CN-120851340-B - Three-dimensional equivalent surface extraction and quantization method and system for aviation emission

CN120851340BCN 120851340 BCN120851340 BCN 120851340BCN-120851340-B

Abstract

The invention discloses an aviation emission-oriented three-dimensional equivalent surface extraction quantization method and system, which comprise the steps of obtaining flight track data, constructing a three-dimensional voxel grid, mapping emission data to corresponding space voxels, further constructing a three-dimensional emission volume field, dividing the three-dimensional emission volume field into a plurality of voxel blocks to obtain local state codes of the voxel blocks, determining an edge set traversed by an equivalent surface in the voxel blocks according to the local state codes, calculating the intersection point position of the edge and the equivalent surface to obtain a three-dimensional equivalent surface grid, obtaining the minimum value and the maximum value of the emission volume field according to the three-dimensional emission volume field, determining emission volume threshold values, wherein each emission volume threshold value corresponds to an equivalent surface of one emission volume, and calculating to obtain geometric parameter characteristics of the equivalent surface. The invention aims to solve the problems of insufficient geometric precision, single structure identification, lack of depth quantization and the like in the prior art.

Inventors

FU XIN
ZHAO ZHONGYI
XU ZHENGHE
ZHANG HENGCAI
SU JUAN

Assignees

济南大学

Dates

Publication Date: 20260508
Application Date: 20250606

Claims (7)

1. The three-dimensional equivalent surface extraction and quantization method for aviation emission is characterized by comprising the following steps of: Constructing a three-dimensional voxel grid, mapping the emission data to corresponding space voxels, complementing voxel nodes and constructing a three-dimensional emission field; Dividing the three-dimensional emission quantity field into a plurality of voxel blocks, judging the vertex states of the voxel blocks, obtaining local state codes of the voxel blocks, determining an edge set traversed by an equivalent surface in the voxel blocks according to the local state codes, calculating the intersection point positions of the edge and the equivalent surface, forming a triangular patch set according to the intersection point, and splicing the triangular patches into a three-dimensional equivalent surface grid; obtaining the minimum value and the maximum value of the discharge volume field according to the three-dimensional discharge volume field, and determining discharge volume thresholds, wherein each discharge volume threshold corresponds to an equivalent surface of discharge volume; Calculating to obtain geometric parameter characteristics of the isosurface according to the isosurface of the discharge amount; The method comprises the steps of calculating the intersection point position, namely firstly calculating a voxel block edge direction unit vector, wherein the formula is as follows: wherein, the method comprises the steps of, As the side direction vector, the direction vector, For the length of the side of the plate, And Is the vertex position of two ends; Then, the directional derivatives of the function in the edge direction, i.e. the projection of the function gradient in this direction, are calculated at the vertices at both ends, respectively, with the formula: , wherein, the method comprises the steps of, 、 Two-point gradients respectively; And (3) the following steps: wherein, the method comprises the steps of, Representing the proportional position of the intersection point on the edge, c is a set isosurface threshold value, Is the function value corresponding to the vertex at one end of the edge, Is the function value corresponding to the vertex at the other end of the edge, The corresponding function values are: wherein, the method comprises the steps of, Representing the parameters of a three-dimensional Hermite interpolation function constructed along the edge A function value at the location; is a basis function, specifically: 、、、 Order-making machine Obtaining intersection parameters after solving, and obtaining the space coordinates of the intersection, wherein the space coordinates are as follows: = ( - ) Wherein, the method comprises the steps of, Is an intersection point parameter; the method for determining the discharge amount threshold comprises manual setting and automatic generation, wherein the manual setting is used for manually setting the discharge amount threshold and meets the following conditions: wherein, the method comprises the steps of, As a set of emission threshold values, For the minimum value of the discharge amount field, Is the maximum value of the discharge amount field; The automatic generation is that a threshold interval of the discharge amount is input, a threshold sequence is generated according to the threshold interval of the discharge amount, and the formula is as follows: Wherein k is a positive integer number representing a kth automatically generated emission threshold, N is a total number of automatically generated emission thresholds, Is the emissions threshold interval.
2. The three-dimensional iso-surface extraction and quantization method for aviation emission according to claim 1, wherein the voxel nodes are complemented by a three-dimensional empirical Bayesian Kriging interpolation method, specifically, emission predicted values are calculated at target positions, expressed as: wherein, the method comprises the steps of, Is the first The observed values of the points of the samples, For the corresponding weight coefficient(s), And n is the total number of sample points participating in interpolation calculation.
3. The three-dimensional iso-surface extraction and quantization method for aviation emission as set forth in claim 1, wherein each voxel block is composed of eight vertexes, the state of each vertex is marked as 1 when the value of each vertex is greater than or equal to a set threshold value, the state of each vertex is marked as 0 when the value of each vertex is smaller than the set threshold value, each vertex corresponds to a binary state bit, and the eight binary state bits are combined into a binary number according to the sequence of vertex numbers, namely the local state code of the voxel block.
4. The method for extracting and quantifying the three-dimensional isosurface for aviation emission according to claim 1, wherein the geometric parameter characteristics of the isosurface obtained by calculation comprise surface area, volume, average curvature and average height; The surface area is: wherein, the method comprises the steps of, Is the first The surface area of the individual iso-surfaces, Is the first A set of triangular patches of equal-valued surfaces, Is the area of a single triangular patch; The volume is as follows: wherein, the method comprises the steps of, Is the first The volume of the individual iso-surfaces, Is the first The volume area surrounded by the isosurfaces, dV is the volume infinitesimal, Is that Is used to determine the unit normal vector of (c), Is the centroid position vector of the corresponding patch; the average curvature is: wherein, the method comprises the steps of, Is the first The average curvature of the individual iso-surfaces, Is the first The total number of vertices on the respective isosurfaces, First, the On the equivalent surface of Average curvature of individual vertices And Respectively the first On the equivalent surface of Two principal curvatures at the vertices; the average height is: wherein, the method comprises the steps of, Is the first Average height of the isosurfaces Is the first On the equivalent surface of The height coordinates of the vertices.
5. The three-dimensional equivalent surface extraction and quantization system for aviation emission is characterized by comprising the following modules: The emission volume field construction module is configured to acquire flight track data and obtain emission data of each track point, construct a three-dimensional voxel grid, map the emission data to corresponding space voxels, complement voxel nodes and further construct a three-dimensional emission volume field; The three-dimensional isosurface calculation module is configured to divide a three-dimensional emission volume field into a plurality of voxel blocks, judge the vertex states of the voxel blocks, obtain local state codes of the voxel blocks, determine an edge set traversed by an isosurface in the voxel blocks according to the local state codes, calculate the intersection point positions of the edge and the isosurface, form a triangular surface patch set according to the intersection point, and splice the triangular surface patches into a three-dimensional isosurface grid; The multi-threshold extraction module is configured to obtain the minimum value and the maximum value of the emission volume field according to the three-dimensional emission volume field, and determine emission volume thresholds, wherein each emission volume threshold corresponds to an equivalent surface of the emission volume; the quantization module is configured to calculate geometrical parameter characteristics of the isosurface according to the isosurface of the emission quantity; The method comprises the steps of calculating the intersection point position, namely firstly calculating a voxel block edge direction unit vector, wherein the formula is as follows: wherein, the method comprises the steps of, As the side direction vector, the direction vector, For the length of the side of the plate, And Is the vertex position of two ends; Then, the directional derivatives of the function in the edge direction, i.e. the projection of the function gradient in this direction, are calculated at the vertices at both ends, respectively, with the formula: , wherein, the method comprises the steps of, 、 Two-point gradients respectively; And (3) the following steps: wherein, the method comprises the steps of, Representing the proportional position of the intersection point on the edge, c is a set isosurface threshold value, Is the function value corresponding to the vertex at one end of the edge, Is the function value corresponding to the vertex at the other end of the edge, The corresponding function values are: wherein, the method comprises the steps of, Representing the parameters of a three-dimensional Hermite interpolation function constructed along the edge A function value at the location; is a basis function, specifically: 、、、 Order-making machine Obtaining intersection parameters after solving, and obtaining the space coordinates of the intersection, wherein the space coordinates are as follows: = ( - ) Wherein, the method comprises the steps of, Is an intersection point parameter; the method for determining the discharge amount threshold comprises manual setting and automatic generation, wherein the manual setting is used for manually setting the discharge amount threshold and meets the following conditions: wherein, the method comprises the steps of, As a set of emission threshold values, For the minimum value of the discharge amount field, Is the maximum value of the discharge amount field; The automatic generation is that a threshold interval of the discharge amount is input, a threshold sequence is generated according to the threshold interval of the discharge amount, and the formula is as follows: Wherein k is a positive integer number representing a kth automatically generated emission threshold, N is a total number of automatically generated emission thresholds, Is the emissions threshold interval.
6. A computer readable storage medium having stored thereon a program, which when executed by a processor performs the steps of a three-dimensional iso-surface extraction quantization method for aviation emissions according to any one of claims 1-4.
7. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor performs the steps of a three-dimensional iso-surface extraction quantization method for aviation emission according to any one of claims 1-4 when the program is executed.

Description

Three-dimensional equivalent surface extraction and quantization method and system for aviation emission Technical Field The invention relates to the technical field of aviation emission, in particular to a three-dimensional iso-surface extraction and quantization method and system for aviation emission. Background With the continuous development of the air transportation industry, the problem of aviation emission in airports and surrounding areas is becoming more and more interesting. Aircraft can emit large amounts of carbon oxides and nitrogen oxides during take-off and landing, and the diffusion of these pollutants presents a distinct three-dimensional spatial signature. When aviation emission is studied, the three-dimensional equivalent surface extraction and feature quantization technology is very critical, and the three-dimensional equivalent surface extraction and feature quantization technology can intuitively present the spatial distribution of emission and perform quantization analysis. At present, the prior art in the field of aviation emission research comprises a track inversion and bottom emission modeling method, a fuel consumption segmentation correction based segment emission accounting method, an airport ground multisource high-resolution emission list based method, an airport emission modeling method based on improved LTO circulation and meteorological parameter optimization and Marching Cubes algorithm, wherein the track inversion and bottom emission modeling method is combined with flight activity data and aviation environment design tool output to carry out fine granularity division on a flight path and an emission source, so that high-space-time resolution pollutant emission modeling of an airport area is realized, and although the method can output fine granularity emission path data, complete three-dimensional continuous quantity field expression is not formed, and modeling capability of an integral space structure is lacked; the method for accounting the emission of the air section based on the fuel consumption subsection correction establishes a multi-component pollutant emission accounting system by improving a fuel consumption model and introducing model details and the like, improves the accuracy of emission estimation of different flight phases, but the output result still stays at a numerical total level and cannot show the evolution trend of emission in space, builds a ground multi-source emission list based on an airport ground multi-source high-resolution emission list by collecting actual operation data, quantifies the space distribution characteristics of pollutants of an airport and a sliding area, focuses on meshing modeling in the horizontal direction, does not fully consider the emission characteristics of an aircraft in the vertical direction, leads to insufficient reduction capability of a three-dimensional structure, corrects emission height setting based on an airport emission modeling method based on improving LTO circulation and weather parameter optimization by fusing weather data based on traditional LTO stage division, improves the rationality of near-ground emission estimation, the Marching Cubes algorithm is used as a classical three-dimensional equivalent surface extraction method, is widely applied to scenes such as medical image processing, geological modeling, fluid field visualization and the like, generally depends on a single threshold value and linear interpolation, is easy to generate problems of boundary blurring and structural distortion in a high-gradient discharge area, lacks a geometric quantization function, and is difficult to support quantitative description and comparative analysis of a complex discharge structure. It has been found that aviation emissions fields often exhibit high concentration gradients and complex three-dimensional spatial distributions in areas such as near the ground and landing airlines at airports. In the prior art, a linear interpolation method is mainly adopted, the accuracy of the method is limited when the intersection point of the equivalent surface and the voxel boundary is positioned, and particularly, larger geometric deviation is easy to generate in a high gradient area, so that the generated equivalent surface cannot accurately reflect the space boundary with the rapid change of the discharge amount, and the accuracy of subsequent analysis is affected. Furthermore, the standard method is not robust enough to handle complex or degraded topologies (e.g. small holes, flakes) resulting from interpolation, possibly resulting in discontinuities or distortions in the extracted iso-surface structure. In addition, aviation emissions analysis often requires simultaneous investigation of emissions spatial distribution characteristics at different concentration levels. Existing iso-surface extraction techniques are typically based on a single threshold operation, requiring repeated execution of the algorithm and ext