JP5447598B2 - Time correction device, time measuring device with time correction device, and time correction method - Google Patents

Description

  The present invention relates to a time adjustment device that performs time adjustment based on a signal from a position information satellite such as a GPS satellite, a time measuring device with a time adjustment device, and a time adjustment method.

In a GPS (Global Positioning System) system, which is a system for positioning its own position, a GPS satellite having an orbit or the like orbiting the earth is used, and this GPS satellite is provided with an atomic clock. For this reason, GPS satellites have extremely accurate time information (GPS time).
In order to obtain the GPS satellite time information, the receiver side that receives the signal from the GPS satellite shows TOW (Time of Week, GPS time, weekly from the beginning of the week) of the signals from the GPS satellite. Information in seconds)) (for example, Patent Document 1).
Moreover, since the signal received in this way is a signal transmitted from a GPS satellite at an altitude of about 20,000 km, an error (error) may occur in the data. Therefore, so-called “parity check” is performed in order to detect such data errors.
Specifically, in the parity check, a data string to be transmitted is divided by a certain number, and a result (parity bit) calculated between each bit in the data string is attached to the back of the data string to transmit the data. . The receiving side determines that there is no error in data if the attached parity bit matches each bit operation result in the received data string.

JP 2001-59864 A (summary etc.)

  However, in this parity check, there is a possibility that even if another data string having the same even / odd etc. is received by mistake, it may be determined as a correct data string, and as a result, the time may be corrected based on incorrect time information. There was a problem that there was.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a time adjustment device, a time measuring device with a time adjustment device, and a time adjustment method that can reliably and quickly determine whether the time information transmitted from a position information satellite is correct or incorrect. .

  According to the present invention, the problem is that, according to the present invention, a satellite signal receiving unit that receives a satellite signal that is divided and transmitted from a position information satellite, a time information acquisition unit that acquires time information from the satellite signal, A zone identification information acquisition unit that acquires zone identification information of the zone to which time information belongs, a correspondence identification information calculation unit that calculates corresponding zone identification information corresponding to the zone identification information based on the time information, and the zone identification And a section identification information determination unit that determines whether the section identification information is correct based on the information and the corresponding section identification information.

According to the configuration, a time information acquisition unit that acquires time information from a satellite signal, a zone identification information acquisition unit that acquires zone identification information of the zone to which the time information belongs, and zone identification information based on the time information A corresponding identification information calculation unit that calculates corresponding division identification information, and a division identification information determination unit that determines whether the division identification information is correct based on the division identification information and the corresponding division identification information.
The time information has different contents depending on the section to which the time information belongs. For example, the time information of, for example, “subframe 1”, which is section identification information, for example, the Z count indicates the time at the beginning of the next section, for example, “subframe 1”.
Thus, the time information and the section to which the time information belongs have a close relationship. Therefore, in the above configuration, the time information acquisition unit acquires time information (for example, “Z count”), and the block identification information acquisition unit acquires block identification information (for example, subframe 1).

Then, the correspondence identification information calculation unit can calculate the corresponding partition identification information (for example, a numerical value “1” after the calculation) based on the Z count. This calculation result is a reliable value because the Z count and the subframe number “1” have a certain regularity.
Thereafter, the section identification information determination unit determines the corresponding section identification information (for example, “1”) and the section identification information (for example, “subframe 1”), so that the time information (for example, Z count) is correct. This can be quickly and reliably determined.
In the above example, since the numerical value “1” matches, the information is accurate. On the other hand, when the numerical values are different, the received satellite signal has an error, and the satellite signal is received again.
Thus, in the above-described configuration, even if data errors are overlooked by the conventional “parity check” or the like, it is possible to reliably determine whether the data is correct or not, and to set the time synchronization time. It can be shortened.

  Preferably, the satellite signal has page information for distinguishing a plurality of the same section identification information having different contents, a page information acquisition unit for acquiring the page information, and the time information. A corresponding page information calculation unit that calculates corresponding page information corresponding to the page information, and a page information determination unit that determines whether the page information is correct based on the page information and the corresponding page information. Is a time correction device.

According to the above configuration, the satellite signal has page information for distinguishing a plurality of identical section identification information having different contents, and is based on the page information acquisition unit that acquires the page information and the time information. A corresponding page information calculation unit that calculates corresponding page information corresponding to the page information, and a page information determination unit that determines whether the page information is correct based on the page information and the corresponding page information.
That is, even with the same segment identification information, for example, subframe 5, etc., there are a plurality, for example, 25 on the satellite signal. In this case, since the contents of the same subframe 5 are different, these 25 are distinguished by page information such as the number of pages, for example.
The page information such as the number of pages and the time information such as the Z count have a close relationship via the partition identification information such as the subframe 5. For example, the time information of the Z count of the subframe 5 of 25 pages, which is page information, has a relationship of indicating the time of the start portion of the next subframe 1.

Thus, the page information such as page 25 in the partition identification information such as the subframe 5 and the time information such as the Z count have a certain regularity.
Therefore, in the above configuration, the page information acquisition unit acquires page information (for example, “25” or the like) for distinguishing the section identification information (subframe 5 or the like). Then, the corresponding page calculation unit calculates the corresponding page information (for example, “25”, etc.) corresponding to the page information based on the acquired time information (for example, Z count).
At this time, the calculation result is a reliable value because the page information (25, etc.) and the time information (for example, Z count) in the section identification information (subframe 5, etc.) have a certain regularity. It becomes.

Then, the page information determination unit determines whether the actual page information is correct based on the actual page information acquired by the page information acquisition unit and the corresponding page information (for example, “25”, etc.) that is the calculation result. .
In the above example, if the numerical value “25” matches, the information is accurate. If the numerical values do not match, the received satellite signal has an error, and the satellite signal is received again. Become.
In this way, in the above configuration, even if data errors are overlooked by the conventional “parity check” or the like, it is possible to more accurately determine correctness without overlooking, and the time synchronization time can be reduced. It can be shortened.

  Preferably, the section includes a plurality of small sections, and the time information small section having the time information among the small sections includes small section identification information that can be distinguished from the other small sections, and receives the satellite signal. A time information sub-compartment signal reception determination unit that determines whether the satellite signal corresponding to the time information sub-part has been received, and the sub-partition identification information from the satellite signal corresponding to the time information sub-part A time division correction apparatus comprising: a small block identification information determination unit that determines whether or not there is.

According to the above configuration, the section includes a plurality of small sections, and the time information subsection having time information among the small sections includes the small section identification information that can be distinguished from other small sections, and includes a satellite signal receiving unit. Is a time information small section signal reception determination unit that determines whether or not a satellite signal corresponding to the time information small section has been received, and a small section that determines whether or not there is small section identification information from the satellite signal corresponding to the time information small section. A section identification information determination unit.
That is, the satellite signal section (for example, subframe) includes, for example, a HOW word (one subframe of 10 words) that is a time information subsection, and receives this time information subsection (for example, HOW word). If so, time information (for example, Z count) is received at the same time.
The time information small section (for example, HOW word) is provided with small section identification information (for example, a specific bit is 0) that can be distinguished from other small sections (for example, other words).

For this reason, the time information sub-compartment signal receiving unit determines whether or not a satellite signal corresponding to the time information sub-compartment (for example, a HOW word) has been received. The section determines whether or not the small section identification information (for example, the specific bit is 0) exists in the time information small section (for example, HOW word). If the small partition identification information exists, it is determined that it is a correct time information small partition (for example, HOW word). If the small partition identification information does not exist, the small partition is identified as a time information small partition (for example, The satellite signal is received again.
As described above, in the above-described configuration, even when data errors are overlooked by the conventional “parity check” or the like, it is possible to more reliably determine the sub-division where the time information is arranged without overlooking it. And time synchronization time can be shortened.

  According to the present invention, the problem is that, according to the present invention, a satellite signal receiving unit that receives a satellite signal that is divided and transmitted from a position information satellite, a time information acquisition unit that acquires time information from the satellite signal, A zone identification information acquisition unit that acquires zone identification information of the zone to which time information belongs, a correspondence identification information calculation unit that calculates corresponding zone identification information corresponding to the zone identification information based on the time information, and the zone identification And a section identification information determination unit that determines whether the section identification information is correct based on the information and the corresponding section identification information.

  According to the present invention, the problem is that, according to the present invention, the satellite signal receiving unit receives the satellite signal transmitted from the position information satellite after being divided into sections, and the time information acquiring unit is based on the satellite signal. A time information acquisition step for acquiring time information, a zone identification information acquisition unit for acquiring zone identification information for the zone to which the time information belongs, and a correspondence identification information calculation unit for the time information. A corresponding identification information calculation step for calculating corresponding identification information corresponding to the identification information, and an identification information determination unit that determines whether the identification information is correct based on the identification information and the corresponding identification information. And a zone identification information judging step for judging.

It is the schematic which shows the wristwatch with a GPS time correction apparatus which is a time measuring apparatus with a time correction apparatus which concerns on this invention, for example. It is the schematic which shows the main hardware configurations etc. inside the wristwatch with GPS. It is the schematic which shows the main software configurations etc. of the wristwatch with GPS. It is the schematic which shows the data in the various program storage part of FIG. It is the schematic which shows the data in the various data storage part of FIG. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with GPS concerning 1st Embodiment. It is another schematic flowchart which shows the main operation | movement etc. of the wristwatch with GPS concerning 1st Embodiment. It is a schematic explanatory drawing which shows a satellite signal. It is a schematic explanatory drawing which shows the HOW word of FIG.8 (b). It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time adjustment apparatus which is the time measuring apparatus with a time adjustment apparatus concerning 2nd Embodiment. It is the other schematic which shows the main software configurations etc. of the wristwatch with a GPS time adjustment apparatus which is the time measuring apparatus with a time adjustment apparatus concerning 2nd Embodiment. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with a GPS time correction apparatus concerning 2nd Embodiment. It is the schematic explanatory drawing shown about 5 words among the 10 words which comprise the sub-frame of Fig.8 (a). It is a schematic explanatory drawing which shows the page ID / sub-frame SVID correspondence data of FIG. It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time correction apparatus which is the time measuring apparatus with a time correction apparatus concerning the 3rd Embodiment of this invention. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with a GPS time correction apparatus concerning 3rd Embodiment.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

(First embodiment)
FIG. 1 is a schematic diagram showing a timepiece with a time adjustment device according to the present invention, for example, a wristwatch 10 with a GPS time adjustment device (hereinafter referred to as a “watch 10 with GPS”), and FIG. 2 shows the GPS of FIG. FIG. 2 is a schematic diagram showing a main hardware configuration and the like inside the wristwatch 10.
As shown in FIG. 1, a GPS wristwatch 10 has a dial 12 on its surface, hands 13 such as long hands and short hands, and a display 27 formed of LEDs and the like for displaying various messages. Yes. The display 27 may be an LCD, an analog display or the like in addition to the LED.

  Further, as shown in FIG. 1, the GPS wristwatch 10 has an antenna 11, and this antenna 11 receives a signal from a GPS satellite 15 orbiting around the earth in a predetermined orbit, for example. It is the composition to do. The GPS satellite 15 is an example of a position information satellite.

Further, as shown in FIG. 2, the GPS wristwatch 10 includes a time display device 21, a GPS device 20, and the like, and has a configuration that also functions as a computer.
Further, the time display device 21 in the present embodiment is configured to function as a so-called electronic timepiece. Hereinafter, each configuration shown in FIG. 2 will be described.
As shown in FIG. 2, the GPS wristwatch 10 includes a bus 16 to which a CPU (Central Processing Unit) 17, a RAM (Random Access Memory) 18, a ROM (Read Only Memory) 19, and the like are connected. ing.
In addition, a GPS device 20 that receives a satellite signal transmitted from the GPS satellite 15 is connected to the bus 16. Further, a time display device 21 is also connected to the bus 16.

Specifically, the GPS device 20 includes an antenna 11, an RF unit that uses a signal received by the antenna 11 as an intermediate frequency (I / F), a baseband unit that demodulates the signal, and the like. ing. That is, the GPS device 20 is configured to be able to take out a signal received from the GPS satellite 15a or the like of FIG. 1 as a GPS signal via the antenna 11, the RF unit, the baseband unit, or the like. Thus, the GPS device 20 is an example of a satellite signal receiving unit.
The GPS signal (an example of a satellite signal) includes highly accurate GPS time information (Z count) based on an atomic clock. The GPS time signal will be described later. Thus, the GPS device 20 is an example of a time information acquisition unit.

  The time display device 21 connected to the bus 16 includes a real-time clock (RTC) 22 composed of an IC (semiconductor integrated circuit), a display 27, and the like. The bus 16 is also connected with a solar cell 23 serving as a power source.

  As described above, the bus 16 has a function of connecting all devices and is an internal bus having an address and a data path. The RAM 18 and the like process a predetermined program and also control a ROM 19 and the like connected to the bus 16. The ROM 19 stores various programs and various information.

FIG. 3 is a schematic diagram showing a main software configuration of the GPS wristwatch 10.
As shown in FIG. 3, the GPS wristwatch 10 has a control unit 28, and the control unit 28 processes various programs in the various program storage units 30 and various data in the various data storage units 40 shown in FIG. 3. It is the composition to do.
In FIG. 3, the various program storage unit 30 and the various data storage unit 40 are shown separately. However, the data is not actually stored separately as described above, and is convenient for explanation. It is described separately for this purpose.

4 is a schematic diagram showing data in the various program storage units 30 of FIG. 3, and FIG. 5 is a schematic diagram showing data in the various data storage units 40 of FIG.
6 and 7 are schematic flowcharts showing main operations and the like of the GPS wristwatch 10 according to the present embodiment.

Hereinafter, the operations of the GPS wristwatch 10 according to the present embodiment will be described according to the flowcharts of FIGS. 6 and 7, and the various programs and various data of FIGS.
First, when the GPS wristwatch 10 corrects the time of the RTC 22 in FIG. 1, first, as shown in ST <b> 1 in FIG. 6, the satellite signal reception operation of the GPS satellite 15 is started. Specifically, the satellite signal reception operation program 31 of FIG. 4 operates. Thereafter, the process proceeds to ST2, and a search for capturing the GPS satellite 15 is executed. This is an operation for capturing the GPS satellite 15 orbiting the earth, and the GPS device 20 of FIG. 1 operates, specifically, the GPS satellite search operation program 32 of FIG. 4 operates.

Next, the process proceeds to ST3. In ST3, it is determined whether or not the search for all satellites is completed. That is, it is determined whether or not the search has been completed for all of the GPS satellites 15 or the like orbiting the earth. Specifically, the determination is performed by the all-satellite search end determination program 33 of FIG. If it is determined that the search for all the GPS satellites 15 and the like has been completed, the acquisition of the GPS satellites 15 and the like is terminated because power is wasted.
On the other hand, if the search for all the GPS satellites 15 and the like is not completed in ST3, the process proceeds to ST4. In ST4, it is determined whether or not the GPS satellite 15 or the like has actually been captured, and specifically, the satellite capture determination program 34 operates (an example of a satellite signal reception process).
If it is determined in ST4 that the GPS satellite 15 or the like has been captured, the process proceeds to ST5 and it is determined whether or not the reception time has timed out. In other words, the GPS device 20 in FIG. 1 is configured to operate for a long time and prevent power consumption from increasing.

Next, the process proceeds to ST6 and it is determined whether or not the Z count has been acquired. Before describing this step, the satellite signal from the GPS satellite 15 will be described.
FIG. 8 is a schematic explanatory diagram showing satellite signals.
A signal is transmitted from the GPS satellite 15 in units of one frame (30 seconds) as shown in FIG. This one frame has five subframes (one subframe is 6 seconds). Each subframe has 10 words (1 word is 0.6 seconds).
The head word of each subframe is a TLM word in which TLM (Telemetry word) data is stored, and in this TLM word, as shown in FIG. Is stored.
The word following the TLM is a HOW word in which HOW (hand over word) data is stored, and GPS time information (Z count) of a GPS satellite called TOW (Time of Week) is stored at the top thereof. .
This Z count stores the time of the start portion of the TLM of the next subframe.
The GPS time is displayed in seconds since 0:00 every Sunday, and returns to 0 at 0:00 on the next Sunday.

Returning to ST6 in FIG. 6, in this ST6, it is determined whether or not TOW data is received from the HOW word of the satellite signal shown in FIG. 8B received from the GPS satellite 15 (time information). An example of an acquisition process).
Here, if it is certain that the TOW data has been received, the time data (Z count) obtained from the TOW data by calculation or the like becomes highly accurate GPS time data.
Specifically, whether or not the Z count data has been acquired is determined by operating the Z count acquisition availability determination program 35 of FIG. Then, the Z count registration program 36 of FIG. 4 operates on the acquired Z count data, that is, the time data at the timing of the start portion of the TLM preamble of the next subframe shown in FIG. It is registered as the Z count data 41 in FIG. For example, “00:10:00” or the like.
That is, when this time (Z count) is the time calculated from the subframe “1”, it indicates the time of the rising portion of the preamble of the TLM word of “subframe 2” to be transmitted next. Become.

However, as described above, the satellite signal from the GPS satellite 15 received by the GPS device 20 of FIG. 1 may be error data. If it is error data, the acquired data is also incorrect, and as a result, the time of the RTC 22 in FIG. 1 cannot be accurately corrected.
Therefore, in the present embodiment, the steps after ST7 are executed.

In ST7, a subframe ID is acquired (an example of a section identification information acquisition step). FIG. 9 is a schematic explanatory diagram showing the HOW word of FIG.
As shown in FIG. 9, the HOW word consists of 30 bits (bits), and the first 1 to 17 bits are TOW data. After that, 20 bits to 22 bits are data of “subframe ID” which is the number of the subframe to which the HOW word belongs.
Specifically, for example, when the HOW word in FIG. 9 is the HOW word of “subframe 1”, data “1” is transmitted as the subframe ID.

Therefore, in ST7 of FIG. 6, the subframe ID data of bits 20 to 22 following the TOW data of FIG. 9 is acquired, and the result is registered as the subframe ID data 42 of FIG.
Specifically, the subframe ID acquisition / registration program 37 of FIG. 4 operates to register the subframe ID, for example, “1” in the subframe ID data 42.
Here, the subframe ID acquisition / registration program 37 is an example of a partition identification information acquisition unit, the subframe is an example of a partition, and the subframe ID number is an example of the partition identification information. .

Next, the process proceeds to ST8, and a subframe ID is calculated based on the Z count (an example of a correspondence identification information calculation step). That is, the time data called Z count shown in the TOW data in FIG. 9 is closely related to the subframe, as is the timing data of the start portion of the preamble that is the start portion of the subframe. ing.
Specifically, the Z count is obtained by multiplying the TOW data by four, the subframe ID is synchronized with the Z count, and starts from “subframe 1” at the beginning of the week. In addition, based on the TOW data, the ID of the subframe in which the TOW data exists, that is, the “number” can be predicted.
The formula is “(subframe ID) = ((TOW + 4) mod 5) +1”.
Here, “mod” indicates a remainder value when Y is divided by X in the case of XmodY.

That is, in ST8, the subframe ID calculation program 38 operates, and the above formula is executed by this program. Specifically, the TOW data that is the basic data is obtained from the Z count data 41 of FIG. 5, and the TOW data is substituted into the above equation to obtain the subframe ID.
The calculated subframe ID obtained in this way is registered as the calculated subframe ID data 43 in FIG. For example, this numerical value is “1”.
That is, the subframe ID calculation program 38 is an example of a correspondence identification information calculation unit, and the calculation subframe ID data 43 is an example of corresponding partition identification information.

Next, the process proceeds to ST9. In ST9, it is determined whether or not the calculated subframe ID matches the acquired subframe ID (an example of a section identification information determination step).
That is, the subframe ID comparison program 39 of FIG. 4 operates, and the subframe ID data 42 of FIG. 5 is compared with the operation subframe ID data 43 to determine whether or not they match.
If they match, it is found that the received satellite signal is not error data but TOW data of the subframe, and the Z count (time information) obtained based on the TOW data is also highly reliable data. It turns out that it is.
Thus, the subframe ID comparison program 39 is an example of the section identification information determination unit.

  Next, the process proceeds to ST10. In ST10, it is determined whether the parity check is successful. This parity check is performed, for example, using 29 bits and 30 bits of the previous word and 25 bits and 28 bits of the current word. As a result, it is determined whether or not there is an error in the data. Specifically, the parity check determination program 131 of FIG.

As described above, in this embodiment, the error of the data of the satellite signal received from the GPS satellite 15 is determined by the parity check. This is based on whether or not each bit operation result in the specific data string matches. Therefore, there is a case where it is determined that the data is correct even though there is an error, and the Z count is calculated based on the determination to correct the time. With this, the time cannot be corrected with high accuracy.
In this respect, in the present embodiment, not only the parity check but also the subframe ID is predicted by calculation or the like from the received Z count, and the predicted calculation subframe ID data 43 is the subframe ID actually received. By determining whether or not it matches the frame ID data 42, it is possible to quickly and accurately determine whether the received data is correct or incorrect.

  By the way, after ST10, reception of the satellite signal is completed at ST11, and time correction for correcting the RTC 22 of FIG. 1 is executed at ST12. Specifically, the time correction execution program 132 of FIG. 4 is operated and executed.

(Second Embodiment)
FIGS. 10 and 11 are schematic diagrams showing a main software configuration and the like of a wristwatch 100 with a GPS time correction device, for example, a timekeeping device with a time correction device according to the second embodiment of the present invention. 12 is a schematic flowchart showing main operations and the like of the wristwatch 100 with a GPS time adjustment device according to the present embodiment.
Specifically, FIG. 10 is a schematic diagram showing data in various program storage units 300 according to the present embodiment, and FIG. 11 shows data in various data storage units 400 according to the present embodiment. FIG.
Since the configuration of the wristwatch 100 with the GPS time correction device according to the present embodiment is similar to the configuration of the GPS wristwatch 10 according to the first embodiment described above, the common configuration is the same. The description will be omitted by using the reference numerals or the like or describing the fact, and hereinafter, the description will focus on the differences.

Hereinafter, the features of this embodiment will be described with reference to the flowchart of FIG. First, in the present embodiment, ST1 to ST10 of FIG. 6 and FIG. 7 of the first embodiment described above are performed in the same manner.
Further, ST10 to ST12 of the first embodiment are similarly performed. That is, this embodiment is characterized in that a process as shown in FIG. 12 is inserted between ST9 and ST10 of the first embodiment.
That is, before the parity check in ST10 of FIG. 12, it is determined in ST21 whether or not the received subframe number is “5”.
Specifically, the subframe ID determination program 131 in FIG. 10 operates to make a determination with reference to the subframe ID data 42 in FIG.

Here, “subframe 5” will be described. As shown in FIG. 8, the satellite signal from the GPS satellite 15 has subframe units, for example, five types of subframes. Among them, “subframe 5” includes almanac information (rough orbit information) of all GPS satellites and the like, so the amount of information is large, and one subframe is not sufficient, and a total of 25 subframes. 5, the information is divided and arranged.
For this reason, there are 25 “subframes 5” in the satellite signal, and each subframe 5 is divided by the number of pages. For example, “Sub-frame 5” of “3 pages”.

Therefore, when the subframe ID data 42 acquired in ST7 of the present embodiment is “5”, that is, “frame 5”, it is necessary to determine how many frames the frame 5 is.
Therefore, in this embodiment, it is determined whether or not it is “subframe 5” in ST21 of FIG. 12. If it is subframe 5, the process proceeds to ST22.
In ST22, the SVID of the received “subframe 5” is acquired, and the page ID of the “subframe 5” is acquired based on the acquired SVID.
Specifically, the SVID acquisition program 332 of the subframe of FIG. 10 operates, but the details are as follows. The SVID is an example of page information.

FIG. 13 is a schematic explanatory view showing five words among the ten words constituting the subframe of FIG.
As shown in FIG. 13, data corresponding to the page ID of the subframe called SVID is arranged in the third word of the subframe.
FIG. 14 is a schematic explanatory diagram showing the page ID / subframe SVID correspondence data 441 of FIG.
That is, FIG. 14 stores data of “page ID” corresponding to “SVID” shown in FIG. 13, that is, “page number”.
Then, when the SVID acquisition program 332 of the subframe in FIG. 10 operates to acquire the “SVID” data of the word 3 in FIG. 13, the page ID acquisition program 333 in FIG. 10 operates thereafter, and this “SVID” The page ID data can be acquired based on the above data and the page ID / subframe SVID correspondence data 441 in FIG.
The page ID acquired in this way is registered as page ID data 442 in FIG. For example, 10 pages.
Thus, the SVID acquisition program 332 of the subframe is an example of the page information acquisition unit.

  The page ID data 442 only needs to be accurate, but there may be a data error in the satellite signal transmitted from the GPS satellite 15. If this data error is left as it is, the result is accurate. Therefore, there is a possibility that a problem arises in that a correct Z count cannot be obtained and the time cannot be adjusted accurately.

That is, in ST23, the page ID is calculated from the Z count data of FIG.
The page ID (see FIG. 14) and time information such as Z count are closely related. For example, the time information of the Z count of the subframe 5 of page 25, which is page information, has a relationship indicating the time of the start portion of the next subframe 1, and the page information such as the page 25 of the subframe 5 The time information such as the Z count has a certain regularity.
Specifically, the page ID shown in FIG. 14 is synchronized with the Z count of each subframe, and the page ID is “1” at the beginning of the week, that is, has a structure starting from page 1.
For this reason, as shown by the following expression, the page ID of the subframe 5 in which the TOW data exists, that is, the “number of pages” can be predicted based on the TOW data.
When “TOW” is “0”, page ID = 10 ”, and when“ TOW is not “0”, (page ID) = ((TOW−1) ÷ 5) mod 25 ”+1 Is.
Here, “mod” indicates a remainder value when Y is divided by X in the case of XmodY.

That is, the page ID calculation program 334 in FIG. 10 calculates the page ID based on the received “TOW” according to the above formula, and registers the result as the calculated page ID data 443 in FIG.
Here, the page ID calculation program 334 is an example of a corresponding page information calculation unit.

Next, proceeding to ST24, it is determined whether or not the calculated page ID matches the acquired ID. Specifically, the page ID comparison program 335 in FIG. 10 operates to compare the page ID data 442 in FIG. 11 with the calculated page ID data 443.
If they match as a result of the comparison, the data of the actually received page ID is accurate, and in subsequent ST12, the time is corrected based on this data.
On the other hand, if the comparison results do not match, it is determined that there is a data error, and the satellite signal is received again.
Thus, the page ID comparison program 335 is an example of a page information determination unit.

As described above, according to the present embodiment, it is possible to more reliably determine whether the page ID of a subframe that differs depending on the number of pages is correct.
Thereafter, in the present embodiment, the parity check (ST10) is further performed to determine whether or not there is an error in the data.
That is, in this embodiment, an error can be detected quickly without performing a parity check calculation.

(Third embodiment)
FIG. 15 is a schematic diagram showing a main software configuration of a timepiece with a time adjustment device according to the third embodiment of the present invention, for example, a wristwatch with a GPS time adjustment device 200, and FIG. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch 200 with a GPS time correction apparatus concerning this Embodiment.
Specifically, FIG. 15 is a schematic diagram showing data in various program storage units 500 according to the present embodiment.
Since the configuration of the wristwatch 200 with the GPS time correction device according to the present embodiment is similar to the configuration of the GPS wristwatch 10 according to the first embodiment described above, the common configuration is the same. The description will be omitted by using the reference numerals or the like or describing the fact, and hereinafter, the description will focus on the differences.

Hereinafter, the features of the present embodiment will be described with reference to the flowchart of FIG. First, in the present embodiment, ST1 to ST5 in FIG. 6 and FIG. 7 of the first embodiment described above are similarly performed.
Further, ST6 to ST12 of the first embodiment are similarly performed. That is, this embodiment is characterized in that a process as shown in FIG. 16 is performed between ST5 and ST6 of the first embodiment.
That is, if satellite acquisition is successful in ST4 of FIG. 16 and then the reception time is not timed out in ST5, it is determined whether or not a HOW word is detected in ST31. If a HOW word is detected, HOW is detected in ST32. A step of determining whether bit 29 and bit 30 of the word are “0” is added.
This word is an example of a small section, and the HOW word is an example of a time information small section. Further, the bit 29 and the bit 30 being “0” is an example of the small block identification information.

First, the meaning of adding such a process will be described. As shown in FIG. 9 described in the second embodiment, time data (Z count) is acquired based on TOW data included in the HOW word. Therefore, in the received satellite signal, the part other than the HOW word is mistakenly recognized as the HOW word, and the Z count (time data) is obtained by calculating, etc., assuming that bits 1 to 17 are TOW data. As a result, there is a problem that time correction cannot be performed with high accuracy.
Therefore, in the present embodiment, in ST32, when the wristwatch 200 with the GPS time correction device determines whether or not the data that seems to be HOW data has been acquired, and if the data that seems to be the HOW word is acquired, in ST32, It is going to judge whether it is a really correct HOW word.

Specifically, the determination as to whether or not it is correct is performed as follows. In other words, the HOW word shown in FIG. 9 has a feature that is not found in other word data. That is, bit 29 and bit 30 are always “0”.
Therefore, in the present embodiment, the feature of the HOW word is used to determine whether the received data that seems to be a HOW word is really a correct HOW word.

This will be described according to the process of FIG. First, in ST31, the HOW word detection program 531 of FIG. 15 is operated, and it is determined whether or not the wristwatch 200 with a GPS time correction device has detected data that seems to be a HOW word of the satellite signal of the GPS satellite 15.
Next, in ST32, the bit 29 and bit 30 data confirmation program 532 of the HOW word in FIG. 15 operates. Specifically, the program 532 determines whether or not 29 bits and 30 bits of the received data that seems to be a HOW word are “0”, and these bits 29 and 30 are “0”. If yes, the process proceeds to ST6.
Thus, the HOW word detection program 531 is an example of the HOW word detection program 531, and the bit 29 and bit 30 data confirmation program 532 of the HOW word is an example of the small partition identification information determination unit.

  As described above, in this embodiment, since it is possible to confirm that the HOW word includes TOW which is time data, other data is mistakenly recognized as a HOW word, and an erroneous time based on the data is recognized. Acquisition of data can be prevented quickly and in advance.

  The present invention is not limited to the above-described embodiment. In the above-described embodiment, a GPS satellite orbiting the earth is described as an example of the position information satellite. However, the position information satellite of the present invention is not limited to this, and a geostationary satellite, a quasi-zenith satellite, and the like are also included. included.

  DESCRIPTION OF SYMBOLS 10 ... Wristwatch with GPS time correction device, 11 ... Antenna, 12 ... Dial, 13 ... Hand, 15 ... GPS satellite, 20 ... GPS device, 21 ... Time display Equipment: 22 ... RTC, 23 ... Solar cell, 27 ... Display, 31 ... Satellite signal reception operation program, 32 ... GPS satellite search operation program, 33 ... End of all satellite search Judgment program 34 ... Satellite capture judgment program 35 ... Z count acquisition availability determination program 36 ... Z count registration program 37 ... Subframe ID acquisition, registration program 38 ... Subframe ID calculation program, 39 ... subframe ID comparison program, 41 ... Z count data, 42 ... subframe ID data, 43 ... performance Subframe ID, 131 ... parity check decision program 132 ... time correction execution program.

Claims (7)

A satellite signal receiving unit that receives satellite signals transmitted from the position information satellite in units of sections;
A time information acquisition unit for acquiring time information from the satellite signal;
A section identification information acquisition unit that acquires section identification information of the section to which the time information belongs;
A corresponding identification information calculation unit that calculates corresponding block identification information corresponding to the block identification information based on the time information;
A zone identification information determination unit that determines whether the zone identification information is correct based on the zone identification information and the corresponding zone identification information;
The time correction apparatus , wherein when the section identification information determination unit determines that the section identification information is incorrect, a process for determining an error of the satellite signal by a parity check is not performed . The time adjustment device according to claim 1 , further comprising a time correction execution unit that corrects a real-time clock when the partition identification information determination unit determines that the partition identification information is correct . The satellite signal has page information for distinguishing a plurality of the same section identification information having different contents.
A page information acquisition unit for acquiring this page information;
A corresponding page information calculation unit for calculating corresponding page information corresponding to the page information based on the time information;
A page information determination unit that determines whether the page information is correct based on the page information and the corresponding page information;
The time correction apparatus according to claim 1, further comprising: The satellite signal is a GPS satellite signal transmitted from a GPS satellite;
The time information is TOW (Time of Week) information included in the GPS satellite signal,
The correspondence identification information calculation unit, the correspondence partition identification information,
Corresponding partition identification information = ((TOW information) +4) mod 5) +1
The time correction apparatus according to claim 1, wherein the time correction apparatus calculates the time. The satellite signal is a GPS satellite signal transmitted from a GPS satellite;
The time information is TOW (Time of Week) information included in the GPS satellite signal,
The corresponding page information calculation unit
When the TOW information is 0, the corresponding page information is set to 10.
When the TOW information is other than 0,
The corresponding page information = ((TOW information-1) ÷ 5) mod 25 + 1
The time correction apparatus according to claim 3, wherein the time correction apparatus calculates the time. A time display unit having a real-time clock;
A satellite signal receiving unit that receives satellite signals transmitted from the position information satellite in units of sections;
A time information acquisition unit for acquiring time information from the satellite signal;
A section identification information acquisition unit that acquires section identification information of the section to which the time information belongs;
A corresponding identification information calculation unit that calculates corresponding block identification information corresponding to the block identification information based on the time information;
A zone identification information determination unit that determines whether the zone identification information is correct based on the zone identification information and the corresponding zone identification information;
A time correction execution unit that corrects the real-time clock when the partition identification information determination unit determines that the partition identification information is correct;
A time measuring device with a time adjustment device characterized by comprising: A satellite signal receiving unit for receiving a satellite signal transmitted from the position information satellite after being divided for each section;
A time information acquisition unit for acquiring time information from the satellite signal; and
A section identification information acquisition unit that acquires section identification information of the section to which the time information belongs;
A correspondence identification information calculation step in which a correspondence identification information calculation unit calculates corresponding division identification information corresponding to the division identification information based on the time information;
A zone identification information determination unit that determines whether the zone identification information is correct based on the zone identification information and the corresponding zone identification information;
The time correction method , wherein when the section identification information is determined to be incorrect in the section identification information determination step, a process of determining an error of the satellite signal by a parity check is not performed .

Images