Building surveying and mapping method based on three-dimensional laser scanning

Abstract

The invention relates to the technical field of building surveying and mapping, and discloses a building surveying and mapping method based on three-dimensional laser scanning, and the method comprises the steps: determining a building to be surveyed and mapped, collecting the basic size information of the building to be surveyed and mapped, and determining the initial scanning frequency of laser scanning according to the basic size information; dividing the to-be-mapped building into a plurality of scanning areas, and establishing a three-dimensional model of the to-be-mapped building according to the point cloud data; the surveying and mapping integrity of the three-dimensional model is identified, and whether the initial scanning frequency is adjusted or not is judged according to the surveying and mapping integrity; when it is judged that the initial scanning frequency is adjusted, determining a scanning compensation coefficient of the initial scanning frequency according to the geometric complexity; determining a scanning optimization coefficient of the initial scanning frequency based on the environment data; and determining a scanning adjustment coefficient according to the scanning compensation coefficient and the scanning optimization coefficient, and obtaining a scanning adjustment frequency. According to the invention, the working efficiency can be greatly improved, the investment of manpower and material resources is reduced, and the accuracy and reliability of measured data are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of building surveying and mapping, and in particular to a building surveying and mapping method based on three-dimensional laser scanning. Background Art

[0002] In today's construction industry, accurate and accurate architectural surveying plays a vital role in the planning of the entire building design, the execution of the construction process, and the maintenance of the building in the later stage. Traditional architectural surveying technology often relies on manual field measurement, which not only requires a lot of time and labor, but is also easily interfered by various human factors during the operation, which may cause deviations in the measurement data and affect the final measurement accuracy.

[0003] Therefore, it is necessary to design a building surveying and mapping method based on three-dimensional laser scanning to solve the problems existing in current technology. Summary of the invention

[0004] In view of this, the present invention proposes a building surveying and mapping method based on three-dimensional laser scanning, aiming to solve the problem that traditional building surveying and mapping technology often relies on manual field measurement, which not only requires a lot of time and labor, but is also easily interfered by various human factors during operation, which may cause deviations in the measurement data and affect the final measurement accuracy.

[0005] The present invention proposes a building surveying and mapping method based on three-dimensional laser scanning, comprising the following steps:

[0006] S100: determining a building to be surveyed, collecting basic size information of the building to be surveyed, and determining an initial scanning frequency of laser scanning according to the basic size information;

[0007] S200: dividing the building to be surveyed into a plurality of scanning areas, emitting a laser beam to each of the scanning areas according to the initial scanning frequency, and obtaining an echo signal reflected from the scanning area, generating point cloud data according to the echo signal, and establishing a three-dimensional model of the building to be surveyed according to the point cloud data;

[0008] S300: Identifying the surveying and mapping completeness of the three-dimensional model, and determining whether to adjust the initial scanning frequency according to the surveying and mapping completeness;

[0009] S400: When it is determined that the initial scanning frequency is to be adjusted, the geometric complexity of the building to be surveyed is collected, and a scanning compensation coefficient of the initial scanning frequency is determined according to the geometric complexity; environmental data of the building to be surveyed is collected, and a scanning optimization coefficient of the initial scanning frequency is determined based on the environmental data; a scanning adjustment coefficient is determined according to the scanning compensation coefficient and the scanning optimization coefficient, and the initial scanning frequency is adjusted according to the scanning adjustment coefficient to obtain a scanning adjustment frequency.

[0010] Further, when determining the initial scanning frequency of the laser scanning according to the basic size information, it includes:

[0011] The basic size information includes the surveying length, surveying height and surveying total area;

[0012] The initial scanning frequency is obtained by the following formula:

[0013]

[0014] Among them, f0 represents the initial scanning frequency; C represents the constant coefficient, which is used to represent the performance of laser scanning; A represents the total surveying area; H represents the surveying height; L represents the surveying length; and P represents the scanning precision factor.

[0015] Furthermore, identifying the surveying and mapping completeness of the three-dimensional model includes:

[0016] Collecting the density of point cloud data corresponding to each scanning area in the three-dimensional model, recorded as point cloud density;

[0017] Obtaining a threshold of the point cloud density of the scanning area corresponding to each point cloud density, recorded as a point cloud density threshold;

[0018] Comparing the point cloud density with a point cloud density threshold, extracting the number of the scanning areas where the point cloud density is greater than or equal to the point cloud density threshold, and recording it as the number of scanning areas;

[0019] A quantity ratio of the number of scanned areas to a threshold value of the number of scanned areas is obtained, and the quantity ratio is recorded as the surveying and mapping completeness.

[0020] Further, judging whether to adjust the initial scanning frequency according to the surveying and mapping completeness includes:

[0021] When the surveying and mapping completeness is greater than or equal to 0.85, determining not to adjust the initial scanning frequency;

[0022] When the surveying and mapping completeness is less than 0.85, it is determined that the initial scanning frequency is to be adjusted.

[0023] Furthermore, when the geometric complexity of the building to be surveyed is collected and the scanning compensation coefficient of the initial scanning frequency is determined according to the geometric complexity, it includes:

[0024] Collecting regional feature values ​​of all the scanning areas and constructing a set of regional feature values;

[0025] Calculating the geometric complexity of the building to be mapped according to the set of regional feature values;

[0026] The geometric complexity is obtained by the following formula:

[0027]

[0028] Among them, GC represents geometric complexity; CV(Si) represents the i-th regional eigenvalue in the regional eigenvalue set; maxCV(S) represents the maximum value of the regional eigenvalue in the regional eigenvalue set; ωi represents the weight coefficient corresponding to the i-th regional eigenvalue in the regional eigenvalue set.

[0029] Furthermore, when the geometric complexity of the building to be surveyed is collected and the scanning compensation coefficient of the initial scanning frequency is determined according to the geometric complexity, it also includes:

[0030] Setting a scanning compensation coefficient interval, wherein the scanning compensation coefficient interval includes a first scanning compensation coefficient, a second scanning compensation coefficient, and a third scanning compensation coefficient;

[0031] Comparing the geometric complexity with a first geometric complexity and a second geometric complexity, and determining a scanning compensation coefficient of the initial scanning frequency according to the comparison result; wherein the first geometric complexity is smaller than the second geometric complexity;

[0032] When the geometric complexity is less than or equal to the first geometric complexity, the first scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency;

[0033] When the geometric complexity is greater than the first geometric complexity and less than or equal to the second geometric complexity, the second scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency;

[0034] When the geometric complexity is greater than the second geometric complexity, the third scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency.

[0035] Further, when determining the scanning optimization coefficient of the initial scanning frequency based on the environmental data, it includes:

[0036] The environmental data include temperature, humidity, light intensity and atmospheric pressure;

[0037] Calculate the environmental impact coefficient of the building to be mapped according to the temperature, humidity, light intensity and atmospheric pressure;

[0038] The environmental impact coefficient is compared with historical data, and the scanning optimization coefficient of the initial scanning frequency is determined according to the comparison result.

[0039] Furthermore, when determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result, it includes:

[0040] When there is a historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, extracting a historical scanning optimization coefficient corresponding to the historical environmental impact coefficient;

[0041] When there is no historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, calculating the maximum environmental similarity between the historical environmental impact coefficient and the historical data, and determining the scanning optimization coefficient according to the maximum environmental similarity;

[0042] The maximum environment similarity is obtained by the following formula:

[0043]

[0044] Smax=max(S1,S2,…Sn);

[0045] Among them, Sj represents environmental similarity; EI represents the current environmental impact coefficient; EHj represents the jth historical environmental impact coefficient in the historical data; Smax represents the maximum environmental similarity; Sn represents the environmental similarity between the nth historical environmental impact coefficient and the current environmental impact coefficient, and j = 1, 2,…, n.

[0046] Furthermore, when determining the scanning optimization coefficient according to the maximum environment similarity, it includes:

[0047] Setting a scanning optimization coefficient interval, wherein the scanning optimization coefficient interval includes a first scanning optimization coefficient, a second scanning optimization coefficient, and a third scanning optimization coefficient;

[0048] Comparing the maximum environment similarity with the first maximum environment similarity and the second maximum environment similarity, and determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result; wherein the first maximum environment similarity is less than the second maximum environment similarity;

[0049] When the maximum environment similarity is less than or equal to the first maximum environment similarity, the first scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency;

[0050] When the maximum environment similarity is greater than the first maximum environment similarity and less than or equal to the second maximum environment similarity, the second scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency;

[0051] When the maximum environment similarity is greater than the second maximum environment similarity, the third scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency.

[0052] Further, the initial scanning frequency is adjusted according to the scanning adjustment coefficient to obtain the scanning adjustment frequency, including:

[0053] Calculating the scanning adjustment coefficient according to the scanning compensation coefficient and the scanning optimization coefficient;

[0054] The product value of the scanning adjustment coefficient and the initial scanning frequency is used as the scanning adjustment frequency;

[0055] The scanning adjustment coefficient is obtained by the following formula:

[0056] P = k1 × b + k2 × y;

[0057] Among them, P represents the scanning adjustment coefficient; b represents the scanning compensation coefficient; y represents the scanning optimization coefficient; k1 represents the first influence coefficient; k2 is the first influence coefficient.

[0058] Compared with the prior art, the beneficial effect of the present invention is that the architectural surveying and mapping method based on 3D laser scanning provided by the present invention can quickly and accurately obtain the geometric information of the building through the 3D laser scanning technology and generate a high-precision 3D model. This model can not only be used for architectural surveying and design, but also for the maintenance, repair, renovation of the building and the digital archiving of historical buildings. Through this method, work efficiency can be greatly improved, the investment of manpower and material resources can be reduced, and the accuracy and reliability of the measurement data can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0060] Figure 1 A flowchart of a building surveying and mapping method based on three-dimensional laser scanning provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0062] See also Figure 1 As shown, in some embodiments of the present application, this embodiment provides a building surveying and mapping method based on three-dimensional laser scanning, comprising the following steps:

[0063] S100: determining a building to be surveyed, collecting basic size information of the building to be surveyed, and determining an initial scanning frequency of laser scanning according to the basic size information;

[0064] S200: dividing the building to be surveyed into a plurality of scanning areas, emitting a laser beam to each of the scanning areas according to the initial scanning frequency, and obtaining an echo signal reflected from the scanning area, generating point cloud data according to the echo signal, and establishing a three-dimensional model of the building to be surveyed according to the point cloud data;

[0065] S300: Identifying the surveying and mapping completeness of the three-dimensional model, and determining whether to adjust the initial scanning frequency according to the surveying and mapping completeness;

[0066] S400: When it is determined that the initial scanning frequency is to be adjusted, the geometric complexity of the building to be surveyed is collected, and a scanning compensation coefficient of the initial scanning frequency is determined according to the geometric complexity; environmental data of the building to be surveyed is collected, and a scanning optimization coefficient of the initial scanning frequency is determined based on the environmental data; a scanning adjustment coefficient is determined according to the scanning compensation coefficient and the scanning optimization coefficient, and the initial scanning frequency is adjusted according to the scanning adjustment coefficient to obtain a scanning adjustment frequency.

[0067] In this embodiment, the building to be measured refers to any building that requires accurate three-dimensional measurement, such as historical buildings, modern buildings, bridges, tunnels, etc.

[0068] In this embodiment, the three-dimensional model refers to a digital representation of a building obtained by three-dimensional laser scanning technology, which can accurately reflect the geometric shape, size and spatial position of the building. The three-dimensional model not only contains the appearance features of the building, but also includes detailed information on the internal structure, providing important data support for the maintenance, restoration and renovation of the building. Through the three-dimensional model, a variety of applications such as virtual reality display, structural analysis, historical evolution comparison, etc. can be carried out, which greatly improves the efficiency and accuracy of building mapping. When constructing a three-dimensional model, advanced data processing algorithms such as point cloud registration, fusion and surface reconstruction technology are used to construct and refine the three-dimensional model.

[0069] It can be understood that the architectural surveying and mapping method based on 3D laser scanning provided in this embodiment can quickly and accurately obtain the geometric information of the building and generate a high-precision 3D model through 3D laser scanning technology. This model can not only be used for architectural surveying and design, but also for building maintenance, repair, renovation and digital archiving of historical buildings. Through this method, work efficiency can be greatly improved, the investment of manpower and material resources can be reduced, and the accuracy and reliability of the measurement data can be guaranteed.

[0070] Specifically, when determining the initial scanning frequency of the laser scanning according to the basic size information, it includes:

[0071] The basic size information includes the surveying length, surveying height and surveying total area;

[0072] The initial scanning frequency is obtained by the following formula:

[0073]

[0074] Among them, f0 represents the initial scanning frequency; C represents the constant coefficient, which is used to represent the performance of laser scanning; A represents the total surveying area; H represents the surveying height; L represents the surveying length; and P represents the scanning precision factor.

[0075] In this embodiment, the preferred value of the scanning precision factor P is 1. When the building surveying and mapping accuracy requirements are high, the value of P can be appropriately increased to increase the scanning frequency and ensure the acquisition of more accurate point cloud data. In actual operation, the value range of P is usually between 1 and 3, and the specific value needs to be determined according to the actual surveying and mapping accuracy requirements and site conditions.

[0076] In this embodiment, the preferred value of the constant coefficient C is 0.5, which is obtained based on the performance of the laser scanning device and the actual application scenario. When it is necessary to improve the scanning efficiency, the C value can be appropriately reduced to reduce the scanning frequency, thereby reducing the scanning time; conversely, if it is necessary to improve the density and accuracy of the point cloud data, the C value should be appropriately increased. It should be noted that the adjustment of the C value must be carried out under the premise of ensuring the stable operation of the scanning device to avoid overheating or damage to the device due to excessive frequency.

[0077] In this embodiment, the surveying length refers to the longest straight-line distance of the building, the surveying height refers to the vertical distance from the ground to the highest point of the building, and the surveying total area refers to the floor area of ​​the building. Through these basic dimension information, the initial scanning frequency can be accurately calculated to ensure the efficiency and accuracy of the laser scanning. In practical applications, the acquisition of these dimension information can be completed by traditional measuring tools or by satellite positioning systems (such as GPS). Once these basic dimensions are determined, the initial scanning frequency can be calculated according to the above formula, laying the foundation for the subsequent three-dimensional model construction.

[0078] Specifically, identifying the surveying and mapping completeness of the three-dimensional model includes:

[0079] Collecting the density of point cloud data corresponding to each scanning area in the three-dimensional model, recorded as point cloud density;

[0080] Obtaining a threshold of the point cloud density of the scanning area corresponding to each point cloud density, recorded as a point cloud density threshold;

[0081] Comparing the point cloud density with a point cloud density threshold, extracting the number of the scanning areas where the point cloud density is greater than or equal to the point cloud density threshold, and recording it as the number of scanning areas;

[0082] A quantity ratio of the number of scanned areas to a threshold value of the number of scanned areas is obtained, and the quantity ratio is recorded as the surveying and mapping completeness.

[0083] Specifically, judging whether to adjust the initial scanning frequency according to the surveying and mapping completeness includes:

[0084] When the surveying and mapping completeness is greater than or equal to 0.85, determining not to adjust the initial scanning frequency;

[0085] When the surveying and mapping completeness is less than 0.85, it is determined that the initial scanning frequency is to be adjusted.

[0086] In this embodiment, the point cloud density threshold refers to a key parameter used to evaluate the quality of point cloud data. It represents the minimum density requirement of point cloud data in each scanning area in the three-dimensional model. The setting of the point cloud density threshold depends on the specific needs and accuracy requirements of the surveying and mapping task. For example, if high-precision architectural surveying and mapping is required, the point cloud density threshold will be set higher to ensure the details and accuracy of the three-dimensional model. On the contrary, if the surveying and mapping task does not require particularly high accuracy, the point cloud density threshold can be appropriately lowered to improve scanning efficiency. The setting of the point cloud density threshold is crucial to ensuring the quality of three-dimensional laser scanning data, which directly affects the subsequent construction of the three-dimensional model and the accuracy of the surveying and mapping results.

[0087] In this embodiment, the threshold value of the number of scanning areas is pre-set according to the complexity of the building and the mapping accuracy requirements. For buildings with higher complexity, such as buildings with complex decorations or structures, the threshold value of the number of scanning areas will be set higher to ensure the integrity and accuracy of the three-dimensional model. For buildings with relatively simple structures, the threshold value of the number of scanning areas can be relatively low. In this way, the mapping requirements of different buildings can be flexibly adapted while ensuring the quality of the three-dimensional model.

[0088] Specifically, the geometric complexity of the building to be surveyed is collected, and the scanning compensation coefficient of the initial scanning frequency is determined according to the geometric complexity, including:

[0089] Collecting regional feature values ​​of all the scanning areas and constructing a set of regional feature values;

[0090] Calculating the geometric complexity of the building to be mapped according to the set of regional feature values;

[0091] The geometric complexity is obtained by the following formula:

[0092]

[0093] Among them, GC represents geometric complexity; CV(Si) represents the i-th regional eigenvalue in the regional eigenvalue set; maxCV(S) represents the maximum value of the regional eigenvalue in the regional eigenvalue set; ωi represents the weight coefficient corresponding to the i-th regional eigenvalue in the regional eigenvalue set.

[0094] In this embodiment, the regional characteristic value refers to a value used to describe the geometric characteristics of each scanned area, such as the curvature, angle, complexity of the boundary, etc. of the area. These characteristic values ​​can reflect the degree of geometric change of the building surface and are an important basis for evaluating the geometric complexity of the building. By calculating the characteristic value of each area and combining it with the corresponding weight coefficient, the geometric complexity of the entire building can be obtained. The calculation of geometric complexity helps to determine the scanning compensation coefficient, so as to appropriately adjust the initial scanning frequency to meet the mapping needs of buildings of different complexities.

[0095] In this embodiment, the weight coefficient ωi is set based on the evaluation of the importance of the geometric features of the building. For example, for areas with complex decorations or structures, the corresponding weight coefficient may be higher, because the geometric features of these areas have a greater impact on the mapping integrity of the overall building. On the contrary, for relatively simple or less critical areas, the weight coefficient may be lower. In this way, it can be ensured that the 3D laser scanning technology pays more attention to key areas during the mapping process, thereby improving the accuracy and efficiency of the overall mapping.

[0096] Specifically, when collecting the geometric complexity of the building to be surveyed and mapping and determining the scanning compensation coefficient of the initial scanning frequency according to the geometric complexity, it also includes:

[0097] Setting a scanning compensation coefficient interval, wherein the scanning compensation coefficient interval includes a first scanning compensation coefficient, a second scanning compensation coefficient, and a third scanning compensation coefficient;

[0098] Comparing the geometric complexity with a first geometric complexity and a second geometric complexity, and determining a scanning compensation coefficient of the initial scanning frequency according to the comparison result; wherein the first geometric complexity is smaller than the second geometric complexity;

[0099] When the geometric complexity is less than or equal to the first geometric complexity, the first scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency;

[0100] When the geometric complexity is greater than the first geometric complexity and less than or equal to the second geometric complexity, the second scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency;

[0101] When the geometric complexity is greater than the second geometric complexity, the third scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency.

[0102] In this embodiment, the first geometric complexity and the second geometric complexity are pre-set according to the type of building and the mapping accuracy requirements. For example, for historical buildings or modern buildings with complex structures, the first geometric complexity and the second geometric complexity will be set higher to ensure that the three-dimensional model can accurately reflect the details and complexity of the building. For buildings with relatively simple or standard structures, these two values ​​can be relatively low. In this way, it is possible to flexibly adapt to the mapping needs of different buildings while ensuring the quality of the three-dimensional model.

[0103] Specifically, when determining the scanning optimization coefficient of the initial scanning frequency based on the environmental data, it includes:

[0104] The environmental data include temperature, humidity, light intensity and atmospheric pressure;

[0105] Calculate the environmental impact coefficient of the building to be mapped according to the temperature, humidity, light intensity and atmospheric pressure;

[0106] The environmental impact coefficient is compared with historical data, and the scanning optimization coefficient of the initial scanning frequency is determined according to the comparison result.

[0107] In this embodiment, the environmental impact coefficient (EIC) is calculated by the following formula:

[0108] EIC=(T×α)+(H×β)+(L×γ)+(P×δ);

[0109] Among them, EIC stands for environmental impact coefficient; T stands for temperature; H stands for humidity; L stands for light intensity; P stands for atmospheric pressure; α, β, γ and δ stand for weight coefficients corresponding to temperature, humidity, light intensity and atmospheric pressure respectively. The setting of these weight coefficients is based on the evaluation of the influence of environmental factors to ensure that the efficiency and accuracy of 3D laser scanning are optimized under different environmental conditions.

[0110] Specifically, when determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result, it includes:

[0111] When there is a historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, extracting a historical scanning optimization coefficient corresponding to the historical environmental impact coefficient;

[0112] When there is no historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, calculating the maximum environmental similarity between the historical environmental impact coefficient and the historical data, and determining the scanning optimization coefficient according to the maximum environmental similarity;

[0113] The maximum environment similarity is obtained by the following formula:

[0114]

[0115] Smax=max(S1,S2,…Sn);

[0116] Among them, Sj represents environmental similarity; EI represents the current environmental impact coefficient; EHj represents the jth historical environmental impact coefficient in the historical data; Smax represents the maximum environmental similarity; Sn represents the environmental similarity between the nth historical environmental impact coefficient and the current environmental impact coefficient, and j = 1, 2,…, n.

[0117] In this embodiment, historical data refers to environmental data and historical environmental impact coefficients collected during previous three-dimensional laser scanning surveying and mapping processes. When there is a historical environmental impact coefficient that matches the current environmental impact coefficient, the corresponding historical scanning optimization coefficient can be used directly, so that the scanning frequency can be quickly adjusted to adapt to the current environmental conditions. If there is no record in the historical data that matches the current environmental impact coefficient, it is necessary to calculate the maximum environmental similarity with the historical data to determine a suitable scanning optimization coefficient. The calculation of the maximum environmental similarity takes into account the combined effects of multiple environmental factors such as temperature, humidity, light intensity, and atmospheric pressure, ensuring that the efficiency and accuracy of three-dimensional laser scanning are optimized under different environmental conditions. In this way, it can be ensured that under various environmental conditions, three-dimensional laser scanning technology can provide high-quality surveying and mapping data, thereby improving the overall efficiency and accuracy of building surveying and mapping.

[0118] Specifically, when determining the scanning optimization coefficient according to the maximum environment similarity, it includes:

[0119] Setting a scanning optimization coefficient interval, wherein the scanning optimization coefficient interval includes a first scanning optimization coefficient, a second scanning optimization coefficient, and a third scanning optimization coefficient;

[0120] Comparing the maximum environment similarity with the first maximum environment similarity and the second maximum environment similarity, and determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result; wherein the first maximum environment similarity is less than the second maximum environment similarity;

[0121] When the maximum environment similarity is less than or equal to the first maximum environment similarity, the first scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency;

[0122] When the maximum environment similarity is greater than the first maximum environment similarity and less than or equal to the second maximum environment similarity, the second scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency;

[0123] When the maximum environment similarity is greater than the second maximum environment similarity, the third scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency.

[0124] In this embodiment, the first maximum environmental similarity and the second maximum environmental similarity are pre-set based on statistical analysis of historical data. For example, for common environmental conditions, such as sunny weather or indoor environment, the first maximum environmental similarity and the second maximum environmental similarity will be set lower because the environmental impact under these conditions is relatively small. For extreme weather or special environmental conditions, such as high temperature and humidity or strong light, these two values ​​will be set higher to ensure that the efficiency and accuracy of three-dimensional laser scanning under these conditions are optimized. In this way, it is possible to flexibly adapt to the needs of architectural surveying and mapping under different environmental conditions while ensuring the quality of the three-dimensional model and the reliability of the surveying and mapping data.

[0125] Specifically, the initial scanning frequency is adjusted according to the scanning adjustment coefficient to obtain the scanning adjustment frequency, including:

[0126] Calculating the scanning adjustment coefficient according to the scanning compensation coefficient and the scanning optimization coefficient;

[0127] The product value of the scanning adjustment coefficient and the initial scanning frequency is used as the scanning adjustment frequency;

[0128] The scanning adjustment coefficient is obtained by the following formula:

[0129] P = k1 × b + k2 × y;

[0130] Among them, P represents the scanning adjustment coefficient; b represents the scanning compensation coefficient; y represents the scanning optimization coefficient; k1 represents the first influence coefficient; k2 is the first influence coefficient.

[0131] In this embodiment, the first influence coefficient k1 and the second influence coefficient k2 are pre-set according to the performance of the three-dimensional laser scanning device and the specific requirements of the scanning task. The first influence coefficient k1 mainly reflects the influence of the scanning compensation coefficient b on the initial scanning frequency, while the second influence coefficient k2 reflects the adjustment effect of the scanning optimization coefficient y on the initial scanning frequency. By reasonably setting these two influence coefficients, it can be ensured that the scanning adjustment frequency can not only meet the accuracy requirements of the surveying and mapping tasks, but also adapt to the impact of environmental changes on scanning efficiency. For example, when high-precision surveying and mapping is required, the value of k1 may be increased to ensure that the adjustment effect of the scanning compensation coefficient on the final scanning frequency is more significant; and when the environmental conditions change greatly, the value of k2 may be increased to strengthen the adjustment effect of the scanning optimization coefficient on the scanning frequency. In this way, the scanning frequency can be flexibly adjusted to adapt to different surveying and mapping needs and environmental conditions, thereby improving the application efficiency and data quality of three-dimensional laser scanning technology in architectural surveying and mapping.

[0132] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0133] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0135] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A building surveying and mapping method based on three-dimensional laser scanning, characterized in that: include: Determine a building to be surveyed, collect basic size information of the building to be surveyed, and determine an initial scanning frequency of laser scanning according to the basic size information; Divide the building to be surveyed into a plurality of scanning areas, emit a laser beam to each of the scanning areas according to the initial scanning frequency, obtain an echo signal reflected from the scanning area, generate point cloud data according to the echo signal, and establish a three-dimensional model of the building to be surveyed according to the point cloud data; Identifying the surveying and mapping completeness of the three-dimensional model, and determining whether to adjust the initial scanning frequency according to the surveying and mapping completeness; When it is determined that the initial scanning frequency is to be adjusted, the geometric complexity of the building to be surveyed is collected, and a scanning compensation coefficient of the initial scanning frequency is determined based on the geometric complexity; environmental data of the building to be surveyed is collected, and a scanning optimization coefficient of the initial scanning frequency is determined based on the environmental data; a scanning adjustment coefficient is determined based on the scanning compensation coefficient and the scanning optimization coefficient, and the initial scanning frequency is adjusted based on the scanning adjustment coefficient to obtain a scanning adjustment frequency.

2. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 1 is characterized in that: When determining the initial scanning frequency of the laser scanning according to the basic size information, it includes: The basic size information includes the surveying length, surveying height and surveying total area; The initial scanning frequency is obtained by the following formula: Among them, f0 represents the initial scanning frequency; C represents the constant coefficient, which is used to represent the performance of laser scanning; A represents the total surveying area; H represents the surveying height; L represents the surveying length; and P represents the scanning precision factor.

3. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 1 is characterized in that: Identifying the surveying and mapping completeness of the three-dimensional model includes: Collecting the density of point cloud data corresponding to each scanning area in the three-dimensional model, recorded as point cloud density; Obtaining a threshold of the point cloud density of the scanning area corresponding to each point cloud density, recorded as a point cloud density threshold; Comparing the point cloud density with a point cloud density threshold, extracting the number of the scanning areas where the point cloud density is greater than or equal to the point cloud density threshold, and recording it as the number of scanning areas; A quantity ratio of the number of scanned areas to a threshold value of the number of scanned areas is obtained, and the quantity ratio is recorded as the surveying and mapping completeness.

4. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 3 is characterized in that: When judging whether to adjust the initial scanning frequency according to the surveying and mapping completeness, it includes: When the surveying and mapping completeness is greater than or equal to 0.85, determining not to adjust the initial scanning frequency; When the surveying and mapping completeness is less than 0.85, it is determined that the initial scanning frequency is to be adjusted.

5. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 1, characterized in that: Collecting the geometric complexity of the building to be surveyed and mapping, and determining the scanning compensation coefficient of the initial scanning frequency according to the geometric complexity, includes: Collecting regional feature values ​​of all the scanning areas and constructing a set of regional feature values; Calculating the geometric complexity of the building to be mapped according to the set of regional feature values; The geometric complexity is obtained by the following formula: Among them, GC represents geometric complexity; CV(Si) represents the i-th regional eigenvalue in the regional eigenvalue set; maxCV(S) represents the maximum value of the regional eigenvalue in the regional eigenvalue set; ωi represents the weight coefficient corresponding to the i-th regional eigenvalue in the regional eigenvalue set.

6. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 5 is characterized in that: When collecting the geometric complexity of the building to be surveyed and mapping and determining the scanning compensation coefficient of the initial scanning frequency according to the geometric complexity, the method further includes: Setting a scanning compensation coefficient interval, wherein the scanning compensation coefficient interval includes a first scanning compensation coefficient, a second scanning compensation coefficient, and a third scanning compensation coefficient; Comparing the geometric complexity with a first geometric complexity and a second geometric complexity, and determining a scanning compensation coefficient of the initial scanning frequency according to the comparison result; wherein the first geometric complexity is smaller than the second geometric complexity; When the geometric complexity is less than or equal to the first geometric complexity, the first scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency; When the geometric complexity is greater than the first geometric complexity and less than or equal to the second geometric complexity, the second scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency; When the geometric complexity is greater than the second geometric complexity, the third scanning compensation coefficient is selected as the scanning compensation coefficient of the initial scanning frequency.

7. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 6 is characterized in that: When determining the scanning optimization coefficient of the initial scanning frequency based on the environmental data, it includes: The environmental data include temperature, humidity, light intensity and atmospheric pressure; Calculate the environmental impact coefficient of the building to be mapped according to the temperature, humidity, light intensity and atmospheric pressure; The environmental impact coefficient is compared with historical data, and the scanning optimization coefficient of the initial scanning frequency is determined according to the comparison result.

8. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 7 is characterized in that: When determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result, it includes: When there is a historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, extracting a historical scanning optimization coefficient corresponding to the historical environmental impact coefficient; When there is no historical environmental impact coefficient corresponding to the environmental impact coefficient in the historical data, calculating the maximum environmental similarity between the historical environmental impact coefficient and the historical data, and determining the scanning optimization coefficient according to the maximum environmental similarity; The maximum environment similarity is obtained by the following formula: Smax=max(S1,S2,…Sn); Among them, Sj represents environmental similarity; EI represents the current environmental impact coefficient; EHj represents the jth historical environmental impact coefficient in the historical data; Smax represents the maximum environmental similarity; Sn represents the environmental similarity between the nth historical environmental impact coefficient and the current environmental impact coefficient, and j = 1, 2,…, n.

9. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 8, characterized in that: When determining the scanning optimization coefficient according to the maximum environment similarity, it includes: Setting a scanning optimization coefficient interval, wherein the scanning optimization coefficient interval includes a first scanning optimization coefficient, a second scanning optimization coefficient, and a third scanning optimization coefficient; Comparing the maximum environment similarity with the first maximum environment similarity and the second maximum environment similarity, and determining the scanning optimization coefficient of the initial scanning frequency according to the comparison result; wherein the first maximum environment similarity is less than the second maximum environment similarity; When the maximum environment similarity is less than or equal to the first maximum environment similarity, the first scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency; When the maximum environment similarity is greater than the first maximum environment similarity and less than or equal to the second maximum environment similarity, the second scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency; When the maximum environment similarity is greater than the second maximum environment similarity, the third scanning optimization coefficient is selected as the scanning optimization coefficient of the initial scanning frequency.

10. The architectural surveying and mapping method based on three-dimensional laser scanning according to claim 9, characterized in that: The initial scanning frequency is adjusted according to the scanning adjustment coefficient to obtain the scanning adjustment frequency, including: Calculating the scanning adjustment coefficient according to the scanning compensation coefficient and the scanning optimization coefficient; The product value of the scanning adjustment coefficient and the initial scanning frequency is used as the scanning adjustment frequency; The scanning adjustment coefficient is obtained by the following formula: P = k1 × b + k2 × y; Wherein, P represents the scanning adjustment coefficient; b represents the scanning compensation coefficient; y represents the scanning optimization coefficient; k1 represents the first influence coefficient; k2 is the second influence coefficient.

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