Urban rail transit signal system train section position positioning method and electronic device

Abstract

This invention provides a method and electronic device for locating train sections in an urban rail transit signaling system, comprising: dividing the track into several sections; storing a line section information table, a UWB base station-to-section information correspondence table, and a UWB positioning system interface information table for each section; obtaining ranging information of two paired first UWB base stations and second UWB base stations based on the UWB positioning system interface information table and the UWB base station-to-section information correspondence table; performing geometric validity verification based on the first UWB base station ranging information, the second UWB base station ranging information, and the distance between the first and second UWB base stations; calculating the preliminary position of the train's UWB tag based on the line section information table; and calculating the final position of the train's UWB tag based on the preliminary position of the train's UWB tag and the line section information table.

Description

Technical Field

[0001] This invention relates to the field of train positioning technology, and in particular to a method and electronic device for locating the position of a train section in an urban rail transit signaling system. Background Technology

[0002] Existing urban rail transit train positioning technologies can be divided into train occupancy detection technology and train continuous positioning technology.

[0003] Train occupancy detection mainly includes two technologies: axle counting and track circuits. Axle counting involves installing axle sensors at the beginning and end of a track section. When a train wheel passes, it sends a signal pulse. Indoor equipment calculates the number of wheelsets entering or leaving based on the increase or decrease in axle count, thus determining the occupancy status of the section. Track circuits divide the track into different sections, with a power supply and receiving end set in each section. When a train passes through an empty section, the new transmission circuit short-circuits the original circuit, and the signal changes from green to red to indicate occupancy.

[0004] Fixed block signaling, specifically train occupancy detection, suffers from low track utilization, hindering improvements in train operation efficiency. Therefore, the industry employs moving block signaling based on continuous train positioning technology to enhance track utilization. Currently, the mainstream continuous train positioning technology combines point positioning devices and speed measurement technology. Point positioning devices primarily consist of transponders and beacons, while speed measurement technologies include wheel and axle speed sensors, Doppler radar, and accelerometers. Point positioning devices are typically installed in the center of the track, while train point sensors are installed under the train. When the train's point sensors pass the point sensors installed on the track, the train obtains absolute positioning information. This information, combined with the train speed measured by speed measurement and the distance traveled over time, yields continuous train positioning.

[0005] Experts and scholars have also proposed other continuous positioning methods, such as satellite positioning, video positioning, and retrieval positioning. Satellite positioning involves installing satellite signal receivers on the train, obtaining the satellite distance based on the signal reception time, then applying the principle of tri-sphere intersection to obtain latitude and longitude coordinates, and finally using a position mapping algorithm to locate the train on the track. Video positioning schemes use onboard cameras to identify fixed-position markers such as kilometer markers and hexagonal markers, calculating the train's position from the known location of these markers, or installing cameras along the track to locate the train within a monitored area. Retrieval positioning involves collecting and labeling images of all areas where the train is traveling. Onboard cameras capture current images in real time and match them with a database to obtain the position information of similar frames, thus achieving train positioning.

[0006] In recent years, wireless positioning methods based on Ultra Wide Band (UWB) technology have become an important development direction for continuous train positioning technology due to their advantages of high positioning accuracy and no cumulative error. This scheme deploys base stations along the track and tags on the train. The distance between the tags and base stations is obtained through two-way communication. Then, the tag coordinates are calculated using the coordinates of the ground-based fixed base stations, and finally, the train's position on the track is obtained through a position correspondence algorithm.

[0007] The aforementioned prior art has the following drawbacks: 1. The positioning method of train occupancy detection can only locate a train occupying a fixed section, but cannot obtain the actual position of the train. Once a section is occupied, other trains are not allowed to enter. This scheme results in a track section only supporting one train's occupation, which restricts the operational efficiency of rail transit.

[0008] 2. In continuous positioning technology combining point-based positioning devices and speed measurement technology, when a train starts from a stationary state, it cannot obtain a position. After the train starts moving, it still cannot achieve positioning when passing a point-based positioning device because the direction is unknown. Positioning can only be achieved when the train passes two point-based positioning devices consecutively. On the other hand, due to the inherent error in speed measurement technology, a cumulative error will occur after integration over time. This error cannot be overcome and can only be eliminated when the train passes the point-based positioning device again. Therefore, continuous positioning technology combining point-based positioning devices and speed measurement technology has the disadvantages of long positioning start-up time and continuously increasing cumulative error between point-based positioning devices.

[0009] 3. Satellite positioning systems rely on air-to-ground wireless channels, calculating satellite distance based on the speed of light and the time difference between reception and reception. Therefore, in obstructed environments such as tunnels and depots, satellite signals may not be received or may propagate non-linearly, making it impossible to calculate accurate satellite distances and hindering positioning functionality. Video positioning relies on image recognition accuracy, which cannot achieve 100% accuracy, and blind spots exist between fixed landmarks. Search-based positioning also cannot achieve 100% accuracy, and its speed depends on high-performance hardware, resulting in high costs and significant latency.

[0010] 4. Currently, the application of UWB technology generally involves deploying three base stations on the ground to define a coordinate plane. Train tags calculate the coordinates by measuring the distance between the three base stations, using the principle of three-circle intersection, and obtaining the train's position on the track through a position correspondence algorithm. However, with the increase in the number of ground base stations, it becomes difficult to measure the coordinates of all base stations on the same plane. Furthermore, in long areas such as tunnels and depots where the tracks are obstructed by pillars, the installation location requirements are high, making on-site construction difficult. Summary of the Invention

[0011] To address the cumbersome process of existing technologies, the present invention aims to provide a method and electronic device for locating train sections in an urban rail transit signaling system, which can overcome the delay in the initial positioning process of continuous positioning technology that combines point positioning equipment and speed measurement technology.

[0012] To achieve the above objectives, the present invention adopts the following technical solution: A method for locating train sections in an urban rail transit signaling system includes: The track is divided into several sections; Save the following tables for each section: a table of line section information, a table of correspondence between UWB base stations and section information, and a table of UWB positioning system interface information. Based on the UWB positioning system interface information table and the correspondence table between UWB base stations and section information, the ranging information of the first UWB base station and the ranging information of the second UWB base station are obtained for two pairs. The UWB base station ranging information includes the ranging information between the train UWB tag and the UWB base station. Geometric validity verification is performed based on the ranging information of the first UWB base station, the ranging information of the second UWB base station, and the distance between the first UWB base station and the second UWB base station; Based on the line section information table, the preliminary location of the train's UWB tag is calculated; Based on the preliminary location of the train's UWB tag and the line section information table, the final location of the train's UWB tag is calculated.

[0013] As a further improvement of the present invention, the correspondence table between UWB base stations and segment information includes: pairing information; The steps of obtaining the ranging information of two paired first UWB base stations and the ranging information of the second UWB base station based on the UWB positioning system interface information table and the correspondence table between UWB base stations and segment information include: Obtain the ranging information of the first UWB base station from the UWB positioning system interface information table; The base station adjacent to the first UWB base station is identified as the second UWB base station; Determine whether the first UWB base station and the second UWB base station are paired based on the pairing information; If pairing fails, positioning fails, and the system iteratively determines a matching base station as the second UWB base station from the UWB positioning system interface information table.

[0014] As a further improvement of the present invention, in each segment, the starting point of the segment is defined as the left side and the ending point of the segment is defined as the right side; If the pairing is successful, it also includes: If the second UWB base station is to the left of the first UWB base station, then the ranging information of the first UWB base station and the ranging information of the second UWB base station are swapped, so that the first UWB base station is to the left of the second UWB base station.

[0015] As a further improvement of the present invention, the first UWB base station ranging information includes: the distance between the train UWB tag and the first UWB base station; the second UWB base station ranging information includes: the distance between the train UWB tag and the second UWB base station; the step of performing geometric validity verification based on the first UWB base station ranging information, the second UWB base station ranging information, and the distance between the first UWB base station and the second UWB base station includes: If the sum of the distance between the train's UWB tag and the first UWB base station and the distance between the train's UWB tag and the second UWB base station is less than or equal to the distance between the first UWB base station and the second UWB base station, then the geometric validity check is successful; otherwise, the geometric validity check fails.

[0016] As a further improvement of the present invention, the step of calculating the preliminary location of the train's UWB tag based on the line section information table includes: Based on the distance between the train's UWB tag and the first UWB base station, and the distance between the train's UWB tag and the second UWB base station, a first horizontal distance, a second horizontal distance, and a vertical distance are calculated. The first horizontal distance is the horizontal distance between the train's current position and the first UWB base station, the second horizontal distance is the horizontal distance between the train's current position and the second UWB base station, and the vertical distance is the vertical distance between the current train position and the line connecting the first UWB base station and the second UWB base station. The pairing information of the first UWB base station and the second UWB base station is traversed. When the vertical distance meets the set conditions, the validity of the train tag position in the j-th track is determined. Calculate the distance compensation value based on the line segment information table; Based on the distance compensation value and the first or second horizontal distance, the initial position of the train's UWB tag is calculated.

[0017] As a further improvement of the present invention, the line section information table includes: the curve information of the section, if the train tag position is valid in the j-th track; Based on the curve information of the section, calculate the distance compensation value required for the first UWB base station to shift to the right by the first horizontal distance along the j-th track; The initial position is obtained by adding the first horizontal distance and the distance compensation value; If the train tag position is invalid in the j-th track group; Based on the curve information of the section, calculate the distance compensation value required for the second UWB base station to shift to the right by the second horizontal distance along the j-th track; The initial position is obtained by adding the second horizontal distance and the distance compensation value.

[0018] As a further improvement of the present invention, the step of calculating the final location of the train UWB tag based on the preliminary location of the train UWB tag and the line section information table includes: If there is a turnout in the section where the initial position is located, calculate the distance between the initial position and the turnout point; If the distance is greater than the first set threshold, the preliminary position will be determined as the final position; If the distance is less than the first set threshold, the location positioning will fail.

[0019] As a further improvement of the present invention, if the distance between the current location and the base station is greater than the second preset threshold, a geometric validity check is performed. If the distance between the current location and the base station is less than the second preset threshold, the location positioning will fail.

[0020] As a further improvement of the present invention, if the geometric legality verification is successful, the distance between the train UWB tag and the first UWB base station is determined as the first horizontal distance, the distance between the train UWB tag and the second UWB base station is determined as the second horizontal distance, and the vertical distance is set to 0. If the geometric validity check fails, the first horizontal distance is calculated based on the distance between the train UWB tag and the first UWB base station, the distance between the train UWB tag and the second UWB base station, and the distance between the first UWB base station and the second UWB base station. The second horizontal distance is calculated based on the first horizontal distance and the distance between the first UWB base station and the second UWB base station; The vertical distance is calculated based on the first horizontal distance and the distance between the train's UWB tag and the first UWB base station.

[0021] The present invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes the program stored in the memory, it implements the above-described method for locating train sections in an urban rail transit signaling system.

[0022] The beneficial effects of this invention are as follows: Based on UWB technology, this invention obtains the real-time position of a train in any scenario within urban rail transit without positioning delay, overcoming the initial positioning delay inherent in continuous positioning technologies that combine point positioning devices and speed measurement technology. During train operation, it obtains continuous, accurate, and real-time positioning of the train without cumulative errors. This overcomes the limitations of low positioning accuracy in track sections and the error accumulation inherent in continuous positioning technologies that combine point positioning devices and speed measurement technology. Attached Figure Description

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a flowchart of the train section location positioning method for the urban rail transit signaling system described in this invention; Figure 2 This is another flowchart of the train section location positioning method for urban rail transit signaling system described in this invention; Figure 3 This is the data structure for the line segment information described in this invention; Figure 4 This is the data structure for the correspondence between UWB base stations and segment information as described in this invention; Figure 5 This is the data structure of the UWB positioning system interface described in this invention; Figure 6 This is a schematic diagram of coordinates in this invention; Figure 7 This is the first group of track sections in this invention; Figure 8 This is the second group of track sections in this invention; Figure 9 The third group of track sections in this invention; Figure 10 This is an example diagram of base station pairing information according to the present invention; Figure 11 This is a detailed flowchart of steps S3 to S6 of the present invention; Figure 12 This is an example diagram of a typical scenario 1 of the present invention; Figure 13 This is an example diagram of typical scenario 2 of the present invention; Figure 14 This is an example diagram of typical scenario 3 of the present invention; Figure 15 Diagram of the laboratory testing environment; Figure 16 To ensure accurate parking test results. Detailed Implementation

[0025] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a method for locating train sections in an urban rail transit signaling system, such as... Figure 1 and Figure 2 As shown, it includes: S1. Based on axle counting and turnouts, the track is divided into several physical sections; each section has a start point and an end point. If two sections are connected, the start point of the latter section coincides with the end point of the former section. Each section's start point can connect to a maximum of two section ends, and each section's end point can connect to a maximum of two section starts. A section endpoint can connect to a maximum of three sections, and that endpoint is a turnout point. The start and end points of each section are defined as the endpoint first passed by a train traveling forward with its odd-numbered end without changing ends. The other end is the end point. The train's position is represented by the section number and its offset distance from the start point within that section. If a train traveling upwards passes the section start point first and then the section end point, then traveling downwards, it passes the section end point first and then the section start point.

[0027] S2. Save the following tables for each section: a table of line section information, a table of correspondence between UWB base stations and section information, and a table of UWB positioning system interface information. These three basic data tables are pre-entered static tables that describe the basic information of the positioning system.

[0028] In one implementation, the line segment information table includes: basic segment information and connection information. The basic information (SegmentLink) includes: segment number (segId), segment length (segLen), number of curves (curveCount), and curve information (curveArr). The connection information includes the forward (beginSegNor) and lateral (beginSegRev) segment numbers connecting the starting point, and the forward (endSegNor) and lateral (endSegRev) segment numbers connecting the ending point. The UML diagram of the data structure is shown in Figure 3. The curve information includes the curve radius (curveRadius) and the offsets at the starting point (offBegin) and ending point (offEnd) of the current segment.

[0029] The correspondence between UWB base stations and track segments is the relationship between base stations and track segments after the base station is set up. Based on this relationship, the train's location information is obtained after the train's UWB tag completes distance measurement with the ground base station. This includes UWB base station information and UWB base station pairing information. The UML diagram of the data structure is shown in Figure 4. BaseInfo contains UWB base station information, including the device name (equName), base station number (baseId), base station height above the track surface (height), the number (segId) and offset (segOff) of the nearest track segment, the number of pairing information with other base stations (groupCount), and the pairing index (groupPairs). The pairing index is automatically generated by the program at startup based on the pairing information to reduce query overhead during computation. BaseGroupPair is the pairing information for UWB base stations, including a unique pairing number (groupIdx), the number of track segment groups to be distinguished for pairing (groupTrackNum), the pairing base station number (baseId), and the base station's information in the track segment groups to be distinguished (groupTrack). The base station information in the track segment group (BaseInTrack) includes the segment number (segId), offset, and the minimum (minDist) and maximum (maxDist) distances from the base station connection line.

[0030] The UWB positioning system interface information is the distance between the train's UWB tag and the ground UWB base station. This base station ranging information (BaseDistIfr) includes the number of base stations (count) and the distance information (baseDisArr) that the train's UWB tag completes ranging within one positioning cycle (100ms). The data structure UML diagram is shown below. Figure 5 As shown in the figure. The distance information includes the base station ID (baseId) and the distance.

[0031] As one implementation method, a coordinate system needs to be defined before positioning is implemented. In the coordinate system, all distances are expressed in centimeters and all indices are numbers.

[0032] A schematic diagram of the coordinate system is shown below. Figure 6 As shown.

[0033] The segment information (SegmentLink) mainly describes the relationship information of segments 1-11. For example, the segId of segment 7 is 7; segLen is 8000; beginSegNor is 6; beginSegRev is invalid; endSegNor is 8; and endSegRev is 11. The curve information is filled in according to the line data. For example, curveCount of 1 indicates that it contains 1 curve; the curveDegree is 40; the curve start point offBegin is 4000; and the curve end point is 8000.

[0034] UWB base station information (BaseInfo) mainly describes the information of base stations 1-10. For example, the equName of base station 7 is base7; baseId is 7; height is 400; segId is 5; and segOff is 7000.

[0035] The UWB base station pairing information (BaseGroupPair) mainly describes the combination information of two base stations. It is designed so that the current base station has pairing relationships with the two preceding base stations and the two following base stations. There is no sequential relationship between the base stations in the pairing relationship. Two base stations that cross uplink and downlink boundaries are not paired. For example, base station 5 is paired with base stations 1, 3, 7, and 9. Assume the number of base stations on the same side is... And satisfy Then the number of pairs is If there are branch lines or multiple tracks within the line-of-sight (LOS) range between two paired base stations, the tracks that need to be distinguished need to be divided into multiple track segment groups, and the base station's information (BaseInTrack) within each track segment group needs to be compiled. A track segment group may contain a certain track repeatedly.

[0036] Taking the pairing of base stations 3 and 7 as an example, assuming that segments 6-9 are all within the LOS range, then the area between base stations 3 and 7 should be divided into three track segment groups, such as... Figure 7 As shown, the first group consists of segments 1, 2, 3, 4, and 5, where 1 and 5 are partially contained; as... Figure 8 As shown, the second group consists of 6, 7, 11, 10, 4, and 5, where 6 and 5 are partially contained; as... Figure 9 As shown, the third group consists of 6, 7, 8, and 9, with 6 and 9 being partially contained. If an X-shaped crossover exists in the middle, an additional track segment group needs to be added.

[0037] In the pairing information of base stations 3 to 7, `groupIdx` is the unique index identifier for the pairing, generally set to the index value of all pairing arrays, assumed to be 3; the number of track segment groups to be distinguished, `groupTrackNum`, has a value of 3; `baseId1` is 3; `baseId2` is 7; the information of the base station pointed to by `baseId1` in the track segment group is `groupTrack1`, with a length of 3; the information of the base station pointed to by `baseId2` in the track segment group is `groupTrack2`, with a length of 3. The first group of track segment group information contains `BaseInTrack` information with an index of 0 for both `groupTrack1` and `groupTrack2`, and so on, with the second group of track segment group information containing `BaseInTrack` information with an index of 1. For example... Figure 10 As shown, in all track segment groups of groupTrack1 and groupTrack2, minDist and maxDist are the same; in groupTrack1, segId and offset represent the vertical position of base station 3 in each track segment group; in groupTrack2, segId and offset represent the vertical position of base station 7 in each track segment group. If the position of a paired base station in a track segment group is difficult to measure, it can be set to invalid, but only one paired base station can be set to invalid. For example, if the position of base station 3 is invalid in the third track segment group, the position of base station 7 in that track segment group must be valid. The intermediate segments of the track segment group are automatically obtained by the path finding algorithm and do not need to be reflected in the track segment group information of the pairing information.

[0038] Furthermore, Figure 4 The pairing information includes the IDs of the two base stations and the location of each base station in all segments of the current packet. (Reference) Figure 7-9 In this scenario, base stations 3 and 7 are paired, resulting in three groups within each group. Base station 3 has a position within each group, and base station 7 has a position within each group. The pairing information is sorted primarily by the ID of base station 1, and secondarily by the ID of base station 2, forming an ordered array. Using the ID as the pairing index, the process of finding group information by pairing two base stations is as follows: using the IDs of base station 1 and base station 2 in the distance information, a binary search is performed to find the pairing information composed of the IDs of base station 1 and base station 2. The vertical distance determines which group it belongs to, and the horizontal distance determines its position.

[0039] S3, such as Figure 11As shown, the positioning method is initialized as follows: Since the train positioning algorithm frequently performs data lookups in the basic data table, it is necessary to sort the basic data table by key to improve lookup efficiency. Therefore, during the initialization of the train positioning algorithm, the segment number, base station number, and unique pairing number from the three tables are sorted. Furthermore, the data obtained from the UWB positioning system interface information table defined in the data structure is based on the base station number. When looking up base station pairs, it consumes significant computational resources. Therefore, the train positioning algorithm in this application also pre-calculates the pairing index between the current base station and the paired base station and stores it in the data structure of the current base station to avoid the time consumption caused by this lookup.

[0040] S4. Based on the UWB positioning system interface information table and the correspondence table between UWB base stations and section information, obtain the ranging information of the first pair of UWB base stations and the ranging information of the second pair of UWB base stations. The UWB base station ranging information includes the ranging information between the train UWB tag and the UWB base station.

[0041] In one implementation method, step S4 includes: Obtain the ranging information of the first UWB base station from the UWB positioning system interface information table. Let the number of UWB base stations be n, where n≥2.

[0042] The base station adjacent to the first UWB base station is designated as the second UWB base station.

[0043] The pairing information is used to determine whether the first UWB base station and the second UWB base station are paired.

[0044] If pairing fails, positioning fails, and the system iteratively determines a matching base station as the second UWB base station from the UWB positioning system interface information table.

[0045] In the specific implementation process, first set i=0 and obtain the ranging information of UWB base station i, set j=i+1 and obtain the ranging information of UWB base station j. After obtaining multiple pairs of paired base stations from all UWB base stations, the candidate dual base station location calculation process is entered, namely steps S5 to S7.

[0046] If pairing fails, then j = j + 1, and re-evaluate whether the UWB base station i and UWB base station j match, until j ≥ n.

[0047] As one implementation method, after the first UWB base station and the second UWB base station are successfully paired, the method further includes: If the second UWB base station is to the left of the first UWB base station, then the ranging information of the first UWB base station and the ranging information of the second UWB base station are swapped, so that the first UWB base station is to the left of the second UWB base station. That is, the first UWB base station represents the information of the left base station, and the second UWB base station represents the information of the right base station.

[0048] As one implementation method, the pairing method between the first UWB base station and the second UWB base station is as follows: By using the numbering information of the first and second UWB base stations, the base station information is searched in the line segment information table, and the pairing of the first and second UWB base stations is determined by the base station information.

[0049] S5. Perform geometric validity verification based on the ranging information of the first UWB base station, the ranging information of the second UWB base station, and the distance between the first UWB base station and the second UWB base station.

[0050] The first UWB base station ranging information includes the distance 'a' between the train UWB tag and the first UWB base station, and the second UWB base station ranging information includes the distance 'b' between the train UWB tag and the second UWB base station. The specific geometric validity verification steps are as follows: If the sum of the distance *a* between the train's UWB tag and the first UWB base station and the distance *b* between the train's UWB tag and the second UWB base station is less than or equal to the distance *c* between the first and second UWB base stations, then the geometric validity check is successful; otherwise, the geometric validity check fails. That is, when *a+b≤c*, a triangle cannot be formed, and the geometric validity check fails.

[0051] As one implementation method, before performing geometric validity verification, the method further includes: If the distance between the current location and the base station is greater than the second preset threshold (a < thre || b < thre), then a geometric validity check is performed; if the distance between the current location and the base station is less than the second preset threshold, then location positioning fails. This step determines whether the current location is too close to the base station.

[0052] S6. Based on the line section information table, calculate the preliminary location of the train's UWB tag.

[0053] As one implementation method, step S6 includes: Based on the distance 'a' between the train's UWB tag and the first UWB base station, and the distance 'b' between the train's UWB tag and the second UWB base station, calculate the first horizontal distance 'r1', the second horizontal distance 'r2', and the vertical distance 'h'. The first horizontal distance 'r1' is the horizontal distance between the train's current position and the first UWB base station, the second horizontal distance 'r2' is the horizontal distance between the train's current position and the second UWB base station, and the vertical distance 'h' is the vertical distance between the current train position and the line connecting the first and second UWB base stations.

[0054] If the geometric validity check is successful, the distance 'a' between the train UWB tag and the first UWB base station is determined as the first horizontal distance 'r1', the distance 'b' between the train UWB tag and the second UWB base station is determined as the second horizontal distance 'r2', and the vertical distance 'h' is set to 0. If the geometric validity check fails, then three methods are used, such as... Figure 12 , Figure 13 , Figure 14 In the typical scenario shown, the first horizontal distance r1 is calculated based on the distances a between the train's UWB tag and the first UWB base station, b between the train's UWB tag and the second UWB base station, and c between the first UWB base station and the second UWB base station. The second horizontal distance r2 is calculated based on the first horizontal distance r1 and the distance c between the first UWB base station and the second UWB base station. The vertical distance h is calculated based on the first horizontal distance r1 and the distance a between the train's UWB tag and the first UWB base station. The specific calculation formulas are as follows: ; ; ; The pairing information of the first UWB base station and the second UWB base station is traversed. When the vertical distance h meets the set conditions, the validity of the train tag position in the j-th track group is determined. If it is valid, the train tag is considered to be located in the current track group.

[0055] If the train tag position is valid on the j-th track, the initial position calculation method for the train UWB tag is as follows: Based on the curve information of the section, calculate the distance compensation value required for the first UWB base station to shift to the right by a first horizontal distance r1 along the j-th track. First, based on the position of the train label, offset the train to the right along the current track group by r1, and record the curve information encountered during the offset. Record the curve radius as R and the distance in the curve as d, then calculate the compensation distance. The following formula can be used for approximate calculation.

[0056] ; The first horizontal distance r1 and the distance compensation value are... Preliminary position obtained by addition Reservation successful.

[0057] If the train tag position is invalid in the j-th track group, the initial position calculation method for the train UWB tag is as follows: Based on the curve information of the section, calculate the distance compensation value required for the second UWB base station to shift to the right by a second horizontal distance r2 along the j-th track. .

[0058] The second horizontal distance r2 and the distance compensation value The initial position obtained by addition indicates successful pre-positioning.

[0059] S7. Based on the preliminary location of the train's UWB tag and the line section information table, calculate the final location of the train's UWB tag.

[0060] After successful positioning, if a turnout exists in the section where the preliminary position is located, the distance between the preliminary position and the turnout point is calculated. If the distance is greater than the first preset threshold, the preliminary position is determined as the final position; if the distance is less than the first preset threshold, the position positioning fails. The first preset threshold can be 150 centimeters.

[0061] During the traversal of track segment groups from the first group to the last group, if any group is successfully located, the train position calculation process ends. Otherwise, the position calculation fails, and the position settlement process ends.

[0062] The method for determining the turnout is as follows: If the distance between the location and the starting point of the section is within a set threshold range, based on the connection relationship of the sections where the initial location is located, if the starting point of the section connects to two sections, or the ending point of the preceding section connected to the starting point of the section connects to two sections, then the initial location is determined to be an indistinguishable area of ​​the turnout.

[0063] If the distance between the location and the end point of the section is within the first set threshold range, and the end point of the section connects two sections according to the connection relationship of the initial location, or the starting point of the subsequent section connected to the end point of the section connects two sections, then the initial location is determined to be an indistinguishable area of ​​the turnout.

[0064] Steps S4 to S7 constitute the dual-base station location calculation process. When the train passes through a curve, a correction is required, and the algorithm uses a compensation distance. Corrections are made. The compensation distance is calculated based on a line-of-sight distance of 100 meters, a curved track with a curve radius of R. The table of common values ​​is shown in Table 1.

[0065] Table 1. Error caused by replacing curves with straight lines. Curve radius (m) Straight-line error over 100 meters (cm) 250 68 300 47 350 34 400 26 450 21 500 17 Currently, subway mainline turnouts are generally No. 9 turnouts, turnouts No. 12 turnouts are used in turnaround sections, and No. 7 turnouts are generally used in depots. The horizontal distance obtained during the dual-base station train position calculation has a certain angle with the turnout siding. The position error caused by using a straight line to replace the siding length is shown in Table 2.

[0066] Table 2. Maximum Error of Straight Line Substitute for Side Line in Turnout Section turnout type Switch angle cosine value Distance from the fork to the point after the fork (m) The difference in length between the straight line and the lateral line (cm) No. 7 turnout 8°07′48″ 0.9899 12.5 12.6 No. 9 turnout 6°20′25″ 0.9939 15 9.15 No. 12 turnout 4°45′49″ 0.9965 21 7.35 While disregarding the inherent ranging error of UWB technology, some error will occur in train position calculations in curves and turnout areas. However, this error will not exceed 80.6 cm (curve radius 250, passing through turnout No. 7). This is a significant advantage compared to traditional track section positioning or continuous positioning technology combining point positioning devices and speed measurement. Furthermore, UWB-based wireless positioning methods do not have cumulative errors, reducing train uncertainty to within 1 meter, resulting in a significant improvement in train positioning accuracy. In platform areas, the track is generally a straight section, which conforms to… Figure 12 In this scenario, the distance error can be considered equal to the ranging error of UWB technology. According to published literature and actual testing, the ranging accuracy of UWB is approximately 10cm, which is sufficient to support precise stopping. When the train is near the turnout area, due to the inherent error of UWB technology, the track cannot be determined within a certain range in this area without train route information. Therefore, this invention designs a system where the train position is not output within 150cm of the turnout area to prevent position positioning errors. However, if the train obtains route information during position calculation, the turnout area will be successfully positioned without the need for an error-prevention calculation process.

[0067] In summary, the train section location positioning method for urban rail transit signaling systems of the present invention has the following beneficial effects: 1. Obtain the real-time position of the train in any scenario in urban rail transit without positioning delay, overcoming the initial positioning delay of continuous positioning technology that combines point positioning equipment and speed measurement technology.

[0068] 2. During train operation, obtain continuous, accurate, and real-time positioning of the train without cumulative errors. Overcome the limitations of low positioning accuracy in track sections and the cumulative errors of continuous positioning technology combining point positioning equipment and speed measurement technology.

[0069] 3. Set up a testing environment in the laboratory to conduct tests (e.g., Figure 15 As shown in the figure, the test results show that the track resolution is 20cm, which can accurately distinguish the position of the UWB terminal in each section.

[0070] 4. Due to limitations in on-site equipment deployment capabilities, base stations were deployed near the on-site platform to test the accuracy of parking, such as... Figure 16The test results showed that the positioning difference between the continuous positioning technology using point positioning equipment and speed measurement technology and the positioning technology in this patent was 24.31cm, 6cm, and 42.90cm. 75% of the positioning differences were within 29cm, and 95% of the errors were within 101cm. During the stopping phase, the average position error was 6.5cm and the standard deviation was 10.39cm, which met the requirements for precise stopping.

[0071] Based on the same inventive concept, the present invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes the program stored in the memory, it implements the above-described method for locating train sections in an urban rail transit signaling system.

[0072] The communication bus mentioned above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc.

[0073] The communication interface is used for communication between the aforementioned terminal and other devices.

[0074] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0075] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0076] In this description, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0077] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0078] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A method for locating train sections in an urban rail transit signaling system, characterized in that, include: The track is divided into several sections; Save the following tables for each section: a table of line section information, a table of correspondence between UWB base stations and section information, and a table of UWB positioning system interface information. Based on the UWB positioning system interface information table and the correspondence table between UWB base stations and section information, the ranging information of the first UWB base station and the ranging information of the second UWB base station are obtained for two pairs. The UWB base station ranging information includes the ranging information between the train UWB tag and the UWB base station. Geometric validity verification is performed based on the ranging information of the first UWB base station, the ranging information of the second UWB base station, and the distance between the first UWB base station and the second UWB base station; Based on the line section information table, the preliminary location of the train's UWB tag is calculated; Based on the preliminary location of the train's UWB tag and the line section information table, the final location of the train's UWB tag is calculated.

2. The method for locating train sections in an urban rail transit signaling system according to claim 1, characterized in that, The table of correspondence between UWB base stations and segment information includes: pairing information; The steps of obtaining the ranging information of two paired first UWB base stations and the ranging information of the second UWB base station based on the UWB positioning system interface information table and the correspondence table between UWB base stations and segment information include: Obtain the ranging information of the first UWB base station from the UWB positioning system interface information table; The base station adjacent to the first UWB base station is identified as the second UWB base station; Determine whether the first UWB base station and the second UWB base station are paired based on the pairing information; If pairing fails, positioning fails, and the system iteratively determines a matching base station as the second UWB base station from the UWB positioning system interface information table.

3. The method for locating train sections in an urban rail transit signaling system according to claim 2, characterized in that, Within each segment, the starting point of the segment is defined as the left side, and the ending point of the segment is defined as the right side; If the pairing is successful, it also includes: If the second UWB base station is to the left of the first UWB base station, then the ranging information of the first UWB base station and the ranging information of the second UWB base station are swapped, so that the first UWB base station is to the left of the second UWB base station.

4. The method for locating train sections in an urban rail transit signaling system according to claim 1, characterized in that, The first UWB base station ranging information includes the distance between the train UWB tag and the first UWB base station; the second UWB base station ranging information includes the distance between the train UWB tag and the second UWB base station; the step of performing geometric validity verification based on the first UWB base station ranging information, the second UWB base station ranging information, and the distance between the first UWB base station and the second UWB base station includes: If the sum of the distance between the train's UWB tag and the first UWB base station and the distance between the train's UWB tag and the second UWB base station is less than or equal to the distance between the first UWB base station and the second UWB base station, then the geometric validity check is successful; otherwise, the geometric validity check fails.

5. The method for locating train sections in an urban rail transit signaling system according to claim 4, characterized in that, The step of calculating the preliminary location of the train's UWB tag based on the line section information table includes: Based on the distance between the train's UWB tag and the first UWB base station, and the distance between the train's UWB tag and the second UWB base station, a first horizontal distance, a second horizontal distance, and a vertical distance are calculated. The first horizontal distance is the horizontal distance between the train's current position and the first UWB base station, the second horizontal distance is the horizontal distance between the train's current position and the second UWB base station, and the vertical distance is the vertical distance between the current train position and the line connecting the first UWB base station and the second UWB base station. The pairing information of the first UWB base station and the second UWB base station is traversed. When the vertical distance meets the set conditions, the validity of the train tag position in the j-th track is determined. Calculate the distance compensation value based on the line segment information table; Based on the distance compensation value and the first or second horizontal distance, the initial position of the train's UWB tag is calculated.

6. The method for locating train sections in an urban rail transit signaling system according to claim 5, characterized in that, The line section information table includes: curve information of the section, if the train tag position is valid in the j-th track group; Based on the curve information of the section, calculate the distance compensation value required for the first UWB base station to shift to the right by the first horizontal distance along the j-th track; The initial position is obtained by adding the first horizontal distance and the distance compensation value; If the train tag position is invalid in the j-th track group; Based on the curve information of the section, calculate the distance compensation value required for the second UWB base station to shift to the right by the second horizontal distance along the j-th track; The initial position is obtained by adding the second horizontal distance and the distance compensation value.

7. The method for locating train sections in an urban rail transit signaling system according to claim 1, characterized in that, The step of calculating the final location of the train's UWB tag based on the initial location of the train's UWB tag and the line section information table includes: If there is a turnout in the section where the initial position is located, calculate the distance between the initial position and the turnout point; If the distance is greater than the first set threshold, the preliminary position will be determined as the final position; If the distance is less than the first set threshold, the location positioning will fail.

8. The method for locating train sections in an urban rail transit signaling system according to claim 1, characterized in that, If the distance between the current location and the base station is greater than the second preset threshold, then a geometric validity check is performed; If the distance between the current location and the base station is less than the second preset threshold, the location positioning will fail.

9. The method for locating train sections in an urban rail transit signaling system according to claim 5, characterized in that, If the geometric validity check is successful, the distance between the train UWB tag and the first UWB base station is determined as the first horizontal distance, the distance between the train UWB tag and the second UWB base station is determined as the second horizontal distance, and the vertical distance is set to 0. If the geometric validity check fails, the first horizontal distance is calculated based on the distance between the train UWB tag and the first UWB base station, the distance between the train UWB tag and the second UWB base station, and the distance between the first UWB base station and the second UWB base station. The second horizontal distance is calculated based on the first horizontal distance and the distance between the first UWB base station and the second UWB base station; The vertical distance is calculated based on the first horizontal distance and the distance between the train's UWB tag and the first UWB base station.

10. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes the program stored in the memory, it implements the train section location positioning method of the urban rail transit signaling system as described in any one of claims 1-9.

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