Visual positioning device, method and equipment for train in tunnel and medium

Abstract

The invention relates to a visual positioning device, method and equipment for a train in a tunnel and a medium. The device comprises a vehicle-mounted controller, a vehicle-mounted visual odometer, a train surface identification code, a trackside visual beacon, a trackside visual counter axle and feature points arranged in the tunnel according to a set distance. The vehicle-mounted visual odometer collects trackside visual beacons and feature points, and the trackside visual odometer collects train surface identification codes; the vehicle-mounted controller obtains the current speed and the relative displacement from the vehicle-mounted visual odometer, calculates the current position in the line according to the trackside visual beacon and conducts calibration and positioning, and meanwhile obtains the current position in the line from the trackside visual odometer and conducts calibration and positioning, so that continuous speed measurement and positioning of the train are achieved. Compared with the prior art, the method has the advantages that the redundancy and availability of the positioning system are enhanced, the cost is lower and the like.

Description

Technical Field

[0001] The present invention relates to a rail transit signal system, and in particular to a visual positioning device, method, equipment and medium for a train in a tunnel. Background Art

[0002] At present, there are two commonly used speed measurement and positioning methods in the rail transit signal industry. One is to use a photoelectric / Hall speed sensor combined with a ground beacon, and the other is to use a satellite virtual transponder combined with a speed sensor. The former's positioning accuracy depends on the density of beacons, and the system cost is relatively high. The latter's satellite signal is easily affected by tunnels, buildings, etc., has high requirements for terrain, and has low universality.

[0003] After searching, Chinese patent publication number CN111114593A discloses a subway train autonomous positioning device, system and method based on multi-information fusion, which specifically discloses an inertial navigation device for autonomous navigation and positioning of subway trains and calculation of inertial navigation positioning information; a visual device for monitoring image beacons set at fixed positions beside the subway track and calculating visual positioning information; a data processing device for receiving information reported by the inertial navigation device and the visual device, performing information fusion and obtaining fused positioning information; although the patent uses a visual device to achieve positioning, the visual device is used to measure the distance between the front of the vehicle and the landmark, and the information collected by the visual device is only used as a source of fusion information, and its weight is not clear, and it does not involve operations when the on-board autonomous positioning system fails.

[0004] At the same time, Chinese patent publication number CN116946214A discloses a train positioning and speed measurement system, method, equipment and medium based on visual recognition, which specifically includes: a mileage sign with a QR code, arranged beside the track at a set distance; a camera, used to collect the QR code image on the mileage sign; a security host, connected to the camera, used to parse the QR code image collected by the camera, identify the mileage sign in front, and use the positioning pattern on the QR code to calculate the distance from the vehicle to the mileage sign in front through a distance measurement algorithm. Although the patent uses a visual device to achieve positioning, the visual device is used for distance measurement, and it can only measure the distance when there is a kilometer mark within the viewing range, which is a non-continuous distance measurement method.

[0005] In addition, Chinese patent publication number CN116136404A discloses a low-cost, all-regional train control vehicle-mounted equipment speed measurement and positioning method and device. Specifically, if the satellite signal status is in a failed state, a multi-sensor fusion method is used to establish an inertial sensor error model, and the difference between the inertial sensor and other sensor measurement values ​​is used to estimate the inertial sensor error and perform feedback correction to obtain the final train status information. Although the patent uses visual equipment to achieve positioning, the specific positioning process of the visual equipment is not involved, and the information collected by the visual equipment is only used as a fusion information source, and the weight is not clear.

[0006] It can be seen that the speed measurement and positioning methods commonly used in the prior art cannot take into account both cost and universality in the tunnel environment, and the publicly available solutions using visual positioning cannot be used alone (there is a problem of inability to position continuously), and require the assistance of other types of speed measurement and positioning equipment, and lack countermeasures after failure. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a visual positioning device, method, equipment and medium for trains in tunnels.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] According to a first aspect of the present invention, there is provided a visual positioning device for a train in a tunnel, the device comprising an onboard controller, an onboard visual odometer, a train surface identification code, a trackside visual beacon, a trackside visual axle counter, and feature points arranged at set distances inside the tunnel;

[0010] The on-board visual odometer collects trackside visual beacons and feature points, and the trackside visual axle meter collects train surface identification codes; the on-board controller obtains the current speed and relative displacement from the on-board visual odometer, calculates the current position in the line according to the trackside visual beacons and performs calibration positioning, and at the same time obtains the current position in the line from the trackside visual axle meter and performs calibration positioning, thereby realizing continuous speed measurement and positioning of the train.

[0011] As a preferred technical solution, the on-board controller includes a first computing unit and a first storage device, the first computing unit obtains an electronic route map containing trackside visual beacon information from the first storage device, and the first storage device is used to store the electronic route map and train parameters.

[0012] As a preferred technical solution, the on-board visual odometer includes a first camera and a first image processing unit. The first camera acquires trackside images and trackside visual beacons and sends them to the first image processing unit. The first image processing unit calculates the relative running distance of the train based on the acquired trackside images and positions and calibrates the train based on the trackside visual beacons.

[0013] As a preferred technical solution, the train surface identification code includes a first QR code and a first bar code, both corresponding to the train's unique identification code.

[0014] As a preferred technical solution, the trackside visual beacon includes up and down direction identifications and a second QR code and a second bar code, and the second QR code and the second bar code both correspond to the unique identification code of the visual beacon in the electronic route map.

[0015] As a preferred technical solution, the trackside visual axle counting system includes a second camera, a second image processing unit and a communication device. The second camera collects the train surface identification code and sends it to the second image processing unit. The second image processing unit identifies the train, calculates the train position, and sends a position message to the train through the communication device, and at the same time sends the train position message to the control center.

[0016] As a preferred technical solution, the characteristic points arranged at set distances inside the tunnel include reflective letter and number patterns, and are not repeated along the entire line.

[0017] As a preferred technical solution, the distance between each two feature points is determined by the field of view of the camera of the on-board visual odometer, ensuring that when the train is at a set speed, the image collected in each cycle contains at least one feature point.

[0018] According to a second aspect of the present invention, a positioning method using the visual positioning device for trains in a tunnel is provided, the method comprising the following steps:

[0019] Step S1, the onboard controller pre-stores an electronic route map containing the trackside visual beacon information, and the trackside visual axle counter pre-stores the identification codes of all trains that may run on the route;

[0020] Step S2, the train performs positioning initialization according to the trackside visual beacon;

[0021] Step S3, the on-board visual odometer periodically acquires the trackside image and calculates the relative running distance, and the on-board controller accumulates the running distance;

[0022] Step S4, when the trackside visual beacon is detected, the on-board visual odometer performs positioning calibration;

[0023] Step S5, when the trackside visual axle counter detects a train passing by, it identifies the train and continuously calculates the train position, then sends a position message to the train and simultaneously sends a train position message to the control center;

[0024] Step S6: When a communication failure occurs in the train, or a failure occurs in the onboard controller, or a failure occurs in the onboard visual odometer, the trackside visual axle counter detects the train position and reports the faulty train position to the control center.

[0025] As a preferred technical solution, the trackside visual beacon information in step S1 includes a unique identification code of each visual beacon and its position on the track.

[0026] As a preferred technical solution, the specific process of positioning initialization in step S2 is as follows:

[0027] The on-board visual odometer detects a trackside visual beacon, identifies a unique identification code of the beacon based on a second QR code and a second barcode on the trackside visual beacon, obtains a basic position based on the position of the unique identification code on a route map, obtains an offset of the basic position based on a distance difference between a focal center of a first camera and a center of the beacon, and obtains a running direction based on an up and down direction identification on the beacon combined with a displacement direction relative to the beacon in two cycles before and after, thereby calculating an initialization positioning of the train.

[0028] As a preferred technical solution, the relative running distance is calculated in step S3 as follows:

[0029] Step S301, training static image data of feature points in the tunnel to obtain an initialization model;

[0030] Step S302, combining the dynamic image data taken at low, medium and high vehicle speeds, continuing to train the initialization model to obtain a basic model;

[0031] Step S304, adding noise data to the dynamic image data, training the basic model, and obtaining the application model;

[0032] Step S305, in the field application, the application model is used to identify the feature points in the collected image, and the relative distance of the same feature point in two consecutive cycles is calculated to obtain the relative running distance of the train.

[0033] As a preferred technical solution, the positioning calibration in step S4 is specifically as follows:

[0034] Step S401, the onboard controller calculates the position of the train according to the position of the visual beacon, which is the same as the positioning initialization process in step S2;

[0035] Step S402, the onboard controller accumulates the relative displacement fed back by the visual odometer in each cycle to obtain the second train position;

[0036] Step S403, correcting the train position 2 according to the train position 1 to obtain the train position 3, that is, obtaining a more accurate train position.

[0037] As a preferred technical solution, the identification of the train and continuous calculation of the train position in step S5 is specifically as follows:

[0038] Step S501, training a model for identifying trains for trackside visual axle counting;

[0039] Step S502, pre-marking and calibrating absolute position points within the viewing range of the second camera of the trackside visual axle counting system, which serve as reference points for locating the train position in subsequent processes;

[0040] Step S503, when a train is identified to pass (in two consecutive cycles, the train goes from not appearing in the picture to appearing in the picture), the train identification code is identified (and mutually verified) through the QR code and barcode on the train body, the train identity is determined, and the absolute position of the train is calculated through the pre-calibrated reference point;

[0041] Step S504, continuously update the position of the train (the updating method is the same as the calculation of the relative running distance in step S3) until the train leaves the viewing range of the camera.

[0042] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory and a processor, wherein a computer program is stored in the memory, and the method described above is implemented when the processor executes the program.

[0043] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the program implements the method described when executed by a processor.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1) The train visual positioning technology of the present invention only uses onboard visual sensors and visual tags and visual sensors on the trackside. Compared with traditional beacons, odometers and axle counters, the equipment is simpler and the deployment, operation and maintenance costs are lower.

[0046] 2) The present invention fully considers the failure of the on-board equipment and provides a backup positioning mode through the trackside visual axle counter, thereby enhancing the redundancy and availability of the positioning system;

[0047] 3) The present invention uses a visual sensor to achieve the positioning process. Compared with the traditional speed measurement and positioning device, which is prone to idling slip errors and the satellite positioning technology, which is prone to signal interruption inside the tunnel, the present invention can better achieve improved positioning accuracy and positioning availability. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A flow chart of a method for visual positioning of a train in a tunnel provided by an embodiment of the present invention;

[0049] Figure 2 A diagram showing the structure of a visual positioning device for a train in a tunnel provided by an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of the deployment of a visual positioning device for a train in a tunnel provided by an embodiment of the present invention;

[0051] Figure 4 A flowchart of initialization positioning of a method for visual positioning of a train in a tunnel provided by an embodiment of the present invention;

[0052] Figure 5 A flow chart of a method for visual positioning of a train in a tunnel provided by one embodiment of the present invention, in which a trackside visual axle counting method is used to detect the positioning of a train. DETAILED DESCRIPTION

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

[0054] Figure 1 This is a flow chart of a method for visual positioning of a train in a tunnel according to an embodiment of the present invention. The specific process is as follows:

[0055] Step S1: The onboard controller pre-stores an electronic route map including the information of the trackside visual beacons, and the trackside visual axle counter pre-stores the identification codes of all trains that may run on the route, wherein the information of the trackside visual beacons includes the unique identification code of each visual beacon and its position on the route;

[0056] Step S2: Initialization of the train positioning according to the trackside visual beacon;

[0057] Among them, the positioning initialization process includes the on-board visual odometer detecting the trackside visual beacon, identifying the unique identification code of the beacon based on the QR code and barcode on the beacon, obtaining the basic position based on the position of the unique identification code on the route map, obtaining the relative offset based on the distance difference between the camera focal center and the beacon center, and obtaining the running direction based on the up and down direction identification on the beacon combined with the displacement direction of the beacon relative to the beacon in the previous and next cycles, thereby calculating the initialization positioning of the train.

[0058] Step S3: The visual odometer of the train periodically acquires the trackside image and calculates the relative running distance, and the onboard controller accumulates the running distance;

[0059] Among them, the process of calculating the relative running distance includes training the static image data of the feature points in the tunnel in advance to obtain an initialization model; then combining the dynamic image data shot at low, medium and high speeds to continue training the initialization model to obtain a basic model; finally, adding noise data on the basis of the dynamic image data, training the basic model, and obtaining an application model; in the field application, the application model is used to identify the feature points in the collected image, calculate the relative distance of the same feature point in two consecutive cycles before and after, and obtain the relative running distance of the train.

[0060] Step S4: When the trackside visual beacon is detected, the visual odometer of the train performs positioning calibration;

[0061] Among them, the positioning calibration process includes: first, the on-board controller calculates the train position 1 according to the position of the visual beacon, which is the same as the positioning initialization process in step S2; secondly, the on-board controller also accumulates the relative displacement feedback from the visual odometer every cycle to obtain the train position 2; finally, the train position 2 is corrected according to the train position 1 to obtain the train position 3, that is, a more accurate train position.

[0062] Step S5: When the trackside visual axle counter detects a train passing by, it identifies the train, continuously calculates the train position, and sends a position message to the train, and at the same time sends a train position message to the control center;

[0063] Among them, the process of detecting, identifying the train and continuously updating the train position includes training a model for identifying trains for trackside axle counting in advance, and the training process is the same as the training process in step S3; pre-marking and calibrating absolute position points within the field of view of the trackside visual axle counting camera as reference points for locating the train position in subsequent processes; in formal engineering applications, when a train is recognized to pass (in two consecutive cycles, the train goes from not appearing in the picture to appearing in the picture), the train identification code is identified (and mutually verified) through the QR code and barcode on the train body, the train identity is determined, and the absolute position of the train is calculated through the pre-calibrated reference points; the train position is continuously updated (the update method is the same as the calculation of the relative running distance in step 3) until the train leaves the camera's field of view.

[0064] Step S6: When a communication failure occurs on the train, or a failure occurs on the train's onboard controller, or a failure occurs on the train's visual odometer device, the visual axle counter on the trackside detects the train's position and reports the faulty train's position to the control center.

[0065] Figure 4 The present invention is a flowchart of initialization positioning of a visual positioning method for a train in a tunnel in an embodiment of the present invention. When the train is in motion, the visual odometer detects a visual beacon beside the track; by identifying the QR code and the barcode, the unique identification code of the beacon is identified; it is determined whether the beacon identification code corresponding to the QR code is consistent with the beacon identification code corresponding to the barcode, if not, the information of the visual beacon is discarded, if consistent, further processing is performed; the legality of the visual beacon is determined in combination with the stored electronic route map and the naming rules of the beacon identification code, if not, the visual beacon is discarded, if legal, further processing is performed; the position of the visual beacon in the electronic route map is searched; the offset between the center of the camera and the center of the visual beacon is calculated; the running direction of the train is determined according to the up and down signs of the visual beacon and the movement direction of the two cycles before and after; the distance traveled by the train from capturing the visual beacon to completing the calculation is calculated; and the initialization positioning of the final train is obtained.

[0066] Figure 5The present invention is a flow chart of a method for visual positioning of trains in tunnels in an embodiment of the present invention. The visual axle counter on the trackside detects the passing of a train, that is, the train appears in the screen from not appearing in the screen; identifies the QR code and barcode on the surface of the train, and identifies the unique train identification code corresponding to the two; determines whether the beacon identification code corresponding to the QR code and the beacon identification code corresponding to the barcode are consistent, if not, an alarm is sent to the control center and an image is uploaded, if consistent, further processing is performed; combined with the stored identification codes of all trains that may appear on the line and the naming rules of the train identification code, the legality of the train identification code is determined, if not legal, an alarm is sent to the control center and an image is uploaded, if legal, further processing is performed; combined with the position of the pre-calibrated reference point, the offset between the reference point and the position of the train identification code is calculated, thereby calculating the absolute positioning of the train; and the positioning of the train is reported to the control center.

[0067] The above is an introduction to a method embodiment. The following is a further explanation of the solution of the present invention through an apparatus embodiment.

[0068] Figure 2 The present invention is a diagram of a visual positioning device for a train in a tunnel in an embodiment of the present invention, wherein the device includes an on-board controller 50, an on-board visual odometer 400, a train surface identification code 40, a trackside visual beacon 100, a trackside visual axle counter 300, and feature points 200 arranged at a set distance inside the tunnel. The on-board controller 50 includes a first computing unit 501 and a first storage device 502, the on-board visual odometer 400 includes a first camera 30 and a first image processing unit 60, the trackside visual axle counter 300 includes a second camera 70 and a second image processing unit 80 and a communication device, and the trackside visual beacon 100 includes an up and down sign 20 and a two-dimensional code and a barcode 10.

[0069] Figure 3This is a deployment diagram of a visual positioning device for a train in a tunnel in an embodiment of the present invention, wherein an onboard controller 50 and an onboard visual odometer 400 are installed on the train, a train surface identification code 40 is sprayed on the train surface, and trackside visual beacons 100, trackside visual axle counters 300, and feature points 200 arranged at set distances inside the tunnel are arranged on both sides of the trackside in the tunnel. Among them, the first computing unit in the onboard controller is used to calculate the positioning information of the train based on the relative displacement obtained from the visual odometer of the train, the identification code information of the visual beacon, the position calibration information obtained from the control center, and the electronic map, visual beacon identification code and position information obtained from the first storage device. The image processing unit and communication device of the trackside visual axle counter capture the train identification code information based on the camera, combined with all possible train identification codes that may appear on the pre-stored line, pre-demarcate and calibrate the absolute position point information, calculate the position of the passing train, and send it to the control center 500.

[0070] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0071] The embodiment of the present invention also provides an electronic device including a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or computer program instructions loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for device operation can also be stored. The CPU, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0072] Multiple components in the device are connected to the I / O interface, including: input units, such as keyboards, mice, etc.; output units, such as various types of displays, speakers, etc.; storage units, such as disks, optical disks, etc.; and communication units, such as network cards, modems, wireless communication transceivers, etc. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunication networks.

[0073] The processing unit performs the various methods and processes described above, such as methods S1 to S6. For example, in some embodiments, methods S1 to S6 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via a ROM and / or a communication unit. When the computer program is loaded into the RAM and executed by the CPU, one or more steps of methods S1 to S6 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S1 to S6 in any other appropriate manner (e.g., by means of firmware).

[0074] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0075] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0076] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0077] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A visual positioning device for trains in tunnels, characterized in that: The device comprises an on-board controller (50), an on-board visual odometer (400), a train surface identification code (40), a trackside visual beacon (100), a trackside visual axle counter (300), and characteristic points arranged at set distances inside a tunnel; The on-board visual odometer (400) collects the trackside visual beacon (100) and feature points, and the trackside visual axle counter (300) collects the train surface identification code (40); the on-board controller (50) obtains the current speed and relative displacement from the on-board visual odometer (400), calculates the current position in the line according to the trackside visual beacon (100), and performs calibration positioning, and simultaneously obtains the current position in the line from the trackside visual axle counter (300) and performs calibration positioning, thereby realizing continuous speed measurement and positioning of the train.

2. According to claim 1, a visual positioning device for trains in tunnels, characterized in that: The on-board controller (50) comprises a first computing unit (501) and a first storage device (502), wherein the first computing unit (501) obtains an electronic route map including trackside visual beacon information from the first storage device (502), and the first storage device (502) is used to store the electronic route map and train parameters.

3. According to claim 1, a visual positioning device for trains in tunnels, characterized in that: The on-board visual odometer (400) comprises a first camera (30) and a first image processing unit (60); the first camera (30) acquires a trackside image and a trackside visual beacon (100) and sends the acquired trackside image to the first image processing unit (60); the first image processing unit (60) calculates the relative running distance of the train based on the acquired trackside image, and performs positioning calibration on the train based on the trackside visual beacon (100).

4. According to claim 1, a visual positioning device for trains in tunnels, characterized in that: The train surface identification code (40) comprises a first two-dimensional code and a first bar code, both corresponding to the train unique identification code.

5. The visual positioning device for trains in tunnels according to claim 1, characterized in that: The trackside visual beacon (100) comprises an up and down direction mark (20) and a second two-dimensional code and a second bar code (10), wherein the second two-dimensional code and the second bar code (10) both correspond to a unique identification code of the visual beacon in an electronic route map.

6. The visual positioning device for trains in tunnels according to claim 1, characterized in that: The trackside visual axle counter (300) comprises a second camera (70), a second image processing unit (80) and a communication device. The second camera (70) collects a train surface identification code (40) and sends it to the second image processing unit (80). The second image processing unit (80) identifies the train, calculates the train position, and sends a position message to the train through the communication device, and simultaneously sends the train position message to the control center.

7. The visual positioning device for trains in tunnels according to claim 1, characterized in that: The characteristic points arranged at set distances inside the tunnel include reflective letter and number patterns, and are not repeated along the entire line.

8. The visual positioning device for trains in tunnels according to claim 7, characterized in that: The distance between each two characteristic points is determined by the viewing range of a camera of the on-board visual odometer (400), ensuring that at a set speed, the image collected in each cycle contains at least one characteristic point.

9. A positioning method using the visual positioning device for trains in tunnels according to claim 1, characterized in that: The method comprises the following steps: Step S1, the onboard controller (50) pre-stores an electronic route map containing trackside visual beacon information, and the trackside visual axle counter (300) pre-stores identification codes of all trains that may run on the route; Step S2, the train performs positioning initialization according to the trackside visual beacon (100); Step S3, the on-board visual odometer (400) periodically acquires the trackside image and calculates the relative running distance, and the on-board controller (50) accumulates the running distance; Step S4, when the trackside visual beacon (100) is detected, the on-board visual odometer (400) performs positioning calibration; Step S5, when the trackside visual axle counter (300) detects a train passing by, it identifies the train and continuously calculates the train position, then sends a position message to the train and simultaneously sends the train position message to the control center; Step S6, when a communication failure occurs in the train, or a failure occurs in the onboard controller (50), or a failure occurs in the onboard visual odometer (400), the trackside visual axle meter (300) detects the train position and reports the faulty train position to the control center.

10. The positioning method according to claim 9, characterized in that: The trackside visual beacon information in step S1 includes a unique identification code of each visual beacon and its position on the track.

11. The positioning method according to claim 9, characterized in that: The specific process of positioning initialization in step S2 is as follows: The on-board visual odometer (400) detects a trackside visual beacon (100), identifies a unique identification code of the beacon based on a second two-dimensional code and a second barcode on the trackside visual beacon (100), obtains a basic position based on the position of the unique identification code on a route map, obtains an offset of the basic position based on a distance difference between a focal length center of a first camera (30) and a center of the beacon, and obtains a running direction based on an up and down direction identification on the beacon combined with a displacement direction relative to the beacon in two previous and subsequent cycles, thereby calculating an initialization position of the train.

12. The positioning method according to claim 9, characterized in that: The relative running distance calculated in step S3 is specifically: Step S301, training static image data of feature points in the tunnel to obtain an initialization model; Step S302, combining the dynamic image data taken at low, medium and high vehicle speeds, continuing to train the initialization model to obtain a basic model; Step S304, adding noise data to the dynamic image data, training the basic model, and obtaining the application model; Step S305, in the field application, the application model is used to identify the feature points in the collected image, and the relative distance of the same feature point in two consecutive cycles is calculated to obtain the relative running distance of the train.

13. The positioning method according to claim 9, characterized in that: The positioning calibration in step S4 is specifically as follows: Step S401, the onboard controller calculates the position of the train according to the position of the visual beacon; Step S402, the onboard controller accumulates the relative displacement fed back by the visual odometer in each cycle to obtain the second train position; Step S403, correcting the train's position 2 according to the train's position 1 to obtain the train's position 3.

14. The positioning method according to claim 9, characterized in that: The step S5 of identifying the train and continuously calculating the train position is specifically as follows: Step S501, training a model for the trackside visual axle counter (300) to identify trains; Step S502, pre-marking and calibrating absolute position points within the viewing range of the second camera of the trackside visual axle counter (300) as reference points for locating the train position in subsequent processes; Step S503, when a train is identified to pass, the train identification code is identified through the QR code and barcode on the train body, the train identity is determined, and the absolute position of the train is calculated through the pre-calibrated reference point; Step S504, continuously updating the position of the train until the train leaves the viewing range of the camera.

15. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the program, the method according to any one of claims 9 to 14 is implemented.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 9 to 14 is implemented.

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