A regional search control method based on geographic information system

Abstract

A regional search and control method based on Geographic Information System (GIS). This invention relates to the field of unmanned aerial vehicle (UAV) reconnaissance technology, specifically to a regional search and control method based on GIS. The invention uses Web Mercator projection to convert geographic coordinates into planar coordinates, and then, combined with the current field of view of the optoelectronic platform, calculates the length and width of the projected field of view, plans the motion trajectory, and employs a "bow"-shaped scanning pattern to achieve regional search control of the optoelectronic platform. The method includes the following steps: acquiring the geographic coordinate information of the target point; converting the geographic coordinate information into planar rectangular coordinate information based on Web Mercator projection; calculating the projected length and width of the current field of view; calculating the number of scanning steps required based on the planar rectangular coordinate information and the projected length and width of the current field of view; and the optoelectronic platform performing a "bow"-shaped scanning pattern based on the projected length and width of the current field of view and the number of scanning steps required.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) reconnaissance technology, and more specifically to a regional search and control method based on geographic information systems. Background Technology

[0002] Regional search and control, as a core application of Geographic Information Systems (GIS) in fields such as emergency management, resource exploration, and security monitoring, directly impacts the accuracy of scenario response and the efficiency of resource scheduling. Under the traditional technical framework, the entire process of regional search faces multiple technical bottlenecks:

[0003] At the path planning level, the manual-led path planning mode has exposed defects such as insufficient dynamic adaptability and high redundancy in path planning, resulting in generally low search coverage (average coverage is only 75%-85%), which makes it difficult to meet the needs of full-domain perception in complex environments.

[0004] In the geographic boundary calculation stage, there is a lack of automated algorithms for extracting geographic coordinate boundaries. The existing calculation process relies heavily on manual experience to construct rules, resulting in problems such as fragmented algorithm logic, cumbersome and redundant calculation steps, and low computational efficiency, which restricts the real-time performance and accuracy of regional searches.

[0005] The aforementioned technical pain points are coupled together, causing traditional regional search solutions to exhibit limitations such as slow response, resource waste, and coverage blind spots when facing dynamic scene changes and multi-source data fusion. There is an urgent need to break through existing technical barriers through automated extraction algorithms. Summary of the Invention

[0006] To address the problems of low efficiency, poor dynamic adaptability, path redundancy, and insufficient coverage in traditional manual path planning methods, this invention proposes a regional search control method based on a Geographic Information System (GIS). It uses Web Mercator projection to convert geographic coordinates into planar coordinates, and then, combined with the current field of view of the photoelectric platform, calculates the length and width of the projected field of view, plans the motion trajectory, and employs a "bow"-shaped scanning pattern to achieve control over the regional search of the photoelectric platform.

[0007] The method includes the following steps:

[0008] S1. Obtain the geographic coordinates of the target point;

[0009] S2. Convert geographic coordinate information into plane rectangular coordinate information based on Web Mercator projection;

[0010] S3. Calculate the projected length and width of the current field of view;

[0011] S4. Based on the Cartesian coordinate information and the projection length and width of the current field of view, calculate the number of scan steps required;

[0012] S5, the photoelectric platform performs "bow"-shaped scanning based on the projection length and width of the current field of view and the number of scanning steps required.

[0013] Furthermore, the geographic coordinate information of the target point includes: the longitude of the target point. and the latitude of the target point .

[0014] Furthermore, the specific method for converting geographic coordinate information into Cartesian coordinate information based on Web Mercator projection is as follows: using the formula: and Calculate Cartesian coordinates ,in, Represents the Earth's radius. express Longitude.

[0015] Furthermore, the calculation of the projected length and width of the current field of view is specifically performed using the formula: and Calculate, where, and These represent the projected length and width of the current field of view, respectively. Indicates the longitudinal field of view. Indicates the encoder pitch angle. Indicates the pseudo-range value. Indicates horizontal resolution. This indicates the vertical resolution.

[0016] Furthermore, the number of steps required for scanning is determined by the formula: and , calculate, where, and These represent the number of horizontal and vertical steps that need to be scanned, respectively. and Both represent the boundaries of the region search. Axis coordinates and Both represent the boundaries of the region search. Axis coordinates.

[0017] Furthermore, the specific implementation of the "bow"-shaped scanning is as follows:

[0018] S61, Optoelectronic platform horizontal scanning Each step moves 80%n. ;

[0019] S62, when At that time, the photoelectric platform performs one longitudinal scan, with each step moving 80% of the height. , Reset steps;

[0020] Conversely, continue executing S61;

[0021] S63, when and When both values ​​are 0, the scan ends.

[0022] Conversely, S61 and S62 are executed in a loop.

[0023] The beneficial effects of the method described in this invention are as follows:

[0024] (1) The method described in this invention uses Web Mercator projection for coordinate transformation, treating the Earth as a standard sphere (radius 6378137 meters), eliminating the need for complex calculations of ellipsoid parameters and improving projection efficiency. As the mainstream projection method for Internet map services, compared with Gauss projection, Web Mercator projection does not require central meridian limitation and is suitable for national or global scale maps.

[0025] (2) When calculating the projection length and width of the current field of view in the field of view-mesh mapping calculation module, the method of the present invention combines the known aircraft parameters and pod attributes to simplify the calculation steps, save platform resources, and can be adjusted in real time according to the current pod status, which has the characteristics of flexibility and convenience.

[0026] (3) The method described in this invention adopts a “bow” shaped path through a regular parallel turning path to ensure no dead angle coverage of rectangular or regular areas, which is especially suitable for scenarios that require full-area search. The “bow” shaped path is naturally adapted to gridded map segmentation. By decomposing the area into equal-width sub-areas and scanning them sequentially, it can effectively avoid missing areas caused by obstacles or terrain segmentation. Compared with the spiral path, the bow shape reduces the turning frequency by traveling in long straight lines, reducing the platform disturbance that may be caused by turning. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method described in this embodiment;

[0028] Figure 2 This is a schematic diagram showing the relationship between the photoelectric pod and the target point described in this embodiment;

[0029] Figure 3 This is a schematic diagram showing the projected length and width of the current field of view as described in this embodiment;

[0030] Figure 4 This is a schematic diagram of the "bow" shaped scanning method described in this embodiment. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This embodiment provides a regional search and control method based on a geographic information system, the flowchart of which is shown below. Figure 1 As shown, the method includes the following steps:

[0033] S1. Obtain the geographic coordinates of the target point.

[0034] The relevant operations in step S1 will be introduced with specific examples:

[0035] The geographic coordinate information of the target point includes: the longitude of the target point. Latitude of the target point And height.

[0036] S2. Based on the Web Mercator projection, geographic coordinate information is converted into plane rectangular coordinate information.

[0037] The relevant operations in step S2 will be introduced with specific examples:

[0038] Compared with traditional methods, the method described in this invention uses Web Mercator projection to transform geographic coordinates, which simplifies the calculation steps and improves the running speed.

[0039] The conversion of geographic coordinate information to Cartesian coordinate information based on Web Mercator projection is specifically achieved through the following formula: and Calculate Cartesian coordinates ,in, Represents the Earth's radius. express Longitude.

[0040] S3. Calculate the projected length and width of the current field of view.

[0041] The relevant operations in step S3 will be introduced with specific examples:

[0042] To calculate the projected length and width of the current field of view, it is necessary to first calculate the distance (pseudorange value) from the current electro-optical pod to the target point. ),like Figure 2 As shown, the pseudorange value is estimated based on the pod height, ground elevation, and the angle of the photoelectric pod encoder. The conversion formula is as follows: ,in, Indicates the pod height. Indicates ground elevation. Indicates the encoder pitch angle

[0043] like Figure 3 As shown, according to the relationship of field of view projection, the length within the image frame is directly proportional to the actual distance to the ground; that is, the larger the image frame within the field of view, the larger the projected area. This is based on trigonometric functions. This proportional relationship can be mapped to the proportional relationship between focal length and pseudorange. The length of the field of view projection can be obtained by the height of the pod platform, the ground elevation, and the encoder angle of the pod.

[0044] The projection length and width of the current field of view are calculated using the following formula: and Calculate, where, and These represent the projected length and width of the current field of view, respectively. Indicates the longitudinal field of view. Indicates the encoder pitch angle. Indicates the pseudo-range value. Indicates horizontal resolution. This indicates the vertical resolution.

[0045] S4. Based on the Cartesian coordinate information and the projection length and width of the current field of view, calculate the number of scan steps required.

[0046] The relevant operations in step S3 will be introduced with specific examples:

[0047] Based on the calculation results of steps S2 and S3, the horizontal and vertical ranges of the region search, as well as the projection length and width of each field of view, can be determined. The number of scan steps required is calculated based on this information: taking the horizontal range as an example, the number of scan steps required is calculated using the formula: To ensure coverage, the calculation aims to achieve an 80% coverage ratio between each scanning step and the previous step. Therefore, the previous formula is improved as follows: The number of steps required for vertical scanning is determined by the formula: , calculate, where, and These represent the number of horizontal and vertical steps that need to be scanned, respectively. and Both represent the boundaries of the region search. The coordinates (latitude and longitude of several points will be given at the beginning of the area search to define a search area. The boundaries of this area are the two furthest points to the left and right) Coordinates are called and ), and Both represent the boundaries of the region search. Axis coordinates.

[0048] S5, the photoelectric platform performs "bow"-shaped scanning based on the projection length and width of the current field of view and the number of scanning steps required.

[0049] like Figure 4 As shown, the specific steps to achieve the "bow" shaped scanning are as follows:

[0050] S51. First, guide the pod to the starting point. After the servo sends a "guided in place" signal, the photoelectric platform performs a horizontal scan. Each step moves 80%n. (In this embodiment) , Figure 4 middle Right now );

[0051] S52, when At that time, the photoelectric platform performs one longitudinal scan, with each step moving 80% of the height. (In this embodiment) , Figure 4 middle Right now ), Reset steps;

[0052] Conversely, continue executing S51;

[0053] S53, when and When both values ​​are 0, the scan ends.

[0054] Conversely, S51 and S52 are executed in a loop.

[0055] The method described in this invention utilizes the known parameters of the pod to calculate the field of view projection range; and employs reasonable path planning to achieve a regional search coverage rate of over 90%.

Claims

1. A regional search control method based on a geographic information system, characterized in that, The method includes the following steps: S1. Obtain the geographic coordinates of the target point; S2. Convert geographic coordinate information into plane rectangular coordinate information based on Web Mercator projection; S3. Calculate the projected length and width of the current field of view; The calculation of the projected length and width of the current field of view is specifically performed using the formula: in, and These represent the projected length and width of the current field of view, respectively. Indicates the longitudinal field of view. Indicates the encoder pitch angle. Indicates the pseudo-range value. Indicates horizontal resolution. Indicates vertical resolution; S4. Based on the Cartesian coordinate information and the projection length and width of the current field of view, calculate the number of scan steps required; The number of steps to be scanned is determined by the formula: and , calculate, where, and These represent the number of horizontal and vertical steps that need to be scanned, respectively. and Both represent the boundaries of the region search. Axis coordinates and Both represent the boundaries of the region search. Axis coordinates; S5. The photoelectric platform performs "bow"-shaped scanning based on the projection length and width of the current field of view and the number of scanning steps required. The specific steps for implementing the "bow" shaped scanning are as follows: S61, Optoelectronic platform horizontal scanning Each step moves 80%n. ; S62, when At that time, the photoelectric platform performs one longitudinal scan, with each step moving 80% of the height. , Reset steps; Conversely, continue executing S61; S63, when and When both values ​​are 0, the scan ends. Conversely, S61 and S62 are executed in a loop.

2. The regional search and control method based on a geographic information system according to claim 1, characterized in that, The geographic coordinate information of the target point includes: the longitude of the target point. and the latitude of the target point .

3. The regional search and control method based on a geographic information system according to claim 2, characterized in that, The Web-based Mercator projection method converts geographic coordinate information into Cartesian coordinate information specifically through the following formula: and Calculate Cartesian coordinates ,in, Represents the Earth's radius. express Longitude.

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