Building health assessment method and system based on two-dimensional / three-dimensional fusion technology

Abstract

The invention discloses a building health assessment method and system based on a two-dimensional / three-dimensional fusion technology. The method comprises the following steps: carrying out omnibearing scanning on an indoor space of a building and collecting image data; key building structures in the image data are extracted, and a plurality of building structure images are obtained; identifying damage in the building structure image to obtain a damage identification result; the maximum value of the areas of all the damage areas of the same damage serves as the final damage area of the damage, and a two-dimensional damage information evaluation result of the building is obtained through calculation; obtaining a three-dimensional damage information evaluation result of the building based on three-dimensional reconstruction; and obtaining the health condition of the whole building based on the two-dimensional damage information evaluation result and the three-dimensional damage information evaluation result. The method is applied to the field of building detection, and the comprehensive damage assessment of the building on the three-dimensional level can be effectively realized by fusing the two-dimensional damage assessment and the three-dimensional reconstruction result.

Description

Technical Field

[0001] The present invention relates to the technical field of building detection, and in particular to a building health assessment method and system based on two-dimensional / three-dimensional fusion technology. Background Art

[0002] With the acceleration of urbanization, the health monitoring and management of building structures has become a key issue for urban safety and sustainable development. In natural disasters, engineering accidents or long-term service of buildings, buildings may suffer varying degrees of structural damage, which not only directly threatens their own structural integrity, but also may pose a major hidden danger to the safety of residents. Therefore, the development of an efficient and accurate building health assessment system has extremely important practical significance and wide application value.

[0003] At present, traditional methods of building health assessment mainly rely on on-site inspection and remote sensing image analysis. On-site inspection usually requires professionals to carry handheld devices and enter the construction site to inspect and evaluate structural damage, and the inspection results rely on the accumulation of engineering experience. This method is not only labor-intensive and time-consuming, but also faces potential dangers and high uncertainty. On the other hand, remote sensing image analysis technology extracts feature information such as color, spectrum, shape, texture, and shadow from images to design algorithms for distinguishing between built-up areas and non-built-up areas. However, such methods based on prior knowledge are easily affected by the limitations of building area characteristics, and due to resolution limitations, it is difficult to effectively identify minor damage to buildings.

[0004] In addition, existing building health assessment systems usually focus on the damage detection of single building components (such as walls, beams, columns, etc.), ignoring the comprehensive assessment of the overall three-dimensional space of the building. This limitation makes it difficult to accurately grasp the true health status of the building as a whole, especially in the health assessment of complex spatial structures such as floors and rooms. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a building health assessment method and system based on two-dimensional / three-dimensional fusion technology, which can effectively realize a comprehensive damage assessment of the building at the three-dimensional level by fusing the two-dimensional damage assessment with the three-dimensional reconstruction results.

[0006] To achieve the above object, the present invention provides a building health assessment method based on two-dimensional / three-dimensional fusion technology, comprising the following steps: Step 1, perform an all-round scan of the indoor space of the building and collect image data during the scanning process; Step 2, extracting key building structures from each of the image data to obtain a number of building structure images, wherein the key building structures include beams, columns, floors, ceilings and walls; Step 3, identifying damage in the building structure image based on a neural network to obtain damage identification results in all the building structure images, wherein the damage identification results include the area of ​​the damaged region and the confidence level; Step 4: after eliminating the damage identification results with a confidence level less than a set threshold, the maximum value of the damage area among all damage identification results of the same damage is taken as the final damage area of ​​the damage; Step 5: calculate the corresponding damage assessment result based on the final damage area of ​​each damage, and combine the damage assessment results corresponding to all damages to obtain the two-dimensional damage information assessment result of the building; Step 6, performing three-dimensional reconstruction of the indoor space of the building based on the image data, and obtaining a three-dimensional damage information assessment result of the building based on the three-dimensional reconstruction; Step 7: Based on the two-dimensional damage information assessment result and the three-dimensional damage information assessment result, the health status of the entire building is obtained, and normalization processing is performed to obtain the final assessment result of the building.

[0007] In one embodiment, in step 5, the calculation process of the damage assessment result is:

[0008] in, The damage assessment results are: is the final damaged area, that is, the number of damaged pixels, is the total number of pixels in the image of the building structure where the damage is located.

[0009] In one embodiment, in step 5, the damage assessment results corresponding to all the damages are integrated to obtain a two-dimensional damage information assessment result of the building, specifically: Classify all damages into one of the following categories: crack damage, hole damage, and spalling damage according to the actual situation; Calculate the average value of the damage assessment results of all crack damages as the crack damage assessment result; Calculate the average value of the damage assessment results of all hole damages as the hole damage assessment result; Calculate the average value of the damage assessment results of all spalling damages as the spalling damage assessment result; The crack damage assessment result, the hole damage assessment result, and the spalling damage assessment result are weighted to obtain the two-dimensional damage information assessment result.

[0010] In one embodiment, step 6 is specifically: Performing three-dimensional reconstruction of the indoor space of the building based on the image data to obtain three-dimensional point cloud data of each key building structure in each building after damage; Compare and calculate the 3D point cloud data of each key building structure after damage with the corresponding 3D point cloud data before damage to obtain the volume change and deflection change of each key building structure; Classify all key building structures as beams, columns, floors, ceilings and walls; Calculate the average volume change and the average deflection change of all beams, calculate the average volume change and the average deflection change of all columns, calculate the average volume change and the average deflection change of all floors, and calculate the average volume change and the average deflection change of all walls; The volume damage assessment result is obtained by weighting the average value of the volume changes of beams, columns, floors, ceilings and walls; The deflection damage assessment result is obtained by weighting the average value of the deflection changes of beams, columns, floors, ceilings and walls; The volume damage assessment result and the deflection damage assessment result are the three-dimensional damage information assessment result.

[0011] In one embodiment, in step 7, based on the two-dimensional damage information assessment result and the three-dimensional damage information assessment result, the health status of the entire building is obtained as follows:

[0012] in, For the health of the building, is the two-dimensional damage information assessment result, is the volume damage assessment result, is the deflection damage assessment result, , , is the weight coefficient, Provide an initial condition assessment of the building.

[0013] In one embodiment, in step 7, the normalization process is performed to obtain the final evaluation result of the building as follows:

[0014] in, For the final evaluation results, is the normalized maximum value of the evaluation structure; when At that time, the building's health assessment was level 1 damage; when At that time, the building's health assessment was level 2 damage; when At that time, the building's health assessment was level 3 damage; when At that time, the building's health assessment was level 4 damage.

[0015] To achieve the above object, the present invention further provides a building health assessment system based on two-dimensional / three-dimensional fusion technology, which uses the above method to assess the health status of a building. The building health system includes: A data acquisition module, used to collect image data of indoor space of a building; A two-dimensional image processing module is used to evaluate and obtain the two-dimensional damage information evaluation results of the building; A three-dimensional reconstruction processing module is used to evaluate and obtain the three-dimensional damage information evaluation results of the building; The data fusion processing module is used to output the final assessment results and damage level of the building.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: 1. The present invention detects and analyzes damage to building components on a two-dimensional level, and generates a weight file of its impact on the overall health of the building by comprehensively evaluating the degree of damage to each building component. At the same time, the geometric volume change, displacement, and deformation information of the building components are analyzed through three-dimensional reconstruction technology. Finally, the health assessment weights of different building components are comprehensively obtained by integrating the two-dimensional damage assessment with the three-dimensional reconstruction results, thereby realizing a comprehensive damage assessment of the building on a three-dimensional level, and providing a new solution for building health assessment. 2. The present invention has the characteristics of high accuracy, strong adaptability and wide application range, and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 Flow chart of a building health assessment method based on two-dimensional / three-dimensional fusion technology in an embodiment of the present invention; Figure 2 4 is a structural block diagram of a building health assessment system based on two-dimensional / three-dimensional fusion technology in an embodiment of the present invention.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] Example 1 like Figure 1 The figure shows a building health assessment method based on two-dimensional / three-dimensional fusion technology disclosed in this embodiment (hereinafter referred to as "building health assessment method"), which mainly includes the following steps: Step 1, perform an all-round scan of the indoor space of the building and collect image data during the scanning process; Step 2, extracting key building structures from each image data to obtain a number of building structure images, wherein the key building structures include beams, columns, floors, ceilings and walls; Step 3, identifying damage in the building structure image based on the neural network, and obtaining damage identification results in all building structure images, the damage identification results including the area of ​​the damaged area and the confidence level; Step 4: after eliminating the damage identification results with a confidence level less than a set threshold, the maximum value of the damage area among all damage identification results of the same damage is taken as the final damage area of ​​the damage; Step 5: calculate the corresponding damage assessment result based on the final damage area of ​​each damage, and combine the damage assessment results corresponding to all damages to obtain the two-dimensional damage information assessment result of the building; Step 6, performing three-dimensional reconstruction of the indoor space of the building based on the image data, and obtaining a three-dimensional damage information assessment result of the building based on the three-dimensional reconstruction; Step 7: Based on the two-dimensional damage information assessment results and the three-dimensional damage information assessment results, the health status of the entire building is obtained, and normalization processing is performed to obtain the final assessment result of the building.

[0024] The building health assessment method in this embodiment mainly includes four parts: image acquisition (i.e., step 1 above), two-dimensional image processing (i.e., steps 2 to 5 above), three-dimensional point cloud processing (i.e., step 6 above) and final assessment (i.e., step 7 above). Damage detection and analysis of building components are performed on a two-dimensional level, and a weight file of its impact on the overall building health status is generated by comprehensively assessing the degree of damage of each building component. At the same time, the geometric volume change, displacement, and deformation information of the building components are analyzed by three-dimensional reconstruction technology. Finally, by fusing the two-dimensional damage assessment with the three-dimensional reconstruction results, the health assessment weights of different building components are comprehensively obtained, and a comprehensive damage assessment of the building on a three-dimensional level is achieved, providing a new solution for building health status assessment.

[0025] In the image acquisition part of step 1, a multi-rotor drone is used as a data acquisition platform. The multi-rotor drone is equipped with a high-precision camera to realize remote control of the drone for obstacle avoidance and data collection, thereby realizing all-round scanning and image acquisition of the indoor space of the building, solving the problem of the danger of manual data collection. At the same time, the flexibility of the drone greatly improves the efficiency of data collection.

[0026] The two-dimensional image processing part in step 2 to step 5 is mainly divided into two parts: building component detection and segmentation and damage category detection.

[0027] The building component detection part is mainly used to identify the key building structures and damaged areas of the building from the image data. For damaged buildings, there are obvious differences between the damage characteristics of their internal structure and external macroscopic features, which may lead to misassessment of damage results based on remote sensing images. For example, the exterior wall of a building may show only minor damage, while its internal structure may have suffered serious damage. The existence of this difference makes it impossible for traditional macroscopic assessment methods to accurately reflect the actual damage status of the building.

[0028] In order to solve this problem, this embodiment proposes a method that uses building structure components as detection elements, focusing on identifying the internal structure of the building and the type of damage. First, the key building structures inside the building (including beams, columns, floors, ceilings and walls) are selected as the research objects, and the three common damage categories of cracks, holes and peeling are used as detection targets. That is, the image data is first segmented to obtain a number of building structure images, and then the building structure images are feature extracted based on the neural network to realize the identification of damage in the building structure images. Among them, in order to ensure the accuracy of feature extraction, the confidence of the feature extraction result is set, and the detection results with a confidence less than the set threshold are screened out, thereby reducing false detection. As for the specific structure of the neural network and its training process, they are relatively conventional technical means, and this embodiment will not be repeated.

[0029] The damage category detection part is mainly to avoid the situation where the damage category is incorrectly identified due to camera errors and shooting angle errors. This is because the same damage type may have different performance characteristics under different viewing angles, which brings challenges to damage identification. For example, a completely collapsed wall may only appear as a small hole from a side view. The inconsistent morphology caused by this difference in viewing angle may cause errors in the damage area assessment, which in turn affects the accuracy of the overall damage assessment.

[0030] In order to solve this problem, this embodiment compares the detection areas of the same damage on different building structure images and extracts the maximum value of the damage area as the final damage area of ​​the damage, thereby effectively avoiding the situation where the damage category is misidentified due to camera error and shooting angle error. That is, in the specific implementation process of step 5, the calculation process of the damage assessment result for a certain damage is:

[0031] in, The damage assessment results are: is the final damaged area, that is, the number of damaged pixels, is the total number of pixels in the image of the building structure where the damage is located.

[0032] Through the above formula, the damage assessment results of all damages in the internal space of the building can be calculated. However, in the actual assessment of the building, different damage types have different effects on the assessment results. Therefore, the damage assessment results of all damages in this embodiment cannot be generalized. Based on this, this embodiment proposes a method for obtaining the overall two-dimensional damage information assessment results of the building by integrating different types of damage, specifically: First, the damages identified from all building structures are classified into one of the following categories: crack damage, hole damage, and spalling damage according to their shapes and other actual conditions. Then, the average value of the damage assessment results of all crack damages is calculated as the crack damage assessment result; the average value of the damage assessment results of all hole damages is calculated as the hole damage assessment result; the average value of the damage assessment results of all spalling damages is calculated as the spalling damage assessment result; Finally, the crack damage assessment results, hole damage assessment results, and spalling damage assessment results are weighted to obtain the two-dimensional damage information assessment results.

[0033] In the actual assessment process of a building, it is difficult to observe the changes in physical quantities at the three-dimensional level from a two-dimensional image, such as changes in volume, changes in deflection, etc. However, the detection of physical quantities is a very convincing factor in the damage assessment of a building. Therefore, in the three-dimensional point cloud processing part of step 6 of this embodiment, by comparing the changes in volume and deflection of the key building structure before and after damage, the three-dimensional damage information assessment result of the building is obtained. The specific implementation process is as follows: Based on the image data, the indoor space of the building is reconstructed in three dimensions to obtain the three-dimensional point cloud data of each key building structure in each building after damage; Compare and calculate the 3D point cloud data of each key building structure after damage with the corresponding 3D point cloud data before damage to obtain the volume change and deflection change of each key building structure; Classify all key building structures as beams, columns, floors, ceilings and walls; Calculate the average volume change and the average deflection change of all beams, calculate the average volume change and the average deflection change of all columns, calculate the average volume change and the average deflection change of all floors, and calculate the average volume change and the average deflection change of all walls; The volume damage assessment result is obtained by weighting the average value of the volume changes of beams, columns, floors, ceilings and walls; The deflection damage assessment result is obtained by weighting the average value of the deflection changes of beams, columns, floors, ceilings and walls; The volume damage assessment results and deflection damage assessment results are the three-dimensional damage information assessment results.

[0034] After obtaining the 3D damage information assessment results, the health status of the entire building can be obtained by combining the 2D damage information assessment results with the 3D damage information assessment results, specifically:

[0035] in, For the health of the building, is the two-dimensional damage information assessment result, is the volume damage assessment result, The deflection damage assessment result , , , is the weight coefficient, To conduct an initial condition assessment of the building; For the calculated After normalization, the final evaluation result of the building can be obtained:

[0036] in, For the final evaluation results, is the normalized maximum value of the evaluation structure; when At that time, the building's health assessment was level 1 damage; when At that time, the building's health assessment was level 2 damage; when At that time, the building's health assessment was level 3 damage; when At that time, the building's health assessment was level 4 damage; Level 1 and 2 damage are classified as mild damage, at which point the building is slightly damaged and does not affect its basic functions and structural integrity. Level 3 damage is classified as moderate damage, and it is considered that the building has reached the point where it needs to be repaired, otherwise it may be dangerous to live in and needs to be repaired in a timely manner. Level 4 damage is classified as severe damage, at which point the building has completely lost its original architectural function.

[0037] It is worth noting that although this embodiment Figure 1 The steps in the process are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0038] Example 2 Based on the building health assessment method based on two-dimensional / three-dimensional fusion technology in Example 1, this embodiment discloses a building health assessment system based on two-dimensional / three-dimensional fusion technology. Figure 2 The building health assessment system includes a data acquisition module, a two-dimensional image processing module, a three-dimensional reconstruction processing module and a data fusion processing module. Specifically: The data acquisition module is used to collect image data of the indoor space of the building; The two-dimensional image processing module is used to evaluate and obtain the two-dimensional damage information evaluation results of the building; The three-dimensional reconstruction processing module is used to evaluate and obtain the three-dimensional damage information evaluation results of the building; The data fusion processing module is used to output the final assessment results and damage level of the building.

[0039] In this embodiment, the specific working process and working principle of the data acquisition module, the two-dimensional image processing module, the three-dimensional reconstruction processing module and the data fusion processing module are the same as those in the method of Embodiment 1, so they are not described in detail in this embodiment. Each unit module can be implemented in whole or in part by software, hardware and a combination thereof, and each unit module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above unit modules.

[0040] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A building health assessment method based on two-dimensional / three-dimensional fusion technology, characterized in that: The steps include: Step 1, perform an all-round scan of the indoor space of the building and collect image data during the scanning process; Step 2, extracting key building structures from each of the image data to obtain a number of building structure images, wherein the key building structures include beams, columns, floors, ceilings and walls; Step 3, identifying damage in the building structure image based on a neural network to obtain damage identification results in all the building structure images, wherein the damage identification results include the area of ​​the damaged region and the confidence level; Step 4: after eliminating the damage identification results with a confidence level less than a set threshold, the maximum value of the damage area among all damage identification results of the same damage is taken as the final damage area of ​​the damage; Step 5: calculate the corresponding damage assessment result based on the final damage area of ​​each damage, and combine the damage assessment results corresponding to all damages to obtain the two-dimensional damage information assessment result of the building; Step 6, performing three-dimensional reconstruction of the indoor space of the building based on the image data, and obtaining a three-dimensional damage information assessment result of the building based on the three-dimensional reconstruction; Step 7: Based on the two-dimensional damage information assessment result and the three-dimensional damage information assessment result, the health status of the entire building is obtained, and normalization processing is performed to obtain the final assessment result of the building.

2. The building health assessment method based on two-dimensional / three-dimensional fusion technology according to claim 1 is characterized in that: In step 5, the calculation process of the damage assessment result is: in, The damage assessment results are: is the final damaged area, that is, the number of damaged pixels, is the total number of pixels in the image of the building structure where the damage is located.

3. The building health assessment method based on 2D / 3D fusion technology according to claim 1 is characterized in that: In step 5, the damage assessment results corresponding to all the damages are integrated to obtain the two-dimensional damage information assessment result of the building, specifically: Classify all damages into one of the following categories: crack damage, hole damage, and spalling damage according to the actual situation; Calculate the average value of the damage assessment results of all crack damages as the crack damage assessment result; Calculate the average value of the damage assessment results of all hole damages as the hole damage assessment result; Calculate the average value of the damage assessment results of all spalling damages as the spalling damage assessment result; The crack damage assessment result, the hole damage assessment result, and the spalling damage assessment result are weighted to obtain the two-dimensional damage information assessment result.

4. The building health assessment method based on two-dimensional / three-dimensional fusion technology according to claim 1, 2 or 3, characterized in that: Step 6 is as follows: Performing three-dimensional reconstruction of the indoor space of the building based on the image data to obtain three-dimensional point cloud data of each key building structure in each building after damage; Compare and calculate the 3D point cloud data of each key building structure after damage with the corresponding 3D point cloud data before damage to obtain the volume change and deflection change of each key building structure; Classify all key building structures as beams, columns, floors, ceilings and walls; Calculate the average volume change and the average deflection change of all beams, calculate the average volume change and the average deflection change of all columns, calculate the average volume change and the average deflection change of all floors, and calculate the average volume change and the average deflection change of all walls; The volume damage assessment result is obtained by weighting the average value of the volume changes of beams, columns, floors, ceilings and walls; The deflection damage assessment result is obtained by weighting the average value of the deflection changes of beams, columns, floors, ceilings and walls; The volume damage assessment result and the deflection damage assessment result are the three-dimensional damage information assessment result.

5. The building health assessment method based on 2D / 3D fusion technology according to claim 4 is characterized in that: In step 7, based on the two-dimensional damage information assessment result and the three-dimensional damage information assessment result, the health status of the entire building is obtained as follows: in, For the health of the building, is the two-dimensional damage information assessment result, is the volume damage assessment result, is the deflection damage assessment result, , , is the weight coefficient, Provide an initial condition assessment of the building.

6. The building health assessment method based on 2D / 3D fusion technology according to claim 5 is characterized in that: In step 7, the normalization process is performed to obtain the final evaluation result of the building as follows: in, For the final evaluation results, is the normalized maximum value of the evaluation structure; when At that time, the building's health assessment was level 1 damage; when At that time, the building's health assessment was level 2 damage; when At that time, the building's health assessment was level 3 damage; when At that time, the building's health assessment was level 4 damage.

7. A building health assessment system based on two-dimensional / three-dimensional fusion technology, characterized in that: Using the method described in any one of claims 1 to 6 to assess the health status of a building; The building health system includes: A data acquisition module, used to collect image data of indoor space of a building; A two-dimensional image processing module is used to evaluate and obtain the two-dimensional damage information evaluation results of the building; A three-dimensional reconstruction processing module is used to evaluate and obtain the three-dimensional damage information evaluation results of the building; The data fusion processing module is used to output the final assessment results and damage level of the building.

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