KR20230033532A - Robot for diagnosing security of construction - Google Patents

Abstract

According to an embodiment of the present invention, provided is a system for using a structure safety diagnosis inspection based on a wall-attached driving body using wind power, which is able to mount devices such as a camera, non-destructive inspection device, and three-dimensional scanner on a main body, secure a variety of information of a structure wall by the wireless remote control, transmit the secured images and inspection information through a transmission/reception module, analyze the received information, prepare a digital exterior examination net diagram on a two-dimensional level and a three-dimensional level of the structure, divide the inspection unit section of the exterior examination net diagram, set coordinates, and mark points of cracks and the like. In addition, the system is able to point out the relevant position by the wall-attached driving body based on GPS or the survey reference point whenever coordinates are provided, be easily repaired, recheck the coordinates after the repair, increase the quality of the safety inspection and reliability of the diagnosis, mount additional measuring devices, and have greater efficiency in the safety diagnosis of structures.

Description

Structure safety diagnosis robot {Robot for diagnosing security of construction}

The propeller of the present invention is rotated at high speed to attach the (100) body to the structure wall with the necessary lift, and the safety inspection sensor and parts of the facility are mounted on the main body based on the driving motor and wheels to drive the structure wall, so that the facility can be controlled wirelessly. It relates to a device that performs the task of securing safety inspection data.

Structures such as buildings, power plants, bridges, and chemical plants are becoming larger and more advanced, and the importance of safety inspection of structures for aging after completion is increasing. In safety inspection, the equipment applied to photography, ultrasonic inspection, surface wave measurement, impact response method, vibration method, impact echo method, and elastic wave-based nondestructive inspection method is applied in a relatively simple way, but the inspector directly approaches the inspection area. It is necessary to work and measure the size of the crack, but in the case of the wall of the structure, it is difficult for inspectors to access and it is cumbersome to perform various tasks.

As an embodiment, a vision camera is universal for safety inspection of structures, but it is necessary to take close-up pictures, measure the exact distance between the camera and the structure to secure the size of the crack, or install a reference mark on the surface of the structure. There is a high risk of In this way, the safety inspection of structures raises problems such as dependence on manpower, difference in inspection level between skilled and unskilled people, decrease in work efficiency due to inspection of a vast area, and increase in inspection cost.

As an alternative to this, research on wall-climbing robots is being actively conducted, and recently, steel structure climbing-based robots using permanent magnet wheels have been partially applied to structure safety diagnosis. In addition, the operating method of a gondola with wires or rails installed on the structure is applied, but the use of the device is limited, and the limitations of reduced work efficiency and high cost have not been overcome.

Wall-climbing robots using the propeller's wind power are easy to climb regardless of steel or non-ferrous structures, but when the main body approaches the wall, an abnormal vortex occurs due to the propeller's wake, which pushes the main body and interferes with wall attachment. In order to run on a wall, gripping force is required between the wall and the tire. In the wall, the weight of the main body not only does not affect the gripping force, but rather causes slippage, so strong attachment that exceeds the weight of the main body is required.

Therefore, due to the limit of stable attachment force only with the technology for suppressing abnormal vortex due to the propeller wake and the half-applied force of wind power, it is necessary to increase the output of the currently used motor or engine or to develop a new attachment technology. In addition to the half-application of wind power, lift is generated more, and the components of the force are combined to strengthen the adhesive force so that it can be safely attached to the wall while driving. It is an invention of a device that performs inspection.

In the present invention, when manufacturing a moving body capable of wall-attached running, when eradicating on a wall, as a method of suppressing abnormal vortices generated by the wake flow gas of the propeller, a cover made of polymer and metal plate (102) gas outlet, ( 111) Gas direction conversion unit, (107) gas flow passage, (102) gas inlet wrapped around and connected, (111) gas direction conversion unit is formed to discharge gas in the vertical direction of the frame, (105) gas inlet location is installed in the horizontal direction at an angle of about 90 degrees to allow gas to be sucked in, so that it is located parallel to the gas flow direction and the wall, so that it does not receive gas flow resistance due to the wake, suppressing the occurrence of abnormal vortices.

In order to achieve the above technical task (100), the main body needs to secure tire and gripping force on the wall so that it can drive and stop while generating frictional force, and also needs to increase gripping force to prevent slipping in a stopped state. should grow Therefore, the size of the adhesive force is preferably 1.5 or more and 10 times or less of the total weight of the moving body.

In the present invention, a motor and a propeller are configured in one or more (101) wind power generators to support the wall-attached movable body (100) and generate lift required for wall attachment, (102) gas outlet and (111) The gas direction conversion part is connected with a polymer or metal plate, and the (107) gas flow passage and (105) gas inlet are opened to form a gap with the wall by opening the lower part. The lifting force is attached to the wall through a flat wing-shaped frame with an open lower part (112).

(100) The attachment force of the main body increases as the output size of the motor or engine increases, and (112) the attachment force increases as the area of the flat wing-shaped frame with the lower part open increases.

Therefore, it is possible to secure video data such as cracks, peeling, peeling, mesh cracks, rebar exposure, water leakage, deterioration, voids, material separation, and whitening in the case of concrete structures through the safety inspection system for structures using wall-mounted mobile bodies. In the case of , it is advantageous to secure data on cracks, coating conditions, and corrosion conditions, so a more precise exterior survey network can be created.

A system for constructing an external survey network map indicating the damage state of a structure includes a data transmission/reception module, a program for constructing a digital external survey network map for a target structure, a stored memory, and a processor executing the program stored in the memory.

By executing the program, the processor receives the picture or scanned image of the structure by the vision camera through the data transmission/reception module, analyzes it from the obtained image, extracts a dimensional unit, and performs image stitching to sequentially connect a plurality of unit images. to generate an integrated image subject to damage detection, detect the distribution and range of damage in the integrated image through the learned damage information detection model, and perform a quantification process on the detected damage information to obtain quantified damage information. A digital exterior survey network map is created, but it is marked with coordinates, and more specifically, the exterior survey network map is enlarged to confirm the state of damage on the coordinates, and it can be checked at the site at any time through the coordinates. It can be confirmed as the point where the moving body teaches.

In the acquisition of information according to the creation of the structure safety diagnosis external survey network map of the present invention, it is advantageous to secure external image data of large structures that are difficult to access by using the image equipment mounted on the wall-mounted vehicle-based structure safety inspection device. Based on the data obtained, a digital exterior survey network can be automatically built through processing and artificial intelligence, and a number is assigned to each picture of the digital exterior survey network, which is advantageous in identifying the point of the problem.

More specifically, by operating a vision camera, a thermal imaging camera, a 3D scanner, and a non-destructive measuring device together with the main body, photo or video data of various characteristics are secured, and a digital exterior survey network map is produced through the data, so It is possible to drastically reduce the professional manpower time and cost invested in mortality.

In the case of photographed photos, a number is indicated for each frame, which is advantageous for finding data, and it is possible to reduce and enlarge the digital exterior survey network map because it is possible to reduce and enlarge the photo, and the basic unit area of the exterior survey network map is ^1m2 , the basic unit is further divided into 0.1m ² , the divisional unit is further divided into 0.01m ² , and the minimum divisional unit is 1mm ² so that the point in question can be observed in more detail, and the repair of the problem point and can be used to predict maintenance.

Since the structure is tall and massive, it is important to find problem points such as cracks and reconfirm the points accurately.

It is possible to create a digital external survey network map and convert it to PDF, etc., and the external survey network can also be divided into inspection unit areas, and the area can be expressed in coordinates, and the coordinates are two-dimensional coordinates on the X and Y axes. , or X-axis, Y-axis, and Z-axis three-dimensional coordinates, respectively.

The method of finding the coordinates in the field is important. Since the wall-attached traveling movable body can be moved to designated coordinates by receiving GPS (global positioning system) or surveying information, it is to find the coordinates. As an example, if the coordinates are provided to the construction company, the construction company uses the wall-attached moving body to check the problem point and builds it, thereby improving accuracy and reliability in inspection and construction, and the secured data is more advantageous for safety management and maintenance. can be used However, GPS errors and surveying errors can be reduced with technological progress in the future, while photogrammetry can further reduce the error range.

In addition, by mounting parts such as a cleaning device and a painting device on a wall-attached movable body, it can be used for structural safety diagnosis, maintenance, exterior wall cleaning, and wall painting of large structures.

The external survey network according to an embodiment of the present invention is also advantageous in securing external video data of large structures that are difficult to access by attaching and detaching video equipment to the wall-attached running body-based structure safety inspection device in information acquisition, and secured data. Based on this, it is possible to automatically build a digital exterior survey network map through processing and artificial intelligence. A number is assigned to each photo of the digital exterior survey network map, which is advantageous in identifying the problem point.

More specifically, by operating a vision camera, thermal imaging camera, 3D scanner, and non-destructive measuring device together with the main body, photo or video data of various characteristics are secured, and digital exterior survey network maps are advantageous for production through the data. It can drastically reduce the time and cost of professional manpower invested in the external survey network.

Ultrasonic inspection, surface wave measurement, impact echo method, impact response method, vibration method applied to structure safety diagnosis Non-destructive inspection method based on elastic waves has simple equipment, light weight, and simplified execution method, so it can be installed on the unmanned wall-mounted indestructible object 100. It is advantageous, and with the automation of advanced non-destructive technology for safety diagnosis of large structures, the vast area of large structures can be quickly and leveled up.

In the case of the photographed photos, a number is indicated for each frame, which is advantageous for finding data, and it is possible to reduce and enlarge the photo. Therefore, the basic unit area of the digital exterior survey network is set to 1 m ² in width and length, and the basic unit is divided into 0.1 m ² By dividing the division unit into 0.01m ² and further dividing it into a minimum division unit of 1mm ² , the problem point can be observed in more detail, and it can be used to predict repair and maintenance of the problem point.

The divided area of the exterior survey network map can be marked with coordinates, and the coordinates are marked with 2-dimensional coordinates of the X and Y axes, or 3-dimensional coordinates of the X, Y, and Z axes, respectively. Coordinates can be found on-site at any time, and if the coordinates are provided to the construction company as an example, the construction company uses a (100) wall-attached vehicle to the wall to check the problem point, and improves accuracy and reliability in inspection and construction by constructing. and the secured data can be used more advantageously for safety management maintenance.

1 is an exemplary side view in which one embodiment of the present invention is applied to a mobile body with wind power having one propeller
Figure 2 is an exemplary front view of applying one embodiment of the present invention to a mobile body with wind power having one propeller
3 is an embodiment of generating an abnormal vortex according to wall proximity
Figure 4 is a detailed view applied to Figure 1 Example in which lift is generated by the flow of gas
5 is an embodiment explaining the Venturi effect

In this specification, 1) the shape, size, ratio, angle, number, etc. shown in the accompanying drawings are schematic and may be slightly changed. 2) Since the drawings are drawn from the observer's point of view, the direction or position of the drawings may be variously changed according to the observer's position. 3) Even if the drawing numbers are different, the same reference numerals may be used for the same parts. 4) When 'includes, has, consists of', etc., other parts may be added unless 'only' is used. 5) When described in the singular, it can be interpreted in the plural as well. 6) Even if the shape, size comparison, positional relationship, etc. are not described as 'weakly or substantially', they are interpreted so as to include a normal error range. 7) Even if terms such as 'after ~, before ~, then, subsequently, at this time' are used, they are not used in the meaning of limiting the temporal location. 8) Terms such as 'first, second, third' are simply used selectively, interchangeably or repeatedly for convenience of classification and are not interpreted in a limited sense. 9) If the positional relationship of two parts is explained by '~ on, ~ on ~, ~ on the bottom, ~ beside, ~ on the side', etc., one or more other parts between the two parts unless 'right' is used. may be located. 10) When parts are electrically connected with '~ or', it is interpreted to include not only the parts alone but also in combination, but when they are electrically connected with 'either ~ or,', only the parts are interpreted.

(100) In order to support the structure of the main body, (112) a flat wing-shaped frame with an open lower part is installed, and then (111) gas direction conversion unit and (101) wind power generator are connected to form a wind power device. When operated, (103) gas discharge and (106) gas inflow were interlocked in the gas flow.

(100) When the (113) wheel installed on the main body touches the wall of the structure (120), a certain gap is created between the wall and the (112) flat wing-shaped frame with the lower part open, and the gas flows through the gap , (105) the area of the gas inlet is relatively narrow, (107) the gas flow passage is inclined, and the area through which the gas flows gradually expands, (111) is connected to the gas direction conversion unit, and (102) flows out to the gas outlet let it be

(105) The area of the gas inlet is relatively narrower than the area of the (102) gas outlet, and (107) the gas flow passage is inclined so that the area through which the gas flows gradually expands and flows to the (102) gas outlet. In the Venturi effect, when a fluid passes through a narrow diameter part in a pipe through which fluid flows, the flow velocity increases and the pressure decreases due to the energy conservation law, so that lift is generated using the phenomenon. The Venturi effect is described by the Bernoulli equation below. becomes,

When the pressure at point 1 in the above figure is P ₁ and the flow velocity is V ₁ , and the pressure at point 2 is P ₂ and the flow velocity is V ₂ , assuming that the heights of the two points are the same, the two sides of each side Since the second term can be deleted, the following equation is obtained.

Therefore, as the gas passes through the narrow (105) gas inlet, (124) the flow rate increases, and as the law of conservation of energy (123) decreases the pressure, the (112) around the flat wing-shaped frame with the lower part open and (120) the wall It is the principle that lift is generated even when the moving object is stably attached to the wall. (FIG. 6)

Although the directions of the lift acting on the airfoil and the lift acting on the open frame wings are opposite, the generated lift can be expressed by the equation of FIG. 7 .

The air flow applies an incompressible flow so that the density of air does not change throughout the air flow and the same flow is applied, and the air flow around the open-bottom frame wings applies an incompressible flow Throughout the flow, the density of the air does not change and the same flow is applied to all.

The adhesion generation section is (100) the wall adhesion of the main body is (101) the (121) reaction thrust obtained by releasing the gas with the wind power generator and (112) the (105) gas in the flat wing-shaped frame with the lower part open It is the sum of (122) lift in the range from the inlet to the (111) gas direction converter.

The size of the thrust of the wall-attached (100) main body increases as the output of the motor or engine (currently applied to flight) that operates the propeller increases, and as the number of wind power devices increases, the output increases, and the lower (112) As the area of the flat wing-shaped frame with the lower part open increases, the thrust increases.

The main body of the wall attachment (100) is controlled by a wireless control device. To increase the attachment force of the main body by stopping or gusting wind, the attachment force is adjusted by increasing the RPM (revolution per minute) of the propeller motor or engine, and the wall irregularities or obstacles are controlled by wheels. When crossing the road, the pilot judges the detour or crossing by looking at the monitor situation. When crossing the obstacle, the gap between the wheel and the wall widens, so that the resulting adhesion suppresses the attenuation (130) to narrow the gas intake control and the motor or engine By increasing the number of revolutions and increasing adhesion, it can overcome obstacles.

On the other hand, wall-mounted driving is completely different from driving conditions on general roads. In general, the driving force and the braking force are generated by the vertical drag force and the gripping force of the tire. In the case of the wall (126), it is necessary to provide an attachment force equal to or greater than the weight of the main body due to mismatch between the direction of gravity and the direction of attachment force. The friction force varies depending on the condition of the wall surface, tire friction force, tire air pressure, tire area, etc., and the friction force of a car is usually proportional to the (113) normal force acting perpendicularly to the tire. The total weight of the main body on the wall should provide horizontal attachment force to stop the potential energy falling by gravity, and this is why it should be greater than the weight of the main body in consideration of gusts and wall surface conditions.

The size of the (113) adhesive force of the wall attachment (100) main body is preferably more than 1 times to less than 10 times the weight of the main body. If the vertical drag is less than 1 times, there is a risk of slipping or falling due to a gust of wind due to lack of vertical drag. As the size of the flat wing-shaped frame with the lower part open increases, (100) the size of the moving body increases, and (101) the problem of cost increase due to the purchase of a motor or engine of a wind power generator with a high output specification there is.

The yellow mark indicated by the arrow indicates the state in which the main body is attached to the wall with 18% output from each of the four motors mounted on the fuselage. Therefore, an extra output for an increase in weight due to the attachment of the measuring equipment mounted on the main body remains.

The wall-mounted vehicle is equipped with a Bluetooth, Wifi-based remote control module and is controlled wirelessly, and a cradle is installed to attach and detach the wall-mounted vehicle-based structure safety inspection measurement equipment to obtain information on the exterior survey network. High-resolution camera, thermal imaging camera, non-destructive inspection, 3D scanner, ground penetration radar, etc. can be selected and used. In the embodiment of taking pictures and videos, pictures and videos are taken while the mobile body moves for a certain section or overlaps the movement and stop.

As shown in Figure 12, when the wall of the structure and the body tire come into contact, a certain distance and angle are maintained between the camera mounted on the camera cradle and the subject. Since it is filmed, it is possible to measure points, length, area, and dimensions through a size adjustment program.

As an embodiment, it is possible to obtain photos and images by irradiating various lights in the non-destructive inspection to see through the inside of the wall, and to obtain 2-dimensional and 3-dimensional measurement dimensions by analyzing the obtained image and gap data of cracks.

When taking a picture, the distance between the previously taken picture and the newly taken area may be adjusted through the distance measurement sensor to have an overlapping area of a certain distance, and the picture may be taken.

A number is marked on each frame of the photographed picture to help in finding data, and since the photo can be reduced or enlarged, the digital exterior survey network map can be converted into a file such as PDF and can be enlarged or reduced.

The basic unit area of the exterior survey network map is 1m ² in width and length, and the basic unit is divided into 0.1m ² , and the divisional unit is further divided into 0.01m ² to make the minimum divisional unit 1mm ² . By subdividing the basic unit area, problem points can be enlarged and observed in more detail, and it can be used to predict repair and maintenance of problem points.

Since it can be displayed in coordinates based on the basic unit of the exterior survey network map, the point in question is accurately recognized and, in some cases, it is possible to reconfirm. This is because it is easy to reconfirm the branch.

The coordinates of the external survey network map can be expressed as two-dimensional coordinates of the X and Y axes, or three-dimensional coordinates of the X, Y, and Z axes, respectively.

When marking the coordinates, in the case of a circle or cylinder, the starting point of the coordinates is arbitrarily designated by the site manager, and the point is marked on the site and displayed on the exterior survey network map to confirm the location through the wall climbing vehicle-based structure safety inspection device. do.

As an example, one coordinate of the Sejong Nuclear Power Plant in the external survey network map 01-SS X08.312-Y16.212 (NE32.12.2~1) is power plant unit 1, a drawing in the south direction, X-axis 8m312mm point and Y-axis 16m212mm point northeast 32 ㅀ This is the marking of the crack occurrence point with a length of 12mm and a width of 1~2mm.

If the corresponding coordinates are delivered to the constructor, the constructor can check the crack condition at the point taught by the wall-mounted driving robot-based structure safety diagnosis device and can start construction. It is possible to respond promptly according to the discovery of a problem, and it is expected that this record will be preserved and systematized for structure safety diagnosis to increase the speed, safety, economy, and efficiency, thereby increasing the reliability of safety inspection.

Non-destructive inspection method using wall-attached running body The main goal is to carry out scientific and efficient inspection of damage, defect, and deterioration by installing non-contact acoustic sensor-based non-destructive inspection equipment for large concrete structures. As examples of non-destructive inspection methods using wall-attached running bodies, hydraulic dam concrete barrier wall deterioration investigation using impact echo method, delamination investigation of nuclear power plant outer wall using impact echo method, corrosion state investigation of dam wall reinforcement using electric resistance method, shock response It can be applied to inspections such as wall peeling investigations and leaks of high-rise buildings using the law.

In the process of carrying out tasks such as building safety diagnosis on the wall, the wall-mounted moving device interferes with the measurement of the measuring device due to the vibration and noise of the wind power device. There is a moving body equipped with a device, and the front and rear moving device has a wind power device and a moving device, and the wind power device and the moving device are not installed, and the (100) body equipped with only the measuring device is towed and attached to the wall and moved when moving. Therefore, it is possible to use a method to increase the effect of measurement by providing a certain gap (distance) due to traction so that vibration and noise are offset.

Components of the wall-attached movable body-based structure safety diagnosis (100) body may be provided regardless of the inside or outside of the body, and may be provided in various positions according to each function and need.

In the main body 100 work, the battery 127 is used for less than 2 hours of work, and a cable 128 is connected from the outside for more than 2 hours of work, a power line is included in the cable, the material of the cable, the external It is not limited to caliber, length, etc. Depending on the height of the structure, the supplied cable 128 can be adjusted, and the cable 128 is connected to the wall-mounted driving platform and the structure safety diagnosis device main body 100 while being wound or unwound from the roller.

The cable 128 is connected to the wall-mounted driving robot base and the main body 100 of the structure safety diagnosis device to serve as a safety cable to prevent falling to the ground due to unexpected reasons such as power outages and gusts during structure inspection.

It can be used for cleaning work by receiving and spraying dry ice particles for cleaning through the cable 128 and spraying them on the contaminated and rusted parts of the wall of the structure.

The driving cameras 116, which provide images to the wireless control monitor for controlling the main body 100, are installed in the front and rear of the main body 100, respectively, and are used as information for wireless control driving through the images.

100: wall-attached traveling movable body
101: wind generator
102: gas outlet
103: outgassing
104: action
104-1: reaction
105: gas inlet
106: gas intake
107: gas flow passage
108: lift
109: wheel
110: ground pressure
111: gas direction conversion unit
112: flat wing-shaped frame with open lower part
113: normal force
114: bonnet (cover)
115: Measuring device (high resolution camera, thermal imaging camera, non-destructive measuring equipment, etc.)
116: camera module for viewing and controlling the moving object as a monitor
117: LED light
118: non-destructive testing measuring device
119: transmitting and receiving device
120: structure wall
121: Reaction thrust generation section
122: lift generating section
123: pressure reduction
124: flow rate increase
125: Measuring device holder (high resolution camera, thermal imaging camera, non-destructive measuring equipment, etc.)
126: gravity direction
127: battery
128 wire cable
129: control
130: gas intake control

Claims (10)

When wheels are installed on a flat wing-shaped frame with an open lower part and the wheel touches the wall, a certain gap is formed between the open flat frame wing and the wall, and gas is sucked through the gap, and the area of the gas intake When passing through the gas flow passage, the area gradually widens to connect to the gas outlet, and when the gas is released in a relatively large area, the gas flow rate sucked into the narrow gap increases, and the lift generated as the air pressure decreases is transferred to the wall. Wall-attached structure safety inspection device to be attached
Under the condition of 3, the gas inlet gap can widen when the wall wheels go over bumps or obstacles, so the safety check device for wall-mounted structures equipped with gas control valves that can narrow or widen the gas control gap.
Wall-attached and wheel-driven type, wall-attached running body base, structure safety inspection device
A wall-mounted structure safety inspection device that improves adhesion by combining the lifting force generated as the air pressure decreases and the gas flow speed increases by releasing gas to the outside with the wind power device and inhaling the gas through the narrow gap and the force of the reaction.
Wall-attached running body-based structure safety inspection device having an adhesive force of 1 to 10 times the weight of the moving body attached to the wall
A wall-mounted running body-based structure safety diagnosis device that is easy to attach and detach high-resolution cameras, thermal imaging cameras, 3D scanners, and non-destructive test devices by installing a camera cradle on a moving body.
An exterior survey network map is prepared based on the secured photographic data, but it is expressed in two dimensions of X-axis and Y-axis or in three dimensions of X-axis, Y-axis, and Z-axis. The unit area of measurement of the exterior survey network map is divided into coordinates can be displayed The basic area of the measurement unit is based on 1,000 × 1000 mm, the basic area is subdivided into 100 × 100 mm, further subdivided into 10 mm × 10 mm, and further subdivided into 1 mm × 1 mm. coordinate notation
The exterior survey network is also indicated in coordinates, and it is indicated in 2-dimensional coordinates of the structure name, structure number, date, X-coordinate, Y-coordinate, or 3-dimensional coordinate of X-coordinate, Y-coordinate, and Z-coordinate. If the inspector provides the coordinates to the constructor, the constructor finds the coordinates and constructs them. After construction, the inspector also confirms the construction status, so the inspection and response methods are systematized for wall-attached vehicle-based structure safety. Diagnosis method
When marking the coordinates of a structure, in the case of a circle or cylinder, the starting point of the coordinates is arbitrarily designated by the site manager, and the point is marked on the map. , and the Y coordinates are sequentially divided from the bottom left to the right in the horizontal direction.
As an example, Sejong Power Plant 01-SS X08.612-Y16.212C220-712
Sejong Power Plant Unit 1, in the south direction, the crack distribution area is 220m wide and 712mm long at the X-axis 8m612mm point and the Y-axis 16m212mm point.
According to claim 1,
The wall-mounted driving robot-based structure safety diagnosis device further includes a receiver for receiving a signal transmitted remotely
Wall-mounted driving robot-based structure safety diagnosis device .

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