JP5217006B2 - High-precision time synchronization apparatus, high-precision time synchronization method, and program - Google Patents

Description

  The present invention relates to a high-accuracy time synchronization apparatus, a high-accuracy time synchronization method, and a program. The present invention particularly relates to a high-accuracy time synchronization apparatus, a high-accuracy time synchronization method, and a program that output a high-accuracy time signal.

A technique for improving the reception accuracy of a JJY signal by a radio timepiece has been devised (see, for example, Patent Document 1 and Patent Document 2). Further, a technique has been devised in which a plurality of information processing apparatuses are synchronized with each other by supplying time signals to the plurality of information processing apparatuses and synchronizing the internal clocks of the plurality of information processing apparatuses with a standard time (for example, (See Patent Document 3). For example, a plurality of information processing apparatuses can be synchronized by supplying JJY signals to the plurality of information processing apparatuses and synchronizing the internal clocks of the plurality of information processing apparatuses with the standard time.
JP 2007-107891 A JP 2007-139705 A JP 2005-520447 A

  However, since the error of the time indicated by the JJY signal differs depending on the reception position of the JJY signal, the accuracy that can guarantee the time indicated by the JJY signal is about 100 milliseconds. For this reason, in a system that synchronizes a plurality of information processing apparatuses using a JJY signal, the plurality of information processing apparatuses cannot be synchronized with high accuracy.

  In order to solve the above-described problem, in the first embodiment of the present invention, a high-accuracy time synchronization device corrects a JJY signal input unit for inputting a JJY signal and a correction value corresponding to the reception position of the JJY signal. A correction value acquisition unit acquired from the value storage unit, a high-accuracy time correction unit that corrects the time indicated by the JJY signal input by the JJY signal input unit with a correction value corresponding to the reception position of the JJY signal, and a high-accuracy time correction A JJY signal output unit that outputs a JJY signal indicating the time corrected by the unit.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows an example of a high-accuracy time synchronization system 10 according to the embodiment. The high accuracy time synchronization system 10 includes a JJY unit 100A, a JJY unit 100B, a high accuracy time synchronization device 110A, a high accuracy time synchronization device 110B, a synchronization target device 120A, a synchronization target device 120B, and a management device 140.

  In the following description, the JJY unit 100A and the JJY unit 100B may be referred to as the JJY unit 100. In addition, the high-accuracy time synchronizer 110A and the high-accuracy time synchronizer 110B may be referred to as the high-accuracy time synchronizer 110. Also, the synchronization target device 120A and the synchronization target device 120B may be referred to as the synchronization target device 120.

  The synchronization target device 120A and the synchronization target device 120B perform processing in synchronization with each other. Specifically, the synchronization target device 120A and the synchronization target device 120B each receive a JJY signal that can be used as a time signal indicating the standard time. Then, the synchronization target device 120A and the synchronization target device 120B each synchronize the built-in clock at the time indicated by the received JJY signal. As a result, the internal clock of the synchronization target device 120A and the internal clock of the synchronization target device 120B are synchronized with each other.

  The synchronization target device 120A and the synchronization target device 120B each perform processing based on the time indicated by the internal clock. Therefore, the synchronization target device 120A and the synchronization target device 120B can perform processing in synchronization with each other.

It is preferable that the synchronization target device 120A and the synchronization target device 120B each receive a highly accurate JJY signal. Each synchronized devices 120A and synchronized equipment 120 B is, by receiving a high-precision JJY signal, the synchronized device 120A and synchronized device 120B is able to perform processing in synchronization with each other with high accuracy .

  The management device 140 centrally controls the plurality of synchronization target devices 120 via the network 130. The management apparatus 140 may control the synchronization target device 120 so that the synchronization target device 120 does not perform the high-accuracy time synchronization processing. The management apparatus 140 may provide the synchronization target device 120 with various types of information such as the JJY reception status and JJY signal correction information.

  The JJY unit 100 receives a JJY signal emitted from a reference radio wave oscillation station using an antenna included in the JJY unit 100. The JJY unit 100 outputs the received JJY signal to the synchronization target device 120.

  The reference radio oscillation station outputs the timing signal and the JJY information in association with each other. The reference radio wave oscillation station periodically outputs a timing signal and JJY information. For example, the reference radio oscillation station outputs a timing signal and JJY information every second.

  Similarly, the JJY unit 100 outputs a timing signal and JJY information in association with each other. The JJY unit 100 periodically outputs a timing signal and JJY information. For example, the JJY unit 100 outputs a timing signal and JJY information every second.

  The high-accuracy time synchronizer 110 is provided on the communication path of the JJY signal between the JJY unit 100 and the synchronization target device 120. The high-accuracy time synchronization apparatus 110 controls the input of the JJY signal to the synchronization target device 120 on the communication path of the JJY signal between the JJY unit 100 and the synchronization target device 120.

  Specifically, the high-accuracy time synchronizer 110 receives the JJY signal output from the JJY unit 100. The high-accuracy time synchronizer 110 corrects the received JJY signal with a correction value corresponding to the position at which the JJY unit 100 has received the radio wave emitted from the reference radio wave oscillation station. In addition, the high-accuracy time synchronization device 110 outputs the corrected JJY signal to the synchronization target device 120.

  The high-accuracy time synchronizer 110 can also correct the received JJY signal with a correction value corresponding to the time or time zone when the JJY unit 100 receives the radio wave emitted from the reference radio wave oscillation station. The high-accuracy time synchronizer 110 can also correct the received JJY signal with a correction value according to the weather at the time or time zone when the JJY unit 100 receives the radio wave emitted from the reference radio wave oscillation station.

  Based on the corrected JJY signal, the high-accuracy time synchronizer 110 can synchronize the time of the built-in clock included in the high-accuracy time synchronizer 110 with the standard time with high accuracy. Therefore, the high-accuracy time synchronization apparatus 110 outputs a JJY signal indicating the time of the built-in clock included in the high-accuracy time synchronization apparatus 110 to the synchronization target device 120, so that the high-accuracy JJY signal is output to the synchronization target device 120. Can supply.

  As described above, according to the high-accuracy time synchronization system 10 of the present embodiment, the high-accuracy time synchronization device 110 is provided on the communication path between the JJY unit 100 and the synchronization target device 120, thereby outputting from the JJY unit 100. The error of the JJY signal can be corrected. For this reason, a highly accurate JJY signal can be supplied to the synchronization target device 120. Therefore, a plurality of synchronization target devices 120 can be synchronized with high accuracy.

  For example, there is a communication system for a mobile phone that uses LTE (Long Term Evolution) or OFDM (Orthogonal Frequency Division Multiplexing). In such a communication system, communication quality or communication speed may be improved by simultaneously transmitting data from a plurality of radio base stations to one communication terminal at the same time. In this case, a plurality of radio base stations can be synchronized with high accuracy by applying the high-accuracy time synchronization system 10 of the present embodiment to the communication system.

  In addition, there are communication systems that use other communication methods or other communication standards, such as a wireless LAN (Local Area Network) and WiMAX (World Wide Interoperability for Microwave Access). Even in such a communication system, there are cases where communication quality or communication speed can be improved by wirelessly transmitting data simultaneously from a plurality of wireless base stations to one communication terminal. Also in this case, a plurality of radio base stations can be synchronized with high accuracy by applying the high accuracy time synchronization system 10 of the present embodiment to the communication system.

  In the high-accuracy time synchronization system 10, an existing communication system may be used except for the high-accuracy time synchronization apparatus 110 and the management apparatus 140. For example, the high-accuracy time synchronization system 10 may be constructed by providing the high-accuracy time synchronization device 110 on the communication path of the JJY signal between the JJY unit 100 and the synchronization target device 120 with respect to the existing communication system. .

  In this case, the standard of the JJY signal input / output interface of the high-accuracy time synchronizer 110 is preferably the same as the standard of the JJY signal input / output interface used for connection between the JJY unit 100 and the synchronization target device 120. For example, when RS-422 is used as the standard of the JJY signal input / output interface used to connect the JJY unit 100 and the synchronization target device 120, the standard of the JJY signal input / output interface of the high-precision time synchronizer 110 is used. Is preferably RS-422. Thereby, when the use of the high-accuracy time synchronizer 110 is started, the high-accuracy time synchronizer 110 can be easily connected to the existing communication system. Further, when the use of the high-accuracy time synchronization device 110 is abolished, the existing communication system can be easily restored.

  FIG. 2 shows an example of a JJY signal output from the high-accuracy time synchronizer 110. The high-accuracy time synchronizer 110 outputs a JJY signal having a timing signal 201, JJY information 202, and JJY control information 203.

  The high-accuracy time synchronizer 110 outputs JJY information 202 having time data. The high-accuracy time synchronizer 110 includes JJY information 202 having various information related to JJY, such as the time when the JJY signal is received, the latitude and longitude of the point where the JJY signal is received, the accuracy of the JJY signal, and the weather at the time when the JJY signal is received. May be output. The high-accuracy time synchronizer 110 may output the JJY information 202 in the NMEA0183 format.

The high-accuracy time synchronizer 110 outputs a timing signal 201 that indicates the timing to synchronize with the time data indicated in the JJY information. For example, the high-accuracy time synchronizer 110 outputs a high-accuracy timing signal 201 that is synchronized with the standard time with microsecond accuracy or nanosecond accuracy.

  The high-accuracy time synchronizer 110 also periodically outputs a timing signal 201 and JJY information 202. For example, the high-accuracy time synchronizer 110 outputs the timing signal 201 and the JJY information 202 at a cycle of 1 second.

  Further, the high-accuracy time synchronizer 110 may input / output JJY control information 203 as control information related to input / output of a JJY signal. For example, the high-accuracy time synchronizer 110 may output JJY control information 203 indicating that the supply of the timing signal 201 and the JJY information 202 is started or stopped.

  The synchronization target device 120 receives the timing signal 201 and the JJY information 202 output from the high-accuracy time synchronization device 110. The synchronization target device 120 synchronizes the time indicated in the JJY information 202 with the time of the internal clock of the synchronization target device 120 at the timing when the timing signal 201 is received. As a result, the synchronization target device 120 can synchronize the time of the built-in clock with the standard time with micro sec accuracy or nano sec accuracy. The synchronization target device 120 may synchronize the time indicated in the JJY information 202 with the time of the internal clock of the synchronization target device 120 every time the timing signal 201 is received.

  FIG. 3 shows a functional configuration example of the high-accuracy time synchronization apparatus 110A according to the embodiment. Hereinafter, the functional configuration of the high-accuracy time synchronization apparatus 110A will be described. The high-accuracy time synchronizer 110B has the same functional configuration as the high-accuracy time synchronizer 110A. For this reason, description of the functional structural example of the high precision time synchronizer 110B is abbreviate | omitted.

  The high-accuracy time synchronization device 110A includes a JJY emulator unit 300, a JJY emulator control unit 320, and a communication unit 340. The JJY emulator unit 300 includes a JJY signal input unit 302, a correction value acquisition unit 303, a high-accuracy time correction unit 305, a built-in clock time adjustment unit 310, a built-in clock 312, and a JJY signal output unit 314. The JJY emulator unit 300 includes a GPS unit 306, a GPS signal input unit 308, a GPS accuracy determination unit 309, a correction value calculation unit 311, a correction value recording unit 313, and a correction value storage unit 315.

  The JJY signal input unit 302 inputs a JJY signal. Specifically, the JJY signal input unit 302 inputs the JJY signal transmitted from the JJY unit 100A. The JJY signal input unit 302 may input a JJY signal having a timing signal and JJY information.

  The correction value acquisition unit 303 acquires a correction value corresponding to the reception position of the JJY signal input by the JJY signal input unit 302 from the correction value storage unit 315. Specifically, the correction value acquisition unit 303 acquires a correction value corresponding to the position at which the JJY unit 100A has received the JJY signal from the correction value storage unit 315. For example, the correction value acquisition unit 303 acquires a correction value with microsecond accuracy or nanosecond accuracy from the correction value storage unit 315.

  The correction value acquisition unit 303 may acquire a correction value corresponding to the distance from the reference radio wave transmission station to the JJY unit 100A from the correction value storage unit 315. Further, the correction value acquisition unit 303 may acquire a correction value corresponding to the topography from the reference radio wave transmission station to the JJY unit 100A from the correction value storage unit 315. The correction value acquisition unit 303 may acquire a correction value according to the environment from the reference radio wave transmission station to the JJY unit 100A from the correction value storage unit 315.

  The correction value acquisition unit 303 may acquire a correction value further corresponding to the time or time zone when the JJY signal input by the JJY signal input unit 302 is received. For example, the correction value acquisition unit 303 acquires a correction value further corresponding to the time or time zone when the JJY unit 100A receives the JJY signal. You may acquire the correction value further according to the state of the ionosphere in the time or time slot | zone when the JJY signal which the JJY signal input part 302 input was received.

  The correction value acquisition unit 303 may acquire a correction value further according to the weather at the time or time period when the JJY signal input by the JJY signal input unit 302 is received. For example, the correction value acquisition unit 303 acquires a correction value that further corresponds to the weather at the time or time period when the JJY unit 100A receives the JJY signal.

  The high-accuracy time correction unit 305 corrects the time indicated by the JJY signal input by the JJY signal input unit 302 with the correction value acquired by the correction value acquisition unit 303. For example, the high-accuracy time correction unit 305 corrects the time indicated by the JJY signal input by the JJY signal input unit 302 with the correction value according to the reception position of the JJY signal acquired by the correction value acquisition unit 303.

  The high-accuracy time correction unit 305 may correct the time indicated by the JJY signal input by the JJY signal input unit 302 with a correction value further acquired according to the time or time zone acquired by the correction value acquisition unit 303. The high-accuracy time correction unit 305 corrects the time indicated by the JJY signal input by the JJY signal input unit 302 with a correction value acquired by the correction value acquisition unit 303 and further according to the weather in the time period or time zone. Also good.

  The built-in clock time adjustment unit 310 synchronizes the time of the built-in clock 312 with the time corrected by the high-accuracy time correction unit 305. For example, the built-in clock time adjustment unit 310 increases the time of the built-in clock 312 by correcting the period of the timing signal output from the oscillator included in the built-in clock 312 based on the time corrected by the high-accuracy time correction unit 305. You may synchronize with the time which the precision time correction | amendment part 305 correct | amended. In this case, the built-in clock time adjustment unit 310 corrects the period of the timing signal output from the oscillator included in the built-in clock 312 with microsecond accuracy or nanosecond accuracy based on the time corrected by the high-accuracy time correction unit 305. Thus, the time of the internal clock 312 may be synchronized with the time corrected by the high-accuracy time correction unit 305 with high accuracy.

  The JJY signal output unit 314 outputs a JJY signal indicating the time corrected by the high accuracy time correction unit 305. The JJY signal output unit 314 may output a JJY signal having a timing signal indicating the time corrected by the high-accuracy time correction unit 305 and JJY information. The JJY signal output unit 314 may output a JJY signal indicating the time of the internal clock 312 after the high-accuracy time correction unit 305 corrects the time of the internal clock 312.

  The JJY signal output unit 314 may output a JJY signal having the same format as the JJY signal input by the JJY signal input unit 302. For example, the JJY signal output unit 314 may output a JJY signal having a timing signal and time data in the same format as the timing signal and time data included in the JJY signal input by the JJY signal input unit 302.

  The GPS unit 306 receives radio waves emitted from a plurality of GPS satellites by the antenna of the GPS unit 306, respectively. The GPS unit 306 generates a GPS signal that can be used as a time signal indicating the standard time, based on information indicated by the plurality of received radio waves. Then, the GPS unit 306 outputs the generated GPS signal.

  More specifically, the GPS unit 306 generates a timing signal and GPS information that can be used as a time signal. Then, the GPS unit 306 outputs the generated timing signal and GPS information in association with each other. The GPS unit 306 periodically outputs a timing signal and GPS information. For example, the GPS unit 306 outputs a timing signal and GPS information every second. The GPS unit 306 may be provided outside the high-accuracy time synchronizer 110A.

  The GPS signal input unit 308 inputs a GPS signal. For example, the GPS signal input unit 308 inputs a GPS signal indicating standard time. The GPS signal input unit 308 may input a GPS signal transmitted from the GPS unit 306 as a GPS signal. Further, the GPS signal input unit 308 may input a GPS signal having a timing signal and GPS information transmitted from the GPS unit 306.

  The GPS accuracy determination unit 309 determines the accuracy of the GPS signal input by the GPS signal input unit 308. The GPS accuracy determination unit 309 may determine the accuracy of the GPS signal input by the GPS signal input unit 308 based on the number of GPS satellites indicated by the GPS signal input by the GPS signal input unit 308.

  For example, if the GPS signal input by the GPS signal input unit 308 indicates a value of “4” or more as the number of GPS satellites, the GPS accuracy determination unit 309 determines the accuracy of the GPS signal input by the GPS signal input unit 308. May be determined to be high. On the other hand, when the GPS signal input by the GPS signal input unit 308 indicates a value less than “3” as the number of GPS satellites, the GPS accuracy determination unit 309 determines the accuracy of the GPS signal input by the GPS signal input unit 308. May be determined to be low.

  The GPS accuracy determination unit 309 may determine the accuracy of the GPS signal input by the GPS signal input unit 308 based on the GPS reception state indicated by the GPS signal input by the GPS signal input unit 308. For example, if the GPS signal input by the GPS signal input unit 308 indicates “DGPS” or “positioning complete” as the GPS reception state, the GPS accuracy determination unit 309 receives the GPS signal input by the GPS signal input unit 308. It may be determined that the accuracy of is high. On the other hand, if the GPS signal input from the GPS signal input unit 308 indicates “unreceivable”, “receiving”, or “single positioning” as the GPS reception state, the GPS accuracy determination unit 309 receives the GPS signal input. It may be determined that the accuracy of the GPS signal input by the unit 308 is low.

  The correction value calculation unit 311 calculates a correction value by comparing the time indicated by the GPS signal input by the GPS signal input unit 308 with the time indicated by the JJY signal input by the JJY signal input unit 302. For example, the correction value calculation unit 311 calculates the correction value by subtracting the time indicated by the JJY signal input by the JJY signal input unit 302 from the time indicated by the GPS signal input by the GPS signal input unit 308.

  The correction value recording unit 313 records the correction value calculated by the correction value calculation unit 311 in the correction value storage unit 315 in association with the reception position of the JJY signal input by the JJY signal input unit 302. When the GPS accuracy determination unit 309 determines that the accuracy of the GPS signal input by the GPS signal input unit 308 is equal to or greater than a predetermined value, the correction value recording unit 313 displays the correction value calculated by the correction value calculation unit 311 as JJY. The signal may be recorded in the correction value storage unit 315 in association with the reception position of the JJY signal input by the signal input unit 302.

  When the GPS accuracy determination unit 309 determines that the number of GPS satellites indicated in the GPS signal input by the GPS signal input unit 308 is equal to or greater than a predetermined number, the correction value calculation unit 311 The calculated correction value may be recorded in the correction value storage unit 315 in association with the reception position of the JJY signal input by the JJY signal input unit 302. For example, when the GPS accuracy determination unit 309 determines that the number of GPS satellites indicated in the GPS signal input by the GPS signal input unit 308 is four or more, the correction value recording unit 313 corrects the correction value calculation unit. The correction value calculated by 311 may be recorded in the correction value storage unit 315 in association with the reception position of the JJY signal input by the JJY signal input unit 302.

  The correction value recording unit 313 records the correction value calculated by the correction value calculation unit 311 in the correction value storage unit 315 in further association with the time or time zone when the JJY signal input by the JJY signal input unit 302 is received. Also good. The correction value recording unit 313 further associates the correction value calculated by the correction value calculation unit 311 with the weather in the time or time zone when the JJY signal input by the JJY signal input unit 302 is received. May be recorded.

  The correction value storage unit 315 stores a correction value corresponding to the reception position of the JJY signal. The correction value storage unit 315 may store a correction value further corresponding to the time or time zone when the JJY signal is received. The correction value storage unit 315 may store a correction value that further corresponds to the weather at the time or time period when the JJY signal is received. The correction value storage unit 315 may be provided outside the high-accuracy time synchronization apparatus 110A.

  The communication unit 340 receives various information transmitted from various information processing apparatuses connected to the network 130. For example, the communication unit 340 may receive various control information transmitted from the management device 140 connected to the network 130.

  The JJY emulator control unit 320 controls each unit included in the JJY emulator unit 300. As a result, the JJY emulator control unit 320 controls the high-precision time synchronization processing by the JJY emulator unit 300. The JJY emulator control unit 320 may control the JJY emulator unit 300 so that the JJY emulator unit 300 does not perform high-precision time synchronization processing. The JJY emulator control unit 320 may control the JJY emulator unit 300 based on the control signal transmitted from the management device 140 so that the JJY emulator unit 300 does not perform high-precision time synchronization processing.

  FIG. 4 shows an example of the flow of processing by the high-accuracy time synchronizer 110A. First, the JJY signal input unit 302 inputs the JJY signal transmitted from the JJY unit 100A (S401). Next, the JJY emulator control unit 320 determines whether or not to perform high-accuracy time synchronization processing (S402).

  When the JJY emulator control unit 320 determines that the high-precision time synchronization processing is not performed (S402: No), the JJY signal output unit 314 outputs the JJY signal input in S401 to the synchronization target device 120A (S403). , Return to S401. On the other hand, when the JJY emulator control unit 320 determines that high-precision time synchronization processing is to be performed (S402: Yes), the correction value acquisition unit 303 corrects the correction value according to the reception position of the JJY signal input in S401, and S401. The correction value corresponding to the time zone when the JJY signal input in step S4 is received is acquired from the correction value storage unit 315 (S404).

  Then, the high-accuracy time correction unit 305 corrects the time indicated by the JJY signal input in S401 with the correction value acquired in S404 (S405). Furthermore, the internal clock time adjustment unit 310 synchronizes the time of the internal clock 312 with the time corrected in S405 (S406). Then, the JJY signal output unit 314 outputs a JJY signal indicating the time corrected in S405 (S407), and the process returns to S401.

  The high-accuracy time synchronization device 110A periodically executes the above-described processing. For example, the high-accuracy time synchronization apparatus 110A executes the above-described process at a cycle of 1 second. As a result, the high-accuracy time synchronization device 110A can periodically supply a highly accurate JJY signal to the synchronization target device 120A.

  FIG. 5 shows another example of the processing flow by the high-accuracy time synchronizer 110A. First, the GPS signal input unit 308 inputs the GPS signal output from the GPS unit 306 (S501).

  Next, the GPS accuracy determination unit 309 determines whether or not the GPS signal input in S501 indicates a value of “4” or more as the number of GPS satellites (S502). When the GPS accuracy determination unit 309 determines that the GPS signal input in S501 does not indicate a value of “4” or more as the number of GPS satellites (S502: No), the process returns to S501.

  On the other hand, when the GPS accuracy determination unit 309 determines that the GPS signal input in S501 indicates a value of “4” or more as the number of GPS satellites (S502: Yes), the correction value calculation unit 311 A correction value is calculated. Then, the correction value recording unit 313 converts the correction value calculated in S503 into the reception position of the JJY signal input by the JJY signal input unit 302 and the time zone when the JJY signal input by the JJY signal input unit 302 is received. The correction value is stored in the correction value storage unit 315 (S504), and the process returns to S501.

  The high-accuracy time synchronization device 110A periodically executes the above-described processing. For example, the high-accuracy time synchronization apparatus 110A executes the above-described process at a cycle of 1 second. Thereby, the high-accuracy time synchronization device 110A can continuously accumulate the correction value in the correction value storage unit 315. As the correction value storage unit 315 accumulates more correction values, the high-accuracy time synchronizer 110A can correct the JJY signal with higher accuracy.

  FIG. 6 shows a delay amount from the standard time indicated by the JJY signal. FIG. 6A shows the delay amount according to the reception position of the JJY signal. The amount of delay of the JJY signal varies depending on the reception position of the JJY signal. For example, the delay amount of the JJY signal varies depending on the distance from the reference radio wave transmission station to the reception position of the JJY signal, the topography, and the environment. However, in the present embodiment, since the reception position of the JJY signal, which is the position of the JJY unit 100, does not vary, the delay amount according to the reception position of the JJY signal does not vary.

  FIG. 6B shows a delay amount corresponding to the time zone in which the JJY signal is received. For example, an ionosphere that reflects a JJY signal exists above the earth. The state of the ionosphere varies depending on the intensity of ultraviolet rays from the sun. Along with this, the amount of reflection of the JJY signal by the ionosphere varies. Therefore, the delay amount of the JJY signal varies depending on the time zone, season, and the like.

  FIG. 7 shows an example of correction values stored in the correction value storage unit 315. FIG. 7A shows the correction value corresponding to the reception position of the JJY signal stored in the correction value storage unit 315. The correction value storage unit 315 stores a correction value with microsecond accuracy according to the reception position of the JJY signal. In this embodiment, since the delay amount according to the reception position of the JJY signal does not vary, the correction value storage unit 315 stores a fixed value as a correction value according to the reception position of the JJY signal.

  FIG. 7B shows correction values stored in the correction value storage unit 315 according to the time zone when the JJY signal is received. The correction value storage unit 315 stores a correction value with micro-sec accuracy corresponding to the time zone when the JJY signal is received.

  In the example shown in FIG. 7B, the correction value storage unit 315 stores the correction value in units of time, but may store a more detailed correction value. For example, the correction value storage unit 315 may store correction values in minutes or seconds. In the example shown in FIG. 7B, the correction value storage unit 315 stores hourly correction values regardless of the time, but may store hourly correction values for each time. . For example, the correction value storage unit 315 may store correction values in units of hours, minutes, or seconds for each season, month, or day.

  When the latitude of the reception position of the JJY signal is “35N66” and the longitude is “139E76”, the high-accuracy time synchronization apparatus 110 responds to the reception position of the JJY signal from the correction value storage unit 315. “4534.5 (micro sec)” is acquired as the correction value. In addition, when the current time is “6:00”, the high-accuracy time synchronization apparatus 110 sets “1245.6 (micro sec)” as the correction value according to the time zone of the JJY signal from the correction value storage unit 315. get. The high-accuracy time synchronizer 110 corrects the time indicated by the received JJY signal with these acquired correction values.

  The high-accuracy time synchronization apparatus 110 can add or update the correction value to the correction value storage unit 315. For example, when a GPS signal is received at a certain time T, the correction value at time T may not be stored in the correction value storage unit 315. In this case, the high-accuracy time synchronizer 110 calculates a correction value by comparing the received GPS signal with the received JJY signal, and then uses the calculated correction value as a correction value at time T to obtain a correction value storage unit. 315 can be stored.

  In addition, a correction value with low accuracy may be stored in the correction value storage unit 315. In this case, the high-accuracy time synchronization device 110 receives the high-accuracy GPS signal, calculates the high-accuracy correction value, and then calculates the correction value stored in the correction value storage unit 315. The correction value can be updated. For example, the high-accuracy time synchronization apparatus 110 may record the correction value stored in the correction value storage unit 315 and information related to the accuracy of the GPS signal in association with each other. Then, the accuracy of the calculated correction value is stored in the correction value storage unit 315 by comparing the accuracy of the recorded GPS signal with the accuracy of the GPS signal determined by the GPS accuracy determination unit 309. It may be determined whether or not the accuracy is higher than the accuracy. As described above, the high-accuracy time synchronization apparatus 110 can improve the accuracy of the correction value stored in the correction value storage unit 315 by adding or updating the correction value as needed.

  Thus, according to the high-accuracy time synchronization system 10 of the present embodiment, the delay amount from the standard time of the time indicated by the JJY signal output from the JJY unit 100 can be corrected with high accuracy. For this reason, a highly accurate JJY signal can be supplied to each of the plurality of synchronization target devices 120. Then, the time indicated by each internal clock of the plurality of synchronization target devices 120 and the standard time can be synchronized with high accuracy. Therefore, a plurality of synchronization target devices 120 can be synchronized with high accuracy.

  In the present embodiment, the high-accuracy time synchronization device 110 that supplies the corrected JJY signal to the synchronization target device 120 after correcting the JJY signal has been described as an example, but the present invention is not limited thereto. For example, the high-accuracy time synchronization device 110 may correct the GPS signal or NTP signal and then supply the corrected GPS signal or NTP signal to the synchronization target device 120. The high-accuracy time synchronization device 110 may correct the external clock signal that does not correspond to any of the JJY signal, the GPS signal, and the NTP signal, and then supply the corrected external clock signal to the synchronization target device 120. .

  FIG. 8 shows an example of the hardware configuration of the high-accuracy time synchronizer 110. The high-accuracy time synchronizer 110 includes a CPU peripheral unit having a CPU 1505, a RAM 1520, a graphic controller 1575, and a display device 1580 that are connected to each other by a host controller 1582. The high-accuracy time synchronization apparatus 110 includes an input / output unit having a communication I / F 1530, a hard disk drive 1540, and a CD-ROM drive 1560 that are connected to a host controller 1582 by an I / O (input / output) controller 1584. . Further, the high-accuracy time synchronization apparatus 110 includes a legacy input / output unit having a ROM 1510 connected to an I / O controller 1584, an FD (flexible disk) drive 1550, and an I / O (input / output) chip 1570.

  The host controller 1582 connects the RAM 1520 to the CPU 1505 and the graphic controller 1575 that access the RAM 1520 at a high transfer rate. The CPU 1505 operates based on programs stored in the ROM 1510 and the RAM 1520 to control each unit. The graphic controller 1575 acquires image data generated by the CPU 1505 or the like on a frame buffer provided in the RAM 1520 and displays the image data on the display device 1580. Alternatively, the graphic controller 1575 may include a frame buffer that stores image data generated by the CPU 1505 or the like.

  The I / O controller 1584 connects the host controller 1582 to the communication I / F 1530, the hard disk drive 1540, and the CD-ROM drive 1560, which are relatively high-speed input / output devices. The communication I / F 1530 communicates with other devices via a network. The hard disk drive 1540 stores programs and data used by the CPU 1505. The CD-ROM drive 1560 reads a program or data from the CD-ROM 1595 and provides it to the hard disk drive 1540 via the RAM 1520.

  The I / O controller 1584 is connected to the ROM 1510, the FD drive 1550, and the relatively low-speed input / output device of the I / O chip 1570. The ROM 1510 stores a boot program executed by the CPU 1505 when the high-accuracy time synchronizer 110 is started up, a program depending on the hardware of the high-accuracy time synchronizer 110, and the like. The FD drive 1550 reads a program or data from the flexible disk 1590 and provides it to the hard disk drive 1540 via the RAM 1520. The I / O chip 1570 connects various input / output devices via the FD drive 1550, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like.

  A program provided to the hard disk drive 1540 via the RAM 1520 is stored in a recording medium such as the flexible disk 1590, the CD-ROM 1595, or an IC card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 1540 in the high-accuracy time synchronization apparatus 110 via the RAM 1520, and executed by the CPU 1505. The program that is installed and executed in the high-accuracy time synchronization apparatus 110 works on the CPU 1505 or the like to cause the computer to function as each functional unit included in the high-accuracy time synchronization apparatus 110 described with reference to FIGS.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 shows an example of a high-accuracy time synchronization system 10 according to an embodiment. An example of the JJY signal which the high precision time synchronizer 110 outputs is shown. The functional structural example of 110 A of high precision time synchronizers which concern on embodiment is shown. An example of the flow of processing by the high-accuracy time synchronization apparatus 110A is shown. The other example of the flow of processing by 110 A of high precision time synchronizers is shown. This indicates the amount of delay from the standard time indicated by the JJY signal. An example of the correction value stored in the correction value storage unit 315 is shown. An example of the hardware configuration of the high-accuracy time synchronizer 110 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 High precision time synchronization system 100A JJY unit 100B JJY unit 110A High precision time synchronizer 110B High precision time synchronizer 120 Synchronization target device 130 Network 140 Management apparatus 300 JJY emulator part 302 JJY signal input part 303 Correction value acquisition part 305 High precision Time correction unit 306 GPS unit 308 GPS signal input unit 309 GPS accuracy determination unit 310 Built-in clock time adjustment unit 311 Correction value calculation unit 312 Built-in clock 313 Correction value recording unit 314 JJY signal output unit 315 Correction value storage unit 320 JJY emulator control unit 340 communication unit 1505 CPU
1510 ROM
1520 RAM
1530 Communication I / F
1540 Hard disk drive 1550 FD drive 1560 CD-ROM drive 1570 I / O chip 1575 Graphic controller 1580 Display device 1582 Host controller 1584 I / O controller 1590 Flexible disk 1595 CD-ROM

Claims (12)

A JJY signal input unit for inputting a JJY signal;
A correction value acquisition unit that acquires a correction value according to the reception position of the JJY signal from a correction value storage unit;
A high-accuracy time correction unit that corrects the time indicated by the JJY signal input by the JJY signal input unit with the correction value according to the reception position of the JJY signal;
A high-accuracy time synchronization apparatus comprising: a JJY signal output unit that outputs a JJY signal indicating the time corrected by the high-accuracy time correction unit. A built-in clock,
A built-in clock time adjustment unit that synchronizes the time of the built-in clock with the time corrected by the high-accuracy time correction unit;
The high-accuracy time synchronizer according to claim 1, wherein the JJY signal output unit outputs the JJY signal indicating the time of the built-in clock. The correction value acquisition unit acquires the correction value further corresponding to the time or time zone when the JJY signal was received,
The high-accuracy time synchronizer according to claim 2, wherein the high-accuracy time correction unit corrects the time indicated by the JJY signal input by the JJY signal input unit with the correction value further corresponding to a time or a time zone. The correction value acquisition unit acquires the correction value further according to the weather in the time or time zone when the JJY signal is received,
4. The high-accuracy time synchronization device according to claim 3, wherein the high-accuracy time correction unit corrects the time indicated by the JJY signal input by the JJY signal input unit with the correction value further according to the weather in the time or the time zone. .   The high-accuracy time synchronization apparatus according to claim 4, wherein the JJY signal output unit outputs the JJY signal having the same format as the JJY signal input by the JJY signal input unit. A GPS signal input unit for inputting a GPS signal;
A correction value calculation unit that calculates a correction value by comparing the time indicated by the GPS signal and the time indicated by the JJY signal input by the JJY signal input unit;
The high-accuracy time synchronization apparatus according to claim 5, further comprising: a correction value recording unit that records the correction value calculated by the correction value calculation unit in the correction value storage unit in association with the reception position of the JJY signal. A GPS accuracy judging unit for judging the accuracy of the GPS signal,
The correction value recording unit associates the correction value calculated by the correction value calculation unit with the reception position of the JJY signal when the GPS accuracy determination unit determines that the accuracy of the GPS signal is equal to or higher than a predetermined value. The high-accuracy time synchronization apparatus according to claim 6, wherein the high-accuracy time synchronization apparatus records the correction value in a storage unit. The GPS accuracy determination unit determines the accuracy of the GPS signal based on the number of GPS satellites indicated by the GPS signal,
The correction value recording unit associates the correction value calculated by the correction value calculation unit with the reception position of the JJY signal when the GPS accuracy determination unit determines that the number of GPS satellites is a predetermined number or more. The high-accuracy time synchronization apparatus according to claim 7, wherein the high-accuracy time synchronization apparatus records the correction value in a storage unit.   9. The high-accuracy time according to claim 8, wherein the correction value recording unit records the correction value calculated by the correction value calculation unit in the correction value storage unit in further association with a time or a time zone when the JJY signal is received. Synchronizer.   10. The correction value recording unit according to claim 9, wherein the correction value recording unit records the correction value calculated by the correction value calculation unit in the correction value storage unit in further association with the weather at the time or time zone when the JJY signal is received. Precision time synchronizer. A JJY signal input stage for inputting a JJY signal;
A correction value acquisition step of acquiring a correction value according to the reception position of the JJY signal from the correction value storage unit;
A high-accuracy time correction step of correcting the time indicated by the JJY signal input in the JJY signal input step with the correction value according to the reception position of the JJY signal;
A high-accuracy time synchronization method comprising: a JJY signal output step of outputting a JJY signal indicating the time corrected by the high-accuracy time correction step. A program for a high-accuracy time synchronizer, comprising:
A JJY signal input unit for inputting a JJY signal;
A correction value acquisition unit that acquires a correction value according to the reception position of the JJY signal from a correction value storage unit;
A high-accuracy time correction unit that corrects the time indicated by the JJY signal input by the JJY signal input unit with the correction value according to the reception position of the JJY signal;
A program that functions as a JJY signal output unit that outputs a JJY signal indicating the time corrected by the high-accuracy time correction unit.

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