JP5083923B1 - Inspection method for communication tower - Google Patents

Abstract

[PROBLEMS] To check a communication tower that can perform work without omission, check state changes with high accuracy, reduce costs, shorten work time, and improve work efficiency by simplifying work. Provide a method.
In a method for inspecting a state change occurring in communication towers 1, 21, a plurality of outer peripheral installation positions P1, P3 spaced circumferentially on the outer periphery side of communication towers 1, 21 on the ground 2 are provided. Steps of photographing the inspection range by the photographing device 4 in a state where the installed photographing device 4 is turned and directed to the inspection range of the communication towers 1 and 21, and a step of recording an image obtained by photographing, Observing a change in the state of the communication towers 1 and 21 based on the recorded images.
[Selection] Figure 2

Description

  The present invention relates to a method for inspecting a state change occurring in a communication tower.

  In a steel tower equipped with a communication antenna or the like, its state may change due to exposure to wind and rain, deterioration over time, etc. (hereinafter referred to as “state change”). As the type of state change, for example, deformation, cracking, breakage, rust, etc. of structures constituting the tower, loosening of fastening members such as screws, nuts, bolts, washers, omission, rust, discoloration of plated parts, etc. Examples include peeling, discoloration of the painted portion, deformation of the welded portion, cracking, breakage, rust, and the like. Such a state change is not preferable in order to stably maintain a steel tower, which is a large and high-rise building, over a long period of time. Therefore, the presence or absence of a state change is regularly checked, and when a problem state change is confirmed, the steel tower is repaired.

  As described above, in order to maintain the tower stably over a long period of time, it is necessary for the inspection work to observe multiple inspection points of the tower without omission and to detect state changes with high accuracy. Has been. In order to meet such a high demand, in the conventional inspection work, the presence or absence of a state change is determined by direct visual observation by an operator. For example, as in Patent Document 1, a scaffold is installed on a steel tower, and an operator climbs the steel tower using this scaffold, moves to an inspection location, and observes the inspection location by directly observing the inspection location. The presence or absence of the state change of the location is judged. Such inspection work is also performed on the entire steel tower.

  Also, climbing a steel tower to move to an inspection location and judging whether or not there is a change in state requires a high level of skill from the workers, and many workers are required to acquire such high skills. Need experience. Therefore, the inspection of the steel tower is mainly performed by experienced workers who are experienced.

JP 2010-126959 A

  However, the scaffold used in the inspection work of Patent Document 1 is heavy due to demands for durability, strength, and the like. In the inspection work of Patent Document 1, the heavy weight scaffold is placed at a high place such as the upper part of the steel tower. It is installed in a state where it is lifted up. It takes a lot of labor to lift such a heavy scaffold and to install the scaffold at a high place. In addition, when a communication tower or the like is installed in a mountainous area, transporting a heavy weight scaffold to the mountainous area also requires a lot of labor. Furthermore, in many cases, there are forests around the steel tower in mountainous areas, and parking lots are provided around the steel tower in urban areas, making it difficult to secure sufficient space around the steel tower. Yes. Therefore, it is difficult to store materials used for the installation of scaffolding around the steel tower.

  In addition, it takes a lot of time for an operator to climb a steel tower using a scaffold to move to a check point and to determine the presence or absence of a state change with high accuracy. In particular, when the entire tower is to be inspected, it is necessary for the worker to move over the entire tower and determine the presence or absence of state changes at many inspection points with high accuracy. Is spent. It is also very difficult for an operator to determine whether or not there is a state change in a high place such as the upper part of a steel tower and in an unstable state. As described above, the inspection work of the steel tower is mainly performed by experienced workers who are experienced, but in order to nurture skilled workers, a great deal of labor, cost, and time are required. Become. Therefore, it is desired to simplify the inspection work.

  The present invention has been made in view of such a situation, and its purpose is to be able to carry out the work reliably without fail, to check the state change with high accuracy, to reduce the cost, and to shorten the work time. Another object of the present invention is to provide a communication tower inspection method that can improve work efficiency by simplifying work.

In order to solve the problem, the inspection method for a communication tower according to the present invention is a method for checking a change in a state generated in a communication tower installed on the ground, around the base of the communication tower on the ground , spaced from the center of the communication towers against the outer periphery of the communication towers in a direction towards the outer periphery, and a plurality of outer peripheral installation position spaced in a circumferential direction of the communication towers, the step of installing a shooting device And turning the installed imaging device so that its optical axis is directed to at least one of an area in a direction horizontal to the ground and an area on the upper side with respect to the horizontal direction to be in the inspection range of the communication tower. In this state, the step of photographing the inspection range by the photographing device, the step of recording the image obtained by the photographing, and observing the state change of the communication tower based on the recorded image That and a step.

  In the communication tower inspection method of the present invention, when the communication tower has a polygonal cross section, the plurality of outer peripheral installation positions correspond to corners of the polygonal cross section.

  In the communication tower inspection method of the present invention, when the communication tower has a circular cross section, the plurality of outer peripheral installation positions are at least three.

  In the communication tower inspection method of the present invention, in the step of photographing, a photographing device installed at an internal installation position located in the center of the communication tower on the ground is further used.

  In the method for checking a communication tower according to the present invention, a state change generated in a communication load attached to an upper part or an intermediate part in the height direction of the communication tower is checked.

  In the communication tower inspection method of the present invention, a high-sensitivity video camera is used as the photographing device.

  In the communication tower inspection method of the present invention, the state change of the communication tower is a loosening of the fastening member provided in the communication tower.

  In the communication tower inspection method of the present invention, the state change of the communication tower is a discoloration or shape change of the surface of an element provided in the communication tower.

According to the present invention, the following effects can be obtained.
In a method for checking a state change occurring in a communication tower installed on the ground , a direction from the center of the communication tower toward the outer periphery with respect to the outer periphery of the communication tower around the base of the communication tower on the ground spaced apart, and a plurality of outer peripheral installation position spaced in a circumferential direction of the communication towers, comprising the steps of: installing a shooting device, the installed imaging device, the horizontal and the optical axis with respect to ground Photographing the inspection range with the imaging device in a state of turning to at least one of the area in the horizontal direction and the upper area with respect to the horizontal direction and facing the inspection range of the communication tower; Recording an image obtained by the photographing, and observing a state change of the communication tower based on the recorded image. Therefore, since the inspection work can be completed on the ground where the equipment such as the photographing apparatus can be easily transported and installed and it is easy to maintain a stable state, a heavy weight scaffolding is used for a communication tower as in the past. There is no need to carry it around and install it, and there is no need for the operator to climb the tower. For example, when the entire tower is inspected, it is not necessary for the worker to move over a wide range. As a result, work time can be shortened, work can be simplified, work efficiency can be improved, and cost can be reduced. In particular, since the imaging device is installed at a plurality of outer peripheral installation positions spaced apart in the circumferential direction on the outer peripheral side of the communication tower on the ground, the communication from the plurality of outer peripheral installation positions in a stable state. A wide range of the outer periphery of the steel tower can be photographed reliably and with high accuracy without omission. Recording the image thus captured, and based on the recorded image, the state change of the communication tower is compared with data that is a criterion for the state change in a stable place other than the communication tower. Since it can be observed, the inspection work can be simplified, and a wide range of the communication tower can be inspected reliably and with high accuracy without omission. By simplifying the work, even an inexperienced worker can easily perform the inspection work, and can reduce much labor, cost, and time for raising the worker. Therefore, it is possible to remarkably improve the work efficiency and significantly reduce the cost compared with the conventional case. Furthermore, it is only necessary to secure a space for installing the imaging device at a plurality of outer peripheral installation positions spaced apart in the circumferential direction on the outer peripheral side of the communication tower, and a space for storing materials for the scaffold as in the past. Therefore, inspection work can be carried out efficiently within a limited range.

  In the communication tower inspection method of the present invention, when the communication tower has a polygonal cross section, the plurality of outer peripheral installation positions correspond to corners of the polygonal cross section. Alternatively, when the communication tower has a circular cross section, the plurality of outer peripheral installation positions are at least three. Therefore, a wide range of the communication tower can be photographed reliably and with high accuracy without omission, and as a result, the wide range of the communication tower can be inspected without omission and with high accuracy.

  In the communication tower inspection method of the present invention, in the photographing step, an imaging device installed at an internal installation position located in the center of the communication tower on the ground is further used. Even in a wide range, it is possible to photograph reliably and with high accuracy without omission, and as a result, it is possible to inspect the wide range of the communication tower with certainty and high accuracy without omission.

  In the communication tower inspection method of the present invention, since the state change occurring in the communication load attached to the upper or middle part of the communication tower in the height direction is checked, an important function in the communication tower Even when inspecting only a mounted object such as an antenna that fulfills the requirements, the working time can be shortened, the work can be simplified, the working efficiency can be improved, and the cost can be reduced.

  In the communication tower inspection method of the present invention, since a high-sensitivity video camera is used as the photographing device, the communication tower, in particular, the upper part of the communication tower located away from the ground is photographed with high accuracy. The communication tower can be inspected with high accuracy.

  In the method for inspecting a communication tower according to the present invention, the state change of the communication tower is a discoloration or a shape change of the surface of an element provided in the communication tower. Deformation, cracks, damage, rust, etc. of objects, discoloration of plated parts, peeling of paint parts, discoloration, etc., lack of fastening members such as screws, nuts, bolts, washers, rust, etc., deformation, cracks, damage of welded parts , Rust, etc. can be checked reliably.

It is a side view which shows roughly an example of the state which is checking the communication tower using the inspection system and inspection method which concern on 1st Embodiment of this invention. In the AA cross section of FIG. 1, it is a figure which shows roughly an example of the state which is inspecting the communication tower using the inspection system and inspection method which concern on 1st Embodiment of this invention. It is a side view which shows the state which the looseness generate | occur | produced in the nut used as an inspection object. It is a side view showing an example of a communication tower checked using the inspection system and method according to the first embodiment of the present invention. It is a side view which shows roughly the operation | work which image | photographs the whole leg part of a communication tower using the inspection system and method which concern on 1st Embodiment of this invention. It is a side view which shows roughly the operation | work which image | photographs the whole some skeleton member located between the legs of a communication tower using the inspection system and method which concern on 1st Embodiment of this invention. It is a cross-sectional view which shows the outline of the state which is checking the communication tower using the system and method which concern on 2nd Embodiment of this invention.

[First Embodiment]
An inspection system using the inspection method for a communication tower (hereinafter referred to as “steel tower”) according to the first embodiment of the present invention will be described below.
As shown in FIGS. 1 and 2, the steel tower 1 has a skeleton that extends upward from the ground 2 and has a quadrangular pyramid shape, and the cross section of the steel tower 1 has a quadrangular shape. . The inspection system 3 used for inspecting the steel tower 1 includes a video camera 4 configured as a photographing device for photographing the steel tower 1. The inspection system 3 includes a recording device 5 that records an image taken by the video camera 4. The inspection system 3 includes a monitor 6 configured as an observation device that observes a change in the state of the steel tower 1 based on an image recorded by the recording device 5.

  The steel tower 1 is provided with legs 7 along the entire vertical direction of the steel tower 1 corresponding to the four corners 1a, and a plurality of skeleton members 8 are provided between the legs 7. ing. A load is attached to the steel tower 1. As an example, as shown in FIG. 1, an antenna 9 is attached to the top of the steel tower 1. The antenna 9 is attached to the tower 1 by a fastening member, and a cable (not shown) is connected to the antenna 9, and a connector (not shown) for connecting the cable to the antenna 9 is provided. A plurality of nuts 10 as fastening members are attached to the steel tower 1 by screwing with bolts 11 attached to the steel tower 1 as screw elements (see FIG. 3). Moreover, the steel tower 1 is subjected to welding, plating, painting, and the like (not shown).

  The video camera 4 is configured to be turnable so that the optical axis 4a is directed upward with respect to the ground 2 and the optical axis 4a is directed to the left and right in the horizontal direction. By such turning, the video camera 4 is directed to the inspection range of the steel tower 1. Here, as an example, the video camera 4 may have the following performance, but is not limited thereto. The video camera 4 may be a high sensitivity video camera. The video camera 4 may have a far end focal length of 1000 mm or more. It is preferable that the video camera 4 can shoot a moving image with full high-definition recording. In terms of brightness, the video camera 4 may include a high-sensitivity CCD having a sensitivity of F11 or higher and a minimum subject illumination of 0.016 lux or higher. It is preferable that the video camera 4 is configured to be able to record audio. The video camera 4 may have a dynamic range of 600% or more.

  In FIG. 1, the recording device 5 is shown outside the video camera 4, but the recording device 5 may be built in the video camera 4. The monitor 6 is configured to be able to display an image recorded by the recording device 5.

The installation position of the video camera 4 will be described.
With reference to FIGS. 1 and 2, the video camera 4 is installed at four outer peripheral installation positions P <b> 1 located on the outer peripheral side of the steel tower 1 on the ground 2. The four outer peripheral installation positions P <b> 1 are spaced apart from each other in the outer peripheral direction so as to correspond to the four corners 1 a of the steel tower 1, and are located at a predetermined distance d from the root outer periphery of the steel tower 1. The video camera 4 is installed at an internal installation position P2 located at the center 1b of the steel tower 1 on the ground 2.

The video camera 4 when checking the looseness of the nut 10 will be described.
Referring to FIG. 3, when checking the looseness of the nut 10, the video camera 4 is provided between the nut 10 and a washer 12 urged toward the nut mounting surface 1 c of the steel tower 1 facing the nut 10. The gap G is photographed. Furthermore, when the distance G is the distance h and the distance h is equal to or greater than a predetermined distance threshold value, it is determined that the nut 10 is loose. Therefore, it is required to be able to check that the distance h of the gap G is equal to or greater than the above-described distance threshold in the photographed and recorded image. Here, when photographing the gap G, the optical axis 4a of the video camera 4 is at an angle w with respect to the nut mounting surface 1c, and the video camera 4 is photographing an inspection range close to the outer peripheral installation position P1. When the video camera 4 captures an inspection range away from the outer peripheral installation position P1, the angle w becomes small. However, when the angle w increases, it becomes difficult to check the gap G.

The nut 10 to be inspected will be described.
As a representative example, as shown in FIG. 4, the steel tower 1 is a standard 40-meter-high angle steel tower, and the steel tower 1 is divided into 17 parts B1 to B17 in the height direction to determine the inspection range. In this case, the ratio R of the number of nuts 10 requiring confirmation on the strength of the steel tower 1 with respect to the total number of nuts 10 provided in each of the parts B1 to B17 was determined as follows.
When the strength of the fastening member is F and the design stress is c, the safety factor S is expressed by the following (Equation 1).
S = F / c (Formula 1)
Next, if the total number of nuts 10 provided in each of the parts B1 to B17 is N, the number M of nuts 10 that require confirmation on the strength of the steel tower 1 is expressed by the following (Equation 2).
M = N / S (Formula 2)
As a result of such calculation, the ratio R described above has a value as shown in Table 1.

  According to Table 1, the inspection range of the tower 1 is set at a ratio of about 1/3 of the height of the tower 1, the upper part 13 corresponding to the parts B1 to B9, the intermediate part 14 corresponding to the parts B10 to B14, When divided into the lower part 15 corresponding to the parts B15 to B17, the following can be confirmed. As for the nuts 10 in the upper portion 13, the number of nuts 10 that is 70% or more and less than 100% of the total number may be photographed and observed. As for the nuts 10 in the intermediate portion 14, the number of nuts 10 that is 75% or more and less than 100% of the total number may be photographed and observed. As for the nuts 10 in the lower portion 15, a number of nuts 10 that are 80% or more and less than 100% of the total number may be photographed and observed. Therefore, even when the video camera 4 cannot capture all the nuts 10 because the nut 10 is hidden by a structure provided on the steel tower 1 when the steel tower 1 is imaged from the video camera 4 on the ground 2, at least the above-mentioned. By photographing, recording, and observing the nut 10 at the ratio, the steel tower 1 can be surely inspected as in the past. In addition, the time for photographing and observing the nut 10 having the above-described ratio is remarkably shortened. The antenna 9 of the steel tower 1 is generally attached to the upper part 13 including the top part of the steel tower 1 or the intermediate part 14.

  In addition, since an ordinary steel tower has a structure in which the required strength increases from the bottom to the top, even if the steel tower is other than the standard 40-meter-high angle steel tower, The number of nuts 10 that need to be inspected at the part and the lower part is the same. If all of the nuts 10 provided in the upper part 13, the intermediate part 14, and the lower part 15 of the tower 1 can be photographed, all the nuts 10 (that is, 100% of the total number of nuts 10) are photographed. And may be observed. Moreover, based on the ratio R in each site | part B1-B17 of the steel tower 1 of Table 1, the steel tower 1 is divided | segmented by ratios other than 1/3 of the height, and with respect to the total number of nuts 10 in each of these divided parts. The ratio of the number of nuts 10 to be photographed and observed may be determined. For example, the ratio of dividing the steel tower 1 may be 1/2, 1/4, 1/5, or the like of the height of the steel tower 1, and the steel tower 1 may not be divided equally. Based on the ratio R in each part B1 to B17 of the steel tower 1 in Table 1, the ratio of the number of nuts 10 to be photographed and observed with respect to the total number of nuts 10 may be set in any way.

  Furthermore, in addition to the monitor 6, a looseness determination unit that determines the looseness of the nut 10 may be provided as the observation device. The looseness determination unit determines whether the nut 10 is loosened based on the distance threshold of the gap G. It should be configured to be possible. As an observation device, in addition to the monitor 6, a discoloration determining unit that determines discoloration occurring on the surface of the element of the steel tower 1 may be provided. Discoloration corresponding to rust, etc., screw, nut 10, bolt 11, washer 12 and other fastening members, discoloration of plated parts, peeling of paint parts, discoloration, cracks, damage, rust etc. of welded parts, It is good to be comprised so that determination is possible based on the color used as a reference | standard. As an observation device, in addition to the monitor 6, a deformation determination unit for determining the shape change of the elements of the steel tower 1 may be provided, and the coating portion is peeled off such as deformation, cracks, breakage, etc. of the structure constituting the steel tower 1. The shape change corresponding to deformation, cracking, breakage, etc. of the welded part, such as missing of a fastening member such as a screw, nut 10, bolt 11 and washer 12, etc., can be determined based on the reference shape. Also good. In addition to the monitor 6, a combination of a looseness determination unit and a color change determination unit may be provided as an observation device. As an observation device, in addition to the monitor 6, a combination of a looseness determination unit and a deformation determination unit may be provided. As an observation apparatus, in addition to the monitor 6, a combination of a color change determination unit and a deformation determination unit may be provided. In addition to the monitor 6, a combination of a looseness determination unit, a color change determination unit, and a deformation determination unit may be provided as an observation device.

An inspection method for the tower 1 according to the first embodiment will be described.
The video camera 4 is installed at one of the four outer peripheral installation positions P1.
Next, the outer periphery of the steel tower 1 is photographed and the photographed image is recorded. First, the leg portion 7 of the steel tower 1 is photographed. As shown in FIG. 5, in this photographing, the video camera 4 is continuously photographed while turning the video camera 4 from the bottom to the top of the leg 7, and the images thus photographed are recorded on the recording device 5. To record. Thereafter, the skeleton member 8 located in the right range of the leg portion 7 is photographed from the outer peripheral installation position P1 where the video camera 4 is installed toward the steel tower 1. As shown in FIGS. 2 and 6, in this shooting, the video camera 4 is directed from the bottom to the top so as to repeatedly draw a Z-shape and / or a U-shape with respect to the range on the right side of the leg 7. The skeleton member 8 on the right side of the leg 7 is continuously photographed while turning, and the image thus photographed is recorded in the recording device 5. Thereafter, the skeleton member 8 located in the left range of the leg portion 7 is photographed from the outer peripheral installation position P1 where the video camera 4 is installed toward the steel tower 1. As shown in FIGS. 2 and 6, in this shooting, the video camera 4 is swung upward from below so as to repeatedly draw a Z-shape or a U-shape with respect to the left side range of the leg portion 7. Then, the skeleton member 8 on the left side of the leg 7 is continuously photographed, and the photographed image is recorded in the recording device 5.
Next, the antenna 9 attached to the tower 1 is photographed, and the photographed image is recorded. The antenna 9 is continuously photographed with the video camera 4 facing the upper antenna 9, and the images thus photographed are recorded in the recording device 5. It should be noted that, particularly when the antenna 9 is photographed, it is preferable that the fastening member, cable, connector and the like of the antenna 9 are photographed.
As described above, the video camera 4 shoots the steel tower 1, the antenna 9, and the like, and records the shot images in the recording device 5 at the other positions in the four outer peripheral installation positions P 1.
Further, the video camera 4 was installed at the internal installation position P2, and the inside of the tower 1 was continuously photographed while the video camera 4 was swung from the horizontal direction and from the bottom to the top. The image is recorded in the recording device 5.
An image recorded in the recording device 5 by these operations is displayed on the monitor 6, and the operator observes the state change of the tower 1.

  Changes in the state of the tower 1 include deformation, cracks, breakage, rust, etc. of the structure constituting the tower 1, loosening, omission, rust, etc. of the fastening members such as screws, nuts 10, bolts 11, washers 12, etc. If the welded part is deformed, cracked, damaged, rusted, etc., such as peeling or discoloration of the paint part, etc., the steel tower 1 is repaired. In order to confirm the looseness of the nut 10, the nuts 10 of the upper part 13 are photographed and observed with respect to 70% or more of the total number of the nuts. About the nut 10 of the intermediate part 14, 75% or more of the nut 10 is image | photographed and observed with respect to the total number. About the nut 10 of the lower part 15, 80% or more of nuts 10 are image | photographed and observed with respect to the total number. Furthermore, when the distance h of the gap G between the nut 10 and the nut mounting surface 1c of the tower 1 is equal to or greater than a predetermined distance threshold value, it is determined that the nut 10 has become loose.

  As described above, according to the first embodiment of the present invention, it is easy to transport and install the equipment of the video camera 4, and the inspection work can be completed on the ground 2 where it is easy to maintain a stable state. There is no need to carry and install a heavy weight scaffold around the communication tower as in the past, and it is not necessary for the worker to climb the tower. For example, when the entire tower 1 is inspected, the worker has a wide range. No need to move. As a result, work time can be shortened, work can be simplified, work efficiency can be improved, and cost can be reduced. In particular, since the video camera 4 is installed at the outer periphery installation position P1 of the tower 1 on the ground 2, the inspection of the wide range such as the entire tower 1 from the outer periphery installation position P1 on the ground 2 that can maintain a stable state is omitted. You can shoot reliably and accurately. Since the image thus captured is recorded and the state change of the pylon 1 can be observed based on the recorded image in a stable place other than the pylon while being compared with data that is a criterion for the state change. Work can be simplified, and a wide range of the tower 1 can be inspected reliably and with high accuracy without leakage. By simplifying the work in this way, even an inexperienced worker can easily carry out the inspection work, and much labor, cost, and time for raising the worker can be reduced. Therefore, it is possible to remarkably improve the work efficiency and significantly reduce the cost as compared with the conventional case. Furthermore, since it is only necessary to secure a space at the outer peripheral installation position P1 where the video camera 4 is installed on the outer peripheral side of the steel tower 1, it is not necessary to secure a space for storing materials for the scaffold as in the conventional case. In comparison, the inspection work can be carried out efficiently within a limited range.

  According to 1st Embodiment of this invention, since the video camera 4 is installed in the internal installation position P2 located in the inside of the steel tower 1, it can image | photograph reliably and with high precision about the inside of the steel tower 1, As a result, a wide range of the steel tower 1 can be inspected reliably and with high accuracy without leakage.

  According to the first embodiment of the present invention, since the video camera 4 is a high-sensitivity camera, the tower 1, particularly the upper part 13 of the communication tower 1 at a position away from the ground 2 is photographed with high accuracy. The tower 1 can be inspected with high accuracy.

  According to 1st Embodiment of this invention, since the discoloration or shape change of the surface of the element provided in the steel tower 1 can be inspected as the state change of the steel tower 1, the deformation | transformation of the structure which comprises the steel tower 1, a crack, damage Rust, discoloration of plated parts, peeling of paint parts, discoloration, etc., missing of fastening members such as screws, nuts 10, bolts 11, washers 12, etc., deformation of welded parts, cracks, breakage, rust, etc. Can be checked reliably.

[Second Embodiment]
A tower inspection system and inspection method according to a second embodiment of the present invention will be described below. The inspection system and inspection method for the tower according to the second embodiment are basically the same as the inspection system and inspection method for the tower according to the first embodiment. Elements similar to those in the first embodiment will be described using the same symbols and names as those in the first embodiment. Here, a configuration different from the first embodiment will be described.

  In the second embodiment, the same inspection system 3 as in the first embodiment is used. In the second embodiment, as shown in FIG. 7, the steel tower 21 has a skeleton member 22 that extends upward from the ground 2 and is formed in a columnar shape. It has a circular shape with 21a. Three antenna columns 23 are provided on the outer periphery of the steel tower 21 and are spaced apart from each other in the circumferential direction. Although not particularly illustrated, the antenna column 23 is attached to the upper part or middle part of the steel tower 21 divided in the same manner as in the first embodiment. Furthermore, a plurality of nuts 10 are attached to the steel tower 21 as fastening members. The steel tower 21 is subjected to welding, plating, painting, and the like.

The installation position of the video camera 4 will be described.
Referring to FIG. 7, the video camera 4 is installed at three outer peripheral installation positions P3 located on the outer peripheral side of the steel tower 21 on the ground 2. The three outer circumferential installation positions P3 are located in the middle between the antenna columns 23 in the circumferential direction, and are located at a predetermined distance d from the base outer circumference of the steel tower 21 as in the first embodiment (not shown). ).

An inspection method for the tower 21 according to the second embodiment will be described.
The video camera 4 is installed at one of the three outer peripheral installation positions P3.
Next, the steel tower 21 is photographed and the photographed image is recorded. First, the skeleton member 22 located between the antenna columns 23 of the steel tower 21 is photographed. Similar to the photographing of the skeleton member 8 of the first embodiment, in this photographing, the video camera 4 repeatedly draws the Z shape and / or the U shape with respect to the inspection range of the skeleton member 22 of the steel tower 21. The frame member 22 of the steel tower 21 is continuously photographed while turning from below to above, and the image thus photographed is recorded in the recording device 5. Thereafter, the antenna pillar 23 on the right side is photographed from the outer peripheral installation position P3 where the video camera 4 is installed toward the steel tower 21. As with the shooting of the legs 7 of the first embodiment, the video camera 4 is continuously shot from the lower side of the right antenna column 23 while the right side of the antenna column 23 is continuously shot. The captured image is recorded in the recording device 5. Thereafter, the antenna pillar 23 on the left side is photographed from the outer peripheral installation position P3 where the video camera 4 is installed toward the steel tower 21. As with the shooting of the legs 7 of the first embodiment, the left antenna column 23 is continuously shot while the video camera 4 is swung from the lower side of the left antenna column 23 upward. The captured image is recorded in the recording device 5.
In this way, photographing the steel tower 21 by the video camera 4 and recording the photographed image on the recording device 5 are repeatedly performed at other positions in the three outer peripheral installation positions P3.

  As described above, according to the second embodiment of the present invention, the same effect as in the first embodiment can be obtained.

  Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

  For example, as a first modification of the present invention, only the antenna 9 of the tower 1 or only the antenna column 23 of the tower 21 may be inspected in the first embodiment or the second embodiment. Even when only the antenna 9 or the antenna column 23 that performs an important function in the steel towers 1 and 21 is inspected, the work time can be shortened, the work can be simplified, and the work efficiency can be improved and the cost can be reduced.

  As a second modification of the present invention, the cross section of the steel tower 1 of the first embodiment may be a polygon other than a square shape. In this case, the outer peripheral installation position of the video camera 4 may be located corresponding to the polygonal corner of the cross section. The same effect as the first embodiment can be obtained.

  As a third modification of the present invention, the internal installation positions P2 of the video camera 4 of the first embodiment may be located at a plurality of locations around the center 1b of the steel tower 1. The same effect as the first embodiment can be obtained.

  As an inspection method using the video camera 4 installed at the outer peripheral installation position P1 in the first embodiment as a fourth modification of the present invention, the leg 7 of the tower 1, the range on the left side of the leg 7, the leg 7 Shooting and recording may be performed in the order of the range on the right side. Photographing and recording may be performed in the order of the left range of the steel tower 1, the leg portion 7, and the right range of the leg portion 7. Photographing and recording may be performed in the order of the left range of the steel tower 1, the right range of the leg 7, and the leg 7. Photographing and recording may be performed in the order of the range on the right side of the steel tower 1, the leg portion 7, and the range on the left side of the leg portion 7. Photographing and recording may be performed in the order of the range on the right side of the steel tower 1, the left side of the leg 7, and the range of the leg 7. In addition, before shooting and recording using the video camera 4 installed at the outer peripheral installation position P1, shooting or recording using the video camera 4 installed at the internal installation position P2 may be performed. The same effect as the first embodiment can be obtained.

  As a fifth modification of the present invention, the number of outer peripheral installation positions P3 of the video camera 4 of the second embodiment may be four or more. The same effect as the second embodiment can be obtained.

  As a sixth modification of the present invention, in the second embodiment, the video camera 4 is installed at an internal installation position located at the center 21a of the steel tower 21 on the ground 2 and the steel tower 21 is installed by the video camera 4 thus installed. The inside may be photographed. Further, the internal installation positions may be located at a plurality of locations around the center 21a of the steel tower 21. Shooting or recording using the video camera 4 installed at such an internal installation position may be performed before or after shooting and recording using the video camera 4 installed at the outer circumferential installation position P3. The inside of the tower 21 of the second embodiment can also be photographed reliably and with high accuracy without leakage, and as a result, a wide range of the tower 21 can be inspected with certainty and high accuracy without leakage.

  As a seventh modification of the present invention, in the inspection method of the second embodiment, photographing and recording may be performed in the order of the skeleton member 22 of the steel tower 21, the left antenna column 23, and the right antenna column 23. Photographing and recording may be performed in the order of the right antenna column 23, the skeleton member 22 of the steel tower 21, and the left antenna column 23. Photographing and recording may be performed in the order of the right antenna column 23, the left antenna column 23, and the skeleton member 22 of the steel tower 21. Photographing and recording may be performed in the order of the left antenna column 23, the skeleton member 22 of the steel tower 21, and the right antenna column 23. Photographing and recording may be performed in the order of the left antenna column 23, the right antenna column 23, and the skeleton member 22 of the steel tower 21. The same effect as the second embodiment can be obtained.

  As an eighth modification of the present invention, in the first embodiment and the second embodiment, the photographing apparatus may be other than the video camera 4. For example, the imaging device may be a camera that captures a still image. The same effects as those in the first embodiment and the second embodiment can be obtained.

  As a ninth modification of the present invention, in the first and second embodiments, a plurality of video cameras 4 are installed at an outer peripheral installation position and / or an internal installation position, and the plurality of video cameras 4 are simultaneously installed in a steel tower. One inspection range may be photographed. Inspection time can be shortened and inspection work can be made more efficient.

[Example 1]
Example 1 using the inspection method according to the first embodiment of the present invention will be described. The steel tower 1 is a standard 40-meter-high angle steel tower, and each part B1-B17 of such a steel tower 1 was image | photographed with the inspection method which concerns on 1st Embodiment. In addition, the distance d between the outer periphery installation position P1 and the root outer periphery of the steel tower 1 was 2.5 m. As a result, the ratio T of the number of nuts 10 that could be photographed with respect to the total number of nuts 10 in each part B1 to B17 was a value as shown in Table 2.

  According to Table 2, in the inspection method of the present invention, the video camera 4 installed on the ground 2 was able to photograph 80% or more of the nut 10 in the entire tower 1.

[Example 2]
Example 2 using the inspection method according to the first embodiment of the present invention will be described. In a state where the optical axis 4a of the video camera 4 is 60 degrees with respect to the nut mounting surface 1c, a gap G is formed between the nut 10 and the nut 10 biased toward the nut mounting surface 1c. The case where it was formed and the case where the gap G was not formed were photographed. In Example 2, the nut 10 is M22, the distance threshold of the gap G is set to 2 mm, and the distance h of the gap G is set to 2 mm. As a result of such photographing, when the angle w is 60 degrees, the nut 10 that does not have a gap and does not loosen is clearly distinguished from the nut 10 that has a gap and has loosened, It was observed that the nut was loosened.

DESCRIPTION OF SYMBOLS 1 Steel tower 1a Corner part 2 Ground 3 Inspection system 4 Video camera 5 Recording apparatus 6 Monitor 9 Antenna 10 Nut 11 Bolt 12 Washer 13 Upper part 14 Middle part 21 Steel tower 23 Antenna pillars B1-B17 Site G Clearance P1, P3 Outer periphery installation position P2 Inside Installation position d, h Distance w Angle

Claims (8)

In the method of checking the state change that occurs in the communication tower installed on the ground,
A plurality around the base of the communication tower on the ground , spaced apart from the outer periphery of the communication tower in the direction from the center of the communication tower toward the outer periphery, and spaced in the circumferential direction of the communication tower the outer circumference installation position of the steps for installing the shooting device,
The installed photographing apparatus is turned so that its optical axis is directed to at least one of a region in a direction horizontal to the ground and a region on the upper side with respect to the horizontal direction, and is directed to the inspection range of the communication tower. Photographing the inspection range with the photographing device in a state;
Recording an image obtained by the photographing;
Observing a state change of the communication tower based on the recorded image.   The method according to claim 1, wherein, when the communication tower has a polygonal cross section, the plurality of outer peripheral installation positions correspond to corners of the polygonal cross section.   The method according to claim 1, wherein when the communication tower has a circular cross section, the plurality of outer peripheral installation positions are at least three.   The method according to any one of claims 1 to 3, further comprising using an imaging device installed at an internal installation position located in the center of the communication tower on the ground in the imaging step.   The method as described in any one of Claims 1-4 which checks the state change which generate | occur | produces in the load for communication attached to the upper part or intermediate part of the height direction of the said communication tower.   The method according to claim 1, wherein a high-sensitivity video camera is used as the photographing device.   The method according to any one of claims 1 to 6, wherein the state change of the communication tower is a loosening of a fastening member provided in the communication tower. The method according to any one of claims 1 to 6, wherein the state change of the communication tower is a color change or a shape change of a surface of an element provided in the communication tower.

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