JPH0420810A - Measuring method for distance between electric wire and tree or the like - Google Patents

Abstract

PURPOSE:To accurately measure a distance by photographing a tree and an electric wire simultaneously from a direction crossing a power transmission line by two cameras which are mounted with a constant interval on a self running machine on a string upper than the electric wire to be measured. CONSTITUTION:Two cameras B, C mounted with a constant interval (a) on a self running machine 1 which is hung from a string 4 extended along an electric wire 3 close to a tree 2 record the tree and the electric wire 3 simultaneously at a predetermined position to obtain a set of two photographs. On one set of the photographs, distances p1, p2, q1, q2 from center lines of the photographing to images of the electric wire 3 and the tree 2 are measured to calculate angles B'1, B'2, C'1, C'2 between the tree W with respect to the recording direction and the existing direction of the electric wire T, and then the angles are converted into angles B1, B2, C1, C2 with respect to a line connecting between the cameras B, C. Then a distance (d) between the tree 2 and the electric wire 3 is calculated based on the angles B1, B2, C1, C2 and the interval (a) between the cameras B, C. Thus a distance between the electric wire and the tree or the like can be correctly measured without missing a tree which is closest to the electric wire.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides a system for accurately grasping the separation distance between electric wires and nearby obstacles such as trees when maintaining and operating power transmission lines for transporting and supplying electric power. io+ that helps prevent accidents
This relates to a method of measuring the separation distance between trees, etc.
It is mainly used in the field of power transportation equipment industry.

[Prior art and problems to be solved by the invention] When a tree or the like approaches a special high-voltage power transmission line, a flashover accident occurs, and the grounding relay on the power transmission line operates, causing a power outage state and disrupting the power supply. In the worst case scenario, this can lead to wildfires as trees and other objects are destroyed by fire.

For this reason, when maintaining and operating power transmission lines, it is necessary to accurately understand the distance from trees, etc. near the power lines, and take measures such as cutting down trees that approach the limit distance.

In order to safely operate power transmission lines, it is sufficient to cut down trees that may come close to a sufficiently safe range. However, in order to cut down trees, it is necessary to negotiate with the owner of the tree, and unnecessary extra cutting can harm the national interest.

For this reason, when maintaining and operating power transmission lines, it is necessary to accurately understand the distance between power lines and trees, etc., and to maintain a necessary and sufficient distance at all times in anticipation of tree growth. be.

Measuring the separation distance between power transmission line wires and trees, etc. has conventionally been performed using the following methods 1), 2), and 3), but each method has its own problems.

l) A method in which an insulating measuring rod is extended from the ground to measure the height of the electric wire and the tree to find the distance between them.

Because power transmission lines are often installed in mountainous areas, this method can make it very difficult for maintenance workers with measuring sticks to reach tree-lined locations close to power lines; In difficult locations, it is not easy to see the trees closest to the power lines from the ground, and there is a risk of overlooking the trees closest to the power lines.

Also, if the trees are not directly under the power line, but are approaching from the side of the power line, to determine the separation distance, the height of each tree,
It is necessary to draw a diagram based on the distance of each measurement point, and errors are likely to be included in the measured values.

2) Climb up a steel tower, look out in the direction in which the wires run, and visually compare the distance between the wire and approaching trees and the distance between the wires (known) to estimate the separation distance.

This method requires a lot of effort from the maintenance worker and is prone to errors. In particular, since the wires are viewed from the track direction, it is difficult to determine the wire position on the cross section of the wire, including approaching trees.

3) A method in which power is cut off and a worker hovers over the power line to directly measure the separation distance from approaching trees, etc.

With this method, if the wire is not thick enough, workers may not be able to ride in the air for safety reasons, and measurements may not be possible.

In addition, the wires droop due to the weight of the worker riding in the air, so the true separation distance cannot be obtained unless the amount of droop is corrected. However, calculating the amount of droop is not easy because the configuration of the transmission tvA path is different. do not have.

Therefore, this invention measures the separation distance between electric wires and trees etc. accurately and without overlooking the closest tree etc. by taking pictures with a stereo camera.
The purpose is to ensure thorough maintenance and operation of power transmission lines.

[Means for Solving the Problems] The present invention provides two units installed in a direction intersecting the direction of a power transmission line on an electric wire or an overhead ground wire installed above or to the side of an electric wire whose separation distance from a tree, etc. is to be measured. A self-propelled machine equipped with cameras mounted at regular intervals is run, and the two cameras simultaneously take pictures of trees, etc. and power lines at preset intervals in the direction of the power transmission line, and the shooting direction of each camera is determined from each set of two pictures. The present invention provides a method for calculating and measuring the distance between the electric wire and the tree using a geometric method based on the angle between the electric wire and the tree, etc., and the distance between the electric wire and the camera.

[Effect]

In the above method, the self-propelled aircraft (1) carries out an overhead wire installed along a 1tia (3) approaching a tree, etc. (2), as shown in Fig. 1, such as an overhead ground wire for lightning protection ( 4)
It is suspended from and propels itself. Trees, etc. (2) and electric wires (3) are simultaneously photographed at predetermined points using two cameras B and C, and a set of two photographs is obtained for each photographing point. This 2
A set of photographs can be written as P'-P'', Q- if the cross-sectional view of the electric wire including the center of the photographing directions of the two cameras shown in Fig. 2 is drawn by matching the photographic direction with the photograph. Q'.As can be seen from the positional relationship between the image of the photo and the electricity wA (2) and trees etc. (3) in this cross-sectional view, t! By measuring the distances pt s p2 , qt, and q2 from (2) to the position of the image of the tree, etc. (3), respectively, the tree, etc. W with respect to the shooting direction of camera B and C,
The angle of the direction of existence of the electric wire T adjacent to this /B, ", ΔB
2", /C3', /C2" can be obtained. Furthermore, these angles are calculated as angles with respect to the straight line connecting cameras B and C.
Convert to B1, /B2, /C1, ZC2. Self-propelled machine (1
Since the distance a between the cameras B and C mounted on the camera B and C is known, the distance d between a tree or the like and the electric wire can be determined from these angles and the distance a using a geometric calculation method.

〔Example〕

FIG. 1 shows two cameras B,
The self-propelled machine (1) with C is shown mounted on an overhead wire on a power transmission line. This power transmission line consists of electric wires R, S, T, R',
This is a general structure in which S' and T' are arranged in a hexagonal arrangement and an overhead ground wire G for lightning protection is arranged above them. In this embodiment, the self-propelled machine (1) is mounted on the overhead ground wire G (overhead line), but the self-propelled machine (1) is placed on the overhead ground wire G (overhead line), and the self-propelled machine (1) is connected to the electric wire to be measured and obstacles such as trees approaching it. Two cameras B and C
It may be placed on the electric wire (for example, R) as long as it is in a position where it can be photographed at the same time.
When the cameras B and C of the stand are placed apart in a direction orthogonal to the overhead ground line G, the angle θ in FIG. 1 is the range.

Next, a specific configuration example of the self-propelled machine (1) used in the present invention will be described with reference to FIGS. 3(a) and 3(b).

In Figures 3(a) and (b), (5) and (5) are support members with hook-shaped upper parts, and are made into a self-propelled rectangular frame by connecting members (6) at the upper part and underframes (7) at the lower part. It makes up the exterior of the aircraft. Drive wheels (8) (8) are rotatably mounted in the hook-shaped portions of the struts (5) (5). This drive wheel (8) (8) has a U-shaped groove so that it can run on overhead wires (overhead ground wires or electric wires), and the drive motor (9)
(9).

(10) is a roller with a U-shaped groove, and the lower end is a support (5)
The roller (10) is mounted on a Y-shaped rod (11) that is pin-connected to the
(Electric wire or overhead ground wire) and drive wheel (8) (
8) It has the role of preventing wheels from coming off and slipping.

If a drive motor is also attached to the 20th roller (10), overall academic performance can be improved.

(13) is a beam for attaching cameras B and C to the self-propelled aircraft (1), and is attached orthogonally to the connecting member (6) to keep cameras B and C supported at both ends at a constant distance. It also has the role of keeping the two downward-facing camera axes parallel.

(14) is the travel counter, flexible shirt) (
15), the rotation of the drive wheel (8) is transmitted to this;
It counts the number of rotations and sends a signal to release the camera shutter every preset count. This is to ensure that the photographing intervals in the power transmission line direction are set so that the photographing fields of view overlap to avoid overlooking approaching trees, etc.

(16) is a storage battery for the drive motor (9) (9).

Cameras B and C are motor-driven cameras with wide-angle and deep-field lenses, and are equipped with the function of simultaneously cutting the shanks in response to a signal from the counter (14). Naorimara B and C may use a video camera, and when taking still images from the tape and printing them,
Any device may be used as long as it has a function that allows simultaneous extraction of left and right images B and C.

Next, a procedure for calculating the distance fid between an electric wire and a nearby tree or the like from a set of two photographs taken by cameras B and C will be described.

As shown in Figure 2, if you measure the distances P, P', q, and q' from the center of the photo of the electric wire and approaching tree on a pair of photos, you can calculate the distances P, P', q, and q' based on the characteristics of the lens of the camera used. camera B,
Angle of their direction of existence with respect to the imaging center line of C/B
,°, /B2', /C,', ZC2' can be specified, and furthermore, ZB, , ZB, , ZCl, ZC2 can be found as angles with respect to the straight line connecting cameras B and C.

7B, , B2, CI, and C2 are determined, the opening angle of the distance a between the cameras seen from the line and each point of existence such as a tree, etc. ZAI = 180' - (ZB, 10/'CI) Z
A2=180°−(/B2+lC2) can be obtained.

Focusing on the triangle connecting each point of the electric wire, tree, etc. and one camera C, the distance @d between the electric wire T and the tip W of the tree can be determined from the above equation.

Based on the above principle, even if the self-propelled aircraft with the camera attached rolls sideways, or even if the overhead ground wire on which it is mounted falls, the distance a between the two cameras and the camera axis direction will remain unchanged, and the distance a to be measured will remain the same. Measurement is possible as long as you can take photos that capture the points at the same time.

In the above calculation method, two cameras B and C are placed at a constant interval in a direction perpendicular to the electric wire to be measured, and obstacles such as trees are located at the center of the image taken by these two cameras. This was the case where the electric wire and the obstacle, such as a tree, were present in a vertical plane that included the axis, but if two cameras could simultaneously photograph the electric wire and an obstacle such as a tree, it would be possible to measure the separation distance. For example, the two cameras may take images from the side or above, and if there are no obstacles such as trees in the cross section of twA that includes the central axis of the image taken by each camera (but if there are no obstacles such as trees) The separation distance can be similarly determined by performing geometric calculations.

〔Effect of the invention〕

According to this invention, if the overhead wire is installed in a position where it is possible to simultaneously photograph the electric wire and the trees, etc. approaching the electric wire, the operator can accurately approach the electric wire and this S without a person riding on the electric wire. It is possible to determine the distance from trees, etc. In particular, when running a self-propelled aircraft on a grounded overhead wire for lightning protection, there is no need to shut down the power transmission line, so it has the feature that it does not interfere with the power transmission, which is the purpose of the power transmission line.

[Brief explanation of the drawing]

FIG. 1 is a positional relationship diagram in a cross section of an electric wire, showing a state in which an electric wire and an obstacle such as a tree approaching the electric wire are photographed by a camera mounted on a self-propelled machine. FIG. 2 is a geometric positional relationship diagram showing the procedure for calculating the separation distance from a set of two photographs of the bottle. FIGS. 3(a) and 3(b) are a side view and a front view of a self-propelled machine used in the present invention. (1)-m-self-propelled machine-(2)-trees, etc., (3)-electric wires,
(4) - Overhead line, (B) (CL-m-camera.

Claims (1)

[Claims] A self-propelled machine equipped with two cameras mounted at a fixed interval runs in the direction intersecting the wires on the overhead wire along which you want to measure the separation distance from obstacles such as trees. From the respective positions of the electric wire and obstacle in a pair of captured images, determine the angle of the direction of their existence with respect to each camera, and calculate the separation distance between the electric wire and the obstacle from these angles and the distance between the cameras. A method for measuring the separation distance between electric wires and trees, etc.