difference in the positional relationship of these two triangles over time. In this way, the configuration of an embodiment that is combined with an actual unmanned aircraft control system will be described below, with the aim of realizing a measurement system that is simple (low cost), highly accurate, and can inspect facilities with high efficiency.

FIG. 1 shows (a) a side view in a direction parallel to the track, and (b) a plan view, in which the shape of an electric wire stretched on a steel tower tilted in a direction perpendicular to the track is measured by the system of Example 1. As shown in FIG. 1, among the three steel towers 1 to 3 arranged in a generally straight line, the middle steel tower 2 is assumed to be inclined in a direction perpendicular to the railroad tracks. For example, the three-dimensional shapes of the electric wires 4 and 5 can be obtained from a plurality of images taken from a drone using the SfM (Structure from Motion) method. Alternatively, LiDAR may be used to directly measure the three-dimensional shape of the monitored object.

From the three-dimensional shape of the electric wires 4 and 5 thus obtained, the inclination of the steel tower is estimated from the positional relationship of the following two triangles. The first triangle consists of the wire fixing position A1, the wire fixing position B1, and the lowest point C1 of the wire. The second triangle consists of the wire fixing position A2, the wire fixing position B2, and the lowest wire point C2. The slackness (slackness) of the electric wires 4 and 5 is estimated from the shape of these triangles, that is, the height of the triangle whose base is the line connecting the two electric wire fixing positions and whose apex is the lowest point.

Note that FIG. 1 shows the shape of the electric wire in a windless state, and each triangle lies within a vertical plane. On the other hand, if there is a constant wind, the shape of the wire can be calculated analytically by assuming a catenary line, for example. At this time, the positional relationship between the two triangles can be known by correcting the triangle formed by the two fixed positions and one lowest point position by considering the deviation from the vertical direction.

FIG. 2 is (a) a side view in a direction parallel to the track, and (b) a plan view, in which the shape of an electric wire stretched on a steel tower inclined in a direction parallel to the track is measured by the system of Example 2. As shown in FIG. 2, among the three steel towers 1 to 3 arranged in a generally straight line, the middle steel tower 2 is assumed to be inclined in a direction parallel to the railroad tracks.

As in Example 1, the inclination of the steel tower is estimated from the positional relationship between the following two triangles. The first triangle consists of the wire fixing position A1, the wire fixing position B1, and the lowest point C1 of the wire. The second triangle consists of the wire fixing position A2, the wire fixing position B2, and the lowest wire point C2. The inclination of the steel tower 2 is estimated from the positional relationship of these two triangles, and the slackness (sagness) of the electric wires 4 and 5 is estimated from the shape of the triangle. In the case of Fig. 2, unlike Fig. 1, the angle formed by the plane containing each of the two triangles remains 0 degrees and does not change, but by paying attention to the sag of the two triangles, it is possible to You can know the slope of 2.

FIG. 3 shows (a) a side view in a direction parallel to the track, and (b) a plan view, in which the shape of electric wires strung on steel towers whose installation topography has changed is measured by the system of Example 3. As shown in Figure 3, of the three steel towers 1 to 3, the ground surface (also simply referred to as "ground surface") 6 on which the middle steel tower 2 is installed has been deformed into a convex shape due to topographical changes. It is assumed that there is

As in Examples 1 and 2, the inclination of the steel tower is estimated from the positional relationship of the following two triangles. The first triangle consists of the wire fixing position A1, the wire fixing position B1, and the lowest point C1 of the wire. The second triangle consists of the wire fixing position A2, the wire fixing position B2, and the lowest wire point C2. The inclination of the steel tower can be estimated from the positional relationship of these two triangles, and the abnormality of the topography can be estimated from the shape of the triangle.

FIG. 4 is a side view in the parallel direction of the track in which the shape of electric wires strung on steel towers erected on various terrains is measured by the system of Example 4, and (a) is a diagram illustrating protrusions on the ground surface. , and (b) are diagrams illustrating depressions on the ground surface. As shown in FIG. 4, it is assumed here that vegetation 8, buildings 9, or topographic changes 10 exist on a horizontal ground surface 6. In this case, if the density of the buildings 9 and vegetation 8 is high, it becomes difficult to estimate the inclination of the steel tower and the sag of the electric wire using the ground surface 6 as a reference.

Therefore, instead of using the ground surface 6 as a reference, the inclination of the steel tower is estimated from the positional relationship between the following two triangles, as in Examples 1 to 3. The first triangle consists of the wire fixing position A1, the wire fixing position B1, and the lowest point C1 of the wire. The second triangle consists of the wire fixing position A2, the wire fixing position B2, and the lowest wire point C2. The inclinations of the steel towers 1 to 3 are determined from the positional relationship of these two triangles. Anomalies in the topography can be estimated from the inclinations of these steel towers 1 to 3 and the triangular shape, that is, the three-dimensional shape of the electric wires 4 and 5.

A conventional problem has been that in order to detect the inclination of a steel tower, it has not been possible to know the inclination of the steel tower even if only a captured image of the tower itself is obtained. In order to know this, it was necessary to compare the reference ground surface 6 and a photographed image of the steel tower itself. However, the ground surface 6 is not necessarily constant due to vegetation 8 and topographical changes. Therefore, even if the drone's on-board acceleration sensor could detect the vertical shape and height, there was still room for improvement in the detection accuracy.

In contrast, the systems of Examples 3 and 4 shown in FIGS. 3 and 4 determine the wire shape and tower inclination from the three-dimensional shape or two-dimensional shape obtained from the photographed images of the wires 4 and 5. As a result, changes in the shape of the electric wire can be obtained without using the ground surface 6 as a reference, so the inclination of the steel tower can be determined without being influenced by changes in the ground surface 6. In addition, the shape of the wire is a catenary, so it can be formulated taking into account the influence of wind. Therefore, even if some images are missing, correction is easy.

FIG. 5 shows (a) a side view in a direction parallel to the track, (b) a plan view, and a front view in a direction parallel to the track, which are measured by the system of Example 5 to estimate the inclination of a steel tower tilted in a direction perpendicular to the track. This is an example of estimating the inclination of the tower from the positional relationship of two triangles in the case where the central tower 2 among the three towers 1 to 3 shown in Example 1 is inclined in a direction perpendicular to the railway line. . If the slope of a 100m high steel tower is 1°, the point where the two triangles connect will move 1.75m. A displacement of this magnitude can be easily detected within the normal accuracy range of the SfM method, and this method of measuring tower inclination is effective.

FIG. 6 is a perspective view showing an outline of a measurement method for measuring the shape of the electric wire 14 using the system of the sixth embodiment. The system of Example 6 uses a drone 15 to measure the shape of an electric wire. The measurement data acquired by the drone 15 is acquired from the steel towers 11 to 13, in which three or more towers are arranged adjacent to each other in a generally straight line, and their surroundings, as will be described later with reference to FIGS. 6 to 12. That is, in the measurement method for measuring the shape of the electric wire 14, measurement data of each of the first steel tower 11 to the third steel tower 13 and measurement data of the electric wire 14 continuously stretched thereon are used.

The measurement data of the electric wire 14 includes the shape of the electric wire 14 stretched between the first steel tower 11 and the second steel tower 12, and the electric wire stretched between the second steel tower 12 and the third steel tower 13. It consists of 14 shapes and more. The system of the sixth embodiment determines the inclination from the photographed images of these electric wires 14, that is, from the three-dimensional shape or the two-dimensional shape.

On the other hand, in order to obtain a three-dimensional image by SfM in Example 1 of FIG. 1, a plurality of images taken from different angles are required. Regarding the plurality of images required in this way, images from two directions can be acquired according to the flight path 16 of the drone 15 shown in FIG. In order to improve the quality of three-dimensional images, it is effective to increase the number of images used for SfM, and this can be achieved by increasing the number of times the drone 15 moves back and forth in FIG. 6.

FIG. 7 is a perspective view showing an overview of a measurement method for measuring the shape of an electric wire using the system of Example 7. In order to obtain a three-dimensional image by SfM in the first embodiment, it is desirable that the shooting conditions for a plurality of images taken from different angles satisfy a required standard. The shooting conditions are determined by the drone's flight plan for power transmission and distribution equipment and the shooting specifications (distance, angle, exposure, etc.). FIG. 7 shows, as an example, the positional relationship among the drone 15, the electric wire 14, and the sun 20.

For example, it is preferable that the center line of the camera angle for photographing the electric wire 14 from the drone 15 be within ±45° with respect to the direction of the shadow projected on the ground surface 6 by the sun 20 irradiating the vertical rod. As a general rule, it is effective for the cameraman to use a camera angle that allows him to take pictures in direct sunlight, such as with the sun 20 on his back. That is, the sun 20 should preferably be within ±45° from the front behind the cameraman with respect to the center line of the camera angle. With the flight path 17 designed to follow this general principle, the quality of the three-dimensional image can be improved by uniformizing the direction of light irradiation of the object onto the elongated electric wire 14 in the generally horizontal direction.

FIG. 8 is an explanatory diagram of the relationship with UTM in the system of Example 8. As shown in FIG. 8, when a plurality of drones owned by a plurality of owners fly, what is required is an unmanned traffic management (UTM) 18 that manages the operation of the drones and the like. This has roles such as managing flight routes and altitudes, managing and analyzing data, permitting flights, real-time monitoring, and preventing entry into no-fly areas. This is a system that serves as the infrastructure and platform for unmanned air traffic control, as shown in UTM18 in Figure 8.

Operated by Unmanned Vehicle Traffic Management Company/Organization 19. The power transmission and distribution equipment inspection management application 22 is operated by a drone operating company 23 and a power transmission and distribution equipment inspection management company 24. By cooperating with the UTM 18, the power transmission and distribution equipment inspection management application 22 can operate safely without interfering with other drones 15.

Another embodiment that implements the functions shown in the eighth embodiment is shown in FIG. FIG. 9 is an explanatory diagram of the relationship with the UTM 25 in the system of the ninth embodiment. As shown in FIG. 9, the UTM 25 includes modules depending on the application, such as a power supply inspection management module and a road inspection management module. As a result, the drone operator 23 and the inspection management operator 24 can have the UTM 25 handle the operation of the drone 15 and optimize the shooting conditions without being aware of the compatibility between the UTM 25 and the power transmission and distribution equipment inspection management application. Note that a module refers to a functional configuration consisting of hardware and software.

FIG. 10 is an explanatory diagram of the electric wire management application/module (hereinafter also referred to as "inspection application module" for short) 26 in the system of the tenth embodiment. As shown in FIG. 10, the inspection application module 26 is a computer device that has storage for storing programs and data, a CPU, and a communication function, and grasps the shape of the object to be monitored through SfM using the drone 15. In SfM, a three-dimensional point cloud is generated by estimating the camera position and orientation from multi-view image measurement data. More details are as follows.

The inspection application module 26 performs flight/photography control on the drone 15 and receives local information from the drone 15. More specifically, flight plans for power transmission and distribution equipment are programmed. In addition to programs, the storage stores data such as tower shapes, tower locations, wire shapes, topography, solar altitude, etc. The inspection application module 26 also executes a program for optimizing photographing specifications (distance, angle, exposure, etc.).

It is necessary that the multi-view images taken here are suitable for SfM processing. To improve the shape accuracy of multi-view images of electric wires by optimizing the flight plan and imaging specifications that allow highly accurate SfM processing for the special shape of electric wires (thin and long, the overall shape is a catenary line). Can be done.

FIG. 11 is a system according to an eleventh embodiment, and is a functional block diagram of estimation and prediction by the electric wire inspection management application/module (inspection application module) 26 of FIG. 10. As shown in FIG. 11, the inspection application module 26 uses the wire shape calculation value 27 and the wire shape measurement history 28 to determine estimated values (current) 31 and predicted values (future) regarding the tower inclination and wire sag. )32 and are calculated respectively. More details are as follows.

The inspection application module 26 performs geometric calculation 29 or machine learning 30 using at least one of the wire shape calculation value 27 and the wire shape measurement history 28 . A predicted value (future) 32 is obtained by machine learning 30. An estimated value (current) 31 is calculated by this machine learning 30 and geometric calculation 29. In order to obtain the current estimated value 31 using the inspection application module 26 in FIG. A current estimate 31 is obtained.

Additionally, in SfM, a three-dimensional point cloud is generated by estimating the camera position and orientation from multi-view image measurement data. It is necessary that the multi-view images taken here are suitable for SfM processing. SfM processing can be performed with high accuracy on the special shape of electric wires (thin and long, the overall shape is a catenary line).By optimizing the flight plan and imaging specifications, it is possible to improve the shape accuracy of electric wires.

FIG. 12 is a schematic explanatory diagram of measuring the shape of electric wires 14 stretched across steel towers 11 to 13 that stand on variously changed terrain using the system of Embodiment 12, including (a) a perspective view before tilting occurs; (b) It is a perspective view after tilting occurs. FIG. 13 shows contours of the main parts of the towers 11 to 13 extracted from FIGS. 12(a) and 12 (b) in order to detect the inclination. FIG. 3 is a perspective view of the rear side, and (c) a perspective view of the front and back sides of the tilting.

As shown in FIGS. 12 and 13, a measurement data generation unit (no reference numeral), which will be described later with reference to FIG. It is preferable to determine the shape of the electric wire 14 or the inclination of the steel towers 11 to 13 from the image data. In SfM using the drone 15 described above with reference to FIG. 10, the camera position and orientation are estimated from multi-view image measurement data to generate a three-dimensional point group, so more accurate measurement results can be obtained.

In the system of Embodiment 12, the drone control unit (included with reference numerals 18, 22, 25, and 26 in each figure) is connected to three adjacent steel towers 1 to 3 in FIG. 12(a) and in FIG. 12(b). It is preferable to generate the flight paths 16 and 17 of the drone 15 so that the range including each point where the electric wire 14 is suspended from the steel towers 11 to 13 is photographed three or more times. By photographing the range, for example, three or more times, it is possible to realize SfM using multi-view image measurement data, and it is also possible to extract differences over time using multi-view image measurement data taken at different photographing times.

Here, the drone control units 18, 22, 25, and 26 are also referred to as flight control, including flight control, and include UTMs 18 and 25 in each figure, power transmission and distribution equipment inspection management application (app) 22, and electric wire inspection management application/module. Included in 26.

In the system of the twelfth embodiment, the measurement data generation unit generates the image data of the electric wire 14 over time so that the image data of the electric wire 14 is superimposed before and after the occurrence of inclination to show the difference over time in FIG. 12(c). It is preferable to find the shape change of the electric wire 14 or the steel towers 11 to 13 from the difference. That is, in the system of Example 12, it can be clearly shown in FIG. 12 that the shape before the occurrence of the tilt (a) has changed to the shape after the occurrence of the tilt (b). Here, since the difference in the image data of the electric wire 14 over time, that is, the change in the shape of the electric wire, can be obtained without using the ground surface 6 as a reference, the inclination of the steel tower 12 can be adjusted without being affected by changes in the ground surface 6. Desired.

FIG. 14 is a functional block diagram for explaining estimation and prediction operations in the system of the thirteenth embodiment. As shown in Figure 14, the system of Example 13 measures the power transmission and distribution equipment at its location, so it has configuration requirements that are convenient for on-site preparation and excellent convenience even when not on site. and a ground center with configuration requirements convenient to be installed at the location. Note that the above-mentioned measurement data generation unit is configured by the functions described using FIG. 14, and its overall operation contributes to the purpose of generating measurement data and measuring and maintaining power transmission and distribution equipment.

As shown in FIG. 14, the power transmission and distribution equipment inspection management application (app) 22 includes an input unit (not shown) for inputting inspection information indicated by thick arrows. This input unit receives the following measurement data measured using the drone 15 as inspection information. That is, as shown in FIGS. 6 to 12, the measurement data used as inspection information includes the measurement data of each of the first to third steel towers 11 to 13 in which three or more towers are adjacent to each other, and It consists of measurement data of the electric wire 14 to be stretched. The measurement data of the electric wire 14 consists of the shape of the electric wire 14 between the first and second steel towers 11 and 12 and the shape of the electric wire 14 between the first and third steel towers 11 and 13.

As shown in FIG. 14, the image processing/analysis system 33 includes an estimation section (not shown) that outputs analysis results indicated by thick arrows, and constitutes the main part of the measurement data generation section. The estimation unit estimates the inclination of the first to third steel towers 11 to 13 based on the measurement data as the received inspection information. Regarding this estimation, the present system computes and calculates the inclination of each of the steel towers 11 to 13 from a photographed image of the electric wire 14, that is, a three-dimensional shape or a two-dimensional shape. Next, estimation and prediction in the system of Example 13 will be explained in more detail using the functional block diagram of FIG. 14.

At the site, the flight of the drone 15 is controlled by a power transmission and distribution equipment inspection management application (app) 22 . The application 22 controls the camera mounted on the drone 15 to take pictures according to the plan, and controls the flight so that the picture plan is realized. The drone 15 sends a plurality of images taken by the camera as inspection information to the application 22 by wireless communication. The inspection information may be stored in a storage (not shown) mounted on the drone 15 and retrieved upon landing for use in the application 22.

On the other hand, the ground center is equipped with a UTM 18 and an image processing/analysis system 33. The unmanned aircraft management (UTM) 18 is as described above using FIG. The image processing/analysis system 33 generates the three-dimensional point group described above using FIG. This three-dimensional point cloud generation uses SfM to estimate the camera position and orientation from multi-view image measurement data in order to grasp the shape of the object to be monitored using the drone 15. In that way, the measurement system obtains a more accurate current estimate 31 that is independent of terrain conditions such as terrain shape and vegetation.

The image processing/analysis system 33 outputs not only the current estimated value 31 but also the future predicted value 32 as an analysis result and feeds it back to the local application 22. The application 22 into which the current estimated value 31 and the future predicted value 32 are input controls the drone 15 to fly/photograph necessary to obtain confirmation thereof.

As a result, this system is capable of measuring the following three categories without depending on the topographical shape, vegetation, or other terrain conditions. First, the inclination angle and direction of transmission towers (steel towers) 1 to 3 and 11 to 13 can be measured. Second, the bending and sagging of the electric wire 14 is measured, and any cut points can be detected. Thirdly, it is possible to calculate a current estimated value 31 and a future predicted value 32 regarding the shape of the surrounding topography of the power transmission and distribution equipment. In particular, this system can accurately grasp the current state of the inclinations of the steel towers 1 to 3 and 11 to 13, or the slackness of the electric wires 14 strung on these towers, and can also predict the future.

The measurement system according to the embodiment of the present invention (hereinafter referred to as "this system") can be summarized as follows.
[1] When measuring power transmission and distribution equipment, this system determines the inclination of steel towers 1 to 3 and 11 to 13, or the sag of the electric wires 14 strung on these towers, and uses the data obtained from this for measurement and maintenance. This is a measurement system used for indicators.

This system includes a drone control unit included in reference numerals 18, 22, 25, and 26 in each figure, and a measurement data generation unit having the overall configuration of FIG. 14. The drone control units 18, 22, 25, and 26 cause the drone 15 equipped with a camera to fly along the electric wire 14. The measurement data generation unit determines the shape of the electric wire 14 or the steel towers 1 to 3 and 11 to 13 from the image data of the electric wire 14 acquired by a camera mounted on the drone 15. For example, as shown in FIG. 6, the three-dimensional shape of the electric wire 14 can be determined from a plurality of images taken by the drone 15 using the SfM (Structure from Motion) method.

In this system, the inclinations of the steel towers 1 to 3 and 11 to 13 are determined from changes in the shape of the electric wires 14, so it is not affected by changes in the ground surface 6. Here, the shape of the wire is a catenary, and it can be formulated taking into account the influence of wind. Therefore, even if some images are missing, correction is easy. Therefore, with this system, the inclination of the steel tower can be accurately determined regardless of the topographical state.

In other words, this system can perform measurements classified into the following three types without depending on the topographical shape, vegetation, or other topographical conditions. First, the inclination angle and direction of the steel towers (transmission towers) 1 to 3 and 11 to 13 can be measured. Second, the bending and sagging of the electric wire 14 is measured, and any cut points can be detected. Third, it is possible to measure the current value of the shape of the surrounding topography of power transmission and distribution equipment.

In addition, in this system, the measurement data generation unit is configured to change the image data of the electric wire 14 over time so that the image data of the electric wire 14 is superimposed before and after the occurrence of inclination to show the difference over time in FIG. 12(c). From the difference, a change in the shape of the electric wire 14 or the steel towers 11 to 13 is determined. That is, in FIG. 12, this system can clearly show that the shape before the occurrence of the tilt (a) has changed to the shape after the occurrence of the tilt (b). Here, since the difference in the image data of the electric wire 14 over time, that is, the change in the shape of the electric wire, can be obtained without using the ground surface 6 as a reference, the inclination of the tower can be determined without being affected by the fluctuations in the ground surface 6. It will be done.

[2] As shown in FIGS. 12 and 13, the measurement data generation unit calculates the electric wire 14 from three-dimensional or two-dimensional image data of the electric wire 14 strung on at least three adjacent steel towers 11 to 13. It is preferable to determine the shape or inclination of the steel towers 11 to 13. In SfM using Drone 15, as shown in Figures 6 to 10, the camera position and orientation are estimated from multi-view image measurement data and a 3D point cloud is generated, resulting in more accurate measurement results. is obtained.

[3] In order to realize the above [1] and [2], it is preferable to generate the flight paths 16 and 17 of the drone 15 in the present system shown in FIGS. 6 to 13. That is, the drone control units 18, 22, 25, and 26 control each point at which the electric wire 14 is suspended from the three adjacent steel towers 1 to 3 in FIG. 12(a) and the steel towers 11 to 13 in FIG. 12(b). It is a good idea to take pictures of the area that includes 3 or more times. By photographing the range three or more times, it is possible to realize SfM using multi-view image measurement data, and also to extract differences over time using multi-view image measurement data taken at different times.

[4] It is preferable that the drone control units 18, 22, 25, and 26 generate the flight paths 16, 17 of the drone 15 so that each point included in the range is photographed at a different photographing angle. Thereby, the camera of the drone 15 can more reliably acquire multi-view image measurement data obtained from different photographing angles.

[5] As shown in FIG. 10, in SfM using the drone 15, the camera position and orientation are estimated from multi-view image measurement data, and a three-dimensional point cloud of the monitored object is generated. Using a three-dimensional point cloud, it is possible to grasp the shape of the power transmission and distribution equipment, which is the object to be monitored, in chronological order. In this way, in this system, the measurement data generation unit acquires and accumulates three-dimensional or two-dimensional image data of the electric wire 14 using a three-dimensional point group grasped in time series, and uses the accumulated learning data to Based on this, it is preferable to predict the inclination of the steel towers 1 to 3 and 11 to 13 or the sag of the electric wire 14.

In other words, this system can perform measurements in the following three categories without depending on the topographical shape, vegetation, or other terrain conditions. First, it is possible to measure the inclination angle and direction of power transmission towers (steel towers) 1 to 3 and 11 to 13. Second, the bending and sagging of the electric wire 14 is measured, and any cut points can be detected. Thirdly, it is possible to accurately measure the current value of the shape of the surrounding topography of power transmission and distribution equipment, and even predict changes in it.

[6] In this system, the camera should take pictures in consideration of weather conditions, especially the angle of sunlight and the subject. That is, it is preferable for the drone 15 to generate the flight paths 16 and 17 so that the camera mounted on the drone 15 can obtain a camera angle that allows the camera mounted on the drone to photograph the subject with the sunlight behind it to avoid backlighting. Preferably, the camera obtains image data of the electric wire by optimizing photographing specifications including at least one of photographing distance, photographing angle, and photographing exposure conditions.

1 to 3, 11 to 13: Steel tower, 4, 5, 14: Electric wire, 6: Ground surface (ground surface), 7: Earth surface undulations (convex), 8: Vegetation, 9: Buildings, 10: Ground surface undulations ( (concave), 15: Drone, 16, 17: Drone flight path, 18, 25: UTM (drone control unit, flight control unit), 19: Unmanned aircraft traffic management company/organization, 20: Sun, 21: Before tilting Steel tower, 22: Power transmission and distribution equipment inspection management application (drone control unit, flight control unit), 23: Drone operator, 24: Power transmission and distribution equipment inspection management business, 26: Wire inspection management application/module (inspection application module) , 27: Wire shape calculation value, 28: Wire shape measurement history, 29: Geometric calculation, 30: Machine learning, 31: Estimated value (current), 32: Predicted value (future), 33: Image processing/analysis system

Claims (12)

A measurement system that measures the inclination of the steel tower or the sag of the wire as data for measuring and maintaining a steel tower in power transmission and distribution equipment or an electric wire stretched on the steel tower,
a drone control unit that causes a drone equipped with a camera to fly along the electric wire;
a measurement data generation unit that calculates the shape of the electric wire or the steel tower from image data of the electric wire acquired by the drone;
Equipped with
The measurement data generation unit determines the shape of the electric wire or the steel tower from the temporal difference in the image data of the electric wire.
measurement system. The measurement data generation unit determines the shape of the electric wire or the inclination of the steel tower from three-dimensional or two-dimensional image data of the electric wire stretched between at least three adjacent steel towers.
The measurement system according to claim 1. The drone control unit generates a flight path of the drone so as to photograph a range including each point where the electric wire is suspended from the three adjacent steel towers three or more times.
The measurement system according to claim 2. The drone control unit generates a flight path of the drone so that each point included in the range is photographed at a different photographing angle.
The measurement system according to claim 3. The measurement data generation unit acquires and accumulates three-dimensional or two-dimensional image data of the electric wire, and predicts the inclination of the steel tower or the sag of the electric wire based on the accumulated learning data.
The measurement system according to claim 2. The camera obtains the image data of the electric wire by optimizing photographing specifications including at least one of a photographing distance, a photographing angle, and a photographing exposure condition.
The measurement system according to any one of claims 1 to 5. A measurement method for measuring data for maintaining a steel tower in power transmission and distribution equipment or electric wires strung on the steel tower, the method comprising:
Fly a drone equipped with a camera along the electric wire,
Obtaining shape data of the electric wire or the steel tower from image data of the electric wire acquired by the drone,
Determining the shape of the electric wire or the steel tower from the temporal difference in image data of the electric wire,
Based on the change in shape, at least the inclination of the steel tower or the sag of the electric wire is calculated and maintained;
Measurement method. Determining the shape of the electric wire or the inclination of the steel tower from three-dimensional or two-dimensional image data of the electric wire stretched across at least three adjacent steel towers,
The measuring method according to claim 7. Generating a flight path for the drone so as to photograph a range including each point where the electric wire is suspended from the three adjacent steel towers three or more times;
The measuring method according to claim 8. generating a flight path for the drone so that each point included in the range is photographed at a different photographing angle;
The measuring method according to claim 9. acquiring and accumulating three-dimensional or two-dimensional image data of the electric wire, and predicting the inclination of the steel tower or the sag of the electric wire based on the accumulated learning data;
The measuring method according to claim 8. The camera obtains the image data of the electric wire by optimizing photographing specifications including at least one of a photographing distance, a photographing angle, and a photographing exposure condition.
The measuring method according to any one of claims 7 to 11.

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