Air quality influence rapid evaluation method based on OBD of heavy-duty diesel vehicle

Abstract

The invention discloses a heavy diesel vehicle OBD-based air quality influence rapid evaluation method, and relates to the technical field of air quality rapid evaluation. The method comprises the steps of 1, compiling a heavy diesel vehicle emission list based on OBD data, 2, gridding emission list generation items, 3, MEIC list downscaling distribution and 4, heavy diesel vehicle emission influence evaluation. In the first step, in heavy diesel vehicle emission list compilation based on OBD data, the restriction problem that a mobile emission source emission list is restricted by a data bottleneck and cannot be finely distributed to a grid is avoided, and the influence of the driving working condition of the heavy diesel vehicle on the pollutant emission amount is reduced. In the step 2, in a grid emission list generation technology, a background list is provided for contribution analysis of atmospheric combined pollution, so that the probability of occurrence of interaction between pollution emission of the heavy diesel vehicle and other pollution sources in the atmosphere is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of rapid air quality assessment, and in particular to a method for rapid air quality impact assessment based on an OBD of a heavy-duty diesel vehicle. Background Art

[0002] In recent years, with economic growth, urbanization and significant improvement in living standards, the number of motor vehicles in the target city has increased year by year. The Sichuan Basin, to which the target city belongs, has a unique terrain. The basin is low in elevation, while the surrounding mountains are at a high altitude, which makes the atmospheric stratification stability of the boundary layer in the basin higher than that of other areas at the same latitude. In addition, the frequency of calm winds in the basin is high, and the diffusion conditions of atmospheric pollutants are poor, which causes the continuous accumulation of atmospheric pollutants in the basin, and the concentration remains high. The emitted pollutants will not only enter the human body directly through breathing, but also form acid rain and react chemically with other pollutants in the air. Under certain conditions, photochemical smog will be produced and participate in the formation of haze, affecting air quality and endangering human health. The emitted pollutants will not only enter the human body directly through breathing, but also form acid rain and react chemically with other pollutants in the air. Under certain conditions, photochemical smog will be produced and participate in the formation of haze, affecting air quality and endangering human health. Although researchers have made significant progress in the study of motor vehicle atmospheric pollutant emission inventories, there are still some problems. Therefore, it is necessary to quickly evaluate the air quality impact of heavy-duty diesel vehicle OBD.

[0003] Existing technologies such as the invention patent application with announcement number: CN115293567A discloses a dynamic air pollution control system and method, including a multi-source heterogeneous integrated data platform, a comprehensive decision-making one-picture platform, an emission inventory management system, a heavy pollution emergency assessment system, a mobile source management system, a source tracking and cause analysis system, and a grid-based supervision system; the control method includes problem identification, comprehensive decision-making, execution feedback, and effect evaluation. The system of the invention can collect and produce a wealth of air pollution-related monitoring and forecasting data, break the island effect of multi-source heterogeneous data, automatically discover air pollution events with agility and accuracy, and realize the high informatization, automation, and quantitative evaluation of air pollution control business processes; the control method deeply utilizes the data and numerical patterns collected by the sensor network to realize problem discovery and analysis, and can quickly apply cutting-edge analysis technology, fully mobilize the execution of multi-level control personnel, and improve the scientificity and systematicness of the dynamic air pollution control business.

[0004] Based on the above solutions, it can be found that the existing rapid assessment method of air quality impact based on heavy-duty diesel vehicle OBD can meet the basic requirements, but there are also some potential defects and challenges, which are specifically reflected in the following aspects: 1. The existing technology on the compilation technology of high spatiotemporal resolution emission inventory for heavy-duty diesel vehicles based on OBD data is not in-depth enough, and it is not possible to complete the refined assessment of pollution emissions of heavy-duty diesel vehicles. It reduces the problem of no high-precision real-time emission inventory for heavy-duty diesel vehicles, reduces the efficiency of solving the problem that the emission inventory of mobile emission sources cannot be finely allocated to the grid due to the "data bottleneck", and ignores the impact of driving conditions of heavy-duty diesel vehicles on pollutant emissions.

[0005] Second, the existing technology does not pay enough attention to the air quality impact assessment technology based on the OBD heavy-duty diesel vehicle emission inventory. Due to the inaccurate simulation analysis of the spatiotemporal impact of heavy-duty diesel vehicles on air quality that implements "OBD-CMAQ", it reduces the problem of providing more accurate data support for the formulation of heavy-duty diesel vehicle control measures and driving route planning, resulting in the inability to provide a background list for the contribution analysis of atmospheric complex pollution, thereby increasing the probability of interaction between heavy-duty diesel vehicle pollution emissions and other pollution sources in the atmosphere. Summary of the invention

[0006] The purpose of the present invention is to provide a rapid assessment method for air quality impact based on the OBD of a heavy-duty diesel vehicle, which solves the problems existing in the background technology.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a rapid assessment method for the air quality impact based on the OBD of heavy-duty diesel vehicles, which specifically includes: step one, preparation of a heavy-duty diesel vehicle emission inventory based on OBD data, step two, generation of gridded emission inventory items, step three, MEIC inventory downscaling allocation and step four, heavy-duty diesel vehicle emission impact assessment.

[0008] Step 1. Preparation of heavy-duty diesel vehicle emission inventory based on OBD data: Comprehensively analyze the OBD data, supplement, screen and quality control the data through big data methods, improve data availability, and implement the high spatiotemporal resolution emission inventory preparation project for heavy-duty diesel vehicles based on OBD data.

[0009] Step 2. Gridded emission inventory generation project: Based on the high spatiotemporal resolution heavy-duty diesel vehicle OBD emission inventory obtained through balancing, a gridded emission inventory generation project is established to realize the conversion of the heavy-duty diesel vehicle OBD emission inventory to the air quality model inventory, and obtain the heavy-duty diesel vehicle OBD emission inventory, realizing spatial allocation, temporal allocation, and species allocation to generate an XYHT four-dimensional emission inventory.

[0010] Step 3: MEIC inventory downscaling allocation: Through the high-resolution integrated inventory of atmospheric pollutants, combined with gridded GDP, population, road network and land use type data, downscaling allocation is carried out to form a basic inventory, and then the MEIC downscaled emission inventory is obtained to analyze the impact of heavy-duty diesel vehicles on atmospheric complex pollutants.

[0011] Step 4: Heavy-duty diesel vehicle emission impact assessment: Based on the Weather Research and Forecasting Model and the public multi-scale air quality model, high-resolution meteorological field data for the target city center is established. Based on the heavy-duty diesel vehicle OBD emission inventory and the MEIC downscaled emission inventory, an assessment of the impact of heavy-duty diesel vehicles on air quality is conducted.

[0012] Furthermore, the specific analysis method of the heavy-duty diesel vehicle high spatiotemporal resolution emission inventory compilation project based on OBD data is as follows: A. Read the OBD data Excel file and perform basic quality control: first, sort the data time, calculate the time interval between the two data through the xith data and the xi+1 data, obtain the time length of the two data, and calculate the distance between the two data through the longitude and latitude data, that is, the distance traveled within the time.

[0013] Secondly, determine the data time interval and set the driving distance of data with too large a time interval to 0 to avoid the situation where the distance calculated by the longitude and latitude of two points is too different from the actual situation after the data is interrupted for too long.

[0014] Finally, the vehicle speed of this section is calculated by combining the distance and time interval calculated by the longitude and latitude, and the data with the calculated vehicle speed greater than or equal to 200 is set to 0. At the same time, it is compared with the instantaneous speed recorded in the OBD data to analyze the relationship between the calculated driving speed and the instantaneous speed.

[0015] B. Trajectory path completion based on OBD data: Two trajectory correction technologies are used, namely straight line correction and GPS+ straight line correction. Straight line correction extends a certain section of the running trajectory by adding equidistant trajectory points between two GPS data points with a long span. GPS+ straight line correction first determines the possible path of the heavy-duty diesel vehicle through a collection of GPS trajectories over a period of time, connects the two GPS data points with a long span through the minimum distance method, and further connects the running trajectory through straight line correction on this basis. A weather research and forecasting model simulation grid is established for the target city center, and a 1km resolution meteorological element simulation is carried out. The latitude and longitude information in the OBD data of the heavy-duty diesel vehicle is combined to obtain the temperature and relative humidity of the corresponding grid, and the altitude data is combined to perform meteorological correction for pollution emissions.

[0016] The heavy-duty diesel vehicle pollution emission inventory is calculated by the following formula: , where For the The heavy-duty diesel vehicle benchmark emission factors for the following pollutants are It is the number of the pollutant type. is the meteorological correction factor, which is calculated based on relative humidity, temperature and altitude. is the speed correction factor, which is calculated based on the nonlinear interpolation of the guide factor data and the speed of the heavy-duty diesel vehicle. Expressed as Distance travelled by a heavy diesel vehicle, , is the vehicle number, Expressed as the number of vehicles, calculated from longitude and latitude.

[0017] Furthermore, the specific analysis method for establishing a gridded emission inventory generation project is as follows: a large amount of heavy-duty diesel vehicle OBD data is processed, and the emissions are calculated to obtain emission data with longitude and latitude information. This data has a high temporal and spatial resolution, and the time and spatial scales need to be redistributed before it can be used for model evaluation. The emission data is reprojected to obtain Lambert coordinate information, and then spatial gridding is performed in combination with the starting coordinates and grid resolution of the model grid, and gridded hourly emission data is generated in combination with the simulation time period.

[0018] Emissions inventory includes heavy-duty diesel vehicles , , CO and HC emissions, including and HC need to be assigned to species, and the calculated Directly obtain OBD data A comparison is required.

[0019] The data is processed using programming languages ​​to generate the NetCDF format gridded emission inventory required for CMAQ model simulation. The data is based on Lambert space projection and has spatial distribution properties. At the same time, time allocation is performed based on vehicle travel time obtained from OBD data.

[0020] Furthermore, the analysis of the impact of heavy-duty diesel vehicles on atmospheric composite pollutants is specifically conducted by using a high-resolution integrated inventory of atmospheric pollutants and taking the heavy-duty diesel vehicle inventory as an incremental inventory. To meet the needs of air quality simulation in the target city, the following data are proposed to be used to allocate the MEIC inventory: 1) Industry: 1Km resolution gridded GDP data plus weighted allocation, combined with high-resolution land use type data for correction; 2) Electricity: Use thermal power generation POI for weighted allocation; 3) Civilian: Redistribution using 1km resolution gridded population data; 4) Transportation: Use OpenStreetsMap road network data for redistribution; 5) Agriculture: Redistribution using land use type data; 6) Open burning of biomass: Redistribution using land use type data; 7) Ships: grid evenly distributed; After the redistribution is completed, a 1km spatial resolution gridded emission inventory suitable for the simulation of this study, namely the urban benchmark inventory, is established. Combined with the Guidelines for the Compilation of Emission Inventories of Air Pollution Sources of the Ministry of Ecology and Environment, additional calculations are made for road dust emissions, soil dust emissions and natural source emissions, thereby obtaining a background emission inventory that basically covers the needs of the simulation of this study.

[0021] Furthermore, the specific analysis method for evaluating the impact of heavy-duty diesel vehicles on air quality is as follows: taking 2022 as the base year, selecting January, April, July and October to represent the four seasons, and conducting meteorological field simulation in the target city center, i.e. the first and second circles, with a maximum resolution of 1 km in three layers to obtain high-resolution meteorological field data.

[0022] The heavy-duty diesel vehicle emission inventory and downscaling benchmark inventory obtained from Parts 2 and 3 were integrated to establish the assessment inventory required for this study. The inventory data was further spatially allocated according to the model nested grids to obtain gridded data that matched the spatial resolution of the simulation area. Time allocation sequences and species allocation sequences were established, and industrial point sources were vertically allocated, ultimately generating a four-dimensional gridded emission inventory with XYHT.

[0023] Using the EPA open source third-generation multiscale air quality model, CMAQ, based on the meteorological field data simulated by the WRF model and the assessment checklist generated in this study, an atmospheric environmental impact assessment of heavy-duty diesel vehicles in the target city center was conducted. and The concentration contribution of heavy-duty diesel vehicles to summer The nonlinear response relationship of Impact assessment.

[0024] The beneficial effects of the present invention are as follows: in step one, in the preparation of the emission inventory of heavy-duty diesel vehicles based on OBD data, the OBD data is comprehensively analyzed, and the data is supplemented, screened and quality-controlled through big data methods to improve data availability, thereby realizing a high spatiotemporal resolution emission inventory preparation technology for heavy-duty diesel vehicles based on OBD data, avoiding the problem that the emission inventory of mobile emission sources cannot be finely allocated to the grid due to the "data bottleneck", and reducing the impact of the driving conditions of heavy-duty diesel vehicles on pollutant emissions.

[0025] In step 2, the gridded emission inventory generation technology, the high spatiotemporal resolution heavy-duty diesel vehicle OBD emission inventory obtained through balancing is used to establish a gridded emission inventory generation technology, realize the conversion of the heavy-duty diesel vehicle OBD emission inventory to the air quality model inventory, obtain the heavy-duty diesel vehicle OBD emission inventory, realize spatial allocation, time allocation, and species allocation, and generate an XYHT four-dimensional emission inventory, which provides more accurate data support for the formulation of heavy-duty diesel vehicle control measures and driving route planning, and provides a background inventory for the contribution analysis of atmospheric complex pollution, thereby reducing the probability of interaction between heavy-duty diesel vehicle pollution emissions and other pollution sources in the atmosphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 The present invention is a schematic flow chart of the steps for implementing the method.

[0028] Figure 2 Schematic diagram of the mileage difference between different OBD data completion methods.

[0029] Figure 3 Interpolate big data of OBD data.

[0030] Figure 4 Linear interpolation for OBD data.

[0031] Figure 5 It is the original OBD data.

[0032] Figure 6 It is a specific implementation plan diagram.

[0033] Figure 7 Spatial distribution of NO2 baseline inventory simulation results and different OBD data contribution concentrations (winter).

[0034] Figure 8 , Fig. 9 The absolute value and percentage of heavy-duty diesel vehicles’ contribution to NO2 concentration (in summer). DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Reference Figure 1 As shown, the present invention provides a method for rapid assessment of air quality impact based on the OBD of heavy-duty diesel vehicles, including: Step 1, preparation of an emission inventory for heavy-duty diesel vehicles based on OBD data: Comprehensively analyzing the OBD data, supplementing, screening and quality controlling the data through big data methods, improving data availability, and realizing a high spatiotemporal resolution emission inventory preparation project for heavy-duty diesel vehicles based on OBD data.

[0037] It should be noted that OBD stands for on-board diagnostics.

[0038] In the above embodiment, the specific analysis method of the heavy-duty diesel vehicle high spatiotemporal resolution emission inventory compilation project based on OBD data is as follows: A. Read the OBD data Excel file and perform basic quality control: first, sort the data time, calculate the time interval between the two data through the xith data and the xi+1 data, and obtain the time length of the two data, and calculate the distance between the two data through the longitude and latitude data, that is, the distance traveled within the time.

[0039] Secondly, determine the data time interval and set the driving distance of data with too large a time interval to 0 to avoid the situation where the distance calculated by the longitude and latitude of two points is too different from the actual situation after the data is interrupted for too long.

[0040] It should be noted that the time is 10 minutes, that is, 600 seconds. The large interval of data collection is caused by vehicle stop, system failure or data transmission interruption. The large interval is prone to error accumulation. The distance is set to 0 to ensure that there will be no erroneous distance calculation due to data discontinuity, thereby ensuring the accuracy and reliability of data analysis.

[0041] Finally, the vehicle speed of this section is calculated by combining the distance and time interval calculated by the longitude and latitude, and the data with the calculated vehicle speed greater than or equal to 200 is set to 0. At the same time, it is compared with the instantaneous speed recorded in the OBD data to analyze the relationship between the calculated driving speed and the instantaneous speed.

[0042] Trajectory path completion based on OBD data: Two trajectory correction technologies are used, namely straight line correction and GPS+ straight line correction. Straight line correction extends a certain section of the running trajectory by adding trajectory points of equal distance between two GPS data points with a long span. GPS+ straight line correction first determines the possible path of the heavy-duty diesel vehicle through a collection of GPS trajectories over a period of time, connects two GPS data points with a long span through the minimum distance method, and further connects the running trajectory through straight line correction on this basis.

[0043] like Figure 2 As shown, taking the OBD data sample in October 2022 as an example, the data sample includes 286 vehicle OBD data. There are differences in data collection quality for different heavy-duty diesel vehicles. After reading the OBD data and quality control, the mileage was 289,000 kilometers. After linear correction of the missing data within the time interval of X minutes, the mileage increased to 355,000 kilometers. After using GPS data for completion, the mileage further increased to 416,000 kilometers. Compared with direct reading, the mileage increased by 43.7%, which improved the accuracy of heavy-duty diesel vehicle emission calculation and spatial distribution of pollution emissions to a certain extent.

[0044] Select a specific driving trajectory, and the differences in driving trajectories obtained by different data processing methods are as follows: Figure 3 , Figure 4 and Figure 5 As shown in the figure, the red points are the original trajectory points of the OBD data, and the black points are the corrected trajectory points. The two coincide when read directly.

[0045] from Figure 3 , Figure 4 and Figure 5 It can be seen from the figure that compared with the directly read OBD trajectory data, the trajectory after linear interpolation is extended, and the trajectory after big data interpolation is extended again. Combined with the actual situation, the final result is more accurate than the original data. Therefore, in terms of driving trajectory, the effect after big data interpolation is better than linear interpolation and original data, and is more in line with the actual situation. A weather research and forecast model simulation grid is established for the target city center, and a 1Km resolution meteorological element simulation is carried out. Combined with the latitude and longitude information in the OBD data of heavy-duty diesel vehicles, the temperature and relative humidity of the corresponding grid are obtained, and the meteorological correction of pollution emissions is carried out in combination with the altitude data.

[0046] The heavy-duty diesel vehicle pollution emission inventory is calculated by the following formula: , where For the The heavy-duty diesel vehicle benchmark emission factors for the following pollutants are It is the number of the pollutant type. is the meteorological correction factor, which is calculated based on relative humidity, temperature and altitude. is the speed correction factor, which is calculated based on the nonlinear interpolation of the guide factor data and the speed of the heavy-duty diesel vehicle. Expressed as Distance travelled by a heavy diesel vehicle, , is the vehicle number, Expressed as the number of vehicles, calculated from longitude and latitude.

[0047] It should be noted that BEFi is obtained from the National Environmental Protection Inventory Compilation Guidelines.

[0048] It should be noted that the target central urban area takes the central urban area of ​​Chengdu as an example.

[0049] Step 2. Gridded emission inventory generation project: Based on the high spatiotemporal resolution heavy-duty diesel vehicle OBD emission inventory obtained through balancing, a gridded emission inventory generation project is established to realize the conversion of the heavy-duty diesel vehicle OBD emission inventory to the air quality model inventory, and obtain the heavy-duty diesel vehicle OBD emission inventory, realizing spatial allocation, temporal allocation, and species allocation to generate an XYHT four-dimensional emission inventory.

[0050] In the above embodiment, the specific analysis method for establishing a gridded emission inventory generation project is as follows: a large amount of heavy-duty diesel vehicle OBD data is processed, and the emissions are calculated to obtain emission data with longitude and latitude information. The data has a high temporal and spatial resolution, and the time and spatial scales need to be redistributed before they can be used for model evaluation. The emission data is reprojected to obtain Lambert coordinate information, and then spatial gridding is performed in combination with the starting coordinates and grid resolution of the model grid, and gridded hourly emission data is generated in combination with the simulation time period.

[0051] Emissions inventory includes heavy-duty diesel vehicles , , CO and HC emissions, including and HC need to be assigned to species, and the calculated Directly obtain OBD data A comparison is required.

[0052] It should be noted that the species spectrum is based on literature research.

[0053] The data is processed using programming languages ​​to generate the NetCDF format gridded emission inventory required for CMAQ model simulation. The data is based on Lambert space projection and has spatial distribution properties. At the same time, time allocation is performed based on vehicle travel time obtained from OBD data.

[0054] It should be noted that the CMAQ model is a public multi-scale air quality model.

[0055] Step 3: MEIC inventory downscaling allocation: Through the high-resolution integrated inventory of atmospheric pollutants, combined with gridded GDP, population, road network and land use type data, downscaling allocation is carried out to form a basic inventory, and then the MEIC downscaled emission inventory is obtained to analyze the impact of heavy-duty diesel vehicles on atmospheric complex pollutants.

[0056] In the above embodiment, the analysis of the impact of heavy-duty diesel vehicles on atmospheric composite pollutants is specifically conducted by using a high-resolution integrated inventory of atmospheric pollutants and taking the heavy-duty diesel vehicle inventory as an incremental inventory. To meet the needs of air quality simulation in the target city, the following data are proposed to be used to allocate the MEIC inventory: 1) Industry: 1Km resolution gridded GDP data is used with weighted allocation, and is corrected in combination with high-resolution land use type data; 2) Electricity: Use thermal power generation POI for weighted allocation; 3) Civilian: Redistribution using 1km resolution gridded population data; 4) Transportation: Use OpenStreetsMap road network data for redistribution; 5) Agriculture: Redistribution using land use type data; 6) Open burning of biomass: Redistribution using land use type data; 7) Ships: grid evenly distributed; After the redistribution is completed, a 1km spatial resolution gridded emission inventory suitable for the simulation of this study, namely the urban benchmark inventory, is established. Combined with the Guidelines for the Compilation of Emission Inventories of Air Pollution Sources of the Ministry of Ecology and Environment, additional calculations are made for road dust emissions, soil dust emissions and natural source emissions, thereby obtaining a background emission inventory that basically covers the needs of the simulation of this study.

[0057] It should be noted that the inventory has a spatial resolution of 10 km. After downscaling, it can be used as a background inventory to carry out urban-scale air quality simulation. Compared with the earlier MEIC inventory version, the data has a higher spatial resolution. In order to better evaluate the impact of heavy-duty diesel vehicles on environmental air quality, the present invention intends to use this data as a background simulation inventory.

[0058] Step 4: Heavy-duty diesel vehicle emission impact assessment: Based on the Weather Research and Forecasting Model and the public multi-scale air quality model, high-resolution meteorological field data for the target city center is established. Based on the heavy-duty diesel vehicle OBD emission inventory and the MEIC downscaled emission inventory, an assessment of the impact of heavy-duty diesel vehicles on air quality is conducted.

[0059] In the above embodiment, the impact of heavy-duty diesel vehicles on air quality is evaluated, and the specific analysis method is as follows: taking 2022 as the base year, selecting January, April, July, and October to represent the four seasons, and conducting a meteorological field simulation in the target city center, i.e., the first and second circles, with a maximum resolution of 1 km in three layers to obtain high-resolution meteorological field data.

[0060] It should be noted that, taking 2022 as the base year, April, July and October are selected to represent the four seasons, and the Weather Research and Forecast Model is driven by referring to the fifth-generation reanalysis data ERA5 published by the European Centre for Medium-Range Weather Forecasts.

[0061] The heavy-duty diesel vehicle emission inventory and downscaling benchmark inventory obtained from Parts 2 and 3 were integrated to establish the assessment inventory required for this study. The inventory data was further spatially allocated according to the model nested grids to obtain gridded data that matched the spatial resolution of the simulation area. Time allocation sequences and species allocation sequences were established, and industrial point sources were vertically allocated, ultimately generating a four-dimensional gridded emission inventory with XYHT.

[0062] Using the EPA open source third-generation multiscale air quality model, CMAQ, based on the meteorological field data simulated by the WRF model and the assessment checklist generated in this study, an atmospheric environmental impact assessment of heavy-duty diesel vehicles in the target city center was conducted. and The concentration contribution of heavy-duty diesel vehicles to summer The nonlinear response relationship of Impact assessment. Figure 6 As shown in the figure, according to the set scenario, the activity level and emission factor of the emission sources are adjusted in combination with the OBD emission grid inventory and the urban benchmark inventory to generate the emission inventory under the scenario.

[0063] It should be noted that the WRF model is a forecast model.

[0064] Scenario concentration usually refers to the concentration of pollutants emitted by vehicles under specific conditions, such as specific driving patterns, traffic conditions, vehicle load, etc. Background concentration refers to the concentration of pollutants in the environment without the impact of vehicle emissions.

[0065] Using OBD heavy-duty diesel vehicle emission data, it is possible to assess the heavy-duty diesel vehicle’s emissions of pollutants such as Contributions such as Figure 7 As shown in Figure 2, OBD heavy-duty diesel vehicle emissions in summer From the perspective of the impact caused by concentration, its contribution is mainly concentrated in the second circle of the target city and some third circle districts and counties. The contribution of the northern area of ​​the main urban area is also prominent, which is related to the construction volume of different districts and counties. Among them, the districts and counties with higher contribution concentrations include Wenjiang District, Jinniu District, Xindu District, Shuangliu District, Dujiangyan City and Jianyang City. In addition, there is also a relatively obvious high-value area in the southern part of Jinjiang District.

[0066] OBD heavy-duty diesel vehicle summer emissions to target city state control stations The contribution of concentration, such as Figure 8 and Fig. 9 As shown, heavy-duty diesel vehicles have a higher impact on vehicle use in summer than in winter. The contribution to concentration is more significant, with the average contribution of national control stations reaching 1.37ug / m3, accounting for 5.6% of the average contribution. The national control station with the largest contribution value is Shilidian, which contributes 2.25ug / m3 and accounts for 7.8%. Comparing the impact of the three OBD heavy-duty diesel vehicle emission balance on concentration contribution, GFXOBD has a higher overall contribution.

[0067] It should be noted that A is the benchmark simulation, B is RAWOBD, C is LINOBD, and D is GFXOBD.

[0068] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A rapid assessment method for air quality impact based on heavy-duty diesel vehicle OBD, characterized in that: include: Step 1: Preparation of heavy-duty diesel vehicle emission inventory based on OBD data: Comprehensively analyze OBD data, supplement, screen and quality control the data through big data methods, improve data availability, and implement the high-temporal and spatial resolution emission inventory compilation project for heavy-duty diesel vehicles based on OBD data; Step 2: Gridded emission inventory generation project: Based on the high spatiotemporal resolution heavy-duty diesel vehicle OBD emission inventory obtained through accounting, a gridded emission inventory generation project is established to realize the conversion of the heavy-duty diesel vehicle OBD emission inventory to the air quality model inventory, obtain the heavy-duty diesel vehicle OBD emission inventory, realize spatial allocation, time allocation, and species allocation, and generate the XYHT four-dimensional emission inventory; Step 3: MEIC inventory downscaling allocation: Through the high-resolution integrated inventory of air pollutants, combined with gridded GDP, population, road network and land use type data, downscaling allocation is performed to form a basic inventory, and then the MEIC downscaled emission inventory is obtained to analyze the impact of heavy-duty diesel vehicles on atmospheric composite pollutants; Step 4: Heavy-duty diesel vehicle emission impact assessment: Based on the Weather Research and Forecasting Model and the public multi-scale air quality model, high-resolution meteorological field data for the target central urban area is established. Based on the heavy-duty diesel vehicle OBD emission inventory and the MEIC downscaled emission inventory, an assessment of the impact of heavy-duty diesel vehicles on air quality is conducted.

2. The method for rapid assessment of air quality impact based on heavy-duty diesel vehicle OBD according to claim 1 is characterized in that: The specific analysis method of the heavy-duty diesel vehicle high temporal and spatial resolution emission inventory compilation project based on OBD data is as follows: A. Read the OBD data Excel file and perform basic quality control: first sort the data time, calculate the time interval between the two data by the xith data and the xi+1 data, and get the time length of the two data, and calculate the distance between the two data by the longitude and latitude data, that is, the distance traveled within the time; Secondly, determine the data time interval and set the driving distance of the data with a large time interval to 0 to avoid the distance calculated by the longitude and latitude of two points being too different from the actual situation after the data is interrupted for too long. Finally, the vehicle speed of the section is calculated by combining the distance and time interval calculated by the longitude and latitude, and the data with the calculated vehicle speed greater than or equal to 200 is set to 0. At the same time, it is compared with the instantaneous speed recorded in the OBD data to analyze the relationship between the calculated driving speed and the instantaneous speed; B. Trajectory path completion based on OBD data: Two trajectory correction technologies are used, namely straight line correction and GPS+ straight line correction. The straight line correction extends a certain section of the running trajectory by adding equidistant trajectory points between two GPS data points with a long span. The GPS+ straight line correction first determines the possible path of the heavy-duty diesel vehicle through the GPS trajectory collection of a certain period of time, connects the two GPS data points with a long span through the minimum distance method, and further connects the running trajectory through straight line correction on this basis. A weather research and forecast model simulation grid is established for the target city center, and a 1km resolution meteorological element simulation is carried out. Combined with the latitude and longitude information in the OBD data of heavy-duty diesel vehicles, the temperature and relative humidity of the corresponding grid are obtained, and the pollution emission meteorological correction is carried out in combination with the altitude data; The heavy-duty diesel vehicle pollution emission inventory is calculated by the following formula: , where For the The heavy-duty diesel vehicle benchmark emission factors for the following pollutants are It is the number of the pollutant type. is the meteorological correction factor, which is calculated based on relative humidity, temperature and altitude. is the speed correction factor, which is calculated based on the nonlinear interpolation of the guide factor data and the speed of the heavy-duty diesel vehicle. Expressed as Distance travelled by a heavy diesel vehicle, , is the vehicle number, Expressed as the number of vehicles, calculated from longitude and latitude.

3. The method for rapid assessment of air quality impact based on heavy-duty diesel vehicle OBD according to claim 1 is characterized in that: The specific analysis method for establishing a gridded emission inventory generation project is as follows: After processing a large amount of heavy-duty diesel vehicle OBD data and calculating the emissions, we obtain emission data with latitude and longitude information. This data has high temporal and spatial resolution and needs to be redistributed in time and space before it can be used for model evaluation. After reprojecting the emission data and obtaining Lambert coordinate information, we spatially grid the data in combination with the starting coordinates and grid resolution of the model grid, and generate gridded hourly emission data in combination with the simulation time period. Emissions inventory includes heavy-duty diesel vehicles , , CO and HC emissions, including and HC need to be assigned to species, and the calculated Directly obtain OBD data A comparison is required; The data is processed using programming languages ​​to generate the NetCDF format gridded emission inventory required for CMAQ model simulation. The data is based on Lambert space projection and has spatial distribution properties. At the same time, time allocation is performed based on vehicle travel time obtained from OBD data.

4. The method for rapid assessment of air quality impact based on heavy-duty diesel vehicle OBD according to claim 1 is characterized in that: The specific analysis method for analyzing the impact of heavy-duty diesel vehicles on atmospheric composite pollutants is as follows: Through the high-resolution integrated inventory of atmospheric pollutants, the heavy-duty diesel vehicle inventory is used as an incremental inventory. In order to meet the air quality simulation needs of the target city, the following data are proposed to be used to allocate the MEIC inventory: 1) Industry: 1Km resolution gridded GDP data plus weight allocation, combined with high-resolution land use type data for correction; 2) Electricity: Use thermal power generation POI for weighted allocation; 3) Civilian: Redistribution using 1km resolution gridded population data; 4) Transportation: Use OpenStreetsMap road network data for redistribution; 5) Agriculture: Redistribution using land use type data; 6) Open burning of biomass: Redistribution using land use type data; 7) Ships: grid evenly distributed; After the redistribution is completed, a 1km spatial resolution gridded emission inventory suitable for the simulation of this study, namely the urban benchmark inventory, is established. Combined with the Guidelines for the Compilation of Emission Inventories of Air Pollution Sources of the Ministry of Ecology and Environment, additional calculations are made for road dust emissions, soil dust emissions and natural source emissions, thereby obtaining a background emission inventory that basically covers the needs of the simulation of this study.

5. The method for rapid assessment of air quality impact based on heavy-duty diesel vehicle OBD according to claim 1 is characterized in that: The specific analysis method for evaluating the impact of heavy-duty diesel vehicles on air quality is as follows: Taking 2022 as the base year, select April, April, July and October to represent the four seasons, and conduct meteorological field simulation in the target city center with three layers of nesting, i.e. the first and second circles, with the highest resolution of 1 km, to obtain high-resolution meteorological field data; The heavy-duty diesel vehicle emission inventory and downscaling benchmark inventory obtained from Parts 2 and 3 were integrated to establish the assessment inventory required for this study. The inventory data was further spatially allocated according to the model nested grids to obtain gridded data that matched the spatial resolution of the simulation area. Time allocation sequences and species allocation sequences were established, and industrial point sources were vertically allocated, etc., to finally generate a four-dimensional gridded emission inventory with XYHT. Using the EPA open source third-generation multiscale air quality model, CMAQ, based on the meteorological field data simulated by the WRF model and the assessment checklist generated in this study, an atmospheric environmental impact assessment of heavy-duty diesel vehicles in the target city center was conducted. and The concentration contribution of heavy-duty diesel vehicles to summer The nonlinear response relationship of Impact assessment.

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