Rail transit anti-interference communication system and device

Abstract

The present application belongs to the field of rail transit anti-interference communication technology, and relates to a rail transit anti-interference communication system and device. The system comprises a vehicle-mounted communication subsystem and a ground communication subsystem fixed on both sides of the track. The vehicle-mounted communication subsystem comprises a vehicle-mounted antenna and a vehicle-mounted transceiver. The ground communication subsystem comprises a base station antenna and a base station transceiver. A vehicle-mounted shunt impedance dissipation module is connected in series between the vehicle-mounted antenna and the vehicle-mounted transceiver. A base station shunt impedance dissipation module is connected in series between the base station antenna and the base station transceiver. The shunt impedance dissipation module comprises a signal main path and multiple levels of impedance dissipation branches connected in parallel on the signal main path. The effect is that the over-impedance mismatch effect guides the traction harmonic to deviate from the signal main path and enter the corresponding dissipation branch to be converted into heat energy dissipation. The effective communication signal in the working frequency band can be normally transmitted along the main path to achieve interference suppression.

Description

Technical Field

[0001] This invention belongs to the field of anti-interference communication technology for rail transit, and particularly relates to an anti-interference communication system and device for rail transit. Background Technology

[0002] During the operation of rail transit vehicles, the on-board traction converter continuously generates multi-band traction harmonics, which mix into the vehicle-to-ground communication radio frequency lines, interfering with the stable transmission of data.

[0003] Current solutions for reducing traction harmonics include active digital cancellation devices and fixed LC passive filter circuits.

[0004] Active digital cancellation devices require a computing chip, external power supply, and supporting control program. Under conditions of vehicle vibration and temperature changes, hardware failures and program malfunctions can easily occur, resulting in signal processing delays. Fixed LC passive filter circuits rely on resonance principles to block interference and can filter harmonic frequency bands within a fixed range. However, when changes in traction conditions cause harmonic frequency shifts, resonance peaks appear, amplifying some frequency band interference signals and interfering with normal signal transmission. Summary of the Invention

[0005] The objective of this invention is to provide a rail transit anti-interference communication system and device that solves the technical problems of low reliability of existing active filtering schemes and poor adaptability and easy resonance of passive filtering schemes.

[0006] The embodiments of the present invention are implemented as follows: An anti-interference communication system for rail transit includes an on-board communication subsystem and a ground communication subsystem fixed on both sides of the track. The on-board communication subsystem includes an on-board antenna and an on-board transceiver. The ground communication subsystem includes a base station antenna and a base station transceiver. An on-board shunt impedance dissipation module is connected in series between the on-board antenna and the on-board transceiver. A base station shunt impedance dissipation module is connected in series between the base station antenna and the base station transceiver. The shunt impedance dissipation module includes a main signal path and multiple impedance dissipation branches connected in parallel to the main signal path. Each impedance dissipation branch corresponds to a traction harmonic interference of a preset frequency band. Through impedance mismatch, the interference signal of the corresponding frequency band is deviated from the main signal path and shunt to the dissipation branch of this level. It is converted into heat dissipation in the dissipation branch, while the effective communication signal in the working frequency band is transmitted along the main signal path.

[0007] Each impedance dissipation branch includes a coupling capacitor. One end of the coupling capacitor is connected to the main signal path, and the other end is connected to one end of the dissipation resistor. The other end of the dissipation resistor is connected to the common ground terminal. The coupling capacitors of each level of impedance dissipation branch correspond to the traction harmonics of different frequency bands.

[0008] The multi-stage impedance dissipation branches are arranged sequentially along the main signal path in order of frequency band from low to high, so that the traction harmonics are successively diverted and consumed from low to high.

[0009] The main signal path is equipped with corresponding module slots. Each level of dissipation branch module is connected in parallel to the main signal path through the slots, so as to facilitate the replacement of branch modules with corresponding parameters according to the traction harmonic characteristics of the line.

[0010] The grounding terminal of the on-board shunt impedance dissipation module is connected to the train body grounding system, and the heat and residual interference energy generated by the impedance dissipation branch are released through the train body grounding system. The grounding terminal of the base station shunt impedance dissipation module is connected to the track grounding system.

[0011] The shunt impedance dissipation module includes a signal input port and a signal output port connected to the main signal path at both ends, and a multi-stage dissipation branch connected in parallel to the main signal path; a fine-tuning inductor is connected in series in the main signal path; each stage of the dissipation branch is composed of a coupling capacitor and a dissipation resistor connected in series, and the capacitance of each stage of the coupling capacitor is different.

[0012] An anti-interference communication device for rail transit includes a sealed metal housing, the metal housing being provided with an input coupling port, an output communication port, a main signal path, a multi-stage impedance dissipation branch, and a grounding dissipation terminal; The input coupling port and the output communication port are fixed to the side wall of the sealed metal housing, and the main signal path is set inside the sealed metal housing. The two ends of the main signal path are respectively connected to the input coupling port and the output communication port. The multi-stage impedance dissipation branches are connected in parallel on the main signal path. Each stage of impedance dissipation branch corresponds to a traction harmonic of a preset frequency band. Through impedance mismatch, the interference signal of the corresponding frequency band is diverted to the branch and converted into heat dissipation. The grounding dissipation terminal is disposed on a sealed metal housing, and the ends of the impedance dissipation branches are all connected to the grounding dissipation terminal.

[0013] The multi-stage impedance dissipation branches are arranged sequentially along the main signal path, with the impedance parameters of each branch changing progressively. Each of the multi-stage impedance dissipation branches is equipped with a shunt impedance dissipation module. The shunt impedance dissipation module includes a signal input port and a signal output port that are respectively connected to the main signal path. A fine-tuning inductor is connected in series in the main signal path for calibrating the impedance matching of the working frequency band. Each stage of impedance dissipation branch is composed of a coupling capacitor and a dissipation resistor connected in series, and the capacitance of the coupling capacitors at each stage is different.

[0014] The sealed metal housing is equipped with module slots, and each impedance dissipation branch is equipped with a plug. The plugs are inserted into the slots to achieve parallel connection with the main signal path.

[0015] The sealed metal housing is made of aluminum alloy. The inner wall of the sealed metal housing is provided with an insulating and heat-conducting module corresponding to the installation position of the impedance dissipation branch. The insulating and heat-conducting module and the dissipation resistor in the dissipation branch are connected by plugging.

[0016] The positive effects of this invention are: By guiding traction harmonics away from the main signal path through impedance mismatch, they enter the corresponding dissipation branch and are converted into heat dissipation. The effective communication signal within the operating frequency band can be transmitted normally along the main path, thus achieving interference suppression. The shunt impedance dissipation module is composed of passive components such as resistors and capacitors, requiring no external power supply line and not involving computing chips or control programs. There is no risk of program crashes or chip failures in operating environments with strong vehicle vibration and temperature fluctuations, and the signal transmission process reduces delay. Unlike traditional resonant filter structures, when the traction harmonic frequency dynamically shifts with operating conditions, no additional resonance peaks are generated, thus avoiding the problem of interference signals being amplified. It can adapt to the dynamic changes of multi-band traction harmonics during line operation.

[0017] The module is connected in series on the feeder path between the antenna and the transceiver, serving only as a passive adapter for connection to the line. During on-site installation, no modifications to the existing hardware structure and built-in programs of the vehicle-mounted or base station communication equipment are required; it can be put into operation after completing the feeder connector and grounding connection. The impedance dissipation branch adopts a slot-plug structure. To address differences in harmonic distribution across different lines, maintenance personnel can individually replace the corresponding branch unit to achieve parameter adaptation without disassembling and replacing the entire module. The device housing uses a die-cast aluminum alloy sealed structure, providing both electromagnetic shielding and heat conduction. Heat generated by branch dissipation can be dissipated outwards through the housing, making it suitable for trackside and vehicle-mounted outdoor installation environments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the architecture of a rail transit anti-interference communication system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal circuit structure of the shunt impedance dissipation module provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal cross-sectional structure of the rail transit anti-interference communication device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the overall external structure of the rail transit anti-interference communication device provided in an embodiment of the present invention.

[0019] Legend: 1—Vehicle-mounted antenna; 2—Vehicle-mounted transceiver; 3—Vehicle-mounted shunt impedance dissipation module; 4—Base station antenna; 5—Base station transceiver; 6—Base station shunt impedance dissipation module; 7—Main signal path; 8—Impedance dissipation branch; 9—Coupling capacitor; 10—Dissipation resistor; 11—Fine-tuning inductor; 12—Module slot; 13—Sealed metal housing; 14—Input coupling port; 15—Output communication port; 16—Grounding dissipation terminal; 17—Insulation and heat conduction module. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments: In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] Example 1 An anti-interference communication system for rail transit includes an onboard communication subsystem fixed to a vehicle and a ground communication subsystem fixed to the trackside. The onboard communication subsystem includes an onboard antenna 1 and an onboard transceiver 2, with an onboard shunt impedance dissipation module 3 connected in series in the feeder lines of the onboard antenna 1 and the onboard transceiver 2. The ground communication subsystem includes a base station antenna 4 and a base station transceiver 5, with a base station shunt impedance dissipation module 6 connected in series in the feeder lines of the base station antenna 4 and the base station transceiver 5.

[0023] The vehicle-mounted shunt impedance dissipation module 3 and the base station shunt impedance dissipation module 6 use the same circuit, with only the grounding terminal connected to the train body grounding system and the track grounding system respectively. They can simultaneously shunt and dissipate traction harmonics in the two-way communication lines of the vehicle and the track, thereby achieving interference suppression.

[0024] The shunt impedance dissipation module includes a main signal path 7, which is a rigid conductor trace fixed on an insulating support substrate. The two ends of the main signal path are connected to the signal input port and the signal output port, respectively, forming the main transmission line of the radio frequency signal. Along the signal transmission direction of the main signal path 7, there are multiple levels of impedance dissipation branches 8 connected in parallel. Each level of impedance dissipation branch 8 corresponds to a preset traction harmonic frequency band. Each level of impedance dissipation branch 8 is composed of a coupling capacitor 9 and a dissipation resistor 10 connected in series. One end of the coupling capacitor 9 is connected to the main signal path 7, and the other end is connected to the dissipation resistor 10. The ends of the dissipation resistor 10 are all connected to the common ground terminal. The coupling capacitors 9 of each impedance dissipation branch 8 have different capacitance values, which vary step by step to distinguish their corresponding harmonic frequency bands. Traction harmonics of different frequencies can be diverted by the corresponding branches.

[0025] In actual operation, the radio frequency signal, which mixes traction harmonics and effective communication signals, enters the main signal path 7 from the input terminal and is transmitted forward. When the signal flows through the access point of a certain stage impedance dissipation branch 8, if the signal frequency falls into the harmonic frequency band corresponding to that branch, the coupling capacitor 9 exhibits low impedance characteristics for that frequency band. The main signal path 7 forms a local impedance mismatch at this point, and the harmonic signal of the corresponding frequency band deviates from the main transmission path and is diverted into the impedance dissipation branch 8 of this stage. When flowing through the dissipation resistor 10, the electrical energy is converted into heat energy and released outward through the grounding terminal and the heat-conducting structure, thereby dissipating and eliminating interference energy. For the effective communication signal within the operating frequency band, the coupling capacitors 9 at each stage exhibit high impedance characteristics, the main signal path 7 remains in a matched state, the effective signal is not diverted by the branch, and continues to be transmitted backward along the main signal path 7 to the transceiver end, ensuring that normal communication is not affected.

[0026] Since the entire shunt impedance dissipation module consists only of passive components such as capacitors, resistors, and inductors, without external power supply lines or processing chips and control programs, there is no risk of program crashes or chip failures under conditions of vehicle vibration and fluctuating ambient temperature, and no additional processing delays are introduced. Furthermore, this system does not rely on resonant frequency selection to block interference; the branch structure does not contain resonant circuits composed of inductors and capacitors, thus avoiding the formation of fixed resonant peaks. When changes in traction conditions cause dynamic shifts in harmonic frequencies, the capacitive reactance of coupling capacitor 9 only changes smoothly with the frequency, and the shunt ratio of the corresponding branch increases or decreases accordingly, affecting the harmonic dissipation efficiency. This avoids the impedance abrupt changes and signal reflection amplification problems that occur in resonant filtering when the frequency deviates from the resonant point, thus adapting to the dynamic changes in multi-band traction harmonics during line operation.

[0027] The multi-stage impedance dissipation branch 8 is arranged sequentially along the transmission direction of the main signal path 7, in order of increasing frequency band. Harmonics are dissipated step by step in order of increasing frequency, which can avoid the reflection and superposition of harmonics of different frequency bands in the path, and further improve the stability of interference suppression and overall dissipation efficiency.

[0028] A fine-tuning inductor 11 is also connected in series in the main signal path 7. The overall impedance matching degree of the working frequency band can be calibrated by adjusting the inductor parameters, thereby reducing the insertion loss of effective communication signals and ensuring the transmission efficiency and signal quality of normal communication.

[0029] On the main signal path 7, at the corresponding position of each stage of impedance dissipation branch 8, a module slot 12 is provided. The module slot 12 has a built-in elastic conductive contact. The end of the impedance dissipation branch 8 is provided with a corresponding plug. By plugging the plug into the module slot 12, electrical parallel connection with the main signal path 7 can be achieved. When facing the differences in traction harmonic distribution of different lines, or when the harmonic characteristics change after the line operating conditions are adjusted, the maintenance personnel can directly unplug the impedance dissipation branch 8 with the corresponding parameters and replace it with an impedance dissipation branch 8 that matches the new frequency band. There is no need to disassemble and replace the entire dissipation module. The parameter adjustment is more flexible and the maintenance cost is lower.

[0030] In terms of system grounding settings, the common grounding terminal of the on-board shunt impedance dissipation module 3 is connected to the train body grounding system, and the heat and residual interference energy generated by the branch dissipation can be fully released through the vehicle body grounding system; the common grounding terminal of the base station shunt impedance dissipation module 6 is connected to the track grounding system, and the energy is released by relying on the trackside grounding equipment to ensure the stability and safety of the module operation.

[0031] Example 2 An anti-interference communication device for rail transit integrates an on-board shunt impedance dissipation module 3 or a base station shunt impedance dissipation module 6 into a sealed metal housing 13, forming an independent standardized device. The sealed metal housing 13 is integrally formed by die-casting of aluminum alloy. The side wall of the housing is fixed with an input coupling port 14 and an output communication port 15 through a flange structure. Both ports use standard radio frequency coaxial connectors, which can be directly connected to existing communication feeders and are compatible with common radio frequency feeder specifications. The two ends of the main signal path 7 inside the housing are respectively connected to the input coupling port 14 and the output communication port 15. Multi-stage impedance dissipation branches 8 are connected in parallel on the main signal path 7. The grounding terminals of all dissipation branches are uniformly connected to the grounding dissipation terminal 16. The grounding dissipation terminal 16 penetrates the side wall or bottom of the sealed metal housing 13. An insulating seal is installed between the grounding dissipation terminal 16 and the metal housing 13 to ensure the overall sealing and shielding performance of the housing and realize the electrical insulation lead-out of the grounding terminal for external field grounding system.

[0032] The interior of the sealed metal housing 13 is a hollow mounting cavity. An insulating and heat-conducting module 17 is fixed to the inner wall of the cavity corresponding to the mounting position of each impedance dissipation branch 8. The insulating and heat-conducting module 17 is made of a material with both insulating and heat-conducting properties. One side of the insulating and heat-conducting module 17 is tightly fitted and fixed to the inner wall of the housing, while the other side has a insertion slot adapted to the shape of the dissipation resistor 10. The inner wall contour of the insertion slot matches the outer wall contour of the dissipation resistor 10. The main signal path 7 and the module slot 12 are fixed to the support structure at the bottom of the cavity. The opening direction of the insertion slot is consistent with the insertion direction of the module slot 12. When the impedance dissipation branch 8 is inserted into the slot, the dissipation resistor 10 on the impedance dissipation branch 8 is simultaneously embedded into the insertion slot of the insulating and heat-conducting module 17. The outer wall of the impedance dissipation branch 8 and the inner wall of the slot of the insulating and heat-conducting module 17 are tightly fitted, forming a reliable heat-conducting mating surface.

[0033] During operation, the heat generated by the dissipation resistor 10 is transferred to the insulating heat-conducting module 17 through the contact surface, and then transferred by the insulating heat-conducting module 17 to the sealed metal housing 13. The heat is released to the outside through the outer surface of the sealed metal housing 13, which can regulate the operating temperature of the internal components of the sealed metal housing 13. When the impedance dissipation branch 8 is replaced, the dissipation resistor 10 is pulled out from the insertion slot of the insulating heat-conducting module 17 along with the impedance dissipation branch 8, and the insulating heat-conducting module 17 remains on the inner wall of the housing.

[0034] Meanwhile, the aluminum alloy sealed housing can form a complete electromagnetic shielding layer, which can not only block the interference of the complex external electromagnetic environment on the sealed metal housing 13, but also prevent the internal signals of the sealed metal housing 13 from leaking outward.

[0035] When installing and using this communication device in the field, simply connect the input coupling port 14 to the antenna side via a feeder, connect the output communication port 15 to the transceiver side via a feeder, and then connect the grounding dissipation terminal 16 to the corresponding field grounding system to complete the installation and put it into operation.

[0036] The foregoing has broadly outlined some aspects and features of the various embodiments and should be interpreted as merely illustrative of potential applications. Other beneficial results can be obtained by applying the disclosed information in different ways or by combining aspects of the disclosed embodiments. Further aspects and a more complete understanding can be obtained based on the detailed description of exemplary embodiments with reference to the accompanying drawings, within the scope defined by the claims.

[0037] The above embodiments provide a detailed description of the present invention. Of course, the above description is not intended to limit the present invention, nor is the present invention limited to the examples described above. Any changes, modifications, additions, reductions, or substitutions made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.

Claims

1. A rail transit anti-interference communication system, comprising an onboard communication subsystem and a ground communication subsystem fixed on both sides of the track, wherein the onboard communication subsystem includes an onboard antenna and an onboard transceiver, and the ground communication subsystem includes a base station antenna and a base station transceiver, characterized in that: A vehicle-mounted antenna and a vehicle-mounted transceiver are connected in series with a vehicle-mounted shunt impedance dissipation module, and a base station antenna and a base station transceiver are connected in series with a base station shunt impedance dissipation module. The shunt impedance dissipation module includes a main signal path and multiple impedance dissipation branches connected in parallel to the main signal path. Each impedance dissipation branch corresponds to a traction harmonic interference of a preset frequency band. Through impedance mismatch, the interference signal of the corresponding frequency band is deviated from the main signal path and shunt to the dissipation branch of this level. It is converted into heat dissipation in the dissipation branch, while the effective communication signal in the working frequency band is transmitted along the main signal path.

2. The anti-interference communication system for rail transit according to claim 1, characterized in that, Each impedance dissipation branch includes a coupling capacitor. One end of the coupling capacitor is connected to the main signal path, and the other end is connected to one end of the dissipation resistor. The other end of the dissipation resistor is connected to the common ground terminal. The coupling capacitors of each level of impedance dissipation branch correspond to the traction harmonics of different frequency bands.

3. The anti-interference communication system for rail transit according to claim 1, characterized in that, The multi-stage impedance dissipation branches are arranged sequentially along the main signal path in order of frequency band from low to high, so that the traction harmonics are successively diverted and consumed from low to high.

4. The anti-interference communication system for rail transit according to claim 1, characterized in that, The main signal path is equipped with corresponding module slots. Each level of dissipation branch module is connected in parallel to the main signal path through the slots, so as to facilitate the replacement of branch modules with corresponding parameters according to the traction harmonic characteristics of the line.

5. The rail transit anti-interference communication system according to claim 1, characterized in that, The grounding terminal of the on-board shunt impedance dissipation module is connected to the train body grounding system, and the heat and residual interference energy generated by the impedance dissipation branch are released through the train body grounding system. The grounding terminal of the base station shunt impedance dissipation module is connected to the track grounding system.

6. The anti-interference communication system for rail transit according to claim 1, characterized in that, The shunt impedance dissipation module includes a signal input port and a signal output port connected to the main signal path at both ends, and a multi-stage dissipation branch connected in parallel to the main signal path; a fine-tuning inductor is connected in series in the main signal path; each stage of the dissipation branch is composed of a coupling capacitor and a dissipation resistor connected in series, and the capacitance of each stage of the coupling capacitor is different.

7. A rail transit anti-interference communication device, characterized in that, It includes a sealed metal housing, which is equipped with an input coupling port, an output communication port, a main signal path, a multi-stage impedance dissipation branch, and a grounding dissipation terminal; The input coupling port and the output communication port are fixed to the side wall of the sealed metal housing, and the main signal path is set inside the sealed metal housing. The two ends of the main signal path are respectively connected to the input coupling port and the output communication port. The multi-stage impedance dissipation branches are connected in parallel on the main signal path. Each stage of impedance dissipation branch corresponds to a traction harmonic of a preset frequency band. Through impedance mismatch, the interference signal of the corresponding frequency band is diverted to the branch and converted into heat dissipation. The grounding dissipation terminal is disposed on a sealed metal housing, and the ends of the impedance dissipation branches are all connected to the grounding dissipation terminal.

8. The anti-interference communication device for rail transit according to claim 7, characterized in that, The multi-stage impedance dissipation branches are arranged sequentially along the main signal path, with the impedance parameters of each branch changing progressively. Each of the multi-stage impedance dissipation branches is equipped with a shunt impedance dissipation module. The shunt impedance dissipation module includes a signal input port and a signal output port that are respectively connected to the main signal path. A fine-tuning inductor is connected in series in the main signal path for calibrating the impedance matching of the working frequency band. Each stage of impedance dissipation branch is composed of a coupling capacitor and a dissipation resistor connected in series, and the capacitance of the coupling capacitors at each stage is different.

9. The anti-interference communication device for rail transit according to claim 7, characterized in that, The sealed metal housing is equipped with module slots, and each impedance dissipation branch is equipped with a plug. The plugs are inserted into the slots to achieve parallel connection with the main signal path.

10. The anti-interference communication device for rail transit according to claim 7, characterized in that, The sealed metal housing is made of aluminum alloy. The inner wall of the sealed metal housing is provided with an insulating and heat-conducting module corresponding to the installation position of the impedance dissipation branch. The insulating and heat-conducting module and the dissipation resistor in the dissipation branch are connected by plugging.

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