Road vehicle monitoring method and system based on distributed optical fiber vibration sensing technology

Abstract

The invention provides a road vehicle monitoring method and system based on a distributed optical fiber vibration sensing technology. The method comprises the following steps: acquiring a vibration signal; drawing a vehicle space-time trajectory diagram based on the vibration signal; extracting a vehicle trajectory based on the vehicle space-time trajectory diagram; and obtaining vehicle information according to the vehicle trajectory. According to the road vehicle monitoring method, the vehicle vibration signals are collected based on the DAS technology, the vehicle tracks are extracted from the vehicle space-time track diagram through the image processing algorithm, the traffic flow and the vehicle speed are monitored, long-distance and long-time-period dense monitoring can be achieved without deploying extra equipment, the processing process is convenient and visual, the monitoring result is efficiently obtained, and the monitoring efficiency is improved. In combination with an image processing technology, traffic flow information and vehicle speed information at any time and place on the road within a long distance and a long time period can be obtained without processing a large amount of data, and all-directional monitoring of the road is realized.

Description

Technical Field

[0001] The present application relates to the technical field of road vehicle monitoring, and in particular to a road vehicle monitoring method and system based on distributed optical fiber vibration sensing technology. Background Art

[0002] Monitoring of road vehicles, including traffic flow and speed information, plays a very important role in identifying abnormal road traffic conditions, providing navigation information for drivers, and formulating traffic light change strategies at various intersections. Traditional road monitoring solutions mainly rely on cameras or lidar, but such solutions are greatly affected by environmental factors, and the deployment density of cameras cannot achieve comprehensive and intensive road monitoring.

[0003] In recent years, a vehicle monitoring method based on distributed acoustic sensing (DAS) has been proposed and gradually applied to road monitoring tasks. In short, DAS uses the existing communication optical fiber laid under the road to emit a special modulated laser to it and demodulate the reflected laser to obtain vibration information at any position in the optical fiber. These vibrations are caused by vehicles driving on the road. By further processing them, information such as traffic flow and speed at any position on the road can be obtained, thereby realizing the monitoring of road vehicles.

[0004] There are many vehicle monitoring methods based on DAS technology. In the invention patent CN116955990A, based on the DAS signal, the collected vibration signal is converted into an image of the spatiotemporal distribution of vibration for processing, and the vehicle type and speed are further identified by fitting and classifying the pixels. However, the patent cannot detect the traffic volume and speed at the same time in the case of long-distance, long-time and high-density traffic.

[0005] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present application provides a road vehicle monitoring method and system based on distributed optical fiber vibration sensing technology, aiming to solve the problem in the prior art that it is impossible to simultaneously detect traffic flow and speed under long-distance, long-time, and high-density traffic conditions.

[0007] The present application provides a road vehicle monitoring method using distributed optical fiber vibration sensing technology, including the steps of: obtaining vibration signals; drawing a space-time trajectory diagram of the vehicle based on the vibration signals; extracting the vehicle trajectory line based on the space-time trajectory diagram of the vehicle; and obtaining vehicle information based on the vehicle trajectory line. The road vehicle monitoring method of the present application collects vehicle vibration signals based on DAS technology, and uses image processing algorithms to extract vehicle trajectories from the space-time trajectory diagram of the vehicle to monitor vehicle flow and speed. It can achieve intensive monitoring over long distances and long time periods without deploying additional equipment. The processing process is convenient and intuitive, and the monitoring results can be obtained efficiently. Combined with image processing technology, it can obtain traffic flow information and speed information at any time and place on the road over long distances and long time periods without a large amount of data processing, thereby achieving all-round road monitoring.

[0008] This application is implemented through the following technical solutions:

[0009] The first aspect of the present application is to provide a road vehicle monitoring method based on distributed optical fiber vibration sensing technology, comprising the following steps:

[0010] Obtain vibration signal;

[0011] Drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0012] Extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph;

[0013] Vehicle information is obtained according to the vehicle trajectory.

[0014] Specifically, the obtaining of the vibration signal comprises the steps of:

[0015] The laser pulse acts on a distributed optical fiber, and the distributed optical fiber receives the reflected scattered signal;

[0016] Based on an optical time domain reflectometer, the phase change of the scattered signal is demodulated to obtain the strain rate;

[0017] The strain rate of the distributed optical fiber within a target time at a target distance is collected and converted into the vibration signal.

[0018] Specifically, the method of drawing a space-time trajectory diagram of the vehicle based on the vibration signal comprises the steps of:

[0019] Preprocessing the vibration signal to extract target information;

[0020] splicing to obtain a continuous signal within the target time according to the target information;

[0021] According to the continuous signal, the signal features of the position node and the time node corresponding to the position node are extracted, and the space-time trajectory diagram of the vehicle is drawn.

[0022] Specifically, the preprocessing of the vibration signal to extract the target information includes removing the mean, removing the linear trend, filtering, and denoising the vibration signal, thereby extracting the target information including the vehicle information.

[0023] Specifically, the vehicle time-space trajectory diagram includes a horizontal axis, a vertical axis and colored lines, wherein the horizontal axis represents distance, the vertical axis represents time, and any colored line represents the vehicle driving trajectory generated by the target vehicle as time and space change.

[0024] Specifically, the extracting of the vehicle trajectory line based on the vehicle spatiotemporal trajectory graph comprises the steps of:

[0025] Graying the vehicle space-time trajectory diagram to form a grayscale image;

[0026] Binarize the grayscale image and corresponding data to obtain a binary image;

[0027] Based on the Hough algorithm, lines are detected from the binary image to extract vehicle trajectory lines.

[0028] Specifically, obtaining vehicle information according to the vehicle trajectory line includes counting the vehicle flow in any time period according to the vehicle trajectory line, specifically including:

[0029] Select the target location and target time period;

[0030] marking a target area on the vehicle trajectory map;

[0031] The number of vehicles in the target area is calculated, that is, the vehicle flow rate of the target location within the target time period.

[0032] Specifically, obtaining the vehicle information according to the vehicle trajectory line includes calculating the travel speed of the target vehicle according to the vehicle trajectory line, and specifically includes:

[0033] selecting a target trajectory segment of the vehicle trajectory line of the target vehicle;

[0034] Extracting a first position and a first time of a starting point, and a second position and a second time of an ending point of the target trajectory segment;

[0035] The inverse of the slope of the target trajectory segment is calculated according to the first position, the second position, the first time, and the second time to obtain the driving speed.

[0036] The second aspect of the present application is to provide a road vehicle monitoring system based on distributed optical fiber vibration sensing technology, comprising:

[0037] Data acquisition module: used to obtain vibration signals;

[0038] Drawing module: used for drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0039] Analysis module: used for extracting vehicle trajectory lines based on the vehicle spatiotemporal trajectory diagram, and obtaining vehicle information according to the vehicle trajectory lines, wherein the vehicle information includes vehicle flow and vehicle speed.

[0040] The third aspect of the present application is to provide a storage medium, which is a non-transitory computer-readable storage medium, storing a program of a road vehicle monitoring method based on distributed optical fiber vibration sensing technology, and when the program is executed by a processor, the following steps are implemented:

[0041] Obtain vibration signal;

[0042] Drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0043] Extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph;

[0044] Vehicle information is obtained according to the vehicle trajectory.

[0045] Compared with the prior art, this application mainly has the following beneficial effects:

[0046] The present application provides a road vehicle monitoring method using distributed optical fiber vibration sensing technology, including the steps of: obtaining vibration signals; drawing a space-time trajectory diagram of the vehicle based on the vibration signals; extracting the vehicle trajectory line based on the space-time trajectory diagram of the vehicle; and obtaining vehicle information based on the vehicle trajectory line. The road vehicle monitoring method of the present application collects vehicle vibration signals based on DAS technology, and uses image processing algorithms to extract vehicle trajectories from the space-time trajectory diagram of the vehicle to monitor vehicle flow and speed. It can achieve intensive monitoring over long distances and long time periods without deploying additional equipment. The processing process is convenient and intuitive, and the monitoring results can be obtained efficiently. Combined with image processing technology, it can obtain traffic flow information and speed information at any time and place on the road over long distances and long time periods without a large amount of data processing, thereby achieving all-round road monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1This is a flow chart of a road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to an embodiment of the present application.

[0049] Figure 2 This is a vehicle space-time trajectory diagram of an embodiment of the present application.

[0050] Figure 3 4 is a flow chart of extracting a vehicle trajectory line from a vehicle space-time trajectory diagram according to an embodiment of the present application.

[0051] Figure 4 Schematic diagram of a method for counting vehicle flow at a target location during a target time period according to an embodiment of the present application.

[0052] Figure 5 This is a schematic diagram of a road vehicle monitoring system based on distributed optical fiber vibration sensing technology according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the implementation methods of this application to clearly and completely describe the technical solutions in the implementation methods of this application. Obviously, the described implementation methods are only part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] It should be understood that the terms used in this specification of the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. As used in the specification of the embodiments of the present application and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0055] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0056] like Figure 1 As shown, the first aspect of the present application is to provide a road vehicle monitoring method based on distributed optical fiber vibration sensing technology, comprising the steps of:

[0057] S1, obtain vibration signal;

[0058] S2. Drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0059] S3, extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph;

[0060] S4. Obtain vehicle information according to the vehicle trajectory.

[0061] Specifically, step S1, obtaining a vibration signal, comprises the steps of:

[0062] S11, a laser pulse acts on a distributed optical fiber, and the distributed optical fiber receives a reflected scattered signal;

[0063] S12, based on an optical time domain reflectometer, demodulating the phase change of the scattered signal to obtain a strain rate;

[0064] S13, collecting the strain rate of the distributed optical fiber within a target time at a target distance, and converting it into the vibration signal.

[0065] Specifically, road vehicle monitoring based on distributed acoustic sensing (DAS) technology uses existing communication optical fibers laid under the road to emit special modulated lasers to them and demodulate the reflected lasers to obtain vibration information at any position in the optical fiber. These vibrations are caused by vehicles on the road. By further processing them, information such as traffic flow and speed at any position on the road can be obtained, thereby realizing the monitoring of road vehicles.

[0066] Specifically, the embodiment of the present application uses optical time domain reflectometry (OTDR) technology to demodulate its phase change and obtain the strain rate of each section of the optical fiber, collects the vibration signal caused by the vehicle driving on the road at a certain distance in real time, and converts it into a digital signal. Preferably, the time resolution of the collected signal is 1khz. For spatial resolution, each section of optical fiber with a fixed length (gauge length) is set as a series of signal channels, and each channel can be equivalent to a vibration sensor to record the average strain rate within the gauge length. The track spacing or spatial resolution can reach the meter level. After a period of collection, the original spatiotemporal vibration information is obtained, which is demodulated and converted into a vibration signal.

[0067] Specifically, step S2, drawing a vehicle space-time trajectory diagram based on the vibration signal, includes the steps of:

[0068] S21, preprocessing the vibration signal to extract target information;

[0069] S22, splicing to obtain continuous signals within the target time according to the target information;

[0070] S23. Extract signal features of position nodes and time nodes corresponding to the position nodes according to the continuous signal, and draw the space-time trajectory diagram of the vehicle.

[0071] Specifically, in step S21, the vibration signal is preprocessed to extract target information, including removing the mean, removing the linear trend, filtering, and denoising the vibration signal, so as to extract the target information containing vehicle information. Due to the high sampling rate and the large number of signal channels, the amount of data collected by DAS is often large, requiring accurate and efficient processing and analysis methods. The original vibration information is stored in the form of h5 files, each of which is 30 seconds long. Through preprocessing, cleaning and extraction of useful information, a longer recording signal is spliced ​​to ensure that it contains sufficient vehicle information, and through splicing, the information of each vehicle is connected accordingly.

[0072] Specifically, Figure 2 As shown, it is a vehicle time-space trajectory diagram of an embodiment of the present application, including abscissa, ordinate and colored lines, wherein the abscissa represents distance d, the ordinate represents time t, and any colored line represents the vehicle driving trajectory of the target vehicle generated by the time-space change. The colored lines in the figure can be dark red and blue lines, representing the vibration signals generated by the detected target vehicle as the time-space changes, reflecting the driving trajectory of the target vehicle.

[0073] The obtained vehicle spatiotemporal trajectory map contains not only vehicle trajectory information but also background noise information. Therefore, image processing is required to remove the background noise information and extract clean vehicle trajectories.

[0074] Specifically, step S3, based on the vehicle spatiotemporal trajectory graph, extracting the vehicle trajectory line, comprises the steps of:

[0075] S31, graying the vehicle space-time trajectory diagram to form a grayscale image;

[0076] S32, binarizing the grayscale image and corresponding data to obtain a binary image;

[0077] S33. Based on the Hough algorithm, detect lines from the binary image and extract vehicle trajectory lines.

[0078] like Figure 3As shown, it is a flow chart of extracting vehicle trajectory lines from a vehicle space-time trajectory diagram according to an embodiment of the present application. First, the vehicle space-time trajectory diagram is grayed to form a grayscale image, and then a threshold value K is set for binarization to obtain a binary image. After graying and binarization, the image background noise information can be effectively eliminated and the vehicle trajectory can be highlighted. After binarization, the Hough detection algorithm is performed to detect all the straight lines in the diagram. Specifically, the screening conditions are set, including the threshold for determining the number of straight line points, the minimum length L1 of the detected straight line, the longest breakpoint L2 allowed in the straight line, and the slope range [k1, k2] allowed for the straight line. Most of the straight lines that do not meet the requirements can be excluded, and the remaining straight lines are used as the final result of the detected vehicle trajectory. Each straight line represents a vehicle trajectory line.

[0079] Specifically, after obtaining the vehicle trajectory line, vehicle information can be extracted therefrom, including the traffic flow at the target location within a specific time period and the driving speed of a certain vehicle.

[0080] Specifically, step S4, obtaining vehicle information according to the vehicle trajectory line, includes:

[0081] S41, counting the vehicle flow in any period of time according to the vehicle trajectory line;

[0082] S42. Obtaining vehicle information according to the vehicle trajectory line, including calculating the driving speed of any vehicle according to the vehicle trajectory line.

[0083] Specifically, step S41, counting the vehicle flow in any period of time according to the vehicle trajectory line, includes:

[0084] S411, selecting a target location and a target time period;

[0085] S412, marking a target area on the vehicle trajectory map;

[0086] S413: Calculate the number of vehicles in the target area, that is, the vehicle flow rate of the target location in the target time period.

[0087] like Figure 4 As shown, it is a schematic diagram of the traffic flow statistics method of the target position in the target time period of an embodiment of the present application, which shows the traffic flow at position d in the time period t1 to t2. In this time period, there are 5 white vehicle trajectory lines corresponding to position d, so the traffic flow is 5.

[0088] Specifically, S42, obtaining vehicle information according to the vehicle trajectory line, including calculating the driving speed of the target vehicle according to the vehicle trajectory line, specifically includes:

[0089] selecting a target trajectory segment of the vehicle trajectory line of the target vehicle;

[0090] Extracting a first position and a first time of a starting point, and a second position and a second time of an ending point of the target trajectory segment;

[0091] The inverse of the slope of the target trajectory segment is calculated according to the first position, the second position, the first time, and the second time to obtain the driving speed.

[0092] Specifically, in one embodiment, a segment of any vehicle trajectory line is selected, the starting position is set to the first position d1, the ending position is set to the second position d2, the starting time corresponding to the starting position is the first time t1, and the ending position is the second time t2, then the calculation formula of the vehicle speed v is:

[0093]

[0094] The positive and negative signs of the vehicle speed represent different driving directions of the vehicle, that is, the present application can obtain the forward and reverse vehicle speed information respectively, thereby achieving complete monitoring.

[0095] like Figure 5 As shown, the second aspect of the present application is to provide a road vehicle monitoring system 10 based on distributed optical fiber vibration sensing technology, comprising:

[0096] Data acquisition module 11: used to obtain vibration signals;

[0097] Drawing module 12: used for drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0098] The analysis module 13 is used to extract the vehicle trajectory line based on the vehicle spatiotemporal trajectory diagram, and obtain vehicle information according to the vehicle trajectory line, wherein the vehicle information includes vehicle flow and vehicle speed.

[0099] A third aspect of the present application is to provide a storage medium, which is a non-transitory computer-readable storage medium, storing a program of a road vehicle monitoring method based on distributed optical fiber vibration sensing technology, and when the program is executed by a processor, the following steps are implemented:

[0100] Obtain vibration signal;

[0101] Drawing a space-time trajectory diagram of the vehicle based on the vibration signal;

[0102] Extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph;

[0103] Vehicle information is obtained according to the vehicle trajectory.

[0104] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-temporary computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0105] In summary, the present application provides a road vehicle monitoring method using distributed optical fiber vibration sensing technology, including the steps of: obtaining vibration signals; drawing a space-time trajectory diagram of the vehicle based on the vibration signals; extracting vehicle trajectory lines based on the space-time trajectory diagram of the vehicle; and obtaining vehicle information based on the vehicle trajectory lines. The road vehicle monitoring method of the present application collects vehicle vibration signals based on DAS technology, and uses image processing algorithms to extract vehicle trajectories from the space-time trajectory diagram of the vehicle to monitor vehicle flow and speed. It can achieve intensive monitoring over long distances and long time periods without deploying additional equipment. The processing process is convenient and intuitive, and the monitoring results can be obtained efficiently. Combined with image processing technology, it can obtain traffic flow information and speed information at any time and place on the road over long distances and long time periods without a large amount of data processing, thereby achieving all-round road monitoring.

[0106] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology, characterized in that: The following steps are involved: Obtain vibration signal; Drawing a space-time trajectory diagram of the vehicle based on the vibration signal; Extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph; Vehicle information is obtained according to the vehicle trajectory.

2. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 1, characterized in that: The step of obtaining the vibration signal comprises the following steps: The laser pulse acts on a distributed optical fiber, and the distributed optical fiber receives the reflected scattered signal; Based on an optical time domain reflectometer, the phase change of the scattered signal is demodulated to obtain the strain rate; The strain rate of the distributed optical fiber within a target time at a target distance is collected and converted into the vibration signal.

3. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 2, characterized in that: The method of drawing a space-time trajectory diagram of a vehicle based on the vibration signal comprises the steps of: Preprocessing the vibration signal to extract target information; splicing to obtain a continuous signal within the target time according to the target information; According to the continuous signal, the signal features of the position node and the time node corresponding to the position node are extracted, and the space-time trajectory diagram of the vehicle is drawn.

4. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 3, characterized in that: The preprocessing of the vibration signal to extract the target information includes removing the mean, removing the linear trend, filtering, and denoising the vibration signal, thereby extracting the target information including the vehicle information.

5. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 1, characterized in that: The vehicle space-time trajectory diagram includes a horizontal axis, a vertical axis and colored lines, wherein the horizontal axis represents distance, the vertical axis represents time, and any one of the colored lines represents the vehicle driving trajectory generated by the target vehicle as time and space change.

6. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 1, characterized in that: The method of extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph comprises the steps of: Graying the vehicle space-time trajectory diagram to form a grayscale image; Binarize the grayscale image and corresponding data to obtain a binary image; Based on the Hough algorithm, lines are detected from the binary image to extract vehicle trajectory lines.

7. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 6, characterized in that: The obtaining of vehicle information according to the vehicle trajectory line includes counting the vehicle flow in any period of time according to the vehicle trajectory line, specifically including: Select the target location and target time period; marking a target area on the map of the vehicle trajectory; The number of vehicles in the target area is calculated, that is, the vehicle flow rate of the target location within the target time period.

8. A road vehicle monitoring method based on distributed optical fiber vibration sensing technology according to claim 6, characterized in that: The obtaining of vehicle information according to the vehicle trajectory line includes calculating the travel speed of the target vehicle according to the vehicle trajectory line, specifically including: selecting a target trajectory segment of the vehicle trajectory line of the target vehicle; Extracting a first position and a first time of a starting point, and a second position and a second time of an ending point of the target trajectory segment; The inverse of the slope of the target trajectory segment is calculated according to the first position, the second position, the first time, and the second time to obtain the driving speed.

9. A road vehicle monitoring system based on distributed optical fiber vibration sensing technology, characterized in that: include: Data acquisition module: used to obtain vibration signals; Drawing module: used for drawing a space-time trajectory diagram of the vehicle based on the vibration signal; Analysis module: used for extracting vehicle trajectory lines based on the vehicle spatiotemporal trajectory diagram, and obtaining vehicle information according to the vehicle trajectory lines, wherein the vehicle information includes vehicle flow and vehicle speed.

10. A storage medium, characterized in that: The storage medium is a non-transitory computer-readable storage medium, storing a program of a road vehicle monitoring method based on distributed optical fiber vibration sensing technology, and when the program is executed by a processor, the following steps are implemented: Obtain vibration signal; Drawing a space-time trajectory diagram of the vehicle based on the vibration signal; Extracting a vehicle trajectory line based on the vehicle spatiotemporal trajectory graph; Vehicle information is obtained according to the vehicle trajectory.

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