A method for accurately finding a leakage position when an outer wall has structural leakage

Abstract

This invention discloses a method for accurately locating the leakage point when structural leakage occurs in an exterior wall, comprising the following steps: First, infrared thermal imaging is used to detect and determine the leakage wet area on the outer side of the exterior wall; based on the location of the leakage wet area on the outer side of the exterior wall, a handheld infrared thermal imager is used to photograph the inner side of the exterior wall corresponding to the identified leakage wet area. If no leakage wet area is identified, it is determined to be a non-structural leakage; if a leakage wet area is identified, X-ray DR imaging combined with a grid-based partitioning method is used to locate the leakage point within the leakage wet area on the inner side of the exterior wall; if the leakage point is not found, the search area is expanded to the location on the inner side of the exterior wall corresponding to the leakage wet area on the outer side of the exterior wall. This invention innovatively uses a method combining "infrared screening and X-ray fluoroscopy" to accurately locate the structural leakage point of an exterior wall, achieving safe, efficient, accurate, and non-destructive diagnosis and location of potential leakage hazards.

Description

Technical Field

[0001] This invention relates to the field of building inspection technology, specifically to a method for accurately locating the leakage point when structural leakage occurs in an exterior wall. Background Technology

[0002] The long-term performance and safety of building envelopes have received unprecedented attention. As a key component of building envelopes, exterior walls directly bear the core function of resisting external environmental erosion and maintaining the stability of the indoor physical environment. Their engineering quality has transcended basic protective functions, becoming a comprehensive performance indicator integrating structural durability, energy efficiency, and life-cycle safety, directly affecting the building's service life and the health and safety of its users. It is worth noting that exterior wall leakage, due to its hidden nature, conductive nature, and systemic hazards, has become a core hidden danger that must be eradicated in the construction of "good houses." Its harm extends far beyond surface defects: at the structural level, seeping water will continuously cause internal steel corrosion and concrete protective layer peeling, fundamentally weakening the durability and safety of the load-bearing system; at the functional level, it directly leads to wall mold and insulation failure, seriously deteriorating the indoor health environment and potentially causing secondary disasters. Therefore, timely and accurate detection and diagnosis of exterior wall leakage is not only a necessary step in ensuring building safety and improving building quality, but also an important foundation for promoting the transformation of the construction industry towards high-quality, refined, and sustainable development.

[0003] The formation mechanism of exterior wall leakage is complex. It is not caused by a single factor, but is the result of the long-term coupled effects of multiple factors, including design defects, material properties, construction techniques, structural deformation, and environmental influences. From the perspective of the depth and severity of the leakage path, it can be divided into two basic types: surface layer leakage and structural leakage. Surface layer leakage mainly refers to moisture remaining only in non-structural layers such as the exterior wall finish, insulation layer, or plaster layer. Although it may cause cosmetic damage and reduced insulation performance, it has not yet endangered the structural safety of the building. Structural leakage, on the other hand, refers to moisture infiltrating into the load-bearing structure such as concrete and masonry through various gaps, such as cracks and joints. Its harm is insidious and systemic, fundamentally weakening the durability and load-bearing capacity of the building. Based on engineering practice and research, the key factors that cause exterior wall cracks and ultimately lead to structural leakage mainly include: 1. Material shrinkage stress: Drying shrinkage and temperature shrinkage occur during the hardening process of cement mortar or concrete. When the shrinkage stress exceeds the tensile strength of the material, a micro-to-macro crack system will form, providing an initial channel for moisture penetration. 2. Temperature stress: The temperature difference cycle that building exterior walls undergo year-round leads to differences in the thermal expansion coefficients of different materials. This incoordination deformation creates huge temperature stress concentrations at structurally weak points (such as the corners of door and window openings), which are eventually released in the form of cracks. 3. Defects in precast panel joints: For buildings using precast wall panels such as autoclaved lightweight concrete (ALC) panels, the vertical and horizontal joints between the panels are a key aspect of waterproofing. If the elastic sealant at the joints ages or fails, or if the sealant is not fully filled, the joints will become a concentrated release point for structural deformation. If the joint design is unreasonable or the construction quality is poor, through cracks that spread along the joint are very likely to form at the joints. 4. Substandard Material Quality: Using substandard raw materials, such as inferior cement or aggregates with excessive mud content, directly reduces the mechanical properties and durability of the materials, exacerbating the formation and development of cracks. 5. Construction Holes and Post-Anchoring Defects: During construction, temporary installations such as tower cranes and construction elevators often involve pre-drilling or creating attachment holes in the wall. If these holes are not properly sealed or filled with micro-expansion concrete in stages, cold joints and weak areas will form, easily leading to gaps under alternating structural and wind loads. In summary, factors such as material shrinkage, temperature stress, joint defects, material quality, and construction holes collectively induce and form various types of cracks in building exterior walls. These defects weaken or penetrate the continuity and sealing of the exterior wall, forming the main physical channels for moisture penetration, ultimately leading to structural leakage. Therefore, accurately locating various cracks in the exterior wall is crucial for eradicating leakage problems and ensuring the long-term performance of the exterior wall.

[0004] In the on-site detection of exterior wall leakage problems, infrared thermography is currently the most widely used technology in the industry. This method is based on the thermal radiation characteristics and heat transfer laws of objects, and identifies potential leakage areas by detecting the temperature difference on the wall surface. Specifically, because water has a high specific heat capacity, when there is leakage in the wall, the rate of temperature rise or fall in the damp area is significantly different from that in the dry area. During the day, under sunlight or ambient temperature rise conditions, the damp area heats up slowly due to the heat absorption of water evaporation, appearing as a relatively low-temperature "cold spot." At night, during the cooling process, the damp area releases stored heat slowly, appearing as a relatively high-temperature "hot spot." The current standard operating procedure in the industry is as follows: First, conduct an on-site survey and develop a technical plan that includes factors such as detection time, shooting position, angle, and distance; then, use infrared thermography equipment to simultaneously acquire visible light and infrared images of the area to be tested, recording the environment and shooting parameters; in the data processing stage, abnormal areas are identified by analyzing and comparing the two types of images.

[0005] However, this method has the following significant limitations: 1. The detection results can only reflect the surface temperature anomaly area and cannot accurately locate the actual location of the leak. Leaks often use internal wall gaps as the core channel, and the "leaking wet area" formed by the diffusion of moisture inside the wall is much larger than the actual gap size. Infrared thermography can only show the "area-like" anomaly formed by the diffusion of humidity, and cannot accurately pinpoint the source of the leak, i.e., the specific location of the internal gap. 2. When conducting indoor inspections, space conditions are severely constrained. Fixed facilities such as office furniture, cabinets, and decorative components make it difficult to conduct large-scale, continuous inspections. Moving large quantities of items is not only labor-intensive and costly, but also difficult to obtain cooperation from users due to the serious impact on their normal lives. 3. This method can cause serious secondary damage in subsequent repair stages. Because it is impossible to accurately locate the internal gaps, the repair process has to adopt a crude strategy of "large-scale dissection", which means opening up the entire exterior wall cladding, insulation layer and even structural layer of the abnormal area for inspection. This operation not only causes large-scale structural damage and decorative damage, but may also cause irreversible damage to historical buildings or facades using special processes. At the same time, it may also face strong resistance from the owners due to the large scope of construction.

[0006] Therefore, given the systemic shortcomings of existing detection methods that "see the wet but not the cracks, see the surface but not the inside," the industry urgently needs a new non-destructive testing technology paradigm that can integrate macroscopic screening and microscopic diagnosis, achieve precise insight from the "leakage area" to the "crack path," and effectively distinguish the types of leakage. Summary of the Invention

[0007] The technical problem to be solved by this invention is to provide a method for accurately locating the leakage point when structural leakage occurs in the exterior wall, effectively constructing a complete technical link from rapid area identification to precise leakage location, and providing innovative technical support for the construction of "good houses".

[0008] To address the aforementioned technical problems, this invention provides a method for accurately locating the leakage point when structural leakage occurs in an external wall, comprising the following steps: First, infrared thermography was used to detect and identify the leaking and damp areas on the outside of the exterior wall; Based on the location of the leaking wet area on the outside of the exterior wall, a handheld infrared thermal imager is used to photograph the corresponding inner part of the exterior wall. The photographic results are used to determine whether there is a leaking wet area on the inner part of the exterior wall. If no leaking wet area is identified, it is determined to be a non-structural leak, and the search for the leaking location of the current exterior wall ends; if a leaking wet area is identified, it is determined to be a structural leak, and the next step is performed. First, use X-ray DR imaging to locate the leak within the wet area on the inside of the exterior wall; If the leak cannot be found, expand the search area to the location on the inside of the exterior wall corresponding to the leaking wet area on the outside of the exterior wall. Among them, the X-ray DR imaging method is as follows: the leaking wet area is divided into several grids to be inspected, and each grid is inspected by X-ray DR imaging. Based on the difference in the degree of X-ray absorption between the defective part and the normal part in the wall, the location of the leak is found by analyzing the gray-scale difference in the X-ray image.

[0009] Furthermore, the determination of the leakage and damp area on the outer side of the exterior wall is carried out by taking pictures of the outer side of the exterior wall using an infrared thermal imager mounted on a drone platform. Image processing technology and temperature measurement algorithms are used to analyze the temperature anomaly areas in the infrared thermal image to determine the leakage and damp area. When using an unmanned aerial vehicle (UAV) platform equipped with an infrared thermal imager to photograph the exterior wall, the flight path of the UAV is first planned, and the UAV platform is controlled to automatically fly and photograph along the route pre-planned based on the three-dimensional model of the target building.

[0010] Furthermore, based on the GNSS position, flight attitude, and camera parameters recorded by the drone during filming, the pixel coordinates corresponding to the leakage wet area are calculated into spatial three-dimensional coordinates on the building's three-dimensional model using photogrammetry principles, in order to obtain the three-dimensional spatial position of the leakage wet area on the outer side of the exterior wall. This position is then used to provide location guidance for verification at the corresponding location on the inner side of the exterior wall using a handheld infrared thermal imager.

[0011] Furthermore, in X-ray DR imaging, an X-ray machine and an imaging plate are used to take X-ray images. The X-ray machine is located inside the outer wall, and the imaging plate is moved outside the outer wall by a wall-climbing robot. The wall-climbing robot includes a safety rope, a traction mechanism, an imaging plate mounting mechanism, and a climbing height measurement module. The imaging plate is mounted on the imaging plate mounting mechanism, which is suspended below the traction mechanism. The traction mechanism climbs up and down along the climbing track provided by the safety rope. The climbing height measurement module is located on the traction mechanism and is used to measure the climbing height of the traction mechanism.

[0012] Furthermore, the X-ray machine is equipped with a mobile lifting device at its bottom, which consists of a hydraulic lifting platform vehicle and a mobile electric lifting frame, with a lifting range covering 250 mm to 5000 mm.

[0013] Furthermore, the size of the grid to be inspected is less than or equal to the size of the imaging plate.

[0014] Furthermore, the wall-climbing robot performs strip-type imaging on each grid to be inspected based on a pre-defined grid division. That is, after controlling the wall-climbing robot to complete imaging of all grids to be inspected in a single grid strip in the vertical direction, the wall-climbing robot returns to the bottom to reset and moves horizontally to the next adjacent grid strip, that is, moves to the left or right by a length equal to or slightly less than one grid. The process of rising, falling and moving horizontally is repeated until all grids to be inspected are traversed, and the entire leakage wet area is photographed.

[0015] Furthermore, during the X-ray imaging process, the tube voltage of the X-ray machine is set according to the wall material: a high tube voltage is used for irradiation of dense concrete walls; a low tube voltage is used for irradiation of lightweight infill walls. When the object of inspection is the joint between a concrete wall and an infill wall, a split-exposure imaging method is used to take two pictures. First, the picture is taken under low tube voltage to optimize the display of internal defects and joint conditions of the infill wall or lightweight material wall. Then, the picture is taken under high tube voltage to detect internal defects of the concrete wall.

[0016] The beneficial effects of this invention are: 1. This invention proposes a method for accurately locating the leakage point when structural leakage occurs in an exterior wall. Through the synergistic innovation of "large-area screening with infrared thermography" and "precise X-ray DR imaging," a non-destructive testing technology system is constructed that achieves "precise positioning from the outside to the inside, from the surface to the core," thus solving the core technical contradiction of "seeing moisture but not cracks, seeing the surface but not the inside." Because infrared thermography alone is limited by the moisture diffusion effect, it can only identify a large wet area of ​​leakage and cannot accurately locate the specific location of the root cause defects such as cracks and holes leading to leakage. This invention innovatively integrates infrared thermography and X-ray DR imaging. First, infrared thermography is used to achieve large-area rapid screening to pinpoint the range of the wet area of ​​leakage. Then, X-ray DR imaging is used within the wet area for grid-based perspective scanning, truly achieving precise positioning from the "leakage area" to the "crack path," significantly improving the accuracy and reliability of the detection.

[0017] 2. This invention adopts the detection logic of "from the outside to the inside, precise positioning". That is, firstly, infrared thermal imaging is used to screen the outside of the outer wall to locate the leakage wet area. Then, the corresponding inner area of ​​the outer wall is precisely checked. In this way, the workload of indoor detection is focused on a few highly suspicious specific rooms and walls. This method minimizes the intrusion into the indoor space and significantly improves the convenience and feasibility of detection.

[0018] 3. Since X-ray DR imaging requires extremely high precision in the alignment of the equipment, and building exterior walls are high-altitude vertical surfaces, conventional methods are insufficient to achieve accurate and stable equipment placement. This invention innovatively uses a wall-climbing robot as the platform for mounting the imaging panel, combined with a safety rope and a climbing height measurement module, to achieve accurate and stable placement of the imaging panel on the outside of the exterior wall. At the same time, the indoor mobile lifting device flexibly adjusts the horizontal and vertical position of the X-ray machine, enabling the engineering application of X-ray DR imaging in the detection of leaks in building exterior walls, effectively expanding the applicability of this technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the infrared thermal imaging detection results of the outer side of the exterior wall according to the present invention; Figure 2 This is an infrared thermal image verification map of the inner side of the outer wall of room 1 corresponding to the wet area 1 of the present invention; Figure 3 This is a schematic diagram of the grid-based division of the leakage wet area on the inner side of the exterior wall of room 1 according to the present invention; Figure 4 This is a schematic diagram of the equipment arrangement inside and outside the exterior wall of the present invention; Figure 5 This is a DR image of the leakage gap in the wet area 1 of this invention; Figure 6 This is a schematic diagram of the actual leakage location of the wet area 1 of the present invention; Figure 7 This is a DR image of the leakage holes in the wet area 2 of this invention.

[0020] The following are the labels in the diagram: 1. Mobile lifting device; 2. X-ray machine; 3. Traction mechanism; 4. Imaging plate mounting mechanism; 5. Climbing height measurement module; 6. Safety rope; 7. Imaging plate. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0022] Reference Figure 1 As shown, an embodiment of the method for accurately locating the leakage location when structural leakage occurs in the exterior wall according to the present invention is as follows: In a residential building with a reinforced concrete shear wall structure that has already been put into use, if the traditional infrared thermography method is used for outdoor detection, the leakage area obtained in the results is large, making it impossible to accurately locate the actual location of the leakage. If the infrared thermography method is used indoors, the fixed furniture such as wardrobes and beds are placed close to the wall, causing great interference, low efficiency, and difficulty in obtaining the cooperation of the owners. Moreover, the single infrared thermography method can only identify the temperature anomaly area formed by wet areas, but cannot accurately locate the internal gaps that are the root cause of leakage. Therefore, this project innovatively adopts the method for accurately locating the structural leakage location of the exterior wall by combining "infrared screening and X-ray fluoroscopy" proposed in this invention, aiming to achieve safe, efficient, accurate and non-destructive diagnosis and location of leakage hazards.

[0023] When using the method for accurately locating structural leaks in exterior walls according to this invention to inspect this project, the following equipment system is employed: Macroscopic screening equipment for the exterior wall: A DJI Matrice 4T drone, integrating a high-resolution infrared thermal imaging module, using image processing technology and temperature calculation algorithms to perform rapid, non-contact, large-area scanning of the exterior wall facade (in accordance with the China Engineering Construction Standardization Association standard "Technical Specification for Intelligent Non-destructive Testing of Building Envelope Systems" T / CECS 1884—2025); and software for calculating the three-dimensional coordinates of the leaking wet area based on photogrammetry and computer vision technology, used to process the data collected by the drone and achieve intelligent identification and spatial positioning of the leaking wet area. Verification equipment for the interior wall: A handheld high-precision infrared thermal imager, used for localized and targeted verification of the interior wall surface corresponding to the specific wet area screened by the drone. X-ray DR imaging equipment: An X-ray machine 2 mounted on a mobile lifting device 1 is arranged on the interior wall. On the outer side of the exterior wall, a wall-climbing robot consisting of a traction mechanism 3, an imaging plate mounting mechanism 4, and a climbing height measurement module 5 is deployed. A suspended safety rope 6 is positioned at a corresponding location on the roof. The wall-climbing robot climbs up and down the exterior wall along the safety rope, which passes through the traction mechanism and has an adjustable climbing speed. The climbing height measurement module consists of an encoder and pulleys driven by the safety rope. It calculates the climbing height based on the number of rotations of the pulleys and the pulley size, and wirelessly transmits the height data to a real-time height display device. An imaging plate 7 is installed inside the imaging plate mounting mechanism. The imaging plate works with an X-ray machine to take X-ray images.

[0024] The mobile lifting device consists of a hydraulic lifting platform vehicle and a mobile electric lifting frame, with a lifting range covering 250mm to 5000mm to meet both shooting and movement / lifting requirements. A positioning and alignment system transmitter probe can also be installed on the imaging plate mounting mechanism of the wall-climbing robot. On the inner side of the outer wall, a person manually holds the main unit of the positioning and alignment system and its receiver probe for alignment. The transmitter probe on the imaging plate mounting mechanism on the outer side of the outer wall emits a signal, which is received by the receiver probe and displayed on the main unit. When the signals are aligned, it indicates that the imaging plate is in position and imaging can begin.

[0025] This invention utilizes the synergistic innovation of "large-area infrared thermal imaging screening" and "precise X-ray DR imaging" to perform targeted diagnosis of structural leakage problems in exterior walls. It mainly includes three stages: rapid macroscopic screening of the exterior wall, targeted verification and leakage type identification of the interior wall, and non-destructive imaging to locate the actual leakage location. The specific implementation process is as follows: The first phase aims to conduct a large-area, rapid, non-contact screening of the building's exterior walls. On a clear, calm day, operators piloted a DJI Matrice 4T drone, equipped with a high-precision infrared thermal imaging module, to inspect the east-facing exterior wall of the residential building. Before inspection, the drone's flight path was planned, and the platform was controlled to automatically fly and capture images along a pre-planned route based on a 3D model of the target building. During flight, the integrated high-resolution infrared thermal imaging module simultaneously acquired visible light and infrared images of the area, recording environmental and shooting parameters such as inspection time, shooting position, angle, and distance. After imaging, the data was transmitted to software that calculates the 3D coordinates of the leaking wet area using photogrammetry and computer vision technology. This software, utilizing artificial intelligence and image recognition technology, automatically analyzed and compared the two types of images, identifying areas with abnormal temperatures—areas that differ significantly from dry areas and exhibit abnormal "cold spot" signals on the infrared thermal image. Based on the GNSS position (longitude, latitude, altitude), flight attitude, and camera parameters recorded by the drone during filming, and using photogrammetry principles, the pixel coordinates of the leaking wet area are proportionally calculated into spatial three-dimensional coordinates on the building's three-dimensional model, thereby accurately obtaining the three-dimensional spatial location of the leaking wet area on the outer side of the exterior wall. According to the data analysis results, such as... Figure 1 As shown, three potential low-temperature anomaly zones were identified on the outer walls of the 10th, 8th, and 7th floors, respectively, and labeled as wet zone 1, wet zone 2, and wet zone 3. These zones were then confirmed to correspond to rooms 1, 2, and 3 within the building. This phase utilized a drone with an integrated infrared thermal imaging module for large-area rapid screening on the outer walls, significantly improving detection efficiency and avoiding any initial disturbance to the interior spaces. Simultaneously, the use of automated data analysis software reduced reliance on subjective human experience, enabling rapid identification and location of leaking wet zones on the outer walls, providing precise coordinate guidance for subsequent targeted verification.

[0026] The second phase, through targeted verification of the inner side of the exterior walls and identification of leakage types, aims to minimize disruption to the interior space. Based on the three-dimensional spatial location of the leaking wet areas screened on the outer side of the exterior walls, inspectors do not need to enter all rooms or move furniture for large-area scanning. Instead, they can directly locate the specific wall surface of the room corresponding to the wet area, focusing the indoor work on a few highly suspicious specific walls, minimizing disruption to the interior space and greatly improving convenience and feasibility. When using a handheld high-precision infrared thermal imager to conduct targeted verification of the specific wall surface of the room corresponding to the located leaking wet area, the operator aims the thermal imager at the corresponding wall surface and carefully observes the image results to determine whether there is a leaking wet area on the inner side of the exterior wall at that corresponding location. If a leaking wet area is identified, it is determined to be a structural leak in the area, based on the wet areas already found on the outer side; if no leaking wet area is identified, it is determined to be a non-structural leak. The review results showed that significant low-temperature anomalies were found on the inner exterior walls of rooms 1 and 3, corresponding to wet zones 1 and 3, respectively; however, no significant low-temperature anomalies were found on the inner exterior wall of room 2, corresponding to wet zone 2. Wet zones 1 and 3 were identified as structural leaks due to significant temperature anomalies detected on both the inner and outer sides of their exterior walls; wet zone 2 was identified as a non-structural leak because temperature anomalies were only detected on the outer side of its exterior wall, with no temperature changes on the corresponding inner side. The results are shown in Table 1. This stage, by accurately identifying the type of leak, reduced the subsequent precise detection scope from multiple detection surfaces to two detection areas, greatly improving the feasibility and economy of the detection process.

[0027] Table 1. Results of Leakage Type Determination

[0028] The third stage involves non-destructive X-ray imaging to locate the actual leakage point, providing precise positioning for subsequent repairs. For wet areas 1 and 3, which have been identified as structural leaks, X-ray imaging is performed sequentially for precise location. This is the core aspect of this invention that overcomes the limitations of existing technologies. The following section uses the X-ray inspection of wet area 1 as an example to explain the operation process in detail. Figure 2 The image shown is a verification image of the inner exterior wall of room 1 corresponding to wet zone 1. Based on the infrared thermal image of the inner exterior wall of room 1 corresponding to wet zone 1 and the size of the imaging panel (430 mm × 350 mm), the leakage wet zone on the inner exterior wall is divided into grids, as shown below. Figure 3 As shown, the size of each grid cell to be inspected is made smaller than or equal to the size of the imaging plate. Figure 4The diagram shows the equipment layout. On the inner side of the outer wall, a mobile lifting device aligns the X-ray machine's emission port with the center of the first grid to be inspected. The X-ray machine maintains a vertical distance of approximately 800 mm from the inner wall surface. This ensures that after the image plate is positioned on the outer side of the outer wall, the X-ray machine maintains a vertical distance of approximately 1 to 1.1 meters from the imaging plate, guaranteeing optimal imaging results. The mobile lifting device has a lifting range of 250 mm to 5000 mm. A positioning and alignment system host and its receiving probe are also arranged. The emission probe is located directly above the imaging plate on the outer side of the outer wall, and the vertical distance between the center of the emission probe and the center of the imaging plate is a fixed value of 235 mm. The receiving probe is positioned on the inner wall surface directly above the grid area to be inspected. To ensure that the center of the imaging plate and the center of the grid to be inspected are collinear in the horizontal direction, the emission probe and the receiving probe must be aligned horizontally. Therefore, the distance from the receiving probe to the center of the grid to be inspected is equal to the distance from the emission probe to the center of the imaging plate, both being 235 mm. The receiving probe is positioned 235 mm directly above the center point of the grid to be inspected. On the outside of the exterior wall, based on the building plan and the planar coordinates of the indoor grid center point, the corresponding position of the grid center point on the roof is determined. The upper end of the safety rope is fixed here to ensure that the vertical projection of the safety rope passes through the center point of the grid to be inspected. Then, the wall-climbing robot is started to carry the imaging plate up the safety rope.

[0029] The wall-climbing robot is controlled to perform strip-style imaging of the target area based on a pre-defined grid. Specifically, on the outer side of the wall, after the robot completes imaging of a single grid strip vertically, it returns to the bottom to reset. Then, an operator on the roof adjusts the lateral position of the safety rope, moving it horizontally to the next adjacent strip—that is, moving it to the left or right by a distance equal to or slightly less than one grid length. Simultaneously, on the inner side of the wall, the X-ray machine and receiving probe move synchronously, ensuring that the X-ray machine's emission port, the center of the grid to be inspected, and the center of the imaging plate remain on the same horizontal line, and that the receiving probe is always positioned 235 mm directly above the center of the grid to be inspected. This lifting and lateral movement process is repeated until the entire wet area to be inspected is completely covered, achieving full imaging of the entire leaking wet area. During X-ray imaging, the X-ray tube voltage is set according to the differences in wall materials: for dense concrete walls, due to their high density and strong absorption, a high-voltage (260-280V) is used for irradiation; for lightweight infill walls, due to their low density and weak absorption, a low-voltage (120-130V) is used. When the object of inspection is the joint between a concrete wall and an infill wall, a two-stage exposure imaging method is used. First, an image is taken at a low-voltage setting to optimize the display of internal defects and joint conditions in the infill or lightweight material wall; then, an image is taken at a high-voltage setting to detect internal defects in the concrete wall. Finally, based on the difference in X-ray absorption between areas with leakage defects and normal areas within the wall, areas with grayscale differences in the X-ray image are analyzed to accurately locate the leakage point and pinpoint its exact location. In this embodiment, during the X-ray inspection of wet area 1, the wall-climbing robot is controlled according to... Figure 3 The planned grid is used for strip imaging from left to right. Starting from the first grid on the lower left, the wall-climbing robot climbs upwards to complete the first strip imaging and then returns to the bottom to reset. Subsequently, the operator on the roof adjusts the lateral position of the upper end of the safety rope, moving it horizontally to the right to the next adjacent strip. The moving distance is equal to or slightly less than the length of one grid, that is, the moving distance is equal to or slightly less than the length of the imaging plate (430 mm). The above lifting and lateral movement process is repeated until the entire wet area 1 is completely covered, achieving full imaging of the leaking wet area.

[0030] The obtained DR image results, such as Figure 5 , Figure 6 As shown, a clear crack is visible in the image corresponding to wet area 1, clearly revealing the specific location of the leak. Repeating the above steps for wet area 3 will yield an image of its leak location, as shown below. Figure 7 As shown, unlike wet area 1, the leakage in wet area 3 was caused by inadequate sealing of the holes. This stage of the operation enabled the transition from "presumed area" to "diagnosed root cause of leakage," providing precise guidance for subsequent maintenance work.

[0031] If the leak is not found in the wet area inside the exterior wall, the search area is expanded to the location on the inside of the exterior wall corresponding to the wet area outside the exterior wall. The area is first divided into grids, and then X-ray fluoroscopy is used to search for the leak.

[0032] Through the aforementioned three-tiered progressive detection process, this case fully demonstrates the novel detection logic constructed by this invention: "rapid macroscopic screening and intelligent positioning of the exterior wall → targeted verification and leakage type identification of the interior wall → non-destructive visualization and precise positioning of the leakage path." Ultimately, the actual location of the structural leakage was accurately pinpointed, achieving precise detection of structural leakage in building exterior walls that is localizable, diagnosable, and quantifiable. This effectively solves the core pain points that have long plagued the industry: "high misjudgment rate, ambiguous positioning, and significant destructive repair requirements."

[0033] The embodiments described above are merely preferred embodiments for fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A method for accurately locating the leakage point when structural leakage occurs in an exterior wall, characterized in that, Includes the following steps: First, infrared thermography was used to detect and identify the leaking and damp areas on the outside of the exterior wall; Based on the location of the leaking wet area on the outside of the exterior wall, a handheld infrared thermal imager is used to photograph the corresponding inner part of the exterior wall. The photographic results are used to determine whether there is a leaking wet area on the inner part of the exterior wall. If no leaking wet area is identified, it is determined to be a non-structural leak, and the search for the leaking location of the current exterior wall ends; if a leaking wet area is identified, it is determined to be a structural leak, and the next step is performed. First, use X-ray DR imaging to locate the leak within the wet area on the inside of the exterior wall; If the leak cannot be found, expand the search area to the location on the inside of the exterior wall corresponding to the leaking wet area on the outside of the exterior wall. Among them, the X-ray DR imaging method is as follows: the leaking wet area is divided into several grids to be inspected, and each grid is inspected by X-ray DR imaging. Based on the difference in the degree of X-ray absorption between the defective part and the normal part in the wall, the location of the leak is found by analyzing the gray-scale difference in the X-ray image.

2. The method for accurately locating the leakage point when structural leakage occurs in an external wall, as described in claim 1, is characterized in that... The determination of the leakage and damp area on the outside of the outer wall is carried out by taking pictures of the outside of the outer wall with an infrared thermal imager on a drone platform. Image processing technology and temperature measurement algorithm are used to analyze the temperature anomaly areas in the infrared thermal image to determine the leakage and damp area. When using an unmanned aerial vehicle (UAV) platform equipped with an infrared thermal imager to photograph the exterior wall, the flight path of the UAV is first planned, and the UAV platform is controlled to automatically fly and photograph along the route pre-planned based on the three-dimensional model of the target building.

3. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 2, is characterized in that... Based on the GNSS position, flight attitude, and camera parameters recorded by the drone during filming, the pixel coordinates corresponding to the leakage wet area are calculated into spatial three-dimensional coordinates on the building's three-dimensional model according to the principle of photogrammetry. This is to obtain the three-dimensional spatial position of the leakage wet area on the outer side of the exterior wall, which is then used to provide location guidance for verification at the corresponding location on the inner side of the exterior wall using a handheld infrared thermal imager.

4. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 1, is characterized in that... In X-ray DR imaging, an X-ray machine and an imaging plate are used to take X-ray images. The X-ray machine is located inside the outer wall, and the imaging plate is moved outside the outer wall by a wall-climbing robot. The wall-climbing robot includes a safety rope, a traction mechanism, an imaging plate mounting mechanism, and a climbing height measurement module. The imaging plate is mounted on the imaging plate mounting mechanism, which is suspended below the traction mechanism. The traction mechanism climbs up and down along the climbing track provided by the safety rope. The climbing height measurement module is located on the traction mechanism and is used to measure the climbing height of the traction mechanism.

5. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 4, is characterized in that... The X-ray machine is equipped with a mobile lifting device at its bottom, which consists of a hydraulic lifting platform vehicle and a mobile electric lifting frame, with a lifting range covering 250 mm to 5000 mm.

6. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 4, is characterized in that... The size of the grid to be inspected is less than or equal to the size of the imaging plate.

7. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 4, is characterized in that... The wall-climbing robot performs strip-type imaging based on a pre-defined grid division. That is, after controlling the wall-climbing robot to complete imaging of all the grids to be inspected in a single grid strip in the vertical direction, the wall-climbing robot returns to the bottom to reset and moves horizontally to the next adjacent grid strip, that is, moves to the left or right by a length equal to or slightly less than one grid. The process of rising, falling and moving horizontally is repeated until all the grids to be inspected are traversed, and the entire leakage wet area is photographed.

8. The method for accurately locating the leakage point when structural leakage occurs in an exterior wall, as described in claim 4, is characterized in that... During the X-ray imaging process, the tube voltage of the X-ray machine is set according to the wall material: a high tube voltage is used for dense concrete walls, and a low tube voltage is used for lightweight infill walls. When the object of inspection is the joint between a concrete wall and an infill wall, a split-exposure imaging method is used to take two pictures. First, the picture is taken under low tube voltage to optimize the display of internal defects and joint conditions of the infill wall or lightweight material wall. Then, the picture is taken under high tube voltage to detect internal defects of the concrete wall.

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