JP4884247B2 - Time correction apparatus and time correction program - Google Patents

Description

  The present invention relates to a time correction device and a time correction program for correcting time according to a time signal.

  2. Description of the Related Art Conventionally, there are watches equipped with a time adjustment device that adjusts the time using radio broadcast time signals. NHK (Nippon Broadcasting Corporation) time signal transmits 440 Hz forecast sound that lasts 0.1 seconds three times at 1 second intervals, and then sends 880 Hz correct sound that decays 1 second after 1 second. It is the composition.

For example, in Patent Document 1, a received signal is received when a forecast sound and a correct sound are received, the duration and pulse interval of the received signal are measured, and all measured values coincide with those of a regular time signal. Is a time signal.
JP 60-49285 A

  With the thing of patent document 1, although the time signal can be determined with high precision, if even one of the measured duration and pulse interval falls outside the predetermined allowable range, it is determined that the time signal is not. For this reason, the thing of patent document 1 had the problem that it was easy to miss the opportunity of acquisition of a time signal by returning by a strict judgment depending on the reception situation. In addition, by increasing the predetermined allowable range, it is possible to increase the acquisition opportunity of the time signal, but the time correction accuracy decreases.

  Therefore, an object of the present invention is to determine a time signal with high accuracy while securing an opportunity to acquire the time signal, and to enable time correction with high accuracy.

In order to achieve the above object, a time correction apparatus according to a first aspect of the present invention is
In a time adjustment device that receives a radio wave superimposed with a time signal composed of a plurality of forecast sounds and correct sound and corrects the time based on the time signal,
A forecast sound detection means for outputting a first detection signal indicating that a forecast sound has been detected when a signal of a first frequency is detected in the signal obtained by receiving the radio wave;
Correct sound detection means for outputting a second detection signal indicating that a correct sound is detected when a signal of a second frequency is detected in the signal obtained by receiving the radio wave;
Based on the output timing of the first detection signal, a first effective range for determining whether the first detection signal next to the first detection signal is output at an appropriate timing The first effective range is set last, and the second effective range for determining whether or not the second detection signal following the first detection signal is output at an appropriate timing is set last. Effective range setting means for setting narrower than the effective range of,
The timing of receiving the second detection signal within the second effective range after sequentially receiving the plurality of first detection signals within the first effective range set by the effective range setting means Effective range detection means for outputting a time correction signal as the time indicated by the time signal;
With
Time correction is performed based on the output timing of the time correction signal.

In the time adjustment device,
Timer means for starting a time measuring operation by the first detection signal;
The effective range setting unit may sequentially set the first effective range and the second effective range based on the time measured by the timer unit.

In the time adjustment device,
The timer means restarts time measurement every time the first detection signal is received,
The effective range setting means sets the effective range of the second first detection signal based on the time when the first detection signal is first received and measurement is started, and the second first detection signal is set in the effective range. When there is one detection signal, measurement is started upon receipt of the second first detection signal, the effective range of the third first detection signal is set based on the time, and the effective range is set to the effective range. When there is the third first detection signal, measurement is started by receiving the third first detection signal, and the effective range of the second detection signal is set based on time. May be.

The time correction program according to the second aspect of the present invention is:
A time correction program for causing a computer to execute a process for correcting a time based on a plurality of forecast sounds superimposed on radio waves and a time signal composed of correct sound sounds,
Output from the forecast sound detecting means for outputting a first detection signal indicating that a forecast sound has been detected when a signal of the first frequency is detected in the signal obtained by receiving the radio wave to the computer. A forecast sound detection process for monitoring the first detection signal;
Output to the computer from a correct sound detection means for outputting a second detection signal indicating that a correct sound is detected when a signal of a second frequency is detected in the signal obtained by receiving the radio wave. A correct sound detection process for monitoring the second detection signal,
Based on the output timing of the first detection signal, a first effective range for determining whether the first detection signal next to the first detection signal is output at an appropriate timing The first effective range is set last, and the second effective range for determining whether or not the second detection signal following the first detection signal is output at an appropriate timing is set last. Effective range setting processing to set narrower than the effective range of
The timing of receiving the second detection signal within the second effective range after sequentially receiving the plurality of first detection signals within the first effective range set by the effective range setting process An effective range detection process for outputting a time correction signal as the time indicated by the time signal;
And the time adjustment processing is performed based on the output timing of the time adjustment signal.

In the time correction program,
A timer process for starting a time measuring operation by the first detection signal is executed;
The effective range setting process may sequentially set the first effective range and the second effective range based on the time measured by the timer process.

In the time correction program,
The timer process restarts time measurement every time the first detection signal is received,
The effective range setting process sets the effective range of the second first detection signal based on the time when the measurement is started upon receiving the first first detection signal, and the second effective detection range is set in the effective range. When there is a first detection signal, measurement is started upon receipt of the second first detection signal, the effective range of the third first detection signal is set based on time, and the effective range is set. When the third first detection signal is present, measurement is started upon receiving the third first detection signal, and the effective range of the second detection signal is set based on the time. It may be.

In the time correction program,
The timer process, the effective range setting process and the effective range detection process are a set of generation processes for generating the time correction signal,
Each time the first detection signal is received, execution control processing for starting execution of the new generation processing is executed,
The time adjustment process may be performed based on the output timing of the time adjustment signal output from any of the generation processes.

In the time correction program,
The generation process uses the first detection signal received first after the execution is started as its first detection signal;
The time adjustment process may be performed based on the output timing of the time adjustment signal output first from any of the generation processes.

  According to the time correction apparatus and the time correction program of the present invention, it is possible to determine a time signal with high accuracy while securing an opportunity to acquire a time signal, and thus it is possible to correct time with high accuracy.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of a time adjustment device 10 applied to the embodiment of the present invention.

  The FM radio receiver 1 receives an FM broadcast radio wave received by an antenna 1a, demodulates it into an audio signal including a forecast sound and a correct report sound, and outputs it.

  The low-pass filter 2 is for cutting harmonic noise of the signal output from the radio receiver 1.

  The tone decoders 3a and 3b are circuits that output a detection signal by turning on the output transistor when a signal having a preset frequency is input. The tone decoders 3a and 3b detect frequencies of 440 Hz and 880 Hz, respectively.

  A CPU (Central Processing Unit) 4 controls the entire time adjustment device. Further, the CPU 4 receives the detection signals of the tone decoders 3a and 3b at the input terminal, and executes a process of correcting time information measured internally in accordance with the detection signals of the tone decoders 3a and 3b. Software for this processing, that is, a time correction program is stored in a ROM (Read Only Memory) (not shown), and is executed using a RAM (Random Access Memory) (not shown) as a work area. The CPU 4 forms a computer that executes the time correction program together with the ROM and RAM.

  The CPU 4 performs this processing at a predetermined timing, for example, 15 seconds before and after noon, and after detecting the detection signal of the tone decoder 3a, in other words, the forecast sound three times, in other words, the detection signal of the tone decoder 3b. When the correct alarm sound is detected, the timing of noon (12:00 p.m.) is specified, and the time information measured internally is corrected accordingly.

  Further, the time information corrected by the CPU 4 may be written in an RTC (Real Time Clock) (not shown), or the time may be corrected by triggering the RTC at a timing of 1 second synchronized with the correct alarm sound. .

  FIG. 2 is a timing chart showing a time report of FM broadcasting. The time signal is composed of three forecast sounds and one correct report sound. In the case of NHK FM broadcasting, the forecast sound is broadcast at a frequency of 440 Hz and the correct report sound is broadcast at 880 Hz. The first forecast sound continues for 0.1 seconds, and the next second forecast sound continues after 0.9 seconds. Similarly, the 880 Hz corrective sound continues for 1 second or more 0.9 seconds after the third predicted sound.

  FIG. 3 is a schematic diagram schematically showing the main part of the time correction process executed by the CPU 4.

  The forecast sound detection process 31a is a process for monitoring the generation of a detection signal from the tone decoder 3a, that is, a forecast sound of 440 Hz, and setting a forecast sound flag indicating that a forecast sound has been generated when the detection signal is generated. . Other processing uses the latest forecast sound flag.

  The correct sound detection processing 31b monitors the detection signal from the tone decoder 3b, that is, the generation of a correct sound of 880 Hz, and sets a correct sound flag indicating that the correct sound has been generated when the detection signal is generated. It is a process to make. Other processing uses the latest forecast sound flag.

  The timer process 32 is a timer process that measures the elapsed time after the forecast sound is generated in response to the forecast sound flag by the forecast sound detection process 31. For example, the timer process 32 receives an effective range flag, which will be described later, and repeats the measurement of the elapsed time each time a new forecast sound flag is received when this flag is set, and sets the measurement flag each time.

  The valid range setting process 33 receives the elapsed time measured by the timer process 32, and when a forecast sound flag or a normal sound flag indicating that the next forecast sound or a normal sound has been generated stands, the effective range setting process 33 regards these as valid flags This is a process for setting a time range.

  For example, the effective range setting process 34 is an effective range that allows the second predicted sound flag to rise for 0.1 second (± 100 milliseconds) around 1 second from the rising of the predicted sound flag for the first predicted sound. 1 effective range), and 0.05 second (± 50 milliseconds) around 1 second from the rise of the second predicted sound flag received in this effective range (first effective range) is the third predicted sound flag. The effective range (second effective range) that allows the rising of the second prediction range, and 0.01 second (± 10 mm) around 1 second from the rising of the third forecast sound flag received in this effective range (second effective range) Second) is set as an effective range (third effective range) that allows the rising of the correct alarm flag, and an effective range flag indicating the period within the effective range is set. This processing may be the following processing, for example.

  When receiving the measurement flag of the timer process 32, the valid range setting process 33 counts this. The effective range setting process 33 sets an effective range flag when the count value is 0 which is an initial value. When the count value becomes 1, the valid range setting process 33 sets the first threshold value for the elapsed time set in the RAM (not shown) to 0.90 seconds (900 milliseconds) and sets the second threshold value to 1.1 seconds (1100). The effective range flag is once lowered, the effective range flag is set when the elapsed time measured by the timer process 32 reaches 900 milliseconds, and the effective range is reached when the elapsed time measured by the timer process 32 reaches 1100 milliseconds. Lower the flag.

  When the count value reaches 2, the valid range setting process 33 sets the first threshold value for the elapsed time set in the RAM (not shown) to 0.95 seconds (950 milliseconds) and sets the second threshold value to 1.05 seconds (1050). The effective range flag is once lowered, the effective range flag is set when the elapsed time measured by the timer process 32 reaches 950 milliseconds, and the effective range is set when the elapsed time measured by the timer process 32 reaches 1050 milliseconds. Lower the flag.

  In the effective range setting process 33, when the count value becomes 3, the first threshold value for the elapsed time set in the RAM (not shown) is set to 0.99 seconds (990 milliseconds), and the second threshold value is set to 1.01 seconds (1010). The effective range flag is once lowered, the effective range flag is set when the elapsed time measured by the timer process 32 reaches 990 milliseconds, and the effective range is set when the elapsed time measured by the timer process 32 reaches 1010 milliseconds. The flag is lowered and the count value is reset to zero.

  These effective ranges are merely examples. In the present invention, any setting may be used as long as the range is narrowed sequentially from the predicted sound to the correct sound, and can be changed as appropriate.

  The valid range detection process 33 monitors the forecast sound flag of the forecast sound detection process 31a, the correct report sound flag of the correct report sound detection process 31b, and the valid range flag of the valid range setting process 33, and when the valid range flag is set. By detecting the forecast sound flag in the third effective range after detecting the forecast sound flag in the first and second effective ranges, the forecast sound flag or the correct sound flag is valid. This is a process of specifying the generation timing, in other words, the time notified by the time signal. The effective range detection process 33 is to specify the generation timing of a valid correct alarm sound and output a time correction signal (time correction flag). With this time adjustment signal, the time measured inside or outside the CPU 4 is corrected to a time synchronized with the time signal.

  Next, the operation of the time adjustment device of this embodiment will be described with reference to the timing chart of FIG.

  The CPU 4 activates the FM radio receiver 1, the low-pass filter 2, and the tone decoders 3a and 3b at a predetermined timing, for example, at 15 seconds before and after noon, and starts a time signal detection process.

  When the first forecast sound is detected by the forecast sound detection process 31a, the timer process 32 is started and the measurement of the elapsed time is started. At this time, the effective range of the next forecast sound is set for the effective time setting process 33. When 100 milliseconds before and after the timer process 32 measures 1 second is set as an effective range, the second forecast sound is detected 1 second after the timer process 32 starts measuring the elapsed time. When the second forecast sound is detected just after one second, the valid time detection process 34 determines that the first valid range of 1 second ± 100 milliseconds is valid and determines the valid range of the next forecast sound (second The effective time setting process is set to 1 second ± 50 milliseconds, and detection of the third forecast sound is started. At this time, if the second forecast sound cannot be detected after 1 second ± 100 milliseconds, for example, if a forecast sound is detected after 1.5 seconds, the valid time detection process 34 determines that the second forecast sound is invalid, and the first forecast sound. It returns to the process which detects this.

  Next, when the third forecast sound is detected within the second effective range of 1 second ± 50 milliseconds, the valid time detection process determines that the predicted sound is valid and detects the next correct sound. To start. At this time, the valid time setting process 33 sets the third valid range as 1 second ± 10 milliseconds. When it is determined that the valid time detection process is within the third valid range and the next correct sound is valid, a time correction flag is set as if a valid correct sound was detected, in other words, a time correction signal is output. Thus, the time signal detection process ends.

  Thus, the time correction signal is output with an accuracy of ± 10 milliseconds with respect to the third forecast sound.

  Next, processing for correcting the internal clock of the CPU 4 is performed using the time correction signal as a time correction flag. This is because the time indicated by the time signal, for example, noon (12:00 p.m.) is set in the internal clock of the CPU 4 and time measurement is started at the timing synchronized with the time correction flag. This is a process for correcting the internal clock so as to measure the time synchronized with the time. Further, the time indicated by the time signal, for example, the time advanced by 1 second from 12:00 p.m. is set in the internal clock of the CPU 4, and the circuit for the detection timing of the time correction flag and the actual noon timing thereof is set. In addition, in consideration of the delay due to the processing, the internal clock may be corrected by starting the time measurement of the second at the obtained timing of 12:00:01 pm.

  Similarly, this time correction signal output may be used to trigger a clock external to the CPU 4 such as an RTC to instruct time correction.

  As described above, the time correction apparatus according to the present embodiment gradually narrows the effective range for evaluating the effectiveness from the first forecast sound to the correct report sound. For this reason, it is possible to maintain high time correction accuracy and prevent erroneous correction while securing a time signal acquisition opportunity.

  In the time adjustment device of the above-described embodiment, the CPU 4 executes the process of generating the first forecast sound, that is, the detection signal from the tone decoder 3a as a trigger, but the present invention is limited to this. Instead, a time correction signal generation process is started for each detection signal from the tone decoder 3a, a plurality of generation processes are executed in parallel, and a time obtained from any one of these generation processes You may make it use a correction signal for time correction.

  For example, as shown in FIG. 5, the processing configuration includes timer processing 32, effective range setting processing 33, and effective range detection processing 34 shown in FIG. 3, and time correction signal generation processing 51 (51a, 51b, 51c and 51d indicate similar generation processes), and in the initial state of the time signal detection process, only one generation process 51a is executed as in the above embodiment, and the execution control process is performed each time a detection signal is received from the tone decoder 3a. 52 starts the generation process 51, which are executed in parallel, generate time correction signals for each of them, and synchronize the time correction signal first generated by the OR process 53 with the correct sound. To do.

  The execution control process 52 monitors the rise of the forecast sound flag of the forecast sound detection process 31a and starts the generation process 51 at each rise, for example, starts the generation processes 51b, 51c and 51d at every rise of the forecast sound flag. It is a process to make. In this way, the CPU 4 executes the generation processes 51a, 51b, 51c, and 51d in parallel. The number of generation processes 51 to be executed in parallel may be appropriately limited in consideration of the processing capability of the CPU 4. Each generation process 51 ends when the rising of the forecast sound flag or the correct sound flag is not detected in the effective range.

  The logical sum processing 53 sets a time correction flag used for time correction when the time correction flag is first set by any of the generation processes 51.

  Next, the operation of the time adjustment apparatus according to the embodiment that performs the processing shown in FIG.

  At the beginning of the time signal detection process, only the generation process 51a is performed as in the process shown in FIG. As shown in FIG. 4, an appropriate effective range is set if the detection signal initially used as the forecast sound is normal, but if not, the subsequent forecast sound and correct report sound cannot be detected. Therefore, in the time adjustment device of the present embodiment, the generation process 51 is newly started up by the execution control process 52 at the rise of the forecast sound flag. For example, the generation process 51b is started at the rise of the first forecast sound flag. At this time, in the generation process 51a, the timer process 32 is started, and an effective range of 1 second ± 100 milliseconds is set from the rise of the forecast sound flag at this time.

  When the second forecast sound flag rises, the generation process 51b starts the timer process 32 as the first forecast sound flag received by itself, and an effective range of 1 second ± 100 milliseconds from the rise of the forecast sound flag at this time is obtained. Is set. If the timing at which the second forecast sound flag rises is within the valid range previously set in the generation process 51a, the generation process 51a is continuously executed, and if it is not within the valid range, the generation process 51a ends.

  When the second forecast sound flag rises, the execution control process 52 newly starts the generation process 51c.

  When the third forecast sound flag rises, the generation process 51c starts the timer process 32 as the first forecast sound flag received by itself, and an effective range of 1 second ± 100 milliseconds from the rise of the forecast sound flag at this time is obtained. Is set. If the timing at which the third forecast sound flag rises is within the effective range previously set in the generation processes 51a and 51b, the generation processes 51a and 51b are continuously executed. .

  At this time, the generation processes 51a and 51b detect using the effective ranges of 1 second ± 50 milliseconds and 1 second ± 100 milliseconds from the previous rise of the forecast sound flag, respectively.

  When the third forecast sound flag rises, the execution control process 52 newly starts the generation process 51d.

  Now, the normal forecast sound is detected from the first time to the third time, and then the normal correct sound is detected. The generation process 51a sets the time correction flag when it detects the rising of the correct alarm sound flag within the effective range of 1 second ± 10 milliseconds from the previous rising edge of the predicted sound flag. The logical sum processing 53 uses this as a time correction flag synchronized with the time indicated by the time signal, for example, noon (12:00 p.m. 12 pm). This time correction flag corrects the time of the internal clock of the CPU 4 as in the above embodiment.

  For the above operation, if the first forecast sound flag is not due to a regular forecast sound but is caused by erroneous detection of noise as a forecast sound, the generation processing 51a is set based on the detection sound flag. The normal forecast sound flag may not be detected within the effective range, and the process may end. Even in this case, in the generation process 51b executed with the previous forecast sound flag, if the count process of the timer process 32 is started by the rise of the regular forecast sound flag, 1 second ± from the rise of the regular forecast sound flag Set an effective range of 10 milliseconds. As a result, in the generation process 51b, it is possible to detect the normal forecast sound flag following the previous normal forecast sound flag within the correctly set effective range.

  Similarly, if the first and second forecast sound flags are caused by erroneous detection, the generation processing 51a and 51b may not detect the regular forecast sound flag and may end. By the generation process 51c executed with the previous forecast sound flag, the regular forecast sound flag can be detected within the valid range set correctly.

  In this way, even if the forecast sound flag caused by false detection continues, the normal forecast sound flag that follows is used as the reference for setting the correct effective range in the last started generation process 51, and the generation that is started last. In the process 51, a normal forecast sound flag and a correct report sound flag can be detected, and a time correction flag can be generated.

  As described above, in the process of the time adjustment device shown in FIG. 5, an acquisition opportunity can be secured further than the processing of the time adjustment device time signal shown in FIG. 3 of the present embodiment, and high time correction accuracy is maintained. It becomes possible to prevent erroneous correction.

It is a block diagram which shows the circuit structure of the time correction apparatus concerning embodiment of this invention. It is a timing chart which shows the structure of the time signal which the time correction apparatus shown in FIG. 1 receives. It is a schematic diagram which shows the outline | summary of the time signal detection process of the time correction apparatus shown in FIG. It is a timing chart for description of operation | movement of the time correction apparatus shown in FIG. It is a schematic diagram which shows the outline | summary of the other time signal detection process of the time correction apparatus shown in FIG.

Explanation of symbols

3a tone decoder 3b tone decoder 4 CPU
31a Predictive sound detection processing 31b Corrective sound detection processing 32 Timer processing 33 Effective range setting processing 34 Effective range detection processing 51a to 51d Generation processing 52 Execution control processing

Claims (8)

In a time adjustment device that receives a radio wave superimposed with a time signal composed of a plurality of forecast sounds and correct sound and corrects the time based on the time signal,
A forecast sound detection means for outputting a first detection signal indicating that a forecast sound has been detected when a signal of a first frequency is detected in the signal obtained by receiving the radio wave;
Correct sound detection means for outputting a second detection signal indicating that a correct sound is detected when a signal of a second frequency is detected in the signal obtained by receiving the radio wave;
Based on the output timing of the first detection signal, a first effective range for determining whether the first detection signal next to the first detection signal is output at an appropriate timing The first effective range is set last, and the second effective range for determining whether or not the second detection signal following the first detection signal is output at an appropriate timing is set last. Effective range setting means for setting narrower than the effective range of,
The timing of receiving the second detection signal within the second effective range after sequentially receiving the plurality of first detection signals within the first effective range set by the effective range setting means Effective range detection means for outputting a time correction signal as the time indicated by the time signal;
With
A time adjustment device for performing time adjustment based on the output timing of the time adjustment signal. Timer means for starting a time measuring operation by the first detection signal;
The time adjustment device according to claim 1, wherein the effective range setting unit sequentially sets the first effective range and the second effective range based on the time measured by the timer unit. The timer means restarts time measurement every time the first detection signal is received,
The effective range setting means sets the effective range of the second first detection signal based on the time when the measurement was started upon receiving the first first detection signal,
When the second first detection signal is in the effective range, measurement is started in response to the second first detection signal, and the validity of the third first detection signal is based on time. A range is set, and when the third first detection signal is in the effective range, measurement is started in response to the third first detection signal, and the second detection signal is based on the time. The time adjustment device according to claim 2, wherein the effective range is set. A time correction program for causing a computer to execute a process for correcting a time based on a plurality of forecast sounds superimposed on radio waves and a time signal composed of correct sound sounds,
Output from the forecast sound detecting means for outputting a first detection signal indicating that a forecast sound has been detected when a signal of the first frequency is detected in the signal obtained by receiving the radio wave to the computer. A forecast sound detection process for monitoring the first detection signal;
Output to the computer from a correct sound detection means for outputting a second detection signal indicating that a correct sound is detected when a signal of a second frequency is detected in the signal obtained by receiving the radio wave. A correct sound detection process for monitoring the second detection signal,
Based on the output timing of the first detection signal, a first effective range for determining whether the first detection signal next to the first detection signal is output at an appropriate timing The first effective range is set last, and the second effective range for determining whether or not the second detection signal following the first detection signal is output at an appropriate timing is set last. Effective range setting processing to set narrower than the effective range of
The timing of receiving the second detection signal within the second effective range after sequentially receiving the plurality of first detection signals within the first effective range set by the effective range setting process An effective range detection process for outputting a time correction signal as the time indicated by the time signal;
And a time correction process based on the output timing of the time correction signal. A timer process for starting a time measuring operation by the first detection signal is executed;
The time correction program according to claim 4, wherein the effective range setting process sequentially sets the first effective range and the second effective range based on the time measured by the timer process. The timer process restarts time measurement every time the first detection signal is received,
The effective range setting process sets the effective range of the second first detection signal based on the time when the measurement is started upon receiving the first first detection signal, and the second effective range is set in the effective range. When there is a first detection signal, measurement is started upon receipt of the second first detection signal, the effective range of the third first detection signal is set based on time, and the effective range is set. When the third first detection signal is present, measurement is started in response to the third first detection signal, and the effective range of the second detection signal is set based on the time. The time correction program according to claim 5. The timer process, the effective range setting process and the effective range detection process are a set of generation processes for generating the time correction signal,
Each time the first detection signal is received, execution control processing for starting execution of the new generation processing is executed,
The time correction program according to any one of claims 4 to 6, wherein the time correction process is performed based on the output timing of the time correction signal output from any of the generation processes. The generation process uses the first detection signal received first after the execution is started as its first detection signal;
The time correction program according to claim 7, wherein the time correction process is performed based on an output timing of the time correction signal output first from any of the generation processes.