An underground electronic fence system based on UWB accurate personnel positioning

Abstract

The application relates to the technical field of downhole electronic fences, and particularly discloses a downhole electronic fence system based on UWB accurate personnel positioning, which comprises a data acquisition module: a modeling unit is used to acquire three-dimensional information of a coal mine underground, and a three-dimensional map is established; a regional planning unit is used to mark a predicted dangerous area in a work cycle on the map; a site selection module is used to extract an edge line of the dangerous area, generate a quasi-square area and an external graph, determine a center position of the external graph, and set an infrared emission point which can rotate by 360 degrees at the center; a fence planning module is used to update the edge line of the dangerous area in real time; a target emission point is determined according to the real-time edge line, an emission angle range is adjusted, infrared rays scan the boundary of the dangerous area back and forth at a preset speed, and UWB technology is used to monitor whether personnel enter the dangerous area and trigger a warning; the system dynamically delimits the dangerous area and gives real-time warnings, and personnel safety is ensured.

Description

Technical Field

[0001] This invention relates to the field of underground electronic fence technology, specifically to an underground electronic fence system based on UWB for precise personnel positioning. Background Technology

[0002] Coal mine shafts are specialized engineering structures used for mining underground coal resources. They typically consist of shafts, roadways, working faces, and supporting safety facilities. Because coal mines often contain mined-out goafs or closed, abandoned roadways, these areas can pose fatal hazards due to roof collapses, gas accumulation, or water accumulation. Therefore, electronic fences are often installed for real-time monitoring and to prevent personnel from approaching. In the field of safety monitoring, pulsed electronic fences are commonly used, belonging to anti-theft alarm systems, but they cannot be used in underground coal mines.

[0003] Current technologies for managing critical hazardous areas in mines often employ a combination of manual inspections, physical fencing, and video surveillance, leading to frequent problems. Manual inspections rely excessively on personnel's safety awareness, resulting in a high degree of subjectivity in judging violations; they also suffer from blind spots due to limited visibility, making management loopholes easy to exploit. Furthermore, physical fencing and video surveillance struggle to accurately identify violators, making it difficult to trace violations, fostering a sense of impunity, and lacking tiered alarm and early warning functions.

[0004] While electronic fences have been applied to early warning systems in critical hazardous areas of coal mines, current methods, including precise personnel positioning, infrared sensing, and machine vision recognition technology, still have limitations. Infrared sensing electronic fences can only operate within the sensor's sensing area, resulting in complex installation, small coverage, and low flexibility. Machine vision recognition electronic fences are highly susceptible to environmental interference, covering only the camera area, and similarly suffer from narrow coverage and poor anti-interference capabilities. Furthermore, existing systems do not consider the changing characteristics of hazardous areas underground due to environmental factors, necessitating urgent improvement. Summary of the Invention

[0005] The purpose of this invention is to provide an underground electronic fence system for precise personnel positioning based on UWB, and to solve the following technical problems.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An underground electronic fence system based on UWB for precise personnel positioning includes:

[0008] Data acquisition module: used to create a 3D information map and mark all predicted danger zones;

[0009] Location selection module: Obtain the edge lines of all predicted danger zones, obtain several pseudo-square regions based on the edge lines, and obtain the circumcircle of the pseudo-square regions; obtain the center of the circumcircle, and set an infrared emission point that can rotate 360° at each center;

[0010] The fence planning module includes an edge line planning unit, an infrared path adjustment unit, and a monitoring module; the edge line planning unit determines the danger zone in real time.

[0011] The infrared path adjustment unit acquires the edge line of the danger zone and records it as the real-time edge line; it divides the real-time edge line into several line segments according to the vertices of the danger zone, acquires all the target circumcircles where each line segment is located, and acquires several infrared emission points corresponding to each target circumcircle, all of which are recorded as target emission points; for any target emission point, it acquires all the emission angles of the target emission point when the projection point of the target emission point is on the line segment, and obtains the emission angle range; the target emission point emits infrared rays back and forth at a preset sliding speed within the emission angle range.

[0012] The monitoring module uses UWB technology to monitor whether underground personnel have entered the dangerous area and issues an early warning.

[0013] As a further aspect of the present invention: the three-dimensional information includes roadway information, equipment information and geological information. The roadway information includes the center point coordinates, width, height and slope of the roadway. The equipment information includes the external dimensions, position coordinates and attitude angles of each piece of equipment. The equipment includes coal mining machines, tunneling machines, transportation equipment and ventilation equipment. The geological information includes the thickness, dip angle and strike of the coal seam.

[0014] As a further aspect of the present invention: the process of establishing the three-dimensional information map includes:

[0015] A three-dimensional surface model of a coal mine is constructed based on a surface reconstruction algorithm. Three-dimensional information obtained by laser scanning technology is acquired, and the three-dimensional information is converted into point cloud data. The point cloud data is then connected into triangular patches using a triangular meshing method to obtain a continuous surface. On the continuous surface, solid objects are modeled to obtain a three-dimensional information map. The solid objects include equipment, coal seams, and rocks.

[0016] As a further aspect of the present invention: the work cycle is the total time period for construction in the coal mine;

[0017] The moment when construction begins underground in the coal mine is recorded as the start time, and the predicted completion time is recorded as the completion time. The time period consisting of the start time and the completion time is recorded as the total time period.

[0018] As a further aspect of the present invention: the process of obtaining all predicted hazardous areas includes:

[0019] Obtain accident records, which include all accidents and their causes that occurred during past underground construction work in coal mines; extract all areas where accidents occurred from the accident records, label them as accident-prone areas, and extract the spatial coordinates and environmental features of the accident-prone areas to obtain the accident characteristics of the accident-prone areas; on the three-dimensional information map, areas that meet the accident characteristics are labeled as predicted danger areas.

[0020] As a further aspect of the present invention: the process of obtaining the pseudo-square region includes:

[0021] Obtain the projection of the predicted danger area onto the ground plane, and obtain the geometric shape formed by the edge lines of the projection. Obtain all vertices of the geometric shape, and obtain the two vertices that are farthest apart, and record these two vertices as endpoints. Obtain the line connecting the two endpoints, and obtain the length of the line, which is recorded as the side length of the square. Obtain the center point of the geometric shape, and establish a square region based on the side length of the square. Obtain the center point of the square region, which is recorded as the center point of the square. Align the center point of the square with the center point, and the area occupied by the square region on the three-dimensional information map at this time is recorded as the pseudo-square region.

[0022] As a further aspect of the present invention: when setting an infrared emitting point that can rotate 360° at the center, the maximum rotation trajectory of the infrared emitting point is set as the circumcircle corresponding to the infrared emitting point.

[0023] As a further aspect of the present invention: the process of obtaining the target circumcircle of the line segment includes:

[0024] Obtain all points on the line segment. For any circumcircle, if all points on the line segment are located inside the circumcircle, then the circumcircle is denoted as the target circumcircle of the line segment.

[0025] The beneficial effects of this invention are:

[0026] This invention utilizes 3D modeling and real-time data updates to dynamically identify and mark hazardous areas underground, adapting to environmental changes (such as equipment movement and geological shifts) and avoiding the lag of traditional static fencing. Combining high-precision positioning (centimeter-level error) with UWB technology and infrared scanning, it monitors personnel positions in real time, triggering an immediate warning upon entry into a hazardous area, reducing false alarms and missed alarms, and improving safety. Employing 360° rotatable infrared emitters, it covers irregular hazardous areas with an outer circle, optimizing equipment layout and reducing blind spots. A pseudo-square area algorithm simplifies installation complexity and reduces deployment costs. Based on accident data, it automatically identifies and predicts hazardous areas, adjusting the infrared scanning path in real-time using edge lines to achieve intelligent risk prediction and proactive protection. Compared to traditional infrared or visual technologies, UWB and infrared working together are less affected by underground dust, light, and other environmental factors, resulting in higher stability. Attached Figure Description

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of a method for an underground electronic fence system based on UWB for precise personnel positioning according to the present invention;

[0029] Figure 2 This is an overall architecture diagram of an underground electronic fence system based on UWB for precise personnel positioning according to the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Existing technologies suffer from limitations such as limited coverage, low flexibility, and poor anti-interference capabilities. To address these issues, this system constructs an underground electronic fence based on UWB technology. Due to the wide coverage area of ​​UWB signals and the absence of blind spots within that coverage area, the coverage range of the electronic fence is significantly improved. Adding new targets only requires installing identification cards to establish an electronic fence, enhancing its flexibility. Furthermore, the stability of UWB signal transmission allows it to adapt to complex underground working conditions and provides strong anti-interference capabilities. For complex underground environments, this system monitors and analyzes various environmental factors, generating electronic fences for hazardous areas in real time.

[0032] Please see Figure 1 As shown, this invention is an underground electronic fence system for precise personnel positioning based on UWB, comprising:

[0033] Data acquisition module: includes a modeling unit and a regional planning unit; the modeling unit is used to acquire three-dimensional information of the coal mine and establish a three-dimensional information map of the coal mine; the regional planning unit marks all predicted hazardous areas within the operation cycle on the three-dimensional information map;

[0034] Through 3D modeling, the underground spatial structure (tunnels, equipment, geological layers) is realistically reproduced, providing a visual basis for fence planning; combined with data from past accidents, potentially dangerous areas (such as goaf areas and equipment operating areas) are intelligently predicted, allowing for the early deployment of protective measures; environmental data (such as newly excavated tunnels and moving equipment) is updated in real time to ensure that the electronic fence always covers the newest dangerous areas, avoiding blind spots; and high-precision data acquisition (such as laser scanning + UWB positioning) reduces misjudgments and missed alarms, improving the accuracy of early warnings.

[0035] In a preferred embodiment of the present invention, the three-dimensional information includes roadway information, equipment information, and geological information. The roadway information includes the center point coordinates, width, height, and slope of the roadway. The equipment information includes the external dimensions, position coordinates, and attitude angles of each piece of equipment. The equipment includes coal mining machines, tunneling machines, transportation equipment, and ventilation equipment. The geological information includes the thickness, dip angle, and strike of the coal seam.

[0036] The acquisition of the three-dimensional information is based on laser scanning technology; for example, a laser scanner is used to scan objects such as roadways, equipment, and coal walls in a coal mine. The laser scanner emits a laser beam, which is reflected back and received by a receiver when it hits the surface of the object. By measuring the round-trip time of the laser beam, the distance between the object and the scanner can be calculated. At the same time, by rotating and moving the scanner, distance data at different angles and positions can be obtained, thereby constructing the three-dimensional outline of the object.

[0037] In a preferred embodiment of the present invention, the process of establishing the three-dimensional information map includes:

[0038] A three-dimensional surface model of a coal mine is constructed based on a surface reconstruction algorithm. Three-dimensional information obtained by laser scanning technology is acquired, and the three-dimensional information is converted into point cloud data. The point cloud data is then connected into triangular patches using a triangular meshing method to obtain a continuous surface. On the continuous surface, solid objects are modeled to finally obtain a three-dimensional information map. The solid objects include equipment, coal seams, and rocks.

[0039] In a preferred embodiment of the present invention, the work cycle is the total time period for construction in the coal mine.

[0040] The moment when construction begins underground in the coal mine is recorded as the start time, and the predicted completion time is recorded as the completion time. The time period consisting of the start time and the completion time is recorded as the total time period.

[0041] In a preferred embodiment of the present invention, the process of obtaining all predicted hazardous areas includes:

[0042] Obtain accident records, which include all accidents and their causes that occurred during past underground coal mine operations; extract all areas where accidents occurred from the accident records, designate them as accident-prone areas, and extract the spatial coordinates and environmental features of the accident-prone areas to obtain the accident characteristics of the accident-prone areas; on the three-dimensional information map, areas that meet the accident characteristics are designated as predicted danger areas;

[0043] It should be noted that the process of determining the predicted danger zone (i.e., the electronic fence area) also includes:

[0044] The electronic fence system's communication base station transmits signals through two antennas, with a one-way coverage area of ​​≥200m and a two-way coverage area of ​​≥400m. The positioning accuracy for static targets underground reaches approximately 0.2m, and the positioning accuracy for dynamic targets reaches approximately 6.5m.

[0045] By combining the 2000 coordinate system with a GIS model, a novel simulation and inverse calculation method for three-dimensional coordinate domains was developed. Through precise calculation of two-dimensional and three-dimensional coordinates in key and high-risk areas, the absolute location of personnel underground can be determined.

[0046] The main process of the simulation inverse calculation method in the three-dimensional coordinate domain is as follows:

[0047] (1) Based on the 2000 coordinate system, the downhole CAD engineering Figure 2 The two-dimensional coordinate system is simulated and inversely calculated to establish a unified two-dimensional coordinate system in the well.

[0048] (2) The elevation data of the underground CAD engineering drawing is converted into Z-axis coordinate values ​​through a self-developed algorithm, so as to realize the reverse calculation of the three-dimensional coordinates of all objects in a unified coordinate system;

[0049] (3) Based on the three-dimensional coordinate data of the reverse calculation, the three-dimensional coordinate domain of the fence coverage area is set to realize the judgment of the behavior of underground personnel crossing the fence.

[0050] By embedding AI video algorithms into multifunctional information mine lamps and utilizing image target detection algorithms based on convolutional neural networks, personnel can be identified and hazards can be detected, enabling rapid response and handling of underground hazards.

[0051] (1) Use the continuous frame action recognition and human trajectory recognition functions of convolutional neural network algorithm to monitor and judge human behavior, such as falling, fighting, injury, etc., and make timely emergency response.

[0052] (2) The image detection algorithm developed based on convolutional neural network has realized the identification and judgment of dangerous sources such as flames, smoke, and smoking, ensuring safe production in the mine.

[0053] By using the 3D GIS platform provided by the system, the system can arbitrarily define and remove electronic fence areas, and automatically generate electronic fence areas within a specified range based on environmental monitoring values ​​and equipment operating status, thereby enabling real-time judgment, alarm, and recording of non-whitelisted personnel's intrusion into the fence underground.

[0054] (1) Electronic fences can be manually planned for key locations and high-risk areas underground. Just mark the starting point, turning point and ending point on the three-dimensional GIS model, and the system can obtain the three-dimensional absolute coordinates of each point. Combined with the three-dimensional coordinate domain data of the tunnel, the three-dimensional coordinates of the fence boundary and turning point are automatically calculated, and the coordinate domain of the electronic fence is intelligently completed.

[0055] (2) The real-time monitoring data of the well is judged by the safety judgment model. When any area is judged to have a safety risk, an electronic fence is automatically generated according to the preset rules, and the fence crossing judgment is realized by combining the personnel location data.

[0056] (3) A dynamic electronic fence is implemented using positioning cards and a high-precision positioning system. The identification card is embedded in the dynamic equipment underground to locate the equipment in real time. The area where the dynamic equipment is located is set as the electronic fence area, and the electronic fence area will be updated in real time as the dynamic equipment moves.

[0057] Location selection module: Obtain the edge lines of all predicted danger zones, obtain several pseudo-square regions based on the edge lines, and obtain the circumcircle of the pseudo-square regions; obtain the center of the circumcircle, and finally obtain several center points, and set an infrared emission point that can rotate 360° at each center point;

[0058] In a preferred embodiment of the present invention, the process of obtaining the pseudo-square region includes:

[0059] Obtain the projection of the predicted danger zone onto the ground plane, and obtain the geometric shape formed by the edge lines of the projection. Obtain all vertices of the geometric shape, and obtain the two vertices that are farthest apart, and record these two vertices as endpoints. Obtain the line connecting the two endpoints, and obtain the length of the line, which is recorded as the side length of the square. Obtain the center point of the geometric shape, and establish a square region based on the side length of the square. Obtain the center point of the square region, which is recorded as the center point of the square. Align the center point of the square with the center point, and the area occupied by the square region on the three-dimensional information map at this time is recorded as the pseudo-square region.

[0060] In a preferred embodiment of the present invention, when an infrared emitting point that can rotate 360° is set at the center, the maximum rotation trajectory of the infrared emitting point is set as the circumcircle corresponding to the infrared emitting point.

[0061] The core task of the site selection module is to optimize the deployment location of infrared emitters based on the hazardous area information provided by the data acquisition module, ensuring that the electronic fence can completely cover the boundary of the hazardous area; extract the geometric edge lines of the hazardous area from the 3D map, perform geometric approximation on irregular hazardous areas, find the two farthest points (maximum distance endpoints) of the edge lines as the reference side length, and construct a square area with its center coinciding with the geometric center of the hazardous area, forming a pseudo-square area; transform complex irregular areas into more easily covered square or near-square structures to facilitate subsequent deployment of infrared emitters; calculate the minimum circumcircle for each pseudo-square area to ensure that the entire area can be covered by infrared rays, and deploy infrared emitters that can rotate 360° at the center of the circumcircle to maximize the scanning range to cover the boundary of the hazardous area; if the shape or position of the hazardous area changes (such as equipment movement), recalculate the circumcircle and adjust the scanning angle of the infrared emitters to ensure that the fence remains effective at all times.

[0062] The fence planning module includes an edge line planning unit, an infrared path adjustment unit, and a monitoring module; the edge line planning unit determines the danger zone in real time.

[0063] The infrared path adjustment unit acquires the edge line of the danger zone and records it as the real-time edge line; it divides the real-time edge line into several line segments according to the vertices of the danger zone, acquires all the target circumcircles where each line segment is located, and acquires several infrared emission points corresponding to each target circumcircle, all of which are recorded as target emission points; for any target emission point, it acquires all the emission angles of the target emission point when the projection point of the target emission point is on the line segment, and obtains the emission angle range; the target emission point emits infrared rays back and forth at a preset sliding speed within the emission angle range.

[0064] The monitoring module uses UWB technology to monitor whether underground personnel have entered the dangerous area and issues an early warning.

[0065] In a preferred embodiment of the present invention, the process of the edge line planning unit determining the danger zone in real time includes:

[0066] The regions on the three-dimensional information map that meet the accident characteristics are acquired in real time and recorded as danger zones; and several adjacent danger zones are merged into one danger zone.

[0067] In a preferred embodiment of the present invention, the process of obtaining the target circumcircle of the line segment includes:

[0068] Obtain all points on a line segment. For any circumcircle, if all points on the line segment are located inside the circumcircle, then the circumcircle is denoted as the target circumcircle of the line segment.

[0069] In a preferred embodiment of the present invention, the process of determining the emission angle range includes:

[0070] Obtain all emission angles of the target emission point when the projection point of the target emission point is on the line segment, and obtain the emission angle range;

[0071] In a preferred embodiment of the present invention, the process of setting the sliding speed includes:

[0072] The sliding speed is the time consumed by the target launch point to slide once within the launch angle range. The length of the line segment is obtained, and an initial sliding speed v0 is set. Therefore, the sliding speed... Where k is a correction coefficient and k > 1, and L is the length of the line segment;

[0073] In a preferred embodiment of the present invention, the process by which the monitoring module monitors whether underground personnel have entered the danger zone includes:

[0074] If the target emission point detects that the infrared rays are blocked, it transmits an early warning signal to the monitoring module. The monitoring module acquires the early warning signal and determines the coordinate range of the line segment corresponding to the target emission point on the three-dimensional information map based on the early warning signal. The monitoring module acquires the position coordinates of each downhole personnel based on UWB, selects the downhole personnel whose position coordinates are closest to the coordinate range, records them as early warning personnel, and issues a prompt to the early warning personnel.

[0075] This invention constructs a three-dimensional geographic information map based on the user's existing engineering data, displaying the location, range, and real-time status of electronic fences, as well as the location and real-time status of coal mining machines and safety monitoring equipment. It automatically creates electronic fences in the corresponding areas based on monitoring data of coal mining machines, supports, gas, etc., and user-defined fence rules. Users can freely create electronic fence areas on the three-dimensional map according to their actual needs.

[0076] The system utilizes intrinsically safe communication base stations, intrinsically safe card reader substations, personnel identification cards, vehicle identification cards, intrinsically safe identification card search devices, explosion-proof and intrinsically safe DC regulated power supplies, information mine lamps, intrinsically safe LED displays, intrinsically safe audible and visual alarms, and underground industrial ring networks as carriers to construct a foundation for the collection, transmission, and aggregation of product-level data. This foundation interfaces with a ground-based data center and, combined with the system platform, forms a complete system for data collection, transmission, aggregation, processing, analysis, push, display, and feedback. The overall architecture diagram is shown below. Figure 2 As shown;

[0077] Vehicle identification cards, personnel identification cards, and information-enabled mining lamps communicate with the intrinsically safe mine communication base station via built-in UWB antennas, while the video, telephone, and intercom data from the information-enabled mining lamps communicate with the base station via built-in WiFi antennas. This data is transmitted to the host computer and system mainframe via ring network switches and core switches. Utilizing technologies such as precise positioning, AI video algorithms, backend systems, databases, and 3D GIS, underground tunnel modeling is performed, enabling functions such as personnel location query and management, real-time status query, alarms, dispatching, and autonomous electronic fence demarcation.

[0078] The information-enabled mining lamp not only possesses basic lighting and positioning functions but also incorporates an AI video algorithm backend, enabling it to identify hazardous behaviors and working conditions. Furthermore, the information-enabled mining lamp supports one-to-one and one-to-many intercom communication, including communication with the dispatch platform, communication between any two mining lamps, and the ability to autonomously create multiple intercom groups. As an essential piece of equipment for underground personnel, the information-enabled mining lamp integrates multiple functions, ensuring personnel safety while reducing the burden of carrying it.

[0079] The intrinsically safe communication base station for mining serves as the system's data transmission hub, primarily transmitting location, video, and voice data. It can also connect to underground sensors and automatic monitoring systems, offering strong scalability. Its power supply is a mining-grade explosion-proof and intrinsically safe DC regulated power supply with a built-in battery management system, providing over 4 hours of backup time to ensure system stability in emergencies. The communication base station connects via Ethernet / 485, and its power status is centrally managed and monitored on the system platform.

[0080] Furthermore, this system adopts a multi-level dynamic path planning architecture, realizing risk avoidance path planning through three stages: environmental perception, real-time calculation, and intelligent guidance. Specifically, it includes:

[0081] The range of hazardous areas is monitored in real time through infrared transmitters and a UWB system. The real-time location of workers is obtained through the UWB system, including information such as terrain, obstacles, and safety exits. Preset safety zones or exit locations are used to discretize the environmental map into a grid (such as an occupied grid map). Hazardous areas are marked as impassable areas, and safe areas are marked as passable areas. The shortest path is searched using heuristic functions (such as Euclidean distance). When the boundary of the hazardous area changes, the environmental map is reconstructed and the path is replanned.

[0082] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the invention.

Claims

1. A downhole electronic fence system based on UWB precise personnel positioning, characterized in that, The application relates to a coal mine danger area monitoring system, which comprises the following modules: a data acquisition module for establishing a three-dimensional information map and marking all predicted danger areas; a site selection module for obtaining edge lines of all predicted danger areas, obtaining a plurality of quasi-square areas according to the edge lines, and obtaining circumscribed circles of the quasi-square areas; obtaining the centers of the circumscribed circles and setting first infrared emission points capable of rotating by 360 degrees at the centers; a fence planning module comprising an edge line planning unit, an infrared path adjusting unit and a monitoring module; the edge line planning unit determines danger areas in real time; the infrared path adjusting unit obtains edge lines of the danger areas, which are recorded as real-time edge lines; the real-time edge lines are divided into a plurality of line segments according to vertices of the danger areas, all target circumscribed circles where the line segments are located are obtained, and a plurality of second infrared emission points corresponding to the target circumscribed circles are obtained, which are recorded as target emission points; for any target emission point, all emission angles of the target emission point when a projection point of the target emission point is on a line segment are obtained, an emission angle range is obtained, and the target emission point emits infrared rays back and forth at a preset sliding speed within the emission angle range; the monitoring module monitors whether underground personnel enter the danger areas based on UWB technology and gives an early warning; an obtaining process of the quasi-square area comprises the following steps: an projection of the predicted danger area on a horizontal plane is obtained, a geometric figure formed by edge lines of the projection is obtained, all vertices of the geometric figure are obtained, and two vertices with the largest distance are recorded as end points; a line connecting the two end points is obtained, the length of the line is recorded as a square side length; a center point of the geometric figure is obtained, and a square area is established according to the square side length; a center point of the square area is recorded as a square center point; the square center point is coincided with the center point, and the area of the square area on the three-dimensional information map is recorded as a quasi-square area; an obtaining process of all predicted danger areas comprises the following steps: an accident record is obtained, the accident record comprises all accidents and accident causes that occur when construction is carried out underground in the past; all areas where accidents occur in the accident record are extracted, recorded as accident-prone areas, and spatial coordinates and environmental characteristics of the accident-prone areas are extracted to obtain accident characteristics of the accident-prone areas; on the three-dimensional information map, areas meeting the accident characteristics are recorded as predicted danger areas; a process in which the edge line planning unit determines danger areas in real time comprises the following steps: danger areas meeting the accident characteristics on the three-dimensional information map are obtained in real time and recorded as danger areas; and a plurality of adjacent danger areas are combined into one danger area.

2. The underground electronic fence system based on UWB precise personnel positioning according to claim 1, characterized in that, the data acquisition module comprises a modeling unit and a region planning unit; the modeling unit is used for acquiring three-dimensional information underground of a coal mine and establishing a three-dimensional information map of the coal mine underground; and the region planning unit marks all predicted danger areas in a work period on the three-dimensional information map.

3. The underground electronic fence system based on UWB precise personnel positioning according to claim 2, characterized in that, The three-dimensional information includes roadway information, equipment information and geological information, the roadway information includes the center point coordinates, width, height and slope of the roadway, the equipment information includes the external dimensions, position coordinates and attitude angle of each equipment, the equipment includes a coal mining machine, a tunneling machine, a transportation equipment and a ventilation equipment, and the geological information includes the thickness, dip angle and strike of the coal seam.

4. The underground electronic fence system based on UWB precise personnel positioning according to claim 2, characterized in that, The three-dimensional information map is established by: constructing a three-dimensional surface model of the underground coal mine based on a surface reconstruction algorithm, obtaining three-dimensional information obtained based on a laser scanning technology, converting the three-dimensional information into point cloud data, connecting the point cloud data into triangular facets using a triangular meshing method to obtain a continuous surface, and modeling an entity object on the continuous surface to obtain a three-dimensional information map, the entity object including equipment, a coal seam and rock.

5. The underground electronic fence system based on UWB precise personnel positioning according to claim 2, characterized in that, The operation cycle is a total time period of construction in the underground coal mine. A time when the construction in the underground coal mine starts is recorded as a start time, a predicted completion time is obtained and recorded as a completion time, a time period composed of the start time and the completion time is obtained and recorded as a total time period.

6. The underground electronic fence system based on UWB precise personnel positioning according to claim 1, characterized in that, The process of obtaining the target circumscribed circle of the line segment includes: all points on the line segment are located inside the circumscribed circle, the circumscribed circle is recorded as the target circumscribed circle of the line segment.

7. The underground electronic fence system based on UWB precise personnel positioning according to claim 1, characterized in that, The process in which the monitoring module monitors whether there is an underground person entering the dangerous area includes: If the target emission point detects that the infrared rays are blocked, a warning signal is transmitted to the monitoring module, the monitoring module obtains the warning signal, determines the coordinate range of the line segment corresponding to the target emission point on the three-dimensional information map according to the warning signal, obtains the position coordinates of each underground person based on UWB, selects an underground person closest to the coordinate range, records the underground person as a warning person, and sends a prompt to the warning person.

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