Low-precision trajectory data processing method and system based on Delaunay triangulation network

Abstract

The present invention provides a method and system for processing low-precision trajectory data based on a Delaunay triangulation network. The method includes: obtaining low-precision trajectory data; extracting the first trajectory point and obtaining a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions; based on the set of trajectory points, performing Delaunay triangulation calculation to obtain the corresponding triangulation network; screening multiple triangles in the triangulation network and counting the number of valid triangles; based on the number of valid triangles, determining whether the first trajectory point needs to be filtered out; according to the filtered low-precision trajectory data, repeating steps 2 to 5 until all trajectory points in the low-precision trajectory point data are processed, and obtaining the remaining trajectory points. The present invention filters low-precision trajectory data based on a Delaunay triangulation network, solves the problems of filtering low-precision trajectory drift and sparse trajectory segments, and improves the reliability of the road network.

Description

Technical Field

[0001] The present invention relates to the field of high-precision map making, and more specifically, to a method and system for processing low-precision trajectory data based on a Delaunay triangulation network. Background Art

[0002] The production of crowdsourced high-precision maps not only needs to process high-precision trajectories, but also needs to be able to process low-precision trajectory data. This can reduce costs and be compatible with different data sources. However, the drift of low-precision trajectories is generally relatively serious. For a certain trajectory, if there are few other trajectories with a similar shape, the possibility of drift is relatively large, or if only very few trajectories pass through a certain section of the road, its reliability is also questionable. Therefore, in order to eliminate the interference caused by trajectory drift to the generated road network and improve the reliability of the road network, it is necessary to perform preprocessing of filtering low-precision trajectories. Summary of the Invention

[0003] The present invention provides a method and system for processing low-precision trajectory data based on a Delaunay triangulation network for the technical problems existing in the prior art.

[0004] According to the first aspect of the present invention, there is provided a method for processing low-precision trajectory data based on a Delaunay triangulation network, including:

[0005] Step 1, obtaining low-precision trajectory data;

[0006] Step 2, extracting the first trajectory point from the low-precision trajectory data, and obtaining a set of trajectory points whose distance and angle difference from the first trajectory point satisfy set conditions;

[0007] Step 3, performing Delaunay triangulation calculation based on the set of trajectory points to obtain a corresponding triangulation network;

[0008] Step 4, screening a plurality of triangles in the triangulation network and counting the number of valid triangles;

[0009] Step 5, judging whether the first trajectory point needs to be filtered out based on the number of valid triangles;

[0010] Step 6, according to the filtered low-precision trajectory data, repeating Steps 2 to 5 until all trajectory points in the low-precision trajectory point data are processed, and obtaining the remaining trajectory points.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Optionally, in Step 2, obtaining a set of trajectory points whose distance and angle difference from the first trajectory point satisfy set conditions includes:

[0013] When the distance between the trajectory point and the first trajectory point is less than the threshold d0 and the angle difference is less than the threshold θ0, the trajectory point meets the set condition, and all trajectory points that meet the set condition are obtained.

[0014] Optionally, step 4 of screening multiple triangles in the triangular mesh and counting the number of valid triangles includes:

[0015] When the three side lengths of a triangle in the triangular mesh are less than or equal to the length threshold d1 and the angles of the three interior angles of the triangle are all less than or equal to the angle threshold θ1, the triangle is a valid triangle, and the number of all valid triangles is counted.

[0016] Optionally, step 5 of determining whether the first trajectory point needs to be filtered out based on the number of valid triangles includes:

[0017] If the number of valid triangles is less than the threshold k0, the corresponding trajectory point needs to be filtered out; otherwise, the corresponding trajectory point is retained.

[0018] According to the second aspect of the present invention, a low-precision trajectory data processing system based on a Delaunay triangular mesh is provided, including:

[0019] A first acquisition module for acquiring low-precision trajectory data; and acquiring a set of trajectory points whose distance and angle difference from the first trajectory point in the extracted low-precision trajectory data meet the set conditions;

[0020] A calculation module for performing Delaunay triangular mesh calculation based on the set of trajectory points to obtain a corresponding triangular mesh;

[0021] A statistics module for screening multiple triangles in the triangular mesh and counting the number of valid triangles;

[0022] A judgment module for judging whether the first trajectory point needs to be filtered out based on the number of valid triangles;

[0023] A second acquisition module for repeatedly calling the first acquisition module, calculation module, statistics module, and judgment module according to the filtered low-precision trajectory data until all trajectory points in the low-precision trajectory point data are processed, and acquiring the retained trajectory points.

[0024] Optionally, the first acquisition module acquiring a set of trajectory points whose distance and angle difference from the first trajectory point in the extracted low-precision trajectory data meet the set conditions includes:

[0025] When the distance between the trajectory point and the first trajectory point is less than the threshold d0 and the angle difference is less than the threshold θ0, the trajectory point meets the set condition, and all trajectory points that meet the set condition are obtained.

[0026] Optionally, the statistical module screens multiple triangles in the triangular mesh and counts the number of valid triangles, including:

[0027] When the three side lengths of a triangle in the triangular mesh are less than or equal to the length threshold d1 and the angles of the three interior angles of the triangle are all less than or equal to the angle threshold θ1, the triangle is a valid triangle, and the number of all valid triangles is counted.

[0028] Optionally, the judgment module is used to judge whether the first trajectory point needs to be filtered out based on the number of valid triangles, including:

[0029] If the number of valid triangles is less than the threshold k0, the corresponding trajectory point needs to be filtered out; otherwise, the corresponding trajectory point is retained.

[0030] According to the third aspect of the present invention, an electronic device is provided, including a memory and a processor. When the processor executes a computer management program stored in the memory, the steps of the low-precision trajectory data processing method based on the Delaunay triangular mesh are implemented.

[0031] According to the fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer management program is stored. When the computer management program is executed by a processor, the steps of the low-precision trajectory data processing method based on the Delaunay triangular mesh are implemented.

[0032] A low-precision trajectory data processing method and system based on the Delaunay triangular mesh provided by the present invention filter low-precision trajectory data based on the Delaunay triangular mesh, solve the problems of filtering low-precision trajectory drift and sparse trajectory segments, and improve the reliability of the road network. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of a low-precision trajectory data processing method based on the Delaunay triangular mesh provided by the present invention;

[0034] Figure 2 It is a schematic structural diagram of a low-precision trajectory data processing system based on the Delaunay triangular mesh provided by the present invention;

[0035] Figure 3 It is a schematic hardware structure diagram of a possible electronic device provided by the present invention;

[0036] Figure 4Schematic diagram of the hardware structure of a possible computer-readable storage medium provided by the present invention. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. In addition, the technical features in each embodiment or a single embodiment provided by the present invention can be combined with each other arbitrarily to form a feasible technical solution. Such combination is not restricted by the order of steps and / or the pattern of structural composition, but must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0038] Based on the problems in the background art, the present invention proposes a method for filtering low-precision trajectory data. After obtaining the original low-precision trajectory, for the trajectory points therein, first obtain a set of trajectory points whose distances and angles are within a certain range from it, perform Delaunay triangulation calculation, and then screen the results of the triangulation. Count the number of Delaunay triangles for each point in the point set. Only the points whose quantity reaches a certain threshold can be retained, otherwise they will be filtered out. Ignore the processed point set, and repeat the above operations with all the remaining trajectory points until the loop ends, thus completing the entire filtering process.

[0039] Figure 1 Flowchart of a method for processing low-precision trajectory data based on Delaunay triangulation provided by the present invention, as Figure 1 shown, the method includes:

[0040] Step 1, obtain low-precision trajectory data.

[0041] Step 2, extract the first trajectory point from the low-precision trajectory data, and obtain a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions.

[0042] It can be understood that it is necessary to filter the trajectory points in the entire low-precision trajectory dataset. First, extract the first trajectory point in the low-precision trajectory dataset, and starting from the first trajectory point, obtain the set of trajectory points in its vicinity. The conditions to be met are as follows: the distance from the first trajectory point is less than the threshold d0, and the angle difference is less than the threshold θ0, and obtain the set of trajectory points that meet the conditions.

[0043] Step 3: Based on the set of trajectory points, perform Delaunay triangulation calculation to obtain the corresponding triangulation network.

[0044] It can be understood that based on the set of trajectory points obtained in Step 2, perform Delaunay triangulation calculation to obtain the corresponding triangulation network, where the triangulation network is composed of several triangles.

[0045] Step 4: Screen multiple triangles in the triangulation network and count the number of valid triangles.

[0046] It can be understood that screen several triangles in the triangulation network. Among them, the side length of a triangle cannot be greater than the threshold d1, and the angles of the three interior angles of the triangle cannot exceed the threshold θ1. Only the triangles that meet these two conditions are valid triangles, and the triangles that do not meet the conditions are excluded. One reason is to exclude the interference of trajectory points that may not be on the same road surface, and the other is to remove the triangulation network generated due to trajectory deflection. Such a triangulation network is generated by adjacent points of the same trajectory and is meaningless. In this way, the result of valid triangles is obtained, and the number of valid triangles is counted.

[0047] Step 5: Based on the number of valid triangles, determine whether the first trajectory point needs to be filtered out.

[0048] It can be understood that make a judgment according to the number of valid triangles corresponding to the trajectory points. If the number of valid triangles is less than the threshold k0, the trajectory point needs to be filtered out from the original low-precision trajectory dataset. If the number of valid triangles is greater than or equal to the threshold k0, the trajectory point is retained.

[0049] Step 6: According to the filtered low-precision trajectory data, repeat Steps 2 to 5 until all trajectory points in the low-precision trajectory point data are processed, and obtain the retained trajectory points.

[0050] It can be understood that based on the low-precision trajectory data from which the trajectory points that do not meet the conditions are filtered out, repeat Steps 2 to 5 until all trajectory points in the low-precision trajectory point data are processed, and obtain the set of retained trajectory points, which is the filtering result of the Delaunay triangulation network.

[0051] Figure 2 The following is a structural diagram of a low-precision trajectory data processing system based on Delaunay triangulation provided by an embodiment of the present invention. As Figure 2 shown, the system includes a first acquisition module 201, a calculation module 202, a statistics module 203, a judgment module 204, and a second acquisition module 205, where:

[0052] The first acquisition module 201 is configured to acquire low-precision trajectory data; and based on the first trajectory point in the extracted low-precision trajectory data, acquire a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions;

[0053] The calculation module 202 is configured to perform Delaunay triangulation calculation based on the set of trajectory points to obtain the corresponding triangulation;

[0054] The statistics module 203 is configured to screen multiple triangles in the triangulation and count the number of valid triangles;

[0055] The judgment module 204 is configured to judge whether the first trajectory point needs to be filtered out based on the number of valid triangles;

[0056] The second acquisition module 205 is configured to repeatedly call the first acquisition module, calculation module, statistics module, and judgment module according to the filtered low-precision trajectory data until all trajectory points in the low-precision trajectory point data are processed, and acquire the remaining trajectory points.

[0057] Wherein, the first acquisition module 201, based on the first trajectory point in the extracted low-precision trajectory data, acquires a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions, including: when the distance between the trajectory point and the first trajectory point is less than the threshold d0, and the angle difference is less than the threshold θ0, then the trajectory point meets the set conditions, and all trajectory points that meet the set conditions are acquired.

[0058] The statistics module 203 screens multiple triangles in the triangulation and counts the number of valid triangles, including: when the three side lengths of the triangle in the triangulation are less than or equal to the length threshold d1, and the angles of the three interior angles of the triangle are all less than or equal to the angle threshold θ1, then the triangle is a valid triangle, and the number of all valid triangles is counted.

[0059] The judgment module 204 is configured to judge whether the first trajectory point needs to be filtered out based on the number of valid triangles, including: if the number of valid triangles is less than the threshold k0, then the corresponding trajectory point needs to be filtered out; otherwise, the corresponding trajectory point is retained.

[0060] It can be understood that a low-precision trajectory data processing system based on Delaunay triangulation provided by the present invention corresponds to the low-precision trajectory data processing method based on Delaunay triangulation provided in the foregoing embodiments. The related technical features of the low-precision trajectory data processing system based on Delaunay triangulation can refer to the related technical features of the low-precision trajectory data processing method based on Delaunay triangulation, which will not be elaborated here.

[0061] Please refer to Figure 3 , Figure 3 , which is a schematic diagram of an embodiment of an electronic device provided by an embodiment of the present invention. As Figure 3 shown, an embodiment of the present invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored on the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 1311, it implements the steps of a method for processing low-precision trajectory data based on a Delaunay triangulation network.

[0062] Please refer to Figure 4 , Figure 4 , which is a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. As Figure 4 shown, this embodiment provides a computer-readable storage medium 1400, on which a computer program 1411 is stored. When the computer program 1411 is executed by a processor, it implements the steps of a method for processing low-precision trajectory data based on a Delaunay triangulation network.

[0063] A method and system for processing low-precision trajectory data based on a Delaunay triangulation network provided by an embodiment of the present invention have the following advantages:

[0064] (1) Different from the methods of using Delaunay triangulation networks for other road network constructions, the method of the present invention imposes restrictions on the distance and angle of the data set for constructing the triangulation network, so that to a large extent, it can be ensured that the selected point set belongs to the same road;

[0065] (2) After generating the triangulation network, the triangulation network is filtered according to the side length and the interior angle of the triangulation network, so that the interference of the triangulation network generated due to the unevenness of the trajectory deflection can be removed.

[0066] It should be noted that in the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailedly described in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0068] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general purpose computers, special purpose computers, embedded computers or other programmable data processing devices to produce a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0069] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction means that implements the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0070] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0071] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0072] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for processing low-precision trajectory data based on Delaunay triangulation, characterized in that, Including: Step 1, obtaining low-precision trajectory data; Step 2, extracting the first trajectory point from the low-precision trajectory data, and obtaining a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions; Step 3, based on the set of trajectory points, performing Delaunay triangulation calculation to obtain the corresponding triangulation; Step 4, screening a plurality of triangles in the triangulation and counting the number of valid triangles; wherein, when the three side lengths of a triangle in the triangulation are all less than or equal to the length threshold d1, and the angles of the three interior angles of the triangle are all less than or equal to the angle threshold θ1, then the triangle is a valid triangle, and the number of valid triangles in the triangulation is counted; Step 5, based on the number of valid triangles, determining whether the first trajectory point needs to be filtered out; wherein, if the number of valid triangles is less than the threshold k0, the corresponding trajectory point needs to be filtered out; Step 6, according to the filtered low-precision trajectory data, repeatedly execute Step 2 to Step 5 until all trajectory points in the low-precision trajectory point data are processed, and obtain the remaining trajectory points.

2. The method for processing low-precision trajectory data according to claim 1, characterized in that, In the said Step 2, obtaining a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions includes: When the distance between a trajectory point and the first trajectory point is less than the threshold d0, and the angle difference is less than the threshold θ0, then the trajectory point meets the set conditions, and all trajectory points that meet the set conditions are obtained.

3. A system for processing low-precision trajectory data based on Delaunay triangulation, characterized in that, Including: The first acquisition module is used to obtain low-precision trajectory data; and based on the first trajectory point extracted from the obtained low-precision trajectory data, obtaining a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions; The calculation module is used to perform Delaunay triangulation calculation based on the set of trajectory points to obtain the corresponding triangulation; The statistics module is used to screen a plurality of triangles in the triangulation and count the number of valid triangles; wherein, when the three side lengths of a triangle in the triangulation are all less than or equal to the length threshold d1, and the angles of the three interior angles of the triangle are all less than or equal to the angle threshold θ1, then the triangle is a valid triangle, and the number of valid triangles in the triangulation is counted; The judgment module is used to determine whether the first trajectory point needs to be filtered out based on the number of valid triangles; wherein, if the number of valid triangles is less than the threshold k0, the corresponding trajectory point needs to be filtered out; The second acquisition module is used to repeatedly call the first acquisition module, the calculation module, the statistics module and the judgment module according to the filtered low-precision trajectory data until all trajectory points in the low-precision trajectory point data are processed, and obtain the remaining trajectory points.

4. The system for processing low-precision trajectory data according to claim 3, characterized in that, The first acquisition module, based on the first trajectory point extracted from the obtained low-precision trajectory data, obtaining a set of trajectory points whose distance and angle difference from the first trajectory point meet the set conditions includes: When the distance between a trajectory point and the first trajectory point is less than the threshold d0, and the angle difference is less than the threshold θ0, then the trajectory point meets the set conditions, and all trajectory points that meet the set conditions are obtained.

5. An electronic device, characterized in that, It includes a memory and a processor, and when the processor is used to execute a computer management program stored in the memory, the steps of the method for processing low-precision trajectory data based on the Delaunay triangulation network as described in claim 1 or 2 are implemented.

6. A computer-readable storage medium, characterized in that, A computer management program is stored thereon, and when the computer management program is executed by the processor, the steps of the method for processing low-precision trajectory data based on the Delaunay triangulation network as described in claim 1 or 2 are implemented.

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