A train network message survival delay calculation method, device and medium

Abstract

The present application relates to a kind of train network message survival delay calculation method, equipment and medium, the method includes the following steps: step S1, the optimal internal device message survival delay is calculated;Step S2, define the maximum delay T1 of underestimation of reference time point sent by on-board controller product LH;Step S3, according to network type, calculate the worst case LH transmission delay T2;Step S4, calculate the delay T3 of message calculation period when LH receives message in the worst case;Step S5, calculate the maximum delay T4 of message calculation period to next message processing time point in the worst case.Compared with prior art, the present application has the advantages of meeting the reliability and real-time of TACS system communication, and improving data processing speed capacity.

Description

Technical Field

[0001] This invention relates to train signal control systems, and more particularly to a method, device, and medium for calculating the lifespan delay of train network messages. Background Technology

[0002] With the continuous development of computer and communication technologies in the rail transit field, urban rail transit vehicles are moving towards greater intelligence and autonomy. The Train Autonomous Operation System (TACS) based on vehicle-to-vehicle communication (V2V) achieves safer and more efficient goals through vehicle-to-vehicle cooperation. TACS system equipment communication requires a lifetime delay to determine message validity. Without a lifetime delay, the network message receiver cannot know whether a message has expired; if the calculated lifetime delay is too short, network congestion will cause received messages to be judged invalid and discarded, preventing the receiver from obtaining valid messages.

[0003] A search of Chinese Patent Publication No. CN116866954A reveals a method for train wireless network delay compensation control. Specifically, it discloses the following steps: collecting delay data between the central control unit and the traction control unit to form a delay sequence; processing the delay sequence to obtain residual and component values; constructing a delay prediction model and inputting the obtained residual and component values ​​into the delay prediction model to obtain the predicted delay value for the next moment; inputting the predicted delay value for the next moment into the train operation controller, and implementing train operation control through the train operation controller; and constructing an evaluation index to evaluate the control performance of the train operation controller. However, this existing patent does not cover the accurate calculation process of train wireless network delay. Therefore, how to accurately calculate the train network message survival delay information becomes a technical problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a method, device and medium for calculating the life delay of train network messages.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] According to a first aspect of the present invention, a method for calculating the lifespan delay of train network messages is provided, the method comprising the following steps:

[0007] Step S1: Calculate the optimal internal device message lifetime delay;

[0008] Step S2: Define the maximum delay T1 of the LH transmission reference time underestimation for the vehicle controller product;

[0009] Step S3: Calculate the worst-case LH transmission delay T2 based on the network type;

[0010] Step S4: Calculate the delay T3 of the message calculation period received by LH in the worst case.

[0011] Step S5: Calculate the maximum delay T4 from the message calculation cycle to the next message processing time in the worst case.

[0012] As a preferred technical solution, the delay in step S1 is the maximum delay from the start time of LH to the message expiration time.

[0013] As a preferred technical solution, the maximum delay from the start time of LH to the message expiration time is specifically calculated as: the maximum delay from the underestimated LH sending time to the message calculation cycle in the worst case + the maximum delay T4 from the message calculation cycle to the next message processing time in the worst case.

[0014] As a preferred technical solution, the maximum delay from the underestimated LH sending time to the message calculation period in the worst-case scenario is specifically calculated as follows:

[0015] The maximum delay T1 due to the underestimation of the LH transmission reference time + the worst-case LH transmission delay T2 + the worst-case delay T3 of the LH message reception calculation period.

[0016] As a preferred technical solution, T1 in step S2 is calculated as: product cycle * (1 + product cycle offset rate).

[0017] As a preferred technical solution, T2 in step S3 is calculated as follows:

[0018] If both communicating parties are wireless networks: T2 = network transmission cycle * 2 + transmission delay between the product and the wired network;

[0019] If one party is a wireless network and the other is a wired network: T2 = network transmission cycle + transmission delay between the product and the wired network;

[0020] If both communicating parties are wired networks: T2 = Transmission delay between the product and the wired network.

[0021] As a preferred technical solution, the specific calculation process of step S4 is as follows:

[0022] Step S41: Obtain the maximum tolerable number of packet losses and calculate the number of messages sent during the sending activity;

[0023] Step S42: Obtain the sending time according to the control type;

[0024] Step S43: Calculate the number of sending cycles for each control type based on the calculated number of message sending times and sending time;

[0025] Step S44: Obtain the cycle time and product cycle offset rate, and calculate the maximum duration from the start of the sending activity to the next sending activity based on the results of step S43, the cycle time, and the product cycle offset rate.

[0026] Step S45: Calculate the worst-case delay T3 of the message calculation period received by LH, where T3 = maximum duration of the sending activity + worst-case transmission delay of receiving selected LH after unselected LH arrives - worst-case transmission delay of selected LH.

[0027] As a preferred technical solution, step S42 specifically includes:

[0028] If it's a CC car or a WTC The WRC controller sends a message for one product cycle;

[0029] If it is a WTC vehicle, the two types of activity time are calculated based on the total number of vehicles and the number of priority vehicles, and then allocated to priority vehicles and non-priority vehicles respectively. The sending activity time of priority vehicles and non-priority vehicles are combined.

[0030] As a preferred technical solution, the formula for calculating the activity time of the priority vehicle is as follows:

[0031]

[0032] Reference_activity_period represents the activity reference period for non-priority vehicles; activation_count represents the number of priority vehicles activated within the reference period.

[0033] The formula for calculating the activity time for non-priority vehicles is as follows:

[0034]

[0035] Here, count_of_non_priority_trains represents the number of non-priority trains, count_of_cycles represents the number of cycles of non-priority trains, and period is the activity time of priority trains.

[0036] As a preferred technical solution, the specific calculation process of step S5 is as follows:

[0037] T4 = Maximum delay at the start of the transmission cycle + Worst-case network transmission delay + Maximum delay in message reception and processing + Maximum delay from the start of the cycle to the reference time.

[0038] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0039] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] 1) This invention satisfies the reliability and real-time performance requirements of the TACS system communication and improves data processing speed.

[0042] 2) This invention considers the characteristic parameters of different controller products to ensure the accuracy of delay calculation, such as the product cycle offset rate in step S1, and the underestimation delay time of the transmission reference time for trackside products and on-board products in step S2. By subtracting the worst-case transmission delay of the selected cycle in step S4, the delay time from the message reception cycle to the message calculation cycle under the worst-case scenario is reduced, thereby optimizing the message lifespan delay time of the train network. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the specific process of the method of the present invention;

[0044] Figure 2 This is a schematic diagram of the message life delay process of the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] Network message lifetime delay needs to consider whether the message has lasting validity. When the validity check is true, the optimal internal device message lifetime delay with lasting validity is calculated; otherwise, the optimal internal device message lifetime delay without lasting validity is calculated. Messages with lasting validity have a longer lifespan than messages without lasting validity. Some messages sent from the trackside to the vehicle require lasting validity, such as vehicle compliance messages or position detection messages. Some messages sent from the vehicle to the trackside require lasting validity, such as the controlled status of a signal. The validity of this type of network message needs to be maintained until the next message is processed. When the receiver receives the next message, the message age is calculated to be less than the expiration date to ensure that the currently processed message is up-to-date.

[0047] like Figure 1 As shown, the present invention provides a method for calculating the lifespan delay of train network messages, which specifically includes the following steps:

[0048] Step 1: Calculate the optimal internal device message lifetime delay using an optimization algorithm. The calculation is based on the corresponding types and control devices of the sender and receiver, the receiver's priority, and the maximum delay from the start time of the LH (loop hour) to the message expiration time.

[0049] Furthermore, the maximum delay from the start time of LH to the message expiration time is calculated. The calculation method is the maximum delay from the underestimated LH sending time to the message calculation cycle in the worst case + the maximum delay from the message calculation cycle to the next message processing time in the worst case (e.g., Figure 2 As shown in T4).

[0050] Furthermore, the maximum delay from the underestimated LH sending time to the message calculation period in the worst case is calculated as follows: the maximum underestimated delay (T1) of the LH sending reference time + the LH transmission delay in the worst case (T2) + the delay of the LH receiving the message calculation period in the worst case (T3).

[0051] Step 2: Define the maximum delay (T1) of the LH transmission reference time underestimation of the vehicle controller product as a product-specific parameter; define the calculation method of the maximum delay (T1) of the LH transmission reference time underestimation of the trackside controller product as: product cycle * (1 + product cycle offset rate).

[0052] Step 3: Calculate the worst-case LH transmission delay (T2) based on the network type. When both communicating parties are wireless networks, the worst-case LH transmission delay is calculated as: network transmission period * 2 + transmission delay between the product and the wired network. When one party is a wireless network and the other a wired network, the worst-case LH transmission delay is: network transmission period + transmission delay between the product and the wired network. When both communicating parties are wired networks, the worst-case LH transmission delay is the transmission delay between the product and the wired network.

[0053] Step 4: Calculate the worst-case delay (T3) in the message reception calculation period for LH. The worst-case scenario for the network message reception calculation period is considered as follows:

[0054] (1) The LH that arrives after the LH is not selected arrives is exactly at the beginning of the calculation cycle.

[0055] (2) The message has been spreading on the Internet for the longest time.

[0056] The sender's processing time after receiving the unselected LH coincides with the start of the message calculation cycle. The delay calculation for the message calculation cycle of receiving the LH in this worst-case scenario is based on the worst-case transmission delay of the selected LH, the worst-case transmission delay of receiving the selected LH after the unselected LH arrives, the receiver's corresponding type, the receiver's control device, and the receiver's priority.

[0057] Detailed calculation process:

[0058] 1) Obtain the maximum tolerable number of packet losses and calculate the number of messages sent during the sending activity.

[0059] 2) Obtain the sending time based on the control type.

[0060] If it is a CC car or a WTC / WRC controller, it is sent as a product cycle.

[0061] If it is a WTC vehicle, the activity time for the two types of vehicles needs to be calculated based on the total number of vehicles and the number of priority vehicles, and then allocated to priority vehicles and non-priority vehicles respectively.

[0062] The calculation formula for the activity time of priority vehicles is as follows: Reference_activity_period represents the activity reference period time of non-priority vehicles; activation_count represents the number of priority vehicles activated within the reference period.

[0063]

[0064] The calculation formula for non-priority vehicles is as follows: count_of_non_priority_trains represents the number of non-priority vehicles; count_of_cycles represents the number of cycles for non-priority vehicles; and period is the activity time of priority vehicles.

[0065]

[0066] Combine the sending activity times of priority vehicles and non-priority vehicles.

[0067] 3) Calculate the number of sending cycles for each control type based on the calculated number of message sending times and sending time.

[0068] 4) Obtain the cycle time and product cycle offset. Based on the results of step 3, the cycle time, and the product cycle offset, calculate the maximum duration from the start of the sending activity to the next sending activity.

[0069] 5) Calculate the worst-case delay of the message calculation period received by LH. The calculation method is: the maximum duration from the start of the sending activity to the next sending activity plus the maximum delay minus the minimum delay.

[0070] Further calculations are performed on the worst-case scenario, specifically the delay in the LH receiving the message calculation period. The calculation method is: maximum duration of the sending activity + worst-case transmission delay of receiving the selected LH after the arrival of the unselected LH - worst-case transmission delay of the selected LH.

[0071] Step 5: Calculate the maximum delay (T4) from the message calculation cycle to the next message processing time in the worst case. The calculation method is: maximum delay at the start of the sending cycle + worst-case network transmission delay + maximum delay from message reception and processing + maximum delay from the start of the cycle to the reference time.

[0072] The maximum delay at the start of the transmission cycle for vehicle-mounted products is a specific parameter. The maximum delay at the start of the transmission cycle for trackside products is 2 * product cycle * (1 + product cycle offset rate). The worst-case network transmission delay calculation process is the same as step 3. The maximum delay for message reception and processing is calculated based on the sender's corresponding type, the sender's control equipment, the sender's priority, the receiver's control equipment, and the worst-case network transmission delay. The maximum delay from the start of the vehicle-mounted product cycle to the reference time is a specific parameter, while the maximum delay from the start of the trackside product cycle to the reference time is 0.

[0073] The above is an introduction to the method embodiments. The following embodiments using electronic devices and storage media will further illustrate the solution of the present invention.

[0074] This invention also provides an electronic device including a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0075] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0076] The processing unit executes the various methods and processes described above, such as methods S1 to S5. For example, in some embodiments, methods S1 to S5 may be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of methods S1 to S5 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S1 to S5 by any other suitable means (e.g., by means of firmware).

[0077] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0078] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0079] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for calculating the lifespan delay of train network messages, characterized in that, The method includes the following steps: Step S1: Calculate the optimal internal device message lifetime delay; Step S2, define the maximum delay T1 of the underestimation of the reference time for LH transmission by the vehicle controller product, where LH is the cycle hour; Step S3: Calculate the worst-case LH transmission delay T2 based on the network type; Step S4: Calculate the delay T3 of the message calculation period received by LH in the worst case. Step S5: Calculate the maximum delay T4 from the message calculation cycle to the next message processing time in the worst case. The delay in step S1 is the maximum delay from the start time of LH to the message expiration time. The maximum delay from the start time of LH to the message expiration time is specifically calculated as: the maximum delay from the underestimated LH sending time to the message calculation cycle in the worst case + the maximum delay from the message calculation cycle to the next message processing time T4 in the worst case. The worst-case scenario, specifically the maximum delay from the underestimated LH sending time to the message calculation period, is calculated as follows: The maximum delay T1 due to the underestimation of the LH transmission reference time + the worst-case LH transmission delay T2 + the worst-case delay T3 of the LH receiving message calculation period; In step S2, T1 is calculated as follows: T1 of the trackside controller product = product cycle × (1 + product cycle offset rate). The calculation of T2 in step S3 is as follows: If both communicating parties are using wireless networks: T2 = network transmission period Transmission latency between 2+ products and wired networks; If one party is a wireless network and the other is a wired network: T2 = network transmission cycle + transmission delay between the product and the wired network; If both communicating parties are wired networks: T2 = transmission delay between the product and the wired network; The specific calculation process for step S4 is as follows: Step S41: Obtain the maximum tolerable number of packet losses and calculate the number of messages sent during the sending activity; Step S42: Obtain the sending time according to the control type; Step S43: Calculate the number of sending cycles for each control type based on the calculated number of message sending times and sending time; Step S44: Obtain the cycle time and product cycle offset rate, and calculate the maximum duration from the start of the sending activity to the next sending activity based on the results of step S43, the cycle time, and the product cycle offset rate. Step S45: Calculate the worst-case delay T3 of the message calculation period received by LH, where T3 = maximum duration of sending activity + worst-case transmission delay of receiving selected LH after unselected LH arrives - worst-case transmission delay of selected LH. The specific calculation process for step S5 is as follows: T4 = Maximum delay at the start of the sending cycle + Worst-case network transmission delay + Maximum delay in message reception and processing + Maximum delay from the start of the cycle to the reference time.

2. The method for calculating the lifespan delay of train network messages according to claim 1, characterized in that, Step S42 specifically involves: If it is a CC car or a WTC / WRC controller, the sending time is one product cycle; If it is a WTC vehicle, the two types of activity time are calculated based on the total number of vehicles and the number of priority vehicles, and then allocated to priority vehicles and non-priority vehicles respectively. The sending activity time of priority vehicles and non-priority vehicles are combined.

3. The method for calculating the lifespan delay of train network messages according to claim 2, characterized in that, The formula for calculating the activity time for priority vehicles is as follows: Reference_activity_period represents the activity reference period for non-priority vehicles; activation_count represents the number of priority vehicles activated within the reference period. The formula for calculating the activity time for non-priority vehicles is as follows: Here, count_of_non_priority_trains represents the number of non-priority trains, count_of_cycles represents the number of cycles of non-priority trains, and period is the activity time of priority trains.

4. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 3.

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