JPH06103968B2 - Image processor for overhead line inspection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] Since the present invention automatically performs visual inspection of overhead lines such as power lines, an abnormality of the overhead line is automatically detected from an image captured by a television camera. The present invention relates to an image processing device for inspecting overhead lines.

[Conventional technology]

Conventionally, this type of overhead line has been inspected by a person walking or riding a helicopter and directly visually confirming it with binoculars. There is a method of shooting with VTR and recording it on the VTR, or recording on the VTR while running with a TV camera mounted on a self-propelled inspection machine that runs on an overhead line as shown in Japanese Utility Model Publication No. Sho 61-192614. It is taken. In this case, after returning and collecting, the VTR video is played back to check if there is any abnormality on the person watching the monitor TV.

Abnormalities to be detected include wire breakage, melt marks, foreign matter adhesion, rust, and twisted wire unevenness as shown in FIGS. 5 (a) to 5 (c). If such a thing is left unattended, the number of wires gradually increases, and the wires may loosen, which may lead to a major accident such as a ground fault or a short circuit. Therefore, it is necessary to promptly detect and take action.

[Problems to be Solved by the Invention]

In such a conventional visual inspection of an overhead line, it is necessary for a person to watch the television for a long time to make a judgment, which causes problems such as fatigue and oversight.

The present invention has been made to solve the above problems, and image processing for overhead line inspection that can automatically perform anomaly detection work for overhead lines, which is conventionally performed by a person watching a monitor television. The purpose is to obtain the device.

[Means for Solving the Problems]

An overhead line inspection image processing apparatus according to the present invention processes an image of an overhead line taken by a television camera to detect the position of the overhead line in the image, and a predetermined area including the overhead line or the overhead line. The density of the image of a predetermined area on the outer side adjacent to is calculated at a plurality of points and compared with each other to find an abnormality in the overhead line.

[Action]

The overhead line inspection image processing device according to the present invention detects the position of the overhead line in the input image, and calculates the image density of a predetermined region including the overhead line or a predetermined outside region adjacent to the overhead line at a plurality of locations. Then, the anomaly of the overhead line is found by making a mutual comparison.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, (1) is an overhead line to be inspected, (2) is a helicopter, (3) is an imaging system, and (4) is a reproduction VT.
R, (5) is an image processing device, (6) is a monitor TV,
(7) is a display.

In this embodiment, the video of the overhead line (1) is captured by the television camera (31) from the helicopter (2), and the recording VTR (3
It is recorded in 2), played back in the playback VTR (4) after returning and analyzed by the image processing device (5), and if a defective part is found, it is displayed on the display (7) and at that time, a person (not shown). No.) confirms the contents by watching the monitor television (6).

An image processing device (5) takes in a video signal (a), samples it at a predetermined resolution, and converts it into a two-dimensional digital image, a video AD converter (51), and a video memory (52) for storing the converted digital image. Generates an ALU unit (53) that performs the following arithmetic processing on the image stored in the video memory, a video DA converter (54) for displaying the arithmetic result on a monitor TV, and a VTR control signal (b). It is composed of a control unit (55) that controls a series of operations such as image input, calculation, and display while advancing images sequentially.

The minimum constituent unit of the sampled digital image is called a pixel.

Next, the operation of the image processing apparatus (5) will be described by taking an abnormal overhead line as shown in FIG. 5 (b) as an example. FIG. 2 shows the processing flow.

First, the digital image sampled by the video AD converter (51) is loaded into the video memory (52). An example of the input image is shown in FIG. Here, for simplification, an image in which the overhead line portion is binarized to "1" and the background to "0" is described.

Next, the position of the overhead line in the input digital image is detected. This searches for a pixel of "1", for example, from the top and bottom of the left and right edges of the screen and from the bottom to the top. Third
In the example of the figure, A, B, A ', and B'are the positions of the left and right ends of the overhead line where they were detected. However, if there is noise in the background portion of the image, the correct left and right end positions of the overhead line cannot be detected. In that case, either remove the noise component beforehand by smoothing processing (for details, refer to the image processing technical manual), or It is desirable to detect the position of the overhead line at multiple points and determine by majority vote.

Next, based on the calculated position of the overhead line, as shown in FIG. 3, a region of a certain size (here, vertical 4
× Horizontal 4) is set, and the average brightness in the area is calculated. For example, there are 14 "1" s in the leftmost area, so the average brightness is 14/16. This operation is performed at regular intervals from the left end to the right end of the overhead line (here, half the left and right length of the area)
Move while moving. In the example of FIG. 3, the average brightness of each area is as follows from the left in order.

Here, when the average brightnesses of the respective areas are compared with each other, it can be seen that there is an abrupt change in the sixth and seventh areas, and there is an abnormality in this area. As a mutual comparison of the average brightness, a difference of a certain value or more from the average brightness of the adjacent areas If there is, it may be judged as abnormal.

Although the average brightness is calculated in the above, the size of the area is constant, and thus the cumulative value in the area may be used instead. Further, considering the change in brightness of the normal part of the overhead line, etc., the brightness may be appropriately weighted according to the brightness, and the average may be taken.

Further, the size of the area and the interval of movement are set to optimum values based on the size of the abnormality to be detected.

The above processing is sequentially performed while advancing the VTR screen by screen, and if an abnormality is detected, it is displayed on the display (7).

In the above-mentioned embodiment, the case where there is an abnormality inside the overhead wire is described, but there is no abnormality inside the overhead wire due to a wire breakage on the back side, etc. If the background in the vicinity of the line has a uniform density, the width of the region can be similarly detected by expanding it to the outside of the overhead line.

Further, as a more accurate method for finding the outer contour abnormality, as shown in FIG. 4, the positions A, B, A ′, at the left and right ends of the overhead line are
After detecting B ', set a region of a certain size (here, vertical 2 × horizontal 4) in the part outside the overhead line and adjacent to the overhead line, and compare them with each other in the same way as above to check for abnormalities. locate. In the example of FIG. 4, the average brightness of the area above the overhead line is from the left, The average brightness of the area under the overhead line is from left to right. It can be seen that there is an abnormality above the overhead line.

In this way, by setting the regions in the adjacent portions on the outside of the overhead line, it is possible to more accurately detect the abnormality in the outer contour of the overhead line.

In the above embodiment, the image taken from the helicopter was targeted, but it may be taken from the ground with a telescope or the like, or may be taken with a self-propelled inspection machine.

Further, in the above embodiment, the image recorded in the VTR is reproduced and judged, but the image processing device is mounted on a helicopter or a self-propelled inspection machine, or the photographing system and the image processing device are connected by a communication line. Alternatively, the determination may be performed online.

Further, in the above embodiment, when an abnormality is found, the display is immediately notified, but if the abnormal portion is stored in memory and can be confirmed collectively, the work can be performed more efficiently.

Although the above embodiment has described the case where an image other than the overhead line is not included, flying objects (small birds, etc.) may be mixed in, and buildings and trees may be detected in the background. May be erroneously determined to be abnormal.
Therefore, the above erroneous determination can be prevented by performing the determination process on a plurality of consecutive frames and determining the abnormality only when the position of the foreign matter moves in accordance with the moving speed of the screen.

〔The invention's effect〕

As described above, according to the present invention, the image of the overhead line is detected by the overhead line inspection image processing device in the position of the overhead line in the input image, and the density within a predetermined area is calculated at a plurality of locations. Since it is configured to automatically detect an abnormality in the overhead line by making mutual comparisons, it is not necessary for a person to watch the television for a long time to make a decision, and it is possible to avoid problems such as fatigue and oversight. effective.

[Brief description of drawings]

FIG. 1 is a system configuration diagram using an image processing device for overhead line inspection according to an embodiment of the present invention, FIG. 2 is a processing flow chart of the image processing device, and FIGS. 3 and 4 show image processing examples. Explanatory drawings and FIGS. 5 (a) to 5 (c) are partial views showing examples of abnormalities of overhead lines. In the figure, (1) is an overhead line, (2) is a helicopter,
(3) is a photographing system, (4) is a VTR for reproduction, (5) is an image processing device, (6) is a monitor television, and (7) is a display. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] Claim: What is claimed is: 1. An overhead line inspection image processing apparatus for inspecting the overhead line by taking an image of the overhead line with a TV camera and processing the resulting image to check the position of the overhead line. An image processing apparatus for inspecting an overhead line, characterized in that an abnormality in the overhead line is detected by calculating the densities of images in a predetermined area including the plurality of locations and comparing them with each other. 2. An overhead line inspection image processing device for inspecting the overhead line by photographing the overhead line with a television camera and processing the obtained image to inspect the position of the overhead line. An image processing apparatus for inspecting an overhead line, characterized in that an abnormality in the overhead line is detected by calculating the densities of images in a predetermined area which are adjacent to each other and do not include the overhead line, and compare them with each other. 3. In a plurality of consecutive frames of an image,
3. The overhead line inspection image processing apparatus according to claim 1, wherein when the same abnormality is detected, it is determined as an abnormality to prevent erroneous determination.