Traffic monitoring device, traffic monitoring system, traffic monitoring method, and program

Abstract

To detect stopping of a vehicle group on a road or traveling of the vehicle group at a speed equal to or less than a threshold value without preparing a pattern for matching or a learning model in advance.SOLUTION: A traffic monitoring device according to the present disclosure includes a calculation unit configured to acquire, from a measurement device that performs optical fiber sensing using an optical fiber laid along a road, vibration data indicating vibration generated by a vehicle traveling on the road, and calculate, for each section of the road, an average speed value of a vehicle group traveling in the section based on the acquired vibration data, and a detection unit configured to detect a stop of the vehicle group or traveling of the vehicle group at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a traffic monitoring device, a traffic monitoring system, a traffic monitoring method, and a program. [Background technology]

[0002] In December 2020, heavy snowfall caused thousands of vehicles to become stranded on the Kanetsu Expressway. For this reason, in recent years, importance has been placed on early detection of a group of vehicles stopped on a road or traveling at a speed below a threshold (a group of vehicles traveling at a speed close to stopping).

[0003] CCTV (Closed-circuit Television) and other surveillance cameras are installed at frequent intervals on urban expressways, making it possible to carry out the above detection relatively early.

[0004] On the other hand, there are few surveillance cameras installed on suburban expressways where the impact of heavy snow is a concern, and therefore, the cost of installing and maintaining the surveillance cameras to perform the above detection would be enormous.

[0005] Therefore, optical fiber sensing, which can monitor traffic flow on roads continuously and at low cost by using optical fibers already installed for communication purposes, has recently been attracting attention, and it is expected that optical fiber sensing will be used to perform the above detection.

[0006] For example, Patent Document 1 discloses a technology for detecting road congestion by acquiring the vehicle position on a road using optical fiber sensing, and performing pattern matching between the vehicle position history and a matching pattern, which is a congestion pattern (a pattern of the vehicle position history when congestion occurs), or by using a learning model that has learned the congestion pattern. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2022 / 185922 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, according to the technology disclosed in Patent Document 1, it is possible to detect road congestion using optical fiber sensing. However, the technique disclosed in Patent Document 1 has a problem in that it is necessary to prepare a matching pattern or a learning model in advance.

[0009] Therefore, the object of the present disclosure is to provide a traffic monitoring device, a traffic monitoring system, a traffic monitoring method, and a program that can detect a group of vehicles stopped on a road or traveling at a speed below a threshold without preparing a matching pattern or learning model in advance. [Means for solving the problem]

[0010] A traffic monitoring device according to one aspect comprises: a calculation means for acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and for calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection means for detecting whether a group of vehicles is stopped or traveling at a speed equal to or lower than a threshold value based on the time transition of the average speed value for each section of the road.

[0011] A traffic monitoring system according to one aspect includes: the traffic monitoring device; The measuring device; The management device.

[0012] A traffic monitoring method according to one aspect includes: 1. A traffic monitoring method performed by a traffic monitoring device, comprising: a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection step of detecting whether the group of vehicles is stopped or traveling at a speed equal to or lower than a threshold value based on the time transition of the average speed value for each section of the road.

[0013] In one aspect, the program comprises: On the computer, a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; A detection procedure is executed to detect whether a group of vehicles is stopped or traveling at a speed equal to or lower than a threshold value based on the time transition of the average speed value for each section of the road. [Effects of the Invention]

[0014] According to the above-described aspects, it is possible to provide a traffic monitoring device, a traffic monitoring system, a traffic monitoring method, and a program that can detect a group of vehicles stopping on a road or a group of vehicles traveling at a speed below a threshold without preparing a matching pattern or a learning model in advance. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating a schematic configuration example of a traffic monitoring system according to the present disclosure. [Figure 2] 10A and 10B are diagrams illustrating an example of visualization of vibration data derived by the measurement device according to the present disclosure. [Figure 3] 10A and 10B are diagrams illustrating an example of a detection operation by a detection unit according to the present disclosure. [Figure 4] 10A and 10B are diagrams illustrating an example of a detection operation by a detection unit according to the present disclosure. [Figure 5] 10A and 10B are diagrams illustrating an example of a detection operation by a detection unit according to the present disclosure. [Figure 6] FIG. 2 is a flow diagram illustrating an example of a schematic operation flow of a traffic monitoring device according to the present disclosure. [Figure 7] FIG. 2 is a block diagram illustrating a schematic hardware configuration example of a computer that realizes the traffic monitoring device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings have been omitted and simplified as appropriate for clarity of explanation. In addition, in each of the following drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, specific numerical values ​​shown below are merely examples to facilitate understanding of the present disclosure, and are not limited thereto.

[0017] First, a configuration example of a traffic monitoring system 1 according to the present disclosure will be described. FIG. 1 is a diagram showing a schematic configuration example of a traffic monitoring system 1 according to the present disclosure. As shown in FIG. 1, a traffic monitoring system 1 according to the present disclosure includes a measurement device 20, a traffic monitoring device 30, and a management device 40.

[0018] As will be described later, the optical fiber 10 is laid along the road R. There are no particular limitations on the laying method of the optical fiber 10, as long as it is laid along the road R. In the following, it is assumed that the optical fiber 10 is buried in the road R along the road R, but it may also be laid overhead on a structure such as a utility pole.

[0019] The measuring device 20 is connected to an optical fiber 10 laid along a road R. Therefore, the measuring device 20 is installed near the road R. On the other hand, the traffic monitoring device 30 and the management device 40 may be installed in any location, and may be placed on the cloud, for example.

[0020] The measuring device 20 performs optical fiber sensing using an optical fiber 10 laid along the road R, and is realized by, for example, a DAS (Distributed Acoustic Sensing) device. Specifically, the measuring device 20 measures vibrations generated by a vehicle traveling on the road R based on an optical signal (backscattered light) received from the optical fiber 10.

[0021] Furthermore, the measurement device 20 derives vibration data indicating the vibrations measured by the optical fiber sensing. Specifically, the measurement device 20 derives vibration data by accumulating the vibrations measured by the optical fiber sensing in the time direction and distance direction for a certain period of time.

[0022] FIG. 2 is a diagram illustrating an example of visualization of vibration data derived by the measurement device 20. In FIG. In Fig. 2, the lower diagram shows the traffic situation on road R. The upper diagram shows vibration data, with the horizontal axis indicating the position where the vibration occurred (the distance of the optical fiber 10 from the measuring device 20) and the vertical axis indicating the time when the vibration occurred. The more positive the vertical axis, the older the data.

[0023] In the vibration data shown in FIG. 2, a vehicle traveling on road R is represented by a single diagonal line. The positive or negative slope of the line indicates the direction in which the vehicle is traveling. In the example of FIG. 2, a vehicle represented by a line with a positive slope is traveling in a direction approaching the measurement device 20, and a vehicle represented by a line with a negative slope is traveling in a direction away from the measurement device 20. The absolute value of the slope of the line represents the speed of the vehicle. In the example of FIG. 2, the smaller the absolute value of the slope of the line, the faster the vehicle is traveling.

[0024] The traffic monitoring device 30 includes a calculation unit 31 and a detection unit 32 . The calculation unit 31 acquires vibration data derived by the measuring device 20 (for example, vibration data visualized as shown in Figure 2), and calculates the average speed value of the group of vehicles traveling on each section of road R based on the acquired vibration data.

[0025] The detection unit 32 detects whether the vehicle group is stopped or traveling at a speed equal to or less than a threshold value based on the time transition of the average speed value for each section of the road R calculated by the calculation unit 31. Note that traveling at a speed equal to or less than the threshold value of the vehicle group means traveling at a speed close to stopping. Therefore, the threshold value may be set to any speed within the range of, for example, greater than 0 km / h and equal to or less than 20 km / h. The detection operation by the detection unit 32 will be described in detail later. The detection unit 32 notifies the management device 40 of the detection result that the vehicle group has stopped or that the vehicle group is traveling at a speed equal to or lower than the threshold.

[0026] The management device 40 is a device that receives a notification of the detection result of the vehicle group being stopped or traveling at a speed below a threshold from the detection unit 32. The management device 40 is realized by a device installed in, for example, a road control center.

[0027] Next, the detection operation by the detection unit 32 will be described in detail. 3 to 5 are diagrams illustrating an example of the detection operation by the detection unit 32. In FIG. In Figures 3 to 5, the lower diagrams show the traffic conditions on road R at each time. The upper diagrams show the time transition of the average speed values ​​for each section r1 to r5 on road R up to the time shown in the lower diagram, with the horizontal axis representing the position (the distance of the optical fiber 10 from the measuring device 20) and the vertical axis representing the time. The more negative the vertical axis is (the downward direction in the diagram), the newer the data. The calculation unit 31 calculates the average speed values ​​at one-minute intervals. Therefore, t(n+1) = t(n)+1 (n = 1, 2, 3, ...).

[0028] As shown in Fig. 3, at time t2, traffic flow is in a normal state, and at this time, an average speed value exists in all sections r1 to r5.

[0029] At the next time t3, the group of vehicles stops or travels at a speed below the threshold. At this time, there is no average speed value in the front sections r4 and r5. On the other hand, there is an average speed value in the rear section r3.

[0030] When a group of vehicles is stopped, no vibrations are generated due to the movement of the vehicles, and therefore, optical fiber sensing by the measurement device 20 cannot detect vibrations due to the movement of the vehicles. Furthermore, when a group of vehicles is traveling at a speed below a threshold, optical fiber sensing by the measurement device 20 can only detect weak vibrations that cannot be distinguished from being stopped. Therefore, when a group of vehicles is stopped or traveling at a speed below a threshold, the calculation unit 31 cannot calculate the average speed value of the group of vehicles, and therefore, no average speed value exists.

[0031] As shown in FIG. 4, at the following time t4, the state in which the vehicle group is stopped or traveling at a speed equal to or lower than the threshold continues from time t3.

[0032] At the next time t6, the section where the group of vehicles is stopped or traveling at a speed below the threshold extends further back. At this time, the following vehicles gradually stop or travel at a speed below the threshold. As a result, there is no longer an average speed value in section r3. In other words, the section where there is no average speed value extends further back. The length of this section r3 corresponds to the extension of the length of the group of vehicles that are stopped or traveling at a speed below the threshold.

[0033] As shown in FIG. 5, at the following time t7, the state in which the vehicle group is stopped or traveling at a speed equal to or lower than the threshold continues from time t6.

[0034] 3 to 5, when a group of vehicles is stopped or traveling at a speed below the threshold, there is a section ahead where there is no average speed value, and a section behind where there is an average speed value. This state continues as long as the group of vehicles is stopped or traveling at a speed below the threshold.

[0035] In light of the above, the detection unit 32 may detect a group of vehicles stopping or traveling at a speed below the threshold value when there is a section ahead where there is no average speed value and a section behind where there is an average speed value.

[0036] However, the same situation can occur if only one snowplow or broken-down vehicle is stopped during snowfall. Therefore, the detection unit 32 may detect that the group of vehicles is stopped or traveling at a speed below the threshold value of the group of vehicles when there is a section ahead where there is no average speed value and a section behind where there is an average speed value, and this state continues for a predetermined period of time.

[0037] Furthermore, when the detection unit 32 detects that a group of vehicles has stopped or that a group of vehicles is traveling at a speed equal to or lower than a threshold, the detection unit 32 may notify the management device 40 of the detection result.

[0038] Furthermore, the detection unit 32 may identify the length of a group of vehicles that are stopped or traveling at a speed below the threshold based on the length of a section where there is no average speed value ahead and the length of a section where there is an average speed value behind. For example, at times t3 and t4, the detection unit 32 may identify the length of a group of vehicles that are stopped or traveling at a speed below the threshold as the length of section r3. At times t6 and t7, the detection unit 32 may identify the length of a group of vehicles that are stopped or traveling at a speed below the threshold as the length of sections r2 and r3.

[0039] Next, an example of the flow of operations of the traffic monitoring device 30 will be described. FIG. 6 is a flow diagram illustrating an example of a schematic operation flow of the traffic monitoring device 30. As shown in FIG. 6, first, the calculation unit 31 acquires vibration data indicating vibrations generated by a vehicle traveling on the road R from a measurement device 20 that performs optical fiber sensing using an optical fiber 10 laid along the road R (step S11).

[0040] Next, the calculation unit 31 calculates, for each section of the road R, the average speed value of the group of vehicles traveling on that section, based on the vibration data acquired from the measurement device 20 (step S12). Thereafter, the detection unit 32 detects whether the vehicle group is stopped or traveling at a speed equal to or lower than the threshold value, based on the time transition of the average speed value for each section of the road R calculated by the calculation unit 31 (step S13).

[0041] As described above, according to the first embodiment, the calculation unit 31 acquires vibration data indicating vibrations caused by vehicles traveling on road R from the measurement device 20 that performs optical fiber sensing using optical fiber 10 laid along road R, and calculates the average speed value of a group of vehicles traveling on each section of road R based on the acquired vibration data. The detection unit 32 detects whether the group of vehicles is stopped or traveling at a speed below a threshold based on the time transition of the average speed value for each section of road R. This makes it possible to detect whether a group of vehicles is stopped on road R or traveling at a speed below a threshold without preparing a matching pattern or a learning model in advance.

[0042] <Hardware configuration of traffic monitoring device> FIG. 7 is a block diagram showing an example of a schematic hardware configuration of a computer 90 that realizes the traffic monitoring device 30. As shown in FIG.

[0043] 7, the computer 90 includes a processor 91, a memory 92, a storage 93, an input / output interface (input / output I / F) 94, and a communication interface (communication I / F) 95. The processor 91, the memory 92, the storage 93, the input / output interface 94, and the communication interface 95 are connected by a data transmission path for transmitting and receiving data to and from each other.

[0044] The processor 91 is, for example, an arithmetic processing device such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The memory 92 is, for example, a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The storage 93 is, for example, a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a memory card. The storage 93 may also be a memory such as a RAM or a ROM.

[0045] A program is stored in the storage 93. When the program is loaded into a computer, it contains a set of instructions (or software code) that causes the computer 90 to perform one or more functions of the traffic monitoring device 30 described above. The components of the traffic monitoring device 30 described above may be realized by the processor 91 reading and executing the program stored in the storage 93. Furthermore, the storage function of the traffic monitoring device 30 described above may be realized by the memory 92 or the storage 93.

[0046] The above-described programs may also be stored on non-transitory computer-readable media or tangible storage media. By way of example and not limitation, computer-readable media or tangible storage media include RAM, ROM, flash memory, SSD or other memory technology, CD (Compact Disc)-ROM, DVD (Digital Versatile Disc), Blu-ray® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The programs may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0047] The input / output interface 94 is connected to a display device 941, an input device 942, a sound output device 943, etc. The display device 941 is a device that displays a screen corresponding to drawing data processed by the processor 91, such as an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube) display, or a monitor. The input device 942 is a device that accepts operational inputs from an operator, such as a keyboard, a mouse, or a touch sensor. The display device 941 and the input device 942 may be integrated and realized as a touch panel. The sound output device 943 is a device that outputs sound corresponding to audio data processed by the processor 91, such as a speaker.

[0048] The communication interface 95 transmits and receives data to and from an external device. For example, the communication interface 95 communicates with the external device via a wired communication path or a wireless communication path.

[0049] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0050] Furthermore, each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessarily required to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0051] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. (Appendix 1) a calculation means for acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and for calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection means for detecting whether a group of vehicles is stopped or whether the group of vehicles is traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. Traffic monitoring equipment. (Appendix 2) the detection means detects that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value when there is a section ahead where there is no average speed value and a section behind where there is an average speed value; 10. A traffic monitoring device as described in Appendix 1. (Appendix 3) the detection means detects that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value when a state in which there is a section ahead where there is no average speed value and a section behind where there is an average speed value continues for a predetermined period of time; 10. A traffic monitoring device as described in Appendix 1. (Appendix 4) the detection means identifies the length of the group of vehicles that are stopped or traveling at a speed equal to or less than the threshold based on the length of a section where there is no average speed value ahead and the length of a section where there is an average speed value behind. 4. A traffic monitoring device according to claim 2 or 3. (Appendix 5) When the detection means detects that the vehicle group has stopped or that the vehicle group has traveled at a speed equal to or lower than a threshold, the detection means notifies the management device of the detection result. 10. A traffic monitoring device as described in Appendix 1. (Appendix 6) a traffic monitoring device according to claim 5; The measuring device; The management device, Traffic monitoring system. (Appendix 7) 1. A traffic monitoring method performed by a traffic monitoring device, comprising: a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection step of detecting whether a group of vehicles is stopped or whether a group of vehicles is traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. Traffic monitoring methods. (Appendix 8) In the detection step, when there is a section ahead where there is no average speed value and there is a section behind where there is an average speed value, it is detected that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value. 7. A traffic monitoring method as set forth in claim 7. (Appendix 9) On the computer, a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection step of detecting whether a group of vehicles is stopped or traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. program. (Appendix 10) In the detection procedure, when there is a section ahead in which an average speed value does not exist and there is a section behind in which an average speed value exists, the vehicle group is detected as having stopped or traveling at a speed equal to or less than a threshold value. 10. The program described in Appendix 9.

[0052] Note that some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 5 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 7 and 9 in the same dependency relationship as Supplementary Notes 2 to 5. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0053] 1. Traffic monitoring system 10 Optical Fiber 20 Measuring equipment 30 Traffic monitoring device 31 Calculation section 32 Detection unit 40 Management device 90 Computer 91 processors 92 memory 93 Storage 94 Input / Output Interface 941 Display device 942 Input Device 943 Sound Output Device 95 Communication Interface R road

Claims

1. a calculation means for acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and for calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection means for detecting whether a group of vehicles is stopped or whether the group of vehicles is traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. Traffic monitoring equipment.

2. the detection means detects that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value when there is a section ahead where there is no average speed value and a section behind where there is an average speed value; 2. A traffic monitoring device according to claim 1.

3. the detection means detects that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value when a state in which there is a section ahead where there is no average speed value and a section behind where there is an average speed value continues for a predetermined period of time; 2. A traffic monitoring device according to claim 1.

4. the detection means identifies the length of the group of vehicles that are stopped or traveling at a speed equal to or less than the threshold based on the length of a section where there is no forward average speed value and the length of a section where there is a rearward average speed value.

4. A traffic monitoring device according to claim 2 or 3.

5. When the detection means detects that the vehicle group has stopped or that the vehicle group has traveled at a speed equal to or lower than a threshold, the detection means notifies the management device of the detection result.

2. A traffic monitoring device according to claim 1.

6. A traffic monitoring device according to claim 5; The measuring device; The management device, Traffic monitoring system.

7. 1. A traffic monitoring method performed by a traffic monitoring device, comprising: a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection step of detecting whether a group of vehicles is stopped or whether a group of vehicles is traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. Traffic monitoring method.

8. In the detection step, when there is a section ahead where there is no average speed value and there is a section behind where there is an average speed value, it is detected that the vehicle group is stopped or that the vehicle group is traveling at a speed equal to or lower than a threshold value.

8. A method for traffic monitoring according to claim 7.

9. On the computer, a calculation step of acquiring vibration data indicating vibrations caused by vehicles traveling on a road from a measurement device that performs optical fiber sensing using optical fibers laid along the road, and calculating, for each section of the road, an average speed value of a group of vehicles traveling on that section based on the acquired vibration data; and a detection step of detecting whether a group of vehicles is stopped or traveling at a speed equal to or lower than a threshold based on a time transition of the average speed value for each section of the road. program.

10. In the detection procedure, when there is a section ahead in which an average speed value does not exist and there is a section behind in which an average speed value exists, the vehicle group is detected as having stopped or traveling at a speed equal to or less than a threshold value. The program according to claim 9.

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