JP5375275B2 - Electronic timepiece with satellite signal receiving apparatus and reception control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic timepiece with a satellite signal reception device, capable of executing in a short time, reception processings, at positioning time for calculating a present place by receiving positional information. <P>SOLUTION: A wrist watch with GPS includes a reception means for receiving a satellite signal, a reception control means, a clocking means, and an external operation member. The reception control means includes a time information correction means for receiving a satellite signal transmitted from a GPS satellite, and correcting a time; a positioning processing means for receiving the satellite signals transmitted from three or more position information satellites, and performing positioning processings; a satellite arrangement table generating means 606 for generating a satellite arrangement table for storing reception time and received information of the position information satellites, when the satellite signals is received by the time information correction means; and a positioning search order setting means 607 for setting the order for searching for the position information satellites in the satellite arrangement table, in the order of each position information satellite having a closer reception time to the operating time of the positioning processing means, when the positioning processing means is operated by external operation. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electronic timepiece with a satellite signal receiving device that receives a satellite signal from a position information satellite such as a GPS satellite and acquires the time, and a reception control method thereof.

In a GPS (Global Positioning System) system, which is a system for positioning its own position, a GPS satellite having an orbit around the earth is used, and a signal is received from this satellite to determine the current position of the receiver. Positioning devices have been put into practical use.
The GPS satellite is equipped with an atomic clock. For this reason, the GPS satellite has extremely accurate time information (GPS time, satellite time information).
For this reason, an electronic timepiece that receives a signal (navigation message) from a GPS satellite and acquires and displays time information has been proposed (see Patent Document 1).

The electronic timepiece of Patent Document 1 prepares an alert table that stores the reception history of past GPS satellites, and when receiving time information, refers to the alert table and selects the most suitable satellite for current reception. Thus, the reception process can be performed quickly by performing the reception.
The alert table is created by performing a repeated reception operation for 8 minutes for several hours (ideally about one day) at the beginning of installation of the apparatus. That is, the satellite signals of the GPS satellites captured by each receiving operation are received, the Doppler frequency and navigation data are collected, and stored in the alert table corresponding to the reception time.

Japanese Patent Laid-Open No. 10-10251

  However, since the electronic timepiece of Patent Document 1 receives at intervals of 8 minutes in order to create an alert table, the power consumption becomes very large. For this reason, there is a problem that it cannot be used in a battery-driven electronic timepiece like a wristwatch, and is difficult to use unless it is an electronic timepiece that can supply power from an external power source such as a building outlet or a car battery.

  In addition, the electronic timepiece of Patent Document 1 selects a GPS satellite to be received with reference to the alert table when receiving time information. Since it is only necessary to receive the signal, the processing is completed within 30 seconds even if there is no past reception history data. Therefore, while there are few merits to refer to the alert table, a large amount of power is required to create the alert table. From this point of view, there is a problem that it cannot be applied particularly to a battery-driven electronic timepiece.

Furthermore, Patent Document 1 corresponds to only the time measurement process for receiving time information, and does not disclose any positioning process for obtaining the current location.
However, for example, immediately after a system reset, a satellite that can search and receive all satellites at a cold start in which reception for positioning is started from a state in which almanac data that is orbit information data of each satellite is not held. TTFF (Time To First Fix) is lengthened. For this reason, shortening TTFF at the time of positioning is calculated | required.

  An object of the present invention is to provide an electronic timepiece with a satellite signal receiving device and a reception control method thereof that can execute reception processing at the time of positioning for receiving position information and calculating a current location in a short time.

An electronic timepiece with a satellite signal receiving device of the present invention includes a receiving means for receiving a satellite signal transmitted from a position information satellite, a receiving control means for controlling the receiving means to perform a receiving process, and a time measuring means for measuring time. And the external operation member, and the reception control means is activated when the time measured by the time measuring means reaches a set reception time, captures at least one position information satellite, Time information correction means for receiving a satellite signal transmitted from an information satellite, acquiring time information included in the satellite signal, and correcting the time measured by the time measuring means, and capturing three or more position information satellites Receiving the satellite signals transmitted from the position information satellites, obtaining the position information included in the satellite signals and performing the positioning process, and receiving the satellite signals by the time information correcting means. When the positioning processing means is activated by the operation of the satellite arrangement table creating means for creating the satellite arrangement table storing the reception time and the received position information satellite information, and the external operation member. And a positioning search order setting means for setting the order of searching for the position information satellites in the order of the position information satellites whose reception time is close to the operation time of the positioning processing means in the satellite arrangement table.

  According to the present invention, at the time of the reception processing of the past time information, the satellite arrangement table storing the reception time of the satellite signal and the information of the received position information satellite is created. When the positioning processing means is activated by the operation of the external operation member, the positioning search order setting means refers to the information stored in the satellite arrangement table, and at the time when the positioning processing means is activated, The search order is set in the order of the position information satellites whose reception times are close to each other. That is, the positioning search order setting means sets the search order from the position information satellite that can be received at the closest reception time to the operation time of the positioning processing means in the satellite arrangement table. If signals from a plurality of position information satellites can be received at the same time, the search order may be set in order of increasing signal strength among them.

Here, since a location information satellite, for example, a GPS satellite, goes through the same activation almost every 24 hours, if a location information satellite that has previously received a satellite signal has a reception time close, There is a high possibility of receiving. In particular, the positioning processing means must acquire three or more position information satellites, and efficiently receive satellite signals necessary for positioning by searching from position information satellites that are highly likely to be received. be able to. In addition, the search processing time can be shortened, and the position information satellite can be reliably captured and the positioning information can be acquired.
Therefore, even during cold start positioning reception that does not hold almanac data, it is possible to search from satellites that are highly likely to be received, so the time to acquire the satellite can be shortened, and TTFF (Time To First Fix) ) Can be shortened.
The search order is set with reference to the satellite arrangement table only at the time of positioning reception, and the search order is not set when receiving time information. For this reason, even when the satellite arrangement table is not sufficiently created, the time information reception process can be executed without any problem.

  In the electronic timepiece with a satellite signal receiving device according to the present invention, the positioning search order setting means includes the positioning process among the reception time stored in the satellite arrangement table and the position information satellite data received at the reception time. It is preferable that position information satellites whose time difference in reception time with respect to the operation time of the means is equal to or greater than a set time are not searched.

When the position information satellite rotates at a cycle of about 24 hours like a GPS satellite, it is highly possible that a position information satellite having a large difference in reception time with respect to the operation time of the positioning processing means cannot be captured even after searching. For example, if the position information satellite is a GPS satellite, the position information satellite is moving in a cycle of 24 hours, so the difference in the reception time with respect to the operation time of the positioning processing means is a maximum of 12 hours. It is difficult to capture.
Therefore, when the data of the satellite arrangement table is not sufficiently prepared, the position information satellite data at the reception time close to the operation time of the positioning processing means (for example, the reception time within which the time difference is within 6 hours) is not accumulated. If the nearest reception time is 6 hours or more, the position information satellites are not searched, and other position information satellites are searched, thereby improving the possibility of capturing the position information satellites. Search processing time can also be shortened.

In the electronic timepiece with a satellite signal receiving device of the present invention, the satellite arrangement table creating means includes:
The process of setting a reception time for each predetermined time divided by a predetermined interval and operating the time information correction means to receive a satellite signal is performed at least once a day and the number of the set reception times. The satellite arrangement table is created by performing reception processing of satellite signals at all the reception times in a plurality of days, and information on the position information satellites that can be received at all the set reception times is stored. After the satellite arrangement table is completed, the satellite signal reception cycle by the time information correction means is preferably changed to a longer period than the reception cycle at the time of the satellite arrangement table creation process .

The satellite arrangement table creation means sets a reception time for each predetermined time obtained by dividing one day at a predetermined interval. For example, the reception time is set at intervals of 30 minutes from “0: 0 (0:00)” to “23:30 (23:30)”. In this case, in order to perform reception at all reception times, it is necessary to perform reception for 24 hours / 0.5 hours = 48 times.
Although it is possible to perform this reception in one day, the power consumption is large and the reception result depends greatly on the reception environment, for example, whether or not the watch is placed in a room where reception is difficult. .

On the other hand, according to the present invention, since reception processing is performed at all reception times in a plurality of days, the number of receptions per day can be reduced and power consumption can be suppressed. In particular, when a rechargeable secondary battery is used, the reception process can be continued by restoring the voltage by charging.
Also, if reception processing is performed distributed over a plurality of days, reception processing can be performed in various reception environment states, and the probability of reception can be improved.
Further, for example, when the satellite arrangement table is created by performing the reception processing 48 times, for example, when reception is performed seven times a day, if all receptions are successful, the satellite arrangement table is created in seven days (one week). Can be created.
Once the satellite arrangement table is created, each location information satellite can be received at approximately the same time unless the location of use changes significantly by several hundred kilometers or more, so the satellite arrangement table needs to be updated frequently. There is no. Therefore, even if reception is performed seven times a day for seven days at the time of creation, it is sufficient to receive satellite signals thereafter once a day.
In addition, if the satellite arrangement table is updated by receiving even once a day, the satellite will become unusable due to equipment maintenance, orbit correction, etc. Can be updated to

At this time, the satellite constellation tabulation unit, after the previous KiMamoru star arrangement table is completed, the reception cycle of the satellite signal by the time information adjustment unit and once a day, and the reception time is 1 day It is preferable to set the reception time shifted by the predetermined interval every time .

For example, when the predetermined interval is set at an interval of 30 minutes, reception is performed by shifting by 30 minutes every day . In this case, by performing reception processing on all set time at 48 days, Ru can also update the data of the satellite constellation table.

  The electronic timepiece with a satellite signal receiving device of the present invention comprises time difference setting means for setting a time difference of time measured by the time measuring means by operation of the external operation member, and the satellite arrangement table creating means comprises the time difference When the time difference is corrected by the setting means, the data of the satellite arrangement table is reset, the time information correction means is operated to receive the satellite signal, and the reception time and the received position information satellite information are Preferably, the stored satellite arrangement table is created again.

The time at which each position information satellite can be received varies from place to place on the earth. In other words, the same satellite arrangement table can be used as long as it has not moved as much as several hundred kilometers or more from the point where the satellite arrangement table is created. However, since the time at which the same position information satellite can be received also changes when it moves greatly, if the satellite arrangement table is used as it is, it takes time to capture the position information satellite.
In the present invention, when the time difference is corrected by operating the time difference setting means, it is predicted that the time has greatly moved from the area where the satellite arrangement table was created last time, so the data of the satellite arrangement table is reset. Again, the satellite signal is received at the destination and the satellite arrangement table is created again. For this reason, the satellite location table that is not suitable for the location is not used at the destination, and the satellite information table suitable for the destination is created again, so that the location information satellite can be captured at the destination. Can be done efficiently.

In the electronic timepiece with a satellite signal receiving device of the present invention, it is preferable that the time information correcting means does not receive rough orbit information of the position information satellite.
According to the present invention, since the rough orbit information (almanac) is not acquired during the satellite signal reception processing by the time information correction means, only the time information needs to be received, the reception time can be shortened, and the power consumption is also reduced. it can. For this reason, even if the reception processing of time information is performed a plurality of times a day, a reduction in power consumption can be suppressed.

  In the electronic timepiece with a satellite signal receiving device of the present invention, the satellite arrangement table creating means includes, in the satellite arrangement table, reception time, satellite number, frequency offset data corresponding to the Doppler frequency, SNR data corresponding to the signal strength, C / It is preferable to store pseudorange data corresponding to the code phase for A code correlation.

  If such information is stored in the satellite arrangement table, the position information satellite with the best reception state can be grasped when a plurality of position information satellites can be captured at a certain reception time. Therefore, the positioning search order setting means can be set to search from the position information satellite with the best reception state at each reception time, and the satellite search process during the positioning process can be efficiently performed in a short time. In addition, the positioning information can be acquired in a short time.

  In the electronic timepiece with a satellite signal receiving device of the present invention, the satellite arrangement table creating means receives the satellite signals from a plurality of position information satellites when the time information correcting means is operated to receive the satellite signals. Preferably, information on a predetermined number of position information satellites with good reception signal conditions is stored in the satellite arrangement table.

When the satellite information is received by the time information correction means, satellite signals from 6 to 7 position information satellites may be received. In such a case, the satellite arrangement table creating means can also store information on all the position information satellites received at the reception time. However, in that case, the reception processing time in the time information correction means becomes longer and the power consumption also increases.
On the other hand, in the present invention, only information on a predetermined number, for example, four position information satellites is stored in the satellite arrangement table. Therefore, the processing time at the time of reception by the time information correction means can be shortened, and the power consumption can be suppressed.
When positioning processing is performed by the positioning processing means, it is necessary to receive satellite signals from three or more, usually four position information satellites, so information on one or two position information satellites is stored in the satellite arrangement table. Compared to the case where only three pieces of information are stored, if three or four pieces of information are stored, the satellite search processing during the positioning processing can be performed efficiently.

  In the electronic timepiece with a satellite signal receiving device according to the present invention, the positioning processing means captures the position information satellite when the position information satellite can be acquired by searching the position information satellite in the order set by the positioning search order setting means. The process of acquiring satellite orbit data from the satellite signal of the position information satellite and the process of performing positioning calculation until the user completes the reception completion operation with an external operation member, or until the power supply voltage drops below the set voltage If the position information satellite cannot be acquired repeatedly, orbit information data cannot be acquired, or positioning calculation cannot be performed, the positioning is repeated until a preset timeout time is reached. It is preferable to search the position information satellites in the order set by the search order setting means and acquire the satellites.

According to the present invention, the positioning processing means acquires satellite orbit data (almanac data) from the captured satellite signal of the position information satellite, and performs the positioning calculation until the power supply voltage drops below the set voltage. This can be continued until the user performs a reception completion operation.
For this reason, for example, if the user wears the electronic timepiece as a wristwatch and performs a positioning operation, the distance traveled and the time during running can be measured, so the running distance, speed, The pace can be measured and displayed. For this reason, the user can always grasp his / her running state and the like and can perform appropriate training.
Further, since the positioning process is stopped when the power supply voltage falls below the set value, the system down due to the power supply voltage drop can be prevented.
Further, if the position information satellite cannot be acquired, orbit information data cannot be obtained, or if the positioning calculation cannot be performed, the positioning search order setting means performs until the preset time-out time is reached. Searching for location information satellites in the set order. Therefore, when the user performs a positioning operation, the positioning process can be performed as much as possible to measure the moving distance or the like. In addition, if any one of the satellite acquisition, orbit information data acquisition, and positioning calculation cannot be performed, the satellite search process is stopped when the timeout time (for example, 2 to 3 minutes) is reached. Even when a positioning operation is erroneously performed in an environment where signals cannot be received, it is possible to prevent the useless reception process from being continued.

The present invention comprises a receiving means for receiving a satellite signal transmitted from a position information satellite, a receiving control means for controlling the receiving means to perform a receiving process, a time measuring means for measuring time, and an external operation member. A reception control method for an electronic timepiece with a satellite signal receiving device, wherein when the time measured by the time measuring means reaches a set reception time, at least one position information satellite is captured and the position information is acquired. Receiving a satellite signal transmitted from the satellite, acquiring time information included in the satellite signal and correcting the time measured by the time measuring means, and capturing three or more position information satellites; When receiving satellite signals transmitted from those position information satellites, acquiring position information included in the satellite signals and performing positioning processing, and receiving satellite signals by the time correction step, A satellite arrangement table creating step for creating a satellite arrangement table in which information of a received time and received position information satellite is stored, and a position information satellite when the positioning processing step is executed by operating the external operation member. And a positioning search order setting step for setting the order of searching for the position information satellites having the reception time closest to the operation time of the positioning processing means in the satellite arrangement table.

  Also in the present invention, the same operational effects as the electronic timepiece with the satellite signal receiving device can be obtained.

It is the schematic which shows the wristwatch with GPS of this embodiment. It is a schematic sectional drawing of the wristwatch with GPS of FIG. It is a block diagram which shows the main hardware constitutions etc. inside the GPS wristwatch of FIG. It is a figure for demonstrating the structure of a navigation message. . It is a figure which shows the structure of the control part of a wristwatch with GPS. It is a figure which shows the structure of the baseband part of the wristwatch with GPS. It is a figure which shows an example of the time slot | zone when a GPS satellite appears in the sky. It is a figure showing an example of the change of the elevation angle of a GPS satellite. It is a figure which shows an initial reception time table. It is a figure which shows an update reception time table. It is a figure which shows a satellite arrangement | positioning table. It is a flowchart which shows the procedure at the time of a time measurement process. It is a flowchart which shows the procedure at the time of a positioning process.

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

[First Embodiment]
FIG. 1 is a schematic view showing a GPS wristwatch 1 which is an electronic timepiece with a satellite signal receiving device according to the present invention, and FIG. 2 is a schematic sectional view of FIG. FIG. 3 is a schematic diagram showing the main hardware configuration of the GPS wristwatch 1.
As shown in FIG. 1, the GPS wristwatch 1 includes a time display unit including a dial 2 and hands 3. An opening is formed in a part of the dial plate 2, and a display 4 composed of an LCD display panel or the like is incorporated.

The pointer 3 includes a second hand, a minute hand, an hour hand, and the like, and is driven by a step motor through a gear.
The display 4 is composed of an LCD display panel or the like.
The GPS wristwatch 1 receives satellite signals from a plurality of GPS satellites 5 orbiting the earth in a predetermined orbit to acquire satellite time information, correct internal time information, or position information. In addition, various information such as a running distance, speed, pace, and the like during running can be displayed on the display 4.
The GPS satellite 5 is an example of the position information satellite in the present invention, and a plurality of GPS satellites 5 exist above the earth. Currently, about 30 GPS satellites 5 orbit.

  The GPS wristwatch 1 is provided with a crown 6 as an external operation member and buttons 7 and 8. The GPS wristwatch 1 is configured to perform reception processing and reception result display processing by manually operating the crown 6 and the buttons 7 and 8.

For example, when the button 7 is pressed for several seconds (for example, 3 seconds) or longer, the GPS wristwatch 1 performs positioning reception processing (reception processing in the positioning mode). The time reception process for receiving time information (reception process in the time measurement mode) is automatically performed at a preset reception time, but may be executed by pressing the button 8 for several seconds or more, for example. .
On the other hand, when the button 7 is pressed for a short time, the GPS wristwatch 1 displays the reception result in the immediately preceding reception mode by the dial 2 and the pointer 3. For example, when the reception is successful in the time measuring mode, the second hand moves to the 5 second position, and when the reception is successful in the positioning mode, the second hand moves to the 10 second position. If the reception fails, the second hand moves to the 20-second position.
These instructions by the second hand are also performed during reception. That is, the second hand moves to the 5 second position during reception in the timekeeping mode, and the second hand moves to the 10 second position during reception in the positioning mode. If the GPS satellite 5 cannot be captured, the second hand moves to the 20-second position.

[Structure of GPS wristwatch]
Next, the internal structure of the GPS wristwatch 1 will be described.
As shown in FIG. 2, the GPS wristwatch 1 includes an outer case 17 made of a metal such as stainless steel (SUS) or titanium.
The exterior case 17 is formed in a substantially cylindrical shape, and a surface glass 160 is attached to the opening on the surface side via the bezel 16. The bezel 16 is made of a non-metallic material such as ceramic in order to improve satellite signal reception performance. A back cover 26 is attached to the opening on the back side of the exterior case 17.

Inside the outer case 17, a step motor for driving the pointer 3, the GPS antenna 11, a battery 24, and the like are arranged.
The step motor is a general one used for a timepiece including a motor coil 19, a stator (not shown), a rotor, and the like. This step motor drives the pointer 3 via a gear.

The GPS antenna 11 is a patch antenna that receives satellite signals from a plurality of GPS satellites 5 orbiting the earth over a predetermined orbit. The GPS antenna 11 is arranged on the surface (back side) opposite to the time display surface of the dial 2 and is configured to receive radio waves that have passed through the front glass 160 and the dial 2.
For this reason, the dial 2 and the surface glass 160 are made of a material that transmits radio waves that are satellite signals transmitted from the GPS satellite 5. For example, the dial 2 is made of plastic. The bezel 16 is made of ceramics in order to improve the reception performance of the satellite signal.

A circuit board 25 is disposed on the back cover side of the GPS antenna 11, and a battery 24 is disposed on the back cover side of the circuit board 25.
The circuit board 25 includes various circuits such as a receiving circuit (GPS receiving unit) 30 that processes a signal received by the GPS antenna 11 and a control unit 41 that controls a step motor that drives the pointer 3 as will be described later. An element (such as an IC) is attached. The GPS receiving unit 30 and the control unit 41 are driven by electric power supplied from the battery 24.

  The battery 24 is a secondary battery such as a lithium ion battery. And the magnetic sheet 21 is arrange | positioned under the battery 24 (back cover side), and the coil 22 for charging is arrange | positioned through the magnetic sheet 21. As shown in FIG. Therefore, the battery 24 can be charged with electric power from an external charger by electromagnetic induction by the charging coil 22. Further, the magnetic sheet 21 can bypass the magnetic field. For this reason, the magnetic sheet 21 can reduce the influence of the battery 24 and can perform energy transmission efficiently. And the back glass 23 is arrange | positioned in the center part of the back cover 26 for electric power transfer.

[Navigation message]
Here, the navigation message, which is a satellite signal transmitted from the GPS satellite 5, will be described before the details of the circuit configuration of the GPS wristwatch 1 are described. The navigation message is modulated into satellite radio waves as 50 bps data.
4A to 4C are diagrams for explaining the configuration of the navigation message.
As shown in FIG. 4A, the navigation message is configured as data with a main frame of 1500 bits as a unit. The main frame is divided into five sub-frames 1 to 5 each having 300 bits. Data of one subframe is transmitted from each GPS satellite 5 in 6 seconds. Accordingly, data of one main frame is transmitted from each GPS satellite 5 in 30 seconds.

  Subframe 1 includes satellite correction data such as week number data. The week number data is information representing a week including the current GPS time information. The starting point of the GPS time information is January 6, 1980, 00:00:00 in UTC (Coordinated Universal Time), and the week starting on this day is the week number 0. Week number data is updated on a weekly basis.

  The subframes 2 and 3 include ephemeris parameters (detailed orbit information of each GPS satellite 5). The subframes 4 and 5 include almanac parameters (general orbit information of all GPS satellites 5).

  Further, subframes 1 to 5 include, from the beginning, a TLM (Telemetry) word storing 30-bit TLM (Telemetry word) data and a HOW word storing 30-bit HOW (hand over word) data. It is.

  Accordingly, TLM words and HOW words are transmitted from the GPS satellite 5 at intervals of 6 seconds, whereas satellite correction data such as week number data, ephemeris parameters, and almanac parameters are transmitted at intervals of 30 seconds.

  As shown in FIG. 4B, the TLM word includes preamble data, a TLM message, a reserved bit, and parity data.

  As shown in FIG. 4C, the HOW word includes GPS time information called TOW (Time of Week, also referred to as “Z count”). In the Z count data, the elapsed time from 0 o'clock every Sunday is displayed in seconds, and it returns to 0 at 0 o'clock on the next Sunday. That is, the Z count data is information in units of seconds indicated every week from the beginning of the week. This Z count data indicates GPS time information at which the first bit of the next subframe data is transmitted. For example, the Z count data of subframe 1 indicates GPS time information at which the first bit of subframe 2 is transmitted. The HOW word also includes 3-bit data (ID code) indicating the ID of the subframe. That is, ID codes “001”, “010”, “011”, “100”, and “101” are included in the HOW words of subframes 1 to 5 shown in FIG.

  The GPS receiver can acquire GPS time information by acquiring the week number data included in the subframe 1 and the HOW word (Z count data) included in the subframes 1 to 5. However, if the GPS receiver has previously acquired the week number data and is counting the elapsed time from the time when the week number data was acquired internally, the current GPS satellites can be acquired without acquiring the week number data. Can be obtained. Therefore, the GPS receiver can know the current time other than the date by acquiring the Z count data. For this reason, the GPS receiver normally acquires only the Z count data as the current time.

  The TLM word, HOW word (Z count data), satellite correction data, ephemeris parameter, almanac parameter, etc. are examples of satellite information in the present invention.

In the present invention, reception in the time measurement mode means reception of Z count data that is time information. Z count data can also be acquired from one GPS satellite 5. Since the Z count data is included in each subframe, it is transmitted at intervals of 6 seconds.
For this reason, reception in the timekeeping mode means that the number of captured satellites is at least one, the time required to acquire one piece of Z count data is at most 6 seconds, and the information that can be acquired is Z count data ( Time information) and means that the ephemeris parameter or almanac parameter is not received.
One Z-count data can be acquired in 6 seconds, and the reception can be completed in a short time of 12-18 seconds even when acquiring 2-3 Z-count data for verification of the received data. it can.

On the other hand, in the present invention, receiving in the positioning mode means receiving ephemeris parameters that are orbit information of each GPS satellite 5 for three or more satellites. This is because it is necessary to acquire ephemeris parameters from at least three GPS satellites 5 for positioning. Since the ephemeris parameter is included in subframes 2 and 3, it can be acquired by performing reception for 18 seconds at the shortest (reception from subframes 1 to 3). Therefore, when capturing and receiving a plurality of GPS satellites 5 at the same time, in order to obtain positioning data by performing ephemeris parameter reception and positioning calculation, approximately 30 seconds to 1 minute in a cold start state in which no almanac data is held. I need time.
Therefore, the positioning mode reception means that the number of captured satellites is at least 3, the reception time is about 30 seconds to 1 minute, and the information that can be acquired is Z count data (time information) and ephemeris parameters. The almanac parameter means processing that is not received.

In the GPS wristwatch 1, in principle, the reception process in the timekeeping mode is an automatic reception process that is automatically received at a predetermined time, and the reception process in the positioning mode is a manual reception process by a user operation. Therefore, in the present invention, it is possible to operate by switching between the time measuring mode and the positioning mode.
In the timekeeping mode, GPS week number data is included in subframe 1, so if you want to get even date information, start automatic reception processing at 0 or 30 seconds per minute when subframe 1 is transmitted. If the reception start time is set so that it can be performed, the time information and date information can be received in the shortest required time.
In the time measurement mode, in addition to the automatic reception process at a predetermined time, a process for automatically receiving a predetermined condition may be provided. Here, the predetermined condition is, for example, automatic reception in the timekeeping mode when it is detected that the vehicle has moved to the outdoors where time information can be easily received. For example, if a solar panel is provided, the fact that it has moved outdoors can be detected by the amount of power generated by the solar panel. Since reception in the timekeeping mode is normally performed once a day, automatic reception processing under a predetermined condition is performed once a day only when reception fails in automatic reception processing at a predetermined time. This may be done to ensure reception.

[Circuit configuration of GPS wristwatch]
Next, the circuit configuration of the GPS wristwatch 1 will be described. As shown in FIG. 3, the GPS wristwatch 1 includes a GPS antenna 11, a GPS receiving unit 30, a display control unit 40, and a power supply device 90.
The GPS wristwatch 1 receives a satellite signal from at least one GPS satellite 5 and corrects the internal time information based on GPS time information, and satellite signals from a plurality of GPS satellites 5. A positioning mode for receiving and performing positioning calculation is configured to be executable.

Hereinafter, each configuration shown in FIG. 3 will be described.
[Configuration of GPS receiver]
The GPS receiver 30 includes a SAW (Surface Acoustic Wave) filter 31, an RF (Radio Frequency) unit 50, and a baseband unit 60. The SAW filter 31 performs a process of extracting a satellite signal from the signal received by the GPS antenna 11. That is, the SAW filter 31 is configured as a band-pass filter that passes a 1.5 GHz band signal.

  As will be described below, the RF unit 50 and the baseband unit 60 acquire satellite information such as orbit information and GPS time information included in the navigation message from the 1.5 GHz band satellite signal extracted by the SAW filter 31. I do.

  The RF unit 50 includes an LNA (Low Noise Amplifier) 51, a mixer 52, a VCO (Voltage Controlled Oscillator) 53, a PLL (Phase Locked Loop) circuit 54, an IF amplifier 55, an IF (Intermediate Frequency) filter 56, an ADC (ADC). (A / D converter) 57 and the like.

  The satellite signal extracted by the SAW filter 31 is amplified by the LNA 51. The satellite signal amplified by the LNA 51 is mixed with the clock signal output from the VCO 53 by the mixer 52 and down-converted to an intermediate frequency band signal. The PLL circuit 54 compares the phase of the clock signal obtained by dividing the output clock signal of the VCO 53 with the reference clock signal, and synchronizes the output clock signal of the VCO 53 with the reference clock signal. As a result, the VCO 53 can output a clock signal with a stable frequency accuracy of the reference clock signal. For example, several MHz can be selected as the intermediate frequency.

  The signal mixed by the mixer 52 is amplified by the IF amplifier 55. Here, by the mixing in the mixer 52, a high frequency signal of several GHz is generated together with the signal in the intermediate frequency band. Therefore, the IF amplifier 55 amplifies a high frequency signal of several GHz along with the signal in the intermediate frequency band. The IF filter 56 passes the signal in the intermediate frequency band and removes the high frequency signal of several GHz (precisely, attenuates to a predetermined level or less). The intermediate frequency band signal that has passed through the IF filter 56 is converted to a digital signal by an ADC (A / D converter) 57.

The baseband unit 60 includes a DSP (Digital Signal Processor) 61, a CPU (Central Processing Unit) 62, and an SRAM (Static Random Access Memory) 63. The baseband unit 60 is connected to a crystal oscillation circuit with temperature compensation circuit (TCXO: Temperature Compensated Crystal Oscillator) 65, a flash memory 66, and the like.
A crystal oscillation circuit (TCXO) 65 with a temperature compensation circuit generates a reference clock signal having a substantially constant frequency regardless of the temperature.

The flash memory 66 stores time difference information and a satellite arrangement table. The time difference information is information in which the time difference of each of a plurality of areas into which geographic information is divided is defined. Details of the satellite arrangement table will be described later.
When set to the timekeeping mode or the positioning mode, the baseband unit 60 performs a process of demodulating the baseband signal from the digital signal (intermediate frequency band signal) converted by the ADC 57 of the RF unit 50.

In addition, when set to the timekeeping mode or the positioning mode, the baseband unit 60 generates a local code having the same pattern as each C / A code in a satellite search process to be described later, and includes each of the baseband signals included in the baseband signal. Processing for correlating the C / A code and the local code is performed. Then, the baseband unit 60 adjusts the local code generation timing so that the correlation value for each local code has a peak. If the correlation value is equal to or greater than the threshold value, the baseband unit 60 synchronizes with the GPS satellite 5 of the local code (ie , GPS satellite 5 is captured).
Here, the GPS system employs a CDMA (Code Division Multiple Access) system in which all GPS satellites 5 transmit satellite signals of the same frequency using different C / A codes. Therefore, the GPS satellite 5 can be searched by controlling the search order of the satellites by controlling the generation order of the local codes.

  Further, the baseband unit 60 demodulates the navigation message by mixing the local code having the same pattern as the C / A code of the captured GPS satellite 5 and the baseband signal, and orbit information and GPS time information included in the navigation message. And the like are acquired and stored in the SRAM 63.

[Configuration of display control unit]
The display control unit 40 includes a control unit (CPU) 41, a driving circuit 42 for the hands 3, and an LCD driving circuit 43 for the display 4.
The control unit 41 includes an RTC (real time clock) 45 and a storage unit 46 as hardware.
The RTC 45 counts internal time information using a reference signal output from the crystal resonator.
The storage unit 46 stores time data and positioning data output from the GPS receiving unit 30, as will be described later. The storage unit 46 also stores time difference data corresponding to the positioning information, and the local time of the current location can be calculated from the internal time information and time difference data measured by the RTC 45.

Functionally, the control unit 41 functions as a time information correction unit 411, a positioning processing unit 412, a display control unit 413, and a voltage detection control unit 414 as shown in FIG.
The time information correction unit 411 performs a process of receiving the time information (time data) and correcting the internal time.
The positioning processing means 412 performs positioning data reception processing when a positioning operation is performed.
The display control means 413 performs processing for controlling the display of the pointer 3 and the display 4 via the drive circuit 42 and the LCD drive circuit 43.
The voltage detection control means 414 performs voltage detection processing of the secondary battery 24 by controlling the operation of a voltage detection circuit 93 described later.

On the other hand, the baseband unit 60 is also provided with a CPU 62, and this CPU 62 functions when a time information reception process or positioning process is instructed from the control unit 41.
That is, as shown in FIG. 6, the baseband unit 60 includes a satellite search unit 601, a reception level acquisition unit 602, a satellite information acquisition unit 603, a positioning calculation unit 604, a time calculation unit 605, a satellite arrangement table creation unit 606, a positioning unit. It functions as search order setting means 607.
Therefore, the reception control means of the present invention includes the baseband unit 60 of the GPS receiving unit 30 and the control unit 41 of the display control unit 40.

Specifically, the satellite search means 601 executes a process for searching for the GPS satellite 5. At this time, as will be described later, at the time of positioning reception, the satellites are searched in the search order set by the positioning search order setting means 607.
The reception level acquisition unit 602 acquires the reception level of the received satellite signal. Specifically, SNR data corresponding to the signal strength is acquired.
The satellite information acquisition unit 603 acquires information on the received satellite signal. Specifically, the satellite number of the received satellite signal, frequency offset data corresponding to the Doppler frequency, and pseudorange data corresponding to the code phase for C / A code correlation are acquired.

The positioning calculation means 604 performs positioning calculation of the current location using satellite orbit information (ephemeris) of three or more received satellite signals. The positioning data calculated by the positioning calculation means 604 is output to the control unit 41.
The time calculation unit 605 performs a process of calculating the current time based on the Z count acquired from the received satellite signal. The time data calculated by the time calculation means 605 is also output to the control unit 41.

The satellite arrangement table creation means 606 stores each information acquired by the satellite information acquisition means 603 together with the reception time in the satellite arrangement table 660 stored in the flash memory 66, as will be described later, at the time information reception processing. .
The positioning search order setting means 607 refers to the satellite arrangement table 660 stored in the flash memory 66 during the positioning process, and sets the order in which the GPS satellites 5 are searched.

[Configuration of power supply device]
The power supply device 90 includes a charging coil 22, a charging control circuit 28, a secondary battery 24, a first regulator 91, a second regulator 92, and a voltage detection circuit 93.

The secondary battery 24 supplies driving power to the display control unit 40 via the first regulator 91 and supplies driving power to the GPS receiving unit 30 via the second regulator 92.
The charging coil 22 supplies power to the secondary battery 24 through the charge control circuit 28 to charge the secondary battery 24.
The voltage detection circuit 93 monitors the voltage of the secondary battery 24 and outputs it to the control unit 41. Therefore, the control part 41 can grasp | ascertain the voltage of the secondary battery 24, and can control a reception process.

  In the present embodiment, a rechargeable secondary battery such as a lithium ion battery is used as the battery 24, but a primary battery such as a lithium battery may be used. In addition, the charging method in the case where a secondary battery is provided is not limited to the charging method provided by the charging coil 22 and charging by an electromagnetic induction method from an external charger as in the present embodiment. You may charge by providing electric power generation mechanisms, such as a solar cell.

[GPS satellite orbit]
Next, the orbit of a GPS satellite, which is a specific example of the position information satellite in the present embodiment, will be described. FIG. 7 shows a time zone in which all 31 GPS satellites (G01 to G31) appear in the sky (example of a city on January 1, 2009). In FIG. 7, a thick solid line indicates a time zone in which each GPS satellite can be received when a GPS satellite having an elevation angle of 10 degrees or more is set as a capture target, that is, when the elevation mask is set to 10 degrees. Yes.
As can be seen from this figure, when the elevation mask is set to 10 degrees, about 4 to 8 GPS satellites can always be captured. Since the GPS satellites pass the same orbit approximately every 24 hours, the satellite arrangement table 660 can be created if reception is performed every hour or every 30 minutes.

On the other hand, FIG. 8 is a diagram showing changes in the elevation angle of the GPS satellites over time. As an example, the change in elevation angle of each GPS satellite from 0 o'clock to 9 o'clock in FIG. 7 is shown.
Here, when the elevation angle is high, the distance between the GPS satellite and the GPS wristwatch 1 is short, so the pseudorange data becomes small. Also, since the signal is strong, the SNR increases and the relative speed decreases, so the frequency shift decreases. In addition, when the elevation angle is low and the satellite is rising, the distance to the GPS satellite is large, so the pseudorange data is large, the SNR is small, and the Doppler frequency is high. On the other hand, when a GPS satellite is going to sink, the pseudorange data is large, the SNR is small, and the Doppler frequency is low.
Therefore, these SNR, Doppler frequency, and pseudorange data are stored as satellite information in the satellite arrangement table 660, and if these data are read during the time measurement process, the satellite orbit can be easily determined without acquiring the almanac. Can be predicted.

[Configuration of time table]
Next, in this embodiment, the initial reception time table 461 and the update reception time table 462 in which the time at which automatic reception by the time information correction unit 411 is performed are stored in the storage unit 46 will be described.
As will be described later, the initial reception time table 461 is used when the satellite arrangement table 660 is created, and the updated reception time table 462 is used after the satellite arrangement table 660 is created.

As shown in FIG. 9, the initial reception time table 461 is set to receive 48 times in seven days from Monday to Sunday. That is, Monday is set to receive 7 times at intervals of 3 hours and a half until 3:00, 3:30, 7:00, 10:30, 14:00, 17:30, 21:00. Yes. Similarly, from Tuesday to Saturday, the first time is shifted every 30 minutes, and it is set to receive seven times at intervals of 3 hours and half from the first time.
On Sunday, the first time is shifted from Saturday by 30 minutes, and the reception is set to be performed six times at intervals of 3 hours and half from the first time. Accordingly, it is set to receive 7 times × 6 days + 6 times × 1 day = 48 times in one week.

  On the other hand, the update reception time table 462 is set to receive once a day as shown in FIG. 10 and the reception time is shifted by 30 minutes every day. Therefore, when 48 days have elapsed, the reception processing is set to be performed 48 times with the reception time shifted by 30 minutes.

[Configuration of satellite arrangement table]
Next, the satellite arrangement table 660 stored in the flash memory 66 of the GPS receiver 30 in the present embodiment will be described.
The satellite arrangement table 660 stores the satellite information acquired by the satellite information acquisition unit 603 for each reception time. Here, as described in the initial reception time table 461, the reception time is an interval of 30 minutes from 0:00. Therefore, when the satellite arrangement table 660 is completed, 48 reception times exist.

In the satellite arrangement table 660, as shown in FIG. 11, the reception time and the satellite information of the reception satellites 1 to 4 are stored. Specifically, the satellite information stores satellite number SV, SNR data corresponding to signal intensity, frequency offset data corresponding to Doppler frequency, and pseudorange data corresponding to code phase for C / A code correlation. Yes.
In addition, when receiving satellite signals from a plurality of position information satellites at the reception time, the reception satellites 1 to 4 store the reception satellites 1 to 4 in order of the position information satellites with the highest signal level (SNR). Yes. Therefore, when there are three received satellite signals, only the receiving satellites 1 to 3 are stored. When two satellite signals are received, only the receiving satellites 1 and 2 are stored. Is remembered.

[Receive processing]
Hereinafter, the procedure of the reception process in the GPS wristwatch 1 of the present embodiment will be described.
First, automatic time measurement processing by the time information correction means 411 will be described with reference to the flowchart of FIG.

[Automatic timing processing]
The time information correction means 411 of the GPS wristwatch 1 first checks whether or not the satellite arrangement table 660 is incomplete (step 1, hereinafter, step is abbreviated as “S”).
Here, the time information correction means 411 refers to the initial reception time table 461 when the satellite arrangement table 660 is not completed (S2), and refers to the update reception time table 462 when it is completed (S3).

Next, the time information correction unit 411 determines whether or not the internal clock timed by the RTC 45 has reached the reception time (reception timing) set in the reception time tables 461 and 462 (S4).
For example, the time information correction unit 411 refers to the initial reception time table 461 after the system reset or when the satellite arrangement table 660 is reset by a time difference change operation, and grasps the current day of the week from the internal time, It is determined whether or not each reception time set for the day of the week has been reached.
If the reception time is not reached in S4, the time information correcting unit 411 repeatedly executes the determination process in S4.
On the other hand, when the reception time comes in S4, the time information correction unit 411 outputs a control signal instructing the baseband unit 60 to start reception, and starts reception processing in the timekeeping mode (S5).
Here, when the reception process of S5 is performed with reference to the initial reception time table 461, the scheduled reception is performed several times a day, and acquisition of satellite information and Z count is attempted.
On the other hand, when the satellite arrangement table 660 is completed, the reception process is performed once a day because the reception process of S5 is performed with reference to the updated reception time table 462. This is because once the reception is successful and the Z count can be acquired, there is no need to perform further reception on that day. In other words, from the accuracy of the RTC 45, if the time is adjusted once a day, there will be no shift of more than 1 second per day.

When the reception process is started, the satellite search means 601 performs a satellite search process (S6).
Then, the satellite search means 601 determines whether the satellite has been captured (S7). If the satellite search means 601 determines that it has not been captured in S7, it determines whether or not the elapsed time from the start of reception in S5 has reached a predetermined timeout time (for example, 1 to 2 minutes) (S8).

The satellite search means 601 ends the reception when the time-out period elapses in S8 and time-out occurs (S9).
On the other hand, if the time-out is not timed out in S8, the satellite search means 601 executes again from the satellite search process in S6.

When it is determined that the satellite has been captured in S7, the satellite search unit 601 determines whether a predetermined reception time has elapsed (S10). Here, the predetermined reception time is set to about 30 seconds to 1 minute. If “No” is determined in S10, the processes in S7 and S10 are repeated.
A plurality of satellite signals (satellite data) are received by continuing the reception process during the predetermined reception time (about 30 seconds to 1 minute).

  Next, the reception level acquisition unit 602 acquires the signal level (SNR) of each received satellite data, and the satellite information acquisition unit 603 acquires satellite information from the reception signal. Then, the satellite arrangement table creation unit 606 refers to the SNR acquired by the reception level acquisition unit 602, selects the satellite having the best condition (SNR is large and pseudorange data is small), and the satellite information acquisition unit 603 Of the acquired satellite data, data up to four satellites in descending order of SNR are stored in the satellite arrangement table 660 (S11). At this time, the reception level acquisition unit 602 stores the captured satellite information in the satellite arrangement table 660 regardless of whether the Z count has been acquired.

The satellite information acquisition unit 603 continues to receive the satellite signal under the best condition and determines whether the Z count has been acquired (S12).
If it has been acquired in S12, the time calculation means 605 confirms the consistency of the acquired Z count (S13). Specifically, when the first Z count is acquired, the time calculation means 605 compares the Z count with the time data of the RTC 45 of the control unit 41, and matches whether or not the difference is within a predetermined value. It is confirmed whether or not it is removed (S13). In S13, if the compared time difference is too large (for example, if there is a difference of 5 seconds or more), it is determined that the matching is not achieved.
If it is determined “No” in S12 and S13, the satellite information acquisition unit 603 determines that the elapsed time after the best time satellite is selected after the predetermined time has elapsed in S10 is a predetermined timeout time (for example, It is determined whether or not 30 seconds have elapsed (S14).

If “No” is determined in S14, the processes in S12 and S13 are repeated. In the GPS satellite signal, the Z count can be received at intervals of 6 seconds. Therefore, if the timeout time of S14 is 30 seconds, it can be determined whether the Z count is received and matched until the timeout occurs. Therefore, if the acquired Z count is not consistent with the internal time, the Z count of the subframe after the next 6 seconds is acquired.
When the time calculation means 605 acquires a plurality of Z counts, when the plurality of Z counts are consistent with each other, that is, when the data is at intervals of 6 seconds, the time calculation means 605 acquires the acquired Z counts. It is determined that (time data) is consistent (S13).

When the time-out occurs in S14, the satellite information acquisition unit 603 ends the reception (S9).
On the other hand, if it can be confirmed in S13 that the alignment is achieved, the satellite information acquisition unit 603 ends the reception (S15), the time calculation unit 605 outputs the time data to the control unit 41, and the time information correction of the control unit 41 is corrected. The means 411 corrects the time information based on the acquired time data (S16). When the time is corrected, the display control unit 413 corrects the display of the pointer 3 via the drive circuit 42.

Thus, the reception processing of time information at each reception time and the data storage processing of the satellite arrangement table 660 are completed. Therefore, while it is determined as “Yes” in S1, the processing from S1 to S16 is performed at the reception time stored in the initial reception time table 461, and the data of each reception time in the satellite arrangement table 660 is accumulated. Is done.
On the other hand, after the data of all the reception times in the satellite arrangement table 660 is accumulated, it is determined as “No” in S1, so the update reception time table 462 is referred to in S3, and S4 to S16 are included in the reception time. Process. That is, reception is performed once a day.

[Positioning process]
Next, processing when the user performs a positioning operation by operating the button 7 or the like will be described based on the flowchart shown in FIG.
First, the positioning processing means 412 determines whether or not there is a positioning operation (S21), and if there is a positioning operation, outputs a control signal to the baseband unit 60 and starts reception processing in the positioning mode. (S22). As described above, the positioning processing unit 412 according to the present embodiment operates only when a positioning operation is performed by the user, and does not automatically execute the positioning process. That is, the positioning process needs to capture a plurality of satellites and receive positioning data, and cannot be executed unless the surroundings are free from obstacles and the reception environment is good. If the positioning process is automatically executed, the process may be performed in a place where the reception environment is not good, and a useless reception process may be executed. For this reason, in the present embodiment, the reception process is performed only when the user performs the positioning process manually so that the reception process can be performed when the user determines that the reception environment is good, and the useless reception process is performed. Is preventing.

When the start of reception is instructed, the positioning search order setting means 607 of the baseband unit 60 receives from the satellite arrangement table 660 stored in the flash memory 66 the reception time closest to the current time, that is, the time when the positioning operation is performed. Are read out and the satellite search order is set (S23).
Then, the satellite search unit 601 performs satellite search processing based on the set satellite search order (S24). Specifically, for example, when 31 GPS satellites 5 are present, first, the satellite search means 601 generates a local code having the same pattern as the C / A code of the first satellite number SV in the search order. Next, the satellite search means 601 calculates a correlation value between the C / A code and the local code included in the baseband signal. If the C / A code and local code included in the baseband signal are the same code, the correlation value has a peak at a predetermined timing, but if the code is different, the correlation value does not have a peak and is always almost zero.

Therefore, the satellite search means 601 adjusts the local code generation timing so that the correlation value between the C / A code and the local code included in the baseband signal is maximized, and the correlation value is greater than or equal to a predetermined threshold value. Determines that the GPS satellite 5 having the satellite number SV has been captured. At this time, the reception level acquisition unit 602 acquires the signal level of the satellite signal, and the satellite search unit 601 determines that the GPS satellite 5 has been captured when the signal level is equal to or higher than a predetermined level.
The satellite search means 601 performs such satellite search processing in the order set by the positioning search order setting means 607, and captures each satellite in the search order.

The satellite search means 601 determines whether a predetermined number (three) or more of satellite signals necessary for positioning have been captured (S25).
If “Yes” is determined in S25, the satellite information acquisition unit 603 determines whether satellite orbit data (ephemeris) has been acquired from the captured satellite signal (S26).
When it is determined “Yes” in S26, the positioning calculation unit 604 performs positioning calculation based on the acquired satellite orbit data and determines whether the positioning calculation is completed (S27).

  When it is determined “No” in S25, S26, and S27, the satellite search unit 601 determines whether the timeout time has elapsed (S28). That is, the satellite search means 601 determines whether or not the elapsed time from the start of reception has exceeded a preset timeout time. Here, the timeout time is usually a time during which the positioning process can be completed if the satellite signal can be received, and is set to about 3 to 5 minutes, for example.

The satellite search means 601 ends the reception process when it is determined in S28 that the timeout has occurred (S29).
On the other hand, if it is determined in S28 that the timeout has not occurred, the satellite search means 601 returns to the satellite search process S24 and searches for satellites other than the already searched satellites. That is, the positioning search order setting means 607 sets a satellite other than the first satellite number among the satellites with the second closest reception time as the next search order of the satellite with the reception time closest to the positioning operation time, Next, an unsearched satellite is set among the satellites having the third closest reception time. For this reason, the satellite search means 601 sequentially searches from the satellites with the closest reception times.
For example, when satellite orbit data of two satellite signals can be acquired among the first four satellites having the reception time, the remaining two satellite orbit data in the second satellite having the reception time are obtained. Get it. That is, the satellite search process may be performed sequentially until the number of satellite orbit data necessary for positioning calculation can be acquired.

When it is determined as “Yes” in S27, the positioning calculation unit 604 outputs the positioning data to the control unit 41, and the positioning processing unit 412 of the control unit 41 stores the positioning data in the storage unit 46 and the display control unit. The positioning result is displayed on the display 4 via the LCD drive circuit 43 by 413 (S30).
The control unit 41 confirms whether or not an operation for terminating reception has been performed by the user (S31). Here, if the end operation has been performed, the reception ends (S29).

On the other hand, if the termination operation has not been performed, the control unit 41 detects the voltage of the secondary battery 24 by the voltage detection circuit 93 via the voltage detection control means 414, and determines whether the power supply voltage has dropped below a predetermined voltage. (S32).
Here, when the voltage drops below the predetermined voltage, the control unit 41 ends the reception in order to cause a system down if the reception process is continued as it is (S29).
On the other hand, if the power supply voltage is equal to or higher than the predetermined voltage, the processes of S25 to S32 are repeated until a reception end operation is performed.
Accordingly, since the positioning data is sequentially input to the control unit 41, the movement distance of the user wearing the GPS wristwatch 1 can be known, and the time taken for the movement can be grasped by measuring the internal time of the RTC 45. . For this reason, for example, the travel distance and time during running can be measured, and the travel distance, speed, pace, etc. can be measured and displayed on the display 4 based on the data. For this reason, the user can always grasp his / her running state and the like and can perform appropriate training.

[Effects of First Embodiment]
According to the present embodiment, the satellite information such as the received satellite number and SNR is stored in the satellite arrangement table 660 during the time measurement process for acquiring time information, and the satellite arrangement table 660 is referred to during the positioning process. Since the search order is set based on the satellite number that can be received at the reception time close to the time of processing, the GPS satellite 5 that is highly likely to be received at that time even during cold start without the almanac data. You can search. For this reason, time TTFF until the satellite signal required for positioning is acquired can be shortened, and positioning information can be acquired in a short time. For this reason, the power consumption at the time of positioning processing can also be reduced, and the duration time can be extended even in a battery-powered timepiece such as a wristwatch.

The search order is set with reference to the satellite arrangement table 660 only at the time of positioning reception, and the search order is not set when receiving time information. For this reason, even when the satellite arrangement table 660 is not sufficiently created, the time information reception process can be executed without any problem, and the user's convenience can be prevented from being lowered.
Furthermore, time information can be received in a short time even if the search order is not set by the positioning search order setting means 607 during the time measurement process. In other words, the time measurement process only needs to capture one GPS satellite 5, so the search time can be shortened, and the Z count is transmitted every 6 seconds, so if even one satellite can be captured, the time information is It can be received in a short time of about 30 seconds at the longest.

  Further, since the satellite arrangement table 660 is stored at the reception time at intervals of 30 minutes, even in the case of the positioning process in which the reception time cannot be set because it is performed by the user's operation, the satellite arrangement table 660 has a positioning process time. Since data within 30 minutes is stored, the search order can be set by satellites that can be sufficiently received even at the positioning processing time, and the possibility of capturing satellite signals can be improved.

Further, when the satellite arrangement table 660 is created, it is received seven times a day based on the initial reception time table 461 and created in one week. For this reason, compared to the case where the number of receptions per day is increased, the power consumption per day can be suppressed, and the reception results are placed in a reception environment, for example, a room where the clock is difficult to receive. The possibility of being greatly influenced by whether or not it is possible can be reduced.
In addition, the satellite arrangement table 660 can be created in a short period of time compared to the case where the satellite arrangement table 660 is created with seven or more days. That is, in this embodiment, since the balance between the power consumption per day and the creation period of the satellite placement table 660 is considered, the satellite placement table 660 can be created efficiently.

Furthermore, once the satellite arrangement table 660 is created, the update reception time table 462 is updated by reception processing once a day, so that power consumption can be further reduced.
In addition, since the accuracy as a clock is about ± 0.5 seconds per day in a normal quartz watch, it is sufficient to receive time information once a day. In this case, the time accuracy can be sufficiently maintained. .

  Further, since the satellite arrangement table 660 stores four pieces of satellite information at each reception time, the search order can be set with the number of satellites necessary for positioning reception. If five or more pieces of satellite information are stored, satellite acquisition at the time of positioning becomes faster, but the reception time at the time of time measurement processing becomes longer and power consumption increases. Therefore, if four pieces of satellite information are stored as in the present embodiment, the positioning process can be performed in a short time, and the power consumption during the time measurement process can be suppressed.

[Modification]
In addition, this invention is not limited to said each embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention.
For example, the positioning search order setting means 607 has a time difference with respect to the operation time of the positioning processing means 412 in the reception time stored in the satellite arrangement table 660 and the position information satellite data received at the reception time. Position information satellites with reception times longer than the set time may not be searched.
In this way, especially when the data of the satellite arrangement table 660 is not sufficiently prepared, the position information satellite at the reception time close to the operation time of the positioning processing means 412 (for example, the reception time within which the time difference is within 6 hours). When the nearest reception time is 6 hours or more, those location information satellites are not searched, and other location information satellites are searched for by capturing the location information satellites. The possibility of being able to be improved can be improved and the search processing time can be shortened.

  In addition, it includes time difference setting means for setting the time difference of the time measured by the time measuring means by operating the external operation members such as buttons 7 and 8, and the satellite arrangement table creating means 606 corrects the time difference by the time difference setting means. In such a case, the data in the satellite arrangement table 660 may be reset. In this case, since the satellite arrangement table 660 is initialized, the time information correction unit 411 is operated to receive a satellite signal, and the satellite arrangement in which the reception time and the received position information satellite information are stored. The table 660 may be created again.

  In this way, when the satellite arrangement table 660 has moved greatly from the area where the satellite arrangement table 660 was created last time, the data of the satellite arrangement table 660 is reset, and the satellite signal is received again at the destination to receive the satellite arrangement table 660. 660 can be created again. For this reason, the satellite arrangement table 660 that is not suitable for the location is not used at the destination, and the satellite information table 660 suitable for the destination is created again, so that the position information satellite can be captured even at the destination. Processing can be performed efficiently.

In the satellite arrangement table 660, reception times are set at intervals of 30 minutes, but may be set at intervals of 1 hour. In this case, the setting of the reception time in the initial reception time table 461 and the update reception time table 462 may be changed as appropriate.
The initial reception time table 461 is received seven times a day, but may be received eight or more times, or may be received six times or less.
Furthermore, although the update reception time table 462 is set to receive once a day, it may be set to receive two or more times.
In addition, when time measurement processing at the time set in the initial reception time table 461 or the update reception time table 462 fails, it is detected that the user has moved to the outdoors to secure reception once a day. The time measurement process may be automatically performed. As a method of detecting that the vehicle has moved outdoors, for example, a method of installing a solar panel on the GPS wristwatch 1 and determining whether the vehicle is outdoors by changing the amount of power generation can be used.

The satellite information stored in the satellite arrangement table 660 needs to store at least the satellite number SV for setting the search order of the satellites, but does not necessarily store other data.
Further, although the satellite arrangement table 660 stores four pieces of satellite information, five or more pieces of satellite information may be stored.

  Moreover, although the above-mentioned embodiment demonstrated the GPS satellite as an example of a position information satellite, not only a GPS satellite but a Galileo (EU), GLONASS (Russia), Hokuto (China) as a position information satellite of this invention. Other global navigation satellite systems (GNSS), etc., or position information satellites that transmit satellite signals including time information such as geostationary satellites such as SBAS and quasi-zenith satellites may be used.

  The electronic timepiece with a satellite signal receiving device of the present invention is not limited to a combination timepiece having the hands 3 and the display 4, but may be applied to a digital timepiece having only a display. Furthermore, the present invention is not limited to a wristwatch, and may be applied to various watches such as a pocket watch, and devices having an electronic watch function such as a mobile phone, a digital camera, and various portable information terminals.

  DESCRIPTION OF SYMBOLS 1 ... GPS wristwatch, 5 ... GPS satellite, 11 ... GPS antenna, 30 ... GPS receiving part, 40 ... Display control part, 41 ... Control part, 42 ... Drive circuit, 43 ... LCD drive circuit, 46 ... Memory | storage part, 50 ... RF part, 60 ... Baseband part, 66 ... Flash memory, 411 ... Time information correction means, 412 ... Positioning processing means, 413 ... Display control means, 414 ... Voltage detection control means, 461 ... Initial reception time table, 462 ... Update reception time table, 601 ... satellite search means, 602 ... reception level acquisition means, 603 ... satellite information acquisition means, 604 ... positioning calculation means, 605 ... time calculation means, 606 ... satellite arrangement table creation means, 607 ... positioning search order Setting means, 660... Satellite arrangement table.

Claims (10)

Receiving means for receiving satellite signals transmitted from the position information satellite;
Receiving control means for controlling the receiving means to perform receiving processing;
A time measuring means for measuring time;
An external operation member,
The reception control means includes
It is activated when the time measured by the time measuring means reaches a set reception time, captures at least one position information satellite, receives a satellite signal transmitted from the position information satellite, and receives the satellite signal. Time information correcting means for acquiring time information included in the time and correcting the time measured by the time measuring means;
Positioning processing means for capturing three or more position information satellites, receiving satellite signals transmitted from those position information satellites, acquiring position information included in the satellite signals, and performing positioning processing;
When the satellite information is received by the time information correction means, the satellite arrangement table creating means for creating the satellite arrangement table storing the reception time and the received position information satellite information;
When the positioning processing means is operated by the operation of the external operation member, the order in which the position information satellites are searched is changed to the order of the position information satellites whose reception time is close to the operation time of the positioning processing means in the satellite arrangement table. An electronic timepiece with a satellite signal receiving device, comprising: a positioning search order setting means for setting. The electronic timepiece with a satellite signal receiving device according to claim 1,
In the positioning search order setting means, the time difference of the reception time with respect to the operation time of the positioning processing means in the reception time stored in the satellite arrangement table and the position information satellite data received at the reception time is set time. An electronic timepiece with a satellite signal receiver characterized in that the above-mentioned position information satellites are not searched. The electronic timepiece with a satellite signal receiving device according to claim 1 or 2,
The satellite arrangement table creation means includes
Set the reception time for each predetermined time divided by a certain interval,
The process of receiving the satellite signal by operating the time information correction means is performed at least once a day and less than the number of the set reception times, and the satellite signal reception process at all the reception times in a plurality of days To create the satellite arrangement table ,
After the position information satellite information that has been received at all the set reception times is stored and the satellite arrangement table is completed, the satellite signal reception cycle by the time information correction means is changed to the satellite arrangement table creation process. An electronic timepiece with a satellite signal receiving device, wherein the electronic timepiece is changed to a period longer than the reception cycle . The electronic timepiece with a satellite signal receiving device according to claim 3,
The satellite arrangement table creation means includes
Received after the previous KiMamoru star arrangement table is completed, the reception cycle of the satellite signal by the time information adjustment unit and once a day, and the reception time is shifted the predetermined intervals min each time elapses 1 day An electronic timepiece with a satellite signal receiving device, characterized in that the time is set . The electronic timepiece with a satellite signal receiving device according to any one of claims 1 to 4,
A time difference setting means for setting a time difference of time measured by the time measuring means by operation of the external operation member;
The satellite arrangement table creation means includes
When the time difference is corrected by the time difference setting means, the data of the satellite arrangement table is reset, the time information correction means is operated to receive the satellite signal, the reception time, and the received position information satellite An electronic timepiece with a satellite signal receiving device, wherein a satellite arrangement table storing information is created again. The electronic timepiece with a satellite signal receiving device according to any one of claims 1 to 5,
The electronic timepiece with a satellite signal receiving device, wherein the time information correcting means does not receive rough orbit information of a position information satellite. The electronic timepiece with a satellite signal receiving device according to any one of claims 1 to 6,
The satellite arrangement table creation means includes
The satellite arrangement table stores reception time, satellite number, frequency offset data corresponding to Doppler frequency, SNR data corresponding to signal strength, and pseudorange data corresponding to code phase for C / A code correlation. An electronic watch with a satellite signal receiver. In the electronic timepiece with a satellite signal receiving device according to any one of claims 1 to 7,
The satellite arrangement table creation means includes
When a satellite signal is received from a plurality of position information satellites when the time information correction means is operated and the satellite signal is received, information on a predetermined number of position information satellites with good reception signal conditions is placed in the satellite arrangement. An electronic timepiece with a satellite signal receiving device, which is stored in a table. The electronic timepiece with a satellite signal receiving device according to any one of claims 1 to 8,
The positioning processing means includes
If the position information satellite can be acquired by searching the position information satellite in the order set by the positioning search order setting means, a process for acquiring satellite orbit data from the satellite signal of the acquired position information satellite, and positioning calculation And repeatedly performing the process until the user performs a reception completion operation with the external operation member or until the power supply voltage drops below the set voltage,
If the position information satellite cannot be acquired, orbit information data cannot be acquired, or positioning calculation cannot be performed, the positioning search order setting means until a preset time-out time is reached An electronic timepiece with a satellite signal receiving device, wherein the satellites are searched by searching for position information satellites in the order set by. Receiving means for receiving satellite signals transmitted from the position information satellite;
Receiving control means for controlling the receiving means to perform receiving processing;
A time measuring means for measuring time;
A reception control method for an electronic timepiece with a satellite signal receiving device including an external operation member,
When the time measured by the time measuring means reaches the set reception time, at least one position information satellite is captured and a satellite signal transmitted from the position information satellite is received and included in the satellite signal. A time correction step of correcting the time measured by the time measuring means by
A positioning process step of capturing three or more position information satellites, receiving satellite signals transmitted from the position information satellites, acquiring position information included in the satellite signals, and performing a positioning process;
When a satellite signal is received by the time correction step, a satellite arrangement table creation step of creating a satellite arrangement table in which the reception time and the received position information satellite information are stored;
When the positioning processing step is executed by operating the external operation member, the order in which the position information satellites are searched in the satellite arrangement table is the order of the position information satellites whose reception time is closest to the operation time of the positioning processing means. Positioning search order setting process to be set to
A reception control method for an electronic timepiece with a satellite signal reception device.

Images