Time synchronization method and device of distributed power locomotive, locomotive and storage medium

Abstract

The invention discloses a time synchronization method and device for a distributed power locomotive, the locomotive and a storage medium. The time synchronization method and device are applied to any locomotive in a distributed power locomotive cluster. The method comprises the following steps: when a locomotive is a slave control locomotive in a distributed power locomotive cluster and the Beidou time service of the locomotive fails, switching the time of the locomotive to a first local time corresponding to the locomotive; determining a first time deviation between the first local time and first target time corresponding to a slave clock of a master control locomotive in the distributed power locomotive cluster; the Beidou time service of the master control locomotive is valid, and the first target time is obtained by correcting second local time corresponding to the master control locomotive by a slave clock of the master control locomotive based on a second time deviation; correcting the first local time based on the first time deviation to obtain first correction time; and switching the time of the locomotive to the first correction time. By adopting the method, the time synchronization control precision between the master locomotive and the slave locomotive can be improved.

Description

Technical Field

[0001] This application relates to the field of rail transit technology, and in particular to a time synchronization method, device, locomotive, and storage medium for a distributed power locomotive. Background Technology

[0002] Wireless synchronous control systems, as a key control technology for distributed power trains, achieve synchronous control of master and slave locomotives. The master locomotive interacts with each slave locomotive via wireless communication to exchange commands, status, and fault information, thus achieving synchronous control of all slave locomotives. Train dynamics tests show that the synchronization of master and slave locomotives directly affects the longitudinal dynamic performance of the train; better synchronization results in better longitudinal dynamic performance and smoother operation, and vice versa. Currently, wireless synchronous control systems typically use Long-Term Evolution for Railways (LTE-R), Global System for Mobile Communications-Railway (GSM-R), and radio communication for command transmission. The synchronization control accuracy of master and slave locomotives is relatively low due to the impact of wireless communication delays.

[0003] Therefore, improving the time synchronization control accuracy between master and slave locomotives has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a distributed power locomotive control method, device, locomotive, and storage medium, which can help improve the time synchronization control accuracy between master and slave locomotives.

[0005] In a first aspect, embodiments of this application provide a time synchronization method for distributed power locomotives, applied to any locomotive in a distributed power locomotive cluster; each locomotive in the distributed power locomotive cluster uses the time synchronized by the BeiDou satellite positioning system as the time corresponding to the master clock, and the time of the processor board as the local time corresponding to the slave clock; the method includes:

[0006] When the locomotive is a slave locomotive in a distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, the locomotive's time will be switched to the locomotive's corresponding first local time.

[0007] Determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the BeiDou time synchronization of the master locomotive is valid; the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the second time deviation of the slave clock of the master locomotive; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive.

[0008] The first local time is corrected based on the first time deviation to obtain the first corrected time;

[0009] The locomotive's time is switched to the first correction time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0010] In one embodiment, determining the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster includes: sending a time synchronization request to the master locomotive in the distributed power locomotive cluster, and determining the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster through a precise time protocol.

[0011] In one embodiment, the BeiDou time synchronization of all slave locomotives in the distributed power locomotive cluster is effective. The method further includes: when the locomotive is the master locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, switching the locomotive's time to the third local time corresponding to the locomotive; designating the slave locomotive closest to the locomotive among all slave locomotives as the first target slave locomotive; determining a third time deviation between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive; the second target time is obtained by correcting the fourth local time corresponding to the first target slave locomotive based on the fourth time deviation; the fourth time deviation is the time deviation between the fourth local time and the time corresponding to the master clock of the first target slave locomotive; correcting the third local time based on the third time deviation to obtain a second corrected time; and switching the locomotive's time to the second corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0012] In one embodiment, the number of at least one candidate slave locomotive with valid BeiDou time synchronization among all slave locomotives in the distributed power locomotive cluster is less than the total number of slave locomotives; the method further includes: when the locomotive is the master locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, switching the locomotive's time to a third local time; designating the candidate slave locomotive closest to the master locomotive among at least one candidate slave locomotive as the second target slave locomotive; determining a fifth time deviation between the third local time and the third target time corresponding to the slave clock of the second target slave locomotive; the third target time is the time difference between the second target slave locomotive and the master locomotive's slave clock. The slave clock is corrected based on the fifth local time corresponding to the second target slave locomotive based on the sixth time deviation; the sixth time deviation is the time deviation between the fifth local time and the time corresponding to the master clock of the second target slave locomotive; the third local time is corrected based on the fifth time deviation to obtain the third corrected time; the locomotive time is switched to the third corrected time; a time synchronization request is received from at least one slave locomotive whose BeiDou time synchronization has failed, so that at least one slave locomotive whose BeiDou time synchronization has failed can determine the time deviation between its local time and the third corrected time, and correct its local time based on the time deviation.

[0013] In one implementation, the BeiDou time synchronization of any locomotive in the distributed power locomotive cluster fails. The method further includes: when the locomotive is a slave locomotive in the distributed power locomotive cluster, sending a time synchronization request to the master locomotive in the distributed power locomotive cluster, determining a seventh time deviation between the locomotive's local time and the master locomotive's local clock through a precise time protocol; correcting the locomotive's local clock based on the seventh time deviation to obtain a fourth corrected time; and switching the locomotive's time to the fourth corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0014] In one embodiment, the method further includes: when the locomotive's BeiDou time synchronization is effective, controlling the slave clock in the locomotive to send a time synchronization request to the master clock in the locomotive, determining the target time deviation between the slave clock in the locomotive and the master clock in the locomotive through a precise time protocol; controlling the slave clock to correct the local time of the locomotive based on the target time deviation to obtain a fifth corrected time, so as to achieve time synchronization between the slave clock in the locomotive and the master clock in the locomotive.

[0015] In one embodiment, the method further includes: when the locomotive is any slave locomotive in a distributed power locomotive cluster, and the master locomotive and slave locomotive in the distributed power locomotive cluster have completed time synchronization, parsing the control command from the master locomotive in the distributed power locomotive cluster to obtain the target execution time of the control command; the control command includes the target execution time of the control command; and executing the control command at the target execution time.

[0016] Secondly, this application provides a time synchronization device for distributed power locomotives, applied to any locomotive in a distributed power locomotive cluster; each locomotive in the distributed power locomotive cluster uses the time synchronized by the BeiDou satellite positioning system as the master clock time and the processor board time as the local time corresponding to the slave clock; the device includes:

[0017] The time switching module is used to switch the locomotive's time to the locomotive's first local time when the locomotive is a slave locomotive in a distributed power locomotive cluster and the locomotive's Beidou time synchronization fails.

[0018] The time deviation determination module is used to determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the Beidou time synchronization of the master locomotive is valid; the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the second time deviation of the slave clock of the master locomotive; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive.

[0019] The time correction module is used to correct the first local time based on the first time deviation to obtain the first corrected time;

[0020] The time switching module is also used to switch the locomotive's time to the first correction time in order to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0021] Thirdly, this application provides a locomotive, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the method mentioned in the first aspect above.

[0022] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method mentioned in the first aspect above.

[0023] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method mentioned in the first aspect above.

[0024] The aforementioned time synchronization method, device, locomotive, and storage medium for distributed power locomotives are applied to any locomotive in a distributed power locomotive cluster. Each locomotive in the cluster uses the time synchronized by the BeiDou satellite positioning system as its master clock and the time on the processor board as its local time. When a locomotive is a slave locomotive in the cluster and its BeiDou time synchronization fails, the locomotive's time is switched to its corresponding first local time. A first time deviation is determined between the first local time and the first target time corresponding to the slave clock of the master locomotive in the cluster. The master locomotive's BeiDou time synchronization is valid, and the first target time is obtained by correcting the master locomotive's corresponding second local time based on a second time deviation. The second time deviation is the time difference between the second local time and the time corresponding to the master clock of the master locomotive. The first local time is corrected based on the first time deviation to obtain a first corrected time. The locomotive's time is switched to the first corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster. Using this method, when the locomotive is a slave locomotive and its BeiDou time synchronization fails, the first target time of the slave clock of the master locomotive with effective BeiDou time synchronization is obtained by correcting the local time of the slave clock based on the time deviation between the local time of the slave clock and the time of the master clock. This eliminates the delay between the master clock and the slave clock in the wireless synchronous control system. Therefore, the first target time is the high-precision time of the master locomotive. Thus, the first time deviation between the first local time and the first target time of the locomotive is also high-precision. Therefore, the first corrected time obtained by correcting the first local time based on the high-precision first time deviation can achieve time synchronization with other locomotives in the distributed power locomotive group, thereby improving the time synchronization control accuracy between the master and slave locomotives. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram illustrating an application scenario of a time synchronization method for a distributed power locomotive provided in an embodiment of this application;

[0027] Figure 2 This is a flowchart illustrating a time synchronization method for a distributed power locomotive provided in an embodiment of this application;

[0028] Figure 3 This is a flowchart illustrating another time synchronization method for distributed power locomotives provided in an embodiment of this application;

[0029] Figure 4 This is a schematic diagram of the structure of a time synchronization device for a distributed power locomotive provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] The application scenarios of the time synchronization method for distributed power locomotives provided in the embodiments of this application are described below.

[0033] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of a time synchronization method for distributed power locomotives provided in an embodiment of this application. The distributed power locomotive cluster can also be considered as multiple locomotives running in parallel. Figure 1 The image shows a wirelessly coupled train consisting of multiple locomotives, with multiple cars (e.g., 105-108 cars) spaced between each pair of locomotives. The locomotive at the front in the direction of travel is the master control locomotive, and the others are slave control locomotives. Wireless communication exists between the master and slave control locomotives. Each locomotive includes a wireless synchronous control system, control unit, and actuators. The master control locomotive also includes a detection unit for detecting driver commands.

[0034] In the case where the locomotive is a slave locomotive in a distributed power locomotive cluster and its BeiDou time synchronization fails, the locomotive's time is switched to its corresponding first local time; a first time deviation is determined between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the master locomotive's BeiDou time synchronization is effective, and the first target time is obtained by correcting the master locomotive's corresponding second local time based on the slave clock of the master locomotive using a second time deviation; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive; the first local time is corrected based on the first time deviation to obtain a first corrected time; the locomotive's time is switched to the first corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster. Using this method, when the locomotive is a slave locomotive and its BeiDou time synchronization fails, the first target time of the slave clock of the master locomotive with effective BeiDou time synchronization is obtained by correcting the local time of the slave clock based on the time deviation between the local time of the slave clock and the master clock. This eliminates the delay between the master clock and the slave clock in the wireless synchronization control system. Therefore, the first target time is the high-precision time of the master locomotive. Thus, the first time deviation between the first local time and the first target time of the locomotive is also high-precision. Therefore, a high-precision first corrected time can be obtained by correcting the first local time based on the high-precision first time deviation. Switching the locomotive's time to the high-precision first corrected time can achieve time synchronization with other locomotives in the distributed power locomotive cluster, thereby improving the time synchronization control accuracy between the master and slave locomotives.

[0035] Please see Figure 2 , Figure 2 This is a flowchart illustrating a time synchronization method for distributed power locomotives provided in an embodiment of this application. This method can be applied to any locomotive in a distributed power locomotive cluster; each locomotive in the cluster uses the time synchronized by the BeiDou satellite positioning system as its master clock and the processor board's time as its local slave clock. For example... Figure 2 As shown, the time synchronization method for this distributed power locomotive may include, but is not limited to, the following steps:

[0036] S201. When the locomotive is a slave locomotive in a distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, the locomotive's time is switched to the locomotive's corresponding first local time.

[0037] In other words, a slave locomotive whose BeiDou time synchronization fails can switch its time to the locomotive's corresponding first local time. This first local time corresponds to the time on the slave locomotive's processor board.

[0038] During the operation of heavy-haul trains, due to the numerous and long tunnels, the BeiDou signal may be blocked or even unusable, which may cause the locomotive's BeiDou timing to fail.

[0039] In one alternative implementation, before step S201, the locomotive can determine its own role information, which is either a master locomotive or a slave locomotive.

[0040] In some embodiments, the locomotive may determine its own role information by: obtaining the role information corresponding to the locomotive's identifier based on the correspondence relationship; the correspondence relationship includes the correspondence between the role information and the identifier of each locomotive in the distributed power locomotive cluster, and the role information is either the master locomotive or the slave locomotive.

[0041] Optionally, the mapping relationship can be a table preset on the locomotive (denoted as the mapping relationship table), or it can be a table preset in a database that the locomotive can access (denoted as the mapping relationship table). There is no limitation here. This mapping relationship table includes the mapping relationships between the identifiers of multiple locomotives and the information of multiple roles. For example, this mapping relationship can be shown in Table 1 below.

[0042] Table 1 Correspondence Table

[0043]

[0044] For example, assuming the locomotive is identified as locomotive 2, the locomotive can be identified as a slave locomotive in the distributed power locomotive cluster based on Table 1 above.

[0045] S202. Determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the Beidou time synchronization of the master locomotive is valid, and the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the second time deviation of the slave clock of the master locomotive; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive.

[0046] In one alternative implementation, the locomotive determines the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster. This can be achieved by the locomotive using a time synchronization protocol to determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster.

[0047] In one optional implementation, before step S202, when the BeiDou time synchronization of the master locomotive is effective, the slave clock of the master locomotive can determine the time deviation (i.e., the second local time) between the local time (i.e., the second time deviation) and the time corresponding to the master clock; the local time is corrected based on the time deviation to achieve time synchronization between the master and slave clocks.

[0048] S203. Correct the first local time based on the first time deviation to obtain the first corrected time.

[0049] In one alternative implementation, the locomotive corrects the first local time based on the first time deviation to obtain the first corrected time. This correction time can be obtained by summing the first time deviation and the first local time.

[0050] S204. Switch the locomotive's time to the first correction time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0051] In this embodiment, when the locomotive is a slave locomotive in a distributed power locomotive cluster and its BeiDou time synchronization fails, the locomotive's time is switched to the locomotive's corresponding first local time; a first time deviation is determined between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the master locomotive's BeiDou time synchronization is effective, and the first target time is obtained by correcting the master locomotive's corresponding second local time based on the second time deviation; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive; the first local time is corrected based on the first time deviation to obtain a first corrected time; the locomotive's time is switched to the first corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster. Using this method, when the locomotive is a slave locomotive and its BeiDou time synchronization fails, the first target time of the slave clock of the master locomotive with effective BeiDou time synchronization is obtained by correcting the local time of the slave clock based on the time deviation between the local time of the slave clock and the time of the master clock. This eliminates the delay between the master clock and the slave clock in the wireless synchronous control system. Therefore, the first target time is the high-precision time of the master locomotive. Thus, the first time deviation between the first local time and the first target time of the locomotive is also high-precision. Therefore, the first corrected time obtained by correcting the first local time based on the high-precision first time deviation can achieve time synchronization with other locomotives in the distributed power locomotive group, thereby improving the time synchronization control accuracy between the master and slave locomotives.

[0052] In one alternative implementation, Figure 2In step S202 of the time synchronization method for distributed locomotives, the locomotive determines the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed locomotive cluster. This may include: sending a time synchronization request to the master locomotive in the distributed locomotive cluster, and determining the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed locomotive cluster through a precise time protocol.

[0053] Among them, the Precision Time Protocol (PTP) is a protocol used for clock synchronization in computer networks, aiming to achieve high-precision time synchronization at the nanosecond level.

[0054] In some embodiments, the process by which the locomotive determines the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster through a precise time protocol may include, but is not limited to, the following steps:

[0055] Step 1: The locomotive sends a time synchronization request to the master locomotive in the distributed power locomotive cluster, and the master locomotive receives the time synchronization request from the locomotive; the BeiDou time synchronization of the master locomotive is valid.

[0056] Step 2: In response to the time synchronization request, the main control locomotive sends a synchronization message to the locomotive, and the locomotive receives the synchronization message from the main control locomotive.

[0057] Step 3: The main control locomotive records the time T1 of sending the synchronization message and sends a follow message to the locomotive. Correspondingly, the locomotive receives the follow message, which includes the time T1 of sending the synchronization message.

[0058] Step 4: The locomotive records the time T2 when it receives the synchronization message, and extracts the time T1 when the main locomotive sends the synchronization message from the follow-up messages.

[0059] Step 5: The locomotive sends a delay request message to the main control locomotive, and the main control locomotive receives the delay request message from the locomotive; the delay request message includes the time T3 when the delay request message was sent.

[0060] Step 6: The main control locomotive records the time T4 for receiving the delay request message.

[0061] Step 7: In response to the delay request message, the main control locomotive sends a delay request response message to the locomotive, and the locomotive receives the delay request response message accordingly; the delay request response message includes the time T4 for receiving the delay request message.

[0062] Step 8: The locomotive parses the delay request response message to obtain time T4.

[0063] Step 9: The locomotive constructs a system of equations based on time T1, time T2, time T3, and time T4.

[0064] The system of equations can be represented by the following formula (1).

[0065] (1)

[0066] In formula (1), offset represents the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; delay represents the link delay.

[0067] Step 10: The locomotive solves the equations to obtain the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster.

[0068] Using this implementation method, the slave locomotive can accurately determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster, which is beneficial for subsequently determining the first correction time that is synchronized with the target time corresponding to the slave clock of the master locomotive.

[0069] In one alternative implementation, Figure 2 In the distributed locomotive time synchronization method shown, the BeiDou time synchronization of all slave locomotives in the distributed locomotive cluster is valid. Even if the locomotive is the master locomotive in the distributed locomotive cluster and its BeiDou time synchronization fails, the locomotive's time can be switched to its corresponding third local time. The slave locomotive closest to the master locomotive among all slave locomotives is designated as the first target slave locomotive. A third time deviation is determined between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive. The second target time is obtained by correcting the fourth local time of the first target slave locomotive based on the fourth time deviation. The fourth time deviation is the time difference between the fourth local time and the time corresponding to the master clock of the first target slave locomotive. The third local time is corrected based on the third time deviation to obtain a second corrected time. The locomotive's time is switched to the second corrected time to achieve time synchronization with other locomotives in the distributed locomotive cluster.

[0070] Among them, the third local time corresponding to the locomotive is the time of the processor board of the main control locomotive.

[0071] In other words, when the BeiDou time synchronization of all slave locomotives in the distributed power locomotive cluster is effective, but the BeiDou time synchronization of the master locomotive fails, the master locomotive can first switch its time to local time, and then determine the time deviation between the target time and the slave clock of the nearest slave locomotive; and correct the local time based on the time deviation.

[0072] In some embodiments, the locomotive determines the third time deviation between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive by sending a time synchronization request to the first target slave locomotive and determining the third time deviation between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive through a precise time protocol. In other words, a master locomotive whose BeiDou time synchronization fails can determine the time deviation between its local time and the target time corresponding to the slave clock of the nearest slave locomotive by sending a time synchronization request to the nearest slave locomotive.

[0073] In some embodiments, the locomotive corrects the third local time based on the third time deviation to obtain the second corrected time. This can be achieved by using the sum of the third time deviation and the third local time as the second corrected time.

[0074] Using this implementation method, when the BeiDou time synchronization of the master locomotive fails and the BeiDou time synchronization of all slave locomotives is effective, the master locomotive can switch to local time and determine the time deviation with the nearest slave locomotive. Based on this time deviation, time synchronization between the master locomotive and the slave locomotives can be achieved.

[0075] In one alternative implementation, Figure 2In the distributed locomotive time synchronization method shown, the number of at least one candidate slave locomotive with valid BeiDou time synchronization among all slave locomotives in the distributed locomotive cluster is less than the total number of slave locomotives; the locomotive can also switch its time to a third local time if it is the master locomotive in the distributed locomotive cluster and its BeiDou time synchronization fails; the candidate slave locomotive closest to the master locomotive among at least one candidate slave locomotive is designated as the second target slave locomotive; a fifth time deviation is determined between the third local time and the third target time corresponding to the slave clock of the second target slave locomotive; the third target time is the second target slave locomotive's... The slave clock in the locomotive is corrected based on the fifth local time corresponding to the second target slave locomotive based on the sixth time deviation; the sixth time deviation is the time deviation between the fifth local time and the time corresponding to the master clock of the second target slave locomotive; the third local time is corrected based on the fifth time deviation to obtain the third corrected time, and the locomotive's time is switched to the third corrected time; a time synchronization request is received from at least one slave locomotive whose BeiDou time synchronization has failed, so that at least one slave locomotive whose BeiDou time synchronization has failed can determine the time deviation between its local time and the third corrected time, and correct its local time based on the time deviation.

[0076] Among them, the third local time corresponding to the locomotive is the time of the processor board of the main control locomotive.

[0077] For example, suppose a distributed locomotive cluster includes one master locomotive and three slave locomotives (denoted as slave locomotive 1, slave locomotive 2, and slave locomotive 3). The BeiDou time synchronization of the master locomotive and slave locomotive 1 is unavailable. Also suppose the distance between the master locomotive and slave locomotives 1, 2, and 3 increases sequentially. In this case, the master locomotive can determine the time deviation between its local time and the target time corresponding to the slave clock of slave locomotive 2. Then, it corrects its local time based on the time deviation to obtain the corrected local time. When it receives a time synchronization request from slave locomotive 1, it causes slave locomotive 1 to determine the time deviation between its local time and the corrected local time corresponding to the master locomotive, and corrects its local time based on the time deviation.

[0078] In some embodiments, the locomotive determines the fifth time deviation between the third local time and the third target time corresponding to the slave clock of the second target locomotive by sending a time synchronization request to the second target locomotive and determining the fifth time deviation between the third local time and the second target time corresponding to the slave clock of the second target locomotive through a precise time protocol. That is, a master locomotive whose BeiDou time synchronization fails can determine the time deviation between its local time and the target time corresponding to the slave clock of the nearest slave locomotive by sending a time synchronization request to a slave locomotive with valid BeiDou time synchronization.

[0079] In some embodiments, the locomotive corrects the third local time based on the third time deviation to obtain the second corrected time. This can be achieved by using the sum of the third time deviation and the third local time as the second corrected time.

[0080] In this implementation, when the BeiDou time synchronization of the master locomotive fails and not all slave locomotives have valid BeiDou time synchronization (i.e., the number of at least one candidate slave locomotive with valid BeiDou time synchronization is less than the total number of slave locomotives), the master locomotive can switch to its local time and determine the time deviation between itself and the nearest candidate slave locomotive among the at least one candidate slave locomotive with valid BeiDou time synchronization. Based on this time deviation, time synchronization between the master and slave locomotives is achieved. Since slave locomotives do not directly interact with each other, a slave locomotive with invalid BeiDou time synchronization can first switch to its local time and send a time synchronization request to the master locomotive. Based on the time deviation between its local time and a third corrected time, time synchronization between the slave locomotive with invalid BeiDou time synchronization and the master locomotive is achieved.

[0081] In one alternative implementation, Figure 2 In the distributed locomotive time synchronization method shown, the BeiDou time synchronization of any locomotive in the distributed locomotive cluster is invalid. The locomotive can also send a time synchronization request to the master locomotive in the distributed locomotive cluster when it is a slave locomotive. Through a precise time protocol, the seventh time deviation between the locomotive's local time and the master locomotive's local clock is determined. Based on the seventh time deviation, the locomotive's local clock is corrected to obtain the fourth corrected time. The locomotive's time is then switched to the fourth corrected time to achieve time synchronization with other locomotives in the distributed locomotive cluster.

[0082] In some embodiments, if the locomotive is a slave locomotive in a distributed power locomotive cluster, it can also switch its time to the local time; then, it sends a time synchronization request to the master locomotive in the distributed power locomotive cluster.

[0083] Using this implementation method, when the BeiDou time synchronization of the master locomotive and all slave locomotives fails, both master and slave locomotives switch to their local time, and the local time of the master locomotive is used as the standard time to achieve time synchronization between the master and slave locomotives.

[0084] In one alternative implementation, Figure 2 In the time synchronization method of the distributed power locomotive shown, the locomotive can also control the slave clock in the locomotive to send a time synchronization request to the master clock in the locomotive when the locomotive's Beidou time service is effective. Through the precise time protocol, the target time deviation between the slave clock in the locomotive and the master clock in the locomotive is determined. The slave clock is then controlled to correct the locomotive's local time based on the target time deviation to obtain the fifth corrected time, so as to achieve time synchronization between the slave clock in the locomotive and the master clock in the locomotive.

[0085] Please see Figure 3 , Figure 3 This is a schematic diagram illustrating the interaction process between the master and slave clocks when the BeiDou time synchronization of a locomotive is effective, as provided in an embodiment of this application. Figure 3 As shown, the interaction process may include the following steps:

[0086] S301, The slave clock sends a time synchronization request to the master clock, and the master clock receives the time synchronization request from the slave clock accordingly.

[0087] S302. In response to the time synchronization request, the master clock sends a synchronization message to the slave clock, and the slave clock receives the synchronization message accordingly.

[0088] S303, The master clock records the time T1′ when the synchronization message is sent.

[0089] S304. The master clock sends a follow message to the slave clock, and the slave clock receives the follow message accordingly. The follow message includes the time T1′ when the synchronization message was sent.

[0090] S305. Record the time T2′ of receiving the synchronization message from the clock, and extract the time T1′ of sending the synchronization message from the follow message.

[0091] S306. After a delay of a random duration, the slave clock sends a delay request message to the master clock. Correspondingly, the master clock receives the delay request message from the slave clock, which includes the time T3′ when the delay request message was sent.

[0092] S307, The master clock records the time T4′ when the delay request message is received.

[0093] S308. The master clock sends a delay request response message to the slave clock. Correspondingly, the slave clock receives a delay request response message from the master clock. The delay request response message includes the time T4′ at which the delay request message was received.

[0094] S309. Construct a system of equations based on the clocks T1′, T2′, T3′, and T4′, which includes time offsets.

[0095] The system of equations can be represented by the following formula (2).

[0096] (2)

[0097] In formula (2), offset represents the target time deviation between the master and slave clocks; delay represents the link delay between the master and slave clocks.

[0098] S310. Solve the equations from the clock to obtain the target time deviation from the master clock.

[0099] In some implementations, it is assumed that the link delay between the master and slave clocks is symmetrical, and the target time deviation between the master and slave clocks can be expressed as the following formula (3).

[0100] (3)

[0101] S311. The local time of the slave clock is corrected based on the target time deviation to obtain the corrected local time, so as to realize the time synchronization between the master and slave clocks inside the locomotive.

[0102] In some embodiments, when the local time of the slave clock is corrected based on the target time deviation to obtain the corrected local time, the following formula (4) can be used.

[0103] (4)

[0104] In formula (4), This represents the corrected local time; Ts represents the local time; offset represents the target time deviation between the master and slave clocks.

[0105] In other words, the clock can use the sum of the target time deviation and the local time as the corrected local time.

[0106] This implementation method avoids the problem of discrepancies between the master clock and slave clock caused by the processing delay of the timing board and the transmission delay of Ethernet, which would result in a deviation between the BeiDou timing received by the processor board and the actual time.

[0107] In one alternative implementation, Figure 2In the distributed locomotive time synchronization method shown, the locomotive can also, when it is any slave locomotive in the distributed locomotive cluster and the master locomotive and slave locomotive in the distributed locomotive cluster have completed time synchronization, parse the control command from the master locomotive in the distributed locomotive cluster to obtain the target execution time of the control command; the control command includes the target execution time of the control command; at the target execution time, the control command is executed.

[0108] With this implementation method, since the master locomotive and slave locomotive have achieved time synchronization, the master locomotive and slave locomotive can execute control commands simultaneously, thereby achieving time synchronization control between the master and slave locomotives.

[0109] It should be noted that the BeiDou timing in this application can also be Global Positioning System (GPS) timing, and this application does not limit it to that.

[0110] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0111] Based on the same inventive concept, this application also provides a time synchronization device for a distributed power locomotive to implement the time synchronization method for the distributed power locomotive described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the time synchronization device for distributed power locomotives provided below can be found in the limitations of the time synchronization method for distributed power locomotives described above, and will not be repeated here.

[0112] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a time synchronization device for a distributed power locomotive provided in an embodiment of this application. Figure 4As shown, the time synchronization device for the distributed power locomotive is applied to any locomotive in the distributed power locomotive cluster; each locomotive in the distributed power locomotive cluster uses the time synchronized by the BeiDou satellite positioning system as the master clock time and the processor board time as the local time corresponding to the slave clock; the device may include, but is not limited to:

[0113] The time switching module 401 is used to switch the locomotive's time to the locomotive's first local time when the locomotive is a slave locomotive in a distributed power locomotive cluster and the locomotive's Beidou time synchronization fails.

[0114] The time deviation determination module 402 is used to determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the Beidou time synchronization of the master locomotive is valid; the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the second time deviation of the slave clock of the master locomotive; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive.

[0115] The time correction module 403 is used to correct the first local time based on the first time deviation to obtain the first corrected time;

[0116] The time switching module is also used to switch the locomotive's time to the first correction time in order to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0117] In one embodiment, when determining the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster, the time deviation determination module 402 is specifically used to: send a time synchronization request to the master locomotive in the distributed power locomotive cluster, and determine the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster through a precise time protocol.

[0118] In one embodiment, the BeiDou time synchronization of all slave locomotives in the distributed power locomotive cluster is valid; the time switching module 401 is further used to switch the locomotive's time to the third local time corresponding to the locomotive when the locomotive is the master locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails; the time deviation determination module 402 is further used to designate the slave locomotive closest to the locomotive among all slave locomotives as the first target slave locomotive; determine the third time deviation between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive; the second target time is obtained by correcting the fourth local time corresponding to the first target slave locomotive based on the fourth time deviation of the slave clock in the first target slave locomotive; the fourth time deviation is the time deviation between the fourth local time and the time corresponding to the master clock of the first target slave locomotive; the time correction module 403 is further used to correct the third local time based on the third time deviation to obtain the second corrected time; the time switching module 401 is further used to switch the locomotive's time to the second corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0119] In one embodiment, the number of at least one candidate slave locomotive with valid BeiDou time synchronization among all slave locomotives in the distributed power locomotive cluster is less than the total number of slave locomotives; the time switching module 401 is further configured to switch the locomotive's time to a third local time when the locomotive is the master locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails; the time deviation determination module 402 is further configured to designate the candidate slave locomotive closest to the locomotive among at least one candidate slave locomotives as the second target slave locomotive; and determine a fifth time deviation between the third local time and the third target time corresponding to the slave clock of the second target slave locomotive; the third target time is the slave clock of the second target slave locomotive. The time correction module 403 is used to correct the fifth local time corresponding to the second target slave locomotive based on the sixth time deviation; the sixth time deviation is the time deviation between the fifth local time and the time corresponding to the master clock of the second target slave locomotive; the time correction module 403 is also used to correct the third local time based on the fifth time deviation to obtain the third corrected time; the time switching module 401 is also used to switch the locomotive's time to the third corrected time; receive a time synchronization request from at least one slave locomotive whose Beidou time synchronization has failed, so that at least one slave locomotive whose Beidou time synchronization has failed can determine the time deviation between its local time and the third corrected time, and correct its local time based on the time deviation.

[0120] In one embodiment, the BeiDou time synchronization of any locomotive in the distributed power locomotive cluster fails; the time deviation determination module 402 is further configured to send a time synchronization request to the master locomotive in the distributed power locomotive cluster when the locomotive is a slave locomotive in the distributed power locomotive cluster, and determine the seventh time deviation between the local time of the locomotive and the local clock of the master locomotive through a precise time protocol; the time correction module 403 is further configured to correct the local clock of the locomotive based on the seventh time deviation to obtain the fourth corrected time; the time switching module 401 is further configured to switch the time of the locomotive to the fourth corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

[0121] In one embodiment, the time deviation determination module 402 is further configured to control the slave clock in the locomotive to send a time synchronization request to the master clock in the locomotive when the locomotive's BeiDou time synchronization is effective, and determine the target time deviation between the slave clock in the locomotive and the master clock in the locomotive through a precise time protocol; the time correction module 403 is further configured to control the slave clock to correct the local time of the locomotive based on the target time deviation to obtain a fifth corrected time, so as to achieve time synchronization between the slave clock in the locomotive and the master clock in the locomotive.

[0122] In one embodiment, the apparatus may further include a processing unit. The processing unit is configured to, when the locomotive is any slave locomotive in a distributed power locomotive cluster, and the master locomotive and slave locomotives in the distributed power locomotive cluster have completed time synchronization, parse control instructions from the master locomotive in the distributed power locomotive cluster to obtain the target execution time of the control instructions; the control instructions include the target execution time for executing the control instructions; and execute the control instructions at the target execution time.

[0123] The modules in the time synchronization device of the aforementioned distributed power locomotive can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the terminal device in hardware form or independent of it, or stored in the memory of the terminal device in software form, so that the processor can call and execute the operations corresponding to each module.

[0124] In one exemplary embodiment, a locomotive is provided, the internal structure of which can be shown in the following diagram. Figure 5As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a time synchronization method for a distributed power locomotive. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0125] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0126] In one exemplary embodiment, this application provides a locomotive including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the time synchronization method for the distributed power locomotive described above.

[0127] In one exemplary embodiment, this application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps in the above-described time synchronization method for distributed power locomotives.

[0128] In one exemplary embodiment, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps in the time synchronization method for the distributed power locomotive described above.

[0129] It should be noted that the data involved in this application (including but not limited to acquired data, data used for analysis, and stored data) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0130] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0131] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0132] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A time synchronization method for a distributed power locomotive, characterized in that, It is applied to any locomotive in a distributed power locomotive cluster; each locomotive in the distributed power locomotive cluster uses the time synchronized by the Beidou satellite positioning system as the time corresponding to the master clock and the time of the processor board as the local time corresponding to the slave clock. The method includes: If the locomotive is a slave locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, the locomotive's time will be switched to the locomotive's corresponding first local time. A first time deviation is determined between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the BeiDou time synchronization of the master locomotive is valid; the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the slave clock of the master locomotive using the second time deviation; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive. The first local time is corrected based on the first time deviation to obtain the first corrected time; The locomotive's time is switched to the first corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

2. The method according to claim 1, characterized in that, Determining the first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster includes: A time synchronization request is sent to the master locomotive in the distributed power locomotive cluster, and a first time deviation between the first local time and the first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster is determined through a precise time protocol.

3. The method according to claim 1, characterized in that, The BeiDou time synchronization is effective for all slave locomotives in the distributed power locomotive cluster; the method further includes: If the locomotive is the main control locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, the locomotive's time will be switched to the locomotive's corresponding third local time. The locomotive closest to the target locomotive among all the target locomotives is designated as the first target locomotive. A third time deviation is determined between the third local time and the second target time corresponding to the slave clock of the first target slave locomotive; the second target time is obtained by correcting the fourth local time corresponding to the first target slave locomotive based on the fourth time deviation of the slave clock in the first target slave locomotive; the fourth time deviation is the time deviation between the fourth local time and the time corresponding to the master clock of the first target slave locomotive. The third local time is corrected based on the third time deviation to obtain the second corrected time; The locomotive's time is switched to the second corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

4. The method according to claim 1, characterized in that, In the distributed power locomotive cluster, the number of candidate slave locomotives with valid BeiDou timing among all slave locomotives is less than the total number of slave locomotives; the method further includes: If the locomotive is the main control locomotive in the distributed power locomotive cluster and the locomotive's BeiDou time synchronization fails, the locomotive's time will be switched to a third local time. The candidate slave locomotive that is closest to the locomotive among the at least one candidate slave locomotives is designated as the second target slave locomotive; A fifth time deviation is determined between the third local time and the third target time corresponding to the slave clock of the second target locomotive; the third target time is obtained by correcting the fifth local time of the second target locomotive based on a sixth time deviation by the slave clock in the second target locomotive; the sixth time deviation is the time deviation between the fifth local time and the time corresponding to the master clock of the second target locomotive. The third local time is corrected based on the fifth time deviation to obtain the third corrected time, and the locomotive time is switched to the third corrected time. Receive a time synchronization request from at least one slave locomotive whose BeiDou time synchronization has failed, so that the at least one slave locomotive whose BeiDou time synchronization has failed determines the time deviation between its local time and the third corrected time, and corrects its local time based on the time deviation.

5. The method according to claim 1, characterized in that, The BeiDou time synchronization of any locomotive in the distributed power locomotive cluster is lost; the method further includes: When the locomotive is a slave locomotive in the distributed power locomotive cluster, a time synchronization request is sent to the master locomotive in the distributed power locomotive cluster, and the seventh time deviation between the local time of the locomotive and the local clock of the master locomotive is determined through a precise time protocol. The locomotive's local clock is corrected based on the seventh time deviation to obtain the fourth corrected time; The locomotive's time is switched to the fourth corrected time to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: When the locomotive's BeiDou time synchronization is effective, the slave clock in the locomotive is controlled to send a time synchronization request to the master clock in the locomotive, and the target time deviation between the slave clock and the master clock in the locomotive is determined through a precise time protocol. The slave clock is controlled to correct the local time of the locomotive based on the target time deviation to obtain a fifth corrected time, so as to achieve time synchronization between the slave clock and the master clock in the locomotive.

7. The method according to any one of claims 1 to 5, characterized in that, The method further includes: When the locomotive is any slave locomotive in a distributed power locomotive cluster, and the master locomotive and slave locomotive in the distributed power locomotive cluster have completed time synchronization, the control command from the master locomotive in the distributed power locomotive cluster is parsed to obtain the target execution time of the control command; the control command includes the target execution time of executing the control command. At the target execution time, the control command is executed.

8. A time synchronization device for a distributed power locomotive, characterized in that, It is applied to any locomotive in a distributed power locomotive cluster; each locomotive in the distributed power locomotive cluster uses the time synchronized by the Beidou satellite positioning system as the time corresponding to the master clock and the time of the processor board as the local time corresponding to the slave clock. The device includes: The time switching module is used to switch the locomotive's time to the locomotive's corresponding first local time when the locomotive is a slave locomotive in the distributed power locomotive cluster and the locomotive's Beidou time synchronization fails. The time deviation determination module is used to determine a first time deviation between the first local time and a first target time corresponding to the slave clock of the master locomotive in the distributed power locomotive cluster; the BeiDou time synchronization of the master locomotive is valid; the first target time is obtained by correcting the second local time corresponding to the master locomotive based on the slave clock of the master locomotive using a second time deviation; the second time deviation is the time deviation between the second local time and the time corresponding to the master clock of the master locomotive. The time correction module is used to correct the first local time based on the first time deviation to obtain the first corrected time; The time switching module is also used to switch the locomotive's time to the first corrected time in order to achieve time synchronization with other locomotives in the distributed power locomotive cluster.

9. A locomotive, characterized in that, The method includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 6.

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