JP2009198280A - Overhead electric wire measurement apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overhead electric wire measurement apparatus for measuring the ground height of an electric wire, based on an image obtained from an area sensor or a line sensor by image processing. <P>SOLUTION: The overhead electric wire measurement apparatus comprises: an imaging means for imaging the overhead electric wire 4 between utility poles 3 by the area sensor 1 or the line sensor 6, and obtaining the input image; a binarization process means for applying a binarization process to the input image, enhancing an electric wire portion in the input image, and creating a binarized image; an electric wire edge detecting means for detecting an edge 9 of the electric wire portion 7 in the binarized image, and creating edge data; and an electric wire ground height calculating means for calculating the ground height of the electric wire by using the edge data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an overhead wire measuring apparatus.

When constructing an electric wire so that it is aerial on the road (on the roadway), the distance between the lowermost part of the electric wire and the road surface is required to be 4.5 meters or more according to the Road Act Construction Order. Here, Article 11-2, Paragraph 1 (a) of the Road Act Construction Ordinance is shown.
[Road Law Construction Order Article 11-2, Paragraph 1 a]
The distance between the bottom of the wire and the road surface is 5 meters (4.5 meters if it is attached to the existing wire and other technical issues are unavoidable and there is little risk of hindering the road structure or traffic) If it is on the sidewalk, it must be at least 2.5 meters).

  Moreover, when constructing an electric wire on a road, both the supporting points of the electric wires need not be higher than 4.5 meters, and there is a slack in the electric wire between the two supporting points. This degree of sag is called sag, and it means the difference in height between the wire support point and the lowest point of the curve formed by the wire. And an electric wire is constructed so that it may have an appropriate slackness.

For this reason, when an electric wire is installed on the road, the distance between the lowermost part of the electric wire and the road surface may not satisfy the value of the Road Act Construction Ordinance due to an inappropriate sag due to periodic inspections after construction. There is no need to check.
For the measurement, measure the distance between the electric wire and the road surface directly with a measuring instrument such as a measure, measure using the principle of triangulation, or measure with a sensor measuring instrument using a laser distance sensor, ultrasonic distance sensor, etc. There is a way.
In addition, there is a device that measures the sag itself, such as a method for measuring the sag of a filament and a sag measuring device (see Patent Document 1 below). This is because the sag of the wire straddled between the power poles is not based on visual measurement etc. It is a device that makes it possible to measure the slackness of the filaments below.

The above-described method and apparatus for measuring the sag of an electric wire can be classified as follows.
(1) Method of using a measuring instrument such as a measure (2) Method of measuring using the principle of triangulation (3) Method of measuring using a sensor measuring instrument (laser distance sensor, ultrasonic distance sensor, etc.)
(4) A method for measuring the sag of a filament and a sag measuring device (see Patent Document 1 below)

JP 2007-121219 A

  As described above, for the measurement of the slackness of the electric wire, (1) a method of directly measuring the distance between the electric wire and the road surface with a measuring instrument such as a measure, (2) a method of measuring using the principle of triangulation, (3) There is a method of measuring using a sensor measuring instrument using a laser distance sensor, an ultrasonic distance sensor, or the like. Moreover, there are devices that measure the sag itself, such as (4) a method for measuring the sag of a filament and a sag measuring device (see Patent Document 1 above), and each has the following problems.

(1) Method of using a measuring instrument such as a measure It is dangerous because it comes into contact with an electric wire during measurement.
(2) Method of measuring using the principle of triangulation The principle of triangulation requires measurement from the reference point and other reference points, and it takes time and effort to obtain the distance between the electric wire and the road surface.
(3) Measurement using a sensor measuring instrument (laser distance sensor, ultrasonic distance sensor, etc.)
The measuring instrument is affected by temperature changes, etc., and must be used after it is adapted to the measurement environment.
In particular, when using laser light, it is necessary to consider the influence on the human body, so care must be taken in handling.
(4) A method for measuring the sag of a filament and a sag measuring device (see Patent Document 1)
A photographic image is used so that the left and right utility poles and the wire straddled between the utility poles fit in the image. Thereafter, the sag is obtained by image analysis.
However, since sag is the difference in height between the wire support point and the lowest point of the curve formed by the wire, if the ground height at the wire support point and the ground height at the bottom of the wire are different, simply The distance between the lowermost part of the wire and the road cannot be obtained by subtracting the sag from the height of the utility pole support point.

  In view of the above, an object of the present invention is to provide an overhead electric wire measuring device for measuring the ground height of an electric wire by image processing from an image obtained from an area sensor or a line sensor.

The overhead wire measuring apparatus according to the first invention for solving the above-mentioned problems is
An imaging means for imaging an electric wire suspended between utility poles by an area sensor or a line sensor to obtain an input image;
Binarization processing means for creating a binarized image in which the electric wire portion is emphasized by binarization processing of the input image;
Electric wire part edge detection means for detecting edge of the electric wire part in the binarized image and creating edge data;
An electric wire ground height calculating means for calculating the ground height of the electric wire using the edge data is provided.

The overhead wire measuring apparatus according to the second invention for solving the above problem is the overhead wire measuring apparatus according to the first invention.
The electric wire is continuously imaged along the electric wire, and the ground height of the electric wire is continuously measured.

  ADVANTAGE OF THE INVENTION According to this invention, the overhead electric wire measuring apparatus for measuring the ground height of an electric wire by image processing from the image obtained from an area sensor or a line sensor is realizable.

The overhead electric wire measuring apparatus according to the present invention can measure the ground height of an electric wire by image processing from an image obtained from an area sensor or a line sensor.
Hereinafter, the Example of the overhead wire measuring apparatus which concerns on this invention is described using figures.

  Hereinafter, a first embodiment of the overhead electric wire measuring apparatus according to the present invention will be described. In addition, the overhead electric wire measuring apparatus which concerns on a present Example measures the ground height of an electric wire with a static point measuring system.

FIG. 1 is a diagram showing an installation example of the overhead wire measuring apparatus according to the present embodiment.
In the overhead wire measuring apparatus according to the present embodiment, an area sensor is used as an image input means.
As shown in FIG. 1, the overhead wire measuring apparatus according to the present embodiment has the utility poles 3 standing on both sides of the road 2, and when the wires 4 are suspended so as to cross the road between these utility poles 3. The area sensor 1 is installed so as to look up vertically from the road 2 (on the ground), and is further installed in a direction orthogonal to the overhead electric wire 4. Thereby, the electric wire 4 is imaged by the area sensor 1 in the imaging range indicated by E.

Next, the apparatus configuration of the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 2 is a diagram illustrating a device configuration of the overhead wire measuring device according to the present embodiment.
As shown in FIG. 2, in the overhead wire measuring apparatus according to the present embodiment, the area sensor 1 outputs the captured image as an image signal to the first memory 10 and stores the image in the first memory 10 as an area sensor image. The area sensor image stored in the first memory 10 is output to the second memory 11 and stored in the second memory 11. The second memory 11 also stores various parameters required for processing in a binarization processing unit 12, a wire unit edge detection unit 13, and a wire ground height calculation unit 14 which will be described later.

The second memory 11 is connected to a binarization processing unit 12, an electric wire edge detection unit 13, and an electric wire ground height calculation unit 14.
The binarization processing unit 12 acquires parameters and area sensor images from the second memory 11. Then, the binarization processing unit 12 performs binarization processing on the area sensor image based on the parameters to create a binarized image, and outputs the binarized image to the second memory 11. Save the binarized image.

  Further, the electric wire edge detection unit 13 acquires parameters and a binarized image from the second memory 11. Then, the wire portion edge detection unit 13 performs the wire portion edge detection process on the binarized image based on the parameters to calculate edge data, outputs the edge data to the second memory 11, and outputs the edge data to the second memory 11. Save the data.

  The wire ground height calculation unit 14 acquires parameters and edge data from the second memory 11. The wire ground height calculation unit 14 performs wire ground height calculation processing on the edge data based on the parameters to calculate the wire ground height data, outputs the wire ground height data to the second memory 11, and sends the wire ground height data to the second memory 11. Save ground clearance data.

Next, a procedure for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 3 is a flowchart of a process for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment.

  As shown in FIG. 3, after the process is started, an area sensor image is first acquired from the area sensor 1 in the first step S11. After the process of 1st step S11 is complete | finished, the process of 2nd step S12 is performed.

  In the second step S12, the binarization processing unit 12 performs binarization processing so as to separate the electric wire 4 and the background portion on the area sensor image. At this time, as a binarization processing method, for example, there is a method in which a threshold value is determined by a fixed value and divided.

  However, when the threshold value is determined by a fixed value and divided, there may be a problem that the electric wire 4 is not extracted depending on the environment at the time of imaging. Therefore, in order to cope with the difference in environment at the time of imaging, the discriminant analysis binarization method is mainly used. The discriminant analysis binarization method is a method for determining a threshold according to an image.

  In the histogram of each area sensor image, there is “a cluster of the number of pixels gathered in a certain range of luminance values”, and when the area sensor image is binarized, intra-class variance and inter-class variance regarding the background and pattern area A relatively good threshold value is determined for any image so that the dispersion ratio of the image is maximized.

FIG. 4 is a diagram illustrating a binarized image of the electric wire unit according to the present embodiment.
By using the discriminant analysis binarization method described above, a binarized image in which the wire portion 7 is black and the background portion 8 is white as shown in FIG.
After the process of 2nd step S12 is complete | finished, the process of 3rd step S13 is performed.

  In 3rd step S13, the electric wire part edge detection part 13 performs an electric wire part edge detection process so that the edge point of the both sides of the electric wire part 7 represented by black on the binarized image may be detected. When these edge points are searched from the left with respect to a certain line, the point where the background portion 8 changes from white to black of the electric wire portion 7 is the edge point on the left side of the electric wire portion 7 and from the black of the electric wire portion 7 to the background portion 8. Can be detected as an edge point on the right side of the electric wire portion 7.

FIG. 5 is a diagram illustrating a state of the edge detection of the electric wire part according to the present embodiment.
By performing this process for each binning line from the top to the bottom of the binarized image, it is possible to detect the edge 9 of the wire portion 7 related to one binarized image as shown in FIG. The edge data on both sides of can be calculated.
After the process of the third step S13 is completed, the process of the fourth step S14 is executed.

第４ステップＳ１４の処理が終了した後、処理を終了する。 In the fourth step S14, by using the edge data on both sides of the wire portion 7 detected from the binarized image by the wire ground height calculation unit 14, the distance between the edge points on both sides on one line of the area sensor image is calculated. An electric wire ground height calculation process is performed for the width of the electric wire 4 on the area sensor image. Here, since the value obtained by multiplying the image resolution [mm / pixel], which is the degree of the actual size [mm] with respect to one pixel [pixel], by the width on the area sensor image of the wire 4 is the diameter of the wire 4, the sensor width From the area sensor 1 to the wire 4 from the width [mm], the number of sensor pixels Spix [pixel], the lens focal length f [mm], the diameter I [mm] of the wire 4 and the width N [pixel] on the image of the wire 4 Calculate the height of. Then, the height hs [mm] from the ground to the area sensor 1 is added to this value to obtain the ground height h [mm] from the ground to the electric wire 4. A formula for obtaining the ground clearance from the ground to the electric wire 4 is shown in the following formula (1).

After the process of 4th step S14 is complete | finished, a process is complete | finished.

Here, the measurement accuracy of the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 6 is a diagram for explaining the measurement accuracy of the overhead wire measuring apparatus according to the present embodiment. In FIG. 6, y is the imaging range, f is the focal length from the lens 5 to the area sensor 1, x is the sensor width, and θ is the angle of view.
The measurement accuracy depends on the angle of view θ of the lens 5 used in the overhead wire measuring apparatus. This is because the imaging range y of the background of the electric wire 4 changes depending on the angle of view θ of the lens 5. And when the distance of an overhead wire measuring apparatus and the electric wire 4 becomes long, if the same lens 5 is used, a measurement precision will worsen.

  However, measurement accuracy can be maintained by using an appropriate lens 5 corresponding to the distance. That is, when the distance increases, the measurement accuracy can be maintained by using a telephoto lens.

  The resolution of the area sensor 1 is, for example, 100/7500 = 13 [μ / pixel] when the imaging range x is 100 [mm] and the number of sensor pixels is 7500 [pixels]. Therefore, the width of the electric wire 4 can be measured in units of 13 [μ / pixel].

  Here, as an example, in the above formula (1), h = 5000 [mm], I = 10 [mm], f = 135 [mm], Spix = 7500 [pix], and Swidth = 35.02 [mm] The following describes that the number of pixels of the width of the electric wire 4 occupying the width on the area sensor image is changed by the lens 5 to be used and the measurement accuracy is changed.

From the above formula (1), when the lens 5 having 135 [mm] is used, the wire width 10 [mm] is about 57 [pixel]. Therefore, the imaging range y (image width) is (10/57) × 7500 = about 1315 [mm]. The resolution is 170 [μ / pixel].
Moreover, when the lens 5 of 600 [mm] is used, the electric wire width 10 [mm] is about 256 [pixels]. Therefore, the imaging range y (image width) is (10/256) × 7500 = about 292 [mm]. The resolution is 39 [μ / pixel].
As described above, when the telephoto lens is used, the imaging range is narrowed. As a result, the accuracy per pixel is improved accordingly.

As described above, the overhead wire measuring apparatus according to the present embodiment has the following effects.
(1) Since it is a non-contact method, there is no need to consider the danger of contact.
(2) Since the ground height of the electric wire 4 can be measured by one measurement, it does not take time and effort to measure many times like the triangulation method.
(3) It is not necessary to consider the influence on the human body as compared with the method using laser light.
(4) There is no need to use the measuring instrument after it has been adapted to the environment.
(5) The minimum height can be measured by imaging the location where the ground height from the road 2 to the electric wire 4 seems to be the lowest.

  Hereinafter, a second embodiment of the overhead wire measuring apparatus according to the present invention will be described. In addition, the overhead wire measuring apparatus which concerns on a present Example measures the ground height of an electric wire by a continuous measurement system. Further, unlike the first embodiment, the overhead wire measuring apparatus according to the present embodiment uses a line sensor as an image input means.

FIG. 7 is a diagram illustrating an installation example of the overhead wire measuring apparatus according to the present embodiment.
As shown in FIG. 7, the overhead electric wire measuring apparatus according to the present embodiment has the electric poles 3 standing on both sides of the road 2, and the electric wires 4 are suspended between the electric poles 3 so as to cross the road 2. The line sensor 6 is installed so as to look up vertically upward from the ground, and is further installed in a direction in which the scanning lines of the electric wire 4 and the line sensor 6 are orthogonal to each other. The line sensor 6 continuously images the electric wire 4 along the electric wire 4 as indicated by an arrow M. Thereby, an image is taken so that the scanning line of the line sensor 6 crosses the electric wire 4. Thereby, the electric wire 4 is continuously imaged by the area sensor 6 along the electric wire 4 in the imaging range indicated by e.

Next, the apparatus configuration of the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 8 is a diagram illustrating a device configuration of the overhead wire measuring device according to the present embodiment.
As shown in FIG. 8, in the overhead wire measuring apparatus according to the present embodiment, the line sensor 6 outputs the captured image to the line sensor image creating unit 20 as an image signal. The line sensor image creation unit 20 outputs the line sensor image to the first memory 10 and stores the line sensor image in the first memory 10. The line sensor image stored in the first memory 10 is output to the second memory 11 and stored in the second memory 11. The second memory 11 includes various parameters and line sensor images required for processing in a binarization processing unit 12, a wire unit edge detection unit 13, a wire ground height calculation unit 14, and a data storage unit 21 to be described later. The line position is also stored.

The second memory 11 is connected to a binarization processing unit 12, an electric wire part edge detection unit 13, an electric wire ground height calculation unit 14, and a data storage unit 21.
The binarization processing unit 12 acquires parameters and line sensor images from the second memory 11. Then, the binarization processing unit 12 performs binarization processing on the area sensor image based on the parameters to create a binarized image, and outputs the binarized image to the second memory 11. Save the binarized image.

  Further, the electric wire edge detection unit 13 acquires parameters and a binarized image from the second memory 11. Then, the wire portion edge detection unit 13 performs the wire portion edge detection process on the binarized image based on the parameters to calculate edge data, outputs the edge data to the second memory 11, and outputs the edge data to the second memory 11. Save the data.

  The wire ground height calculation unit 14 acquires parameters and edge data from the second memory 11. Then, the wire ground height calculation unit 14 performs wire ground height calculation processing on the edge data based on the parameters to calculate the wire ground height data, and outputs the wire ground height data to the second memory 11. The ground clearance data is stored in

  Further, the data storage unit 21 acquires the line sensor image, the line position, and the wire ground height data from the second memory 11. And the data storage part 21 records a line sensor image, a line position, and electric wire ground height data. Therefore, it is possible to browse and analyze these data recorded later.

Next, a procedure for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 9 is a flowchart of a process for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment.

  As shown in FIG. 9, after starting the process, first, an image signal is acquired from the line sensor 6 in the first step S <b> 21. After the process of 1st step S21 is complete | finished, the process of 2nd step S22 is performed.

In the second step S22, the line sensor image creation unit 20 creates a line sensor image (planar image) by arranging the luminance signals of the scanning lines obtained from the line sensor 6 in time series, and sequentially uses them as an input image.
After the process of the second step S22 is completed, the process of the third step S23 is executed.

  In the third step S23, the line sensor image creating unit 20 determines whether or not the creation of the line sensor image is completed. If the creation of the line sensor image is completed, the fourth step S24 is executed, and the line sensor image is created. If the creation has not been completed, the first step S21 and the second step S22 are executed again.

  In 4th step S24, a binarization process is performed by a binarization process part so that the electric wire 4 and a background part may be separated on a line sensor image. At this time, as a binarization processing method, the discriminant analysis binarization method is used in the same manner as in the first embodiment.

FIG. 4 is a diagram illustrating a binarized image of the electric wire unit according to the present embodiment.
By using the discriminant analysis binarization method described above, a binarized image in which the wire portion 7 is black and the background portion 8 is white as shown in FIG.
After the process of 4th step S24 is complete | finished, the process of 5th step S25 is performed.

  In 5th step S25, the electric wire part edge detection part 13 performs an electric wire part edge detection process so that the edge point of the both sides of the electric wire part 7 represented with black on the binarized image may be detected. When these edge points are searched from the left with respect to a certain line, the point where the background portion 8 changes from white to black of the electric wire portion 7 is the edge point on the left side of the electric wire portion 7 and from the black of the electric wire portion 7 to the background portion 8. Can be detected as an edge point on the right side of the electric wire portion 7.

FIG. 5 is a diagram illustrating a state of the edge detection of the electric wire part according to the present embodiment.
By performing this process for each binning line from the top to the bottom of the binarized image, it is possible to detect the edge 9 of the wire portion 7 related to one binarized image as shown in FIG. The edge data on both sides of can be calculated.
After the process of 5th step S25 is complete | finished, the process of 6th step S26 is performed.

In the sixth step S26, the distance between the edge points on both sides of one line of the line sensor image is determined by using the edge data on both sides of the wire portion 7 detected from the binarized image by the wire ground height calculation unit 14. An electric wire ground height calculation process is performed for the width of the electric wire 4 on the line sensor image. Here, since the value obtained by multiplying the image resolution [mm / pixel], which is the degree of the actual size [mm] with respect to one pixel [pixel], by the width on the line sensor image of the wire 4 is the diameter of the wire 4, the sensor width From the line sensor 6 to the wire 4 from the width [mm], the number of sensor pixels Spix [pixel], the lens focal length f [mm], the diameter I [mm] of the wire 4 and the width N [pixel] on the image of the wire 4 Calculate the height of. Then, the height hs [mm] from the ground to the line sensor 6 is added to this value to obtain the ground height h [mm] from the ground to the electric wire 4. A formula for obtaining the ground clearance from the ground to the electric wire 4 is shown in the above formula (1).
After the sixth step is completed, the seventh step is executed.

In the seventh step S27, the data storage unit 21 records the ground height from the ground to the electric wire 4, the line sensor image used for the calculation, and data indicating the corresponding line number.
After the process of 7th step S27 is complete | finished, the process of 8th step S28 is performed.

  In the eighth step S28, it is determined whether or not there is a next line input. If there is no next line input, the process ends. If there is a next line input, the process in the first step S21 is executed again.

As described above, the overhead wire measuring apparatus according to the present embodiment has the following effects.
(1) Since it is a non-contact method, there is no need to consider the danger of contact.
(2) Since the ground height of the electric wire 4 can be measured by one measurement, it does not take time and effort to measure many times like the triangulation method.
(3) It is not necessary to consider the influence on the human body as compared with the method using laser light.
(4) There is no need to use the measuring instrument after it has been adapted to the environment.
(5) The overhead electric wire section on the road 2 can be continuously measured.
(6) For the device user, it is obvious at which portion of the wire 4 on the road 2 the ground clearance is low, so that it is easy to judge.

  The third embodiment of the overhead wire measuring apparatus according to the present invention will be described below. The overhead electric wire measuring apparatus according to the present embodiment measures the ground height of the electric wire by a static point measuring method with detailed accuracy. Further, unlike the first embodiment, the overhead wire measuring apparatus according to the present embodiment uses a line sensor as an image input means.

FIG. 7 is a diagram illustrating an installation example of the overhead wire measuring apparatus according to the present embodiment.
As shown in FIG. 7, the overhead electric wire measuring apparatus according to the present embodiment has the electric poles 3 standing on both sides of the road 2, and the electric wires 4 are suspended between the electric poles 3 so as to cross the road 2. Similarly to the second embodiment, the line sensor 6 is installed so as to look up vertically upward from the ground, and is further installed in a direction in which the scanning lines of the electric wire 4 and the line sensor 6 are orthogonal to each other. The line sensor 6 continuously images the electric wire 4 along the electric wire 4 as indicated by an arrow M. Thereby, an image is taken so that the scanning line of the line sensor 6 crosses the electric wire 4. Then, one image is continuously captured along the electric wire 4. Thereby, the electric wire 4 is continuously imaged by the area sensor 6 along the electric wire 4 for one image within the imaging range indicated by e.
As shown in FIG. 7, the overhead electric wire measuring apparatus according to the present embodiment has the electric poles 3 standing on both sides of the road 2, and the electric wires 4 are suspended between the electric poles 3 so as to cross the road 2. The line sensor 6 is installed so as to look up vertically upward from the ground, and is further installed in a direction in which the scanning lines of the electric wire 4 and the line sensor 6 are orthogonal to each other. Thereby, an image is taken so that the scanning line of the line sensor 6 crosses the electric wire 4.

Next, the apparatus configuration of the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 10 is a diagram illustrating a device configuration of the overhead wire measuring device according to the present embodiment.
As shown in FIG. 10, in the overhead wire measuring apparatus according to the present embodiment, the line sensor 6 outputs the captured image to the line sensor image creating unit 20 as an image signal. The line sensor image creation unit 20 outputs the line sensor image to the first memory 10 and stores the line sensor image in the first memory 10. The line sensor image stored in the first memory 10 is output to the second memory 11 and stored in the second memory 11. The second memory 11 also stores various parameters required for processing in a binarization processing unit 12, a wire unit edge detection unit 13, and a wire ground height calculation unit 14 which will be described later.

The second memory 11 is connected to a binarization processing unit 12, an electric wire edge detection unit 13, and an electric wire ground height calculation unit 14.
The binarization processing unit 12 acquires parameters and line sensor images from the second memory 11. Then, the binarization processing unit 12 performs binarization processing on the line sensor image based on the parameters to create a binarized image, and outputs the binarized image to the second memory 11. Save the binarized image.

  Further, the electric wire edge detection unit 13 acquires parameters and a binarized image from the second memory 11. Then, the wire portion edge detection unit 13 performs the wire portion edge detection process on the binarized image based on the parameters to calculate edge data, outputs the edge data to the second memory 11, and outputs the edge data to the second memory 11. Save the data.

  The wire ground height calculation unit 14 acquires parameters and edge data from the second memory 11. Then, the wire ground height calculation unit 14 performs wire ground height calculation processing on the edge data based on the parameters to calculate the wire ground height data, and outputs the wire ground height data to the second memory 11. The ground clearance data is stored in

Next, a procedure for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment will be described.
FIG. 11 is a flowchart of a process for calculating the ground height from the ground to the electric wire by performing a thumbtack process on the input image in the overhead wire measuring apparatus according to the present embodiment.

  As shown in FIG. 11, after starting the process, first, an image signal is acquired from the line sensor 6 in the first step S31. After the process of the first step S31 is completed, the process of the second step S32 is executed.

In the second step S32, the line sensor image creation unit 20 creates a line sensor image (planar image) by arranging one scanning line image (luminance) signal obtained from the line sensor 6 in time series, and the input image. Use as As a result, the line sensor 6 generally has higher resolution performance than the area sensor 1 of the first embodiment, so that more accurate measurement can be performed.
After the process of the second step S32 is completed, the process of the third step S33 is executed.

  In the third step S33, the line sensor image creating unit 20 determines whether or not the creation of the line sensor image is completed. When the creation of the line sensor image is completed, the fourth step S34 is executed, and the line sensor image is created. If the creation has not been completed, the first step S31 and the second step S32 are executed again.

  In 4th step S34, the binarization process part 12 performs a binarization process so that the electric wire 4 and a background part may be separated on a line sensor image. At this time, as a binarization processing method, the discriminant analysis binarization method is used in the same manner as in the first embodiment.

FIG. 4 is a diagram illustrating a binarized image of the electric wire unit according to the present embodiment.
By using the discriminant analysis binarization method described above, a binarized image in which the wire portion 7 is black and the background portion 8 is white as shown in FIG.
After the process of 4th step S34 is complete | finished, the process of 5th step S35 is performed.

  In 5th step S35, the electric wire part edge detection part 13 performs an electric wire part edge detection process so that the edge point of the both sides of the electric wire part 7 represented by black on the binarized image may be detected. When these edge points are searched from the left with respect to a certain line, the point where the background portion 8 changes from white to black of the electric wire portion 7 is the edge point on the left side of the electric wire portion 7 and from the black of the electric wire portion 7 to the background portion 8. Can be detected as an edge point on the right side of the electric wire portion 7.

FIG. 5 is a diagram illustrating a state of the edge detection of the electric wire part according to the present embodiment.
By performing this process for each binning line from the top to the bottom of the binarized image, it is possible to detect the edge 9 of the wire portion 7 related to one binarized image as shown in FIG. The edge data on both sides of can be calculated.
After the process of 5th step S35 is complete | finished, the process of 6th step S36 is performed.

In the sixth step S36, the distance between the edge points on both sides on one line of the line sensor image is obtained by using the edge data on both sides of the wire portion 7 detected from the binarized image by the wire ground height calculation unit 14. An electric wire ground height calculation process is performed for the width of the electric wire 4 on the line sensor image. Here, since the value obtained by multiplying the image resolution [mm / pixel], which is the degree of the actual size [mm] with respect to one pixel [pixel], by the width on the line sensor image of the wire 4 is the diameter of the wire 4, the sensor width From the line sensor 6 to the wire 4 from the width [mm], the number of sensor pixels Spix [pixel], the lens focal length f [mm], the diameter I [mm] of the wire 4 and the width N [pixel] on the image of the wire 4 Calculate the height of. Then, the height hs [mm] from the ground to the line sensor 6 is added to this value to obtain the ground height h [mm] from the ground to the electric wire 4. A formula for obtaining the ground clearance from the ground to the electric wire 4 is shown in the above formula (1).
After the process of 6th step S36 is complete | finished, a process is complete | finished.

  As described above, according to the overhead wire measuring apparatus according to the present embodiment, in addition to the effect of the first invention, the line sensor 6 generally has a resolution performance as compared with the area sensor 1 of the first embodiment. Since it is high, more precise measurement can be performed.

  The present invention can be used, for example, in an apparatus for measuring the height of an overhead electric wire from the ground to the electric wire.

It is the figure which showed the example of installation of the overhead wire measuring apparatus which concerns on 1st Example of this invention. It is the figure which showed the apparatus structure of the overhead wire measuring apparatus which concerns on 1st Example of this invention. It is a flowchart of the process which calculates the ground height from the ground to an electric wire by thumbtacking the input image in the overhead wire measuring apparatus which concerns on 1st Example of this invention. It is the figure which showed the binarized image of the electric wire part which concerns on the 1st-3rd Example of this invention. It is the figure which showed the mode of the edge detection of the electric wire part which concerns on the 1st-3rd Example of this invention. It is a figure explaining the measurement accuracy of the overhead wire measuring device concerning the 1st example of the present invention. It is the figure which showed the example of installation of the overhead wire measuring apparatus which concerns on the 2nd Example of this invention. It is the figure which showed the apparatus structure of the overhead wire measuring apparatus which concerns on the 2nd Example of this invention. It is a flowchart of the process which calculates the ground height from the ground to an electric wire by thumbtacking the input image in the overhead wire measuring apparatus which concerns on 2nd Example of this invention. It is the figure which showed the apparatus structure of the overhead wire measuring apparatus which concerns on the 3rd Example of this invention. It is a flowchart of the process which calculates the ground height from the ground to an electric wire by thumbtacking the input image in the overhead wire measuring device which concerns on 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Area sensor 2 Road 3 Electric pole 4 Electric wire 5 Lens 6 Line sensor 7 Electric wire part 8 Background part 9 Edge 10 1st memory 11 Second memory 12 Binarization processing part 13 Electric wire part edge detection part 14 Electric wire ground height calculation part 20 Line Sensor image creation unit 21 Data storage unit

Claims (2)

An imaging means for imaging an electric wire suspended between utility poles by an area sensor or a line sensor to obtain an input image;
Binarization processing means for creating a binarized image in which the electric wire portion is emphasized by binarization processing of the input image;
Electric wire part edge detection means for detecting edge of the electric wire part in the binarized image and creating edge data;
An overhead electric wire measuring apparatus comprising: an electric wire ground height calculating means for calculating the ground height of the electric wire using the edge data. The overhead electric wire measuring apparatus according to claim 1, wherein the electric wire is continuously imaged along the electric wire and the ground height of the electric wire is continuously measured.

Images