A rail transit line area network transmission method

Abstract

The present invention discloses a line area network transmission method in the field of rail transit, which relates to the field of rail transit network transmission technology. The line topology is mapped into a line transmittable area EZU set, a line transmission area series Range set within the EZU, and a line area transmission minimum unit Quantum set within the Range. During regional transmission, instead of directly transmitting the Abscissa value, the line is divided into a set of multiple EZUs according to business needs. The sender and receiver only transmit the line area information in the required EZU, and the original area starting point Abscissa, Track number and area direction that need to be transmitted are merged into the starting point Quantum number, thereby reducing the consumption of transmission line resources. The transmitting parties pre-agree on the EZU to be used and select the required general length of Quantum, thereby determining the accuracy of line area transmission. The general length of Quantum can be set according to business needs, which improves the flexibility of the algorithm.

Description

Technical Field

[0001] The present invention relates to the field of rail transit network transmission technology, and more specifically to a line area network transmission method in the rail transit field. The method can be used in a TACS train control system in the rail transit field to transmit line areas between a carborne controller (CC), a wayside resource controller (WRC), and a wayside train controller (WTC). Background Art

[0002] In traditional CBTC (Communication Based Train Control) systems, trains rely on movement authorizations calculated by ground equipment to operate. In contrast, the TACS (Train Autonomous Circumambulate System) system, which utilizes onboard equipment, allows trains to autonomously calculate movement authorizations and utilizes train-to-train communication to obtain the safe positions of other trains for train separation protection.

[0003] To safely and accurately measure the train's safe position, the train's location information needs to be transmitted between multiple devices such as CC / WRC / WTC. This location information is represented by line coordinate information (Abscissa).

[0004] In current solutions, track areas are typically transmitted in plain text. The main contents transmitted include: the coordinates of the area's starting point (including the track number and Abscissa), the area length, the area direction (the direction of the area's starting point, Abscissa increasing or Abscissa decreasing, 1 bit, incrementing: 0, decrementing: 1), and the location of diverging turnouts (each diverging turnout is 1 bit, positioned: 0, reversed: 1). Based on the area's starting point coordinates, the receiver can find a unique point on the line as the starting point. Starting from this point, the receiver expands the area along the direction of the area. Upon encountering a diverging turnout, the receiver determines the direction of expansion (turnout positioning or reversed) based on the diverging turnout's position information. This process continues until the expanded length matches the received area length. This results in the area information transmitted by the sender, ensuring consistent understanding of the transmitted information between the sender and receiver.

[0005] While this transmission method ensures information consistency between both parties, it often consumes significant network resources. As line length increases, the line coordinates (Abscissa) and track numbers also increase, and the number of bits consumed by this method to transmit the line area also increases.

[0006] In addition, due to the limitations of network resources and the inherent defects of binary representation of decimals, it is impossible to achieve a complete match between the transmitted data and the actual data when transmitting line coordinates. The decimal part of the line coordinates will inevitably have a certain degree of precision loss. The way to reduce this loss is to increase the number of bits occupied by the decimal part. The accuracy of the data is also positively correlated with the consumed network resources. Therefore, it is necessary to find a balance between the two and design a serialization method for mapping line coordinates to network bytes and a deserialization algorithm used by the receiver to parse the data.

[0007] Current technical research focuses more on implementing higher-level applications after route-area transmission, rather than on the technology behind route-area transmission itself. For example, the patent "A Railway-Specific Electronic Map and System" (Patent No.: CN110110030A) describes an algorithm for mapping route mileposts to electronic route maps. After receiving positioning information, the terminal transmits the milepost information to a backend database. The database then maps the milepost information to railway route data on the digital map based on a pre-established route map. However, the document does not address the specific method for transmitting route milepost information within the network.

[0008] Searches for relevant papers reveal existing data compression algorithms, but research on accuracy loss is lacking. For example, the paper "Research on Real-Time Compression Methods for Massive Railway BIM Data" (Peng Lihui, Railway Computer Applications, Issue 5, 2016) describes an algorithm that compresses three-dimensional coordinates into two-dimensional coordinates, thereby reducing network transmission resources. The paper "Research on High-Speed ​​Railway BIM Data Modeling Based on LS-SVM" (Qi Zixiang, Railway Engineering Technology and Economy, Issue 6, 2018) also proposes a BIM data modeling and transmission method based on the least squares support vector machine (LS-SVM), which transmits model parameters and training sample data instead of raw data, improving data transmission efficiency. However, these papers only discuss data compression algorithms and fail to address the data distortion caused by network data transmission. Rail transit is a safety system that is closely linked to public safety, and safety is always our bottom line. Data distortion is unavoidable, but algorithmic design can minimize this distortion and mitigate its safety impact. Summary of the Invention

[0009] To overcome the shortcomings of the aforementioned prior art, the present invention discloses a method for network transmission of line areas in the rail transit field. To reduce network transmission resource consumption, the present invention designs an algorithm to optimize the transmission of line area information within the network. Furthermore, to enhance system security, a serialization and deserialization algorithm for converting line areas into network byte information is developed to mitigate the negative impact of precision loss.

[0010] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0011] A rail transit line area network transmission method, comprising:

[0012] Map the line topology into a set of line transmission areas (EZUs), a set of line transmission area series (Ranges) within the EZUs, and a set of line area transmission minimum units (Quantums) within the Ranges.

[0013] During regional network transmission, the line is divided into multiple EZU sets. The sender and receiver use the line area serialization and deserialization methods in the required EZU to transmit and convert the line area information. The line area information includes the starting point Quantum number, the number of Quantums, and the diverging turnout position information. The Quantum number is obtained by combining the line coordinates of the starting point of the area to be transmitted, the starting track Track number, and the area direction information.

[0014] When transmitting over a regional network, the sender and receiver agree in advance on the EZU to be used and select the required Quantum length to determine the transmission accuracy of the line area. The Quantum length is set according to business needs.

[0015] When accuracy is lost in the transmission area, the required estimation strategy is selected based on business needs while ensuring security.

[0016] 1. Mapping of Line Topology Information

[0017] 1.1 Line Transmission Area Set

[0018] Preferably, the jurisdiction of each trackside resource manager WRC is defined as an EZU, and the train controller XTC and the trackside resource manager WRC interact with the line area based on this EZU; for communication between XTCs, the scope of the entire line is defined as EZU.

[0019] 1.2 Line Transmission Area Series

[0020] Preferably, in each EZU, the EZU is divided into multiple Ranges with the EZU boundary, the Track boundary and the location of the switch on the Track as endpoints, and the number of Quantums in a Range is less than or equal to 1024; and direction information is distinguished when dividing the Range.

[0021] 1.3 Line Area Transmission Minimum Unit

[0022] Preferably, the length of the minimum unit Quantum of the line area transmission is the area transmission accuracy, and the standard length of Quantum is 2 n meters, of which n It is an integer and is configurable.

[0023] 1.4 Quantum Structure in Range

[0024] Preferably, each Range is filled with multiple Quantums. When the Range is not an integer multiple of the standard length of Quantum, a remainder is left after the Range is filled with multiple Quantums. This remainder is represented by a remainder Quantum. The length of the remainder Quantum is less than the standard length of Quantum. The remainder Quantum exists at the two end regions of the Range. If the Range is in the Abscissa increasing direction, the remainder Quantum is located at the end of the Range. If the Range is in the Abscissa decreasing direction, the remainder Quantum is located at the beginning of the Range.

[0025] After completing the Quantum filling of the Range, each Quantum is numbered. Within the same EZU, each Quantum is assigned a unique number. Within the same Range, the Quantum numbers increase continuously, and the number of Quantums is less than or equal to 1024. The Quantum numbers between different Ranges may not be continuous.

[0026] 1.5 Establishing the link relationship between Ranges

[0027] 1.5.1 Range endpoints are EZU boundaries

[0028] Preferably, the link relationship between Ranges includes: if the current Range endpoint is an EZU boundary, the Range has no next or previous linked Range.

[0029] 1.5.2 Range endpoints are track boundaries

[0030] Preferably, the link relationship between Ranges includes:

[0031] If the current range ends at a track boundary, the system searches for the adjacent track along the range direction and records the Abscissa of the boundary point as A1. In the adjacent track's range, the system finds the range starting at A1, which is the next linked range of the current range.

[0032] If the current range starts at a track boundary, find the adjacent track in the opposite direction of the range in the route topology and record the Abscissa of the boundary point as A2. In the adjacent track's range, find the range with A2 as its endpoint. This is the previous linked range of the current range.

[0033] 1.5.3 The endpoint of the Range is the location of the turnout

[0034] Preferably, the link relationship between Ranges includes:

[0035] If the end point of the current range is a diverging turnout along the range direction, then the current range has two next linked ranges, namely the ranges in the positioning and reverse areas on the diverging turnout with the diverging turnout as the starting point;

[0036] If the starting point of the current Range is a diverging turnout along the direction of the Range, the previous linked Range of the current Range is the Range on the Track where the diverging turnout is located, with the same direction as the diverging turnout and with the diverging turnout as its end point;

[0037] If the end point of the current Range is a converging turnout along the direction of the Range, the next linked Range of the current Range is the Range on the Track where the converging turnout is located, with the same direction as the converging turnout and with it as the starting point;

[0038] If the starting point of the current Range is a converging turnout along the Range direction, the current Range has two previous linked Ranges, namely the Ranges in the upper positioning and reverse positioning areas of the converging turnout with the converging turnout as the end point.

[0039] Preferably, when designing the link relationship between Ranges, two link Ranges are reserved at both ends of each Range, namely the link in the positioning direction and the link in the reverse direction; if the endpoint of the Range is an EZU boundary or a Track boundary, there is only one link Range corresponding to the endpoint, which is the positioning direction Range by default.

[0040] 2. Serialization method of line area

[0041] Preferably, the method of transmitting line area information by using a line area serialization method includes:

[0042] Select the corresponding EZU based on the device types of both the sender and receiver, and determine the regional transmission accuracy;

[0043] According to the structure of the required transmission area in the line topology, determine the location information of the divergent turnouts passing through the area;

[0044] According to the coordinate information of the starting point of the route area and the direction of the route area, confirm the range of the starting point coordinates and the starting point quantum number;

[0045] Map the length of the line region to the number of desired Quantums.

[0046] Preferably, the estimation strategy includes overestimation, underestimation and no overestimation or underestimation:

[0047] The overestimation is that the starting point of the transmission area is selected as the Quantum where the starting point Abscissa is located, and the end point of the transmission area is selected as the Quantum where the end point Abscissa is located. The final result is that the actual transmission area is larger than the area to be transmitted;

[0048] For the underestimation, the starting point of the transmission area selects the next Quantum of the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects the previous Quantum of the Quantum where the end point Abscissa is located; if the starting and ending Quantums are not the boundary Quantums of the range in which they are located, then the next Quantum number is the selected Quantum number plus 1, and the previous Quantum number is the selected Quantum number minus 1; if the starting and ending Quantums are the boundary Quantums of the range in which they are located, then according to the line topology and the range link relationship, the end point Quantum of the previous linked range of the range in which the selected Quantum is located is the previous Quantum of the selected Quantum, and the starting point Quantum of the next linked range of the range in which the selected Quantum is located is the next Quantum of the selected Quantum;

[0049] The said no over-estimation or under-estimation, the starting point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the starting point; the ending point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the ending point.

[0050] 3. Deserialization method of line area

[0051] Preferably, the converting of the line area information by using the line area deserialization method includes: after receiving the line area transmitted by the sending device via the network, the receiving device converts the network-transmitted Quantum information into line area Abscissa information by using the deserialization method, including:

[0052] According to the EZU information agreed upon by both parties, find the corresponding Quantum in the EZU data based on the starting point Quantum information. The Range where the Quantum is located is the starting point Range, and the starting point of the Quantum is the regional starting point Abscissa.

[0053] According to the number of Quantums and the switch location information, start from the starting point Quantum and traverse the starting point Range and its next linked Range in sequence until the number of traversed Quantums reaches the number of Quantums required in the received data, and find the end point Quantum. The end point of this Quantum is the area end point Abscissa.

[0054] Count the lengths of all Quantums to get the length of the transmission area.

[0055] To sum up, in order to ensure the security of line area transmission on the network, and at the same time to reduce network resource consumption and improve user convenience, this patent proposes a new line area network transmission method, specifically, it includes the following contents.

[0056] 1. Define the concept of exchangeable zone union (EZU) and divide the line into different EZU zones. Different EZUs can be selected as the basis for regional transmission based on different sending and receiving devices, reducing network resource consumption.

[0057] 2. Defines the concept of line transmission area series (Range), divides the line area in the EZU into a set of multiple Ranges, and establishes a link relationship for each Range based on the line topology;

[0058] 3. Defines the minimum unit of line area transmission (Quantum), divides each range into a set of multiple Quantums, and supports manual configuration of the general length of Quantum, that is, the line area transmission accuracy, which can be flexibly selected according to business needs, improving flexibility;

[0059] 4. A scheme is proposed to map the actual line topology into a dataset composed of EZU / Range / Quantum, which facilitates subsequent serialization and deserialization operations;

[0060] 5. A serialization algorithm for line areas is proposed, which optimizes the existing Abscissa plaintext transmission scheme to transmit Quantum information, reducing network resource consumption;

[0061] 6. Due to the inherent limitations of transmission accuracy and the conversion of decimal-type Abscissa to byte representation, this patent proposes two estimation algorithms: overestimation and underestimation. In actual use, the required estimation algorithm can be flexibly selected based on business needs and comprehensive consideration of system security performance, thereby improving the security of line area transmission;

[0062] 7. A deserialization algorithm for line areas is proposed. After receiving the area information of network transmission, the receiver can accurately parse the network transmission area according to the deserialization algorithm, ensuring the consistency between the sender and the receiver.

[0063] Beneficial effects of the present invention:

[0064] The present invention proposes a line area network transmission method in the field of rail transit, which maps the line topology into a set of EZU (Exchangeable zone union, a set of line transferable areas), Range (a series of line transmission areas) and Quantum (the smallest unit of line area transmission).

[0065] During zone transmission, the Abscissa value is not transmitted directly. Instead, the line is divided into multiple EZU sets according to business needs. The sender and receiver only transmit the line zone information in the required EZU. The original zone starting point Abscissa, Track number and zone direction to be transmitted are combined into the starting point Quantum number, reducing the consumption of transmission line resources.

[0066] The transmitting parties pre-agreed on the EZU to be used and selected the required Quantum length, thereby determining the transmission accuracy within the line area. The Quantum length can be set based on business needs, increasing the flexibility of the algorithm.

[0067] In addition, when facing accuracy loss in the transmission area, the required estimation strategy (underestimation or overestimation) can be flexibly selected according to business needs while ensuring security, thereby improving the security of the algorithm.

[0068] In summary, the line area transmission algorithm proposed in this patent has significant improvements in security, flexibility and line resource consumption compared to existing solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is an example of EZU partitioning in the present invention;

[0070] Figure 2 This is an example of Range division in the present invention;

[0071] Figure 3 It is the Quantum structure within the Range of the present invention;

[0072] Figure 4 It is the line transmission area of ​​the present invention;

[0073] Figure 5 This is the Quantum structure of the transmission area of ​​the present invention. DETAILED DESCRIPTION

[0074] The following will provide a clear and complete description of the concept, specific structure and technical effects of the present invention in conjunction with the embodiments and drawings, so as to fully understand the purpose, features and effects of the present invention.

[0075] A line area network transmission method in the rail transit field maps the line topology into a set of EZU (Exchangeable zone union, line exchangeable zone set), Range (line transmission zone series) and Quantum (line area transmission minimum unit).

[0076] During zone transmission, instead of transmitting the Abscissa value directly, the line is divided into multiple EZU sets according to business needs. The sender and receiver only transmit the line zone information in the required EZU. The original zone starting point Abscissa, Track number, and zone direction information that need to be transmitted are combined into the starting point Quantum number, reducing the consumption of transmission line resources.

[0077] The transmitting parties pre-agreed on the EZU to be used and selected the required Quantum length, thereby determining the transmission accuracy within the line area. The Quantum length can be set based on business needs, increasing the flexibility of the algorithm.

[0078] In addition, when facing accuracy loss in the transmission area, the required estimation strategy (underestimation or overestimation) can be flexibly selected according to business needs while ensuring security, thereby improving the security of the algorithm.

[0079] In summary, the line area transmission algorithm proposed in this patent has significant improvements in security, flexibility and line resource consumption compared to existing solutions.

[0080] The line area transmission algorithm proposed in this patent mainly includes the following contents:

[0081] 1. Mapping of line topology information;

[0082] 2. Serialization algorithm for line area;

[0083] 3. Deserialization algorithm for line area;

[0084] 1. Mapping of line topology information

[0085] 1.1 Line Transmission Area Set

[0086] First, we define the exchangeable zone union (EZU).

[0087] In actual engineering applications, a line is often divided into multiple WRC jurisdictions. Each WRC protects resources within its own jurisdiction to ensure safe system operation. During vehicle operation, the XTC (CC or WTC) requests resources from the WRC in the corresponding area and calculates movement authorization. Each WRC only transmits information about the line area within its jurisdiction. Therefore, the jurisdiction of each WRC can be defined as an EZU. XTCs and WRCs interact with each other based on this EZU.

[0088] For communication between XTCs, since the operating range of the vehicle is the entire line area, the relevant EZU is defined as the range of the entire line.

[0089] According to the EZU defined above, different EZUs can be selected as the basis for subsequent operations when communicating between XTC and WRC or between XTCs. Figure 1 shown.

[0090] 1.2 Series of line transmission areas

[0091] Second, we define a series of line transmission areas (Range) within each EZU.

[0092] Within each EZU, the EZU is divided into multiple ranges, with the EZU boundary, track boundary, and track switch locations as endpoints. Furthermore, if a range is long, containing more than 1024 quanta (see 1.3 Minimum Unit for Line Area Transmission), it is necessary to split the range to reduce memory usage and improve computational efficiency. In other words, the number of quanta within a range cannot exceed 1024. It is important to note that line areas transmitted over the network carry directional information, so this directional information must also be considered when dividing ranges.

[0093] The division of Range in EZU is as follows Figure 2 As shown, Track 3 is only partially within the EZU (for example, if the EZU falls under the jurisdiction of a WRC, Track 3 is only partially within the WRC). Therefore, Range 4 extends from the EZU boundary to the intersection of Track 3 and Track 4. Range 12 overlaps with Range 4 in terms of location, but in the opposite direction. Track 4 is within the EZU and has a switch, so Track 4 can be split into two ranges (Range 5 and Range 6). Similarly, two ranges (Range 13 and Range 14) overlap with Range 5 and Range 6 in terms of location, but in the opposite direction.

[0094] 1.3 Line Area Transmission Minimum Unit

[0095] Finally, we define the minimum unit (Quantum) of line area transmission. The length of this minimum unit is the accuracy of area transmission.

[0096] According to the binary representation of decimal fractions, the length of Quantum is generally 2 n meters, where n is an integer. If higher accuracy is required, reduce the value of n. For example, when n = -4, the accuracy can reach 0.0625 meters. If accuracy is not too high, increase the value of n to reduce network resource consumption. For example, when n = 0, the accuracy is 1 meter. Hereinafter, this parameter n is referred to as the Quantum base 2 logarithm.

[0097] According to the EZU classification, different devices must use a specific EZU for communication. Therefore, once the Quantum base 2 logarithm is determined, the same standard should be used throughout the EZU. In other words, the Quantum base 2 logarithm value represents the accuracy of regional transmission. This parameter is configurable, increasing flexibility, allowing users to select different values ​​based on the required accuracy requirements.

[0098] 1.4 Quantum Structure in Range

[0099] Each Range can be considered as consisting of multiple Quantums. Since the length of the Range is not fixed, it is most likely not the standard length of Quantum (i.e. 2 Quantum base 2 logarithm), so after the Range is filled with multiple Quantums, there will inevitably be a remainder. This remainder area is still represented by one Quantum, but the length of this Quantum is less than the standard length. Depending on the direction of the area, this Quantum generally exists at the two end areas of the Range. If the Range is in the Abscissa increasing direction, this Quantum is located at the end of the Range. If the Range is in the Abscissa decreasing direction, this Quantum is located at the beginning of the Range.

[0100] After filling the range with quanta, each quanta must be numbered. Within the same EZU, each quanta has a unique number. Within the same range, quanta numbers must increase sequentially, but the total number of quanta cannot exceed 1024. That is, the difference between the starting and ending quanta numbers cannot exceed 1023. Quanta numbers between different ranges can be discontinuous.

[0101] by Figure 2 For example, if the user sets the regional transmission accuracy to 1 meter, that is, the Quantum base 2 logarithm of this EZU is configured to 0, and if the Abscissa range of this area is [100 meters to 108.5 meters], the structure of Quantum in Range is as follows: Figure 3 As shown. It can be seen that the direction of Range4 is the Abscissa increasing direction, which contains 9 Quantums numbered 1 to 9; the direction of Range12 is the Abscissa decreasing direction, and also contains 9 Quantums numbered 12 to 20. The length of this area is 8.5 meters, so this area can be composed of 8 Quantums with a length of 1 meter and 1 Quantum with a length of 0.5 meters. For Range4, in the Abscissa increasing direction, let the Quantum with a length of 0.5 meters be located at the end (i.e., Quantum 9); for Range12, in the Abscissa decreasing direction, let the Quantum with a length of 0.5 meters be located at the beginning (i.e., Quantum 12). It can be seen that although the Quantum ordering methods of the two Ranges are different, the final Quantum structure of the two is the same.

[0102] 1.5 Establishing Link Relationships Between Ranges

[0103] After completing the range and quantum division, you need to establish the link relationship between each range. According to the range division method, the connection point between two ranges is the EZU boundary, the track boundary, or the location of the switch on the track. Therefore, the link relationship between ranges can be determined using the following method.

[0104] 1.5.1 Range endpoints are EZU boundaries

[0105] If the current Range endpoint is an EZU boundary, it can be seen from the Range direction that it has no next or previous linked Range. Figure 2 For example, for Range4, its starting point is the EZU boundary, so Range4 has no previous linked Range; for Range12, its end point is the EZU boundary, so Range12 has no next linked Range.

[0106] 1.5.2 Range endpoints are track boundaries

[0107] If the current Range ends at the Track boundary, then in the line topology, find the adjacent Track of the Track where the current Range is located along the Range direction, and record the Abscissa of the boundary point as A1. In the Range of the adjacent Track, find the Range with A1 as the starting point, which is the next linked Range of the current Range. Figure 2 For example, for Range 6, it is located on Track 4. In the line topology, the adjacent Track of Track 4 is found along the direction of Range 6, which is Track 5. The boundary coordinates are recorded as A1. There are two Ranges in Track 5, among which the starting coordinates of Range 7 are A1. Range 7 is the next linked Range of Range 6.

[0108] Similarly, if the current Range starts at the Track boundary, find the adjacent Track of the current Range in the opposite direction of the Range in the line topology, and record the Abscissa of the boundary point as A2. In the Range of the adjacent Track, find the Range with A2 as the end point, which is the previous linked Range of the current Range. Figure 2 For example, for Range 5, which is located on Track 4, the adjacent Track of Track 4 is found in the line topology along the opposite direction of Range 5, which is Track 3. The recorded boundary coordinates are A2. There are two Ranges in Track 3, among which the end point coordinates of Range 4 are A2. Range 4 is the previous linked Range of Range 5.

[0109] 1.5.3 The endpoint of the Range is the location of the turnout

[0110] Depending on the type of turnout, the scenario where the Range endpoint is the turnout location can be divided into the following two cases.

[0111] 1.5.3.1 Divergent turnouts along the Range direction

[0112] If the end point of the current Range is a diverging turnout along the direction of the Range, then the current Range has two next linked Ranges, namely the Ranges in the positioning and reverse areas on the diverging turnout with the diverging turnout as the starting point. Figure 2 Taking Range5 in the figure as an example, its end point is the divergent turnout along the direction of Range5, then its next linked Range has two, namely, Range6 with the divergent turnout as the starting point in the divergent turnout positioning area, and Range8 with the divergent turnout as the starting point in the divergent turnout anti-position area.

[0113] If the starting point of the current Range is a diverging turnout along the direction of the Range, the previous linked Range of the current Range is the Range on the Track where the diverging turnout is located, which is in the same direction as the diverging turnout and ends at the diverging turnout. Figure 2 Take Rang6 / Range8 in the example, the starting point of both is the diverging turnout along the Range direction, which is located on Track4. There are 4 Ranges on Track4, namely Range5 / Range6 / Range13 / Range14. The Ranges in the same direction as the diverging turnout are Range5 / Range6, among which the Range with the diverging turnout as the end point is Range5. Therefore, the previous linked Range of Rang6 / Range8 is Range5.

[0114] 1.5.3.2 Converging turnouts along the Range direction

[0115] If the end point of the current Range is a convergent turnout along the direction of the Range, the next linked Range of the current Range is a Range on the Track where the convergent turnout is located, with the same direction as the convergent turnout and with it as the starting point. Figure 2Take Range2 / Range8 in the example, their endpoints are the converging turnout along the Range direction, which is located on Track2. There are four Ranges on Track2, namely Range2 / Range3 / Range10 / Range11. The Ranges in the same direction as the converging turnout are Range2 / Range3, among which the Range with the converging turnout as the starting point is Range3. Therefore, the next linked Range of Range2 / Range8 is Range3.

[0116] If the starting point of the current Range is a convergent turnout along the Range direction, the current Range has two previous linked Ranges, namely the Ranges in the positioning and reverse areas on the convergent turnout with the convergent turnout as the end point. Figure 2 Taking Range 13 in the figure as an example, its starting point is the converging turnout along the direction of Range 13, then there are two linked Ranges, namely, Range 14 in the converging turnout positioning area with the converging turnout as the end point, and Range 16 in the converging turnout reverse area with the converging turnout as the end point.

[0117] After establishing the relationship between Ranges according to the above principles, we can get Figure 2 The link relationships between ranges are shown in Table 1 below. Note: When designing link relationships, two link ranges are reserved at each end of each range: a link in the positioning direction and a link in the reverse direction. If a range endpoint is an EZU boundary or a Track boundary, there is only one link range corresponding to that endpoint, which defaults to the "positioning direction" range.

[0118] Table 1 Range link relationship

[0119]

[0120] 2. Serialization algorithm of line area

[0121] In the existing line area transmission algorithm, the information that needs to be transmitted includes the coordinate information of the area starting point (including Track number and Abscissa), area length, area direction, and divergent turnout position information.

[0122] The regional transmission method proposed in this patent only needs to transmit the starting point Quantum number, the number of Quantums, and the diverging turnout location information. The Abscissa of the starting point of the region, the starting point Track number, and the regional direction information are combined into the starting point Quantum number, thereby greatly reducing the network resources consumed by regional transmission.

[0123] The specific algorithm is as follows: First, the corresponding EZU is selected based on the device types of both the transmitter and receiver, and the regional transmission accuracy is determined. Second, based on the structure of the required transmission area in the line topology, the location information of the diverging turnouts passing through the area is determined. Third, based on the coordinates of the starting point of the line area and the direction of the line area, the range of the starting coordinates and the starting quantum number are determined. Finally, the length of the line area is mapped to the required number of quanta.

[0124] by Figure 4 For example, the line area in the WRC and CC needs to transmit Figure 4 The area information in the example is as follows: the starting coordinate information is [Track number: 3, Abscissa: 103.5 meters], the ending coordinate information is [Track number: 2, Abscissa: 306.3 meters], and the area length is 140.1 meters. The serialization algorithm is as follows:

[0125] 2.1 Confirm EZU and accuracy

[0126] The sending and receiving sides in this area are WRC and CC, so select the EZU corresponding to the WRC jurisdiction. Assume that the required regional transmission accuracy is 1 meter, that is, the Quantum base 2 logarithm is set to 0.

[0127] 2.2 Determine the divergent turnouts passing through the area

[0128] according to Figure 4 It can be seen from the regional information that this area passes through a divergent turnout, and the turnout position is reversed.

[0129] 2.3 Confirm the starting point coordinate information

[0130] from Figure 5 As can be seen from the Range example, [Track number: 3, Abscissa: 103.5 meters] is located in Quantum4 in Range4, so the starting point Quantum number is 4.

[0131] 2.4 Confirm the required amount of Quantum

[0132] Similar to step 2.3, determine the range and quantum number of the destination Abscissa. Then, starting from the starting quantum, traverse each range of the EZU according to the range link relationship and the location of the diverging turnouts until the destination quantum is found. Record the number of quantums traversed during this process; this is the number of quantums required for the transmission area.

[0133] by Figure 4For example, the end point is [Track number: 2, Abscissa: 306.3 meters], which is located on Range 3. Assume that the Quantum distribution of Range 3 is as follows. Figure 5 As shown, the end point Quantum is Quantum57.

[0134] The starting point Quantum is in Range 4, and its next link is Range 5. Range 5 has two next links. According to the switch information, the opposite range should be selected, that is, Range 8. The next link of Range 8 is Range 3. It can be seen that the area to be transferred is located on Range 4, Range 5, Range 8 and Range 3 in sequence. The number of Quantums in the traversal process is calculated as follows: Range 4, 6 (Quantum 4 to Quantum 9); Range 5 and Range 8, the above ranges are included in the transfer area as a whole. Figure 5 It can be seen that the number of quanta contained in the two is 30 and 100 respectively, totaling 130 quanta; Range3, 6 (Quantum52~Quantum57). Therefore, the total number of quanta required is 142.

[0135] Comparing existing solutions with the solution described in this patent, the number of bits required to transmit this area is shown in Table 2. It can be seen that the solution described in this patent significantly reduces network byte overhead. As the line length increases, the Abscissa and Track numbers also increase, and the network resource advantage of this solution becomes increasingly obvious.

[0136] Table 2 Comparison of transmission network resources in line areas

[0137]

[0138] 2.4 Confirmation Estimation Algorithm

[0139] Due to transmission accuracy limitations, there's a discrepancy between the area actually transmitted and the area to be transmitted. For example, consider the line area [Start Track Number: 3, Start Abscissa: 103.5 meters; End Track Number: 2, End Abscissa: 306.3 meters]. After serialization, the actual transmitted area becomes [Start Track Number: 3, Start Abscissa: 103 meters; End Track Number: 2, End Abscissa: 307.2 meters]. This indicates that the serialized area exceeds the area to be transmitted, potentially posing a security risk in safety-related systems.

[0140] For example, the CC transmits a clean area to the WRC, informing the WRC device that after CC cleaning, there are no unknown vehicles in the cleaned area. If the network transmits an area larger than the actual clean area, it will mistakenly cause the WRC to believe that some uncleaned areas have been cleaned, posing a security risk.

[0141] Therefore, this patent proposes an estimation method for line area serialization, including overestimation and underestimation. When transmitting line areas between devices, the estimation algorithm can be flexibly selected according to business needs.

[0142] For overestimation, the serialization algorithm mentioned above is used. The starting point of the transmission area is selected as the Quantum where the starting point Abscissa is located, and the end point of the transmission area is selected as the Quantum where the end point Abscissa is located. The final result is that the actual transmission area is slightly larger than the area to be transmitted.

[0143] In contrast, underestimation aims to make the actual transmission area slightly smaller than the area to be transmitted while being as close as possible to the area to be transmitted. Specifically, the starting point of the transmission area selects the next Quantum of the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects the previous Quantum of the Quantum where the end point Abscissa is located. If the starting and ending Quantums are not the boundary Quantums of the Range in which they are located, then the next Quantum number is the selected Quantum number plus 1, and the previous Quantum is the selected Quantum number minus 1. In the above example, if the underestimation method is used, the starting and ending Quantums obtained are Quantum5 and Quantum56 respectively. If the starting and ending Quantums are the boundary Quantums of the Range in which they are located, then according to the line topology and the Range link relationship, the end point Quantum of the previous linked Range of the Range in which the selected Quantum is located is the previous Quantum of the selected Quantum, and the starting point Quantum of the next linked Range of the Range in which the selected Quantum is located is the next Quantum of the selected Quantum.

[0144] It's worth noting that if the starting point Abscissa is located at the intersection of two Quantums, the corresponding Quantum should be the Quantum with that Abscissa as the starting point. If the ending point Abscissa is located at the intersection of two Quantums, the corresponding Quantum should be the Quantum with that Abscissa as the ending point. For example, if the starting point Abscissa is 103 meters, the starting Quantum is Quantum 4; if the ending point Abscissa is 307.2 meters, the ending Quantum is Quantum 57. In this scenario, accurate transmission across the line area is achieved without overestimation or underestimation.

[0145] 3. Deserialization algorithm of line area

[0146] After receiving the line area transmitted by the sending device through the network, the receiving device can use the deserialization algorithm to convert the Quantum information transmitted by the network into the line area Abscissa information. The specific algorithm is as follows:

[0147] First, according to the EZU information agreed upon by both parties, the corresponding Quantum is found in the EZU data based on the starting point Quantum information. The Range where the Quantum is located is the starting point Range, and the starting point of the Quantum is the area starting point Abscissa.

[0148] Secondly, based on the number of Quantums and the switch location information, start from the starting point Quantum and traverse the starting point Range and its next linked Range in sequence until the number of traversed Quantums reaches the number of Quantums required in the received data. The end point of the Quantum can be found, and the end point of the Quantum is the regional end point Abscissa.

[0149] Finally, the length of all Quantums is counted to get the length of the transmission area.

[0150] Taking the transmission line area in Table 2 as an example, it is assumed that the sender uses the over-estimation method.

[0151] This area is transmitted between CC and WRC, so both parties agree that the EZU is the EZU corresponding to the WRC's jurisdiction. In this EZU, find the starting point Quantum (Quantum4), and its starting point Abscissa is the starting point Abscissa of the area, which is 103 meters.

[0152] Starting from Quantum4 of Range4, we search backwards. In this Range, we can traverse 6 Quantums (Quantum4~Quantum9), which is less than the number of Quantums transmitted by the network (142). There are 136 Quantums left to be found. The next linked Range of Range4 is Range5. There are 30 Quantums in Range5, which does not meet the remaining number of Quantums to be traversed (136). We continue to search backwards. There are 106 Quantums left to be found. There are two next linked Ranges in Range5. According to the divergent turnout direction information transmitted by the network, its next link Range should be the reverse link Range, that is, Range8. There are a total of 100 Quantums in Range8, which does not meet the remaining number of Quantums to be traversed (106). Continuing to search backward, there are 6 Quantums left to be found; the next link Range of Range8 is Range3. After traversing 6 Quantums in Range3, Quantum57 is found, which is the terminal Quantum. Its terminal Abscissa is the regional terminal Abscissa, 307.2 meters.

[0153] The length of all quanta found during the traversal is calculated as the line area length. Quantum 4 through Quantum 9 in Range 4 have a total length of 5.5 meters; all quanta in Range 5 have a total length of 30 meters; all quanta in Range 8 have a total length of 100 meters; and Quantum 52 through Quantum 57 in Range 3 have a total length of 6 meters. The total length of the line area is 141.5 meters.

[0154] The resulting area starts at Abscissa 103 meters on Track 3 and ends at Abscissa 307.2 meters on Track 2, passing through a diverging switch with a reversed position. This area is slightly larger than the sender's pending transmission area, meeting the overestimation requirement, as shown in Table 3 below.

[0155] Table 3 Deserialization algorithm example

[0156]

[0157] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalents or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A rail transit line area network transmission method, characterized in that: include: Map the line topology into a set of line transmission areas (EZUs), a set of line transmission area series (Ranges) within the EZUs, and a set of line area transmission minimum units (Quantums) within the Ranges. During regional network transmission, the line is divided into multiple EZU sets. The sender and receiver use the line area serialization and deserialization methods in the required EZU to transmit and convert the line area information. The line area information includes the starting point Quantum number, the number of Quantums, and the diverging turnout position information. The Quantum number is obtained by combining the line coordinates of the starting point of the area to be transmitted, the starting track Track number, and the area direction information. When transmitting over a regional network, the sender and receiver agree in advance on the EZU to be used and select the required Quantum length to determine the transmission accuracy of the line area. The Quantum length is set according to business needs. When accuracy is lost in the transmission area, the required estimation strategy is selected based on business needs while ensuring security.

2. A rail transit line area network transmission method according to claim 1, characterized in that: The jurisdiction of each trackside resource manager (WRC) is defined as an EZU. The train controller (XTC) and the trackside resource manager (WRC) interact with each other in the line area based on this EZU. For communication between XTCs, the entire line is defined as an EZU. In each EZU, the EZU boundary, the track boundary, and the location of the switch on the track are used as endpoints to divide the EZU into multiple ranges. The number of quanta in a range is less than or equal to 1024. Direction information is distinguished when dividing the range. The length of the minimum unit Quantum of the line area transmission is the area transmission accuracy, and the standard length of Quantum is 2 n meters, of which n It is an integer and is configurable.

3. A rail transit line area network transmission method according to claim 1, characterized in that: Each Range is filled with multiple Quantums. When the Range is not an integer multiple of the standard length of Quantum, there is a remainder left after the Range is filled with multiple Quantums. This remainder is represented by a remainder Quantum. The length of the remainder Quantum is less than the standard length of Quantum. The remainder Quantum exists at the two end areas of the Range. If the Range is in the Abscissa increasing direction, the remainder Quantum is located at the end of the Range. If the Range is in the Abscissa decreasing direction, the remainder Quantum is located at the beginning of the Range. After completing the Quantum filling of the Range, each Quantum is numbered. Within the same EZU, each Quantum is assigned a unique number. Within the same Range, the Quantum numbers increase continuously, and the number of Quantums is less than or equal to 1024. The Quantum numbers between different Ranges are discontinuous.

4. A rail transit line area network transmission method according to claim 1, characterized in that: The link relationship between Ranges includes: if the current Range endpoint is an EZU boundary, the Range has no next or previous linked Range.

5. A rail transit line area network transmission method according to claim 1, characterized in that: The link relationship between Ranges includes: If the current range ends at a track boundary, the system searches for the adjacent track along the range direction and records the boundary point's Abscissa as A1. In the adjacent track's range, the system finds the range starting at A1, which is the next linked range of the current range. If the current range starts at a track boundary, find the adjacent track in the opposite direction of the range in the route topology and record the boundary point's Abscissa as A2. In the adjacent track's range, find the range with A2 as its endpoint. This is the previous linked range of the current range.

6. A rail transit line area network transmission method according to claim 1, characterized in that: The link relationship between Ranges includes: If the end point of the current range is a diverging turnout along the range direction, then the current range has two next linked ranges, namely the ranges in the positioning and reverse areas on the diverging turnout with the diverging turnout as the starting point; If the starting point of the current Range is a diverging turnout along the direction of the Range, the previous linked Range of the current Range is the Range on the Track where the diverging turnout is located, with the same direction as the diverging turnout and with the diverging turnout as its end point; If the end point of the current Range is a converging turnout along the direction of the Range, the next linked Range of the current Range is the Range on the Track where the converging turnout is located, with the same direction as the converging turnout and with it as the starting point; If the starting point of the current Range is a converging turnout along the Range direction, the current Range has two previous linked Ranges, namely the Ranges in the upper positioning and reverse positioning areas of the converging turnout with the converging turnout as the end point.

7. A rail transit line area network transmission method according to claim 1, characterized in that: When designing the link relationship between Ranges, two link Ranges are reserved at both ends of each Range, namely the link in the positioning direction and the link in the reverse direction. If the endpoint of a Range is an EZU boundary or a Track boundary, there is only one link Range corresponding to the endpoint, which is the positioning direction Range by default.

8. A rail transit line area network transmission method according to claim 1, characterized in that: The method of transmitting line area information by using the line area serialization method includes: Select the corresponding EZU based on the device types of both the sender and receiver, and determine the regional transmission accuracy; According to the structure of the required transmission area in the line topology, determine the location information of the divergent turnouts passing through the area; According to the coordinate information of the starting point of the route area and the direction of the route area, confirm the range of the starting point coordinates and the starting point quantum number; Map the length of the line region to the number of desired Quantums.

9. A rail transit line area network transmission method according to claim 1, characterized in that: The method of converting the line area information by using the line area deserialization method includes: after receiving the line area transmitted by the sending device via the network, the receiving device converts the network-transmitted Quantum information into line area Abscissa information by using the deserialization method, including: According to the EZU information agreed upon by both parties, find the corresponding Quantum in the EZU data based on the starting point Quantum information. The Range where the Quantum is located is the starting point Range, and the starting point of the Quantum is the regional starting point Abscissa. According to the number of Quantums and the switch location information, start from the starting point Quantum and traverse the starting point Range and its next linked Range in sequence until the number of traversed Quantums reaches the number of Quantums required in the received data, and find the end point Quantum. The end point of this Quantum is the area end point Abscissa. Count the lengths of all Quantums to get the length of the transmission area.

10. A rail transit line area network transmission method according to claim 1, characterized in that: The estimation strategies include overestimation, underestimation and no overestimation: The overestimation is that the starting point of the transmission area is selected as the Quantum where the starting point Abscissa is located, and the end point of the transmission area is selected as the Quantum where the end point Abscissa is located. The final result is that the actual transmission area is larger than the area to be transmitted; For the underestimation, the starting point of the transmission area selects the next Quantum of the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects the previous Quantum of the Quantum where the end point Abscissa is located; if the starting and ending Quantums are not the boundary Quantums of the range in which they are located, then the next Quantum number is the selected Quantum number plus 1, and the previous Quantum number is the selected Quantum number minus 1; if the starting and ending Quantums are the boundary Quantums of the range in which they are located, then according to the line topology and the range link relationship, the end point Quantum of the previous linked range of the range in which the selected Quantum is located is the previous Quantum of the selected Quantum, and the starting point Quantum of the next linked range of the range in which the selected Quantum is located is the next Quantum of the selected Quantum; The said no over-estimation or under-estimation, the starting point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the starting point; the ending point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the ending point.

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