Highway optical fiber point position calibration method based on distributed sound wave sensing signals

Abstract

The invention discloses an expressway optical fiber point position calibration method based on distributed sound wave sensing signals, and the method comprises the following steps: converting facility stake marks on an expressway into optical fiber point positions, extracting an optical fiber signal feature set, enabling the feature set to be recognized and matched with facilities, and finally carrying out the linear calibration of any optical fiber point position stake mark. According to the highway optical fiber point location calibration method based on the distributed sound wave sensing signals, all point locations of the optical fiber are calibrated to the highway stake mark, so that information such as accidents, road conditions and early warning based on optical fiber calculation can be positioned to the specific stake mark, and the accuracy is improved.

Description

Technical Field

[0001] The invention relates to the field of traffic information technology, and in particular to a method for calibrating optical fiber points on a highway based on distributed acoustic wave sensing signals. Background Art

[0002] Distributed optical fiber sensing (DAS) technology is a sensing technology that emits laser beams and uses the principles of optical reflection, scattering and interference to detect sound and vibration signals in the environment. Distributed optical fiber sensing technology can use existing communication optical fibers to achieve long-distance, large-capacity continuous detection of roads and vehicles within a range of 20 to 50 kilometers.

[0003] For example, among the currently disclosed patent technologies, the announcement number CN114566040B and the patent name are a high-speed accident location system and method based on the buried optical cable of a communication company, including a high-speed accident location system composed of an underground communication optical cable, a distributed optical fiber vibration detector and a data processing unit, and an accident location method based on the system, which monitors the driving status of vehicles along the expressway in real time. Once an abnormal event occurs, the nature of the event is immediately determined and the time and location of the event are given, so that the relevant departments can initiate relevant feedback measures and broadcast warnings to vehicles in the accident section, which greatly improves the feedback efficiency of accidents on the expressway. The system uses distributed optical fiber sensing technology to focus on the location of accidents when they occur on the expressway.

[0004] Secondly, there is the patent with publication number CN118629213A and patent name "A highway traffic condition evaluation and warning integrated system based on distributed optical fiber", which includes a sensing optical fiber, which is laid along the extension direction of the highway lane to capture sound waves or vibration signals; a distributed optical fiber signal receiving component and a data processing module, which receives the sound wave or vibration signal transmitted by the sensing optical fiber and processes the signal into practical information; a highway traffic condition evaluation module, whose input end receives the practical information transmitted by the distributed optical fiber signal receiving component and the data processing module, and whose output is the traffic condition evaluation result of each section of the highway; a highway traffic warning response module, which receives the evaluation result transmitted by the highway traffic condition evaluation module. The system can perform multi-level fine-grained evaluation of the traffic conditions of each section of the highway through distributed optical fiber sensing technology, and control the warning lights on the highway to present different colors and flashing frequencies or sound alarms at the same time according to the evaluation results.

[0005] The above technologies are all based on the absolute distance of optical fiber to output accident, road conditions, and warning locations, but they ignore the fact that optical fiber may be bent, spliced, and coiled on highways, which may cause the actual geographical distance to be shorter than the optical fiber distance. For example, due to the construction and laying of optical fiber, its absolute length cannot represent the geographical distance; during highway operation, information on events and road conditions needs to be converted into road pile numbers; highway pile numbers are not absolutely accurate, so the calibration of optical fiber distance on pile numbers is not proportional. In view of this, it is necessary to improve this technology. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for calibrating optical fiber points on highways based on distributed acoustic wave sensing signals, so that all points on the optical fiber can be calibrated to the highway pile numbers, so that information such as accidents, road conditions, and warnings calculated based on the optical fiber can be located at specific pile numbers.

[0007] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0008] A method for calibrating optical fiber points on a highway based on distributed acoustic wave sensing signals comprises the following steps:

[0009] Step 1: Convert the facility pile number on the highway to the optical fiber point;

[0010] Step 2: Extracting the optical fiber signal feature set;

[0011] Step 3: Identify and match the feature set with the facility;

[0012] Step 4: Linear calibration of any optical fiber point number.

[0013] In the above technical solution, the optical fiber signal feature set extraction in step 2 includes:

[0014] a. Send pulses to the communication optical fiber pre-laid on the main line of the highway along the road;

[0015] b. The data acquisition system DAS collects and obtains the original vibration signal when the vehicle passes through the sensor fiber. c. Collect 10 minutes of vibration data and take the maximum vibration phase at each point

[0016]

[0017] d. Calculate the vibration threshold T = quantile (M, 1-Q)

[0018] e. Take a continuous point segment greater than T and generate a feature set A

[0019] f. If the number of feature sets is greater than the number of facilities, T = T + 1, repeat step e.

[0020] In the above technical solution, the highway structure is extracted in step 1. The highway has communication optical fibers laid along the main line of the highway. When encountering toll units and tunnel units, it is necessary to leave the main line and perform jumpering in the corresponding machine room, resulting in huge optical attenuation. Therefore, the optical fiber can be segmented into units according to the optical attenuation changes.

[0021] In the above technical solution, the process of segmenting the optical fiber into units in step 1 includes the following steps:

[0022] S11, the continuous optical fiber is counted as the optical fiber length F, and the front and rear jumper points are the first toll station and the second toll station respectively;

[0023] S12, calculating the actual road distance D = the pile number of the second toll station - the pile number of the first toll station through the highway structure information;

[0024] S13, extract all facilities from the first toll station to the second toll station through the highway structure information, B i For the i-th facility, P i = the starting pile number of facility i minus the pile number of the first toll station, L i For Facility B i length;

[0025] S14. Calculate the total length of the facility

[0026] S15. Calculate the proportion of facility length

[0027] S16, Facility i starting point

[0028] S17, facility i end point

[0029] In the above technical solution, during the identification and matching process between the feature set and the facility in step 3:

[0030] First, establish the distance matrix O;

[0031] The horizontal axis represents facility B i , where B i0 is the starting point of the facility, B i1 It is the end point of the facility;

[0032] The vertical axis is the feature set A j , where A j0 is the starting point of the collection, A j1 is the end point of the collection;

[0033] O ij Indicates facility B i With set A j The F1 score distance,

[0034] The formula is:

[0035] Then a dynamic programming algorithm is used to find the deviation matrix P, where the formula is:

[0036]

[0037] In the above technical solution, in step 4, when the optical fiber discrete points are calibrated, linear normalization is used to divide the intermediate points, where the formula is:

[0038]

[0039] In the above technical solution, the signal frequency of the original vibration signal when the data acquisition system DAS in step 2 collects the sensing optical fiber is 2000HZ, that is, 2000 frames of vibration data are generated per point per second, V nm is the vibration phase value of the mth frame at the nth optical fiber point.

[0040] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects:

[0041] The highway optical fiber point calibration method based on distributed acoustic wave sensor signals of the present invention calibrates all optical fiber points to highway pile numbers, so that information such as accidents, road conditions, and warnings calculated based on optical fiber can be located to specific pile numbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a logic flow chart of the highway optical fiber point calibration method based on distributed acoustic wave sensor signals of the present invention;

[0044] Figure 2 It is a point map before the optical fiber point calibration of the highway based on the distributed acoustic wave sensor signal of the present invention;

[0045] Figure 3 It is a point map after the optical fiber point positions of the highway are calibrated based on the distributed acoustic wave sensor signal of the present invention;

[0046] Figure 4 This is the optical fiber point map of the highway communication optical fiber of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0048] Please refer to Figures 1 to 3 As shown, the present invention discloses a method for calibrating optical fiber points on a highway based on distributed acoustic wave sensing signals. First, the facility pile numbers on the highway are converted into optical fiber points. In this process, characteristic points (such as jump points, bridges, tunnels, etc.) in the optical fiber signals are extracted to match the pile numbers of the highway, thereby calibrating the correspondence between the optical fiber points and the highway pile numbers. Therefore, it is necessary to extract the highway structure.

[0049] The communication optical fiber is laid along the main line of the expressway. When encountering toll units and tunnel units, it is necessary to leave the main line and jumper in the corresponding machine room, resulting in huge optical attenuation. Therefore, the optical fiber can be segmented into units according to the optical attenuation change. In the embodiment of the present invention, the subsequent implementation is in 0-16km units, where each point of the original optical fiber data represents 10m, so there are 1600 points in 16km. Please refer to Figure 4 shown.

[0050] The implementation process includes the following steps:

[0051] 1. The optical fiber length F is 0-16 km, and the front and rear jumper points are the first toll station and the second toll station respectively;

[0052] 2. Calculate the actual road distance D = the pile number of the second toll station - the pile number of the first toll station through the highway structure information;

[0053] 3. Extract all facilities from the first toll station to the second toll station through the highway structure information, B i For the i-th facility, P i = the starting pile number of facility i minus the pile number of the first toll station, L i For Facility B i length;

[0054] 4. Calculate the total length of the facility

[0055] 5. Calculate the proportion of facility length

[0056] 6. Facility i starting point

[0057] 7. Facility i terminal point

[0058] Table 1 below shows the starting and ending pile numbers and optical fiber starting and ending positions of the 23 facilities between the first toll station and the second toll station:

[0059] Table 1

[0060]

[0061]

[0062] Secondly, the optical fiber signal feature set is extracted, and the process includes the following steps:

[0063] 1. Send pulses to the communication optical fiber pre-laid on the main line of the highway along the road direction;

[0064] 2. The DAS system collects and obtains the original vibration signal when the vehicle passes through the sensor fiber. The signal frequency is 2000HZ, that is, 2000 frames of vibration data are generated per point per second. nm is the vibration phase value of the mth frame at the nth optical fiber point;

[0065] 3. Collect 10 minutes of vibration data and take the maximum vibration phase at each point

[0066]

[0067] 4. Calculate the vibration threshold T = quantile (M, 1-Q)

[0068] 5. Take the point segments that are continuous and greater than T to generate the feature set A

[0069] 6. If the number of feature sets is greater than the number of facilities, T=T+1, repeat step 5.

[0070] Table 2 below shows the set of 23 detected optical fiber signal features:

[0071] Table 2

[0072]

[0073]

[0074] The feature set and the facility are identified and matched. The identification and matching process in this embodiment includes the following steps:

[0075] 1. Establish a 23*23 distance matrix O;

[0076] 2. The horizontal axis represents facility B i , where B i0 is the starting point of the facility, B i1 The end point of the facility.

[0077] 3. The vertical axis is the feature set A j , where A j0 is the starting point of the collection, A j1 The end point of the collection.

[0078] 4. O ij Indicates facility B i With set A j The F1 score distance is:

[0079]

[0080]

[0081]

[0082] 5. Use the dynamic programming algorithm to find the deviation matrix P. The dynamic programming (DP) algorithm is usually used to solve a problem with optimal properties. In this type of problem, there may be many feasible solutions, each of which corresponds to a value. The dynamic programming algorithm is similar to the divide-and-conquer method. Its basic idea is to decompose the problem to be solved into several sub-problems, solve the sub-problems first, and then get the solution to the original problem from the solutions to these sub-problems.

[0083] The formula for the deviation matrix P obtained by the dynamic programming algorithm is:

[0084]

[0085] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 1 2 27 49 66 88 108 129 149 171 191 212 233 264 293 321 354 385 421 457 493 528 562 595 2 29 3 12 21 38 55 73 90 110 129 149 168 198 226 253 284 315 350 384 420 454 488 520 3 33 13 3 5 16 28 43 57 75 91 110 127 155 181 207 237 266 300 333 367 400 433 464 4 30 24 6 3 10 19 31 43 58 73 90 107 133 157 182 210 238 271 303 336 368 400 430 5 37 41 18 11 3 5 12 20 31 42 56 69 92 114 136 163 188 219 249 281 311 342 371 6 36 54 31 20 6 3 6 11 20 29 41 53 74 94 114 139 163 192 221 251 280 309 337 7 37 57 45 32 12 6 3 5 11 17 26 36 55 72 91 114 136 163 190 219 247 275 302 8 36 58 60 45 20 11 5 2 6 11 18 26 43 59 76 97 118 143 169 196 222 249 275 9 39 62 75 60 32 20 10 6 2 4 8 13 27 40 54 73 91 115 138 163 188 213 237 10 37 63 80 75 43 29 17 10 4 2 5 9 21 33 46 63 80 102 125 148 172 196 219 11 39 65 83 91 56 41 26 17 7 5 2 4 13 23 34 49 64 84 104 127 148 171 192 12 38 65 86 100 70 52 35 25 12 8 3 3 11 19 28 42 56 74 93 114 135 156 176 13 49 77 97 113 93 73 53 41 25 20 12 10 3 4 7 14 22 35 49 65 81 97 114 14 51 89 110 126 117 95 73 59 40 33 23 19 5 4 4 9 15 25 36 50 64 79 93 15 56 96 127 144 145 121 97 81 60 51 39 33 12 10 8 5 6 13 20 30 41 52 64 16 54 99 134 160 171 147 120 103 79 69 54 47 20 17 13 5 5 10 16 25 34 45 55 17 61 106 144 173 194 178 149 130 104 92 75 66 33 29 23 11 10 5 6 10 15 21 27 18 59 109 150 182 206 207 177 156 127 114 95 85 46 41 33 18 15 5 5 9 13 18 24 19 58 107 150 187 214 234 204 181 150 136 115 104 59 53 43 25 20 7 5 8 11 15 20 20 60 109 152 190 222 245 232 207 175 159 137 124 74 67 56 34 28 10 8 5 6 8 11 21 58 108 152 192 224 252 259 233 199 182 158 144 89 81 69 43 36 15 11 6 5 7 9 22 58 109 153 193 226 255 279 259 223 206 179 164 105 96 82 54 46 20 15 8 6 5 6 23 57 107 151 191 226 257 283 285 247 228 201 185 121 112 96 65 55 26 20 10 8 6 5

[0086] The route with the minimum deviation loss is shown in red in the table above.

[0087] One feature for multiple facilities: feature set 14 corresponds to facilities 14 and 15, and the longer facility 15 is taken. Multiple features for one facility: feature sets 18 and 19 correspond to facility 19, and the longer feature set 18 is taken.

[0088] facility Facility starting point Facility End Feature Collection Feature starting point Characteristic endpoint 1 189.8 196.5 1 195 198 2 245 251.7 2 249 255 3 288.1 292.1 3 293 294 4 310.2 313.3 4 314 316 5 372 375.8 5 377 378 6 405.4 408.4 6 408 410 7 449 452.4 7 449 452 8 481.7 485.4 8 481 482 9 539.8 544.8 9 538 544 10 566.9 569.7 10 565 567 11 620.6 623.1 11 616 618 12 651 652.9 12 646 647 13 837 840.1 13 829 831 14 860.7 861.4 / / / 15 912.4 914.9 14 900 901 16 1037.8 1040.4 15 1025 1027 17 1077.3 1084 16 1061 1067 18 1235.3 1245.6 17 1233 1243 / / / 18 1261 1261 19 1284.7 1291.4 19 1287 1296 20 1379.7 1388.4 20 1380 1389 21 1410.3 1433.7 21 1401 1425 22 1474.6 1485.8 22 1469 1480 23 1502.9 1505.9 23 1502 1504

[0089] Finally, the stake number of any optical fiber point is linearly calibrated. According to the bridge serial number, the corresponding relationship between the bridge starting stake number, the bridge end stake number and the optical fiber point is obtained. The points in the middle part of the two bridges are evenly distributed. For example, if the distance between the two bridges is 1 kilometer, there are 90 points, that is, the distance between the points in this section is not 10 meters but 11.1 meters.

[0090] In this process, the discrete points of the optical fiber were calibrated with stake numbers. For example, the optical fiber point 1502 was calibrated as the starting stake number 1480875 of facility 23, and the optical fiber point 1504 was calibrated as the ending stake number 1480904 of facility 23. Linear normalization was used to divide the intermediate points.

[0091]

[0092] In this embodiment, an example is given as follows: for example, the optical fiber point 1503 belongs to the point 1502-1504 interval, that is, it is located at the stake number 1480875-1480904, and its calibrated stake number is

[0093] The optical fiber point 1490 belongs to the point 1480-1502 interval, that is, it is located at stake 1480712-1480875, and its calibrated stake number is

[0094] In summary, the method for calibrating optical fiber points on highways based on distributed acoustic wave sensor signals of the present invention converts the facility pile numbers on the highway into optical fiber points, and then extracts the optical fiber signal feature set, so that the feature set is identified and matched with the facilities, and all optical fiber points are calibrated to the highway pile numbers, so that information such as accidents, road conditions, and warnings calculated based on optical fiber can be located at specific pile numbers to improve accuracy.

[0095] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A method for calibrating optical fiber points on a highway based on distributed acoustic wave sensing signals, characterized in that: The following steps are involved: S1, the location of the facility pile number on the highway to the fiber optic point; S2, optical fiber signal feature set extraction; S3, feature set and facilities are identified and matched; S4. Linear calibration of stake number at any optical fiber point.

2. The method for calibrating optical fiber points on highways based on distributed acoustic wave sensing signals according to claim 1, characterized in that: The optical fiber signal feature set extraction of S2 includes: a. Send pulses to the communication optical fiber pre-laid on the main line of the highway along the road; b. The data acquisition system DAS collects and obtains the original vibration signal when the vehicle passes through the sensor optical fiber. c. Collect 10 minutes of vibration data and take the maximum vibration phase at each point d. Calculate the vibration threshold T = quantile(M,1-Q); e. Take a continuous point segment greater than T to generate a feature set A; f. If the number of feature sets is greater than the number of facilities, T = T + 1, repeat step e.

3. The highway optical fiber point calibration method based on distributed acoustic wave sensing signals according to claim 2 is characterized in that: In the above S1, the structure of the expressway is extracted. The expressway has communication optical fibers laid along the main line. When encountering toll units and tunnel units, it is necessary to leave the main line and perform jumpering in the corresponding machine room, resulting in huge optical attenuation. Therefore, the optical fiber can be segmented into units according to the optical attenuation change.

4. The method for calibrating optical fiber points on highways based on distributed acoustic wave sensing signals according to claim 3, characterized in that: The process of performing unit segmentation on the optical fiber in S1 comprises the following steps: S11, the continuous optical fiber is counted as the optical fiber length F, and the front and rear jumper points are the first toll station and the second toll station respectively; S12, calculating the actual road distance D = the pile number of the second toll station - the pile number of the first toll station through the highway structure information; S13, extract all facilities from the first toll station to the second toll station through the highway structure information, B i For the i-th facility, P i = the starting pile number of facility i minus the pile number of the first toll station, L i For Facility B i length; S14. Calculate the total length of the facility S15. Calculate the proportion of facility length S16, Facility i starting point S17, facility i end point 5. The highway optical fiber point calibration method based on distributed acoustic wave sensing signals according to claim 1 is characterized in that: The feature set in S3 is used in the process of identification and matching with the facility: First, establish the distance matrix O; The horizontal axis represents facility B i , where B i0 is the starting point of the facility, B i1 It is the end point of the facility; The vertical axis is the feature set A j , where A j0 is the starting point of the collection, A j1 is the end point of the collection; O ij Indicates facility B i With set A j The F1 score distance, The formula is: Then a dynamic programming algorithm is used to find the deviation matrix P, where the formula is:

6. The highway optical fiber point calibration method based on distributed acoustic wave sensing signals according to claim 4 is characterized in that: In S4, when the optical fiber discrete points are calibrated, linear normalization is used to divide the intermediate points, where the formula is:

7. The method for calibrating optical fiber points on a highway based on distributed acoustic wave sensing signals according to claim 6, characterized in that: The signal frequency of the original vibration signal when the data acquisition system DAS in S2 collects the sensing optical fiber is 2000HZ, that is, 2000 frames of vibration data are generated per point per second. nm is the vibration phase value of the mth frame at the nth optical fiber point.

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