JP3241486B2 - Measurement seismic intensity meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring seismometer having a function of measuring a seismic intensity due to an earthquake, collecting information on temporal shaking, and issuing an early warning.

[0002]

2. Description of the Related Art In order to mechanize seismic intensity judgment based on bodily sensation, the administrative agency (the Meteorological Agency) works to formulate the human bodily sensation (algorithmization). From fiscal year, a certification system was established to certify seismic intensity meters that meet these criteria. As a result,
By installing it in many local governments and public facilities, it has become possible to take further measures against regional earthquakes.

According to a method of determining a seismic intensity based on such a development standard (hereinafter referred to as a development standard seismic intensity), a maximum value of a shaking acceleration (unit, gal) measured during one minute including an earthquake continuation period. the a _max, so that should be established based on seismic a calculated value I _max by substituting the equation river angle (1) are stipulated, the research and development of seismic intensity meter which satisfies such criteria are made Was.

I _max = 2 × log (a _max ) +0.7 (1)

[0005]

By the way, the criterion for determining the seismic intensity described above, that is, "the maximum value of the sway acceleration measured during one minute including the duration of the earthquake is calculated by the equation of river angle (1).
In the conventional measurement seismograph satisfying the criterion on the need for a seismic "the calculated value I _max by substituting the,
Measure and store the acceleration data for one minute from the time when the shaking due to the earthquake was detected, and after one minute, determine the maximum value of the acceleration and substitute it into the equation (1) of the river angle to calculate the seismic intensity and generate an alarm signal and It was configured to output at the same time.

However, most frequent earthquakes are several tens.
Since the process is completed in seconds, there is a problem that if a warning is issued after a lapse of one minute, the warning is meaningless, and this is a serious problem particularly in the case of a large earthquake.

The present invention solves such a conventional alarm delay, and realizes a seismic intensity meter capable of providing early warning and seismic intensity information while satisfying the above-mentioned standard of seismic intensity. Aim.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an acceleration sensor which measures a swing acceleration in synchronization with a predetermined sampling frequency to generate acceleration data. The acceleration data output from the storage unit is stored in the storage unit one by one, and the determination unit determines that the time when the acceleration data exceeds a preset threshold is the earthquake occurrence time. Calculating a short-period seismic intensity based on the maximum value of the acceleration data group before the first predetermined period (for example, 10 seconds) before the time and generating alarm information;
Furthermore, a second predetermined time (for example,
Each time (one second) elapses, the process of calculating the short-term seismic intensity based on the maximum value of the acceleration data group before the first predetermined period is performed based on the earthquake occurrence time or a predetermined third period (for example, (At least for a period of at least 60 seconds), and the maximum value of the plurality of short-term seismic intensities obtained in the third period is set as the determined reference seismic intensity.

[0009] In addition, a display unit is provided for displaying a short-term seismic intensity and generating an alarm in synchronization with the calculation unit obtaining a short-term seismic intensity every time the second predetermined time elapses.

[0010] The acceleration data is data of components in at least two horizontal directions of east-west and north-south.

[0011]

According to the present invention having such a configuration, since the seismic intensity information and the warning information are issued for a short period of time immediately from the detection time of the occurrence of the earthquake, a highly reliable early warning can be realized. In addition, since the short-term seismic intensity is repeatedly obtained for a period of at least 60 seconds from the time of the earthquake occurrence, and the maximum value of the plurality of short-term seismic intensity is set as a reference seismic intensity, it is possible to provide seismic intensity information compliant with the standard. it can.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a measuring seismometer according to the present invention. First, the external configuration will be described with reference to FIG. 1. The minimum system configuration of this seismic intensity meter is as follows.
The main body 1 of the seismic intensity meter and the amplitude of the tremor are represented by three directions of acceleration data A _EW (t) and A _NS (East-West (EW), North-South ( _NS ), and _Up -Down (UD) directions. t) and A _UD (t). Further, by connecting the optional external display device 3 to the main body 1 via a transmission line or the like, a system capable of performing an earthquake warning even in a place away from the main body 1 can be realized. In addition to the external display device 3, it has a function of connecting to various measuring instruments on the market and transmitting data to a public telephone line.

Further, acceleration data A _EW (t) and A _NS transmitted from the acceleration sensor 2 are provided on a panel portion of the main body 1.
(t), and a relatively small printer unit 4 made of a thermal printer or the like over time analog record A _UD (t), the established with reference seismic I _max information the numerical display of the further within 1 minute each fine period (in this example, every 1 second) seismic intensity obtained in (hereinafter, short-term seismic intensity of) I sequentially histogram displays and the liquid crystal display unit 5 for to numeric display an earthquake occurrence time t _g And operation switches 6 for the user to input various control commands and menu settings, and acceleration data A _EW (t) and A _NS (A) to external recording media such as an IC memory card or a floppy disk inserted by the user. t), A
An external storage unit 7 for storing _UD (t) and data of the standard seismic intensity and the short-term seismic intensity is provided.

[0014] the external display device 3 includes a high-luminance display unit 8 for numerically displaying the development reference seismic intensity I _max and earthquake occurrence time t _g of body 1 is analyzed, sound device such as a speaker for alarm 9
Is provided.

FIG. 2 shows the internal system configuration of the main body 1.
The description will be based on a 16-bit microprocessor (MP) that monitors the occurrence of an earthquake and performs analysis processing after the occurrence of the earthquake.
U) 10 is built in, and an internal bus (address, data, control bus, and other buses necessary for the system) 11 centered on the MPU 10 is an operation panel to which the liquid crystal display unit 5 and the operation switch group 6 are connected. Interface circuit 12, a time signal detection circuit 14 for forming data of the current time from a signal obtained by receiving a commercial FM broadcast by a tuner circuit 13, a read-only memory (ROM) and a MPU 10 for storing predetermined programs and data in advance. Random access memory (R
AM), a timing circuit 17 for forming various timing signals from a reference clock generated by a built-in crystal oscillator 16, a printer interface 18 to which the printer unit 4 is connected, and an external storage unit 7 to which the external storage interface circuit 19 is connected
And acceleration data A transmitted from the acceleration sensor 2
A data input interface circuit 20 for inputting _EW (t), A _NS (t), A _UD (t), etc., and for transmitting various analyzed data to the external display device 3 and a public telephone line. A data conversion interface circuit 22 for supplying the data to a modem 21 and acceleration data A _EW measured to an externally connected analog recorder or the like 23 as an option
A sweep signal and a synchronization timing signal are supplied to an analog output interface circuit 24 that performs D / A conversion of (t), A _NS (t), and A _UD (t) and outputs the same, and an externally connected analog recorder 23 and the like. 16-bit data output interface 28 to which a coupler circuit 25 and two systems of alarm output circuits 26 and 27 are connected.

Further, an AC / DC converter circuit 29 for converting a commercial AC voltage to a DC voltage, a rechargeable battery 30, and a battery 30 maintained at a constant voltage based on the output of the AC / DC converter circuit 29. A battery holding circuit 31 that outputs a predetermined DC voltage, a DC / DC converter circuit 32 that converts the output voltage of the battery holding circuit 31 to a more stable predetermined DC voltage, and a power control circuit 33 that performs power control of the entire system Provided. Then, a predetermined DC voltage generated by the DC / DC converter circuit 32 is supplied to the system in the main body 1 and the acceleration sensor 2.

As described above, by connecting various circuits and devices to the internal bus 11 centering on the MPU 10 via various interface circuits, a computer system exhibiting various functions is realized. By setting the menu according to 6, M
The connection between the PU 10 and these various circuits and devices can be specified. The acceleration sensor 2 has a built-in A / D converter that converts the analog value of the measured acceleration into 16-bit acceleration data A _EW (t), A _NS (t), and A _UD (t) and outputs the converted data. By transmitting data to the main unit 1 based on the RS-422 standard, it can be installed at a location about 1 km away from the main unit 1.
The data conversion interface circuit 22 supplies data based on the RS-232C standard to the modem 21 and data based on the RS-442 standard to the external display device 3, thereby providing the external display device with the data. 3 can be installed at a location about 1 km away from the main body 1.

Next, the operation of the seismic intensity meter having such a structure will be described with reference to FIGS. First, when the power is turned on, the internal system of the main body 1 and the acceleration sensor 2 are activated, and in step 100 of FIG.
Starts the measurement synchronized with the predetermined sampling frequency f ₀ , and at the step 110, the acceleration sensor 2
The acceleration data A _EW (t), A _NS (t), and A _UD (t) are sequentially stored in the RAM in the storage unit 15. Since the measurement processing of steps 100 and 110 is performed independently of the processing of the MPU 10 by DMA transfer or the like, the measurement processing is repeated in synchronization with the sampling frequency f ₀ until the power is turned off. The RAM has a capacity for storing the acceleration data A _EW (t), A _NS (t), and A _UD (t) for at least one minute. When the storage capacity is exceeded, old data is discarded by the FIFO function. I will do it. In this embodiment, the sampling frequency f ₀ is set to 100 Hz (in other words, the sampling cycle is 10 ms).
When the user sets predetermined options, the interfaces 18, 22, and 24 are activated, so that the acceleration data A _EW (t), A _NS (t), and A _UD (t) are transmitted to the printer unit 4.
, A modem 21, an external analog recorder 23, etc., and real-time recording and actual waveform recording become possible.

On the other hand, the MPU 10 performs the processing of steps 120 to 250 shown in FIG. First, the acceleration data A sequentially input in synchronization with the sampling frequency f _0
EW (t), A _NS (t), and A _UD (t) are compared with threshold values Th _EW , Th _NS , and Th _UD that are predetermined respectively, and A _EW (t) ≧ Th _EW , A _NS (t) ≧ Th _NS , A _UD (t) ≧
When it is detected that at least one of the conditions in the Th _UD is satisfied, it is determined that an earthquake has occurred, and step 130 is performed.
When none of these conditions is satisfied, the processing of step 120 is repeated to monitor the occurrence of an earthquake.

Next, in step 130, to enter the time data from the time signal detection circuit 14, further timer in MPU 10 - circuit, starts the time measurement from earthquake detection time t _g, at step 140, earthquake detection Time t _g
The elapsed time for each second from is counted. Then, every time one second elapses, the seismic intensity analysis processing of steps 150 to 240 is repeated. That is, 1 second, 2 seconds, 3 seconds from time t _g.
Steps 150 to 2 each time 1 second elapses
Step 40 is repeated.

Time t_gWhen the first second has elapsed since
In the description of the processing of FIG.
And time t_g10 seconds before (ie, time t_g
-10 seconds to time t_gPeriod until) T_cSampler inside
Acceleration data A for the last 10 seconds_EW(t), A_NS
(t), A_UD(t) and time t_g10 seconds to 11 seconds before
The previous period (ie, time t_g-11 seconds to time t_g-1
Period up to 0 seconds) T_fDuring the 1 second
Speed data A_EW(t), A_NS(t), A_UD(t) and time t_g
From the time till one second elapses (ie, time t_gOr time t
_g+1 second period) T_b1 second sampled during
Acceleration data A between_EW(t), A_NS(t), A _UD(t) and R
After reading from AM, as shown in FIG.
T_f, T_c, T_bFor a total of 12 seconds
Acceleration data A_EW(t), A_NS(t), A_UDform (t)
You. FIGS. 5A to 5E show one type of acceleration data.
A_EW(t) is shown only.
Speed data A_EW(t), A_NS(t), A_UD(t) is formed.

Next, in step 160, the period T _f
And T _b of the acceleration data _{A EW (t), A NS} (t), for each of the A _UD (t), performs the cosine taper process. That is, the period T _f in the acceleration data _{A EW (t), A NS} (t), for each of the A _UD (t), as shown in FIG. 5 (b), the time t _g -
A window function C _f (t) composed of a cosine function that changes to 0 at 11 seconds and to a predetermined value G at time t _g −10 seconds
Weighted acceleration data A in one period T _{b
For each of EW} (t), A _NS (t) and A _UD (t), FIG.
(C), the predetermined value G at time t _g, the time t _g +
By weighting a window function C _b (t) composed of a cosine function that changes to 0 in one second, acceleration data A _EW (t), A _NS (t), and A _{UD for} periods T _f and T _b are obtained.
Both ends of (t) are gradually reduced to zero. By this processing, occurrence of an error when performing a Fourier transform in step 180 described later is reduced.

Next, at step 170, FIG.
(D), the period T _f and T sides of period _b T _f0, T _b0 (i.e., T _f0 = corresponds to T _b0 = 4.24 sec) 0 data to each one by 424 By adding the data, the data D _EW (t) for the analysis process, which is a group of a total of 2048 data, respectively, corresponding to the acceleration data A _EW (t), A _NS (t), and A _UD (t). D _NS (t) and D _UD (t).

Next, in step 180, a Fourier transform process (in this embodiment, a discrete FFT is applied) for each of the analysis data D _EW (t), D _NS (t), and D _UD (t). ), _Each spectrum S _EW
(f), S _NS (f), and S _UD (f) are obtained.

Next, in step 190, each of the spectra S _EW (f), S _NS (f), and S _UD (f) is multiplied by the correction filter W (f) to obtain a correction spectrum F _EW ( f), F _NS (f), and F _UD (f). The correction filter W (f) is a so-called window function expressed by the following equation (2).

W (f) = {1−exp (−f / f ₀ ) ^X ｝ ^0.5 · (k / f) ^0.5 (2) where X and k are predetermined constants, and f ₀ is a sampling frequency. .

Next, in step 200, an inverse Fourier transform (in this embodiment, a discrete inverse FFT is applied) is performed on each of the correction spectra F _EW (f), F _NS (f), and F _UD (f). By doing so, the inverse transformed data R on the time axis
_EW (t), R _NS (t), and R _UD (t) are obtained.

Next, in step 210, the two horizontal components of inversely transformed data R _EW (t), R _EW in the east-west direction and the north-south direction.
Data corresponding to the period _Tc for _NS (t) is extracted, and the maximum amplitude value (absolute value) within the period _Tc is obtained. That is, as shown in FIG.
If the maximum amplitude value of the inverse transformed data R _EW in _c (t) a _EW, the maximum amplitude value of the period T inverse transform data in _c R _NS (t) and a _NS, whichever is greater maximum amplitude of Find the value. Furthermore,
The maximum amplitude value a _max obtained in this manner is calculated by the above equation (1).
To obtain the short-term seismic intensity I.

Next, at step 220, the inversely converted data R _EW (t), R _NS (t), R _UD (t) and the data of the short-term seismic intensity I are stored in the RAM. Further, in step 230, the MPU 10 causes the liquid crystal display unit 5 to display a histogram of the seismic intensity I for a short period of time, and at the same time generates alarm data of the occurrence of an earthquake. When an external display device 3 or a telephone line is connected to the main unit 1, the short-term seismic intensity
Since the data and the alarm data of the occurrence of the earthquake are transmitted, the alarm can be issued immediately after the occurrence of the earthquake.

Next, in step 240, the seismic occurrence time t _g from whether or not elapsed 60 seconds determination performed based on the count value of the timer circuit, in the case of yet not passed the process is repeated from step 140 .

Then, in step 140, the following 1
When the elapse of the second is detected, the acceleration data A _EW (t), A _NS (t), and A _UD (t) further shifted by one second are used in steps 150 to 240 shown in FIGS.
Is performed. Therefore, as shown in FIG. 6, when one second has elapsed from the earthquake detection time t _g , the period T _c = T ₁
Acceleration data A _EW (t), A _NS (t), A _UD (t) contained in
Acceleration data A _EW (t) for each second on both sides
, A _NS (t), and A _UD (t), perform cosine taper processing, and further form data obtained by adding 424 zero data on both sides, and form data for analysis. by analyzing processes, seeking short-term seismic intensity I after a lapse of one second, and an alarm data at the same time, when after two seconds from earthquake detection time t _g is the acceleration included in the period T _c = T ₂ Based on the data A _EW (t), A _NS (t), and A _UD (t), acceleration data A _EW (t), A _NS of 1 second are provided on both sides.
(t) and A _UD (t) are added to perform cosine taper processing, and then data obtained by adding 424 zero data on both sides is further formed, and these analysis data are analyzed. By doing so, the seismic intensity I for a short period after the lapse of 2 seconds is obtained, and at the same time, alarm data is generated.

Then, the same processing is repeated each time one second elapses thereafter. Therefore, as shown in FIG. 6, every time one second elapses, the acceleration data of T _c = T ₃ , T ₄ . The process of obtaining the short-term seismic intensity I based on A _EW (t), A _NS (t), and A _UD (t) is repeated.

Next, in step 240, the timer circuit counts the 60 seconds from earthquake detection time t _g, the process proceeds to step 250. In step 250,
The acceleration data A _EW (t), A for each of the periods T _{1 to} T _60
NS (t), since the total of 60 short-term seismic intensity I which is based on A _UD (t) is been obtained, further obtains the maximum value I _max in these short-term seismic intensity I, the maximum value I _max and it determines established reference seismic intensity and stores data for this formulation criteria seismic intensity I _max in the RAM. Further, the data of the determined reference seismic intensity I _max is numerically displayed on the liquid crystal display device 5. Incidentally, when the external display device 3 and the telephone line is connected to the main body 1 also transmits the alarm data of the data and earthquake established reference seismic intensity I _max for these.

Then, the processing shifts to the processing from step 140 again, and the monitoring processing of the occurrence of the earthquake is continued.

FIG. 7 shows an example of the acceleration data A _EW (t), A _NS (t), and A _UD (t) recorded on the printer unit 4. That is, when the user sets a menu in advance by the operation switch group 6, the change in the posting of the acceleration data A _EW (t), A _NS (t) and A _UD (t) from the earthquake occurrence time t _g is recorded in an analog manner. You.

[0036] Also, FIG. 8, for short-term seismic intensity I obtained every elapse one second the earthquake time t _g, seeking short-term seismic intensity I as a maximum value for each 10 seconds the earthquake time t _g An example of the display is shown. That is, when the user previously set menu in advance by operating the switch group 6, as the recording formulate reference seismic intensity I _max in the printer unit 4 when the elapsed 60 seconds from the earthquake occurrence time t _g, every 10 seconds For a short period of time. Incidentally, indicating that description of "seismic intensity 5.65" in FIG. 8 is a development reference seismic intensity I _max.

As described above, the user operates the operation switch group 6
By operating, various menus can be selected.

Acceleration data A from earthquake occurrence time tg
_The changes in the postings of _EW (t), A _NS (t), and A _UD (t) are recorded in analog form.

[0039] Thus, according to this embodiment, since the alarm process seeking short-term seismic intensity I immediately every second from earthquake detection time t _g, it is possible to realize the early warning, the alarm delay It can contribute to prevention. In addition, development and at the same time after one minute from the earthquake detection time t _g standard seismic intensity I _max
Therefore, the seismic intensity specified by the administrative agency can be provided.

In this embodiment, the acceleration data A _EW (t), A _NS (t), and A _UD (t) are set for 10 seconds every one second from the earthquake detection time t _g. Although the seismic intensity I is obtained for a short period, the present invention is not limited to every one second, and the seismic intensity may be obtained every arbitrary time as long as an early warning is realized. Furthermore, the seismic intensity I was determined for a short period based on the acceleration data A _EW (t), A _NS (t), and A _UD (t) set in sections of 10 seconds each. However, the present invention is not limited to 10 seconds. Any section may be set on condition that the short-term seismic intensity I can be analyzed with high accuracy. Further, acceleration data A _EW (t), A
Similarly, the sampling frequency for measuring _NS (t) and A _UD (t) may be arbitrarily set.

[0041]

According to the present invention as described above,
A short-term seismic intensity is obtained based on the maximum value of the acceleration data group from the time of the occurrence of the earthquake to a time before the first predetermined period, alarm information is generated, and further, every second predetermined time elapses from the time of the occurrence of the earthquake. The process of obtaining a short-term seismic intensity based on the maximum value of the acceleration data group before the first predetermined period is repeated over a period of at least 60 seconds from the above-mentioned earthquake occurrence time. Since the arithmetic processing is performed with the maximum value of the short-term seismic intensity as the development reference seismic intensity, a highly reliable early warning can be realized based on the short-term seismic intensity information and the warning information. In addition, since the short-term seismic intensity is repeatedly obtained for a period of at least 60 seconds from the time of the earthquake occurrence, and the maximum value of the plurality of short-term seismic intensity is set as a reference seismic intensity, it is possible to provide seismic intensity information compliant with the standard. It is possible to provide a device which has an excellent function of being able to perform the operation and is effective for regional earthquake countermeasures.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a system configuration of a measuring seismic intensity meter according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the system configuration of the measuring seismic meter according to one embodiment in more detail.

FIG. 3 is a flowchart for further explaining the operation of the embodiment.

FIG. 4 is a flowchart for further explaining the operation of the embodiment.

FIG. 5 is an explanatory diagram for describing in detail an operation for obtaining a seismic intensity;

FIG. 6 is an explanatory diagram for further describing an operation for obtaining a seismic intensity;

FIG. 7 is an explanatory diagram illustrating an example of content recorded in a printer unit.

FIG. 8 is an explanatory diagram showing another example of the content recorded in the printer unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Acceleration sensor, 3 ... External display device, 4 ...
Printer section, 5: liquid crystal display section, 6: operation switch group, 7
... external storage unit, 8 ... high brightness display unit, 9 ... sounding device, 10
... MPU, 11 ... Internal bus, 12, 18, 19, 20,
22, 24, 28 interface, 13 tuner circuit, 14 time signal detection circuit, 15 storage unit, 16 crystal oscillator, 17 timing circuit, 21 modem, 23 ...
Analog decoder, 25, coupler circuit, 26, 27
... alarm output circuit, 29 ... AC / DC converter circuit, 3
0: battery, 31: battery holding circuit, 32: DC /
DC converter circuit, 33 ... power control circuit.

Continuation of the front page (56) References JP-A-3-262929 (JP, A) JP-A-2-309284 (JP, A) JP-A-56-109024 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G01V 1/28

Claims (5)

(57) [Claims] 1. An acceleration sensor for measuring a swing acceleration in synchronization with a predetermined sampling frequency and generating the acceleration data; a storage unit for sequentially storing acceleration data output from the acceleration sensor; A determination means for determining whether or not the acceleration data exceeds a preset threshold value, and determining when the acceleration data exceeds the preset threshold value as an earthquake occurrence time; A short-term seismic intensity is calculated based on the maximum value of the acceleration data group up to one predetermined period before, warning information is generated, and a second seismic intensity is calculated from the earthquake occurrence time.
The process of obtaining the short-term seismic intensity based on the maximum value of the acceleration data group before the first predetermined period each time the predetermined time elapses is repeated over a predetermined third period from the earthquake occurrence time, Calculating means for setting a maximum value of the plurality of short-term seismic intensities obtained in the third period as a reference standard seismic intensity. 2. The seismograph of claim 1, wherein the third period is at least 60 seconds. 3. The method according to claim 1, wherein the first predetermined time is 10 seconds, and the second predetermined time is 1 second.
Measurement seismic intensity meter described in. 4. A display means for displaying a short-term seismic intensity and generating an alarm in synchronization with the calculation means obtaining a short-term seismic intensity every time the second predetermined time elapses. The measurement seismic intensity meter according to claim 1. 5. The measurement seismometer according to claim 1, wherein the acceleration data is data of components in at least two horizontal directions of east-west and north-south.