Monitoring methods

Abstract

To improve an environment of work of cutting a slab without cutting a girder located under the slab in a structure such as a bridge.SOLUTION: A monitoring method for monitoring a state of a structure including a girder extending in a horizontal direction and a plate-shaped body laid on the girder, includes: a step S11 of forming a hole penetrating the plate-shaped body in a direction perpendicular to an upper surface of the plate-shaped body at a position not overlapping with a region in which the girder extends in the plate-shaped body; a step S12 of inserting an imaging device having an imaging unit provided on a rod-shaped main body into the hole from above the plate-shaped body such that an imaging range of the imaging unit includes a point of contact between the girder and the plate-shaped body; and a step S13 of displaying a captured image generated by imaging by the imaging unit on a display device arranged above the plate-shaped body.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a monitoring method for monitoring the condition of a structure such as a bridge. [Background technology]

[0002] Patent Document 1 discloses a method of cutting a concrete deck slab using a cutter from above the deck slab and removing the cut deck slab. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-158124 Summary of the Invention [Problem to be solved by the invention]

[0004] In the construction of bridges and other structures, there is a need to cut only the deck slab without cutting the girders underneath. In this type of work, workers stationed below the deck slab have traditionally monitored the structure to ensure the girders were not cut. However, the space below the deck slab is a poor working environment for workers due to the dust and noise generated when cutting the deck slab. Furthermore, there is a risk of concrete fragments from deteriorated areas falling off when cutting the deck slab.

[0005] The present invention has been made in consideration of the above points, and aims to improve the work environment for cutting deck slabs in structures such as bridges without cutting the girders underneath the deck. [Means for solving the problem]

[0006] A monitoring method according to one aspect of the present invention is a method for monitoring the status of a structure including a girder extending horizontally and a plate-like body laid on the girder, and includes the steps of: forming a hole that penetrates the plate-like body in a direction perpendicular to the top surface of the plate-like body at a position that does not overlap with the area where the girder extends; inserting an imaging device having an imaging unit mounted on a rod-shaped main body into the hole from above the plate-like body so that the imaging range of the imaging unit includes the contact point between the girder and the plate-like body; and displaying the image generated by the imaging unit on a display device arranged above the plate-like body.

[0007] The structure may be a bridge, and the plate-like body may be a deck slab of the bridge.

[0008] The monitoring method further includes a step of cutting the plate-like body from above using a cutting device, and in the displaying step, the captured image may be displayed on the display device during or before cutting the plate-like body.

[0009] The imaging unit may capture an image of the imaging range including an area where an area where the girder extends intersects with a line along which the plate-like body is to be cut by the cutting device.

[0010] The monitoring method may further include the step of suspending the plate-shaped object after it has been cut by the cutting device by inserting a wire into the hole.

[0011] The imaging device may further include a drop prevention portion for preventing the imaging device from dropping when the imaging device is inserted into the hole facing downward in a direction perpendicular to the upper surface of the plate-like body.

[0012] In the displaying step, the captured image may be displayed on the display device in a state in which the imaging device inserted into the hole is supported by the fall prevention part.

[0013] The imaging device may further have an illumination unit that irradiates light around the imaging device, and in the displaying step, the captured image may be displayed on the display device while the illumination unit irradiates the light onto the contact point between the beam and the plate-like body.

[0014] The imaging device may further have a wireless communication unit that transmits the captured image to the display device, which is a communication terminal, and in the displaying step, the captured image may be displayed on the display device via wireless communication. [Effects of the Invention]

[0015] According to the present invention, it is possible to improve the work environment for cutting deck slabs in structures such as bridges without cutting the girders underneath the deck slabs. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a monitoring system according to an embodiment. [Figure 2] 1 is a schematic diagram for explaining the overall configuration of an imaging apparatus according to an embodiment. [Figure 3] FIG. 2 is a schematic diagram for explaining the configuration of an imaging unit. [Figure 4] FIG. 2 is a schematic diagram for explaining the configuration of an illumination unit. [Figure 5] FIG. 2 is a schematic diagram illustrating the configuration of a protective member. [Figure 6] 5A and 5B are schematic diagrams for explaining the configuration of a fall prevention unit. [Figure 7] FIG. 10 is a schematic diagram for explaining a method of forming a hole in a deck slab. [Figure 8] 10A and 10B are schematic diagrams for explaining a method of inserting an imaging device into a hole. [Figure 9] 10A and 10B are schematic diagrams for explaining a method of displaying a captured image on a communication terminal. [Figure 10] FIG. 1 is a flowchart illustrating a monitoring method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] [Overview of the monitoring system] 1 is a schematic diagram of a monitoring system according to this embodiment. The monitoring system is a system for monitoring the status of a structure such as a bridge, which includes a girder G extending horizontally and a deck S laid on the girder G. The monitoring system includes an imaging device 1 and a communication terminal 2. The monitoring system may include multiple imaging devices 1 and multiple communication terminals 2.

[0018] The deck S is a plate-like body that constitutes a structure such as a bridge. The deck S is, for example, a concrete deck. The deck S has a hole S1 that penetrates vertically to the top surface of the deck S. The hole S1 is formed, for example, by a core drill.

[0019] The deck S is laid on girders G extending horizontally. The girders G extending horizontally means that they are horizontal or approximately horizontal with respect to the ground, and includes being arranged at a slope of a predetermined angle (for example, an angle of 0 degrees or more and 10 degrees or less) with respect to the ground. If the structure is a bridge, the girders G extend in the extension direction of the road that the bridge constitutes. The girders G are, for example, steel girders. The cross section of the girders G has, for example, an I-shape, with flanges provided on the top and bottom. The cross section of the girders G may also have other shapes, such as a box-shape (rectangular shape) or a T-shape.

[0020] A worker uses a cutting device C to cut the deck slab S without cutting the girders G underneath the deck slab S. The cutting device C is, for example, a concrete cutter. The worker cuts the deck slab S by, for example, moving the cutting device C horizontally above the deck slab S.

[0021] The imaging device 1 is a device that captures images of the deck slab S during or before cutting by the cutting device C. When inserted into the hole S1, the imaging device 1 captures an image of an imaging range that includes the contact point between the girder G and the deck slab S. The imaging device 1 also has a fall prevention unit, which will be described later, and is configured so that it will not fall while inserted into the hole S1 even if it is not supported by a worker. The imaging device 1 transmits the captured image to the communication terminal 2 via wireless communication.

[0022] The communication terminal 2 is a computer used by a user above the deck S. The communication terminal 2 is a display device having a display unit such as a liquid crystal display for displaying the captured image generated by the imaging device 1. The communication terminal 2 is, for example, a smartphone, a tablet terminal, a personal computer, etc. The user of the communication terminal 2 is, for example, a worker performing work to cut the deck S. The user of the communication terminal 2 may also be a person other than the worker, such as a manager who manages the work.

[0023] An outline of a method for monitoring the status of a structure in the monitoring system according to this embodiment will be described below. A worker forms a hole S1 that penetrates the deck slab S in a direction perpendicular to the top surface of the deck slab S at a position on the deck slab S that does not overlap with an area where the girder G extends. The worker forms the hole S1 by, for example, using a core drill to drill a hole in the deck slab S in a direction perpendicular to the top surface of the deck slab S.

[0024] The worker inserts the imaging device 1 into the hole S1 from above the deck S so that the imaging range of the imaging device 1 includes the contact point between the girder G and the deck S. The imaging device 1 displays the captured image, which is generated by capturing an image of the imaging range including the contact point between the girder G and the deck S, on the communication terminal 2 placed above the deck S. The worker cuts the deck S using the cutting device C while referring to the captured image on the communication terminal 2.

[0025] With a monitoring system having such a configuration, workers do not need to monitor the underside of the deck S to prevent the girders G from being cut, and are therefore less susceptible to dust, noise, and the like that is generated when cutting the deck S. Therefore, the monitoring system can improve the work environment for cutting the deck S without cutting the girders G underneath the deck S.

[0026] [Configuration of imaging device 1] 2 is a schematic diagram illustrating the overall configuration of the imaging device 1 according to this embodiment. The imaging device 1 includes a main body 11, an imaging unit 12, an illumination unit 13, a fall prevention unit 14, and a control unit 15.

[0027] The main body 11 is a rod-shaped structure that is longer than the thickness of the deck S to be worked on. The main body 11 has a shape that extends along a predetermined longitudinal direction D. At least a portion of the main body 11 along the longitudinal direction D is hollow and tubular. For ease of visibility, FIG. 2 shows the longitudinal direction D of the main body 11 and a plane P perpendicular to the longitudinal direction D.

[0028] The imaging unit 12 is a device provided on the main body 11 for capturing an image of the surroundings of the main body 11. The imaging unit 12 is, for example, an imaging device such as a digital camera that captures an image of a predetermined imaging range to generate a captured image. The detailed configuration of the imaging unit 12 will be described later with reference to FIG. 3.

[0029] The illumination unit 13 is a device provided on the main body 11 that irradiates light onto the imaging range of the imaging unit 12. The illumination unit 13 has a light source such as an LED (Light Emitting Diode). The detailed configuration of the illumination unit 13 will be described later with reference to FIG. 4.

[0030] The main body 11 may be configured, for example, by connecting the illumination unit 13 and the imaging unit 12 to one end of a cylindrical support body. Alternatively, the main body 11 may be configured, for example, by attaching the illumination unit 13 and the imaging unit 12 inside the cylindrical support body. Alternatively, the main body 11 may be, for example, a device in which the illumination unit 13 and the imaging unit 12 are integrated.

[0031] The height of the illumination unit 13 in the direction perpendicular to the longitudinal direction D of the main body 11 is equal to or less than the height of the imaging unit 12 in the direction perpendicular to the longitudinal direction D of the main body 11. In other words, the illumination unit 13 is configured so as not to protrude further than the imaging unit 12 in the direction perpendicular to the longitudinal direction D of the main body 11. With this configuration, the imaging device 1 can prevent the illumination unit 13 from colliding with the wall surface of the hole S1 when a worker inserts the imaging unit 12 into the hole S1 in the deck slab S.

[0032] The fall prevention unit 14 is a stopper for preventing the imaging device 1 from falling when inserted into the hole S1 of the deck S. The fall prevention unit 14 is provided closer to one end of the main body 11 than the imaging unit 12 and the lighting unit 13, and prevents the imaging device 1 from falling when the main body 11 is inserted into the hole S1 so that the other end of the main body 11 faces downward in a direction perpendicular to the upper surface of the deck S. The detailed configuration of the fall prevention unit 14 will be described later using FIG. 6.

[0033] In this embodiment, an imaging unit 12, an illumination unit 13, and a fall prevention unit 14 are provided on the main body 11 in this order from one end of the main body 11. Alternatively, an illumination unit 13, an imaging unit 12, and a fall prevention unit 14 may be provided on the main body 11 in this order from one end of the main body 11. The distance between the imaging unit 12 and the illumination unit 13 and the fall prevention unit 14 is equal to or greater than the thickness of the deck S that is the target of work. This allows the imaging unit 12 to capture an image of the contact point between the girder G and the deck S, and the illumination unit 13 to irradiate light into the imaging range of the imaging unit 12, when the imaging device 1 is inserted into the hole S1.

[0034] With this configuration, the imaging device 1 can be inserted into the hole S1 from above the deck S, and an image of the contact point between the girder G and the deck S can be displayed on the communication terminal 2. This eliminates the need for workers to monitor the underside of the deck S to prevent the girder G from being cut, and therefore reduces exposure to dust, noise, etc. that are generated when the deck S is cut.

[0035] The control unit 15 includes a wireless communication unit 151 that transmits the captured image generated by the imaging unit 12 to the communication terminal 2 via wireless communication, and a battery 152 that supplies power to the imaging unit 12 and the illumination unit 13. The control unit 15 may further include other components such as a control circuit for the imaging unit 12 and a control circuit for the illumination unit 13.

[0036] The wireless communication unit 151 is connected to the imaging unit 12 via a cable 16, at least a portion of which passes through the inside of the main body 11. The battery 152 is connected to the imaging unit 12 and the illumination unit 13 via a cable 16, at least a portion of which passes through the inside of the main body 11. With this configuration, the imaging device 1 can reduce the risk of the imaging unit 12 and the illumination unit 13 becoming flooded.

[0037] The control unit 15 is housed in, for example, a box-shaped housing and is installed on a wall or floor above the floor slab S. If the control unit 15 is located below the floor slab S, wireless communication between the wireless communication unit 151 and the communication terminal 2 may be blocked by the floor slab S, which may prevent the communication terminal 2 from displaying captured images in real time, for example. In contrast, by installing the control unit 15 above the floor slab S like the communication terminal 2, wireless communication will no longer be blocked by the floor slab S, and the communication conditions between the wireless communication unit 151 and the communication terminal 2 can be improved.

[0038] Furthermore, although the control unit 15 is configured as a member independent of the main body 11 in this embodiment, it may be integrated with the main body 11. In this case, it is desirable that the control unit 15 be provided on the other end of the main body 11 opposite the end where the imaging unit 12 and the illumination unit 13 are provided. In other words, it is desirable that the control unit 15 be provided on the side of the main body 11 opposite the imaging unit 12 and the illumination unit 13, with the fall prevention unit 14 sandwiched between them. As a result, when the imaging device 1 is inserted into the hole S1, the control unit 15 is located above the floor slab S, thereby improving the communication conditions between the wireless communication unit 151 and the communication terminal 2.

[0039] The main body 11 further has a light-transmitting protective member 17 that covers the imaging unit 12 and the illumination unit 13. The protective member 17 is waterproof to prevent water from outside the main body 11 from coming into contact with the imaging unit 12 and the illumination unit 13. The detailed configuration of the protective member 17 will be described later with reference to FIG. 5.

[0040] The main body 11 is provided with a ventilation section 18 for moving air between the internal space of the main body 11 and the external space. The ventilation section 18 is, for example, a louver. It is desirable that the ventilation section 18 has a structure that allows air to pass through but does not allow water to pass through, so that the waterproofness of the main body 11 can be maintained. By providing ventilation between the internal space of the main body 11 and the external space, the ventilation section 18 can reduce the risk of abnormal operation or damage to the imaging section 12 and the illumination section 13 due to heat accumulated in the internal space of the main body 11.

[0041] Fig. 3 is a schematic diagram for explaining the configuration of the imaging unit 12. Fig. 3 shows the side and front of an exemplary imaging unit 12. The imaging unit 12 has an imaging element 121 for capturing an image of a predetermined imaging range, and a housing 122 that supports the imaging element 121.

[0042] The imaging unit 12 has an imaging element 121 that captures an image over a range of 180 degrees or more, preferably a range of 360 degrees, on a plane P perpendicular to the longitudinal direction D of the main body 11. The imaging element 121 is, for example, a CMOS (Complementary Metal-Oxide-Semiconductor) sensor.

[0043] The imaging unit 12 may include, for example, a plurality of imaging elements 121 that enable imaging over a range of 180 degrees or more. The imaging unit 12 may also include, for example, a wide-angle lens that causes light to be incident on the imaging elements 121 over a range of 180 degrees or more. With this configuration, even when the imaging device 1 is inserted into the hole S1 in the deck S and the relationship between the orientation of the imaging unit 12 and the contact point between the girder G and the deck S is not visible to the worker, the worker can easily include the contact point between the girder G and the deck S in the imaging range of the imaging unit 12.

[0044] The housing 122 has a rectangular parallelepiped shape (long and narrow shape) with a longitudinal direction that coincides with the longitudinal direction D of the main body 11. With this configuration, the worker can easily insert the imaging device 1 into the hole S1 in the deck S.

[0045] Fig. 4 is a schematic diagram for explaining the configuration of the illumination unit 13. Fig. 4 shows the front of an exemplary illumination unit 13. The illumination unit 13 has a light source 131 that emits light and a support 132 that supports the light source 131.

[0046] The lighting unit 13 has a light source 131 that emits light over a range of 180 degrees or more, preferably a 360-degree range, on a plane P perpendicular to the longitudinal direction D of the main body 11. The light source 131 is, for example, an LED. The lighting unit 13 may include, for example, a plurality of light sources 131 (for example, four) that can emit light over a range of 180 degrees or more. The lighting unit 13 may also include, for example, a light guide plate that guides the light emitted by the light source 131 over a range of 180 degrees or more. With this configuration, even when the imaging device 1 is inserted into the hole S1 in the deck slab S and the relationship between the orientation of the lighting unit 13 and the contact point between the girder G and the deck slab S is not visible to the worker, the worker can easily emit light from the lighting unit 13 to the contact point between the girder G and the deck slab S.

[0047] The support 132 supports the light source 131 at a predetermined angle. The support 132 may also have an angle adjustment unit such as a screw for changing the direction in which the light source 131 emits light. With this configuration, the operator can adjust the angle of the light source 131 so that the light source 131 emits light into the imaging range of the imaging unit 12.

[0048] Fig. 5 is a schematic diagram for explaining the configuration of the protective member 17. Fig. 5 shows the front of an exemplary protective member 17 that covers the imaging unit 12 and the illumination unit 13. The protective member 17 covers the imaging unit 12 and the illumination unit 13 to prevent them from coming into contact with water outside the main body 11. The protective member 17 is a light-transmitting member, and is made of, for example, acrylic.

[0049] In the protective member 17, the light transmittance of the second portion 172 that covers the illumination unit 13 is lower than the light transmittance of the first portion 171 that covers the imaging unit 12. The light transmittance of the second portion 172 is reduced by, for example, applying a translucent paint. With this configuration, the light emitted by the illumination unit 13 is diffused as it passes through the protective member 17, allowing the illumination unit 13 to irradiate light over a wider range.

[0050] 5 schematically shows a direction D1 in which the imaging unit 12 captures an image and a direction D2 in which the illumination unit 13 emits light. The illumination unit 13 is attached to the main body 11 so that the direction D2 in which the illumination unit 13 emits light is at an angle approaching the direction D1 in which the imaging unit 12 captures an image. The angle of the direction D2 in which the illumination unit 13 emits light is, for example, 5 to 10 degrees toward the imaging unit 12 (upward in the vertical direction) with respect to a plane P perpendicular to the longitudinal direction D of the main body 11. With this configuration, the illumination unit 13 can emit light toward the imaging range of the imaging unit 12.

[0051] Furthermore, it is desirable to set the distance between the imaging unit 12 and the illumination unit 13 and the angle of the illumination unit 13 so that the light emitted by the illumination unit 13 does not directly enter the imaging element 121 of the imaging unit 12. This makes it possible to prevent problems such as blown-out highlights in the captured image caused by the light emitted by the illumination unit 13 directly entering the imaging element 121.

[0052] 6 is a schematic diagram illustrating the configuration of fall prevention unit 14. Fall prevention unit 14 has protrusion 141 protruding from the side surface of main body 11, opening 142 into which main body 11 is inserted, and position adjustment unit 143 for adjusting the position of fall prevention unit 14 on main body 11.

[0053] The protrusion 141 is a member that protrudes from the side surface of the main body 11 in at least two directions perpendicular to the longitudinal direction D of the main body 11. It is desirable that the protrusion 141 protrudes from the side surface of the main body 11 within a range of 360 degrees on a plane P perpendicular to the longitudinal direction D of the main body 11. The protrusion 141 contacts the wall surface that forms the hole S1 in the floor slab S, thereby preventing the imaging device 1 inserted into the hole S1 in the floor slab S from falling.

[0054] The protrusion 141 is placed, for example, on the upper wall surface that forms the hole S1 (i.e., the upper surface of the floor slab S around the hole S1), thereby supporting the imaging device 1 so that it does not fall out of the hole S1.

[0055] Furthermore, the protrusion 141 may support the imaging device 1 so that it does not fall out of the hole S1, for example, by being inscribed on the inner wall surface that forms the hole S1 (i.e., the inner wall surface of the hole S1). In this case, the protrusion 141 includes an elastic member such as a spring or rubber, and applies force to the inner wall surface that forms the hole S1 to fix the imaging device 1 in the hole S1.

[0056] With this configuration, when imaging the imaging range including the contact point between the girder G and the deck S, the worker does not need to hold the imaging device 1 to prevent it from falling out of the hole S1, thereby reducing the burden on the worker.

[0057] In this embodiment, the protrusion 141 is configured as a member that is removable from the main body 11, but it may also be integrated with the main body 11. That is, a part of the side surface of the main body 11 may be configured as the protrusion 141. Furthermore, the protrusion 141 may be switchable between a protruding state in which it protrudes from the side surface of the main body 11 and a non-protruding state in which it does not protrude from the side surface of the main body 11. In this case, for example, the protrusion 141 is stored inside the main body 11 in the non-protruding state, and protrudes from the side surface of the main body 11 in response to a predetermined operation performed by an operator on the imaging device 1, thereby entering the protruding state.

[0058] The position adjustment unit 143 is a member for changing the position of the fall prevention unit 14 along the longitudinal direction D of the main body 11. The position adjustment unit 143 includes, for example, a screw. With the main body 11 inserted into the opening 142, the worker moves the fall prevention unit 14 to the desired position and tightens the screw of the position adjustment unit 143. The fastening force of the screw causes the protrusion 141 to deform so that the inner diameter of the opening 142 becomes smaller, so that the inner wall surface of the opening 142 comes into contact with the side of the main body 11, and the position of the fall prevention unit 14 is fixed. With this configuration, the imaging device 1 can adjust the position of the fall prevention unit 14 to a position suitable for deck slabs S of various thicknesses.

[0059] The position adjustment unit 143 is not limited to the specific configuration shown here, and may be capable of changing the position of the fall prevention unit 14 in other ways. For example, the position adjustment unit 143 may be configured to be engageable with each of a plurality of engagement units provided on the side of the main body 11, and the position of the fall prevention unit 14 may be changed by engaging with one of the plurality of engagement units. Alternatively, the main body 11 may have a male thread, the fall prevention unit 14 may have a female thread, and thread grooves may be provided on the surface of the main body 11 and the surface of the opening 142, thereby changing the position of the fall prevention unit 14.

[0060] [Monitoring method explanation] The following describes a monitoring method for monitoring the status of a structure such as a bridge using the above-mentioned imaging device 1. First, a worker forms a hole S1 in a deck S for inserting the imaging device 1. The worker forms the hole S1 by, for example, using a core drill to drill the deck S in a direction perpendicular to the top surface of the deck S.

[0061] FIG. 7 is a schematic diagram illustrating a method for forming a hole S1 in a deck S. FIG. 7 shows a portion of the deck S and a plurality of holes S1 formed on the deck S. A planned cutting line S2, which is a virtual line to be cut by a cutting device C, is shown on the deck S. Also, on the deck S, a region where a girder G extends below the deck S is shown by a dashed line. The region where the girder G extends includes the point of contact between the girder G and the deck S.

[0062] The worker forms a hole S1 that penetrates the deck S in a direction perpendicular to the upper surface of the deck S at a position that does not overlap with the area in the deck S where the girder G extends. In other words, the hole S1 is formed at a position different from the point of contact between the girder G and the deck S. This allows the imaging device 1, inserted into the hole S1, to capture an image of the imaging range including the point of contact between the girder G and the deck S.

[0063] It is desirable for the worker to form the hole S1 at a position that is not on a straight line including the planned cutting line S2 (i.e., a straight line extending from the planned cutting line S2). This allows the imaging device 1 to capture an image from an oblique direction relative to the planned cutting line S2, thereby preventing a situation in which the contact point between the girder G and the deck slab S is hidden by the cutting device C itself that is cutting the deck slab S.

[0064] It is desirable for the worker to form a hole S1 between two girders G that extend parallel to each other. This allows the imaging device 1 to capture an image of the contact points between the two girders G and the deck S while inserted into one hole S1, thereby reducing the effort required to monitor the condition of the structure using the imaging device 1.

[0065] It is desirable that the worker form a plurality of holes including hole S1 for inserting the imaging device 1. This allows the worker to lift the deck slab S after cutting by inserting wires into the plurality of holes including hole S1, as will be described later.

[0066] Next, the worker inserts the imaging device 1 into the hole S1. FIG. 8 is a schematic diagram illustrating a method for inserting the imaging device 1 into the hole S1. The worker inserts the imaging device 1 into the hole S1 from above the deck S so that the imaging range of the imaging unit 12 includes the contact point between the girder G and the deck S. The imaging unit 12 captures an image of the imaging range including the area A where the area where the girder G extends intersects with the planned cutting line S2. The lighting unit 13 also irradiates light around the imaging device 1, thereby providing a sufficient amount of light to the imaging range of the imaging unit 12 below the deck S. This allows the imaging device 1 to provide the worker with an image that allows him or her to confirm that the cutting device C will not cut the girder G below the deck S.

[0067] When the imaging device 1 is inserted into the hole S1 vertically downward relative to the upper surface of the deck S, the fall prevention unit 14 contacts the wall surface that forms the hole S1, thereby supporting the imaging device 1 inserted into the hole S1. This eliminates the need for the worker to continue holding the imaging device 1 to prevent it from falling out of the hole S1, thereby reducing the burden on the worker.

[0068] With the imaging device 1 inserted into the hole S1 supported by the fall prevention unit 14, a worker begins work using the cutting device C from above the deck slab S to cut the deck slab S along the planned cutting line S2. Furthermore, during or before cutting the deck slab S, the imaging device 1 displays on the communication terminal 2 (display device) an image of the contact point between the girder G and the deck slab S. Here, the imaging device 1 displays on the communication terminal 2 an image that was captured while the imaging device 1 inserted into the hole S1 was supported by the fall prevention unit 14 and while the lighting unit 13 was irradiating light onto the contact point between the girder G and the deck slab S.

[0069] 9 is a schematic diagram for explaining a method for displaying a captured image on the communication terminal 2. The imaging device 1 transmits the captured image generated by the imaging unit 12 capturing an image to the communication terminal 2 arranged above the deck S via wireless communication by the wireless communication unit 151. The imaging device 1 may transmit still images as captured images sequentially at predetermined time intervals, or may constantly transmit moving images as captured images.

[0070] The communication terminal 2 displays the captured image 21 transmitted by the imaging device 1 on the display unit. As shown in FIG. 9, the captured image 21 shows the relative positions of the girder G, the deck S, and the blade of the cutting device C. The communication terminal 2 is held above the deck S by a worker operating the cutting device C. This allows the worker to confirm that the cutting device C will not cut the girder G below the deck S while operating the cutting device C, thereby enabling the work of cutting the deck S to proceed efficiently.

[0071] After completing cutting of the deck S using the cutting device C, the worker may use the hole S1 to lift up the deck S after cutting. For example, the worker inserts wires into multiple holes including the hole S1 illustrated in FIG. 7. The worker then uses a crane or the like to pull up the wires, thereby lifting and moving the deck S after cutting. This allows the hole S1 for inserting the imaging device 1 to be reused to lift up the deck S, thereby reducing the effort required to cut and remove the deck S.

[0072] [Monitoring method flow] 10 is a flowchart of the monitoring method according to this embodiment. First, an operator forms a hole S1 that penetrates the deck S in a direction perpendicular to the top surface of the deck S at a position on the deck S that does not overlap with an area where the girder G extends (S11).

[0073] The worker inserts the imaging device 1 into the hole S1 from above the deck S so that the imaging range of the imaging unit 12 includes the contact point between the girder G and the deck S (S12). When the imaging device 1 is inserted into the hole S1 vertically downward relative to the upper surface of the deck S, the fall prevention unit 14 contacts the wall surface that forms the hole S1, thereby supporting the imaging device 1 inserted into the hole S1.

[0074] The imaging device 1 starts displaying the captured image on the communication terminal 2 by transmitting the captured image generated by the imaging unit 12 via wireless communication by the wireless communication unit 151 to the communication terminal 2 placed above the deck S (S13).

[0075] With the imaging device 1 inserted into the hole S1 supported by the fall prevention part 14, the worker uses the cutting device C from above the floor slab S to cut the floor slab S along the planned cutting line S2 (S14). After completing cutting of the floor slab S using the cutting device C, the worker removes the imaging device 1 from the hole S1 and ends the display of the captured image on the communication terminal 2 (S15).

[0076] The worker inserts wires into a plurality of holes including hole S1. Then, the worker uses a crane or the like to pull up the wires, thereby lifting and moving the deck slab S after cutting (S16).

[0077] [Effects of the embodiment] The imaging device 1 according to this embodiment is inserted into the hole S1 from above the deck S, and can display an image of the contact point between the girder G and the deck S on the communication terminal 2. Because workers do not need to monitor the underside of the deck S to prevent the girder G from being cut, they are less susceptible to dust, noise, etc. that are generated when cutting the deck S. This allows the monitoring system to improve the work environment for cutting the deck S without cutting the girder G underneath.

[0078] Furthermore, since the imaging device 1 has a fall prevention part 14 for preventing the imaging device 1 from falling, when capturing an image of an imaging range including the contact point between the girder G and the deck S, the worker does not need to continue holding the imaging device 1 to prevent it from falling from the hole S1, thereby reducing the burden on the worker. The worker can cut the deck S using the cutting device C while referring to the captured image captured by the imaging device 1 on the communication terminal 2, so the work of cutting the deck S can be efficiently carried out without cutting the girder G below the deck S.

[0079] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0080] 1. Imaging device 11 Main unit 12 Imaging unit 121 Image sensor 122 Case 13 Lighting Department 131 Light source 132 Support 14 Fall prevention part 141 Protrusion 142 Opening 143 Position adjustment section 15 Control Unit 151 Radio Communication Department 152 Batteries 16 Cable 17 Protective materials 18 Ventilation section 2. Communication terminals

Claims

1. A monitoring method for monitoring a condition of a structure including a girder extending in a horizontal direction and a deck laid on the girder, comprising: forming a hole that penetrates the deck slab in a direction perpendicular to the upper surface of the deck slab at a position that does not overlap with an area in which the girder extends in the deck slab; Inserting an imaging device having an imaging unit provided on a rod-shaped main body into the hole from above the deck slab so that an imaging range of the imaging unit includes a contact point between the girder and the deck slab; Cutting the deck using a cutting device from above the deck; During or before cutting the deck, the imaging device is inserted into the hole, and the imaging unit captures an image of the underside of the deck from below the deck, and the captured image is displayed on a display device arranged above the deck; A monitoring method comprising:

2. The imaging unit images the imaging range including an area where the girder extends and a line along which the deck slab is to be cut by the cutting device intersect. The monitoring method of claim 1 .

3. The method further includes the step of lifting the deck slab after it has been cut by the cutting device by inserting a wire into the hole. The monitoring method according to claim 1 or 2.

4. The imaging device further includes a fall prevention portion for preventing the imaging device from falling when the imaging device is inserted into the hole in a direction perpendicular to the upper surface of the deck. A monitoring method according to any one of claims 1 to 3.

5. In the displaying step, the captured image is displayed on the display device while the imaging device inserted into the hole is supported by the fall prevention part. The monitoring method according to claim 4.

6. the imaging device further includes an illumination unit that irradiates light around the imaging device; In the displaying step, the captured image is displayed on the display device while the lighting unit is irradiating the light onto the contact point between the girder and the deck. A monitoring method according to any one of claims 1 to 5.

7. the imaging device further includes a wireless communication unit for transmitting the captured image to the display device, which is a communication terminal; In the displaying step, the captured image is displayed on the display device via wireless communication. A monitoring method according to any one of claims 1 to 6.

Images