Method and device for applying unmanned aerial vehicle modeling to urban microenvironment assessment

Abstract

The invention discloses a method and device for applying unmanned aerial vehicle modeling to urban microenvironment assessment, and belongs to the technical field of environmental meteorological monitoring, and the method comprises the steps: carrying out the inclined shooting of urban street buildings based on an unmanned aerial vehicle flight platform, and obtaining the three-dimensional data of terrains and features; generating a three-dimensional space layout model of buildings and other ground features in the area; low-altitude atmospheric environment parameters in the area are obtained based on the unmanned aerial vehicle flight platform; overlapping the low-altitude atmospheric environment parameters into the three-dimensional space layout model to form spatial-temporal distribution assimilation data, and generating complex boundary conditions of the simulation area; on the basis of the complex boundary conditions and the three-dimensional space layout model of the simulation area, the spatial and temporal distribution of an air flow field and an atmospheric pollutant concentration field and an air quality index are obtained through calculation with a CFD method, and urban microenvironment evaluation is completed; according to the invention, the unmanned aerial vehicle flight platform and the corresponding technology are applied to the quantitative evaluation of the urban block scale microenvironment, which is convenient and fast, and low in cost.

Description

Technical Field

[0001] The invention relates to a method and a device for applying unmanned aerial vehicle modeling to urban microenvironment assessment, belonging to the technical field of environmental meteorological monitoring. Background Art

[0002] Highly precise and simulated three-dimensional block models and environmental meteorological data are of great significance to improving the accuracy and precision of simulation of environmental meteorological variables at the urban block scale, and can further realize the detailed assessment of urban air quality, ecological environment and other aspects, providing a scientific basis for the refined control of atmospheric environmental pollution at the urban block scale.

[0003] Chinese patent CN118133640A provides a method, device and storage medium for evaluating air pollution at the block scale, which can evaluate air pollution with high accuracy at the block scale. However, this method collects urban modeling, environmental and meteorological spatiotemporal variables by manpower, which is very slow and costly, and many of the collected data cannot be used in the subsequent numerical model, which is inefficient. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method and device for applying drone modeling to urban microenvironment assessment. The method and device are based on the integration of oblique shooting modeling, environmental meteorological monitoring and other technologies of the drone flight platform with the block-scale refined aerodynamic numerical method, and applied to urban microenvironment assessment, which is convenient, fast and low-cost.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a method for applying drone modeling to urban microenvironment assessment, comprising: Oblique photography of urban street buildings based on the UAV flight platform to obtain three-dimensional data of terrain and objects; Generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of terrain and objects; Based on the UAV flight platform equipped with microenvironment and micrometeorological monitoring equipment, the low-altitude atmospheric environmental parameters in the area are obtained; The low-altitude atmospheric environmental parameters are superimposed on the three-dimensional spatial layout model, and the temporal and spatial distribution assimilation data of environmental meteorological variables at the scale of urban blocks are formed through interpolation processing and data fusion technology; Generate complex boundary conditions of the simulation area based on assimilated data in time and space; Based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area, the CFD method is used to calculate the spatiotemporal distribution of the air flow field, atmospheric pollutant concentration field and the air quality index to complete the urban microenvironment assessment.

[0006] Furthermore, the method of taking oblique photos of urban street buildings based on the UAV flight platform to obtain three-dimensional data of terrain and objects includes: Use a drone carrying a visible light oblique shooting device to take high-frequency continuous reciprocating shots of the area of ​​interest; During the filming process, the drone recorded in high resolution from multiple angles to capture detailed information of surface buildings and other terrain features; Maintain the continuous shooting frequency to ensure that the information repetition rate in the continuously generated photos reaches the set threshold and obtain three-dimensional data of terrain and objects.

[0007] Furthermore, the method further includes: performing error correction on the image data obtained by tilted shooting, and the formula is as follows: (1); (2); Where x represents the image point coordinates along the heading direction of the horizontal position after error correction, y represents the image point coordinates along the lateral direction of the horizontal position after error correction, x' represents the correction value of the error caused by the film deformation along the heading direction of the horizontal position, and y' represents the correction value of the error caused by the film deformation along the lateral direction of the horizontal position. Indicates the correction value of the error caused by lens distortion in the horizontal position along the heading direction. It represents the correction value of the error caused by lens distortion in the lateral direction of the horizontal position, dx represents the correction value of the error caused by atmospheric refraction in the heading direction of the horizontal position, dy represents the correction value of the error caused by atmospheric refraction in the lateral direction of the horizontal position, δx represents the correction value of the error caused by the curvature of the earth in the heading direction of the horizontal position, and δy represents the correction value of the error caused by the curvature of the earth in the lateral direction of the horizontal position.

[0008] Furthermore, generating a three-dimensional spatial layout model of buildings and other objects in the region based on the three-dimensional data of terrain and objects includes: Import the three-dimensional data of terrain and objects obtained by photography into the three-dimensional modeling software and algorithms; Use algorithms to process three-dimensional data of terrain and objects to generate three-dimensional spatial position coordinates of a large number of ground image points in the area of ​​interest; Generate a three-dimensional spatial layout model of buildings and other objects based on the three-dimensional spatial position coordinates.

[0009] Furthermore, the microenvironment and micrometeorological monitoring equipment carried by the UAV flight platform is used to obtain low-altitude atmospheric environmental parameters in the area, including: Carrying micro-environment and micro-meteorological monitoring equipment on the drone, including anemometers, hygrometers, thermometers, and air quality sensors; During the flight, the drone monitors and records the low-altitude atmospheric environmental parameters in the area in real time, including low-altitude wind speed, humidity, temperature information, and ground and low-altitude air quality data. The air quality data includes the concentration of atmospheric pollutants and the temporal and spatial distribution information of atmospheric visibility. The atmospheric pollutants include PM 2.5 、PM 10 , CO and NO2.

[0010] Furthermore, based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area, the CFD method is used to calculate the spatiotemporal distribution of the air flow field, the atmospheric pollutant concentration field, and the air quality index, including: Import the three-dimensional space layout model into the air fluid dynamics calculation formula, generate the grid and optimize the grid quality, and finally export the grid; Based on the complex boundary conditions of the grid and simulation area, the temporal and spatial distribution of air flow field, atmospheric pollutant concentration field and air quality index are calculated; Wherein, the air fluid mechanics calculation formula is: (3); (4); In the formula is the fluid density, t is the time, u is the velocity vector of the fluid, is the gradient operator, represents the rate of change of fluid density with time, It indicates the rate of change of velocity over time and reflects the acceleration of the fluid. is the convection term, which describes the effect of fluid velocity on its own flow. is the fluid pressure, is the pressure gradient term, which represents the effect of pressure change on fluid motion. is the kinematic viscosity, is the Laplace operator, which represents the spatial variation of the velocity field. is the viscosity term, describing the viscosity effect inside the fluid, is the external force term, which represents the external force acting on the fluid.

[0011] Furthermore, the method further includes: generating a corresponding near-surface wind field or concentration field spatial grid numerical simulation field based on the three-dimensional spatial layout model, performing four-dimensional variational assimilation with the environmental meteorological field monitoring spatial station data, and generating a high-resolution gridded environmental meteorological variable field of near-surface urban blocks; The four-dimensional variational assimilation calculation formula is as follows: (5); (6); Where K represents the gain matrix, k Indicates the analysis-forecast cycle step number, y k is the observation vector, Indicates k The analytical field at the time step, is the background field, H k is the observation operator, which transforms the variables in the pattern space into the observation space, M k Forecast mode.

[0012] Furthermore, the method also includes: visualizing and interactively displaying the three-dimensional spatial layout model and its time dynamics through a user interaction interface for quantitative evaluation of microenvironment at the scale of urban blocks.

[0013] In a second aspect, the present invention provides a device for applying drone modeling to urban microenvironment assessment, comprising: The first acquisition module is used to acquire three-dimensional terrain data obtained by obliquely photographing urban streets and buildings based on the UAV flight platform; The first generation module is used to generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of the terrain and objects; The second acquisition module is used to obtain low-altitude atmospheric environment parameters in the area based on the microenvironment and micrometeorological monitoring equipment carried by the UAV flight platform; The fusion module is used to superimpose low-altitude atmospheric environmental parameters into the three-dimensional spatial layout model, and to form assimilated data of the spatiotemporal distribution of environmental meteorological variables at the scale of urban blocks through interpolation processing and data fusion technology; The second generation module is used to generate complex boundary conditions of the simulation area based on the assimilated data of spatiotemporal distribution; The calculation module is used to calculate the temporal and spatial distribution of air flow field, atmospheric pollutant concentration field and air quality index based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area using CFD method to complete the urban microenvironment assessment.

[0014] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the aforementioned methods.

[0015] In a fourth aspect, the present invention provides a computer device, comprising: Memory, for storing computer programs / instructions; A processor is used to execute the computer program / instructions to implement the steps of any of the aforementioned methods.

[0016] In a fifth aspect, the present invention provides a computer program product, comprising a computer program / instruction, which implements the steps of any one of the aforementioned methods when executed by a processor.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method and device for applying drone modeling to urban microenvironment assessment, and applies drone flight platforms and corresponding technologies to quantitative assessment of urban block-scale microenvironment. The drone flight platform is used to collect three-dimensional spatial position information of ground element image points and near-ground atmospheric environmental parameters, and a three-dimensional refined model of the urban block scale is established. Based on this, simulation calculations of atmospheric flow and pollutant diffusion at the block scale are further carried out. The invention conducts refined assessments of urban air quality, ecological environment, etc., and provides technical support for related refined management and control; The present invention utilizes the UAV flight platform to carry out three-dimensional modeling of terrain and objects, and to collect low-altitude and near-ground environmental and meteorological data, thereby integrating the UAV surveying and mapping technology that can generate the initial boundary conditions for subsequent CFD numerical calculations. This is the technical point of the present invention, and will ultimately serve the work of three-dimensional refined microenvironmental and micrometeorological assessment at the scale of urban blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall technical process of integrating UAV modeling and data monitoring technology into urban microenvironment assessment; Figure 2 Schematic diagram of starting a test flight of a UAV in an embodiment of the present invention; Figure 3 The drone continuously collects images from different angles at the same location during tilt shooting, and then the schematic diagram of multivariate linear equations can be established in combination with the three-dimensional position information of the shooting position; Figure 4 It is a schematic diagram of the local effect of the key area in the above panoramic area; Figure 5 It is a schematic diagram of the three-dimensional model of terrain and features in a certain study area established in the block scale model; Figure 6 This is a schematic diagram of the results of near-ground assessment of environmental meteorology at the urban block scale based on UAV modeling and data monitoring fusion technology. The arrows indicate wind direction and the color scale indicates wind speed. Figure 7 This is a schematic diagram of the results of near-ground assessment of environmental meteorology at the urban block scale based on UAV modeling and data monitoring fusion technology. The arrows indicate wind direction and the color scale indicates turbulence intensity. Figure 8 This is a schematic diagram of the results of environmental meteorological assessment based on the application of drone modeling and data monitoring fusion technology to the scale of urban blocks. The streamlines represent the airflow trajectory and the color scale represents the wind speed. Fig. 9 It is a schematic diagram of the results of environmental meteorological assessment based on the application of drone modeling and data monitoring fusion technology to urban block scale. The streamlines represent the diffusion trajectories of pollutants and the color scale represents the concentration of pollutants. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0020] Embodiment 1: This embodiment introduces a method for applying drone modeling to urban microenvironment assessment, including: Oblique photography of urban street buildings based on the UAV flight platform to obtain three-dimensional data of terrain and objects; Generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of terrain and objects; Based on the UAV flight platform equipped with microenvironment and micrometeorological monitoring equipment, the low-altitude atmospheric environmental parameters in the area are obtained; The low-altitude atmospheric environmental parameters are superimposed on the three-dimensional spatial layout model, and the temporal and spatial distribution assimilation data of environmental meteorological variables at the scale of urban blocks are formed through interpolation processing and data fusion technology; Generate complex boundary conditions of the simulation area based on assimilated data in time and space; Based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area, the CFD method is used to calculate the spatiotemporal distribution of the air flow field, atmospheric pollutant concentration field and the air quality index to complete the urban microenvironment assessment.

[0021] The method for applying drone modeling to urban microenvironment assessment provided in this embodiment specifically involves the following steps: 1. Oblique photography and modeling of urban street buildings based on UAV flight platforms: Use UAVs to carry visible light oblique photography equipment to perform high-frequency continuous reciprocating photography of the area of ​​interest, and strive to record the surface buildings and other terrain information in the area of ​​interest at multiple angles and with high resolution. In addition, a certain frequency must be maintained during continuous photography to ensure that the information in the continuously generated photos has a sufficient repetition rate (generally more than 70%), and finally obtain terrain-related data files.

[0022] 2. Based on the terrain data files obtained above, with the help of 3D modeling algorithms and imaging software, generate the 3D spatial position coordinates of a large number of ground image points in the area of ​​interest: screen and integrate the image data, atmospheric environmental parameters, and pollutant concentration data collected by the UAV flight platform, add the image control point measurement data, and use the 3D modeling software to obtain the initial 3D model of the simulation area through aerial triangulation calculation, multi-view impact matching, point cloud model construction and texture mapping; And error correction is performed on the image data obtained by tilted shooting, the formula is as follows: (1); (2); Where x represents the image point coordinates along the heading direction of the horizontal position after error correction, y represents the image point coordinates along the lateral direction of the horizontal position after error correction, x' represents the correction value of the error caused by the film deformation along the heading direction of the horizontal position, and y' represents the correction value of the error caused by the film deformation along the lateral direction of the horizontal position. Indicates the correction value of the error caused by lens distortion in the horizontal position along the heading direction. represents the correction value of the error caused by lens distortion in the horizontal position along the lateral direction, dx represents the correction value of the error caused by atmospheric refraction in the horizontal position along the heading direction, dy represents the correction value of the error caused by atmospheric refraction in the horizontal position along the lateral direction, δx represents the correction value of the error caused by the earth curvature in the horizontal position along the heading direction, and δy represents the correction value of the error caused by the earth curvature in the horizontal position along the lateral direction; Based on the error-corrected data, a three-dimensional spatial layout model of buildings and other landforms in the area is further generated.

[0023] 3. Environmental meteorological sensors based on flight platforms are used to collect low-altitude and near-ground atmospheric environmental parameters in the area of ​​interest, including but not limited to low-altitude wind speed, humidity and temperature information, ground and low-altitude air quality data such as the concentration of major atmospheric pollutants and the temporal and spatial distribution information of atmospheric visibility; The main air pollutants include but are not limited to PM 2.5 、PM 10 , six atmospheric environmental parameters such as CO and NO2, and other atmospheric pollutants in specific industrial or process areas, such as volatile organic compounds emitted by human and natural vegetation, and malodorous gases such as methyl mercaptan.

[0024] 4. The collected environmental and meteorological variables and their spatial distribution are superimposed on the three-dimensional spatial layout model of the city, and the three-dimensional data fusion and post-processing are interpolated and completed to form the assimilated data of the spatiotemporal distribution of environmental and meteorological variables at the scale of urban blocks, providing refined initial boundary conditions for the next step of numerical solution of air flow and pollution diffusion at the scale of urban blocks.

[0025] Using the urban block-scale air pollution assessment method, device and storage medium provided by the inventor in CN118133640A, a high-precision numerical simulation of air pollution is performed at the block scale, and the spatiotemporal distribution of the air flow field and the air pollutant concentration field and the air quality index of the area of ​​interest at the block scale are obtained by the CFD method; The method is characterized in that: the initial three-dimensional model is introduced into the air fluid dynamics calculation formula, the mesh is generated and the mesh quality is optimized, and finally the mesh is exported; The air fluid mechanics calculation formula: (3); (4); In the formula is the fluid density, t is the time, u is the velocity vector of the fluid, is the gradient operator, represents the rate of change of fluid density with time, It indicates the rate of change of velocity over time and reflects the acceleration of the fluid. is the convection term, which describes the effect of fluid velocity on its own flow. is the fluid pressure, is the pressure gradient term, which represents the effect of pressure change on fluid motion. is the kinematic viscosity, is the Laplace operator, which represents the spatial variation of the velocity field. is the viscosity term, describing the viscosity effect inside the fluid, is the external force term, which represents the external force acting on the fluid.

[0026] 6. Generate the corresponding near-surface wind field or concentration field spatial grid numerical simulation field based on the above three-dimensional model, and perform four-dimensional variational assimilation with the environmental meteorological field monitoring space station data to generate a high-resolution grid environmental meteorological variable field that is more in line with the real near-surface urban block; The four-dimensional variational assimilation calculation formula is as follows: (5); (6); Where K represents the gain matrix, k Indicates the analysis-forecast cycle step number, y kis the observation vector, Indicates k The analytical field at the time step, is the background field, H k is the observation operator, which transforms the variables in the pattern space into the observation space, M k Forecast mode.

[0027] 7. The refined spatial environmental meteorological three-dimensional model and its temporal dynamics obtained by monitoring and simulation calculations are visualized and interactively displayed through a user interactive interface for quantitative assessment of the microenvironment at the urban block scale.

[0028] This embodiment applies the UAV flight platform and corresponding technologies to the quantitative assessment of the microenvironment at the scale of urban blocks. The UAV flight platform is used to collect the three-dimensional spatial position information of ground element image points and the near-ground atmospheric environment parameters, establish a three-dimensional refined model at the scale of urban blocks, and further carry out simulation calculations of atmospheric flow and pollutant diffusion at the scale of blocks. This invention conducts refined assessments of urban air quality, ecological environment, etc., and provides technical support for related refined management and control.

[0029] The technical point of the present invention is to use the UAV flight platform to carry out three-dimensional modeling of terrain and objects, and to collect low-altitude and near-ground environmental and meteorological data, so as to integrate and generate the initial boundary conditions for subsequent CFD numerical calculations. This will ultimately serve the work of three-dimensional refined micro-environmental and micro-meteorological assessment at the scale of urban blocks.

[0030] The contents involved in the above embodiment are described below in conjunction with a preferred embodiment.

[0031] The specific process of this embodiment is as follows Figure 1 , using the UAV flight platform, aerial photography of complex urban building blocks that require micro-environmental assessment and governance is carried out and environmental meteorological data is collected. After data fusion and assimilation, high-resolution three-dimensional spatial complex boundary conditions of the region are generated; the spatial unstructured grid required for numerical calculation is further constructed; on this basis, numerical simulation is carried out to generate the three-dimensional distribution of refined wind field, turbulence and concentration diffusion in the area.

[0032] Preparation: According to the needs of the target area, detailed inspections are carried out on many aspects such as the matching degree of the UAV system, the onboard power, the working conditions of the sensors and cameras, etc. to ensure the smooth progress of the mission and the orderly progress of on-site mapping.

[0033] GPS calibration is performed on the drone to ensure that sufficient satellite signals are received in an open area, and the calibration status is checked after the drone is connected using software. Professional flight planning software is used to arrange image control points and plan routes for the target area to ensure flight safety while meeting simulation requirements to the greatest extent possible.

[0034] Step 1: The drone takes aerial photos along the specified route and collects environmental meteorological data and three-dimensional data of terrain and objects; After the equipment debugging and route mapping plan are confirmed, the drone takes off. Figure 3 As shown. The aircraft enters the cruise state according to the specified route, and uses the five-dimensional flight camera equipped with the system to shoot the ground and extract the coordinates of various elements. Under the premise of meeting the flight attitude requirements, the aircraft will theoretically image the same surface point multiple times, but at a specific flight track point, the same surface point can be collected from five aerial angles.

[0035] Furthermore, by matching the flight speed with the shutter speed, the same location is photographed from multiple angles to obtain continuous images. Then, the multivariate linear equation is established in combination with the three-dimensional position information of the camera position to solve the three-dimensional position coordinates of each image point, and finally the high-resolution geometric shape of all terrain objects in the area is generated. The specific imaging effect is as follows: Figure 4 shown.

[0036] At the same time, the drone is equipped with meteorological sensors, including wind speed, humidity and temperature, atmospheric pollutant concentration detection equipment, etc., to collect environmental meteorological data in the area during flight. The data can be collected regularly or continuously and sent back to the ground station for analysis in real time.

[0037] The main air pollution emission sources covered in this scope, including: traffic emissions on key roads in the area, catering emissions, residential emissions in residential areas, etc., are photographed and located, and real-time monitoring data on their emission intensity is obtained by replacing pollution-related sensors.

[0038] Step 2: Multi-dimensional fusion and post-processing of environmental meteorological data and terrain and object 3D data Based on the above drone imaging data collection results, a three-dimensional fine-grained modeling was carried out in the 1km x 1km area around the case area. The model effect is as follows: Figure 4 Furthermore, the spatial range and computational grid resolution required for the final three-dimensional numerical simulation are determined according to project requirements. It is required to give priority to the distribution pattern of the flow field around the building while appropriately simplifying the irregular details and shape complexity of some buildings, so as to reduce the number of grids and numerical calculations of subsequent three-dimensional environmental meteorological variables. Specific three-dimensional model examples are as follows: Figure 5 .

[0039] The real-time monitoring data of emission intensity collected above and the real-time monitoring data of regional environmental meteorological variables (mainly including wind speed, wind direction, and, surface temperature, humidity, etc.) are superimposed on the urban three-dimensional spatial layout model, and the three-dimensional data fusion and post-processing are interpolated and completed to form the spatiotemporal distribution assimilation data of environmental meteorological variables at the urban block scale, providing refined initial boundary conditions for the next step of numerical solution of air flow and pollution diffusion at the urban block scale.

[0040] Step 3: Numerical simulation of microclimate and microenvironment at block scale By using the urban block-scale air pollution assessment method, device and storage medium provided by the inventor in CN118133640A, high-precision numerical simulation of air pollution is performed at the block scale, and the spatiotemporal distribution of the air flow field and the atmospheric pollutant concentration field and the air quality index of the area of ​​interest at the block scale are obtained through the CFD method.

[0041] Step 4: Use monitoring data to assimilate the numerical simulation field to generate a high-resolution gridded environmental meteorological variable field that is more in line with the actual near-ground urban blocks. The collection density of environmental meteorological field monitoring data is lower than that of terrain data, but it is mainly not on the surface but in the vertical space of the atmosphere (point or vertical column). It needs to be pre-processed with special environmental meteorological software (such as NCL, netCDF) to generate three-dimensional spatial site data.

[0042] After the corresponding near-surface wind field or concentration field spatial grid numerical simulation field is generated based on the above three-dimensional building model, the environmental meteorological field monitoring spatial station data described in this article is assimilated with it to improve the spatial resolution and accuracy of the final output result display. The final simulation result is referenced Figure 6 , Figure 7 , Figure 8 and Fig. 9 .

[0043] Step 5: Based on the simulation results of the environmental meteorological field and combined with sensitivity experiments on initial values ​​related to urban buildings and pollution source layout, scientific demonstration of urban air quality compliance planning and emission reduction measures such as micro-environment air quality assessment, main pollution components and main source contribution assessment, and regional governance decision-making effectiveness assessment are carried out.

[0044] Embodiment 2: This embodiment provides a device for applying drone modeling to urban microenvironment assessment, comprising: The first acquisition module is used to acquire three-dimensional terrain data obtained by obliquely photographing urban streets and buildings based on the UAV flight platform; The first generation module is used to generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of the terrain and objects; The second acquisition module is used to obtain low-altitude atmospheric environment parameters in the area based on the microenvironment and micrometeorological monitoring equipment carried by the UAV flight platform; The fusion module is used to superimpose low-altitude atmospheric environmental parameters into the three-dimensional spatial layout model, and to form assimilated data of the spatiotemporal distribution of environmental meteorological variables at the scale of urban blocks through interpolation processing and data fusion technology; The second generation module is used to generate complex boundary conditions of the simulation area based on the assimilated data of spatiotemporal distribution; The calculation module is used to calculate the temporal and spatial distribution of air flow field, atmospheric pollutant concentration field and air quality index based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area using CFD method to complete the urban microenvironment assessment.

[0045] The specific functional implementation of each of the above modules can be found in the relevant contents of the method in Example 1 and will not be elaborated here.

[0046] Embodiment 3, this embodiment provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods described in Embodiment 1 are implemented.

[0047] Embodiment 4: This embodiment provides a computer device, including: Memory, for storing computer programs / instructions; A processor is used to execute the computer program / instructions to implement the steps of any method described in Example 1.

[0048] Embodiment 5: This embodiment provides a computer program product, including a computer program / instruction, which implements the steps of any method described in Embodiment 1 when executed by a processor.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

[0050] It should be understood by those skilled in the art that the embodiments of the present disclosure may be provided as methods, systems or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present disclosure may take 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 code.

[0051] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks 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 produce 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.

[0052] 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.

[0053] 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.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure rather than to limit its protection scope. Although the present disclosure has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the disclosed claims to be approved.

Claims

1. A method for applying drone modeling to urban microenvironment assessment, characterized in that: include: Oblique photography of urban street buildings based on the UAV flight platform to obtain three-dimensional data of terrain and objects; Generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of terrain and objects; Based on the UAV flight platform equipped with microenvironment and micrometeorological monitoring equipment, the low-altitude atmospheric environmental parameters in the area are obtained; The low-altitude atmospheric environmental parameters are superimposed on the three-dimensional spatial layout model, and the temporal and spatial distribution assimilation data of environmental meteorological variables at the scale of urban blocks are formed through interpolation processing and data fusion technology; Generate complex boundary conditions of the simulation area based on assimilated data in time and space; Based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area, the CFD method is used to calculate the spatiotemporal distribution of the air flow field, atmospheric pollutant concentration field and the air quality index to complete the urban microenvironment assessment.

2. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The method of obliquely photographing urban street buildings based on the UAV flight platform to obtain three-dimensional data of terrain and objects includes: Use drones carrying visible light oblique shooting equipment to take high-frequency continuous reciprocating shots of the area of ​​interest; During the filming process, the drone recorded in high resolution from multiple angles to capture detailed information of surface buildings and other terrain features; Maintain the continuous shooting frequency to ensure that the information repetition rate in the continuously generated photos reaches the set threshold and obtain three-dimensional data of terrain and objects.

3. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The method further includes: performing error correction on the image data obtained by tilted shooting, and the formula is as follows: （1）; （2）; Where x represents the image point coordinates along the heading direction of the horizontal position after error correction, y represents the image point coordinates along the lateral direction of the horizontal position after error correction, x' represents the correction value of the error caused by the film deformation along the heading direction of the horizontal position, and y' represents the correction value of the error caused by the film deformation along the lateral direction of the horizontal position. Indicates the correction value of the error caused by lens distortion in the horizontal position along the heading direction. It represents the correction value of the error caused by lens distortion in the lateral direction of the horizontal position, dx represents the correction value of the error caused by atmospheric refraction in the heading direction of the horizontal position, dy represents the correction value of the error caused by atmospheric refraction in the lateral direction of the horizontal position, δx represents the correction value of the error caused by the curvature of the earth in the heading direction of the horizontal position, and δy represents the correction value of the error caused by the curvature of the earth in the lateral direction of the horizontal position.

4. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The method of generating a three-dimensional spatial layout model of buildings and other objects in the region based on the three-dimensional data of the terrain and objects includes: Import the three-dimensional data of terrain and objects obtained by photography into the three-dimensional modeling software and algorithms; Use algorithms to process three-dimensional data of terrain and objects to generate three-dimensional spatial position coordinates of a large number of ground image points in the area of ​​interest; Generate a three-dimensional spatial layout model of buildings and other objects based on the three-dimensional spatial position coordinates.

5. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The microenvironment and micrometeorological monitoring equipment carried on the UAV flight platform is used to obtain low-altitude atmospheric environmental parameters in the area, including: Carrying micro-environment and micro-meteorological monitoring equipment on the drone, including anemometers, hygrometers, thermometers, and air quality sensors; During the flight, the drone monitors and records the low-altitude atmospheric environmental parameters in the area in real time, including low-altitude wind speed, humidity, temperature information, and ground and low-altitude air quality data. The air quality data includes the concentration of atmospheric pollutants and the temporal and spatial distribution information of atmospheric visibility. The atmospheric pollutants include PM 2.5 、PM 10 , CO and NO2.

6. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: Based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area, the CFD method is used to calculate the temporal and spatial distribution of the air flow field, the atmospheric pollutant concentration field and the air quality index, including: Import the three-dimensional space layout model into the air fluid dynamics calculation formula, generate the grid and optimize the grid quality, and finally export the grid; Based on the complex boundary conditions of the grid and simulation area, the temporal and spatial distribution of air flow field, atmospheric pollutant concentration field and air quality index are calculated; Wherein, the air fluid mechanics calculation formula is: (3)； (4)； In the formula is the fluid density, t is the time, u is the velocity vector of the fluid, is the gradient operator, represents the rate of change of fluid density with time, It indicates the rate of change of velocity over time and reflects the acceleration of the fluid. is the convection term, which describes the effect of fluid velocity on its own flow. is the fluid pressure, is the pressure gradient term, which represents the effect of pressure change on fluid motion. is the kinematic viscosity, is the Laplace operator, which represents the spatial variation of the velocity field. is the viscosity term, describing the viscosity effect inside the fluid, is the external force term, which represents the external force acting on the fluid.

7. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The method further comprises: generating a corresponding near-surface wind field or concentration field spatial grid numerical simulation field based on the three-dimensional spatial layout model, performing four-dimensional variational assimilation with the environmental meteorological field monitoring spatial station data, and generating a high-resolution grid environmental meteorological variable field of near-surface urban blocks; The four-dimensional variational assimilation calculation formula is as follows: （5）； （6）； Where K represents the gain matrix, k Indicates the analysis-forecast cycle step number, y k is the observation vector, Indicates k The analytical field at the time step, is the background field, H k is the observation operator, which transforms the variables in the pattern space into the observation space, M k Forecast mode.

8. The method of applying drone modeling to urban microenvironment assessment according to claim 1, characterized in that: The method also includes: visualizing and interactively displaying the three-dimensional spatial layout model and its time dynamics through a user interaction interface for quantitative evaluation of microenvironment at the scale of urban blocks.

9. A device for applying drone modeling to urban microenvironment assessment, characterized in that: include: The first acquisition module is used to acquire three-dimensional terrain data obtained by obliquely photographing urban streets and buildings based on the UAV flight platform; The first generation module is used to generate a three-dimensional spatial layout model of buildings and other objects in the area based on the three-dimensional data of the terrain and objects; The second acquisition module is used to obtain low-altitude atmospheric environment parameters in the area based on the microenvironment and micrometeorological monitoring equipment carried by the UAV flight platform; The fusion module is used to superimpose low-altitude atmospheric environmental parameters into the three-dimensional spatial layout model, and to form assimilated data of the spatiotemporal distribution of environmental meteorological variables at the scale of urban blocks through interpolation processing and data fusion technology; The second generation module is used to generate complex boundary conditions of the simulation area based on the assimilated data of spatiotemporal distribution; The calculation module is used to calculate the spatiotemporal distribution of air flow field, atmospheric pollutant concentration field and air quality index based on the complex boundary conditions and three-dimensional spatial layout model of the simulation area using CFD method to complete the urban microenvironment assessment.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 8 are implemented.

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