A Building Measurement Method Based on UAV Remote Sensing

Abstract

This invention discloses a building measurement method based on UAV remote sensing. In the field of building measurement technology, the method utilizes GPS to acquire the initial position information of the UAV, measures surrounding building information, constructs an initial 3D building model, records the UAV's movement trajectory, randomly selects trajectory points from the trajectory, and continues until all layers of building information in a multi-layer framework are measured, outputting the building model. The advantages of this invention are: by extracting trajectory points and calculating the distance to adjacent trajectories, the coverage integrity of the current layer can be verified, avoiding repeated or missed measurements; data is extracted according to a preset cycle, avoiding redundant sampling, reducing data volume while ensuring coverage of key points, and shortening the overall measurement time; the measurement methods of LiDAR, millimeter-wave radar, and ultrasonic radar are broken down into measurement units, verification units, and auxiliary measurement methods; and abnormal data is identified and eliminated through data comparison of different combinations.

Description

Technical Field

[0001] This invention relates to the field of building surveying technology, specifically a building surveying method based on unmanned aerial vehicle (UAV) remote sensing. Background Technology

[0002] As a fundamental link in engineering construction, urban planning, and building information technology, the technical requirements of building surveying are constantly upgrading with the development of the construction industry. Traditional building surveying mainly relies on ground surveying equipment such as total stations and levels to gradually construct the building outline through single-point measurements. At the same time, the rise of technologies such as building information technology and digital twin cities has put forward new requirements for building surveying: "high precision, high efficiency, and full-element".

[0003] Common building surveying methods often use single time or spatial intervals without dynamically adjusting to factors such as UAV speed and building structural complexity. They also make it difficult to verify coverage by calculating the distance between trajectory points, resulting in holes on the surface of the building model. Furthermore, the lack of dynamic adjustment based on edge curvature makes it easy to miss some areas. To address these issues, we propose a building surveying method based on UAV remote sensing. Summary of the Invention

[0004] The purpose of this invention is to provide a building measurement method based on unmanned aerial vehicle (UAV) remote sensing.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a building measurement method based on unmanned aerial vehicle (UAV) remote sensing, the building measurement method comprising the following steps:

[0006] S100: Use GPS to obtain the initial position information of the drone, measure the surrounding building information, and obtain the initial building information;

[0007] S200: Construct an initial 3D building model using the initial building information, and set the cycle time. and spatial distance Building information measured by the drone is extracted sequentially using periodic time and spatial distance. At the same time, a multi-layer frame is constructed, and an adjacent distance threshold is set for the multi-layer frame. , where the adjacent distance threshold It is 50cm;

[0008] S300, Set up measurement unit and verification unit, respectively, to extract the initial building information measurement method for measurement unit and verification unit, and use the remaining measurement method as auxiliary measurement method in measurement unit;

[0009] S400 assigns weights to the measurement methods and auxiliary measurement methods in the measurement unit, and then refines the dimensions of the building in the initial three-dimensional building model using the building information and data obtained from the measurement unit and the verification unit, to obtain the output building model.

[0010] As a further aspect of the present invention: In S200, when recording the movement trajectory of the UAV in the multi-layer frame, trajectory points are randomly extracted from the movement trajectory, and the straight-line distance between these trajectory points and adjacent movement trajectories is... At this point, the building information measurement of a single layer in the multi-layer frame is completed. Then, the building information measurement of the remaining layers is carried out until the building information measurement of all layers in the multi-layer frame is completed, thereby obtaining multi-angle building measurement data.

[0011] As a further aspect of the present invention: In step S200, the usage permission for cycle time is higher than the usage permission for spatial distance, and when extracting building information measured by the drone, the building information obtained in the first instant is regarded as the origin building information. Then, the drone's moving speed is set, and the time taken for the drone to move at the set moving speed is determined. Then obtain the building information measured at the current location of the drone;

[0012] After completing the building information measurement, the drone was controlled to move again. At this time, the drone moved a certain distance. Then, the drone was used again to measure building information, and then the next time the drone was used to measure building information, it was done at a periodic time. To determine the location for the next measurement based on the standard;

[0013] In S200, the user has the permission to edit the number of layers in a multi-layer frame and the threshold for adjacent distances;

[0014] When the drone's movement trajectory is recorded, the range and size values ​​of the measured building are obtained, and a stereoscopic measurement model is constructed in a multi-layer frame using the range and size values ​​of the measured building. At the same time, the edge lines of the stereoscopic measurement model are defined to form a closed stereoscopic measurement model, thus obtaining a closed model.

[0015] Once the drone moves to the edge of the closed model, the drone's direction of movement is actively adjusted so that it moves along the edge line. At the same time, the drone's movement trajectory is extracted, and the extraction distance is set.

[0016] The extraction distance is the trajectory segmentation threshold set by the user, with a default value of 2m. The drone's movement trajectory is divided into X trajectory segments based on the extraction distance, and the edge lines are regarded as fixed trajectories. Then, the fixed trajectories are regarded as the drone's movement trajectory.

[0017] As a further aspect of the present invention: In S200, after the trajectory segments are obtained, the starting points and ending points of different trajectory segments are included as trajectory points, and the trajectory points are mapped onto adjacent moving trajectories. At this time, the line segment from which the trajectory point reaches the adjacent moving trajectory is the mapping line, and the mapping line is perpendicular to the adjacent moving trajectory. The distance values ​​between different trajectory points and adjacent moving trajectories are calculated, and the distance values ​​are sorted in descending order. The first distance value and the corresponding trajectory point are extracted to obtain the target point.

[0018] As a further aspect of the present invention: In S200, after the target point is obtained, the midpoint of the mapping line is intercepted, and the line is extended from the midpoint as the starting point, so that the midpoint extends to the edge line of the closed model, and the extension line of the midpoint is obtained. The extension line is parallel to the adjacent movement trajectory. At this time, the intersection of the extension line and the edge line is taken as the extension intersection point. Then, the UAV is controlled to move to the extension intersection point and the UAV moves along the extension line of the midpoint.

[0019] As a further aspect of the present invention: in S200, the distance values ​​between different trajectory points and adjacent movement trajectories are... The calculation formula is as follows:

[0020] ;

[0021] in The three-dimensional spatial position of the trajectory point. This is the intersection of the mapping line and the adjacent movement trajectory.

[0022] As a further aspect of the present invention: in S300, the user has the authority to edit the number of building measurement methods, and the number of auxiliary measurement methods is... ,in This represents the total number of building surveying methods, including LiDAR, millimeter-wave radar, and ultrasonic radar. .

[0023] As a further aspect of the present invention: In step S400, after the weights are determined, the influence of the building information measured by the auxiliary measurement method on the building information in the measurement unit is determined according to the weights of the auxiliary measurement methods, and the building values ​​measured in the measurement unit and the building values ​​measured by the auxiliary measurement method are extracted simultaneously, thereby calculating the final building values ​​output by the measurement unit. The calculation formula is as follows:

[0024] ;

[0025] in To assist in the weighting of measurement methods, For the weight of the measurement unit, These are the building values ​​measured within the measurement unit. The building values ​​measured using auxiliary measurement methods.

[0026] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows:

[0027] 1. This invention can verify the coverage integrity of the current layer by extracting trajectory points and calculating the distance to adjacent trajectories, avoiding repeated measurements or missed measurements. It also extracts data according to a preset cycle to avoid redundant sampling, reduce the amount of data while ensuring the coverage of key points. It completes the measurement of each layer from the bottom layer to the top layer in sequence, and can simultaneously build the basic framework of the 3D model. It can measure and model at the same time, shortening the overall measurement time. It breaks down the measurement methods of lidar, millimeter-wave radar and ultrasonic radar into measurement units, verification units and auxiliary measurement methods. By comparing data from different combinations, it can identify and eliminate abnormal data.

[0028] 2. This invention ensures data timeliness in dynamic scenarios and guarantees sampling density in static scenarios. At the same time, it constructs a closed model based on the building area size, which clarifies the measurement range of the UAV, reduces the probability of flying out of the building area or missing edge structures. The edge line of the closed model serves as a trajectory constraint, enabling the UAV to fly along the building outline, improving the geometric consistency between the model surface and the actual building, and enhancing the integrity of the measurement. By mapping the perpendicular relationship between the line and adjacent trajectories, the trajectory spacing is accurately quantified, avoiding the subjective errors of traditional manual judgment.

[0029] 3. This invention ensures that the trajectory of the UAV remains equidistant from the building surface when it moves along the extension line of the edge line, avoiding missed edge measurements due to deviations in turning angle. The unified distance calculation method facilitates the comparison of measurement data from different projects and different equipment, improves data reusability, enhances the scalability of the solution, and the auxiliary measurement method can compensate for the shortcomings of the main sensor, thereby improving data reliability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the method flow in an embodiment of the present invention. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0032] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1:

[0034] This invention discloses a building measurement method based on UAV remote sensing. In the protection of ancient buildings such as the Yingxian Wooden Pagoda in Shanxi Province, the building structures have suffered from erosion over thousands of years, resulting in potential hazards such as deformation of brackets and cracking of beams and columns. Traditional measurement methods require manual climbing of scaffolding for contact measurement, which may cause secondary damage to the fragile wooden structure and is difficult to capture three-dimensional data of complex components such as eaves and coffered ceilings. In this case, the building measurement method based on UAV remote sensing uses multi-sensor fusion technology to perform non-contact scanning of the building, which can quickly acquire point cloud data with millimeter-level accuracy and construct a complete three-dimensional model.

[0035] Therefore, in order to effectively solve the above problems, this application proposes a building measurement method based on UAV remote sensing, as shown in the attached figures of the specification. Figure 1 As shown, the building surveying method includes the following steps:

[0036] S100: Use GPS to obtain the initial position information of the drone, measure the surrounding building information, and obtain the initial building information;

[0037] S200: Construct an initial 3D building model using the initial building information, and set the cycle time. and spatial distance Building information measured by the drone is extracted sequentially using periodic time and spatial distance. At the same time, a multi-layer frame is constructed, and an adjacent distance threshold is set for the multi-layer frame. , where the adjacent distance threshold It is 50cm;

[0038] In S200, when recording the movement trajectory of the UAV in a multi-layered frame, trajectory points are randomly selected from the movement trajectory, and the straight-line distance between these trajectory points and adjacent movement trajectories is recorded. At this point, the building information measurement of a single layer in the multi-layer frame is completed. Then, the building information measurement of the remaining layers is carried out until the building information measurement of all layers in the multi-layer frame is completed, thereby obtaining multi-angle building measurement data.

[0039] S300, Set up measurement unit and verification unit, respectively, to extract the initial building information measurement method for measurement unit and verification unit, and use the remaining measurement method as auxiliary measurement method in measurement unit;

[0040] S400: Assign weights to the measurement methods and auxiliary measurement methods in the measurement unit, and then refine the dimensions of the building in the initial three-dimensional building model using the building information and data obtained from the measurement unit and the verification unit to obtain the output building model.

[0041] Software for building 3D architectural models, such as SketchUp, Autodesk Revit, and Autodesk 3ds Max.

[0042] Specifically, the process involves acquiring the drone's initial position information, measuring surrounding building information, using this initial building information to construct an initial 3D building model, and setting a time interval. and spatial distance The system sequentially extracts building information measured by the drone using periodic time and spatial distance, while simultaneously constructing a multi-layered framework. The drone's movement trajectory is recorded within this framework, and trajectory points are randomly selected from these trajectories. The straight-line distance between each trajectory point and adjacent trajectories is then calculated. At this point, the building information measurement of a single layer in the multi-layer framework is completed. Then, the building information measurement of the remaining layers is carried out until the building information measurement of all layers in the multi-layer framework is completed. The initial building information measurement methods are extracted for the measurement unit and the verification unit respectively. The remaining measurement method is used as an auxiliary measurement method in the measurement unit. Weights are assigned to the measurement methods in the measurement unit and the auxiliary measurement method. Then, the initial building model is improved by the building information obtained from the measurement unit and the verification unit to obtain the output building model.

[0043] Example 2:

[0044] In the S200, the usage permission for cycle time takes precedence over the usage permission for spatial distance. Furthermore, when extracting building information measured by the drone, the building information acquired first is considered the origin building information. Then, the drone's movement speed is set, and the time it takes for the drone to move at the set speed is determined. Obtain building information measured from the current location of the drone;

[0045] After completing the building information measurement, the drone was controlled to move again. At this time, the drone moved a certain distance. Then, the drone was used again to measure building information, and then the next time the drone was used to measure building information, it was done at a periodic time. To determine the location for the next measurement based on the standard;

[0046] S200: Users have permission to edit the number of layers in a multi-layer frame and the threshold for adjacent distances.

[0047] When the drone's movement trajectory is recorded, the range and size values ​​of the measured building are obtained, and a stereoscopic measurement model is constructed in a multi-layer frame using the range and size values ​​of the measured building. At the same time, the edge lines of the stereoscopic measurement model are defined to form a closed stereoscopic measurement model, thus obtaining a closed model.

[0048] After the closed model is formed, the S200 transmits the closed model data to the UAV.

[0049] Once the drone moves to the edge of the closed model, the drone's direction of movement is actively adjusted so that it moves along the edge line. At the same time, the drone's movement trajectory is extracted, and the extraction distance is set.

[0050] The extraction distance is the user-defined trajectory segmentation threshold, with a default value of 2m. Based on the extraction distance, the drone's movement trajectory is divided into X trajectory segments, and the edge lines are regarded as fixed trajectories. Then, the fixed trajectories are regarded as the drone's movement trajectory.

[0051] In S200, after the trajectory segments are obtained, the starting and ending points of different trajectory segments are included as trajectory points. The trajectory points are mapped onto adjacent moving trajectories. At this time, the line segment from which the trajectory point reaches the adjacent moving trajectory is the mapping line, and the mapping line is perpendicular to the adjacent moving trajectory. The distance values ​​between different trajectory points and adjacent moving trajectories are calculated, and the distance values ​​are sorted in descending order. The first distance value and the corresponding trajectory point are extracted to obtain the target point.

[0052] Where X is an unknown;

[0053] Specifically, when extracting building information measured by the drone, the building information acquired at the first moment is considered the origin building information. Then, the drone's movement speed is set, and the building information measured at the drone's current position is acquired. After completing the measurement of the building information, the drone is controlled to move again to measure the building information. When the drone's movement trajectory is recorded, the range dimensions of the measured building are obtained, and a 3D measurement model is constructed in a multi-layer frame based on the range dimensions of the measured building. At the same time, the edge lines of the 3D measurement model are delineated to form a closed 3D measurement model. The closed model data is transmitted to the drone. When the drone moves to the closed... After identifying the edge line of the model, the drone's movement direction is actively adjusted to allow it to translate along the edge line. Simultaneously, the drone's movement trajectory is extracted, and an extraction distance is set. Based on this distance, the drone's movement trajectory is divided into X trajectory segments, with the edge line considered a fixed trajectory. These fixed trajectories are included in the judgment of adjacent movement trajectories. After obtaining the trajectory segments, the start and end points of different trajectory segments are identified as trajectory points. These trajectory points are then mapped onto adjacent movement trajectories. The line segment where a trajectory point reaches an adjacent movement trajectory is the mapping line, and the mapping line is perpendicular to the adjacent movement trajectory. The first distance value and the corresponding trajectory point are then extracted.

[0054] Example 3:

[0055] In S200, after the target point is obtained, the midpoint of the mapping line is intercepted, and the extension is carried out with the midpoint as the starting point, so that the midpoint is extended to the edge line of the closed model, and the extension line of the midpoint is obtained. The extension line is parallel to the adjacent movement trajectory. At this time, the intersection of the extension line and the edge line is taken as the extension intersection point. Then, the UAV is controlled to move to the extension intersection point and the UAV moves along the extension line of the midpoint.

[0056] In S200, the distance values ​​between different trajectory points and adjacent movement trajectories are... The calculation formula is as follows:

[0057] ;

[0058] in The three-dimensional spatial position of the trajectory point. The point where the mapping line intersects with the adjacent movement trajectory;

[0059] In S300, users have the authority to edit the number of building measurement methods, while the number of auxiliary measurement methods is... ,in This represents the total number of building surveying methods, including LiDAR, millimeter-wave radar, and ultrasonic radar. ;

[0060] In S400, after the weights are determined, the influence of the building information measured by the auxiliary measurement method on the building information in the measurement unit is determined according to the weight of the auxiliary measurement method. At the same time, the building values ​​measured in the measurement unit and the building values ​​measured by the auxiliary measurement method are extracted, thereby calculating the final building values ​​output by the measurement unit. The calculation formula is as follows:

[0061] ;

[0062] in To assist in the weighting of measurement methods, For the weight of the measurement unit, These are the building values ​​measured within the measurement unit. These are building values ​​measured using auxiliary measurement methods;

[0063] Specifically, the midpoint of the mapping line is intercepted, and the line is extended from the midpoint to the edge of the closed model, obtaining the extension line of the midpoint. This extension line is parallel to the adjacent movement trajectory. The intersection of the extension line and the edge line is taken as the extension intersection point. The drone is then controlled to move to this intersection point and move along the extension line of the midpoint. The distances between different trajectory points and adjacent movement trajectories are calculated. The influence of the building information measured by the auxiliary measurement method on the building information in the measurement unit is determined according to the weight of the auxiliary measurement method. The building values ​​measured in the measurement unit and the building values ​​measured by the auxiliary measurement method are extracted simultaneously to calculate the final building values ​​output by the measurement unit. .

[0064] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A building measurement method based on UAV remote sensing, characterized in that, The building surveying method includes the following steps: S100: Use GPS to obtain the initial position information of the drone, measure the surrounding building information, and obtain the initial building information; S200. Construct an initial 3D building model using the initial building information and set the cycle time. and spatial distance Building information measured by the drone is extracted sequentially using periodic time and spatial distance, and a multi-layer frame is constructed. Adjacent distance thresholds are set for the multi-layer frame. The adjacent distance threshold It is 50cm; In step S200, when recording the movement trajectory of the UAV in the multi-layer frame, trajectory points are randomly extracted from the movement trajectory, and the straight-line distance between these trajectory points and adjacent movement trajectories is recorded. At this point, the building information measurement of a single layer in the multi-layer frame is completed. Then, the building information measurement of the remaining layers is carried out until the building information measurement of all layers in the multi-layer frame is completed, thereby obtaining multi-angle building measurement data. S300, Set up measurement unit and verification unit, respectively, to extract the initial building information measurement method for measurement unit and verification unit, and use the remaining measurement method as auxiliary measurement method in measurement unit; S400 assigns weights to the measurement methods and auxiliary measurement methods in the measurement unit, and then refines the dimensions of the building in the initial three-dimensional building model using the building information and data obtained from the measurement unit and the verification unit, to obtain the output building model.

2. The building surveying method based on UAV remote sensing according to claim 1, characterized in that: In step S200, the usage permission for cycle time is higher than that for spatial distance. Furthermore, when extracting building information measured by the drone, the building information acquired immediately is considered the origin building information. Then, the drone's movement speed is set, and the time it takes for the drone to move at the set speed is determined. Then obtain the building information measured at the current location of the drone; After completing the building information measurement, the drone was controlled to move again. At this time, the drone moved a certain distance. Then, the drone was used again to measure building information, and then the next time the drone was used to measure building information, it was done at a periodic time. To determine the location for the next measurement based on the standard; In S200, the user has the permission to edit the number of layers in a multi-layer frame and the threshold for adjacent distances; When recording the movement trajectory of the drone, the range and size values ​​of the measured building are obtained, and a three-dimensional measurement model is constructed in a multi-layer frame based on the range and size values ​​of the measured building. At the same time, the edge lines of the three-dimensional measurement model are defined to form a closed three-dimensional measurement model, thus obtaining a closed model.

3. A building surveying method based on UAV remote sensing according to claim 2, characterized in that: S200 transmits the closed model data to the UAV after the closed model is formed; Once the drone moves to the edge of the closed model, the drone's direction of movement is actively adjusted so that it moves along the edge line. At the same time, the drone's movement trajectory is extracted, and the extraction distance is set. The extraction distance is the trajectory segmentation threshold set by the user, with a default value of 2m. The drone's movement trajectory is divided into X trajectory segments based on the extraction distance, and the edge lines are regarded as fixed trajectories. Then, the fixed trajectories are regarded as the drone's movement trajectory.

4. The building surveying method based on UAV remote sensing according to claim 3, characterized in that: In step S200, after the trajectory segments are obtained, the starting and ending points of different trajectory segments are included as trajectory points. The trajectory points are mapped onto adjacent moving trajectories. At this time, the line segment from which the trajectory point reaches the adjacent moving trajectory is the mapping line, and the mapping line is perpendicular to the adjacent moving trajectory. The distance values ​​between different trajectory points and adjacent moving trajectories are calculated, and the distance values ​​are sorted in descending order. The first distance value and the corresponding trajectory point are extracted to obtain the target point.

5. A building surveying method based on UAV remote sensing according to claim 4, characterized in that: In step S200, after the target point is obtained, the midpoint of the mapping line is intercepted, and the line is extended from the midpoint to the edge of the closed model, so that the midpoint extends to the edge of the closed model, thus obtaining the extension line of the midpoint. The extension line is parallel to the adjacent movement trajectory. At this time, the intersection of the extension line and the edge line is taken as the extension intersection point. Then, the UAV is controlled to move to the extension intersection point and move along the extension line of the midpoint.

6. A building surveying method based on UAV remote sensing according to claim 4, characterized in that: In step S200, the distance values ​​between different trajectory points and adjacent movement trajectories are... The calculation formula is as follows: ； in The three-dimensional spatial position of the trajectory point. This is the intersection of the mapping line and the adjacent movement trajectory.

7. A building surveying method based on UAV remote sensing according to claim 1, characterized in that: In S300, the user has the authority to edit the number of building measurement methods, and the number of auxiliary measurement methods is... ,in This represents the total number of building surveying methods, including LiDAR, millimeter-wave radar, and ultrasonic radar. .

8. A building surveying method based on UAV remote sensing according to claim 1, characterized in that: In step S400, after the weights are determined, the influence of the building information measured by the auxiliary measurement method on the building information in the measurement unit is determined according to the weight of the auxiliary measurement method. At the same time, the building values ​​measured in the measurement unit and the building values ​​measured by the auxiliary measurement method are extracted, thereby calculating the final building values ​​output by the measurement unit. The calculation formula is as follows: ； in To assist in the weighting of measurement methods, For the weight of the measurement unit, These are the building values ​​measured within the measurement unit. The building values ​​measured using auxiliary measurement methods.

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