Line area network transmission method in rail transit field

Abstract

The invention discloses a line area network transmission method in the field of rail transit, and relates to the technical field of rail transit network transmission, and a line topology is mapped into a line transmissible area EZU set, a line transmission area series Range set in the EZU and a line area transmission minimum unit Quantum set in the Range. According to the invention, during area transmission, a numerical value of Abscisa is not directly transmitted, a line is divided into a set of a plurality of EZUs according to service requirements, a receiving party and a transmitting party only transmit line area information in the required EZUs, and original area starting points Abscisa, Track numbers and area directions needing to be transmitted are combined into starting point Quantum numbers, so that consumption of transmission line resources is reduced. The two transmission parties appoint the adopted EZU in advance, and select the required Quantum general length, thereby determining the transmission precision of the line area. And the general length of Quantum can be set according to service requirements, so that the flexibility of the algorithm is improved.

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, which can be used for TACS train control system in the rail transit field, and for line area transmission between a carborne controller (CC), a wayside resource controller (WRC) and a wayside train controller (WTC). Background Art

[0002] In the traditional CBTC system (Communication Based Train Control System), trains rely on the movement authorization calculated by ground equipment to perform driving operations. Compared with CBTC, in the TACS system (Train Autonomous Circumambulate System), with on-board equipment as the core, trains autonomously calculate movement authorization and obtain the safe position of other trains through vehicle-to-vehicle communication to achieve train interval protection.

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

[0004] In the current scheme, the line area is generally transmitted in plain text, and the content transmitted mainly includes: coordinate information of the starting point of the area (including Track number and Abscissa), area length, area direction (direction of the starting point of the area, Abscissa increase direction or Abscissa decrease direction, 1 bit, increment: 0, decrement: 1) and divergent turnout position information (each divergent turnout 1 bit, positioning: 0, reverse position: 1), etc. The receiver can find a unique point in the line as the starting point based on the coordinate information of the starting point of the area, and start from the starting point and expand the area along the direction of the area. When encountering a divergent turnout, the direction of expansion (turnout positioning or turnout reverse position) is determined according to the divergent turnout position information, until the extended length is consistent with the received area length, the area information transmitted by the sender can be obtained, thereby ensuring that the sender and the receiver have a consistent understanding of the transmitted information.

[0005] However, although the above transmission method can ensure the consistency of information between the two parties, it often consumes a lot of network resources. As the line length increases, the line coordinates (Abscissa) and Track number will also increase, and the number of bits consumed by transmitting the line area in this way will also increase.

[0006] In addition, due to the limitations of network resources and the inherent defects of binary representation of decimals, it is impossible to completely match the transmitted data with 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] In current technical research, more attention is paid to the upper-layer applications after realizing line area transmission, and less attention is paid to the technical research of line area transmission itself. For example, the patent "A Railway-specific Electronic Map and System" (patent number: CN110110030A) introduces a mapping algorithm from line mileage marks to line electronic maps. After the terminal obtains the positioning information, it transmits the mileage mark information to the background database. The database maps the mileage mark information to the railway line data in the digital map according to the pre-established line map. However, the article does not mention the specific transmission method of line mileage mark information in the network.

[0008] In the search results of relevant papers, there are corresponding data compression algorithms, but there is still a lack of research on precision loss. For example, the paper "Research on Real-time Compression Methods for Massive Railway BIM Data" (Peng Lihui, "Railway Computer Applications", Issue 5, 2016) mentioned an algorithm that reduces the resources consumed by network transmission by compressing three-dimensional coordinates into two-dimensional coordinates. 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 designed a BIM data modeling and transmission method based on the least squares support vector machine (LS-SVM), so that model parameters and training sample data are transmitted instead of original data, improving data transmission efficiency. However, the above literature only mentions data compression algorithms, and does not mention research on data distortion caused by network data transmission. As a safety system closely related to people's safety, rail transit has always been our bottom line for safety. Data distortion cannot be avoided, but algorithm design can be used to prevent such distortion from causing safety impacts. Summary of the invention

[0009] In order to overcome the defects in the above-mentioned prior art, the present invention discloses a method for network transmission of line areas in the field of rail transit. In order to reduce the resources consumed by network transmission, the present invention designs an algorithm to optimize the transmission mode of line area information in the network. At the same time, in order to improve the safety performance of the system, a serialization and corresponding deserialization algorithm for converting line areas into network byte information is determined to reduce the negative impact caused by precision loss.

[0010] In order to achieve the above objectives, the technical solution adopted by the present invention is: A line area network transmission method in the field of rail transportation, comprising: Map the line topology into a set of line transmission areas EZU, a set of line transmission area series Range within EZU, and a set of line area transmission minimum units Quantum within Range; During regional network transmission, the line is divided into multiple EZU sets. The sender and receiver use the serialization method and deserialization method of the line area 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 divergent turnout position information. The Quantum number is obtained by combining the regional starting point line coordinates Abscissa, the starting point track Track number, and the regional direction information to be transmitted. When transmitting in 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 the transmission area accuracy is lost, the required estimation strategy is selected based on business needs while ensuring security.

[0011] 1. Mapping of line topology information 1.1 Line Transmission Area Set 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 each other in the line area based on this EZU; for communication between XTCs, the scope of the entire line is defined as the EZU.

[0012] 1.2 Line transmission area series Preferably, in each EZU, the EZU is divided into multiple Ranges with the EZU boundary, the Track boundary and the position of the switch on the Track as endpoints, and the number of Quantums in a Range is less than or equal to 1024; and the direction information is distinguished when dividing the Range.

[0013] 1.3 Line area transmission minimum unit 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 m, of which n Is an integer and is configurable.

[0014] 1.4 Quantum Structure in Range Preferably, each Range is filled with multiple Quantums. When the Range is not an integer multiple of the standard length of Quantum, a surplus is left after the Range is filled with multiple Quantums. The surplus is represented by a surplus Quantum. The length of the surplus Quantum is less than the standard length of Quantum. The surplus Quantum exists at the two end regions of the Range. If the Range is in the Abscissa increasing direction, the surplus Quantum is located at the end of the Range. If the Range is in the Abscissa decreasing direction, the surplus Quantum is located at the beginning of the Range. After completing the Quantum filling of the Range, each Quantum is numbered; in the same EZU, each Quantum is set with a unique number; in the same Range, the Quantum numbering is continuously increased, and the number of Quantums is less than or equal to 1024; the Quantum numbers between different Ranges may not be continuous.

[0015] 1.5 Establish the link relationship between Ranges 1.5.1 Range endpoints are EZU boundaries 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.

[0016] 1.5.2 Range endpoints are track boundaries Preferably, the link relationship between Ranges includes: If the end point of the current Range is the boundary of the Track, then find the adjacent Track of the Track where the current Range is located in the line topology 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; If the starting point of the current Range is the Track boundary, find the adjacent Track of the Track where the current Range is located 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.

[0017] 1.5.3 The endpoint of the Range is the location of the turnout Preferably, the link relationship between Ranges includes: If the end point of the current Range is a diverging turnout along the Range direction, the current Range has two next linked Ranges, namely, the Ranges starting from the diverging turnout in the positioning and reverse positioning areas on the diverging turnout; 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 a 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 a 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 with the converging turnout as the end point in the positioning and reverse positioning areas on the converging turnout.

[0018] 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.

[0019] 2. Serialization method of line area Preferably, the method of transmitting the line area information by using the line area serialization method includes: Select the corresponding EZU according to the device types of both the sender and the 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 line area and the direction of the line area, confirm the range where the starting point coordinates are located and the starting point Quantum number; Map the length of the line region to the number of Quantums required.

[0020] Preferably, the estimation strategy includes overestimation, underestimation and neither over-estimation nor under-estimation: The overestimation is that the starting point of the transmission area selects the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects 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; The underestimation is that 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 point Quantum are not the boundary Quantum of the Range, then the next Quantum number is the selected Quantum number plus 1, and the previous Quantum is the selected Quantum number minus 1; if the starting and ending point Quantum are the boundary Quantum of the Range, then according to the line topology and the Range link relationship, the end point Quantum of the previous linked Range of the Range where 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 where 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 Quantum; the ending point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the ending point Quantum.

[0021] 3. Deserialization method of line area Preferably, 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 through the network, the receiving device uses the deserialization method to convert the Quantum information transmitted through the network into the line area Abscissa information, including: According to the EZU information agreed by both parties, find the corresponding Quantum in the EZU data according to 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 Quantum and the switch position information, start from the starting point Quantum and traverse the starting point Range and its next link Range in sequence until the number of traversed Quantum reaches the number of Quantum required in the received data, and find the end point Quantum. The end point of this Quantum is the regional end point Abscissa. Count the lengths of all Quantums to get the length of the transmission area.

[0022] 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.

[0023] 1. Define the concept of exchangeable zone union (EZU) and divide the line into different EZU areas. Different EZUs can be selected as the basis for regional transmission according to different sender and receiver devices, thus reducing network resource consumption; 2. Defines the concept of line transmission area series (Range), divides the line area in EZU into a set of multiple Ranges, and establishes a link relationship for each Range based on the line topology; 3. Defines the minimum unit (Quantum) for line area transmission, 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, thus improving flexibility; 4. A scheme is proposed to map the actual line topology into a data set composed of EZU / Range / Quantum, which is convenient for subsequent serialization and deserialization operations; 5. A serialization algorithm for the line area is proposed, which optimizes the existing Abscissa plaintext transmission scheme to transmit Quantum information, reducing network resource consumption; 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, namely over-estimation and under-estimation. In actual use, the required estimation algorithm can be flexibly selected according to business needs and comprehensive consideration of system security performance, thereby improving the security of line area transmission; 7. A deserialization algorithm for the line area is proposed. After receiving the area information of network transmission, the receiver can accurately parse the network transmission area according to the deserialization algorithm to ensure the consistency between the sender and the receiver.

[0024] Beneficial effects of the present invention: 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).

[0025] During regional transmission, the Abscissa value is not transmitted directly. Instead, 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 regional starting point Abscissa, Track number and regional direction that need to be transmitted are merged into the starting point Quantum number, reducing the consumption of transmission line resources.

[0026] The transmission parties pre-agreed on the EZU to be used and selected the required Quantum general length, thereby determining the accuracy of line area transmission. The Quantum general length can be set according to business needs, which improves the flexibility of the algorithm.

[0027] In addition, when faced with loss of accuracy in the transmission area, the required estimation strategy (underestimation or overestimation) can be flexibly selected based on business needs while ensuring security, thereby improving the security of the algorithm.

[0028] 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

[0029] Figure 1 This is an example of EZU partitioning of the present invention; Figure 2 This is an example of Range division of the present invention; Figure 3 It is a Quantum structure within the Range of the present invention; Figure 4 It is the line transmission area of ​​the present invention; Figure 5 This is the Quantum structure of the transmission area of ​​the present invention. DETAILED DESCRIPTION

[0030] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and drawings to fully understand the purpose, characteristics and effects of the present invention.

[0031] A line area network transmission method in the field of rail transit 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).

[0032] During regional transmission, the Abscissa value is not transmitted directly. Instead, 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 regional starting point Abscissa, Track number and regional direction information that need to be transmitted are merged into the starting point Quantum number, reducing the consumption of transmission line resources.

[0033] The transmission parties pre-agreed on the EZU to be used and selected the required Quantum general length, thereby determining the accuracy of line area transmission. The Quantum general length can be set according to business needs, which improves the flexibility of the algorithm.

[0034] In addition, when faced with loss of accuracy in the transmission area, the required estimation strategy (underestimation or overestimation) can be flexibly selected based on business needs while ensuring security, thereby improving the security of the algorithm.

[0035] 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.

[0036] The line area transmission algorithm proposed in this patent mainly includes the following contents: 1. Mapping of line topology information; 2. Serialization algorithm of line area; 3. Deserialization algorithm of line area; 1. Mapping of line topology information 1.1 Line Transmission Area Set First, we define the exchangeable zone union (EZU).

[0037] In actual engineering applications, a line is often divided into multiple WRC jurisdictions, and each WRC protects the resources in its own jurisdiction to ensure the safe operation of the system. During vehicle operation, XTC (CC or WTC) will apply for resources from the WRC in the corresponding area and then calculate the mobile authorization. Each WRC only transmits the line area information within its own jurisdiction. Therefore, the jurisdiction of each WRC can be defined as an EZU, and XTC and WRC interact with each other in the line area based on this EZU.

[0038] As for the 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.

[0039] According to the EZU defined above, different EZUs can be selected as the basis for subsequent operations when XTCs communicate with WRCs or when XTCs communicate with each other. Figure 1 shown.

[0040] 1.2 Series of line transmission areas Second, we define the series (Range) of line transmission areas within each EZU.

[0041] In each EZU, the EZU is divided into multiple Ranges with the EZU boundary, Track boundary, and the location of the turnout on the Track as endpoints. In addition, if the Range is long and contains more than 1024 Quantums (see 1.3 Line Area Transmission Minimum Unit for details), in order to reduce running memory and improve computing efficiency, this Range needs to be split, that is, the number of Quantums in a Range cannot exceed 1024. It is worth noting that the line area transmitted on the network carries directional information, so the directional information also needs to be distinguished when dividing the Range.

[0042] The division of Range in EZU is as follows Figure 2 As shown in the figure, only a part of Track3 is within the EZU (for example, this EZU is under the jurisdiction of a WRC, and only a part of Track3 is within the WRC), so Range4 is from the EZU boundary to the junction of Track3 and Track4, and Range12 overlaps with Range4 in terms of regional position, but the regional direction is opposite to it. Track4 is within the EZU and there is a switch, so Track4 can be split into two Ranges (Range5 and Range6). There are also two Ranges (Range13 and Range14) that overlap with Range5 and Range6 in terms of regional position, but the regional direction is opposite to it.

[0043] 1.3 Line Area Transmission Minimum Unit Finally, we define the minimum unit (Quantum) of line area transmission. The length of this minimum unit is the accuracy of area transmission.

[0044] According to the binary representation of decimal fractions, the length of Quantum is generally 2 nmeters, where n is an integer. If the accuracy requirement is high, the value of n can be reduced. For example, when n=-4, the accuracy can reach 0.0625 meters. If the accuracy requirement is not too high, the value of n can be increased to reduce network resource consumption. For example, when n=0, the accuracy is 1 meter. In the following text, this parameter n is called Quantum base 2 logarithm.

[0045] According to the EZU division, different devices need to use a specified EZU for communication. Therefore, once the Quantum base 2 logarithm is determined, the same standard should be used throughout the EZU, that is, the value of the Quantum base 2 logarithm represents the accuracy of regional transmission. This parameter is configurable, which increases flexibility. Users can select different values ​​according to the required accuracy requirements.

[0046] 1.4 Quantum Structure in Range Each Range can be considered as composed of multiple Quantums. Since the length of the Range is uncertain, 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 surplus. This surplus area is still represented by one Quantum, but the length of this Quantum is less than the standard length. According to 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.

[0047] After completing the Quantum filling of the Range, each Quantum needs to be numbered. In the same EZU, each Quantum has a unique number; in the same Range, the Quantum number must be continuously increased, but the number of Quantums cannot exceed 1024, that is, the difference between the starting Quantum and the ending Quantum number cannot exceed 1023; the Quantum numbers between different Ranges can be discontinuous.

[0048] by Figure 2 For example, assume that the user sets the regional transmission accuracy to 1 meter, that is, the Quantum base 2 logarithm of this EZU is configured to 0. Assume that the Abscissa range of this area is [100 meters to 108.5 meters]. The structure of Quantum in Range is as follows: Figure 3As 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 it 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 (that is, Quantum 9); for Range12, in the Abscissa decreasing direction, let the Quantum with a length of 0.5 meters be located at the beginning (that is, Quantum 12). It can be seen that although the Quantum sorting methods of these two Ranges are different, their Quantum structures are ultimately the same.

[0049] 1.5 Establishing the link relationship between Ranges After completing the Range and Quantum division, it is necessary to establish the link relationship between each Range. From the Range division method, it can be known that the connection point between two Ranges is the EZU boundary, Track boundary or the location of the switch on the Track, so the link relationship between Ranges can be determined in the following way.

[0050] 1.5.1 Range endpoints are EZU boundaries 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.

[0051] 1.5.2 Range endpoints are track boundaries If the end point of the current Range is the Track boundary, then find the adjacent Track of the Track where the current Range is located in the line topology 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 2For example, for Range6, it is located on Track4. Along the direction of Range6, the adjacent Track of Track4 is found in the line topology as Track5, and the boundary coordinates are recorded as A1. There are two Ranges in Track5, among which the starting coordinates of Range7 are A1. Range7 is the next linked Range of Range6.

[0052] 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 Range5, it is located on Track4. In the line topology, along the opposite direction of Range5, the adjacent Track of Track4 is found to be Track3, and the recorded boundary coordinates are A2. There are two Ranges in Track3, among which the end point coordinates of Range4 are A2, and Range4 is the previous linked Range of Range5.

[0053] 1.5.3 The endpoint of the Range is the location of the turnout According to the difference in turnout types, the scenario where the Range endpoint is the turnout location can be divided into the following two cases.

[0054] 1.5.3.1 Divergent turnouts along the Range direction If the end point of the current Range is a diverging turnout along the Range direction, the current Range has two next linked Ranges, namely, the Ranges starting from the diverging turnout in the positioning and reverse areas on the diverging turnout. Figure 2 Taking Range5 in as an example, its end point is the divergent turnout along the direction of Range5, then there are two next linked Ranges, namely, Range6 in the divergent turnout positioning area with the divergent turnout as the starting point, and Range8 in the divergent turnout anti-positioning area with the divergent turnout as the starting point.

[0055] 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 a 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. Figure 2Take Rang6 / Range8 in as an example, the starting points of both are divergent turnouts along the Range direction, which are located on Track4. There are 4 Ranges on Track4, namely Range5 / Range6 / Range13 / Range14. The Range in the same direction as the divergent turnout is Range5 / Range6, among which the Range with the divergent turnout as the end point is Range5. Therefore, the previous linked Range of Rang6 / Range8 is Range5.

[0056] 1.5.3.2 Converging turnouts along the Range direction 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 that is in the same direction as the convergent turnout and has the convergent turnout as its starting point. Figure 2 Take Range2 / Range8 in as an example, their end points are the converging turnout along the Range direction, which is located on Track2. There are 4 Ranges on Track2, namely Range2 / Range3 / Range10 / Range11. The Range in the same direction as the converging turnout is 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.

[0057] 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 with the converging turnout as the end point in the positioning and reverse areas on the converging turnout. Figure 2 Taking Range 13 in 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.

[0058] After establishing the relationship between Ranges according to the above principles, we can get Figure 2 The link relationship between each Range is shown in Table 1 below. Note: When designing the link relationship, 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.

[0059] Table 1 Range link relationship 2. Serialization algorithm of line area 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.

[0060] The regional transmission method proposed in this patent only needs to transmit the starting point Quantum number, the number of Quantums and the divergent turnout location information. The Abscissa of the starting point of the area, 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.

[0061] The specific algorithm is as follows: First, according to the type of equipment on both the sending and receiving sides, select the corresponding EZU and determine the regional transmission accuracy. Secondly, according to the structure of the required transmission area in the line topology, determine the location information of the divergent turnouts that the area passes through. Thirdly, according to the starting point coordinate information of the line area and the direction of the line area, confirm the Range where the starting point coordinates are located and the starting point Quantum number. Finally, map the length of the line area to the number of required Quantums.

[0062] by Figure 4 For example, the line area in the WRC and CC needs to transmit Figure 4 The area information in the table has the starting point coordinate information as [Track number: 3, Abscissa: 103.5 meters], the end point coordinate information as [Track number: 2, Abscissa: 306.3 meters], and the area length as 140.1 meters. The serialization algorithm is as follows: 2.1 Confirm EZU and accuracy The sending and receiving sides in this area are WRC and CC, so you can select the EZU corresponding to the WRC jurisdiction. Assume that the required regional transmission accuracy is 1 meter, that is, Quantum base 2 logarithm is set to 0.

[0063] 2.2 Determine the divergent turnouts passing through the area according to Figure 4 From the regional information in , it can be seen that the area passes through a divergent turnout, and the turnout position is reversed.

[0064] 2.3 Confirm the starting point coordinate information from Figure 5 From the Range example, we can see that [Track number: 3, Abscissa: 103.5 meters] is located in Quantum4 in Range4, so the starting point Quantum number is 4.

[0065] 2.4 Confirm the number of Quantums required Similar to step 2.3, determine the range and quantum number of the end point Abscissa. Then, starting from the starting point Quantum, traverse each range of the EZU in turn according to the range link relationship and the location of the divergent turnout until the end point Quantum is found. Record the number of Quantums traversed in this process, which is the number of Quantums required for the transmission area.

[0066] by Figure 4 For 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.

[0067] The starting point Quantum is in Range4, and its next link Range is Range5. Range5 has two next links. According to the turnout information, the reverse range should be selected, that is, Range8. The next link of Range8 is Range3. It can be seen that the area to be transmitted is located on Range4, Range5, Range8 and Range3 in sequence. The number of Quantums in the traversal process is calculated: Range4, 6 (Quantum4~Quantum9); Range5 and Range8, the above ranges are included in the transmission area as a whole. According to Figure 5 It can be seen that the number of Quantums contained in the two are 30 and 100 respectively, totaling 130 Quantums; Range3, 6 (Quantum52~Quantum57). Therefore, the total number of Quantums required is 142.

[0068] Comparing the existing solution 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 has a significant reduction in network byte overhead. As the line length increases, the Abscissa and Track numbers will also increase, and the network resource advantage of this solution will become more obvious.

[0069] Table 2 Comparison of line area transmission network resources 2.4 Confirmation Estimation Algorithm Due to the limitation of transmission accuracy, there is an accuracy error between the area actually transmitted in the network and the area to be transmitted. Taking the line area [Starting point Track number: 3, Starting point Abscissa: 103.5 meters; Ending point Track number: 2, Ending point Abscissa: 306.3 meters] as an example, after serialization, the area actually transmitted is [Starting point Track number: 3, Starting point Abscissa: 103 meters; Ending point Track number: 2, Ending point Abscissa: 307.2 meters]. It can be seen that the area after serialization exceeds the area to be transmitted, which may bring security risks in safety-related systems.

[0070] For example, CC transmits the cleaning area to 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 cleaning area, it will mistakenly cause WRC to believe that some uncleaned areas have been cleaned, thus causing security risks.

[0071] Therefore, this patent proposes an estimation method for line area serialization, including overestimation and underestimation. When line area transmission is performed between devices, the estimation algorithm used can be flexibly selected according to business needs.

[0072] For overestimation, that is, the serialization algorithm mentioned above, the starting point of the transmission area selects the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects 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.

[0073] In contrast, underestimation aims to make the actual transmission area slightly smaller than the area to be transmitted while being as close to the area to be transmitted as possible. 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 point Quantum are not the boundary Quantum of the Range, 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 points Quantums obtained are Quantum5 and Quantum56 respectively. If the starting and ending points Quantum are the boundary Quantum of the Range, then according to the line topology and the Range link relationship, the end point Quantum of the previous linked Range of the Range where 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 where the selected Quantum is located is the next Quantum of the selected Quantum.

[0074] It is worth noting that if the starting point Abscissa is exactly at the junction of two Quantums, the corresponding Quantum should be the Quantum with the Abscissa as the starting point; if the end point Abscissa is exactly at the junction of two Quantums, the corresponding Quantum should be the Quantum with the Abscissa as the end point. For example, if the starting point Abscissa is 103 meters, the starting point Quantum is Quantum4; if the end point Abscissa is 307.2 meters, the end point Quantum is Quantum57. In this scenario, accurate transmission of the line area can be completed without over-estimation or under-estimation.

[0075] 3. Deserialization algorithm of line area After receiving the line area transmitted by the sending device through the network, the receiving device can use the reverse sequence algorithm to convert the Quantum information transmitted by the network into the line area Abscissa information. The specific algorithm is as follows: First, according to the EZU information agreed upon by both parties, the corresponding Quantum is found in the EZU data according to 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.

[0076] Secondly, according to the number of Quantum and the switch location information, start from the starting point Quantum and traverse the starting point Range and its next link Range in sequence until the number of traversed Quantum reaches the number of Quantum required in the received data, then the end point Quantum can be found. The end point of this Quantum is the regional end point Abscissa.

[0077] Finally, by counting the lengths of all Quantums, the length of the transmission area can be obtained.

[0078] Taking the transmission line area in Table 2 as an example, it is assumed that the sender adopts the over-estimation method.

[0079] This area is transmitted between CC-WRC, so the two parties agree that the EZU is the EZU corresponding to the jurisdiction of WRC. Find the starting point Quantum (Quantum4) in this EZU, and its starting point Abscissa is the starting point Abscissa of the area, which is 103 meters.

[0080] Starting from Quantum4 of Range4, we search backwards. We can traverse 6 Quantums (Quantum4~Quantum9) in this Range, 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, i.e. Range8. There are 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.

[0081] The length of all Quantums found during the traversal process is counted to get the line area length. Quantum4~Quantum9 of Range4 has a total length of 5.5 meters; all Quantums of Range5 have a total length of 30 meters; all Quantums of Range8 have a total length of 100 meters; Quantum52~Quantum57 of Range3 have a total length of 6 meters; that is, the total length of the line area is 141.5 meters.

[0082] Finally, the area obtained is: starting from Abscissa 103 meters of Track3 and ending at Abscissa307.2 of Track2, passing through a divergent turnout in the middle, and the turnout position is the reverse area. It can be seen that this area is slightly larger than the area to be transmitted by the sender, meeting the overestimation requirement, as shown in Table 3 below.

[0083] Table 3 Deserialization algorithm example The above is a specific description of the implementation mode of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalents or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A method for line area network transmission in the field of rail transit, characterized in that: include: Map the line topology into a set of line transmission areas EZU, a set of line transmission area series Range within EZU, and a set of line area transmission minimum units Quantum within Range; During regional network transmission, the line is divided into multiple EZU sets. The sender and receiver use the serialization method and deserialization method of the line area 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 divergent turnout position information. The Quantum number is obtained by combining the regional starting point line coordinates Abscissa, the starting point track Track number, and the regional direction information to be transmitted. When transmitting in 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 the transmission area accuracy is lost, the required estimation strategy is selected based on business needs while ensuring security.

2. A rail transit line area network transmission method as claimed in claim 1, characterized in that: 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 each other in the line area based on this EZU; for communication between XTCs, the scope of the entire line is defined as EZU; In each EZU, the EZU boundary, the Track boundary, and the location of the turnout on the Track are used as endpoints to divide the EZU into multiple Ranges. The number of Quantums 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 m, of which n Is an integer and is configurable.

3. A rail transit line area network transmission method as claimed in claim 1, characterized in that: Each Range is composed of multiple Quantum fillings. When the Range is not an integer multiple of the standard length of Quantum, the Range is filled with multiple Quantums and there is a surplus left. This surplus is represented by a surplus Quantum. The length of the surplus Quantum is less than the standard length of Quantum. The surplus Quantum exists at the two end areas of the Range. If the Range is in the Abscissa increasing direction, the surplus Quantum is located at the end of the Range. If the Range is in the Abscissa decreasing direction, the surplus Quantum is located at the beginning of the Range. After completing the Quantum filling of the Range, each Quantum is numbered; in the same EZU, each Quantum is set with a unique number; in the same Range, the Quantum numbering is continuously increased, and the number of Quantums is less than or equal to 1024; the Quantum numbers between different Ranges may not be continuous.

4. A rail transit line area network transmission method as claimed in 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 as claimed in claim 1, characterized in that: The link relationship between Ranges includes: If the end point of the current Range is the boundary of the Track, then find the adjacent Track of the Track where the current Range is located in the line topology 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; If the starting point of the current Range is the Track boundary, find the adjacent Track of the Track where the current Range is located 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.

6. A rail transit line area network transmission method as claimed in 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, the current Range has two next linked Ranges, namely, the Ranges starting from the diverging turnout in the positioning and reverse positioning areas on the diverging turnout; 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 a 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 a 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 with the converging turnout as the end point in the positioning and reverse positioning areas on the converging turnout.

7. A rail transit line area network transmission method as claimed in 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 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.

8. A rail transit line area network transmission method as claimed in claim 1, characterized in that: The method of transmitting line area information by using the line area serialization method comprises: Select the corresponding EZU according to the device types of both the sender and the 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 line area and the direction of the line area, confirm the range where the starting point coordinates are located and the starting point Quantum number; Map the length of the line region to the number of Quantums required.

9. A rail transit line area network transmission method as claimed in 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 through the network, the receiving device uses the deserialization method to convert the Quantum information transmitted through the network into the line area Abscissa information, including: According to the EZU information agreed by both parties, find the corresponding Quantum in the EZU data according to 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 Quantum and the switch position information, start from the starting point Quantum and traverse the starting point Range and its next link Range in sequence until the number of traversed Quantum reaches the number of Quantum required in the received data, and find the end point Quantum. The end point of this Quantum is the regional 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 as claimed in claim 1, characterized in that: The estimation strategies include overestimation, underestimation and no over-estimation: The overestimation is that the starting point of the transmission area selects the Quantum where the starting point Abscissa is located, and the end point of the transmission area selects 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; The underestimation is that 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 point Quantum are not the boundary Quantum of the Range, then the next Quantum number is the selected Quantum number plus 1, and the previous Quantum is the selected Quantum number minus 1; if the starting and ending point Quantum are the boundary Quantum of the Range, then according to the line topology and the Range link relationship, the end point Quantum of the previous linked Range of the Range where 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 where 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 Quantum; the ending point Abscissa is located at the junction of two Quantums, and the corresponding Quantum takes the Abscissa as the ending point Quantum.

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