JP5428167B2 - 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 around the earth is used, and this GPS satellite is provided with an atomic clock. Such GPS satellites have extremely accurate time information (GPS time).
As an example of a GPS device using a GPS system, a time correction method using this time information, or a radio wave that corrects a display time by analyzing a time code included in a long standard wave instead of a GPS satellite A timepiece has been proposed (Patent Document 1).
In addition, the GPS satellite time information is updated at a predetermined cycle. Therefore, the time information after this predetermined period is predicted, the predicted time of the GPS satellite is calculated, and the position information of itself is obtained using the predicted time. For this reason, a method has been proposed that can be obtained even when the GPS satellite pseudorange and position measurement are not excellent in the reception environment (Patent Document 2).

On the other hand, a method for correcting the time using time information (GPS time) of a GPS satellite has been proposed (Patent Document 3).
According to this method, the navigation message is acquired at full power (the CPU is operated and the respective units are operating) immediately after the power is turned on. And the time information contained in the acquired navigation message is acquired, and time calculation is performed. After that, the next correction timing is obtained by calculating the time from the relationship between the accuracy of the crystal that generates the reference clock signal of the GPS device and the accuracy of the required clock. That is, the time for acquiring the next navigation message (the CPU is in a stopped state and called sleep mode) is obtained. Then, the navigation message is acquired again after the elapse of the sleep mode, and the time is corrected based on the time information from the navigation message.

However, in this method, it takes time to acquire a navigation message immediately after turning on the power or from the sleep mode, so that power consumption increases. Further, when it is desired to reduce power consumption, it is unsuitable to acquire a navigation message. The time for correcting the next time information is calculated from the relationship between the accuracy of the crystal that generates the reference clock signal of the GPS device and the accuracy of the required clock. For this reason, there is a problem that the timing for correcting the time needs to be adjusted by each device.
JP-A-11-21858 (paragraphs 0002 and 0003) Japanese Patent Laid-Open No. 11-125666 Japanese Patent Laid-Open No. 10-82875

  SUMMARY OF THE INVENTION An object of the present invention is to provide a time adjustment device, a time adjustment device with a time adjustment device, and a time adjustment method capable of receiving time data efficiently in a short time and correcting the time without increasing power consumption. To do.

  According to the present invention, the subject is a reception unit that receives a satellite signal transmitted from a position information satellite, a time information generation unit that generates time information, and the time information generated by the time information generation unit. A generation time information storage unit that stores time information, and information before the start of the specific unit of the satellite signal transmitted for each specific unit from the position information satellite is generated as pre-start information based on the generation time information. A time adjustment device having a start information generation unit, wherein the reception unit starts a search for the position information satellite at a predetermined timing based on the pre-start information, and the identification of the satellite signal A stop unit that detects and stops the unit, and the generation time information is achieved by a time adjustment device that corrects the time at a timing when the reception unit stops. That.

  According to the above configuration, the receiving unit performs the search for the position information satellite at a predetermined timing between the start of the specific unit of the satellite signal and the start thereof, and detects and stops the specific unit of the satellite signal. The generation time information is corrected at the timing of stopping the reception unit. For this reason, the time adjustment device can correct the time with the shortest reception time.

  Preferably, the specific unit of the satellite signal includes satellite time information which is time information of the position information satellite, and the receiving unit acquires the satellite time information and determines whether the satellite time information is correct or incorrect. A satellite time information storage unit that stores the satellite time information that is determined to be correct by the determination unit as correct satellite time information, and corrects the generated time information based on the correct satellite time information. And a time adjustment unit for making correction display time information.

According to the above configuration, the receiving unit has the determination unit that acquires the satellite time information of the position information satellite, that is, the Z count, and determines whether the acquired satellite time information is correct or incorrect. When the determination unit determines that it is correct, the time information on the time display unit is corrected based on the satellite time information.
For this reason, the time adjustment device can correct the time at a predetermined timing regardless of the performance of the device, and corrects the time based on the satellite time information determined to be correct. Corrections can be made.

  Preferably, the difference between the generation time information that is the current time correction amount and the satellite time information is a threshold shift amount that is a time shift amount corresponding to an elapsed time from the generation time information at the time of the previous time correction. A threshold deviation determination unit that determines whether the range exceeds the threshold deviation amount, and when the threshold deviation determination unit determines that the range exceeds the threshold deviation amount range, the time correction unit The time correction apparatus is characterized in that the generation time information is not corrected based on the information.

According to the above configuration, the current time correction amount when the time correction unit corrects exceeds the threshold shift amount range that is the time shift amount corresponding to the elapsed time from the generation time information at the previous time correction. A threshold value deviation determination unit for determining whether or not When the threshold deviation determination unit determines that the current time correction amount exceeds the threshold deviation amount range, the time correction unit does not perform time information using the current satellite time information. .
For this reason, if the current satellite time information is uncertain, the time is corrected based on the satellite time information, and the amount of deviation does not increase further.

  Preferably, the specific unit of the satellite signal is configured as a frame information unit in which one of five subframe information units including at least the satellite time information is a unit, and the receiving unit includes the first subframe information unit. The time correction apparatus is configured to receive the satellite time information in frame information units.

  According to the above-described configuration, the satellite time information acquired by the receiving unit acquires the satellite time information in the first subframe information unit of the satellite signal, so that time correction can be reliably performed at a predetermined time. Is possible.

  Preferably, the information before the head generated by the start information generation unit is configured to correct the generation time information at a timing of 0 seconds or 30 seconds.

  According to the said structure, the information before the head which a start information generation part produces | generates corrects production | generation time information at the timing of 0 second or 30 seconds. For this reason, when the time adjustment device corrects the time, the time is corrected at the timing of 0 seconds or 30 seconds, so that the user can use it easily.

  Preferably, the first subframe information unit includes position information satellite health information indicating a satellite state of the position information satellite, and the reception unit has passed a predetermined time from the previous correction of the generation time information. The position information satellite health information is acquired, and further includes a health state determination unit that determines the state of the position information satellite based on the position information satellite health information. It is a time correction device.

According to the above configuration, the reception unit acquires the position information satellite health information indicating the satellite state of the position information satellite when a predetermined time has elapsed since the previous correction of the generation time information. And it has a health state judgment part which judges the state of a position information satellite, that is, the operating state of the satellite and whether the satellite itself is in a normal state or an abnormal state.
For this reason, when a certain time has elapsed since the previous correction of the generation time information, position information satellite health information indicating the satellite state of the position information satellite is acquired. For this reason, when the state of the position information satellite has changed since the previous reception, the time can be adjusted according to the state. If it is determined that there is an abnormality in the position information satellite, the satellite time information from the position information satellite is not used for time adjustment. For this reason, the time adjustment device does not adjust the time based on the abnormal satellite time information.

  Preferably, when the health state determination unit determines that the position information satellite is in a normal state based on the position information satellite health information, the threshold shift determination unit determines that the threshold shift amount exceeds the range. In this case, the receiving unit is configured to further acquire the satellite time information in the subframe information unit next to the satellite signal, and each satellite time information in the subframe information unit is obtained as satellite time information. The satellite time information storage unit that stores the data as data, and the satellite time information data in which at least two of the satellite time information data are within a range corresponding to one subframe information unit of the satellite signal. The time correction unit is configured to correct the generation time information by using the time correction unit.

  According to the configuration, when the health state determination unit determines that the satellite state of the position information satellite is normal, that is, when the health state determination unit determines that there is no abnormality in the position information satellite, When the range of the threshold deviation amount is exceeded, the satellite time information of the first subframe information unit is regarded as having some trouble. The receiving unit acquires satellite time information of the next subframe information unit. When the satellite time information acquired from each subframe information unit is compared, and consistency is obtained with at least two satellite time information, time correction is performed using the satellite time information. For this reason, the time adjustment device can reliably perform time adjustment with high accuracy.

  Preferably, when the health state determination unit determines that the position information satellite is not in a normal state based on the position information satellite health information, the reception unit receives the other position information satellite. It is the time correction apparatus characterized by having.

  According to the above configuration, when it is determined that the position information satellite health information of the position information satellite is not normal, that is, when it is determined that there is some abnormality in the position information satellite, the other position information satellites are received. It has become. Therefore, the time information can be corrected by the satellite time information of the satellite signal from the position information satellite without any abnormality. For this reason, the time adjustment device can reliably perform time adjustment with high accuracy.

  Preferably, the first subframe information unit includes week number information that is count information of elapsed time from the start point of the satellite time information, and generates the time information of the time correction device. The internal time counter includes calendar information, and when the calendar information is changed, the receiving unit is configured to acquire the week number information, and the calendar information is the week number. The time correction device is characterized in that it is configured to be corrected based on information.

  According to the configuration, the receiving unit acquires the week number information included in the first subframe information unit of the satellite signal from the position information satellite. For this reason, when the calendar information in the time adjustment device is changed or reset by the user's operation, the time adjustment device can correct it based on the week number information. Convenient.

  According to the present invention, the subject is a reception unit that receives a satellite signal transmitted from a position information satellite, a time information generation unit that generates time information, and the time information generated by the time generation unit. A generation time information storage unit for storing information, and a start of generating information before the start of the specific unit of the satellite signal transmitted from the position information satellite for each specific unit as pre-start information based on the generation time information An information generator, and a time measuring device with a time correction device, wherein the receiving unit starts a search for the position information satellite at a predetermined timing based on the pre-start information, and the satellite signal And a stop unit that detects and stops the specific unit, and the generation time information is time-corrected at a stop timing of the receiving unit. It is achieved by when the apparatus.

  According to the present invention, the problem is identified from a time information generation step for generating time information, a generation time information storage step for storing the time information generated in the time generation step as generation time information, and a position information satellite. A start information generating step of generating information before the start of the specific unit of the satellite signal transmitted for each unit as pre-start information based on the generation time information, and searching for the position information satellite based on the pre-start information Of the generation time information at a timing of stopping the stop step of the reception step, a reception step of starting a stop step of detecting and stopping the specific unit of the satellite signal This is achieved by a time correction method comprising the step of performing time correction.

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 correction device according to the present invention, for example, a wristwatch 10 with a GPS time correction device (hereinafter referred to as “GPS wristwatch 10”), and FIG. 2 is a schematic diagram of FIG. FIG. FIG. 3 is a schematic diagram showing the main hardware configuration of the GPS wristwatch 10 of FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the GPS wristwatch 10 displays a time display unit on which a dial 12, a second hand, a minute hand, an hour hand and other hands 13 are arranged, and various messages of latitude and longitude. A display 14 including an LCD display panel is formed. The display 14 displays message information as well as position information such as latitude, longitude, and city name. The pointer 13 is driven by a step motor including a motor coil 19 and the like via a gear.

As shown in FIG. 2, the GPS wristwatch 10 has a GPS antenna 11. The GPS antenna 11 is provided in the GPS device 40 (see FIG. 3). The GPS antenna 11 is a patch antenna that receives satellite signals from a plurality of GPS satellites 15 orbiting the earth over a predetermined orbit. The GPS antenna 11 is disposed on the surface of the dial 12 opposite to the time display surface. The dial 12 is formed of plastic or the like that is a material that transmits radio waves that are signals from the GPS satellite 15.
Note that the GPS satellites 15 are examples of position information satellites, and a plurality of GPS satellites 15 exist above the earth.
Further, the outer case 17 is made of a metal such as SUS or titanium. The bezel 16 is preferably made of ceramics in order for the GPS antenna 11 provided in the GPS device 40 to improve the performance of receiving satellite signals from the GPS satellite 15. The battery 24 is a secondary battery such as a lithium ion battery. And the magnetic sheet 21 is arrange | positioned under the battery 24, and the coil 22 for charging is arrange | positioned through the magnetic sheet 21. As shown in FIG. Therefore, the battery 24 can be charged with electric power from an external charger by electromagnetic induction by the charging coil 22. Further, the magnetic sheet 21 can bypass the magnetic field. For this reason, the magnetic sheet 21 can reduce the influence of the battery 24 and can perform energy transmission efficiently. And the back glass part 23 is arrange | positioned in the center part of the back cover 26 for electric power transfer.
The GPS wristwatch 10 is configured as described above.

As shown in FIG. 3, the GPS wristwatch 10 includes a time display device 45, a GPS device 40, and a time correction device 44, and has a configuration that also functions as a computer. Further, the display 14 shown in FIGS. 1 and 2 is also connected.
Hereinafter, each configuration shown in FIG. 3 will be described.
As shown in FIG. 3, the GPS wristwatch 10 includes, for example, a GPS device 40 which is a receiving unit, and a signal received from the GPS satellite 15 of FIG. The baseband unit 30 extracts a signal via a frequency (radio frequency) 27.
That is, the filter (SAW) 31 is a band-pass filter and extracts a 1.5 GHz satellite signal. The satellite signal extracted in this way is amplified by the LNA, mixed with the signal of the VCO 41 by the mixer 46, and down-converted to IF (intermediate frequency). The clock signal for the PLL circuit 34 is generated from a crystal oscillation circuit (TCXO) 32 with a temperature compensation circuit. The down-converted satellite signal passes through an IF filter 35 and an IF amplifier, and is converted into a digital signal by an ADC (A / D converter) 42. The baseband unit 30 calculates satellite signals based on the control signal. Time data and the like obtained by the baseband unit 30 are stored in the storage unit, and the corrected time information is displayed through the drive circuit 43.

Thus, the receiving device 40a, which is a part of the GPS device 40, includes the RF unit 27 and the baseband unit 30, and the RF unit 27 includes a PLL circuit 34, an IF filter 35, a VCO 41, an ADC (A / D conversion). Instrument) 42 and the like.
The baseband unit 30 includes a DSP (Digital Signal Processor) 39, a CPU (Central Processing Unit) 36, and an SRAM (Static Random Access Memory) 37, a crystal oscillation circuit (TCXO) 32 with a temperature compensation circuit, and a flash memory. 33 etc. are also connected. An RTC (real time clock) 38 is disposed in the control unit 20 and is an example of a time information generation unit that generates time information. The RTC 38 is counted up with a reference clock determined by a crystal resonator connected to the control unit 20.

The charging coil 22 charges the secondary battery, which is the battery 24, through the charging control circuit 28, and supplies driving power to the time adjustment device 44 and the like through the regulator 29. And the control part 20 can send a control signal to the receiver 40a, and can control the reception operation | movement of the GPS apparatus 40 via the control part 20 now.
That is, the timepiece mechanism in the present embodiment is a so-called electronic timepiece.
The RTC 38 is an example of a time information generation unit that generates time information. The GPS device 40 is an example of a receiving unit that receives a satellite signal transmitted from a position information satellite (for example, the GPS satellite 15). And the internal time data 73b (refer FIG. 7) which is the time information produced | generated by RTC38 is an example of production | generation time information.

4 to 7 are schematic diagrams showing the main software configuration of the GPS wristwatch 10, and FIG. 4 is an overall view.
As shown in FIG. 4, the GPS wristwatch 10 has a control unit 20. The control unit 20 executes various programs in the various program storage units 50 shown in FIG. 4, and processes various data in the first various data storage unit 60 and various data in the second various data storage unit 70. It has a configuration.
In FIG. 4, the various program storage unit 50, the first various data storage unit 60, and the second various data storage unit 70 are shown separately, but actually the data is stored separately in this way. However, they are shown separately for convenience of explanation.
The first various data storage unit 60 in FIG. 6 mainly shows data stored in advance. Further, the second various data storage unit 70 in FIG. 7 mainly shows data after the data in the first various data storage unit 60 is processed by the programs in the various program storage units 50.
FIG. 5 is a schematic diagram showing data in the various program storage units 50 of FIG. 4, and FIG. 6 is a schematic diagram showing data in the first various data storage units 60 of FIG. FIG. 7 is a schematic diagram showing data in the second various data storage unit 70 of FIG.
8 and 9 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. 8 and 9, and the various programs and various data of FIGS.

First, in ST10 of FIG. 8, it is determined whether or not the GPS wristwatch 10 is at the reception timing.
Specifically, the reception timing determination program 51 in FIG. 5 determines whether the time information generated by the RTC 38 is the time correction timing data 61a in FIG.
Here, the time correction timing data 61a is set based on the following time, for example. Assuming that the time accuracy of the GPS wristwatch 10 is about 0.5 seconds at the maximum, the number of times the satellite signal is received from the GPS satellite 15 or the like to correct the time may be a few times a day. . Therefore, it is preferable that the GPS wristwatch 10 is in an environment in which satellite signals can be easily received from a certain GPS satellite 15. Therefore, it is preferable that the time correction timing data 61a serving as the reception timing is set with reference to the time in an environment where reception is easy. Therefore, the time when the user is not using the GPS wristwatch 10 and is likely to be removed from his arm and placed indoors, for example, 2 am or 3 am in the middle of the night, is a standard. It is said. Alternatively, the commuting time zone in which the user is using the GPS wristwatch 10 and the usage environment is highly likely to be outdoors, for example, 7 am or 8 am, is used as a reference.
In the present embodiment, the time adjustment timing data 61a is set so that the time adjustment can be performed by acquiring time data at the timing of 0 seconds or 30 seconds. As will be described later, the specific unit of the satellite signal of the GPS satellite 15 is frame data. This frame data includes five subframe data (subframe 1 to subframe 5). That is, the time correction timing data 61a is set before the start of the subframe 1, which is the head of the frame data. “Before the start of subframe 1” is data before the preamble data at the head of so-called subframe 1, and is data in which the activation time of the RF unit 27 of the GPS device 40 and the search time of the GPS satellite 15 are estimated. Therefore, for example, it is about 10 seconds before the beginning of subframe 1. That is, for example, the reception timing is set so that the time is corrected at a timing of 0 seconds with reference to 2 am. Specifically, the time correction timing data 61a is data before 2:00 am, for example, about 10 seconds. Then, the reception timing determination program 51 of FIG. 5 determines whether the time information generated by the RTC 38 is 1:59:50 am, which is the time correction timing data 61a. Alternatively, for example, the reception timing is set so that the time is adjusted at a timing of 30 seconds with 7 am as a reference. Specifically, the reception timing determination program 51 of FIG. 5 determines whether the time information generated by the RTC 38 is 7:00:20 am, which is the time correction timing data 61a.

That is, the reception timing related to the time correction timing is a predetermined timing. For example, the time display is performed when the second hand of the pointer 13 arranged on the dial 12 of the time display device 45 is 0 second or 30 seconds. The timing is such that the display time of the device 45 is corrected. As will be described later, since the head of subframe 1 is transmitted at the timing of 0 seconds and 30 seconds, the GPS device 40 can receive at the timing of 0 seconds and 30 seconds. For example, time information can be acquired by detecting the start of subframe 1.
Then, the reception timing determination program 51 of FIG. 5 counts at the RTC 38 and determines whether the time correction timing data 61a has been reached. That is, the reception timing determination program 51 is an example of a start information generation unit that generates reception timing based on the internal time data 73b generated by the RTC 38.
If the reception timing has not been reached, the count is performed until the reception timing is reached.

On the other hand, if the reception timing determination program 51 of FIG. 5 determines that the reception timing has been reached, the process proceeds to ST11 and starts reception. That is, the GPS device 40 described above is activated to prepare for the GPS satellite 15 to be searched.
Specifically, as described in FIG. 3 above, the GPS device 40 starts to operate and receives a GPS signal, which is a satellite signal, from the GPS antenna 11. The pattern is generated.

  Then, the process proceeds to ST12 and a satellite search is started. In other words, the satellite search program 52 in FIG. 5 searches the GPS satellites 15 that can be synchronized by the GPS device 40 adjusting the generation timing of the C / A code pattern of the GPS satellites 15.

Next, proceeding to ST13, the GPS device 40 adjusts the generation timing of the C / A code pattern of the GPS satellite 15 and determines whether it takes a certain time or more until synchronization is possible. Specifically, the reception stop determination program 57 in FIG. 5 counts the time from the start of reception and determines whether it takes time to search for the GPS satellite 15. If it takes more than a certain amount, it is determined that a timeout has occurred, the process proceeds to ST14, and the reception ends. That is, the reception stop determination program 57 of FIG. 5 determines that it is time-out when a predetermined time has elapsed, and forcibly ends the operation of the GPS device 40.
For this reason, when the GPS wristwatch 10 is in an environment incapable of receiving, for example, indoors, if the GPS device 40 is operated forever, power is consumed. For this reason, in such a case, the operation of the GPS device 40 is terminated when a certain time has elapsed, so that wasteful power consumption can be reduced.

On the other hand, if it is not timed out in ST13, the process proceeds to ST15.
In ST15, it is determined whether the GPS satellite 15 has been captured. That is, in the satellite search program 52 of FIG. 5, the GPS device 40 searches for the GPS satellite 15 and synchronizes. Then, it is determined whether or not a navigation message which is a satellite signal of a GPS satellite 15 to be described later can be demodulated.
If the GPS satellite 15 cannot be acquired, the process returns to ST12, and the GPS satellite 15 is searched again to acquire another GPS satellite 15.

On the other hand, if the GPS satellite 15 can be captured, the process proceeds to ST16 to acquire a satellite signal message.
Here, before explaining the process of ST16, a navigation message which is a signal (satellite signal) transmitted from the GPS satellite 15 will be explained.

FIG. 18 is a schematic explanatory diagram showing GPS satellite signals.
As shown in FIG. 18A, a signal is transmitted from each GPS satellite 15 in units of one frame data (30 seconds). This one frame data has five subframe data, that is, subframe 1 to subframe 5 (one subframe data is 6 seconds). Each subframe data has 10 words (one word is 0.6 seconds).
In addition, the first word of each subframe data is a TLM word in which TLM (Telemetry word) data is stored. In the TLM word, as shown in FIG. Stored.
The word following the TLM is a HOW word in which HOW (hand over word) data is stored, and the GPS time information of a GPS satellite called TOW (Time of Week, also referred to as “Z count”) is stored at the top thereof. Has been.
The GPS time information is displayed in seconds since 0 o'clock every Sunday, and returns to 0 o'clock on the next Sunday. In other words, the GPS time information is information in seconds indicated every week from the beginning of the week, and the elapsed time is a number expressed in units of 1.5 seconds. The GPS time information is also referred to as Z count (hereinafter referred to as “Z count data”), and is a clue that the GPS device 40 knows the current time.

The week number of the GPS time information is assigned to the week, and is included in the navigation message that is a satellite signal from the GPS satellite 15 as week number data.
The starting point of this GPS time information is 16:00, January 6, 1980 in UTC (Universal Coordinated Time), and the week starting on this day has a week number 0. And the receiving side is the structure which can acquire GPS time information by acquiring the data of a week number and elapsed time (second).
The week number data is data that is updated on a weekly basis.
Therefore, if the week number data is once acquired on the receiving side and the elapsed time from the time when the week number data was acquired is counted, it is acquired without acquiring the week number data again. The current week number data of the GPS satellite 15 is known from the current week number data and the elapsed time. Therefore, if the Z count data is acquired, the current GPS time can be roughly estimated. For this reason, normally, only the Z count data is obtained, so that the receiving operation on the receiving side is performed in a short time, and thus low power consumption can be achieved.
Also, depending on the situation, the acquired week number data may be deleted, the count of elapsed time from the time when the week number data was acquired may deviate, or a certain time may elapse after the week number data is acquired. In such a case, if the week number data is also received from the satellite signal from the GPS satellite 15, the receiving side acquires the current GPS time information from the newly received week number data and the Z count data. Be able to.

As shown schematically in FIG. 18, the navigation message included in the signal from the GPS satellite 15 is data whose frame data (main frame configuration) is 50 bps and whose total number of bits is 1500 bits as the main frame.
The main frame data is divided into five subframe data each having 300 bits (300 bits) (FIG. 18A).
One frame data corresponds to 30 seconds. Accordingly, one of the subframe data is data corresponding to 6 seconds. As described above, the first two words of each subframe data include ZLM (TOW) data of TLM word and HOW word. The Z count data starts from subframe 1 and is every 6 seconds for each subframe data. That is, subframe 1 to subframe 5 have Z count (TOW) data of TLM words and HOW words. The Z count (TOW) data is time information of the next subframe data. For example, the Z count data of subframe 1 is the time data of subframe 2.

Further, as shown in FIGS. 18A and 18B, the navigation message which is a satellite signal from the GPS satellite 15 includes the preamble data, the TOW of the HOW word, each subframe data, for example, the ephemeris (each GPS satellite 15 Detailed orbit information for each), almanac (general orbit information of all GPS satellites 15), UTC data (world coordinating time information, etc.). More specifically, the subframe data of the navigation message is from subframe 1 to subframe 5, and the frame data is composed of these five subframe data as one unit. The subframe data is composed of 1 to 10 word data as described above.
In the word 3 of the subframe 1, as shown in FIG. 17, both the above-described week number (WN) data and the satellite health state (SVhealth or satellite health information) which is the signal data indicating the operation state of the GPS satellite 15 itself. Each data that indicates). FIG. 17 is a schematic conceptual diagram for explaining a part of each word data (WORD 1 to WORD 5) of the subframe 1.

Since the signal from the GPS satellite 15 is transmitted as described above, the GPS reception in the present embodiment is phase-synchronized with the C / A code from the GPS satellite 15.
That is, in order to acquire such frame data of the GPS satellite 15, the GPS device 40 on the receiving side needs to synchronize with the signal of the GPS satellite 15.
In this case, a C / A code (1023 chip (1 ms)) is used particularly for synchronization in units of 1 ms. This C / A code (1023 chip (1 ms)) is different for each of a plurality of GPS satellites 15 orbiting the earth and is unique.
Therefore, when a satellite signal of a specific GPS satellite 15 is received, it is received by generating a C / A code unique to any GPS satellite 15 from the GPS device 40 as a receiving unit and performing phase synchronization. Be able to.
When synchronized with the C / A code (1023 chip (1 ms)), the TLM word preamble data and HOW word of the subframe data can be received, and the Z count data of the HOW word can be acquired. Then, after acquiring the Z count (TOW) data of the TLM word and the HOW word, the GPS device 40 can also acquire the week number information (WN) data and the satellite health condition information (SVhealth) data (see FIG. 17).

Then, the operating state of the GPS satellite 15 itself being received can be determined from the satellite health state information (SVhealth) data. That is, if the GPS satellite 15 itself has some trouble or is a test satellite, it can be determined from the satellite health state information (SVhealth) data.
Then, it is possible to determine whether or not the acquired Z count data is reliable by performing a parity check. That is, it is possible to confirm correctness with the parity data after the TOW data of the HOW word. If an error is confirmed by the parity check, the Z count data can be regarded as having some abnormality and not used for time correction.

As described above, the frame data in FIG. 18 is an example of a frame information unit, and the subframe data is an example of a subframe data information unit, which is an example of a specific unit of a satellite signal. The Z count (TOW) data is an example of satellite time information of the position information satellite (GPS satellite 15). The week number information (WN) data is an example of week number information that is count information of elapsed time from the starting point of the satellite time information. The Z count data, week number (WN) data, TLM word, HOW word, etc. are examples of satellite signal information. The satellite health status information (SVhealth) data is an example of location information satellite health information indicating the satellite status of the location information satellite, and is an example of another satellite information unit.
The navigation message which is the satellite signal of the GPS satellite 15 is configured as described above.

Therefore, if the satellite can be captured in ST15, the process proceeds to ST16. In ST16, it is determined whether the Z count data has been acquired.
Specifically, the time data acquisition program 53 of FIG. 5 acquires Z count (TOW) data, which is an example of the satellite time information described above, from a navigation message that is a satellite signal from the GPS satellite 15. And it is memorize | stored in the receiving satellite time information storage part 71 of FIG. 7 as receiving satellite time data 71a. That is, acquiring the Z count data means that the Z count (TOW) data can be acquired after the synchronization is established with the preamble data of the TLM word as described above. Then, the time information consistency determination program 501 in FIG. 5 determines whether or not the received satellite time data 71a in FIG. 7 which is the acquired Z count (TOW) data is reliable. The time information consistency determination program 501 performs the parity check as described above. In other words, the time information consistency determination program 501 confirms the correctness with the parity data after the TOW data of the HOW word. If an error in the Z count data is confirmed by the parity check of the time information consistency determination program 501, the acquired Z count data is regarded as having some abnormality and is not used for time correction. Therefore, if an abnormality is found, the time data acquisition program 53 in FIG. 5 considers that the Z count data could not be acquired, and returns to ST10.

  On the other hand, if the time information consistency determination program 501 determines that there is no abnormality, the time data acquisition program 53 of FIG. 5 determines that the acquired Z count data can be used for time correction, and stores the received satellite time information. The reception satellite time data 71 a in the unit 71 is stored as the first reception time data 73 a 1 of the reception time data 73 a in the time data storage unit 73. In this case, the process proceeds to ST17 in FIG.

In ST17, it is determined whether the Z count data of subframe 1 has been acquired.
Specifically, the subframe confirmation program 54 of FIG. 5 determines whether the Z count data of the subframe 1 is based on the acquired Z count data. That is, the subframe confirmation program 54 in FIG. 5 uses the first reception time data 73a1 from the first reception time data 73a1 of the reception time data 73a in the time data storage unit 73 in FIG. It comes to judge whether it is.

Therefore, even if the GPS device 40 intends to receive and acquire the Z count data of the subframe 1 at a predetermined reception timing, it is actually the Z frame of the subframe 2 that is the next subframe data. There may be a case where count (TOW) data or Z count (TOW) data of subframe 5 which is subframe data of the previous frame data is received.
Even in such a case, the GPS wristwatch 10 has the subframe confirmation program 54 shown in FIG. 5, so the GPS wristwatch 10 reliably acquires the Z count (TOW) data of the subframe 1. Can be done.

If the subframe confirmation program 54 of FIG. 5 determines in ST17 that the first reception time data 73a1 that is the acquired Z count data is not the Z count data of subframe 1, the process proceeds to ST18.
In ST18, the reception stop determination program 57 temporarily stops the reception of the GPS device 40.
In ST19, the subframe number of the subframe data is confirmed from the acquired Z count (TOW) data.
As described above, the Z count (TOW) data is data transmitted from the GPS satellite 15 accurately every 6 seconds in synchronization with UTC. For this reason, the GPS wristwatch 10 knows which subframe data is received from the acquired Z count data. For this reason, for example, when the accuracy of the RTC 38, which is an example of the time generation unit of the internal time data 73b, is greatly deviated in some situation, when the deviation is 6 seconds or more, the reception start timing is also deviated. It will shift by the minute. Even if the Z count data of subframe 1 is intended to be acquired, the Z count data of other subframe data may be acquired. Even in such a case, since the GPS wristwatch 10 has the subframe confirmation program 54 of FIG. 5, it can be confirmed which subframe data it is. Therefore, in ST19, the subframe number of the acquired subframe data is confirmed, and the process proceeds to ST20.

In ST20, the reception timing of the next subframe 1 is set. Specifically, the reception timing setting program 58 in FIG. 5 sets the reception timing of the next subframe 1 from the confirmed subframe number, the time information of the acquired Z count data, and the internal time data 73b. Then, returning to ST10, it waits until the set reception timing and starts reception. During this time, the GPS device 40, which is an example of a receiving unit, is temporarily stopped.
Here, in FIG. 9, the process proceeds from ST23 to symbol C, which indicates that the process proceeds to symbol C in FIG. 8 and returns to ST10. The same applies to the other symbols A and B in FIGS.

On the other hand, if it is determined in ST17 that the Z count data of subframe 1 has been acquired, the process proceeds to ST21. In ST21, the above-described satellite health state information (SV health, also referred to as satellite health information) data is acquired.
Specifically, the other satellite information acquisition program 55 in FIG. 5 acquires satellite health state information (also referred to as SVhealth or satellite health information) data included in word 3 of subframe 1 of the satellite signal of GPS satellite 15 described above. To do. The other satellite information acquisition program 55 in FIG. 5 stores the acquired satellite health state information data as the satellite health state data 72a of the satellite health state information storage unit 72 in FIG.

Next, the process proceeds to ST22, where it is confirmed whether the satellite health state data 72a indicates that the GPS satellite 15 is normal. Specifically, the satellite health status confirmation program 56 in FIG. 5 determines the status of the GPS satellite 15 based on the satellite health status data 72a in FIG. 7 which is the acquired satellite health status information data.
That is, as described above, the satellite health state data 72a, which is the acquired satellite health state information data, is data representing the operation state of the GPS satellite 15 and is a code representing the state of the satellite. Since the satellite health status data 72a indicates that there is some abnormality when the code data is other than 0, it can be seen that the GPS satellite 15 cannot be used. If it is normal, the code data of the satellite health state data 72a is 0, so that the satellite is in a normal state.
Therefore, the satellite health status data 72a of FIG. 7 can be confirmed if there is any malfunction or the like in the GPS satellite 15. That is, it can be determined whether or not the satellite signal from the GPS satellite 15 is reliable.

If the satellite health status data 72a in FIG. 7 indicates an abnormality of the GPS satellite 15 in ST22, the process proceeds to ST23. In ST23, the reception stop determination program 57 of FIG. 5 temporarily stops the reception of the GPS device 40. Then, the reception satellite change program 59 in FIG. 5 stores the change reception satellite synchronization data 74a in the change reception satellite synchronization information storage unit 74 in FIG. 7 so as to change the GPS satellite 15 to be received. Then, returning to ST10, reception is started based on the changed reception satellite synchronization data 74a.
For this reason, when the satellite health state data 72a (an example of the position information satellite health information) that is the satellite health state information data acquired from the GPS satellite 15 (an example of the position information satellite) is not in a normal state, Since it is determined that there is an abnormality and another GPS satellite 15 (an example of a position information satellite) is received, time information is obtained by a satellite signal from a GPS satellite 15 (an example of a position information satellite) that has no abnormality. Can be corrected. For this reason, it becomes possible to perform time correction with high accuracy.

On the other hand, if it is determined in ST22 that the satellite health status data 72a does not indicate abnormality of the GPS satellite 15, the process proceeds to ST24.
In ST24, it is determined whether or not the internal time information is consistent. Specifically, the threshold value deviation determination program 503 in FIG. 5 determines the amount of deviation between the internal time data 73b in FIG. 7 generated by the RTC 38, which is the current time information, and the first reception time data 73a1 in the reception time data 73a. Then, it is determined whether the consistency verification threshold value data 62a of the consistency verification threshold value storage unit 62 in FIG. The consistency verification threshold data 62a is, for example, about 0.5 seconds per day. This is due to the accuracy of the crystal (crystal resonator) connected to the control unit 20 (see FIG. 3) serving as the reference clock source oscillation.
The RTC 38 is counted up with a reference clock determined by a crystal resonator connected to the control unit 20.

If the consistency is not obtained in ST24, the process proceeds to ST25.
That is, the internal time data 73b is a value related to the performance of the generated RTC 38. The internal time data 73b is caused by a frequency shift of a crystal (quartz crystal unit) serving as a reference clock for the RTC 38 (hereinafter also referred to as a frequency shift of the RTC 38). Therefore, when the frequency deviation becomes large due to some influence and the deviation amount between the internal time data 73b in FIG. 7 and the first reception time data 73a1 becomes larger than the consistency verification threshold data 62a in FIG. Therefore, it is determined that consistency has not been achieved, and the process proceeds to ST25.
In ST25, the time data acquisition program 53 of FIG. 5 obtains the Z count data of subframe 2 and subframe 3 as the next subframe data from the same GPS satellite 15 as when the Z count data of subframe 1 was acquired. get. Then, the Z count data of subframe 2 and the Z count data of subframe 3 are stored in the second reception time data 73a2 and the third reception time data 73a3 of the reception time data 73a of the time data storage unit 73 in FIG. . Incidentally, also in this case, the time information consistency determination program 501 of FIG. 5 described above performs a parity check which is a correct / incorrect determination of each Z count data.

  Next, the process proceeds to ST26, and the Z count data in which the consistency is obtained at least twice is adopted for each of the Z count data of subframe 1, subframe 2, and subframe 3. That is, the reception time data consistency determination program 505 of FIG. 5 receives the first reception time data 73a1, the second reception time data 73a2, and the third reception time data 73a3 which are the reception time data 73a in the time data storage unit 73 of FIG. When there is a shift of 6 seconds or 12 seconds, which is a shift amount corresponding to each subframe data, the reception time data 73a with the consistency is adopted. . That is, as described above, the subframe data is transmitted in units of 6 seconds, and the Z count data of each subframe data is also shifted by 6 seconds. Therefore, since the first reception time data 73a1 is the Z count data of subframe 1 and the second reception time data 73a2 is the Z count data of subframe 2, these Z count data are shifted by 6 seconds. Since the third reception time data 73a3 is the Z count data of the subframe 3, the difference from the first reception time data 73a1 is 12 seconds. The second reception time data 73a2 and the third reception time data 73a3 are 6 seconds apart. Accordingly, the reception time data 73a that is within the shift amount corresponding to the subframe data is adopted. As described above, when the frequency shift of the RTC 38 generating the internal time data 73b is large, the consistency with the internal time data 73b is not determined.

That is, as shown in the schematic image diagram of the reception time (reception period) in FIG. 16, the image in the case of acquiring up to the Z count data of this subframe 3 is a sequence as shown in FIG.
In this case, the GPS device 40 starts the reception operation about 10 seconds before the head of the subframe 1 and operates for the time to acquire the Z count (TOW) data of the subframe 3. Therefore, the GPS device 40 only takes about 15 seconds from the beginning of the subframe 1 to obtain the Z count data of the subframe 3 even in the reception time in this case. Can do. In this case, when the satellite health state confirmation program 56 (an example of the health state determination unit) in FIG. 5 determines that the satellite state of the GPS satellite 15 (an example of the information satellite) is normal, that is, the satellite health. When the state confirmation program 56 (health condition determination unit) determines that the GPS satellite 15 (positional information satellite) has no abnormality, the range of the consistency verification threshold data 62a (an example of the threshold deviation amount) in FIG. Is exceeded, the Z count data (an example of the first subframe information unit) of subframe 1 (an example of the first subframe information unit) is regarded as having some trouble, and the GPS device 40 (an example of a receiving unit) Z count data (an example of satellite time information) of subframes 2 and 3 (an example of the next subframe information unit) is acquired.
Then, when the data in the reception time data 73a of FIG. 7 which is the Z count data of the subframes 1, 2, and 3 is compared, and the consistency is obtained with at least two satellite time information, the satellite time information is Use to correct the time.
Therefore, it becomes possible to perform time correction with high accuracy.

  Here, the reception time data 73a of FIG. 7 in which the consistency of each Z count data of subframe 1, subframe 2, and subframe 3 is adopted is adopted. For example, the Z count of subframe 2 is adopted. When the consistency between the data and the internal time data 73b in FIG. 7 is within the consistency verification threshold data 62a in FIG. 6 described above, the reception ends without obtaining the Z count data of subframe 3 May be. A schematic image of the reception time (reception period) in this case is a sequence as shown in FIG. That is, reception of the GPS device 40 is started from before the subframe 1, a satellite search is performed, Z count (TOW) data is acquired from the top of the subframe 1, and satellite health state information data (satellite health) of the word 3 is further acquired. 16 is simply health) and is stored in the satellite health state data 72a of FIG. 7, and a reception stop period for temporarily stopping reception is provided, and the next subframe data which is subframe 2 is set. Reception is performed again from the front, and Z count (TOW) data is acquired.

That is, the GPS device 40 of the GPS wristwatch 10 receives the subframe 1. At this time, as described above, the Z count (TOW) data of the HOW word is acquired via the TLM.
The Z count (TOW) data is the data of the satellite time information as described above, and the Z count data is obtained from the GPS satellite 15.
Therefore, it is not necessary to acquire other data, for example, data such as ephemeris and almanac shown in FIG. However, as shown in FIG. 18 (a), subframes are transmitted in order from subframe 1 (A) to subframe 5 (E), and each subframe data is sequentially transmitted from a word of TLM to a word such as an ephemeris. Will be sent.
For this reason, for example, even when the GPS device 40 wants to obtain only the Z count (TOW) data stored in the HOW word of the subframe data, for example, the subframe 1 (A) of FIG. After obtaining the HOW Z count (TOW) data, the satellite correction data from word 3 and word 4 to word 10 of frame 1 is received, and the HOW Z count (TOW) data of subframe 2 is obtained. It is like that.
In this case, the GPS device 40 of the GPS wristwatch 10 continues to receive during that time, resulting in a large power consumption.

Therefore, for example, as shown in FIG. 16 (d), after receiving the word data of HOW in subframe 1 and receiving up to word 3 including week number data and satellite health condition information data, the next second sub Until the TLM word data of the frame is transmitted, a reception stop period is provided so that the power for the satellite signal reception operation of the GPS device 40 is reduced from the battery 24 via the regulator 29. If it does in this way, the power consumption by the receiving operation of the GPS apparatus 40 can be made small.
Specifically, the GPS device 40 is already synchronized with the C / A code of the GPS satellite 15. For this reason, it synchronizes with the start position of the TLM word in subframe 1. Then, the HOW Z count (TOW) data, which is the next word data following the TLM, can be acquired.
The subframe data is 6-second data and 10-word data, so the reception time of each word data is 0.6 seconds.
Therefore, after 1.2 seconds from the start of the TLM word of the subframe 1 and measured by the RTC 23 or the like, the power supply supplied from the battery 24 to the GPS device 40 via the regulator 29 as shown in FIG. In this case, the Z count (TOW) data of subframe 1 can be acquired.

  Since the sub-frame data is 10 word data, the period of 4.8 seconds corresponding to the time of 8 word data is set as the above-described reception stop period, and again as the reception period after the reception stop period elapses. If the power supply from the battery 24 to the GPS device 40 via the regulator 29 is increased, the TLM and HOW Z count (TOW) data of the subframe 2 can be acquired. Similarly, the reception stop period is set again after 1.2 seconds. Then, the Z count (TOW) data of subframe 1 and subframe 2 can be acquired. And since the reception stop period is provided, power consumption can be reduced. Such a reception stop period can be determined by the reception stop determination program 57 and the reception timing setting program 58 of FIG.

  Actually, since there is an error such as RTC23, the above-mentioned 1.2 seconds and 4.8 seconds are set so that the reception can be started a little before (FIG. 16 (d)). Similarly, if the Z count (TOW) data of subframe 3 is acquired, the reception time (reception period) can be shortened, and the Z count (TOW) for achieving consistency while reducing power consumption. Data can be acquired three times.

Next, in ST27, the reception stop determination program 57 of FIG. 5 stops the reception of the GPS device 40 and ends the reception of the satellite signal from the GPS satellite 15.
In ST28, the time information correction program 502 in FIG. 5 corrects the internal time data 73b in FIG. 7 based on the reception time data 73a. In this case, the reception time data 73a of FIG. 7 employed in the above process is used. The time corrected by the time information correction program 502 in FIG. 5 is stored as the clock display time data 73c in FIG.
Then, the clock display time data correction program 504 in FIG. 5 corrects the display time on the dial 13 and the display 14 of the dial 12 of the GPS wristwatch 10 based on the clock display time data 73c in FIG. ing.
The GPS wristwatch 10 is adapted to correct the time as described above.

Here, the RTC 38 is an example of a time information generation unit that generates time information. The internal time data 73b is an example of the time information generated by the RTC 38, which is an example of a time generation unit. The time data storage unit 73 is an example of a generation time information storage unit. The reception timing determination program 51 is an example of a start information generation unit. The start information generation unit is generated based on the generation time information. The generation time information is information before the timing of receiving the preamble data of subframe 1 which is the head of the satellite signal transmitted from the GPS satellite 15 which is an example of the position information satellite for each frame unit. The GPS device 40 is an example of a receiving unit. Further, the pre-start information is information about 10 seconds before 0 seconds and 30 seconds, which are predetermined timings, and takes into account time for satellite search and the like.
The satellite search program 52 is an example of a start unit that starts searching for position information satellites. The reception stop determination program 57 and the reception timing setting program 58 detect and stop subframe data that is a specific unit of satellite signals. It is an example of the stop part to perform.
For this reason, the GPS wristwatch 10 can correct the time in the shortest reception time.

The Z count (TOW) data is an example of satellite time information that is time information of a position information satellite. The time information consistency determination program 501 is an example of a determination unit that determines whether the satellite time information is correct or incorrect.
The reception time data 73a is an example of satellite time information, and the time data storage unit 73 is also an example of a satellite time information storage unit.
The time information correction program 502 (an example of a time correction unit) corrects the internal time data 73b (an example of time generation information) based on the reception time data 73a (an example of normal satellite time information), and displays clock display time data 73c. (An example of corrected display time information).
For this reason, the GPS wristwatch 10 can correct the time at a predetermined timing regardless of the performance of the device, and corrects the time based on the satellite time information determined to be correct. Corrections can be made.

Further, the time information consistency determination program 501 determines that the difference between the internal time data 73b, which is an example of generation time information that is the current time correction amount, and the reception time data 73a, which is an example of satellite time information, is a consistency verification threshold value. This is an example of a threshold deviation determination unit that determines whether the range of the data 62a is exceeded. The consistency verification threshold value data 62a is an example of a threshold deviation amount that is a time deviation amount corresponding to the elapsed time from the generation time information at the time of the previous time correction.
When the time information consistency determination program 501 determines that (an example of the threshold deviation determination unit) exceeds the range of the consistency verification threshold data 62a (an example of the threshold deviation amount), the time information correction program 502 (An example of a time correction unit) is configured not to correct internal time data (an example of time generation information) based on reception time data 73a (an example of current satellite time information).
For this reason, if the current satellite time information is not certain, the time is corrected based on the satellite time information, and the amount of deviation does not increase further.

The GPS wristwatch 10 starts receiving by the reception stop determination program 57 of the GPS device 40, the time data acquisition program 53 acquires the satellite time information from the satellite signal, and the subframe confirmation program 54 confirms it. Z count (TOW) data, which is satellite time information of subframe 1, which is an example of the first subframe information unit of the satellite signal, is acquired. For this reason, the time adjustment can be surely performed at predetermined timings of 0 seconds and 30 seconds, which is convenient for the user. Further, since the GPS wristwatch 10 only needs to receive the Z count data of the subframe 1, power consumption can be suppressed.
Since the satellite health status data 72a, which is an example of the position information satellite health information indicating the satellite status, has the satellite health status confirmation program 56 that is an example of a health status determination unit that determines the status of the location information satellite. It is possible to determine the state of the position information satellite, that is, whether it is in a normal state or an abnormal state. For this reason, the time is not corrected using the satellite time information of the position information satellite having an abnormality. When receiving the time information, it is easy to determine whether the time information is reliable by acquiring the position satellite health status information in addition to the Z count data. And when obtaining the Z count data and the position satellite health status information as the time information, since these data are acquired from the subframe 1, the reception time can be shortened and the power consumption can be suppressed. Yes.

(Second Embodiment)
Since the GPS wristwatch 10 of the second embodiment has many configurations that are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and different points will be mainly described.
That is, FIGS. 1 to 4 and FIG. 6, which are schematic explanatory diagrams of the GPS wristwatch 10, have the same configuration as that of the first embodiment.
FIG. 12 is a schematic flowchart showing an operation state of the GPS wristwatch 10 according to the second embodiment. Since the GPS wristwatch 10 according to the second embodiment is mostly shared with the first embodiment, different parts are mainly shown in FIG. That is, the steps before and after the schematic flowchart of FIG. 12 are the same as the steps of the first embodiment. Therefore, in the schematic flowcharts of the first embodiment of FIGS. 8 and 9, from the start to the reception timing process of ST10 to the confirmation process of the Z count data of subframe 1 of ST17, and confirmation in ST17 If not, the process proceeds to ST18, then reaches ST20, and returns to ST10, and the process of adjusting the time in ST21, ST22, ST24 to ST28 and ending is the same. Therefore, in FIG. 12, a part is omitted.
Therefore, in the schematic flowchart of FIG. 12, a part of the process after confirming that the Z count data of subframe 1 has been acquired in ST17 is partially added.
In other words, the second embodiment is different from the first embodiment in that the process from ST17 to ST21 is a process of confirming the time since the time information that was the last successful reception was corrected. Have been added. Further, after ST22, a process ST31 for storing the reception success time is added during the process of ST24, which is omitted here.

Accordingly, since various parts of the various program storage units and various data storage units in FIG. 4 are added in relation to this schematic flowchart, schematic conceptual diagrams are shown in FIGS. 10 and 11, respectively. FIG. 10 illustrates various program storage units 150, and FIG. 11 illustrates a second various data storage unit 170. Here, as described above, the functions of the various program storage unit 150 and the second various data storage unit 170, the points illustrated separately for convenience of explanation, and the like are the same as in the first embodiment. It has become. The difference is that a reception success time acquisition program 506 and a previous reception elapsed time confirmation program 507 are added to the various program storage units 150 in FIG. 10, and the second various data storage unit 170 in FIG. The point is that the previous reception success time data 75a of the success time storage unit 75 is added.
Therefore, in the following, the operation of the GPS wristwatch 10 of the second embodiment will be described according to the schematic flowchart of FIG. 12, focusing on the differences from the first embodiment. Explain.

  As described above, in ST17, it is confirmed whether or not the Z count data acquired from the GPS satellite 15 is that of the subframe 1. If it is confirmed that the Z count data is subframe 1, the process proceeds to ST30 in FIG.

In ST30, it is determined whether it is within a certain time from the previous successful reception time.
Specifically, the previous reception elapsed time confirmation program 507 in FIG. 10 compares the elapsed time from the previous reception success time data 75a in FIG. 11 with the internal time data 73b to determine whether it is within a certain time. .
Here, the certain time is set as a time during which the satellite health condition data 72a may be updated or a time within the valid period of the ephemeris. For example, it is about 4 hours.
That is, when the satellite health state data 72a, which is the satellite health state information indicating the state of the GPS satellite 15, has been changed, the updated state can be known by acquiring the satellite health state data 72a again. .

If it is determined in ST30 that it is within a certain period of time, for example, 4 hours from the previous successful reception, the subsequent data is not received and is matched with the internal time information in ST24 (see FIG. 9). The process proceeds to the sex confirmation process. In this case, the satellite health status data 72a (see FIG. 11) is not changed from the previous reception, and the GPS satellite 15 can be regarded as normal and the time can be corrected.
That is, the reception time in this case is a sequence as shown in FIG. 16A of the schematic image diagram of the reception time (reception period) in FIG. In FIG. 16A, the GPS device 40 starts receiving operation about 10 seconds before the beginning of the subframe 1 and operates only for the time to acquire the Z count (TOW) data of the subframe 1. Yes.
As described above, the GPS wristwatch 10 according to the present embodiment has a GPS satellite in the case where a predetermined time has not elapsed since the last successful reception time data 75a (see FIG. 11), which is the time when the generation time information was corrected last time. 15 (an example of a position information satellite) is considered to be in a normal state based on satellite health state (SVhealth) data 72a (an example of position information satellite health information) acquired at the time of the previous time correction. . Then, the GPS device 40 (an example of a receiving unit) is stopped only with the Z count data (an example of satellite time information) of subframe 1. For this reason, the GPS wristwatch 10 has a shorter reception time and can reduce power consumption.

On the other hand, if it is determined in ST30 that a fixed time, for example, 4 hours has elapsed since the correction of the internal time data 73b, which is the previous successful reception, the process proceeds to the next ST21.
In ST21, satellite health state (SVhealth) information data is acquired as in the first embodiment described above. Next, similarly to the above-described first embodiment, the process proceeds to ST22 and the state of the GPS satellite 15 is confirmed.
In ST22, if the satellite health state (SVhealth) data 72a of FIG. 11 which is the satellite health state information data indicates that it is not normal, the process proceeds to ST23 as in the first embodiment.
On the other hand, in ST22, when the satellite health state (SVhealth) data 72a of FIG. 11 which is the acquired satellite health state information data indicates normal, the process proceeds to ST31.

In ST31, this time is stored as a reception success time. Specifically, the reception success time acquisition program 506 in FIG. 10 determines that the satellite health state (SVhealth) data 72a in FIG. 11 is normal in the previous reception success time storage unit 75 in FIG. The time information of the Z count data acquired from is stored as the last successful reception time data 75a.
Therefore, the previous reception success time data 75a stored in the previous reception success time storage unit 75 in FIG. 11 is the time when the satellite signal of the GPS satellite 15 is successfully received.
And it progresses to the process of ST24 of FIG. 9 demonstrated in 1st Embodiment.

Here, the reception time (reception period) in this case will be described. The sequence is as shown in FIG. 16B of the schematic image diagram of the reception time (reception period) in FIG. In FIG. 16B, the GPS device 40 starts a reception operation about 10 seconds before the head of subframe 1 and receives the data of word 3 following the Z count (TOW) data of subframe 1. It only works for hours.
For this reason, the reception time shorter than the reception time in FIG. For this reason, it is possible to reduce power consumption, and more accurate time correction can be performed with the updated week number data.

That is, as described above, the GPS device 40 (an example of a receiving unit) of the GPS wristwatch 10 according to the second embodiment has passed a predetermined time from the previous successful reception time data 75a (at the time of the previous correction of the generation time information). The satellite health status data 72a (an example of the location information satellite health information) is acquired, and the status of the GPS satellite 15 (an example of the location information satellite) is determined based on the satellite health status data 72a. A health condition determination unit (satellite health condition confirmation program 56) is further provided.
For this reason, when the state of the GPS satellite 15 (an example of the position information satellite) has changed since the previous reception, the time can be adjusted according to the state. If it is determined that there is an abnormality in the GPS satellite 15 (an example of the position information satellite), the Z count (an example of the satellite time information) from the GPS satellite 15 (an example of the position information satellite) Do not use when. For this reason, time correction is not performed based on the Z count (an example of satellite time information) of the GPS satellite 15 having an abnormality. Subsequent processes are the same as those described in the first embodiment.

(Third embodiment)
Since the GPS wristwatch 10 of the third embodiment has many configurations that are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and different points will be mainly described.
That is, FIGS. 1 to 4 and FIG. 6, which are schematic explanatory diagrams of the GPS wristwatch 10, have the same configuration as that of the first embodiment.
FIG. 15 is a schematic flowchart showing an operation state of the GPS wristwatch 10 according to the third embodiment. Since the GPS wristwatch 10 according to the third embodiment is mostly shared with the first embodiment, FIG. 15 shows mainly the different portions.
That is, the processes before and after the schematic flowchart of FIG. 15 are the same as the processes of the first embodiment. Therefore, in the schematic flowcharts of the first embodiment of FIGS. 8 and 9, from the start to the reception timing process of ST10 to the confirmation process of the Z count data of subframe 1 of ST17, and confirmation in ST17 If not, the process proceeds to ST18, then reaches ST20, and the process of returning to ST10 and the process of adjusting and ending the time in ST21 to ST28 are the same, and therefore a part of them is omitted in FIG. .
Therefore, in the schematic flowchart of FIG. 15, a part of the process after confirming that the Z count data of subframe 1 has been acquired in ST17 is partially added.
That is, the third embodiment is different from the first embodiment in that in the steps from ST17 to ST21, a step of confirming whether the calendar information of the GPS wristwatch 10 has been changed or disappeared, and the week number A process of acquiring data and a process of updating calendar information are added.

Therefore, a part of various program storage units and various data storage units in FIG. For this reason, schematic conceptual diagrams are shown in FIGS. 13 and 14, respectively. FIG. 13 shows various program storage units 250, and FIG. 14 shows a second various data storage unit 270, respectively. Here, as described above, the functions of the various program storage units 250 and the second various data storage units 270, the points shown separately for convenience of explanation, and the like are the same as in the first embodiment. It has become. The difference is that a week number (WN) information acquisition program 508, a calendar information confirmation program 509, and a calendar information rewriting program 510 are added to the various program storage units 250 in FIG. 13, and the second various types in FIG. The week number data 76a of the week number data storage unit 76, the calendar information data 77a of the calendar information storage unit 77, and the calendar rewriting history data 78a of the calendar rewriting history storage unit 78 are added to the data storage unit 270.
Therefore, in the following, the operation of the GPS wristwatch 10 of the third embodiment will be described according to the schematic flowchart of FIG. 15 with a focus on differences from the first embodiment. Explain.

As described above, in ST17, it is confirmed whether or not the Z count data acquired from the GPS satellite 15 is that of the subframe 1. If it is confirmed that the Z count data is for subframe 1, the process proceeds to ST40 in FIG.
In ST40, it is determined whether the calendar information has been changed or lost.
Specifically, the calendar information confirmation program 509 in FIG. 13 confirms the calendar rewriting history data 78a in the calendar rewriting history storage unit 78 in FIG. 14, and the calendar information data 77a in the calendar information storage unit 77 is changed or lost. Determine whether you are doing.
The calendar rewriting history data 78a of the calendar rewriting history storage unit 78 includes, for example, information when the calendar information data 77a is changed by an operation of a user operation button or the like, or calendar information data of the calendar information storage unit 77. Information is recorded when 77a is reset and lost.
In such a case, the GPS wristwatch 10 needs to update and correct the calendar information data 77a.

For this reason, when it is determined in ST40 that the change has been made, the process proceeds to ST41.
In ST41, the GPS device 40 further acquires week number (WN) data following the Z count of the subframe 1 of the navigation message which is a satellite signal from the GPS satellite 15.
Specifically, the week number (WN) information acquisition program 508 of FIG. 13 acquires the week number (WN) data from the word 3 following the Z count of the subframe 1 of the navigation message that is the satellite signal from the GPS satellite 15. And it memorize | stores in the week number data storage part 76 of FIG. 14 as week number data 76a. Since the week number (WN) information of the navigation message which is a satellite signal is included in the word 3 which is the word data of the subframe 1 as described above, the GPS device 40 until the word 3 is received, The reception stop determination program 57 of FIG. 13 determines to operate. Then, from this received word 3, the week number (WN) information acquisition program 508 in FIG. 13 acquires week number (WN) data and stores it as week number data 76a in the week number data storage unit 76 in FIG. To do.

Next, in ST42, the calendar information rewriting program 510 in FIG. 13 updates the calendar information data 77a in the calendar information storage unit 77 in FIG. 14 based on the week number data 76a in FIG.
On the other hand, if it is determined in ST40 that no change has been made, the process proceeds to ST21. Since this step is the same as that of the first embodiment, a description thereof will be omitted. Steps subsequent to ST21 are the same as those in the first embodiment.
Therefore, subframe 1 (an example of the first subframe unit) includes week number data 76a (an example of week number information (WN)) that is count information of the elapsed time from the starting point of the satellite time information. When the calendar information data 77a (an example of calendar information) is changed, the GPS device 40 (an example of a receiving unit) acquires week number data 76a (an example of week number information). The information data 77a (an example of calendar information) is modified by the calendar information rewriting program 510 based on the week number data 76a (an example of week number information (WN)).
Therefore, when the calendar information data 77a in the GPS wristwatch 10 is changed or reset by the user, the week number data 76a can be acquired and corrected, which is more convenient for the user. It is.

  The present invention is not limited to the above-described embodiments. Each of the above-described embodiments has been described with respect to GPS satellites. However, the present invention is not limited to GPS satellites, but can be applied to other global navigation satellite systems (GNSS) such as Galileo and GLONASS, geostationary satellites such as SBAS, and quasi-zenith satellites. A position information satellite that transmits a satellite signal including time information such as may be used.

It is the schematic which shows the wristwatch with a GPS time correction apparatus. FIG. 2 is a schematic end view of the wristwatch with a GPS time correction device in FIG. 1. It is the schematic which shows the main hardware structures etc. inside the wristwatch with a GPS time correction apparatus of FIG. 1, FIG. FIG. 3 is an overall schematic diagram illustrating a main software configuration and the like of the wristwatch with a GPS time correction device in FIGS. 1 and 2. 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 1st various data storage part of FIG. It is the schematic which shows the data in the 2nd various data storage part of FIG. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with a GPS time correction apparatus concerning 1st Embodiment. It is a schematic flowchart which shows the main operation | movement etc. of the wristwatch with a GPS time correction apparatus concerning 1st Embodiment. It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time correction apparatus concerning 2nd Embodiment. It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time correction apparatus concerning 2nd Embodiment. It is a partial schematic flowchart which shows the main steps of the wristwatch with a GPS time adjustment device according to the second embodiment. It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time correction apparatus concerning 3rd Embodiment. It is the schematic which shows the main software structures etc. of the wristwatch with a GPS time correction apparatus concerning 3rd Embodiment. It is a partial schematic flowchart which shows the main steps of the wristwatch with a GPS time correction device according to the third embodiment. It is a schematic explanatory drawing for demonstrating the concept of reception operation | movement of the wristwatch with a GPS time correction apparatus concerning this embodiment. 3 is a schematic conceptual diagram for explaining word data of subframe 1. FIG. It is a schematic explanatory drawing which shows a GPS satellite signal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Wristwatch with GPS time correction device, 15 ... GPS satellite, 38 ... RTC (real time clock), 40 ... GPS device, 40a ... Reception device, 50 ... Various program storage units, 51 ... Reception timing judgment program, 52 ... Satellite search 53, time data acquisition program, 54 ... subframe confirmation program, 55 ... other satellite information acquisition program, 56 ... satellite health condition confirmation program, 57 ... reception stop determination program, 58 ... reception timing setting program, 59 ... reception satellite Change program, 501 ... Time information consistency determination program, 502 ... Time information correction program, 503 ... Threshold deviation determination program, 504 ... Clock display time data correction program, 505 ... Reception time data consistency determination program, 506 ... Reception success time Acquisition program 507 ... last received elapsed time confirmation program, 508 ... week number (WN) information acquisition program, 509 ... calendar information confirmation program, 510 ... calendar information rewriting program, 60 ... first various data storage unit, 61a ... time correction Timing data, 62a ... consistency verification threshold data, 70 ... second various data storage unit, 71a ... received satellite time data, 72 ... satellite health status storage unit, 72a ... satellite health status data, 73 ... time data storage unit, 73a ... Reception time data, 73a1 ... First reception time data, 73a2 ... Second reception time data, 73a3 ... Third reception time data, 73b ... Internal time data, 73c ... Clock display time data, 75a ... Previous reception success time Data, 76a ... Week number data, 77a ... Calendar information data, 78a ... Karen Over rewriting history data.

Claims (8)

A receiving unit for receiving a satellite signal transmitted from the position information satellite;
A time information generator for generating time information;
Among the satellite signals transmitted from the position information satellite in units of subframes, the sub information includes satellite time information which is time information of the position information satellite and position information satellite health information indicating a state of the position information satellite. A start information generating unit that generates pre-start information that is a time before the beginning of the frame is transmitted;
Based on the time information and the pre-start information, a start unit that operates the reception unit to periodically start reception of the position information satellite;
At least a stop unit that stops reception by the receiving unit when acquiring the satellite time information and the position information satellite health information,
A time correction unit that corrects the time information generated by the time information generation unit based on the acquired satellite time information;
A threshold deviation determination unit that determines whether a difference between the time information generated by the time information generation unit that is the current time correction amount and the satellite time information exceeds a predetermined threshold deviation amount range;
A health state determination unit that determines the state of the position information satellite based on the position information satellite health information;
A satellite information storage unit that stores each satellite time information of the subframe information unit as satellite time information data;
Have
When the health state determination unit determines that the position information satellite is in a normal state based on the position information satellite health information,
When the threshold shift determination unit determines that the threshold shift amount exceeds the range, the reception unit further acquires the satellite time information of the next subframe information unit of the satellite signal. And
The time correction unit uses the satellite time information data in which at least two of the satellite time information data are within a range of deviation of one subframe information unit of the satellite signal, and A time correction device configured to be corrected. The receiving unit includes a determination unit that determines whether the satellite time information is correct or incorrect.
A satellite time information storage unit that stores the satellite time information determined to be correct by the determination unit as normal satellite time information;
Have
The time correction unit corrects the time information generated by the time information generation unit based on the primary satellite time information;
The time correction apparatus according to claim 1. 3. The time according to claim 1 , wherein the threshold shift amount is a time shift amount corresponding to an elapsed time from the time information generated by the time information generation unit at the time of the previous time correction. Correction device.   4. The pre-start information is configured to correct the time information generated by the time information generation unit at a timing of 0 seconds or 30 seconds. The time correction device according to item. A health condition determination unit that determines the status of the position information satellite based on the position information satellite health information;
When the health state determination unit determines that the position information satellite is not in a normal state based on the position information satellite health information, the reception unit is configured to receive another position information satellite. The time correction apparatus according to claim 1, wherein the time correction apparatus is characterized. The subframe including satellite time information that is time information of the position information satellite and position information satellite health information that indicates a state of the position information satellite is a week number that is count information of progress from the starting point of the satellite time information. Contains information,
The internal time counter of the time information generation unit that generates time information of the time correction device includes calendar information, and when the calendar information is changed, the reception unit acquires the week number information The time correction apparatus according to claim 1, wherein the calendar information is corrected based on the week number information. A receiving unit for receiving a satellite signal transmitted from the position information satellite;
A time information generator for generating time information;
Among the satellite signals transmitted from the position information satellite in units of subframes, the sub information includes satellite time information which is time information of the position information satellite and position information satellite health information indicating a state of the position information satellite. A start information generating unit that generates pre-start information that is a time before the beginning of the frame is transmitted;
Based on the time information and the pre-start information, a start unit that operates the reception unit to periodically start reception of the position information satellite;
At least a stop unit that stops reception by the receiving unit when acquiring the satellite time information and the position information satellite health information,
A time correction unit that corrects the time information generated by the time information generation unit based on the acquired satellite time information;
A threshold deviation determination unit that determines whether a difference between the time information generated by the time information generation unit that is the current time correction amount and the satellite time information exceeds a predetermined threshold deviation amount range;
A health state determination unit that determines the state of the position information satellite based on the position information satellite health information;
A satellite information storage unit that stores each satellite time information of the subframe information unit as satellite time information data;
Have
When the health state determination unit determines that the position information satellite is in a normal state based on the position information satellite health information,
When the threshold shift determination unit determines that the threshold shift amount exceeds the range, the reception unit further acquires the satellite time information of the next subframe information unit of the satellite signal. And
The time correction unit uses the satellite time information data in which at least two of the satellite time information data are within a range of deviation of one subframe information unit of the satellite signal, and It becomes the composition to correct
Timekeeping device with time correction device. A time information generation step for generating time information;
Among the satellite signals transmitted from the position information satellite in units of subframes, the sub information includes satellite time information which is time information of the position information satellite and position information satellite health information indicating a state of the position information satellite. A start information generating step for generating pre-start information that is a time before the beginning of the frame is transmitted;
Based on the time information and the pre-start information, a start step of periodically starting reception of the position information satellite by operating the receiving unit;
At least the step of stopping reception by the receiving unit when the satellite time information and the position information satellite health information are acquired,
A time correction step of correcting the time information generated by the time information generation unit based on the acquired satellite time information ;
A threshold deviation determination step for determining whether a difference between the time information generated by the time information generation unit that is the current time correction amount and the satellite time information exceeds a predetermined threshold deviation amount range;
A health state determination step of determining a state of the position information satellite based on the position information satellite health information;
A satellite information storage step for storing each satellite time information in the subframe information unit as satellite time information data;
Have
When the health state determination unit determines that the position information satellite is in a normal state based on the position information satellite health information,
If it is determined that the threshold shift amount exceeds the threshold shift amount in the threshold shift determination step, the satellite time information of the subframe information unit next to the satellite signal is further acquired,
In the time adjustment step, the time information is obtained by using the satellite time information data in which at least two of the satellite time information data are within a range corresponding to one subframe information unit of the satellite signal. Correct
Time correction method.

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