Method for judging approaching of target to preset area in geographic coordinate system
By decomposing the boundary segments in the geographical coordinate system and calculating the shortest distance from the target point to the boundary line, the difficulty of judging the target is solved, the accuracy of safety monitoring is improved, and it is suitable for safety prevention of borders and sensitive facilities.
Patent Information
- Application Number
- CN202510435982.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-08-15
AI Technical Summary
In geographical coordinate systems, it is difficult for the prior art to easily programmatically judge the proximity or distance relationship between the target and a specific area, resulting in insufficient accuracy of security monitoring.
By obtaining the boundary line of the preset area, decomposing it into multiple boundary line segments, calculating the positional relationship between the target point and each boundary line segment, and calculating the shortest distance between the target point and the boundary line based on the positional relationship, and determining whether the target point is close to the preset area based on the preset threshold.
It improves the accuracy of safety monitoring in specific areas, prevents misjudgment, and is suitable for safety prevention at borders and around sensitive facilities.
Smart Images
Figure CN120492550A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of target detection technology, and more specifically to a method and device for determining whether a target is approaching a preset area in a geographic coordinate system. Background Art
[0002] With the development of society, the security protection requirements for specific areas (borders, areas around sensitive facilities) are becoming increasingly higher. Among them, at the technical implementation level, the judgment of the proximity of the target to a specific area is a common problem that needs to be solved. The solution to this problem usually involves setting the boundary line of a specific area, decomposing the boundary line into multiple boundary segments, and then calculating the shortest distance from the target to each boundary segment separately, and finally selecting the minimum value of these distances as the shortest distance from the target to the specific area. When the shortest distance is less than or equal to the set threshold, it is judged to be close, and subsequent disposal actions are triggered; when the shortest distance is greater than the set threshold, it is judged to be far away, and no subsequent disposal actions are triggered. It is difficult to simply and programmatically judge the proximity or distance relationship between the target and a specific area in a geographic coordinate system. Summary of the Invention
[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present application proposes a method for judging whether a target is close to a preset area in a geographic coordinate system, comprising: obtaining a boundary line of the preset area, decomposing the boundary line into multiple boundary segments, and obtaining the geographic coordinates of the two endpoints of each boundary segment; determining the positional relationship between the target point and all boundary segments based on the geographic coordinate distance from the target point to the two endpoints of each boundary segment and the corresponding geographic coordinate distance between the two endpoints of each boundary segment; determining the shortest distance from the target point to the boundary line based on a positional relationship calculation formula; and judging whether the target point is close to the preset area based on the relationship between the shortest distance and a preset threshold.
[0004] Optionally, the positional relationship between the target point and all boundary segments is determined based on the geographical coordinate distance from the target point to the two endpoints of each boundary segment and the corresponding geographical coordinate distance between the two endpoints of each boundary segment, including: for any boundary segment, configuring the target point as C, the two endpoints of the boundary segment as B and A, a as the distance between the two endpoints A and B of the boundary segment, b as the distance from the target point C to the endpoint B of the boundary segment, and c as the distance from the target point C to the endpoint A of the boundary segment; when condition a is satisfied 2 +c 2 2 When the angle CAB is an obtuse angle or a straight angle, the target point C is determined to be on the left side of the boundary line segment AB, wherein the left side of the line segment AB is defined as point C being outside the line segment AB and close to point A; when condition a is satisfied 2 +b 2 <c2 When the angle CBA is an obtuse angle or a straight angle, the target point C is determined to be on the right side of the boundary segment AB, where the right side of the line segment AB is defined as point C being outside the line segment AB and close to point B; under other conditions, the target point C is located on / above / below the line of the boundary segment AB.
[0005] Optionally, the position relationship-based calculation formula determines the shortest distance from the target point to the boundary line, including: when the target point C is located on the left side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is c, and when the target point C is located on the right side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is b; when the target point C is located on / above / below the boundary line segment AB, the vertical distance from the target point C to the boundary line segment AB is calculated based on Heron's formula and the triangle area formula, and the vertical distance is used as the shortest distance from the target point C to the boundary line segment AB; based on the above steps, the shortest distance from the target point C to each boundary line segment is calculated, and the minimum value of the shortest distances from the target point to all boundary line segments is taken as the shortest distance from the target point to the boundary line.
[0006] Optionally, the calculation of the vertical distance from the target point C to the boundary segment AB based on Heron's formula and the triangle area formula includes: calculating the area S of the triangle ABC determined by the target point C and the two endpoints A and B of the boundary segment AB based on Heron's formula; calculating the ratio of twice the area S of the triangle ABC to the geographic coordinate distance a between the two endpoints A and B of the boundary segment to obtain the vertical distance from the target point to the boundary segment.
[0007] Optionally, the geographic coordinates of the two endpoints of each target point and boundary segment are longitude and latitude.
[0008] Optionally, judging whether the target point is close to the preset area based on the relationship between the shortest distance and a preset threshold includes: if the shortest distance from the target point to the boundary line is less than or equal to the preset threshold, then judging that the target point is close to the preset area; if the shortest distance from the target point to the boundary line is greater than the preset threshold, then judging that the target point is far away from the preset area.
[0009] Optionally, the preset threshold is dynamically determined according to different scenarios.
[0010] Optionally, the boundary line of the preset area is determined based on map drawing.
[0011] In order to achieve the above-mentioned purpose, the present application also provides a device for judging whether a target is close to a preset area in a geographic coordinate system, including: a boundary line segment determination module, used to obtain the boundary line of the preset area, and decompose the boundary line into multiple boundary line segments, and obtain the geographic coordinates of the two endpoints of each boundary line segment; a position relationship determination module, used to determine the position relationship between the target point and all boundary line segments based on the geographic coordinate distance from the target point to the two endpoints of each boundary line segment and the corresponding geographic coordinate distance between the two end points of each boundary line segment; a distance calculation module, used to determine the shortest distance from the target point to the boundary line based on a position relationship calculation formula; a target state judgment module, used to judge whether the target point is close to the preset area based on the relationship between the shortest distance and a preset threshold.
[0012] The embodiments of the present application provide a method and device for judging whether a target is close to a preset area in a geographic coordinate system. Compared with the prior art, the method and device have the following beneficial effects: obtaining the boundary line of the preset area, decomposing the boundary line into multiple boundary segments, and obtaining the geographic coordinates of the two endpoints of each boundary segment; determining the positional relationship between the target point and the boundary segment based on the geographic coordinate distance from the target point to the two shortest endpoints of the boundary line and the geographic coordinate distance between the two endpoints of the boundary segment; determining the shortest distance from the target point to the boundary line based on the positional relationship calculation formula; judging whether the target point is close to the preset area based on the relationship between the shortest distance from the target point to the boundary line and a preset threshold. The present application can effectively improve the accuracy of security monitoring of a specific area and prevent misjudgment by accurately calculating the shortest distance from the target point to the boundary line in the geographic coordinate system, thereby preventing misjudgment, and assisting users in security precautions in places such as borders and around sensitive facilities. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] To more clearly illustrate the technical solution of this application, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.
[0014] Figure 1 A flowchart of a method for determining that a target is approaching a preset area in a geographic coordinate system provided in an embodiment of the present application;
[0015] Figure 2 A schematic diagram showing a method for determining that a target is approaching a preset area in a geographic coordinate system provided by an embodiment of the present application, wherein point C is on the left side of line segment AB;
[0016] Figure 3 A schematic diagram showing a method for determining that a target is approaching a preset area in a geographic coordinate system provided by an embodiment of the present application, wherein point C is on the right side of line segment AB;
[0017] Figure 4 A schematic diagram showing a method for determining that a target is approaching a preset area in a geographic coordinate system provided by an embodiment of the present application, wherein point C is above line segment AB;
[0018] Figure 5 A schematic diagram showing a method for determining that a target is close to a preset area in a geographic coordinate system provided by an embodiment of the present application, in which point C is below line segment AB;
[0019] Figure 6 A schematic diagram (1) of a method for determining that a target is close to a preset area in a geographic coordinate system provided in an embodiment of the present application shows point C on line segment AB, where point C does not coincide with point A or point B;
[0020] Figure 7 A schematic diagram (2) of a method for determining that a target is close to a preset area in a geographic coordinate system provided in an embodiment of the present application shows point C on line segment AB, where point C coincides with point A;
[0021] Figure 8 A method for determining that a target is close to a preset area in a geographic coordinate system provided by an embodiment of the present application is shown in FIG3 , where point C is on line segment AB, and point C coincides with point B;
[0022] Figure 9 A schematic diagram of calculating the shortest distance from a target point to a boundary line in a method for determining that a target is close to a preset area in a geographic coordinate system provided in an embodiment of the present application;
[0023] Figure 10 This is a structural block diagram of a device for determining whether a target is close to a preset area in a geographic coordinate system provided in an embodiment of the present application. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.
[0025] This specification provides method operation steps such as embodiments or flowcharts, but may include more or fewer operation steps based on routine or non-inventive work. When implemented in an actual system or server product, the methods shown in the embodiments or figures may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment).
[0026] In the geographic coordinate system, there is no formula similar to the rectangular coordinate system to directly calculate the distance from a point to a line. Generally, the most widely used formula is to calculate the distance between two points based on longitude and latitude, such as the spherical distance formula, the spherical cosine theorem, and the Vincent formula.
[0027] refer to Figure 1 , Figure 1 This application provides a method for determining whether a target is close to a preset area in a geographic coordinate system. The method can be executed by a processor on a server or client side, and the method may include:
[0028] S10: Obtain a boundary line of a preset area, decompose the boundary line into multiple boundary line segments, and obtain the geographic coordinates of two endpoints of each boundary line segment.
[0029] In the actual execution process of this step, the application first obtains the set specific area boundary line and decomposes the boundary line into multiple boundary segments. Through this step, the coordinates of the two endpoints of each boundary segment in the geographic coordinate system, that is, the longitude and latitude, are obtained.
[0030] S20 . Determine the positional relationship between the target point and all boundary line segments based on the geographic coordinate distance from the target point to the two endpoints of each boundary line segment and the geographic coordinate distance between the corresponding two endpoints of each boundary line segment.
[0031] It should be noted that specific methods for calculating the distance between two points based on longitude and latitude can include the spherical distance formula, the spherical cosine theorem, the Vincent formula, the plane projection method, etc., which will not be repeated here.
[0032] In one embodiment of the present application, the positional relationship between the target point and all boundary segments is determined based on the geographic coordinate distance from the target point to the two endpoints of each boundary segment and the geographic coordinate distance between the two endpoints of each corresponding boundary segment, including:
[0033] For any boundary line segment, configure the target point as C, the endpoints of the boundary line segment as B and A respectively, a is the distance between the endpoints A and B of the boundary line segment, b is the distance from the target point C to the endpoint B of the boundary line segment, and c is the distance from the target point C to the endpoint A of the boundary line segment;
[0034] When the condition a is met 2 +c 2 2 When angle CAB is an obtuse angle or a straight angle, the target point C is determined to be on the left side of the boundary line segment AB, where the left side of the line segment AB is defined as point C being outside the line segment AB and close to point A.
[0035] When the condition a is met 2 +b 2 <c 2 When angle CBA is an obtuse angle or a straight angle, the target point C is determined to be on the right side of the boundary line segment AB, where the right side of the line segment AB is defined as point C being outside the line segment AB and close to point B;
[0036] Under other conditions, the target point C is located on / above / below the boundary segment AB.
[0037] During the specific execution process, the processor assumes that the target point is point C, the boundary segment is line segment AB, the corresponding endpoints are points A and B, and the lengths of line segments AB, BC, and AC are a, b, and c respectively. The processor uses the generalization of the converse of the Pythagorean theorem to determine the positional relationship between point C and line segment AB. There are three cases:
[0038] If a 2 +c 2 2 , point C is on the left side of line segment AB, such as Figure 2 As shown;
[0039] If a 2 +b 2 <c 2 , point C is on the right side of line segment AB, such as Figure 3 As shown;
[0040] In addition to the above two cases, point C is on, above, or below line segment AB, such as Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 shown.
[0041] if(a*a+c*c <b*b)
[0042] { / / Point C is on the left side of line segment AB}
[0043] else if(a*a+b*b <c*c)
[0044] { / / Point C is on the right side of line segment AB}
[0045] else
[0046] { / / Point C is on, above, or below line segment AB}
[0047] S30: Determine the shortest distance from the target point to the boundary line based on a position relationship calculation formula.
[0048] In an embodiment of the present application, step S30 may include the following execution process:
[0049] S301. When the target point C is located on the left side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is c. When the target point C is located on the right side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is b.
[0050] S302. When the target point C is on / above / below the boundary line segment AB, the vertical distance from the target point C to the boundary line segment AB is calculated based on Heron's formula and the triangle area formula, and the vertical distance is used as the shortest distance from the target point C to the boundary line segment AB.
[0051] S303 . Based on the above steps, the shortest distances from the target point C to each boundary line segment are calculated, and the minimum value of the shortest distances from the target point C to all boundary line segments is taken as the shortest distance from the target point to the boundary line.
[0052] During the specific execution process, the processor calculates the shortest distance from the target point to the boundary line segment according to the following situations. There are several situations according to the positional relationship between the target point and the boundary line segment:
[0053] 1. Point C is on the left side of line segment AB, such as Figure 2 As shown, the shortest distance D = the length of line segment AC, which is c;
[0054] 2. Point C is on the right side of line segment AB, such as Figure 3 As shown, the shortest distance D = the length of line segment BC, which is b;
[0055] 3. Point C is above or below line segment AB, such as Figure 4 、 Figure 5 As shown, the shortest distance D = the perpendicular distance from point C to line segment AB;
[0056] 4. Point C is on line segment AB. Figure 6 、 Figure 7 、 Figure 8 As shown, the shortest distance D=0.
[0057] In an embodiment of the present application, step S302 may include the following execution process:
[0058] S3021. Calculate the area of a triangle defined by the target point and the two endpoints of the boundary segment based on Heron's formula;
[0059] S3022. Calculate the ratio of the area of the triangle twice to the geographic coordinate distance between the two end points of the boundary segment to obtain the perpendicular distance from the target point to the boundary segment.
[0060] During the specific execution process, for the above two cases 3 and 4, the processor does not perform further differentiated calculations. It uniformly uses Heron's formula to calculate the area of triangle ABC, and then uses the triangle area calculation formula to infer the perpendicular distance from point C to line segment AB, as shown below.
[0061] Area of triangle ABC
[0062] in, Then, the shortest distance Among them, S is the area of triangle ABC, and a is the length of line segment AB, that is, the length of the boundary segment.
[0063] It should be noted that the endpoints of all the above line segments are obtained in geographic coordinates.
[0064] The pseudo code used to implement this step is as follows:
[0065] if(a*a+c*c <b*b)
[0066] {D=c}
[0067] else if(a*a+b*b <c*c)
[0068] {D=b}
[0069] else
[0070] {p=(a+b+c) / 2; S=sqrt(p*(pa)*(pb)*(pc)); D=2*S / a}
[0071] Repeat the above steps to calculate the shortest distance from the target point to each boundary segment: D1, D2, D3, D4, ..., D n .
[0072] In the specific execution process, the processor calculates the shortest distance from the target point to the boundary line (i.e., the specific area). The minimum value of the shortest distance from the target point to each boundary line segment is the shortest distance from the target point to the boundary line (i.e., the specific area). Figure 9 As shown, assuming that the shortest distance from the target point to each boundary segment is D1, D2, D3, D4, ..., D n , then the shortest distance from the target point to the boundary line (i.e., a specific area) is:
[0073] D min =min(D1,D2,D3,D4,…,D n )
[0074] S40: Determine whether the target point is close to a preset area based on the relationship between the shortest distance and a preset threshold.
[0075] The processor determines whether the target point is close to or far from a specific area. When the shortest distance from the target point to the boundary line (i.e., the specific area) is less than or equal to a set threshold, it is judged as close; when the shortest distance from the target point to the boundary line (i.e., the specific area) is greater than the set threshold, it is judged as far away.
[0076] In an embodiment of the present application, step S40 may include the following execution process:
[0077] S401: If the shortest distance from the target point to the boundary line is less than or equal to a preset threshold, it is determined that the target point is close to a preset area;
[0078] S402: If the shortest distance from the target point to the boundary line is greater than a preset threshold, it is determined that the target point is far away from the preset area.
[0079] In one embodiment of the present application, the preset threshold is dynamically determined according to different scenarios, and the different scenarios include security protection of specific areas (borders, around sensitive facilities).
[0080] In one embodiment of the present application, the boundary line of the preset area is determined based on map drawing.
[0081] In summary, this application discloses a method for determining whether a target is approaching a specific area in a geographic coordinate system, including the steps of setting the boundary line of the specific area, calculating the shortest distance from the target point to each boundary line segment, calculating the shortest distance from the target point to the boundary line (i.e., the specific area), and determining whether the target is approaching or far from the specific area. This method can effectively improve the accuracy of security monitoring in specific areas and prevent misjudgments by accurately calculating the shortest distance from the target point to the boundary line (i.e., the specific area) in the geographic coordinate system to determine proximity to the specific area. It is suitable for security precautions in places such as borders and around sensitive facilities.
[0082] refer to Figure 10 On the basis of the above embodiments, the present application also proposes a device for judging whether a target is close to a preset area in a geographic coordinate system, which is used to solve the same technical problem in the method claims. The device 100 for judging whether a target is close to a preset area in a geographic coordinate system includes: a boundary segment determination module 1001 obtains the boundary line of the preset area, decomposes the boundary line into multiple boundary segments, and obtains the geographic coordinates of the two endpoints of each boundary segment; a position relationship determination module 1002 is used to determine the position relationship between the target point and all boundary segments based on the geographic coordinate distance from the target point to the two endpoints of each boundary segment and the geographic coordinate distance between the two endpoints of each boundary segment; a distance calculation module 1003 is used to determine the shortest distance from the target point to the boundary line based on the position relationship calculation formula; a target state judgment module 1004 is used to judge whether the target point is close to the preset area based on the relationship between the shortest distance and the preset threshold.
[0083] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.
[0084] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.
[0085] The above are only preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.
Claims
1. A method for determining whether a target is close to a preset area in a geographic coordinate system, characterized in that: include: Obtaining the boundary line of a preset area, decomposing the boundary line into multiple boundary segments, and obtaining the geographic coordinates of the two endpoints of each boundary segment; Determine the positional relationship between the target point and all boundary segments based on the geographic coordinate distance from the target point to the two endpoints of each boundary segment and the geographic coordinate distance between the corresponding two endpoints of each boundary segment; Determine the shortest distance from the target point to the boundary line based on the position relationship calculation formula; Whether the target point is close to the preset area is determined based on the relationship between the shortest distance and the preset threshold.
2. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 1, wherein: The determining of the positional relationship between the target point and all boundary segments based on the geographical coordinate distance from the target point to the two endpoints of each boundary segment and the corresponding geographical coordinate distance between the two endpoints of each boundary segment includes: For any boundary line segment, configure the target point as C, configure the endpoints of the boundary line segment as B and A respectively, a is the distance between the endpoints A and B of the boundary line segment, b is the distance from the target point C to the endpoint B of the boundary line segment, and c is the distance from the target point C to the endpoint A of the boundary line segment; When the condition a is met 2 +c 2 2 When angle CAB is an obtuse angle or a straight angle, it is determined that the target point C is located on the left side of the boundary line segment AB, wherein the left side of the line segment AB is defined as point C being located outside the line segment AB and close to point A; When the condition a is met 2 +b 2 <c 2 When angle CBA is an obtuse angle or a straight angle, it is determined that the target point C is located on the right side of the boundary line segment AB, wherein the right side of the line segment AB is defined as point C being outside the line segment AB and close to point B; Under other conditions, the target point C is located on / above / below the boundary line segment AB.
3. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 2, wherein: The method of determining the shortest distance from the target point to the boundary line based on the position relationship calculation formula includes: When the target point C is on the left side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is c. When the target point C is on the right side of the boundary line segment AB, the shortest distance from the target point C to the boundary line segment AB is b. When the target point C is on / above / below the boundary line segment AB, the vertical distance from the target point C to the boundary line segment AB is calculated based on Heron's formula and the triangle area formula, and the vertical distance is taken as the shortest distance from the target point C to the boundary line segment AB; Based on the above steps, the shortest distance from the target point C to each boundary line segment is calculated, and the minimum value of the shortest distances from the target point C to all boundary line segments is taken as the shortest distance from the target point to the boundary line.
4. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 3, wherein: The method of calculating the vertical distance from the target point C to the boundary line segment AB based on Heron's formula and the triangle area formula includes: Calculate the area S of triangle ABC defined by the target point C and the two endpoints A and B of the boundary line segment AB based on Heron's formula; The perpendicular distance from the target point to the boundary segment is obtained by calculating the ratio of the area S of the double triangle ABC to the geographic coordinate distance a between the two endpoints A and B of the boundary segment.
5. The method for determining whether a target is close to a preset area in a geographic coordinate system according to any one of claims 1 to 4, wherein: The geographic coordinates of the two endpoints of each target point and boundary segment are both longitude and latitude.
6. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 1, wherein: The determining whether the target point is close to the preset area according to the relationship between the shortest distance and the preset threshold value includes: If the shortest distance from the target point to the boundary line is less than or equal to a preset threshold, it is determined that the target point is close to the preset area; If the shortest distance from the target point to the boundary line is greater than a preset threshold, it is determined that the target point is far away from the preset area.
7. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 6, wherein: The preset threshold is dynamically determined according to different scenarios.
8. The method for determining whether a target is close to a preset area in a geographic coordinate system according to claim 1, wherein: The boundary line of the preset area is determined based on map drawing.
9. A device for determining whether a target is close to a preset area in a geographic coordinate system, characterized in that: include: A boundary segment determination module is used to obtain the boundary line of a preset area, decompose the boundary line into multiple boundary segments, and obtain the geographic coordinates of the two endpoints of each boundary segment; a position relationship determination module, configured to determine the position relationship between the target point and all boundary segments based on the geographical coordinate distances from the target point to the two endpoints of each boundary segment and the geographical coordinate distances between the corresponding two endpoints of each boundary segment; A distance calculation module is used to determine the shortest distance from the target point to the boundary line based on a position relationship calculation formula; The target state judgment module is used to judge whether the target point is close to the preset area based on the relationship between the shortest distance and the preset threshold.