Grid-based collision warning method and system for low-altitude aerial vehicles

Abstract

The application relates to the field of low-altitude flight, in particular to a low-altitude aircraft collision early warning method and system based on a grid. The method comprises the following steps: acquiring low-altitude three-dimensional data of a target area, performing grid division on the low-altitude three-dimensional data to obtain a plurality of first grids; marking each first grid by using a grid code and marking the type of each first grid by using a grid type code; marking an obstacle grid by using an obstacle code; for each airspace grid, determining whether there is an obstacle grid within a preset range by using a grid search method; if yes, calculating the distance between each obstacle grid and the airspace grid, and generating obstacle information of the airspace grid; determining the airspace grid where a target low-altitude aircraft is located based on flight data of the target low-altitude aircraft, acquiring the corresponding obstacle information of the airspace grid, and judging whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data. The application can improve the safety of low-altitude aircraft flight.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-altitude flight, and particularly relates to a low-altitude aircraft collision warning method and system based on a grid. BACKGROUND

[0002] With the continuous development of aviation technology, low-altitude aircraft including small civil aircraft, helicopters and a large number of unmanned aerial vehicles are widely used in many fields, such as aerial photography, agricultural plant protection, logistics distribution and the like. However, the low-altitude flight environment is complex and changeable, and there are many uncertain factors, such as obstacles such as high-rise buildings in cities, which brings great safety challenges to low-altitude flight.

[0003] In the related art, a low-altitude aircraft uploads flight data of itself to a server, and the server calculates distances between the low-altitude aircraft and obstacles in real time according to the flight data and low-altitude three-dimensional data of a city to perform collision warning. However, the data calculation amount involved in this warning method is large, and the timeliness is poor. SUMMARY

[0004] Therefore, it is necessary to provide a low-altitude aircraft collision warning method and system based on a grid, a computer device and a computer readable storage medium in view of the above technical problems.

[0005] In a first aspect, an embodiment of the present application provides a low-altitude aircraft collision warning method based on a grid, and the method comprises the following steps.

[0006] Obtaining low-altitude three-dimensional data of a target region, and performing grid division on the low-altitude three-dimensional data to obtain a plurality of first grids;

[0007] Marking each first grid by using grid coding, marking a type of each first grid by using grid type coding, and the type of the first grid comprises an airspace grid and an obstacle grid; and marking the obstacle grid by using obstacle coding;

[0008] For each airspace grid, determining whether there is an obstacle grid within a preset range by using a grid search method; if yes, calculating distances between each obstacle grid and the airspace grid, and generating obstacle information of the airspace grid in combination with the grid coding and the obstacle coding corresponding to each obstacle grid;

[0009] Determining an airspace grid in which a target low-altitude aircraft is located based on flight data of the target low-altitude aircraft, obtaining obstacle information corresponding to the airspace grid, and judging whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data.

[0010] In some embodiments, the marking of the obstacle grid by using obstacle coding comprises:

[0011] determining whether two of the obstacle grids are adjacent, and if so, determining that the obstacle grids belong to the same obstacle and marking the obstacle grids with the same obstacle code.

[0012] In some embodiments, for each of the airspace grids, a grid search method is used to determine whether there is an obstacle grid within a preset range; if so, the distance between each of the obstacle grids and the airspace grid is calculated, and the obstacle information of the airspace grid is generated in combination with the grid code and the obstacle code corresponding to each of the obstacle grids, including:

[0013] For the first airspace grid to be searched in the search queue, the first grid adjacent to it is searched, and whether it is an obstacle grid is determined according to its grid type code; if so, it is determined whether the number of obstacle codes searched is greater than the maximum number of obstacles; if so, the search is ended; if less than the maximum number of obstacles, the obstacle code of the obstacle grid is obtained, the distance between the first airspace grid and the first grid is calculated, and a four-tuple of the first airspace grid is generated; if the first grid is an airspace grid, the airspace grid is added to the search queue, and the search is continued along the six directions adjacent to the first grid until the search range reaches the preset range; the obstacle information of the first airspace grid is generated according to all the four-tuples.

[0014] The above grid search method is repeated until each airspace grid in the search queue completes the grid search, and the obstacle information of each airspace grid is generated.

[0015] In some embodiments, the obstacle information corresponding to the airspace grid is obtained, and the obstacle collision risk of the target low-altitude aircraft is determined in combination with the flight data, including:

[0016] The distance between the airspace grid and the obstacle grid is obtained based on the obstacle information.

[0017] The flight speed of the target low-altitude aircraft is obtained based on the flight data, and the corresponding preset distance is determined based on the flight speed.

[0018] If the distance between the airspace grid and the obstacle grid is less than the preset distance, it is determined that the target low-altitude aircraft has an obstacle collision risk.

[0019] In some embodiments, the method further comprises:

[0020] The low-altitude three-dimensional data is divided into a plurality of second grids by grid division, and each of the second grids includes a plurality of the first grids.

[0021] The method for determining whether there is an obstacle grid in the preset range for each airspace grid comprises:

[0022] For an airspace grid, first, the first grids in the second grid where the airspace grid is located are sequentially traversed, and the obstacle grids therein are determined according to the grid type code of the first grids; then, the second grids in the preset range of each direction of the airspace grid are sequentially traversed, and it is determined whether there is an obstacle grid in the second grids, if there is, the first grids in the second grids are sequentially traversed, and the obstacle grids therein are determined according to the grid type code of the first grids.

[0023] In some embodiments, the method further comprises:

[0024] When the low-altitude three-dimensional data is updated, the first grid corresponding to the updated area is acquired;

[0025] The first grid corresponding to the updated area is re-marked by using the grid code, and the type of the first grid corresponding to the updated area is re-marked by using the grid type code; and the obstacle grid is marked by using the obstacle code;

[0026] For the airspace grid in the preset range from the first grid corresponding to the updated area, it is determined by using the grid search method whether there is an obstacle grid in the preset range; if yes, the distance between each obstacle grid and the airspace grid is calculated, and the obstacle information of the airspace grid is updated in combination with the grid code and the obstacle code corresponding to each obstacle grid.

[0027] In some embodiments, the low-altitude three-dimensional data is divided into a plurality of first grids by using the grid division method.

[0028] The low-altitude three-dimensional data in different preset height intervals is divided by using different grid division granularity; wherein, the larger the preset height interval is, the larger the grid division granularity is.

[0029] In a second aspect, an embodiment of the present application provides a low-altitude aircraft collision warning system based on a grid, which comprises:

[0030] A grid division module is configured to acquire low-altitude three-dimensional data of a target area, and divide the low-altitude three-dimensional data into a plurality of first grids by using a grid division method.

[0031] A grid marking module is configured to mark each first grid by using a grid code, mark the type of each first grid by using a grid type code, wherein the type of the first grid comprises an airspace grid and an obstacle grid, and mark the obstacle grid by using an obstacle code.

[0032] a distance calculation module, configured to determine, for each airspace grid, whether there is an obstacle grid within a preset range by using a grid search method; if yes, calculate the distance between each obstacle grid and the airspace grid, and generate the obstacle information of the airspace grid in combination with the grid code and the obstacle code corresponding to each obstacle grid;

[0033] a risk prediction module, configured to determine the airspace grid where the target low-altitude aircraft is located based on the flight data of the target low-altitude aircraft, acquire the obstacle information corresponding to the airspace grid, and judge whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data.

[0034] In a third aspect, an embodiment of the present application provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the first aspect.

[0035] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the processor executes the steps of the first aspect when executing the computer program.

[0036] The above method, system, computer device and storage medium acquire low-altitude three-dimensional data of a target region, divide the low-altitude three-dimensional data into a plurality of first grids by grid division, mark each first grid by using a grid code, mark the type of each first grid by using a grid type code, the type of the first grid includes an airspace grid and an obstacle grid, mark the obstacle grid by using an obstacle code, determine, for each airspace grid, whether there is an obstacle grid within a preset range by using a grid search method, if yes, calculate the distance between each obstacle grid and the airspace grid, and generate the obstacle information of the airspace grid in combination with the grid code and the obstacle code corresponding to each obstacle grid, determine the airspace grid where a target low-altitude aircraft is located based on the flight data of the target low-altitude aircraft, acquire the obstacle information corresponding to the airspace grid, and judge whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data. The present application can quickly judge whether the target low-altitude aircraft has an obstacle collision risk, and improve the safety of low-altitude aircraft flight. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 FIG. 1 is a flowchart of a low-altitude aircraft collision warning method based on grid in an embodiment of the present application;

[0038] Figure 2 FIG. 4 is a flowchart of determining an obstacle collision risk in an embodiment of the present application;

[0039] Figure 3 FIG. 6 is a flowchart of updating obstacle information in an embodiment of the present application;

[0040] Figure 4 Figure 1 is a schematic diagram of a structure of a low-altitude aircraft collision warning system based on a grid in an embodiment. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those skilled in the art, the present application can also be applied to other similar scenarios without creative labor on the basis of these drawings. Unless the context clearly indicates otherwise or otherwise stated, the same reference numbers in the drawings represent the same structures or operations.

[0042] As shown in the present application and claims, unless the context clearly indicates otherwise or otherwise stated, the words "one", "a", "an", and / or "the" do not specifically refer to the singular, but can also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0043] Although the present application makes various references to certain modules in the device according to the embodiments of the present application, however, any number of different modules can be used and run on the computing device and / or processor. The modules are only illustrative, and different aspects of the device and method can use different modules.

[0044] It should be understood that when a unit or module is described as "connected", "coupled" to other units, modules or blocks, it can mean direct connection or coupling, or communication with other units, modules or blocks, or there can be intermediate units, modules or blocks, unless the context clearly indicates otherwise. The term "and / or" used herein can include any and all combinations of one or more related listed items.

[0045] As shown in the present application and claims, unless the context clearly indicates otherwise or otherwise stated, the words "one", "a", "an", and / or "the" do not specifically refer to the singular, but can also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. Figure 1 As shown in the present application and claims, unless the context clearly indicates otherwise or otherwise stated, the words "one", "a", "an", and / or "the" do not specifically refer to the singular, but can also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0046] S102, obtaining low-altitude three-dimensional data of a target area, and performing grid division on the low-altitude three-dimensional data to obtain a plurality of first grids.

[0047] In some example embodiments, the low-altitude three-dimensional data is divided into grids by using a grid division method such as a GeoSOT grid, a Beidou grid, etc.

[0048] S104, marking each first grid with a mesh code and marking the type of each first grid with a mesh type code, the type of the first grid including a space grid and an obstacle grid; and marking the obstacle grids belonging to the same obstacle with the same obstacle code.

[0049] After the low-altitude three-dimensional data grid is divided, each first grid is marked with a unique mesh code. Each first grid has its own location information f(longitude, latitude, height), where longitude represents longitude, latitude represents latitude, and height represents height.

[0050] The low-altitude three-dimensional data is used to determine whether each first grid is a space grid or an obstacle grid, and the type of each first grid is marked with a mesh type code.

[0051] The obstacle grids belonging to the same obstacle are marked with the same obstacle code obstacleld, and the obstacle grids belonging to different obstacles are marked with different obstacle codes obstacleld, such as marking the obstacle of a tower or a bridge with a unique obstacle code obstacleld.

[0052] In some embodiments, it is determined whether two obstacle grids are adjacent, and if so, it is determined that the obstacle grids belong to the same obstacle and are marked with the same obstacle code.

[0053] In some embodiments, the ground surface grids in the first grid are also marked with a ground surface type code, such as a road, a lake surface, a mountain area, etc.

[0054] S106, for each space grid, it is determined by a mesh search method whether there is an obstacle grid within a preset range; if so, the distance between each obstacle grid and the space grid is calculated, and the obstacle information of the space grid is generated in combination with the mesh code and the obstacle code corresponding to each obstacle grid.

[0055] In some embodiments, for a certain space grid, there can be multiple obstacles within its preset range, in which case the nearest part of the obstacle can be selected.

[0056] After obtaining the obstacle information of each space grid, the obstacle information is stored in association with the mesh code of each space grid. If there is no obstacle grid within the preset range of some space grids, the obstacle information of the space grid is empty.

[0057] S108, determine the airspace grid where the target low-altitude aircraft is located based on the flight data of the target low-altitude aircraft, obtain the obstacle information corresponding to the airspace grid, and determine whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data.

[0058] The flight data includes low-altitude flight data of the target low-altitude aircraft, such as position, direction, speed, altitude, and the like. According to the position information of the target low-altitude aircraft, the airspace grid where the target low-altitude aircraft is located can be determined, and the corresponding grid code can be obtained to search for the corresponding obstacle information.

[0059] When it is determined that the target low-altitude aircraft has an obstacle collision risk, an alarm information is generated and output to the target low-altitude aircraft for timely alarm.

[0060] In this embodiment, the obstacle information of each airspace grid is obtained before the obstacle collision risk detection, so that when the obstacle collision risk detection is performed, only the flight data of the target low-altitude aircraft needs to be obtained to quickly obtain the obstacle information through searching, and whether there is an obstacle collision risk can be determined in time. Compared with the prior art, the data calculation amount of the technical solution is smaller, the obstacle collision risk detection is faster, and the safety of the low-altitude aircraft flight is improved.

[0061] In some embodiments, for each airspace grid, whether there is an obstacle grid in a preset range is determined by a grid search method, including:

[0062] For an airspace grid, the grids in the preset range of each direction of the airspace grid are sequentially searched, and whether the first grid is an obstacle grid is determined according to the grid type code of the first grid.

[0063] In a specific embodiment, before the grid search, a search condition fun(meshCode, maxDistance, obstacleCount) needs to be set, where meshCode represents the airspace grid to be searched; maxDistance represents the maximum distance from the obstacle, by which the preset range of each direction can be determined; and obstacleCount represents the maximum number of obstacles.

[0064] When the grid search is performed, the search queue is initialized, and the first airspace grid meshCode start to be searched is determined, and the first grid meshCode head, according to the grid type code of the obstacle grid, determine whether the obstacle grid is an obstacle grid, if yes, determine whether the number of the searched obstacle codes is greater than the maximum number of obstacles obstacleCount, if yes, end the search; if less than the maximum number of obstacles obstacleCount, obtain the obstacle code obstacleId of the obstacle grid, and calculate the distance Distance between the airspace grid meshCode start and the first grid meshCode head , generate the quadruple (meshCode start , obstacleId, meshCode head , Distance) of the airspace grid. If the adjacent first grid meshCode head is an airspace grid, add the airspace grid to the search queue, and continue to search in the six directions adjacent to the first grid meshCode head . Repeat the above steps for each adjacent first grid that has not been processed until the search range reaches the preset range. After the grid search for the airspace grid meshCode start is completed, process all quadruples to obtain the obstacle information of the airspace grid meshCode start . Repeat the above grid search method for the airspace grids in the search queue to obtain the obstacle information of all airspace grids.

[0065] In some embodiments, as shown in Figure 2 , the obtaining the obstacle information corresponding to the airspace grid, and determining whether the target low-altitude aircraft has an obstacle collision risk based on the flight data includes:

[0066] S202, obtaining the distance between the airspace grid and the obstacle grid based on the obstacle information;

[0067] S204, obtaining the flight speed of the target low-altitude aircraft based on the flight data, and determining a preset distance corresponding to the flight speed;

[0068] S206, if the distance between the airspace grid and the obstacle grid is less than the preset distance, determining that the target low-altitude aircraft has an obstacle collision risk.

[0069] The preset distance is determined according to the flight speed of the target low-altitude aircraft, and the faster the flight speed, the greater the corresponding preset distance. When the distance between the airspace grid and the obstacle grid is less than the preset distance, it is determined whether the target low-altitude aircraft has an obstacle collision risk. This embodiment realizes adaptive adjustment of triggering an obstacle collision risk according to the flight data of the target low-altitude aircraft.

[0070] Due to the huge number of first grids obtained after the low-altitude three-dimensional data is grid-divided, the efficiency of grid search using the first grids is low.

[0071] To solve the technical problem, in some embodiments, the low-altitude three-dimensional data is grid-divided into a plurality of second grids, and each second grid includes a plurality of first grids. The first grid can be understood as a sub-grid of the second grid, for example, a second grid includes 64 first grids. Each first grid includes a label of the second grid.

[0072] For a space grid, first, the first grids in the second grid where the space grid is located are sequentially traversed, and the obstacle grids in the first grids are determined according to the grid type codes of the first grids; then, the second grids within a preset range in each direction of the space grid are sequentially traversed, and it is determined whether there is an obstacle grid in the second grids; if there is, the first grids in the second grids are sequentially traversed, and the obstacle grids in the first grids are determined according to the grid type codes of the first grids.

[0073] The same grid search method as that of the first grid can be used for the second grid, which will not be described in detail in this embodiment.

[0074] Compared with the grid search using the first grids, the grid search method used in this embodiment adopts a hierarchical search manner, first searches the second grids to quickly determine whether there is an obstacle grid, and then searches the first grids in the case where there is an obstacle grid to quickly locate the obstacle grid, thereby improving the grid search efficiency.

[0075] In some embodiments, as shown in Figure 3 the method further includes:

[0076] S302, when the low-altitude three-dimensional data is updated, a first grid corresponding to an updated area is acquired;

[0077] S304, the first grid corresponding to the updated area is re-labeled using a grid code, the type of the first grid corresponding to the updated area is re-labeled using a grid type code, and the obstacle grids are labeled using an obstacle code;

[0078] S306, for a space grid within a preset range from the first grid corresponding to the updated area, it is determined whether there is an obstacle grid within the preset range by using a grid search method; if yes, the distances between each obstacle grid and the space grid are calculated, and the obstacle information of the space grid is updated in combination with the grid code and the obstacle code corresponding to each obstacle grid.

[0079] In existing technologies, when low-altitude 3D data is updated, it is necessary to re-grid, re-mark, and re-search the grid to generate obstacle information for all updated low-altitude 3D data. Therefore, the amount of data to be processed is large and the processing time is long.

[0080] In this embodiment, only the first grid corresponding to the updated area needs to be re-marked, and obstacle information is generated by re-grid search. Compared with the prior art, the amount of data processing is reduced and the data processing time is greatly shortened.

[0081] In some embodiments, different granularities of gridding are used for low-altitude 3D data in different preset altitude ranges; wherein, the larger the preset altitude range, the larger the granularity of the corresponding gridding.

[0082] In one example embodiment, the grid size is 100m x 100m in the height range of 500m to 1000m, and 10m x 10m in the height range of 0m to 500m.

[0083] It is understandable that in relatively high-altitude areas, the probability of obstacles is lower, so a larger-granularity mesh can be used; in relatively low-altitude areas, the probability of obstacles is higher, so a smaller-granularity mesh is required. The mesh generation method used in this embodiment significantly reduces the mesh generation time.

[0084] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0085] In one embodiment, such as Figure 4 As shown, this embodiment of the invention provides a grid-based low-altitude aircraft collision warning system, the system comprising:

[0086] The grid division module 402 is used to acquire low-altitude three-dimensional data of the target area and divide the low-altitude three-dimensional data into several first grids.

[0087] The grid marking module 404 is configured to mark each of the first grids by using a grid code, mark a type of each of the first grids by using a grid type code, and mark the obstacle grids by using an obstacle code, wherein the type of the first grids comprises a space grid and an obstacle grid.

[0088] The distance calculation module 406 is configured to, for each of the space grids, determine whether there is an obstacle grid within a preset range by using a grid search method, if yes, calculate a distance between each of the obstacle grids and the space grid, and generate obstacle information of the space grid in combination with the grid code and the obstacle code corresponding to each of the obstacle grids.

[0089] The risk prediction module 408 is configured to determine a space grid in which a target low-altitude aircraft is located based on flight data of the target low-altitude aircraft, acquire obstacle information corresponding to the space grid, and determine whether the target low-altitude aircraft has an obstacle collision risk in combination with the flight data.

[0090] In an embodiment, the embodiment of the present application provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in any one of the above-mentioned grid-based low-altitude aircraft collision warning method embodiments when executing the computer program.

[0091] In an embodiment, the embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps in any one of the above-mentioned grid-based low-altitude aircraft collision warning method embodiments.

[0092] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, the computer program can include the processes of the above-mentioned embodiments. Any reference to a memory, storage, database or other medium in each embodiment provided by the present application can include at least one of a non-volatile and volatile memory. The non-volatile memory can include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory or an optical storage, etc. The volatile memory can include a random access memory (RAM) or an external cache memory. As an illustration but not limitation, the RAM can be in various forms, such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), etc.

[0093] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, any combination of the technical features should be considered as within the scope of the present disclosure, as long as the combination is not contradictory.

[0094] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A grid-based low-altitude aircraft collision warning method, characterized in that, The method includes: Acquire low-altitude three-dimensional data of the target area, and divide the low-altitude three-dimensional data into several first grids; Each of the first grids is marked using grid coding, and the type of each of the first grids is marked using grid type coding, wherein the types of the first grids include airspace grids and obstacle grids; and the obstacle grids are marked using obstacle coding. For each of the aforementioned spatial grids, a grid search method is used to determine whether there are obstacle grids within a preset range; if so, the distance between each obstacle grid and the aforementioned spatial grid is calculated, and obstacle information for the aforementioned spatial grid is generated by combining the grid code and obstacle code corresponding to each obstacle grid. Based on the flight data of the target low-altitude aircraft, the airspace grid in which it is located is determined, the obstacle information corresponding to the airspace grid is obtained, and the flight data is combined to determine whether the target low-altitude aircraft has a risk of collision with obstacles.

2. The method according to claim 1, characterized in that, The step of marking the obstacle grid using obstacle coding includes: Determine whether two obstacle grids are adjacent. If so, determine that the obstacle grids belong to the same obstacle and mark them using the same obstacle code.

3. The method according to claim 1, characterized in that, For each of the aforementioned spatial grids, a grid search method is used to determine whether there are obstacle grids within a preset range; If so, the distance between each obstacle grid and the spatial grid is calculated, and the obstacle information of the spatial grid is generated by combining the grid code and obstacle code corresponding to each obstacle grid, including: For the first spatial grid to be searched in the search queue, search the first grid adjacent to it. Determine whether it is an obstacle grid based on its grid type code. If it is, check if the number of obstacle codes found is greater than the maximum number of obstacles. If so, end the search. If it is less than the maximum number of obstacles, obtain the obstacle code of the obstacle grid and calculate the distance between the first spatial grid and the first grid, generating a quadruple for the first spatial grid. If the first grid is a spatial grid, add it to the search queue and continue searching along the six directions adjacent to the first grid until the search range reaches a preset range. Generate obstacle information for the first spatial grid based on all the quadruples. Repeat the steps of the above grid search method until each spatial grid in the search queue completes the grid search and generates obstacle information for each spatial grid.

4. The method according to claim 1, characterized in that, The step of obtaining obstacle information corresponding to the airspace grid and determining whether the target low-altitude aircraft has a risk of obstacle collision in combination with the flight data includes: The distance between the spatial grid and the obstacle grid is obtained based on the obstacle information; The flight speed of the target low-altitude aircraft is obtained based on the flight data, and the corresponding preset distance is determined based on the flight speed; If the distance between the airspace grid and the obstacle grid is less than a preset distance, then the target low-altitude aircraft is determined to have a risk of obstacle collision.

5. The method according to claim 1, characterized in that, The method further includes: The low-altitude three-dimensional data is divided into several second grids, and each second grid includes multiple first grids; The step of determining whether an obstacle grid exists within a preset range for each of the aforementioned spatial grids using a grid search method includes: For a given airspace grid, firstly, the first grid in the second grid containing the airspace grid is traversed sequentially, and obstacle grids are determined according to the grid type code of the first grid. Then, the second grid within a preset range in each direction of the airspace grid is traversed sequentially to determine whether there are obstacle grids in the second grid. If there are, the first grid in the second grid is traversed sequentially, and obstacle grids are determined according to the grid type code of the first grid.

6. The method according to claim 1, characterized in that, The method further includes: When the low-altitude three-dimensional data is updated, the first grid corresponding to the updated area is obtained; The first grid corresponding to the updated region is re-marked using grid coding, and the type of the first grid corresponding to the updated region is re-marked using grid type coding; and the obstacle grid is marked using obstacle coding. For spatial grids within a preset range that are the first grid corresponding to the update area, a grid search method is used to determine whether there are obstacle grids within the preset range; if so, the distance between each obstacle grid and the spatial grid is calculated, and the obstacle information of the spatial grid is updated by combining the grid code and obstacle code corresponding to each obstacle grid.

7. The method according to claim 1, characterized in that, The step of dividing the low-altitude three-dimensional data into several first grids includes: For low-altitude 3D data with different preset altitude ranges, different granularities of gridding are used; wherein, the larger the preset altitude range, the larger the granularity of the corresponding gridding.

8. A grid-based low-altitude aircraft collision warning system, characterized in that, The system includes: The grid division module is used to acquire low-altitude three-dimensional data of the target area and divide the low-altitude three-dimensional data into several first grids. A grid marking module is used to mark each of the first grids using grid encoding, and to mark the type of each of the first grids using grid type encoding, wherein the types of the first grids include spatial grids and obstacle grids; and to mark the obstacle grids using obstacle encoding. The distance calculation module is used to determine whether there are obstacle grids within a preset range for each of the spatial grids using a grid search method; if so, it calculates the distance between each obstacle grid and the spatial grid, and generates obstacle information for the spatial grid by combining the grid code and obstacle code corresponding to each obstacle grid. The risk prediction module is used to determine the airspace grid in which the target low-altitude aircraft is located based on its flight data, obtain the obstacle information corresponding to the airspace grid, and determine whether the target low-altitude aircraft has a risk of obstacle collision in combination with the flight data.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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