Leaky coaxial cable fault positioning method and system based on differential received signal strength

Abstract

The invention provides a leaky coaxial cable fault positioning method and system based on differential received signal strength, and the method comprises the steps: analyzing common faults of a leaky coaxial cable and the influence of the common faults on the received signal strength in combination with the distribution of wireless base stations and the transmission characteristics of the leaky coaxial cable; the method comprises the following steps: detecting the received signal strength of a leaky coaxial cable in real time by using a mobile terminal, carrying out equidistant sampling according to train position information, or sampling at equal time intervals when no position information exists, and uploading the current received signal strength information to an operation and maintenance center; the operation and maintenance center carries out differential processing on the collected signal intensity data, and the signal level attenuation rate is kept constant under the fault-free condition; and when the fault occurs, the signal level attenuation rate is obviously changed at the fault point, so that accurate fault positioning is realized. According to the invention, the construction and maintenance cost of leaky coaxial cable fault detection equipment can be obviously reduced, and the precision and efficiency of leaky coaxial cable fault positioning are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail transit, and in particular relates to a leaky cable fault locating method and system based on differential received signal strength. Background Art

[0002] At present, it has become an important task to determine the cause of the leaky cable failure and locate the fault section. For example, in order to ensure the safe operation of the railway system, the leaky cable is usually installed at a high place and straightened to prevent the leaky cable from collapsing, so it is often subjected to a large tensile force, which can easily break the core wire of the leaky cable; the humid environment of the tunnel will cause the inner conductor and the outer conductor of the leaky cable to corrode. The characteristic impedance of the leaky cable will become very small, resulting in the failure of most signals to be transmitted normally; the length of the railway tunnel is long, and the laying of the leaky cable is sometimes very complicated. Due to improper operation or irregular installation by workers, the connection accessories of the leaky cable will be loose and the connection will become loose; the leaky cable is mainly fixed by professional clamps in the railway operation system. Because the clamps are subjected to long-term vibration when the train passes, and are also used in harsh environments for a long time, they are prone to aging, causing the clamps to loosen and fall off, causing the leaky cable to fall, which will seriously affect the safe operation of the railway.

[0003] At present, the main methods for locating leaky cable faults include: (1) Pure manual inspection to detect leaky cable faults. This method has a large workload and low work efficiency. The inspection quality is difficult to guarantee. The work has safety hazards and is highly dangerous. (2) Video acquisition and playback inspection. The detection quality of this method is difficult to guarantee, and the storage device utilization rate is low. (3) Leaky cable fault location method based on time domain reflection method. When a pulse signal propagates in the cable medium and encounters impedance mismatch, partial or full reflection will occur. By observing the time difference between the reflected signal and the incident signal, the distance between the cable fault point and the test point is calculated under the condition of constant speed. This method will affect the selection of fault detection signals due to the transmission attenuation characteristics of the leaky cable and the existence of a fault test blind area. The operation of the required inspection instrument is complicated, and the failure rate and maintenance cost are high. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a leaky cable fault location method and system based on differential received signal strength.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] On one hand, the present invention provides a leaky cable fault location method based on differential received signal strength, comprising the following steps:

[0007] Step S1: When there is no fault in the leaky cable, a leaky cable signal strength curve under normal conditions is drawn in combination with the leaky cable installation data and the distance between base stations;

[0008] Step S2: generating a leaky cable normal signal strength attenuation rate graph by performing a differential operation on the signal strength curve of the leaky cable in a normal state;

[0009] Step S3: Detecting the actual signal strength of the leaky cable based on the mobile terminal;

[0010] Step S4: drawing a curve graph of actual leaky cable signal strength according to the actual signal strength of the leaky cable and the distance between base stations;

[0011] Step S5: generating an actual leaky cable signal strength attenuation rate graph through differential operation according to the actual leaky cable signal strength curve graph;

[0012] Step S6: Compare the actual leaky cable signal strength attenuation rate graph with the normal leaky cable signal strength attenuation rate graph, and determine the specific location of the leaky cable fault based on the similarities and differences between the two signal strength attenuation rate graphs within a unit distance.

[0013] Furthermore, the step S1 specifically includes the following steps:

[0014] Step S11: In the absence of a fault, using a dedicated measuring device, measure the signal strength along the entire length of the leaky cable between the two base stations at a first preset distance interval, and record the signal strength value of each measuring point;

[0015] Step S12: Analyze the influence of different environmental conditions on the signal by combining the collected data to determine the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station;

[0016] Step S13: according to the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station and the recorded signal strength value of each measuring point, a leaky cable signal strength curve under normal conditions is drawn to show the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station.

[0017] Furthermore, the signal strength value at each measuring point is a radiated wireless signal strength value of the leaky cable at the measuring point.

[0018] Furthermore, the step S2 specifically includes the following steps:

[0019] Step S21: Select the signal strength values ​​of two adjacent measuring points, calculate the difference, and divide it by the first preset distance to obtain the signal strength attenuation rate between the two measuring points;

[0020] Step S22: Arrange all calculated signal strength attenuation rates in order of distance from the base station to generate a leaky cable normal signal strength attenuation rate graph.

[0021] Furthermore, the mobile terminal includes a data acquisition module, a security encryption module and a data transmission module, and is installed on a train.

[0022] Furthermore, the step S3 specifically includes the following steps:

[0023] Step S31: Determine whether the location information of the train on which the mobile terminal is installed is known, if known, execute step S32, if unknown, execute step S33;

[0024] Step S32: When a train equipped with a mobile terminal passes by a leaky cable to be detected, the data acquisition module of the mobile terminal measures the signal strength of the leaky cable at a first preset distance interval according to the train position information, encrypts the measured data through the security encryption module, and sends the data to the operation and maintenance center through the data transmission module of the mobile terminal;

[0025] Step S33: When a train equipped with a mobile terminal passes by a leaky cable with a fault to be detected, the mobile terminal measures the signal strength of the leaky cable at the first preset time interval according to the maximum travel speed of the train in this time period, encrypts the measured data through a security encryption module, and then sends it to the operation and maintenance center through the data transmission module of the mobile terminal.

[0026] Furthermore, the data transmission module of the mobile terminal transmits the encrypted data to the operation and maintenance center through the 5G public and private network.

[0027] Furthermore, the step S4 specifically includes the following steps:

[0028] Step S41: The operation and maintenance center receives the data transmitted by the mobile terminal, decrypts it, and determines whether there is train location information. If yes, step S42 is executed; if no, step S43 is executed;

[0029] Step S42: according to the distribution of the leaky cable, the distance between the leaky cable and the base station, the position information of the train and the measured leaky cable signal strength data, a curve of the actual leaky cable signal strength under actual conditions is drawn in which the leaky cable signal strength changes with the distance between the leaky cable and the base station;

[0030] Step S43: Calculate and draw a curve of actual leaky cable signal strength versus distance based on the data sampled at equal time intervals and in combination with the maximum distance that the train may travel.

[0031] Furthermore, the specific location of the leaky cable fault is determined based on the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. When the signal strength attenuation rate at a certain unit distance is different, the section of the leaky cable fails. The actual location of the section of the leaky cable is calculated based on the distribution of the leaky cable and the distance between the leaky cable and the base station. The specific location of the leaky cable fault is determined based on the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. The specific location of the leaky cable fault is compared at the same location. The signal strength attenuation rate of the actual leaky cable in a certain location interval is different from the received signal strength attenuation rate of the leaky cable under normal conditions, thereby determining the leaky cable fault in the location interval.

[0032] Another aspect of the present invention provides a leaky cable fault location system based on differential received signal strength, comprising a mobile terminal and an operation and maintenance center;

[0033] The mobile terminal includes a data acquisition module, a security encryption module and a data transmission module. The data acquisition module is used to collect the signal strength of the leaky cable at different positions and select sampling intervals for equidistant or equal time interval sampling. The security encryption module is used to encrypt the collected data. The data transmission module is used to transmit the encrypted data to the operation and maintenance center through the 5G public and private network.

[0034] The operation and maintenance center is used to receive and decrypt data sent by the mobile terminal, and draw an actual leaky cable signal strength curve graph based on the data, generate an actual leaky cable signal strength attenuation rate graph, and determine the actual position of the faulty leaky cable based on the actual leaky cable signal strength attenuation rate graph and the leaky cable normal signal strength attenuation rate graph.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] (1) The present invention proposes a leaky cable fault location method based on differential received signal strength. By utilizing the radio wave propagation characteristics of the leaky cable, measuring the leaky cable signal strength and performing differential operations, the fault location of the leaky cable is obtained by comparison, which significantly reduces the construction and maintenance costs of the leaky cable fault detection equipment and greatly improves the accuracy and efficiency of leaky cable fault location.

[0037] (2) The present invention realizes automatic data collection and analysis by installing the detection mobile terminal on the train, reducing the need for manual intervention.

[0038] (3) The present invention achieves real-time fault detection by adopting efficient transmission through the 5G network.

[0039] (4) The present invention is applicable to railways, subway tunnels, airports and other complex scenarios where leaky cables need to be laid, providing reliable technical guarantee for communication security and operation and maintenance in these fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the structural diagram of the leaky cable fault location system.

[0041] Figure 2 The figure is a flow chart of a leaky cable fault location method based on differential received signal strength.

[0042] Figure 3 The figure is a leaky cable signal strength curve diagram showing the leaky cable receiving signal strength under normal conditions and the distance between the leaky cable and the base station.

[0043] Figure 4 This is a graph showing the attenuation rate of the received signal strength of the leaky cable per unit distance under normal conditions.

[0044] Figure 5 The figure is a leaky cable signal strength curve diagram showing the leaky cable receiving signal strength versus the distance between the leaky cable and the base station when a fault occurs.

[0045] Figure 6 This is a graph showing the attenuation rate of the received signal strength of the leaky cable within a unit distance when a fault occurs.

[0046] Figure 7 Schematic diagram of equal time interval sampling when there is no train location information.

[0047] Figure 8 This is a flow chart of the leaky cable fault locating software in Example 1 of the present invention.

[0048] Fig. 9 This is a diagram showing the output results of the leaky cable fault locating software in Example 1 of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] Embodiment 1:

[0051] This embodiment provides a leaky cable fault location method based on differential received signal strength, comprising the following steps:

[0052] Step S1: When there is no fault in the leaky cable, a leaky cable signal strength curve under normal conditions is drawn in combination with the leaky cable installation data and the distance between base stations. Step S1 specifically includes the following steps:

[0053] Step S11: In the absence of a fault, using a dedicated measuring device, measure the signal strength along the entire length of the leaky cable between the two base stations at a first preset distance interval, and record the signal strength value of each measuring point, wherein the signal strength value of each measuring point is the radiated wireless signal strength value of the leaky cable at the measuring point;

[0054] Step S12: Analyze the influence of different environmental conditions on the signal by combining the collected data to determine the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station;

[0055] Step S13: according to the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station and the recorded signal strength value of each measuring point, a leaky cable signal strength curve under normal conditions is drawn to show the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station.

[0056] Step S2: generating a leaky cable normal signal strength attenuation rate graph by performing a differential operation on the signal strength curve of the leaky cable under normal conditions; Step S2 specifically includes the following steps:

[0057] Step S21: Select the signal strength values ​​of two adjacent measuring points, calculate the difference, and divide it by the first preset distance to obtain the signal strength attenuation rate between the two measuring points;

[0058] Step S22: Arrange all calculated signal strength attenuation rates in order of distance from the base station to generate a leaky cable normal signal strength attenuation rate graph.

[0059] Step S3: Based on the mobile terminal detecting the actual signal strength of the leaky cable, the mobile terminal includes a data acquisition module, a security encryption module and a data transmission module, which are installed on the train. Step S3 specifically includes the following steps:

[0060] Step S31: Determine whether the location information of the train on which the mobile terminal is installed is known, if known, execute step S32, if unknown, execute step S33;

[0061] Step S32: When a train equipped with a mobile terminal passes by a leaky cable to be detected, the data acquisition module of the mobile terminal measures the signal strength of the leaky cable at a first preset distance interval according to the train position information, encrypts the measured data through the security encryption module, and sends the data to the operation and maintenance center through the data transmission module of the mobile terminal;

[0062] Step S33: When a train equipped with a mobile terminal passes by a leaky cable with a fault to be detected, the mobile terminal measures the signal strength of the leaky cable at the first preset time interval according to the maximum travel speed of the train in this time period, encrypts the measured data through a security encryption module, and then sends it to the operation and maintenance center through the data transmission module of the mobile terminal.

[0063] Step S4: Draw an actual leaky cable signal strength curve graph according to the actual signal strength of the leaky cable and the base station distance. Step S4 specifically includes the following steps:

[0064] Step S41: The operation and maintenance center receives the data transmitted by the mobile terminal, decrypts it, and determines whether there is train location information. If yes, step S42 is executed; if no, step S43 is executed;

[0065] Step S42: according to the distribution of the leaky cable, the distance between the leaky cable and the base station, the position information of the train and the measured leaky cable signal strength data, a curve of the actual leaky cable signal strength under actual conditions is drawn in which the leaky cable signal strength changes with the distance between the leaky cable and the base station;

[0066] Step S43: Calculate and draw a curve of actual leaky cable signal strength versus distance based on the data sampled at equal time intervals and in combination with the maximum distance that the train may travel.

[0067] Step S5: generating an actual leaky cable signal strength attenuation rate graph through differential operation according to the actual leaky cable signal strength curve graph;

[0068] Step S6: Compare the actual leaky cable signal strength attenuation rate graph with the normal leaky cable signal strength attenuation rate graph, and determine the specific location of the leaky cable fault according to the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. When the signal strength attenuation rate of a certain unit distance is different, the section of the leaky cable fails, and the actual location of the section of the leaky cable is calculated according to the distribution of the leaky cable and the distance between the leaky cable and the base station. The specific location of the leaky cable fault is determined according to the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. The signal strength attenuation rate of the actual leaky cable in a certain position interval is different from the received signal strength attenuation rate of the leaky cable in a normal state, thereby determining the leaky cable fault in the position interval.

[0069] Embodiment 2:

[0070] The parts not mentioned in this embodiment are the same as those in Embodiment 1.

[0071] This embodiment proposes a method for locating a leaky cable fault by differential received signal strength. The radio wave propagation characteristics of the leaky cable are utilized, that is, the received signal strength decreases linearly with the increase of the distance between the leaky cable and the base station. The signal strength is weakest at the midpoint between the two base stations, and then increases linearly with the decrease of the distance from the base station. Therefore, the change in signal strength within a unit distance can be regarded as a constant, and the position of the leaky cable fault can be effectively located by performing differential operations on it.

[0072] Figure 1 The structure diagram of the leaky cable fault location system provided by an example of the present invention is shown, including a mobile terminal, a wireless base station, a leaky cable and an operation and maintenance center.

[0073] Figure 2 The flow chart of the leaky cable fault location method based on differential received signal strength provided by an embodiment of the present invention is shown, and includes the following processing steps:

[0074] Step S1: Combine the leaky cable distribution and the distance between base stations to draw Figure 3 The signal strength curve graph under normal conditions is shown.

[0075] In actual operation, the installation environment of the leaky cable must be clarified first, including the length, type, layout method (such as layout along railways and subway tunnels) and relative position of the leaky cable to the base station. Then, based on the transmission characteristics of the leaky cable, such as attenuation coefficient and environmental impact, the signal strength loss of the leaky cable per unit distance is calculated.

[0076] Specifically, this can be achieved through the following steps:

[0077] Signal measurement: When there is no fault, use a dedicated measuring device to measure the signal strength at fixed intervals (such as every 10 meters) along the entire length of the leaky cable. Record the signal strength value at each measuring point.

[0078] Characteristic analysis: By analyzing the collected data, determine the relationship between the signal strength of the leaky cable under normal conditions and the distance. At this time, the influence of different environmental conditions (such as humidity, temperature, mechanical stress, etc.) on the signal should be considered to establish a more accurate model.

[0079] Curve drawing: Based on the above analysis results, draw a curve showing the relationship between the signal strength of the leaky cable and the distance. This curve will be used as a standard curve for comparison with the actual measurement results in subsequent steps.

[0080] Step S2: Perform differential operation on the received signal strength to generate Figure 4 The decay rate diagram is shown.

[0081] After drawing the signal strength curve under normal conditions, the next step is to perform a differential operation on the curve to obtain the signal strength attenuation rate per unit distance. Specifically, this can be achieved by the following steps:

[0082] Differential calculation: Select the signal strength values ​​of two adjacent measurement points, calculate their difference, and divide it by the distance between the two points to get the signal strength attenuation rate. For example, suppose the distance between the two measurement points is 10 meters, and the signal strengths are S and S. 1 and S 2 , then the decay rate is (S 1 -S 2 ) / 10.

[0083] Graph generation: Arrange the attenuation rates of all measurement points in order of position to generate a signal strength attenuation rate graph. This graph will show the attenuation law of signal strength at different positions of the leaky cable. If there is no fault, the graph should show a smooth change trend.

[0084] Consistency check: To ensure the accuracy of differential calculations, the distances between all measurement points must be consistent. If the spacing is inconsistent, the measurement data may need to be interpolated or otherwise processed to eliminate the error caused by the distance difference.

[0085] Step S3: Detecting the actual received signal strength based on the mobile terminal.

[0086] In practical applications, the signal strength of the leaky cable is detected by a mobile terminal configured on the train. The mobile terminal usually includes a data acquisition module, a security encryption module and a data transmission module to ensure the accuracy and security of data acquisition.

[0087] Mobile terminal deployment: The mobile terminal is installed on a train or other mobile equipment, and uses its data acquisition module to detect the signal strength of the leaky cable along the way in real time.

[0088] Data collection:

[0089] When train location information is available: When the train location information is known, the mobile terminal performs sampling at a preset distance interval (such as every 10 meters), and the collected signal strength data is more representative and accurate.

[0090] When there is no train location information: Figure 7 As shown in Figure 1, if the train position information is unknown, sampling is performed at time intervals. By calculating the maximum distance that the train may travel within the time interval, it is ensured that the data collected at different time points can cover all possible signal changes.

[0091] Data processing: The collected data is encrypted by the security encryption module and transmitted to the operation and maintenance center through the 5G public and private network. The operation and maintenance center decrypts and analyzes the data to determine whether there is a cable leakage fault.

[0092] Step S4: Draw Figure 5 The graph shows the relationship between the actual received signal strength of the leaky cable and the distance between it and the base station.

[0093] Based on the data collected by the mobile terminal in S3, combined with the distribution of leaky cables and the distance between the leaky cables and the base station, a curve showing the relationship between the leaky cable receiving signal strength and the distance between the leaky cable and the base station in actual conditions is drawn.

[0094] When there is train position information: Use the data of equidistant sampling to draw the actual signal strength curve of the leaky cable. At this time, the curve should reflect the actual signal strength at each measuring point along the leaky cable.

[0095] When there is no train location information: Based on the data sampled at equal time intervals and the maximum distance the train may travel, the actual signal strength versus distance curve is calculated and plotted. This curve helps to infer the signal changes along the leaky cable even when there is no location information.

[0096] Step S5: Perform differential calculation on the actual received signal strength of the leaky cable to generate Figure 6 The graph shows the attenuation rate of the received signal strength of the leaky cable within the actual unit distance.

[0097] With the distance between the leaky cable and the base station as the horizontal axis and the difference in received signal strength within a unit distance as the vertical axis, a graph of the attenuation rate of received signal strength of the leaky cable within a unit distance is obtained in actual situations.

[0098] When there is train position information: perform differential calculation on the signal strength data obtained by sampling at equal distances to generate the actual attenuation rate diagram.

[0099] When there is no train position information: perform differential operations on the data sampled at equal time intervals, calculate the possible maximum travel distance in each period of time, and generate the corresponding attenuation rate graph.

[0100] Step S6: Compare the actually obtained received signal strength attenuation rate graph of the leaky cable with the received signal strength attenuation rate graph of the leaky cable in a normal state, and determine the specific location of the leaky cable fault according to the similarities and differences between the two signal strength attenuation rate graphs within a unit distance.

[0101] When there is train location information: compare the attenuation rate graphs at the same location. If the actual signal attenuation rate in a certain section deviates significantly from the normal value, it indicates that there may be a leaky cable fault in that area.

[0102] When there is no train location information: through differential calculation of the travel distance at the maximum speed, if abnormal points still appear in the attenuation rate diagram, the interval where the fault point is located can be located.

[0103] Embodiment 3:

[0104] The parts not mentioned in this embodiment are the same as those in Embodiment 1.

[0105] Figure 8 The flowchart of the leaky cable fault location software is shown, including importing data, judging whether there is train position information, if yes, performing differential operation on the received signal strength, generating a received signal strength attenuation rate diagram within a unit distance, and analyzing the fault location; if no, calculating the train travel distance within the time period at the maximum running speed of the train, performing differential operation on the received signal strength, generating a received signal strength attenuation rate diagram within a unit distance, and analyzing the fault location.

[0106] The following is the leaky cable received signal strength data of a certain line of Shanghai Metro based on sampling at equal time intervals of mobile terminals, as shown in Table 1:

[0107]

[0108]

[0109] The data in Table 1 are Figure 2 The leaky cable fault locating software shown performs calculations and outputs results.

[0110] like Fig. 9 As shown in the figure, under normal working conditions, the attenuation rate of the received signal strength remains stable and uniform. At this time, the relationship between the signal strength and the distance between the leaky cable and the base station shows a smooth attenuation curve, indicating that the signal decays at a constant rate during transmission. However, when a leaky cable fails, the attenuation rate of the received signal strength changes significantly at the fault point. Specifically, the signal attenuation rate near the fault point increases suddenly and forms obvious abnormal peaks or valleys. The signal attenuation rate image before and after the fault point shows sudden fluctuations or irregular changes. After the fault occurs, the signal attenuation rate returns to normal levels, indicating that the impact of the fault is limited to a specific area. By analyzing this significant change in the signal strength attenuation rate, we can accurately locate the fault point of the leaky cable.

[0111] Through the above implementation, the present invention can realize efficient and accurate positioning of leaky cable faults in complex railway or subway environments. Its main advantages are:

[0112] (1) High degree of automation: The present invention can automatically collect and analyze data, reducing the need for human intervention.

[0113] (2) Strong real-time performance: Through the efficient transmission of the 5G network, real-time fault detection is achieved.

[0114] (3) Wide adaptability: Effective cable leakage detection can be performed regardless of whether there is train location information.

[0115] The present invention is applicable to railways, subway tunnels, airports and other complex scenarios where leaky cables need to be laid, and provides reliable technical guarantee for communication security and operation and maintenance in these fields.

[0116] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0117] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A leaky cable fault location method based on differential received signal strength, characterized in that: The following steps are involved: Step S1: When there is no fault in the leaky cable, a leaky cable signal strength curve under normal conditions is drawn in combination with the leaky cable installation data and the distance between base stations; Step S2: generating a leaky cable normal signal strength attenuation rate graph by performing a differential operation on the signal strength curve of the leaky cable in a normal state; Step S3: Detecting the actual signal strength of the leaky cable based on the mobile terminal; Step S4: drawing a curve graph of actual leaky cable signal strength according to the actual signal strength of the leaky cable and the distance between base stations; Step S5: generating an actual leaky cable signal strength attenuation rate graph through differential operation according to the actual leaky cable signal strength curve graph; Step S6: Compare the actual leaky cable signal strength attenuation rate graph with the normal leaky cable signal strength attenuation rate graph, and determine the specific location of the leaky cable fault based on the similarities and differences between the two signal strength attenuation rate graphs within a unit distance.

2. A leaky cable fault location method based on differential received signal strength according to claim 1, characterized in that: The step S1 specifically includes the following steps: Step S11: In the absence of a fault, using a dedicated measuring device, measure the signal strength along the entire length of the leaky cable between the two base stations at a first preset distance interval, and record the signal strength value of each measuring point; Step S12: Analyze the influence of different environmental conditions on the signal by combining the collected data to determine the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station; Step S13: according to the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station and the recorded signal strength value of each measuring point, a leaky cable signal strength curve under normal conditions is drawn to show the relationship between the signal strength of the leaky cable under normal conditions and the distance from the base station.

3. A leaky cable fault location method based on differential received signal strength according to claim 2, characterized in that: The signal strength value at each measuring point is the radiated wireless signal strength value of the leaky cable at the measuring point.

4. A leaky cable fault location method based on differential received signal strength according to claim 1, characterized in that: The step S2 specifically includes the following steps: Step S21: Select the signal strength values ​​of two adjacent measuring points, calculate the difference, and divide it by the first preset distance to obtain the signal strength attenuation rate between the two measuring points; Step S22: Arrange all calculated signal strength attenuation rates in order of distance from the base station to generate a leaky cable normal signal strength attenuation rate graph.

5. The method for locating a leaky cable fault based on differential received signal strength according to claim 1, characterized in that: The mobile terminal comprises a data acquisition module, a security encryption module and a data transmission module, and is installed on a train.

6. A leaky cable fault location method based on differential received signal strength according to claim 1, characterized in that: The step S3 specifically comprises the following steps: Step S31: Determine whether the location information of the train on which the mobile terminal is installed is known, if known, execute step S32, if unknown, execute step S33; Step S32: When a train equipped with a mobile terminal passes by a leaky cable to be detected, the data acquisition module of the mobile terminal measures the signal strength of the leaky cable at a first preset distance interval according to the train position information, encrypts the measured data through the security encryption module, and sends the data to the operation and maintenance center through the data transmission module of the mobile terminal; Step S33: When a train equipped with a mobile terminal passes by a leaky cable with a fault to be detected, the mobile terminal measures the signal strength of the leaky cable at the first preset time interval according to the maximum travel speed of the train in this time period, encrypts the measured data through a security encryption module, and then sends it to the operation and maintenance center through the data transmission module of the mobile terminal.

7. A leaky cable fault location method based on differential received signal strength according to claim 6, characterized in that: The data transmission module of the mobile terminal transmits the encrypted data to the operation and maintenance center through the 5G public and private network.

8. The method for locating a leaky cable fault based on differential received signal strength according to claim 1, characterized in that: The step S4 specifically comprises the following steps: Step S41: The operation and maintenance center receives the data transmitted by the mobile terminal, decrypts it, and determines whether there is train location information. If yes, step S42 is executed; if no, step S43 is executed; Step S42: according to the distribution of the leaky cable, the distance between the leaky cable and the base station, the position information of the train and the measured leaky cable signal strength data, a curve of the actual leaky cable signal strength under actual conditions is drawn in which the leaky cable signal strength changes with the distance between the leaky cable and the base station; Step S43: Calculate and draw a curve of actual leaky cable signal strength versus distance based on the data sampled at equal time intervals and in combination with the maximum distance that the train may travel.

9. The method for locating a leaky cable fault based on differential received signal strength according to claim 1, characterized in that: The specific location of the leaky cable fault is determined according to the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. When the signal strength attenuation rate of a certain unit distance is different, the section of the leaky cable fails. The actual location of the section of the leaky cable is calculated according to the distribution of the leaky cable and the distance between the leaky cable and the base station. The specific location of the leaky cable fault is determined according to the similarities and differences between the two signal strength attenuation rate graphs within a unit distance. The comparison is performed at the same position. The signal strength attenuation rate of the actual leaky cable in a certain position interval is different from the received signal strength attenuation rate of the leaky cable in a normal state, thereby determining the leaky cable fault in the position interval.

10. A leaky cable fault location system based on differential received signal strength, characterized in that: Including mobile terminals and operation and maintenance center; The mobile terminal includes a data acquisition module, a security encryption module and a data transmission module. The data acquisition module is used to collect the signal strength of the leaky cable at different positions and select sampling intervals for equidistant or equal time interval sampling. The security encryption module is used to encrypt the collected data. The data transmission module is used to transmit the encrypted data to the operation and maintenance center through the 5G public and private network. The operation and maintenance center is used to receive and decrypt data sent by the mobile terminal, and draw an actual leaky cable signal strength curve graph based on the data, generate an actual leaky cable signal strength attenuation rate graph, and determine the actual position of the faulty leaky cable based on the actual leaky cable signal strength attenuation rate graph and the leaky cable normal signal strength attenuation rate graph.

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