CN112052549A - Method for selecting roads in small mesh gathering area - Google Patents

Method for selecting roads in small mesh gathering area Download PDF

Info

Publication number
CN112052549A
CN112052549A CN202010939435.8A CN202010939435A CN112052549A CN 112052549 A CN112052549 A CN 112052549A CN 202010939435 A CN202010939435 A CN 202010939435A CN 112052549 A CN112052549 A CN 112052549A
Authority
CN
China
Prior art keywords
mesh
small
road
meshes
area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010939435.8A
Other languages
Chinese (zh)
Other versions
CN112052549B (en
Inventor
李成名
吴伟
戴昭鑫
武鹏达
殷勇
印洁
郭沛沛
吴政
马照亭
刘晓丽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chinese Academy of Surveying and Mapping
Original Assignee
Chinese Academy of Surveying and Mapping
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chinese Academy of Surveying and Mapping filed Critical Chinese Academy of Surveying and Mapping
Priority to CN202010939435.8A priority Critical patent/CN112052549B/en
Publication of CN112052549A publication Critical patent/CN112052549A/en
Application granted granted Critical
Publication of CN112052549B publication Critical patent/CN112052549B/en
Priority to AU2021102429A priority patent/AU2021102429A4/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/18—Network design, e.g. design based on topological or interconnect aspects of utility systems, piping, heating ventilation air conditioning [HVAC] or cabling
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/29—Geographical information databases
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/10—Complex mathematical operations
    • G06F17/18—Complex mathematical operations for evaluating statistical data, e.g. average values, frequency distributions, probability functions, regression analysis
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/10—Segmentation; Edge detection
    • G06T7/11—Region-based segmentation

Abstract

The invention discloses a road selection method for a small mesh gathering area, which is applied to the technical field of geographic mapping, redefines calculation starting meshes by simultaneously considering the edge characteristics and the mesh density of the small meshes, and changes the calculation starting meshes into a pair of adjacent small meshes from one small mesh, thereby solving the problems that the calculation starting meshes are positioned in the middle of the small mesh gathering area, the result of mesh elimination is difficult to control, and the spatial distribution structure of an original road net is easy to change; meanwhile, the isolated section is eliminated based on the connection sequence of the strokes, so that the space structure loss caused by some left strokes is avoided. The method reasonably selects the gathering small mesh area in the road network, thereby ensuring the integrity and the connectivity of the road in the area after the road is integrated.

Description

Method for selecting roads in small mesh gathering area
Technical Field
The invention relates to the technical field of geographic mapping, in particular to a road selection method for a small-mesh gathering area.
Background
The road network on the map is an objective construction of the communication and distribution condition of the road network in the real geographic world, and is a skeleton element of the map. Generally, road networks have various grades, complex relationships and network shapes, so how to well realize multi-scale continuous expression of the road networks is a difficult problem. The road network is formed by connecting all the road sections to form a series of meshes, and when multi-scale continuous expression is carried out, the meshes of the road network need to be scientifically eliminated, so that the connectivity and integrity of the road can be maintained, and the spatial shape and the density characteristics of the road network can be accurately reflected when the multi-scale expression is ensured.
Road network is one of the main infrastructure elements in each scale map. In order to obtain continuous multi-scale spatial representation, map synthesis is often required for a road network, and the key core of the synthesis lies in how to reasonably select roads, so that important roads are reserved, secondary roads are eliminated, and the spatial characteristics and network structure of the roads are maintained, as well as the basic semantic, topological and geometric characteristics of the roads.
Under these constraints, how to effectively maintain the spatial distribution structure of the road network is a difficult point, and therefore, in recent years, researchers at home and abroad have conducted a great deal of research on the structure selection of the road network. For example, the method proposed by mourning et al for selecting roads based on mesh density of road network is to delete all small meshes whose mesh density exceeds a threshold value in sequence, and delete the section with the minimum importance in each small mesh, so that the overall characteristics of the road network and the local density change of different areas can be effectively reflected, and therefore, the method is often used for selecting the road network in dense road areas. The study of plum, shilin, et al shows that the method has the best effect on the selection of a road section spanning one or two meshes, and Wuwei, Touya, and the like apply the mesh-based method to the selection of urban roads and also obtain good effect. However, the existing method is suitable for a road area which occupies most isolated small meshes on a map, but some gathered small meshes exist in a residential district or a large factory area, and the typical spatial characteristics of the road in the area can be damaged by the existing mesh-based road selection method. Although the number of the gathered small mesh areas on the map is small, unreasonable selection of them still affects the overall quality of road selection to some extent.
Therefore, the technical staff in the field needs to solve the problem how to provide a method for selecting a small-mesh gathering area road, which is used for reasonably selecting a gathering small-mesh area in a road network so as to ensure the integrity and connectivity of the integrated roads in the area.
Disclosure of Invention
In view of the above, the invention provides a method for selecting roads in a small mesh aggregation area, which is used for reasonably selecting aggregation small mesh areas in a road network, so that the integrity and connectivity of the roads in the areas after the integration are ensured.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for selecting roads in a small mesh gathering area is characterized by comprising the following specific steps:
s1: identifying small mesh gathering areas according to original road network data, and putting the small mesh gathering areas into a candidate set to be processed;
s2: optionally, selecting a small mesh gathering zone;
s3: determining a starting mesh pair according to the small mesh aggregation area;
s4: deleting the shared arc section of the calculation mesh pair, identifying the road stroke where the shared arc section is located, sequentially identifying the mesh pair taking the arc section of the stroke as the shared arc section according to the connection direction of the stroke, deleting the shared arc section at the same time, completing road elimination of the corresponding mesh pair, and marking a newly generated mesh;
s5: identifying new starting cell pairs in the small cell accumulation zone without considering the newly generated cells in S4;
s6: repeatedly executing S4-S5 until a new calculation mesh pair cannot be found, and completing the round of road network selection;
s7: calculating the density of newly generated meshes after the road network is selected, and re-identifying the small meshes in the aggregation area;
s8: repeating S3-S7 until all newly generated mesh densities are smaller than the mesh density threshold, executing S11, otherwise, judging that only two adjacent small meshes exist in the aggregation area, executing S9, otherwise, judging that only one adjacent small mesh exists, and executing S10; greater than 2, perform S3;
s9: deleting the shared arc segment of the two adjacent small cells, calculating the cell density, and if the cell density is greater than the cell density threshold value, executing S10; if it is less than the mesh density threshold, then S12 is performed;
s10: removing the isolated small meshes from the road according to a mesh removing algorithm;
s11: the road selection of the gathering area is finished;
s12: and repeating S2-S11 until all roads in the small-mesh gathering area in the candidate set are selected.
Preferably, in the method for selecting a road in a small mesh aggregation area, the step S1 is as follows:
constructing a node-arc section-polygon topology for original road network data, wherein a closed area corresponding to a topological polygon is a mesh;
calculating the density of each mesh in the road network, determining a mesh density threshold value by using a sample graph statistical method, and constructing a road string by taking the mesh with the mesh density exceeding the threshold value as a small mesh;
traversing all the small meshes of the road network, and identifying a small mesh gathering area, namely a road area with the quantity of the adjacent small meshes being more than or equal to 2; and putting the small mesh aggregation area into a candidate set to be processed.
Preferably, in the method for selecting a road in a small cell concentration area, in S3, the adjacency relationship between two small cells is calculated based on a node arc polygon topology, and the two small cells are judged to be adjacent to each other; meanwhile, extracting the boundary of each gathering area according to the topological structure of the small meshes, and taking the boundary as hard constraint;
the calculation starting meshes are defined by considering the edge characteristics and the mesh density of the small meshes, and two adjacent small meshes which are positioned at the edge of the gathering area and have the smallest sum of the mesh densities are used as calculation starting mesh pairs.
Preferably, in the method for selecting a road having a small mesh aggregation area, the mesh density threshold value calculation method compares mesh density distribution curves of two scales before and after integration of the road network (the scale before integration is larger than the scale after integration), and takes a corresponding value of a split node having a significantly different curve as the density threshold value.
According to the technical scheme, compared with the prior art, the small mesh aggregation area road selection method reasonably selects the aggregation small mesh area in the road network, so that the integrity and connectivity of the integrated roads in the area are guaranteed. The invention redefines the calculation starting mesh by simultaneously considering the edge characteristics and the mesh density of the small meshes, and changes the calculation starting mesh from one small mesh to a pair of adjacent small meshes, thereby solving the problems that the calculation starting mesh is positioned in the middle of the gathering area of the small meshes, the result of mesh elimination is difficult to control, and the spatial distribution structure of the original road net is easy to change; meanwhile, the isolated section is eliminated based on the connection sequence of the strokes, so that the space structure loss caused by some left strokes is avoided.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a flow chart of a method of the present invention;
FIG. 2(a) is a schematic diagram of a first order neighborhood defining a starting cell versus a cell having a density of 0.42 in an embodiment of the present invention;
FIG. 2(b) is a schematic diagram of a first order neighborhood defining a mesh to mesh density of 0.38 in an embodiment of the present invention;
FIG. 2(c) is a schematic view of a new round of mesh pairs;
FIG. 3(a) is a schematic view of strokes for a starting cell pair and its shared arc segment in an embodiment of the present invention;
FIG. 3(b) is a schematic diagram of elimination results based on the order of strokes connection;
FIG. 3(c) is a schematic diagram of the elimination results (descending order) based on the mesh density method;
FIG. 4(a) is a first schematic diagram of iterative identification of calculation mesh pairs and processing in an embodiment of the present invention; wherein the starting mesh (orange) and the associated strokes (red) in the first round;
FIG. 4(b) is a schematic view of an iterative identification of calculation mesh pairs and processing of an embodiment of the present invention, wherein the first round and the newly formed mesh are selected (orange);
fig. 4(c) is a third schematic diagram of iterative identification of starting mesh pairs and processing in an embodiment of the present invention, wherein the starting mesh pairs (blue) and associated strokes (red) in the second round;
FIG. 4(d) is a diagram illustrating a fourth iteration of identifying calculation mesh pairs and processing, which is the final selection result, according to an embodiment of the present invention;
FIG. 5 is a graph of data used in experiments performed in examples of the present invention;
FIG. 6 is a graph of the shape similarity results obtained for two comparative methods of treating a gathering zone containing 2 small cells in accordance with an embodiment of the present invention;
FIG. 7(a) is a graph illustrating the results of a first exemplary zone processed by a first method for an accumulation zone comprising 2 small cells in accordance with an embodiment of the present invention;
FIG. 7(b) is a schematic representation of the results of a first exemplary zone processed by the method of the present invention comprising 2 small cells in an exemplary embodiment of the present invention;
FIG. 7(c) is a graph illustrating the results of a first method of gathering a zone containing 2 small cells processing a second exemplary zone in accordance with an embodiment of the present invention;
FIG. 7(d) is a graph illustrating the results of a second exemplary zone processed by the method of the present invention comprising 2 small cells in an exemplary embodiment of the present invention;
FIG. 8(a) is a graph showing the similarity of shape obtained by processing an aggregation zone containing more than 2 cells using two comparison methods according to an embodiment of the present invention;
FIG. 8(b) is a graph showing the results of the area coefficient of variation obtained by two comparison methods in an embodiment of the present invention in which the aggregation region includes 2 or more small cells;
FIG. 9(a) is a graph illustrating the results of a first exemplary zone processed by a first method for an exemplary aggregate zone comprising more than 2 cells according to embodiments of the present invention;
FIG. 9(b) is a graph showing the results of a first exemplary zone processed by the method of the present invention for an exemplary accumulation zone comprising more than 2 cells in an embodiment of the present invention;
FIG. 9(c) is a graph illustrating the results of a first method of processing a second exemplary region of an exemplary aggregate region comprising more than 2 small cells according to an embodiment of the present invention;
FIG. 9(d) is a graph illustrating the results of a second exemplary zone processed by the method of the present invention in an exemplary accumulation zone comprising more than 2 cells in accordance with an embodiment of the present invention;
FIG. 9(e) is a graph illustrating the results of a first method of processing a third exemplary region of an exemplary aggregate region comprising more than 2 cells according to an embodiment of the present invention;
fig. 9(f) is a schematic diagram of the processing results of the method of the present invention for a third exemplary zone comprising an exemplary aggregate zone of 2 or more small cells in an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a method for selecting a road in a small-mesh gathering area, including the following steps:
s1: identifying small mesh gathering areas according to original road network data, and putting the small mesh gathering areas into a candidate set to be processed;
s101, constructing a node-arc section-polygon topology for original road network data, wherein a closed area corresponding to a topological polygon is a mesh;
s102, calculating the density of each mesh in the road network, determining a mesh density threshold value by using a sample graph statistical method, and defining the mesh with the mesh density exceeding the threshold value as a small mesh;
s103, traversing all the small meshes of the road network, identifying small mesh aggregation areas, namely road areas with the quantity of the adjacent small meshes being more than or equal to 2, and placing the aggregation areas into a candidate set to be processed;
s2: optionally, selecting a small mesh gathering zone;
s3: determining a starting mesh pair according to the small mesh aggregation area;
s4: deleting the shared arc section of the calculation mesh pair, identifying the road stroke where the shared arc section is located, sequentially identifying the mesh pair taking the arc section of the stroke as the shared arc section according to the connection direction of the stroke, deleting the shared arc section at the same time, completing road elimination of the corresponding mesh pair, and marking a newly generated mesh;
s5: identifying new starting cell pairs in the small cell accumulation zone without considering the newly generated cells in S4;
s6: repeatedly executing S4-S5 until a new calculation mesh pair cannot be found, and completing the round of road network selection;
s7: calculating the density of newly generated meshes after the road network is selected, and re-identifying the small meshes in the aggregation area;
s8: repeating S3-S7 until all newly generated mesh densities are smaller than the mesh density threshold, executing S11, otherwise, judging that only two adjacent small meshes exist in the aggregation area, executing S9, otherwise, judging that only one adjacent small mesh exists, and executing S10; greater than 2, perform S3;
s9: deleting the shared arc segment of the two adjacent small cells, calculating the cell density, and if the cell density is greater than the cell density threshold value, executing S10; if it is less than the mesh density threshold, then S12 is performed;
s10: removing the road of the isolated small mesh according to the existing mesh removing algorithm;
s11: the road selection of the gathering area is finished;
s12: and repeating S2-S11 until all roads in the small-mesh gathering area in the candidate set are selected.
Further, in step S102, the mesh density threshold value calculating method compares mesh density distribution curves of two scales before and after the road network is synthesized, and takes the corresponding value of the split node with obviously different curves as the density threshold value, such as 0.016m/m2Considered to be the mesh density threshold for a 1:50000 urban road network to transition from 1: 10000. Wherein, the cells having a cell density greater than the threshold value are defined as small cells.
Further, in step S103, the road network is divided into three types of regions according to the number of adjacent small meshes: 1) A small cell aggregate area where there are 2 or more adjacent small cells; 2) an isolated region of small cells, wherein there is only one small cell and no adjacent small cells; 3) other areas without small cells.
Further, according to the node arc polygon topology, the adjacency relation between the two small meshes is calculated. Two small cells (i.e., polygons) are considered to be adjacent to each other if they share a common arc segment. Meanwhile, the boundary of each gathering area is extracted according to the topological structure of the small meshes and is used as a hard constraint, namely, the boundary is directly reserved and is not eliminated in the elimination process.
As shown in fig. 2, the present embodiment deals with the selection of the mesh pair in step S3.
For the commonly used mesh-based method, the smallest mesh with the highest mesh density is selected as the initial mesh. If the starting mesh is located in the middle of a small mesh gathering area, the result of mesh elimination is difficult to control and the spatial distribution structure of the original road net is easily changed. Thus, embodiments of the present invention redefine a starting cell by considering both edge characteristics and cell density of small cells, and change the starting cell from one small cell to a pair of adjacent small cells.
The embodiment of the invention redefines the mesh from mesh elimination as two adjacent meshes, the sum of the mesh densities of which is the largest and which is located at the outermost layer of the gathering zone. Embodiments of the present invention introduce a first order neighborhood of small cells to start the computation of the cells. For a small cell, the first order neighborhood is formed by the neighborhood small cells with which they share a common line segment or node. Obviously, the small cells at the border have the least number of small cells in the first-order neighborhood.
As shown in fig. 2(a), for a mesh density of 0.42 (blue), the first order neighborhoods are meshes with densities of 0.40, 0.38, and 0.28 (pink), and the number of small meshes in the first order neighborhoods is 3. Similarly, in fig. 2(b), for a mesh density of 0.38 (blue), the first order neighborhood includes meshes of densities 0.42, 0.40, 0.28, 0.26, and 0.34 (pink), and the number is 5. Thus, a mesh with a density of 0.42 is closer to the edge of the net than a mesh with a density of 0.38. Further, the small mesh pairs formed by the meshes with the densities of 0.42 and 0.40 (orange) had the largest total mesh density, and these meshes were selected as starting meshes, as shown in fig. 2 (c).
As shown in fig. 3, the present embodiment is explained with respect to the arc segment elimination in step S4.
For the starting cells in S3, the shared arc segments between the cells are marked. Then, identify the stroke where the shared arc segment is located, and determine other mesh pairs sharing other arc segments in the stroke. The arc segment elimination process used in the method is a stroke connection sequence. The advantage of this approach is that the loss of spatial structure due to some legacy strokes can be avoided. As shown in fig. 3(a), meshes with densities of 0.42 and 0.40 (orange) are defined as pairs of starting meshes, and the strokes in which the shared arcs are located are marked. Other mesh pairs sharing other links in the stroke are sequentially eliminated, and the elimination result is shown in fig. 3 (b). Fig. 3(c) shows the result of the elimination proposed by moustache et al, based on the consideration of the density of the cells in descending order, it can be seen that the original spatial structure of the small cells is destroyed.
As shown in fig. 4, a new calculation mesh pair is identified without considering the newly formed mesh obtained in step S6. As shown in fig. 4(a), two small cells adjacent to each other in orange are a pair of starting cells of the first round, and the newly formed cell (orange in fig. 4 (b)) will not participate in the recognition of the starting cell of the second round. Therefore, as shown in fig. 4(c), two adjacent small cells displayed in blue are the starting cells of the second round, and the final selection result is shown in fig. 4 (d).
As shown in fig. 5-9, are tests performed in this example to verify the reliability and superiority of the method of the invention.
FIG. 5 shows data used in the experiment, which is the original road data in a 1:10000 topographic map of a certain region in Jiangsu province, and the spatial range of the data is 23.91 multiplied by 18.67km2The comprehensive target scale is 1: 50000. The mesh density threshold was set at 0.016m/m at a ratio of 1:500002。
The test area contained a total of 1782 cells, 471 small cells and 1311 non-small cells. The details of the classification of the 471 small cells are shown in table 1. Of these, 23.77% of the small cells were isolated small cells, and the remaining small cells formed 64 aggregation regions. Thus, the small cells of the experimental zone have a pronounced aggregation behavior. In the gathering area of the small cells, the minimum number of the small cells is 2, which means that two adjacent small cells are required to form one gathering area, and the maximum gathering area is composed of 47 small cells.
Table 1 detailed classification of cells in test area
Figure RE-GDA0002702371490000101
To verify the effect of the method of the invention, a comparative test was carried out in two ways: one is that the mesh-based method proposed by the huyunshu performs all the mesh processing, and the other is that the isolated small meshes are processed by the mesh-based method of the huyunshu first, and the gathering meshes are processed by the method proposed by the present invention. For 112 isolated small cells, the results were the same since both comparison methods were mesh-based cancellation methods. This example will be described mainly with respect to the elimination of the aggregating meshes.
For 32 aggregate areas consisting of 2 small cells, the two comparison methods yielded 10 areas with the same results, accounting for 31.25% of all aggregate areas; and the number of regions with larger differences in the selection results is 22, and accounts for 68.75% of all the aggregation regions. The selection results were quantitatively evaluated using Shape Similarity (SS). The shape similarity formula is as follows:
Figure RE-GDA0002702371490000102
where n denotes the total number of cells associated with the accumulation area and i is the ith small cell, BAReaiIndicates the area of the i-th small cell, AArea, before selectioniShowing the cell area containing the original i-th small cell after selection. Obviously, when the SS value is 1, the road mesh shape similarity before and after the selection result is optimal.
By calculation, the SS results obtained for the two comparative methods are shown in fig. 6. Wherein the SS values of 10 aggregated regions having the same selection result are all 1, and the shape characteristics of the meshes are not changed. However, there were significant differences in SS values for the remaining 22 aggregation zones. With the first accumulation zone, which contains 2 cells, the minimum value of SS is 0.01, which means that one (or both) of the two cells in the zone merge into a very large contiguous cell and the area of the original cell changes dramatically, using the first method. While the SS values for the second method (the method of the present invention) are both 1, which indicates that two small cells can form a new cell with a cell density satisfying the threshold. A similar situation occurs for the other 21 aggregation zones. Therefore, the method has small influence on the spatial structure of the road network and can better reserve local characteristics.
Figure 7 shows the results obtained with two comparative methods, in which two typical aggregation areas with the same selection result and different results are obtained. As can be seen from fig. 7(a) and 7(b), the selection results of the two different methods are the same for the first exemplary region, and the least important part of the small cells is the common part a. However, as shown in fig. 7(c) and 7(d), the least important parts of the cells are not always the common part a, and thus, the two methods produce different selection results for the second typical area. Intersecting the first method, the selection result produced by the method of the invention better maintains the compact structure of the small meshes and maintains the connectivity of the road strokes of the road section b.
For 32 aggregated regions consisting of 2 or more small meshes, the selection results were quantitatively evaluated using Shape Similarity (SS) and coefficient of area variation (CVA). The formula for CVA is as follows:
Figure RE-GDA0002702371490000111
wherein σareaDenotes the standard deviation, μ, of the area of the small cells in the focal zoneareaIs the average area of the small cells in the accumulation zone. CVA is used to measure the uniformity of the cells in the gathering area. The smaller the CVA value, the more uniform the area distribution. Fig. 8 shows SS and CVA for two methods per aggregation area.
As shown in fig. 8(a), the SS values of the 32 aggregation regions obtained by the first method ranged from [0.03, 0.78], indicating that the areas of all the small cells varied to different degrees. In contrast, the SS values of these aggregation areas obtained by the method of the present invention are all 1, and the boundary constraint ensures that the spatial structure of the original aggregation area is not changed in general. As shown in fig. 8(b), the CVA values of the 27 aggregation areas obtained by the method of the present invention were decreased compared to the CVA values of the original aggregation areas, while the CVA values of the 26 aggregation areas obtained by the first method were increased, indicating that the density distribution of the result of the method of the present invention is more uniform than that of the first method.
Fig. 9 shows the results obtained with two comparative methods for 32 accumulation zones of 2 or more small cells, three representative accumulation zones of minimum (3), median (8) and maximum (47) number of cells being selected. It can be found that: in fig. 9(a) and (b), for the first typical area (the minimum number of small meshes), the first method eliminates the links a, b, c according to the low importance of the links, largely changing the spatial structure of the road network in that area. In contrast, the method considers boundary constraint, eliminates isolated road strokes and d, and the selection result better reflects the road network structure; in fig. 9(c) and (d), for the second exemplary region (small mesh count, etc.), the first method eliminates the links a, b, c, d, h, and g in 4 different strokes, with poor results. Compared with the prior art, the method adopts the arc section sequential identification elimination algorithm, only eliminates two road strokes (one is formed by the sections a and b, and the other is formed by the sections e, f and g) in the gathering area, and the obtained result is more reasonable; in fig. 9(e) and (f), for the third exemplary zone (the largest number of small cells), the method of the present invention maintains the cell distribution density better than the first method. The selection results of the two methods are obviously different in the areas where the strokeS of the three roads of S1, S2 and S3 are located, wherein the storage of S1 has an important influence on the uniformity of distribution density, and clear outlines can be obtained by storing strokeS 3. In addition, the method of the invention completely reserves the strokeS2, and better reflects the road connectivity.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. A method for selecting roads in a small mesh gathering area is characterized by comprising the following specific steps:
s1: identifying small mesh gathering areas according to original road network data, and putting the small mesh gathering areas into a candidate set to be processed;
s2: optionally, selecting a small mesh gathering zone;
s3: determining a starting mesh pair according to the small mesh aggregation area;
s4: deleting the shared arc section of the calculation mesh pair, identifying the road stroke where the shared arc section is located, sequentially identifying the mesh pair taking the arc section of the stroke as the shared arc section according to the connection direction of the stroke, deleting the shared arc section at the same time, completing road elimination of the corresponding mesh pair, and marking a newly generated mesh;
s5: identifying new starting cell pairs in the small cell accumulation zone without considering the newly generated cells in S4;
s6: repeatedly executing S4-S5 until a new calculation mesh pair cannot be found, and completing the round of road network selection;
s7: calculating the density of newly generated meshes after the road network is selected, and re-identifying the small meshes in the aggregation area;
s8: repeating S3-S7 until all newly generated mesh densities are smaller than the mesh density threshold, executing S11, otherwise, judging that only two adjacent small meshes exist in the aggregation area, executing S9, otherwise, judging that only one adjacent small mesh exists, and executing S10; greater than 2, perform S3;
s9: deleting the shared arc segment of the two adjacent small cells, calculating the cell density, and if the cell density is greater than the cell density threshold value, executing S10; if it is less than the mesh density threshold, then S12 is performed;
s10: removing the isolated small meshes from the road according to a mesh removing algorithm;
s11: the road selection of the gathering area is finished;
s12: and repeating S2-S11 until all roads in the small-mesh gathering area in the candidate set are selected.
2. The method for selecting a road in a small-mesh gathering area as claimed in claim 1, wherein the step of S1 is as follows:
constructing a node-arc section-polygon topology for original road network data, wherein a closed area corresponding to a topological polygon is a mesh;
calculating the density of each mesh in the road network, determining a mesh density threshold value by using a sample graph statistical method, and constructing a road string by taking the mesh with the mesh density exceeding the threshold value as a small mesh;
traversing all the small meshes of the road network, and identifying a small mesh gathering area, namely a road area with the quantity of the adjacent small meshes being more than or equal to 2; and putting the small mesh aggregation area into a candidate set to be processed.
3. The method according to claim 2, wherein in S3, the adjacency relationship between two small meshes is calculated based on a node arc polygon topology, and the two small meshes are judged to be adjacent to each other; meanwhile, extracting the boundary of each gathering area according to the topological structure of the small meshes, and taking the boundary as hard constraint;
the calculation starting meshes are defined by considering the edge characteristics and the mesh density of the small meshes, and two adjacent small meshes which are positioned at the edge of the gathering area and have the smallest sum of the mesh densities are used as calculation starting mesh pairs.
4. The method for selecting a road in a small mesh aggregation zone according to claim 2, wherein the mesh density threshold calculation method compares mesh density distribution curves of two scales in front of and behind a road network, and takes the corresponding values of split nodes with obviously different curves as density thresholds.
CN202010939435.8A 2020-09-09 2020-09-09 Method for selecting roads in small mesh gathering area Active CN112052549B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202010939435.8A CN112052549B (en) 2020-09-09 2020-09-09 Method for selecting roads in small mesh gathering area
AU2021102429A AU2021102429A4 (en) 2020-09-09 2021-05-10 Method for selecting roads in a small-mesh accumulation area

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010939435.8A CN112052549B (en) 2020-09-09 2020-09-09 Method for selecting roads in small mesh gathering area

Publications (2)

Publication Number Publication Date
CN112052549A true CN112052549A (en) 2020-12-08
CN112052549B CN112052549B (en) 2021-03-05

Family

ID=73611354

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010939435.8A Active CN112052549B (en) 2020-09-09 2020-09-09 Method for selecting roads in small mesh gathering area

Country Status (2)

Country Link
CN (1) CN112052549B (en)
AU (1) AU2021102429A4 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114722353A (en) * 2022-05-20 2022-07-08 山东省国土测绘院 Multilayer natural resource geographic entity statistical method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103258043A (en) * 2013-05-23 2013-08-21 南京师范大学 POI simplifying parallel computing method based on road mesh hierarchical structure division
CN105701204A (en) * 2016-01-12 2016-06-22 中国测绘科学研究院 Road network based electronic map POI extraction method and display method
CN110008602A (en) * 2019-04-10 2019-07-12 中国测绘科学研究院 Take the road network choosing method of multiple features coordination under a kind of large scale into account
WO2020033767A1 (en) * 2018-08-09 2020-02-13 Zoox, Inc. Procedural world generation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103258043A (en) * 2013-05-23 2013-08-21 南京师范大学 POI simplifying parallel computing method based on road mesh hierarchical structure division
CN105701204A (en) * 2016-01-12 2016-06-22 中国测绘科学研究院 Road network based electronic map POI extraction method and display method
WO2020033767A1 (en) * 2018-08-09 2020-02-13 Zoox, Inc. Procedural world generation
CN110008602A (en) * 2019-04-10 2019-07-12 中国测绘科学研究院 Take the road network choosing method of multiple features coordination under a kind of large scale into account

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114722353A (en) * 2022-05-20 2022-07-08 山东省国土测绘院 Multilayer natural resource geographic entity statistical method

Also Published As

Publication number Publication date
CN112052549B (en) 2021-03-05
AU2021102429A4 (en) 2021-06-24

Similar Documents

Publication Publication Date Title
CN111639237B (en) Electric power communication network risk assessment system based on clustering and association rule mining
CN105787977B (en) The method that building vector boundary simplifies
CN110008602B (en) Road network selection method considering multi-feature coordination under large scale
CN106326637A (en) Link predicting method based on local effective path degree
CN110442994A (en) A kind of 3D printing sliced sheet processing method based on graph theory
CN113297429B (en) Social network link prediction method based on neural network architecture search
CN110312206A (en) Based on the improved mobile phone signaling data trip recognition methods of dynamic space threshold value
CN111027574A (en) Building mode identification method based on graph convolution
CN112052549B (en) Method for selecting roads in small mesh gathering area
CN107818338B (en) Method and system for building group mode identification facing map synthesis
CN115618249A (en) Low-voltage power distribution station area phase identification method based on LargeVis dimension reduction and DBSCAN clustering
CN103164487B (en) A kind of data clustering method based on density and geological information
Lin et al. A new density-based scheme for clustering based on genetic algorithm
CN114329867B (en) Scale-free network robustness measuring method based on die body
CN112380267B (en) Community discovery method based on privacy graph
CN113393129B (en) Massive building multi-scale block combination method considering road network association constraint
CN111985065A (en) Road automatic selection technology based on gravitational field theory
CN115169501A (en) Community detection method based on close similarity of common neighbor node clustering entropy
CN115186882A (en) Clustering-based controllable load spatial density prediction method
CN109033746A (en) A kind of protein complex recognizing method based on knot vector
CN112035592B (en) Road network isolated mesh elimination method based on stroke tip characteristics
CN110222842A (en) A kind of network model training method, device and storage medium
CN114691744A (en) Method for mining micro map user association rule under constraint of propagation force
CN110427569B (en) Improved density peak value overlapping community discovery method based on rough set theory
CN115086179B (en) Detection method for community structure in social network

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant