Distributed control system and time synchronization method
By performing anomaly diagnosis and dynamic adjustment on the time pulse signal in the distributed control system, the time data station was selected, which solved the system jump problem caused by time information anomalies and improved the accuracy and consistency of time synchronization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CLP SIX INTELLIGENT SYST CO LTD
- Filing Date
- 2025-09-15
- Publication Date
- 2026-07-31
AI Technical Summary
Existing distributed control systems lack a mechanism for detecting the integrity of standard time sources, which leads to system time jumps when time information is abnormal, affecting system consistency and accuracy.
By receiving three consecutive time pulse signals from the target data station for anomaly diagnosis, a contender request is generated to select the time data station, and the time correction mechanism is dynamically adjusted to ensure time synchronization.
It achieves accuracy and consistency in time management within the distributed system, enhancing the precision and stability of system control.
Smart Images
Figure CN121050390B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of automation control technology, and more specifically, to a distributed control system and a time synchronization method. Background Technology
[0002] With the rapid development of industrial automation technology, distributed control systems are widely used in intelligent manufacturing, power systems, rail transportation, and other fields. In distributed control systems, accurate time synchronization is crucial for achieving collaborative work among multiple nodes, sequential recording of events, and data consistency.
[0003] In existing technologies, distributed control systems typically obtain a time source from a fixed clock node and synchronize it with other nodes. However, existing implementations mainly focus on the transmission of time information and basic clock adjustment, lacking a mechanism for detecting the integrity of the standard time source. When the standard reference time jumps due to master clock failure, external interference, or malicious attacks, the system directly propagates the abnormal time information to all slave nodes, causing a jump in the overall system time. Summary of the Invention
[0004] The purpose of this application is to provide a distributed control system and a time synchronization method to improve the accuracy and consistency of system time.
[0005] In a first aspect, the present invention provides a time synchronization method for a distributed control system, the method comprising: The target data station determines whether the time pulse signal transmission is abnormal based on the three consecutive received time pulse signals; If not, the data station generates a contender request and sends it to other data stations, the contender request including at least the data station identifier; All data stations determine the time data station based on all the contender requests in this round; The time data station responds to time synchronization requests sent by other data stations via a preset protocol by sending time information to other data stations to complete time correction for all data stations.
[0006] In an optional implementation, the three consecutive time pulse signals are designated as a first time pulse signal, a second time pulse signal, and a third time pulse signal. The target data station determines whether the time pulse signals are being transmitted abnormally using the following method: Calculate the first GPS time difference between the GPS time indicated by the first time pulse signal and the GPS time indicated by the second time pulse signal; Calculate the second GPS time difference between the GPS time indicated by the second time pulse signal and the GPS time indicated by the third time pulse signal; Calculate the difference between the first GPS time difference and the second GPS time difference, and use it as the third GPS time difference; Determine whether the third GPS time difference is greater than the first preset value; If so, then the time pulse signal transmission is abnormal.
[0007] In an optional implementation, before the target data station determines that the time pulse signal transmission is abnormal, the method further includes: Calculate the first local reception time difference between the local reception time of the first time pulse signal and the local reception time of the second time pulse signal; Calculate the second local reception time difference between the local reception time of the second time pulse signal and the local reception time of the third time pulse signal; Calculate the difference between the first local reception time difference and the second local reception time difference, and use it as the third local reception time difference; Determine whether the third local reception time difference is greater than the second preset value; If so, proceed with the steps to determine if the time pulse signal transmission is abnormal.
[0008] In an optional implementation, the target data station is connected to the GPS timing module to obtain time pulse signals sent by the GPS timing module at preset time intervals.
[0009] In an optional implementation, for each data station, the time data station is determined by: determining whether the data station indicated by all the contender requests in this round has been selected within a historical time period as to determine whether a historical time data station exists; if so, the target historical data station is taken as the time data station.
[0010] In an optional implementation, if no historical data station exists in the data station indicated by all the contender requests in this round, the time data station is determined by sorting the data station identifiers of all the contender requests in this round according to a preset order.
[0011] In an optional implementation, the target data station with the smallest data station identifier is determined from the sorted data station identifiers and designated as the time data station.
[0012] In an optional implementation, the time data station performs time correction in the following manner: Determine whether the difference between the local time and the GPS time indicated by the time pulse signal is less than a third preset value; If it is not less than, then the GPS time indicated by the time pulse signal will be used as the local time of the data station; If it is less than, then keep the local time unchanged.
[0013] In an optional implementation, other data stations perform time correction in the following ways: Based on the communication process corresponding to the time synchronization request completed with the time data station through a preset protocol, the communication delay is determined. If the communication latency does not meet the requirements, the local time shall remain unchanged; If the communication latency meets the requirements, the local time of the data station is updated based on the time information sent by the time data station.
[0014] Secondly, the present invention provides a distributed control system, the control system including multiple data stations, wherein the target data station determines whether the time pulse signal is transmitted abnormally based on three consecutive received time pulse signals; If not, the data station generates a contender request and sends it to other data stations, the contender request including at least the data station identifier; All data stations determine the time data station based on all the contender requests in this round; In response to time synchronization requests sent by other data stations via a preset protocol, the time data station sends time information to other data stations to complete time correction for all data stations.
[0015] This application provides a distributed control system and time synchronization method. The method includes: a target data station determining whether the time pulse signal transmission is abnormal based on three consecutive received time pulse signals; if not, the data station generates a master competition request and sends it to other data stations, the master competition request including at least a data station identifier; all data stations determine the time data station based on all master competition requests in this round; the time data station responds to time synchronization requests sent by other data stations through a preset protocol and sends time information to other data stations to complete time correction for all data stations. By diagnosing the time signal and dynamically adjusting the standard time source, the accuracy and consistency of the distributed system time are ensured. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of a distributed control system provided in an embodiment of this application; Figure 2 A flowchart illustrating a time synchronization method for a distributed control system provided in this application embodiment. Detailed Implementation
[0018] Currently, the common method for achieving time synchronization in distributed control systems is for a master clock node with a standard reference time to send time stamps to all other slave nodes at fixed time intervals via network broadcast. Each node then corrects its local clock upon receiving the time stamps. However, because GPS time can also fluctuate, this can lead to time asynchrony within the distributed control system, affecting system control performance.
[0019] Based on this, this application provides a distributed control system and a time synchronization method.
[0020] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.
[0021] Figure 1 This is a schematic diagram of a distributed control system provided in an embodiment of this application. Figure 2 A flowchart illustrating a time synchronization method for a distributed control system provided in this application embodiment.
[0022] like Figure 1 and Figure 2 As shown, the distributed control system may include multiple data stations, and the target data station may be connected to a GPS timing module (Global Positioning System). Time synchronization methods may include: S1. The target data station determines whether the time pulse signal transmission is abnormal based on the three consecutive received time pulse signals.
[0023] The control module of one or more data stations can be connected to the GPS timing module via a serial port and receive time pulse signals sent by the GPS timing module at preset time intervals. Here, the data station can be a computer.
[0024] Here, the time pulse signal can be a second pulse signal or a minute pulse signal.
[0025] The target data station determines whether the time pulse signals are being transmitted abnormally using the following method: (The three consecutive time pulse signals are designated as the first, second, and third time pulse signals.) Calculate the first GPS time difference between the GPS time indicated by the first time pulse signal and the GPS time indicated by the second time pulse signal; Calculate the second GPS time difference between the GPS time indicated by the second time pulse signal and the GPS time indicated by the third time pulse signal; Calculate the difference between the first GPS time difference and the second GPS time difference, and use it as the third GPS time difference; Determine whether the third GPS time difference is greater than the first preset value; If so, then the time pulse signal transmission is abnormal.
[0026] In one implementation, after receiving three consecutive second pulse signals, the control module calculates the time difference between the two received second pulse signals. If the third GPS time difference is greater than 50 milliseconds, it indicates that the second pulse signal transmission is abnormal and the time source provided by the GPS timing module has a jump error.
[0027] The time pulse signal can also be a minute pulse signal, in which case the preset value can be 10 seconds. This preset value can be adjusted according to the actual control precision.
[0028] Furthermore, before the target data station determines the time pulse signal transmission anomaly, it can also calculate the first local reception time difference between the local reception time of the first time pulse signal and the local reception time of the second time pulse signal. Calculate the second local reception time difference between the local reception time of the second time pulse signal and the local reception time of the third time pulse signal; Calculate the difference between the first local reception time difference and the second local reception time difference, and use it as the third local reception time difference; Determine whether the third local reception time difference is greater than the second preset value; If so, proceed with the steps to determine if the time pulse signal transmission is abnormal.
[0029] While monitoring the time transmitted by GPS, the data station also monitors the time received locally. This can avoid GPS time source anomalies and verify the local time, thereby ensuring time synchronization among data stations in the distributed control system and increasing the accuracy of system control.
[0030] S2. If not, the data station generates a contest for the lead and sends it to other data stations. The contest for the lead includes at least the data station identifier.
[0031] If the time pulse signal acquired by the data station does not change, the main control module can generate a mastering request based on the data station's identifier and send it to other data stations. The data station identifier can be a data station ID or IP address, etc.
[0032] S3. All data stations determine the time data station based on the data station identifiers indicated by all contender requests received in this round.
[0033] In the current round, each data station may receive leader requests from multiple other data stations. For each data station, the time data station is determined as follows: Determine if any historical data station exists for the data station indicated by all the claims made by the current contenders; if so, designate that historical data station as the time data station. Here, a historical data station is a data station used to store historical data.
[0034] If no historical data station exists as indicated by any of the contender requests in this round, the data station identifiers of all the data stations indicated by the contender requests in this round are sorted according to a preset order to determine the time data station. For example, from the sorted data station identifiers, the target data station with the smallest data station identifier is determined as the time data station.
[0035] The master control requests here include received master control requests and master control requests generated locally by the data station.
[0036] Furthermore, it can be determined whether the target data station has continuously sent N rounds of master contention requests. If so, historical data stations and data station identifiers can be prioritized among these target data stations. This can further ensure the accuracy of synchronization time.
[0037] S4. In response to time synchronization requests sent by other data stations through a preset protocol, the time data station sends time information to other data stations to complete time correction for all data stations.
[0038] The selected data station serves as the time source for the distributed control system. It can respond to time synchronization requests sent by other data stations via the NTP protocol and send time information to other data stations through a preset protocol.
[0039] The time data station can perform time correction in the following ways: Determine whether the difference between the local time and the GPS time indicated by the time pulse signal is less than a third preset value; if it is not less than, then the GPS time indicated by the time pulse signal is used as the local time of the data station; if it is less than, then the local time remains unchanged.
[0040] In a specific embodiment, the third preset value can be 50 milliseconds.
[0041] Other data stations can perform time correction in the following ways: Based on the communication process corresponding to the time synchronization request completed with the time data station through a preset protocol, the communication delay is determined; if the communication delay does not meet the requirements, the local time is kept unchanged; if the communication delay meets the requirements, the local time of the data station is updated based on the time information sent by the time data station.
[0042] Specifically, other data stations can send time synchronization requests to the time data station based on the NTP protocol and record their local transmission time. The time server records the time of receiving the time synchronization request and generates a feedback data packet, which includes the time data station's current local time, the local time of receiving the request, and the local time of responding to the request. Other data stations receive the feedback data packet sent by the time data station and record the reception time. Furthermore, other data stations can calculate communication metrics such as time offset and latency to determine whether to update their local time. For example, if the communication latency is greater than a preset latency, it is determined that the latency does not meet the requirements; otherwise, it is determined that the latency meets the requirements.
[0043] If the local time of the data station is inconsistent with the local time of the time data station, it can be updated based on the local time of the time data station.
[0044] This application provides a distributed control system and a time synchronization method that, by diagnosing time signals and dynamically adjusting a standard time source, ensures the accuracy and consistency of time in the distributed system.
[0045] Based on the same inventive concept, this application also provides a distributed control system. The control system includes multiple data stations. A target data station determines whether the time pulse signal is abnormally transmitted based on three consecutive received time pulse signals. If not, the data station generates a master competition request and sends it to other data stations. The master competition request includes at least a data station identifier. All data stations determine the time data station based on all master competition requests in this round. The time data station responds to time synchronization requests sent by other data stations through a preset protocol and sends time information to other data stations to complete the time correction of all data stations.
[0046] In a preferred embodiment, the three consecutive time pulse signals are a first time pulse signal, a second time pulse signal, and a third time pulse signal, respectively. The target data station determines whether the time pulse signal transmission is abnormal by means of the following method: Calculate the first GPS time difference between the GPS time indicated by the first time pulse signal and the GPS time indicated by the second time pulse signal; Calculate the second GPS time difference between the GPS time indicated by the second time pulse signal and the GPS time indicated by the third time pulse signal; Calculate the difference between the first GPS time difference and the second GPS time difference, and use it as the third GPS time difference; Determine whether the third GPS time difference is greater than the first preset value; If so, then the time pulse signal transmission is abnormal.
[0047] In a preferred embodiment, before the target data station determines that the time pulse signal transmission is abnormal, the method further includes: Calculate the first local reception time difference between the local reception time of the first time pulse signal and the local reception time of the second time pulse signal; Calculate the second local reception time difference between the local reception time of the second time pulse signal and the local reception time of the third time pulse signal; Calculate the difference between the first local reception time difference and the second local reception time difference, and use it as the third local reception time difference; Determine whether the third local reception time difference is greater than the second preset value; If so, proceed with the steps to determine if the time pulse signal transmission is abnormal.
[0048] In a preferred embodiment, the target data station is connected to a GPS timing module to obtain time pulse signals sent by the GPS timing module at preset time intervals.
[0049] In a preferred embodiment, for each data station, the time data station is determined by: determining whether the data station indicated by all the contenders' requests in this round has been selected within a historical time period as to determine whether a historical time data station exists; if so, the target historical data station is taken as the time data station.
[0050] In a preferred embodiment, if the data station indicated by all the contender requests in this round does not have a historical data station, the data station identifiers of the data stations indicated by all the contender requests in this round are sorted in a preset order to determine the time data station.
[0051] In a preferred embodiment, the target data station with the smallest data station identifier is determined from the sorted data station identifiers and is used as the time data station.
[0052] In a preferred embodiment, the time data station performs time correction in the following manner: Determine whether the difference between the local time and the GPS time indicated by the time pulse signal is less than a third preset value; If it is not less than, then the GPS time indicated by the time pulse signal will be used as the local time of the data station; If it is less than, then keep the local time unchanged.
[0053] In a preferred embodiment, other data stations perform time correction in the following manner: Based on the communication process corresponding to the time synchronization request completed with the time data station through a preset protocol, the communication delay is determined. If the communication latency does not meet the requirements, the local time shall remain unchanged; If the communication latency meets the requirements, the local time of the data station is updated based on the time information sent by the time data station.
[0054] This application provides a distributed control system that diagnoses time signals and dynamically adjusts the standard time source, thereby ensuring the accuracy and consistency of time in the distributed system.
[0055] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.
[0056] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0057] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.
[0058] It should be noted that if the function is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0059] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.
[0060] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A time synchronization method of a distributed control system, characterized by, The method includes: The target data station determines whether the time pulse signal transmission is abnormal based on three consecutive time pulse signals received from the Global Positioning System. If not, the data station generates a contender request and sends it to other data stations, the contender request including at least the data station identifier; All data stations determine the time data station based on all the contender requests in this round; The time data station responds to time synchronization requests sent by other data stations through a preset protocol by sending time information to other data stations to complete time correction for all data stations; For each data station, the time data station is determined in the following way: Determine whether any historical data stations exist for the data stations indicated by all the claims in this round of contest; If so, then that historical data station will be used as the time data station; If none of the historical data stations are indicated by the data stations requested by all contenders in this round; Based on the data station identifiers indicated by all the data stations requested by the contenders in this round, the time data stations are sorted in a preset order to determine the time data stations.
2. The method of claim 1, wherein, The target data station determines whether the time pulse signals are being transmitted abnormally using the following method: (The three consecutive time pulse signals are designated as the first, second, and third time pulse signals.) Calculate the first GPS time difference between the GPS time indicated by the first time pulse signal and the GPS time indicated by the second time pulse signal; Calculate the second GPS time difference between the GPS time indicated by the second time pulse signal and the GPS time indicated by the third time pulse signal; Calculate the difference between the first GPS time difference and the second GPS time difference, and use it as the third GPS time difference; Determine whether the third GPS time difference is greater than the first preset value; If so, then the time pulse signal transmission is abnormal.
3. The method of claim 2, wherein, Before the target data station determines the time pulse signal transmission anomaly, the following steps are also included: Calculate the first local reception time difference between the local reception time of the first time pulse signal and the local reception time of the second time pulse signal; Calculate the second local reception time difference between the local reception time of the second time pulse signal and the local reception time of the third time pulse signal; Calculate the difference between the first local reception time difference and the second local reception time difference, and use it as the third local reception time difference; Determine whether the third local reception time difference is greater than the second preset value; If so, proceed with the steps to determine if the time pulse signal transmission is abnormal.
4. The method of claim 1, wherein, The target data station is connected to the GPS timing module to obtain time pulse signals sent by the GPS timing module at preset time intervals.
5. The method of claim 4, wherein, From the sorted data station identifiers, the target data station with the smallest identifier is determined and designated as the time data station.
6. The method of claim 2, wherein, Time data stations perform time correction in the following ways: Determine whether the difference between the local time and the GPS time indicated by the time pulse signal is less than a third preset value; If it is not less than, then the GPS time indicated by the time pulse signal will be used as the local time of the data station; If it is less than, then keep the local time unchanged.
7. The method of claim 6, wherein, Other data stations perform time correction in the following ways: Based on the communication process corresponding to the time synchronization request completed with the time data station through a preset protocol, the communication delay is determined. If the communication latency does not meet the requirements, the local time shall remain unchanged; If the communication latency meets the requirements, the local time of the data station is updated based on the time information sent by the time data station.
8. A distributed control system, characterized by The time synchronization method applicable to any one of claims 1 to 7, wherein the control system includes multiple data stations, The target data station determines whether the time pulse signal transmission is abnormal based on the three consecutive received time pulse signals; If not, the data station generates a contender request and sends it to other data stations, the contender request including at least the data station identifier; All data stations determine the time data station based on all the contender requests in this round; In response to time synchronization requests sent by other data stations via a preset protocol, the time data station sends time information to other data stations to complete time correction for all data stations.