JP3264350B2 - Time generation device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time generator for generating a current time accurately synchronized with an absolute time by using a GPS (Global Positioning System) receiver, and a geophysical application system thereof.

[0002]

2. Description of the Related Art In geophysical exploration such as seismic and volcanic exploration, an artificial seismic source applies a seismic wave to the surface of the earth, which travels below the earth and is reflected by the difference in elastic impedance at the interface between various underground layers. Or it is refracted.
Detectors, called seismometers or geophones, located along the surface of the earth and / or in the borehole, generate analog electric seismic signals in response to the reflection and / or refraction of the seismic waves to be detected. Sampling, digitizing and recording seismic signals. The recorded seismic data is subsequently processed and analyzed to determine the nature and structure of the subsurface formation.

[0003] Various portable seismic exploration systems are known. The first type of portable seismic survey system uses a cableless seismic recording system, which digitally records seismic signals generated by seismometers or geophones, and is often used to do this. There is no need for conductor cables or other means such as wireless or wired telemetry to transmit seismic data to a central recording point.
The second type of portable seismic survey system employs various telemetry systems, which relay the acquired seismic data to a central recording point via a wireless communication link or fiber optic cable. Has become.

[0004]

However, in the seismic and volcanic exploration system, if it is possible to observe where and how the magma is moving in the volcanic body, it is possible to accurately predict an eruption or the like. However, the work of relaying volcanic bodies or the like on mountainous terrain with cables is enormous, dangerous and expensive, and the above-mentioned portable seismic exploration system of the second type is not practical. There is also a system for observation using a wireless communication link, but the wireless communication link device is generally transported and installed by a vehicle or the like because the entire device is large and heavy and consumes a large amount of power. However, the observation area is not always accessible from all directions of 360 ° by vehicle etc. due to topographical obstacles such as valleys and rivers, and the first type of portable earthquake / volcano exploration system that transports and installs observation equipment manually is adaptable. Generally, it is excellent in terms of cost, etc.

[0005] An example of an adaptive earthquake group recording apparatus as one of such portable earthquake exploration systems of the first type is described in Japanese Patent Application Laid-Open No. 62-162987. In this adaptive seismometer group recording device, the operating system is downloaded by an RF transceiver, and acquisition and processing of seismic signals are remotely controlled, but a plurality of adaptive seismometer group recording devices are operated simultaneously. In this case, there is a problem that the time cannot be easily and accurately adjusted because the physical distances of the respective adaptive seismograph group recording devices are independently set. The accuracy of the time adjustment directly affects the accuracy of distance measurement of magma and tomography. For example, if time adjustment is performed using a time signal of a broadcasting station, the conventional 10
It is extremely difficult to improve the accuracy within msec, and when the propagation speed of the seismic wave is 4-6 km / sec, a measurement error of 200-400 m cannot be avoided.

[0006] Between such distant points on the earth,
GPS is known as a system that accurately obtains each observation position and accurately corrects an absolute time common to the world. A time generating apparatus for generating a current time synchronized with an absolute time using a positioning GPS receiver is disclosed in
No. 0882. However, in the time generating device described in the above publication, the positioning GPS receiver is operated for 24 hours, and the internal counter is reset by the synchronization clock pulse output from the GPS receiver every second, so that the vehicle or It can be used in an environment where there is no inconvenience in power supply such as an office, but in an environment where power supply is limited such as a mountain area or a desert, the power consumption of a GPS receiver is about 1.
There was a problem that it could not be used easily because it was relatively large, around 5W.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to operate a GPS receiver in a low power consumption mode and to accurately synchronize with an absolute time with low power consumption. It is an object of the present invention to provide a time generating device for generating a current time and to provide a geophysical application exploration system thereof.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a time generator, and an object of the present invention is to provide a GPS receiver for extracting time data and a clock pulse synchronized with an absolute time from a GPS reception signal, and a predetermined frequency. An oscillator that generates a pulse signal at, a storage unit that stores the latest time data obtained by the GPS receiver as a reference time, a counter that counts a pulse signal obtained by the oscillator,
The count value of the counter is divided by the set frequency of the oscillator, and the result is added to the reference time stored in the storage means to obtain the current time, and the calculation means is coupled to the GPS receiver. A counter reset signal generating means for generating a reset signal for the counter by confirming that a clock pulse obtained by the GPS receiver is within a predetermined period of 10 μsec to 1 msec; At the time of resetting the counter, within the period of 10 μsec to 1 msec, and in synchronization with the absolute time, and the accuracy of the counter value measured by the counter is reset at the time of resetting the counter. This is achieved by performing time correction according to the frequency stability accuracy of the oscillator so as to fall within a predetermined accuracy range.

It is another object of the present invention to provide a GPS receiver for extracting time data and a clock pulse synchronized with an absolute time from a GPS reception signal, a pulse generation means for generating a pulse signal at a predetermined frequency, Reference time storage means for sequentially storing and updating the latest time data obtained by the receiver as a reference time, a counter for counting pulse signals obtained by the pulse generation means, and setting the count value of this counter to the pulse generation means. Calculating means for obtaining the current time by dividing the result by the frequency and adding the reference time stored in the reference time storing means to the result; and a clock coupled to the calculating means and the GPS receiver and obtained by the GPS receiver. A counter reset for generating a reset signal for the counter after confirming that a pulse is within a predetermined period. Power control means coupled to the signal generating means and the arithmetic means for controlling the power of the GPS receiver to be turned on and off, wherein the absolute accuracy of the counter value measured by the counter is within a predetermined accuracy range, GP
It is also achieved by intermittently supplying power to the S receiver and the counter reset signal generating means by the power control means.

[0010] The present invention also relates to a time generating method using a time generating device. The above object of the present invention is to provide a time generating device for extracting time data and a clock pulse synchronized with an absolute time from a GPS reception signal. A GPS receiver, an oscillator for generating a pulse signal at a predetermined frequency, storage means for storing the latest time data obtained by the GPS receiver as a reference time, and a counter for counting the pulse signal obtained by the oscillator. Divides the count value of the counter by the set frequency of the oscillator, adds the reference time stored in the storage means to the result, and obtains the current time, and is coupled to the calculation means and the GPS receiver. And confirming that the clock pulse obtained by the GPS receiver is within a predetermined period of 10 μsec to 1 msec. Counter reset signal generating means for generating a reset signal for the counter, a) extracting, by the GPS receiver, time data and a synchronous clock pulse synchronized with the absolute time from the GPS received signal, and storing the absolute time. B) a pulse measuring step of measuring a pulse signal from the oscillator with the counter; c) a synchronous clock pulse of the GPS receiving step and a pulse signal of the pulse measuring step by the counter of the counter. Even at the time of reset, within the period of 10 μsec to 1 msec unit,
In addition to synchronizing with the absolute time, time correction is performed in accordance with the frequency stability accuracy of the oscillator so that the accuracy of the counter value measured by the counter falls within a predetermined accuracy range even at the time of resetting the counter. And performing a time correction step.

Further, the above object of the present invention is to provide a GPS receiving step of extracting time data and a clock pulse synchronized with an absolute time from a GPS received signal, a pulse generating step of generating a pulse signal at a predetermined frequency, A reference time storage step of sequentially storing and updating the latest time data obtained in the step as a reference time, and counting a pulse signal generated in the pulse generation step by a counter, and counting the count value at a set frequency of the pulse generation step. Dividing the result to the reference time stored in the reference time storage step to obtain the current time, and confirming that the clock pulse obtained in the GPS reception step is within a predetermined period. A counter reset signal generating step of generating a reset signal of the counter; And a power control step of intermittently supplying power to activate the GPS receiving step and the counter reset signal generating step so that the absolute accuracy of the data value falls within a predetermined accuracy range. You.

The present invention further relates to an autonomous data recorder (ADR) for acquiring, processing and storing sensor output signals from a sensor. B) a time generation device; b) a first solid-state memory; c) electronically downloading a plurality of operating programs provided in the ADR and providing a menu of recording device operating parameters to the first solid-state memory of the ADR. And d) selecting a set of recording device operation parameters from the menu of recording device operation parameters provided by the operating program in response to the absolute time of the time generation device. Processing means for obtaining and processing said sensor signal by means of: e) obtaining from said processing means It is achieved by autonomous data recording apparatus and equipped with second solid state memory for storing sensor data processed.

[0013] The present invention also relates to a physical exploration method for acquiring, processing, storing and integrating sensor signals by an autonomous data recording device arranged at spatially different points. The above objects are as follows: a) Receive absolute time from a GPS reception signal, manage absolute time accuracy, select a set of recording device operation parameters from a menu of recording device operation parameters provided by a resident operating program, and wait. B) obtaining and processing, together with absolute time, sensor signals generated by at least one sensor electronically coupled to each autonomous data recording device according to the selected set of recording device operating parameters; C) The sensor signal recorded in each of the autonomous data recording devices is transferred to the integrated processing device, and the spatial characteristics of the sensor signal are transferred. Also achieved by providing a step of analyzing.

Still another object of the present invention is to: a) receive a spatial position and an absolute time from a GPS reception signal, manage the absolute time accuracy, and select one from a menu of recording device operating parameters provided by a resident operating program. Selecting and waiting a set of recording device operating parameters; b) sensors generated by at least one sensor electronically coupled to each autonomous data recording device according to the selected set of recording device operating parameters. C) obtaining and processing the signal together with the spatial position and the absolute time; c) transferring the sensor signal recorded in each of the autonomous data recording devices to the integrated processing device and analyzing the spatio-temporal characteristics of the sensor signal It can also be achieved by a geophysical survey method.

The present invention also relates to a geophysical exploration system for acquiring, processing, storing and integrating sensation signals by autonomous data recording devices arranged at spatially different points. The above objects are as follows: a) parameter selection setting means for selecting and setting a set of recording device operation parameters from a menu of recording device operation parameters provided by an operating program for each of the autonomous data recording devices; An autonomous data recording device for acquiring, processing and storing sensor signals generated by at least one sensor electronically coupled according to a selected set of recording device operating parameters, together with an absolute time obtained from a GPS reception signal; C) inputting the sensor signal recorded in each of the autonomous data recording devices, and applying the space / time of the sensor signal It is achieved by providing an integrated processing means for analyzing the properties.

Still another object of the present invention is a physical exploration system for acquiring, processing, storing, and integrating sensor signals by an autonomous data recording device deployed in an area of interest in geophysical exploration. B) parameter selection and setting means for selecting and setting a set of recording device operation parameters from a menu of recording device operation parameters provided by an operating program for each of said autonomous data recording devices; An autonomous data recording device for acquiring, processing and storing sensor signals generated by at least one sensor electronically coupled according to a set of recording device operating parameters, together with spatial position and absolute time obtained from a GPS received signal; C) inputting the sensor signal recorded in each of the autonomous data recording devices, and Also achieved by providing an integrated processing means for analyzing during / temporal characteristics.

[0017]

According to the time generator of the present invention, the power supply to the GPS receiver is stopped except during the time correction, so that the absolute time correction can be performed with low power consumption. Therefore, if the batteries have the same capacity, seismic data for a longer time can be recorded, and the weight of the portable data recording device can be significantly reduced. Further, since the time is corrected using the GPS time calibration system, the time can be corrected in units of 10 μsec to 1 msec, and the measurement accuracy of the physical exploration can be drastically improved.

[0018]

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

FIG. 1 shows an example of a hardware configuration of a time generator according to the present invention. A GPS signal received by a GPS antenna 2 is sent to a GPS receiver 4. This G
The PS receiver 4 detects and outputs positioning data from the input GPS signal, and can extract only the time data TD based on the absolute time included in the positioning data. , GPS pulse) CP is reproduced and output. These positioning data, time data TD, and GPS pulse CP are sent to a time correction unit including a microprocessor (hereinafter, MPU) 10 and the like.

The time correction unit includes an MPU 10, an oscillator 6, a counter and a timer module 8 (one or a plurality of counters or timers are incorporated together with a logic circuit), a counter reset means 12, a storage means 14, and an input / output control. It is composed of a unit 16. GPS pulse CP is M
The signal is sent to the PU 10 and is also input to one terminal of an AND gate constituting the reset means 12, and the other input terminal is connected to a control signal XG output from the MPU 10. The output R of the reset means 12
ST is connected to a reset terminal of the clock counter 8 so that the clock counter 8 is directly reset by hardware.

On the other hand, the oscillator 6 generates a constant frequency signal, and serves as an oscillation source of the timer 8. The accuracy of the time calibration process described later is determined by the accuracy of the frequency.
It is desirable that the accuracy is as high as possible. For example, a crystal oscillator with temperature compensation is suitable. The timer / counter module 8 operates not only as a counter for counting the output signal of the oscillator 6 but also as a timer according to the setting conditions from the MPU 10.
1, 2, 5, 10, 20, 50, 10 with 10 setting conditions
It is preferable that the configuration is such that an interrupt clock of 0, 200, 500, 1000, 2000, 5000 milliseconds can be appropriately selected and output. The time counter 8 counts a clock having a set frequency based on the output signal of the oscillator 6 and outputs the clock to the MPU 10 in parallel.
While U10 is in the power saving mode while the function is stopped, it operates independently as a timer for measuring the function stop period.

The MPU 10 inputs the pulse count value from the counter 8 in parallel, activates the time calibration processing routine shown in FIG. 3 using the GPS pulse CP as an interrupt input, updates the reference time, and obtains the current time. The current time data is stored in the storage unit 14 and output to the outside via the input / output control unit 16.

The operation of such a configuration will be described with reference to the time chart of FIG. 2 and the flowchart of FIG.

In the GPS system, as shown in FIG. 2A, the clock pulse CP obtained by the GPS receiver 4 is reproduced in synchronization with the absolute time, and is normally reproduced and output at one second intervals. . The time data TD is also updated every second in a normal state. However, if there are tall trees above the GPS antenna 2 or if the state of the ionosphere changes suddenly due to sunspot activity of the sun, the clock pulse CP cannot always be reliably reproduced at one-second intervals every time.

In the time correction section, the processing shown in FIG. 3 is executed by the MPU 10 to calibrate the time data TD.
Find the reference time and the current time. First, the clock pulse CP output from the GPS receiver 4 at time t1 in FIG. 2A is input to the MPU 10 (step S2). Then, the MPU 10 outputs the next output clock pulse CP.
Is checked during the period t2 as shown in FIG.
After the elapse of the period, the software mono-multi routine is activated to be at the low level for the period t3 (step S3).
8), the latest time data TD output from the GPS receiver 4 is read at the timing shown in FIG. 2D (step S6).

In the example of FIG. 2A, however, the next CP pulse has not arrived within the predetermined period t3 (step S8), the process returns to step S2, and the CP output from the GPS receiver 4 is returned. Waits for pulse input. And FIG.
When the CP pulse is output again at time t4 in (A), the software mono-multi routine is activated again so as to be at the low level during time period t3 after the time period t2 has elapsed (step S8), and FIG. ), The latest time data TD output from the GPS receiver 4 is read into the MPU 10 (step S6).

Next, this time, the next CP pulse is output from the GPS receiver 4 during the check period t3 (step S8), so that only the timer 8 through the reset means 12 causes the CP pulse to rise. In addition to the hardware reset at the falling timing, the time data read in step S6 is adjusted to a time obtained by rounding down the time of seconds or less, and then one second is added and stored as a reference time (step S6).
10). For example, if the time input in step S6 is 0: 0
If the time is 1: 02.03 seconds, the reference time is 0:01:
03.00 seconds.

Thus, when the update of the reference time is completed,
It is checked whether or not there is another process such as sensor input (step S12), and if not, the process returns to step S2. On the other hand, if there is another process, the following formula is calculated from the updated reference time (second) and the count value (N) of the counter 8 to obtain the current time (second), and then another process is executed ( Step S1
4).

[0029]

## EQU1 ## Current time (second) = reference time (second) + count value (N) / timer frequency (Hz) The timer frequency (Hz) is the set frequency of timer 8, and if the timer frequency is 1000 Hz, Resolution is 1
Milliseconds.

Therefore, the time generating device having the above configuration has
Check the CP pulse interval output from the GPS receiver 4 to reset the time counter / timer,
The hardware counter and the software absolute time are updated at the same time when the check CP pulse arrives. Therefore, even if the current time is read at any time by the timer service routine, the current time synchronized with the absolute time can be accurately calculated. Can be answered. In addition, since the current time is obtained by decomposing the interval of the reset pulse RST generated from the CP pulse at a fixed frequency and adding it to the reference time, the current time with high accuracy synchronized with the absolute time is calculated. You can also get.

FIG. 4 corresponding to FIG. 1 shows another embodiment of the time generating apparatus according to the present invention, wherein the devices having the same numbers perform the same functions, respectively.
Power supply means 4 for GPS receiver 4 and digital circuit 20
2a and 42b are provided, and when not in use, the power of the battery 30 is turned on via the power control means 40 coupled to the MPU 10.
The power consumption of the battery 30 is reduced by performing the -OFF control. This is usually the digital circuit 20 and MPU10
Is 40 mA, the transmitter 6 and the counter module 8 are 2 m
For the power consumption of about A, the GPS receiver 4 is 300 mA
Power consumption is very large (the power supply voltage of each device is 5
V is assumed, but if the power supply voltage can be set to around 3 V, it is clear that the power consumption can be further reduced. ), GPS immediately after the absolute time synchronization is completed
Turning off the power of the receiver 4 can greatly reduce the consumption of the battery, and is particularly useful as a time generator for a portable device.

The operation of the time generator shown in FIG. 4 will be described with reference to the flowchart shown in FIG. 5. First, the MPU 10 inputs the approximate current position and the absolute time obtained by another means to the GPS receiver 4. , By performing the same processing as in FIG. 3 to obtain accurate positioning data of the current position,
Synchronize with the GPS absolute time (step S20).

Then, when the CP pulse is input from the GPS receiver 4 during the next CP pulse reception check period t3 shown in FIG. 2B, the GPS time data + 1 is updated and stored in the storage means 14 as a reference time. At the same time, it immediately outputs a power-off command PG1 of the GPS receiver 4 to the power control means 40 (step S22). Further, the next power-on time is calculated (for example, 0.1 ppm) according to the frequency stability accuracy (for example, 0.1 ppm to 10 ppm) of the oscillator 6.
It is sufficient to turn on the power after 150 minutes for accuracy, or 100 seconds for 10 ppm accuracy, or usually at 3 to 6 hour intervals with 1 ppm accuracy. ), The next power-on interrupt occurrence time is set in the MPU activation timer 8 of the timer, and the power of the digital circuit 20 is also turned off via the power control means 40 (step S22). Thereafter, the MPU 10 shifts to the power saving mode (Step S24). In this state, since only the oscillator 6 and the counter module 8 are operating,
The power consumption can be reduced to about 2 mA, less than 1/150.

Thus, when the above-described power-on time is reached, a timer interrupt is generated from the timer 8, and the MPU 10 is restarted (step S26). When the MPU 10 is restarted, first, the power of the digital circuit 20 and the power of the GPS receiver 4 are turned on again via the power control means 40 (step S28). Subsequently, the MPU 10 waits for input of a CP pulse from the GPS receiver 4 (step S30). When the CP pulse arrives, the MPU 10 activates a software mono-multi routine for checking a time interval until the next CP pulse arrives. Time data TD from GPS receiver 4
Is output (step S32), this GPS
The time data is read into the MPU 10 (step S34).

Thus, when the next CP pulse arrives within the predetermined check period t3 (step S36), the time counter of the counter module 8 is reset by hardware via the reset means 12, and counting is started again. At the same time, the power supply to the GPS receiver 4 is immediately cut off from the MPU 10 via the power control means 40, and the GPS time data +1 read in step S34 is updated and stored in the storage means 14 as a reference time (step S3).
8).

Subsequently, it is checked whether or not there is another process (step S40). If there is, the current time is calculated from the reference time and the counter value, and another process such as sensor input is executed (step S42). ). Thereafter, similarly to step S22, the next power-on time is calculated and the timer 8 is turned on.
After the restart timer is set, the power supply to the digital circuit 20 is cut off (step S44).
Then, the process proceeds to the power saving mode of the MPU 10.

Thereafter, the processing of steps S24 to S44 is repeated. Such a power control means makes it possible to maintain the absolute time synchronized with the GPS absolute time with high accuracy and for a long time with minimum power consumption, and in particular, a time generation method effective in a portable device having a limited battery capacity. It is.
It should be noted that in the above-described flowchart, G in step S28
The period from turning on the power to the PS receiver to turning off the power to the GPS receiver in step S38 is usually about 30 seconds to 2 minutes.

Next, an example in which the time generator is applied to geophysical exploration will be described. FIG. 6 is an example of a structure exploration of a volcanic body, in which an artificial earthquake is generated by dynamite 100a, 100b or the like, and this seismic wave is recorded at a large number of observation points (200a to 200m) spatially dispersed in advance, and later recorded. This record data is collected and analyzed to calculate the underground structure of magma and volcanic bodies. However, in order to set the observation points as uniformly as possible in a complex volcanic area, the machine must be transported manually, and a small, lightweight, low-power portable high-precision recording device must be provided. There is.

FIG. 7 corresponding to FIG. 4 is an example of such a portable autonomous data storage device 200a. Devices assigned the same numbers perform the same functions, respectively.
Preamplifiers 52a to 52m, reduction filters 54a to 54
m, an analog circuit 50 composed of a multiplexer 56 and an AD conversion means 58 are coupled to the MPU 10, and its power is controlled on / off by a control signal PGk output from the power control means 40. The input means 70 displayed on the configured display means 20b
The user selects / sets various parameters via the. The preamplifiers 52a to 52m are connected to seismic sensors 60a to 60c and temperature sensors.

The operation of such a configuration will be described with reference to FIGS. 8 to 10. First, measurement conditions such as a sensor are downloaded to the data recording device 200a or the display means 20b and the input means 70 are operated. Initial settings are made (step S60 in FIG. 8). When the vehicle arrives at each observation point, the approximate spatial position and absolute time are input to the MPU 10 via the download data or the input unit 70,
These data are transferred to the GPS receiver 4, and the same processing as the flowchart of FIG. 3 is executed to read out the accurate positioning data of the current position from the GPS receiver 4, and the GPS absolute time and the GPS clock pulse CP are used. Are synchronized (step S60).

Thus, when the initialization is completed, the MPU
10 outputs a command to turn off the power of the GPS receiver 4 and the analog circuit 50 to the power control means 40, and then sets the next power-on time for time correction to the restart timer of the timer 8, and sets the digital circuit 20 a And 20b are cut off (step S62).

Thereafter, the MPU 10 shifts to the power saving mode (step S64). In this state, only the oscillator 6 and the counter module 8 are operating, so that the current consumption can be greatly reduced.

When the above-described power-on time is reached,
A timer interrupt is generated from the timer module 8 and the MPU 1
0 is restarted (step S66). When the MPU 10 is restarted, it first determines whether the cause of the restart is for time correction, sensor measurement at a specified time, or another process. Then, in the case of the restart for the GPS time correction (step S68), the digital circuit 20a and the GPS receiver 4 are turned on, and the GPS time correction processing similar to steps S28 to S38 in FIG. 5 is performed (step S68). Step S70), and proceed to step S84.

In the case of the sensor measurement at the designated time (step S72), first, the power supply of the digital circuit 20a and the analog circuit 50 is turned on, and then the preamplifier, the filter, the AD conversion parameters and the like are read from the storage means 14, Each is set in a predetermined register or the like (step S
74). Thereafter, the counter 8 is monitored until the designated time (step S76). When the designated time comes, the current time is calculated from the reference time and the counter value and stored in the storage means 14, and the outputs of the sensors 60a to 60m are sequentially output. The data is digitized by the A / D conversion means 58 and stored in the storage means 1
4 is written only a predetermined number of times.

FIGS. 9A to 9F and FIG.
0 will be described in more detail with reference to FIG.
As shown in (A), the standby mode and the recording mode are switched and executed, and during that time, the GPS is executed at a time shortly before the accuracy of the oscillator 6 becomes lower than the predetermined accuracy.
The power is re-supplied to the receiver 4 so that the absolute time accuracy is controlled to be always within a predetermined accuracy range (FIG. 9).
(B)). In the standby mode, the power supply control means 4 cuts off the power supply of the analog circuit 50, the digital circuit 20a and the MPU 10 in order to reduce power consumption, and supplies power to each device only when necessary for recording.
0 controls the power supply of each device finely. In the recording i sampling mode, the MPU 10 is restarted at time t30 in FIG. 9C to supply power to the digital circuit 20a and the analog circuit 50, and the multiplexers 56 are sequentially switched in the order specified by the parameters. A / D conversion and sensor output 6
0a to 60m are sequentially digitized (FIG. 9D). Further, the above-mentioned AD conversion data is written in the storage means 14 in a format as shown in FIG. 10 from a pre-trigger start time t31 before the measurement start designated time t32 (FIGS. 9E and 9F). ).

That is, as the i-th data recorded,
Measurement position, measurement time, preamplifier gain, filter condition, AD conversion condition, pretrigger period (window period), external amplifier gain, temperature / humidity, and A of each sensor
A memory that has a D-converted value or the like and is preferably a memory such as a flash memory or a RAM with a built-in battery that does not lose its stored contents when the power is turned on and off.

Thus, when the sensor measurement at the designated time is completed, the power supply of the analog circuit 50 is cut off (step S78), and the process proceeds to step S84.

When other processing such as downloading of the system, transfer of the recording data to the outside, execution of the test program, parameter setting, etc. is executed (step S8).
0), power is supplied only to each necessary device, and each process is executed (step S82).

Further, in step S84, the next GPS time correction start time is compared with the start time of the record i, and the earlier time is set as a restart timer of the timer 8, and the digital circuit 20a The power supply is cut off (step S84).

Incidentally, as shown in FIG.
An antenna having a solar cell panel 1 attached to the periphery thereof is prepared, and the battery 30 is charged by the solar cell panel 1 while the GPS antenna 2 is exposed to the sun, so that the battery life can be further extended. .

On the other hand, the programming structure of the data recording device 200a will be described with reference to FIG. 12. An operating operating program 500 and a downloadable algorithm 510 created by a personal computer (not shown) are stored in a ROM via the input / output control means 16. The data is once read into the buffer memory 420 under the control of the MPU operating program 410 written in, for example, and written to a predetermined address in a flash memory or the like. The sensor outputs sampled in each recording mode are sequentially written to the sensor data memory 600. With such a programming structure,
This is very convenient because data settings to the operation menu and filter algorithms can be easily changed without changing any hardware configuration.

Further, when a plurality of the above-mentioned data recording devices are dispersedly installed on a long bridge, a super-large tanker or a large building and the output of the acceleration sensor synchronized with the absolute time is recorded, a cable laying operation for data collection is unnecessary. Thus, it is possible to easily perform a vibration analysis confirmation operation such as a structural design. Further, by recording the output of the geomagnetic sensor together with the absolute time at the south pole / north pole, etc., it can be useful for the analysis of the aurora phenomenon. Furthermore, one of the above-mentioned data recording devices is fixed to the ground to measure the vibration, and the other data recording device is fixed to a moving body such as a car, and the vibration of the ground and the vibration of the car are simultaneously measured based on the absolute time. By measuring, it is also possible to determine the transfer function between the moving object and the ground,
Various vibration measurements, which were not possible before, can be easily realized.

[0053]

As described above, according to the time generator of the present invention, accurate correction of the absolute time can be realized with low power consumption. In addition, since time correction with a higher precision of one digit can be realized as compared with the conventional method, the accuracy of the physical search can be further improved. Furthermore, since the vibration measurement based on the absolute time can be performed independently for the moving object and the ground,
A transfer function between the moving object and the ground, which could not be measured conventionally, can be easily calculated.

[Brief description of the drawings]

FIG. 1 is a hardware block diagram showing an embodiment of a time generating device according to the present invention.

FIG. 2 is a time chart for explaining the operation.

FIG. 3 is a flowchart for explaining the operation.

FIG. 4 is a hardware block diagram showing an embodiment of another time generating device according to the present invention.

FIG. 5 is a flowchart showing the operation.

FIG. 6 is a diagram for explaining the principle of volcanic exploration.

FIG. 7 is a diagram showing an example of a hardware configuration of a data recording device of the present invention.

FIG. 8 is a flowchart for explaining the operation.

FIG. 9 is a time chart for explaining the operation.

FIG. 10 is an example of a recording format of a reading device.

FIG. 11 is an example of a GPS antenna for both charging and use according to the present invention.

FIG. 12 is a diagram for explaining a program structure of the data recording device of the present invention.

[Explanation of symbols]

 2 GPS antenna 4 GPS receiver 6 Oscillator 8 Timer / counter module 10 MPU 12 Reset means 14 Storage means 16 Input / output control means 20, 20a Digital circuit 20b Display means 30 Battery 40 Power control means 50 Analog circuit 60a-60m Sensor 70 Input means 100, 100a Time generator 200a, 200n Data recorder

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G04G 5/00 G04G 7/02 G04G 1/00 G01V 1/24 G01D 9/00

Claims (29)

(57) [Claims] 1. A time generator, comprising: a GPS receiver for extracting time data and a clock pulse synchronized with an absolute time from a GPS reception signal; an oscillator for generating a pulse signal at a predetermined frequency; Storage means for storing the latest time data obtained in the above as a reference time; a counter for counting pulse signals obtained by the oscillator; a count value of the counter divided by a set frequency of the oscillator; Calculating means for obtaining the current time by adding the reference time stored in the GPS receiver, and a clock pulse obtained from the calculating means and the GPS receiver, which is obtained by the GPS receiver within a predetermined period of 10 μsec to 1 msec. Counter reset signal generating means for generating a reset signal for the counter after confirming that the At the time of resetting the counter, the current time of the generator is synchronized with the absolute time within a period of 10 μsec to 1 msec, and the accuracy of the counter value measured by the counter is determined at the time of resetting the counter. However, the time generator performs time correction according to the frequency stability accuracy of the oscillator so as to fall within a predetermined accuracy range. 2. A time generator for acquiring and recording sensor signals from at least one sensor, comprising:
A GPS receiver that extracts time data and a clock pulse synchronized with an absolute time from a PS reception signal, an oscillator that generates a pulse signal at a predetermined frequency, and stores the latest time data obtained by the GPS receiver as a reference time And a counter for counting the pulse signals obtained by the oscillator, and dividing the count value of the counter by the set frequency of the oscillator, and adding the reference time stored in the storage unit to the result to obtain the current time. And a clock pulse which is coupled to the arithmetic means and the GPS receiver and which is obtained by the GPS receiver is 10 μs
c a counter reset signal generating means for generating a reset signal for the counter after confirming that the time is within a predetermined period of 1 to 1 msec. However, within a period of 10 μsec to 1 msec unit, and in synchronization with the absolute time, so that the accuracy of the counter value measured by the counter is within a predetermined accuracy range even at the time of resetting the counter, A time generator that corrects the time according to the frequency stability accuracy of the oscillator, further acquires the sensor signal together with the current time synchronized with the absolute time, and records the acquired signal in the storage unit. . 3. A power supply control means coupled to said calculation means for controlling on / off of the power of said GPS receiver, so that the accuracy of a counter value measured by said counter falls within a predetermined accuracy range. 3. The time generation device according to claim 1, wherein the power supply unit intermittently supplies power to the GPS receiver and the counter reset signal generation unit. 4. When the power of the GPS receiver and the counter reset signal generating means is turned off by the power control means, the time until the next power-on control is set in the counter. 4. The time generating device according to claim 3, wherein the arithmetic unit is made to stand by in a power saving mode during a lapse of time. 5. The time generating device according to claim 1, wherein a spatial position of the time generating device is recorded from the GPS receiver. 6. The oscillator according to claim 1, wherein said oscillator has a frequency stabilization accuracy of 0.1.
The time generator according to any one of claims 1 to 5, wherein the accuracy is 1 ppm to 10 ppm. 7. The time generator according to claim 3, wherein the power-off control period of the GPS receiver is 100 seconds to 6 hours. 8. The time generator according to claim 1, wherein the oscillator is a temperature-compensated oscillator. 9. The time generating device according to claim 1, wherein a power source of the time generating device is constituted by a rechargeable battery. 10. The time generator according to claim 9, wherein the battery is charged by a solar battery. 11. A GPS connected to the GPS receiver
The time generating device according to any one of claims 1 to 10, wherein the antenna also has a solar cell. 12. The flash memory according to claim 12, wherein:
12. The time generation device according to claim 1, wherein the time generation device comprises a semiconductor RAM memory backed up by a battery. 13. The time generation device according to claim 1, wherein the time generation device is a portable time generation device. 14. The method according to claim 1, wherein the counter is 1, 2, 5, 10,
20, 50, 100, 200, 500, 1000, 20
14. The time generating device according to claim 1, wherein a clock of 00 or 5000 milliseconds can be output. 15. The time generator according to claim 2, wherein the sensor is an acceleration sensor, a magnetic sensor, a seismometer, or a geophone. 16. A recording position, a measurement time, a preamplifier gain, a filter condition, an AD
The time generating device according to any one of claims 2 to 15, wherein the time generating device includes a conversion condition, a pre-trigger period, a window period, an external amplifier gain, temperature / humidity data, or an AD conversion value of each sensor. 17. A time generation method using a time generation device, wherein the time generation device extracts time data and a clock pulse synchronized with an absolute time from a GPS reception signal.
A receiver, an oscillator for generating a pulse signal at a predetermined frequency, storage means for storing the latest time data obtained by the GPS receiver as a reference time, and a counter for counting the pulse signal obtained by the oscillator, Calculating means for dividing the count value of the counter by the set frequency of the oscillator and adding a reference time stored in the storage means to the result to obtain a current time;
And a counter reset signal generating means for generating a reset signal for the counter after confirming that a clock pulse obtained by the GPS receiver is within a predetermined period of 10 μsec to 1 msec. A) a GPS receiving step of extracting time data and a synchronous clock pulse synchronized with an absolute time from a GPS received signal by the GPS receiver and storing the absolute time; b) a pulse signal from the oscillator C) measuring the synchronous clock pulse in the GPS receiving step and the pulse signal in the pulse measuring step within a period of 10 μsec to 1 msec even at the time of resetting the counter.
While synchronizing with the absolute time, time correction is performed according to the frequency stability accuracy of the oscillator so that the accuracy of the counter value measured by the counter falls within a predetermined accuracy range even at the time of resetting the counter. And a time correcting step of performing the following. 18. A time generating method using a time generating device for acquiring and recording a sensor signal from at least one sensor, wherein the time generating device converts time data and absolute time from a GPS reception signal. GPS for extracting synchronized clock pulses
A receiver, an oscillator for generating a pulse signal at a predetermined frequency, storage means for storing the latest time data obtained by the GPS receiver as a reference time, and a counter for counting the pulse signal obtained by the oscillator, Calculating means for dividing the count value of the counter by the set frequency of the oscillator and adding a reference time stored in the storage means to the result to obtain a current time;
And a counter reset signal generating means for generating a reset signal for the counter after confirming that a clock pulse obtained by the GPS receiver is within a predetermined period of 10 μsec to 1 msec. A) a GPS receiving step of extracting time data and a synchronous clock pulse synchronized with an absolute time from a GPS received signal by the GPS receiver and storing the absolute time; b) a pulse signal from the oscillator C) measuring the synchronous clock pulse in the GPS receiving step and the pulse signal in the pulse measuring step within a period of 10 μsec to 1 msec even at the time of resetting the counter.
While synchronizing with the absolute time, time correction is performed according to the frequency stability accuracy of the oscillator so that the accuracy of the counter value measured by the counter falls within a predetermined accuracy range even at the time of resetting the counter. And d) obtaining the sensor signal together with the current time synchronized with the absolute time, and recording the sensor signal in the storage means. 19. The GPS device coupled to the arithmetic means,
The GPS receiver and the counter reset signal generation unit further include a power supply control unit that controls on / off of a power supply of the receiver so that an accuracy of a counter value measured by the counter falls within a predetermined accuracy range. 19. The time generation method according to claim 17, further comprising a GPS power control step of intermittently supplying power by the power control means. 20. The power supply control means, wherein the GPS
When the power supply of the receiver and the counter reset signal generation means is controlled to be turned off, the time until the power supply is next controlled to be turned on is set in the counter. 20. The time generating method according to claim 19, further comprising the step of waiting. 21. The time generating method according to claim 17, further comprising a step of recording a spatial position of the time generating device from the GPS receiver. 22. The oscillator according to claim 19, wherein the oscillator has a frequency stability accuracy,
The time generating method according to any one of claims 17 to 21, wherein the accuracy is 0.1 ppm to 10 ppm. 23. The power-off control period of the GPS receiver is 100 seconds to 6 hours.
The time generation method according to any one of the above items. 24. The time generating method according to claim 17, wherein the oscillator is a temperature-compensated oscillator. 25. The time generating method according to claim 17, wherein a power source of the time generating device is constituted by a rechargeable battery. 26. The storage device, comprising: a flash memory;
26. The time generating method according to claim 17, wherein the time generating method comprises a semiconductor RAM memory backed up by a battery. 27. The time generating method according to claim 17, wherein the time generating device is a portable time generating device. 28. The sensor according to claim 18, wherein the sensor is an acceleration sensor, a magnetic sensor, a seismograph, or a geophone.
The time generation method according to any one of the above. 29. A recording position, a measuring time, a preamplifier gain, a filter condition, an AD
The time generating method according to any one of claims 18 to 28, comprising a conversion condition, a pre-trigger period, a window period, an external amplifier gain, temperature / humidity data, or an AD conversion value of each sensor.