CN219349033U - Leakage cable monitoring system - Google Patents

Abstract

The utility model relates to a cable leakage monitoring system which comprises a cable leakage unit, a combining unit, a service signal unit, a monitoring unit, a site management unit, a transmission unit, a server unit and a network management unit, wherein the cable leakage unit is connected with the combining unit; the service signal unit and the monitoring unit are mutually and independently arranged at the upstream of the combining unit and are respectively connected with the combining unit; the field management unit is respectively connected with the monitoring unit and the transmission unit; the transmission unit is respectively connected with the site management unit and the server unit; the network management unit is arranged on the server unit and is connected with the server unit. The method has the advantages that the monitoring unit monitors the leaky cable unit, and the fault and the occurrence position are accurately and timely judged according to the electromagnetic wave loss time domain and frequency domain conversion method; the setting of the combining unit can ensure that the access monitoring unit monitors the leaky cable without influencing the service signal transmission of the service signal unit.

Description

Leakage cable monitoring system

Technical Field

The utility model relates to the technical field of traffic communication, in particular to a cable leakage monitoring system.

Background

The leaky cable is a leaky coaxial cable for short, and the structure consists of an inner conductor, an insulating medium and an outer conductor with a periodical slot hole. Electromagnetic waves radiate to the outside through the slotted holes while being longitudinally transmitted in the leaky cable; the external electromagnetic field can also be induced into the leakage cable through the slotted hole and transmitted to the receiving end.

The importance of the leaky cable is as follows: 1. urban rail transit and railways mostly adopt leaky coaxial cables to carry out wireless communication coverage of tunnel/track area; 2. the leaky cable is an important carrier for wireless communication such as subway special communication, public security fire control and the like, and communication interruption is caused by the failure of the leaky cable, so that the operation safety of the subway is influenced; 3. and the train signal control ensures important equipment for train-ground data interaction, and sudden faults and signal interruption can cause driving safety accidents.

According to the actual operation condition of a plurality of rail transit after being opened, the system is deeply researched from the aspects of system design, operation maintenance, engineering realization and the like, and the leakage cable performance is found to have important influence on the safe operation of the communication network in the daily operation maintenance of the railway communication network. Because of long-time operation, the joints and jumpers connected with part of the leaky cables start to enter multiple fault periods, such as the faults of dragging, crush injury, skin damage, deformation, excessive bending, skin scratch, corrosion and the like during installation. However, due to practical difficulty in maintenance, such as limitation of factors such as long tunnel and window time, some faults are difficult to find in time, and interruption of communication and vehicle-ground data interaction is caused, so that driving safety is endangered. Therefore, it is important to monitor the leaky cable.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model aims to provide a leaky cable monitoring system so as to solve the technical problems that after the rail transit runs for a long time, a part of joints and jumpers connected with leaky cables start to enter a fault multiple-occurrence stage, but due to the limitation of factors such as long tunnels and window time, some faults are difficult to be found in time, and the communication and train-ground data interaction are interrupted, so that the running safety is endangered.

The above object of the present utility model is achieved by the following technical solutions:

the utility model provides a leaky cable monitoring system which is applied to rail transit and used for monitoring a fault area of a leaky cable, and comprises a leaky cable unit, a combining unit, a service signal unit, a monitoring unit, a field management unit, a transmission unit, a server unit and a network management unit, wherein:

the cable leakage unit is arranged at the downstream of the combining unit and is connected with the combining unit;

the service signal unit and the monitoring unit are arranged on the upstream of the combining unit independently and are connected with the combining unit respectively;

the field management unit is arranged between the monitoring unit and the transmission unit and is respectively connected with the monitoring unit and the transmission unit;

the transmission unit is arranged between the site management unit and the server unit and is respectively connected with the site management unit and the server unit;

the network management unit is arranged on the server unit and is connected with the server unit.

As some of these embodiments, the leaky cable unit includes a number of leaky cables.

As some embodiments thereof, the combining unit includes:

the first signal module is connected with the monitoring unit;

the second signal module is connected with the service signal unit;

the isolation module is arranged between the first signal module and the second signal module and is used for isolating the signals transmitted by the monitoring unit from the signals of the service signal unit;

and the third signal module is connected with the leaky cable unit.

As some of these embodiments, the monitoring unit includes:

the signal receiving and transmitting module is connected with the combining unit and is used for transmitting a test signal, and the combining unit tests the cable leakage unit and receives a reflected signal of the cable leakage unit from the combining unit;

and the calculating module is connected with the signal receiving and transmitting module and is used for measuring and calculating parameters of the reflected signals.

As some embodiments, the test signal frequency band of the monitoring unit is 1645 MHz-1685 MHz, and the test signal frequency band of the service signal unit is 1785 MHz-1805 MHz.

In summary, the beneficial technical effects are as follows:

the monitoring unit monitors the cable leakage unit, and accurately and timely judges faults and occurrence positions according to the electromagnetic wave loss time domain and frequency domain conversion method, so that interruption risks of communication and vehicle-ground data interaction are reduced, and driving safety is ensured; the setting of the combining unit can ensure that the access monitoring unit monitors the leaky cable without influencing the service signal transmission of the service signal unit.

Drawings

FIG. 1 is a block diagram of a leaky cable monitoring system in an embodiment of the utility model;

fig. 2 is a schematic connection diagram of a cable monitoring system according to an embodiment of the utility model.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application; it is apparent that the described embodiments are only a part of the embodiments of the present application, not all of the embodiments, and all other embodiments obtained by a person having ordinary skill in the art without making creative efforts based on the embodiments in the present application are within the scope of protection of the present application.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "top/bottom", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "configured to," "engaged with," "connected to," and the like are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

Examples

As shown in fig. 1-2, the disclosed leaky cable monitoring system is applied to rail transit and is used for monitoring a fault area of a leaky cable and comprises a leaky cable unit, a combining unit, a service signal unit, a monitoring unit, a field management unit, a transmission unit, a server unit and a network management unit, wherein the leaky cable unit is arranged at the downstream of the combining unit and is connected with the combining unit; the service signal unit and the monitoring unit are mutually and independently arranged at the upstream of the combining unit and are respectively connected with the combining unit; the field management unit is arranged between the monitoring unit and the transmission unit and is respectively connected with the monitoring unit and the transmission unit; the transmission unit is arranged between the field management unit and the server unit and is respectively connected with the field management unit and the server unit; the network management unit is arranged on the server unit and is connected with the server unit.

The leaky cable unit comprises a plurality of leaky cables.

The service signal unit of the system transmits wireless communication services of public security/fire control, government network, passenger broadcasting, mobile/communication/telecommunication through the cable leakage unit.

As some of these embodiments, the traffic signal unit is an LTE system.

The electromagnetic wave is transmitted through the leaky cable, attenuation is generated along with the transmission distance, characteristic setting monitoring units are arranged on the characteristics that characteristic impedance is generated at fault points and electromagnetic wave reflection occurs, the output ends of the monitoring units emit electromagnetic waves with specified frequency bands, the electromagnetic waves propagate along the leaky cable, return loss data in a frequency domain range are received when the leaky cable breaks down, return loss data and propagation speed in a time domain are calculated, return loss data in a distance domain are obtained, and the fault position is accurately located.

Specifically, the monitoring unit is installed in the track district, and the monitoring host computer of monitoring unit is the protection level: IP65, fault location accuracy: + -1 m, maximum output power: characteristic impedance of 6 dBm: 50 ohm, effective measurement distance: less than 2 km, standing wave ratio maximum error: 0.1, maximum power consumption: 20W, stray emission: less than or equal to-100 dBm, polling interval: freely set, test frequency: 600-6G is adjustable.

Further, the monitoring unit comprises a signal receiving and transmitting module and a calculating module. The signal receiving and transmitting module is connected with the combining unit and is used for transmitting a test signal, the combining unit tests the leaky cable unit and receiving a reflected signal of the leaky cable unit from the combining unit; the calculating module is connected with the signal receiving and transmitting module and is used for measuring and calculating parameters of the reflected signals.

Standing wave ratio	Transmission loss
		1.0	0.00%
1.1	0.23%
		1.2	0.83
1.3	1.70%
		1.5	4.00%
1.7	6.72%
		2.0	11.11%
2.5	18.37%
		3.0	25.00%
4.0	36.00%
		5.0	44.44%
7.0	56.25%
		10	66.94%
15	76.56%
		20	81.86%

The signal receiving and transmitting module transmits electromagnetic waves with specified frequency bands, the electromagnetic waves propagate along the leaky cable, when the leaky cable fails, return loss data in a frequency domain range is received, reflection is generated at points or areas with changed medium characteristics, and the calculation module measures and calculates the return loss data of the intensity, waveform, time delay, frequency domain, time domain and distance domain of the reflected signals, so that the failure and the failure position are judged.

The combining unit of the system combines the monitoring signal from the monitoring unit with the service signal of the service signal unit and then sends the combined monitoring signal and the service signal into the cable leakage unit, so that low insertion loss and no interference can be realized, the monitoring signal and the service signal are mutually independent, and no influence is caused on the service signal.

Specifically, the combining unit is a combiner, and the protection level of the combiner is: IP65, input loss: less than or equal to 0.3dB, standing wave ratio: load power is less than or equal to 1.3: and is more than or equal to 200W.

Further, the combining unit comprises a first signal module, a second signal module, an isolation module and a third signal module. The first signal module is connected with the monitoring unit; the second signal module is connected with the service signal unit; the isolation module is arranged between the first signal module and the second signal module and is used for isolating the signal transmitted by the monitoring unit from the signal of the service signal unit; the third signal module is connected with the leaky cable unit.

Further, the test signal frequency band of the monitoring unit is 1645 MHz-1685 MHz, and the test signal frequency band of the service signal unit is 1785 MHz-1805 MHz.

The service signal of the service signal unit and the test signal of the monitoring unit are connected into the cable leakage unit after being combined by the combining unit, the isolation module provides enough signal isolation, the insertion loss is less than or equal to 0.3dB, and the condition that the service signal of the service signal unit is not influenced by the connection of the monitoring unit is ensured.

The field management unit is configured as a FAU used by 1 centralized station, is configured in a machine room, gathers field monitoring data, and transmits the field monitoring data to the server unit through the transmission unit to be supervised by the network management unit.

Wherein the transmission unit is a signal and communication transmission network.

The server unit is a central management server, and the network management unit is an NMSOMC network management.

The system has the following functions:

1. and monitoring the health state of the leakage cable and the equipment in real time on line, displaying and recording key index conditions and alarm information.

2. And (5) monitoring the return loss and standing wave value of the whole leaky cable and the link on line.

3. And (3) comprehensively analyzing various indexes of the leaky cable, and performing degradation early warning, fault classification and grading warning.

4. Fault location analysis, positioning accuracy + -1 m.

5. The system user management, configuration management and data backup can carry out statistics processing on the equipment operation data to generate various statistical reports, and the system user management, configuration management and data backup are convenient to view.

The advantages of the system are utilized:

and judging faults and occurrence positions according to the conversion method of the electromagnetic wave loss time domain and the frequency domain. Compared with the traditional TDR time domain reflection measurement technology, the method has the advantages of high measurement precision and larger dynamic range.

The embodiments of the present utility model are all preferred embodiments of the present utility model, and the scope of the present utility model is not limited thereby, and the embodiments can be combined with each other for use, so: all equivalent changes in structure, shape and principle of the utility model should be covered in the scope of protection of the utility model.

Claims (5)

1. The utility model provides a leak cable monitoring system, is applied to in the track traffic, monitors the trouble area of leak cable, its characterized in that includes leak cable unit, closes way unit, service signal unit, monitoring unit, on-the-spot management unit, transmission unit, server unit and network management unit, wherein:

the cable leakage unit is arranged at the downstream of the combining unit and is connected with the combining unit;

the service signal unit and the monitoring unit are arranged on the upstream of the combining unit independently and are connected with the combining unit respectively;

the field management unit is arranged between the monitoring unit and the transmission unit and is respectively connected with the monitoring unit and the transmission unit;

the transmission unit is arranged between the site management unit and the server unit and is respectively connected with the site management unit and the server unit;

the network management unit is arranged on the server unit and is connected with the server unit.

2. The leaky cable monitoring system of claim 1, wherein the leaky cable unit includes a number of leaky cables.

3. The leaky cable monitoring system of claim 1, wherein the combining unit comprises:

the first signal module is connected with the monitoring unit;

the second signal module is connected with the service signal unit;

the isolation module is arranged between the first signal module and the second signal module and is used for isolating the signals transmitted by the monitoring unit from the signals of the service signal unit;

and the third signal module is connected with the leaky cable unit.

4. The leaky cable monitoring system of claim 1, wherein the monitoring unit comprises:

the signal receiving and transmitting module is connected with the combining unit and is used for transmitting a test signal, and the combining unit tests the cable leakage unit and receives a reflected signal of the cable leakage unit from the combining unit;

and the calculating module is connected with the signal receiving and transmitting module and is used for measuring and calculating parameters of the reflected signals.

5. The leaky cable monitoring system according to claim 1, wherein the test signal frequency band of the monitoring unit is 1645 mhz-1685 mhz, and the test signal frequency band of the service signal unit is 1785 mhz-1805 mhz.

Images