Rail transit vehicle and display screen network data analysis method and system

Abstract

The invention discloses a rail transit vehicle and a display screen network data analysis method and system, and the method comprises the steps: judging a subsystem which a data packet belongs to, and sorting and storing corresponding positions of corresponding buffer regions according to the size of heartbeat values of data sub-packets; and detecting whether a complete data packet exists in the buffer area according to the continuity of the life signal, the packet sequence number and the total packet value, obtaining and forming the complete data packet when detecting that a sub-packet sequence meeting the condition exists, analyzing data according to the effective length of the data packet, and transmitting the complete data packet to a display screen for displaying. And the display can timely and accurately display the state data of the 6A system.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to a method and system for analyzing network data of a rail transit vehicle and a display screen. Background Art

[0002] With the popularization of modern rail transit vehicles and the development of digital intelligent technology, rail transit vehicles used to use traction display screens to display the real-time status of the traction control system and locomotive setting functions, brake display screens to display the real-time status of the brake control system and test operations, and 6A display screens to display the 6A system information that endangers safety, such as the brake system, fire protection, high-voltage insulation, train power supply, running gear, and video for the locomotive. Now, the traction display screen, brake display screen, and 6A display screen are integrated to form an intelligent fusion large-screen solution, making it more convenient for drivers and maintenance personnel to use the display screen. All operations can be performed on one display screen. While the integration of three screens brings convenience, it also brings challenges to the development of display screen software. The display screen needs to receive and process more information. Among them, the 6A subsystem and other information displayed on the 6A display screen adopts the UDP data transmission method because of the large amount of data and the need for real-time transmission. The 6A subsystem and PHM system first transmit the data to the 6A central processing host, and then the data is uniformly transmitted to the display screen after being processed by the 6A central processing host. It is mainly divided into 6A protocol data packets, PHM protocol data packets, and trailer protocol data packets. The longest valid protocol data bit is 10847 bytes.

[0003] UDP data transmission has the advantages of high efficiency and low latency. The maximum size of a UDP data packet depends on the MTU (maximum transmission unit) of the network. Usually, the MTU of Ethernet is 1500 bytes. However, since the UDP header occupies 8 bytes and the IP header can occupy 20 bytes, the maximum size of the UDP data payload on Ethernet is 1500 bytes - 8 bytes - 20 bytes = 1472 bytes. When it comes to applications, it is necessary to add header information and tail information at the same time. Therefore, the length of the effective data packet in the rail vehicle network using Ethernet transmission is much less than 1500 bytes. Therefore, when the UDP data packet sent by the 6A central processing host needs to be divided into multiple data packets for transmission, it is necessary to parse and group the received UDP data packets, and combine the received data into a complete protocol data packet according to the protocol to ensure the integrity and timeliness of the data, so as to achieve the purpose of real-time monitoring of the vehicle subsystem status on the display screen.

[0004] In the design process of rail transit control network and monitoring network, security, stability and real-time performance are important considerations. For data that is split into multiple packets for transmission, the data packet grouping used by the display screen at the receiving end is the data sub-packet obtained by splitting the same data packet at the sender. For example, the sender splits the data packet into 5 data sub-packets, namely sub-packet 1, sub-packet 2...sub-packet 5. A group of 5 sub-packets is sent at time 1, and a group of 5 sub-packets is sent at time 2. There is a difference of 5 seconds between time 1 and time 2. Due to factors such as network delay and packet loss, the receiver combines sub-packet 5 at time 1 with sub-packet 1, sub-packet 2, sub-packet 3, and sub-packet 4 at time 2 into a complete data packet. At this time, when displayed, the data are all displayed with normal values, but the data of sub-packet 5 is the vehicle data 5 seconds ago. For example, the brake cylinder pressure value plays a decisive role in whether the vehicle can stop safely. If the brake cylinder pressure value observed by the driver on the display screen is 5 seconds or even earlier, the driver cannot accurately judge the vehicle operation status and cannot apply the corresponding operation, which has a significant impact on vehicle safety. Therefore, the display screen must meet the requirements of real-time, effective and correctness for the network data it receives. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for analyzing network data of a rail transit vehicle and a display screen in view of the deficiencies in the prior art, so as to ensure that the display displays the status data of the 6A system in a timely and accurate manner.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for parsing network data of a rail transit vehicle display screen, comprising the following steps:

[0007] S1, receiving UDP data packets;

[0008] S2, determine whether the heartbeat value of the UDP data packet changes, if so, proceed to step S3; otherwise, return to step S1;

[0009] S3, determine whether the UDP data packet is valid, if so, proceed to step S4; otherwise, return to step S1;

[0010] S4, judging the subsystem to which the UDP data belongs according to the data protocol bit;

[0011] S5, inserting the UDP data packet into the first data buffer according to the heartbeat sequence;

[0012] S6. Determine whether there is a complete set of data packets in the first data buffer. If so, extract the complete data packets and store the valid data in the second data buffer; otherwise, return to step S1.

[0013] In step S6, after the valid data is stored in another data buffer, the corresponding data is displayed on the interface.

[0014] The method of the present invention also includes: when the heartbeat of the UDP data packet does not change within M cycles, or the packet assembly action fails M times, the first data buffer and the second data buffer are cleared, and the valid data after processing (i.e., packet assembly is completed) is displayed on the display screen.

[0015] In step S3, the process of determining whether the UDP data packet is valid includes: checking the data packet header and tail, and if both the data packet header and tail are valid, then determining that the UDP data packet is valid.

[0016] In step S5, after the UDP data packet is inserted into the first data buffer according to the heartbeat sequence, the data heartbeat of the first data buffer before the UDP data packet is smaller than the heartbeat of the UDP data packet, and the data heartbeat of the first data buffer after the UDP data packet is larger than the heartbeat of the UDP data packet.

[0017] The specific implementation process of step S5 includes:

[0018] Get the total number of UDP data packets according to the protocol bit. If the total number of packets is 1, get the effective length of the UDP data packet and assign the effective length to the second data buffer. If the total number of UDP data packets is greater than 1, perform the following operations:

[0019] If the 0th dimension array of the second data buffer is empty, the UDP data packet is copied to the 0th dimension and the process proceeds to step S6;

[0020] Traverse the second data buffer forward starting from the last dimension L of the second data buffer:

[0021] If the heartbeat of the UDP data packet is greater than the heartbeat of the Lth dimension, the data of the i-th dimension is copied to the i-1 dimension, where i ranges from 1 to L, and then the data of the UDP data packet is copied to the Lth dimension;

[0022] If the data heartbeat of the UDP data packet is smaller than the heartbeat of the 0th dimension of the second data buffer, the data of the Lith dimension is copied to the L-i+1th dimension, and then the data of the UDP data packet is copied to the 0th dimension;

[0023] If the data heartbeat of the UDP data packet is smaller than the heartbeat of the Lth dimension, the UDP data packet data is compared with the heartbeat of the L-1 dimension data packet until the heartbeat of the UDP data packet data is larger than the heartbeat of the Lith dimension. Then the data of the Ljth dimension is copied to the Lj-1 dimension, where j ranges from 1 to Li, and the UDP data packet data is copied to the L-i+1th dimension.

[0024] In step S6, the specific implementation process of determining whether there is a complete set of data packets in the first data buffer includes:

[0025] 1) Traverse the second data buffer from the 0th dimension, first find the i-th dimension data with packet number 1, and store the total number of packets NumALL of the i-th dimension data of the UDP data packet, and save the i-th dimension data in the 0th dimension of a temporary data buffer;

[0026] 2) Continue to traverse backward from the i-th dimension. If the heartbeat number of the i+j-th dimension data is the heartbeat number of the i-th dimension plus 1, and the total number of packets of the i-th dimension data and the i+j-th dimension data is the same, then the i+j-th dimension data is saved in the first dimension of a temporary data buffer;

[0027] 3) Repeat the process of step 2) to put data whose heartbeat is 1 greater than the heartbeat of the first dimension data packet and the same as the total number of packets of the first dimension data packet into the second dimension of the temporary data buffer;

[0028] 4) After finding the last data packet whose packet sequence number is the same as the total number of packets, proceed to step 5); if no complete data packet is found after traversing the second data buffer, re-enter step 1);

[0029] 5) Traverse the temporary data buffer starting from the 0th dimension, obtain the valid length of each packet data according to the data protocol, copy it to the first data buffer, and splice each data packet from front to back to form a complete valid data packet.

[0030] As an inventive concept, the present invention also provides a rail transit vehicle display screen network data analysis system, including a memory, a processor and a computer program stored in the memory; the processor executes the computer program to implement the steps of the above method.

[0031] As an inventive concept, the present invention also provides a rail transit vehicle, which adopts the above-mentioned rail transit vehicle display screen network data analysis system.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention parses the received original UDP data packet, determines the subsystem to which the data packet belongs, sorts and stores the corresponding position of the corresponding buffer according to the size of the heartbeat value of the data sub-packet, detects whether there is a complete data packet in the buffer according to the continuity of the life signal, the packet sequence number and the total packet value, and when it is detected that there is a sub-packet sequence that meets the conditions, obtains and composes a complete data packet, parses the data according to the effective length of the data packet, and transmits the complete data packet to the display screen for display, ensuring that the display screen displays the status data of the 6A system in a timely and accurate manner;

[0034] 2. The present invention includes multiple data verifications, including header verification, heartbeat verification, packet sequence number verification and data verification, which improves the correctness and effectiveness of received data;

[0035] 3. When the original data packets of the present invention are combined, it is ensured that the data packets sent at the same time are combined, and the error display caused by delayed packetization of data with time difference is avoided;

[0036] 4. The method of the present invention is used to clean up the data buffer in time when the data is not updated, the heartbeat does not change, and multiple package assembly fails, thereby avoiding the display of data errors caused by erroneous communication and promptly reminding the user to check the device communication problem;

[0037] 5. The present invention determines the combination order according to the packet sequence number, the total number of packets and the heartbeat, and has a greater fault tolerance rate when the data packet sequence is disordered. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] Embodiment 1 of the present invention provides a method for analyzing network data of a rail transit vehicle display screen, comprising the following steps:

[0042] 1) Receive a fixed-length UDP data packet, parse the obtained UDP data packet heartbeat, and compare the heartbeat with the heartbeat of the previous UDP data packet. If they are different, keep and proceed to step 2); if they are the same, repeat step 1);

[0043] 2) According to the protocol, the UDP data packet is analyzed to see whether it is valid data, including the header check and the tail check of the data packet. If the check succeeds, proceed to step 3), otherwise proceed to step 2);

[0044] 3) Parse the UDP data packet data identifier according to the protocol bit, and perform a packet operation on the packet data and its corresponding packet buffer according to the identifier.

[0045] 4) Get the total number of packets of the packet data according to the protocol bit. If the total number of packets of the packet is 1, take the effective length of the packet and assign it to the corresponding data buffer 1. If the total number of packets of the packet is greater than 1, perform the following operations:

[0046] If the 0th dimension array of buffer 2 is empty, the data packet is copied to the 0th dimension and step 6 is performed. The basis for judging whether the data is empty is whether the first few bits of the data in this dimension are consistent with the packet header of the protocol.

[0047] Starting from the last dimension L of the data buffer, the data buffer is traversed forward, which is divided into the following three cases:

[0048] Case 1: If the heartbeat of the packet data is greater than the heartbeat of the Lth dimension, copy the data of the i-th dimension to the i-1 dimension, where the range of i is 1-L, and then copy the packet data to the Lth dimension;

[0049] Case 2: If the heartbeat of the packet data is less than the heartbeat of the buffer's 0th dimension, copy the data of the Lith dimension to the L-i+1th dimension, where i ranges from 1-L, and then copy the packet data to the 0th dimension;

[0050] Case 3: If the heartbeat of the packet data is smaller than the heartbeat of the Lth dimension, the packet data is compared with the heartbeat of the L-1th dimension data packet until the heartbeat of the packet data is larger than the heartbeat of the Lith dimension. Then the data of the Ljth dimension is copied to the Lj-1th dimension, where the range of i is 1-Li, and the packet data is copied to the L-i+1th dimension;

[0051] 5) Find a complete packet from the data buffer:

[0052] A. Traverse data buffer 2 from the 0th dimension, first find the i-th dimension data with packet number 1, store the total number of packets NumALL of the packet, and save it in a temporary data buffer

[0053] 3's 0th dimension;

[0054] B. Continue to traverse backward from the i-th dimension. If the heartbeat number of the i+j-th dimension data is the heartbeat number of the i-th dimension plus 1, and the total number of packets of the i-th dimension data and the i+j-th dimension data is the same, save it in the first dimension of a temporary data buffer 3;

[0055] C. Repeat step B, and put the data with a heartbeat greater than the first dimension data packet by 1 and the same total number of packets as the first dimension data packet into the second dimension of the temporary data buffer 3;

[0056] D. After finding the last data packet with the same packet number as the total number of packets, jump out of the loop and go to the next step;

[0057] E. If a complete packet is not found after traversing data buffer 2, re-enter step 1);

[0058] The temporary data buffer 3 is a two-dimensional array, one dimension of which is used to represent the longest total number of packets M among all data, and the other dimension represents the fixed length of the UDP data packet.

[0059] 6) Starting from the 0th dimension, traverse the temporary data buffer 3, obtain the effective length of each packet data according to the data protocol, copy it to the data buffer 1, and splice it from front to back to form a complete valid data packet.

[0060] The UDP original data packets come from multiple systems such as PHM traction, 6A dynamic control car, 6A trailer and PHM ventilation. The data protocols of each subsystem are inconsistent. When the display screen displays data, it is necessary to obtain the protocol data according to the source subsystem of the data. Therefore, it is necessary to establish a one-dimensional data buffer Data1[M] for different subsystem data according to the source subsystem type of the data. M is the maximum valid data length of each subsystem data protocol, which is used for the display to obtain the data of the corresponding subsystem. PHM traction is a health management system that provides traction system data in train vehicles. 6A dynamic control car is a system that transmits power car and control car data in the monitoring system installed in the train. The power car is a vehicle that provides power in the power-concentrated EMU vehicle formation. At the same time, it has a driver's cab for the driver to drive and is equipped with a vehicle display screen to display vehicle data. The control car is a vehicle that does not provide power in the power-concentrated EMU vehicle formation, but has a driver's cab for the driver to drive and is equipped with a vehicle display screen to display vehicle data. PHM ventilation is a health management system that provides ventilation and cooling system data in train vehicles. The source subsystem type is the data source transmitted by the UDP original data packet, namely the above-mentioned PHM traction, 6A dynamic control vehicle, 6A trailer and PHM ventilation systems. UDP data is sent using a packetization mechanism. The 6A central processing host splits the data of each system into packets and adds a message header and a message tail before sending them, as shown in Table 1 below. In order to store the original data packets of each system for packet assembly operations, a two-dimensional data buffer Data2[N][M] needs to be established, where N is used to represent the number of cacheable UDP original data packets N, M represents the byte length of the UDP data packet, and Data2[i][1..M] represents the i-th UDP original data packet; the packet header represents one of the identifiers used to determine whether the packet data is valid, the heartbeat value increases by 1 on the heartbeat value of the previous packet data each time a packet of data is sent, the data ID is used to parse the corresponding subsystem of the packet data content, the total number of packets represents the number of subpackets split by the subsystem's complete packet data protocol, the packet sequence number refers to the position of the packet data in the total number of subpackets, the valid length of the data area represents the number of bits in the data area that are valid in the protocol data, and the checksum is used to verify the validity of the packet data.

[0061] Table 1 UDP raw data packet protocol

[0062]

[0063] Receive a UDP packet with a fixed length, parse the heartbeat of the obtained UDP packet, and compare this heartbeat with the heartbeat of the UDP packet obtained in the previous cycle to judge the validity of the data. If the two heartbeat values are different, it means the data is valid. Then, according to the protocol, parse whether the UDP packet is valid data, including the header checksum and the tail checksum of the data packet.

[0064] Parse the data identifier - heartbeat of the UDP packet according to the protocol bit, and copy the data of this packet to the buffer Data2[i][M] according to the size of the heartbeat, ensuring that the heartbeat of the buffer data Data2[j][M] (0 <= j < i) before this packet is smaller than the data of this packet, and the heartbeat of the buffer data Data2[j][M] (i < j <= N) after this packet is larger than the data of this packet, so as to facilitate traversing in sequence from front to back when looking for the complete packet data and improve the efficiency of packet assembly.

[0065] Find a complete data protocol packet from the data buffer Data2 according to the total number of packets, heartbeat, and packet sequence number. There are three requirements for forming a complete data protocol packet. Requirement 1: The heartbeat of each packet of data must be continuous. Requirement 2: The packet sequence number of each packet must be continuous. Requirement 2: It must contain the original data packets with the number of the total number of packets. Only by ensuring these three points can a complete, valid, and timely protocol data packet be formed. If the heartbeat is not continuous and the packet sequence number is continuous, data at different times will be displayed on the display screen at the same time, and many of the displayed data are related, resulting in incorrect judgments such as equipment damage by the user. If the packet sequence number is disordered or does not conform to the total number of packets, the data display will be incorrect, and incorrect judgments will also be generated.

[0066] If the heartbeat of the original data packet does not change in 30 cycles (one cycle refers to receiving a UDP packet and performing a packet assembly operation once), or if the packet assembly operation fails 30 times, clear both the data buffer 1 and the data buffer 2, and also clear the data display on the display screen interface, that is: when the system judges that the sending data end is normally connected to the network according to the unchanged life signal of the UDP packet, that is, there is a network communication failure, at this time, the network data of the subsystem port has not been updated and the data is in an invalid state. Therefore, clear all the data in the refreshed interface data buffer to zero and display it on the display screen interface.

[0067] Embodiment 2

[0068] Embodiment 2 of the present invention provides a parsing system corresponding to Embodiment 1 above, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program on the memory to implement the steps of the method in Embodiment 1 above.

[0069] In some implementations, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0070] In some other implementations, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited herein.

[0071] Example 3

[0072] Embodiment 3 of the present invention provides a rail transit vehicle corresponding to the above-mentioned embodiment 2, which adopts the analysis system of the above-mentioned embodiment 2.

[0073] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0074] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for analyzing network data of a rail transit vehicle display screen, characterized in that: The following steps are involved: S1, receive UDP data packet; S2, determine whether the heartbeat value of the UDP data packet changes, if so, proceed to step S3; Otherwise, return to step S1; S3, determine whether the UDP data packet is valid, if so, proceed to step S4; Otherwise, return to step S1; S4, judging the subsystem to which the UDP data belongs according to the data protocol bit; S5, inserting the UDP data packet into the first data buffer according to the heartbeat sequence; S6. Determine whether there is a complete set of data packets in the first data buffer. If so, extract the complete data packets and store the valid data in the second data buffer; otherwise, return to step S1.

2. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: In step S6, after the valid data is stored in another data buffer, the corresponding data is displayed on the interface.

3. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: Also includes: When the heartbeat of the UDP data packet does not change within M cycles, or the packet assembly action fails M times, the first data buffer and the second data buffer are cleared, and the valid data after the packet assembly is completed is displayed on the display screen.

4. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: In step S3, the process of determining whether the UDP data packet is valid includes: checking the data packet header and tail, and if both the data packet header and tail are valid, then determining that the UDP data packet is valid.

5. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: In step S5, after the UDP data packet is inserted into the first data buffer according to the heartbeat sequence, the data heartbeat of the first data buffer before the UDP data packet is smaller than the heartbeat of the UDP data packet, and the data heartbeat of the first data buffer after the UDP data packet is larger than the heartbeat of the UDP data packet.

6. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: The specific implementation process of step S5 includes: Get the total number of UDP data packets according to the protocol bit. If the total number of packets is 1, get the effective length of the UDP data packet and assign the effective length to the second data buffer. If the total number of UDP data packets is greater than 1, perform the following operations: If the 0th dimension array of the second data buffer is empty, the UDP data packet is copied to the 0th dimension and the process proceeds to step S6; Traverse the second data buffer forward starting from the last dimension L of the second data buffer: If the heartbeat of the UDP data packet is greater than the heartbeat of the Lth dimension, the data of the i-th dimension is copied to the i-1 dimension, where i ranges from 1 to L, and then the data of the UDP data packet is copied to the Lth dimension; If the data heartbeat of the UDP data packet is smaller than the heartbeat of the 0th dimension of the second data buffer, the data of the Lith dimension is copied to the L-i+1 dimension, and then the data of the UDP data packet is copied to the 0th dimension; if the data heartbeat of the UDP data packet is smaller than the heartbeat of the Lth dimension, the UDP data packet data is compared with the L-1 dimension data packet heartbeat until the heartbeat of the UDP data packet data is larger than the heartbeat of the Lith dimension, then the data of the Ljth dimension is copied to the Lj-1 dimension, where j ranges from 1 to Li, and the UDP data packet data is copied to the L-i+1th dimension.

7. The method for analyzing network data of a rail transit vehicle display screen according to claim 1, characterized in that: In step S6, the specific implementation process of determining whether there is a complete set of data packets in the first data buffer includes: 1) Traverse the second data buffer from the 0th dimension, first find the i-th dimension data with packet number 1, and store the total number of packets NumALL of the i-th dimension data of the UDP data packet, and save the i-th dimension data of the UDP data packet in the 0th dimension of a temporary data buffer; 2) Continue to traverse backward from the i-th dimension. If the heartbeat number of the i+j-th dimension data is the heartbeat number of the i-th dimension plus 1, and the total number of packets of the i-th dimension data and the i+j-th dimension data is the same, then the i+j-th dimension data is saved in the first dimension of a temporary data buffer; 3) Repeat the process of step 2) to put the data with a heartbeat greater than the first dimension data packet by 1 and the same total number of data packets as the first dimension data packet into the second dimension of the temporary data buffer; 4) After finding the last data packet whose packet sequence number is the same as the total number of packets, proceed to step 5); if no complete data packet is found after traversing the second data buffer, re-enter step 1); 5) Traverse the temporary data buffer starting from the 0th dimension, obtain the valid length of each packet data according to the data protocol, copy it to the first data buffer, and splice each data packet from front to back to form a complete valid data packet.

8. A rail transit vehicle display screen network data analysis system, comprising a memory, a processor and a computer program stored in the memory; characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A rail transit vehicle, characterized in that: It adopts the rail transit vehicle display screen network data analysis system described in claim 8.

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