JP3469509B2 - Measurement method of vibration intensity - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration intensity measuring method used for a seismometer for control or the like.

[0002]

2. Description of the Related Art Conventionally, a seismometer for control has been used as a device for controlling various systems according to the intensity of an earthquake to prevent the spread of damage and the occurrence of secondary disasters. This seismometer for control has a spectrum intensity (hereinafter, SI) that has a high correlation with damage (damage) to the structure.
It has been proposed that the strength of vibration is measured using a value of strength of earthquake motion, and a control signal such as a discrimination signal is output based on the measured strength (Japanese Patent Laid-Open No. 10-123258, etc.).

When an earthquake motion occurs, its acceleration y (t)
The change with time is observed, for example, as shown in FIG. At this time, the temporal changes of the velocity response v (t) and the maximum velocity response Sv (t) of a certain structure are as shown in FIG. 9B. The maximum speed response Sv (t) is the maximum value of the speed response v (t) generated up to that time. Further, the spectral distribution of the maximum velocity response Sv (t) with respect to the natural period T at a time when there is such a vibration is as shown in FIG. 10, and the average value of this distribution is obtained (that is, the shaded area in the figure is By dividing by the integration interval), the SI value at that time can be obtained. The natural period T is determined by the size of the structure, etc., and the main structure is the integration interval (0.1 to 2.
It is known that the natural period T is within the range of 5). For more detailed points, JP-A-62-1284, JP-A-62-128885, and JP-A-62-12.
Reference should be made to known documents such as Japanese Laid-Open Patent Publication No. 886 and Japanese Patent Laid-Open No. 6-214040.

Now, a method of measuring earthquake motion disclosed in Japanese Patent Laid-Open No. 10-123258 will be described as a prior art. The waveform shown in FIG. 11 is a waveform obtained by plotting time-series data of the vibration acceleration y (t) detected by the acceleration detection unit. In the figure, R is the measurement start time, S
Indicates an earthquake occurrence time, and E indicates an earthquake convergence time. This time series data is sampled at an extremely short cycle (for example, 10 msec) and stored in the memory (RAM). In order to obtain the SI value from this time series data in near real time,
When a predetermined time Tp elapses from the time R, the time-series data of the acceleration y (t) obtained up to that time is read from the memory, and first, the speed response value v (t) for each natural period T is once read.
(Equation 1 below), then obtain the maximum velocity response value Sv (t) (Equation 2 below) for each natural period T, and from these, S
I value (the following formula 3) is calculated. Then, a predetermined time Δt
When p has passed, from time (R + Δtp) to time (R
Time series data up to + Tp + Δtp) is read from the memory and the same calculation is performed. Hereinafter, the SI value is calculated every time the time Δtp elapses.

In these equations, t [s] is the current time, τ is the integration period (time), T is the natural period of the structure, h is the damping constant of the structure, and ω is the natural angular frequency (ω). = 2
π / T [rad / s]), ωd is the damping natural angular frequency (ω
d = ω × (1−h ² ) ^1/2 [rad / s]).

[0006]

[Equation 1]

[Equation 2]

[Equation 3]

[0007]

Since the conventional vibration intensity measuring method performs the above-mentioned processing, it is a time series data of the acceleration y (t) at least at the predetermined time Tp.
All the data has to be stored in the memory, and there is a problem that an enormous memory capacity is required in order to obtain a highly accurate calculation result. For example, if the predetermined time Tp is 10 seconds and the sampling period is 10 μsec,
It is necessary to store as many as 1000 values for each data. Although a large-capacity memory device is commercially available,
The use of this is not satisfactory in terms of processing speed and price.

An object of the present invention is to obtain a vibration intensity measuring method which requires an extremely small memory capacity without deteriorating the calculation speed and the calculation accuracy.

[0009]

A method for measuring vibration intensity according to the present invention obtains a speed response value (v (t)) based on an acceleration detection signal from an acceleration detection element, and calculates a maximum speed response from the speed response value. A value (Sv (t)) is calculated, and a seismic intensity (SI) is calculated from the maximum velocity response value. In the method of measuring vibration intensity, the velocity response value (v
(T)) is stored, a maximum value is obtained from a predetermined number (time window) of the stored values, and the maximum value is obtained as the maximum speed response value (S
v (t)), the seismic intensity value (SI) is obtained from the maximum velocity response value, and these calculations are repeatedly performed by shifting the time interval by an integer multiple.

In the vibration intensity measuring method according to the present invention, the velocity response value (v (t)) is obtained based on the acceleration detection signal from the acceleration detecting element, and the maximum velocity response value (Sv (t)) is obtained from this velocity response value. ), And in the method of measuring the vibration intensity to obtain the seismic intensity (SI) from the maximum velocity response value, the velocity response value (v (t)) is sampled at predetermined time intervals,
If the collected value is larger than the stored value of the first storage means (W0), the storage of the first storage means is changed to the collected value,
The larger one of the stored values in the first storage means and the second storage means is set as the maximum speed response value (Sv (t)), and the seismic intensity value (SI) is obtained from the maximum speed response value, and the time interval is set to a predetermined value. Every time when the number reaches the number, the storage value of the second storage means is changed to the storage value of the first storage means and then the storage value of the first storage means is changed to "0".

In the vibration intensity measuring method according to the present invention, the velocity response value (v (t)) is obtained based on the acceleration detection signal from the acceleration detection element, and the maximum velocity response value (Sv (t)) is obtained from this velocity response value. ), And in the method of measuring the vibration intensity to obtain the seismic intensity (SI) from the maximum velocity response value, the velocity response value (v (t)) is sampled at predetermined time intervals,
If the collected value is larger than the stored value of the first storage means (W0), the storage of the first storage means is changed to the collected value,
First storage means and a plurality of other storage means (W1, W
2, W3) is the largest stored value as the maximum speed response value (Sv (t)), and the seismic intensity value (SI) is calculated from this maximum speed response value. First, the storage value of the storage means having the old storage value is sequentially changed to the storage value of the storage means having the old storage value, and the storage value of the second storage means is changed to the storage value of the first storage means. After that, the storage value of the first storage means is changed to "0".

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. FIG. 1 is a block diagram showing a gas supply system to which a waveform recording device based on the spectrum intensity value calculation method of the present invention is applied. In the figure, 1 is a gas manufacturing plant equipped with an explosion-proof zone, 2 is a gas tank, 3 is a high-pressure conduit,
4 is a governor station with an explosion-proof zone, 5 is an emergency shutoff valve, 6 is a medium pressure conduit, 7 is a governor room installed in the explosion-proof zone,
Reference numeral 8 is a low-pressure conduit, 9 is a gas-supplied home, and 10 is a gas-supplied factory. Further, 11 is a monitoring room, 12 and 13 are emergency shutoff instructions, 14 is a governor, and 15 is a governor having an emergency shutoff function.

Reference numeral 16 denotes a semiconductor acceleration sensor capable of measuring three axes (X, Y, Z axes) and outputting a detection signal which changes in response to vibration. Reference numeral 17 denotes vibration discrimination based on the detection signal and outputs a discrimination signal. An arithmetic processing circuit for performing, a reference numeral 18 is a digital (binary) format discrimination signal output from the arithmetic processing circuit 17,
Reference numeral 19 is a mechanical seismic sensor that detects vibration using a pendulum, and 20 is input with the discrimination signal 18 and the output signal of the mechanical seismic sensor 19, and generates a cutoff signal when both are vibration detection. A determination circuit for making 21 perform the shutoff signal, and 22 a governor for shutting off the gas flow path in the explosion-proof area by the shutoff signal 21. Since the semiconductor acceleration sensor 16 and the arithmetic processing circuit 17 are installed in the explosion-proof area, they are housed in the explosion-proof case, and the mechanical seismic sensor 19 and the judgment circuit 20 are installed on the outside wall of the governor room which is the non-explosion-proof area. It is arranged in the board.

As the semiconductor acceleration sensor 16, it is possible to use, for example, a sensor utilizing change in capacitance and its signal processing circuit described in Japanese Patent Laid-Open No. 9-43068. As described in the section of the prior art of the publication, a plurality of pairs of electrostatic capacitance elements provided with electrodes on opposite surfaces of a fixed substrate and a flexible substrate are provided to face each other, and XY parallel to the substrate surface is provided. A plane is set, and changes in the three-dimensional directions of the X-axis, Y-axis, and Z-axis of the Z-axis orthogonal to the plane are calculated based on changes in the capacitance between a plurality of pairs of capacitance elements in the X-, Y-, and Z-axis directions The component is detected. Then, as an acceleration output in the X-axis direction, a capacitance difference between the capacitance elements C21 and C23 (C21-C23), and as an acceleration output in the Y-axis direction, a capacitance difference between the capacitance elements C22 and C24. (C2
2-C24), the capacitance C25 of the capacitance element C25 or C21 + C22 + as the acceleration output in the Z-axis direction.
It can be detected as C23 + C24. Other,
The semiconductor acceleration sensor 16 is not limited to the capacitance type acceleration sensor, and for example, a piezoresistive type or a piezoelectric type acceleration sensor can also be used. Further, the semiconductor acceleration sensor 16 should preferably be capable of measuring three axes (X, Y, Z axes). This enables accurate vibration measurement of seismic motion. Especially in a direct earthquake, the Z axis (vertical)
Since the direction vibrates first, more important measurement information can be obtained.

FIG. 2 is a block diagram showing a detailed structure of the arithmetic processing circuit 17 and its peripheral members according to the first embodiment of the present invention. In the figure, reference numeral 23 is input with the detection signals of the semiconductor acceleration sensor 16 and the outputs of the reference voltage circuit 24 and the correction temperature sensor 25. The detection signals which are these outputs are sampled for each Δt to determine acceleration, temperature,
A sensor interface 26 for outputting (A / D converting) reference voltage data is connected to a memory 27, a real-time clock 28, a backup circuit 29, a power supply circuit 30 and the like, and the acceleration, temperature, reference voltage A control unit, such as a central processing unit (CPU), which receives data, calculates characteristic values of various vibrations, and outputs a discrimination signal 18 in a digital (binary) format, 31 is the discrimination signal 1
8 is a digital output interface for outputting 8 to the outside.

In the control unit 26, 32 is calculated by the SI value calculating unit 32a, which is one measure of the intensity of the seismic motion, the SI value calculated by the seismic intensity calculating unit 32b, and the acceleration calculating unit 32c. Acceleration, and the displacement amount calculated by the displacement amount calculation unit 32d,
It is a calculation value selection means for selecting an arbitrary plurality of calculation values from the respective calculation values of the speed calculated by the speed calculator 32e. That is, the calculated value selection means 32 can provide the optimum setting at the installation site by appropriately combining various calculation functions as necessary. Also, 33 performs vibration discrimination based on these calculated values,
Trigger signal output means for outputting the discrimination signal 18, 34 is a first timer for counting the discrimination time based on the clock signal of the real-time clock 28, and 35 is a first timer for counting the holding time based on the clock signal of the real-time clock 28. Two timers.

Reference numeral 36 is a digital input interface.
Reference numeral 37 is a relay interface for outputting the calculation processing result as a relay contact output signal, 38 is an analog output interface, and 39 is a loader interface. The relay interface 37 is configured so that a circuit such as DC 24 V or AC 100 V can be directly connected to the relay interface 37. Therefore, various loads such as an actuator, a valve, and a large relay are connected to the relay interface 37. It can be operated directly. Further, the relay interface 37 and a contact side circuit (not shown) are electrically separated from each other. The relay interface 37 can be connected not only to the relay but also to a separate insulating type electric component such as a photocoupler or a photoMOS relay. The loader interface 39 includes a loader connection terminal (not shown) for connecting a portable setting device,
For example, the means disclosed in Japanese Patent No. 2523053 gives the calculated value selecting means 32 a setting signal for selecting the calculated value.

The wiring from the external power supply to the power supply circuit 30 and the wiring of each of the interfaces 31, 36, 37, 38, 39 are led out of the explosion-proof case. Also,
Since the determination signal 18 is a digital signal, it is resistant to noise, and even if this wiring is routed from the governor chamber 7 to the control panel, malfunction does not occur easily.

Next, the operation will be described. When the sensor interface samples the detection signal output of the semiconductor acceleration sensor 16 at a predetermined sampling cycle such as every 10 ms and outputs the data of acceleration, temperature, and reference voltage, the control unit 26 outputs these data. -Calculates characteristic values of various vibrations based on the output data, and outputs the discrimination signal 18 in digital (binary) format. Then, for example, when the determination signal 18 is output, the determination circuit 20 outputs the cutoff signal 21 when the output of the mechanical seismic sensor 19 is also vibration detection.
The governor 22 automatically shuts off the gas flow path in the explosion-proof area based on the shutoff signal 21. As a result, even if the low-pressure conduit 8 or the like is cracked by an earthquake, unnecessary gas leakage can be prevented.

If the emergency shutoff instructions 12 and 13 are output from the monitoring room 11 at the same time, the gas flow passage is shut off even in the governor 14 and the governor 15 having an emergency shutoff function, which is more reliable and unnecessary. Gas leakage can be prevented.

Next, an example of measuring the SI value as the seismic intensity will be described below with reference to FIGS. 3 and 4. FIG. 3 is a schematic diagram for explaining the algorithm of the first embodiment of the invention, and FIG. 4 is a flow chart showing the procedure of the first embodiment of the invention. The flow chart of FIG. 4 is executed at the same cycle as the sampling rate at which the acceleration from the semiconductor acceleration sensor 16 is obtained. However, the sampling rate and the calculation cycle .DELTA.t of this flow chart may be different.

The output from the semiconductor acceleration sensor 16 is a time-varying acceleration signal, which is converted into digital data by the sensor interface 23 and then controlled by the control unit 26.
(ST11 in FIG. 4). The SI value calculation unit 32a receiving the acceleration data y (t), the speed response value v (t) at each extremely short calculation interval Δt (for example, 10 msec).
Conversion calculation is performed (ST12 in FIG. 4). This conversion operation is expressed by the above equation 1, but is actually digitally processed using the direct integration method shown in the following equation group 4. As a result, the acceleration value y (t) can be converted into the speed response value v (t) every 1 ms or less, and the time series data of the speed response value v (t) as shown in FIG. Can be obtained in real time.

[0023]

[Equation 4]

A plurality of constants (constant ω in Equation 1) for giving the natural period T are defined in advance (for example, 7), and the velocity response value v (t) is set for each constant (that is, for each natural period T). ) Time series data is calculated. The acceleration sensor 16 outputs acceleration signals in two orthogonal directions (for example, the east-west direction and the north-south direction), and the acceleration signal 36 is calculated.
Since it can be converted into an acceleration signal in an arbitrary direction of 0 degree, the speed response value v (t) in the arbitrary direction can be converted as necessary.
The time series data can be calculated in real time as described above. Needless to say, FIG. 3 represents one certain natural period and one direction.

Acceleration response v (t) to maximum velocity response Sv
An algorithm for obtaining (t) and the SI value will be described. FIG. 3A shows the change over time of the velocity response v (t).
FIG. 3B shows the temporal change of the time window described below with reference to FIG.
Indicates the time variation of the maximum velocity response Sv (t). A predetermined time from the past to the current time by n times the calculation interval Δt (n is an integer) will be referred to as a time window (in FIG. 3, the case of n = 3 is shown as an example for simplicity. Actually, about n = 1000 is applied). Only the value within this time window is stored in the memory area for the velocity response value v (t).

Assuming that the current time is t5, the time window is t2 to t5, and four speed response values v (t2), v (t3), v (t4), v (t5) are stored in the memory area. Is stored (ST13 in FIG. 4). Then, when this time is a multiple of n (here, 1), the following processing is performed (ST14 in FIG. 4). Of these, the one having the largest absolute value is the maximum speed response value Sv at time t5.
It is stored in another memory area as (t5) (ST of FIG. 4).
15). At the same time, the maximum velocity response value Sv (t) is similarly selected for the other natural period T. Then, the SI value (7 average values in the example) at time t5 is obtained from all (7 in the example) maximum speed response values Sv (t) (ST1 in FIG. 4).
6). By the way, the calculation time from the time t5 to obtaining the SI value is about 3 msec.

Next, when the calculation interval Δt elapses from time t5 to time t6, the time window becomes t3 to t6, the speed response value v (t2) is deleted from the memory area, and a new speed response is used instead. The value v (t6) is stored (ST11 to ST13 in FIG. 4). That is, the speed response value stored in the memory area at time t6 is v (t3), v
There are four (t4), v (t5), and v (t6). Hereinafter, similarly to the above, the maximum speed response value Sv at time t6
(T) and SI value are calculated (ST15 and ST1 in FIG. 4).
6).

In the prior art described above, all the acceleration y (t) within the time window range is stored in the memory 27 and all the calculations are performed later.
Since (t) is converted to the speed response v (t) in real time and stored, it is not necessary to calculate the speed response v (t) from the acceleration y (t) every time the SI value is calculated. , Only the comparison procedure for obtaining the maximum value Sv (t) of the speed response v (t) is sufficient, so that the calculation amount is drastically reduced.
The calculation load of the CPU used in the control unit 26 could be greatly reduced.

As described above, according to the first embodiment, the acceleration detection signal y from the semiconductor acceleration sensor 16 is obtained.
Vibration intensity to obtain seismic intensity (SI) from speed response value (v (t)) based on (t), maximum speed response value (Sv (t)) from this speed response value In the measuring method, the velocity response value (v (t)) calculated based on the acceleration detection signal y (t) is stored at each sampling interval of the semiconductor acceleration sensor 16, and a predetermined number (time) of the stored values is stored. The maximum value is obtained from the (window), it is taken as the maximum velocity response value (Sv (t)), the seismic intensity value (SI) is obtained from this maximum velocity response value, and these calculations are performed as integral multiples of the sampling interval (Here 1
It is not necessary to obtain the velocity response value (v (t)) based on the acceleration detection signal y (t) when the seismic intensity value (SI) is obtained, unlike the conventional method, because the seismic intensity value (SI) is obtained.

Therefore, every time the seismic intensity value (SI) is obtained, the velocity response value (v) is calculated based on the same acceleration detection signal y (t).
(T)) is not obtained (that is, the same calculation is not performed redundantly), and the total calculation processing load can be reduced accordingly. Also, compared with the conventional one, at the timing of obtaining the earthquake intensity value (SI), one speed response value calculation at that timing only has to be executed, so the instantaneous calculation processing load at that timing is significantly reduced. You can also do it. Therefore, there is an effect that the calculation load can be significantly reduced without impairing the calculation speed and the calculation accuracy.

Embodiment 2. In the second embodiment, the usage amount of the memory 27 is further reduced as compared with the first embodiment, and will be described with reference to FIGS. 5 and 6. 5 is a schematic diagram for explaining the algorithm of the second embodiment of the present invention, and FIG. 6 is a flow chart showing the procedure of the second embodiment of the present invention. The flow chart of FIG. 6 is carried out at the same cycle as the sampling rate at which the acceleration from the semiconductor acceleration sensor 16 is obtained. However, the sampling rate and the calculation cycle .DELTA.t of this flow chart may be different. Further, the calculation of the speed response v (t) in real time is the same as that of the first embodiment, and therefore detailed description thereof is omitted here (ST24 and ST2 in FIG. 6).
5).

From acceleration response v (t) to maximum velocity response Sv
An algorithm for obtaining (t) and the SI value will be described. FIG. 5A shows the change over time in the velocity response v (t).
5B shows the time change of the time window, and FIG. 5D shows the time change of the maximum velocity response Sv (t). Further, FIG. 5C shows the usage status of the first memory area W0 and the second memory area W2.

The characteristic point of this second embodiment is that
The point is that the length of the time window expands and contracts. The length of the time window at time t1 is t0 to t1, and the time window at time t2 is t.
The time window extends until the length reaches Δt × m (m = 2n−1, n is a constant) as the calculation interval Δt elapses, such as 0 to t2 (n = 4 in the example of FIG. 5). Further, when the time interval Δt has elapsed (that is, when the time reaches an integral multiple of n), the length of the time window is once reduced to Δt × n. Then, with the elapse of the calculation interval Δt again, the length of the time window extends until it reaches the length of Δt × m. After that,
The length of the time window repeats expansion and contraction between Δt × n and Δt × m.

At time t0, the initial value 0 is stored in the first memory area W0 and the second memory area W1. When the calculation time interval Δt elapses and time t1 is reached, the time window becomes t0 to t1 (ST21, ST24,
ST25), the stored value (both 0) of the first memory area W0 is compared with the absolute value of the speed response value v (t1), and if the absolute value of the speed response value v (t1) is larger than W0. The absolute value of the speed response value v (t1) is stored in the first memory area W0 instead of 0 as the maximum speed response value Sv (W0) of W0 (ST26 in FIG. 6). And W0 and W
The larger value of 1 and the maximum speed response S at that time
v (t1) (ST27 in FIG. 6). Then, the SI value at time t5 is obtained from all (7 in the example) maximum speed response values Sv (t) (ST28 in FIG. 6).

When the calculation time interval Δt has further elapsed, the time t
When it becomes 2, the time window becomes t0 to t2 (ST2 in FIG. 6).
1, ST24, ST25), the storage value (Sv (W0)) of the first memory area W0 and the storage value (0) of the second memory area W1 are compared with the absolute value of the speed response value v (t2),
When the absolute value of the speed response value v (t2) is larger than either of them, the first memory area W0 is set to the speed response value v
Rewriting with the absolute value of (t2) (ST26 in FIG. 6), the maximum speed response and SI value are obtained (ST27, ST2 in FIG. 6).
8).

Thereafter, the procedure is repeated at time t3 as described above, and when time t4 is reached (ST21 in FIG. 6),
The value of the second memory area W0 is rewritten to the maximum speed response value Sv (t4) of the first memory area W1 (ST22 of FIG. 6).
At the same time, the value of the first memory area W0 is rewritten to 0 (FIG. 6).
ST23). Further, after this, in the same manner as above, ST24 of FIG.
To ST28, the SI value is calculated.

Further, when the calculation time interval Δt has passed, the time t
5, the time window becomes t0 to t5 (ST2 in FIG. 6).
1, ST24, ST25), the storage value (0) of the first memory area W0 and the storage value (Sv (t
4)) and the absolute value of the speed response value v (t5) are compared,
When the absolute value of the speed response value v (t5) is larger than both of them, the speed response value v (v) is stored in the first memory area W0.
The absolute value of (t5) is stored instead of 0 (S in FIG. 6).
T26). Then, the maximum speed response and the SI value are obtained again (ST27, ST28 in FIG. 6).

These procedures are repeated until the time t
When it reaches 8, the value of the second memory area W1 is rewritten to the maximum speed response value Sv (t8) of the first memory area W0 and the value of the first memory area W0 is rewritten to 0 (S in FIG. 6).
T22, ST23). At this time, Sv (t4) previously stored in the second memory area W1 disappears (that is, the time window from time t0 to t4 disappears).

In the first embodiment of the invention described above, n (five in the example) memory areas are required to store data for the time window, but in the second embodiment, Since two memory areas are sufficient, it is possible to perform the arithmetic processing with a smaller memory 27.

As described above, according to the second embodiment, the acceleration detection signal y from the semiconductor acceleration sensor 16 is obtained.
Vibration intensity to obtain seismic intensity (SI) from speed response value (v (t)) based on (t), maximum speed response value (Sv (t)) from this speed response value In the measuring method, the speed response value (v (t)) based on the acceleration detection signal y (t) is sampled at every sampling interval of the semiconductor acceleration sensor 16, and the first storage means (W0).
If the sampled value is larger than the stored value of No. 1, the memory of the first storage means is changed to the sampled value, and the memory of the first memory means and the other plurality of memory means (W1, W2, W3) is stored. The largest value among the values is taken as the maximum velocity response value (Sv (t)), and the seismic intensity value (SI) is obtained from this maximum velocity response value, and the sampling interval reaches a predetermined number (4 here). , The storage value of the storage means W1 having the old storage value is sequentially changed to the storage value of the storage means W0 having the old storage value, and the storage value of the second storage means W1 is stored in the first storage means W0. Since the value stored in the first storage unit W0 is changed to "0" after the value is changed to the value, the acceleration detection signal y
Comparison for obtaining the maximum value of the speed response v (t) for all the speed response values (v (t)) without having to obtain all the speed response values (v (t)) based on (t) Eliminates the need to carry out procedures.

Therefore, every time the seismic intensity value (SI) is obtained, the velocity response value (v) is calculated based on the same acceleration detection signal y (t).
(T)) is not calculated (that is, the same calculation is not performed repeatedly), and the maximum value of the speed response v (t) is calculated for all speed response values (v (t)). Since it is not necessary to perform the comparison procedure, the total processing load can be reduced accordingly. Further, compared with the first embodiment, the number of times of comparison judgment between speed response values can be halved at the timing of obtaining the earthquake intensity value (SI), so that the instantaneous calculation processing load at the timing is reduced. It can be significantly reduced. Therefore, there is an effect that the calculation load can be significantly reduced without impairing the calculation speed and the calculation accuracy.

Further, since the speed response value v (t) to be stored is reduced by half by carrying out the comparison judgment in real time, the vibration intensity can be measured with an extremely small memory capacity without impairing the calculation speed and the calculation accuracy. There is an effect that can be.

According to the second embodiment, the speed response value (v (t)) is obtained based on the acceleration detection signal y (t) from the semiconductor acceleration sensor 16, and the maximum speed response value (Sv) is obtained from this speed response value. (T)), and in the vibration intensity measuring method for obtaining the seismic intensity (SI) from the maximum velocity response value, in the sampling interval of the semiconductor acceleration sensor 16,
Velocity response value based on the acceleration detection signal y (t) (v
(T)) is sampled and compared with the stored value of the first storage means (W0), if the collected value is larger, the storage of the first storage means W0 is changed to the collected value, and the first storage means W0 Of the stored values of the second storage means W1, the larger one is used as the maximum speed response value (Sv (t)), and the seismic intensity value (SI) is calculated from the maximum speed response value. Then, every time 4) is reached, the storage value of the second storage means W1 is changed to the storage value of the first storage means W0, and then the storage value of the first storage means W0 is changed to "0". Since it is sufficient to store two values, the maximum speed response value obtained from the data of (a time zone formed by combining a predetermined number of time intervals) and the maximum speed response value of the current time window, The minimum memory capacity is extremely small compared to the above case, and There is an effect capable of measuring the vibration intensity without sacrificing calculation speed and calculation accuracy.

Embodiment 3. The third embodiment of the invention is an intermediate invention between the first embodiment and the second embodiment of the invention, and will be described with reference to FIGS. 7 and 8. FIG. 7 is a schematic diagram for explaining the algorithm of the third embodiment of the invention, and FIG. 8 is a flow chart showing the procedure of the third embodiment of the invention. FIG. 7A shows the time change of the velocity response v (t), FIG. 7B shows the time change of the time window described below, and FIG. 7C shows the time window length and the corresponding memory. Fig. 7 (d) shows the maximum velocity response Sv of
The changes over time in (t) are shown. In addition,
The flow chart of FIG. 8 is the semiconductor acceleration sensor 1 described above.
The sampling rate from which the acceleration from 6 is obtained is executed at the same cycle. However, the sampling rate
It is also possible to make the calculation cycle .DELTA.t of this flow chart different from that of the flow chart. This third embodiment corresponds to the memory area increased to four in the second embodiment, and its operation is also similar to that of the second embodiment.
The operation from 0 to t8 will be omitted and simply described below.

Assuming that the current time is t8 and the time t9 has not yet been reached, the length of the time window is t2.
.About.t8, and the speed response v is stored in the first memory area W0.
(T8), but the speed response v (t
6) and v (t7), the larger one of the speed responses v (t4) and v (t5) in the third memory area W2, and the larger one of the speed responses in the fourth memory area W3. It is assumed that the larger one of v (t2) and v (t3) is stored.

At time t9 (ST31 in FIG. 8), the acceleration is first read (ST36 in FIG. 8), and the velocity response v (t
9) is calculated (ST37 of FIG. 8), this value is compared with the stored value v (t8) of the first memory area W0, and the larger one is overwritten in the first memory area W0 (FIG. 8). Of S
T38), the largest value is selected from the stored values of the first to fourth memory areas W0 to W3 and stored in another time series memory area as the maximum speed response Sv (t9) (Fig. 8 ST39), maximum speed response Sv (t
9) SI value is calculated from the value (ST40 in FIG. 8).

At time t10 (ST3 in FIG. 8)
1), the fourth memory area W3 is overwritten with the stored value of the third memory area W2 (ST32 in FIG. 8), and the third memory area W2 is overwritten with the stored value of the second memory area W1 (FIG. 8, ST33), the second memory area W1 is overwritten with the stored value of the first memory area W0 (ST34 in FIG. 8), and the first memory area W0 is overwritten with “0” (ST3 in FIG. 8).
5), the information obtained at times t2 and t3 disappears. Then, similarly to the above, the processes of ST36 to ST40 of FIG. 8 are executed to calculate the SI value.

In this embodiment, the number of memory areas is 4
However, of course, the number is not limited to this, and can be increased or decreased as necessary. Further, the number of calculation intervals Δt corresponding to one memory area has been described as 2 (that is, n = 2), but in actuality, it may be set to about n = 1000.

In the first embodiment of the invention described above, n (for example, 5) memory areas are required to store the data for the time window, but in the third embodiment, it is optional. Since a plurality of (for example, four) memory areas are sufficient, the arithmetic processing can be performed with a smaller memory 27.

As described above, according to the third embodiment, the acceleration detection signal y from the semiconductor acceleration sensor 16 is obtained.
Vibration intensity to obtain seismic intensity (SI) from speed response value (v (t)) based on (t), maximum speed response value (Sv (t)) from this speed response value In the measuring method of 1, the speed response value (v (t)) based on the acceleration detection signal y (t) is sampled at each sampling interval of the semiconductor acceleration sensor 16 and is compared with the value stored in the first storage unit W0. If the value is larger, the storage of the first storage means is changed to the sampled value, and the largest storage value among the storage values of the first storage means and the plurality of storage means (W1, W2, W3) is the maximum. As the speed response value (Sv (t)),
The seismic intensity value (SI) is obtained from this maximum velocity response value, and every time the sampling interval reaches a predetermined number (here, 2), the stored value of the storage means having the old stored value is replaced by the oldest stored value. Sequentially changing to the storage value of the storage means that it has, changing the storage value of the second storage means W1 to the storage value of the first storage means W0, and then changing the storage value of the first storage means W0 to "0". Therefore, it is not necessary to obtain all velocity response values (v (t)) based on the acceleration detection signal y (t) when obtaining the seismic intensity value (SI), unlike the conventional case.
Moreover, it is not necessary to perform the comparison procedure for obtaining the maximum value of the speed response v (t) for all the speed response values (v (t)).

Therefore, every time the seismic intensity value (SI) is obtained, the velocity response value (v) is calculated based on the same acceleration detection signal y (t).
(T)) is not calculated (that is, the same calculation is not performed repeatedly), and the maximum value of the speed response v (t) is calculated for all speed response values (v (t)). Since it is not necessary to perform the comparison procedure, the total processing load can be reduced accordingly. Further, compared to the first embodiment, the number of comparison judgments between speed response values can be reduced to at least half or less at the timing of obtaining the seismic intensity value (SI). The load can be significantly reduced. Therefore, there is an effect that the calculation load can be significantly reduced without impairing the calculation speed and the calculation accuracy.

Further, since the speed response value v (t) to be stored is reduced by carrying out the comparison judgment in real time, it is possible to measure the vibration intensity with an extremely small memory capacity without impairing the operation speed or the operation accuracy. There is an effect that can be.

[0053]

As described above, according to the first aspect of the invention, the velocity response value (v (t)) is obtained based on the acceleration detection signal from the acceleration detecting element, and the maximum velocity response is obtained from this velocity response value. A value (Sv (t)) is obtained, and in a vibration intensity measuring method for obtaining the earthquake intensity (SI) from the maximum velocity response value, the velocity response value (v (t)) is stored at predetermined time intervals, The maximum value is obtained from the predetermined number (time window) of the stored values, and it is used as the maximum velocity response value (Sv (t)). The earthquake intensity value (SI) is obtained from the maximum velocity response value, and Since the calculation of S is repeatedly performed by shifting the time interval by an integer multiple, the seismic intensity value (S
It is not necessary to obtain the velocity response value (v (t)) based on the acceleration detection signal when obtaining I).

Therefore, every time the seismic intensity value (SI) is obtained, the velocity response value (v (t)) is calculated based on the same acceleration detection signal.
Is not obtained (that is, the same calculation is not performed twice), and the total calculation processing load can be reduced accordingly. Also, compared with the conventional one, at the timing of obtaining the earthquake intensity value (SI), one speed response value calculation at that timing only has to be executed, so the instantaneous calculation processing load at that timing is significantly reduced. You can also do it. Therefore, there is an effect that the calculation load can be significantly reduced without impairing the calculation speed and the calculation accuracy.

According to the second and third aspects of the invention, the speed response value (v (t)) is obtained based on the acceleration detection signal from the acceleration detecting element, and the maximum speed response value (Sv (T)), and in the method of measuring the vibration intensity for obtaining the seismic intensity (SI) from this maximum velocity response value, the velocity response value (v (t)) is sampled at every predetermined time interval, and the first memory is stored. When the collected value is larger than the stored value of the means (W0), the storage of the first storage means is changed to the collected value, and the first storage means and the other plurality of storage means (W
1, W2, W3) is the largest stored value as the maximum speed response value (Sv (t)), and the seismic intensity value (SI) is calculated from this maximum speed response value. Each time it reaches, the storage value of the storage means having the old storage value is sequentially changed to the storage value of the storage means having the old storage value, and the storage value of the second storage means is changed to the storage value of the first storage means. Since the stored value of the first storage means is changed to "0" after changing to, the speed response value (v (t)) is calculated based on the acceleration detection signal when the seismic intensity value (SI) is obtained as in the conventional case. And it is not necessary to carry out a comparison procedure for obtaining the maximum value of the speed response v (t) for all speed response values (v (t)).

Therefore, every time the seismic intensity value (SI) is obtained, the velocity response value (v (t)) is calculated based on the same acceleration detection signal.
Is not obtained (that is, the same calculation is not duplicated), and the comparison procedure for obtaining the maximum value of the velocity response v (t) is performed for all the velocity response values (v (t)). Since there is no need to do that,
It is possible to reduce the calculation processing load of Tal. Further, compared with the above, the number of times the speed response values are compared and judged can be reduced to at least half or less at the timing of obtaining the seismic intensity value (SI). Can be significantly reduced. Therefore, there is an effect that the calculation load can be significantly reduced without impairing the calculation speed and the calculation accuracy.

Further, since the speed response value to be compared and judged and stored in real time is reduced, there is an effect that the vibration intensity can be measured with an extremely small memory capacity without impairing the calculation speed and the calculation accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a gas supply system to which the present invention is applied.

FIG. 2 is a block diagram showing a detailed configuration of an arithmetic processing circuit and its periphery according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an algorithm according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing the procedure of the first embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating an algorithm according to the second embodiment of the present invention.

FIG. 6 is a flowchart showing the procedure of the second embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating an algorithm according to the third embodiment of the present invention.

FIG. 8 is a flowchart showing the procedure of the third embodiment of the present invention.

FIG. 9 is a waveform diagram showing the relationship between acceleration, velocity response, and maximum velocity response in a given natural period.

FIG. 10 is a waveform diagram showing a spectrum of maximum velocity response at a certain time point.

FIG. 11 is a waveform diagram showing a conventional technique.

[Explanation of symbols]

1 gas manufacturing plant 2 gas tank 3 high pressure conduit 4 Governor Station 5 Emergency shutoff valve 6 Medium pressure conduit 7 Governor room 8 low pressure conduit 9 home 10 factories 11 Monitoring room 12, 13 Emergency shutdown instruction 14 Governor 15 Governor with emergency shutoff function 16 Semiconductor acceleration sensor 17 Arithmetic processing circuit 18 Discrimination signal 19 Mechanical earthquake sensor 20 Judgment circuit 21 Cutoff signal 22 Governor 23 Sensor Interface 24 Reference voltage circuit 25 Correction temperature sensor 26 Control unit 27 memory 28 real-time clock 29 Backup circuit 30 power circuit 31 Digital output interface 32 calculation value selection means 32a SI value calculator 32b Seismic intensity calculator 32c acceleration calculator 32d Displacement amount calculation unit 32e Speed calculator 33 Trigger signal output means 34 First timer 35 Second timer 36 Digital Input Interface 37 Relay Interface 38 analog output interface 39 loader interface

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hikaru Takubo 2-12-19 Shibuya, Shibuya-ku, Tokyo Yamatakenai Co., Ltd. (72) Inventor Yoshihisa Shimizu 2-26-3 Kayuga, Satte City, Saitama Prefecture (72) Inventor Kenichi Koganemaru 1-48-6-908, Higashiikebukuro, Toshima-ku, Tokyo (56) Reference JP 10-123258 (JP, A) JP 62-12884 (JP, A) JP 8-36062 ( JP, A) JP 3-262930 (JP, A) JP 10-123257 (JP, A) JP 61-234382 (JP, A) JP 3-262929 (JP, A) JP 2000-249771 (JP, A) JP 2000-249772 (JP, A) JP-B 4-35035 (JP, B2) JP-B 6-35935 (JP, B2) JP 2545504 (JP, B2) JP 2800911 ( JP, B2) Patent 2957572 (JP, B1) Kenichi Koganemaru, Zen Shimizu , Takashi Yanada, Hiroyuki Furukawa, Hikaru Takubo, "Method of calculating SI value of new SI sensor", 33rd Geotechnical Engineering Research Meeting-Annual Lectures in 1998 (2 Volume 2)-, Japan, incorporated corporation Geotechnical Society, May 25, 1998, 1233, p. 2471-2472 Ikuo Towata, J .; K. Park, R.M. P. Oruse and Hiroyuki Kano, "Use of spectrum intensity for immediate detection of of subsoil liquefactions, No. 36, 1996, Soils and Foundations, June, J., Japan,". 29-44 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01V 1/00-1/52 G01H 1/00-1/16 G01H 11/00-11/08 JISST file (JOIS)

Claims (3)

(57) [Claims] 1. A method for measuring vibration intensity, wherein a velocity response value is obtained based on an acceleration detection signal from an acceleration detection element, a maximum velocity response value is obtained from this velocity response value, and an earthquake intensity is obtained from this maximum velocity response value. For each predetermined time interval, the speed response value is stored, the maximum value is calculated from the predetermined number of the stored values, and it is set as the maximum speed response value, and the earthquake intensity value is calculated from this maximum speed response value. A method of measuring vibration intensity, characterized in that these calculations are repeatedly performed by shifting the time interval by an integer multiple. 2. A vibration intensity measuring method for obtaining a velocity response value based on an acceleration detection signal from an acceleration detecting element, obtaining a maximum velocity response value from the velocity response value, and obtaining an earthquake intensity from the maximum velocity response value. The speed response value is sampled at every predetermined time interval, and when the collected value is larger than the stored value of the first storage means, the storage of the first storage means is changed to the collected value, and the first storage The larger one of the stored values of the second storage means and the second storage means is set as the maximum speed response value, and the seismic intensity value is obtained from the maximum speed response value, and the storage of the second storage means is performed every time the time interval reaches a predetermined number. A method for measuring vibration intensity, characterized in that the value stored in the first storage means is changed and then the storage value stored in the first storage means is changed to "0". 3. A vibration intensity measuring method for obtaining a velocity response value based on an acceleration detection signal from an acceleration detecting element, obtaining a maximum velocity response value from the velocity response value, and obtaining an earthquake intensity from the maximum velocity response value. The speed response value is sampled at every predetermined time interval, and when the collected value is larger than the stored value of the first storage means, the memory of the first storage means is changed to the collected value, The largest value among the storage values of the storage means and the plurality of other storage means is set as the maximum speed response value, and the seismic intensity value is obtained from the maximum speed response value. The old storage is stored each time the time interval reaches a predetermined number. After that, the storage value of the storage means having the value is sequentially changed to the storage value of the storage means having the old storage value, and the storage value of the second storage means is changed to the storage value of the first storage means. The stored value of one storage means Method of measuring the vibration intensity and changes to 0 '.