JP5261714B2 - High-precision time synchronization apparatus, high-precision time synchronization method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To synchronize a plurality of synchronization-object devices with high precision, even when the precision of a GPS signal output from a GPS unit is low. <P>SOLUTION: This high-precision time synchronizing device is provided with the first time signal input part for inputting the first time signal; the first time signal precision deciding part for deciding the precision of the first time signal; a built-in timepiece; a built-in timepiece time regulating part for synchronizing a time of the built-in timepiece, with the time indicated by the first time signal, and the first time signal output part for outputting the first time signal input by the first time signal input part, when the precision of the first time signal is decided as being a prescribed value or larger, by the first time signal precision deciding part, and for outputting the first time signal indicating the time of the built-in timepiece, when the precision of the first time signal is determined as being smaller than the prescribed value, by the first time signal precision deciding part. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

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 synchronizing a plurality of information processing apparatuses by supplying GPS signals to the plurality of information processing apparatuses and synchronizing a built-in clock of the plurality of information processing apparatuses with a standard time has been devised (for example, Patent Documents). 1). In addition, by using a technique for outputting a pseudo GPS signal (for example, see Non-Patent Document 1 and Non-Patent Document 2), even in a place where radio waves from GPS satellites such as indoors or underground are difficult to reach. A technology that enables GPS positioning has been devised (see, for example, Patent Document 2).
JP 2005-520447 A JP 2007-212162 A GPSEmulator, [online], [search January 10, 2008], Internet <URL: http: // au. geocities. com / emulator tools / GPSEmulator. html> Virtual GPS, [online], Gold-Software Development, [January 10, 2008 search], Internet <URL: http: // www. gold-software. com / VirtualGPS-review 33760. htm>

  However, the GPS signal may not be supplied to the information processing apparatus depending on the reception position and time zone of the radio wave emitted from the GPS satellite. Further, the accuracy of the GPS signal supplied to the information processing apparatus may be low depending on the reception position and time zone of the radio wave emitted from the GPS satellite. In these cases, the above technique cannot synchronize a plurality of information processing apparatuses 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 is provided, and a first time signal input unit that inputs a first time signal and the accuracy of the first time signal are determined. A first time signal accuracy determination unit, a built-in clock, a built-in clock time adjustment unit that synchronizes the time of the built-in clock with the time indicated by the first time signal, and the accuracy of the first time signal is greater than or equal to a predetermined value. When the first time signal accuracy determination unit determines, the first time signal input by the first time signal input unit is output, and if the accuracy of the first time signal is less than a predetermined value, the first time signal accuracy determination unit And a first time signal output unit that outputs a first time signal indicating the time of the built-in clock when it is determined.

  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 GPS unit 100A, a GPS 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 GPS unit 100A and the GPS unit 100B may be referred to as the GPS 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 GPS 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 GPS 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 GPS signal. Each synchronized devices 120A and synchronized equipment 120 B is, by receiving a high-precision GPS signal, and synchronized equipment 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 device 140 may provide the synchronization target device 120 with various types of information such as GPS reception status and GPS signal correction information.

  The GPS unit 100 receives radio waves emitted from a plurality of GPS satellites by the antenna of the GPS unit 100, respectively. The GPS unit 100 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 100 outputs the generated GPS signal toward the synchronization target device 120.

  More specifically, the GPS unit 100 generates a timing signal and GPS information that can be used as a time signal. Then, the GPS unit 100 associates and outputs the generated timing signal and GPS information. The GPS unit 100 periodically outputs a timing signal and GPS information. For example, the GPS unit 100 outputs a timing signal and GPS information every second. The GPS unit 100 can improve the accuracy of the output GPS signal by receiving radio waves from a plurality of GPS satellites.

  The high-accuracy time synchronization device 110 is provided on a communication path for GPS signals between the GPS unit 100 and the synchronization target device 120. The high-accuracy time synchronization device 110 controls the input of the GPS signal to the synchronization target device 120 on the communication path of the GPS signal between the GPS unit 100 and the synchronization target device 120.

  Specifically, the high-accuracy time synchronization device 110 receives the GPS signal output from the GPS unit 100. Then, the high-accuracy time synchronization device 110 controls the GPS signal input to the synchronization target device 120 according to the accuracy of the received GPS signal. For example, when the high-accuracy time synchronization apparatus 110 determines that the accuracy of the received GPS signal is high, it outputs the received GPS signal to the synchronization target device 120. On the other hand, when it is determined that the accuracy of the received GPS signal is low, the high-accuracy time synchronization apparatus 110 generates a GPS signal with higher accuracy than the received GPS signal, and then uses the generated GPS signal as the synchronization target device 120. Output to.

  Based on the received GPS 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. The high-accuracy time synchronizer 110 can further synchronize the time of the built-in clock included in the high-accuracy time synchronizer 110 with the standard time with high accuracy based on the time indicated by the JJY signal or the NTP signal. Therefore, the high-accuracy time synchronization apparatus 110 can supply a high-accuracy GPS signal to the synchronization target device 120 by outputting a GPS signal indicating the time of the built-in clock to the time synchronization target device 120.

  As described above, according to the high-accuracy time synchronization system 10 of the present embodiment, since the high-accuracy time synchronization device 110 is provided on the communication path between the GPS unit 100 and the synchronization target device 120, the output from the GPS unit 100 is performed. Even when the accuracy of the received GPS signal is low, a highly accurate GPS signal can be supplied to the synchronization target device 120. Thereby, the some synchronous object apparatus 120 can be synchronized with high precision.

  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 GPS signal between the GPS unit 100 and the synchronization target device 120 with respect to the existing communication system. .

  In this case, it is preferable that the GPS signal input / output interface standard of the high-accuracy time synchronizer 110 is the same as the GPS signal input / output interface standard used for connection between the GPS unit 100 and the synchronization target device 120. For example, when RS-422 is used as a GPS signal input / output interface standard used to connect the GPS unit 100 and the synchronization target device 120, the GPS signal input / output interface standard of the high-accuracy 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 GPS signal output from the high-accuracy time synchronizer 110. The high-accuracy time synchronizer 110 outputs a GPS signal having a timing signal 201, GPS information 202, and GPS control information 203.

  The high-accuracy time synchronizer 110 outputs GPS information 202 having time data. The high-accuracy time synchronizer 110 outputs GPS information 202 having various GPS-related information such as the time when the GPS satellite is positioned, the latitude and longitude of the location where the GPS satellite is positioned, the accuracy of the GPS signal, and the number of GPS satellites received. May be. The high-accuracy time synchronizer 110 may output GPS 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 GPS 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.

  Further, the high-accuracy time synchronization device 110 periodically outputs the timing signal 201 and the GPS information 202. For example, the high-accuracy time synchronizer 110 outputs the timing signal 201 and the GPS information 202 at a cycle of 1 second.

  The high-accuracy time synchronization apparatus 110 may input / output GPS control information 203 as control information related to input / output of GPS signals. For example, the high-accuracy time synchronization device 110 may output GPS control information 203 indicating that the supply of the timing signal 201 and the GPS information 202 is started or stopped.

  The synchronization target device 120 receives the timing signal 201 and the GPS information 202 output from the high-accuracy time synchronization device 110. The synchronization target device 120 synchronizes the time indicated in the GPS information 202 with the time of the internal clock included in 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 GPS information 202 with the time of the internal clock included in 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 GPS emulator unit 300, a GPS emulator control unit 320, and a communication unit 340. The GPS emulator unit 300 includes a first time signal input unit 302, a first time signal accuracy determination unit 304, a JJY unit 306, a second time signal input unit 308, a built-in clock time adjustment unit 310, a built-in clock 312, and a first time. A signal output unit 314 is included.

  The first time signal input unit 302 inputs a first time signal. For example, the first time signal input unit 302 inputs a first time signal indicating a standard time. The first time signal input unit 302 may input a GPS signal transmitted from the GPS unit 100A as the first time signal. The first time signal input unit 302 may input a GPS signal having a timing signal and GPS information.

  The first time signal accuracy determination unit 304 determines the accuracy of the first time signal input by the first time signal input unit 302. When the first time signal input unit 302 receives a GPS signal, the first time signal accuracy determination unit 304 may determine the accuracy of the GPS signal input by the first time signal input unit 302.

  The first time signal accuracy determination unit 304 determines the accuracy of the GPS signal input by the first time signal input unit 302 based on the number of GPS satellites indicated by the GPS signal input by the first time signal input unit 302. Also good. For example, if the GPS signal input by the first time signal input unit 302 indicates a value of “4” or more as the number of GPS satellites, the first time signal accuracy determination unit 304 It may be determined that the accuracy of the GPS signal input by is high. On the other hand, if the GPS signal input by the first time signal input unit 302 indicates a value less than “3” as the number of GPS satellites, the first time signal accuracy determination unit 304 It may be determined that the accuracy of the GPS signal input by is low.

  The first time signal accuracy determination unit 304 determines the accuracy of the GPS signal input by the first time signal input unit 302 based on the GPS reception state indicated by the GPS signal input by the first time signal input unit 302. Also good. For example, the first time signal accuracy determination unit 304 inputs the first time signal when the GPS signal input by the first time signal input unit 302 indicates “DGPS” or “positioning complete” as the GPS reception state. It may be determined that the accuracy of the GPS signal input by the unit 302 is high. On the other hand, the first time signal accuracy determination unit 304 indicates “unreceivable”, “receiving”, or “single positioning” as the GPS reception state in the GPS signal input by the first time signal input unit 302. In this case, the accuracy of the GPS signal input by the first time signal input unit 302 may be determined to be low.

  The JJY unit 306 receives radio waves emitted from the reference radio wave oscillation station using the antenna of the JJY unit 306. The JJY unit 306 generates a JJY signal that can be used as a time signal indicating the standard time based on information indicated by the received radio wave. Then, the JJY unit 306 outputs the generated JJY signal.

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

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

  Moreover, the 2nd time signal input part 308 may input the NTP signal transmitted via the network 130 from the NTP server as a 2nd time signal. The second time signal input unit 308 may input an NTP signal having a timing signal and NTP information.

  The built-in clock time adjustment unit 310 synchronizes the time of the built-in clock 312 with the time indicated by the first time signal input by the first time signal input unit 302. For example, the built-in clock time adjustment unit 310 corrects the cycle of the timing signal output from the oscillator included in the built-in clock 312 based on the first time signal input by the first time signal input unit 302, thereby causing the built-in clock 312 to be corrected. May be synchronized with the time indicated by the first time signal. 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 based on the first time signal with the microsecond accuracy or the nanosecond accuracy. The time may be synchronized with the time indicated by the first time signal with high accuracy. The built-in clock time adjustment unit 310 may synchronize the time of the built-in clock 312 with the time indicated by the GPS signal input by the first time signal input unit 302.

  The built-in clock time adjustment unit 310 receives the second time signal input when the first time signal accuracy determination unit 304 determines that the accuracy of the first time signal input by the first time signal input unit 302 is less than a predetermined value. The time of the internal clock 312 may be corrected based on the second time signal input by the unit 308. For example, the built-in clock time adjustment unit 310 may correct the time of the built-in clock 312 based on the JJY signal or NTP signal input by the second time signal input unit 308.

  The built-in clock time adjustment unit 310 may correct the time of the built-in clock 312 based on both the JJY signal and the NTP signal input by the second time signal input unit 308. The built-in clock time adjustment unit 310 is based on the second time signal input by the second time signal input unit 308 even when the first time signal input unit 302 does not input the first time signal. The time may be corrected. The built-in clock time adjustment unit 310 is built-in by keeping the period of the timing signal output from the oscillator of the built-in clock 312 constant with high accuracy based on the JJY signal or NTP signal input by the second time signal input unit 308. The time of the clock 312 may be synchronized with the time indicated by the first time signal with high accuracy.

  The first time signal output unit 314 receives the first time signal when the first time signal accuracy determination unit 304 determines that the accuracy of the first time signal input by the first time signal input unit 302 is equal to or higher than a predetermined value. The first time signal input by the input unit 302 is output. On the other hand, when the first time signal accuracy determination unit 304 determines that the accuracy of the first time signal input by the first time signal input unit 302 is less than a predetermined value, the first time signal output unit 314 has a built-in clock. A first time signal indicating the time 312 is output.

  For example, the first time signal output unit 314 determines that the first time signal accuracy determination unit 304 determines that the accuracy of the GPS signal input by the first time signal input unit 302 is equal to or higher than a predetermined value. The GPS signal input by the input unit 302 is output. On the other hand, when the first time signal accuracy determination unit 304 determines that the accuracy of the GPS signal input by the first time signal input unit 302 is less than a predetermined value, the first time signal output unit 314 A GPS signal indicating the time is output.

  In this case, the first time signal output unit 314, when the first time signal accuracy determination unit 304 determines that the number of GPS satellites indicated in the GPS information is equal to or greater than a predetermined number, The GPS signal input by 302 may be output. On the other hand, the first time signal output unit 314 indicates the time of the built-in clock 312 when the first time signal accuracy determination unit 304 determines that the number of GPS satellites indicated in the GPS information is less than a predetermined number. A GPS signal may be output.

  For example, the first time signal output unit 314, when the first time signal accuracy determination unit 304 determines that the number of GPS satellites indicated in the GPS information is “4” or more, the first time signal input unit 314 The GPS signal input by 302 may be output. On the other hand, the first time signal output unit 314 determines the time of the internal clock 312 when the first time signal accuracy determination unit 304 determines that the number of GPS satellites indicated in the GPS information is less than “4”. A GPS signal may be output.

  The first time signal output unit 314 may output a GPS signal having a timing signal and GPS information. The first time signal output unit 314 may output a first time signal other than the GPS signal.

  The first time signal output unit 314 may output a first time signal having the same format as the first time signal input by the first time signal input unit 302. For example, when the first time signal input unit 302 inputs a GPS signal, a GPS signal having the same format as the GPS signal input by the first time signal input unit 302 may be output.

  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 an NTP signal transmitted from an NTP server connected to the network 130. In addition, the communication unit 340 may receive various control information transmitted from the management device 140 connected to the network 130.

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

  The GPS emulator control unit 320 may supply various information received by the communication unit 340 to the GPS emulator unit 300. For example, the GPS emulator control unit 320 may supply the NTP signal received by the communication unit 340 to the second time signal input unit 308 included in the GPS emulator unit 300.

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

  If the GPS emulator control unit 320 determines that the high-precision time synchronization processing is not performed (S402: No), the first time signal output unit 314 outputs the GPS signal input in S401 to the synchronization target device 120A ( S405), the process returns to S401. On the other hand, when the GPS emulator control unit 320 determines that high-accuracy time synchronization processing is to be performed (S402: Yes), the first time signal accuracy determination unit 304 adds “4” to the GPS signal input in S401 as the number of GPS satellites. It is determined whether or not a value greater than or equal to is indicated (S403).

  When the first time signal accuracy determination unit 304 determines that the GPS signal input in S401 indicates a value of “4” or more as the number of GPS satellites (S403: Yes), the built-in clock time adjustment unit 310 Thus, the time of the built-in clock 312 is synchronized with the time indicated by the GPS signal input in S401. Then, the first time signal output unit 314 outputs the GPS signal input in S401 to the synchronization target device 120A (S405), and returns to S401.

  On the other hand, if the first time signal accuracy determination unit 304 determines that the GPS signal input in S401 does not indicate a value of “4” or more as the number of GPS satellites (S403: No), the second time signal The input unit 308 inputs a JJY signal or NTP signal as the second time signal (S406). Then, the built-in clock time adjustment unit 310 corrects the time of the built-in clock 312 based on the JJY signal or NTP signal input in S406 (S407). Then, the first time signal output unit 314 outputs a GPS signal indicating the time of the internal clock 312 to the synchronization target device 120A (S408), and 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. Thereby, the high-accuracy time synchronization device 110A can periodically supply a high-accuracy GPS signal to the synchronization target device 120A.

  As described above, according to the high-accuracy time synchronization system 10 of the present embodiment, even if the accuracy of the GPS signal output from the GPS unit 100 is low, the high-accuracy time synchronization system 10 An accurate GPS signal can be supplied. For this reason, it is possible to synchronize the time indicated by the internal clock of each of the plurality of synchronization target devices 120 and the standard time with high accuracy. Therefore, a plurality of synchronization target devices 120 can be synchronized with high accuracy.

  In the present embodiment, the GPS signal is used as an example of the first time signal and the JJY signal or the NTP signal is used as an example of the second time signal. However, the present invention is not limited to this. For example, a JJY signal or NTP signal may be used as the first time signal. Further, an external clock signal that does not correspond to any of the GPS signal, the JJY signal, and the NTP signal may be used as the first time signal. A GPS signal may be used as the second time signal. Further, an external clock signal that does not correspond to any of the GPS signal, the JJY signal, and the NTP signal may be used as the second time signal.

  FIG. 5 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 GPS 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. 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 GPS unit 100B GPS unit 110A High precision time synchronizer 110B High precision time synchronizer 120 Synchronization object apparatus 130 Network 140 Management apparatus 300 GPS emulator part 302 1st time signal input part 304 1st time signal precision Judgment unit 306 JJY unit 308 Second time signal input unit
310 Built-in clock time adjustment unit 312 Built-in clock 314 First time signal output unit 320 GPS 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 (7)

A first time signal input unit for inputting a first time signal;
A second time signal input unit for inputting a second time signal;
A first time signal accuracy determination unit for determining the accuracy of the first time signal;
A built-in clock,
A built-in clock time adjustment unit that synchronizes the time of the built-in clock with the time indicated by the first time signal;
When the first time signal accuracy determining unit determines that the accuracy of the first time signal is equal to or higher than a predetermined value, the first time signal input by the first time signal input unit is output, and the first time signal is output. A first time signal output unit that outputs a first time signal indicating the time of the built-in clock when the first time signal accuracy determination unit determines that the accuracy of the signal is less than a predetermined value ;
The first time signal input unit inputs a GPS signal,
The first time signal accuracy determining unit determines the accuracy of the GPS signal,
The built-in clock time adjustment unit receives the second time signal input by the second time signal input unit when the first time signal accuracy determination unit determines that the accuracy of the first time signal is less than a predetermined value. Based on the above, the time of the built-in clock is corrected,
The first time signal output unit outputs the GPS signal input by the first time signal input unit when the first time signal accuracy determination unit determines that the accuracy of the GPS signal is equal to or higher than a predetermined value. , wherein when said first time signal accuracy determination unit and the accuracy of the GPS signals is less than a predetermined value is determined, the high precision time synchronization device you output a GPS signal that indicates the time of the internal clock. The first time signal accuracy determination unit determines the accuracy of the GPS signal based on the number of GPS satellites indicated by the GPS signal,
The first time signal output unit outputs the GPS signal input by the first time signal input unit when the first time signal accuracy determination unit determines that the number of GPS satellites is equal to or greater than a predetermined number. and, when the number of the GPS satellites has determined that the first time signal precision determining section is less than the predetermined number, the high precision time according to claim 1 for outputting the GPS signal indicating the time of the internal clock Synchronizer. The second time signal input unit inputs a JJY signal,
When the first time signal accuracy determination unit determines that the accuracy of the GPS signal is less than a predetermined value, the built-in clock time adjustment unit, based on the JJY signal input by the second time signal input unit, The high-accuracy time synchronizer according to claim 1 or 2 , wherein the time of the built-in clock is corrected. The second time signal input unit inputs an NTP signal,
When the first time signal accuracy determination unit determines that the accuracy of the GPS signal is less than a predetermined value, the built-in clock time adjustment unit, based on the NTP signal input by the second time signal input unit, The high-accuracy time synchronizer according to claim 1 or 2 , wherein the time of the built-in clock is corrected. The high-accuracy time synchronization device according to claim 4 , wherein the first time signal output unit outputs the GPS signal having the same format as the GPS signal input by the first time signal input unit. A program for causing a computer to function as the high-accuracy time synchronizer according to any one of claims 1 to 5. A first time signal input stage for inputting a first time signal;
A second time signal input stage for inputting a second time signal;
A first time signal accuracy determination step of determining the accuracy of the first time signal;
A built-in clock time adjustment step for synchronizing the time of the built-in clock with the time indicated by the first time signal;
When the first time signal accuracy determining step determines that the accuracy of the first time signal is greater than or equal to a predetermined value, the first time signal input by the first time signal input step is output, and the first time signal is output. A first time signal output step of outputting a first time signal indicating the time of the built-in clock when the first time signal accuracy determination step determines that the accuracy of the signal is less than a predetermined value;
In the first time signal input step, a GPS signal is input,
In the first time signal accuracy determination step, the accuracy of the GPS signal is determined,
In the built-in clock time adjustment step, the second time input in the second time signal input step when it is determined in the first time signal accuracy determination step that the accuracy of the first time signal is less than a predetermined value. Based on the signal, correct the time of the built-in clock,
The first time signal output step outputs the GPS signal input in the first time signal input step when it is determined in the first time signal accuracy determination step that the accuracy of the GPS signal is greater than or equal to a predetermined value. and, if the accuracy of the GPS signal is determined in said first time signal accuracy determining step is less than the predetermined value, high-precision time synchronization method you output a GPS signal that indicates the time of the internal clock.

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