JPH09280940A - Seismic device - Google Patents

Abstract

The present invention relates to a seismic sensing device that is installed in a gas meter 18 or the like to detect an earthquake, and accurately distinguishes an earthquake from an impact. SOLUTION: Displacement measuring means 12 for measuring its own displacement
A displacement signal output from the displacement measuring means 12 for determining whether or not the displacement signal is an earthquake, an output means 14 for outputting the determination result of the determining means, and a power supply means 17, and the displacement signal is used as the determining means. By using it, it is possible to accurately determine an impact and an earthquake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic device installed in a gas meter, a gas shutoff device or the like to detect an earthquake.

[0002]

2. Description of the Related Art Conventionally, this kind of seismic device is disclosed in
No. 48634 has been known. Less than,
The configuration will be described with reference to FIG.

As shown in FIG. 12, a sphere 3 is rotatably housed in a box body 2 having a concave conical bottom surface 1, and is vertically slidably held by an inner lid 4 of the box body. The lower surface of the disk 5 is brought into contact with the upper surface of the sphere 3 by its own weight, and the plunger 6 provided on the upper surface of the disk 5 is brought into contact with the switch mechanism 7 to move the disk 5 upward. The switch mechanism 7 can be operated by the.

In the above structure, when the box 2 vibrates, the sphere 3 rolls on the conical bottom surface 1 from the center to the end. At this time, since the distance between the bottom surface 1 and the concave spherical surface of the disk 5 is small at the position closer to the end from the center, the plunger 6 is pushed up by the sphere 3 that enters this distance and the contact 8 is turned on.

[0005]

However, in the above-mentioned prior art, although the vibration can be detected, there is a problem in that it is difficult to distinguish the shock motion and the seismic motion that occur when a ball or the like collides.

[0006]

In order to solve the above-mentioned problems, the present invention detects the occurrence of an earthquake from displacement measuring means for measuring the moving distance of the installation portion of this device and the displacement signal output by the displacement measuring means. The determination means for determining, the output means for outputting the determination result of the determination means, the displacement measuring means, the determination means, and the power supply means for driving the output means are provided.

According to the above-mentioned invention, when the displacement signal exceeds the first predetermined value, it is determined that an earthquake occurs, so that it can be accurately distinguished from an impact signal in which the moving distance of the installation portion is short, and the occurrence of an earthquake can be accurately detected. can do.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a displacement measuring means for measuring a moving distance of an installation portion of the present device, and a judging means for judging occurrence of an earthquake from a displacement signal output from the displacement measuring means.
The output means outputs the determination result of the determination means, the displacement measuring means, the determination means, and the power supply means for driving the output means. Then, when the displacement signal exceeds a predetermined value, it is determined as an earthquake, so that it can be accurately distinguished from an impact signal having a small moving distance.

Further, there is provided a displacement measuring means for obtaining a displacement signal by providing a signal converting means for converting a signal of the acceleration sensor into a displacement signal.

Further, there is provided a signal converting means for integrating the signal of the acceleration sensor twice and converting it into a displacement signal. Then, by obtaining the displacement from the signal of the acceleration sensor, it is not necessary to embed the sensor in the ground, and it is possible to easily measure the movement distance of oneself, that is, the displacement of the ground.

Further, the displacement signal after the first predetermined time is the first
It is provided with a judging means for judging that it is an earthquake when the predetermined value of is exceeded. Then, by comparing the displacements, it is possible to accurately determine the earthquake by determining the ground movement distance as the displacement after the final vibration, not the instantaneous value of the displacement.

Further, when the signal of the acceleration sensor is equal to or greater than the second predetermined value and the displacement signal obtained by converting the signal of the acceleration sensor exceeds the first predetermined value, it is determined that there is an earthquake. It is provided with a determining means for performing. Then, when the signal from the acceleration sensor is equal to or higher than the second predetermined value and the displacement after the first predetermined time exceeds the first predetermined value, it is determined that an earthquake occurs, and both conditions are satisfied. By doing so, it is possible to accurately identify the earthquake.

Further, when the signal of the acceleration sensor is equal to or more than the second predetermined value, or when the displacement signal obtained by converting the signal of the acceleration sensor exceeds the first predetermined value, there is an earthquake. The determination means is provided.
Then, when the signal of the acceleration sensor becomes equal to or higher than the second predetermined value or the displacement after the first predetermined time exceeds the first predetermined value, it is determined that there is an earthquake, and thus either condition is satisfied. By determining that it is an earthquake when it occurs, it is possible to make a wider range of earthquake determinations and ensure a wide range of safety in using gas appliances and the like.

Further, a measuring interval control means for measuring the displacement signal by the displacement measuring means at a second predetermined time interval is provided.

Also, the displacement is measured by the displacement measuring means at intervals of the second predetermined time and only during the third predetermined time. Then, by measuring at the second predetermined time interval, the power consumption required for the measurement is reduced as compared with the case where the measurement is always performed, and the time measured at the time interval is set to the third time.
It is possible to avoid measuring an excessively long vibration waveform and reduce the power consumption required for the measurement by setting only the predetermined time.

Further, a displacement measuring means for measuring the displacement in the vertical direction is provided. Then, by measuring the displacement in the vertical direction of an earthquake that is mostly accompanied by vertical motion, it is possible to accurately distinguish from an impact with a small amount of vertical vibration.

Further, a vibration measuring means for measuring the vibration information of the installation portion of the apparatus, a cycle measuring means for measuring the time cycle of the signal output by the vibration measuring means, and a fluctuation of the time cycle by a third predetermined value. A judgment means for judging whether or not it is earthquake vibration information by comparing with a value, an output means for outputting the judgment result of the judgment means, the vibration measurement means, the cycle measurement means, the judgment means and the output means It is equipped with a power supply means.

Further, there is provided cycle measuring means for measuring the time cycle from the time interval of the zero cross points of the signal output by the vibration measuring means.

Further, periodic fluctuation measuring means for measuring the ratio σ / μ of the standard deviation σ of the time period of the signal and the average value μ of the time period, and the ratio σ / μ are compared with a third predetermined value to cause an earthquake. A determination means for determining whether or not it is provided. Then, when the ratio σ / μ is larger than the third predetermined value and there is no regularity in the vibration generation period, it is determined that it is an earthquake, so that not only the vibration level but also the vibration generation period is considered. The accuracy of earthquake judgment can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a seismic device according to Embodiment 1 of the present invention.

In FIG. 1, 9 is a vibration acceleration sensor, and 1 is
Reference numeral 0 is a bandpass filter, 11 is a double integration circuit, 12 is a displacement measuring device as displacement measuring means, 13 is a determining device as determining means, 14 is an output device at the time of earthquake determination as output means, and 15 is a measuring time. A measurement time control device as control means, 16 is an initial value setting device for setting a threshold value used in the determination device 13 and an initial setting value for a predetermined time, and 17 is a battery as power supply means for driving these circuits.

Next, the operation and operation will be described. The seismic sensing device of the present invention is installed inside a gas meter 18 as shown in FIG. 2 to detect the occurrence of an earthquake. When it is determined that an earthquake has occurred, the shutoff valve 19 is closed to stop the supply of gas. It is a thing. For example, when an earthquake occurs, the gas meter 1
A signal is generated from the vibration acceleration sensor 9 installed at 8. After passing the signal through the band pass filter 10 of 0.5 Hz to 20 Hz, the acceleration signal is converted into a displacement signal through the integrating circuit 11 twice. This makes it possible to measure the displacement as the moving distance of the gas meter 18 in which the seismic sensor is installed. Here, 20 is a circuit board of the gas meter control device, 21 is a gas pipe, and 22 is a mounting wall. When the measured displacement signal exceeds the first predetermined value set by the initial value setting device 16,
It is determined that an earthquake has occurred, an output signal is generated from the output device 14, and the shutoff valve 19 is closed. The initial value setting circuit 16 can set the first predetermined value to a large, medium, or small level by a three-step contact switch, and can be set to a large level in a residential area near the road with a lot of traffic vibration. It is possible to prevent malfunction. For example, the large level of the first predetermined value is 5 cm for displacement, and 2c for medium level.
m, 1 cm for small level.

Then, the first predetermined time (for example, 20 seconds)
The absolute value of the subsequent displacement is the level of the first predetermined value (for example,
When it exceeds 2 cm, it is judged as an earthquake.
This is because the impact signal generated when a ball hits the gas meter 18 causes a momentary large displacement as shown in FIG. 3 but returns to a position of almost zero displacement within a few seconds, whereas in the case of an earthquake As shown in Fig. 4, after 20 seconds, a displacement of about -4 cm occurs due to the displacement of the ground due to the earthquake. By utilizing this, it is possible to accurately distinguish between an impact and an earthquake. As can be seen here, the determination of the first predetermined value is performed by using an absolute value even if it is a negative value, so that the determination can be made regardless of whether the value is positive or negative.

Further, in order to detect the occurrence of an earthquake, the acceleration must be constantly measured, but as many earthquake motion waveforms show, the seismic wave lasts from 3 seconds to 10 seconds. Therefore, as shown in FIG. 5, in this apparatus, the second predetermined time is measured at intervals of 2 seconds. Then, the vibration acceleration is measured at intervals of 2 seconds, and it is determined whether or not the vibration acceleration exceeds a second predetermined value (for example, 80 cm / s2; equivalent to seismic intensity 5). If it does not exceed the second predetermined value, it waits again at an interval of 2 seconds, and when it exceeds the second predetermined value, the displacement obtained from the signal conversion is the first displacement. The determination means determines whether or not the value has exceeded a predetermined value. FIG. 6 shows a flowchart thereof.

As described above, by measuring at the second predetermined time interval, it is possible to detect the occurrence of an earthquake without missing it, and it is possible to make the life of the battery 17 much longer than when it is constantly monitored. . The optimum specific cycle is 2 seconds, but it is considered that the specific cycle may be variable in the range of about 1 to 10 seconds according to the life of the battery.
Then, the measurement is performed at the second predetermined interval, but when the vibration acceleration does not reach the predetermined value or more, the measurement is interrupted and some circuits are suspended to reduce the power consumption.

Further, when the vibration acceleration exceeds a predetermined value, the vibration acceleration is measured for the third predetermined time. This may be the same as the first predetermined time (for example, 20 seconds), and as shown in FIG. 4, by using the fact that the displacement of about 4 cm occurs due to the displacement of the ground after 20 seconds, the impact It is possible to accurately discriminate between the earthquake and the earthquake. In this determination, it is necessary to meet the two conditions that the vibration acceleration is equal to or greater than the second predetermined value and the displacement is equal to or greater than the first predetermined value, and the determination criterion is stricter and the determination accuracy is improved. be able to.

Further, as shown in FIG. 2, the acceleration sensor 9 is attached to the circuit board 20 of the control device of the gas meter 18. Since the circuit board 20 is attached in the horizontal direction, the acceleration sensor 9 can measure the vibration acceleration in the direction perpendicular to the surface of the circuit board, that is, in the vertical direction. Further, by obtaining the displacement from the signal of the acceleration sensor, it is not necessary to embed the sensor in the ground, and it is possible to easily measure the movement distance of oneself, that is, the displacement of the ground.

The determination of an earthquake from the vertical vibration acceleration has an advantage that it is very easy to distinguish it from an impact. That is, when the installation method of the gas pipe 21 is as shown in FIG. 2, the vibration due to the impact of a ball or the like is mainly horizontal vibration. Since it does not vibrate unless a considerable force is applied in the vertical direction, it is possible to make a rough judgment even if it is judged by acceleration, but if the earthquake and shock are judged using the vertical displacement as in the present invention, The determination accuracy can be greatly improved.

(Embodiment 2) FIG. 7 is a flow chart showing the determination operation of the seismic sensing apparatus according to Embodiment 2 of the present invention. The difference from the first embodiment is that an earthquake is determined when the acceleration exceeds a second predetermined value or the displacement exceeds a first predetermined value.

In this case, it is necessary to measure the displacement for a second predetermined time in order to measure the displacement. Therefore, the first predetermined time is set to 5 seconds and the second predetermined time is set to 3 seconds. The displacement can be measured with the acceleration within the second predetermined time, the non-measurement time is 2 seconds, and the occurrence of the earthquake can be detected without missing. As a result, it is possible to limit the measurement time to achieve low power consumption, and it is possible to detect the occurrence of an earthquake by both the displacement and the displacement. Therefore, it is possible to make a wider range of earthquake determinations and ensure a wide range of safety in using gas appliances and the like.

Even if the acceleration is small and the displacement is large such that the ground slowly collapses, it can be detected by setting the displacement as a criterion.

(Embodiment 3) FIG. 8 is a block diagram for explaining the structure of a seismic sensing apparatus according to Embodiment 3 of the present invention, FIGS. 9 and 10 are signal waveform diagrams for explaining the operation, and FIG. 11 is for explaining the operation. It is a characteristic diagram. The difference from the first embodiment is that the cycle measuring circuit 23 that measures the time cycle of the signal of the acceleration sensor 9, the cycle fluctuation measuring circuit 24 that measures the fluctuation of the time cycle output from the cycle measuring circuit, and the cycle fluctuation The determination means 25 for determining whether or not there is an earthquake based on the value and the output means 14 for outputting the determination result of the determination means are provided.

Then, the cycle measuring circuit 23 measures the cycle from the time intervals T1 and T2 of the zero cross points of the signal of the acceleration sensor 9 outputted through the band pass filter 10, and the judging means 25 makes the signal. When the ratio σ / μ of the standard deviation σ of the period and the average value μ of the period is equal to or greater than the third predetermined value (for example, 0.2), the earthquake is determined.

Then, as shown in FIGS. 9 and 10, immediately after the vibration acceleration exceeds a second predetermined value (for example, 80 cm / s2; equivalent to seismic intensity 5), the measurement of the vibration cycle is started. Then, the cycle of the vibration acceleration of the shock as shown in FIG. 9 becomes a response waveform of free vibration with damping, and the cycle vibrates at a substantially constant cycle. On the other hand, in the case of an earthquake as shown in FIG. 10, the cycle becomes very random. Fig. 11 shows a statistical chart of the number of occurrences of this cycle. The average value µ1 of the impact cycle, its standard deviation is σ1, and in the case of an earthquake it is also µ2, σ2, and the ratio σ1 / µ1, σ2. When / μ2 is larger than 0.2, it is judged as an earthquake to judge the earthquake, and the judgment accuracy is improved.

[0035]

As described above, according to the seismic device of the present invention, the following effects can be obtained. Displacement measuring means for measuring the displacement of the installation portion of the apparatus, determining means for determining whether or not the displacement signal output by the displacement measuring means is an earthquake, output means for outputting the determination result of the determining means, and power supply means With the provision, it is possible to determine that an earthquake occurs when the displacement signal exceeds the first predetermined value, and it is possible to accurately distinguish from an impact signal with a small displacement.

Further, by providing the signal converting means for converting the signal of the acceleration sensor into the displacement signal and providing the signal converting means by integration as the displacement measuring means for obtaining the displacement signal, it is easy to embed the sensor in the ground. Moreover, it is possible to measure the displacement of the installation portion of the device, that is, the displacement of the ground, and to easily distinguish it from the impact.

Further, the displacement signal after the first predetermined time is the first
By providing a determining means for determining that an earthquake occurs when the value exceeds the predetermined value, the displacement after the first predetermined time is compared to determine the displacement after the final vibration is finished, not the instantaneous value of the displacement. Earthquakes can be accurately discriminated by obtaining the movement distance of the ground.

Further, the signal of the acceleration sensor is equal to or more than the second predetermined value, and the displacement signal after the first predetermined time obtained by converting the signal of the acceleration sensor exceeds the first predetermined value. By providing the determination means for sometimes determining that it is an earthquake, it is an earthquake when the signal of the acceleration sensor exceeds the second predetermined value and the displacement after the first predetermined time exceeds the first predetermined value. It is possible to accurately determine the earthquake by making a determination that both conditions are satisfied and the determination is made when both conditions are satisfied.

Further, the signal of the acceleration sensor is equal to or more than the second predetermined value, or the displacement signal after the first predetermined time obtained by converting the signal of the acceleration sensor exceeds the first predetermined value. When the signal of the acceleration sensor becomes equal to or higher than the second predetermined value or the displacement after the first predetermined time exceeds the first predetermined value by providing a determination unit that determines that it is an earthquake By judging that it is an earthquake,
By determining that there is an earthquake when any of the conditions occurs, it is possible to make a wider range of earthquake determinations and ensure a wide range of safety in using gas appliances and the like.

Further, there is provided a measurement interval control means for measuring the displacement signal by the displacement measuring means at the second predetermined time interval, and at every second predetermined time interval and only during the third predetermined time. By measuring the displacement by the displacement measuring means, the power consumption required for the measurement is reduced as compared with the case where the measurement is carried out at the second predetermined time interval and the measurement is performed at the second predetermined time interval. By setting only the time, it is possible to avoid measuring an excessively long vibration waveform and reduce the power consumption required for the measurement.

Further, by providing the displacement measuring means for measuring the displacement in the vertical direction, by measuring the displacement in the vertical direction of an earthquake that is almost accompanied by the vertical motion, it is possible to obtain a shock with less vertical vibration. The distinction can be made accurately.

Further, by determining whether the cycle of the vibration acceleration is regular or random by using the standard deviation and the average value of the cycle, the earthquake and the shock can be accurately determined.

[Brief description of drawings]

FIG. 1 is a block diagram of a seismic sensor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the installation status of a gas meter equipped with the seismic sensor of the present invention.

[Fig.3] Measurement waveform diagram of displacement of the seismic sensor

[Figure 4] Measurement waveform diagram of displacement of the same seismic device

[Fig. 5] Measurement waveform diagram of vibration acceleration of the same seismic device

FIG. 6 is a flowchart showing a measurement operation of the seismic sensor.

FIG. 7 is a flowchart showing a measuring operation of the same seismic sensing apparatus according to the second embodiment of the present invention.

FIG. 8 is a block diagram of a seismic sensor showing a third embodiment of the present invention.

[Fig. 9] Measurement waveform diagram of vibration acceleration of the same seismic device

[Fig. 10] Measurement waveform diagram of vibration acceleration of the same seismic device

FIG. 11 is a statistical chart showing the measurement data of the seismic sensor.

FIG. 12 is a sectional view of a conventional seismic sensing device.

[Explanation of symbols]

 9 Vibration Acceleration Sensor 11 Integrating Circuit (Signal Converting Means) 12 Displacement Measuring Device (Displacement Measuring Means) 13, 25 Judging Device (Judging Means) 14 Output Device (Output Means) 15 Measuring Time Control Device 17 Battery (Power Means) 23 Cycles Measuring circuit 24 Periodic fluctuation measuring circuit

Claims (12)

[Claims] 1. Displacement measuring means for measuring a moving distance of an installation portion of the apparatus, judging means for judging occurrence of an earthquake from a displacement signal outputted by the displacement measuring means, and a judgment result of the judging means. A seismic sensing apparatus comprising an output means, the displacement measuring means, the determining means, and a power supply means for driving the output means. 2. The seismic sensing apparatus according to claim 1, further comprising displacement measuring means for obtaining a displacement signal by providing a signal converting means for converting a signal of the acceleration sensor into a displacement signal. 3. The seismic sensing apparatus according to claim 2, further comprising a signal converting means for integrating a signal from the acceleration sensor twice and converting the signal into a displacement signal. 4. The seismic sensing apparatus according to claim 1, further comprising: a determination unit that determines that an earthquake occurs when the displacement signal after the first predetermined time exceeds a first predetermined value. 5. An earthquake is determined when the signal of the acceleration sensor is equal to or larger than a second predetermined value and the displacement signal obtained by converting the signal of the acceleration sensor exceeds the first predetermined value. The seismic sensing device according to claim 2 or 3, further comprising: 6. An earthquake occurs when the signal from the acceleration sensor is equal to or greater than a second predetermined value, or when the displacement signal obtained by converting the signal from the acceleration sensor exceeds the first predetermined value. The seismic sensing device according to claim 2 or 3, further comprising a determining means for determining. 7. The seismic sensing apparatus according to claim 1, further comprising a measurement interval control means for measuring a displacement signal by the displacement measuring means at a second predetermined time interval. 8. The seismic sensor according to claim 7, wherein the displacement measuring means measures the displacement at intervals of a second predetermined time and only during a third predetermined time. 9. The seismic sensing device according to claim 1, further comprising a displacement measuring means for measuring the displacement in the vertical direction. 10. A vibration measuring means for measuring vibration information of an installation portion of the apparatus, a cycle measuring means for measuring a time cycle of a signal output by the vibration measuring means, and a fluctuation of the time cycle as a third predetermined value. Judgment means for judging whether or not there is an earthquake by comparing with a value, output means for outputting the judgment result of the judgment means, drive the vibration measurement means, the cycle measurement means, the judgment means and the output means A seismic device equipped with a power supply. 11. The seismic sensing apparatus according to claim 10, further comprising cycle measuring means for measuring a time cycle from a time interval between zero cross points of a signal output by the vibration measuring means. 12. A periodic fluctuation measuring means for measuring a ratio σ / μ of a standard deviation σ of the time period and an average value μ of the time period, and comparing the ratio σ / μ with a third predetermined value. The seismic sensing apparatus according to claim 10, further comprising a determination unit that determines whether or not the seismic response is determined.