A mine electronic fence structure with multipath suppression

Abstract

The utility model discloses a kind of mine electronic fence structures with multipath suppression belong to mine safety protection technical field. Including positioning node, positioning label and control unit;Positioning node is equipped with circular polarized antenna for receiving positioning signal, and positioning node is set in the fixed position of mine roadway;Positioning label is equipped with circular polarized antenna with the same rotation direction of positioning node, for emitting positioning signal;Control unit is connected with positioning node communication, for processing and analysis to positioning signal, calculate the spatial position information of positioning label;Control unit is connected with other equipment or alarm device communication, according to analysis result output control instruction, to realize dynamic monitoring and early warning to mine equipment or personnel;The mine electronic fence structure with multipath suppression of the utility model effectively suppresses multipath interference by adopting circular polarized radiation mode, improves signal transmission stability and positioning accuracy.

Description

Technical Field

[0001] This utility model relates to the field of mine safety protection technology, and in particular to a mine electronic fence structure with multipath suppression. Background Technology

[0002] Currently, most mine electronic fences and anti-collision systems use linearly polarized antennas for signal transmission and target positioning. However, in the complex environment of mines, electromagnetic waves are easily reflected by the metal surfaces of tunnel walls and mechanical equipment, resulting in severe multipath effects. This leads to signal attenuation, increased ranging errors, and positioning drift, seriously impacting the reliability and safety of the system.

[0003] Traditional solutions, such as increasing signal power or deploying multiple base stations, can alleviate the above problems to some extent, but they have drawbacks such as high energy consumption and complex deployment. In addition, existing systems are not good at real-time tracking of dynamic targets, especially in complex areas such as turns and intersections, where monitoring blind spots are prone to occur, failing to meet the requirements of high-precision collision avoidance. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to solve the problem of signal interference and inaccurate positioning caused by multipath effect in the existing mine electronic fence system, this utility model provides a mine electronic fence structure with multipath suppression, which effectively suppresses multipath interference by adopting circular polarization radiation method, thereby improving signal transmission stability and positioning accuracy.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a mine electronic fence structure with multipath suppression, comprising: The positioning node is equipped with a circularly polarized antenna, which is either a left-hand circularly polarized antenna or a right-hand circularly polarized antenna. The positioning node is set at a fixed position in the mine roadway to receive positioning signals. The positioning tag is equipped with a circularly polarized antenna that rotates in the same direction as the positioning node, for transmitting positioning signals; The control unit is communicatively connected to the positioning node and is used to process and analyze the positioning signal to calculate the spatial location information of the positioning tag. The control unit is also communicatively connected to other devices or alarm devices and outputs control commands based on the analysis results to achieve dynamic monitoring and early warning of mining equipment or personnel.

[0006] Therefore, based on the rotational selectivity of circularly polarized antennas (the polarization rotation direction of circularly polarized electromagnetic waves in free space reverses after reflection, such as right-hand circular polarization becoming left-hand circular polarization, while the direct wave retains its original rotation direction. The reflected wave experiences a 15-20 dB attenuation due to polarization mismatch, while the direct wave is received completely), the first reflected wave is naturally filtered out, constructing a stable signal propagation path in complex tunnel environments. This effectively reduces signal fluctuations caused by reflection, diffraction, and other factors, thereby significantly improving the system's positioning robustness in dynamic scenarios. This structure is not only suitable for straight tunnels but also adapts well to complex terrains such as turns and intersections, providing more accurate and reliable technical support for mine safety monitoring.

[0007] Furthermore, the positioning node also includes a node housing and a positioning chip. The circularly polarized antenna and positioning chip are both housed inside the node housing. The positioning chip is electrically connected to the circularly polarized antenna. The positioning chip includes a time-slot synchronization module, a ranging module, an IMU, and a signal processing module. The time-slot synchronization module is used to achieve precise time synchronization between multiple nodes, ensuring that each node performs signal transmission and reception and ranging calculation under a unified time reference. The ranging module achieves high-precision distance measurement based on UWB technology and combines it with an IMU sensor for dynamic compensation of motion state. It uses an extended Kalman filter algorithm to fuse UWB ranging data and IMU inertial data, effectively improving positioning accuracy and stability in non-line-of-sight environments. The signal processing module is responsible for real-time analysis and optimization of the collected data, further enhancing the system's anti-interference capability and response speed, ensuring continuous, reliable, and high-precision positioning services under complex tunnel conditions.

[0008] Furthermore, the positioning tag also includes a tag chip. The circularly polarized antenna rotates in the same direction as the circularly polarized antenna at the positioning node, and the tag chip is electrically connected to the circularly polarized antenna. The tag chip integrates a UWB communication module and an IMU sensor. Through multi-point ranging and data fusion with the positioning node, it achieves accurate calculation of the tag's three-dimensional position. The system as a whole effectively suppresses error disturbances caused by multipath effects in the tunnel through a unified clock synchronization mechanism and data fusion algorithm, improving the stability and reliability of positioning results in dynamic environments. In addition, the UWB communication module integrated inside the tag chip supports high-speed, low-latency data interaction, ensuring a stable communication link even in densely deployed environments. The IMU sensor has high sampling rate and low noise characteristics, enabling it to accurately capture changes in the tag's motion attitude and correct positioning deviations in real time through an extended Kalman filter algorithm. By combining bidirectional ranging and angle estimation between the tag and the node with a three-dimensional spatial model of the tunnel, the system constructs a high-precision, highly robust real-time positioning network, fully meeting the stringent requirements for accurate positioning and dynamic monitoring of personnel and equipment in complex mining environments.

[0009] Furthermore, the positioning tag adopts an intrinsically safe design and can be embedded in mining equipment or worn by personnel; thereby, it outputs location information in real time, realizing dynamic tracking and safety management of underground workers and key equipment.

[0010] Furthermore, the circularly polarized antenna includes a dielectric substrate and a GND structure; an electric dipole is disposed on the dielectric substrate, and the GND structure is located below the dielectric substrate. The GND structure has a terminal open-circuit slot, which serves as a magnetic dipole slot. The magnetic dipole slot and the electric dipole are complementary structures, and both the electric dipole and the magnetic dipole slot are Γ-shaped multi-stub structures. Thus, the electric dipole and the complementary magnetic dipole slot resonate simultaneously, forming an omnidirectional circularly polarized radiation wave in space. Compared to conventional antennas that use, for example, a feed network that meets the requirements of circularly polarized radiation or a special radiator structure (planar two-dimensional or three-dimensional structure) that meets the requirements of circular polarization to achieve circularly polarized radiation, the magnetic-electric complementary structure eliminates the need for a separate feed network and only requires the construction of a pair of complementary Γ-shaped multi-stub magnetic-electric dipoles on a two-dimensional plane. This structure is compact, simple to design, and easy to integrate. This invention addresses the problems of traditional circularly polarized antennas, such as large size and difficulty in efficient integration with existing mining positioning tags and anchor nodes. It achieves high performance within a limited space, making it more suitable for the miniaturization and integration needs of mining wireless equipment.

[0011] Furthermore, if the free space wavelength corresponding to the operating frequency of the circularly polarized antenna is defined as λ, then the size of the gap between the electric dipole and the magnetic dipole is controlled within λ / 4. Through optimized design, both can achieve good impedance matching and circular polarization characteristics in the same frequency band.

[0012] Furthermore, the dielectric substrate has a power supply port inside, which is connected to the electric dipole via a microstrip line. The other end of the microstrip line is connected to the GND structure, so that the gap between the electric dipole and the magnetic dipole forms a complete power supply path.

[0013] Furthermore, the magnetic dipole gap is located on one side of the feed port and is centrally symmetrical with the electric dipole, ensuring good consistency and synergistic effect between the electric dipole and the magnetic dipole gap in the radiation pattern.

[0014] Furthermore, the magnetic dipole gap and the electric dipole are located on the same side of the feed port, forming a coplanar radiation structure, thereby effectively improving the overall radiation efficiency and circular polarization purity of the antenna.

[0015] Furthermore, the circularly polarized antenna at the positioning node is an omnidirectional circularly polarized antenna with an axial ratio ≤3dB and a standing wave ratio ≤2, ensuring stable and reliable signal coverage and reception performance in complex downhole environments.

[0016] Furthermore, the positioning tag adopts a miniaturized circularly polarized antenna with an axial ratio ≤3.5dB and a standing wave ratio ≤3. The circularly polarized antenna supports adaptive switching between right-hand and left-hand circular polarization modes, enabling efficient reception and transmission of wireless radio frequency signals with different polarization modes.

[0017] The beneficial effects of this invention are as follows: The mine electronic fence structure with multipath suppression utilizes a circularly polarized antenna structure for the mine positioning tag and positioning node. Through the unique azimuth selectivity of the circularly polarized antenna, it effectively separates and receives signals of different polarization states, thereby effectively separating multipath signals and achieving pre-filtering of multipath effects in the spatial domain. This design significantly reduces interference caused by signal reflection and refraction, reducing multipath positioning errors by more than 50% compared to linearly polarized antennas. This is particularly significant in tunnel environments with numerous metal devices, thus improving the stability and reliability of the communication system. It effectively suppresses positioning errors caused by multipath effects in complex underground environments, improving signal transmission stability and anti-interference capabilities. Simultaneously, this structure gives the antenna excellent omnidirectional radiation characteristics and high circular polarization purity, further meeting the high precision and high reliability requirements of mine positioning systems, and has broad application prospects and promotional value.

[0018] This utility model presents a mining electronic fence structure with multipath suppression. By adopting a magnetoelectric complementary structure design, it solves the problems of complex and space-consuming traditional omnidirectional circularly polarized antenna structures. Through optimized antenna structure design, it achieves a significant reduction in antenna volume while maintaining high circular polarization performance, thus improving integration and better meeting the needs of mining wireless equipment to develop towards miniaturization and integration. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a schematic diagram of the preferred embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of a circularly polarized antenna.

[0022] In the figure: 1. Positioning node; 2. Positioning tag; 3. Control unit; 4. Reflective surface; 51. Dielectric substrate; 511. Electric dipole; 512. Power supply port; 52. GND structure; 521. Magnetic dipole gap. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0024] Example 1: like Figure 1 As shown, a mine electronic fence structure with multipath suppression includes: a positioning node 1, a positioning tag 2, and a control unit. The positioning node 1 is equipped with a circularly polarized antenna for receiving positioning signals and is located at a fixed position in the mine roadway. The positioning tag 2 is equipped with a circularly polarized antenna for transmitting positioning signals. The control unit 3 is communicatively connected to the positioning node 1 and is used to process and analyze the positioning signals to calculate the spatial position information of the positioning tag 2. The control unit 3 is also communicatively connected to other devices or alarm devices and outputs control commands based on the analysis results to achieve dynamic monitoring and early warning of mine equipment or personnel. Thus, the circularly polarized antenna at the positioning tag 2 emits electromagnetic waves, some of which are reflected by the reflecting surface 4, causing their polarization direction to reverse. Figure 1 The reflected wave k2 changes from right-hand circular polarization to left-hand circular polarization, while the remaining electromagnetic wave maintains its original direction of rotation and propagates. Figure 1 The direct wave k1 is received by positioning node 1, which receives a reflected wave k2 attenuated by 15-20 dB due to polarization mismatch, and the complete direct wave k1. Positioning node 1 can effectively separate multipath signals and naturally filter out the first reflected wave, thus constructing a stable signal propagation path in complex tunnel environments. This effectively reduces signal fluctuations caused by reflection and diffraction, significantly improving the system's positioning robustness in dynamic scenarios. This structure is not only suitable for straight tunnels but also adapts well to complex terrains such as turns and intersections, providing more accurate and reliable technical support for mine safety monitoring.

[0025] in: Positioning node 1 also includes a node housing and a positioning chip. The circularly polarized antenna and positioning chip are both housed inside the node housing. The positioning chip is electrically connected to the circularly polarized antenna. The positioning chip includes a time-slot synchronization module, a ranging module, an IMU (Inertial Measurement Unit), and a signal processing module. The time-slot synchronization module enables precise time synchronization between multiple nodes, ensuring that each node performs signal transmission and reception and ranging calculations under a unified time reference. The ranging module achieves high-precision distance measurement based on UWB technology and dynamically compensates for motion states using an IMU sensor. It fuses UWB ranging data and IMU inertial data using an extended Kalman filter algorithm, effectively improving positioning accuracy and stability in non-line-of-sight environments. The signal processing module is responsible for real-time analysis and optimization of the collected data, further enhancing the system's anti-interference capability and response speed, ensuring continuous, reliable, and high-precision positioning services under complex tunnel conditions.

[0026] The positioning tag 2 also includes a tag chip and a circuit board. The circularly polarized antenna rotates in the same direction as the circularly polarized antenna at positioning node 1. Both the tag chip and the circularly polarized antenna are mounted on the circuit board. The tag chip integrates a UWB communication module and an IMU sensor. Through multi-point ranging and data fusion with positioning node 1, it achieves accurate calculation of the three-dimensional position of positioning tag 2. The optimal communication link is dynamically selected through a polarization matching algorithm to establish an optimal wireless channel with positioning node 1. The system as a whole effectively suppresses error disturbances caused by multipath effects in the tunnel through a unified clock synchronization mechanism and data fusion algorithm, improving the stability and reliability of positioning results in dynamic environments. In addition, the UWB communication module integrated inside the tag chip supports high-speed, low-latency data interaction, ensuring a stable communication link even in densely deployed environments. The IMU sensor has high sampling rate and low noise characteristics, which can accurately capture changes in the tag's motion attitude and correct positioning deviations in real time through an extended Kalman filter algorithm. The system constructs a high-precision, robust real-time positioning network by combining bidirectional distance measurement and angle estimation between tags and nodes with a three-dimensional spatial model of the tunnel, fully meeting the stringent requirements for precise positioning and dynamic monitoring of personnel and equipment in complex mining environments.

[0027] The positioning tag 2 adopts an intrinsically safe design and can be embedded in mining equipment or worn by personnel; thus, it outputs location information in real time, enabling dynamic tracking and safety management of underground workers and key equipment.

[0028] The circularly polarized antenna at positioning node 1 is an omnidirectional circularly polarized antenna with an axial ratio ≤3dB and a standing wave ratio ≤2. The positioning tag 2 uses a miniaturized circularly polarized antenna with an axial ratio ≤3.5dB and a standing wave ratio ≤3. The circularly polarized antenna supports adaptive switching between right-hand and left-hand circular polarization modes, enabling efficient reception and transmission of wireless radio frequency signals with different polarization modes.

[0029] Example 2: Traditional circularly polarized antennas typically rely on complex feed networks or three-dimensional radiator designs to ensure uniform coverage in the horizontal plane while simultaneously satisfying circular polarization characteristics. Such antenna structures are relatively complex and occupy a large amount of space, primarily suitable for external installations and applications with lower space constraints. However, as mining wireless equipment develops towards miniaturization and integration, it places higher demands on the spatial compatibility of antenna systems. Traditional antenna structures struggle to achieve high performance within limited space. To address this issue, the structure of the circularly polarized antenna is optimized based on Example 1, as follows: Reference Figure 2The circularly polarized antenna includes a dielectric substrate 51 and a GND structure 52. An electric dipole 511 is disposed on the dielectric substrate 51, and the GND structure 52 is located below the dielectric substrate 51. The GND structure 52 has a terminal open-circuit slot, which serves as a magnetic dipole slot 521. The magnetic dipole slot 521 and the electric dipole 511 are complementary structures, and both the electric dipole 511 and the magnetic dipole slot 521 are Γ-shaped multi-stub structures. Thus, the electric dipole 511 and the complementary magnetic dipole slot 521 resonate simultaneously and form an omnidirectional circularly polarized radiation wave in space. Compared with conventional antennas, the use of a magnetoelectric complementary structure eliminates the need to construct a separate feed network and only requires the construction of a pair of complementary Γ-shaped multi-stub magnetoelectric dipoles on a two-dimensional plane. This makes the circularly polarized antenna in this embodiment have the advantages of compact structure, simple design, and easy integration. This invention addresses the problems of traditional circularly polarized antennas, such as their large size and difficulty in efficient integration with existing mining positioning tags 2 and positioning nodes 1. It achieves high-performance internal integration within a limited space, better meeting the needs of mining wireless equipment towards miniaturization and integration.

[0030] in: Define the free-space wavelength corresponding to the operating frequency of the circularly polarized antenna as λ, then the size of the electric dipole 511 and the magnetic dipole gap 521 is λ / 4. A feed port 512 is provided inside the dielectric substrate 51. One end of the feed port 512 is connected to the electric dipole 511, and the other end is connected to the GND structure 52, forming a complete feed path. The magnetic dipole gap 521 is located on one side of the feed port 512 and is centrally symmetrically arranged with the electric dipole 511.

[0031] Example 3: The difference from Example 2 is that the magnetic dipole gap 521 and the electric dipole 511 are located on the same side of the feed port 512.

[0032] The above-mentioned mine electronic fence structure with multipath suppression has the following technical effects: 1. Multipath interference suppression: Through the polarization rotation reversal characteristic (RHCP / LHCP conversion), the reflected wave is naturally attenuated by 15-20dB, which reduces the multipath positioning error by more than 50% compared with linear polarized antennas. This is especially significant in tunnel environments with many metal equipment.

[0033] 2. Dynamic environment adaptability: Supports RHCP / LHCP dual-mode switching, dynamically selects the optimal communication link through polarization matching algorithm, and establishes the optimal wireless channel with the positioning node.

[0034] 3. Enhanced system complementarity: The pre-filtering of multipath effects by the circularly polarized antenna complements the back-end multipath suppression methods such as UWB time-domain ranging and IMU inertial navigation, significantly improving positioning stability in non-line-of-sight environments and reducing false alarm rate.

[0035] 4. Miniaturized overall structure: It adopts a small PCB board onboard circularly polarized antenna, which can be directly and efficiently integrated with the main control circuit board of the positioning tag and positioning node, and has the advantages of low cost and compact structure.

[0036] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A mine electronic fence structure with multipath suppression, characterized in that: include: The positioning node (1) is equipped with a circularly polarized antenna for receiving positioning signals. The circularly polarized antenna is either a left-hand circularly polarized antenna or a right-hand circularly polarized antenna. The positioning node (1) is located at a fixed position in the mine roadway. The positioning tag (2) is equipped with a circularly polarized antenna for transmitting positioning signals. The positioning signals are reflected by the mine roadway and then propagated to the positioning node (1). The control unit (3) is communicatively connected to the positioning node (1) and is used to process and analyze the positioning signal.

2. The mining electronic fence structure with multipath suppression as described in claim 1, characterized in that: The positioning node (1) also includes a node housing and a positioning chip. The circularly polarized antenna and the positioning chip are both located inside the node housing, and the positioning chip is electrically connected to the circularly polarized antenna.

3. The mine electronic fence structure with multipath suppression as described in claim 2, characterized in that: The positioning tag (2) also includes a tag chip. The circularly polarized antenna at the positioning tag (2) has the same rotation direction as the circularly polarized antenna at the positioning node (1). The tag chip is electrically connected to the circularly polarized antenna.

4. The mine electronic fence structure with multipath suppression as described in claim 3, characterized in that: The positioning tag (2) is embedded in the mining equipment or worn by personnel.

5. The mine electronic fence structure with multipath suppression as described in claim 4, characterized in that: The circularly polarized antenna includes a dielectric substrate (51) and a GND structure (52); an electric dipole (511) is disposed on the dielectric substrate (51), and the GND structure (52) is disposed below the dielectric substrate (51). A terminal open-circuit slot is formed on the GND structure (52), and the terminal open-circuit slot serves as a magnetic dipole slot (521). The magnetic dipole gap (521) and the electric dipole (511) have a complementary structure, and both the electric dipole (511) and the magnetic dipole gap (521) are Γ-shaped multi-branch structures.

6. The mine electronic fence structure with multipath suppression as described in claim 5, characterized in that: If the free space wavelength corresponding to the operating frequency of the circularly polarized antenna is defined as λ, then the size of the gap (521) between the electric dipole (511) and the magnetic dipole is less than λ / 4.

7. The mine electronic fence structure with multipath suppression as described in claim 6, characterized in that: The dielectric substrate (51) has a power supply port (512) inside. The power supply port (512) is connected to the electric dipole (511) through a microstrip line. The other end of the microstrip line is connected to the GND structure (52).

8. The mine electronic fence structure with multipath suppression as described in claim 7, characterized in that: The magnetic dipole gap (521) is located on one side of the feed port (512) and is centrally symmetrical with the electric dipole (511).

9. The mine electronic fence structure with multipath suppression as described in claim 7, characterized in that: The magnetic dipole gap (521) and the electric dipole (511) are located on the same side of the feed port (512).

10. The mine electronic fence structure with multipath suppression as described in claim 6, characterized in that: The circularly polarized antenna at the positioning node (1) is an omnidirectional circularly polarized antenna with an axial ratio ≤3dB and a standing wave ratio ≤2; the positioning tag (2) is a miniaturized circularly polarized antenna with an axial ratio ≤3.5dB and a standing wave ratio ≤3.

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