A multi-sensor deployment method for target space coverage

Abstract

The present invention relates to a multi-sensor station deployment method for target space coverage, and belongs to the field of sensor monitoring. The method is to grid the deployment candidate space of the monitoring sensor, the monitoring target surface, and the terrain and objects between the deployment candidate space and the monitoring target, and use the parallel maximum upward viewing angle principle to analyze the visibility of each grid in the deployment candidate space of the monitoring sensor and each grid on the target surface moment by moment; and by analyzing the visibility analysis result data at each moment, determine the deployment position of the carrying platform equipped with the monitoring sensor, and realize full space coverage monitoring of the target. Compared with traditional monitoring methods, the present invention has the advantages of flexible deployment and full airspace monitoring without blind spots.

Description

Technical Field

[0001] The invention belongs to the field of multi-sensor monitoring and relates to a multi-sensor station deployment method oriented to target space coverage. Background Art

[0002] Traditional surveillance systems include single-sensor surveillance and multi-sensor surveillance. Among them, the sensor position in the single-sensor surveillance method is fixed, lacks mobility and flexibility, and is easily destroyed. Compared with the traditional single-sensor surveillance method, the multi-sensor surveillance method has the advantages of wide coverage, strong survivability and high cost performance, and is a popular choice for monitoring targets. However, the existing multi-sensor surveillance method cannot well achieve full-space coverage monitoring of the target, and there is a problem of blind spots in monitoring.

[0003] Therefore, the present invention proposes a new method for arranging monitoring sensor locations to achieve full-space coverage monitoring of targets and improve application value. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a multi-sensor (such as drone-mounted platform) station deployment method for target (surface) spatial domain coverage, in order to solve the problems of blind spots in traditional surveillance systems, fixed positions of surveillance video sensors, insufficient mobility, and easy destruction. The present invention grids the candidate spaces for surveillance sensor deployment and the surveillance targets, analyzes the visibility of each spatial grid to the surveillance target grid moment by moment, completes the sensor deployment work, and realizes full spatial domain coverage monitoring of the surveillance targets.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A multi-sensor station deployment method for target space coverage, which grids the station deployment candidate space of monitoring sensors (such as monitoring sensors that can be carried on drones), the monitoring target surface, and the terrain surface between the candidate space and the monitoring target; then, the visibility between the monitoring (drone) candidate grids and the target surface grids is analyzed moment by moment and grid by grid using the parallel maximum upward viewing angle principle; preferably, the station deployment position of the carrying platform (such as drone) carrying the monitoring sensor is determined based on the above visibility analysis result data, so as to achieve full airspace coverage monitoring of the target surface.

[0007] Furthermore, the method specifically comprises the following steps:

[0008] S1: According to the location of the monitoring sensor carrying platform (i.e., UAV) when starting the monitoring mission (hereinafter referred to as the starting location) and the location of the target, multiple corresponding monitoring sensor (i.e., UAV) station deployment candidate space closed surfaces (hereinafter referred to as candidate closed surfaces) are determined at a certain distance interval (which can be but not exclusively the corresponding UAV flight time interval), and a station deployment candidate space closed surface set (hereinafter referred to as candidate closed surface set) is obtained. The monitoring sensor (i.e., UAV) will select a point on the surface in the surface set as the station deployment candidate location; and the above target surface, the candidate closed surface set and the terrain and object surfaces surrounded by them are meshed;

[0009] S2: Using a fast line of sight analysis processing method based on the principle of parallel maximum upward viewing angle, analyze the intervisibility between each grid on each candidate closed surface in the station layout candidate closed surface set and each grid on the terrain surface, and each grid on each candidate closed surface and each grid on the target surface according to the distance from the target from near to far, and store the obtained line of sight analysis result data. Among them, in the stored line of sight analysis result data, search for all grids in the station layout candidate space closed surface set that have line of sight with the grid to obtain the line of sight candidate set.

[0010] In step S2, the rapid line of sight analysis method based on the parallel maximum elevation angle principle is specifically as follows: a cylinder (the cylinder is as small as possible) is set including an alternative closed surface, and the terrain surface of the object and the target surface surrounded by it, and the center of the upper surface of the cylinder is taken as the vertex, and multiple sectors are obtained on the surface, and multiple sector cylinders are generated based on this (the multiple sector cylinders will jointly cover all grids of the alternative closed surface, the terrain surface of the object and the target surface surrounded by it), and the line of sight analysis process between each candidate closed surface grid and the terrain surface grid of the object, and between each candidate closed surface grid and the target center point grid in the above different sector cylinders is parallelized;

[0011] In the above analysis process, when analyzing the inter-visibility from each grid on the next candidate closed surface to the target grid, the inter-visibility analysis results from each grid on the previous candidate closed surface to the center of the target grid should be used.

[0012] S3: In the target surface area not marked as diffused analysis, randomly select a grid on the target surface, and search all grids in the closed surface set of the candidate space that are in line with the grid in the line of sight analysis result data stored in step S2 (hereinafter referred to as the line of sight candidate set); with the grid as the center, diffuse in a certain diffusion mode (such as but not exclusively a spiral mode) in the target surface area not marked as diffused analysis, and update the line of sight candidate set once each time a grid is diffused on the target surface until the number of grids in the line of sight candidate set is just greater than the set threshold. The diffused area of ​​the target surface obtained at this time is defined as the visible area of ​​the target surface, and marked as diffused analysis, and the area and its corresponding line of sight candidate set (hereinafter referred to as the corresponding coverage station candidate set) are stored as the target coverage-corresponding coverage station candidate set.

[0013] S4: Repeat step S3 until all target surface meshes are marked as having been diffused for analysis.

[0014] S5: According to certain evaluation criteria, a station candidate grid is selected from each corresponding coverage station candidate set in the target coverage-corresponding coverage station candidate set to form a multi-surveillance sensor (i.e., UAV) station location set, and each station candidate grid in the set corresponds to a surveillance sensor (i.e., UAV) station candidate location.

[0015] The beneficial effects of the present invention are as follows: the present invention grids the terrain and objects of the monitoring targets by placing monitoring sensors (i.e., drones) as alternatives, and uses the maximum upward viewing angle visibility analysis and parallel processing methods to quickly analyze the visibility between the alternative location grids and the target surface grids. And by analyzing the visibility data at each moment, the location of the monitoring sensor carrying platform (i.e., drone) is determined to achieve full space coverage monitoring of the target. Compared with traditional monitoring methods, the present invention has the advantages of flexible station layout and full airspace monitoring without blind spots.

[0016] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 A schematic diagram of a monitoring scenario of the present invention;

[0019] Figure 2A schematic diagram of a surveillance scenario in which a drone is approaching a target;

[0020] Figure 3 It is a schematic diagram of a closed surface in space;

[0021] Figure 4 It is a schematic diagram of a space closed surface within the range of a fan-shaped cylinder;

[0022] Figure 5 A flowchart for obtaining a through-view alternative set;

[0023] Figure 6 To obtain a schematic diagram of the visible area of ​​the target surface;

[0024] Figure 7 This is a schematic diagram of the drone station location. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0027] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] See also Figure 1 to Figure 7The present invention provides a method for deploying a multi-sensor UAV station for target (surface) spatial domain coverage, and the specific steps are as follows:

[0029] Step 1: For Figure 1 In the monitoring scene shown, the current moment is t1, the monitoring target is A (this target can be considered as a building), and there is a land object B (which can be considered as a building) next to it, which blocks the line of sight. The drone is equipped with a monitoring sensor (which can be, but not only, an image sensor, hereinafter referred to as the sensor for ease of description), and its starting point is at a distance L1 from the monitoring target A. For ease of explanation, this embodiment can (but not only) select a spherical surface with the location of the monitoring target A as the center and passing through the location of the drone as an alternative closed surface. By analogy, as described in the method of the present invention, multiple alternative closed surfaces for station layout can be determined at certain distance intervals to obtain the following: Figure 2 The candidate closed surface set is shown. The candidate closed surfaces in the candidate closed surface set, the monitoring target A surface, the object B surface and other terrain objects of the area class are meshed.

[0030] Step 2: Based on the principle of parallel maximum elevation angle, the rapid line of sight analysis method is used to analyze the grids on the candidate closed surfaces and the grids on the terrain surface (such as Figure 2 As shown in the figure, complete the rapid line-of-sight analysis between each grid on each surface in the station selection closed surface set and each grid on the target surface. In order to make full use of the existing line-of-sight analysis results, follow the steps below to complete the above rapid analysis:

[0031] like Figure 3 As shown, the space closed surface t0 with the largest coverage area among the candidate space closed surfaces for station deployment and the other space closed surfaces it surrounds (including the terrain surface and all grids of the target surface). Figure 3 As shown, the space closed surface (may be but not only be) is a fan-shaped cylinder FC1 (whose nodes are P1, O, P3, P1', O', P3'), FC2 (whose nodes are P1, O, P2, P1', O', P2'), FC3 (whose nodes are P2, O, P3, P2', O', P3') with three common center edges L and the center edge L passes through (but not only is) the target A surface mesh C (may be but not only is the surface center mesh), and all meshes in the above space closed surface t0 are divided into three parts. Among them, FC1 includes the space closed surface t0, other space closed surfaces and terrain features surrounded by the surface R1OR3T; FC2 includes the space closed surface t0, other space closed surfaces and terrain features surrounded by the surface R1OR2T; FC3 includes the space closed surface t0, other space closed surfaces and terrain features surrounded by the surface R2OR3T.

[0032] like Figure 4 As shown, this embodiment takes the visibility from the grids S1 and S2 on the upper surface R1TR3 of the spatial closed surface t0 within the range of the fan-shaped cylinder FC1 as an example to illustrate the visibility analysis method of completing the visibility analysis from the grids on the spatial closed surface to the grids of the target A in parallel within the above three parts.

[0033] like Figure 4 As shown in the figure, it is the inter-visibility from S1 to G1 on target A. The projection of the line S1G1 on the terrain and target can be used to find the grids on the terrain and target that it passes through, as shown in the figure. Figure 4 The gray grid on the projection line in the figure. According to the line-of-sight analysis method based on the maximum upward viewing angle, the tangent values ​​of the viewing angle can be used to replace the corresponding angle for analysis. To improve the efficiency of the analysis, the above analysis process can be processed in parallel in different sector cylinders, such as Figure 5 In the above process, the intervisibility between S1 and G1 and S2 and G2 can be processed in parallel.

[0034] In addition, in the above process, when analyzing the intervisibility from each mesh on the next candidate closed surface to the center of the target mesh, the intervisibility analysis results from each mesh on the previous candidate closed surface to the center of the target mesh can be used to reduce unnecessary calculations.

[0035] Step 3: If Figure 5 As shown, in the target A surface area not marked as diffused analysis, a grid G ​​on the target surface is randomly selected, and in the line of sight analysis result data stored in step 2, all grids in the set of closed surfaces of the candidate station layout space that have line of sight with the grid are searched, such as Figure 5 The dark part OS in the closed surface of the central station candidate space is used to obtain the visual alternative set;

[0036] Taking the G grid as the center, in the target A surface area not marked as diffused analysis, diffuse in a certain diffusion mode (such as but not exclusively a spiral mode), and update the visible candidate set once each time a grid is diffused on the target surface, until the number of grids in the visible candidate set is just greater than the set threshold (10 in this embodiment). The diffused area of ​​the target surface obtained at this time is defined as the visible area of ​​the target surface, such as Figure 6 In the target A, the area marked as V, the area of ​​the closed surface of the station layout candidate space to area V is AS, and it is marked as diffused analysis. At the same time, the area and its corresponding line-of-sight candidate set (i.e., the corresponding coverage station layout candidate set) are stored as target coverage-corresponding coverage station layout candidate set.

[0037] Repeat step 3 until the target surface meshes are all marked as having been diffused. Figure 7All the grids on target A are covered by grids of three different shades of gray, that is, all the grids on the surface of target A can be covered.

[0038] Step 4: According to certain evaluation criteria, select a station candidate grid from each corresponding coverage station candidate set in the target coverage-corresponding coverage station candidate set to form a multi-UAV station location set, in which each station candidate grid corresponds to a UAV station candidate location. Figure 7 In the example, when the three drones are at the selected candidate positions, they can completely cover all the grids on the surface of target A.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A multi-sensor station deployment method for target space coverage, characterized in that: First, the candidate space for the surveillance sensor, the surface of the surveillance target, and the surface of the terrain and objects between the candidate space and the surveillance target are gridded; then, the intervisibility between the candidate grids of the surveillance sensor and the target surface grids is analyzed grid by grid at each moment using the parallel maximum elevation angle principle; finally, the location of the platform carrying the surveillance sensor is determined based on the intervisibility analysis result data at each moment, so as to achieve full space coverage surveillance of the target; the method specifically includes the following steps: S1: According to the starting position and the target position of the sensor-carrying platform when the monitoring task begins, the monitoring sensor station is determined according to the distance interval to obtain a set of candidate closed surfaces for station deployment; and the above monitoring target surface, the candidate closed surface set and the terrain surface surrounded by them are gridded; wherein the starting position is the position of the monitoring sensor-carrying platform when the monitoring task begins; the candidate closed surface is the candidate space closed surface for monitoring sensor station deployment; and the candidate closed surface set is the candidate space closed surface set for station deployment; S2: Using a fast line of sight analysis method based on the principle of parallel maximum upward viewing angle, analyze the intervisibility between each grid on each candidate closed surface in the station layout candidate closed surface set and each grid on the terrain surface, and each grid on the candidate closed surface and each grid on the target surface according to the distance from the target from near to far, and store the obtained line of sight analysis result data; S3: In the target surface area not marked as diffused, a grid of the target surface is randomly selected, and in the line of sight analysis result data stored in step S2, all grids in the closed surface set of the candidate station layout space that are in line of sight with the grid are searched, referred to as the line of sight candidate set; and with the grid as the center, in the target surface area not marked as diffused, the grid is diffused in a diffusion manner, and the line of sight candidate set is updated once each time a grid is diffused in the target surface until the number of grids in the line of sight candidate set is just greater than the set threshold; the diffused area of ​​the target surface obtained at this time, referred to as the target surface visible area, is marked as diffused, and the area and its corresponding line of sight candidate set, referred to as the corresponding coverage station layout candidate set, are stored as the target coverage-corresponding coverage station layout candidate set; S4: repeat step S3 until all target surface meshes are marked as having been diffused for analysis; S5: According to the evaluation criteria, a station candidate grid is selected from each corresponding coverage station candidate set in the target coverage-corresponding coverage station candidate set to form a multi-monitoring sensor station location set, in which each sensor candidate grid corresponds to a monitoring sensor station candidate location.

2. The visual sensor deployment method according to claim 1, characterized in that: In step S2, the fast line of sight analysis method based on the parallel maximum elevation angle principle is specifically as follows: a cylinder including a candidate closed surface, a terrain surface of an object and a target surface enclosed therein is set, a center of an upper surface of the cylinder is taken as a vertex, a plurality of sectors are obtained on the surface, and a plurality of sector-shaped cylinders are generated based on the sectors, and a line of sight analysis process is parallelized between each candidate closed surface mesh and a terrain surface mesh in the above different sector-shaped cylinders, and between each candidate closed surface mesh and a target center point mesh; In the above analysis process, when analyzing the inter-visibility from each grid on the next candidate closed surface to the target grid, the inter-visibility analysis results from each grid on the previous candidate closed surface to the center of the target grid should be used.

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