A method, device, and medium for correcting transmission delay errors in a vehicle-ground wireless communication network

Abstract

The present invention relates to a method, device, and medium for correcting transmission delay errors in a vehicle-ground wireless communication network, which are used to correct the transmission delay of the vehicle-ground wireless communication network connected to the vehicle side and the ground side respectively. The method includes the following steps: obtaining a first delay when the vehicle side and the ground side are directly connected; obtaining a second delay when the vehicle side is connected to the ground side through the vehicle-ground wireless communication network, and obtaining an uncorrected delay based on the first delay and the second delay; obtaining a third delay when the vehicle side and the ground side are directly connected, obtaining a speed difference compensation value based on the first delay and the third delay, and performing error correction based on the uncorrected delay and the speed difference compensation value to obtain the corrected transmission delay of the vehicle-ground wireless communication network. Compared with the prior art, the present invention has the advantages of accurate correction and fast speed.

Description

Technical Field

[0001] The present invention relates to the field of rail transit communication, and particularly to a method, device, and medium for correcting transmission delay errors in a vehicle-ground wireless communication network. Background Art

[0002] The vehicle-ground wireless communication system of high-speed maglev mainly consists of five parts: a train positioning system, a vehicle-mounted radio control unit for operation control, a vehicle-ground wireless communication network, a sectional radio control unit, and a motor control unit for the traction control system. The safe and stable operation of a high-speed maglev train is based on the normal operation of the vehicle-ground wireless communication system. The vehicle-ground wireless communication system realizes two-way, high-speed, real-time, and reliable wireless transmission between the train and ground fixed equipment, meeting the transmission requirements of the operation control system, traction control system, operation voice communication, diagnostic system, and auxiliary information system. In order to test whether the performance of the vehicle-ground wireless communication system can meet the requirements of the high-speed maglev operation control system and the vehicle-ground wireless communication system, and to ensure the safe operation of the train, it is necessary to develop a key performance test system that meets the technical specification requirements of the operation control system and the vehicle-ground wireless communication system for a 600 km / h high-speed maglev line and can be used for on-site actual measurement. At the same time, research on a reasonable evaluation method for the key performance of the high-speed maglev operation control system and the vehicle-ground wireless communication system is carried out to provide a technical basis for the evaluation of the high-speed maglev system. Currently, the test tools used for measuring delay cannot meet the interfaces and protocols of the operation control system and the vehicle-ground wireless communication system based on a 600 km / h high-speed maglev line, and cannot meet the high-precision delay test requirement of 0.1 ms. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a method, device, and medium for correcting transmission delay errors in a vehicle-ground wireless communication network, so as to solve or partially solve the problem that the existing delay test methods cannot meet the requirements of transmission delay error correction in the vehicle-ground wireless communication scenario of high-speed maglev.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] One aspect of the present invention provides a method for correcting transmission delay errors in a vehicle-ground wireless communication network, which is used to correct the transmission delay of the vehicle-ground wireless communication network connected to the vehicle side and the ground side respectively. The method includes the following steps:

[0006] Obtain the first delay when the vehicle side and the ground side are directly connected;

[0007] Obtain the second delay when the vehicle side is connected to the ground side through the vehicle-ground wireless communication network, and based on the first delay and the second delay, obtain the uncorrected delay;

[0008] Obtain the third time delay when the vehicle side and the ground side are directly connected. Based on the first time delay and the third time delay, obtain the speed difference compensation value. Based on the uncorrected time delay and the speed difference compensation value, perform error correction to obtain the corrected vehicle-ground wireless communication network transmission time delay.

[0009] As a preferred technical solution, the obtaining of the first time delay and the third time delay includes the following steps:

[0010] Set up a direct connection test auxiliary unit respectively connected to the vehicle side and the ground side. There is a wired connection between the direct connection test auxiliary unit and the vehicle side, and between the direct connection test auxiliary unit and the ground side;

[0011] After the direct connection test auxiliary unit sends a control signal to the vehicle side and the ground side, the vehicle side or the ground side sends out clock counting information. After the ground side or the vehicle side receives the clock counting information, obtain the first time delay or the third time delay based on the clock speed difference between the two sides.

[0012] As a preferred technical solution, RS485 connections are used between the direct connection test auxiliary unit and the vehicle side, and between the direct connection test auxiliary unit and the ground side.

[0013] As a preferred technical solution, the vehicle side is specifically a positioning unit connected to the operation control vehicle-mounted radio control unit, and the ground side is specifically a traction control system motor control unit connected to the zone radio control unit.

[0014] As a preferred technical solution, both the positioning unit and the traction control system motor control unit include an FPGA.

[0015] As a preferred technical solution, the obtaining of the speed difference compensation value includes the following steps:

[0016] Obtain the speed difference between the third time delay and the first time delay. Based on the time from the start of obtaining the first time delay to the current time, obtain the speed difference compensation value per unit time.

[0017] As a preferred technical solution, it further includes the following steps:

[0018] Based on the first time delay, the second time delay, the third time delay, the uncorrected time delay, and the corrected wireless communication network transmission time delay, store and output statistical parameters including the average time delay, the maximum time delay, and the minimum time delay to the visualization terminal.

[0019] As a preferred technical solution, the corrected vehicle-ground wireless communication network transmission time delay is obtained by the following formula:

[0020] E C= E - E 0 / (T 22 - T 10 )

[0021] Wherein, E C is the transmission delay of the corrected vehicle - ground wireless communication network, E is the uncorrected delay, and E 0 is the difference between the third delay and the first delay, T 10 is the starting moment when the first delay starts to be obtained, and T 22 is the moment when the third delay is obtained.

[0022] Another aspect of the present invention provides an electronic device, including: one or more processors and a memory. The memory stores one or more programs, and the one or more programs include instructions for executing the above - mentioned method for correcting the transmission delay error of the vehicle - ground wireless communication network.

[0023] Another aspect of the present invention provides a computer - readable storage medium, including one or more programs for execution by one or more processors of an electronic device. The one or more programs include instructions for executing the above - mentioned method for correcting the transmission delay error of the vehicle - ground wireless communication network.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) Precise correction and high speed: This method first obtains the clock speed difference between the vehicle side and the ground side in direct connection as the first delay, then obtains the clock speed difference between the vehicle side and the ground side in the vehicle - ground wireless communication network as the second delay, so as to obtain the uncorrected transmission delay of the vehicle - ground wireless communication network. Then, it obtains the clock speed difference between the vehicle side and the ground side in direct connection as the third delay, and calculates the speed difference compensation value to correct the transmission delay of the vehicle - ground wireless communication network. Compared with the prior art, in which there is a problem that the clock offset of the measurement device itself causes inaccurate counting, thus affecting the delay calculation result, this method corrects the transmission delay by obtaining the third delay to eliminate the offset, obtaining an accurate delay result, so as to meet the high - precision delay test requirements of the high - speed maglev vehicle - ground wireless communication system.

[0026] (2) Simple hardware structure: This method adds a direct - connection test auxiliary unit respectively connected to the vehicle side and the ground side on the original structure of the high - speed maglev vehicle - ground wireless communication system to obtain the direct - connection clock speed difference data, with a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of each part in the method for correcting the transmission delay error of the vehicle - ground wireless communication network in Embodiment 1;

[0028] Figure 2Schematic diagram of the connection structure between the vehicle-ground wireless communication network, the operation control vehicle-mounted radio control unit, and the zone radio control unit;

[0029] Figure 3 Schematic diagram of the high-precision time delay calculation principle;

[0030] Figure 4 Connection structure diagram of the conversion of RS485 signal and DB25 interface by the sending unit and the receiving unit;

[0031] Figure 5 Connection structure diagram of the conversion of RS485 signal and DB25 interface by the direct connection test auxiliary unit,

[0032] wherein, 1. Operation control vehicle-mounted radio control unit, 2. Zone radio control unit, 3. Sending unit, 4. Receiving unit, 5. Direct connection test auxiliary unit. Specific implementation manner

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0035] Embodiment 1

[0036] As Figure 1 described, this embodiment provides a method for correcting the transmission time delay error of the vehicle-ground wireless communication network. By using the sending unit 3 (FPGA1), the receiving unit 4 (FPGA2), the direct connection test auxiliary unit 5 (FPGA3), and the high-precision time delay algorithm running on a portable computer, the problem that the existing time delay test software cannot meet the time delay test tool requirements of the high-speed maglev operation control system and the vehicle-ground wireless communication system interface and protocol is solved.

[0037] In this embodiment, a wireless communication network 6 is used between the vehicle and the ground of the high-speed maglev train to connect the operation control vehicle-mounted radio control unit 1 and the zone radio control unit 2, meeting Figure 2The structure shown. The physical interfaces of the operation control vehicle-mounted radio control unit 1 and the zoned radio control unit 2 with the train positioning system and the traction control system respectively all adopt the RS-485 interface mode. The information frame format adopts a character-oriented transmission protocol, and the total length of each information frame is a fixed number of bytes, following the fixed coding method of the system.

[0038] The specific implementation process of this method is as follows:

[0039] Use the sending unit 3 (FPGA1) and the receiving unit 4 (FPGA2) to respectively simulate or replace the positioning unit connected to the operation control vehicle-mounted radio control unit 1 and the motor control unit of the traction control system connected to the zoned radio control unit 2, access the vehicle-ground wireless communication network 6, receive and send clock counting information through RS-485, and test the transmission delay of the vehicle-ground wireless communication network 6.

[0040] Match the working timing of the operation control vehicle-mounted radio control unit 1. After the sending unit 3 receives the control signal sent by the operation control vehicle-mounted radio control unit 1, it sends clock counting information to the operation control vehicle-mounted radio control unit 1.

[0041] Match the working timing of the zoned radio control unit 2. After the receiving unit 4 receives the control signal sent by the zoned radio control unit 2, it starts to work, receives the clock counting information sent by the sending unit 3, records the receiving end clock counting information, and sends the sending clock counting information of the sending unit 3 and the recorded receiving clock counting information to the portable computer terminal through the serial port. The portable computer terminal uses the serial port debugging tool to save the clock counting data packet sent by the receiving unit 4.

[0042] In order to eliminate system errors, a direct connection test auxiliary unit 5 (FPGA3) is developed, which is used to directly connect the data transmission link and simulate the control of the operation control vehicle-mounted radio control unit 1 and the zoned radio control unit 2 over the sending unit 3 and the receiving unit 4 to perform the inherent time delay difference of the direct connection test system. Inside the direct connection test auxiliary unit 5, the data signals of the sending unit 3 and the receiving unit 4 are short-circuited. After pressing the working trigger button on the direct connection test auxiliary unit 5, the direct connection test auxiliary unit 5 sends control signals to the sending unit 3 and the receiving unit 4 to make both ends start sending and recording clock counting information. The connection method of the FPGA with the vehicle-ground wireless communication network and the direct connection test is as Figure 1 shown.

[0043] The three FPGA devices mainly include FPGA of model EP4CE6F17C8, 16Mbit FLASH, 50M crystal oscillator, USB power supply interface and serial port, power switch, battery holder, JTAG interface, button, reset button. The three FPGAs are connected through as Figure 4 , Figure 5The connection method shown uses the MAX485E chip for level conversion to ensure that the FPGA can normally transmit the RS-485 signal required by the matching system through the DB25 connector. Figure 4 (a) shows the structure of the sending unit converting RS485 signals and connecting them to the DB25 interface, and (b) shows the structure of the receiving unit converting RS485 signals and connecting them to the DB25 interface.

[0044] like Figure 1 The direct connection test connection method shown in the figure connects the direct connection test auxiliary unit 5 with the sending unit 3 and the receiving unit 4 through RS-485 to form a direct connection system. Press the switch on the direct connection test auxiliary unit 5 to issue a command to start the delay test system. After running for a certain period of time, the average inherent delay E of the first group of system clocks is measured. 10 , saved as a data file on a portable computer.

[0045] Keep the previous equipment running for a few minutes without powering off, and then connect the direct connection test auxiliary unit 5 to the sending unit 3 and the receiving unit 4 through RS-485 to form a direct connection system. The delay test system automatically starts working and runs for a certain period of time to measure the average inherent delay E of the second group of system clocks 11 , saved as a data file on a portable computer.

[0046] The above two steps can measure the inherent error of the system and save it on the data processing computer for long-term use. If the equipment is not used for a long time, the above steps can be repeated for measurement and calibration.

[0047] like Figure 1 The method for connecting to the vehicle-ground wireless communication network is shown in the figure. The sending unit 3 (FPGA1) and the receiving unit 4 (FPGA2) are connected to the vehicle-ground wireless communication network to be tested through RS-485. The delay E after running for a certain period of time is obtained after passing through the vehicle-ground wireless communication network. 20 , saved as a data file on a portable computer.

[0048] By using the pre-written data processing software on a portable computer that applies the principle of high-precision delay testing, the data files saved from the three measurements can be imported into the software to automatically draw the measured vehicle-to-ground wireless communication network delay curve, and can display statistical parameters such as average delay, maximum delay, minimum delay, etc., and can store the measured data for analysis.

[0049] like Figure 3 As shown in the figure, the principle of high-precision delay correction is as follows:

[0050] 1)T 10At this moment, directly connect and test the sending unit 3 (FPGA1) and the receiving unit 4 (FPGA2) through RS-485 with the direct connection test auxiliary unit 5 (FPGA3). The sending unit 3 sends out the sending clock count information. After the receiving unit 4 receives the data, it transmits both the sending clock count information and the receiving clock count information to the portable computer. After running for a certain period of time, the average inherent delay E of the system clock is obtained. 10 ;

[0051] 2) Connect the sending unit 3 and the receiving unit 4 to the to-be-tested vehicle-ground wireless communication network through RS-485. Use the sending unit 3 (FPGA1) and the receiving unit 4 (FPGA2) to respectively simulate and replace the positioning unit connected to the operation control vehicle-mounted radio control unit and the traction control system motor control unit connected to the section radio control unit. The sending unit 3 sends out the sending clock count information. After the receiving unit 4 receives it, it transmits both the sending clock count information and the receiving clock count information to the portable computer. After running for a certain period of time, the delay E after passing through the vehicle-ground wireless communication network is obtained. 20 ;

[0052] 3) E 20 -E 10 = E, to obtain the transmission delay of the vehicle-ground wireless communication network;

[0053] 4) At time T 12 , keep the operating states of the previous devices without power-off, and directly connect the sending unit 3 and the receiving unit 4 through RS-485 with the direct connection test auxiliary unit 5 again. The sending unit 3 sends out the sending clock count information. After the receiving unit 4 receives the data, it transmits both the sending clock count information and the receiving clock count information to the portable computer. After running for a certain period of time, the average inherent delay E of the system clock is obtained. 11 , after the FPGA runs for a period of time, there is a certain offset in its own clock, resulting in inaccurate counting, affecting the delay calculation result and resulting in low accuracy. Therefore, after actually measuring by accessing the vehicle-ground wireless communication network, it is necessary to conduct a direct connection test again to eliminate the offset and obtain the most accurate delay result;

[0054] 5) E 11 -E 10 = E 0 , to obtain the speed difference E of the sending and receiving clocks of the test system during the test period from T 10 to T 22 ; 0 ;

[0055] 6) E 0 / (T 22 -T 10 ) = E e , to obtain the speed difference compensation value per unit time;

[0056] 7) Perform error correction on the transmission delay of the vehicle-ground wireless communication network to obtain a high-precision delay: E C = E - E e , thus achieving correction.

[0057] This method provides a network transmission delay error correction method with FPGA as the core for system requirements. This method has stable transmission, precise correction, high speed, rich functions, and convenient operation, and can meet the requirements of high-precision delay testing.

[0058] Embodiment 2

[0059] This embodiment provides an electronic device, including: one or more processors and a memory. The memory stores one or more programs, and the one or more programs include instructions for executing the vehicle-ground wireless communication network transmission delay error correction method as described in Embodiment 1.

[0060] Embodiment 3

[0061] This embodiment provides a computer-readable storage medium, including one or more programs for execution by one or more processors of an electronic device. The one or more programs include instructions for executing the vehicle-ground wireless communication network transmission delay error correction method as described in Embodiment 1.

[0062] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for correcting the transmission delay error of a vehicle-ground wireless communication network, characterized in that, it is used to correct the transmission delay of a vehicle-ground wireless communication network respectively connected to the vehicle side and the ground side, and the method includes the following steps: Obtain the first delay when the vehicle side and the ground side are directly connected; Obtain the second delay when the vehicle side is connected to the ground side through the vehicle-ground wireless communication network, and based on the first delay and the second delay, obtain the uncorrected delay; Obtain the third delay when the vehicle side and the ground side are directly connected, based on the first delay and the third delay, obtain the speed difference compensation value, and based on the uncorrected delay and the speed difference compensation value, perform error correction to obtain the corrected transmission delay of the vehicle-ground wireless communication network, The obtaining of the first delay and the third delay includes the following steps: Set a direct connection test auxiliary unit respectively connected to the vehicle side and the ground side, and there is a wired connection between the direct connection test auxiliary unit and the vehicle side, and between the direct connection test auxiliary unit and the ground side; After the direct connection test auxiliary unit sends a control signal to the vehicle side and the ground side, the vehicle side or the ground side sends clock counting information. After the ground side or the vehicle side receives the clock counting information, based on the clock speed difference between the two sides, obtain the first delay or the third delay, The obtaining of the speed difference compensation value includes the following steps: Obtain the speed difference between the third delay and the first delay, and based on the time from the start of obtaining the first delay to the current time, obtain the speed difference compensation value per unit time, The corrected transmission delay of the vehicle-ground wireless communication network is obtained by the following formula: E C =E - E 0 / ( T 22 - T 10 ) Among them, E C is the transmission delay of the corrected train-ground wireless communication network, E is the uncorrected delay, E 0 is the difference between the third delay and the first delay, T 10 is the starting moment when the first delay starts to be obtained, T 22 is the moment when the third delay is obtained.

2. A method for correcting the transmission delay error of a vehicle-ground wireless communication network according to claim 1, characterized in that, RS485 connections are used between the direct connection test auxiliary unit and the vehicle side, and between the direct connection test auxiliary unit and the ground side.

3. A method for correcting the transmission delay error of a vehicle-ground wireless communication network according to claim 1, characterized in that, The vehicle side is specifically a transmitting unit, and the ground side is specifically a receiving unit.

4. A method for correcting the transmission delay error of a vehicle-ground wireless communication network according to claim 3, characterized in that, Both the positioning unit and the traction control system motor control unit include an FPGA.

5. A method for correcting the transmission delay error of a vehicle-ground wireless communication network according to claim 1, characterized in that, It further includes the following steps: Based on the first delay, second delay, third delay, uncorrected delay and corrected transmission delay of the wireless communication network, store and output statistical parameters including average delay, maximum delay and minimum delay to a visualization terminal.

6. An electronic device, characterized in that, includes: One or more processors and a memory, and the memory stores one or more programs, and the one or more programs include instructions for executing the method for correcting the transmission delay error of the vehicle-ground wireless communication network according to any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, including one or more programs executed by one or more processors of an electronic device, the one or more programs including instructions for performing the method for correcting the transmission delay error of the vehicle-ground wireless communication network according to any one of claims 1-5.

Images