JP2000199793A - Timepiece and time correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a timepiece and a time correction method capable of attaining small-sizing and cost reduction of a position measurement device and having accurate time. SOLUTION: A constitution comprises a GPS module for measuring present location by receiving wave from a GPS satellite and a main module. From the GPS module, the result of measured location, time data, etc., are forwarded to the main module side with the reference of a seconds carry 'A' on the hour. In the main module side, the self-holding time is corrected by adding the timing width (1 second) of the second carry on the hour at the time shown by the time data sent, immediately before after elapsing a specific waiting time Δt from the data-forwarding termination time 'D'. In the main module side, next seconds carry 'B' on the hour and the clock timing can be adjusted, without having to directly receive the second carry on the hour.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clock device and a time correction method for correcting the current time of the watch based on information sent from a satellite such as a GPS satellite.

[0002]

2. Description of the Related Art Conventionally, a positioning device using a GPS measures a position by acquiring positioning information called a satellite message included in a radio wave transmitted from a GPS satellite. Among the satellite messages, data such as satellite orbit information and clock correction information are called ephemeris, and data such as general orbit information of all satellites is called almanac. Further, the ephemeris information includes time information of a high-precision atomic clock of each GPS satellite, and by receiving this, the positioning device can have high-precision time in itself.

On the other hand, in such a positioning device, when power saving and reduction in size and weight are required, since the power consumption required for receiving the satellite message is large, the internal structure of the positioning device is shown in FIG. And a GPS module 51 for receiving the current position and measuring the current position, and transmitting the measurement result and the measurement status to the outside.
It is composed of a main module 52 that displays satellite position and reception sensitivity information as a guide for measurement, calculates distance, displays the calculation result, and displays time.
In many cases, the module 51 is operated. In the positioning device having such a configuration, the GPS module 51 operates according to the control signal sent from the main module 52 via the input data line a, and the measurement result and the like are sent to the main module 52 via the output data line b. It is supposed to be sent. Also, a dedicated time synchronization signal line c is provided between the two modules 51 and 52, and the change in the level is used as the timing of the correct time to correct the clock timing on the main module 52 side as described above. It is possible to have an accurate time.

[0004]

SUMMARY OF THE INVENTION However, GPS
When the positioning device including the module 51 and the main module 52 is, for example, a wristwatch type, the following problems occur. In other words, in the above case, it can be said that a coin-type lithium battery is generally used as a power source, but its voltage is about 1.3 to 3.0 V,
The voltage required for the GPS module 51 is about 2.7 V to 3.6 V although it is only at the time of measurement. For this reason, since the voltages at both ends of the time synchronization signal line c are different, a voltage conversion circuit attached to the time synchronization signal line c is separately required, and the mounting area inside the device increases. Further, in order to synchronize clock timing using the time synchronization signal line c, a system that interrupts in a hardware manner by a change in the signal of the time synchronization signal line c, specifically, the main module 5
A peripheral circuit of the CPU on the two sides is required, which is disadvantageous in cost.

[0005] The present invention has been made in view of such a conventional problem, and a clock device and a time correction method capable of having a highly accurate time while reducing the size and cost of a positioning device. The purpose is to provide.

[0006]

According to a first aspect of the present invention, there is provided a timepiece apparatus for receiving information transmitted from a satellite and transmitting data including time data based on the received information. Sending and receiving means for sending, clock means for generating a current time, and the clock based on the sending timing of data sent from the sending and receiving means with reference to the clock timing at the hour obtained in accordance with the reception of the information. Correction means for correcting the generation time of the means. In such a configuration, even when the transmission / reception unit is independent from the others, it is possible to correct the generation time of the clock unit without directly receiving the clock timing at the correct time from the transmission / reception unit.

Further, in the clock device according to the second aspect, the correction means changes the generation time of the clock means at a time when a predetermined waiting time has elapsed from the end of the data transmission from the transmission / reception means. In this case, the time is corrected to a time obtained by adding the timing width of the clock timing of the hour to the time indicated by the time data transmitted immediately before. Even in such a configuration, even when the transmission / reception unit is independent from the others, the generation time of the clock unit can be corrected without directly receiving the clock timing of the hour from the transmission / reception unit.

In the clock device according to a third aspect of the present invention, the predetermined waiting time is a maximum time from the clock timing at the normal time to a start time of data transmission from the transmission / reception means, and It is assumed that the generation time of the means is a time determined based on the correction time at the time when it is corrected in accordance with the time signal. In such a configuration, the generation time of the clock means can be corrected at a timing closer to the clock timing of the hour.

According to a fourth aspect of the present invention, there is provided a receiving / transmitting means for receiving information transmitted from a satellite and transmitting data including time data based on the received information, and generating a current time. A time correction method in a timepiece device comprising a clock means, wherein the transmission / reception means transmits data based on a clock timing at the time obtained at the time of reception of the information, and then a predetermined time from the end of transmission of the data. When the waiting time elapses, the generation time of the clock means is corrected to a time obtained by adding the timing width of the clock timing of the hour to the time indicated by the time data included in the data transmitted immediately before. did. In this method, even when the transmission / reception unit is independent from the others, the generation time of the clock unit can be corrected without directly receiving the clock timing of the hour from the transmission / reception unit.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a positioning device 1 for realizing the timepiece device of the present invention. In the present embodiment, it is assumed that the positioning device 1 is a wristwatch type that operates using a battery as a power supply.

That is, the positioning device 1 includes a main module 2 and a GPS module 3.
The GPS module 3 includes a GPS antenna for receiving an L1 band radio wave from a GPS satellite, a receiving unit 4 including an RF, an A / D, and the like, and a satellite such as ephemeris data and almanac data from the radio wave received by the receiving unit 4. A signal processing unit 5 including a data register, a counter, a decoder, and a CPU for controlling the data registers and counters necessary for decoding the data is provided. The signal processing unit 5 includes the CP
Read-only mask ROM for storing U program
6 and a readable and writable SR used as a register for arithmetic operation of the CPU while storing satellite data received during the position measurement work and used for calculating the current position.
AM7 is connected. The GPS module 3 is connected to the CPU 8 of the main module 2 via an input data line a and an output data line b, and stores position data indicating a current position calculated by the signal processing unit 5 and the satellite. The time data included in the data is transmitted to the CPU 8.

The CPU 8 controls the entire positioning device 1 using the RAM 10 as a working memory according to a control program stored in the ROM 9. The ROM 9 stores, together with the control program, wait time data used for time adjustment of the clock unit 12 described later and accuracy data indicating an error range thereof. Further, the CPU 8 includes a data storage unit 11 for storing map data and positioning system data, a transmitter such as a crystal oscillator for counting the current time, and the transmitter so that a time lag within a predetermined period falls within a predetermined range. A clock unit 1 which includes an adjustment circuit for adjusting the transmission frequency of the clock, generates a current time, and sends it to the CPU 8
2. A switch input unit 13 to which a plurality of switches for operating the positioning device 1 are connected, a small LCD or the like, and a clock display based on the time data counted by the clock unit 12 is usually used for a normal measurement. Are connected to display units 14 for displaying satellite position and reception status data of radio waves, and when the position is determined by measurement, numerical data of the position and data of the map and the current position are displayed.

Next, the operation of the positioning device 1 having the above configuration relating to time adjustment will be described with reference to the flowchart of FIG. That is, when the positioning device 1 starts operating in response to a measurement request signal from the switch input unit 16 in accordance with the operation of the user, the positioning device 1 first activates the GPS module 3 to receive, demodulate and convert a satellite radio wave into a digital signal, The measurement process such as calculating the current position from the signal is started (step S1), and the measurement process is continued for a predetermined time or a predetermined number of times until time data can be received (NO in step S2). Here, if the time data can be received, that is, if the measurement is successful (YES in step S2), a time wait is performed while the measurement result is sent from the GPS module 3 to the main module 2 (step S3). The difference between the correction time to be corrected by the time of the time data obtained in the measurement processing by the module 2 and the time in the clock unit 12 up to that time is the accuracy range secured in the clock unit 12 of the main module 2. It is determined whether the value is within the range (within the inherent error range) (step S4). The range of the accuracy of the device used for the determination here is, of course, a range in consideration of the elapsed time from the previous time adjustment, and specifically, the accuracy data stored in the ROM 9. And the date and time previously stored in the RAM 10 when the last time adjustment was performed.

If the result of the determination is YES and the result is within the above-mentioned predetermined accuracy range, the time of the clock section 12 is adjusted, and the date and time at that time are set to RA.
After storing the result in M10 (step S5), the measurement ends. On the other hand, if the accuracy is not within the above-described predetermined accuracy range, it is determined that erroneous time data has been obtained due to radio interference due to ghost or interference during measurement, and the measurement is terminated without performing time adjustment. . Therefore, in the positioning device 1, erroneous time correction due to radio wave interference can be eliminated, and highly accurate time can be always maintained. Moreover, it is determined whether or not the time data obtained by the GPS module 2 is incorrect data.
Since the correction is performed on the basis of an error inherent in the clock unit 12, incorrect time correction can be prevented more reliably, and highly accurate time can be held more reliably.

Next, the operation relating to the time correction in step S5 will be described with reference to the timing chart of FIG. First, the GPS module 3 during the measurement operation
The data transfer from the to the main module 2 will be described. That is, “A”, “B”,... In FIG. 3A are accurate second carry timings obtained at the hour obtained in the above-described measurement processing.
The PS module 3 performs a current position measurement operation and data transmission to the main module 2. In other words, the GPS module 3 measures at the timing “A” and obtains the result. When the result is obtained, the measurement result, that is, the latitude / longitude data or the like is sent to the main module 2 during the period from the timing “C” to “D” in FIG. Transfer position information and time data. In the present embodiment, the timing “E” in FIG. 2B is the last position of the time data. Here, the time required for the measurement operation (the time between timings "A" to "C") has a fixed range, which is sufficiently shorter than one second, and sufficiently small as the precision of a clock used daily. . Therefore, for example, assuming that this time is a possible maximum value t1, the data transfer time t2 at the above-mentioned timings “C” to “D”
Is a basic transfer time peculiar to the system and is always constant. Therefore, a waiting time Δt (E (E) from the end of data transfer (timing “D”) to the next second carry (timing “B”). −F) can be obtained by waiting time Δt = 1000 msec−t1−data transfer time t2. In the present embodiment, the waiting time Δt is stored in the ROM 9.

The time adjustment (time correction) of the clock unit 12 in the main module 2 is performed when data is transmitted from the GPS module 3 based on the second carry timing “A”, as shown in FIG. After the data acquisition timing “D”, at the moment when the waiting time Δt stored in the ROM 9 has elapsed (timing “G” in (4) of FIG. 4), the time of the clock unit 12 is changed to the timing “C”. ”To“ D ”(time data sent at the previous second carry timing“ A ”) plus one second. Thereby, extremely accurate time adjustment is performed. The timing “H” in (5) of FIG. 4 is the second carry timing of the clock unit 12 immediately before the time adjustment is performed, and the time ΔT of the timings “H” to “G” is adjusted. Timing width.

That is, in the present embodiment, the GPS
Since the main module 2 adjusts the time based on the transfer timing of the data sent from the module 3, time synchronization between the main module 2 and the GPS module 3 for informing the latter of the correct second carry timing at the correct time. Even without a signal data line, extremely accurate time adjustment is possible. Therefore, the data line is not required, and the peripheral circuit of the CPU required for the interrupt processing of the time synchronization signal is not required. Therefore, the mounting area and the number of components of the system in the apparatus can be reduced, and It is possible to reduce the size and cost.

In the above-described time adjustment operation, when the measurement operation is performed under the same condition, the time adjustment can be performed with almost the same accuracy every time. This is because when the measurement operations are the same, the above-described measurement time t1 (the time between timings “A” to “C”) is substantially uniform. Therefore, if the positioning device 1 is provided in advance with a time setting mode in which the above-described time setting operation is performed in response to a predetermined switch operation by the user, for example, the user performs the predetermined operation at the same time every day at the same place. By doing so, the time can be adjusted with the same accuracy every day.

Further, higher accuracy can be obtained by the following method. That is, as a preparation stage,
After performing the above-mentioned time setting operation manually or automatically, the second time adjusting operation is performed again using a time signal of a television or a radio or a time signal of a telephone which emits an accurate time in daily life. At this time, the time difference ta between the time according to the time signal and the time of the clock unit 12 up to that time is stored in the RAM 10. That is, the time difference ta is equal to the measurement time t1 (timing “A” to
(Time between “C”). Then, at the time of the subsequent measurement (or at the time of the time correction process), the time difference ta stored in the RAM 10 is read, and a new waiting time Δt is calculated based on the waiting time Δt = 1000 msec−t1−data transfer time t2−ta. .

Then, the above-described time adjusting operation is performed using the waiting time Δt. Alternatively, in the preparation stage, a new waiting time Δt is calculated, and the calculated waiting time Δt is stored in the RAM 1.
0 beforehand, and RAM1
The above-described time adjustment operation is performed using the waiting time Δt read from 0. Thus, as described above, the waiting time data (12a) of the ROM 9 determined assuming the measurement time t1 (the time between the timings “A” to “C”) as the possible maximum value t1 is used. Compared to the case, the generation time of the clock means can be corrected at a timing closer to the clock timing at the hour. Therefore, more accurate time adjustment can be performed.

In this embodiment, the case where the present invention is applied to the wristwatch-type measuring device 1 has been described. However, the present invention is based on the time information transmitted from a positioning satellite such as a GPS satellite. The same effect can be obtained even when the time is adjusted or obtained in another device.

[0022]

As described above, in the present invention,
Even when the transmission / reception means is independent from the others, it is possible to correct the generation time of the clock means without directly receiving the clock timing of the hour from the transmission / reception means. This eliminates the need for a time synchronization signal line or the like necessary for directly receiving the clock timing, thereby reducing the mounting area and the number of components in the system in the device, and reducing the size and cost of the positioning device. As a result, it is possible to have a highly accurate time. Further, since the generation time of the clock means can be corrected at a timing closer to the clock timing of the hour, it is possible to obtain a more accurate time.

[0023]

[Brief description of the drawings]

FIG. 1 is a block diagram of a positioning device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation related to time adjustment.

FIG. 3 is a timing chart showing time setting timing.

FIG. 4 is a timing chart showing a time alignment determination.

FIG. 5 is a block diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positioning apparatus 2 Main module 3 GPS module 9 ROM 10 RAM 12 Clock part

Claims (4)

[Claims] A receiving means for receiving data sent from a satellite and transmitting data including time data based on the received information; a clock means for generating a current time; A clock device comprising: a correction unit that corrects a generation time of the clock unit based on a transmission timing of data transmitted from the transmission / reception unit with reference to the acquired clock timing at the hour. 2. The method according to claim 1, wherein the correcting unit indicates a generation time of the clock unit by the time data transmitted immediately before a predetermined waiting time has elapsed from the end of data transmission from the transmission / reception unit. 2. The clock device according to claim 1, wherein the time is corrected to a time obtained by adding a timing width of the clock timing at the hour to the time. 3. A method according to claim 1, wherein the predetermined waiting time is a maximum time from the clock timing of the hour to a start of transmission of data from the transmission / reception means, and a generation time of the clock means is corrected in accordance with a time signal. 3. The timepiece device according to claim 2, wherein the time is a time determined based on the correction time at the time when the time has elapsed. 4. A clock device for receiving information transmitted from a satellite, transmitting and receiving data including time data based on the received information, and a clock device for generating current time. In the correction method, after the transmitting and receiving means has transmitted data with reference to the clock timing at the time obtained at the time of reception of the information, at a time when a predetermined waiting time has elapsed from the end of transmitting the data, A time correction method, wherein the generation time of the clock means is corrected to a time obtained by adding the timing width of the clock timing of the hour to the time indicated by the time data included in the data transmitted immediately before.