CN114489237A - Time synchronization method, control system, and computer-readable storage medium - Google Patents

Abstract

The present application is applicable to the field of communication technology, and provides a time synchronization method, a control system, and a computer-readable storage medium. The control system includes a first control unit and at least one second control unit, and the method includes: the first control unit The first standard time is sent to the second control unit, and the first sending time is recorded; the second control unit returns the first feedback information to the first control unit; The first receiving time calculates the first delay time between the first control unit and the second control unit, and sends the first delay time and the current second standard time to the second control unit; the second control unit according to the first delay The time and the second standard time correct the current time of the second control unit to obtain the first corrected time. Through the above method, the time synchronization accuracy between the various control units of the vehicle can be effectively improved.

Description

Time synchronization method, control system, and computer-readable storage medium

technical field

The present application belongs to the field of communication technologies, and in particular, relates to a time synchronization method, a control system, and a computer-readable storage medium.

Background technique

A car control system usually includes multiple control units, and there may be communication interactions between different control units. In addition, the control unit often needs to obtain information from the outside of the car, such as the distance between the car and the car in front, and the time of traffic lights. The control unit adjusts the control strategy in real time according to the interaction information obtained through communication and interaction with other control units and the obtained external information of the vehicle, which requires time synchronization between the control units and between the control units and the external information.

In the prior art, a time standard source is usually set, and the time standard source sends the standard time to each control unit, and each control unit corrects the time by itself according to the received standard time. Existing methods cannot guarantee the accuracy of time synchronization results.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a time synchronization method, a control system, and a computer-readable storage medium, which can effectively improve the time synchronization accuracy between control units of an automobile.

In a first aspect, an embodiment of the present application provides a time synchronization method, which is applied to a control system, where the control system includes a first control unit and at least one second control unit, and the method includes:

The first control unit sends the first standard time to the second control unit through the first communication method, and records the first sending time;

After receiving the first standard time, the second control unit returns the first feedback information to the first control unit through the first communication method;

After receiving the first feedback information, the first control unit calculates the first control unit and the second control unit according to the first transmission time and the first reception time when the first feedback information is received the first delay time between units, and send the first delay time and the current second standard time to the second control unit through the first communication method;

After receiving the first delay time and the second standard time, the second control unit corrects the current time of the second control unit according to the first delay time and the second standard time to obtain the first delay time and the second standard time. a calibration time.

In the embodiment of the present application, through the interaction of time information between the first control unit and the second control unit, the communication delay time between the first control unit and the second control unit is confirmed, and the communication delay time is considered in the process of correcting the time. The delay makes the corrected time closer to the standard time, thereby improving the accuracy of time synchronization.

In a possible implementation manner of the first aspect, after the second control unit receives the first delay time and the second standard time, according to the first delay time and the second standard time Correcting the current time of the second control unit to obtain the first correction time, including:

After receiving the first delay time and the second standard time, the second control unit calculates the first theoretical time according to the current first actual time and the first delay time of the second control unit;

If the time difference between the first theoretical time and the second standard time is within a preset range, the second control unit corrects the second control unit according to the first delay time and the second standard time The current time is obtained to obtain the first correction time.

In a possible implementation manner of the first aspect, after correcting the current time of the second control unit according to the first delay time and the second standard time to obtain the first correction time, the method further include:

The second control unit sends the first correction time to the first control unit through the first communication method;

After receiving the first correction time, the first control unit updates the delay time between the first control unit and the second control unit to obtain a second delay time, and uses the first communication method sending the second delay time and the current third standard time to the second control unit;

After receiving the second delay time and the third standard time, the second control unit corrects the current time of the second control unit according to the second delay time and the third standard time to obtain the first 2. Calibration time.

In a possible implementation manner of the first aspect, after calculating the first theoretical time according to the current first actual time of the second control unit and the first delay time, the method further includes:

If the time difference between the first theoretical time and the second standard time is not within a preset range, the second control unit returns an uncorrected identifier to the first control unit through the first communication method;

If the first control unit receives the uncorrected identifier within the preset time or does not receive the information from the second control unit within the preset time, send the current fourth standard time through the second communication method to the second control unit, and record the second sending time;

After receiving the fourth standard time, the second control unit returns second feedback information to the first control unit through the second communication method;

After receiving the second feedback information, the first control unit calculates the first control unit and the second control unit according to the second transmission time and the second reception time when the second feedback information is received the third delay time between units, and send the third delay time and the current fifth standard time to the second control unit through the second communication method;

After receiving the third delay time and the fifth standard time, the second control unit corrects the current time of the second control unit according to the third delay time and the fifth standard time.

In a possible implementation manner of the first aspect, after the second control unit receives the third delay time and the fifth standard time, according to the third delay time and the fifth standard time Correcting the current time of the second control unit, including:

After receiving the third delay time and the fifth standard time, the second control unit calculates a second theoretical time according to the current second actual time and the third delay time of the second control unit;

If the time difference between the second theoretical time and the fifth standard time is within a preset range, the second control unit corrects the second control unit according to the third delay time and the fifth standard time the current time to obtain the third correction time;

If the time difference between the second theoretical time and the fifth standard time is not within a preset range, the second control unit reports preset fault information.

In a possible implementation manner of the first aspect, the second feedback information includes a first processing time during which the second control unit processes the fourth standard time;

After receiving the second feedback information, the first control unit calculates the first control unit and the second control unit according to the second transmission time and the second reception time when the second feedback information is received A third delay time between cells, including:

After the first control unit receives the second feedback information, the first control unit calculates the third delay according to the second sending time, the first processing time and the second receiving time time.

In a possible implementation manner of the first aspect, after the second control unit receives the first delay time and the second standard time, according to the first delay time and the second standard After time correcting the current time of the second control unit, after obtaining the first correction time, the method further includes:

When the number of times the first control unit calculates the delay time between the first control unit and the second control unit reaches N times, the first control unit calculates the average delay according to the latest calculated delay time N times time, and send the average delay time and the current sixth standard time to the second control unit through the first communication method;

After receiving the average delay time and the sixth standard time, the second control unit corrects the current time of the second control unit according to the average delay time and the sixth standard time to obtain a fourth correction time.

In a second aspect, an embodiment of the present application provides a control system, the control system includes a first control unit and at least one second control unit, wherein:

The first control unit is configured to send the first standard time to the second control unit through a first communication method, and record the first sending time;

The second control unit is configured to return the first feedback information to the first control unit through the first communication method after receiving the first standard time;

The first control unit is configured to, after receiving the first feedback information, calculate the first control unit and the the first delay time between two control units, and send the first delay time and the current second standard time to the second control unit through the first communication method;

The second control unit is configured to correct the current time of the second control unit according to the first delay time and the second standard time after receiving the first delay time and the second standard time, Get the first correction time.

In a third aspect, an embodiment of the present application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes all The time synchronization method according to any one of the above first aspects is realized when the computer program is used.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, and an embodiment of the present application provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, wherein the When the computer program is executed by the processor, the time synchronization method according to any one of the above first aspects is implemented.

In a fifth aspect, an embodiment of the present application provides a computer program product that, when the computer program product runs on a terminal device, enables the terminal device to execute the time synchronization method described in any one of the first aspects above.

It can be understood that, for the beneficial effects of the second aspect to the fifth aspect, reference may be made to the relevant description in the first aspect, which is not repeated here.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present application. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic diagram of a vehicle control system provided by an embodiment of the present application;

2 is a schematic diagram of an interaction flow of a time synchronization method provided by an embodiment of the present application;

3 is a schematic diagram of an interaction flow of a time synchronization method provided by another embodiment of the present application;

FIG. 4 is a schematic structural diagram of a terminal device provided by an embodiment of the present application.

Detailed ways

In the following description, for the purpose of illustration rather than limitation, specific details such as a specific system structure and technology are set forth in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It is to be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described feature, integer, step, operation, element and/or component, but does not exclude one or more other The presence or addition of features, integers, steps, operations, elements, components and/or sets thereof.

It will also be understood that, as used in this specification and the appended claims, the term "and/or" refers to and including any and all possible combinations of one or more of the associated listed items.

As used in the specification of this application and the appended claims, the term "if" may be contextually interpreted as "when" or "once" or "in response to determining" or "in response to detecting ". Similarly, the phrases "if it is determined" or "if the [described condition or event] is detected" may be interpreted, depending on the context, to mean "once it is determined" or "in response to the determination" or "once the [described condition or event] is detected. ]" or "in response to detection of the [described condition or event]".

In addition, in the description of the specification of the present application and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the description, and should not be construed as indicating or implying relative importance.

References in this specification to "one embodiment" or "some embodiments" and the like mean that a particular feature, structure or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean "one or more but not all embodiments" unless specifically emphasized otherwise.

The embodiments of the present application can be applied to an automobile control system. Referring to FIG. 1 , it is a schematic diagram of an automobile control system provided by an embodiment of the present application. As shown in FIG. 1 , the vehicle control system may include an information exchange control unit (V2X-OBU) 11 between the vehicle and the outside world and a plurality of electronic control units (Electronic Control Unit, ECU) 12 .

The V2X-OBU may include a microprocessor (Microprocessor Unit, MPU), a microcontroller (Microcontroller Unit, MCU), and a V2X communication module. V2X-OBU communicates with the outside of the car through the V2X communication module, such as communication with satellites, to obtain satellite timing. V2X-OBU calculates and processes related data required for time synchronization through MPU, and communicates and interacts with other electronic control units through MCU. Among them, MCU and other electronic units can communicate through CAN bus, I/O port or serial port.

In some application scenarios, the MCU can send information to a central gateway (central gateway, CGW) through the CAN bus, and then the central gateway transmits the information to the electronic control unit through the CAN bus. In other application scenarios, the MCU can send information to the electronic control unit through the I/O port.

As shown in the above car control system, in an application scenario, V2X-OBU is responsible for communicating with the outside world of the car, and calculates relevant early warning information based on external information (such as traffic light time, front and rear distance, etc.) and the car's own state information (obtained from the ECU). . The Advanced Driving Assistance System (ADAS) of the car can control the state of the vehicle according to this early warning information, avoid accidents, violations and even illegal driving accidents, so as to improve road traffic safety. In order to accurately calculate and give early warning, it is necessary for V2X-OBU to keep time synchronization with each ECU.

In the prior art, a time standard source is usually set, and the time standard source sends the standard time to each control unit, and each control unit corrects the time by itself according to the received standard time. Existing methods cannot guarantee the accuracy of time synchronization results. To solve this problem, an embodiment of the present application provides a time synchronization method. The method is described below with various embodiments.

In one embodiment, referring to FIG. 2 , it is a schematic diagram of an interaction flow of a time synchronization method provided by an embodiment of the present application. As an example and not a limitation, the method may include the following steps:

S201, the V2X-OBU sends the current standard time t1 to the ECU through the CAN bus, and records the sending time as F1.

S202, after receiving the standard time t1, the ECU returns a feedback message K1 to the V2X-OBU through the CAN bus.

S203, after receiving the feedback information K1, the V2X-OBU calculates the delay time Δt1 between the V2X-OBU and the ECU according to the sending time F1 and the receiving time J1 when the feedback information K1 is received, and delays the delay time through the CAN bus The time Δt1 and the current standard time t2 are sent to the ECU, and the sending time F2 is recorded.

In the embodiment of the present application, after the ECU receives the standard time t1, it may return to the feedback information K1 after a certain waiting time, and the waiting time will affect the calculation of the delay time. To solve this problem, optionally, the feedback information includes the above-mentioned waiting time (that is, the time when the ECU sends the feedback information K1 minus the time when the standard time t1 is received). Correspondingly, S207 may include: the V2X-OBU calculates the delay time Δt1 according to the sending time F1, the waiting time and the receiving time J1.

Specifically, the waiting time is subtracted from the receiving time J1, and then the sending time F1 is subtracted to obtain a time difference value, and the delay time Δt1 is obtained by dividing the time difference value by 2.

S204, after receiving the delay time Δt1 and the standard time t2, the ECU calculates the theoretical time L1 according to the delay time Δt1 and the current local time S1 of the ECU. If the time difference between the theoretical time L1 and the standard time t2 is within the preset range, the ECU corrects the local time of the ECU according to the delay time Δt1 and the standard time t2 to obtain the corrected local time S2. The correction time S2 is sent to the V2X-OBU via the CAN bus.

Specifically, the actual time S1 is subtracted from the delay time Δt1 to obtain the theoretical time L1.

Optionally, the standard time t2 can be added to the delay time Δt1 to obtain the theoretical local time, and then the time difference between the theoretical local time and the current actual time S1 is calculated, and the local time is corrected according to the time difference.

Further, after the ECU calculates the theoretical local time, if the time difference between the theoretical local time and the current local time S1 is within the preset range, and the time difference is less than the preset value (indicating that the ECU local time is different from the standard time) The time gap is small), the ECU can choose not to correct the local time, and send the current local time as the correction time S2 to the V2X-OBU.

S205, after receiving the correction time S2, the V2X-OBU updates the delay time Δt2 between the V2X-OBU and the ECU according to the sending time F2 and the receiving time J2 that receives the correction time S2, and sends the current standard time t3 and ECU to the ECU Update the delay time Δt2, and record the sending time as F3.

S206, after receiving the standard time t3 and the delay time Δt2, the ECU calculates the theoretical time L2 according to the delay time Δt2 and the current local time S3 of the ECU. If the time difference between the theoretical time L2 and the standard time t3 is within the preset range, the ECU corrects the local time of the ECU according to the delay time Δt2 and the standard time t3 to obtain the correction time S4. The correction time S4 is sent to the V2X-OBU via the CAN bus.

After the V2X-OBU receives the correction time S4, it continues to update the delay time between the V2X-OBU and the ECU according to the receiving time J3 and the sending time F3. This cycle keeps the time synchronization between the V2X-OBU and the ECU.

In the above embodiment, the V2X-OBU can be recorded as the first control unit, the ECU can be recorded as the second control unit, the CAN bus can be recorded as the first communication method, the standard time t1 can be recorded as the first standard time, and the standard time t2 can be recorded as the first standard time. It is recorded as the second standard time, the standard time t3 can be recorded as the third standard time, the sending time F1 can be recorded as the first sending time, the feedback information K1 can be recorded as the first feedback information, and the receiving time J1 can be recorded as the first receiving time time, the delay time Δt1 can be recorded as the first delay time, the local time S1 can be recorded as the first actual time, the theoretical time L1 can be recorded as the first theoretical time, the correction time S2 can be recorded as the first correction time, and the delay time Δt2 can be recorded as the first actual time. Denoted as the second delay time, the calibration time S4 may be denoted as the second calibration time.

In the embodiment of the present application, through the interaction of time information between the first control unit and the second control unit, the communication delay time between the first control unit and the second control unit is confirmed, and the communication delay time is considered in the process of correcting the time. The delay makes the corrected time closer to the standard time, thereby improving the accuracy of time synchronization.

In another embodiment, referring to FIG. 3 , it is a schematic diagram of an interaction flow of a time synchronization method provided by another embodiment of the present application. As an example and not limitation, the method may include the following steps:

S301, the V2X-OBU sends the current standard time t1 to the ECU through the CAN bus, and records the sending time as F1.

S302, after receiving t1, the ECU returns a feedback message K1 to the V2X-OBU through the CAN bus.

S303, after receiving the feedback information K1, the V2X-OBU calculates the delay time Δt1 between the V2X-OBU and the ECU according to the sending time F1 and the receiving time J1 when the feedback information K1 is received, and delays the delay time through the CAN bus The time Δt1 and the current standard time t2 are sent to the ECU, and the sending time F2 is recorded.

S301 to S303 are the same as the above-mentioned S201 to S203. For details, please refer to the descriptions in S201 to S203, which will not be repeated here. S304 is another case of S204.

S304, after receiving the delay time Δt1 and the standard time t2, the ECU calculates the theoretical time L1 according to the delay time Δt1 and the current local time S1 of the ECU. If the time difference between the theoretical time L1 and the standard time t2 is not within the preset range, the ECU sends an uncorrected flag to the V2X-OBU through the CAN bus.

The time difference between the theoretical time and the standard time is large, indicating that the time received by the ECU is also inaccurate, and time synchronization cannot be achieved. In this case, it may be caused by a failure of the first communication mode, or may be caused by communication congestion in the first communication mode. At this time, the ECU does not need to correct the local time, and just returns the uncorrected flag to the V2X-OBU. If the first communication method fails, the V2X-OBU cannot receive the uncorrected identification; if the communication in the first communication method is congested, the V2X-OBU can receive the uncorrected identification, but the receiving time may be delayed.

S305, if the V2X-OBU receives the uncorrected flag within the preset time or does not receive the information of the second control unit within the preset time, it sends the current standard time t5 to the ECU through the I/O port, and Record the sending time F4.

The V2X-OBU receives the uncorrected flag, indicating that the first communication mode is faulty, and switches the communication mode. Such as switching from the CAN bus to the I/O port, after switching the communication mode, the time synchronization is performed again.

S306, after receiving the standard time t5, the ECU returns the feedback information K2 to the V2X-OBU through the I/O port.

S307, after the V2X-OBU receives the feedback information K2, it calculates the delay time Δt3 between the V2X-OBU and the ECU according to the sending time F4 and the receiving time J4 when the feedback information K2 is received, and compares the delay time Δt3 and the ECU through the I/O port. The current standard time t6 is sent to the ECU, and the sending time F5 is recorded.

In the embodiment of the present application, the V2X-OBU sends a pulse representing the standard time t5 to the ECU through the I/O port, and the ECU converts the pulse into time information after receiving the pulse. This conversion process requires a certain processing time, which will affect the calculation of the delay time. In order to solve this problem, optionally, the feedback information includes the first processing time for the ECU to process the pulse representing the standard time t5. Correspondingly, S307 may include: the V2X-OBU calculates the delay time Δt3 according to the sending time F2, the first processing time and the receiving time J3.

Specifically, the first processing time is subtracted from the receiving time J3, and then the sending time F2 is subtracted to obtain a time difference, and the delay time Δt3 is obtained by dividing the time difference by 2.

S308, after receiving the delay time Δt3 and the standard time t6, the ECU calculates the theoretical time L4 according to the current local time S7 and the delay time Δt3 of the ECU; if the time difference between the theoretical time L4 and the standard time t6 is within the preset range, the ECU calculates the delay The time Δt3 and the standard time t6 correct the current time of the ECU, obtain the corrected local time S8, and send the corrected time S8 to the V2X-OBU.

After the V2X-OBU receives the correction time S8, it continues to update the delay time between the V2X-OBU and the ECU according to the receiving time J5 and the sending time F5. Loop sequentially to keep the time synchronization between the V2X-OBU and the ECU.

If the time difference between the theoretical time L4 and the standard time t6 is not within the preset range, the ECU reports preset fault information. In this case, the I/O port is also faulty. Since both the CAN bus and the I/O port are faulty, it means that the communication of the control system is faulty and the time synchronization cannot be continued.

Of course, if there is a third communication mode, if the time difference between the theoretical time L4 and the standard time t6 is not within the preset range, the third communication mode can also be switched to continue the time synchronization. The steps for time synchronization using the third communication mode are substantially the same as those described in the above-mentioned embodiments in FIG. 2 and FIG. 3 . For details, refer to the above-mentioned embodiments in FIG. 2 and FIG.

In one embodiment, during the process of time synchronization through the second communication method, the monitoring of the first communication method may be maintained. When the first communication mode returns to normal, the second communication mode can be switched back to the first communication mode.

The steps of S305 to S308 are substantially the same as those of S201 to S204, but the communication method is different. For details, please refer to the descriptions in S201 to S204.

In the above-mentioned embodiment, the I/O port can be recorded as the second communication mode, the standard time t5 can be recorded as the fourth standard time, the transmission time F4 can be recorded as the second transmission time, and the feedback information K2 can be recorded as the second feedback information, The receiving time J4 can be recorded as the second receiving time, the delay time Δt3 can be recorded as the third delay time, the standard time t6 can be recorded as the fifth standard time, the local time S7 can be recorded as the second actual time, and the theoretical time L4 can be recorded as The second theoretical time, the calibration time S8 can be recorded as the third calibration time.

In one embodiment, during the time synchronization process, the method further includes:

When the number of times the first control unit calculates the delay time between the first control unit and the second control unit reaches N times, the first control unit calculates the average delay time according to the latest calculated delay time N times, and communicates with the first communication method sending the average delay time and the current sixth standard time to the second control unit;

After receiving the average delay time and the sixth standard time, the second control unit corrects the current time of the second control unit according to the average delay time and the sixth standard time to obtain a fourth correction time.

During the time synchronization process, the time synchronization may always be performed according to the first communication mode. In this case, the number of times of calculating the delay time refers to the number of times of calculating the delay in the first communication mode. It is also possible to always perform time synchronization according to the second communication method. In this case, the number of times of calculating the delay time refers to the number of times of calculating the delay in the second communication method. It is also possible to first perform time synchronization according to the first communication method, but the first communication method fails during the process, and then the time synchronization is performed according to the second communication method; in this case, the number of times to calculate the delay time refers to the first communication method. Calculate the total number of delays with the second communication method.

Optionally, the method of calculating the average delay time of N times of delay time may adopt average value calculation, sliding filter calculation, and other statistical algorithms, etc., which are not specifically limited herein.

In the embodiment of the present application, setting N times is equivalent to setting a sliding window. Updating the delay between the first control unit and the second control unit using the average delay time calculated from the latest N delay times is equivalent to using the latest average delay in the sliding window to perform time synchronization. Through the above method, the time calibration error caused by the single delay error can be effectively avoided, thereby effectively improving the accuracy of time synchronization.

It should be noted that the above embodiment is only an example of applying the time synchronization method to a vehicle control system. In practical applications, both the first control unit and the second control unit may be ECUs. The above time synchronization method can also be applied to other control systems having multiple control units, or to time synchronization between two control systems, which is not specifically limited here.

It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

FIG. 4 is a schematic structural diagram of a terminal device provided by an embodiment of the present application. As shown in FIG. 4 , the terminal device 4 in this embodiment includes: at least one processor 40 (only one is shown in FIG. 4 ), a memory 41 , and a processor stored in the memory 41 and can be processed in the at least one processor A computer program 42 running on the processor 40, when the processor 40 executes the computer program 42, the steps in any of the foregoing time synchronization method embodiments are implemented.

The terminal device may be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art can understand that FIG. 4 is only an example of the terminal device 4, and does not constitute a limitation on the terminal device 4. It may include more or less components than the one shown, or combine some components, or different components , for example, may also include input and output devices, network access devices, and the like.

The so-called processor 40 may be a central processing unit (Central Processing Unit, CPU), and the processor 40 may also be other general-purpose processors, digital signal processors (Digital Signal Processors, DSP), application specific integrated circuits (Application Specific Integrated Circuits) , ASIC), off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 41 may be an internal storage unit of the terminal device 4 in some embodiments, such as a hard disk or a memory of the terminal device 4 . The memory 41 may also be an external storage device of the terminal device 4 in other embodiments, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, flash memory card (Flash Card), etc. Further, the memory 41 may also include both an internal storage unit of the terminal device 4 and an external storage device. The memory 41 is used to store an operating system, an application program, a boot loader (Boot Loader), data, and other programs, such as program codes of the computer program. The memory 31 can also be used to temporarily store data that has been output or will be output.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented.

The embodiments of the present application provide a computer program product, when the computer program product runs on a terminal device, so that the terminal device can implement the steps in the foregoing method embodiments when executed.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on this understanding, the present application realizes all or part of the processes in the methods of the above embodiments, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When executed by a processor, the steps of each of the above method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include at least: any entity or device capable of carrying the computer program code to the device/terminal device, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory ( RAM, Random Access Memory), electrical carrier signals, telecommunication signals, and software distribution media. For example, U disk, mobile hard disk, disk or CD, etc. In some jurisdictions, under legislation and patent practice, computer readable media may not be electrical carrier signals and telecommunications signals.

In the foregoing embodiments, the description of each embodiment has its own emphasis. For parts that are not described or described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

In the embodiments provided in this application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units. Or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that: it can still be used for the above-mentioned implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the application, and should be included in the within the scope of protection of this application.

Claims (10)

1. A time synchronization method, characterized in that, applied to a control system, the control system comprising a first control unit and at least one second control unit, the method comprising: The first control unit sends the first standard time to the second control unit through the first communication method, and records the first sending time; After receiving the first standard time, the second control unit returns the first feedback information to the first control unit through the first communication method; After receiving the first feedback information, the first control unit calculates the first control unit and the second control unit according to the first transmission time and the first reception time when the first feedback information is received the first delay time between units, and send the first delay time and the current second standard time to the second control unit through the first communication method; After receiving the first delay time and the second standard time, the second control unit corrects the current time of the second control unit according to the first delay time and the second standard time to obtain the first delay time and the second standard time. a calibration time. 2. The time synchronization method according to claim 1, wherein after the second control unit receives the first delay time and the second standard time, according to the first delay time and the second standard time The second standard time corrects the current time of the second control unit to obtain the first corrected time, including: After receiving the first delay time and the second standard time, the second control unit calculates the first theoretical time according to the current first actual time and the first delay time of the second control unit; If the time difference between the first theoretical time and the second standard time is within a preset range, the second control unit corrects the second control unit according to the first delay time and the second standard time The current time is obtained to obtain the first correction time. 3. The time synchronization method according to claim 1 or 2, wherein the first correction time is obtained by correcting the current time of the second control unit according to the first delay time and the second standard time Afterwards, the method further includes: The second control unit sends the first correction time to the first control unit through the first communication method; After receiving the first correction time, the first control unit updates the delay time between the first control unit and the second control unit to obtain a second delay time, and uses the first communication method sending the second delay time and the current third standard time to the second control unit; After receiving the second delay time and the third standard time, the second control unit corrects the current time of the second control unit according to the second delay time and the third standard time to obtain the first 2. Calibration time. 4. The time synchronization method according to claim 2, wherein after calculating the first theoretical time according to the current first actual time of the second control unit and the first delay time, the method further comprises: : If the time difference between the first theoretical time and the second standard time is not within a preset range, the second control unit returns an uncorrected identifier to the first control unit through the first communication method; If the first control unit receives the uncorrected identifier within the preset time or does not receive the information from the second control unit within the preset time, send the current fourth standard time through the second communication method to the second control unit, and record the second sending time; After receiving the fourth standard time, the second control unit returns second feedback information to the first control unit through the second communication method; After receiving the second feedback information, the first control unit calculates the first control unit and the second control unit according to the second transmission time and the second reception time when the second feedback information is received the third delay time between units, and send the third delay time and the current fifth standard time to the second control unit through the second communication method; After receiving the third delay time and the fifth standard time, the second control unit corrects the current time of the second control unit according to the third delay time and the fifth standard time. 5. The time synchronization method according to claim 4, wherein after the second control unit receives the third delay time and the fifth standard time, according to the third delay time and the fifth standard time The fifth standard time corrects the current time of the second control unit, including: After receiving the third delay time and the fifth standard time, the second control unit calculates a second theoretical time according to the current second actual time and the third delay time of the second control unit; If the time difference between the second theoretical time and the fifth standard time is within a preset range, the second control unit corrects the second control unit according to the third delay time and the fifth standard time The current time, get the third correction time; If the time difference between the second theoretical time and the fifth standard time is not within a preset range, the second control unit reports preset fault information. 6. The time synchronization method according to claim 4, wherein the second feedback information comprises a first processing time when the second control unit processes the fourth standard time; After receiving the second feedback information, the first control unit calculates the first control unit and the second control unit according to the second transmission time and the second reception time when the second feedback information is received A third delay time between cells, including: After the first control unit receives the second feedback information, the first control unit calculates the third delay according to the second sending time, the first processing time and the second receiving time time. 7. The time synchronization method according to claim 1, wherein after the second control unit receives the first delay time and the second standard time, according to the first delay time and the second standard time The second standard time corrects the current time of the second control unit, and after obtaining the first correction time, the method further includes: When the number of times the first control unit calculates the delay time between the first control unit and the second control unit reaches N times, the first control unit calculates the average delay according to the latest calculated delay time N times time, and send the average delay time and the current sixth standard time to the second control unit through the first communication method; After receiving the average delay time and the sixth standard time, the second control unit corrects the current time of the second control unit according to the average delay time and the sixth standard time to obtain a fourth correction time. 8. A control system, characterized in that the control system comprises a first control unit and at least one second control unit, wherein: The first control unit is configured to send the first standard time to the second control unit through a first communication method, and record the first sending time; The second control unit is configured to return the first feedback information to the first control unit through the first communication method after receiving the first standard time; The first control unit is configured to, after receiving the first feedback information, calculate the first control unit and the the first delay time between two control units, and send the first delay time and the current second standard time to the second control unit through the first communication method; The second control unit is configured to correct the current time of the second control unit according to the first delay time and the second standard time after receiving the first delay time and the second standard time, Get the first correction time. 9. A terminal device, comprising a memory, a processor and a computer program stored in the memory and running on the processor, wherein the processor implements the computer program as claimed in the claims when executing the computer program The method of any one of 1 to 7. 10 . A computer-readable storage medium storing a computer program, wherein the computer program implements the method according to any one of claims 1 to 7 when the computer program is executed by a processor. 11 .

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