KR102332717B1 - System of detecting crash status level on roofing tile with DRONE and operating method thereof - Google Patents

Abstract

The present invention relates to a system for detecting damage to a roof tile by a drone and a method for operating the same. The damaged state of the roof tiles that protect the roof structures of cultural assets such as buildings from snow and rain can be safely, quickly and precisely analyzed using video images and color separation techniques captured by drones, and location information and image processing technology. The system comprises: a drone photography unit in which a source signal of the acquired image taken simultaneously with visible light, microwave signal, and infrared signal at a location designated by GPS coordinate information and beacon location information for a specific part of the roof of the cultural property is recorded in each frame unit, the acquired image packet frame signal is encrypted, and simultaneous transmission is made on each channel of multiple communication methods; a wireless relay booster in which simultaneous wireless connection is made in short distance with each channel by multiple communication methods of Wi-Fi wireless communication method, FM wireless communication method, and Bluetooth wireless new method to the drone shooting unit, each encrypted acquired image packet frame signal is received, and all are transmitted at the same time; and a tiling condition analysis server in which wired connection is made with the wireless relay booster unit, the acquired image packet frame signal is received through each channel of multiple communication methods, any one acquired image packet frame signal is selected and decoded without transmission error, source signals of the acquired images taken with visible light, microwave and infrared, respectively are estimated, each image processing analysis is performed to estimate the damage grade of the roof tiles, and a final damage grade is detected by processing the arithmetic average of each estimated damage grade.

Description

System of detecting crash status level on roofing tile with DRONE and operating method thereof

The present invention relates to a system for detecting damage to a roof tile by a drone and a method for operating the same, and more particularly, to a damaged state of a tile that protects a roof structure of a cultural property such as a wooden building from snow, rain, etc. It relates to a system for detecting damage to roof tiles by drones and its operation method, which safely, quickly and precisely analyzes damage by applying color separation techniques, photographed location information, and image processing technology to video images.

Traditional buildings containing Korean cultural assets are made of wood, and roofing tiles are used to protect the entire building from snow and rain.

In general, roof tiles are made by forming a selected specific type of soil into the shape of a tile and then roasting it in a high temperature fire to increase durability. and the damaged roof tiles cause snow, rain, etc. to penetrate into the inside of the building and cause the wooden materials to rot, shortening the lifespan of the building.

Buildings using roof tiles, especially those with high preservation value such as cultural properties, should be inspected and repaired for damage frequently.

As a prior art that partially resolves this need, there is a 'method light server for providing cultural properties inspection service using a drone' according to Korean Patent Application No. 10-2019-0178944 (2019. 12. 31.).

1 is a functional block diagram of a system for detecting a tile state by a drone according to an embodiment of the prior art.

Hereinafter, when the prior art will be described in detail with reference to the accompanying drawings, it is a configuration including the server 100 , the database 300 , and the drone 500 .

The server 100 includes hardware consisting of a processor, memory, etc. and software of an application for operation, and further includes a communication unit for wireless communication with the drone 500 , and connects to the database 300 in communication with the drone 500 . ) and records the secured information in the allocated area. The database 300 records and stores sample images for determining a damaged grade for each cultural property or similar cultural property in a separately allocated area.

The drone 500 secures a target image for a designated location of a specific cultural property and transmits it to the server 100 , the server 100 transmits the received target image to the database 300 , and the database 300 transmits the received target image It is a configuration that compares the image with a plurality of sample images, searches for a sample image having a matching rate greater than or equal to a set threshold, and determines the latent damage grade by the searched sample image.

In the prior art, a target image for a specific location of the cultural property to be inspected is photographed with the drone 500, and the server 100 receives the target image and transmits it to the database 300, so the sample closest to the target image in the database 300 It has the advantage of retrieving images and determining the corresponding damage class,

However, the prior art still has not solved the problem that the sample image may not match the target image, and it is practically difficult to secure sample images for all cultural assets in the country, and the storage capacity for recording the sample images must be very large.

In addition, if the target image and the sample image have a matching rate higher than the threshold, the damage grade of the sample image is judged as the damage grade of the photographed target image, so the error is calculated very large. The problem still remains.

Therefore, it was necessary to develop a technology to quickly and precisely judge the damaged grade by analyzing the image signals taken by the roof tiles of cultural properties in various ways.

Republic of Korea Patent Application No. 10-2019-0178944 (2019. 12. 31.) ‘Method of providing cultural properties inspection service using drones Light Server’

The present invention, which was devised to solve the problems and necessity of the prior art as described above, captures the tile image of a wooden cultural property building according to precise location information, but with various electromagnetic waves, and simultaneously secures climate data according to the surrounding environment of the shooting location A system for detecting damage to roof tiles by drones and its operation method that analyzes and judges the damage status of roof tiles safely, accurately and quickly by analyzing the photographed image signals using multiple digital image processing (DSP) techniques. Its purpose is to provide

The system for detecting damage to roof tiles by a drone of the present invention, devised to achieve the above needs and objectives, detects a specific part of the roof of the cultural property 1000 with visible light and microwave signals at a location designated by GPS coordinate information and beacon location information. A drone photographing unit 2000 that records source signals of acquired images taken simultaneously with infrared signals in frame units, encrypts them into acquired image packet frame signals, and transmits them simultaneously through each channel of a plurality of communication methods provided; To the drone photographing unit 2000, wirelessly access each channel by multiple communication methods of the Wi-Fi wireless communication method, the FM wireless communication method, and the Bluetooth wireless communication method at the same time and simultaneously receive the encrypted acquired image packet frame signal and all at the same time a wireless relay booster unit 3000 to transmit; Wired connection to the wireless relay booster unit 3000 and receiving an acquired image packet frame signal through each channel of multiple communication methods, selects and decodes any one acquired image packet frame signal without a transmission error, and transmits visible light and microwave A tile state analysis server (4000) that separates the source signals of each acquired image taken with infrared rays, analyzes each image processing to estimate the damage grade of the tile, and calculates the arithmetic average of each estimated damage grade to detect the final damage grade ); may include.

The drone photographing unit 2000 includes an operation unit 2100 that flies at a location designated by a corresponding control signal; A drone operation control unit 2200 that accesses the operation unit 2100, receives and analyzes GPS coordinate information and beacon position information, outputs a control signal to fly at a designated location, and outputs the corresponding control signal to each configured function unit; a visible ray photographing unit 2300 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 with visible light according to a corresponding control signal of the drone operation control unit 2200; a microwave imaging unit 2400 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as a microwave signal according to a corresponding control signal of the drone operation control unit 2200; an infrared photographing unit 2500 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as an infrared signal according to a corresponding control signal of the drone operation control unit 2200; Ambient climate sensor unit 2610 for detecting ambient climate signals including temperature, humidity, wind direction, wind speed, light quantity, and time by the surrounding climate according to the corresponding control signal of the drone operation control unit 2200, respectively; The source signal of the acquired image photographed by the visible ray photographing unit 2300 according to the corresponding control signal of the drone operation control unit 2200, the source signal of the acquired image photographed by the microwave photographing unit 2400, and the infrared photographing unit 2500 a packet encryption/decryption unit 2620 for encrypting or decrypting the acquired image source signal captured by ) and the ambient climate signal detected by the surrounding climate sensor unit 2610 into an acquired image packet frame signal of a predetermined standard; a Wi-Fi wireless unit 2700 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in a Wi-Fi wireless communication method; an FM radio unit 2800 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in an FM radio communication method; a Bluetooth wireless unit 2900 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in a Bluetooth wireless communication method; may include.

The method of operating a system for detecting damage to a roof tile by a drone of the present invention devised to achieve the above needs and objectives is a damage rating of a roof tile by a drone including a cultural property, a drone photographing unit, a wireless relay booster unit, and a tile condition analysis server In the detection system operating method, when it is determined by the roof tile state analysis server that a command signal for image processing the acquired image source signal photographed and transmitted by the drone photographing unit is input, whether it is a signal photographed with visible light or photographed with a microwave a classification step of classifying a photographing method of whether the signal is a signal or a signal photographed by infrared rays; a color separation step of marking the photographing method divided in the above step, correcting the captured image source signal into a corresponding standard image signal according to the ambient climate signal, and performing color separation processing on the corrected standard image signal; In the color separation step, the boundary line and the outline are extracted from each image signal, respectively, and the damage grade is estimated by comparing it with the standard image signal of the roof tile, respectively, and recorded in the allocated area. A precise detection step of detecting and recording the final damage grade calculated by summing the respective photographing methods; may include.

The present invention of the above configuration captures the roof tiles of a wooden cultural property building worth preserving for a long time by precise location information, accurately secures and records the climatic data of the surrounding environment of the site being photographed at the same time, and records a number of photographed Since the image signal is analyzed by a variety of digital image processing (DSP) techniques, it has the advantage of maintaining the lifespan of cultural properties for a long time by quickly, safely and accurately analyzing the damaged state of the roof tiles.

1 is a functional block diagram of a tile state detection system by a drone according to an embodiment of the prior art;
Figure 2 is a photograph of a crane mobilization visual inspection method for eye inspection of a general wooden cultural property tile;
3 is a functional configuration diagram of a system for detecting a tile state by a drone according to an embodiment of the present invention;
4 is a detailed functional configuration diagram of a drone photographing unit according to an embodiment of the present invention;
5 is a data field configuration diagram of an acquired image packet frame according to an embodiment of the present invention;
6 is an explanatory diagram of an application field for each type of electromagnetic wave according to an embodiment of the present invention;
7 is a flowchart of a method of operating a system for detecting a tile state by a drone according to an embodiment of the present invention;
and
8 is a diagram illustrating a photograph of a normal tile and an abnormal tile taken as an embodiment in order to explain the present invention.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all transformations, equivalents and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the following description, each power supply functional unit for supplying operating power is a natural configuration, and drawings and descriptions will be omitted to simplify the description and clearly explain the technical idea.

Figure 2 is a view of the crane mobilization visual inspection method for eye inspection of a general wooden cultural property tile, Figure 3 is a functional configuration diagram of a tile state detection system by a drone according to an embodiment of the present invention, Figure 4 is this According to an embodiment of the present invention, it is a detailed functional configuration diagram of a drone photographing unit by a drone, Figure 5 is a data field configuration diagram of an acquired image packet frame according to an embodiment of the present invention, and Figure 6 is an embodiment of the present invention According to the embodiment, it is a description of the application field for each type of electromagnetic wave.

Hereinafter, with reference to all the accompanying drawings, according to an embodiment of the present invention will be described in detail the tile damage grade detection system 900 by a drone.

The system 900 for detecting damage to a roof tile by a drone is configured to include a cultural property 1000 , a drone photographing unit 2000 , a wireless relay booster unit 3000 , and a tile state analysis server 4000 .

The cultural property 1000 is a wooden structure and has a roof tile. The cultural property 1000 will be described as including a GPS satellite 1100 that broadcasts a GPS signal and a beacon unit 1200 that provides location information having an error of unit centimeter in a short distance.

In the following description, the short distance is described as a straight-line distance in the range of 0 meters or more to 2 kilometers (Km).

The GPS satellite 1100 is a component that broadcasts a GPS signal analyzed with coordinate information including latitude, longitude, sea level, time, angular velocity, etc. in a relatively low orbit of the Earth, and there are 24 or more GPS satellites in the Earth's orbit. When the satellite 1100 moves along the orbit at regular intervals and receives and analyzes GPS signals from at least three GPS satellites 1100, necessary coordinate information can be extracted, and it is well known that the minimum error range is several tens of centimeters. and further detailed description will be omitted.

The beacon unit 1200 is configured to record and store precisely measured coordinate information of the installed location and information describing the location in detail, and broadcast so that anyone can receive it if only the corresponding frequency matches in a short distance. When a signal transmitted by the beacon unit 1200 is received, a receive signal strength indicator (RSSI) and a precise triangulation method have an error within a few centimeters based on the location where the beacon unit 1200 is installed. Extract location information. The beacon unit 1200 broadcasts the corresponding location information in a Bluetooth wireless communication method and is well known, so a detailed description thereof will be omitted.

The drone photographing unit 2000 shoots a specific part of the roof of the cultural property 1000 at a location designated by GPS coordinate information and beacon location information, respectively, with visible light, microwave signal, and infrared signal, which are classified as electromagnetic wave signals, respectively. The source signal of the captured image is recorded in each frame unit, but the surrounding climate information detected at the same time of shooting is recorded in the frame unit together with the captured image packet frame (5000) signal and each channel by multiple communication method. This is a configuration that eliminates transmission errors because each of them transmits the same content at the same time. Because data without transmission error is used, it can be precisely analyzed.

The drone photographing unit 2000 may further include a visible light illumination unit 2310 for photographing in a shaded area or at night and an infrared illumination unit 2510 for infrared photographing, but each of these lighting units is photographed with visible light. In order to secure a signal, it is very desirable to have a configuration that blinks every 0.5 second in order to secure a clear and accurate image signal.

The drone photographing unit 2000 includes the operation unit 2100, the drone operation control unit 2200, the visible light photographing unit 2300, the microwave photographing unit 2400, the infrared photographing unit 2500, and the surrounding climate sensor unit 2610 and It has a configuration including a packet encryption/decryption unit 2620 , a Wi-Fi radio unit 2700 , an FM radio unit 2800 , and a Bluetooth radio unit 2900 . In addition, although not shown in the drawing for simplicity of the drawing, it further includes a CDMA mobile communication radio unit 2850 and a GPS receiver 2870 .

The operation unit 2100 is configured to receive a corresponding control signal from the drone operation control unit 2200, operate (fly) to a designated location, and stably stay in the air.

The drone operation control unit 2200 connects to the operation unit 2100 and analyzes any one or any one or more of the remote input GPS coordinate information and the received beacon location information to accurately and precisely locate the flight (operation) at the designated destination. It outputs the corresponding control signal to do so, and outputs each corresponding control signal to each configured function unit, and monitors each operation state.

The drone operation control unit 2200 is operated by the built-in operation program and operation data, and if necessary, remotely receives, stores, sets and operates updated or modified operation programs and operation data through the provided radio unit. In addition, it will be explained that an application program that receives the GPS signal, checks the coordinate information of the current location, analyzes the difference from the input coordinate information of the destination, and outputs the corresponding control signal to arrive at the destination is naturally provided.

The drone operation control unit 2200 calculates the position information to fly by first calculating the arithmetic average of the input GPS coordinate information and the beacon position information wirelessly received from the beacon unit 1200 in the field. It operates and stays at the designated location, and the first calculated location information and the beacon location information are processed again by the second arithmetic average to calculate the location information to be operated and hovered again, and the flight and stay to the designated location based on the calculated location information Then, by repeating the second calculated location information and the beacon location information, the third arithmetic average calculation process is performed to calculate the location information to be hovered thirdly, and the flight and hovers to the designated location according to the calculated location information. In other words, since the location information is repeatedly corrected and corrected by the third time, it is relatively very accurate, and it flies and hovers to the designated location according to the precise location information. It is possible to accurately and repeatedly photograph the tiles of the same area at the same location. This method is a very useful technique when constant investigation is required.

It will be explained that the designated location where the drone photographing unit 2000 hovers includes longitude, latitude, sea level, etc., and the error range is within several centimeters, respectively, and receives GPS coordinate information of the designated location.

The visible ray photographing unit 2300 captures an image signal of a tile located on a specific portion of the roof of the cultural property 1000 in visible light according to a corresponding control signal of the drone operation control unit 2200 . The drone operation control unit 2200 may output a corresponding control signal to operate the visible light illumination unit 2310 as necessary.

The microwave imaging unit 2400 captures or scans an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as a microwave signal according to a corresponding control signal of the drone operation control unit 2200 . A commonly known radar scan method may be applied.

The infrared photographing unit 2500 captures an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as an infrared signal according to a corresponding control signal of the drone operation control unit 2200 . The drone operation control unit 2200 may output a corresponding control signal so that the infrared lighting unit 2510 is operated as needed.

That is, the visible ray photographing unit 2300, the microwave photographing unit 2400, and the infrared photographing unit 2500 photograph the tile at the same position, but for regular inspection, the tile at the same position can be repeatedly photographed at any time or at any time. .

Referring to FIG. 6 attached, it can be confirmed which electromagnetic wave is appropriate to use in which field. It is explained that electromagnetic waves include visible light, infrared rays, microwaves, and the like. Remote sensing using electromagnetic waves is a generic term for technology that acquires information about a target using electromagnetic energy, and active technology development is taking place due to its high value for astronomy, geography, civil engineering, and military use. Electromagnetic wave energy has various characteristics according to its wavelength, and it analyzes land use conditions, prepares geological maps, determines soil conditions, classifies crops, identifies forest growth conditions and pests, and classifies species for logging, water resource detection and It is used for a variety of purposes, such as checking the status. In particular, it supports the investigation and monitoring of eco-physical objects and artificial structures on Earth, enabling the detection of changes in dynamic and continuously changing objects.

In the case of color separation processing of image signals taken with electromagnetic signals, various information can be extracted, and it is a technology used for resource exploration, geological exploration, climate survey, coastline change, and volcanic activity monitoring in space. It is one of the technical ideas of the present invention to apply to detect , and this space technology will be described again in detail below.

This technology does not need to move close to the measurement target directly, and allows observation of a wider area at a time from a distance. In addition, as it is possible to repeatedly acquire continuous data with a certain period, it is being used for continuous observation and prediction of changes over time. Among them, image analysis refers to calculating the images obtained by various methods to extract necessary information or to reconstruct it into an image suitable for a specific purpose.

The ambient climate sensor unit 2610 detects ambient climate information signals including temperature, humidity, wind direction, wind speed, light quantity, and time according to the surrounding climate according to the corresponding control signal of the drone operation control unit 2200, respectively. In the case of photographing using electromagnetic waves, since the obtained image signal is affected by the surrounding climate information, it is possible to compensate for the difference compared to the climatic conditions according to the predetermined standards later, and the climatic conditions according to the predetermined standards are repeated experiments. The clearest and most accurate shooting climatic conditions are selected by , which can be updated and modified as needed, recorded in the allocated memory area of the drone shooting unit 2000, and set and updated for the corresponding operation. . Compensation processing may include amplification, attenuation, removal of unnecessary signals, and the like.

The packet encryption/decryption unit 2620 is an acquired image source signal photographed by the visible ray photographing unit 2300 and an acquired image source signal photographed by the microwave photographing unit 2400 according to a corresponding control signal of the drone operation control unit 2200, and infrared rays The acquired image source signal captured by the photographing unit 2500 and the ambient climate information signal detected by the ambient climate sensor unit 2610 are encrypted or decrypted into an acquired image packet frame 5000 signal of a predetermined standard.

The Wi-Fi wireless unit 2700 is activated by the corresponding control signal of the drone operation control unit 2200 and transmits the encrypted acquired image packet frame 5000 signal through the Wi-Fi wireless communication channel in the Wi-Fi wireless communication method. A communication path occupied by the Wi-Fi wireless unit 2700 for communication may be referred to as a Wi-Fi communication channel.

The FM radio unit 2800 transmits the acquired image packet frame 5000 signal activated and operated according to the corresponding control signal of the drone operation control unit 2200 and encrypted using the FM radio communication method through the FM radio communication channel. The communication path occupied by the FM radio unit 2800 for communication may be referred to as an FM communication channel.

The Bluetooth wireless unit 2900 transmits the acquired image packet frame 5000 signal that is activated and operated according to the corresponding control signal of the drone operation control unit 2200 and is encrypted using the Bluetooth wireless communication method through the Bluetooth wireless communication channel. A communication path occupied by the Bluetooth wireless unit 2900 for communication may be referred to as a Bluetooth communication channel.

The Wi-Fi wireless unit 2700, the FM wireless unit 2800, the Bluetooth wireless unit 2900 and the corresponding communication channel consist of a high-speed data transmission network that transmits digital signals at a transmission rate of 1 gigahertz per second or more, respectively, in order to improve the transmission speed. . Therefore, the corresponding data signal is transmitted quickly.

The acquired image packet frame 5000 consists of a total of 185 bytes (bytes) and includes an overhead field, a visible light acquired image data field, a microwave acquired image data field, an infrared acquired image data field, a check data field, and an end field. am.

When the drone operation control unit 2200 cannot record all of the specific data to be recorded in the assigned field area of one acquired image packet frame 5000 because the capacity of the specific data to be recorded is relatively large, it adds the acquired image packet frame 5000 in the following order. data is assigned, the corresponding data is recorded, and an indication that data is concatenated is written to the overhead field area and/or the end field area by assigning a serial number to each corresponding frame, so that the receiving side can perform the necessary data recovery processing make it possible

A byte means a collection of 8 bits, which is the minimum unit for recording the presence or absence of one pulse signal in a digital signal, and if necessary, more than 8 bits are defined as one byte However, in the following description, it is defined that 10 bits constitute one byte for encryption to prevent unauthorized access by unauthorized third parties and theft of valuable information.

The OVHD (overhead) field consists of 10 bytes, and the starting position of the data composing the frame starts recording, the transmission destination, the transmission time, the generation coordinate information, and the total data by bits. When the size and amount of data are large, it can consist of multiple frames, so frame serial number information indicating the connected state is included and recorded.

The visible ray acquired image data field consists of 50 bytes with an interval of 1 byte from the overhead field, and the acquired image source signal captured by the visible ray imaging unit 2300 and the ambient climate signal detected by the surrounding climate sensor unit 2610 is recorded

The microwave acquired image data field consists of 50 bytes with an interval of 1 byte from the visible light acquired image data field, and the acquired image source signal captured by the ultrasound imaging unit 2400 and the ambient climate detected by the ambient climate sensor unit 2610 The signal is recorded.

The infrared acquired image data field consists of 50 bytes with an interval of 1 byte from the microwave acquired image data field, and the acquired image source signal captured by the infrared imaging unit 2500 and the ambient climate signal detected by the ambient climate sensor unit 2610 is recorded

The check (CHK) data field consists of 10 bytes with an interval of 1 byte from the infrared acquired image data field, and the data recorded in the visible light acquired image data field, the microwave acquired image data field, and the infrared acquired image data field If it is determined that an error is included by analyzing each, the cyclic redundancy check (CRC) method and the Hamming code method are sequentially operated to detect duplicate errors and process duplicate repairs.

The END field consists of 10 bytes with an interval of 1 byte from the check data field. Error detection and recovery, retransmission request, data generator information, frame end position, and frame serial number information are included and recorded.

One byte spaced between each data field is not shown in the figure because the figure becomes complicated when shown in the figure.

The wireless relay booster unit 3000 wirelessly connects to the drone photographing unit 2000 at the same time in a short distance using multiple communication methods of the Wi-Fi wireless communication method, the FM wireless communication method, and the Bluetooth wireless communication method, and the encrypted acquired image packet frame (5000) It is a configuration that receives each signal and transmits them all at the same time.

The wireless relay booster unit 3000 is configured to receive a signal of each radio channel transmitted by the drone photographing unit 2000, amplify it to a certain level required for transmission, and output it wirelessly by wire or CDMA mobile communication method. In the following description, a method of outputting by wire will be mainly described.

The tile state analysis server 4000 has a wired connection with the wireless relay booster unit 3000 and receives the acquired image packet frame 5000 signal through each channel of multiple communication methods to receive any one acquired image packet frame without a transmission error. The signal is selected and decoded, and the source signal of the acquired image taken with visible light, microwave and infrared light is separated, respectively, and the damage level of the roof tiles is estimated by image processing analysis of each. It is a configuration for detecting or extracting grades.

When the tile state analysis server 4000 is analyzed and determined that there is no transmission error in the multiple acquired image packet frame 5000 signals via the multiple communication channels, the acquired image packet frame 5000 signal via the channel of the designated priority select It is very natural that the channels of the designated priority are designated in the order of the Wi-Fi wireless communication channel, the FM wireless communication channel, and the Bluetooth wireless communication channel, and the order can be arbitrarily adjusted as needed.

Detailed functions of the tile state analysis server 4000 will be described again in the description of the operation method below.

There are about 8,100 cultural assets in Korea, and the number of management personnel is about 70 as of 2019, and it is analyzed that there is a limit to the safe inspection by caring for cultural assets due to the limited budget. In particular, the Gyeongju and Pohang earthquakes that hit the Korean Peninsula in 2019 caused 63 cultural property damage and approximately 3 billion national treasury was invested. In particular, in order to inspect the damaged state of the wooden cultural tile, it is necessary to visually inspect it using a high-altitude crane, so cost, safety, and time are limited.

As an example, according to the performance table of minor repairs for the cultural property care project in 2016-2017, the item that accounts for the largest portion of the repair of wooden cultural properties is the inspection of damage and cracks in the roof tiles, accounting for 3,297 cases, accounting for the largest portion. Meanwhile, a budget of about 27.6 billion won is secured for the 2020 cultural heritage care project, and a preventive management system is established through regular inspection and monitoring of cultural heritage through 23 care work groups across the country, with the goal of reducing the post-mortem maintenance and repair burden. It is known that there is

The reason why the maintenance of roof tiles for wooden cultural properties is important is that if damage or cracks occur in the roof tiles, the absorption rate increases, water leakage occurs, and the wood part rots, resulting in severe damage. On the other hand, in order to inspect the roof tiles, a high-level crane is used or a direct visual inspection is carried out through a high ladder, so it is very difficult to perform regular inspections with limited manpower while increasing costs due to safety accidents and long-term inspections.

During the inspection of cultural properties, the inspection for damage to tiles is one of the most time-consuming items as it determines the state of damage through visual inspection and detailed inspections such as water absorption, bending strength, and freezing. In the case of a relatively large cultural property, the tiles are randomly extracted to determine the state of damage, and when a problem is found in the roof tiles, it is a maintenance method that replaces up to 30 to 50% of the surrounding tiles based on the point where the problem occurred. is operated with

The current method of tile inspection is inefficient due to insufficient manpower, time and budget, and it is difficult to manage because there is no clear reference point for tile repair and maintenance because maintenance is dependent on visual inspection. In other words, in order to solve fundamental problems such as the lack of manpower and the limitations of visual inspection, we provide a technology to measure the level of damage to the roof tiles of wooden cultural assets using drones to overcome the limitations of cultural heritage management and enable accurate and prompt repair and maintenance. This is the technical idea that we are pursuing.

Papers on the mechanisms of damage to masonry including roof tiles are divided into physical, chemical, and biological weathering and explained. The study of physical weathering is a weathering process in which freeze-thaw occurs (Powers, 1945; 1949, Everett, 1961), a model of rock damage that occurs during submersion and drying (Kiessl, 1989), and the Weathering by salt (Winkler, EM and Wilhelm, EJ, 1970; Winkler, EM, 1973; Chapman, 1980; Sperling and Cooke, 1985; Goudie, 1999; Kuchitsu et al., 1999; Aref et al., 2002; Carlos et al, 2002) are covered.

In the following, the terms tile, stonework, and stone cultural property have the same meaning and will be selectively described in accordance with the context, but will be described as tile if possible.

The study of chemical weathering was suggested by Jenny (1950), Wollast (1967), and Birkeland (1984) by tracing the path of movement of elements that occur when minerals constituting rocks react with water, and the weathering process of masonry was suggested. After that, many researchers explained the weathering process of rocks by tracing the movement paths of elements that occur in the process of weathering rocks. As such studies are actively conducted, various weathering indices have been proposed that can determine the degree of weathering of rocks by quantitative analysis of principal elements (Ruxton, 1968; Paker, 1970; Nesbitt and Young, 1982; Jayaverdena and Izawa, 1994).

The study of biological weathering was conducted in Chl. A study was conducted to evaluate the effect of living things on the roof tiles by calculating the subject of a weathering state based on a and chromaticity (Donner et al., 2002; Schumann et al., 2005), and calculating the environmental factors and the vitality of living things. (Piervittori et al., 2002; Gazzano et al., 2009). Research on damage diagnosis mainly focuses on damage map, ultrasound probe, and infrared thermal image analysis. Fitzner (2004) and Kandemir-Yucel (2006) conducted ultrasonic surveys and IR thermography on historic buildings with internal cavities and found that several factors in the surrounding environment influence the ultrasonic velocity. In addition, research on compressive strength estimation using ultrasonic velocity is in progress by Ranazarn Demirboga (2004) and Matusinovic (2004). A study was conducted to compare the properties of granite by using ultrasonic velocity and the properties of granite.

As such, it can be seen that most of the studies on stone preservation are conducted with professional knowledge in the background, and are focused on damage mechanisms and precise diagnosis. In addition, it was found that studies on conservation treatment and field application were also conducted targeting a single cultural property. Therefore, it was confirmed that a study for the efficient conservation, management and monitoring of a large number of stone structures was necessary.

To establish a systematic monitoring and preservation system for roof tiles in Korea, various studies are being carried out to identify damage factors through diagnosing the degree of weathering damage based on the characteristics of constituent materials. Conservation scientific research on roof tiles has been conducted by many domestic and foreign researchers, including Jiyoung Kim et al. (2009), Mancheol Seo et al. (2001), Myeongseong Lee et al. (2012), Sunmyung Lee et al. (2010), Yugeun Jeon et al. (2008), Younghoon Cho and Chanhee Lee (2011). has been reported and considerable progress has been made. As for the application of the non-destructive diagnostic method to roof tiles, starting with Seokgatap and Dabotap of Bulguksa by Seo Man-cheol (2002), studies have been conducted mainly to understand the mechanical and physical characteristics of each member of stone structures until now. Recently, Jeon Yu-geun et al. (2008) and Lee Chan-hee (2011) provide guidelines for masonry preservation and treatment in the future through the diagnosis of damage using ultrasonic exploration. In addition, for long-term preservation and management of masonry, research on the structural stability diagnosis of masonry masonry through infrared thermal image analysis and 3D image analysis is being actively conducted (Howoong Son and Seongmin Lee, 2003; Byeonggyu Jeon et al., 2008; Younghoon Cho and Chanhee Lee, 2009). In addition, non-destructive techniques that are being practiced in engineering and natural sciences are being applied to masonry.

As such, it was confirmed that studies on the monitoring of roof tiles in Korea showed similar patterns to those of overseas studies. While studies on the damage mechanism of roof tiles and precision diagnosis technology are being actively conducted at home and abroad, studies on long-term monitoring are lacking. As mentioned above, each study is quite effective when applied to a single cultural property, but there are many limitations when applied to a large number of cultural properties due to the research period and lack of professional manpower. In addition, there are many difficulties in systematically converting the research results into a database because the research methods are slightly different. Weathering of roof tiles is a complex natural phenomenon that occurs when physical, chemical, and biological factors act alone or in combination. Therefore, quantitatively representing the state of roof tiles is an important research theme in rock engineering as well as geology and architecture, and various methods are being developed and tried. However, most techniques for evaluating the strength of roof tiles involve the destruction of samples, so it is often not appropriate as a monitoring method for the preservation of cultural properties. Therefore, the state of the tiles indirectly measures the strength of the tiles by using the ultrasonic speed, and the integrated damage evaluation technology that performs XRF analysis and visual inspection in parallel is mainly used. This technology evaluates the degree of damage to tiles step by step from a physical, chemical, biological and structural point of view by synthesizing scientific analysis of measured data and professional judgment on weathering conditions. The evaluation result is expressed as an integer of 5 steps for each element, and quantitative evaluation is possible through the calculation of the integrated damage rate, providing standards for the preservation, treatment and management of roof tiles.

However, while this method can make a relatively accurate diagnosis of the state of the roof tiles, it has limitations in terms of efficiency because it requires specialized technology, equipment, and long-term investigation time. In particular, roof tiles are scattered all over the country, and in most cases, it is difficult to establish an appropriate environment as most of them are in the form of large buildings. Therefore, preventive preservation through blocking of weathering factors is often impossible, and in this case, even if the condition is improved through conservation treatment, additional damage will occur. Weathering that occurs on the surface of a tile commonly causes a change in the color and texture of the surface, so it is expected that the degree of weathering of the tile can be inferred through the change in color. These changes can be quantitatively interpreted through color analysis through photography. In particular, in the field of cultural properties, photographic materials are easy to take and store, and as the most reliable record of the current state, they have vast amounts of data from the past. Therefore, it is possible to analyze changes and make predictions based on them, so more effective conservation management is expected. The color of a rock is determined by the composition and chemical composition of the minerals contained inside, and exhibits its own color by absorption of electromagnetic waves due to electronic transition of major transition elements and lanthanum elements. However, typical weathering patterns such as irregularities and abrasion on the rock surface formed by the removal of surface particles and expansion of gaps, elution and aggregation of specific components, and the growth of lichens and green plants change the color of rocks (Mitsushita, et al. , 1998). In particular, in the field of soil chemistry, the color is used as an important indicator when describing the characteristics of the soil, and the Munsell symbol is used for more objective and quantitative description.

In addition, Nakashima et al. (1989) measured the color of rocks and minerals using a colorimeter and proved that the color changes systematically according to the internal oxidation state and the progress of the chemical reaction. In addition, Nagano and Nakashima (1989) examined the color change according to the weathering of granite using a colorimeter and found that the color of the rock changes systematically to yellowish brown by the generation of iron hydroxide (FeO(OH)) according to the weathering. proved. This series of studies provided the mineralogical and chemical basis for the color change due to weathering through quantitative measurement of rock color.

With the development of space technology and image sensors, a new technology that has recently been attracting attention is remote sensing. Remote sensing refers to finding information about an object in an indirect way using electromagnetic waves such as light or heat from a distant object. In case of using visible light, it is possible to observe various changes in the earth, such as occurrence of red tides, movement of pollutants, changes in coastlines, monitoring of desertification and volcanic activity, using images taken from a long distance. In particular, since it uses photographic data, it is non-destructive, can be investigated from a distance, and it is easy to observe continuous changes.

The current roof tile monitoring management decided whether to preserve it based on the precise diagnosis results after weathering has progressed. Through constant monitoring of the roof tiles, prompt action can be taken in case of an abnormality, so more effective and smooth conservation management is expected. Therefore, in the present invention, image analysis, which is a field of remote sensing, is introduced as a monitoring technique for roof tiles, and the possibility can be confirmed by applying it to a representative roof tiles.

7 is a flowchart of a method of operating a system for detecting damage to a roof tile by a drone according to an embodiment of the present invention, and FIG. 8 is a photograph showing a normal tile and an abnormal tile taken as an embodiment to explain the present invention.

Hereinafter, with reference to all the accompanying drawings, a method of operating a roof tile damage grade detection system by a drone will be described in detail.

In the method of operating a system for detecting damage to a roof tile by a drone, which includes a cultural property, a drone photographing unit, a wireless relay booster unit, and a tile state analysis server, it is by a classification step, and the drone photographing unit photographed and transmitted by the tile state analysis server. When it is determined that a command signal for digital image processing of an image source signal is input (S100), whether a signal photographed with visible light (S110), a signal photographed with a microwave (S120), or a signal photographed with infrared light (S130) Classify the shooting method.

According to the color separation step, the photographing method classified in the classification step is marked or classified to be classified, and the source signal of the captured image is corrected to the corresponding standard image signal by the ambient climate signal (S140), and the corrected standard image The signal is subjected to color separation processing (S150).

An image signal secured by visible light is color-separated into 256 pieces, an image signal secured by an ultrasound signal is color-separated into 8 pieces, and an image signal secured by an infrared signal can be color-separated into 8 pieces. It is very natural that the color separation number can be added or subtracted as needed.

In the precise detection step, the boundary line and the outline are extracted from each image signal separated by color in the color separation step, respectively, the damage grade is estimated by comparing it with the standard image signal of the roof tile, respectively, and recorded in the allocated area (S160). By summing the calculated temporary damage grade and each imaging method, the final damage grade calculated by the arithmetic average is detected and recorded (S170). This process is repeated if necessary (S180).

As shown in the accompanying FIG. 8 , the boundary lines and outlines extracted from the tiles in the normal state and the tiles in the abnormal state are analyzed very differently.

In a tile in a normal state, the outline and outline are relatively constant and similar, but in a tile in an abnormal state, the boundary and outline are additionally generated at the part where damage or shear occurs, so the outline and outline are different and appear very complicated.

If the corresponding image signal taken from the roof tiles is subjected to digital image processing, outlines and outlines can be extracted. Digital image processing technology for extracting outlines and outlines is traded as a program, is well-known and can be easily selected and used, so no more specific details will be provided below. I'm not going to explain.

By analyzing the boundaries and outlines extracted by digital image processing of the image signals photographed in this way, it is possible to accurately determine whether the roof tiles are deformed, weathered or damaged, and to assign the corresponding damage grades automatically or manually.

Although the present invention has been described in detail with respect to the described embodiments, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical spirit of the present invention, and it is natural that such variations and modifications belong to the appended claims.

900: tile state detection system by drone
1000: Cultural property 1100: GPS satellite
1200: beacon unit 2000: drone photography unit
2100: operation unit 2200: drone operation control unit
2300: visible light imaging unit 2400: microwave imaging unit
2500: infrared imaging unit 2610: ambient climate sensor unit
2620: packet encryption/decryption unit 2700: Wi-Fi wireless unit
2800: FM wireless part 2900: Bluetooth wireless part
3000: wireless relay booster unit 4000: tile state analysis server
5000: acquired image packet frame

Claims (3)

delete The source signal of the acquired image taken at the same time as visible light, microwave signal, and infrared signal at a location designated by GPS coordinate information and beacon location information on a specific part of the roof of the cultural property 1000 is recorded in frame units, respectively, as an acquired image packet frame signal A drone photographing unit 2000 that encrypts and transmits each channel of a plurality of communication methods at the same time;
To the drone photographing unit 2000, wirelessly access each channel by multiple communication methods of the Wi-Fi wireless communication method, the FM wireless communication method, and the Bluetooth wireless communication method at the same time, and receive the encrypted acquired image packet frame signal, respectively, and all at the same time a wireless relay booster unit 3000 to transmit;
Wired connection with the wireless relay booster unit 3000, receives the acquired image packet frame signal through each channel of multiple communication methods, selects and decodes any one acquired image packet frame signal without a transmission error, and transmits visible light and microwave A tile state analysis server (4000) that separates the source signals of each acquired image taken with infrared rays, analyzes each image processing to estimate the damage grade of the tile, and calculates the arithmetic average of each estimated damage grade to detect the final damage grade ); In the tile damage rating detection system by a drone comprising a,
The drone photographing unit 2000 is
a navigation unit 2100 that flies at a location designated by the corresponding control signal;
It accesses the navigation unit 2100, analyzes any one or any one or more of the input GPS coordinate information and the received beacon location information, outputs a control signal to fly at a designated location, and sends the corresponding control signal to each of the configured functional units. Drone operation control unit 2200 to output;
a visible ray photographing unit 2300 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 with visible light according to a corresponding control signal of the drone operation control unit 2200;
a microwave imaging unit 2400 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as a microwave signal according to a corresponding control signal of the drone operation control unit 2200;
an infrared photographing unit 2500 for photographing an image signal of a tile located on a specific portion of the roof of the cultural property 1000 as an infrared signal according to a corresponding control signal of the drone operation control unit 2200;
Ambient climate sensor unit 2610 for detecting ambient climate signals including temperature, humidity, wind direction, wind speed, light quantity, and time by the surrounding climate according to the corresponding control signal of the drone operation control unit 2200, respectively;
The source signal of the acquired image photographed by the visible ray photographing unit 2300 according to the corresponding control signal of the drone operation control unit 2200, the source signal of the acquired image photographed by the microwave photographing unit 2400, and the infrared photographing unit 2500 a packet encryption/decryption unit 2620 for encrypting or decrypting the acquired image source signal captured by ) and the ambient climate signal detected by the surrounding climate sensor unit 2610 into an acquired image packet frame signal of a predetermined standard;
a Wi-Fi wireless unit 2700 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in a Wi-Fi wireless communication method;
an FM radio unit 2800 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in an FM radio communication method;
a Bluetooth wireless unit 2900 that is activated and operated according to a corresponding control signal of the drone operation control unit 2200 and transmits an encrypted acquired image packet frame signal in a Bluetooth wireless communication method; A tile damage rating detection system by a drone comprising a. delete

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