JP6390209B2 - Radio clock and display method when receiving radio waves - Google Patents

Description

  The present invention relates to a radio timepiece that receives radio waves from positioning satellites and acquires information related to date and time and a display method when receiving radio waves.

  2. Description of the Related Art Conventionally, there is a technology for receiving date and time information and position information by receiving radio waves from positioning satellites constituting a GNSS (Global Navigation Satellite System) including GPS (Global Positioning System). Radio waves from positioning satellites can be received anywhere in the world as long as the sky is open, and these information can be easily acquired.

  2. Description of the Related Art In recent years, a technique for receiving radio waves from positioning satellites and acquiring information related to date and position has also been adopted in portable electronic watches such as electronic watches. However, in a portable electronic timepiece, power consumption for acquiring information by receiving radio waves from a positioning satellite is significantly higher than power consumption required for normal date and time display. If a large-capacity battery corresponding to a high load is installed in accordance with the reception of radio waves from the positioning satellite, there is a problem that the weight increases and the size increases. Therefore, various techniques for acquiring information by reception with the minimum number of times and time have been proposed. For example, when receiving a radio wave from a positioning satellite, the date and time information and position information are included in a specific position due to its format. There is a technique in which, based on a signal acquired later, a waiting time until a timing at which the signal at the specific position is received is estimated, and reception is interrupted once, and then reception is performed again after the waiting time.

  Since portable electronic watches can be easily carried, radio wave reception may become impossible due to the movement of the user during reception, and power consumption due to failed information acquisition and re-reception In order to avoid an increase in the number of users, it is recommended that the user waits at the reception point during reception. However, as a result of the above-described technique, in these portable electronic watches, the time required to receive the necessary information from the positioning satellite is from a case where it takes a very short time to a conventional time. Can occur widely. Therefore, there is a problem that the user does not know how long to wait after starting reception. Even when waiting for a long time, there may be a case where it is not known whether the reception is successful until the reception is finally completed.

  On the other hand, in Patent Document 1, when receiving a radio wave from a GPS satellite, the subframe ID being received is identified, the estimated time until the ephemeris data is acquired is displayed, and the remaining time is displayed. In the case where it takes time to acquire a positioning satellite, a technique for displaying the remaining time-out until the time-out of acquisition and time-out is disclosed.

JP 2009-236560 A

  However, in the conventional technology, once the necessary number of positioning satellites are acquired, the remaining time display is then uniformly switched, so that the user can be flexibly notified of the reception status according to the reception environment. There is no problem.

  An object of the present invention is to provide a radio timepiece and a display method at the time of radio wave reception capable of notifying a user of a flexible reception status according to a reception environment.

In order to achieve the above object, the present invention
Receiving means for capturing and receiving radio waves from positioning satellites;
Decryption means for obtaining designated information from the received radio waves;
Counting means for counting the reception time by the receiving means;
One or more positioning satellites are selected from the captured positioning satellites, and an estimated reception time required for acquiring the specified information is acquired according to the radio wave reception intensity of the selected positioning satellites. Estimated time acquisition means;
A remaining time display control unit that calculates a remaining time of the acquired estimated reception time with respect to the reception time and causes the display unit to perform display according to the remaining time;
It is a radio timepiece characterized by comprising.

  According to the present invention, when receiving radio waves from a positioning satellite, there is an effect that a user can be notified of a flexible reception status according to the reception environment.

It is a block diagram which shows the function structure of the radio timepiece of embodiment of this invention. It is a figure explaining the format of the navigation message transmitted from a GPS satellite. It is a figure which shows the example of the value memorize | stored as a reception time estimation conversion table. It is a flowchart which shows the control procedure of the position acquisition control process performed in the radio timepiece of this embodiment. It is a flowchart which shows the control procedure of the position acquisition control process performed in the radio timepiece of this embodiment. It is a sequence diagram which shows the example of the exchange between host CPU and module CPU. It is a flowchart which shows the control procedure of the date acquisition control process performed in the radio timepiece of this embodiment. It is a flowchart which shows the control procedure of the date acquisition control process performed in the radio timepiece of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a functional configuration of an electronic timepiece 1 which is an embodiment of a radio timepiece of the present invention.
The electronic timepiece 1 includes a host CPU 41 (Central Processing Unit), a ROM 42 (Read Only Memory), a RAM 43 (Random Access Memory), an oscillation circuit 44, a frequency dividing circuit 45, a time counting circuit 46, and a display unit 47 ( Display means), a display driver 48, a power supply unit 50, a GPS reception processing unit 51 (reception means, decoding means), a reception antenna 52 thereof, an operation unit 53, and the like.

  The host CPU 41 performs various arithmetic processes and controls the overall operation of the electronic timepiece 1. The host CPU 41 loads the control program read from the ROM 42 to the RAM 43 and performs processing related to various operations such as date and time display, timing and display related to the stopwatch function. Further, the host CPU 41 controls on / off of power supply to the GPS reception processing unit 51 and an operation mode (reception mode), and acquires date / time information and position information from the GPS reception processing unit 51 as necessary.

  The ROM 42 is a mask ROM, a rewritable nonvolatile memory, or the like, and stores a control program and initial setting data stored in advance. The control program includes a program 421 related to control such as position acquisition control processing and date acquisition control processing for acquiring various types of information from positioning satellites. Further, the initial setting data includes, for example, information related to time zone ranges and time differences of the time zones, daylight saving time implementation information, and the like.

  The RAM 43 is a volatile memory such as SRAM or DRAM, and provides a working memory space to the host CPU 41 to store temporary data and various setting data.

  The oscillation circuit 44 generates and outputs a predetermined frequency signal determined in advance. For example, a crystal oscillator is used for the oscillation circuit 44.

  The frequency dividing circuit 45 divides the frequency signal input from the oscillation circuit 44 into a frequency signal used by the time measuring circuit 46 or the host CPU 41 and outputs the frequency signal. The frequency of the output signal may be changeable based on the setting by the host CPU 41. Further, the frequency of the oscillation circuit 44 may be output as it is.

  The timer circuit 46 counts the current date and time by counting the number of input signals and adding it to the initial value. As the time counting circuit 46, a value stored in the RAM may be changed by software, or a dedicated counter circuit may be provided.

  The power supply unit 50 supplies power related to the operation of the electronic timepiece 1 to each unit at a predetermined voltage. Here, a solar battery and a secondary battery 500 (power supply means, battery) are used for the power supply unit 50. The solar battery generates electromotive force by light incident on the solar panel and supplies power to each unit such as the host CPU 41. When surplus power is generated, the solar battery stores the secondary battery 500 using the power. On the other hand, when the power that can be generated by the amount of incident light from the outside to the solar panel is insufficient with respect to the power consumption, the power is supplied from the secondary battery 500. Further, the power supply unit 50 directly supplies power to the GPS reception processing unit 51, the display unit 47, and the like based on a control signal from the host CPU 41.

  The power supply unit 50 includes a battery remaining amount detecting unit 501 (remaining amount detecting means), and, for example, an output voltage detection signal of the secondary battery 500 is sent to the host CPU 41 as an index indicating the remaining amount of the secondary battery 500 or as needed. It is output in response to a request from the host CPU 41.

The GPS reception processing unit 51 needs to demodulate and decode the navigation message transmitted by the positioning satellite, received by identifying and capturing the C / A code in synchronization with the radio wave from the positioning satellite via the receiving antenna 52. Information is obtained. Further, when the positioning information is acquired, the GPS reception processing unit 51 demodulates and codes the navigation message for a plurality of satellites, and calculates the current position using the obtained data. As the GPS reception processing unit 51, a module in which a dedicated processing circuit is formed on a single chip is usually used, and separately from the host CPU 41, the ROM 42, and the RAM 43, a module CPU 511 that performs control, and setting data and positioning satellites are used. A storage unit 512 that stores predicted orbit information and the like is provided. The storage unit 512 includes a RAM and a non-volatile memory, and holds necessary data even when no power is supplied to the GPS reception processing unit 51.
The GPS reception processing unit 51 is directly supplied with electric power from the power supply unit 50, and is turned on / off by a control signal from the host CPU 41.

  The GPS reception processing unit 51 responds to a setting or a request from the host CPU 41, in addition to the acquired date and time information and the calculated position information, the number of positioning satellites captured in the reception process, the satellite ID, and each reception intensity ( Since it generally corresponds to SNR (signal-to-noise ratio), the SNR is used as an indicator of received intensity), the elevation angle and azimuth of the positioning satellite, and error information (DOP (Dilution of Position), etc.) of the acquired position Information can be output.

  The operation unit 53 receives an input operation from the user and outputs an electrical signal corresponding to the input operation to the host CPU 41 as an input signal. The operation unit 53 includes, for example, a push button switch. Alternatively, a touch sensor is provided on the display screen of the display unit 47, and functions as a touch panel that outputs an operation signal according to a contact position or a contact mode related to a user's contact operation with the touch sensor, so that the display unit and the operation You may use together.

Next, data received from the positioning satellite and the receiving operation in the electronic timepiece 1 of the present embodiment will be described.
FIG. 2 is a diagram for explaining the format of a navigation message transmitted from a GPS satellite.

  A navigation message transmitted from a GPS satellite is composed of 25 frames in 30-second units. Each frame includes five 6-second subframes, and each subframe includes 10 0.6-second words (WORD).

  Each word is composed of 30 bits. Among these, the formats of WORD1 and WORD2, which are two words from the top of each subframe, are common to all subframes. The first 22 bits of WORD1 represent a telemetry word (TLM), and the further 8 bits of the WORD1 are a preamble that is fixed every time. The leading 22 bits of WORD2 represent a handover word (HOW), and the leading 17 bits are TOW-Count (Time of Week) indicating the date and time (elapsed time within a week) of the day of the week or less.

  On the other hand, each word after WORD 3 shows different contents for each subframe. In WORD3 of the first subframe (subframe 1), the first 10 bits indicate the week number WN. Further, after WORD3 of subframe 2 and subframe 3, orbit data (ephemeris data) of the GPS satellite is included. Subsequent to WORD3 in subframe 4, various correction parameters for obtaining the position and date / time are included, and from WORD3 in subframe 5 to all predicted GPS satellite orbit data (almanac data) are included.

  In the electronic timepiece 1 of the present embodiment, when date / time information or position information (information to be acquired) is acquired from the navigation message, first, the position of the navigation message in the subframe is grasped by identifying the preamble. . Further, the position in the frame is grasped by identifying the subframe ID as necessary. Both the preamble and the subframe ID appear and be detected once within 6 seconds of each subframe. However, when the reception status is poor (SNR is low), the preamble or the like is not necessarily identified with one reception. Accordingly, it may be necessary to receive a plurality of subframes, which may increase the reception time.

The date / time information is obtained by a combination of the week number WN and the weekly elapsed time TOW-Count. Therefore, when the data of subframe 1 is received, the date / time data can be output.
Here, in the electronic timepiece 1 of the present embodiment, the GPS reception processing unit 51 can acquire information indicating a part of the date and time, for example, date data, from the outside, here, the host CPU 41 as a set value. When the GPS reception processing unit 51 acquires the weekly elapsed time TOW-Count, that is, WORD2 of any subframe in a state where the date data is held, the GPS reception processing unit 51 holds the time part of the weekly elapsed time TOW-Count. The date and time is calculated based on the current date and output. Alternatively, the GPS reception processing unit 51 back-calculates the week number WN from the intra-weekly elapsed time TOW-Count and the stored date data, and the date and time obtained from the week number WN and the intra-weekly elapsed time TOW-Count. May be calculated.

  Therefore, in the electronic timepiece 1, the history in which the previous date / time information was acquired is stored in the RAM 43, and the date / time acquisition is performed based on whether or not there is a large difference in the date / time counted by the timing circuit 46 based on the history. You can change the method. That is, when it is assumed that the date and time deviation is small, for example, when one month has not elapsed since the acquisition of the previous date and time, the host CPU 41 outputs date data to the GPS reception processing unit 51 and receives the GPS data. The processing unit 51 calculates only the date and time by receiving only data of one arbitrary subframe without acquiring the week number WN. On the other hand, if there is a possibility that the date and time counted by the time counting circuit 46 may be significantly different, the host CPU 41 does not output date data to the GPS reception processing unit 51, and the GPS reception processing unit 51 receives the week number WN and Receive both the weekly elapsed time TOW-Count and calculate the date and time.

  After receiving WORD1 and identifying the preamble, if the reception conditions are good, WORD2 is subsequently received, and the date and time is received by receiving several words (for example, 2 words) including confirmation of the identified preamble. It is possible to receive information for a short time to complete reception. Also, by receiving one subframe including the identified preamble and about the first 1 to 3 words of the next subframe, the preamble is confirmed and the passage of time is confirmed to obtain more accurate date and time. Subframe reception to be performed can be selected and executed. However, when reception conditions are bad, such as low SNR, it may not be possible to accurately decode by one reception. In such a case, a plurality of subframes are continuously received to check consistency. Must be repeated to specify the exact date and time. Therefore, the reception time is extended from the normal time.

  In order to acquire position information, it is necessary to acquire data and ephemeris data related to the date and time of three or more satellites. Therefore, the necessary reception time is the time until the data of subframes 2 and 3 are normally received. In the electronic timepiece 1 of the present embodiment, navigation messages from a plurality of satellites can be acquired in parallel. Accordingly, the time required for the shortest data reception (positioning reception) necessary to completely receive subframes 2 and 3 is 12 seconds, and the theoretical longest time required for positioning reception is less than 42 seconds. It becomes. Furthermore, when the SNR is low and decoding is not normally performed in the middle, the reception time is extended by receiving multiple times.

  In the electronic timepiece 1 of this embodiment, the estimated value of the total reception time for acquiring information necessary for the type (or each reception mode) of information (position or date) to be acquired at the time of identifying the preamble and after identifying the preamble. (Estimated reception time) is stored as a reception time estimation conversion table in association with various SNR values. As will be described later, this reception time estimation conversion table is stored in either the RAM 43 (initial value is ROM 42) or the storage unit 512 (estimated time storage means) according to the reference source.

  FIG. 3 is a diagram illustrating an example of values stored as a reception time estimation conversion table.

When the SNR is a certain level, here, 30 dB / Hz or more, decoding failure hardly occurs and the estimated reception time becomes substantially constant. On the other hand, when the SNR becomes small, there is a high possibility that decoding will fail, and the number of repetitions for receiving a desired part of the navigation message will increase and the estimated reception time will increase.
From another aspect, in order to keep the estimated reception time below a predetermined upper limit time, the lower limit strength (SNR reference value) of the SNR is set, and the SNR of the radio wave from the receiving satellite to be selected is set to this SNR reference value. It is possible to set reception conditions that are restricted to the above.

Here, as an average reception time for positioning reception, for example, a value of about 35 seconds is set as the estimated reception time regardless of the position of the subframe at the time of preamble identification. However, the setting of the estimated reception time in the electronic timepiece 1 of the present embodiment is not limited to this, and as described above, a different estimated reception time is set and stored depending on the position of the identified subframe. You may let them.
Further, in the electronic timepiece 1, when automatic acquisition and correction of date / time information is performed regularly, the reception start timing is controlled based on the date / time counted by the timer circuit 46, so that a suitable subframe is obtained each time. Since the reception can be started from the position, the estimated reception time may be set according to this case.
Here, the sum of the preamble identification time and the time for acquiring necessary information is shown, but it can be held as a separate value. In this case, since the reception time required for identifying the preamble is not related to the reception mode, it may be held in common for all reception modes.

  The estimated time required to acquire the date and time information and the position information (estimated acquisition time) is the time required for the initial activation process of the GPS reception processing unit 51 (the activation time) and the radio waves from the necessary positioning satellites are captured. Is the sum of the acquisition time required for the above, the estimated reception time described above, and the computation processing time (estimated decoding time) after the reception process. The time required for the initial activation process is common to all reception modes and SNRs, and is estimated to be 2 seconds and stored in the ROM 42, for example. The acquisition time is common to all reception modes. Although this acquisition time may depend on the SNR, it is difficult to predict because the SNR is known only after the radio waves of the positioning satellite are acquired, and is commonly estimated to be, for example, 3 seconds and stored in the ROM 42 regardless of the SNR. Is done. Although the calculation processing time does not depend on the SNR, the calculation processing time differs depending on whether date / time information is acquired or when position information is calculated. For example, the calculation processing time is estimated to be 1 second for acquiring date / time information and 2 seconds for calculating position information. And stored in the ROM 42, respectively.

4 and 5 are flowcharts showing the control procedure of the position acquisition control process executed in the electronic timepiece 1 according to the present embodiment. This position acquisition control process is started by the host CPU 41 when, for example, a positioning command is acquired in response to an input operation to the operation unit 53 by the user. Each process in the position acquisition control process is executed by at least one of the host CPU 41 and the module CPU 511 except those explicitly described. These host CPU 41 and module CPU 511 constitute counting means, estimated time acquisition means, remaining time display control means, warning display control means, and estimated time update means.
Here, the case of radio wave reception from a GPS satellite will be described.

  When the position acquisition control process is started, the host CPU 41 turns on (turns on) the power of the GPS reception processing unit 51 (step S101). At this time, the host CPU 41 starts counting the elapsed time (reception time) since turning on the power. The host CPU 41 also calculates the estimated acquisition time according to the reception mode corresponding to the content to be received by the GPS reception processing unit 51 (here, the positioning reception mode for acquiring data necessary for position calculation) of the remaining time until acquisition. A process of setting the initial value and subtracting the elapsed time from the initial value of the remaining time and counting the remaining time is started, and a control signal is output to the display driver 48 to display the remaining time on the display unit 47 ( Step S102). At this stage, since the actual SNR related to satellite radio wave reception has not been acquired yet, the estimated acquisition time and the remaining time are calculated using a preset SNR, for example, the estimated reception time corresponding to the best SNR value. Set.

On the other hand, the module CPU 511 executes a startup process (step S103). The host CPU 41 or the module CPU 511 (hereinafter collectively referred to as a control unit) determines whether or not the activation process of the GPS reception processing unit 51 has been completed (step S104). If it is determined that the activation processing of the reception processing unit has not been completed (“NO” in step S104), the control unit determines whether or not a predetermined time limit has elapsed since the power was turned on and timed out (Step S105).
As the predetermined time limit, the operation time of the GPS reception processing unit 51 may be determined as a single time, the time until the start process ends, the time until the capture process to be described later, or until the preamble is detected in the navigation message And the time until the necessary information is acquired may be determined separately. These time limits are stored in the ROM 42 and read out when the position acquisition control process is started. Alternatively, only the time limit related to the activation process may be stored in the ROM 42, and the other time limit may be stored in the storage unit 512 and read and used by the module CPU 511 in the GPS reception processing unit 51. Further, the time limit may be changed according to reception conditions, for example, SNR. Further, the change of the time limit may be performed in the middle according to the change of the SNR being received.

  If it is determined that the time-out has not occurred ("NO" in step S105), the process proceeds to step S103. If it is determined that a time-out has occurred ("YES" in step S105), the control unit outputs a control signal to the display driver 48 to cause the display unit 47 to display an error (step S151). Then, the process proceeds to step S182 (see terminal C in FIG. 5).

  If it is determined in step S104 that the activation process has been completed ("YES" in step S104), the host CPU 41 transmits the reception mode and the set value to the GPS reception processing unit 51, and the module CPU 511 The data transmitted by the host CPU 41 is acquired (step S111). At this time, the host CPU 41 also transmits the battery remaining amount information acquired from the battery remaining amount detecting unit 501 to the module CPU 511. At this time, if there is no reception mode or setting value to be set in particular, the host CPU 41 does not need to transmit these data. In this case, the module CPU 511 uses the setting that has been set in the previous time or the like, or selects a reception mode based on the initial setting, and acquires information without a setting value. In addition, information relating to the reception mode in this case can be conversely notified from the module CPU 511 to the host CPU 41.

  The module CPU 511 starts reception of radio waves from the positioning satellite and starts processing for capturing radio waves from the positioning satellite (here, GPS satellite) (step S112). During the execution of this capturing process, the control unit sets an SNR reference value according to the remaining battery level (step S113). The control unit acquires the number of captured positioning satellites and the SNR of radio waves from these positioning satellites (step S114). The control unit selects (three in this case) the positioning satellites that are most suitable for use in the positioning process from the acquired positioning satellites (step S115). The control unit refers to the reception time estimation conversion table and acquires the estimated reception time corresponding to the SNR of the selected positioning satellite (step S116).

  The control unit determines whether or not the number of positioning satellites required for the calculation of the current position is acquired and the SNRs of all the selected positioning satellites are greater than or equal to the above SNR reference value (step S117). . When it is determined that any of the conditions is not satisfied (“NO” in step S117), the control unit determines whether or not the time related to the capture process has exceeded a predetermined time limit and timed out (step S1). S119). If it is determined that the time-out has exceeded the time limit (“YES” in step S119), the process proceeds to step S161 (see terminal B in FIG. 5). If it is determined that the time limit has not been exceeded (“NO” in step S119), the control unit may send a control signal to the display driver 48 and fail to acquire (receive) position data from the display unit 47. The warning display indicating the sex is performed (step S120). Then, the control unit performs the acquisition process again (retry) or monitors the change of the SNR while tracking the acquired positioning satellite, and returns the process to step S114.

  If it is determined in the determination process in step S117 that both conditions are satisfied (“YES” in step S117), the control unit adjusts the remaining time counted to adjust the remaining time. Is displayed on the display unit 47 (step S118). Here, the control unit acquires the estimated reception time corresponding to the SNR, and overwrites the sum of the estimated reception time and the calculation processing time as the remaining time. Thereafter, the process proceeds to step S121 (see terminal A in FIG. 5).

  When the process proceeds to step S121, in FIG. 5, the module CPU 511 starts receiving the navigation message (step S121). The control unit determines whether a preamble included in WORD1 of each subframe is detected in the navigation message (step S122). If it is determined that the preamble has not been detected (“NO” in step S122), the control unit determines whether or not 6 seconds, which is the time for one subframe, has elapsed since the start of reception of the navigation message. Is determined (step S123). When this determination processing is executed by the host CPU 41, the host CPU 41 does not acquire the detailed reception status from the GPS reception processing unit 51, and calculates the elapsed time from the timing branched to “YES” in the processing of step S117. You may count and use for discrimination.

  If it is determined that 6 seconds have elapsed from the start of reception of the navigation message (“YES” in step S123), this is the time when the preamble should always be detected once (detection time). In this case, the control unit sends a control signal to the display driver 48 and the position of the display unit 47 in the position where the preamble (predetermined signal) is not detected (predetermined reception state in which information is not acquired correctly). A warning display indicating the possibility of failure in data acquisition (reception) is performed (step S124), and then the process proceeds to step S125. If it is determined that 6 seconds have not elapsed since the start of reception of the navigation message (“NO” in step S123), the process directly proceeds to step S125.

  In the process of step S125, the control unit determines whether or not a timeout has occurred beyond a predetermined time limit (step S125). If it is determined that the time limit has not been exceeded (“NO” in step S125), the process returns to step S122. If it is determined that the time-out has exceeded the time limit (“YES” in step S125), the process proceeds to step S161.

  If it is determined in step S122 that the preamble has been detected ("YES" in step S122), the navigation message continues to be received, and the control unit counts the remaining time for 1 second. Is determined (step S126). If it is determined that the remaining time is 1 second (“YES” in step S126), the control unit stops counting the remaining time in 1 second, and thereafter, the remaining time is displayed on the display unit 47 as “1 second. "Is continued (step S127). Then, the process proceeds to step S128.

If it is determined that the remaining time is not 1 second (ie, greater than 1 second) (“NO” in step S122), the process proceeds to step S128.
When the process proceeds to step S128, the control unit determines whether or not all the information necessary for positioning (data of subframes 2 and 3) has been acquired (step S128). When it is determined that it has not been acquired (“NO” in step S128), the control unit determines whether or not a predetermined time has elapsed after detection of the preamble (step S129). Here, the predetermined time is set to, for example, 30 seconds, which is a length corresponding to 5 subframes (1 frame). When this determination process is executed by the host CPU 41, the host CPU 41 may perform the determination process based on the elapsed time after branching to “YES” in the process of step S122, or It may be determined whether or not an elapsed time after branching to “YES” in S117 exceeds a predetermined time + 6 seconds.

  If it is determined that the predetermined time has elapsed (“YES” in step S129), the control unit may send a control signal to the display driver 48 and fail to acquire (receive) position data from the display unit 47. Is displayed (step S130). Then, the process proceeds to step S131. If it is determined that the predetermined time has not elapsed (“NO” in step S129), the process proceeds to step S131.

  In the process of step S131, the control unit determines whether or not a timeout has occurred beyond a predetermined time limit (step S131). If it is determined that the time limit has not been exceeded and time-out has not occurred ("NO" in step S131), the processing of the control unit returns to step S126. If it is determined that the time-out has exceeded the time limit (“YES” in step S131), the process proceeds to step S161.

  When the process proceeds from any of the processes of steps S119, S125, and S131 to the process of step S161, the control unit sends a control signal to the display driver 48, and causes the display unit 47 to display that the reception NG has ended (step S161). . Then, the process proceeds to step S181.

  If it is determined in the process of step S128 that all information necessary for positioning has been acquired (“YES” in step S128), the control unit completes reception normally and calculates a position (step S171). Further, the control unit obtains a time zone based on the calculated position, and converts it into time difference information (step S172). The time zone setting information is stored in advance in the ROM 42 and is referred to by the host CPU 41.

  The control unit updates the reception time estimation conversion table based on the current total reception time and the SNR value (step S173). As this update method, for example, the number of past receptions in each SNR value is stored, and the estimated reception time corresponding to the current SNR is weighted by the number of receptions and added and averaged with the current total reception time. A technique is used. Alternatively, the standard deviation is calculated based on the difference between the estimated reception time and the past total reception time, and weighted based on the ratio between the standard deviation and the difference between the estimated reception time and the current total reception time. Or by using various known methods such as setting a restriction that the update is not performed when the current difference is larger than a predetermined value compared to the standard deviation, for example, 3σ or more, or The correction may be performed in combination with the above method.

  The host CPU 41 corrects the date and time counted by the time measuring circuit 46 and the time difference information of the current date and time to be displayed on the display unit 47 (step S174). The control unit sends a control signal to the display driver 48 to cause the display unit 47 to display that the reception has been completed normally (step S175). Then, the process proceeds to step S181.

  When the process proceeds from step S161 or step S175 to step S181, the control unit causes the GPS reception processing unit 51 to complete the operation (step S181). Then, the process proceeds to step S182.

  When the process proceeds from step S181 or step S151 to step S182, the host CPU 41 shuts off (turns off) the power to the GPS reception processing unit 51 (step S182). Then, the position acquisition control process ends.

  FIG. 6 is a sequence diagram illustrating an example of exchange of commands and data between the host CPU 41 and the module CPU 511 when the position acquisition process is executed in the electronic timepiece 1 of the present embodiment.

As described above, the position acquisition control process is executed in parallel depending on the situation, with the control distributed between the host CPU 41 and the module CPU 511. Many processes may be executed by any CPU depending on the design of the GPS reception processing unit 51. For example, the GPS reception processing unit 51 can directly access each unit such as the display driver 48 and the power supply unit 50. All processing other than the first power-on may be executed by the module CPU 511. Conversely, the processing by the GPS reception processing unit 51 is limited to that related to circuit operation, and the host CPU 41 performs all control processing. It is also possible to execute.
Also, the storage destination may be set in accordance with the CPU that executes the process of referring to and updating the reception time estimation conversion table. That is, when the host CPU 41 performs these processes, the initial value of the reception time estimation conversion table is stored in the ROM 42 and the updated data is stored in the RAM 43. When the above-described processing is executed by the module CPU 511, the reception time estimation conversion table may be stored in the storage unit 512.

  On the other hand, these processes can be efficiently allocated to both CPUs in order to eliminate waste due to the overlapping operation of the host CPU 41 and the module CPU 511 and to reduce the load such as the trouble of controlling the amount of communication information and communication timing. I can do it. In addition, it is possible to reduce the manufacturing cost by using a general-purpose GPS receiving module by allocating communication data so as to be limited to a format based on the communication standard of NMEA-0183 (National Marine Electronics Association).

  Here, for example, when the power of the GPS reception processing unit is turned on by the host CPU 41 (step S101), in the GPS reception processing unit 51, the module CPU 511 performs a startup process spontaneously (step S103), and the startup process is completed. Sometimes a completion notice is sent to the host CPU 41. The host CPU 41 starts setting, displaying, and counting the remaining time while waiting for the completion notification (step S102), and, based on the activation completion notification, sets the reception mode and the set value as a GPS reception processing unit. 51 (steps S104 and S111). Further, the host CPU 41 separately counts the elapsed time, determines the timeout (step S105), the execution instruction for the termination process to the GPS reception processing unit 51 (step S181), and the error display or reception NG end display. The control signal related to is output (steps S151 and S161).

  When receiving the reception mode and the set value from the host CPU 41, the module CPU 511 starts radio wave reception from the positioning satellite and executes processing related to acquisition of the positioning satellite (steps S112 to S117). In this case, the reception time estimation conversion table is stored in the storage unit 512 of the GPS reception processing unit 51.

  When the acquisition process is started, the GPS reception processing unit 51 outputs the number of satellites and the SNR value as acquisition information to the host CPU 41 as needed, and the host CPU 41 determines whether a positioning satellite corresponding to the condition of step S117 has been acquired. Based on the above, the process related to the adjustment of the remaining time is performed (step S118), or a timeout determination (step S119) and a warning display regarding the possibility of reception failure are performed (step S120). At this time, the determination processing in step S117 may be performed by the host CPU 41 separately from the module CPU 511 based on the capture information output from the GPS reception processing unit 51. Thereby, it is not necessary to output the determination result itself from the GPS reception processing unit 51. Since the determination conditions are the same, the host CPU 41 can obtain a determination result within a time lag range related to normal communication.

  When the acquisition process is completed, the module CPU 511 starts receiving the navigation message and notifies the host CPU 41 of the reception status as needed (steps S121 to S123, S128, and S129). The host CPU 41 counts the elapsed time in each reception situation, adjusts the warning display and the remaining time according to the time, and determines the timeout (steps S124 to S127, S129 to S131).

  When the necessary information is normally acquired (step S128), the GPS reception processing unit 51 calculates the position and outputs it to the host CPU 41 (step S171). In the GPS reception processing unit 51, the reception time estimation conversion table is corrected (step S173). On the other hand, the host CPU 41 sets time difference information from the acquired date and time information (step S172), and corrects the date and time data and time difference data of the time measuring circuit 46 (step S174).

  The host CPU 41 displays a reception NG end display (step S161) or a reception normal end display (step S175) according to the reception result of the GPS reception processing unit 51.

  In the GPS reception processing unit 51, the module CPU 511 performs termination processing either spontaneously or in response to a command from the host CPU 41 (step S181). When the termination processing is completed, the host CPU 41 supplies power to the GPS reception processing unit 51. It is blocked (step S182).

7 and 8 are flowcharts showing the control procedure of the date acquisition control process executed in the electronic timepiece 1 in the present embodiment.
In this date / time acquisition control process, the process of step S172 is omitted and the processes of steps S171 and S174 are changed to the processes of steps S171a and S174a, compared to the position acquisition control process described above. Also, the remaining time in steps S102 and S118, the reception mode and setting value in step S111, the SNR reference value in steps S113 and S117, the number of reception satellites selected in step S115, the required number of satellites in step S117, and the predetermined number in step S129 Each time corresponds to the acquisition of date and time.
7 and 8 are continuous via terminals D, E, and F. FIG.
In addition, about the process of the same content, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the date and time acquisition control process, either the short-time reception mode or the subframe reception mode is selected and set in FIG. 7 (steps S102 and S111), and date and time information is acquired based on the received radio waves from one satellite ( Step S117). Further, the estimated reception time used for setting the remaining time is read from the reception time estimation conversion table and used according to the selected reception mode (steps S102, S116, S118).

  In the process of step S129 of FIG. 8, the predetermined time is set to 8 seconds including 1 subframe and 3 words in the subframe reception mode, for example, and 3 words is set in the short time reception mode, for example. Set to 2 seconds.

  In the process of step S128, when the information necessary for obtaining the date and time, that is, the data of word 2 is obtained (“YES” in step S128), the control unit completes the reception normally and uses the UTC or the electronic timepiece 1. The date and time in a preset time zone is calculated (step S171a).

  The control unit updates the reception time estimation conversion table based on the current total reception time and the SNR value (step S173). Further, the host CPU 41 corrects the date and time counted by the time measuring circuit 46 (step S174a).

  As described above, the electronic timepiece 1 of this embodiment is designated as receiving means for capturing and receiving radio waves from positioning satellites (GPS satellites), and date / time information, position information, and the like are designated from the received radio waves. A GPS reception processing unit 51 is provided as a decoding means for acquiring information. The host CPU 41 or the module CPU 511 of the GPS reception processing unit 51 counts the reception time of the radio waves from the positioning satellites by the GPS reception processing unit 51, and also specifies the above-described designated information according to the received intensity of the captured radio waves. The estimated reception time required for acquisition of is acquired from the reception time estimation conversion table. And the remaining time with respect to the actual reception time of this acquired estimated reception time is calculated, and the display part 47 is made to display according to this remaining time. Therefore, it is possible to notify the user of a flexible reception status according to the reception environment and the like.

  In addition, during reception by the GPS reception processing unit 51, a predetermined warning indicating that there is a possibility that information acquisition may fail due to detection of occurrence of a predetermined reception situation in which information to be acquired is not acquired correctly, such as a preamble is not detected. Since the display is performed on the display unit 47, the reception level is lowered in the middle due to the movement of the user, the change in the surroundings, the change in the positional relationship between the positioning satellite and the obstacle, or the decoding is difficult due to noise temporarily. In such a case, it is possible to notify the user that reception is not proceeding smoothly during reception.

  In particular, when the signal indicating the preamble or the parity value matching the target portion is not detected within the expected time, the above warning display is performed, so that the user can know that the reception time is prolonged. Can be prepared and give up on information acquisition.

  In addition, since the estimated reception time is determined according to the type of information to be acquired, an appropriate remaining time can be displayed reflecting a large difference in reception time between position acquisition and date acquisition. .

  In addition, when acquiring date / time information, a subframe reception mode and a short-time reception mode are set as reception modes for acquiring the information to be acquired, and an estimated reception time is determined according to each of these reception modes. Therefore, the remaining time according to the estimated acquisition time according to the reception mode set according to the state at the time of reception can be appropriately displayed to let the user know.

  Also, various assumed levels of SNRs and estimated reception times corresponding to the respective SNRs are stored in the reception time estimation conversion table in association with each other, and the estimated reception times corresponding to the SNRs of the captured radio waves are stored in this table. Since the remaining time is calculated and displayed by reading from the reception time estimation conversion table, it is possible to easily display the remaining time by reducing the processing load.

  Further, each time the date / time information or the position information is acquired, the estimated reception time is corrected based on the total reception time of radio waves required for the acquisition and the reception time estimation conversion table is updated. It is possible to approach the estimated reception time according to the usage conditions of each user. Therefore, the remaining time with higher accuracy can be displayed.

  In addition, the set estimated reception time and the counted reception time can each include a time for starting the GPS reception processing unit 51. Accordingly, by reading the estimated reception time, the remaining time display can be easily started from when the GPS reception processing unit 51 is turned on.

  In addition, as the display corresponding to the remaining time, the remaining time with respect to the total time of the estimated reception time and the calculation processing time is shown, so that time lag occurs due to calculation processing related to positioning, etc. after receiving and obtaining the necessary navigation message Can be suppressed. Further, since this calculation process is not affected by the SNR, the time can be estimated almost accurately, and therefore the display accuracy of the remaining time is not lowered.

  In addition, the power supply unit 50 includes a secondary battery 500, a solar battery, and a battery remaining amount detection unit 501, and when acquiring date / time information or position information, the estimated reception time is determined by the battery remaining amount detection unit 501. The radio wave reception condition can be changed so as to be equal to or shorter than the upper limit time determined according to the measured remaining battery level. Therefore, when there is no margin in the remaining battery level, the battery runs out or information cannot be acquired using a receiving method that can acquire desired information more reliably within the time corresponding to the remaining battery level. It is possible to reduce the possibility of a situation in which reception is interrupted on the way.

  In particular, an SNR reference value indicating the lower limit of the SNR is set, and this SNR reference value is increased in accordance with a decrease in the remaining battery level, and only radio waves from a positioning satellite that can obtain a reception intensity higher than this SNR reference value are used. By acquiring desired information, it is possible to more reliably prevent the occurrence of a situation in which reception must be stopped in the middle while information cannot be acquired.

  Further, the above-described display method is adopted at the time of radio wave reception by the radio timepiece, and is executed by the control unit (host CPU 41 and / or module CPU 511). Desired information can be acquired by effectively receiving radio waves while reducing such stress.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the above embodiment, the estimated reception time corresponding to the SNR and the reception mode is stored in the reception time estimation conversion table. However, mathematical expressions and parameters for calculating the estimated reception time with respect to the SNR for each reception mode. May be held. In this case, it is only necessary to correct various coefficients and parameters in the mathematical expression at the end of reception.

In the above embodiment, when a desired signal portion in the navigation message is not detected within the set time, the display unit 47 displays a warning. However, it is necessary within the estimated reception time for other reasons. For example, if the signal strength from the selected receiving satellite is lower than the selected level by a predetermined level or more, the same warning display may be performed. good. In contrast, such a warning display need not always be performed.
Further, the warning display mode is appropriately determined. For example, it may be a blinking operation of a predetermined light or indicator, or these may be accompanied by a display. In addition, even when displaying with characters or the like, the specific wording is not limited to a specific one as long as it is indicated that the radio wave reception from the positioning satellite is not smoothly performed.

  Further, in the above embodiment, the positioning information is obtained by performing positioning reception in order to set the time zone, but the obtained position information is displayed as it is, or for other uses such as sunrise time and date. It may be used to calculate the entry time.

In the above-described embodiment, an electronic timepiece that performs digital display has been described. However, an analog electronic timepiece that displays date and time and various types of information using hands may be used. In this case, the remaining time is displayed using, for example, a second hand or a function hand used for timer display, and a normal display operation may be performed on the hour hand or minute hand. Further, a specific operation for displaying the remaining time such as operating the second hand once every 2 seconds or 3 seconds may be performed. Even if it is a digital display, it is not limited to the case where the remaining time is specifically specified, and the remaining time can be displayed using various known methods such as the position of the indicator, the length of the bar, and the number of points to be displayed. It is possible to display the possibility of information acquisition failure.
In addition, the radio timepiece according to the present invention has a strong demand for reducing power consumption, such as a portable small timepiece and a pocket watch including an electronic wristwatch, and the position of the timepiece may change as the user moves. Any electronic watch may be used.

  In the above embodiment, radio wave reception from GPS satellites has been described as an example. However, the present invention is also applied to reception of other positioning satellites such as GLONASS and Japanese quasi-zenith satellites. I can do it. In this case, Japanese quasi-zenith satellites and the like may be handled in parallel as one of the GPS satellites, while in the case of GLONASS, preamble identification and time setting according to the GPS navigation message format, etc. Each of these may be set and used in accordance with the format of the navigation message of GLONASS.

In the above embodiment, the remaining time of the estimated acquisition time from when the power is turned on until the date / time and position information is acquired is displayed. However, as described above, the total reception time varies depending on the SNR. (Acquisition time and data reception time), and especially in positioning reception and subframe reception, this total reception time accounts for more than half of the time required for information acquisition, so only the remaining time of this estimated reception time is estimated. The remaining time with respect to the sum of the reception time and the activation time, or the remaining time with respect to the sum of the estimated reception time and the calculation processing time may be displayed.
In addition, when the module CPU 511 performs the remaining time counting and / or display control, it is difficult to execute the control until the initial activation is completed. Therefore, the estimated acquisition time excluding the activation time after the activation processing is completed. The remaining time with respect to can be counted and displayed.

  Moreover, in the said embodiment, although the output voltage from the power supply part 50 and the SNR reference value were matched and used, you may measure the residual amount of the secondary battery 500 with another method. Further, instead of directly associating the output voltage with the SNR reference value, the output voltage may be once converted into the reception operable time by the GPS reception processing unit 51 and stored and used.

  In the above embodiment, the SNR reference value is changed according to the remaining battery level, and when the remaining battery level is insufficient, it is limited to the signal from the receiving satellite that can receive radio waves satisfactorily. In addition to or in place of this, other conditions such as changing the number of reception satellites to be selected may be used. As the number of receiving satellites increases, the probability that any of the positioning satellites will fail to acquire necessary information increases, so the estimated reception time that is set increases. Therefore, for example, when the remaining battery level is sufficient, the number of received satellites to be selected is set to 5 or more in the position acquisition control process, and is set to 2 or the like in the date acquisition control process. Then, as the remaining battery level decreases, the position acquisition control process may decrease the number to four or three, and the date / time acquisition control process may decrease the number to one. Further, the timeout time may be changed according to the remaining battery level.

  In addition, when the predicted orbit of each positioning satellite is held, and in the case of date and time acquisition control processing, or even in the position acquisition control processing, the time interval from the previous positioning is short and no large position movement is assumed Then, the elevation angle of the positioning satellite can be calculated based on the predicted orbit, and the lowest elevation angle can be used as the reception condition. If the elevation angle is small, reflected waves from buildings such as buildings and terrain such as hills and mountains are likely to be received, and the received data may be inaccurate due to multipath effects, or position calculation may fail. Therefore, by eliminating such receiving satellites from the selection, it is possible to improve reception accuracy and to suppress an increase in estimated reception time.

  Moreover, in the said embodiment, although the power supply part 50 was provided with the secondary battery 500 which accumulates the surplus electric power by the solar battery and the said solar battery, it is charged using a dry cell or an external charger. A secondary battery may be provided.

In the above embodiment, the estimated reception time is corrected every time or under predetermined conditions after reception of radio waves from the positioning satellite. However, such correction may not be performed.
In addition, specific details such as the configuration, processing contents, and processing order shown in the above embodiment can be changed as appropriate without departing from the spirit of the present invention.

Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and equivalents thereof. .
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.

[Appendix]
<Claim 1>
Receiving means for capturing and receiving radio waves from positioning satellites;
Decryption means for obtaining designated information from the received radio waves;
Counting means for counting the reception time by the receiving means;
Estimated time acquisition means for acquiring an estimated reception time necessary for acquiring the designated information according to the received intensity of the captured radio wave;
A remaining time display control unit that calculates a remaining time of the acquired estimated reception time with respect to the reception time and causes the display unit to perform display according to the remaining time;
A radio-controlled timepiece characterized by comprising:
<Claim 2>
During reception by the receiving means, it is detected that a predetermined reception situation in which the information is not correctly acquired by the decoding means has occurred, and a predetermined warning display indicating the possibility of failure in acquiring the information is displayed on the display means 2. The radio timepiece according to claim 1, further comprising a warning display control unit to be performed.
<Claim 3>
3. The predetermined reception status includes a status in which a predetermined signal corresponding to the specified information is not detected from the received radio wave within a preset detection time. Radio clock.
<Claim 4>
The radio timepiece according to claim 1, wherein the estimated reception time is determined according to a type of information to be acquired.
<Claim 5>
The radio timepiece according to claim 4, wherein a plurality of reception modes of the radio wave for acquiring the acquisition target information are set, and the estimated reception time is determined according to the reception mode.
<Claim 6>
Estimated time storage means for storing a plurality of the reception strengths and the estimated reception times corresponding to the plurality of reception strengths in association with each other,
The radio timepiece according to any one of claims 1 to 5, wherein the estimated time acquisition unit reads out the estimated reception time corresponding to the received intensity of the captured radio wave from the estimated time storage unit. .
<Claim 7>
Each time the information is acquired by the decoding means, the estimated time update means is corrected based on the reception time of the radio wave required for the acquisition and stored in the estimated time storage means. The radio timepiece according to claim 6.
<Claim 8>
The radio timepiece according to claim 1, wherein the estimated reception time and the reception time each include a time for starting the reception unit.
<Claim 9>
9. The display according to the remaining time indicates a total time of the estimated reception time and an estimated decoding time required for obtaining the information by the decoding means. Radio wave clock given in one paragraph.
<Claim 10>
A power supply means for supplying power, including a battery;
A remaining amount detecting means for detecting the remaining amount of the battery;
With
The decoding device according to any one of claims 1 to 9, wherein the decoding unit changes a reception condition related to reception of the radio wave so that the estimated reception time is equal to or less than an upper limit time determined according to the remaining amount. Radio wave clock as described in one.
<Claim 11>
The reception condition includes a lower limit strength of the reception strength,
The decoding means obtains the specified information using only radio waves from a positioning satellite that increases the lower limit intensity according to the decrease in the remaining amount and obtains a received intensity equal to or higher than the lower limit intensity. The radio timepiece according to claim 10.
<Claim 12>
A receiving means for capturing and receiving radio waves from a positioning satellite, a decoding means for obtaining designated information from the received radio waves, and a display means. The display method when receiving radio waves,
A counting step for counting a reception time by the receiving means;
An estimated time acquisition step for acquiring an estimated reception time necessary for acquiring the designated information according to the received intensity of the captured radio wave,
A remaining time display control step of calculating a remaining time for the received time of the acquired estimated receiving time, and causing the display unit to perform display according to the remaining time;
A display method at the time of radio wave reception characterized by including.

1 Electronic clock 41 Host CPU
42 ROM
421 program 43 RAM
44 Oscillator circuit 45 Frequency divider circuit 46 Clock circuit 47 Display unit 48 Display driver 50 Power supply unit 500 Secondary battery 501 Battery remaining amount detection unit 51 GPS reception processing unit 511 Module CPU
512 Storage Unit 52 Reception Antenna 53 Operation Unit

Claims (12)

Receiving means for capturing and receiving radio waves from positioning satellites;
Decryption means for obtaining designated information from the received radio waves;
Counting means for counting the reception time by the receiving means;
One or more positioning satellites are selected from the captured positioning satellites, and an estimated reception time required for acquiring the specified information is acquired according to the radio wave reception intensity of the selected positioning satellites. Estimated time acquisition means;
A remaining time display control unit that calculates a remaining time of the acquired estimated reception time with respect to the reception time and causes the display unit to perform display according to the remaining time;
A radio-controlled timepiece characterized by comprising:   During reception by the receiving means, it is detected that a predetermined reception situation in which the information is not correctly acquired by the decoding means has occurred, and a predetermined warning display indicating the possibility of failure in acquiring the information is displayed on the display means 2. The radio timepiece according to claim 1, further comprising a warning display control unit to be performed.   3. The predetermined reception status includes a status in which a predetermined signal corresponding to the specified information is not detected from the received radio wave within a preset detection time. Radio clock.   The radio timepiece according to claim 1, wherein the estimated reception time is determined according to a type of information to be acquired.   The radio timepiece according to claim 4, wherein a plurality of reception modes of the radio wave for acquiring the acquisition target information are set, and the estimated reception time is determined according to the reception mode. Estimated time storage means for storing a plurality of the reception strengths and the estimated reception times corresponding to the plurality of reception strengths in association with each other,
The said estimated time acquisition means reads the said estimated reception time according to the reception intensity | strength of the radio wave of the selected said positioning satellite from the said estimated time memory | storage means. The radio wave clock described.   Each time the information is acquired by the decoding means, the estimated time update means is corrected based on the reception time of the radio wave required for the acquisition and stored in the estimated time storage means. The radio timepiece according to claim 6.   The radio timepiece according to claim 1, wherein the estimated reception time and the reception time each include a time for starting the reception unit.   9. The display according to the remaining time indicates a total time of the estimated reception time and an estimated decoding time required for obtaining the information by the decoding means. Radio wave clock given in one paragraph. A power supply means for supplying power, including a battery;
A remaining amount detecting means for detecting the remaining amount of the battery;
With
The decoding device according to any one of claims 1 to 9, wherein the decoding unit changes a reception condition related to reception of the radio wave so that the estimated reception time is equal to or less than an upper limit time determined according to the remaining amount. Radio wave clock as described in one. The reception condition includes a lower limit strength of the reception strength,
The decoding means obtains the specified information using only radio waves from a positioning satellite that increases the lower limit intensity according to the decrease in the remaining amount and obtains a received intensity equal to or higher than the lower limit intensity. The radio timepiece according to claim 10. A receiving means for capturing and receiving radio waves from a positioning satellite, a decoding means for obtaining designated information from the received radio waves, and a display means. The display method when receiving radio waves,
A counting step for counting a reception time by the receiving means;
A selection step of selecting one or more positioning satellites from the acquired positioning satellites;
An estimated time acquisition step of acquiring an estimated reception time necessary for acquiring the designated information according to the radio wave reception intensity of the selected positioning satellite ;
A remaining time display control step of calculating a remaining time for the received time of the acquired estimated receiving time, and causing the display unit to perform display according to the remaining time;
A display method at the time of radio wave reception characterized by including.