Method and device for verifying vehicle-mounted clock synchronization system
By connecting to GNSS and using the clock synchronization module to time the synchronized unit in the vehicle, the problem of verification of on-board clock synchronization system is solved, and effective verification of time synchronization in the vehicle's entire domain architecture is achieved.
Patent Information
- Application Number
- CN202311059184.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-22
- Publication Date
- 2025-02-25
AI Technical Summary
There is a lack of effective methods in the prior art to verify whether the on-board clock synchronization system can truly achieve time synchronization within the vehicle's entire domain architecture.
By connecting to the Global Navigation Satellite System (GNSS), each synchronized unit is assigned to time by using the clock synchronization module to synchronize them to the absolute clock source, and by jumping the time of the clock synchronization module, whether each synchronized unit is synchronized with the clock synchronization module is determined based on the generated timestamp information.
It realizes efficient verification of whether multiple sensors and domain controllers of the vehicle are synchronized, without changing the initial configuration and synchronization protocol of vehicle components, and is low-cost and easy to deploy.
Smart Images
Figure CN119519870A_ABST
Abstract
Description
Technical Field
[0001] In general, the present invention relates to vehicle time synchronization technology, and more particularly, to a method and apparatus for verifying a vehicle-mounted clock synchronization system. Background Art
[0002] With the continuous development of technology, vehicles are equipped with various types of sensors, such as cameras, millimeter wave radars, ultrasonic radars, lidars, etc. In addition, vehicles are also equipped with multiple domain controllers, such as cockpit domain, power domain, body domain, chassis domain, etc. In the autonomous driving scenario, the multiple sensors and domain controllers of the vehicle each use built-in hardware clocks, and there may be deviations between different hardware times. If the acquisition time of the data from each sensor is not synchronized, data fusion cannot be performed correctly for decision planning; if the time between the sensor and the domain controller is not synchronized, the planned decision cannot be executed correctly. In addition to autonomous driving, various domain-related functions also require clock synchronization within the global architecture, such as real-time streaming rearview mirror display, real-time information interaction between vehicles and roadside units, etc. Therefore, it is crucial to achieve clock synchronization of multiple sensors and domain controllers of the vehicle.
[0003] In the prior art, the Global Navigation Satellite System (GNSS) is usually used as the absolute clock source. The vehicle-mounted clock synchronization module is connected to the GNSS, and the timing of sensors and domain controllers is achieved based on the pulse per second signal PPS and NMEA instructions or the Precision Time Protocol (PTP). However, there is a lack of effective methods to verify whether the vehicle-mounted clock synchronization system can truly achieve time synchronization within the vehicle's global architecture. Summary of the invention
[0004] In order to achieve clock synchronization between various sensors and domain controllers in the vehicle global architecture, an on-board clock synchronization module connected to the global navigation satellite system (GNSS) can be used to provide time for each synchronized unit so that they are synchronized to the absolute clock source. Clock synchronization in the vehicle global architecture is subject to many factors, such as the performance of the on-board clock synchronization module, the connection between the on-board clock synchronization module and the synchronized unit, etc. It is necessary to confirm whether the on-board clock synchronization system is working properly so that the synchronized unit can be correctly synchronized to the absolute clock source.
[0005] It is desirable to provide a method and apparatus for verifying a vehicle-mounted clock synchronization system, which does not require changes to the initial configuration of vehicle components and the synchronization protocol used, is low-cost and easy to deploy in terms of applicability, and can efficiently verify whether multiple sensors and domain controllers of the vehicle are synchronized.
[0006] According to one aspect of the present invention, a method for verifying a vehicle-mounted time synchronization system is provided, wherein the vehicle-mounted time synchronization system includes a clock synchronization module and at least one synchronized unit, and the method includes: setting the clock synchronization module to a first time value at a first moment; setting the clock synchronization module to a second time value at a second moment; obtaining first timestamp information of the clock synchronization module and second timestamp information of the at least one synchronized unit generated during a jump from the first time value to the second time value; and comparing the first timestamp information with the second timestamp information to determine whether the at least one synchronized unit is synchronized with the clock synchronization module.
[0007] According to another aspect of the present invention, a system for verifying a vehicle-mounted time synchronization system is provided, comprising: a memory; and a processor. The processor is coupled to the memory and configured to enable one or more units to execute any one of the methods according to various embodiments of the present invention.
[0008] According to yet another aspect of the present invention, a computer readable medium is provided, which stores a computer program including instructions, which, when executed by a control unit, cause one or more units to perform the method according to any one of the various embodiments of the present invention.
[0009] According to yet another aspect of the present invention, a vehicle is provided, which includes one or more units for executing the method according to any one of the various embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Various embodiments of the claimed subject matter will now be described by way of example with reference to the accompanying drawings. In the different drawings, the same reference numerals are used to denote the same or similar components.
[0011] Figure 1 FIG. 1 is a block diagram of a vehicle-mounted time synchronization system 100 according to an embodiment of the present invention.
[0012] Figure 2 A flow chart of a method 200 for verifying an in-vehicle time synchronization system according to an embodiment of the present invention is shown.
[0013] Figure 3 A block diagram of a device 300 for verifying an in-vehicle time synchronization system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION
[0014] In the following description, many specific details are set forth to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the present invention can be practiced without one or more of the specific details, or alternative methods, components, etc. can be used to practice the present invention. In some instances, well-known structures and operations are not shown or described in detail to avoid unnecessarily obscuring the present invention.
[0015] It should be understood that the term "vehicle" or other similar terms used herein include general motor vehicles, such as passenger cars (including sports utility vehicles, buses, trucks, etc.), various commercial vehicles, etc., and include hybrid vehicles, electric vehicles, etc. "Based on" used herein means "at least based on", rather than "only based on". "Connected" used herein should be understood to include "directly connected", "indirectly connected" or a combination thereof, and include "wired connection", "wireless connection" or a combination thereof.
[0016] Figure 1 FIG. 1 is a block diagram of a vehicle-mounted time synchronization system 100 according to an embodiment of the present invention. Figure 1 As shown, the vehicle-mounted time synchronization system 100 may include a clock synchronization module 101 and one or more synchronized units 103-1 to 103-N. The clock synchronization module 101 is connected to one or more synchronized units 103-1 to 103-N.
[0017] In one embodiment, the clock synchronization module 101 can be any applicable device or unit in the art that has the function of receiving a clock signal from a clock source and providing time to the synchronized unit, for example, a device or unit that supports various time synchronization protocols such as the pulse per second signal PPS and NMEA instructions or the Precision Time Protocol (PTP), or another example, a device or unit that supports communication protocols such as a CAN bus, a LIN bus, or a PCI-E bus.
[0018] In one embodiment, the synchronized units 103-1 to 103-N may be sensors or controllers in the vehicle that need to be synchronized to a unified clock source, including but not limited to: cameras, millimeter-wave radars, ultrasonic radars, lidars, etc.; electronic control units (ECUs), such as cockpit domain controllers, power domain controllers, body domain controllers, chassis domain controllers, etc.; vehicle clocks, etc.
[0019] like Figure 1 As further shown, the vehicle-mounted time synchronization system 100 may also include a global navigation satellite system (GNSS) 102 , wherein the clock synchronization module 101 is connected to the GNSS 102 .
[0020] In one embodiment, the clock synchronization module 101 may be directly connected to the GNSS 102 .
[0021] In another embodiment, the GNSS 102 is installed together with an inertial measurement unit (IMU) 104 as part of a vehicle-mounted integrated navigation system. In this embodiment, the GNSS 102 can be directly connected to the IMU 104, and the clock synchronization module 101 can be connected to the IMU 104 to receive a clock signal from the GNSS 102. In other embodiments, the GNSS 102 can be installed together with other applicable units in the art, in which embodiment, the GNSS 102 can be directly connected to the applicable unit, and the clock synchronization module 101 can be connected to the applicable unit to receive a clock signal from the GNSS 102.
[0022] The following will be combined Figure 1 A block diagram is used to describe a method for verifying a vehicle-mounted time synchronization system according to an embodiment of the present invention.
[0023] Under normal working conditions, GNSS 102 can be used as a unified clock source to grant time to one or more synchronized units 103-1 to 103-N through the clock synchronization module 101, and each synchronized unit 103-1 to 103-N adds timestamp information to the data independently collected according to the synchronized own time. The applicant notes that since each synchronized unit 103-1 to 103-N may have a delay, it is impossible to directly verify whether each synchronized unit 103-1 to 103-N is truly synchronized to the unified clock source. To this end, it is necessary to make the time of the clock synchronization module 101 jump, and determine whether they are synchronized with each other based on the timestamp information generated at the clock synchronization module 101 and the synchronized units 103-1 to 103-N during the time period when the jump occurs.
[0024] In one aspect of the present invention, the time jump may be caused by setting the clock synchronization module 101 to a first time value at a first moment and setting the clock synchronization module 101 to a second time value at a second moment.
[0025] For example, the time of the clock synchronization module 101 can be set to "1990.01.01.00:00:00" at the first moment, and the clock synchronization module 101 starts to use the timestamp information to grant time to one or more synchronized units 103-1 to 103-N. After a period of time, the time of the clock synchronization module 101 can be set to "2010.01.01.00:00:00" at the second moment, so that the clock synchronization module 101 jumps to the timestamp information to grant time to one or more synchronized units 103-1 to 103-N. Among them, the specific value of the time is only an example and does not limit the scope of the present invention. It can be understood by those skilled in the art that the above-mentioned "setting" operation can be implemented by software, hardware or a combination thereof, for example, the time information of the clock synchronization module 101 is changed in any applicable programming language.
[0026] For another example, before the vehicle-mounted time synchronization system is powered on, the connection between the clock synchronization module 101 and the GNSS 102 may be blocked, and then the vehicle-mounted time synchronization system may be powered on. Since the connection between the clock synchronization module 101 and the GNSS 102 is blocked, the clock synchronization module 101 cannot receive a valid clock signal, and after powering on, it can only provide time to one or more synchronized units 103-1 to 103-N with a default timestamp (e.g., "1980.01.01.00:00:00"). In one embodiment, the default timestamp information may be derived from the initial settings of the clock synchronization module 101. In another embodiment, the default timestamp information may be derived from the initial settings of the IMU 104, and is sent to the clock synchronization module 101 by the IMU 104 when it is unable to receive a valid clock signal from the GNSS 102. After a period of time, the connection between the clock synchronization module 101 and the GNSS 102 can be restored, so that the clock synchronization module 101 receives a valid current clock signal (for example, "2023.07.01.15:30:26"), jumps to the timestamp information and grants time to one or more synchronized units 103-1 to 103-N. In one embodiment, the current clock signal is directly received by the clock synchronization module 101 from the GNSS 102. In another embodiment, the current clock signal is received by the IMU 104 from the GNSS 102 and sent to the clock synchronization module 101. The specific value of the time is only an example and does not limit the scope of the present invention.
[0027] In one embodiment, blocking the connection between the clock synchronization module 101 and the GNSS 102 can be achieved by physical means, such as using a metal mask to block the GNSS to shield its signal, or removing the connection between the clock synchronization module and the GNSS. This method is easy to operate and low-cost. In another embodiment, blocking the connection between the clock synchronization module 101 and the GNSS 102 can be achieved by software, such as controlling the clock synchronization module to ignore information from the GNSS in any applicable programming language. This method is convenient for periodic execution. In another embodiment, blocking the connection between the clock synchronization module 101 and the GNSS 102 can be achieved by hardware, such as by accessing a signal shielding circuit to shield the GNSS signal. In other embodiments, blocking the connection between the clock synchronization module 101 and the GNSS 102 can be achieved by a combination of the above methods.
[0028] In one aspect of the present invention, the timestamp information of the clock synchronization module 101 generated during the jump from the first time value to the second time value and the respective timestamp information of the synchronized units 103-1 to 103-N can be obtained, and the timestamp information of the clock synchronization module 101 is compared with the timestamp information of the synchronized units 103-1 to 103-N to determine whether the synchronized units 103-1 to 103-N are synchronized with the clock synchronization module 101.
[0029] For example, all timestamp information of the clock synchronization module 101 and the synchronized units 103-1 to 103-N generated during the transition from the first time value to the second time value can be obtained. When the sampling frequency of the timestamp information of the clock synchronization module 101 and the synchronized unit is consistent, it can be determined whether the synchronized unit and the clock synchronization module 101 have passed the same time length between the transition from the first time value to the second time value by comparing the number of entries of the timestamp information of the clock synchronization module 101 and the synchronized unit. Further, the timestamp information of the clock synchronization module 101 and the synchronized unit can be compared one by one to see whether they are the same. It can be determined that the synchronized unit is synchronized with the clock synchronization module based on the same number of entries and / or timestamp information of the timestamp information of the clock synchronization module 101 and the synchronized unit.
[0030] For another example, in order to reduce information overhead, only part of the timestamp information of the clock synchronization module 101 and the synchronized units 103-1 to 103-N generated during the transition from the first time value to the second time value may be obtained, and the part of the timestamp information at least includes the most recent timestamp information before the transition from the first time value to the second time value. It may be determined that the synchronized unit is synchronized with the clock synchronization module based at least on the difference between the most recent timestamp information of the clock synchronization module 101 and the synchronized unit before the transition to the second time value being lower than a threshold value.
[0031] In one embodiment, the first time value of the clock synchronization module 101 is set to "1980.01.01.00:00:00", and after a period of time, it is set to the second time value "2023.07.01.15:30:26" at "1980.01.01.00:01:31". The time stamp information from the clock synchronization module 101 has a step size of 1 millisecond, and the most recent time stamp information before the time jump indicates that the clock synchronization module 101 jumps from "1980.01.01.00:01:30.386" to "2023.07.01.15:30:26.000" (three decimal places represent milliseconds). The time stamp information step size from the synchronized unit 103-1 is 1 millisecond, and the most recent time stamp information before the time jump indicates that the synchronized unit 103-1 jumps from "1980.01.01.00:01:30.393" to "2023.07.01.15:30:26.000" (the three decimal places represent milliseconds). The time stamp information step size from the synchronized unit 103-2 is 5 milliseconds, and the most recent time stamp information before the time jump indicates that the synchronized unit 103-2 jumps from "1980.01.01.00:01:29.080" to "2023.07.01.15:30:26.000" (the three decimal places represent milliseconds). The threshold value of the difference between the timestamps can be set to 500 milliseconds, and it can be determined that the synchronized unit 103-1 is synchronized with the clock synchronization module 101, while the synchronized unit 103-2 fails to synchronize with the clock synchronization module 101. The specific values of the time are only examples and do not limit the scope of the present invention. It can be understood by those skilled in the art that the above-mentioned "obtaining", "comparing" and / or "determining" operations can be implemented by software, hardware or a combination thereof.
[0032] In one aspect of the present invention, the method for verifying the vehicle-mounted time synchronization system described above can be periodically executed, and the verification results can be displayed. In one embodiment, when it is detected that a synchronized unit fails to synchronize with the clock synchronization module, a reminder or error message is displayed. It can be understood by those skilled in the art that the above-mentioned "display" operation can be implemented by software, hardware or a combination thereof. Through the method disclosed in the present application, it is possible to efficiently verify whether multiple sensors and domain controllers of the vehicle are synchronized without changing the initial configuration of the vehicle components and the synchronization protocol adopted.
[0033] Figure 2A flow chart of a method 200 for verifying a vehicle-mounted time synchronization system according to an embodiment of the present invention is shown. The vehicle-mounted time synchronization system includes a clock synchronization module and at least one synchronized unit. The synchronized unit includes, but is not limited to: a camera, a millimeter wave radar, an ultrasonic radar, a laser radar; an electronic control unit (ECU), such as a cockpit domain controller, a power domain controller, a body domain controller, a chassis domain controller, etc.; a vehicle clock, etc.
[0034] In step S210, the clock synchronization module is set to a first time value at a first moment.
[0035] In one embodiment, the time information of the clock synchronization module may be set by software, hardware or a combination thereof.
[0036] In another embodiment, the clock synchronization module can be connected to the GNSS. Before the vehicle-mounted time synchronization system is powered on, the connection between the clock synchronization module and the GNSS can be blocked so that the clock synchronization module is set to a default time value. The connection between the clock synchronization module and the GNSS can be blocked by physical, software, hardware or a combination thereof.
[0037] In step S220, the clock synchronization module is set to a second time value at a second moment.
[0038] In one embodiment, the time information of the clock synchronization module may be set by software, hardware or a combination thereof.
[0039] In another embodiment, the clock synchronization module can be connected to the GNSS. After the vehicle-mounted time synchronization system is powered on, the connection between the clock synchronization module and the GNSS can be restored so that the clock synchronization module is set to the current time value. The connection between the clock synchronization module and the GNSS can be restored by physical, software, hardware or a combination thereof.
[0040] In step S230, first timestamp information of the clock synchronization module and second timestamp information of the at least one synchronized unit generated during a period from the first time value to the second time value are obtained.
[0041] In one embodiment, all timestamp information of the clock synchronization module and the synchronized unit generated during the transition from the first time value to the second time value can be obtained. The timestamp information can be obtained by software, hardware or a combination thereof.
[0042] In another embodiment, partial timestamp information of the clock synchronization module and the synchronized unit generated during the transition from the first time value to the second time value can be obtained, and the partial timestamp information at least includes the most recent timestamp information before the transition from the first time value to the second time value. The timestamp information can be obtained by software, hardware, or a combination thereof.
[0043] In step S240, the first timestamp information is compared with the second timestamp information to determine whether the at least one synchronized unit is synchronized with the clock synchronization module.
[0044] In one embodiment, it can be determined that at least one synchronized unit is synchronized with the clock synchronization module based on the fact that the number of entries of all timestamp information generated by the clock synchronization module during the transition from the first time value to the second time value is equal to the number of entries of all timestamp information generated by at least one synchronized unit during the transition from the first time value to the second time value; and / or all timestamp information of the clock synchronization module is the same as each of the timestamp information in all timestamp information of at least one synchronized unit. The above operation can be performed by software, hardware or a combination thereof.
[0045] In another embodiment, it can be determined that at least one synchronized unit is synchronized with the clock synchronization module based on the difference between the latest timestamp information before the clock synchronization module jumps to the second time value and the latest timestamp information before the at least one synchronized unit jumps to the second time value being lower than a threshold value. The above operation can be performed by software, hardware or a combination thereof.
[0046] In an alternative embodiment, the method described with reference to Figure 200 may be performed periodically. The method may be performed periodically by software, hardware, or a combination thereof.
[0047] In an optional embodiment, a message about whether at least one synchronized unit is synchronized with the clock synchronization module may be displayed. The message may be displayed by software, hardware or a combination thereof.
[0048] Figure 3 A block diagram of a device 300 for verifying a vehicle-mounted time synchronization system according to an embodiment of the present invention is shown. In one embodiment, the device may include a control unit or auxiliary system of a vehicle, such as an electronic control unit (ECU), an electronic management unit (EMU), etc., or any suitable processing unit with computing and control capabilities installed on the vehicle. In other embodiments, the device may include a vehicle.
[0049] The example device includes a processor 303 connected to an internal communication bus 301, and the processor 303 is used to execute instructions in a memory 305 to implement the method for verifying the vehicle-mounted time synchronization system described in detail above. Examples of the processor 303 may include a central processing unit (CPU), a microcontroller, and the like. The memory 305 suitable for tangibly embodying computer program instructions and data includes various forms of memory, such as EPROM, EEPROM, and flash memory devices, etc. The device may also include an input interface 307 and an output interface 309. The input interface 307 is used to receive input signals and data, such as data from a clock synchronization module and timestamp data from a synchronized unit. The output interface 309 is used to send output signals and data, such as various commands or signaling for timing the synchronized unit.
[0050] The computer program may include instructions executable by a computer, which are used to cause the processor 303 of the device to perform the method of the present invention for verifying the vehicle-mounted time synchronization system. The program can be recorded on any data storage medium including a memory. For example, the program can be implemented in digital electronic circuits, or in computer hardware, firmware, software, or a combination thereof. The process / method steps described in the present invention can be performed by a programmable processor that executes program instructions to perform methods, steps, operations by operating on input data and generating outputs.
[0051] It should be noted that, in addition to what is described herein, various modifications may be made to the disclosed embodiments and implementations without departing from the scope of the disclosed embodiments and implementations. Therefore, the descriptions and examples herein should be interpreted as illustrative rather than limiting. The scope of the present invention should be measured only by reference to the claims.
Claims
1. A method for verifying a vehicle-mounted time synchronization system, wherein: The vehicle-mounted time synchronization system includes a clock synchronization module and at least one synchronized unit, and the method includes: Setting the clock synchronization module to a first time value at a first moment; At a second moment, the clock synchronization module is set to a second time value; Obtaining first timestamp information of the clock synchronization module and second timestamp information of the at least one synchronized unit generated during a period from the first time value to the second time value; and The first timestamp information is compared with the second timestamp information to determine whether the at least one synchronized unit is synchronized with the clock synchronization module.
2. The method according to claim 1, wherein: The clock synchronization module is connected to a global satellite navigation system (GNSS); Wherein, setting the clock synchronization module to the first time value at the first moment includes: before the vehicle-mounted time synchronization system is powered on, blocking the connection between the clock synchronization module and the GNSS; and The step of setting the clock synchronization module to the second time value at the second moment includes: after the vehicle-mounted time synchronization system is powered on, restoring the connection between the clock synchronization module and the GNSS.
3. The method according to claim 1, comparing the first timestamp information with the second timestamp information to determine whether the at least one synchronized unit is synchronized with the clock synchronization module, comprising: It is determined whether a difference between the latest timestamp information of the clock synchronization module before the jump to the second time value and the latest timestamp information of the at least one synchronized unit before the jump to the second time value is lower than a threshold value.
4. The method according to claim 1, comparing the first timestamp information with the second timestamp information to determine whether the at least one synchronized unit is synchronized with the clock synchronization module, comprising: Determine whether the number of entries of all timestamp information generated by the clock synchronization module during the period from the first time value to the second time value is equal to the number of entries of all timestamp information generated by the at least one synchronized unit during the period from the first time value to the second time value; and / or It is determined whether all the timestamp information of the clock synchronization module is identical to each piece of timestamp information of all the timestamp information of the at least one synchronized unit.
5. The method according to claim 1, further comprising: A message is displayed regarding whether the at least one synchronized unit is synchronized with the clock synchronization module.
6. The method according to claim 1, wherein: The at least one synchronized unit includes one or more of the following: a lidar, an ultrasonic radar, a millimeter-wave radar, a camera, a domain controller and / or a vehicle clock.
7. A system for verifying a vehicle-mounted time synchronization system, comprising: Memory; A processor is coupled to the memory, wherein the processor is configured to cause one or more units to perform the method according to any one of claims 1-6.
8. A computer readable medium storing a computer program comprising instructions which, when executed by a processor, cause one or more units to perform the method according to any one of claims 1 to 6.
9. A vehicle comprising one or more units for performing the method according to any one of claims 1-6.