JP2001174321A - Vibration information acquiring device and earthquake sensing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify an electric structure, to reduce the cost and size, and to increase the reliability on a danger report with high time responsiveness. SOLUTION: The vibration signal Svx by a vibration detecting element 11x is applied to the field effect transistor FET1x of an impedance converting means 13x. The source and drain output voltages Vs, Vd of the FET1x are fed to a full-wave rectifying means 200x, and the absolute value signal Sax is inverted and amplified by an amplifying means 300x. Only the pinch-off voltage Vp of FET2x is level-shifted by the level shifting means 41x of an analog square arithmetic means 400x and applied to the field effect transistor FET2x of a source ground type amplifying square means 42x. The vibration information signals Six, Siy, Siz outputted from X, Y, Z axial direction vibration information acquiring devices 1000x, 1000y, 1000z are added by an addition arithmetic means 2000, and the synthetic acceleration information signal Sc is determined by an earthquake motion level determining means 3000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a vibration information obtaining apparatus for obtaining vibration information by electrically detecting vibration. Further, the present invention relates to a seismic device for sensing earthquake motion by combining a plurality of vibration information acquisition devices. This seismic device is suitably used particularly for issuing an alarm when an earthquake occurs or for stopping a device that needs to be stopped for safety.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Laid-Open Publication No.
There is a seismic intensity meter disclosed in Japanese Patent Publication No. This vibration meter is provided with vibration information acquisition devices for three directions orthogonal to each other. Each vibration information acquisition device has an acceleration sensor, a preceding amplifier, and a seismic motion frequency component (0.1 to 10 Hz).
A band-pass filter that passes only the signal, an amplifier in the subsequent stage, and an absolute value part that takes the absolute value of the amplified seismic signal.
An integrator that integrates the absolute value signal at a predetermined cycle (for example, 1/60 second), an A / D converter that samples the integrated signal at the same cycle and converts it from analog to digital, and a memory that stores the digital signal; An averaging unit that averages data over a predetermined time (for example, 10 seconds) stored in the memory to generate averaged data.

Then, averaging data X, Y, and Z, which are outputs of averaging units of three vibration information acquisition devices, are input, and based on an arithmetic expression, R = (X ² + Y ² + Z ² ) ^1/2 . The arithmetic unit that generates the synthetic acceleration data R, the seismic intensity table storing the correspondence between the acceleration and the seismic intensity of the earthquake, and the generated synthetic acceleration data R and the data read from the seismic intensity table are compared. A comparison unit that determines the seismic intensity and outputs the seismic intensity data, a peak hold unit that takes the maximum value of the seismic intensity data that changes with time, a changeover switch that switches between the instantaneous value and the maximum value of the seismic intensity data, and an instantaneous value or a maximum value. A display unit for displaying a value.

In the above description, the absolute value of the seismic wave signal is obtained in order to obtain amplitude information without omission in time and to improve the accuracy of the integrated value. The integration and the A / D conversion are performed, for example, at a period of 1/60 sec.
60 data are obtained per second. Averaging is the averaging of the data for 10 seconds, which is the average of 600 samples.

[0005] The above equation is obtained by calculating the X of the three-dimensional vector R.
X-, Y-, and Z-axis components, Y-axis components, and Z-axis components
Is a general operation expression for obtaining the magnitude (scalar) of the vector. This calculation result is regarded as acceleration information in the three-dimensional direction.

[0006]

In the above-mentioned prior art seismometer, for example, the circuit configuration is digitized in order to average 600 sample values for 10 seconds. That is, since a large number of sample values that change in time series must be temporarily stored, a memory is required. In order to store the data in a memory, an analog signal must be converted into digital data, and an A / D converter is required. The averaging process of sequentially adding a large number of sample values read from the memory and dividing by the number of samples requires software processing by a microprocessor.

Although not disclosed in the above-mentioned publication, the software processing is specifically, for example, reading out the i-th sample value data Di and storing it in a register R (R ←
Di), after performing a process of adding the contents of the register R and the contents of the accumulator A, storing the result of the addition in the accumulator (A ← A + R), and setting a variable i corresponding to the address.
Is incremented (i ← i + 1), it is determined whether or not the result has reached the number of samples n (i ≧ n?), And the above operation is repeated until the result is reached. Such software processing takes time.

As described above, since the A / D conversion unit, the memory, the averaging unit, the calculation unit, the seismic intensity table, the comparison unit, and the like have a digital configuration, the overall configuration is complicated and large-scale, and cost is low. Large burden on space. Integration into an integrated circuit (IC) is also difficult. In particular, memory is costly. Software creation is also expensive.

[0009] In particular, it takes time to write to, read from, and average the memory, so that the overall processing speed is slow and the processing time is too long. Depending on the purpose, averaging results in extremely dull information as instantaneous vibration energy, which is particularly unsuitable for danger avoidance.

In the above prior art, the instantaneous value is measured, but the instantaneous value is only an average value, not an instantaneous value in a normal sense. X, Y,
The sum of squares of Z represents the energy level of vibration or the absolute value of acceleration.
The accuracy as an instantaneous value is low.

The averaging is probably for the following reason. Seismic vibrations are not accurate sinusoidal waveforms, but rather complex, with extremely diverse waveforms synthesized for each of amplitude, frequency, and phase. Therefore, it is considered that a large number of sample values are averaged to capture the total energy in order to correspond to the actual seismic intensity.

However, averaging causes difficulty in accurately determining the magnitude of an instantaneous ground motion in a strict sense. In particular, in the case of a direct-type earthquake represented by the Great Hanshin Earthquake, the so-called vertical ground motion is extremely rapid and huge, and is considered to be the largest cause of a severe disaster. This is considered to be because a vibration having a short cycle and a large peak value instantaneously arrives. If averaging is performed including such longitudinal vibrations, the time responsiveness is extremely reduced, the amount of instantaneous information is dulled, and the risk level cannot be understood.

The present invention has been made in order to solve the above-mentioned problems, and the electric configuration has been simplified as much as possible.
An object of the present invention is to propose a technology that has a high time response and a high reliability for danger notification while reducing costs and downsizing.

[0014]

A vibration information obtaining apparatus according to the present invention for solving the above-mentioned problems converts a vibration into an electric signal to form a vibration signal, and squares the vibration signal in an analog manner. Thus, a vibration information signal is obtained.

Further, the seismic device according to the present invention combines a plurality of the above-described analog square vibration information acquisition devices so as to capture vibration signals in two or three directions orthogonal to each other, and obtains a vibration information signal based on each square. Are added to obtain a synthetic vibration information signal that is used as a basis for determining the seismic motion level.

According to this method, since the squared signal is analog-squared, the detected vibration signal can be converted in real time and instantaneously to obtain a vibration information signal or a combined acceleration information signal. Therefore, as compared with the conventional technology in which digital signal processing is performed using an A / D converter, a memory, and an MPU (micro processing unit) that performs arithmetic processing, time response is faster and operation stability is improved. It is excellent. Furthermore, since the obtained vibration information signal or composite acceleration information signal is an instantaneous value in a normal sense, the accuracy of information as instantaneous vibration energy is high. Therefore, the present invention is highly effective especially in emergency situations such as issuing an alarm or stopping a device to avoid danger. In addition, the circuit configuration as a whole can be made sufficiently simple. That is, it is possible to realize a vibration information acquisition device or a seismic device with high accuracy and time response while reducing costs and downsizing.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be generally described.

The vibration information acquiring apparatus according to the first aspect of the present invention includes vibration detecting means for electrically detecting vibration and outputting a vibration signal, and analog square calculating means for squaring the vibration signal in an analog manner. It has a configuration.

According to the first aspect of the invention, since the vibration signal is squared in real time and in an analog manner, the vibration information signal can be obtained in a state in which the time response and the operation stability are good. Since the instantaneous value is output according to the square, the sensitivity is increased. In addition, compared to the digital configuration,
Cost reduction and downsizing can be achieved.

A vibration information acquiring apparatus according to a second aspect of the present invention includes a vibration detecting means for electrically detecting vibration and outputting a vibration signal, and inputting the vibration signal and performing full-wave rectification to output an absolute value signal. The apparatus includes a full-wave rectifier and an analog square calculator for squaring the absolute value signal in an analog manner. According to this, since the absolute value signal subjected to full-wave rectification is squared, signal processing is further simplified.

According to a third aspect of the present invention, there is provided the vibration information acquiring apparatus according to the first and second aspects, wherein the analog square calculating means utilizes a voltage-current characteristic of a field-effect transistor. And a level shift voltage substantially equal to the pinch-off voltage of the field-effect transistor. The field effect transistor is given by I _D = (I _DSS / V
Although it has a voltage-current characteristic of (p ² ) × (Vp−V _GS ) ² , in order to make (Vp−V _GS ) ² = Vin ² ,
From Vin = V _GS -Vp, V _GS = Vin, where Vp = Vsh
+ Vsh (corresponding to V5 = V4 + Vsh in the embodiment described later).

According to the third aspect, the vibration information signal which is the square of the detected vibration signal can be obtained using the field effect transistor which is a device having a very simple structure.

According to a fourth aspect of the present invention, there is provided the vibration information acquiring apparatus according to the first to third aspects, wherein the vibration detecting means comprises:
It is configured to include impedance conversion means.

The operation of the fourth invention is as follows. The quantity of electricity detected by the vibration detecting element is generally very weak. To pick it up, you need to use a high resistance. However, if the input impedance is too large, the signal level will be too small. Therefore, in order to raise the signal to a necessary level in signal processing, impedance conversion is performed to reduce the output impedance. Thereby, the weak vibration can be effectively captured. In particular, it is effective in the case of a type that converts vibration into an amount of generated charges.

According to a fifth aspect of the present invention, in the vibration information acquiring apparatus according to the first to fourth aspects, the vibration detecting means is configured as an acceleration detecting means for outputting an acceleration signal as the vibration signal. ing.

The sixth and subsequent inventions of the present application relate to a seismic device.

The sixth embodiment of the present invention provides the above-described fifth embodiment.
The two vibration information acquisition devices according to the present invention are provided for detecting acceleration signals in two directions orthogonal to each other, and an addition operation means for adding acceleration information signals output from the two analog square operation means is further provided. It is configured as having.

The seismic device according to the seventh aspect of the present invention includes the above-described fifth aspect.
The three vibration information acquisition devices of the invention of the present invention are provided for detecting acceleration signals in three directions orthogonal to each other, and an addition operation means for adding acceleration information signals output from the three analog square operation means is further provided. It is configured as having.

According to the sixth or seventh aspect of the invention, the acceleration signal in two or three directions is squared in an analog manner in real time instantaneously, so that the acceleration information signal can be obtained with good time response and operation stability. can do.
Since the instantaneous value is output according to the square, the sensitivity is increased. In addition, cost reduction and downsizing can be achieved as compared with the digital configuration.

An eighth embodiment of the present invention provides the seismic device according to the sixth and seventh aspects, wherein a filter means for passing only a seismic motion frequency component is provided in a stage preceding the analog square calculating means. . Thereby, erroneous determination is reduced.

According to the ninth aspect of the present invention, there is provided the seismic device according to the sixth aspect.
The invention according to any one of the eighth to eighth aspects, further comprising a seismic-motion level determining means for determining a seismic-motion level by comparing the combined acceleration information signal output from the adding operation means with a predetermined threshold value. . According to this, it is highly effective especially in emergency situations, which is an important requirement for seismic devices.

Hereinafter, specific embodiments of a vibration information acquisition device and a vibration sensor according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing an electrical configuration of a vibration information acquiring apparatus according to Embodiment 1 of the present invention. The vibration information acquisition device 1000 includes a vibration detection unit 100 that detects a vibration, converts the vibration into an electric signal, and outputs the electric signal as a vibration signal Sv, and a whole that inputs the vibration signal Sv, performs full-wave rectification and outputs an absolute value signal Sa. Wave rectifier 20
0, and an analog square calculating means 400 that squares the absolute value signal Sa in an analog manner and outputs a vibration information signal Si. Needless to say, the vibration detecting means 100 and the full-wave rectifying means 20
0 is also an analog circuit.

The vibration has such a property that the movement in the positive direction and the movement in the negative direction are alternately repeated from the neutral state. Then, due to its physical properties, the vibration detecting means 100 generates a vibration information signal Si having a waveform that alternately repeats plus and minus when converting the vibration into an electric signal.

The energy of vibration is proportional to the square of the amplitude. Note that it is also proportional to the square of the frequency (angular frequency). Crest value (from the valley to the peak of the wave, almost twice the amplitude)
May be used, but for the convenience of signal processing, the square of the amplitude is used. Therefore, the vibration signal Sv is subjected to full-wave rectification in the full-wave rectifier 200 to generate the absolute value signal Sa.

The analog square operation means 400 generates the vibration information signal Si by squaring the absolute value signal Sa in an analog manner, and calculates the energy of the vibration. Advantageously, the squared vibration information signal Si also emphasizes changes in the vibration signal Sv.

Incidentally, to simplify the vibration signal Sv,
Assuming a sine wave Asinωt, the vibration information signal Si is Acos2
ωt / 2 (accurately, A / 2−Acos2ωt / 2). That is, the frequency is doubled and the period is halved,
A steeper waveform can be obtained.

Vibration detecting means 100, full-wave rectifying means 200
Needless to say, the squaring means 400 also includes an analog circuit. Therefore, the time response from the detection of vibration to the output of the vibration information signal Si is extremely high as compared with the related art using a digital circuit configuration for A / D conversion, memory storage, averaging, and the like. . In addition, the circuit configuration as a whole can be made sufficiently simple. I
C conversion is also relatively simple. As a result, it is possible to advantageously develop cost and space aspects.

Since the time response from the input to the output is extremely high and the obtained vibration information signal Si is an instantaneous value in a normal sense, the accuracy of the information as the instantaneous vibration energy is high. . Therefore, the present invention is highly effective especially in emergency situations such as issuing an alarm or stopping a device to avoid danger.

For the danger notification, a vibration level determining means 500 for determining a vibration level by comparing the vibration information signal Si with a predetermined threshold value Vth is provided at the next stage of the analog square calculating means 400, and an alarm is issued. It may be configured to connect to the means 600. As an application, it may be connected to the display unit 700 or the information processing unit 800 including a microcomputer.

Specific examples of the vibration detecting element in the vibration detecting means 100 include a piezoelectric type, an electrodynamic type, a servo type, and a strain gauge type. In any case, in the type in which vibration is converted into the generated charge amount, the charge is converted into a voltage in the subsequent signal processing, but the peak value of the generated voltage is extremely weak. It is desirable to connect impedance conversion means to the stage.

If the vibration intended for the pickup is in a specific frequency band, a filter means for passing only the vibration frequency component is incorporated in the vibration detecting means 100. As a filter means, a band-pass filter is generally considered, but depending on conditions, a high-pass filter or a low-pass filter may be used. Further, the filter means may be provided before the full-wave rectification means 200 or before the analog square calculation means 400.

In addition, the vibration signal generated by the vibration detecting element in the vibration detecting means 100 is often very weak, and in order to cope with this, an amplifier is inserted at any stage in the circuit. And

The vibration detecting means 100 may be a means for detecting displacement, a means for detecting speed, or a means for detecting acceleration. In an embodiment of a seismic device described later, the device is configured as a means for detecting acceleration.

As described above, by converting the entire configuration into an analog circuit, the total configuration is compared with the conventional technology in which digital signal processing is performed using a memory and an MPU (micro processing unit) for performing arithmetic processing. Time response is fast and operation stability is excellent.
The analog circuit configuration is relatively simple, small, and inexpensive. That is,
Vibration information acquisition device 1000 with high accuracy and time response
Can be realized while reducing costs and downsizing.

It should be noted that the vibration level determining means 500 may have a digital configuration instead of an analog circuit configuration.

(Second Embodiment) In the first embodiment, the vibration detecting means 100 and the analog square calculating means 4
00, a full-wave rectifier 200 is inserted. However, the full-wave rectifier 200 is not necessarily required. As in the second embodiment shown in FIG. A configuration in which the analog square operation means 400 is connected may be employed. This is because (Asinωt) ² = A / 2−Acos2ωt / 2 can be applied as it is, mathematically and analogically, without full-wave rectification.

Note that items which have been described in the first embodiment and which are not described again in the second embodiment also apply to the second embodiment as they are, and a detailed description thereof will be omitted.

(Embodiment 3) Embodiment 3 relates to a seismic device, and detects acceleration signals in two directions orthogonal to each other by using two of the vibration information acquisition devices of Embodiment 1 described above. And an addition calculating means for adding the acceleration information signals output from the two analog square calculating means. Embodiment 3 relates to a seismic device only in a two-dimensional direction (east-west direction and north-south direction) in a horizontal plane.

FIG. 3 shows a seismic device 5 according to the third embodiment of the present invention.
000 is a block diagram showing an electrical configuration of the 000. FIG. The X-axis direction vibration information acquisition device 1000x includes an acceleration detection unit (corresponding to the vibration detection unit of the first embodiment) 100x, a full-wave rectification unit 200x, and an analog square calculation unit 400x. The amplifying means 300x is inserted between the means 200x and the analog squaring means 400x. Similarly, the Y-axis direction vibration information acquisition device 1000y
Acceleration detection means 100y, full-wave rectification means 200y,
It has an amplifying means 300y and an analog square calculating means 400y.

The direction in which the vibration is detected by the vibration detecting element in the acceleration detecting means 100x in the X-axis direction and the direction in which the vibration is detected by the vibration detecting element in the acceleration detecting means 100y in the Y-axis direction are set to be orthogonal to each other.

The vibration information acquisition devices 1000x and 1000y in the X-axis direction and the Y-axis direction may include the filter means and the impedance conversion means as described above.
The filter means is configured to pass only the seismic ground frequency component. Usually, 0.1 to 10 Hz is adopted as the seismic motion frequency component.

Further, the acceleration information signal Six, which is the output of the analog square calculating means 400x in the X-axis direction, and the acceleration information signal Sy, which is the output of the analog square calculating means 400y in the Y-axis direction, are added to generate a combined acceleration information signal Sc. Is provided.

Then, at the next stage of the addition operation means 2000,
A seismic-motion level judging means 3000 for judging the seismic-motion level by comparing the combined acceleration information signal Sc with a predetermined threshold value Vth ₁ is provided, and the alarm means 600 is connected to the next stage. As an application, it may be connected to the display unit 700 or the information processing unit 800 including a microcomputer.

Next, the operation of the seismic device 5000 according to the third embodiment configured as described above will be described.

In the X-axis direction vibration information acquisition device 1000x, the acceleration detecting means 100x detects the vibration in the X-axis direction, converts it into a voltage signal by a resistor, converts the impedance into a voltage signal by an impedance converting means, and outputs it as an acceleration signal Svx. I do. At this time, only the seismic motion frequency component is extracted by the filter means. Acceleration signal S
The vx is full-wave rectified by the full-wave rectifier 200x and outputs an absolute value signal Sax. The amplification means 300x amplifies the absolute value signal Sax and outputs the amplified absolute value signal Sbx. The analog square calculating means 400x squares the absolute value signal Sbx in an analog manner, and calculates the acceleration information signal Six
Is output to the addition operation means 2000.

The same applies to the operation of the Y-axis direction vibration information acquisition device 1000y. The analog square operation means 400y outputs the acceleration information signal Siy to the addition operation means 2000.

The absolute value signal Sbx after amplification in the X-axis direction is represented by the symbol X ', the absolute value signal Sby in the Y-axis direction is represented by Y', and the combined acceleration information signal Sc which is the processing result of the addition operation means 2000. Is represented by Q, then Q = X ′ ² + Y ′ ² .

[0059] seismic motion level checker 3000 receives the composite acceleration information signal Sc (Q), compares it with a predetermined threshold value Vth _1. Result of the comparison, when the level of the composite acceleration information signal Sc (Q) is a threshold value Vth ₁ or more, "H" level of the alarm signal Sar result for outputting, to operate the warning means 600. The combined acceleration information signal Sc output from the addition operation means 2000 is also sent to the display means 700 and the information processing means 800. The alarm unit 600 may be a unit that directly issues an alarm, such as a buzzer, a siren, or a red warning light, or a microprocessor interface in various devices that require an emergency stop or a safe operation.

The above equation is based on the following concept. Y-axis component of two-dimensional vector R, Y
When the axial components are X 'and Y', a general arithmetic expression for calculating the magnitude (scalar) of the vector is R = (X ² + Y ² ) ^1/2, that is, R ² = X ² it is a + Y ^2, in the level determination not harm any be used in the above calculation formula of the square of R Q (= R ^2), from such reasons, which is the output resultant acceleration of the addition operation unit 2000 The information signal Sc is directly input to the seismic motion level determining means 3000.

Assuming that the acceleration signal Svx output from the acceleration detecting means 100x in the X-axis direction is X and the acceleration signal Svy output from the acceleration detecting means 100y in the Y-axis direction is Y, the coefficient is ax = ay = a ₀ X ′ = ax · X = a ₀ · X Y ′ = ay · Y = a ₀ · Y Therefore, the value Q of the composite acceleration information signal Sc is: Q = a ₀ ² · (X ² + Y ² ) Becomes

The obtained composite acceleration information signal Sc is an instantaneous value in a regular meaning, and the accuracy of the basic information for determining the seismic intensity is high. Therefore, the present invention is highly effective especially in emergency situations such as issuing an alarm or stopping a device to avoid danger.

As described above, since both the components of the vibration information acquisition devices 1000x and 1000y in the X-axis direction and the Y-axis direction, and the addition operation means 2000 are configured by analog circuits, the total A
Time response from the detection of vibration to the output of the combined acceleration information signal Sc compared to the conventional technology that performs digital signal processing using an A / D converter, memory, and MPU (micro processing unit) that performs arithmetic processing Is fast and has excellent operation stability. Further, the analog circuit configuration is relatively simple, and the integration into an IC is also relatively simple. That is, it is possible to realize the seismic device 5000 having high accuracy and time response while reducing costs and downsizing.

The seismic-motion level determining means 3000 may have a digital configuration instead of an analog circuit configuration.

(Embodiment 4) The vibration sensor of Embodiment 4 includes the three vibration information acquisition devices of Embodiment 1 described above for detecting acceleration signals in three directions orthogonal to each other. The configuration is provided with an addition operation means for adding the acceleration information signals output from the three analog square operation means. The fourth embodiment relates to a three-dimensional seismic device (east-west direction, north-south direction, and vertical direction).

FIG. 4 shows a seismic device 5 according to a fourth embodiment of the present invention.
000 is a block diagram showing an electrical configuration of the 000. FIG. X-axis direction vibration information acquisition device 1000x, Y in the third embodiment
A Z-axis direction vibration information acquisition device 1000z is provided in addition to the axial direction vibration information acquisition device 1000y. The configuration of the Z-axis direction vibration information acquisition device 1000z is the same as that of the other vibration information acquisition devices, and 100z is an acceleration detection unit (in the first embodiment, which may include a filter unit and an impedance conversion unit). (Equivalent to vibration detection means), 2
00z is a full-wave rectifier, 300z is an amplifier, 400z
Is an analog square operation means. The vibration sensing direction of the vibration detecting element in the acceleration detecting means 100z in the Z-axis direction is
X-axis direction, Y-axis direction acceleration detecting means 100x, 100
It is set to be orthogonal to any of the vibration sensing directions of the vibration detecting element at y.

Then, for the addition operation means 2000,
Analog square computing means 400x in the X-axis direction and the Y-axis direction
The acceleration information signal Siz output from the analog square operation means 400z in the Z-axis direction is input together with the acceleration information signals Six and Sy output from 400y.

The absolute value signal Sbx after amplification in the X-axis direction is represented by the symbol X ', the absolute value signal Sby in the Y-axis direction is represented by Y', and the absolute value signal Sbz in the Z-axis direction is represented by Z '. Denoting the processing result is a composite acceleration information signal Sc addition operation means 2000 in Q, the ^{Q = X '2 + Y'} 2 + Z '2.

The acceleration signal Svx output from the acceleration detection means 100x in the X-axis direction is represented by X, the acceleration signal Svy output from the acceleration detection means 100y in the Y-axis direction is represented by Y, and the acceleration detection means 100z in the Z-axis direction Assuming that the acceleration signal Svz, which is the output, is Z, the coefficient is ax = ay = az
= A ₀ , X ′ = ax · X = a ₀ · X Y ′ = ay · Y = a ₀ · Y Z ′ = az · Z = a ₀ · Z Therefore, the value Q of the combined acceleration information signal Sc ^{_{is, Q = a 0 2 · (}} X 2 + Y 2 + Z 2) become.

For example, if the combined acceleration is 4.25 m / sec ² (425 Gal) or more in a cycle of 2.0 sec,
In a cycle of 0.1 sec, the resultant acceleration is 19 m / sec ² (1
It is said to be equivalent to a seismic intensity of 7 or more (900 Gal) (JMA seismic intensity class).

According to this criterion, the period is 2.0 sec.
In the case of (0.5 Hz), it is determined that the seismic intensity 7 at 18 (≒ 4.25 ²⁾ or more.

The matters described in the third embodiment (FIG. 3) and not described in the fourth embodiment are included in the present embodiment as they are including the operation and effects in addition to the configuration and operation. 4.
Detailed description is omitted.

(Embodiment 5) Embodiment 5 corresponds to a more specific example of the vibration sensor 5000 of Embodiment 4 described above. FIG. 5 shows a seismic device 50 according to the fifth embodiment.
FIG. 6 is a circuit diagram showing an electrical configuration of the circuit of FIG.

As a part for acquiring vibration information in three directions orthogonal to each other in the three-dimensional space, that is, in each of the X-axis direction, the Y-axis direction, and the Z-axis direction, the X-axis direction vibration information acquisition device 1000x and the Y-axis direction vibration information acquisition The apparatus includes a device 1000y and a Z-axis direction vibration information acquisition device 1000z. Furthermore, these three vibration information acquisition devices 1
000x, 1000y, and 1000z are provided with an addition calculating means 2000 for adding vibration information (acceleration information) output from each of them.

These three vibration information acquisition devices 1000
The configurations of x, 1000y, and 1000z are similar to each other. Here, a specific configuration of each vibration information acquisition unit will be described using the X-axis direction vibration information acquisition device 1000x as a representative.

The X-axis direction vibration information acquisition device 1000x
Acceleration detection means 100x, full-wave rectification means 200x,
An amplifying unit 300x and an analog square calculating unit 400x are provided.

The acceleration detecting means 100x converts the electric charge signal output from the vibration detecting element 11x into a voltage signal by converting the electric charge signal output from the vibration detecting element 11x such as a piezoelectric sensor utilizing the piezoelectric effect into an acceleration signal Svx (V1) (FIG. 6). (Refer to (a)) and the impedance conversion means 13x
And

The vibration detecting element 11x and the grounding resistor R11 constitute filter means 12x for passing only the seismic motion frequency component (0.1 to 10 Hz). Since the vibration detecting element 11x such as an acceleration sensor (piezoelectric sensor) is a capacitive element, by connecting the grounding resistor R11 to the filter means 12x, the high-pass filter (H
PF). In this case, since the capacitance of the acceleration sensor 11x is small, the ground resistance R1
It is desirable to set the resistance value of 1 to be large and set the cutoff frequency to be equal to or lower than the low cutoff frequency of the pass band. Generally, the signal band of earthquake motion is 0.1 to 10
Hz, the resistance value of the ground resistor R11 is several M
It is better to have a size of Ω or more. Then, the input impedance becomes the resistance value of the ground resistor R11 and becomes higher.
For example, when the capacitance is 100 pF and the resistance value is 20 GΩ, fc ≒ is obtained from the cutoff frequency fc = １ ／ πCR.
0.08 Hz.

The impedance converting means 13x comprises a field effect transistor FET1x, a source resistor R12, and a drain resistor R13. As the field-effect transistor FET1x, a junction type N-channel type is used.

The full-wave rectifier 200x is composed of a first half-wave rectifier circuit 21x and a second half-wave rectifier circuit 22x. The first half-wave rectifier circuit 21x includes a DC cut capacitor C21, a ground resistor R21, and a rectifying diode D21. Capacitor C21
A high-pass filter is configured by the resistor R21 and cuts a DC component. The second half-wave rectifier circuit 22x is similarly configured and includes a capacitor C22, a ground resistor R22, and a diode D22 as its constituent elements.

The connection point between the acceleration sensor 11x and the ground resistor R11 is connected to the gate electrode G of the field effect transistor FET1x, the source resistor R12 is connected between the source electrode S and the ground GND, and the drain electrode D is connected to the high potential. A drain resistor R13 is connected between the power supply terminal Vcc and the side power supply terminal Vcc. With the above, the impedance conversion means 1
3x are configured.

Outputs are taken out from both the source electrode S and the drain electrode D of the field effect transistor FET1x,
These are input to a first half-wave rectifier circuit 21x and a second half-wave rectifier circuit 22x, respectively. This allows the so-called C
Forming an E division circuit; In the CE division circuit, the phase of the output signal is reversed, and is accompanied by a phase shift of 180 °. That is, the output signal Vs of the source electrode S
And the output signal Vd of the drain electrode D has a phase of 180 °
It is shifted (see FIG. 6B).

When the resistance value of the source resistor R12 is equal to the resistance value of the drain resistor R13, both output signals Vs, Vd
Are almost equal to each other. When the two resistance values are different, the magnitude of both output signals Vs and Vd corresponds to the ratio of the two resistance values, but the phase shift is 180 °. here,
It is assumed that the resistance values of the resistors R12 and R13 are set so that the magnitudes of the output signals Vs and Vd are equal.

The output impedance of both the source electrode S and the drain electrode D can be made smaller than the input impedance. Therefore, the output signal Vs of the source electrode S and the output signal Vd of the drain electrode D are obtained by impedance-converting the input signal. That is, the field effect transistor FET1x and the two resistors R12, R13
Has both a CE dividing circuit function and an impedance conversion function.

The diode D of the first half-wave rectifier circuit 21x
The cathode of the diode 21 and the cathode of the diode D22 of the second half-wave rectifier circuit 22x are connected to each other to form a full-wave rectifier 200x.

Assume that the waveform of the acceleration signal Svx obtained by the acceleration detecting means 100x is a sine wave signal V1 as shown in FIG. This sine wave signal V1 is applied to the gate electrode G of the field effect transistor FET1x. Since the field-effect transistor FET1x is of an N-channel type, a large (saturated) drain current I _DSS flows when the gate voltage is zero. As the gate voltage increases to the negative side, the drain current _ID is reduced, and the level of the output signal Vs, which is the voltage across the source resistor R12, drops. Conversely, the voltage drop due to the drain resistor R13 decreases, and the level of the output signal Vd increases. Since the peak value of the acceleration signal Svx (V1) applied to the gate electrode G is at a very small level, the field effect transistor F
The characteristics of ET1x are almost linear, and a constant DC component V
_The output signals Vs and Vd have phases opposite to each other in a state including ₀ s and V ₀ d.

The lower output signal Vs is input to the first half-wave rectifier circuit 21x, and the direct-current component Vs is applied by a high-pass filter including the capacitor C21 and the ground resistor R21.
₀ s is cut off and becomes a sine wave in phase with the sine wave signal V1. It is rectified as it passes through diode D21 and only the positive half-wave passes. It corresponds to the first half period portion T1 of the positive half wave of the sine wave signal V1. That is, the thick line portion of the output signal Vs in FIG. 6B passes.

The upper output signal Vd is input to the second half-wave rectifier circuit 22x, and the direct current component Vd is passed through a high-pass filter including the capacitor C22 and the ground resistor R22.
₀ d is cut, a sine wave of opposite phase to a sine wave signal V1. Rectified as it passes through diode D22,
Only the positive half wave passes. It corresponds to the second half period portion T2 of the negative half wave of the sine wave signal V1. That is,
The thick line portion of the output signal Vd in FIG. 6B passes.

The two positive half-wave signals whose phases are shifted by 180 ° are combined at a connection point between the two diodes D21 and D22, and become an absolute value signal Sax, that is, a full-wave rectified signal V3 shown in FIG. 6C. .

Next, the amplifying means 300x will be described. This amplifying means 300x includes an operational amplifier 31, a ground resistor R31 connected between its inverting input terminal (-) and the ground GND, and a feedback resistor R32 connected between its output terminal and the inverting input terminal (-). It is composed of The output terminal of the full-wave rectifier 200x is connected to the non-inverting input terminal (+) of the operational amplifier 31x. That is, the amplifying unit 300x is configured as a non-inverting amplifying circuit. The amplification factor is (1 + R32 / R31). The waveform of the output signal V4 of the amplifier 300x is as shown in FIG. This is the amplified absolute value signal Sbx.

Next, the analog square calculating means 400x will be described. This analog square operation means 400x
The voltage-current characteristic (square characteristic) of the field-effect transistor FET2x is used, and a pinch-off voltage Vp of the field-effect transistor FET2x is applied to an input signal.
Level shift voltage Vsh substantially equal to (minus value)
Are added.

The analog squaring means 400x comprises a level shift means 41x and a source-grounded amplification squaring means 42. The level shift means 41x is provided between the output terminal of the amplifying means 300x and the field effect transistor FET.
A decoupling capacitor C41 is inserted between the 2x gate electrode G and a connection point between the decoupling capacitor C41 and the gate electrode G is connected to the level shift voltage Vsh.

The level shift voltage Vsh is set equal to the pinch-off voltage Vp. Since the pinch-off voltage Vp is a negative value, the level shift voltage Vsh is also a negative value.

The reason for providing the level shift means 41x is as follows.

[0095] Voltage-current characteristics of the field effect transistor FET2x of N-channel type in junction has a _{I D = I DSS × (1} -V GS / Vp) 2. Here, _ID is the drain current, _VGS is the gate-source potential difference, Vp is the pinch-off voltage, _IDSS
Is the drain I when the gate-source potential difference V _GS = 0
The value of _D. It should be noted that the value of the pinch-off voltage Vp is negative.

[0096] By transforming the above characteristic equation, a _{I D = (I DSS / Vp} 2) × (V GS -Vp) 2. To square characteristic, the parametric as Vin, to the _{I D = (I DSS / Vp} 2) × Vin 2 may if Vin = V _GS -Vp.

[0097] In order to Vin = V4 V _GS = V5, put the V4 = V5-Vp V5 = V4 + Vp. Here, for convenience, it is assumed that Vp = Vsh. This is the level shift voltage Vsh. That is,
The output voltage V4 of the amplifying means 300x is input, the level is shifted by the level shift means 41x as V5 = V4 + Vsh, and the shifted voltage V5 is applied to the gate electrode G of the field effect transistor FET2x. _ID will be proportional to the square of the output voltage V4 of the amplification means 300x.

[0098] That is, the V5 = V _GS, the Vp = Vsh (negative value), is substituted into _{I D = (I DSS / Vp} 2) × (V GS -Vp) 2, I D = (I DSS / Vp ² ) × (V5−Vsh) ² = ( _IDS / Vp ² ) × (V4) ²

[0099] V4 = (1 + R32 / R31 ) was × V3, also because it is V3arufabui1, as a proportionality constant overall h ₀ x, a _{I D = h 0 x · V1} 2. This means that the drain current _ID is proportional to the acceleration signal Svx (V1) generated by the acceleration detecting means 100x, that is, the square of the output voltage V1.

The output voltage V4 of the amplifying means 300x is input to the level shift means 41x, and the level shift voltage Vsh
Is applied to the gate electrode G of the field effect transistor FET2x as V5 = V4 + Vsh. The waveform of the voltage V5 after the shift is as shown in FIG. It should be noted that Vp (= Vsh) is negative.

The source-grounded amplifying and squaring means 42x is a junction type N-channel type field effect transistor FET2x.
And its gate ground resistance R43 and drain resistance R44
And a decoupling capacitor C42. The drain electrode D of the field effect transistor FET2x is connected to the drain resistance R44 with respect to the high potential side power supply terminal Vcc.
Connected through. Field-effect transistor FET
The 2x source electrode S is grounded to the ground GND. Drain resistance R44 and field effect transistor FET2
The connection point of x with the drain electrode D is the output terminal. Drain electrode D of field effect transistor FET2x
A connection point between the input resistor R44 and the drain resistor R44 is connected to the input resistor R51x in the addition operation means 2000 at the next stage via the decoupling capacitor C42. The connection point between the decoupling capacitor C41 and the input resistor R51x is connected to the low potential side power supply terminal (-Vcc).

In the field effect transistor FET2x, since the source electrode S is grounded, the gate
Source potential difference V _GS is equal to the post-shift voltage V5 applied to the gate electrode G. Since a Vsh = Vp (negative value) assignment, this _{V GS = V5 = V4 + Vsh} = V4 + Vp, characteristic equation of the field effect transistor FET2x, the _{I D = (I DSS / Vp} 2) × (V GS -Vp) 2 Then, the _{I D = (I DSS / Vp} 2) × V4 2. This, after all, is I _D = h ₀ x × V ¹² , as described above. Therefore, the field effect transistor FET2x
Output voltage V6 from the drain electrode D of, the _{V6 = Vcc-R44 × I D} = Vcc-R44 × h 0 x × V1 2.

Here, assuming that the output voltage V1, which is the acceleration signal Svx (V1) detected by the acceleration sensor 11x, is a sine wave, V1 = Asinωt. Then, where _{V6 = Vcc-R44 × h 0} x × A 2 (sinωt) 2, the coefficients as kx, When _{kx = R44 × h 0 x ×} A 2, the ^{V6 = Vcc-kx · sin 2} ωt .

V6 = Vcc−kx (1-cos2ωt) / 2 = Vcc−kx / 2 + (kx / 2) · cos2ωt

The output voltage V6 is just the acceleration signal Sv
Since the output voltage V1 (= Asinωt) as x (V1) must be the square, the output voltage V7 of the square operation means 400x is calculated from the output voltage V6 of the drain electrode D to Vcc.
Must be excluded.

Thus, the decoupling capacitor C42
Is connected to the low potential side power supply terminal (-Vcc) immediately after
The output voltage V7 of the square calculation unit 400x becomes V7 = -kx / 2 + (kx / 2) · cos2ωt = kx · sin 2 ωt.

As a result, the final output terminal of the X-axis direction vibration information acquisition device 1000x is connected to the acceleration information signal S
The output voltage V7 is obtained as ix.

[0108] is a V7 = αx × V1 ^2. That is, the acceleration information signal Six of the voltage V7 proportional to the square of the acceleration signal Svx (V1) detected by the acceleration detecting means 100x is output.

This is because the X-axis direction vibration information acquisition device 100
Since it is for 0x, with the "x" suffix to V1, and V7x = αx · V1x ^2.

The above description is about the X-axis direction vibration information acquisition device 100.
Although the description has been given of the configuration and operation of 0x, the same configuration applies to the Y-axis direction vibration information acquisition device 1000y and the Z-axis direction vibration information acquisition device 1000z. Are all configured with analog circuits.

An output terminal of the X-axis direction vibration information acquisition device 1000x is connected to an addition operation means 200 via an input resistor R51x.
0, connected to the inverting input terminal (-) of the operational amplifier 51, and the output terminals of the Y-axis direction vibration information acquisition device 1000y and the Z-axis direction vibration information acquisition device 1000z are also connected via the input resistors R51y and R51z, respectively.
It is connected to the inverting input terminal (-) of x. As shown in the figure, the addition operation means 2000 also includes an analog circuit.

The three-way vibration information acquisition device 1000x, 1
The acceleration sensor 11i (i = x, y, z) at each of 000y and 1000z has an X axis and a Y axis orthogonal to each other.
It is arranged with a direction to detect acceleration along the axis and the Z axis. That is, the X-axis direction acceleration detecting unit 11x and the Y-axis direction acceleration detecting unit 11y are arranged in a state orthogonal to each other in the horizontal plane of the ground surface, and the Z-axis direction acceleration detecting unit 11z is arranged along the vertical direction. Has been established.

The same operation is performed in the Y-axis direction vibration information acquiring device 1000y and the Z-axis direction vibration information acquiring device 1000z, and the acceleration detecting means 100y, 100z
Thus, acceleration information signals Sy, Siz proportional to the square of the acceleration signals Svy, Svz detected are output. These acceleration information signals Six, Siy, S
iz is input to the addition operation means 2000. The Y-axis direction vibration information acquisition device 1000y, V7y = αy · V1y ² becomes, for Z-axis direction vibration information acquisition device 1000Z, the V7z = αz · V1z ^2.

The addition operation means 2000 includes the operational amplifier 51
x and an input resistor R5 connected to its inverting input terminal (-).
1x, R51y, R51z, and a feedback resistor R52 connected between the output terminal and the inverting input terminal (-). The non-inverting input terminal (+) of the operational amplifier 51x is connected to the ground GND. This addition operation means 200
0 also has the function of inverting amplification.

[0115]

(Equation 1) Becomes Here, assuming that R51x = R51y = R51z = R52, V8 = − (V7x + V7y + V7z). In summary, V8 = - (αx · V1x 2 + αy · V1y 2 + αz · V
1z ² ) X-axis direction vibration information acquisition device 10 for field effect transistor FET2x of source-grounded amplification and squaring means 42x
00x, the Y-axis direction vibration information acquisition device 1000y, and the Z-axis direction vibration information acquisition device 1000z may have the same characteristics. That is, three field effect transistors F
As the ET2i (i = x, y, z), it is preferable to use one having the same characteristics and composed of the same semiconductor wafer.
However, when the characteristics are varied or when a field-effect transistor having a variation must be used, the field-effect transistor FE
T2i (i = x, y, z) drain resistance R44i (i
= X, y, z) as variable resistances and adjusting the resistance values, the coefficients αx, αy, αz can be made equal. That can be a _{αx = αy = αz = α 0} . Therefore, V8 = −α ₀ (V1x ² + V1y ² + V1z ² ).

Here, V1x = X, V1y = Y, V1z
When expressed as = Z, Q = −α ₀ (X ² + Y ² + Z ² ).

That is, a combined acceleration information signal Q (V8) proportional to the sum of squares of the input voltages X, Y, and Z can be obtained. That is, information proportional to the scalar of the three-dimensional vector can be obtained, and the magnitude of the seismic motion can be measured very accurately.

Although not shown, the output terminal of the operational amplifier 51x of the addition operation means 2000 in FIG. 5 is connected to the ground motion level judgment means 30 similar to that shown in FIG.
00, it is connected to the display means 700 and the information processing means 800, and the output terminal of the seismic motion level determination means 3000 is connected to the alarm means 600.

As described above, in the fifth embodiment, since all of the basic circuit configurations as the seismic device 5000 are configured by analog circuits, the three acceleration sensors 11i (i = x, y) are used. , Z), the time response from the detection of the acceleration signal Svi (i = x, y, z) to the output of the combined acceleration information signal Sc (Q) is the A / D conversion unit, the memory or the MPU ( The speed is much higher than that of the digital configuration including a microprocessor, and the operation stability is sufficiently excellent.

As shown in FIG. 5, the analog circuit configuration is relatively simple, and it is easy to form an integrated circuit (IC). That is, the circuit components include a field effect transistor, an operational amplifier, a diode, a resistor,
Because it is a capacitor, it is easy to make it into an IC,
Miniaturization is possible.

Further, the synthesized acceleration information signal Sc obtained by the seismic device 5000 is not an instantaneous value after averaging as in the case of the prior art but an instantaneous value in a normal sense, and The accuracy of the basic information for determination is extremely high. In particular, it is extremely effective for crisis management, such as issuing a warning such as a siren for avoiding danger, or urgently stopping equipment that may cause serious damage due to an earthquake.

[0122]

According to the present invention concerning the vibration information acquisition device or the vibration sensing device, since the square is performed in an analog manner, the detected vibration signal is converted in real time and instantaneously to obtain the vibration information signal or the synthetic acceleration information signal. A /
Compared to the conventional technology that performs digital signal processing using a D converter, a memory, and an MPU (micro processing unit) that performs arithmetic processing, time response can be made faster and operation stability is excellent. It can be. Furthermore, since the obtained vibration information signal or synthesized acceleration information signal is an instantaneous value in a regular sense, the accuracy of the information as instantaneous vibration energy becomes high, and an alarm is issued particularly for avoiding danger. It is possible to increase the effectiveness in an emergency such as stopping the device. In addition, the overall circuit configuration can be made sufficiently simple because of the analog circuit configuration. IC integration is also relatively simple.

As described above, according to the present invention, a vibration information acquisition device or a vibration sensing device having high accuracy and time response can be provided.
It has an excellent effect that it can be realized while reducing costs and downsizing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electrical configuration of a vibration information acquisition device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a vibration information acquisition device according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating an electrical configuration of a seismic device according to Embodiment 3 of the present invention.

FIG. 4 is a block diagram showing an electrical configuration of a seismic device according to Embodiment 4 of the present invention.

FIG. 5 is a circuit diagram showing a specific electrical configuration of an X-axis direction vibration information acquisition device for a seismic device according to Embodiment 5 of the present invention.

FIG. 6 is a waveform chart for explaining the operation of the seismic device according to the fifth embodiment.

[Explanation of symbols]

11x Acceleration sensor (vibration detecting element) 12x Filter means 13x Impedance conversion means 21x First half-wave rectifier circuit 22x Second half-wave rectifier circuit 31x Operational amplifier 41x Level shift means 42x Source-grounded amplification Square means 51x Operational amplifier FET1x Field effect transistor in impedance conversion means FET2x Field effect transistor in analog square calculation means 100, 100i (i = x, y, z) Vibration detection means 200, 200i (i = x, y, z) full-wave rectifier 300i (i = x, y, z) amplifying means 400, 400i (i = x, y, z) analog squaring means 500 vibration level determining means 600 alarm means 700 display Means 800 ... Information processing means 1000 ... Vibration information acquisition device 100 x: X-axis direction vibration information acquisition device 1000y: Y-axis direction vibration information acquisition device 1000z: Z-axis direction vibration information acquisition device 2000: Addition calculation means 3000: Earthquake motion level determination means 5000: Seismic device Sv: Vibration signal Sa: Absolute Value signal Si: Vibration information signal Svx, Svy, Svz: Acceleration signal Sax, Say, Saz: Absolute value signal Sbx, Sby, Sbz: Absolute value signal after amplification Six, Siy, Siz: Acceleration information signal Sc: Synthetic acceleration information Signal Vth, Vth1, Vth2 ... predetermined threshold value Sar ... alarm signal

Claims (9)

[Claims] 1. A vibration detecting means for electrically detecting a vibration and outputting a vibration signal, and an analog square calculating means for squaring the vibration signal in an analog manner. Vibration information acquisition device. 2. A vibration detecting means for electrically detecting vibration and outputting a vibration signal, a full-wave rectifying means for receiving the vibration signal, performing full-wave rectification and outputting an absolute value signal, and the absolute value signal. A vibration information obtaining apparatus comprising: an analog square calculating means for squaring an analog square. 3. The analog square calculating means uses voltage-current characteristics of a field-effect transistor,
3. The vibration information acquisition device according to claim 1, wherein a level shift voltage substantially equal to a pinch-off voltage of the field effect transistor is added to an input signal. 4. The vibration information acquisition device according to claim 1, wherein said vibration detection means includes an impedance conversion means. 5. The vibration information acquiring device according to claim 1, wherein said vibration detecting means is configured as an acceleration detecting means for outputting an acceleration signal as said vibration signal. . 6. The vibration information acquiring apparatus according to claim 5, wherein
And a summation means for adding acceleration information signals output from the two analog square calculation means. Seismic device. 7. The vibration information acquiring device according to claim 5,
And an addition operation means for adding acceleration information signals output from the three analog square operation means. Seismic device. 8. The seismic device according to claim 6, wherein a filter means for passing only a seismic ground motion frequency component is provided at a stage preceding the analog square calculating means. 9. The apparatus according to claim 6, further comprising: a seismic ground motion level judging unit for judging a seismic ground wave level by comparing a combined acceleration information signal output from said adding operation means with a predetermined threshold value. The seismic device according to claim 8.