Airline safety detection method and system based on three-dimensional terrain height

Abstract

The invention relates to the technical field of route detection, and relates to a route safety detection method and system based on three-dimensional terrain height, and the method comprises the steps: dividing a route into a plurality of route segments, and obtaining a plurality of auxiliary lines of the route segments; numbering the auxiliary lines of the route segments; calculating the alarm distance of each sampling point; determining the sampling point with the alarm distance smaller than a preset threshold value as an alarm point; and determining the maximum value and the minimum value of the distance between the alarm point in the auxiliary line and the target endpoint by taking the higher or lower ends of the route segment and the auxiliary line as the target endpoint, and marking an alarm line segment on the route segment. According to the method, the calculation complexity in flight path planning can be reduced, and the flight safety of the aircraft is ensured through accurate terrain safety distance evaluation.

Description

Technical Field

[0001] The present invention generally relates to the field of route detection technology, and more specifically, to a route safety detection method and system based on three-dimensional terrain height. Background Art

[0002] With the development of drone technology, the types and number of aircraft are increasing, and the aviation traffic of aircraft (such as drone aviation traffic) is also increasing, which leads to the increasing risk of flight path conflict with terrain. Especially in cities or complex terrain areas, the conflict between the flight path of drones and obstacles such as buildings and terrain may cause flight safety accidents, affect airspace management, and may also cause property losses or personnel losses. Therefore, how to avoid collisions with ground obstacles while ensuring the smooth completion of flight missions has become a key factor in the safe operation of aircraft.

[0003] In the prior art, in order to ensure the safety of an aircraft's route, a waypoint-based model is usually used to construct a flight path. Waypoints usually refer to specific locations that an aircraft needs to pass through during flight, and the aircraft will complete its flight mission in the order of these waypoints. In route planning, a spherical area is usually constructed based on each waypoint to represent the safe flight range of the aircraft. If terrain or other obstacles appear within the safe flight range of the aircraft (i.e., the spherical area constructed based on waypoints), the aircraft's route needs to be replanned or adjusted to avoid collision between the aircraft and the terrain and ensure flight safety.

[0004] However, when using this spherical safety area for route planning, the amount of calculation is usually large. The specific reason is that the spherical area involves calculations in three-dimensional space, and the calculation dimension and complexity are high. For example, to determine whether the spherical areas of two waypoints overlap, or whether a spherical area intersects with the terrain, complex three-dimensional geometric operations are required. Summary of the invention

[0005] In order to solve the above-mentioned technical problem that the amount of calculation is usually large when using such a circular or spherical safety area for route planning, the present invention provides solutions in the following aspects.

[0006] In a first aspect, a route safety detection method based on three-dimensional terrain height includes: dividing a route into a plurality of route segments, and obtaining a plurality of auxiliary lines of the route segments, wherein the plurality of auxiliary lines are distributed on both sides of the route segments, are parallel to the route segments and are at the same height as the route segments, the route segments and their auxiliary lines are arranged equidistantly according to a preset first distance, the endpoints of the route segments and their auxiliary lines on the same side are in a straight line, and the straight line is perpendicular to the route segments; numbering the auxiliary lines of the route segments, wherein the first auxiliary line on one side of the route segments is numbered. i The auxiliary lines are numberedi , the other side i The auxiliary lines are numbered as - i , i is a positive integer; sampling is performed equidistantly on the auxiliary line according to the preset second distance to obtain sampling points; calculating the k The route segments are numbered n The auxiliary line a The warning distance of sampling points d k,n,a : .

[0007] in x is the first distance, and for the k The number is n The route segment or auxiliary line a sampling points, h k,n,s is the terrain height at its latitude and longitude, h k,n,a For its height, a , k are all positive integers; the sampling points whose warning distance is less than the preset threshold are determined as warning points; the higher or lower end of the route segment and its auxiliary line is taken as the target endpoint, the maximum and minimum values ​​of the distance between the warning point in the auxiliary line and the target endpoint are determined, and the warning line segment is marked on the route segment, wherein the distance between one end of the warning line segment and the target endpoint of the route segment is the minimum value, and the distance between the other end and the target endpoint of the route segment is the maximum value.

[0008] Preferably, a route safety detection method based on three-dimensional terrain height also includes determining whether it is necessary to mark the endpoint of a route segment: for either side endpoint of the route segment, extending the auxiliary line of the route segment at the endpoint on that side by a predetermined distance to obtain an extension line; performing equidistant sampling on the extension line to obtain extended sampling points; obtaining the warning distance of the extended sampling points; and marking the endpoint of the route segment in response to the warning distance of at least one extended sampling point being less than the threshold.

[0009] Preferably, calculate p The route segments are numbered m The auxiliary line b Extend the alarm distance of the sampling point The formula is: .

[0010] Among them, for p The number is m The route segment or auxiliary line b Extended sampling points, is the terrain height at its latitude and longitude, For its height, p , b All are positive integers.

[0011] Preferably, the method further includes: sampling equidistantly at a second distance of a preset size on the route segment to obtain a target sampling point; obtaining a warning distance of the target sampling point; and marking the target sampling point in response to the warning distance of the target sampling point being less than the threshold.

[0012] Preferably, calculate k The first c The warning distance of target sampling points The formula is: .

[0013] Among them, for k The first c target sampling points, is the terrain height at its latitude and longitude, For its height, k , c All are positive integers.

[0014] Preferably, the method further includes determining the first distance and the second distance according to the threshold value; wherein the first distance satisfies the formula: , is the first distance, is the threshold value, is the first coefficient, and ; The second distance satisfies: , is the second distance, is the second coefficient, and .

[0015] Preferably, the threshold is 1 meter.

[0016] Preferably, the warning line segment is marked as the target color through the PolylineGraphics class.

[0017] Preferably, the terrain height at the longitude and latitude of each sampling point is obtained through the sampleTerrainMostDetailed interface of the three-dimensional map engine Cesium.

[0018] In a second aspect, a route safety detection system based on three-dimensional terrain height includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to implement a route safety detection method based on three-dimensional terrain height as described in any one of the above invention contents.

[0019] The beneficial effects of the present invention are: The present invention avoids constructing a safety zone for each waypoint, but instead sets auxiliary lines for the route segment, samples the auxiliary lines, and calculates the distances between multiple points on the route segment and the terrain corresponding to the longitude and latitude based on the height, longitude and latitude of the sampling points, the terrain height corresponding to the longitude and latitude, and the distance between the route segment. Based on this, the present invention can reduce the computational complexity in flight path planning, and ensure the flight safety of the aircraft through accurate terrain safety distance assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is a flowchart of the steps of a route safety detection method based on three-dimensional terrain height according to an embodiment of the present invention; Figure 2 is a schematic diagram of a route segment and its auxiliary lines according to an embodiment of the present invention; Figure 3 is a schematic diagram of an alarm point and an alarm segment according to an embodiment of the present invention; Figure 4 is a schematic diagram of sampling points and extended sampling points of a route segment according to an embodiment of the present invention; Figure 5 It is a structural block diagram of a route safety detection system based on three-dimensional terrain height according to this embodiment. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] Figure 1 The present invention is a flowchart of the steps of a route safety detection method based on three-dimensional terrain height according to an embodiment of the present invention.

[0024] like Figure 1 As shown, a route safety detection method based on three-dimensional terrain height includes steps S1 to S5.

[0025] Step S1: Divide the route into at least one route segment, and obtain multiple auxiliary lines of the route segment.

[0026] The multiple auxiliary lines are in the same plane as the route segment, and are parallel to the route segment, of equal length, equal height, and equidistantly arranged on both sides of the route segment, and the line connecting the endpoints of the route segment and its auxiliary lines is perpendicular to the route segment.

[0027] It should be noted that a route is composed of multiple route segments. Each route segment is configured with multiple auxiliary lines.

[0028] In one embodiment, for any route segment, any auxiliary line of the route segment is parallel to the route segment; any auxiliary line of the route segment has the same height as the route segment, that is, the route segment and its auxiliary line satisfy the formula: ; in, is the height of the first endpoint of the two endpoints of the route segment, is the height of the endpoint corresponding to the first end of the route segment, For this route segment k The height of the first end of the auxiliary line corresponding to the endpoint, For this route segment k The height of the corresponding endpoint of the first end of the auxiliary line.

[0029] The first end of the route segment or its auxiliary line is the end of the line segment (ie, the route segment or its auxiliary line) that is closer to the top, bottom, left, or right.

[0030] In another embodiment, when any auxiliary line of the route segment has the same height as the route segment, the condition satisfied may be: ; Among them, for two points at different positions on the route segment, these two points are recorded as the first point and the second point respectively. is the height of the first point, is the height of the second point. k Two points at different positions on the auxiliary line are recorded as the third point and the fourth point respectively. is the height of the third point, is the height of the fourth point. The distance between the first point and the corresponding endpoint of the first end of the route segment is equal to the distance between the third point and the route segment. k The distance between the first end of the auxiliary line and the corresponding end point of the route segment is equal to the distance between the fourth point and the corresponding end point of the route segment. k The distance between the corresponding endpoints of the first end of the auxiliary line.

[0031] It should be noted that, for any line segment of the route segment and all its auxiliary lines, the first end of the line segment is: the endpoint of the line segment in the predetermined direction in the image.

[0032] Figure 2 is a schematic diagram of a route segment and its auxiliary lines according to an embodiment of the present invention.

[0033] like Figure 2 As shown, the solid line segment is the route segment, and the multiple dotted line segments are the auxiliary lines of the route segment. The first ends of the route segment and its auxiliary lines are both on the straight line E. In this case, the first ends of the route segment and the auxiliary line are the endpoints above or to the right of the corresponding line segment. Straight line E is perpendicular to the endpoints of the route segment and any of its auxiliary lines. The route segment and its auxiliary lines are in the same plane, and the lengths of the route segment and its auxiliary lines are the same. For the route segment and all its auxiliary lines, the distance between any two adjacent line segments is a constant. All auxiliary lines of the route segment are distributed on both sides of the route segment.

[0034] Step S2: Number the auxiliary lines of the route segment.

[0035] The first i The auxiliary lines are numbered i , the other side i The auxiliary lines are numbered as - i , i is a positive integer; sampling is performed equidistantly on the auxiliary line according to the preset second distance to obtain sampling points.

[0036] It should be noted that, for any auxiliary line, the positive or negative value of its number indicates its relative position to the route segment. The auxiliary line with a positive number is located on one side of the route segment, and the auxiliary line with a negative number is located on the other side of the route segment. The absolute value of the auxiliary line number indicates the distance between it and the route segment, and the product of the absolute value of the number and the second distance is equal to the actual distance between the auxiliary line and the route segment.

[0037] Step S3: Calculate the warning distance of each sampling point corresponding to the route segment.

[0038] Among them, calculate the k The route segments are numbered n The auxiliary line a The warning distance of sampling points d k,n,a : ,in x is the auxiliary line spacing, for the k The number is n The route segment or auxiliary line a sampling points, h k,n,s is the terrain height at its latitude and longitude,h k,n,a For its height, a , k All are positive integers.

[0039] It should be noted that the product of the auxiliary line number and the first distance is equal to the distance between any sampling point on the auxiliary line and the route segment. Because the auxiliary line is parallel to the route segment and has the same height as the route segment, the product of the auxiliary line number and the first distance is equal to the horizontal distance between the terrain at the latitude and longitude of any sampling point on the auxiliary line and the route segment.

[0040] Furthermore, the auxiliary line a The difference between the height of the sampling point and the terrain height at its latitude and longitude is the a The vertical distance between the first sampling point and the terrain at its longitude and latitude. Since the auxiliary line is parallel to the route segment and has the same height as the route segment, the vertical distance is the first a The terrain at the latitude and longitude of the sampling point and the route segment a The vertical distance between the sampling points. a The sampling point and the auxiliary line a The straight line corresponding to each sampling point is perpendicular to the route segment.

[0041] Based on this, k The route segments are numbered n The auxiliary line a The alarm distance of sampling points is n The auxiliary line a The topography of the latitude and longitude of the sampling point is k On the route segment a The distance between the sampling points.

[0042] In one embodiment, the threshold is 1 meter.

[0043] It should be noted that the smaller the threshold, the smaller the first distance and the distance used for the first distance. Further, the present invention determines the first distance and the second distance according to the threshold; wherein the first distance satisfies the formula: , is the first distance, is the threshold value, is the first coefficient, and ; The second distance satisfies: , is the second distance, is the second coefficient, and .

[0044] In one embodiment, the terrain height at the longitude and latitude of each sampling point is obtained through the sampleTerrainMostDetailed interface of Cesium.

[0045] Cesium is an open source virtual globe platform, mainly used for developing and displaying 3D geospatial applications. Based on WebGL, Cesium enables high-performance 3D globe and map visualization in the browser. Cesium allows users to create interactive maps, satellite images, terrain, geographic data, etc. Cesium supports many geographic information system (GIS) operations, such as data visualization, 3D modeling, measurement analysis, spatial analysis, etc.

[0046] In Cesium, the sampleTerrainMostDetailed interface is a function used to obtain the terrain height of a certain location (longitude and latitude coordinates), which is suitable for scenes that require high-precision terrain data. The function of this interface is to obtain the terrain height of the specified longitude and latitude position, which is usually used for detailed terrain analysis, such as flight path planning, path selection, ground height calculation, etc.

[0047] Step S4: Determine the sampling point whose alarm distance is less than the preset threshold as the alarm point.

[0048] It should be noted that, from the above, k The route segments are numbered n The auxiliary line a The alarm distance of sampling points is n The auxiliary line a The topography of the latitude and longitude of the sampling point is k On the route segment a The distance between the sampling points, so when the k The route segments are numbered n The auxiliary line a When the alarm distance of a sampling point is less than the preset threshold, it means that k The first route segment a The distance between the first sampling point and the terrain is too close. k The first route segment a Therefore, in this step, the sampling points whose warning distance is less than the preset threshold are first recorded as warning points, and in the subsequent steps, the part of the route segment that is too close to the terrain is obtained through the warning points.

[0049] Step S5: Obtain and mark the warning line segment.

[0050] Among them, for each auxiliary line of the route segment, the distance between the warning point and the first end is calculated, and the target distance of the warning point is recorded, so as to determine the maximum and minimum values ​​of the target distances of each warning point in all auxiliary lines of the route segment; on the route segment, the warning segment is marked, and the distances between the two ends of the warning segment and the first end of the route segment are the maximum and minimum values ​​respectively.

[0051] Figure 3 It is a schematic diagram of an alarm point and an alarm segment according to an embodiment of the present invention.

[0052] like Figure 3 As shown in the figure, line segment P1 is the route segment, and the points on both sides of the route segment are the sampling points of the auxiliary line of the route segment. Among them, the sampling points framed by the dotted line are the warning points. The end above each line segment is the first end of each line segment. The distance between the warning point g1 and the first end of the corresponding auxiliary line is the minimum value (in Figure 3 The distance between the warning point g2 and the first end of the auxiliary line corresponding to it is the maximum value (in Figure 3 One endpoint of the warning segment is p1, and the other endpoint is p2, wherein the distance between the endpoint p1 and the first end of the route segment is the minimum value; and the distance between the endpoint p2 and the first end of the route segment is the maximum value.

[0053] Specifically, Figure 3 As shown, Figure 3 Including the route segment P1 and the sampling points on both sides thereof, the sampling points determined as the alarm points are framed by dotted lines, for example, the alarm points g1 and g2 are both in the dotted frame. Taking the upper end of the route segment as the first end, and the upper end of the auxiliary line of the route segment as the first end, the distance between the alarm point and the first end of the auxiliary line where it is located is obtained, and recorded as the target distance of the alarm point. For example, for the alarm point g1, its target distance is the length of the line segment G1; for the alarm point g2, its target distance is the length of the line segment G2. Then select the alarm point with the largest target distance, which is the alarm point g2; select the alarm point with the largest target distance, which is the alarm point g1. Map the warning point g1 to the route segment to obtain an endpoint p1 of the warning segment, that is, draw a perpendicular line from the warning point g1 to the route segment, with the foot of the perpendicular being the endpoint p1; similarly, map the warning point g2 to the route segment to obtain another endpoint p2 of the warning segment, that is, draw a perpendicular line from the warning point g2 to the route segment, with the foot of the perpendicular being the endpoint p2. Thus, the warning segment is obtained.

[0054] In one embodiment, the present invention uses the PolylineGraphics class to mark the warning line segment as a target color, wherein the target color is usually a relatively eye-catching and bright color such as red or yellow to serve as a warning and attract the attention of personnel.

[0055] It should be noted that PolylineGraphics is a class in Cesium used to represent and draw two-dimensional polylines (i.e. polylines), which are usually used to visualize paths or line segments connecting multiple geographic locations. PolylineGraphics can be created and the properties of line segments, including color, width, line type, etc., can be controlled through the Entity API in Cesium to meet different visualization needs.

[0056] Furthermore, the present invention also includes determining whether it is necessary to mark the endpoint of the route segment: for any side endpoint of the route segment, extending the auxiliary line of the route segment at the endpoint of the side by a predetermined distance to obtain an extension line; performing equidistant sampling on the extension line to obtain extended sampling points; obtaining the warning distance of the extended sampling points; and marking the endpoint of the route segment in response to the warning distance of at least one extended sampling point being less than the threshold. In one embodiment, the distance of the endpoint extension is 10 meters.

[0057] Among them, calculate the p The route segments are numbered m The auxiliary line b Extend the alarm distance of the sampling point The formula is: .

[0058] For p The number is m The route segment or auxiliary line b Extended sampling points, is the terrain height at its latitude and longitude, For its height, p , b All are positive integers.

[0059] Figure 4 Schematic diagram of sampling points and extended sampling points of a route segment according to an embodiment of the present invention.

[0060] like Figure 4 As shown, Figure 4 The solid line segment in is the route segment, the dotted line segment is the extension line of the route segment, the point framed by the dotted line is the extended sampling point, and the other points are sampling points. Based on this, the present invention can calculate the warning distance of the extended sampling point to determine whether each part of the extended line is too close to the building. When there is a part of the extended line that is too close to the building, that is, there is an extended sampling point whose warning distance is less than the threshold, since the extended line is not the actual route, it can only mean that the distance between the endpoint corresponding to the extended line and the terrain is closer, so at this time, the endpoint corresponding to the extended line needs to be marked.

[0061] Specifically, the route segment and its auxiliary line are extended from the first end to obtain an extended line (i.e. Figure 5The dotted line in the figure), the extended line is sampled at equal intervals to obtain the extended sampling points (i.e. Figure 5 The points outlined by the dotted line in the figure).

[0062] Furthermore, the present invention also includes: sampling equidistantly at a second distance of a preset size on the route segment to obtain a target sampling point; obtaining an alarm distance of the target sampling point; and marking the target sampling point in response to the alarm distance of the target sampling point being less than the threshold.

[0063] Among them, calculate the k The first c The warning distance of target sampling points The formula is: .

[0064] For k The first c target sampling points, is the terrain height at its latitude and longitude, For its height, k , c All are positive integers.

[0065] It should be noted that the height difference between the target sampling point and the terrain with the same longitude and latitude is the distance between the two.

[0066] Figure 5 It is a structural block diagram of a route safety detection system based on three-dimensional terrain height according to this embodiment.

[0067] The present invention also provides a route safety detection system based on three-dimensional terrain height. Figure 5 As shown, the system includes a processor and a memory, wherein the memory stores computer program instructions. When the computer program instructions are executed by the processor, a route safety detection method based on three-dimensional terrain height according to the first aspect of the present invention is implemented.

[0068] In the present invention, the aforementioned memory may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, apparatus or device. For example, a computer-readable storage medium may be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory RRAM (Resistive Random Access Memory), a dynamic random access memory DRAM (Dynamic Random Access Memory), a static random access memory SRAM (Static Random-Access Memory), an enhanced dynamic random access memory EDRAM (Enhanced Dynamic Random Access Memory), a high-bandwidth memory HBM (High-Bandwidth Memory), a hybrid memory cube HMC (Hybrid Memory Cube), etc., or any other medium that can be used to store the required information and can be accessed by an application, a module, or both. Any such computer storage medium may be part of a device or accessible or connectable to a device. Any application or module described in the present invention may be implemented using computer-readable / executable instructions that may be stored or otherwise maintained by such a computer-readable medium.

[0069] In the description of this specification, "plurality" or "several" means at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0070] Although this specification has shown and described a number of embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will conceive of many modifications, changes and alternatives without departing from the ideas and spirit of the present invention. It should be understood that in the practice of the present invention, various alternatives to the embodiments of the present invention described herein may be employed.

Claims

1. A route safety detection method based on three-dimensional terrain height, characterized in that: include: The route is divided into at least one route segment, and a plurality of auxiliary lines of the route segment are obtained, wherein the plurality of auxiliary lines are in the same plane as the route segment, and are parallel to the route segment, have the same length, the same height, and are equidistantly arranged on both sides of the route segment, and the line connecting the endpoints of the route segment and its auxiliary lines is perpendicular to the route segment; the auxiliary lines of the route segment are numbered, wherein the auxiliary lines on one side of the route segment are numbered. i The auxiliary lines are numbered i , the other side i The auxiliary lines are numbered as - i , i is a positive integer; sampling is performed equidistantly on the auxiliary line to obtain sampling points; Calculate the k The route segments are numbered n The auxiliary line a The warning distance of sampling points d k,n,a : ； in x is the auxiliary line spacing, for the k The number is n The route segment or auxiliary line a sampling points, h k,n,s is the terrain height at its latitude and longitude, h k,n,a For its height, a , k All are positive integers; Determine the sampling point whose warning distance is less than a preset threshold as the warning point; for each auxiliary line of the route segment, calculate the distance between the warning point and the first end, and record the target distance of the warning point, so as to determine the maximum and minimum values ​​of the target distances of each warning point in all auxiliary lines of the route segment; mark the warning segment on the route segment, and the distances between the two ends of the warning segment and the first end of the route segment are the maximum and minimum values ​​respectively.

2. A route safety detection method based on three-dimensional terrain height according to claim 1, characterized in that: It also includes determining whether the endpoints of the route segment need to be marked: For any end point on one side of the route segment, the auxiliary line of the route segment is extended at the end point on that side by a predetermined distance to obtain an extended line; Take equidistant samples on the extension line to obtain extended sampling points; Get the warning distance of extended sampling point; In response to the warning distance of at least one extended sampling point being less than the threshold, an endpoint of the route segment is marked.

3. A route safety detection method based on three-dimensional terrain height according to claim 2, characterized in that: Calculate the p The route segments are numbered m The auxiliary line b Extend the alarm distance of the sampling point The formula is: ； Among them, for p The number is m The route segment or auxiliary line b Extended sampling points, is the terrain height at its latitude and longitude, For its height, p , b All are positive integers.

4. The route safety detection method based on three-dimensional terrain height according to claim 1 is characterized in that: Also includes: Sampling at equal intervals according to a second distance of a preset size on the route segment to obtain target sampling points; Obtaining the warning distance of the target sampling point; In response to the warning distance of the target sampling point being less than the threshold, the target sampling point is marked.

5. A route safety detection method based on three-dimensional terrain height according to claim 4, characterized in that: Calculate the k The first c The warning distance of target sampling points The formula is: ； Among them, for k The first c target sampling points, is the terrain height at its latitude and longitude, For its height, k , c All are positive integers.

6. A route safety detection method based on three-dimensional terrain height according to claim 1, characterized in that: The method also includes determining the first distance and the second distance according to the threshold; wherein the first distance satisfies the formula: , is the first distance, is the threshold value, is the first coefficient, and ; The second distance satisfies: , is the second distance, is the second coefficient, and .

7. A route safety detection method based on three-dimensional terrain height according to claim 2, characterized in that: The threshold is 1 meter.

8. The route safety detection method based on three-dimensional terrain height according to claim 1 is characterized in that: Use the PolylineGraphics class to mark the warning line segment as the target color.

9. The route safety detection method based on three-dimensional terrain height according to claim 1, characterized in that: The terrain height at the longitude and latitude of each sampling point is obtained through the sampleTerrainMostDetailed interface of the 3D map engine Cesium.

10. A route safety detection system based on three-dimensional terrain height, comprising a processor and a memory, wherein the memory stores a computer program, characterized in that: The processor executes the computer program to implement a route safety detection method based on three-dimensional terrain height as described in any one of claims 1-9.

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