JP2021188969A - Measuring system and measuring method - Google Patents

Abstract

To provide a measuring system and a measuring method capable of evaluating electromagnetic wave passage performance of a variety of lids, including lids for underground structures.SOLUTION: A measuring system 10 comprises: a housing 12 that houses a device 11 for generating an electromagnetic wave; an aperture 13 provided on the housing 12; a lid 14 installed to be attachable to and detachable from the aperture 13; and a measuring device 15 for measuring the electromagnetic wave passing via the aperture 13 covered with the lid 14 to evaluate electromagnetic wave passage performance of the lid 14. A measuring method includes: installing the lid 14 to be attachable to and detachable from the aperture 13 provided on the housing 12 where the device 11 for generating an electromagnetic wave is housed; and measuring the electromagnetic wave passing via the aperture 13 covered with the lid 14 so as to evaluate electromagnetic wave passage performance of the lid 14.SELECTED DRAWING: Figure 1

Description

The present invention relates to a measuring system and a measuring method capable of evaluating electromagnetic wave passing characteristics of a wide variety of lids including lids for underground structures.

In recent years, for underground structures, between a device that generates radio waves installed in an underground structure (for example, a wireless communication device) and a device that receives radio waves installed on the ground (for example, a wireless base station). Communication via a lid has been studied (for example, Patent Documents 1 and 2).
However, Patent Documents 1 and 2 do not describe evaluation of radio wave passing characteristics of a lid for an underground structure.

Japanese Unexamined Patent Publication No. 11-066484 Japanese Unexamined Patent Publication No. 2018-067165

The present invention provides a measuring system and a measuring method capable of evaluating the electromagnetic wave passing characteristics of a wide variety of lids including lids for underground structures.

One aspect of the present invention is to evaluate the electromagnetic wave passage characteristics of a housing that houses a device that generates electromagnetic waves, an opening provided in the housing, a lid that is detachably attached to the opening, and a lid. It is a measurement system including a measuring device for measuring an electromagnetic wave passing through an opening covered with a lid.

In this measurement system, the lid can be detachably attached to the opening provided in the housing. Therefore, only the lid can be changed to a desired condition without changing the conditions other than the lid (for example, the shape, structure, material, etc. of the opening and the housing). In addition, the measuring device can measure the electromagnetic waves passing through the opening covered by the lid. Therefore, it is possible to appropriately evaluate the electromagnetic wave passage characteristics of the lid, including the difference in how the opening is covered due to the difference in the shape, structure, material, and the like of the lid. Therefore, it is possible to provide a measurement system capable of evaluating the electromagnetic wave passing characteristics of a wide variety of lids including lids for underground structures.

The lid may include a through hole that penetrates a position eccentric from the central axis of the lid, in which case the measurement system rotates the housing around the central axis of the lid with respect to the central axis of the lid. It is preferable to further include a rotating device that changes the rotation angle of the through hole.
The lid may also include a non-circular through hole that penetrates the central axis of the lid, again the measurement system by rotating the housing around the central axis of the lid to center the lid. It is more preferable to further include a rotating device that changes the rotation angle of the through hole with respect to the shaft.
According to this rotating device, by rotating the housing around the central axis of the lid instead of around the central axis of the housing, the central axis of the lid is not affected by the positional relationship of the openings provided in the housing. The rotation angle (position, orientation) of the through hole can be arbitrarily changed. Therefore, it is possible to measure the electromagnetic wave in a state where the position and orientation of the through hole are rotated 360 degrees around the central axis of the lid. Therefore, even if the type of lid contains a through hole eccentric from the central axis of the lid or the type of lid contains a non-circular through hole that penetrates the central axis of the lid, it is caused by the difference in the position and orientation of the through hole. It is possible to appropriately evaluate the effect on the electromagnetic wave passage characteristics.

The housing may include a conductive lid receiving member having an opening, and the lid receiving member may include a lid mounting portion to which the lid is attached. By attaching the lid to the conductive lid receiving member, it becomes easy to reduce the influence of the electromagnetic wave passing through the lid receiving member, so that it is easy to accurately evaluate the electromagnetic wave passing characteristic of the lid itself.

The housing may include a dielectric position adjusting member that supports the conductive lid receiving member in a position adjustable manner, and an electromagnetic wave shielding material arranged on the inner wall or the outer wall of the position adjusting member. It is possible to evaluate the influence on the electromagnetic wave passing characteristics due to the difference in the mounting position of the lid (for example, the height of the lid) with a simple configuration.

The housing may include a dielectric lid receiving member having an opening and an electromagnetic wave shielding material arranged on an inner wall or an outer wall of the lid receiving member. By arranging the electromagnetic wave shielding material on the inner wall or the outer wall of the lid receiving member, it becomes easy to reduce the influence of the electromagnetic wave passing through the lid receiving member, so that the electromagnetic wave passing characteristic of the lid itself can be easily evaluated with a simple configuration.

Another aspect of the present invention is to detachably attach a lid to an opening provided in a housing accommodating a device that generates electromagnetic waves, and to be covered with a lid to evaluate the electromagnetic wave passage characteristics of the lid. It is a measurement method including measuring an electromagnetic wave passing through an opening.

Measuring involves measuring electromagnetic waves while rotating the housing around the central axis so that the angle of rotation of the through hole through the eccentric position from the central axis of the lid changes with respect to the central axis. It is preferable to include measuring the electromagnetic wave while rotating the housing around the central axis so that the rotation angle of the non-circular through hole penetrating the axis with respect to the central axis changes.

According to the present invention, it is possible to evaluate the electromagnetic wave passage characteristics of a wide variety of lids including lids for underground structures.

The schematic diagram of the measurement system which is 1st Embodiment of this invention. The schematic diagram which shows the modification of 1st Embodiment. The schematic diagram of the measurement system which is the 2nd Embodiment of this invention. Schematic plan view of the lid of the second embodiment. The schematic diagram which shows the modification of 2nd Embodiment. An example of the evaluation result of the electromagnetic wave transmission characteristic of the lid by the measurement system of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Here, the term "closure" as used herein refers to the fields of underground buried objects in sewers, manhole lids that block openings through underground structural facilities, etc. and the ground, large iron lids, sewage basin lids, and power / communication fields. Openable and closable iron lids for common grooves to protect underground facility equipment and underground cables, power transmission iron lids, power distribution iron lids, buried conduits under the road surface in waterworks and gas pipes, and opening and closing connecting their accessories to the ground. In addition to fire extinguishing plug lids, water control valve lids, sluice valve lids, air valve lids, gas piping lids, water meter lids, etc. (collectively referred to as "underground structure lids") that function as doors, rainwater Includes lids such as grating (lattice) that cover the boxes and side grooves.
Further, the "electromagnetic wave" as used herein means a wave of energy transmitted through space while electric and magnetic fields such as radiation, light, and radio waves affect each other.

FIG. 1 shows an outline of the measurement system 10 according to the first embodiment of the present invention.
The measurement system 10 includes a housing 12 that houses a device (electromagnetic wave generator) 11 that generates electromagnetic waves, an opening 13 provided in the housing 12, a lid 14 that is detachably attached to the opening 13, and a lid. A measuring device 15 for measuring an electromagnetic wave passing through an opening 13 covered with a lid 14 in order to evaluate the electromagnetic wave passing characteristic of the 14 is provided.
The measurement system 10 is installed in a space that is not easily affected by electromagnetic waves due to the external environment (for example, a room having a depth of 7 m, a width of 3 m, and a height of 3 m in which an electromagnetic wave shield is applied to the entire wall surface).

The electromagnetic wave generator 11 housed in the housing 12 includes a battery-powered electromagnetic wave generator (not shown) that generates electromagnetic waves in a frequency band from 1 MHz to 6 GHz at a fixed frequency interval (1 MHz, 5 MHz or 10 MHz). It is equipped with a dipole antenna (not shown) that radiates the electromagnetic wave.

The housing 12 is box-shaped with a circular opening 13 at the top, and is made of a conductive material. Further, the opening portion 13 includes a lid mounting portion 12-1. In this embodiment, the housing 12 is installed on a gantry (desk) 16.

The lid 14 is of a type that is circular and does not include a through hole penetrating the lid 14, and the material thereof is spheroidal graphite cast iron.

The measuring device 15 measures the electromagnetic wave passing through the opening 13 covered with the lid 14 in order to evaluate the electromagnetic wave passing characteristic of the lid 14. In the present embodiment, the measuring device 15 is arranged outside the housing 12 at a position 3 m (reference numeral LL1 in FIG. 1) from the central axis C of the lid so that the height can be changed. Further, an electromagnetic wave absorber 18 is arranged between the opening 13 and the measuring device 15.

As described above, in the measurement system 10 of the present embodiment, the lid 14 can be detachably attached to the lid attachment portion 12-1 provided on the housing 12. Therefore, only the lid 14 can be changed to a desired condition without changing the conditions other than the lid 14 (for example, the shape, structure, material, etc. of the opening 13 and the housing 12). Further, the measuring device 15 can measure the electromagnetic wave passing through the opening 13 covered by the lid 14.
Therefore, the electromagnetic wave passage characteristics of the lid 14 can be appropriately evaluated, including the difference in the covering method of the opening 13 due to the difference in the shape, structure, material, and the like of the lid 14. Therefore, it is possible to evaluate the electromagnetic wave passage characteristics of a wide variety of lids including lids for underground structures.
The "electromagnetic wave passing characteristic" referred to in the present specification refers to the frequency and the position of the measuring device 15 with respect to the electromagnetic wave passing through the opening 13 of the housing 12 covered with the lid 14 as measured by the measuring device 15. It refers to the peculiar property of quantitatively measuring the electric field strength and the like that change depending on the difference in the covering method of the opening 13 due to the difference in the shape, structure, material and the like of the lid.

In this embodiment, the housing 12 is made conductive, but the housing 12 can also be made dielectric (for example, plastic). In this case, for example, as shown in FIG. 2, it is preferable to arrange the electromagnetic wave shielding material 12c (for example, an aluminum plate) on the inner wall of the dielectric housing 12. The inner wall of the housing 12 includes an inner surface 12-2 of the side wall and an inner surface 12-3 of the bottom wall. As a result, it becomes easy to reduce the influence of the electromagnetic wave passing through the dielectric housing 12, and it becomes easy to evaluate the electromagnetic wave passing characteristic of the lid 14 itself with a simple configuration.
The electromagnetic wave shielding material 12c may be arranged on the outer wall of the dielectric housing 12. The outer wall of the housing 12 includes the outer surface 12-4 of the side wall and the outer surface 12-5 of the bottom wall.
Further, although the opening 13 is provided in the upper part of the housing 12 in the present embodiment, the opening 13 can also be provided in the side portion of the housing 12.
Further, in the present embodiment, the housing 12 is provided with a circular opening 13, but for example, the opening 13 can be a square shape such as a quadrangle, and the housing 12 is not a box type but a cylinder type, for example. You can also do it.
Further, the upper portion of the housing 12 may be a lid receiving member having an opening 13 and a lid mounting portion 12-1.

FIG. 3 shows an outline of the measurement system 10A according to the second embodiment of the present invention.
The measurement system 10A evaluates the electromagnetic wave passing characteristics of the housing 12A accommodating the electromagnetic wave generator 11, the opening 13A provided in the housing 12A, the lid 14A detachably attached to the opening 13A, and the lid 14A. A measuring device 15 for measuring an electromagnetic wave passing through an opening 13A covered with a lid 14A and a rotating device 17 are provided.
Also in this embodiment, the entire measurement system 10A is installed in a space that is not easily affected by electromagnetic waves from the external environment.
In this embodiment, the electromagnetic wave generator 11 and the measuring device 15 have the same configuration as that of the first embodiment.

FIG. 4 is a schematic plan view of the lid 14A of the present embodiment. The lid 14A is a circular shape and is of a rainwater inflow type including a plurality of arcuate through holes 14a penetrating a position eccentric from the central axis C, and the material thereof is spheroidal graphite cast iron.

The housing 12A of the present embodiment includes a conductive lid receiving member 12a having a circular opening 13A, and the lid receiving member 12a includes a lid mounting portion 12a-1 for attaching the lid 14A. In the present embodiment, the lid receiving member 12a corresponds to a circular receiving frame that supports the lid for the underground structure, and the material thereof is spheroidal graphite cast iron like the lid 14A. That is, in the present embodiment, the lid receiving member 12a is conductive.

The housing 12A of the present embodiment has a lid receiving member so that the influence on the electromagnetic wave passing characteristics due to the difference in the mounting position of the lid 14A (for example, the height of the lid 14A) can be evaluated with a simple configuration. A cylindrical position adjusting member 12b that supports the position 12a so that the position can be adjusted, and an inner wall 12b-1 and a lower end opening 12b- of the position adjusting member 12b in order to easily reduce the influence of electromagnetic waves passing through the position adjusting member 12b. Includes the electromagnetic wave shielding material 12c arranged in 2.
In the present embodiment, the position adjusting member 12b imitates the lower basin of a manhole (human hole) which is an underground structure, and the material thereof is resin concrete. That is, in the present embodiment, the position adjusting member 12b is dielectric.
The electromagnetic wave shielding material 12c is, for example, an aluminum plate. In the present embodiment, the electromagnetic wave shielding material 12c is arranged on the inner wall 12b-1 and the lower end opening 12b-2 of the position adjusting member 12b, but the outer wall 12b-3 and the lower end opening 12b-2 of the position adjusting member 12b are included. The electromagnetic wave shielding material 12c may be arranged on the bottom surface 12b-4.

The housing 12A is installed on the rotating device 17. The rotating device 17 changes the rotation angle of the through hole 14a with respect to the central axis C by rotating the housing 12A around the central axis C of the lid 14A.
In the present embodiment, the height H1 of the rotating device 17 is 800 mm, the height H2 of the position adjusting member 12b is 200 mm, and the height H3 of the lid receiving member 12a is 110 mm.

In the present embodiment, the electromagnetic wave generator 11 is installed on the electromagnetic wave shielding material 12c of the lower end opening 12b-2 so as to be housed in the cylindrical position adjusting member 12b of the housing 12A.

Further, the measurement system 10A of the present embodiment includes a rotating device 17, which rotates the housing 12A not around the central axis C1 of the housing 12A but around the central axis C of the lid 14A. Thereby, the rotation angle (position) of each through hole 14a with respect to the central axis C of the lid 14A can be arbitrarily changed without being affected by the shape of the housing 12A and the positional relationship of the opening 13A provided in the housing 12A. Can be done. Therefore, it is possible to measure the electromagnetic wave in a state where the position of each through hole 14a is rotated 360 degrees around the central axis C of the lid 14A. Therefore, even in the case of the type of lid 14A including a plurality of through holes 14a eccentric from the central axis C, the influence on the electromagnetic wave passage characteristics due to the difference in the position of each through hole 14a can be appropriately evaluated.
In the present embodiment, the central axis C of the lid 14A (the central axis of the opening 13A), the central axis C1 of the housing 12A, and the rotation central axis C2 of the rotating device 17 all match, but the central axis of the lid 14A. The measurement system 10A can be applied even when C (the central axis of the opening 13A) and the central axis C1 of the housing 12A do not match and are displaced. That is, if the central axis C of the lid 14A (the central axis of the opening 13A) and the rotation central axis C2 of the rotating device 17 match, the rotating device 17 rotates the housing 12A around the central axis C of the lid. Can be done.
Further, in the present embodiment, the lid 14A is a type including a plurality of through holes 14a eccentric from the central axis C, but a non-circular through hole penetrating the central axis C of the lid (for example, a C-shape or an I-shape) It can also be a type that includes an arc shape, etc.). Also in this case, the rotation center axis C2 of the rotation device 17 and the center axis C of the lid are aligned with each other, and the housing 12A is rotated around the center axis C of the lid by the rotation device 17, which is caused by the difference in the orientation of the through holes. It is possible to appropriately evaluate the effect on the electromagnetic wave passage characteristics.

As described above, also in the measurement system 10A of the present embodiment, the lid 14A can be detachably attached to the opening 13A provided in the housing 12A. Therefore, only the lid 14A can be changed to a desired condition without changing the conditions other than the lid 14A (for example, the shape, structure, material, etc. of the opening 13A and the housing 12A). Further, the measuring device 15 can measure the electromagnetic wave passing through the opening 13A covered by the lid 14A.
Therefore, the electromagnetic wave passage characteristics of the lid 14A can be appropriately evaluated, including the difference in the covering method of the opening 13A due to the difference in the shape, structure, material, and the like of the lid 14A. Therefore, it is possible to evaluate the electromagnetic wave passage characteristics of a wide variety of lids including lids for underground structures.

In the present embodiment, the housing 12A is configured to include the conductive lid receiving member 12a and the dielectric position adjusting member 12b, but the present invention is not limited to this, and the position adjusting member 12b can be omitted. However, in this case, as shown in FIG. 5, it is preferable to arrange the electromagnetic wave shielding material 12c in the lower end opening portion 12a-2 of the conductive lid receiving member 12a. Further, the lid receiving member 12a may be made dielectric. In this case, in order to facilitate the reduction of the influence of the electromagnetic wave passing through the dielectric lid receiving member 12a, the electromagnetic wave shielding material 12c is arranged on the inner wall or the outer wall of the lid receiving member 12a in addition to the lower end opening of the lid receiving member 12a. It is preferable to do so.
Further, in the present embodiment, the position adjusting member 12b is dielectric and cylindrical, but the position adjusting member 12b may be dielectric and box-shaped as in the housing 12 shown in FIG.

The materials of the lids 14, 14A, the housing 12, the lid receiving member 12a, the position adjusting member 12b, and the electromagnetic wave shielding material 12c constituting the housing 12A are not limited to the above-described embodiment, and in the case of conductivity, the material is not limited to the above-described embodiment. For example, it may be spheroidal graphite cast iron, steel, aluminum or the like, and in the case of dielectric, it may be, for example, resin concrete, cement, rubber, plastic or the like.

As described with reference to FIGS. 1 to 5, first, the lid 14 is detachably attached to the opening 13 provided in the housing 12 accommodating the device 11 for generating electromagnetic waves, and then the measuring device 15 is used. By measuring the electromagnetic waves passing through the opening 13 covered with the lid 14 in order to evaluate the electromagnetic wave passing characteristics of the lid 14, the electromagnetic wave passing characteristics of a wide variety of lids including lids for underground structures can be obtained. Can be evaluated.
Further, when the lid 14A includes a through hole 14a penetrating the position eccentric from the central axis C of the lid 14A, the penetrating through the position eccentric from the central axis C of the lid 14A when measuring the electromagnetic wave. A type including a through hole 14a eccentric from the central axis C of the lid 14A by measuring electromagnetic waves while rotating the housing 12A around the central axis C of the lid 14A so that the rotation angle of the hole 14a with respect to the central axis C changes. Even with the lid of the above, the influence on the electromagnetic wave passing characteristics due to the difference in the position of the through hole 14a can be appropriately evaluated.
Further, when a non-circular through hole penetrating the central axis C is included, the rotation angle of the non-circular through hole penetrating the central axis C of the lid 14A with respect to the central axis C changes when measuring the electromagnetic wave. By measuring the electromagnetic wave while rotating the housing 12A around the central axis C of the lid 14A, even if the lid has a non-circular through hole penetrating the central axis of the lid 14A, the direction of the through hole is different. It is possible to appropriately evaluate the effect on the electromagnetic wave passage characteristics due to this.

FIG. 6 shows an example of the result of evaluating the electromagnetic wave passing characteristic of the lid 14A shown in FIG. 4 by the measurement system 10A shown in FIG. Specifically, the height of the measuring device 15 is 150 cm from the floor surface, the frequency of the radio wave radiated by the electromagnetic wave generator 11 is 920 MHz, and the rotating device 17 is rotated 360 degrees at a pitch of 5 degrees to measure the electric field strength of the radio waves. Then, a directional characteristic diagram (a graph showing an electric field strength of 360 degrees) was created. According to the directivity diagram of FIG. 6, it can be seen that there is an angle at which the electric field strength is weakened in the shape of the lid 14A shown in FIG. In this way, it is possible to evaluate the electromagnetic wave passage characteristics of a wide variety of lids.
In this example, the electromagnetic wave passage characteristics are evaluated by the directivity diagram, but the present invention is not limited to this.

10, 10A measurement system 11 Device to generate electromagnetic waves (electromagnetic wave generator)
12, 12A Housing 12-1 Closure mounting part 12-2 Inner surface of side wall 12-3 Inner surface of bottom wall 12-4 Outer surface of side wall 12-5 Outer surface of bottom wall 12a Cover receiving member 12a-1 Closure mounting part 12a-2 Lower end Opening 12b Position adjustment member 12b-1 Inner wall 12b-2 Lower end opening 12b-3 Outer wall 12b-4 Bottom surface 12c Electromagnetic wave shielding material 13, 13A Opening 14, 14A Lid 14a Through hole 15 Measuring device 16 Stand (desk)
17 Rotating device 18 Electromagnetic absorber C Central axis of lid C1 Central axis of housing C2 Central axis of rotating device

Claims (9)

A housing that houses a device that generates electromagnetic waves,
The opening provided in the housing and
A lid that can be attached and detached to the opening,
A measurement system including a measuring device for measuring the electromagnetic wave passing through the opening covered with the lid in order to evaluate the electromagnetic wave passing characteristic of the lid. The lid includes a through hole that penetrates a position eccentric from the central axis of the lid.
The measuring system according to claim 1, further comprising a rotating device that changes the rotation angle of the through hole with respect to the central axis by rotating the housing around the central axis. The lid comprises a non-circular through hole that penetrates the central axis of the lid.
The measuring system according to claim 1, further comprising a rotating device that changes the rotation angle of the through hole with respect to the central axis by rotating the housing around the central axis. The housing comprises a conductive lid receiving member having the opening.
The measurement system according to any one of claims 1 to 3, wherein the lid receiving member includes a lid mounting portion for mounting the lid. The housing includes a dielectric position adjusting member that supports the lid receiving member in a position adjustable manner, and a dielectric position adjusting member.
The measuring system according to claim 4, further comprising an electromagnetic wave shielding material arranged on an inner wall or an outer wall of the position adjusting member. The housing has a dielectric lid receiving member having the opening and the housing.
The measuring system according to any one of claims 1 to 3, further comprising an electromagnetic wave shielding material arranged on an inner wall or an outer wall of the lid receiving member. A removable lid can be attached to the opening provided in the housing that houses the device that generates electromagnetic waves.
A measuring method comprising measuring the electromagnetic wave passing through the opening covered with the lid in order to evaluate the electromagnetic wave passing characteristic of the lid. The measurement includes measuring the electromagnetic wave while rotating the housing around the central axis so that the rotation angle of the through hole penetrating the eccentric position from the central axis of the lid changes with respect to the central axis. , The measuring method according to claim 7. The measurement includes measuring the electromagnetic wave while rotating the housing around the central axis so that the rotation angle of the non-circular through hole penetrating the central axis of the lid with respect to the central axis changes. The measuring method according to claim 7.

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