JP5136354B2 - Position / time calculation device and clock - Google Patents

Description

  The present invention relates to a position / time calculation device using GPS and a timepiece including the position / time calculation device.

  Applying GPS (Global Positioning System) to measure the current position and accurate time is applied in many fields, for example, car navigation. Hereinafter, the position measurement using GPS is also referred to as GPS positioning.

  A GPS timepiece device has also been proposed that can receive radio waves from GPS satellites (hereinafter referred to as “GPS radio waves”) and perform GPS positioning. The conventional GPS timepiece is a timepiece circuit 11 for measuring time, a GPS receiving circuit for receiving GPS radio waves, a memory 13 for storing various information, an input unit including input keys, and the like. A display unit including a liquid crystal display device, a CPU, and the like.

  The memory stores GPS frame data received by the GPS receiving circuit, and includes, for example, the latitude and longitude of each city and the time difference from the standard time. In addition, the memory stores programs for realizing various functions of the GPS clock device, data generated by processing in the CPU, and the like. The CPU displays the time measured by the clock circuit on the display unit in accordance with the program stored in the memory.

  In addition, the CPU receives a GPS radio wave in response to an input to the input unit or operates a GPS reception circuit at a predetermined time interval, and acquires frame data included in the GPS radio wave. Further, the CPU calculates the current position and the current time of the GPS timepiece device based on the frame data acquired by the GPS receiving circuit. The CPU corrects the time of the timer circuit based on the calculated current time, and displays the calculated current time on the display unit.

  GPS positioning by the GPS receiving circuit is normally performed under a three-dimensional positioning mode (3D Fix) for receiving GPS radio waves from four or more GPS satellites and a two-dimensional positioning mode for receiving GPS radio waves from three GPS satellites. Is called. In the three-dimensional positioning mode, the three-dimensional coordinates (x, y, z) of the current position of the GPS clock device and the error δ of the time measured by the GPS clock device can be calculated. In the two-dimensional positioning mode, the two-dimensional coordinates (x, y) excluding the height of the current position and the time error δ measured by the GPS GPS clock device can be calculated.

Further, when there are fewer than three GPS satellites that can receive GPS radio waves, only time information may be acquired without measuring the current position.
JP 2007-26041 A Japanese Examined Patent Publication No. 6-75103

  There are often situations where it is difficult to obtain the orbit information and time information of each of the four GPS satellites. In Patent Document 1, in a device equipped with a GPS receiver (a navigation device in Patent Document 1), a change in GPS positioning environment and a change in height (elevation) where the device is located are detected, and two-dimensional positioning is performed. Techniques for switching dimensional positioning have been proposed. With the deterioration of the GPS measurement environment, the number of GPS satellites (number of receptions) from which GPS radio waves should be acquired can be reduced to three by performing two-dimensional positioning.

  Various indicators are known for evaluating positioning errors. For example, PDOP (Position Dilution of Precision) for obtaining the radial direction error of the three-dimensional position, HDOP (Horizontal Division of Precision) for obtaining the error in the horizontal direction, and VDOP (Vertical Dilution) for obtaining the error in the altitude direction. of Precision).

  Patent Document 2 compares the HDOP of a satellite selected for three-dimensional positioning with the HDOP of a satellite selected for two-dimensional positioning. If the former is large, three-dimensional positioning is executed. If the latter is large, A technique for performing two-dimensional positioning is disclosed.

  In particular, a small device using a battery as a power source, such as a wristwatch type GPS timepiece device, is required to reduce power consumption. In order to obtain the correct current time and current position regularly, it is necessary to operate the GPS receiving unit periodically. The current power consumption of the GPS receiver is as high as several tens of milliwatts. Therefore, if the reception operation is performed when the received signal strength of GPS radio waves is low, it takes a long time to acquire orbit information and time information. May fail to receive. As described above, in a small device using a battery as a power source, it is very important to avoid a state in which satisfactory positioning cannot be performed even though a large amount of power is consumed and the battery is consumed.

  In particular, it may not be easy to receive GPS radio waves from a satellite depending on the position of the GPS clock device. For example, when the GPS clock device is located inside a building such as a reinforced concrete building, the number of GPS satellites that can receive GPS radio waves is small, and the received signal strength of GPS radio waves is often small. Therefore, if the number of GPS satellites capable of receiving GPS radio waves is small and the received signal strength of GPS radio waves is expected to be low, especially if it can be detected in advance that the GPS clock device is located indoors, it is useless. It is possible to prevent the GPS receiver from operating.

  The present invention provides a position / time calculation device capable of appropriate positioning depending on the position of the device, for example, whether it is located outdoors or outdoors, and a timepiece including the position / time calculation device. Objective.

An object of the present invention is to receive a radio wave from a GPS satellite and output a signal based on the radio wave, GPS receiving means,
A multi-channel decoder group having a plurality of decoders each receiving a signal output from the GPS receiving means and obtaining GPS frame data for each GPS satellite;
A frame data memory for storing GPS frame data respectively output from decoders constituting the multi-channel decoder group;
A position / time calculation control means for calculating a current position and a current time based on the GPS frame data included in the frame data memory;
Light detecting means for receiving light and outputting a signal corresponding to the intensity of the light;
Periodicity detection means for determining whether or not the signal has a predetermined periodicity based on a signal output from the light detection means;
Positioning mode determining means for determining in which positioning mode the positioning mode should be determined by the two-dimensional positioning mode for positioning by three GPS satellites or the three-dimensional positioning mode for positioning by four or more GPS satellites,
When the periodicity detecting means determines that the signal has a predetermined periodicity, the positioning mode determining means determines that positioning should be performed in a two-dimensional positioning mode, and the periodicity detecting means When it is determined that the signal does not have a predetermined periodicity, the positioning mode determining means determines that positioning should be performed in the three-dimensional positioning mode,
According to the positioning mode, this is achieved by a position / time calculation device characterized in that a predetermined number of decoders operate in the multi-channel record group, and each decoder acquires GPS frame data.

In a preferred embodiment, it comprises a clock means for clocking the current time according to an internal clock,
The positioning mode determining means refers to the current time measured by the time measuring means, and when the current time corresponds to a predetermined time zone corresponding to daytime, the level of the signal output from the light detecting means Is determined to be equal to or higher than a predetermined threshold, and if the level of the signal is equal to or higher than a predetermined threshold, the positioning mode determining means determines that the positioning should be performed in the three-dimensional positioning mode, If it is smaller than the threshold, the periodicity detecting means detects periodicity, and the positioning mode determining means determines a positioning mode based on the periodicity.

  In a more preferred embodiment, the positioning mode determining means refers to the current time measured by the time measuring means, and when the current time corresponds to a predetermined time zone corresponding to night, the periodicity detection The means detects periodicity, and the positioning mode determining means determines the positioning mode based on the periodicity.

  In another preferred embodiment, in the three-dimensional positioning mode, all the decoders of the multi-channel decoder group operate, and in the two-dimensional positioning mode, the number of decoders in the multi-channel decoder group is less than all the decoders. Only a predetermined number, for example, three decoders are active.

  In a preferred embodiment, the position / time calculation means is an index value indicating the degree of goodness of the arrangement state of the GPS satellites in the three-dimensional positioning mode, and is a predetermined first value indicating a limit to be used for positioning. Whether or not positioning is possible is determined using a mask value of 1, and in the two-dimensional positioning mode, positioning is determined using a predetermined second mask value that allows an unfavorable arrangement than the first mask value. Judging.

  In another preferred embodiment, the position / time calculation means is an index value indicating the degree of goodness of the arrangement state of the GPS satellites in the three-dimensional positioning mode, and is a predetermined first value indicating a limit to be used for positioning. Whether or not positioning is possible is determined using a mask value of 1, and positioning is performed without using the mask value in the two-dimensional positioning mode.

In a preferred embodiment, the light detection means has power generation means for generating power in response to light including sunlight,
The periodicity determining means detects a predetermined periodicity in the electric signal based on the electric signal generated by the power generation means.

  In a more preferred embodiment, the periodicity is based on the frequency of a commercial AC power source.

Another object of the present invention is to provide the position / time calculation device,
A time measuring means for measuring the current time according to the internal clock;
This is achieved by a timepiece comprising correction means for correcting the current time of the timekeeping means in accordance with the current time acquired by the position / time calculation device.

  In a preferred embodiment, there is provided display means for displaying the current position acquired by the position / time calculation device.

  According to the present invention, a position / time calculation device capable of appropriate positioning according to the position of the device, for example, whether it is located outdoors or outdoors, and a timepiece including the position / time calculation device are provided. It becomes possible.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of the GPS timepiece device according to the first embodiment of the present invention. As shown in FIG. 1, the GPS timepiece according to the present embodiment includes an antenna 12, a preamplifier circuit 14, a high frequency receiving circuit 16, a GPS signal processing unit 18, a CPU 20, a ROM 22, a RAM 24, a clock circuit 26, and an oscillation circuit. 28, an input unit 30, a display unit 32, and a power supply circuit 34.

  In this embodiment, the antenna 12, the preamplifier circuit 14, and the high frequency receiver circuit 16 constitute a GPS receiver circuit. Further, although the GPS signal processing unit 18 is described as a separate body from the CPU 20 in FIG. 1, it may exist as a circuit different from the CPU or may be incorporated in the CPU. Similarly, a later-described GPS control unit 37 may exist as a circuit different from the CPU, or may be incorporated in the CPU.

  The ROM 22 has a program for realizing various functions of the timepiece device, for example, a positioning mode setting program for determining whether to operate in a two-dimensional positioning mode or a three-dimensional positioning mode described later, a set positioning Stores a program for determining the current position based on GPS frame data acquired from GPS radio waves, a program for correcting time based on GPS frame data, a program for calculating various indexes based on GPS frame data, etc. Has been. The ROM 22 also stores the latitude, longitude, and time difference from the standard time of each city. The RAM 14 temporarily stores the program stored in the ROM 22 and can store data generated in the process of the CPU 20 executing the program.

  The timer circuit 26 measures time according to the internal clock signal generated by the oscillation circuit 28 and calculates the current time. Further, the time measured can be corrected according to the accurate time information acquired by the GPS signal processing unit 18. The input unit 30 has an input key, and a user can give a desired instruction to the GPS clock device. The display unit 32 includes a liquid crystal display device and can display the current time, the current position, and the like.

  As will be described later, the power supply circuit 34 can generate light by receiving light such as sunlight, and can store the generated power in the secondary battery.

  FIG. 2 is a block diagram showing a configuration of the GPS signal processing unit 18 according to the present embodiment. As shown in FIG. 2, it has a multi-channel decoder group 35, a memory 36 and a GPS control unit 37. The multi-channel decoder group 35 includes a plurality of decoders 41 to 4n. Each of the decoders 41 to 4n can decode a GPS signal from one GPS satellite. Therefore, in the present embodiment, it is possible to simultaneously receive GPS signals from n GPS satellites and decode each of them to obtain data (GPS frame data). The memory 36 stores GPS frame data decoded in each of the decoders 41 to 4n. In FIG. 2, the memory 36 is described as being different from the RAM 24, but actually, a part of the RAM 24 may be used as the memory 36.

  The GPS control unit 37 determines the positioning mode according to the program stored in the ROM 22 and developed in the RAM 24, and calculates the current position and the current time according to the determined positioning mode. As will be described in detail later, in this embodiment, the positioning mode includes a 3D Fix mode for performing three-dimensional positioning (3D Fix) and a 2D Fix mode for performing two-dimensional positioning (2D Fix). In the present embodiment, as will be described later, it is determined whether the GPS clock device is located indoors or outdoors and it is determined whether to operate in the 3D Fix mode or the 2D Fix mode. .

  FIG. 3 is a block diagram showing the configuration of the power supply circuit according to the present embodiment. As shown in FIG. 3, the power supply circuit 34 includes a solar power generation device 51, a filter circuit 52, an AD converter 53, a regulator 54, and a secondary battery 55. The solar power generation device 51 accepts light such as fluorescent light and incandescent light in addition to sunlight, converts the received light energy into an electrical signal, and outputs it. As will be described later, the filter circuit 52 includes a low-pass filter (LPF) or a band-pass filter (BPF) that passes signals of 100 Hz and 120 Hz.

  The AD converter 53 supplies digital data indicating the output voltage of the photovoltaic power generator 51 to the CPU 20. The regulator 54 stabilizes the power output from the solar power generation device 51 and applies the power to the secondary battery 55, and the secondary battery 55 stores the power output from the regulator 34. Electric power is supplied from the secondary battery 55 to each component of the timepiece device serving as a load. In the present embodiment, the electric power output from solar power generation device 51 is given to secondary battery 55 and stored in secondary battery 55. Further, the CPU 20 is provided with data indicating the output voltage of the solar power generation device 51.

  FIG. 9 is a diagram for explaining frame data based on GPS radio waves. As shown in FIG. 9A, the GPS frame data is composed of data of a total of 25 pages, with a 1500-bit, 30-second main frame as one page. The main frame is composed of five subframes, and 30 bits of TLM (Telemetry) data and 30 bits of HOW (Handover Word) data are contained in the synchronization word (2 words) at the head of each subframe. include. Subframe 1 to subframe 3 have the same data structure throughout the main frame of 25 pages. However, subframe 4 and subframe 5 have a large amount of data, and are therefore divided into 25 pages and transmitted. ing.

  FIG. 9B is a diagram illustrating information included in each subframe. As shown in FIG. 9B, the subframe 1 includes the satellite clock correction coefficient of the GPS satellite itself that transmits the GPS radio wave, the data update time, and various flags. Subframe 2 and subframe 3 include orbit information (ephemeris) of a GPS satellite itself that transmits GPS radio waves. Subframe 1 to subframe 3 are data specific to GPS satellites that transmit GPS radio waves. On the other hand, in subframe 4 and subframe 5, almanac, which is rough orbit information common to up to 32 GPS satellites in orbit, ionospheric correction coefficient, satellite state (satellite is in operation or paused) Information indicating the status).

  The almanac is rough orbit information, and can be used, for example, to identify a GPS satellite that can receive GPS radio waves by the clock device according to the present embodiment. The ephemeris is detailed orbit information of the GPS satellite, and the ephemeris is referred to specify the position of the GPS satellite.

  The CPU 20 can calculate the current position of the GPS satellite by referring to the almanac and the ephemeris, and obtain the current position of the GPS clock device based on the calculated current position. Note that it takes about 30 seconds to acquire the ephemeris in the GPS frame data. Needless to say, it takes more time to acquire an almanac. Therefore, usually, a technique is adopted in which the almanac and ephemeris are stored in the memory 36, and if they are available (that is, valid), the time required for acquiring the GPS frame data is shortened by using them. ing.

  On the other hand, when the almanac and the ephemeris are not present in the memory, it is called a cold start, and it takes several minutes to acquire the GPS frame data and acquire the data. When the almanac exists in the memory 36, it is called a warm start, and it takes 30 to 60 seconds to acquire data after capturing GPS frame data. On the other hand, when the almanac and valid ephemeris are present, it is called a hot start, and after the GPS frame data is captured, the time required to acquire the data is several seconds.

  Hereinafter, the positioning mode according to the present embodiment will be described. In the present embodiment, GPS positioning is performed in a three-dimensional positioning mode (3Dix mode) for receiving GPS radio waves from four or more GPS satellites, and in a two-dimensional positioning mode for receiving GPS radio waves from three GPS satellites ( 2Dix mode). Under the 3D Fix mode, the three-dimensional coordinates (x, y, z) of the current position of the GPS clock device and the error δ of the time measured by the GPS clock device can be calculated. Under the 2D Fix mode, the two-dimensional coordinates (x, y) excluding the height of the current position and the error δ of the time measured by the GPS clock device can be calculated.

  FIG. 4 is a flowchart showing an example of processing executed in the GSP timepiece device according to the present embodiment. As shown in FIG. 4, the CPU 20 of the GPS timepiece device receives a positioning instruction from the user to the input unit 30 (Yes in Step 401) or when a predetermined positioning time has arrived (Step In step 402, the positioning mode setting process is executed.

  FIG. 5 is a flowchart showing in more detail an example of the positioning mode determination process. As shown in FIG. 5, the CPU 20 acquires the current time from the time measuring circuit 26 (step 501). Next, it is determined whether or not the acquired current time is included in the night time zone (step 502). Here, the information on the night time zone may be stored in the ROM 22 in advance. The ROM 22 may store a set of single time zones that do not take into account the date and time of predetermined time zones (for example, 0:00 to 6 o'clock and 19:00 to 24:00). Or you may memorize | store the group of the several time slot | zone which changes for every season or month.

  When it is determined No in step 502, that is, when the current time is not included in the night time zone (when the current time is included in the daytime time zone), it is used for indoor / outdoor determination according to the current time. A threshold value is acquired (step 503). The threshold for indoor / outdoor determination according to the current time is stored in the ROM 22 as a table in which the current time and the level of the monitor voltage data (monitor voltage level) are associated with each other. The monitor voltage data is output from the AD converter 33 of the power supply circuit 18 and is given to the CPU 20. For example, the CPU 20 may store the given monitor voltage data temporarily in the RAM 24 and read the monitor voltage data temporarily stored from the RAM 24.

  FIG. 6A is a diagram showing a typical example of the monitor voltage level of photovoltaic power generation indoors and outdoors at a certain time. In FIG. 6A, a graph 601 indicated by a straight line indicates a monitor voltage level of photovoltaic power generation outdoors, and a graph 602 indicated by a broken line indicates a monitor voltage level indoors. In FIG. 6 (a), in a time zone corresponding to nighttime (from 0 o'clock to 6 o'clock, from 19 o'clock to 12 o'clock), since the fluorescent lamps are lit indoors, the indoors generate electricity more than the outdoors. The monitor voltage level due to is high. On the other hand, in the time zone corresponding to the daytime (6 o'clock to 19 o'clock), the outdoor monitor voltage level by power generation is larger than the outdoor. Therefore, in the present embodiment, the GPS clock device is installed at each time in a time zone that is not nighttime, that is, a time zone corresponding to daytime (for example, 6:00 to 19:00 in the example of FIG. 6A). A threshold of the monitor voltage level for determining whether it is located inside or outside is determined, and the time and the monitor voltage level are associated with each other and stored in the ROM 22. FIG. 6B is a graph showing the time and the threshold value of the monitor voltage level. In FIG. 6B, a graph indicated by a one-dot chain line 610 indicates a threshold value. In step 505, for example, the peak value of the monitor voltage level or the average value of the peak value is compared with the threshold value.

  CPU20 acquires the monitor voltage level which shows the power generation level of the solar power generation device 51 based on the data output from AD converter 52 (step 504). Next, the CPU 20 determines whether the monitor voltage is equal to or higher than the threshold (monitor voltage ≧ threshold) (step 505). If it is determined Yes in step 505, it is determined that the GPS clock device is located outdoors, and the CPU 20 determines the positioning mode to be 3D Fix mode (step 508). Further, the CPU 20 sets an outdoor PDOP mask value as a PDOP mask value used in positioning (step 509). The outdoor PDOP mask value is a value indicating the goodness of PDOP, that is, a smaller value than the indoor PDOP mask value.

  When it is determined No in step 505, the CPU 20 calculates the frequency of the monitor voltage data. Since the fluorescent lamp blinks in accordance with the frequency of the household AC power supply, when the solar power generation device 51 generates power based on the light of the fluorescent lamp, the output voltage from the solar power generation device 51 is also constant. It vibrates with a frequency of. For example, when a 50 Hz household AC power supply is used, the fluorescent lamp blinks 100 times per second. On the other hand, when a 60 Hz household AC power supply is used, the fluorescent lamp blinks 120 times per second. Therefore, the monitor voltage obtained from the solar power generation device 31 that generates power by receiving the light of these blinking fluorescent lamps also shows a repetitive waveform of 100 times or 120 times per second.

  FIG. 10 is a diagram illustrating an example of monitor voltage data in the present embodiment. As shown in FIG. 10, the monitor voltage data has a continuous basic waveform (see reference numerals 1001 and 1002) that increases from the zero level, decreases again from the peak, and reaches the zero level. For example, in the monitor voltage based on the power generation by the light of the fluorescent lamp lit by the 50 Hz AC power supply, the basic waveform appears 100 times per second, and the light of the fluorescent lamp lit by the 60 Hz AC power supply. In the monitor voltage based on the power generation by, the basic waveform appears 120 times per second. Therefore, for example, the CPU 20 can specify the frequency of the AC power supply by counting the number of basic waveforms per second. More specifically, the peak of the monitor voltage data is detected, a threshold value TH that is slightly smaller than the peak value (for example, 90% of the peak value) is set, and the point ( For example, the number of reference numbers 1011 to 1014 may be counted.

  The CPU 20 determines whether or not the frequency 60 Hz of the AC power supply based on the frequency of the monitor voltage has been detected (step 506). When the frequency 60 Hz is detected (Yes in step 506), the CPU 20 determines that the GPS clock device is located indoors. Also, when the frequency of the AC power supply 50 Hz based on the frequency of the monitor voltage is detected (Yes in step 507), the CPU 20 determines that the GPS clock device is located indoors. Therefore, in these cases, the CPU 20 determines the positioning mode as the 2D Fix mode (step 510). Further, the CPU 20 sets an indoor PDOP mask value as a PDOP mask value used in positioning (step 511).

  In addition, when it is determined No in step 502, that is, when it is determined that the current time is included in a time zone corresponding to nighttime, determination based on the frequency of the monitor voltage (steps 506 and 507) is executed. .

  The positioning mode and the PDOP mask value are given from the CPU 20 to the GPS control unit 37. In the positioning process (step 404) described later, the GPS control unit 37 causes all the decoders 41 to 4n in the multi-channel decoder group 35 to acquire GPS frame data if the positioning mode is the 3D Fix mode. On the other hand, if the positioning mode is the 2D Fix mode, the GPS control unit 37 causes the three decoders (for example, decoders 41 to 43) in the multi-channel decoder group 35 to acquire GPS frame data.

  When the positioning mode setting process (step 403) is completed, the CPU 20 executes the positioning process according to the positioning mode (step 404). 7 and 8 are flowcharts showing an example of the positioning process according to the present embodiment. As shown in FIG. 7, the CPU 20 determines whether or not the set positioning mode is the 3D Fix mode (step 701). When it is determined Yes in step 701, the CPU 20 instructs the GPS control unit 37 to acquire GPG frame data to all the decoders 41 to 4n in the multi-channel decoder group 38 (step 702).

  In response to an instruction from the GPS control unit 37, each of the decoders 41 to 4n in the multi-channel decoder group 38 acquires GPS frame data from the satellite, and stores the GPS frame data in a predetermined area of the memory 36, respectively. . If the number of satellites to be captured is less than the number n of decoders, it is sufficient to operate as many decoders as the number of captured satellites.

  The GPS control unit 37 calculates the PDOP value of each of the four or more satellite groups from the GPS frame data of each satellite stored in the memory 36 (step 703). The GPS control unit 37 compares the calculated PDOP values and identifies the best, that is, the PDOP value indicating the minimum value (step 704). Next, the GPS control unit 37 compares the best PDOP value with the outdoor PDOP mask value, and determines whether or not the best PDOP value is smaller than the outdoor PDOP mask (step 705). If it is determined No in step 705, the process is terminated, and the current position is not calculated from the GPS frame data acquired in the current process.

  If it is determined Yes in step 705, the GPS control unit 37 provides the CPU 20 with the GPS frame data of each satellite showing the best PDOP value. Based on the given GPS frame data, the CPU 20 calculates the three-dimensional coordinates of the current position of the GPS clock device and the error of the current time (step 706).

  If No in step 701, that is, if the positioning mode is the 2D Fix mode, the CPU 20 instructs the GPS control unit 37 to start up the three decoders 41 to 43 in the multi-channel decoder group 38. (Step 801). In response to an instruction from the GPS control unit 37, the three decoders 41 to 43 in the multi-channel decoder group 38 each acquire GPS frame data from the satellite, and store the GPS frame data in a predetermined area of the memory 36, respectively. Store.

  The GPS control unit 37 calculates PDOP values from the GPS frame data of the three satellites stored in the memory 36 (step 802). The GPS control unit 37 compares the calculated PDOP value with the indoor PDOP mask value, and determines whether or not the calculated PDOP value is smaller than the indoor PDOP mask (step 803). If it is determined No in step 803, the process is terminated, and the current position is not calculated from the GPS frame data acquired in the current process.

  If it is determined Yes in step 803, the GPS control unit 37 provides the CPU 20 with the GPS frame data of each satellite indicating the PDOP value. The CPU 20 calculates the two-dimensional coordinates of the current position of the GPS clock device and the error of the current time based on the given GPS frame data (step 804).

  According to the present embodiment, the level of the electrical signal generated by the photovoltaic power generation device (monitor voltage level) is used as a signal corresponding to the intensity of light, and the periodicity of the signal is determined. When the signal has a predetermined periodicity based on the frequency of the AC power supply, it is determined that the GPS clock device is located indoors, and positioning in the two-dimensional positioning mode is executed. Since the number of GPS satellites that can be seen indoors is small and there is a high possibility that highly accurate positioning cannot be expected, only planar coordinate and time errors are acquired in advance by positioning in the two-dimensional positioning mode. Thereby, it becomes possible to perform positioning under an appropriate positioning mode according to the situation of the GPS clock device.

  In this embodiment, when the current time is a time zone corresponding to daytime, it is determined whether or not the signal level is equal to or higher than a predetermined threshold value. This predetermined threshold value is a value for determining indoor or outdoor in a time zone corresponding to daytime. When the signal level is equal to or higher than a predetermined threshold, the positioning mode determining means determines that positioning should be performed in the three-dimensional positioning mode. Therefore, when the possibility that the GPS clock device is located outdoors is considerably high, highly accurate positioning can be performed in the three-dimensional positioning mode.

  Further, in the present embodiment, when the current time is a time zone corresponding to night, the periodicity of the signal is determined by the periodicity detecting means, and when it is determined that the signal is periodic Positioning in the two-dimensional positioning mode is executed. In a time zone corresponding to night, it is determined whether or not the GPS clock device is located indoors, which is a typical place where the fluorescent lamp is lit, and the positioning mode is determined based on this. According to the present embodiment, it is possible to appropriately determine the position of the GPS clock device according to the time zone.

  In the present embodiment, in the three-dimensional positioning mode, all the decoders of the multi-channel decoder group operate and each decoder acquires GPS frame data. On the other hand, in the two-dimensional positioning mode, a smaller number of decoders than the total number of decoders (for example, the minimum required three) operate, and each decoder acquires GPS frame data. This makes it possible to suppress power consumption as much as possible in the two-dimensional positioning mode where high-precision positioning cannot be expected.

  In the present embodiment, in the two-dimensional positioning mode, an index value (for example, PDOP value) indicating the degree of goodness of the arrangement state of the GPS satellites, and a mask value indicating the limit of use for positioning is set to 3 A value that allows an unfavorable arrangement than the mask value in the dimension positioning mode. As a result, in the two-dimensional positioning mode, position calculation can be prioritized over accuracy.

  According to the present embodiment, the level (monitor voltage level) of the electrical signal generated by the solar power generation apparatus is acquired as a signal corresponding to the light intensity. Therefore, a signal corresponding to the intensity of light can be acquired without using a dedicated element for receiving light.

  The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above-described embodiment, the power supply circuit includes the solar power generation device, acquires the monitor voltage for the power generated by the solar power generation device, and detects the frequency of the monitor voltage. However, it is not limited to such a configuration. FIG. 11 is a block diagram showing the configuration of the GPS timepiece device according to the second embodiment of the present invention. As shown in FIG. 11, the GPS clock device includes an antenna 12, a preamplifier circuit 14, a high frequency receiver circuit 16, a GPS signal processor 18, a CPU 20, a ROM 22, a RAM 24, a timer circuit 26, an oscillator circuit 28, an input unit 30, The display unit 32, the light receiving unit 110, and the power supply circuit 134 are included. The power supply circuit 134 includes a regulator 135 and a secondary battery 136 that receive an external household AC power supply. In addition, the light receiving unit 110 includes a light receiving sensor 111, a filter circuit 112, and an AD converter 113.

  In the light receiving unit 110, the light receiving sensor 111 can output a signal corresponding to the received light intensity. A signal from the light receiving sensor 111 is given to the CPU 20 through the filter circuit 112 and the AD converter 113. The filter circuit 112 and the AD converter 113 are the same as the filter circuit 52 and the AD converter 53 according to the first embodiment. Data based on the intensity of light received by the light receiving sensor 111 is given to the CPU 20. Therefore, similarly to the first embodiment, the CPU 20 can calculate the frequency of data and detect the frequency of 60 Hz or 50 Hz of the AC power supply based on the calculated frequency of data.

  In the embodiment, the indoor PDOP mask value is determined in advance as a value larger than the outdoor PDOP mask value, and the indoor PDOP mask value is referred to in the positioning in the two-dimensional positioning mode (2D Fix mode). Thus, it was determined whether positioning is possible in the 2D Fix mode (step 803 in FIG. 8). However, in the two-dimensional positioning mode, the PDOP mask value is not adopted, and the PDOP value by these three satellites and the indoor PDOP mask value are not compared based on GPS radio waves received from the three GPS satellites. , Positioning may be executed.

  By not adopting the PDOP mask value in the 2D Fix mode, the position calculation can be given the highest priority in the two-dimensional positioning mode over the accuracy.

  In the embodiment, in the two-dimensional positioning mode (2D Fix mode), three decoders are operated to obtain GPS frame data of three GPS satellites. However, the present invention is not limited to this, and four or more decoders may be operated. From the viewpoint of power saving, it is desirable not to operate all the decoders as in the three-dimensional positioning mode, but to operate only some of the decoders.

  In the above embodiment, in order to obtain the frequency of the monitor voltage data, the number of points exceeding the threshold is counted at the rising (increase) of the monitor voltage data. However, the present invention is limited to such a method. It is not a thing. For example, other values such as the peak value of the monitor voltage data may be counted. Further, in consideration of noise in the waveform of the monitor voltage, when detecting a 50 Hz AC power supply, the count value per second may not match 100, and the count value is within a predetermined range (for example, 95 ~ 105), it may be determined that the AC power supply is 50 Hz. The same applies when detecting an AC power supply of 60 Hz.

  In addition, the time interval between adjacent points may be measured instead of counting the number of points that exceed the threshold or the peak value when the monitor voltage data rises (increase). . Also in this case, in consideration of the noise of the waveform of the monitor voltage, whether or not the average value of a plurality of time intervals is within a predetermined range (9 ms to 11 ms if the frequency of the AC power supply is 50 Hz). You just have to judge.

FIG. 1 is a block diagram showing a configuration of a GPS timepiece device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of the GPS signal processing unit 18 according to the present embodiment. FIG. 3 is a block diagram showing the configuration of the power supply circuit according to the present embodiment. FIG. 4 is a flowchart showing an example of processing executed in the GSP timepiece device according to the present embodiment. FIG. 5 is a flowchart showing in more detail an example of the positioning mode determination process. FIG. 6A is a diagram showing a typical example of the monitor voltage level of photovoltaic power generation indoors and outdoors at a certain time, and FIG. 6B is a graph showing time and threshold values of the monitor voltage level. FIG. 7 is a flowchart illustrating an example of the positioning process according to the present embodiment. FIG. 8 is a flowchart illustrating an example of the positioning process according to the present embodiment. FIG. 9 is a diagram for explaining frame data based on GPS radio waves. FIG. 10 is a diagram illustrating an example of monitor voltage data in the present embodiment. FIG. 11 is a block diagram showing the configuration of the GPS timepiece device according to the second embodiment of the present invention.

Explanation of symbols

14 Preamplifier circuit 16 High frequency receiver circuit 18 GPS signal processor 20 CPU
22 ROM
24 RAM
26 Clock circuit 28 Oscillation circuit 30 Input unit 32 Display unit 34 Power supply circuit 35 Multi-channel decoder group 36 Memory 37 GPS control unit 41, 42,... Decoder

Claims (10)

GPS receiving means for receiving radio waves from GPS satellites and outputting signals based on the radio waves;
A multi-channel decoder group having a plurality of decoders each receiving a signal output from the GPS receiving means and obtaining GPS frame data for each GPS satellite;
A frame data memory for storing GPS frame data respectively output from decoders constituting the multi-channel decoder group;
A position / time calculation control means for calculating a current position and a current time based on the GPS frame data included in the frame data memory;
Light detecting means for receiving light and outputting a signal corresponding to the intensity of the light;
Periodicity detection means for determining whether or not the signal has a predetermined periodicity based on a signal output from the light detection means;
Positioning mode determining means for determining in which positioning mode the positioning mode should be determined by the two-dimensional positioning mode for positioning by three GPS satellites or the three-dimensional positioning mode for positioning by four or more GPS satellites,
When the periodicity detecting means determines that the signal has a predetermined periodicity, the positioning mode determining means determines that positioning should be performed in a two-dimensional positioning mode, and the periodicity detecting means When it is determined that the signal does not have a predetermined periodicity, the positioning mode determining means determines that positioning should be performed in the three-dimensional positioning mode,
A position / time calculation device, wherein a predetermined number of decoders operate in the multi-channel record group according to the positioning mode, and each decoder acquires GPS frame data. It has a timekeeping means that keeps the current time according to the internal clock,
The positioning mode determining means refers to the current time measured by the time measuring means, and when the current time corresponds to a predetermined time zone corresponding to daytime, the level of the signal output from the light detecting means Is determined to be equal to or higher than a predetermined threshold, and if the level of the signal is equal to or higher than a predetermined threshold, the positioning mode determining means determines that the positioning should be performed in the three-dimensional positioning mode, 2. The position according to claim 1, wherein, when smaller than the threshold value, the periodicity detecting unit detects periodicity, and the positioning mode determining unit determines a positioning mode based on the periodicity. -Time calculation device.   The positioning mode determining means refers to the current time measured by the time measuring means, and the periodicity detecting means detects periodicity when the current time corresponds to a predetermined time zone corresponding to night. The position / time calculation device according to claim 2, wherein the positioning mode determining means determines a positioning mode based on the periodicity.   In the three-dimensional positioning mode, all the decoders of the multi-channel decoder group operate, and in the two-dimensional positioning mode, only a predetermined number of decoders that are smaller than the total number of decoders in the multi-channel decoder group operate. The position / time calculation apparatus according to claim 1, wherein   In the three-dimensional positioning mode, the position / time calculating means uses an index value indicating a good degree of arrangement of GPS satellites, and using a predetermined first mask value indicating a limit to be used for positioning, Whether or not positioning is possible is determined, and in the two-dimensional positioning mode, whether or not positioning is possible is determined using a predetermined second mask value that allows an unfavorable arrangement from the first mask value. The position / time calculation apparatus according to claim 1.   In the three-dimensional positioning mode, the position / time calculating means uses an index value indicating a good degree of arrangement of GPS satellites, and using a predetermined first mask value indicating a limit to be used for positioning, 5. The position / time calculation device according to claim 1, wherein positioning is determined and positioning is performed without using the mask value in the two-dimensional positioning mode. 6. The light detection means has power generation means for generating power in response to light including sunlight,
7. The position according to claim 1, wherein the periodicity determination unit detects a predetermined periodicity in the electric signal based on an electric signal generated by the power generation by the power generation unit. Time calculation device acquisition device.   The position / time calculation apparatus according to any one of claims 1 to 7, wherein the periodicity is based on a frequency of a commercial AC power supply. The position / time calculation device according to any one of claims 1 to 8,
A time measuring means for measuring the current time according to the internal clock;
A timepiece comprising: correction means for correcting the current time of the timekeeping means in accordance with the current time acquired by the position / time calculation device.   The timepiece according to claim 9, further comprising display means for displaying a current position acquired by the position / time calculation device.

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