A method and system for monitoring faults of vehicle-mounted optical cables

Abstract

The present invention relates to a fault monitoring method and system for an on-board optical cable. The on-board optical cable is segmented according to its arrangement position in the vehicle body to form a plurality of segmented intervals and segmented nodes. Temperature detection is performed at each segmented node position outside the on-board optical cable, and a fitted temperature curve of the outside of the on-board optical cable is formed by fitting the multi-point temperature detection information. Fiber optic temperature measurement technology is used inside the on-board optical cable to detect the temperature of the optical fiber to form an actual temperature curve inside the on-board optical cable. The changing trends of the fitted temperature curve and the actual temperature curve are compared in real time to determine whether the on-board optical cable has a fault. The fitted temperature curve and the actual temperature curve are compared in proportion to determine the segmented interval where the fault occurs and calculate the distance between the fault point and the nearest segmented node. The present invention realizes real-time monitoring and fault diagnosis of the on-board optical cable through segmented monitoring, temperature curve fitting, internal and external temperature curve comparison, and fault location.

Description

Technical Field

[0001] The present invention relates to the technical field of monitoring vehicle-mounted optical cables, and in particular to a fault monitoring method and system for vehicle-mounted optical cables. Background Art

[0002] With the development of intelligent and networked automobiles, optical cables play an increasingly important role in automobile communication systems. Due to the complex vehicle operating environment, optical cables are easily affected by factors such as mechanical damage, high temperature, and electromagnetic interference, which can lead to failures. Once an optical cable fails, it will seriously affect the normal operation of the vehicle.

[0003] Generally, when an optical cable fails, the short circuit caused by the fault causes a sharp rise in temperature at the fault location. Existing technologies utilize fiber optic temperature measurement technology to monitor the temperature along the length of the optical cable and determine the location of the fault. However, existing fiber optic temperature measurement technology cannot be directly applied to the measurement of on-board optical cables due to two main problems:

[0004] 1. When displaying the fault location, fiber optic temperature measurement technology can only determine the distance between the fault and the test equipment. However, in vehicle-mounted optical cables, the layout is determined according to the structure of the vehicle body and the needs of electrical equipment. Compared with traditional transmission optical cables, the layout of vehicle-mounted optical cables is more complex, and the fault location cannot be accurately determined by length alone. During maintenance, if the fault location cannot be accurately determined, all components covering the vehicle-mounted optical cables need to be disassembled, which makes maintenance difficult and costly.

[0005] 2. When the vehicle-mounted optical cable is actually used, the temperature changes of the vehicle-mounted optical cable in different installation positions are also different. For example, the temperature of the vehicle-mounted optical cable near the engine will rise rapidly after the engine is started. If the fault is judged based only on the single monitoring indicator of optical fiber temperature measurement technology, on the one hand, it is impossible to accurately set the judgment threshold, and on the other hand, it will be affected by external environmental factors, and there will be a high misjudgment rate. Summary of the Invention

[0006] To this end, the technical problem to be solved by the present invention is to overcome the problem that the existing technology that only uses optical fiber temperature measurement technology in vehicle-mounted optical cables cannot overcome the high misjudgment rate caused by environmental factors and the problem of inability to accurately locate. A vehicle-mounted optical cable fault monitoring method and system are provided, which realizes real-time monitoring and fault diagnosis of vehicle-mounted optical cables through segmented monitoring, temperature curve fitting, internal and external temperature curve comparison and fault location.

[0007] To solve the above technical problems, the present invention provides a method for fault monitoring of a vehicle-mounted optical cable, comprising the following steps:

[0008] The vehicle-mounted optical cable is segmented according to the layout position in the vehicle body to form multiple segment intervals and segment nodes;

[0009] Perform temperature detection at each segment node position outside the vehicle optical cable, and use the multi-point temperature detection information to form a fitting temperature curve outside the vehicle optical cable;

[0010] Utilize optical fiber temperature measurement technology inside the vehicle-mounted optical cable to detect the temperature of the optical fiber and form the actual temperature curve inside the vehicle-mounted optical cable;

[0011] Compare the changing trends of the fitted temperature curve and the actual temperature curve in real time. When it is found that the heating rate of the actual temperature curve at a certain position exceeds the heating rate of the fitted temperature curve, it is judged that there is a fault in the vehicle optical cable at that position. Otherwise, it is judged that the vehicle optical cable is in normal use.

[0012] After determining that the on-board optical cable has a fault, the fitted temperature curve and the actual temperature curve are compared proportionally, and the segmented node position of the external temperature detection module is mapped to the actual temperature curve. Based on this, the segmented interval where the fault occurs is determined and the distance from the fault point to the nearest segmented node is calculated.

[0013] In one embodiment of the present invention, the segmentation standards of the vehicle-mounted optical cable include:

[0014] The vehicle body components are grouped based on each other, and a segment node is set between two adjacent groups of vehicle body components, wherein the vehicle body components are independently detachable components;

[0015] In each group of vehicle body components, a segment node is provided at the bending position of each vehicle-mounted optical cable;

[0016] In each group of vehicle body components, when the vehicle-mounted optical cable has no bends, a plurality of segment nodes are arranged with equal lengths.

[0017] In one embodiment of the present invention, the steps of forming a fitting temperature curve of the exterior of the vehicle optical cable by using multi-point temperature detection information are as follows:

[0018] Assuming segment node positions x 1, x 2… x n Measured temperatures T1, T2…T n Construct a polynomial regression model:

[0019] T ( x )= β 0+ β 1 x + β 2x 2 + β 3 x 3 +…+ β k x k + ε ;

[0020] in: T ( x ) is the temperature with respect to position x function;

[0021] β 0, β 1, β 2,… β k are the coefficients of the polynomial;

[0022] ε is the error term, which represents the random error that cannot be explained by the model;

[0023] Collection location points x i and the corresponding temperature measurement value T i , the location point x i Convert to polynomial features and get the feature matrix X:

[0024] ;

[0025] Solving for the coefficients of a polynomial using the least squares method β 0, β 1, β 2,… β k To minimize the residual sum of squares, the solution of the least squares method can be obtained by the following formula:

[0026] ;

[0027] Where: X is the feature matrix, each row contains x i The power of ;

[0028] T is a column vector of temperature measurements;

[0029] are estimates of the polynomial coefficients.

[0030] In one embodiment of the present invention, infrared temperature measurement technology is used to perform contactless temperature detection at each segment node position outside the vehicle-mounted optical cable.

[0031] In one embodiment of the present invention, temperature detection is performed on each segmented node position outside the vehicle-mounted optical cable under different ambient temperatures, a model of the impact of ambient temperature on the temperature of the optical cable is established, and the formed fitting temperature curve is dynamically corrected in combination with the ambient temperature.

[0032] In one embodiment of the present invention, distributed optical fiber temperature measurement technology is used in a vehicle-mounted optical cable to obtain the temperature distribution along the optical fiber path by measuring the intensity change of the optical signal caused by Rayleigh scattering or Raman scattering in the optical fiber.

[0033] In one embodiment of the present invention, when comparing the changing trends of the fitted temperature curve and the actual temperature curve in real time, a threshold is set to determine whether the temperature difference between the fitted temperature curve and the actual temperature curve exceeds the normal range, wherein: the threshold is determined by the temperature changing trend when an actual simulated vehicle-mounted optical cable fails.

[0034] In one embodiment of the present invention, when comparing the fitted temperature curve and the actual temperature curve in proportion, a visualization process is used to draw the fitted temperature curve and the actual temperature curve on the same scale.

[0035] In one embodiment of the present invention, the following steps are further included:

[0036] When it is determined that the vehicle-mounted optical cable has a fault, the time and location of the fault are recorded and an alarm signal is sent to the central control system;

[0037] Establish a fault database and collect data on each fault that occurs.

[0038] To solve the above technical problems, the present invention further provides a vehicle-mounted optical cable fault monitoring system, which is used to implement the above vehicle-mounted optical cable fault monitoring method, comprising:

[0039] The segmentation module is used to divide the vehicle-mounted optical cable into multiple segment intervals according to the layout position in the vehicle body, and define the segment nodes between each segment;

[0040] The external temperature detection module is set at each segment node to detect the temperature outside the vehicle optical cable and collect multi-point temperature data to form a fitting temperature curve;

[0041] The internal temperature detection module is integrated into the vehicle optical cable and uses optical fiber temperature measurement technology to detect the optical fiber temperature and generate the actual temperature curve;

[0042] The monitoring and analysis module is used to compare the changing trends of the fitted temperature curve and the actual temperature curve in real time, and identify potential fault locations by analyzing the differences between the two. If the heating rate of the actual temperature curve at a certain location exceeds the heating rate of the fitted temperature curve, it is determined that there is a fault in the vehicle optical cable at that location. Otherwise, it is determined that the vehicle optical cable is in normal use.

[0043] After confirming the fault, the fault location module can map the segmented nodes of the external temperature detection module to the actual temperature curve based on the proportional relationship between the fitted temperature curve and the actual temperature curve, thereby determining the specific segmented interval where the fault occurred and its precise distance from the nearest segmented node.

[0044] The above technical solution of the present invention has the following advantages over the prior art:

[0045] The present invention discloses a fault monitoring method and system for an on-board optical cable, which realizes real-time monitoring and fault diagnosis of the on-board optical cable through segmented monitoring, temperature curve fitting, internal and external temperature curve comparison and fault location.

[0046] Among them: In view of the problem that the existing technology only uses optical fiber temperature measurement technology in vehicle-mounted optical cables and cannot overcome the high misjudgment rate caused by environmental factors, the present invention combines external temperature detection and internal optical fiber temperature measurement technology, and judges faults by comparing the changing trends of internal and external temperatures at a certain position. It is more accurate than traditional single temperature detection or temperature difference detection, and can improve the accuracy of fault judgment. Moreover, during actual monitoring, it is impossible to continuously measure the external temperature of the vehicle-mounted optical cable. In order to compare it with the actual temperature curve generated by optical fiber temperature measurement technology, this application adopts point measurement to generate a continuous fitting temperature curve through fitting.

[0047] In response to the problem that the fiber optic temperature measurement technology used in the existing technology cannot accurately locate the fault position in the vehicle body, the present invention adopts a proportional comparison method to calibrate the node positions in the external fitting temperature curve on the internal actual temperature curve. When the actual temperature curve shows that a fault has occurred at a certain position, the corresponding segmented interval where the fault occurred can be determined in the fitting temperature curve, and the distance between the fault point and the nearest segmented node can be calculated based on the proportion, which is very helpful for quickly repairing the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0049] Figure 1 is a flow chart of a fault monitoring method for a vehicle-mounted optical cable of the present invention;

[0050] Figure 2It is a structural block diagram of the vehicle-mounted optical cable fault monitoring system of the present invention. DETAILED DESCRIPTION

[0051] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0052] Example 1

[0053] For fault monitoring of on-board optical cables, there are two main considerations: one is to determine whether a fault occurs, and the other is to determine the exact location of the fault. Compared with traditional directly buried or overhead optical cables, the overall length of on-board optical cables is short, and the lines arranged in the car body are mostly curved according to the distribution of electrical equipment in the car. In addition, the temperature changes greatly due to the influence of vehicle functions according to the layout position. Therefore, as mentioned above, the optical fiber temperature detection technology used in directly buried or overhead optical cables using existing technology is not applicable to judge the fault of on-board optical cables.

[0054] Reference Figure 1 As shown, in order to solve the above problems, the present invention discloses a fault monitoring method for a vehicle-mounted optical cable, comprising:

[0055] Step 1: Segment the vehicle-mounted optical cable according to its layout position in the vehicle body to form multiple segment intervals and segment nodes.

[0056] Specifically, in actual applications, when setting segmentation intervals and segmentation nodes, segmentation standards are formulated according to actual conditions:

[0057] The vehicle body components are grouped based on each other, and a segmentation node is set between two adjacent groups of vehicle body components, wherein the vehicle body components are independently detachable components. In this embodiment, the purpose of segmenting the vehicle optical cable is to accurately find the fault point when judging the fault and repair the fault point. The independently detachable vehicle body components are used as segmentation nodes. When it is determined that a fault occurs in a certain area between two segmentation nodes, the vehicle body components in the area can be directly disassembled, and the vehicle optical cables in the area can be repaired without disassembling the vehicle body components in other positions. This can reduce the work of maintenance and disassembly.

[0058] In each group of vehicle body components, multiple segment nodes can be set according to the actual wiring situation. For example, a segment node is set at the bending position of each vehicle-mounted optical cable. This is because the vehicle-mounted optical cable is prone to bending at the bending position, which may lead to short circuits. When the vehicle-mounted optical cable has no bends, in order to ensure the accuracy of the test, multiple segment nodes can also be set at equidistant lengths. For example, in actual wiring, a segment node is set every 10 to 20 cm. Specifically, the more segment nodes are set, the more accurate the fitted temperature measurement curve constructed, and thus, the more accurate the fault occurrence and fault location monitored.

[0059] Step 2: Perform temperature detection at each segment node position outside the vehicle optical cable, and use the multi-point temperature detection information to fit and form a fitting temperature curve outside the vehicle optical cable.

[0060] During actual monitoring, it is impossible to continuously measure the external temperature of the vehicle-mounted optical cable. In order to compare it with the actual temperature curve generated by the optical fiber temperature measurement technology, this application adopts a point measurement method to generate a continuous fitting temperature curve through fitting.

[0061] Specifically, in order to improve the accuracy of fitting the temperature curve, in this embodiment, a polynomial regression model is established, and the model's ability to fit nonlinear data is enhanced by introducing high-order terms of independent variables. x 1, x 2… x n Measured temperatures T1, T2…T n Construct a polynomial regression model:

[0062] T ( x )= β 0+ β 1 x + β 2 x 2 + β 3 x 3 +…+ β k x k + ε

[0063] in: T ( x ) is the temperature with respect to position x function;

[0064] β 0, β 1, β 2,… βk are the coefficients of the polynomial;

[0065] ε is the error term, which represents the random error that cannot be explained by the model;

[0066] Using the above polynomial regression model, collect location points x i and the corresponding temperature measurement value T i , that is, collecting the actual measured temperature at each segment node position. For example, in this embodiment, the following data points are set: x 1. Measure the temperature at 20°C. x 2. Measure the temperature at 22°C. x 3. Measure the temperature at 25°C. x 4. Measure the temperature at 28°C. x 5. Measurement temperature: 30℃;

[0067] The location point x i Convert to polynomial features and get the feature matrix X and temperature vector T:

[0068]

[0069] Right now:

[0070]

[0071] Solving for the coefficients of a polynomial using the least squares method β 0, β 1, β 2,… β k To minimize the residual sum of squares, the solution of the least squares method can be obtained by the following formula:

[0072]

[0073] Where: X is the feature matrix, each row contains x i The power of ;

[0074] T is a column vector of temperature measurements;

[0075] are estimates of the polynomial coefficients.

[0076] After calculation, the fitting quadratic polynomial can be obtained:

[0077] T ( x )=19.8+2.2 x +0.5 x 2

[0078] A fitting temperature curve can be drawn based on the quadratic polynomial.

[0079] Specifically, when measuring the temperature of each segment node outside the vehicle-mounted optical cable, infrared temperature measurement technology is used, and infrared temperature sensors are used to perform contactless temperature detection, which can reduce the temperature impact of the vehicle-mounted optical cable on the temperature sensor and further improve the measurement accuracy.

[0080] Specifically, when using an infrared temperature sensor to measure the actual temperature of an on-board optical cable, because it is a non-contact measurement, the actual temperature measured will be affected by the ambient temperature, resulting in a certain deviation. Therefore, in order to ensure that the temperature measured in this embodiment is the actual temperature outside the on-board optical cable, the influence of the ambient temperature must also be taken into account when constructing a fitting temperature curve to collect data;

[0081] Therefore, in order to eliminate the influence of ambient temperature, temperature detection is performed on each segment node position outside the vehicle-mounted optical cable under different ambient temperatures, a model of the influence of ambient temperature on the temperature of the optical cable is established, and the formed fitting temperature curve is dynamically corrected in combination with the ambient temperature.

[0082] Step 3: Use optical fiber temperature measurement technology inside the vehicle-mounted optical cable to detect the temperature of the optical fiber and form an actual temperature curve inside the vehicle-mounted optical cable.

[0083] Specifically, fiber optic temperature measurement technology mainly measures temperature based on the changes in the physical properties of light as it propagates through optical fibers. Common fiber optic temperature measurement technologies include:

[0084] Distributed Temperature Sensing (DTS) measures the intensity of the optical signal generated by Rayleigh scattering or Raman scattering in the optical fiber to obtain the temperature distribution along the optical fiber path.

[0085] Fiber Bragg Grating (FBG): Temperature is measured by measuring the change in the wavelength of light reflected by the fiber Bragg grating.

[0086] In this embodiment, distributed fiber temperature measurement (DTS) technology is used to monitor the temperature changes of the on-board optical cable. The optical fiber in the on-board optical cable is directly used as a fiber sensor. A laser is connected to one end of the optical fiber to ensure that the laser's output power and wavelength meet the requirements. A photodetector is connected to the other end of the optical fiber to ensure that the detector can accurately receive the returned optical signal. A data acquisition card is used to collect the optical signal returned from the optical fiber. The optical signal is converted into temperature data through a Raman scattering signal processing algorithm. The temperature data is integrated to form the actual temperature curve.

[0087] Step 4: Compare the changing trends of the fitted temperature curve and the actual temperature curve in real time. When it is found that the heating rate of the actual temperature curve at a certain position exceeds the heating rate of the fitted temperature curve, it is judged that there is a fault in the vehicle optical cable at that position. Otherwise, it is judged that the vehicle optical cable is in normal use.

[0088] In this embodiment, in order to address the problem that the existing technology using only optical fiber temperature measurement technology in vehicle-mounted optical cables cannot overcome the high misjudgment rate caused by environmental factors, external temperature detection and internal optical fiber temperature measurement technology are combined to judge the fault by comparing the changing trends of the internal and external temperatures at a certain position. This is more accurate than traditional single temperature detection or temperature difference detection, and can improve the accuracy of fault judgment.

[0089] In actual applications, temperature changes are mainly caused by two factors, changes in external ambient temperature and temperature changes caused by internal short circuits; when the external ambient temperature changes, because the on-board optical cable has a certain thermal insulation effect, the heating rate of the fitting temperature curve constructed by external detection will definitely be greater than the heating rate of the internal actual temperature curve. At this time, due to the difference in heating rates, a certain temperature difference is also formed. However, in this case, it will not be judged that a fault has occurred, thereby reducing the misjudgment of faults caused by environmental changes; when the temperature changes due to an internal short circuit, because the on-board optical cable has a certain thermal insulation effect, at the location where the fault occurs, the heating rate of the actual internal temperature curve will definitely be greater than the heating rate of the fitting temperature curve constructed by external detection. Therefore, by detecting this situation, it can be determined that a short circuit has occurred in the on-board optical cable at this location.

[0090] Specifically, in the existing data statistics, there will be no other situation that causes the internal actual temperature curve to have a heating rate greater than the heating rate of the fitted temperature curve constructed through external detection. As long as this situation occurs, it can be determined that the on-board optical cable has completed a short-circuit fault. However, in actual applications, in order to reduce the false positive rate of faults, when comparing the changing trends of the fitted temperature curve and the actual temperature curve in real time, a threshold is set to determine whether the temperature difference between the fitted temperature curve and the actual temperature curve exceeds the normal range, where the threshold is determined by the temperature change trend of the actual simulated on-board optical cable when a fault occurs.

[0091] Step 5. After determining that the on-board optical cable has failed, compare the fitted temperature curve and the actual temperature curve in proportion. By comparing the proportional relationship between the fitted temperature curve and the actual temperature curve, map the segmented node position of the external temperature detection module to the actual temperature curve. Based on this, determine the specific segmented interval where the fault occurred and calculate the distance between the fault point and the nearest segmented node.

[0092] To address the problem that the fiber optic temperature measurement technology used in existing technologies cannot accurately locate the fault location in the vehicle body, this embodiment adopts a proportional comparison method to calibrate the node positions in the external fitting temperature curve on the internal actual temperature curve. When the actual temperature curve shows that a fault has occurred at a certain position, the corresponding segmented interval where the fault occurred can be determined in the fitting temperature curve, and the distance between the fault point and the nearest segmented node can be calculated based on the proportion, which is very helpful for quickly repairing the fault.

[0093] Specifically, when comparing the fitted temperature curve and the actual temperature curve in proportion, a visual processing method is used to draw the fitted temperature curve and the actual temperature curve on the same scale, and a graphical user interface is used to display the two temperature curves and their corresponding relationship, so that the operator can make intuitive judgments and make intuitive comparisons, thereby quickly determining the distance between the fault location and the segmentation node. After positioning, it is only necessary to remove the vehicle body components between the two segmentation nodes at the fault location. After finding the corresponding segmentation node, the corresponding proportional calculation can quickly find the fault location, open the skylight at the fault location, and repair the on-board optical cable where the fault occurred.

[0094] Specifically, in practical application, it also includes:

[0095] Step 6. Fault recording and alarm: Record the time and location of the fault, send an alarm signal to the central control system, establish a fault database, and collect data on each fault for subsequent analysis and improvement.

[0096] Example 2

[0097] Reference Figure 2 As shown, the present invention further discloses a vehicle-mounted optical cable fault monitoring system based on the above-mentioned embodiment 1, comprising:

[0098] The segmentation module is used to divide the vehicle-mounted optical cable into multiple segment intervals according to the layout position in the vehicle body, and define the segment nodes between each segment;

[0099] The external temperature detection module is set at each segment node to detect the temperature outside the vehicle optical cable and collect multi-point temperature data to form a fitting temperature curve;

[0100] The internal temperature detection module is integrated into the vehicle optical cable and uses optical fiber temperature measurement technology to detect the optical fiber temperature and generate the actual temperature curve;

[0101] The monitoring and analysis module is used to compare the changing trends of the fitted temperature curve and the actual temperature curve in real time, and identify potential fault locations by analyzing the differences between the two. If the heating rate of the actual temperature curve at a certain location exceeds the heating rate of the fitted temperature curve, it is determined that there is a fault in the vehicle optical cable at that location. Otherwise, it is determined that the vehicle optical cable is in normal use.

[0102] After confirming the fault, the fault location module can map the segmented nodes of the external temperature detection module to the actual temperature curve based on the proportional relationship between the fitted temperature curve and the actual temperature curve, thereby determining the specific segmented interval where the fault occurred and its precise distance from the nearest segmented node.

[0103] The fault monitoring system for the vehicle-mounted optical cable disclosed in the embodiment of the present invention realizes real-time monitoring and fault diagnosis of the vehicle-mounted optical cable through segmented monitoring, temperature curve fitting, internal and external temperature curve comparison and fault location. The technical effects that can be achieved are as described in the above embodiment 1 and will not be repeated here.

[0104] Specifically, in actual application, a fault recording and alarm module is also set up to record the time and location information of the fault, send an alarm signal to the central control system, establish a fault database, and collect data on each fault for subsequent analysis and improvement.

[0105] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0106] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0107] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0108] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0109] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for fault monitoring of a vehicle-mounted optical cable, characterized in that: The following steps are involved: The vehicle-mounted optical cable is segmented according to the layout position in the vehicle body to form multiple segment intervals and segment nodes; Temperature detection is performed at each segment node position outside the vehicle optical cable, and a fitting temperature curve of the vehicle optical cable exterior is formed by fitting the multi-point temperature detection information, wherein the steps of fitting the vehicle optical cable exterior by fitting the multi-point temperature detection information are as follows: Assuming segment node positions x 1, x 2… x n Measured temperatures T1, T2…T n Construct a polynomial regression model: T ( x )= β 0+ β 1 x + β 2 x 2 + β 3 x 3 +…+ β k x k + ϵ ； in: T ( x ) is the temperature with respect to position x function; β 0, β 1, β 2,… β k are the coefficients of the polynomial; ϵ is the error term, which represents the random error that cannot be explained by the model; Collection location points x i and the corresponding temperature measurement value T i , the location point x i Convert to polynomial features and get the feature matrix X: ； Solving for the coefficients of a polynomial using the least squares method β 0, β 1, β 2,… β k To minimize the residual sum of squares, the solution of the least squares method can be obtained by the following formula: ； Where: X is the feature matrix, each row contains x i The power of ; T is a column vector of temperature measurements; are estimates of the polynomial coefficients; Utilize optical fiber temperature measurement technology inside the vehicle-mounted optical cable to detect the temperature of the optical fiber and form the actual temperature curve inside the vehicle-mounted optical cable; Compare the changing trends of the fitted temperature curve and the actual temperature curve in real time. When it is found that the heating rate of the actual temperature curve at a certain position exceeds the heating rate of the fitted temperature curve, it is judged that there is a fault in the vehicle optical cable at that position. Otherwise, it is judged that the vehicle optical cable is in normal use. After determining that the on-board optical cable has a fault, the fitted temperature curve and the actual temperature curve are compared proportionally, and the segmented node position of the external temperature detection module is mapped to the actual temperature curve. Based on this, the segmented interval where the fault occurs is determined and the distance from the fault point to the nearest segmented node is calculated.

2. The method for fault monitoring of a vehicle-mounted optical cable according to claim 1, wherein: The segmentation standards for on-board optical cables include: The vehicle body components are grouped based on each other, and a segment node is set between two adjacent groups of vehicle body components, wherein the vehicle body components are independently detachable components; In each group of vehicle body components, a segment node is provided at the bending position of each vehicle-mounted optical cable; In each group of vehicle body components, when the vehicle-mounted optical cable has no bends, a plurality of segment nodes are arranged with equal lengths.

3. The fault monitoring method for a vehicle-mounted optical cable according to claim 1, wherein: Using infrared temperature measurement technology, non-contact temperature detection is performed at each segment node outside the on-board optical cable.

4. The method for fault monitoring of a vehicle-mounted optical cable according to claim 3, wherein: Under different ambient temperatures, the temperature of each segmented node outside the vehicle-mounted optical cable is detected, a model of the impact of ambient temperature on the temperature of the optical cable is established, and the formed fitting temperature curve is dynamically corrected based on the ambient temperature.

5. The fault monitoring method for a vehicle-mounted optical cable according to claim 1, characterized in that: Distributed optical fiber temperature measurement technology is used in on-board optical cables to obtain the temperature distribution along the optical fiber path by measuring the changes in the intensity of the light signal of Rayleigh scattering or Raman scattering in the optical fiber.

6. The method for fault monitoring of a vehicle-mounted optical cable according to claim 1, wherein: When comparing the changing trends of the fitted temperature curve and the actual temperature curve in real time, a threshold is set to determine whether the temperature difference between the fitted temperature curve and the actual temperature curve exceeds the normal range, where the threshold is determined by the temperature changing trend when a fault occurs in the actual simulated vehicle optical cable.

7. The fault monitoring method for a vehicle-mounted optical cable according to claim 1, characterized in that: When comparing the fitted temperature curve and the actual temperature curve in proportion, a visualization method is used to draw the fitted temperature curve and the actual temperature curve on the same scale.

8. The method for fault monitoring of a vehicle-mounted optical cable according to claim 1, wherein: The following steps are also included: When it is determined that the vehicle-mounted optical cable has a fault, the time and location of the fault are recorded and an alarm signal is sent to the central control system; Establish a fault database and collect data on each fault that occurs.

9. A vehicle-mounted optical cable fault monitoring system, used to implement the vehicle-mounted optical cable fault monitoring method according to any one of claims 1 to 8, characterized in that: include: The segmentation module is used to divide the vehicle-mounted optical cable into multiple segment intervals according to the layout position in the vehicle body, and define the segment nodes between each segment; The external temperature detection module is set at each segment node to detect the temperature outside the vehicle optical cable and collect multi-point temperature data to form a fitting temperature curve; The internal temperature detection module is integrated into the vehicle optical cable and uses optical fiber temperature measurement technology to detect the optical fiber temperature and generate the actual temperature curve; The monitoring and analysis module is used to compare the changing trends of the fitted temperature curve and the actual temperature curve in real time, and identify potential fault locations by analyzing the differences between the two. If the heating rate of the actual temperature curve at a certain location exceeds the heating rate of the fitted temperature curve, it is determined that there is a fault in the vehicle optical cable at that location. Otherwise, it is determined that the vehicle optical cable is in normal use. After confirming the fault, the fault location module can map the segmented nodes of the external temperature detection module to the actual temperature curve based on the proportional relationship between the fitted temperature curve and the actual temperature curve, thereby determining the specific segmented interval where the fault occurred and its precise distance from the nearest segmented node.

Images