JPH10105861A - Sensor signal transmitting method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and remotely measure a prescribed physical states by using the characteristic of induced electromotive force generated from an AC magnetic field as a parameter for judging the presence/absence of the change of a physical state in an object to be measured so as to unnecessitate the installing of a pipe for pulling out a cable and a protecting case. SOLUTION: An AC magnetic field is generated outside a separated area by using an AC current of a fixed frequency and induced electromotive force is generated within the separated area from this AC magnetic field. This is made the driving power of a distortion gage 13a and an AC magnetic field is generated again from power generated on the output side of the gage 13a accompanying the applying of this driving power. Induced power is generated again outside of the separated area from this AC magnetic field and the characteristic of this induced electromotive force, namely an output itself, is used as the parameter for judging the presence/absence of distortion between first and second pipes 17 and 18. The presence/absence of actual distortion is judged based on the ratio of an input voltage by an AC power source and an output voltage making a parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for transmitting a sensor signal, and more particularly to a method for distorting a signal in an underground or underground structure or an underground ground (hereinafter collectively referred to as "in an isolated area"). The present invention relates to a sensor signal transmission method for remotely measuring a temperature (hereinafter, these are collectively referred to as a “physical state”), and a sensor signal transmission device directly used for implementing the method.

[0002]

2. Description of the Related Art Normally, electrical wiring, communication wiring, other wiring, or gas pipes, water pipes, air-conditioning pipes, and other pipes (hereinafter, these are collectively referred to as "pipes, etc.") When the ground or structure is deformed due to an earthquake or land subsidence, it is buried inside the wall, floor, ceiling, etc. of the structure, causing distortion or vibration in the buried piping etc., which leads to destruction There is a risk. In particular, in the case of buried cables that are energized, such as the above-mentioned electrical and communication wirings, the electrical resistance locally increases due to external stress due to earthquakes and the ingress of water. As a result, current concentration occurs, generating heat and causing fire. There is a risk of causing.

[0003] In addition to the above-mentioned pipes, civil engineering buildings such as reinforcing slopes such as tunnel walls and cliffs, breakwaters and seawalls, and the like, are likely to collapse due to stress concentration due to earth pressure fluctuations in addition to vibration due to earthquakes. There is.

[0004] For this reason, there has been a demand and developed a technique for measuring strain or temperature in the ground or in a structure, or in an underground ground, but conventionally, (1) sensors have been developed. Is fixed to an object to be measured, and the output terminal of the sensor is pulled out to the ground with a cable to obtain a required sensor signal, or (2) a method of transmitting the required sensor signal wirelessly is generally adopted. It has become.

[0005]

However, the method (1) using a cable requires not only the work of installing a conduit for guiding the cable to the ground, but also the case where the cable is drawn out from a road. However, there is a problem in that a heavy and small protective case must be installed so as to withstand the damage caused by passing the vehicle and not to impede traffic.

[0006] In the method (2) using wireless transmission,
Although the problems described above do not occur, the burying of the sensor driving battery is an essential condition, and there is a problem that its life is limited and long-term use cannot be expected.

Here, the main objects to be solved by the present invention are as follows. That is, a first object of the present invention is to provide a sensor signal transmission method capable of easily performing remote measurement of a predetermined physical state in a predetermined isolation area without the necessity of installing a cable drawing conduit or a protective case. And a device.

A second object of the present invention is to provide a method and an apparatus for transmitting a sensor signal which can easily measure a predetermined physical state in a predetermined isolated area by remote control without having to bury a battery for driving the sensor. Is to provide.

[0009] Other objects of the present invention will become apparent from the description of the specification, drawings, and particularly from the claims.

[0010]

According to the present invention, in order to solve the above-mentioned problems, in addition to a required sensor, two coils electrically connected to the sensor are buried in an isolated area. In the other coil, an induced electromotive force is generated by a magnetic field given from another coil provided outside (outside the isolation region), and this is used as a drive power source for the sensor. A characteristic is that an AC magnetic field is generated from the electric power generated on the output side of the sensor in response to the application of, and this is received by another coil installed outside the isolation region.

More specifically, in solving the above-mentioned problems, the present invention has been made to achieve the above object by adopting each of the novel characteristic constitution techniques or means listed below. You.

That is, a first characteristic of the method of the present invention is that a change in a predetermined physical state occurring in an object to be measured existing in a predetermined isolation region is determined by a predetermined sensor installed at a key point of the object to be measured. When detecting using the sensor, when transmitting a sensor signal obtained from the sensor remotely to the outside of the isolation region, an AC magnetic field is generated outside the isolation region using a predetermined AC power source, and the AC magnetic field is isolated from the AC magnetic field. An induced electromotive force is generated in the area, and this is used as the driving power of the sensor. With the application of the driving power, an AC magnetic field is generated again from the power generated on the output side of the sensor. In this case, the induced electromotive force is generated again, and the characteristic of the induced electromotive force is used as a parameter for determining the presence or absence of a change in the physical state of the device under test. That.

A second feature of the method of the present invention resides in adopting a configuration of a sensor signal transmission method in which the sensor in the first feature is a predetermined impedance element.

A third feature of the method according to the present invention is that the impedance element according to the second feature is a resistance element whose DC resistance component changes according to a change in a physical state of the device under test. The determination of the presence / absence of a change in the physical state is performed based on the voltage ratio between the AC power supply and the induced electromotive force as a parameter.

A fourth feature of the method of the present invention resides in the adoption of a configuration of a sensor signal transmission method in which the resistive element according to the third feature has a pure resistance component that changes according to the distortion of the device under test.

A fifth feature of the method of the present invention resides in the adoption of a sensor signal transmission method in which the resistance element in the above third feature has a pure resistance component that changes in accordance with a change in the temperature of the device under test. .

According to a sixth aspect of the method of the present invention, the impedance element in the second aspect is a capacitive element whose capacitance component changes in accordance with a change in the physical state of the device under test, and the AC power supply comprises The frequency is variable, and the determination of the presence or absence of a change in the physical state of the device under test is based on the frequency of the AC power supply when the voltage ratio between the AC power supply and the induced electromotive force that forms a parameter takes the maximum value. The present invention resides in adopting a configuration of a sensor signal transmission method performed.

A seventh feature of the method of the present invention resides in the adoption of a configuration of a sensor signal transmission method in which the capacitance element in the sixth feature changes a pure resistance component in accordance with distortion of an object to be measured.

An eighth feature of the method of the present invention resides in adoption of a configuration of a sensor signal transmission method in which the capacitance element in the sixth feature changes a pure resistance component according to a change in the temperature of the device under test. .

On the other hand, a first feature of the apparatus of the present invention is that a change in a predetermined physical state which occurs in an object to be measured which is present in a predetermined isolation region is detected by a predetermined sensor installed at a key point of the object to be measured. When detecting using the sensor signal transmission device for remotely transmitting a sensor signal obtained from the sensor to the outside of the isolation region, a predetermined AC power supply provided outside the isolation region, A first coil electrically connected to generate an AC magnetic field from an electromotive force of the AC power supply;
A second coil which is installed in the isolation region so that a magnetic coupling with the first coil is in the deepest state, and generates an induced electromotive force from an alternating magnetic field generated from the first coil; At the same time as being electrically connected to the second coil via the sensor, the magnetic coupling with the second coil is provided in the shallowest state, and the induction generated from the second coil is provided. A third method for generating an AC magnetic field again from the electric power generated at the output side of the sensor with the application of the electromotive force
And the third coil is installed outside the isolation region such that the magnetic coupling between the third coil and the third coil is the deepest, and the magnetic coupling between the first coil and the third coil is the shallowest. A fourth coil for generating an induced electromotive force again from an AC magnetic field generated from the coil, a transfer characteristic measuring unit for measuring an electric transfer characteristic from the first coil to the fourth coil,
The configuration of the sensor signal transmission device having

A second feature of the device of the present invention is that the first coil, the fourth coil, and the transfer characteristic measuring means in the first feature are configured as a sensor signal transmission device which is housed in a single case. It is in.

A third feature of the device of the present invention is that the transfer characteristic measuring means in the first or second feature is characterized in that a first AC voltmeter connected to a terminal drawn from the first coil, And a second AC voltmeter connected to a terminal drawn from the coil No. 4 and a sensor signal transmission device comprising a sensor signal transmission device.

A fourth feature of the device of the present invention is that
The first to fourth coils in the second or third feature are:
The present invention resides in the configuration adoption of a sensor signal transmission device both of which are in a solenoid shape.

A fifth feature of the device of the present invention is that the first coil and the fourth coil in the above-mentioned fourth feature are arranged such that their central axes are orthogonal on the same plane. The present invention resides in the configuration adoption of a sensor signal transmission device in which the second coil and the third coil are arranged in the same manner as the arrangement of the first coil and the fourth coil.

A sixth feature of the device of the present invention resides in the configuration adoption of a sensor signal transmission device in which the first coil in the fifth feature is symmetrically arranged with respect to the center axis of the fourth coil.

A seventh feature of the present invention resides in the adoption of a sensor signal transmission device in which the fourth coil of the fifth feature is symmetrically arranged with respect to the center axis of the first coil.

An eighth feature of the device according to the present invention is that the sensor according to the first, second, third, fourth, fifth, sixth or seventh feature is a sensor signal transmission device comprising a predetermined impedance element. Configuration adoption.

A ninth feature of the present invention resides in a sensor signal transmission device in which the impedance element according to the eighth feature is a resistance element whose DC resistance component changes in accordance with a change in the physical state of the device under test. In hiring.

A tenth feature of the device of the present invention resides in the configuration adoption of a sensor signal transmission device in which the resistance element according to the ninth feature is connected in series between the second coil and the third coil. is there.

An eleventh feature of the device of the present invention resides in the configuration adoption of a sensor signal transmission device in which the resistance element in the ninth feature is connected in parallel between the second coil and the third coil. is there.

The twelfth feature of the device of the present invention is as follows.
A tenth or eleventh aspect of the present invention resides in the configuration adoption of a sensor signal transmission device in which the resistance element has an element whose pure resistance component changes according to the distortion of the device under test.

A thirteenth feature of the device of the present invention is that
A tenth or eleventh aspect of the present invention resides in the configuration of the sensor signal transmission device in which the resistive element includes an element whose pure resistance component changes according to a change in the temperature of the device under test.

A fourteenth feature of the device of the present invention is that the impedance element in the eighth feature is configured as a sensor signal transmission device in which a capacitance component whose capacitance component changes according to a change in a physical state of the device under test. It is in.

A fifteenth feature of the device of the present invention is that
The characteristic feature of the present invention resides in the configuration adoption of a sensor signal transmission device in which the capacitive element is connected in series between the second coil and the third coil.

The sixteenth feature of the device of the present invention is that
The feature of the present invention resides in the configuration adoption of a sensor signal transmission device in which the capacitive element is connected in parallel between the second coil and the third coil.

The seventeenth feature of the device of the present invention is that
The fourth, fifteenth, or sixteenth feature is that the capacitive element according to the fifteenth or sixteenth aspect adopts a configuration of the sensor signal transmission device including an element whose pure resistance component changes according to distortion of the device under test.

The eighteenth feature of the device of the present invention is that
The fourth, fifteenth, or sixteenth feature is that the capacitive element according to the fifteenth or sixteenth aspect employs a sensor signal transmission device including an element whose pure resistance component changes according to a change in the temperature of the device under test.

[0038]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. (First Embodiment) FIGS. 1A to 1C are diagrams showing the principle of the invention according to the first embodiment, FIG. 2 is an equivalent circuit diagram of the invention shown in FIG. 1, FIGS. FIG. 2B is a layout diagram of a first coil and a fourth coil used in the invention shown in FIG.

First, as shown in FIG. 1, the invention according to the first embodiment includes an AC power supply 1 provided outside the isolation region,
A state in which the magnetic coupling between the first coil 2 which is electrically connected to the AC power supply 1 and generates an AC magnetic field from the electromotive force of the AC power supply 1 and the first coil 2 is the deepest. A second coil 3 which is installed in the isolation region and generates an induced electromotive force from an AC magnetic field generated from the first coil 2, and a resistor R is connected in series with the second coil 3. And at the same time, the magnetic coupling with the second coil 3 is set to the shallowest state, and the application of the induced electromotive force generated from the second coil 3 A third solenoid-like coil 4 for generating an AC magnetic field again from the electric power generated on the output side of the resistor R and the third coil 4 have the deepest magnetic coupling. The state where the magnetic coupling with the coil 2 is the shallowest A fourth coil 5 which is installed outside the isolation region and generates an induced electromotive force again from an AC magnetic field generated from the third coil 4, and a first coil 4 to a fourth coil 5. Voltmeter 6 (second AC voltmeter. “Transfer characteristic measuring means”) connected to the output (terminal drawn out) of the fourth coil 5 as an instrument for measuring the electrical transfer characteristic to the ).

The resistor R shown in the figure has a sensor for detecting a change in a predetermined physical state in a predetermined isolation region, which is usually formed of a predetermined impedance element. Therefore, the electrical function of the sensor is equivalent. It is expressed in.
The resistance R is equal to the resistance of the second coil 3 and the third coil 4.
May be connected in parallel.

Here, the first coil 2 and the fourth coil 5
As shown in the figure, both central axes are arranged so as to be orthogonal on the same plane as shown in the figure, and both the central axes of the second coil 3 and the third coil 4 are also in the same plane as shown in the figure. It is arranged to be orthogonal at the top.

For this reason, when an AC voltage (electromotive force) from the AC power supply 1 is applied to the first coil 2, the generated magnetic field α at that time becomes the center axis of the third coil 4 and the magnetic field α of the fourth coil 5. Since both are orthogonal to the central axis, they do not generate an induced electromotive force as a result, and the second coils 3 arranged so as to have the deepest (parallel) magnetic coupling.
Only results in an induced electromotive force.

Then, due to the induced electromotive force, a current flows through the third coil 4 through the resistor R, and a new AC magnetic field is generated here. Then, the generated magnetic field β at this time is
Similarly to the above principle, since the center axis of the first coil 2 and the center axis of the second coil 3 are both orthogonal to each other, they do not generate induced electromotive force, and An induced electromotive force is generated only in the fourth coil 3 arranged so that the coupling is deepest (in parallel).

That is, the magnetic coupling between the coils is performed between the first coil 2 and the second coil 3 and the third coil 4.
, And only between the fourth coil 5 and each of these coils can be regarded as a transformer. As a result, the configuration of FIG. 1 can be represented by the equivalent circuit of FIG.

When this equivalent circuit is considered, when an AC voltage from the AC power supply 1 is applied to the terminals 2 a and 2 b of the first coil 2, the AC voltage is applied via the second coil 3, the resistor R and the third coil 4. An AC voltage is induced in the terminals 5a and 5b of the fourth coil 5 and detected by the AC voltmeter 6. At this time, the electric voltage from the first coil 2 to the fourth coil 5 is changed. Typical transfer characteristics are inevitably determined by the characteristics of each element constituting FIG. Therefore, if the value of the resistor R changes due to a change in temperature, distortion, or the like, the transfer characteristic naturally changes. By measuring the change in the transfer characteristic, a change in temperature, distortion, or the like can be detected.

In the configuration of FIG. 1, if the first coil 2 and the fourth coil 5 are too close to each other, a part of the magnetic field generated by the first coil 2 does not pass through the resistor R but In some cases, an induced electromotive force is directly generated in the fourth coil 5 to lower the detection sensitivity for a change in the value of the resistor R.

In general, in the case of this type of remote transmission (remote measurement), the fourth coil 5 is arranged apart from the second coil 3 and the third coil 4, but the first coil 5 Since the fourth coil 5 is disposed close to the coil 2, the fourth coil 5 generates a magnetic field α generated by the first coil 2 more than a magnetic field generated by the second coil 3 and a magnetic field β generated by the third coil 4. Because they are directly susceptible to

Therefore, as shown in FIG. 3A, the fourth coil 5 is directly driven by the magnetic field α1 generated by the first coil 2.
The first coil 5 is connected to the first
May be arranged symmetrically with respect to the center axis of the coil 2 (the symmetry plane S
1) Alternatively, as shown in FIG. 3B, the first coil 2 is connected to the fourth coil 5 so that electromotive force is not directly induced in the fourth coil 5 by the magnetic field α2 generated by the first coil 2. It is necessary to devise a method of symmetrical arrangement (symmetric plane S2) with respect to the central axis of the coil 5 of FIG.

To explain the effect of the above arrangement, first, in the case of FIG.
The left half of the figure has a leftward axial component and the right half has a rightward and leftward axial component, and the left half and the right half of the fourth coil 5 have opposite induction components. As a result of the generation of power and the cancellation of these, the induced electromotive force as a whole becomes zero. On the other hand, in the case of FIG. 6B, the generated magnetic field α2 of the third coil always intersects at right angles with respect to the axial component of the fourth coil 5, and the induced electromotive force is applied to the fourth coil 5. Does not occur.

(Second Embodiment) FIG. 4 is an equivalent circuit diagram of the invention according to the second embodiment, and FIG. 5 is an auxiliary diagram for explaining the operation of the invention shown in FIG. Note that the principle configuration of this sensor signal transmission device is the same as that of the above-described first embodiment, and is not shown. In the second embodiment, the same or equivalent elements as those in the first embodiment will be described using the same reference numerals.

First, as shown in FIG. 4, in the invention according to the second embodiment, the resistor R of the device shown in the first embodiment is replaced with a capacitor C.
Are connected in parallel between the second coil 3 and the third coil 4. It is generally known that the present circuit has a resonance frequency determined by the inductance of the coil constituting the circuit and the capacitance of the capacitor C, and that the resonance frequency is inversely proportional to the square root of the capacitance of the capacitor C. ing. Therefore, if the resonance frequency can be detected, the capacitance of the capacitor C can be known, and a required change in temperature, distortion, and the like can be detected.

By the way, the invention according to the second embodiment is
It has the following advantages as compared with the first embodiment. That is, first, in the invention according to the first embodiment, the magnetic fields generated by the first coil 2 and the third coil 4 reach the second coil 3 and the fourth coil 5, respectively. The AC magnetic field at this time is attenuated in the ground and members existing between the coils, and the amount of the attenuation naturally changes depending on the state of the ground and the like. Therefore, the fourth coil 5
Even if the generated voltage is measured, the magnitude of the voltage includes not only the magnitude of the value of the resistance R but also the influence of the ground and the like.

On the other hand, in the invention according to the second embodiment, if the amount of magnetic attenuation also changes due to the influence of the ground or the like, the voltage generated by the fourth coil 5 changes, but this changes the voltage level. It only raises or lowers the whole, but does not change the resonance frequency. Therefore, according to the invention of the second embodiment, it can be said that the influence of the characteristic change of the ground or the like can be reduced more than the invention of the first embodiment.

Further, in the invention according to the second embodiment, since the capacitor C is connected in parallel between the second coil 3 and the third coil 4, for example, as shown in FIG. The magnetic field generated by the third coil 4 can be increased as compared with the case where the capacitor C is connected in series at the location.

That is, in FIG. 4, the impedance between A and B becomes maximum at the resonance frequency of the parallel resonance circuit including the third coil 4 and the capacitor C, and the second coil 3 generates the voltage of this resonance frequency. When it occurs, its second
The current hardly flows through the coil, and no voltage drop occurs due to its own internal resistance. As a result, a voltage similar to the voltage generated by the second coil 3 is applied between A and B.

On the other hand, in FIG. 5, A,
The impedance between B and B becomes extremely small, a large current flows through the second coil 3 and a voltage drop occurs due to the internal resistance. As a result, the voltage applied between A and B becomes the second voltage. The voltage is much lower than the voltage generated by the coil 3. That is, in other words, the voltage applied to the first coil 2 can be increased by connecting the capacitor C in parallel between the second coil 3 and the third coil 4.

[0057]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 6 is a configuration diagram of a sensor signal transmission device according to a first embodiment of the present invention corresponding to the first embodiment, and FIG. 7 is a diagram of the sensor signal transmission device shown in FIG. It is principal part sectional drawing. In the example of the apparatus according to the first embodiment, a description will be given of an example of an apparatus for measuring a distortion at a connection portion of an iron pipe buried in an underground ground from the ground in a non-contact manner.

First, as shown in FIG. 6, the sensor signal transmission device 10 includes an AC power supply 1, a first coil 1, a second coil 3, The first coil 2 includes a third coil 4, a fourth coil 5, and an AC voltmeter 6.
It has an AC voltmeter 11 connected to a terminal drawn from the (connection point to the AC power supply 1) (in the following description, in order to distinguish the two AC voltmeters 6 and 11,
It is connected to the input side as a first AC voltmeter 11,
The one connected to the output side is referred to as a second AC voltmeter 12 (hereinafter, the symbol “6” is not used).
And, between the second coil 3 and the third coil 4,
Sensor units 13 including impedance elements are connected in parallel.

Here, the first AC voltmeter 11 and the second AC voltmeter 12 constitute transfer characteristic measuring means, and this means is connected to the AC power supply 1, the first coil 2, and the fourth coil 5 is housed in a single case 14 so that it can be carried freely. And this case 14
Is set on the ground surface 15 when it is used.

On the other hand, the second coil 3 and the third coil 4 are buried in the underground ground 16 together with the sensor unit 13, and the sensor unit 13 is located on the right side of the figure. 17a of the first conduit 17 located at
And the second pipeline 18 located on the left side of the figure.

The details of the sensor section 11 are described in FIG.
As shown in FIG. 1, as a predetermined impedance element, a strain gauge 1 whose forward resistance component changes according to the strain of an object to be measured.
3a is used, one end of which is directly fixed to a part of the joint 17a of the first conduit 17 and the other end of the first conduit 17 with the mounting base 19 interposed therebetween. The second pipe 18 is fixed to a part of the second pipe 18. That is, in the sensor signal transmission device 10, when the first conduit 17 and the second conduit 18 are displaced in the longitudinal direction, the strain gauge 13a expands and contracts, and the resistance value changes. It has become.

(Example of Method of First Embodiment) Subsequently, the distortion between the first pipe line 17 and the second pipe line 18 is actually caused by the sensor signal transmission device 10 configured as described above. The method for measuring the value will be described.

First, immediately after the sensor unit 13 and the like are buried, the case 14 constituting the device outside the isolation region of the sensor signal transmission device 10 is placed in the sensor unit 1 in the underground ground 16 in the isolation region.
3 is set on the ground surface 15 located in the upper area of the first coil 3, and an AC voltage having a constant frequency is applied to the first coil 2 in a state where no distortion occurs between the first pipe 17 and the second pipe 18. In addition, the ratio between the input voltage and the output voltage at this time is calculated from the indicated value of the first AC voltmeter 11 and the indicated value of the second AC voltmeter 12.

When it is considered that a distortion has occurred between the first conduit 17 and the second conduit 18 after an earthquake or the like, the first coil 2 is again supplied with the same frequency as before. And the ratio between the input voltage and the output voltage is measured. At this time, if the input / output voltage ratio measured this time is different from the initially measured value, the first line 17 and the second line 1
8, it can be determined that a distortion has occurred.

That is, in this sensor signal transmission method, an AC magnetic field is generated outside the isolation region using the AC power supply 1 having a constant frequency, and an induced electromotive force is generated from the AC magnetic field within the isolation region, thereby distorting the generated electromagnetic field. The drive power of the gauge 13a is used, and an AC magnetic field is generated again from the power generated on the output side of the strain gauge 13a with the application of the drive power.

An induced electromotive force is generated again outside the isolation region from the AC magnetic field, and the characteristic of the induced electromotive force, that is, the output voltage itself is set between the first line 17 and the second line 18. Is used as a parameter for determining the presence or absence of the distortion, and the determination of the actual presence or absence of the distortion is performed based on the ratio between the input voltage from the AC power supply 1 and the output voltage constituting the parameter.

Note that the magnetic coupling between the first coil 2 and the second coil 3 and the magnetic coupling between the third coil 4 and the fourth coil 5 are made as deep as possible. For the first coil 2 in the case 14, the underground ground 16
The fourth coil 5 in the case 14 needs to be located immediately above and near the third coil 4 in the underground ground 16.

However, in order to perform this installation operation reliably,
When the embedding of the second coil 3 and the third coil 4 in the underground ground 16 is completed, a mark indicating their positions and directions may be attached to the ground surface 15 with spray paint or the like. Then, a large number of the second coil 3 and the third coil 4 are installed together with the sensor unit 13 at each joint of a plurality of conduits, while a case 14 forming a device outside the isolation region of the sensor signal transmission device 10 is provided. If one is prepared, this can be shared for measurement at each point.

In addition to the above-described setting operation, as a simple method, for example, while the case 14 is actually driven, the whole thereof is slowly rotated in the horizontal direction to obtain a second method.
The point at which the AC voltmeter 12 has the highest indicated value,
Thereby, between the first coil 2 and the second coil 3,
In addition, the third coil 4 and the fourth coil 5 may be substantially parallel to each other to make the magnetic coupling as deep as possible.

(Example of Apparatus of Second Embodiment) FIG. 8 is a sectional view of a main part of a sensor signal transmission apparatus according to a second embodiment of the present invention corresponding to the second embodiment. Note that the overall configuration of the device example according to the second embodiment is the same as that of the device example of the first embodiment, and therefore, the description of the common parts will be omitted. Also, in the device example of the second embodiment, a description will be given of an example of a device that measures the strain at a connection portion of an iron pipe buried in an underground ground from the ground in a non-contact manner.

As shown in the figure, in the sensor signal transmission device 20, a first electrode 23a and a second electrode 23b facing each other are provided as predetermined impedance elements, and according to the distortion of the object to be measured. A capacitor element 23c having a variable capacitance component is used, of which a first electrode 23a is fixed to a part of a joint 27a of a first conduit 27 with a first mount 29a interposed therebetween. It is becoming like.

The second electrode 23b is fixed to a part of the second conduit 28 with the second mount 29b interposed therebetween. That is, in the present sensor signal transmission device 20, when the first pipe 27 and the second pipe 28 are displaced in the longitudinal direction, the first electrode 23a and the second electrode 23b of the capacitor element 23c are connected to each other. Is changed, and the capacitance changes.

(Example of Method of Second Embodiment) Subsequently, the distortion between the first pipe 27 and the second pipe 28 is actually caused by the sensor signal transmission device 20 configured as described above. The method for measuring the value will be described. FIG. 9 is a frequency characteristic diagram of the input / output voltage ratio for explaining the sensor signal transmission method according to the second embodiment.

When an AC voltage is applied to the first coil 2 of the sensor signal transmission device 20, the generated magnetic field reaches the second coil 3 to generate an induced electromotive force. Similarly, the energy is sequentially transmitted to the third coil 4 and the fourth coil 5.

In the above process, the voltage applied to the third coil 4 becomes maximum at the resonance frequency f determined by the inductance of the third coil 4 and the capacitance of the capacitor element 23c. The voltage generated by the coil 2 also becomes maximum. Then, the frequency of the AC power supply 1 is variously varied, and the voltage ratio between the first coil 2 and the fourth coil 5, that is, the input / output voltage ratio is measured and plotted with an oscilloscope. The curve as shown is obtained,
It is understood that the input / output voltage ratio also becomes maximum at the resonance frequency f.

Based on the above principle, in this method example, first, as in the method example of the first embodiment, the first pipe 2
The above-described resonance frequency f is measured in a state where no distortion occurs between the second channel 28 and the second conduit 28. It is assumed that the relationship between the capacitance of the capacitor element 23c and the distortion between the first conduit 27 and the second conduit 28, that is, the amount of displacement, has been accurately measured in advance.

After the earthquake or the like, when it is considered that a distortion has occurred between the first pipe 27 and the second pipe 28, the resonance frequency f is measured. The ratio between f and the initially measured resonance frequency f is determined. As described above, the frequency ratio is determined by the capacitor C (see FIG. 4).
Is inversely proportional to the square root of the capacitance of the capacitor element 23c, the capacitance of the capacitor element 23c after distortion, that is, the amount of deviation between the first conduit 27 and the second conduit 28 can be known from this.

That is, in this sensor signal transmission method, an AC magnetic field is generated outside the isolation region using the AC power source 1 having a variable frequency, and an induced electromotive force is generated within the isolation region from the AC magnetic field, and this is converted into a capacitor. Element 23c
, And an AC magnetic field is generated again from the power generated on the output side of the capacitor element 23c with the application of the driving power.

An induced electromotive force is generated again from the alternating magnetic field outside the isolation region, and the characteristic of the induced electromotive force, that is, the resonance frequency f is determined by the first conduit 27 and the second conduit 28.
Is used as a parameter for determining the presence or absence of distortion between the resonance frequency f and the resonance frequency f when the ratio between the input voltage of the AC power supply 1 and the output voltage constituting the parameter takes the maximum value. It is based on.

In the above-described first embodiment, the input / output voltage ratio at a constant frequency is measured. If the voltage ratio fluctuates due to a change in soil, an error occurs in the distortion measurement. In the second embodiment, the resonance frequency is measured by changing the frequency in various ways. Therefore, even if the voltage ratio fluctuates due to a change in soil properties, the strain measurement is not affected at all.

As described above, the present invention has been described with reference to the first and second embodiments and the apparatus and method according to the first and second embodiments. However, the present invention is not necessarily limited to only the above-described method. Instead, the present invention achieves the object of the present invention and can be appropriately changed and implemented within a range having the effects described below.

For example, in the embodiment, the case of measuring the strain at the connection part of the steel pipeline buried in the underground ground is described as an example. Etc. can also be measured. In this case, a normal temperature sensor is used instead of the strain gauge 13a,
The capacitor element 23c having a temperature coefficient (for example, a capacitor having a dielectric interposed between the first electrode 23a and the second electrode 23b) may be used.

Further, the type of the isolation region to be applied is not limited to the underground ground, but is related to various pipes and the like which can be buried in the various isolation regions described in the section of “Prior Art”. The present invention is applicable.

[0084]

As described above, according to the present invention,
There is no need to install conduits and protective cases for conventional cable drawers, and it is not necessary to bury batteries for driving sensors.
It is possible to easily remotely measure a predetermined physical state in a predetermined isolation region. Moreover, when a resistive element is used as a sensor, errors due to magnetic coupling between coils are eliminated, while when a capacitive element is used, errors due to changes in physical properties of the ground and the like are effectively eliminated. ,
As a result, highly accurate physical state measurement can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing the basic configuration of the invention according to a first embodiment;
(A) is a plan view, (b) is a side view, and (c) is a front view.

FIG. 2 is an equivalent circuit diagram of the invention shown in FIG.

FIG. 3 is a layout diagram of a first coil and a fourth coil used in the invention shown in FIG. 1; FIG. 3 (a) shows a fourth coil arranged symmetrically with respect to a center axis of the first coil; FIG. 7B is a diagram illustrating a case where the first coil is symmetrically arranged with respect to a center axis of the fourth coil.

FIG. 4 is an equivalent circuit diagram of the invention according to the second embodiment.

FIG. 5 is an auxiliary diagram for explaining the operation of the invention shown in FIG. 4;

FIG. 6 is a configuration diagram of a sensor signal transmission device according to a first embodiment of the present invention corresponding to the first embodiment.

FIG. 7 is a sectional view of a main part of the sensor signal transmission device shown in FIG. 6;

FIG. 8 is a sectional view of a main part of a sensor signal transmission device according to a second embodiment of the present invention corresponding to the second embodiment.

FIG. 9 is a frequency characteristic diagram of an input / output voltage ratio for explaining a sensor signal transmission method according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... AC power supply 2 ... First coil 2a, 2b ... Terminal 3 ... Second coil 4 ... Third coil 5 ... Fourth coil 5a, 5b ... Terminal 6 ... AC voltmeter α, α1, α2 ... Generated magnetic field of the first coil β Generated magnetic field of the third coil R Resistance S1, S2 Symmetry plane 10 Sensor signal transmission device (device example according to the first embodiment) 11 First AC voltmeter 12 Second AC voltmeter 13 Sensor part 13a Strain gauge 14 Case 15 Surface 16 Underground ground 17 First pipe 17a Joint 18 Second pipe 19 Mounting base 20 Sensor signal transmission Apparatus (example of apparatus according to the second embodiment) 23a first electrode 23b second electrode 23c capacitor element 27 first pipe 27a joint 28 second pipe 29a first attachment Stand 29b: Second mounting stand

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI // G01V 3/00 G01V 3/00 B

Claims (26)

[Claims] When detecting a change in a predetermined physical state occurring in an object to be measured existing in a predetermined isolation region by using a predetermined sensor installed at a key point of the object to be measured, the sensor is used. In transmitting the sensor signal obtained from the remote control to the outside of the isolation region, an AC magnetic field is generated outside the isolation region using a predetermined AC power source, and an induced electromotive force is generated in the isolation region from the AC magnetic field. This is used as the driving power of the sensor, and an AC magnetic field is generated again from the power generated on the output side of the sensor with the application of the driving power. And generating a characteristic of the induced electromotive force as a parameter for determining whether or not the physical state of the device under test has changed. 2. The method according to claim 1, wherein the sensor is a predetermined impedance element. 3. The resistance element, wherein a DC resistance component changes according to a change in a physical state of the device under test, wherein the determination of presence or absence of a change in the physical state of the device under test is performed. The method according to claim 2, wherein the method is performed based on a voltage ratio between an AC power supply and an induced electromotive force that forms the parameter. 4. The sensor signal transmission method according to claim 3, wherein the resistance element changes a pure resistance component according to a distortion of the device under test. 5. The sensor signal transmission method according to claim 3, wherein the resistance element changes a pure resistance component in accordance with a change in the temperature of the device under test. 6. The impedance element is a capacitance element whose capacitance component changes according to a change in a physical state of the device under test, and the AC power source has a variable frequency. The determination of the presence or absence of a change in the physical state of the object is performed based on the frequency of the AC power supply when the voltage ratio between the AC power supply and the induced electromotive force constituting the parameter takes a maximum value. Item 3. The sensor signal transmission method according to Item 2. 7. The sensor signal transmission method according to claim 6, wherein the capacitance element changes a pure resistance component according to a distortion of the device under test. 8. The sensor signal transmission method according to claim 6, wherein the capacitance element changes a pure resistance component according to a change in the temperature of the device under test. 9. When detecting a change in a predetermined physical state occurring in an object to be measured which is present in a predetermined isolation region by using a predetermined sensor installed at a key point of the object to be measured. A sensor signal transmission device for remotely transmitting a sensor signal obtained from the outside of the isolation area, a predetermined AC power supply provided outside the isolation area, and an AC power supply electrically connected to the AC power supply. A first coil for generating an alternating magnetic field from the electromotive force of the first coil, and a magnetic coupling between the first coil and the first coil is provided in the isolation region so as to form the deepest state. A second coil for generating an induced electromotive force from an alternating magnetic field, and a state in which the second coil is electrically connected to the second coil via the sensor and the magnetic coupling with the second coil is the shallowest. It is equipped to make And a third coil that generates an AC magnetic field again from electric power generated on the output side of the sensor with the application of the induced electromotive force generated from the second coil. The third coil is installed outside the isolation region so as to have a deep state and a magnetic coupling with the first coil which is the shallowest;
A fourth coil that generates an induced electromotive force again from an AC magnetic field generated from the coil of (a), and a transfer characteristic measuring unit that measures an electrical transfer characteristic from the first coil to the fourth coil. A sensor signal transmission device, comprising: 10. The sensor signal transmission device according to claim 9, wherein the first coil, the fourth coil, and the transfer characteristic measuring unit are housed in a single case. 11. A transfer characteristic measuring means, comprising: a first AC voltmeter connected to a terminal drawn from the first coil; and a second AC voltmeter connected to a terminal drawn from the fourth coil. 11. The sensor signal transmission device according to claim 9, wherein the sensor voltage transmission device comprises: 12. The sensor signal transmission device according to claim 9, wherein each of the first to fourth coils has a solenoid shape. 13. The first coil and the fourth coil are arranged such that their central axes are orthogonal to each other on the same plane, and the second coil and the third coil are different from each other. The sensor signal transmission device according to claim 12, wherein the sensor is arranged in the same manner as the arrangement of the first coil and the fourth coil. 14. The sensor signal transmission device according to claim 13, wherein the first coil is symmetrically arranged with respect to a center axis of the fourth coil. 15. The sensor signal transmission device according to claim 13, wherein the fourth coil is symmetrically arranged with respect to a center axis of the first coil. 16. The sensor according to claim 9, wherein said sensor comprises a predetermined impedance element.
16. The sensor signal transmission device according to 14 or 15. 17. The sensor signal transmission device according to claim 16, wherein the impedance element comprises a resistance element whose DC resistance component changes in accordance with a change in a physical state of the device under test. 18. The sensor signal transmission device according to claim 17, wherein the resistance element is connected in series between the second coil and the third coil. 19. The sensor signal transmission device according to claim 17, wherein the resistance element is connected in parallel between the second coil and the third coil. 20. The sensor signal transmission device according to claim 17, wherein the resistance element is an element whose pure resistance component changes according to the distortion of the device under test. 21. The sensor signal transmission device according to claim 17, wherein the resistance element comprises an element whose pure resistance component changes according to a change in the temperature of the device under test. . 22. The sensor signal transmission device according to claim 16, wherein the impedance element comprises a capacitance element whose capacitance component changes according to a change in a physical state of the device under test. 23. The sensor signal transmission device according to claim 22, wherein the capacitance element is connected in series between the second coil and the third coil. 24. The sensor signal transmission device according to claim 22, wherein the capacitance element is connected in parallel between the second coil and the third coil. 25. The sensor signal transmission device according to claim 22, wherein the capacitance element is an element whose pure resistance component changes according to the distortion of the device under test. 26. The sensor signal transmission device according to claim 22, wherein the capacitance element comprises an element whose pure resistance component changes according to a change in the temperature of the device under test. .