JP6458790B2 - Satellite radio wave receiver, radio clock, satellite radio wave receiving method, and program - Google Patents

Description

The present invention relates to a satellite radio wave receiving apparatus, a radio clock , a satellite radio wave receiving method, and a program that receive information from a positioning satellite and acquire information.

  2. Description of the Related Art Conventionally, there is an electronic timepiece (radio timepiece) that receives a radio wave including date / time information and position information and corrects the date / time and sets a time zone. By performing such operations according to the movement of the radio clock user or the passage of a predetermined time, the radio clock easily counts the correct date and time, and at the local time according to the user's current location. The date and time can be displayed.

  As one of information sources for transmitting information related to date and time from the outside by radio waves, there is a positioning satellite according to GNSS (Global Navigation Satellite System). Since radio waves from positioning satellites are received at any place in the world as long as the sky is visible, there are few restrictions, and it is particularly preferably used in portable radio clocks.

  On the other hand, receiving a radio wave from a positioning satellite usually requires a much larger load than a power load necessary for a counting operation and a display operation performed by an electronic timepiece. In portable radio timepieces, especially wristwatches, it is not possible to use a power supply that can easily handle large loads due to the miniaturization and weight reduction. Conventionally, the time required for receiving radio waves from positioning satellites has been shortened by various methods. As a result, technologies for reducing power consumption have been developed.

  However, simply setting an upper limit on the reception time has a problem that the possibility of successful acquisition of information also decreases. Therefore, Patent Document 1 discloses a technique that changes the reception limit time according to the reception intensity from the positioning satellite and does not extend the reception limit time when the remaining battery level is low.

JP 2010-60456 A

  However, even if the reception condition is good, information acquisition is not always successful in a short time due to temporary noise or the like. On the other hand, when the reception status is bad, even if information is acquired, the accuracy is too low, and there may be a problem in practical use. In these cases, there is a low possibility that information acquisition will actually succeed compared to the reception time, and there is a problem that power consumption is likely to be wasted when information acquisition fails.

An object of the present invention is to provide a satellite radio wave receiver, a radio clock , a satellite radio wave reception method, and a program that can acquire information from a positioning satellite more efficiently.

In order to achieve the above object, the present invention
A satellite radio wave receiver that receives radio waves transmitted from the satellite and decodes the received radio wave signals;
A storage unit for storing the decoding result decoded by the satellite radio wave receiving unit for each satellite;
A control unit for controlling the reception operation of the satellite radio wave reception unit;
With
The decryption result includes at least the number of times related to whether or not the decryption was successful,
Wherein, based on the number of times related to whether successful the decryption included in the decoded results stored in the before term memory unit, a satellite the satellite radio receiver is receiving also followed the A satellite radio wave receiver characterized by controlling whether or not a satellite radio wave receiver receives signals.

According to the present invention, there is an effect that it is possible to obtain information from the goodness Ri efficiently positioning satellite.

It is a block diagram which shows the function structure of the electronic timepiece of embodiment of this invention. It is a block diagram which shows the internal structure of a GPS reception process part. It is a flowchart which shows the control procedure of the local time acquisition process performed by the GPS reception process part of the electronic timepiece of 1st Embodiment. 10 is a flowchart illustrating a control procedure of local time acquisition processing according to Modification 1; 10 is a flowchart illustrating a control procedure of local time acquisition processing according to a second modification. It is a block diagram which shows the function structure of the electronic timepiece of 2nd Embodiment. It is a flowchart which shows the control procedure of the local time acquisition process performed by the GPS reception process part of the electronic timepiece of 2nd 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 according to an embodiment of the present invention.
The electronic timepiece 1 is a radio timepiece that can be used by receiving radio waves from a positioning satellite.

  The electronic timepiece 1 of the first embodiment includes a 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, Operation unit 47, standard radio wave reception unit 48 and its antenna 49, GPS reception processing unit 50 and its antenna 51, drive circuit 52, power supply unit 53, second hand 61, minute hand 62, hour hand 63, date The vehicle 64, the function pointer 65, the wheel train mechanisms 71 to 74, the stepping motors 81 to 84, and the like are provided. Hereinafter, a part or all of the second hand 61, the minute hand 62, the hour hand 63, the date indicator 64, and the function pointer 65 are collectively referred to as hands 61 to 65.

  The CPU 41 performs various arithmetic processes and controls the overall operation of the electronic timepiece 1. The CPU 41 controls the pointer operation related to the display of the date and time, operates the standard radio wave reception unit 48, acquires the received data, and calculates the date and time. Further, the CPU 41 corrects the date and time counted by the timer circuit 46 based on the obtained date and time data.

  The ROM 42 stores various control programs 421 executed by the CPU 41 and setting data. The program 421 includes, for example, a program related to operation control in various function modes.

  The RAM 43 provides a working memory space to the CPU 41 and stores temporary data.

The oscillation circuit 44 generates and outputs a predetermined frequency signal. The oscillation circuit 44 includes, for example, a crystal oscillator.
The frequency dividing circuit 45 divides the frequency signal output from the oscillation circuit 44 into a frequency signal used by the CPU 41 or the time measuring circuit 46 and outputs the frequency signal. The output frequency may be set to be changeable by a control signal from the CPU 41.

  The timer circuit 46 counts the current date and time by counting and adding the frequency-divided signal input from the frequency divider circuit 45 to an initial value indicating a predetermined date and time. The date and time counted by the timer circuit 46 can be corrected by a control signal from the CPU 41.

  The operation unit 47 receives an input operation from the user. The operation unit 47 includes a push button switch and a rotation switch. When any one of the push button switches is pressed or released, or the rotation switch is pulled out, rotated, or pushed back, an electrical signal indicating each operation is output to the CPU 41 as an interrupt signal. .

  The standard radio wave receiver 48 receives a long wavelength band radio wave (standard radio wave) using the antenna 49, demodulates the time signal output (TCO) of the standard radio wave subjected to amplitude modulation, and outputs it to the CPU 41. The tuning frequency of the long wavelength band by the standard radio wave receiver 48 is changed according to the transmission frequency from the standard radio wave transmission station to be received under the control of the CPU 41. In addition, the standard radio wave receiver 48 performs various processes for improving the reception sensitivity, digitizes the analog signal at a predetermined sampling frequency, and outputs it to the CPU 41.

  The GPS reception processing unit 50 receives the L1 band (1.57542 GHz) radio wave transmitted from the positioning satellite using the antenna 51, demodulates and decodes the signal (navigation message) from the positioning satellite, and date information And get location information. The acquired information is output to the CPU 41 in a format set based on, for example, the standard of NMEA-0182 (National Marine Electronics Associations). The GPS reception processing unit 50 receives the information to be acquired and the settings related to the output format from the CPU 41 and stores them. In addition, the GPS reception processing unit 50 stores the predicted orbit information of the positioning satellite acquired from the positioning satellite, and can read and use it as necessary at the time of reception. In addition, the GPS reception processing unit 50 stores a time zone correspondence table 502d for acquiring time zone and daylight saving time information corresponding to a designated position.

  The drive circuit 52 receives a control signal from the CPU 41, outputs a drive signal to the stepping motors 81 to 84 according to the control signal at an appropriate timing, and rotationally drives the stepping motors 81 to 84. In the drive circuit 52, the pulse width of the drive signal and the drive voltage can be appropriately adjusted based on the setting input from the CPU 41. In addition, when a control signal for driving a plurality of stepping motors at the same time is input so as not to apply a large load at a time, the drive circuit 52 shifts these drive timings at a minute interval that does not overlap with each other in order. The stepping motor can be driven to rotate.

  The power supply unit 53 supplies power related to the operation of each unit at a predetermined voltage. The power supply unit 53 includes a battery. For example, a replaceable button-type dry battery is used as the battery. Alternatively, a solar panel and a secondary battery may be used as the battery. In addition, when a plurality of different voltages are output from the power supply unit 53, for example, a configuration that can be converted into a desired voltage using a switching power supply or the like can be output.

The stepping motor 81 rotates the second hand 61 via a gear train mechanism 71 that is an array of a plurality of gears. When the stepping motor 81 is driven once, the second hand 61 rotates 6 degrees in one step, and makes a round on the dial by the 60-time operation of the stepping motor 81.
The stepping motor 82 rotates the minute hand 62 and the hour hand 63 via the train wheel mechanism 72. The train wheel mechanism 72 is configured to rotate the hour hand 63 in conjunction with the minute hand 62, and rotates the minute hand 62 by 1 degree and rotates the hour hand 63 by 1/12 degrees.

  The stepping motor 83 rotates the date wheel 64 via the wheel train mechanism 73. Although not limited in particular, the date dial 64 is provided below the dial display dial of the electronic timepiece 1 (back side) so as to be rotatable in parallel with the dial displaying dial. While the dial is provided with an opening, a sign indicating each day of the 1st to 31st days is provided on the circumference facing the opening of the date indicator 64, and the date indicator 64 is rotated. Any one mark is exposed from the opening. When the stepping motor 83 is driven once, the date wheel 64 is rotated by an angle corresponding to one step, and is rotated 360/31 degrees by the rotational movement of 150 steps, and is exposed from the opening of the dial. The date indicator changes by one day. Then, when the date wheel 64 is rotated by 31 days, a date mark indicating the first date is exposed from the opening again.

  The stepping motor 84 rotates the function pointer 65 via the train wheel mechanism 74. The function pointer 65 is not particularly limited, but, for example, rotates around a rotation axis different from that of the second hand 61, the minute hand 62, the hour hand 63, and the date indicator 64, and is used to display contents other than the date / time display or the type thereof. For example, the train wheel mechanism 74 rotates the function pointer 65 by 6 degrees with respect to one rotation of the stepping motor 84.

Next, radio wave reception from a positioning satellite by the GPS reception processing unit 50 will be described.
FIG. 2 is a block diagram showing an internal configuration of the GPS reception processing unit 50.

  The GPS reception processing unit 50 includes an RF unit 501 (Radio Frequency) connected to the antenna 51, a baseband unit 502 connected to the RF unit 501, and the like.

  The RF unit 501 amplifies a signal from the radio wave received by the antenna 51 and converts it to a signal frequency (baseband). The RF unit 501 includes, for example, an LNA (Low Noise Amplifier), a BPF (Band Pass Filter), a local oscillator, a mixer, an IF amplifying unit (Intermediate Frequency), and the like, and sandwiches an intermediate frequency by a superheterodyne method. Convert to baseband signal.

  The baseband unit 502 searches for and acquires signals from each positioning satellite from the signals converted into baseband signals, and demodulates and decodes the captured signals to obtain desired information. The baseband unit 502 includes a capture unit 502a (capture unit), a tracking unit 502b (satellite data acquisition unit), a control unit 502c (information acquisition unit, reception control unit, determination unit) and the like. The acquisition unit 502a sequentially applies the pseudo-noise signal (C / A code) set for each of the acquisition target positioning satellites to the baseband signal, performs inverse spectrum spread, and calculates a correlation value. A signal from a positioning satellite related to the C / A code is searched for and captured. The tracking unit 502b sequentially applies the C / A code of the positioning satellite captured by the capturing unit 502a with the identified phase, demodulates and decodes the navigation message of the positioning satellite, and acquires the current position (acquisition target information). Data necessary for the operation, that is, information (including correction information) regarding the date and time included in the subframes 1 to 3 and predicted trajectory information (ephemeris).

  The control unit 502c controls the operation of the baseband unit 502. The control unit 502c includes a CPU (module CPU), a RAM, a storage unit, and the like. The module CPU performs operations such as on / off of the operations of the capturing unit 502a and the tracking unit 502b and selection control of a positioning satellite to be received, and performs setting and control related to data transmission / reception with the CPU 41. Further, the module CPU calculates (acquires) the current position using the date / time information and the predicted trajectory information acquired by the tracking unit 502b. The RAM is a volatile memory that provides a working memory space to the module CPU. The storage unit stores predicted orbit data (ephemeris and almanac) acquired from positioning satellites, past reception history, and settings related to reception target information, and is read and used as necessary. The capturing unit 502a can search for signals in parallel by a search engine (capturing processing unit, where n is 16 for example) of a plurality of channels ch1 to chn. The tracking unit 502b can perform operations related to signal demodulation and decoding in parallel on a plurality of channels ch1 to chm (m is, for example, 8). When searching the signals of 32 satellites in parallel, the search may be performed alternately every 16 satellites.

  The control unit 502c can turn on and off the operations of the capturing unit 502a and the tracking unit 502b independently. Further, the control unit 502c can set a positioning satellite related to a signal to be captured by the capturing unit 502a. For example, the control unit 502c can exclude a positioning satellite that has already been captured by the capturing unit 502a and is being tracked by the tracking unit 502b. In addition, the control unit 502c uses both positioning satellites according to GPS and GLONASS, or uses only the positioning satellites according to one of the positioning systems. Can be set to expand to Galileo or narrow down to any one.

  Further, when the predicted trajectory information is held at the time of positioning, or when the predicted trajectory information is acquired during reception, the control unit 502c, for example, based on the predicted trajectory information, for example, a signal already captured It is also possible to appropriately exclude positioning satellites related to signals that cannot be received at the same time on the ground surface. Furthermore, when the approximate position information is held in advance, a signal from a positioning satellite at a position where reception is not possible may be excluded from capture targets according to the position information and the current date and time.

Next, the positioning operation in the electronic timepiece 1 will be described.
A signal from a positioning satellite is spectrum-spread with a C / A code unique to each positioning satellite and transmitted by radio waves. Therefore, the capturing unit 502a calculates a correlation value for each C / A code, and identifies a C / A code having a high correlation value and its phase, thereby capturing a signal from a positioning satellite related to the C / A code. The captured signal is continuously demodulated and decoded in the tracking unit 502b with the C / A code and the phase used for the capture.

  When receiving a signal from a GPS positioning satellite (GPS satellite), the demodulated signal is composed of 25 seconds (pages) of 30-second frame data consisting of five 6-second subframes. . Among these, by acquiring the first subframe data (subframe 1) to the third subframe data (subframe 3) in an arbitrary page, date / time information and satellite orbit information necessary for positioning are obtained. Data is acquired. Three-dimensional positioning requires satellite orbit information (satellite position) and date / time information (timing) for four satellites, but if height information is not required, positioning on the ground surface is assumed. In this way, positioning is possible even with satellite orbit information and date / time information for three satellites (the number necessary for obtaining income target information).

  However, depending on the positioning (positioning) of the positioning satellites used for positioning (for example, when the positioning satellites used for positioning are on one straight line), in a three-dimensional space or a two-dimensional plane on the ground surface The position may not be specified with high accuracy. DOP (Dilution of Precision, P (Position) DOP for 4 satellites or more, H (Horizontal) DOP for 2D positioning by satellites) as a parameter representing the positioning accuracy according to such positioning Is calculated. The allowable accuracy is appropriately determined depending on the product and application.

  In the electronic timepiece 1 of the present embodiment, the GPS reception processing unit 50 obtains the data of subframes 1 to 3 from at least three positioning satellites, performs positioning, and the DOP value related to the positioning has a predetermined condition. By satisfying (below a predetermined reference value), it is determined that the positioning result is a correct result.

  FIG. 3 is a flowchart showing a control procedure by the control unit 502c of the local time acquisition process executed by the GPS reception processing unit 50 of the electronic timepiece 1 of this embodiment.

  This local time acquisition process is started in response to detection of a predetermined input operation to the operation unit 47 by the user, for example. Alternatively, it may be automatically started when a predetermined operation condition is satisfied.

  When the local time acquisition process is started, the control unit 502c (module CPU) starts operations of the RF unit 501 and the capturing unit 502a, and performs operations related to reception of radio waves in the L1 band and acquisition of signals from positioning satellites. Is started (step S101). At this time, the control unit 502c starts counting elapsed time (capture elapsed time) after the start of capture.

  The control unit 502c determines whether or not the capture elapsed time has exceeded the set capture timeout time (upper limit time) (step S102). When it is determined that the acquisition timeout period has not been exceeded (“NO” in step S102), the control unit 502c determines whether a new signal from the positioning satellite has been acquired (step S103). If it is determined that the signal has been acquired (“YES” in step S103), the control unit 502c causes the tracking unit 502b to start the demodulation and decoding operation of the navigation message related to the acquired positioning satellite. Capture is terminated by the capture unit 502a (step S104).

  The control unit 502c determines whether or not the number of captured signals (capture number) is equal to or greater than a predetermined number (predetermined number) (step S106). This set number is more than the minimum number of satellites (three) required for positioning, and if acquisition of navigation message fails after acquisition, or a positioning satellite signal with unfavorable positioning may be acquired first. It is a value considering the above, and is normally set to 4 to 8 machines, for example, 5 machines. When it is determined that more than the set number has been captured (“YES” in step S106), the control unit 502c ends the capturing operation by the capturing unit 502a and stops the capturing unit 502a (step S121). At this time, the control unit 502c starts counting the elapsed tracking time from the timing when the capture is finished. If it is determined that more than the set number of signals has not been captured (“NO” in step S106), the process of the control unit 502c proceeds to step S112.

  The control unit 502c determines whether or not the tracking elapsed time has exceeded the set tracking timeout time (step S122). If it is determined that the tracking timeout period has been exceeded (“YES” in step S122), the process of the control unit 502c shifts the process to step S133, ends the reception operation, and ends the local time acquisition process. If it is determined that the tracking timeout period has not been exceeded (“NO” in step S122), the control unit 502c causes the tracking unit 502b to receive a navigation message from three or more positioning satellites among the acquired positioning satellites. It is determined whether or not the data of the middle subframes 1 to 3 has been acquired (step S123).

  When it is determined that the data of subframes 1 to 3 has not been acquired from three or more positioning satellites (“NO” in step S123), the process of the control unit 502c returns to step S122. If it is determined that it has been acquired (“YES” in step S123), then the control unit 502c determines whether or not the acquired positioning result satisfies a predetermined accuracy condition (step S127). The control unit 502c determines whether or not the DOP value is less than or equal to a predetermined reference value, and is less than or equal to the reference value, that is, the positioning result is greater than or equal to a predetermined accuracy (satisfies the predetermined reference). When it is determined (“YES” in step S127), the control unit 502c ends the tracking operation by the tracking unit 502b and stops the tracking unit 502b (step S128). The control unit 502c refers to the time zone correspondence table 502d and identifies the time zone based on the acquired position information (step S129). At this time, the control unit 502c can output the correct date and time and time zone information to the CPU 41 at an appropriate timing to correct the date and time of the clock circuit 46 and the local time to be displayed. Then, the control unit 502c ends the local time acquisition process.

  If it is determined in the determination process in step S127 that the positioning result does not satisfy the accuracy condition (“NO” in step S127), the control unit 502c transmits subframes 1 to 3 from all the acquired positioning satellites. It is determined whether or not data has been acquired (step S131). When it is determined that there is a satellite that has not been acquired, that is, among the captured positioning satellites for which data of subframes 1 to 3 has not been acquired ("NO" in step S131), the control unit 502c The process proceeds to step S122. When it is determined that the data of subframes 1 to 3 has been acquired from all the acquired positioning satellites (“YES” in step S131), the control unit 502c performs the reception process for all the positioning satellites. The process ends (step S133), and the local time acquisition process ends.

  If it is determined in step S103 that a new signal is not captured during the capturing operation by the capturing unit 502a ("NO" in step S103), the control unit 502c determines that the positioning satellite currently captured It is determined whether or not the number of images (number of captures) is “0” (step S111). If it is determined that the number of captures is “0” (“YES” in step S111), the process of the control unit 502c proceeds to step S102. If it is determined that the number of captures is not “0” (“NO” in step S111), the process of the control unit 502c proceeds to step S112.

  When shifting from the process of step S111 or step S106 to the process of step S112, the control unit 502c has acquired data of subframes 1 to 3 by three or more of the positioning satellites captured so far. It is determined whether or not (step S112). If it is determined that the number of acquisitions is less than three satellites or the data of subframes 1 to 3 has not yet been acquired (“NO” in step S112), the control unit 502c performs the following process: The process proceeds to step S102.

  If it is determined in the determination process in step S112 that data of subframes 1 to 3 has been acquired by three or more positioning satellites (“YES” in step S112), the process of the control unit 502c proceeds to step S127. Transition. At this time, the control unit 502c ends the capturing operation by the capturing unit 502a.

  If it is determined in the determination processing in step S102 that the capture elapsed time has exceeded the capture timeout period without exceeding the set number (“YES” in step S102), the control unit 502c has three or more aircraft. It is determined whether or not a positioning satellite has been captured (step S109). If it is determined that three or more aircraft have been captured (“YES” in step S109), the process of the control unit 502c proceeds to step S121. If it is determined that three or more aircraft are not captured (two or fewer aircraft) (“NO” in step S109), the processing of the control unit 502c proceeds to step S133 and receives (captures and tracks). To end local time acquisition processing.

[Modification 1]
Next, modification 1 of the local time acquisition process in the electronic timepiece 1 of the present embodiment will be described.
FIG. 4 is a flowchart illustrating a control procedure by the control unit 502c of the local time acquisition process according to the first modification.

  In this local time acquisition process, the process of step S123 in the local time acquisition process of the above embodiment is divided into steps S123a and S123b, the process of step S112 is divided into steps S112a and S112b, and steps S124 to S126 are further performed. , S113, and S114 are added. Processing other than these is the same, and the same reference numerals are assigned and detailed description is omitted.

  When it is determined in the determination process of step S111 that the number of positioning satellites captured is not “0” (“NO” in step S111), the control unit 502c performs subframe 1 for each of the captured positioning satellites. It is determined whether or not it is the timing when the data of ˜3 is acquired (step S112a). That is, here, after the position in the navigation message is identified for each positioning satellite (or after branching to “YES” in the process of step S112a last time), the control unit 502c performs the subframes 1-3. It is determined whether or not the entire reception period has elapsed. The order of the reception periods is not limited to the order of the subframes 1, 2, and 3. For example, after the subframe 3 is received, the subframes 1 and 2 in the next frame may be received. That is, the data for one frame (one period) may not be started from the subframe 1 according to the signal capture timing (data acquisition start timing).

  If it is determined that it is not the timing at which the data of subframes 1 to 3 is acquired for any of the captured satellites (“NO” in step S112a), the process of control unit 502c returns to step S102. . When it is determined that the data reception period of all the subframes 1 to 3 has elapsed for any satellite (“YES” in step S112a), the control unit 502c determines whether the positioning satellite is at that timing. For a positioning satellite that has failed to acquire data of subframes 1 to 3, “1” is added to the number of receptions (failure history) of the positioning satellite (initial value is “0”) (step S113). In addition, the control unit 502c stops the tracking operation for the positioning satellite whose number of receptions is a predetermined number (predetermined upper limit number), for example, 2 or more (the reception state is below the reference level) (step S114).

  The control unit 502c determines whether or not the data acquisition of the subframes 1 to 3 is made from signals related to three or more positioning satellites (whether or not the number is more than the number necessary for acquisition of acquisition target information) (step S112b). ). If it is determined that three or more devices have been acquired (“YES” in step S112b), the process of the control unit 502c proceeds to step S127. If it is determined that the number is not acquired by three or more units, that is, it is less than the number necessary for positioning (“NO” in step S112b), the process of the control unit 502c returns to step S102.

  In addition, when it is determined in the determination process in step S122 that the elapsed tracking time has not exceeded the tracking timeout time (“NO” in step S122), the control unit 502c determines whether the subordinate positioning satellite is subtracted. It is determined whether or not the data of frames 1 to 3 has been acquired (step S123a). The control unit 502c determines whether or not the reception periods of the subframes 1 to 3 have all elapsed after the position in the navigation message is identified in the signal from each positioning satellite.

If it is determined that it is not the timing at which the data of subframes 1 to 3 is acquired for any of the captured satellites (“NO” in step S123a), the process of control unit 502c returns to step S122. . If it is determined that the timing at which the data of subframes 1 to 3 is acquired in any of the satellites (“YES” in step S123a), the control unit 502c determines that the subpositioning satellite at the timing is the sub For positioning satellites that have failed to acquire data of frames 1 to 3, "1" is added to the number of times the positioning satellites are received (initial value is "0") (step S124). In addition, the control unit 502c stops the tracking operation for the positioning satellite whose number of reception is a predetermined number, for example, two times or more (step S125).
In the following, in the discrimination process in step S131, “all captured satellites” do not include positioning satellites whose tracking has been stopped in the processes in steps S114 and S125 (it is assumed that they were not captured from the beginning).

  The control unit 502c determines whether or not the number of positioning satellites currently being tracked is less than 3 (step S126). If it is determined that it is less than 3 (“YES” in step S126), the process of the control unit 502c proceeds to step S133, ends the receiving operation (step S133), and ends the local time acquisition process. To do.

  If it is determined that the number is not less than 3 (three or more) (“NO” in step S126), the control unit 502c performs data acquisition for subframes 1 to 3 using three or more positioning satellites. It is determined whether or not (step S123b). If it is determined that three or more devices have been acquired (“YES” in step S123b), the process of the control unit 502c proceeds to step S127. If it is determined that three or more devices have not been acquired (“NO” in step S123b), the process of the control unit 502c returns to step S122.

[Modification 2]
FIG. 5 is a flowchart illustrating a control procedure by the control unit 502c of the second modification of the local time acquisition process.
In the modification 2 of the local time acquisition process, steps S106 and S115 are further added to the local time acquisition process of the modification 1. Other processing contents and processing procedures are the same, and the same processes are denoted by the same reference numerals and detailed description thereof is omitted.

  When the tracking unit 502b starts the tracking operation of the newly captured signal in the process of step S104, the control unit 502c causes the capturing unit 502a to remove the signal related to the positioning satellite as the tracking target from the capturing target. The number of search engines to be operated is adjusted according to the number of acquisition target satellites that decreases in step S105 (step S105). For example, when 32 GPS satellites are to be captured in the capture unit 502a having 16 search engines, the capture unit 502a performs processing for searching for signals of the 32 GPS satellites alternately by 16 units. When two GPS satellites are acquired, the control unit 502c stops one search engine and changes the setting so that the search of the remaining 30 GPS satellites is performed alternately by 15 search engines. I can do it. Then, the process of the control unit 502c proceeds to step S106.

  When the acquisition of data from a positioning satellite signal whose number of receptions is equal to or greater than the predetermined number is stopped in the process of step S114, the control unit 502c removes the positioning satellite from being captured by the capturing unit 502a (step S115). That is, once the positioning satellite signal is acquired, the data acquisition of the subframes 1 to 3 fails and the tracking operation is stopped, and then the search is not performed again. Then, the process of the control unit 502c moves to step S112b.

As described above, the electronic timepiece 1 according to the first embodiment searches for and captures a signal from a positioning satellite included in a received radio wave, and demodulates and decodes the captured signal, A tracking unit 502b that acquires subframes 1 to 3 necessary for positioning, and a control unit 502c. The control unit 502c receives the data of subframes 1 to 3 acquired by the tracking unit 502b. To obtain the current position (information acquisition means). The control unit 502c holds a failure history related to data acquisition of the subframes 1 to 3 for each captured signal, and from a signal whose reception state determined based on the failure history is equal to or lower than a predetermined reference level. Signals for acquiring subframes 1 to 3 by the above-described cancellation after the tracking unit 502b stops the acquisition of the data of subframes 1 to 3 and terminates the signal search in the capturing unit 502a under a predetermined condition. When the number is less than three required for positioning, the reception operation by the GPS reception processing unit 50 is terminated (reception control means).
That is, if the tracking time-out time is simply provided for the operation of the tracking unit 502b, the operation is continued until the tracking time-out time elapses regardless of the variation in the capture timing. Since it is determined for each positioning satellite whether reception of subframes 1 to 3 is difficult or not, subframes 1 to 1 are fairly and within the tracking timeout period for the signals of each positioning satellite according to the shift in the acquisition timing. It is possible to determine in advance whether or not the acquisition of 3 can be sufficiently expected and, in turn, whether or not positioning is possible within the tracking timeout period. On the other hand, for signals that can be captured, there is no restriction on whether or not the signals can be used for positioning according to the received signal strength, S / N ratio, etc., and once data acquisition of subframes 1 to 3 is attempted. Since the above-mentioned acquisition expectation is determined, for example, even if the signal strength is severe, the data of subframes 1 to 3 can be acquired in a short time according to the burst noise mixing timing, the reception strength attenuation timing due to fading, etc. If it is possible, the acquired data can be used effectively. By such a determination, when positioning is difficult, the reception operation can be terminated more quickly, and when the reception is continued, the possibility of successful reception can be further increased.
Therefore, it is possible to acquire information from the positioning satellite more efficiently than in the past.

Whether or not a signal other than the signal related to the data of subframes 1 to 3 used for this positioning is captured when the accuracy of the acquired current position does not satisfy a predetermined condition in the control unit 502c. If it is determined that the capturing operation has not been completed or a signal other than the signal used for positioning has been captured, the tracking unit 502b uses the data related to the captured signal. When it is determined that the acquisition is continued, the acquisition operation is completed, and the data of subframes 1 to 3 acquired from all the acquired signals are used for positioning, the GPS reception processing unit 50 Stop receiving radio waves from positioning satellites.
That is, if there is a signal captured later than another signal, or a signal for which data of subframes 1 to 3 cannot be acquired substantially simultaneously with the other signal due to noise or the like, positioning related to the signal is performed. While the positioning satellite positioning changes and the positioning information accuracy can be improved by adding satellites, the required accuracy can be obtained even if all the data of subframes 1 to 3 obtained from the captured signals are used. If it cannot be obtained, it is not possible to desire a change in the configuration in association with the movement of the positioning satellite related to the captured signal in a short time. In addition, in a single positioning operation, there is a higher possibility of reception failure due to movement during operation. Since it is unlikely that a signal from a new positioning satellite will be captured, it is difficult to expect an improvement in accuracy even if the positioning operation is repeated. Therefore, by quickly ending the operation that is unlikely to be measured at a desired accuracy or higher, the possibility of wasting power and time can be reduced.

  In addition, the control unit 502c counts the number of times the tracking unit 502b has failed to acquire the data of the subframes 1 to 3 for each captured signal, and the number of times of failure is equal to or greater than a predetermined number of times. The data acquisition of subframes 1 to 3 is stopped. In other words, it is necessary to quickly give up without receiving time from positioning satellite signals with severe reception conditions, and perform positioning only with signals from positioning satellites that are expected to be able to acquire data in subframes 1 to 3. I can do it. In particular, positioning can be performed quickly and reliably by accurately identifying and using or eliminating signals that are likely to be temporarily difficult to receive due to noise or fading for the received signal strength.

  In addition, the control unit 502c does not cause the capturing unit 502a to search again for the signal for which the data acquisition of the subframes 1 to 3 is stopped. As described above, since it is assumed that there will be no change in a situation where it is difficult to obtain subframes 1 to 3 in a short time, such signal acquisition and tracking are repeated many times, and wasteful time and power are consumed. It can be prevented from being consumed.

When the capturing unit 502a captures a set number of signals more than the number necessary for positioning, the search for the signal is terminated, and the control unit 502c allows three or more sets of signals to be captured before the set number of signals are captured. When subframes 1 to 3 are obtained from the positioning satellite, positioning is performed using the data of the subframes 1 to 3.
In other words, in the past, it was configured to capture signals from a sufficient number of positioning satellites, which is larger than the number of satellites required for positioning, to acquire data, and to perform positioning with high accuracy. Even if signals from the sufficient number of positioning satellites are not captured, if positioning is possible, after positioning is performed, it is determined whether the current position data related to the positioning can be used with accuracy. As a result, if there is a possibility of successful positioning, positioning is performed for the time being. Therefore, the necessary accuracy is usually obtained without waiting for acquisition of the set number of positioning satellites used for positioning and data acquisition of subframes 1 to 3. In the case where the current position is not acquired, the reception process can be terminated while quickly acquiring the current position.

In addition, when the acquisition timeout period has elapsed since the acquisition of the signal from the positioning satellite by the acquisition unit 502a is started, the search is ended, and three or more positioning satellites necessary for the positioning are required before the end of the search. When the signal from is captured, the tracking unit 502b causes the data of subframes 1 to 3 to be acquired from the captured signal.
Therefore, even if the set number of positioning satellites that are desirably used for normal positioning are not acquired, if the minimum three signals required for positioning are acquired, positioning is performed. , The success rate of acquisition of position data can be increased.

The capturing unit 502a includes a plurality of channels, searches for signals from a plurality of positioning satellites in parallel by the plurality of channels, removes the captured signals from the capturing target, and according to the number of remaining signals to be captured. The number of channels used for searching for the signal to be captured is adjusted.
Therefore, even though the number of signals to be searched for is reduced, it is possible to efficiently perform signal capturing operations without wasting power by turning on all channels unnecessarily.

[Second Embodiment]
Next, an electronic timepiece according to a second embodiment will be described.
FIG. 6 is a block diagram illustrating a functional configuration of the electronic timepiece 1a according to the second embodiment.

  This electronic timepiece 1a differs from the electronic timepiece 1 of the first embodiment only in that a measurement unit 54 (measurement means) is added. About the structure of other than this, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The measuring unit 54 is for measuring the posture or the movement state of the electronic timepiece 1a. The measurement unit 54 includes an acceleration sensor 541, an orientation sensor 542, and the like.

  The acceleration sensor 541 is a triaxial sensor for measuring the movement state of the electronic timepiece 1a. For example, the biaxial direction on the display surface of the electronic timepiece 1a (the rotation surface of the hands 61 to 65) and the display surface Measure vertical acceleration. As the acceleration sensor 541, for example, a sensor using piezoelectric resistance is used.

  The direction sensor 542 is a sensor for measuring the attitude (orientation) of the electronic timepiece 1a, and measures the direction of magnetic north. As the direction sensor 542, for example, a sensor using a magnetoresistive element (MR element) is used.

  The ROM 42 stores a determination program for determining the movement state of the electronic timepiece 1a, and the CPU 41 (movement amount calculation means) can determine the movement state of the electronic timepiece 1a by executing the determination program. I can do it. For example, since the direction perpendicular to the ground (vertical direction) is identified by the gravitational acceleration measured by the acceleration sensor 541, the acceleration change in the vertical direction, the acceleration change in the horizontal plane, and the horizontal plane measured by the direction sensor 542 The movement state and movement state of the user are determined by the movement direction and the like. Also, in the case of exercise that involves movement in the horizontal direction, mainly by bicycles or vehicles, the horizontal speed and movement amount (position change amount) are calculated based on the change in the horizontal acceleration (approximate amount) Can be). On the other hand, in the case of movement accompanied by periodic acceleration fluctuations in the vertical direction due to walking and periodic acceleration fluctuations mainly in the display surface of the watch due to arm swing, for example, according to the period of the acceleration fluctuations The number of steps taken by the wearer of the electronic timepiece 1 a can be counted, and the amount of movement can be calculated based on the average stride amount and the movement direction measured by the direction sensor 542. A conventionally well-known pattern can be used as the acceleration change pattern in the vertical direction and the arm swing plane for determining the walking state.

Next, the positioning operation in the electronic timepiece 1a of this embodiment will be described.
In the electronic timepiece 1a of the present embodiment, the movement amount is measured based on the measurement of the measurement unit 54 described above during the positioning operation, and even if the positioning is not successful after the capturing operation is completed, the wearer of the electronic timepiece 1a is If it is determined that the position has moved, that is, the positioning point has changed, positioning is performed again.

  FIG. 7 is a flowchart showing a control procedure by the CPU 41 of the local time acquisition process executed by the GPS reception processing unit 50 of the electronic timepiece 1a of this embodiment.

  In this local time acquisition process, the process of step S121 in the local time acquisition process of Modification 2 of the electronic timepiece 1 of the first embodiment described above is replaced with the process of step S121a, and the processes of steps S130 and S132 are added. The difference was made. The same processes are denoted by the same reference numerals, and detailed description thereof is omitted.

  When branching to “YES” in the determination processing of step S106 or step S109, the control unit 502c ends the signal capturing operation from the positioning satellite and sends a control signal to the CPU 41, based on the measurement data from the measurement unit 54. Then, the movement amount from the timing is calculated (step S121a).

  If it is determined in the determination process in step S126 that the number of positioning satellites currently being tracked is less than three (“YES” in step S126), the control unit 502c performs electronic processing after the capturing operation is ended in step S121. It is determined whether or not the position of the timepiece 1a is moving (step S130). Specifically, the control unit 502c acquires the relative movement distance from the position at the end of the capturing operation, which is measured by the measurement unit 54 and calculated by the CPU 41, and the relative movement distance is set to a predetermined distance ( It is determined whether or not the distance is equal to or greater than the reference distance. If it is determined that the distance is equal to or greater than the predetermined distance (“YES” in step S130), the process of the control unit 502c returns to step S101 to restart the capturing process. If it is determined that the distance is not greater than the predetermined distance (“NO” in step S130), the process of the control unit 502c proceeds to step S133, and the control unit 502c ends the reception operation (step S133).

  If the process branches to “YES” in the process of step S131, the control unit 502c determines whether or not the position of the electronic timepiece 1a has moved after the process of step S121a (step S132). If it is determined that it is moving (“YES” in step S132), the process of the control unit 502c proceeds to step S101, and if it is determined that it is not moving (“NO” in step S132). "), The processing of the control unit 502c proceeds to step S133.

As described above, the electronic timepiece 1a according to the second embodiment includes the measurement unit 54 that measures the movement state, and the CPU 41 calculates the amount of change in position based on the measurement data of the measurement unit 54 (movement amount calculation means). ) When the search for the signal by the capturing unit 502a is stopped under a predetermined condition, and the position change amount from the position where the search is stopped to the position where the acquisition of the current position fails is greater than or equal to a predetermined reference distance The signal search by the capturing unit 502a is resumed.
In this way, instead of simply prolonging the signal search and data acquisition time, even if reception fails once, there is a possibility that the reception position of the radio wave moves during that time and there may be different reception environments Only by searching and capturing again, and continuing the receiving operation, the possibility of acquiring the current position can be increased efficiently.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the above embodiment, the local time acquisition process performs positioning even when signals are received from three positioning satellites. However, since the normal positioning process also requires altitude information, four or more planes are required. The current position information may be calculated and output only when a positioning satellite signal is received.

  In the above embodiment, the case where data of subframes 1 to 3 is received from a GPS satellite has been described. However, when data from another positioning satellite is received, the navigation message format of the positioning satellite is used. It is necessary to obtain the necessary data range accordingly. In addition, a timeout time for capturing and tracking according to the format may be set.

  In the above embodiment, the number of reception failures of data in subframes 1 to 3 that is data necessary for GPS positioning is simply counted, and data from the signal when the number of failures exceeds a predetermined number. If acquisition (tracking) is stopped, but there is a large difference in the number of receptions of subframes 1 to 3 between a signal captured earlier and a signal captured later, a simple failure count Instead, at the time of the second and subsequent receptions, the tracking may be stopped when the failure frequency, for example, the reception failure exceeds 50%.

  In the above-described embodiment, the start of data for one period to be acquired is not limited to subframe 1. However, the propagation delay based on the distance from each positioning satellite is all aligned from subframe 1. The current position may be calculated only when they are received almost simultaneously within the range.

  On the other hand, the current position may be calculated using different frame data for each positioning satellite within one positioning process (local time acquisition process). In this case, even when the number of reception failures of the subframes 1 to 3 reaches the set number, if all the data of the subframes 1 to 3 required until the arrival is acquired from different frames, these subframes It can be used for positioning using data 1 to 3. Furthermore, when the current position is calculated again with insufficient accuracy, the data of subframes 1 to 3 that have been acquired from the signal for which tracking has already been stopped may not be used.

  Further, in the above-described embodiment, after the reception period of the data of subframes 1 to 3 has passed, it is determined collectively whether there is a portion that has failed to be acquired in the received data of subframes 1 to 3, and received “1” is added to the number of times, and reception of the next cycle is continued. However, failure is determined in real time, and if there are multiple failures within one cycle, it is received after the second time. Processing that does not add the number of times may be performed. Alternatively, when the number of receptions is one less than a predetermined number, the process shifts to real-time determination for this signal, and immediately after the failure of data acquisition in subframes 1 to 3 is detected, tracking of the signal is immediately performed. It may be canceled.

  Further, in the above embodiment, the case where ephemeris is acquired in order to perform positioning and acquire current position information has been described. However, if the positioning accuracy of positioning may be coarse, an approximate position can be obtained using almanac. Therefore, when the almanac data of the positioning satellite being captured by any of the positioning satellites can be received, the almanac data may be used.

  In the above embodiment, DOP is used as an accuracy index. However, the accuracy index is not limited to this. For example, an upper limit or a lower limit reference value is provided for the calculated speed or altitude value. If it is out of the range indicated by the reference value, it may be determined that the accuracy is insufficient.

In the above embodiment, the accuracy condition is uniformly determined, but the accuracy condition for the position acquired during the acquisition process or the position acquired without using all the acquired signals is acquired after the acquisition is completed. It may be set stricter than the accuracy condition for the acquired position and the position acquired using all the captured signals.
In this case, after the data of subframes 1 to 3 of three or more satellites are acquired in the determination process of steps S112 and S112b and the process proceeds to the process of step S127, if it is determined that the accuracy condition is not satisfied, the process is performed. It is possible to adopt a procedure for returning to the process of step S102 without shifting to step S131.

  In the second embodiment, the acceleration state 541 and the azimuth sensor 542 are used to determine the movement state and the movement distance is measured. However, other sensors such as a horizontal sensor on the display surface of the electronic timepiece 1a are used. May be.

  In the second embodiment, it is determined whether or not the search can be resumed using the relative movement distance from the end of the capture. However, when it is difficult to accurately estimate the movement direction and accumulate the movement vector amount. In this case, only the cumulative value of the movement amount (scalar) may be used as the reference (reference distance) for determination. In this case, as a result of a series of movements, the relative movement distance may be short when returning to the same point, etc., but the element that attenuates the satellite radio wave, for example, when opening with a shutter or special window in the room returns For example, the reception environment can be improved.

Moreover, although the said modification 1-3 and 2nd Embodiment demonstrated the structure and the process procedure of 1st Embodiment by adding a structure and a process sequentially, these added structures and processes were each independent. Or in an appropriate combination within a possible range. For example, in the local time acquisition process of the first modification, when the process of step S131 is not provided and the determination process of step S127 branches to “NO”, the procedure can return to the process of step S122 as it is. .
In addition, the specific configuration, processing contents, and procedures 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>
Capture means for searching and capturing signals from positioning satellites contained in received radio waves,
Satellite data acquisition means for demodulating and decoding the captured signal, and acquiring data corresponding to acquisition target information among transmission data from the positioning satellite;
Information acquisition means for acquiring the acquisition target information using the acquired data;
A failure history related to the acquisition of the data is held for each of the captured signals, and the acquisition of the data from a signal whose reception state determined based on the failure history is equal to or lower than a predetermined reference level is acquired from the satellite data. If the number of signals for acquiring the data after the acquisition means stops and the search for the signal is terminated under a predetermined condition is less than the number necessary for acquiring the acquisition target information, the satellite data acquisition is performed. A reception control means for causing the means to end the acquisition of the data;
A radio-controlled timepiece characterized by comprising:
<Claim 2>
Discriminating means for discriminating whether or not a signal other than the signal related to the data used for acquiring the acquisition target information is captured when the accuracy of the acquired acquisition target information does not satisfy a predetermined standard With
The reception control means includes
If it is determined that the search for the signal is not completed or a signal other than the signal used to acquire the acquisition target information is captured, the acquisition of the data is continued, The acquisition of the data is terminated when it is determined that the search has been completed and the data acquired from all captured signals has been used to acquire the acquisition target information. Item 1. The radio timepiece according to item 1.
<Claim 3>
The reception control means counts the number of times the data acquisition has failed as the failure history, and stops the acquisition of the data from the signal when the number of failures exceeds a predetermined upper limit number. The radio timepiece according to claim 1 or 2.
<Claim 4>
The radio wave timepiece according to any one of claims 1 to 3, wherein the reception control means does not cause the capturing means to search again for a signal for which acquisition of the data has been stopped.
<Claim 5>
The reception control means includes
When a predetermined number of signals more than the number necessary for acquiring the acquisition target information is captured by the capturing means, the search for the signal is terminated,
If the data is acquired from more than the number of signals necessary for acquisition of the acquisition target information before the predetermined number of signals are captured, the information acquisition means uses the data to acquire the acquisition target information. The radio timepiece according to claim 1, wherein the radio timepiece is acquired.
<Claim 6>
The reception control means includes
If a predetermined upper limit time has elapsed since the search for the signal by the capturing means was started, the search is terminated,
When the number of signals necessary for acquisition of the acquisition target information is acquired by the end timing, the satellite data acquisition unit acquires the data from the acquired signal. The radio timepiece according to any one of claims 1 to 5.
<Claim 7>
The acquisition means includes a plurality of acquisition processing units, searches for signals from a plurality of positioning satellites in parallel by the plurality of acquisition processing units, removes the acquired signals from the acquisition target, and the remaining acquisition target signals. The radio timepiece according to any one of claims 1 to 6, wherein the number of the capture processing units used for searching for the signal to be captured is adjusted according to the number.
<Claim 8>
A measuring means for measuring the movement state;
A moving amount calculating means for calculating a change amount of the position based on measurement data of the measuring means;
With
The reception control means includes
When the search from the signal is stopped under the predetermined condition, and the amount of change from the position where the search is stopped to the position where the acquisition of the acquisition target information fails is greater than or equal to a predetermined reference distance The radio timepiece according to claim 1, wherein the search by the capturing unit is resumed.

1 Electronic Clock 1a Electronic Clock 41 CPU
42 ROM
421 program 43 RAM
44 Oscillator 45 Divider 46 Clock circuit 47 Operation unit 48 Standard radio wave receiver 49 Antenna 50 GPS reception processor 501 RF unit 502 Baseband unit 502a Capture unit 502b Tracking unit 502c Control unit 502d Time zone correspondence table 51 Antenna 52 Drive Circuit 53 Power supply unit 54 Measuring unit 541 Acceleration sensor 542 Direction sensor 61 Second hand 62 Minute hand 63 Hour hand 64 Date wheel 65 Function pointer 71 Wheel train mechanism 72 Wheel train mechanism 73 Wheel train mechanism 74 Wheel train mechanism 81 Stepping motor 82 Stepping motor 83 Stepping motor 84 Stepping motor

Claims (5)

A satellite radio wave receiver that receives radio waves transmitted from the satellite and decodes the received radio wave signals;
A storage unit for storing the decoding result decoded by the satellite radio wave receiving unit for each satellite;
A control unit for controlling the reception operation of the satellite radio wave reception unit;
With
The decryption result includes at least the number of times related to whether or not the decryption was successful,
Wherein, based on the number of times related to whether successful the decryption included in the decoded results stored in the before term memory unit, a satellite the satellite radio receiver is receiving also followed the A satellite radio wave receiver characterized by controlling whether or not the satellite radio wave receiver receives signals. The satellite is a GPS satellite;
The satellite radio wave receiver according to claim 1, wherein the decoding result includes at least the decoding results of subframes 1 to 3. The satellite radio wave receiving device according to claim 1 or 2 ,
A timekeeping section that measures the date and time,
A display unit for displaying the date and time measured by the timer unit;
A radio-controlled timepiece characterized by comprising: A satellite radio wave reception method for a satellite radio wave receiver,
A receiving step for receiving radio waves transmitted from the satellite;
A decoding step of decoding the radio signal received in the receiving step;
A storage step of storing the decoding result decoded in the decoding step for each satellite;
A control step for controlling the receiving operation of the receiving step;
Including
The decryption result includes at least the number of times related to whether or not the decryption was successful,
The control step receives in the reception step based on the number of times related to whether or not the decoding is successful included in the decoding result stored in the storage step corresponding to the satellite received in the receiving step. A satellite radio wave receiving method characterized by controlling whether or not to receive a satellite that is still in operation. A computer comprising: a satellite radio wave receiving unit that receives and decodes radio waves transmitted from a satellite; and a storage unit that stores a decoding result decoded by the satellite radio wave receiving unit for each satellite,
The satellite radio wave reception unit receives the satellite radio wave reception unit based on the number of times related to whether or not the decoding is successfully included in at least the decoding result stored in the storage unit corresponding to the satellite received by the satellite radio wave reception unit. A program for causing a satellite radio wave reception unit to function as a control means for controlling whether or not the satellite radio wave reception unit will continue to receive the satellite.

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