CN111106891A - Relative time synchronization method, device and system - Google Patents
Relative time synchronization method, device and system Download PDFInfo
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- CN111106891A CN111106891A CN201910582608.2A CN201910582608A CN111106891A CN 111106891 A CN111106891 A CN 111106891A CN 201910582608 A CN201910582608 A CN 201910582608A CN 111106891 A CN111106891 A CN 111106891A
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- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
- H04J3/0667—Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays
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- H—ELECTRICITY
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Abstract
The invention relates to the field of radio navigation and communication, and discloses a relative time synchronization method, relative time synchronization equipment and a relative time synchronization system. A method of relative time synchronization, comprising: the two time synchronization nodes A and B transmit time synchronization signals to each other, receive the time synchronization signals from each other, acquire the sending time and the receiving time of the respective signals, and complete the calculation of the relative time difference offset of the two time synchronization nodes, wherein the time synchronization signals are transmitted on a designated carrier channel in a wired transmission medium and a wireless mode, and the time measurement and information transmission functions are realized at the same time; and further adjusting the clock of A or B according to the acquired relative clock offset. The embodiment of the invention can quickly realize the time synchronization among all devices needing synchronization in the whole network, and can greatly reduce the difficulty of networking and implementation by transmitting through the existing transmission medium or a wireless mode.
Description
Technical Field
The present invention relates to the field of radio navigation, and in particular, to a method, device, and system for synchronizing relative time.
Background
Communication systems, navigation systems, and in particular indoor navigation systems, place significant demands on time synchronization. The time synchronization scheme applied to the existing system is a GNSS time synchronization scheme, each communication base station or navigation base station is provided with a GNSS device, GNSS time is provided for each base station, and therefore time synchronization among multiple base stations is achieved. However, it is not practical for indoor communication base stations and indoor navigation base stations, because GNSS signals cannot cover the indoor space, a large number of cables need to be laid for configuring GNSS equipment for each base station, which brings great inconvenience to construction and is high in cost; in addition, not all navigation systems and communication systems need absolute time synchronization, and more importantly, a uniform time relationship, i.e., relative time synchronization, is established between each navigation signal transmitting base station and each communication signal transmitting base station in the system.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a relative time synchronization method, device and system, which solve the problem of time synchronization between a communication system base station and a navigation base station and solve the problems of inconvenient installation and no GNSS signal in the existing scheme.
The invention provides a relative time synchronization method, relative time synchronization equipment and a relative time synchronization system, which are realized as follows:
a method of synchronizing relative time, comprising the steps of:
s1: in the nth time synchronization beat, the clock synchronization node A transmits a time synchronization signal A (n) to the time synchronization node B at the time Ta (n) through a carrier channel A in a wired transmission medium or wireless mode, the time synchronization signal A (n) carries communication information, including but not limited to the transmitting time Ta (n), the receiving time Tar (n-1) when the n-1 th clock synchronization beat time synchronization node A receives the time synchronization signal B (n-1), and the clock synchronization node A records the transmitting time information;
in the nth time synchronization beat, the clock synchronization node B transmits a time synchronization signal B (n) to the time synchronization node A at Tb (n) through a carrier channel B by using a wired transmission medium or a wireless mode, the time synchronization signal B (n) carries communication information, including but not limited to transmitting time Tb (n), receiving time Tbr (n-1) when the n-1 th clock synchronization beat time synchronization node B receives the time synchronization signal A (n-1), and simultaneously the clock synchronization node B records the transmitting time information;
in order to avoid loss of generality, n is 0 as an initial time synchronization beat, Tbr (-1) and Tar (-1) are invalid values, and a (-1) and B (-1) are invalid synchronization signals.
S2: the time synchronization node B receives a time synchronization signal A (n) sent by the time synchronization node A, obtains the arrival time Tbr (n) of the time synchronization signal A (n), the transmitting time Ta (n) of the time synchronization signal, and receives the receiving time Tar (n-1) of the time synchronization signal B (n-1) at the (n-1) th clock synchronization beat;
the time synchronization node A receives a time synchronization signal B (n) sent by the time synchronization node B, obtains the arrival time tar (n) of the time synchronization signal B (n), the transmitting time Tb (n) of the time synchronization signal, and the receiving time Tbr (n-1) of the time synchronization signal A (n-1) received by the n-1 th clock synchronization beat of the time synchronization node B;
s3: for the time synchronization beat n (n >0), the time synchronization node a and the time synchronization node B may calculate the time difference between the time synchronization node a and the time synchronization node B according to the Ta (n-1), the Tar (n-1), the Tb (n-1), and the Tbr (n-1), and adjust one clock of the time synchronization node a or the time synchronization node B to achieve synchronization of the two.
S4: the steps S1, S2, and S3 are repeated to perform time synchronization of the (n + 1) th beat, and time synchronization of the nth time is performed.
Further, in step S1, the time interval between two adjacent clock synchronization ticks n, n +1 is controllable.
Further, in S1, the wired transmission medium includes a coaxial cable, a power line, and an optical fiber.
Further, in step S1, the carrier channel a and the carrier channel B may be the same frequency or different frequencies.
Further, in step S4, the frequency synchronization between the inter-synchronization node a and the time synchronization node B can be further achieved by time synchronization a plurality of times.
The invention also provides time synchronization equipment which is characterized by comprising a clock module, a processing module, a clock synchronization signal generating module, a time synchronization signal processing module, a transmitting module and a receiving module which are connected with each other. The clock module is responsible for providing time and frequency required by the operation of the time synchronization equipment and adjusting the local time and frequency after the time synchronization is finished. And the clock synchronization signal generation module completes generation of the time synchronization signal to be sent. The transmitting module modulates the time synchronization signal generated by the clock synchronization signal generating module and transmits the modulated time synchronization signal to other time synchronization nodes in a carrier channel through a wired transmission medium or a wireless mode. The receiving module receives the time synchronization signals transmitted in the carrier channel from other time synchronization nodes through a wired transmission medium or a wireless mode, and completes related frequency conversion and signal power adjustment work. The time synchronization signal processing module completes the demodulation of the time synchronization signal output by the receiving module and the measurement of the arrival time. The processing module is responsible for completing data preparation and control of the time synchronization signal generation module and data acquisition and control of the time synchronization signal processing module; the time difference calculation between the time synchronization node and other time synchronization nodes is completed according to the acquired data, and the frequency and/or the time difference of the clock module are adjusted according to the system requirements, so that the relative time synchronization is completed; after the relative time synchronization is completed, the time synchronization device may provide the time frequency information to other devices, including the navigation device, the communication device.
Furthermore, the processing module can be connected with a time synchronization server through the Internet to realize network time service.
Furthermore, the clock module can be connected with an external GNSS time service device to complete the synchronization with the GNSS time.
The invention also provides a relative time synchronization system, which comprises at least two time synchronization devices, wherein a plurality of time synchronization nodes form a star network, a bus network, a daisy chain network or a mixed network of the three networks; at least one time synchronization device can be set in the network as a master device, and all other devices are directly or indirectly synchronized with the master device.
Further, the master node may be connected to a GNSS time service device or an NTP server to provide an absolute time reference.
Compared with the prior art, the invention has the advantages that: the data transmission flow among the time synchronization nodes is simplified; the time synchronization can be realized through a wired transmission medium or a wireless mode, when the wired transmission medium is used, the time synchronization of the whole communication and navigation network can be completed through transmitting a time synchronization signal through a power line, and the construction difficulty can be greatly reduced; by connecting the GNSS time service equipment or the NTP server to one time synchronization node, absolute time synchronization can be realized on the basis of relative time synchronization, and the networking cost of the system is reduced.
Drawings
Fig. 1 is an information interaction flowchart of an embodiment of a relative time synchronization method according to the present invention;
FIG. 2 is a schematic diagram of an embodiment of a time synchronization apparatus according to the present invention;
fig. 3 is a schematic diagram of another embodiment of the time synchronization apparatus according to the embodiment of the present invention;
FIG. 4 is a schematic diagram of an embodiment of a time synchronization system according to the present invention;
FIG. 5 is a schematic diagram of another embodiment of the time synchronization system according to the embodiment of the present invention;
fig. 6 is a schematic diagram of another embodiment of the time synchronization system according to the embodiment of the invention. .
Detailed Description
The embodiment of the invention provides a relative time synchronization method, relative time synchronization equipment and a relative time synchronization system.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
The invention will be described in further detail below with reference to the drawings and specific examples.
Fig. 1 is an information interaction flowchart of an embodiment of a relative time synchronization method according to an embodiment of the present invention, where a time synchronization node a and a time synchronization node B both transmit a time synchronization signal to an opposite side and receive a time synchronization signal from the opposite side, and calculating a relative time difference between the time nodes a and B requires at least two adjacent beats to complete, where n is 1 and 0 th beat is an initial time synchronization beat, so as not to lose generality, fig. 1 includes:
at beat 0: the time synchronization node A transmits a synchronization signal A (0) to a time synchronization node B at a transmitting moment Ta (0), receives the synchronization signal B (0) from the time synchronization node B at a Tar (0) moment, acquires the transmitting moment Tb (0) of the transmitting time synchronization signal B (0) and the receiving time Tbr (-1) of the time synchronization node of the previous beat, and the Tbr (-1) is an invalid value because the A (-1) signal does not exist; when the 0 th beat is finished, the valid data acquired by the time synchronization node a includes Ta (0), Tar (0), and Tb (0). The time synchronization node B transmits a synchronization signal B (0) to the time synchronization node A at a transmission time Tb (0), receives the synchronization signal A (0) from the time synchronization node A at a Tbr (0), and acquires the transmission time Ta (0) of the transmission time synchronization signal A (0) and the receiving time Tar (-1) of the time synchronization node of the previous beat, wherein the Tar (-1) is an invalid value because the B (-1) signal does not exist; when the 0 th beat is finished, the valid data acquired by the time synchronization node B includes Tb (0), Tbr (0), and Ta (0).
At beat 1: the time synchronization node A transmits a synchronization signal A (1) to a time synchronization node B at a transmitting time Ta (1), receives the synchronization signal B (1) from the time synchronization node B at a Tar (1) time, and acquires the transmitting time Tb (1) of the transmitting time synchronization signal B (1) and the receiving time Tbr (0) of the time synchronization node of the previous beat; when the 1 st beat is finished, the effective data acquired by the time synchronization node a includes Ta (0), Tar (0), Tb (0), Tbr (0), Ta (1), Tar (1), and Tb (1) in combination with the data of the 0 th beat. The time synchronization node B transmits a synchronization signal B (1) to the time synchronization node A at a transmission time Tb (1), receives the synchronization signal A (1) from the time synchronization node A at a Tbr (1), and obtains the transmission time Ta (1) of the transmission time synchronization signal A (1) and the receiving time Tar (0) of the time synchronization node of the previous beat; when the 1 st beat is finished, the effective data acquired by the time synchronization node B comprises Tb (0), Tbr (0), Ta (0), Tar (0), Tb (1), Tbr (1) and T in combination with the data of the 0 th beata (1); the time difference of the time synchronization node A, B is
At beat 2: the time synchronization node A transmits a synchronization signal A (2) to a time synchronization node B at a transmitting time Ta (2), receives the synchronization signal B (2) from the time synchronization node B at a Tar (2) time, and acquires the transmitting time Tb (2) of the transmitting time synchronization signal B (2) and the receiving time Tbr (1) of the time synchronization node of the previous beat; when the 1 st beat is finished, the effective data acquired by the time synchronization node a includes Ta (1), Tar (1), Tb (1), Tbr (1), Ta (2), Tar (2), and Tb (2) in combination with the data of the 1 st beat. The time synchronization node B transmits a synchronization signal B (2) to the time synchronization node A at a transmission time Tb (2), receives the synchronization signal A (2) from the time synchronization node A at a Tbr (2), and obtains the transmission time Ta (2) of the transmission time synchronization signal A (2) and the receiving time Tar (1) of the time synchronization node of the previous beat; when the 2 nd beat is finished, combining the data of the 1 st beat, the effective data acquired by the time synchronization node B comprises Tb (1), Tbr (1), Ta (1), Tar (1), Tb (2), Tbr (2) and Ta (2); the time difference of the time synchronization node A, B is
Analogizing the subsequent beats once, and for the nth beat, the time synchronization node A transmits a synchronization signal A (n) to the time synchronization node B at the transmitting time Ta (n), receives a synchronization signal B (n) from the time synchronization node B at the time tar (n), and obtains the transmitting time Tb (n) of the transmitting time synchronization signal B (n) and the receiving time Tbr (n-1) of the time synchronization node of the previous beat; when the nth beat is finished, the effective data acquired by the time synchronization node A comprises Ta (n-1), Tar (n-1), Tb (n-1), Tbr (n-1), Ta (n), Tar (n) and Tb (n) by combining with the data of the nth-1 beat. The time synchronization node B transmits a synchronization signal B (n) to the time synchronization node A at a transmission time Tb (n), receives the synchronization signal A (n) from the time synchronization node A at a Tbr (n), and obtains the transmission time Ta (n) of the transmission time synchronization signal A (n) and the receiving of the time synchronization node of the previous beatTime Tar (n-1); when the nth beat is finished, combining the data of the nth-1 beat, the effective data acquired by the time synchronization node B comprises Tb (n-1), Tbr (n-1), Ta (n-1), Tar (n-1), Tb (n), Tbr (n) and Ta (n); the time difference of the time synchronization node A, B is
In the present embodiment, in step S1, the time interval between two adjacent clock synchronization ticks n, n +1 is controllable. The time interval can be adjusted according to the system requirements.
In this embodiment, in step S1, the wired transmission medium includes a coaxial cable, a power line, and an optical fiber.
In this embodiment, in step S1, the carrier channel a and the carrier channel B may have the same frequency or different frequencies.
In this embodiment, in step S4, the frequency synchronization between the time synchronization node a and the time synchronization node B can be further realized by time synchronization for a plurality of times.
Fig. 2 is a schematic diagram of an embodiment of a time synchronization device according to an embodiment of the present invention, and the time synchronization device includes a clock module, a processing module, a clock synchronization signal generation module, a time synchronization signal processing module, a transmitting module, and a receiving module, which are connected to each other.
A clock module: and the system is responsible for providing the time and frequency required by the operation of the time synchronization equipment and adjusting the local time and frequency after the time synchronization is finished.
The clock synchronization signal generation module: and finishing the generation of the time synchronization signal to be transmitted.
A transmitting module: and modulating the time synchronization signal generated by the clock synchronization signal generation module and transmitting the time synchronization signal to other time synchronization nodes in a carrier channel through a wired transmission medium or a wireless mode.
A receiving module: and receiving time synchronization signals transmitted in a carrier channel from other time synchronization nodes through a wired transmission medium or a wireless mode, and finishing related frequency conversion and signal power adjustment work.
The time synchronization signal processing module: and completing the demodulation of the time synchronization signal output by the receiving module and the measurement of the arrival time.
A processing module: the data acquisition and control module is responsible for completing the data preparation and control of the time synchronization signal generation module and completing the data acquisition and control of the time synchronization signal processing module; the time difference calculation between the time synchronization node and other time synchronization nodes is completed according to the acquired data, and the frequency and/or the time difference of the clock module are adjusted according to the system requirements, so that the relative time synchronization is completed; after the relative time synchronization is completed, the time synchronization device may provide the time frequency information to other devices, including the navigation device, the communication device.
Considering the existence of time delay in the transmitting module and the receiving module of the time synchronization device, taking the time synchronization node A, B as an example, the time synchronization node a has the existence of the time delay t of the transmitting moduleaAnd time delay r of receiving moduleaTime synchronization node B has a transmit module delay tbAnd time delay r of receiving moduleb，
Then
Fig. 3 provides a schematic diagram of another embodiment of the time synchronization apparatus according to the embodiment of the present invention, and on the basis of the modules included in fig. 2, the modules include:
NTP server: the NTP server is connected with the processing module, and the time synchronization between the time synchronization node and the NTP server is completed through an NTP protocol, so that the time synchronization node and the real time complete the time synchronization from millisecond level to second level. The time synchronization server is an NTP server, and absolute time synchronization can be realized on the basis of relative time synchronization by connecting GNSS time service equipment or the NTP server on one time synchronization node, so that the networking cost of the system is reduced.
GNSS time service equipment: the GNSS time service equipment is connected with the clock module, the clock module acquires GNSS time from the GNSS time service equipment, local frequency correction is completed through a clock discipline algorithm, time and frequency synchronization with a GNSS system is achieved, and synchronization precision can reach 10ns magnitude.
The NTP server and the GNSS time service equipment are in an OR relationship, and only one time synchronization equipment is connected.
The invention also provides a relative time synchronization system, which comprises at least two time synchronization devices, wherein the time synchronization nodes form a star network, a bus network, a daisy chain network or a mixed network of the three networks; at least one time synchronization device can be set in the network as a master device, and all other devices are directly or indirectly synchronized with the master device.
Fig. 4 is a schematic diagram of an embodiment of a relative time synchronization system according to an embodiment of the present invention, which is a schematic connection diagram of a star network. In the time system, a time synchronization device A is positioned in a network center, and other network time synchronization devices 1, 2, 3 to n are respectively connected with the time synchronization device A to complete relative time synchronization with the time synchronization device A; when the time synchronization equipment A is connected with the GNSS time service equipment, the time synchronization equipment A is synchronized with the GNSS time, and the time synchronization equipment 1-n is synchronized with the time synchronization equipment A to indirectly realize the time synchronization with the GNSS; the GNSS time service equipment can be replaced by an NTP server.
Fig. 5 is a schematic diagram of another embodiment of a relative time synchronization system according to an embodiment of the invention, which is a connection schematic diagram of a bus network. In the time system, a time synchronization device A, a time synchronization device 1, a time synchronization device 2, a time synchronization device 3 and a time synchronization device n are all connected on a bus, and time synchronization can be realized between any two time synchronization devices through the bus; if the time synchronization equipment A is connected with the GNSS time service equipment, the time synchronization equipment A is synchronized with the GNSS time, and the time synchronization equipment 1-n is synchronized with the time synchronization equipment A to indirectly realize the time synchronization with the GNSS; the GNSS time service equipment can be replaced by an NTP server.
Fig. 6 is a schematic diagram of another embodiment of the relative time synchronization system according to the embodiment of the invention, which is a connection schematic diagram of a daisy chain network. Without loss of generality, the time synchronization device 1 is used as a starting node, and the time synchronization device N is used as a tail node; the time synchronization device 1 is connected with the time synchronization device 2, the time synchronization device 2 is connected with the time synchronization devices 1 and 3, the time synchronization device 3 is connected with the time synchronization devices 2 and 4, and so on, the time synchronization device N-1 is connected with the time synchronization devices N-2 and N, and the time synchronization device N is connected with the time synchronization device N-1; time synchronization equipment i +1 and time synchronization equipment i in the network are synchronized (N-1 ≧ i ≧ 1), all nodes are synchronized through synchronization between each two, namely time synchronization equipment 2 and time synchronization equipment 1 are synchronized, time synchronization equipment 3 and time synchronization equipment 2 are synchronized, and so on, time synchronization equipment N and time synchronization equipment N-1 are synchronized. In a special case, the time synchronization device N may be connected to the time synchronization device 1 to form a ring network. If the time synchronization equipment 1 is connected with the GNSS time service equipment, the time synchronization equipment 1 is time-synchronized with the GNSS, and the time synchronization equipment 2-N indirectly realize the time synchronization of all the time synchronization equipment and the GNSS through the transmission between every two time synchronization equipment; the GNSS time service equipment can be replaced by an NTP server.
In this embodiment, the master node may be connected to a GNSS timing device or an NTP server to provide an absolute time reference.
Compared with the prior art, the invention has the advantages that: the data transmission flow among the time synchronization nodes is simplified; the time synchronization can be realized through a wired transmission medium or a wireless mode, when a limited medium is used, a time synchronization signal can be transmitted through a power line, the time synchronization of the whole communication and navigation network is completed, and the construction difficulty can be greatly reduced; by connecting the GNSS time service equipment or the NTP server to one time synchronization node, absolute time synchronization can be realized on the basis of relative time synchronization, and the networking cost of the system is reduced.
The above-described embodiments of the present invention do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (10)
1. A method of relative time synchronization, characterized by:
s1: in the nth time synchronization beat, the clock synchronization node A transmits a time synchronization signal A (n) to the time synchronization node B at the time Ta (n) through a carrier channel A in a wired transmission medium or wireless mode, the time synchronization signal A (n) carries communication information, including but not limited to the transmitting time Ta (n), the receiving time Tar (n-1) when the n-1 th clock synchronization beat time synchronization node A receives the time synchronization signal B (n-1), and the clock synchronization node A records the transmitting time information;
in the nth time synchronization beat, the clock synchronization node B transmits a time synchronization signal B (n) to the time synchronization node A at Tb (n) through a carrier channel B by using a wired transmission medium or a wireless mode, the time synchronization signal B (n) carries communication information, including but not limited to transmitting time Tb (n), receiving time Tbr (n-1) when the n-1 th clock synchronization beat time synchronization node B receives the time synchronization signal A (n-1), and simultaneously the clock synchronization node B records the transmitting time information;
in order to avoid loss of generality, n is 0 as an initial time synchronization beat, Tbr (-1) and Tar (-1) are invalid values, and a (-1) and B (-1) are invalid synchronization signals.
S2: the time synchronization node B receives a time synchronization signal A (n) sent by the time synchronization node A, obtains the arrival time Tbr (n) of the time synchronization signal A (n), the transmitting time Ta (n) of the time synchronization signal, and receives the receiving time Tar (n-1) of the time synchronization signal B (n-1) at the (n-1) th clock synchronization beat;
the time synchronization node A receives a time synchronization signal B (n) sent by the time synchronization node B, obtains the arrival time tar (n) of the time synchronization signal B (n), the transmitting time Tb (n) of the time synchronization signal, and the receiving time Tbr (n-1) of the time synchronization signal A (n-1) received by the n-1 th clock synchronization beat of the time synchronization node B;
s3: for the time synchronization beat n (n >0), the time synchronization node a and the time synchronization node B may calculate the time difference between the time synchronization node a and the time synchronization node B according to the Ta (n-1), the Tar (n-1), the Tb (n-1), and the Tbr (n-1), and adjust one clock of the time synchronization node a or the time synchronization node B to achieve synchronization of the two.
S4: the steps S1, S2, and S3 are repeated to perform time synchronization of the (n + 1) th beat, and time synchronization of the nth time is performed.
2. The time synchronization method according to claim 1, wherein: in step S1, the time interval between two adjacent clock synchronization ticks n, n +1 is controlled.
3. The time synchronization method according to claim 1, wherein: in step S1, the carrier channel a and the carrier channel B have the same frequency or different frequencies.
4. The time synchronization method according to claim 1, wherein: in step S4, the inter-synchronization node a and the time synchronization node B can further perform frequency synchronization by time synchronization a plurality of times.
5. A time synchronization device is characterized by comprising a clock module, a processing module, a clock synchronization signal generating module, a time synchronization signal processing module, a transmitting module and a receiving module which are connected with each other, wherein the clock module provides time and frequency required by the operation of the time synchronization device and adjusts local time and frequency after the time synchronization is finished; the time synchronization signal processing module completes demodulation and arrival time measurement of the time synchronization signal output by the receiving module, the processing module completes data preparation and control of the time synchronization signal generating module, and data acquisition and control of the time synchronization signal processing module are completed; the time difference calculation between the time synchronization node and other time synchronization nodes is completed according to the acquired data, and the frequency and/or the time difference of the clock module are adjusted according to the system requirements, so that the relative time synchronization is completed; after the relative time synchronization is completed, the time synchronization device may provide the time frequency information to other devices, including the navigation device, the communication device.
6. The time synchronization device according to claim 5, wherein the processing module is connected to the time synchronization server via the internet to realize network time service.
7. The time synchronization device of claim 5, wherein the clock module is connected to an external GNSS time service device to complete the synchronization with the GNSS time.
8. A relative time synchronization system comprising at least two time synchronization devices as claimed in claim 5, the relative time synchronization nodes forming a star network, a bus network, a daisy chain network or a hybrid network of the three.
9. The relative time synchronization system according to claim 8, wherein in the star network, a central node is taken as a master node, and all other nodes are synchronized with the master node; in the daisy chain network, a certain node is set as a main node, the main node completes time synchronization with the adjacent node, the adjacent node further completes time synchronization with the adjacent node which does not complete time synchronization, and the like, so that the time synchronization of the whole network is completed; in a bus type network, time synchronization can be realized between any two nodes, and all other nodes are synchronized with a master node through the master node arranged in the system.
10. A relative time synchronisation system according to claim 9, characterised in that the master node is connectable to a GNSS timing apparatus or NTP server to provide an absolute time reference.
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|---|---|---|---|---|
| CN114786248A (en) * | 2022-03-18 | 2022-07-22 | 哈尔滨工业大学 | Wireless sensor chain type networking and clock synchronization method |
| CN114786248B (en) * | 2022-03-18 | 2022-10-25 | 哈尔滨工业大学 | Wireless sensor chain type networking and clock synchronization method |
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