WO2019172183A1 - Measurement device and measurement method - Google Patents

Abstract

A measurement device 1 comprises: an acquisition unit 19 for acquiring reference information associating the distance between an object and a position where reflected waves that are electromagnetic waves produced when predetermined electromagnetic waves transmitted toward the object are reflected at the object are received, a phase of the reflected waves, and a physical property of the object; a transmitting antenna 11 for transmitting electromagnetic waves toward a measurement subject 2; a receiving antenna 12 for receiving reflected waves from the measurement subject 2; and an identification unit 20 for identifying a physical property of the measurement subject 2 on the basis of the phase of the reflected waves received by the receiving antenna 12, by consulting the reference information that corresponds to an object corresponding to the material of the measurement subject 2 and that corresponds to the distance between the measurement subject 2 and the receiving antenna 12.

Description

Measuring apparatus and measuring method

The present invention relates to a measuring apparatus and a measuring method for measuring physical properties of an object to be measured.

A method for measuring the shape of an object using electromagnetic waves is known. Patent Document 1 discloses a technique for detecting a defect such as a crack formed in an object based on the phase of an electromagnetic wave reflected from an object to be measured.

JP 2017-161452 A

Using conventional techniques, it is possible to detect deterioration that causes a change in the shape of the object to be measured. However, when the conventional technique is used, a change in physical properties that does not cause a change in the shape of the object to be measured cannot be detected.

Therefore, the present invention has been made in view of these points, and an object thereof is to provide a measuring apparatus and a measuring method capable of specifying the physical properties of the object to be measured.

The measuring apparatus according to the first aspect of the present invention includes a distance from the object at a position that receives a reflected wave that is an electromagnetic wave generated by reflecting a predetermined electromagnetic wave transmitted toward the object, and the reflected wave. An acquisition unit that acquires reference information in which the phase of the object and the physical properties of the object are associated, a transmission unit that transmits electromagnetic waves toward the object to be measured, and reception that receives the reflected wave from the object to be measured And the reception unit receives the reference information corresponding to the object corresponding to the material of the object to be measured and corresponding to the distance between the object to be measured and the reception unit. A specifying unit that specifies the physical property of the object to be measured based on the phase of the reflected wave.

The specifying unit may specify a physical property that affects a dielectric constant of the object to be measured. The material of the measurement object may be concrete, and the specifying unit may specify the amount of calcium carbonate contained in the measurement object. You may further have a distance change part which changes the distance between the said to-be-measured object and the said receiving part.

The receiving unit includes a plurality of antennas having different positions in a direction in which the transmitting unit transmits the electromagnetic wave, and the specifying unit is based on a phase of a reflected wave received by an antenna selected from the plurality of antennas. The physical properties of the object to be measured may be specified.

The receiving unit includes an antenna that receives the reflected wave, and a plurality of transmission paths each having a different length that transmits the reflected wave received by the antenna to the specifying unit, and the specifying unit includes: You may identify the physical property of the said to-be-measured object based on the phase of the said reflected wave acquired via the transmission line selected from these transmission lines.

The measuring apparatus further includes an operation receiving unit that receives an operation of designating a material of the object to be measured, and the acquisition unit acquires a plurality of pieces of reference information corresponding to a plurality of materials of the object, and the specifying unit May specify the physical property of the object to be measured based on the reference information corresponding to the material indicated by the operation received by the operation receiving unit among the plurality of reference information.

The measuring apparatus further includes an oscillating unit that generates an oscillating signal having a plurality of different frequencies, and the transmitting unit is based on the oscillating signal having a frequency selected based on a material indicated by an operation received by the operation receiving unit. An electromagnetic wave may be transmitted.

The measurement method according to the second aspect of the present invention includes a distance from the object at a position where a reflected wave that is an electromagnetic wave generated by reflecting a predetermined electromagnetic wave transmitted toward the object is reflected on the object, and the reflected wave. Obtaining reference information in which the phase of the object and the physical properties of the object are associated with each other, transmitting an electromagnetic wave from the transmitting antenna toward the object to be measured, and the reflected wave from the object to be measured by the receiving antenna. The reception antenna by referring to the reference information corresponding to the object corresponding to the material of the object to be measured and corresponding to the distance between the object to be measured and the reception antenna. Specifying the physical property of the object to be measured based on the phase of the reflected wave received by the computer.

As the object to be measured, there is prepared a gas contained in a container having at least one surface made of a metal plate and a surface opposite to the surface made of the metal plate made of a material that transmits electromagnetic waves. In the step and the step of transmitting the electromagnetic wave, the electromagnetic wave may be transmitted to the gas from the opposite surface.

According to the present invention, there is an effect that the physical property of the object to be measured can be specified.

It is a figure for demonstrating the outline | summary of a measuring apparatus. It is a figure which shows the internal structure of a measuring apparatus. It is a figure which shows the relationship between the density | concentration of the calcium carbonate contained in the object, and a phase in a reflected wave measured in the predetermined distance as an example of reference | standard information. It is a figure for demonstrating the measuring method of the physical property in case a to-be-measured object is a liquid. It is a figure for demonstrating the influence of a window material. It is a figure which shows the relationship between the density | concentration of sodium chloride aqueous solution and the phase of a reflected wave which were measured in the predetermined distance as an example of reference | standard information. It is a figure which shows the relationship between the volume ratio of ethanol in the ethanol aqueous solution, and the phase of a reflected wave measured in the predetermined distance as an example of reference | standard information. It is a figure for demonstrating the measuring method of the physical property in case a to-be-measured object is gas. It is a figure which shows the relationship between the kind of gas as an example of reference | standard information, and the phase of a reflected wave.

[Outline of measuring apparatus 1]
FIG. 1 is a diagram for explaining an outline of the measuring apparatus 1. The measuring device 1 emits an electromagnetic wave toward the object 2 to be measured and specifies the physical property of the object 2 by analyzing the phase of the electromagnetic wave reflected by the object 2. It is a device. In order to ensure sufficient spatial resolution, it is desirable that the frequency of the electromagnetic wave emitted from the measuring apparatus 1 toward the device under test 2 is from the frequency of the microwave to the frequency of the terahertz wave.

The DUT 2 is a solid, liquid, or gas. The DUT 2 is, for example, concrete, resin, metal, or aqueous solution.

The measuring apparatus 1 includes a transmission antenna 11 that emits an electromagnetic wave toward the device under test 2 and a reception antenna 12 that receives the electromagnetic wave reflected by the device under test 2. The direction in which the sensitivity of the transmitting antenna 11 and the receiving antenna 12 is high is the same, for example, the direction orthogonal to the surface of the DUT 2. The distance between the transmitting antenna 11 and the surface of the device under test 2 is the same as the distance between the receiving antenna 12 and the surface of the device under test 2, for example. The distance and the distance between the receiving antenna 12 and the surface of the DUT 2 do not have to be the same.

The measuring device 1 refers to information (hereinafter, sometimes referred to as reference information) indicating a relationship between physical properties and phases measured in advance, so that the device under test 2 is based on the phase of the electromagnetic wave received by the receiving antenna 12. Identify the physical properties. The inventor has found that the phase of the electromagnetic wave reflected by the object changes depending on the physical property correlated with the dielectric constant of the object, and the physical property of the DUT 2 can be specified based on the phase of the electromagnetic wave received by the receiving antenna 12. It was. As shown in FIG. 1B, when the device under test 2 is a metal, the node of the electromagnetic wave emitted from the transmitting antenna 11 is located on the surface of the device under test 2, but the physical properties of the device under test 2 change. As a result, the phase of the electromagnetic wave on the surface of the device under test 2 changes, so that the phase of the electromagnetic wave received by the receiving antenna 12 also changes depending on the physical properties of the device under test 2.

As shown in FIG. 1 (c), even if the object 2 having the same physical properties is reflected, if the distances between the transmitting antenna 11 and the receiving antenna 12 and the surface of the object 2 are different, the receiving antenna 12 The phase of the received electromagnetic wave has a different value. Therefore, the measuring apparatus 1 may include a distance changing unit (not shown) that changes the distance between the receiving antenna 12 and the DUT 2. In the measuring apparatus 1, the distance between the receiving antenna 12 and the object when the relationship between the physical property and the phase is measured in advance based on a user instruction matches the distance between the receiving antenna 12 and the object to be measured 2. The measurement accuracy can be improved by setting the position of the measurement apparatus 1 as described above.

The measuring apparatus 1 moves the receiving antenna 12 in the front-rear direction (that is, the receiving antenna 12 and the measured object 2 so that the distance between the receiving antenna 12 and the surface of the measured object 2 matches the distance to the measured object 2 input by the user). You may have the actuator which can be moved to the direction to connect the measurement object 2). For example, the measuring apparatus 1 uses the transmission antenna 11 and the reception based on the time difference between the time when the emission of the electromagnetic wave from the transmission antenna 11 is started and the time when the reception antenna 12 starts receiving the electromagnetic wave reflected by the DUT 2. The distance between the antenna 12 and the surface of the DUT 2 is measured, and the receiving antenna 12 is moved by controlling the actuator based on the measurement result.

[Configuration of Measuring Device 1]
FIG. 2 is a diagram illustrating an internal configuration of the measurement apparatus 1. In addition to the transmitting antenna 11 and the receiving antenna 12, the measuring apparatus 1 includes an oscillator 13, a coupler 14, a phase shifter 15, a duplexer 16, a mixer 17, a mixer 18, an acquisition unit 19, and a specific unit. Part 20. The transmission antenna 11 functions as a transmission unit, and the reception antenna 12, the duplexer 16, the mixer 17, and the mixer 18 function as a reception unit.

The oscillator 13 is an oscillator that generates an oscillation signal for generating an electromagnetic wave emitted from the transmission antenna 11. The oscillator 13 generates an oscillation signal in a millimeter wave frequency band, for example. The oscillator 13 inputs the generated oscillation signal to the coupler 14.

The coupler 14 distributes the oscillation signal input from the oscillator 13 to the transmission antenna 11 and the phase shifter 15. The oscillation signal input to the transmission antenna 11 is emitted from the transmission antenna 11 as an electromagnetic wave. The oscillation signal input to the phase shifter 15 is used when separating the electromagnetic wave received by the receiving antenna 12 into an I signal and a Q signal.

The phase shifter 15 generates an in-phase signal in which the phase of the electromagnetic wave received by the receiving antenna 12 is not changed and a phase shift signal in which the phase of the electromagnetic wave received by the receiving antenna 12 is changed by 90 degrees. The phase shifter 15 inputs the in-phase signal to the mixer 17 and inputs the phase shift signal to the mixer 18.

The duplexer 16 inputs the electromagnetic waves received by the receiving antenna 12 separately to the mixer 17 and the mixer 18.
The mixer 17 generates an I signal by mixing the electromagnetic wave received from the duplexer 16 and the in-phase signal. The mixer 18 mixes the electromagnetic wave received from the duplexer 16 and the phase shift signal to generate a Q signal.

The acquisition unit 19 acquires reference information created in advance. For example, the acquisition unit 19 acquires reference information stored in a memory (not illustrated) or reference information stored in an external device. The acquisition unit 19 acquires reference information corresponding to the distance between the surface of the DUT 2 and the receiving antenna 12 among the plurality of reference information corresponding to the plurality of distances. The reference information associates the distance from the object at the position where the reflected wave, which is an electromagnetic wave generated by reflecting a predetermined electromagnetic wave transmitted toward the object, with the object, the phase of the reflected wave, and the physical properties of the object. Information. In the reference information, the amplitude of the reflected wave may be associated with the phase of the reflected wave.

FIG. 3 is a diagram showing the relationship between the concentration of calcium carbonate contained in the object and the phase of the reflected wave, measured at a predetermined distance, as an example of the reference information. The black circles in FIG. 3 indicate the actual measurement results. In FIG. 3, four actually measured results are included, but more actual measurement results may be included. Moreover, although the black circles in FIG. 3 are connected by straight lines, the black circles may be interpolated by curves by an interpolation method such as a Lagrange interpolation method.

The specifying unit 20 specifies the physical property of the DUT 2 based on the phase of the reflected wave received by the receiving antenna 12 by referring to the reference information corresponding to the distance between the DUT 2 and the receiving antenna 12. To do. Specifically, the specifying unit 20 acquires reference information corresponding to the distance between the DUT 2 and the receiving antenna 12 from the acquiring unit 19, and is associated with the phase of the reflected wave in the acquired reference information. The physical property is specified as the physical property of the object 2 to be measured. The specifying unit may specify the physical property of the DUT 2 based on the phase and amplitude of the reflected wave.

The specifying unit 20 specifies a physical property that affects the dielectric constant of the DUT 2, for example. When the material of the DUT 2 is concrete, the specifying unit 20 specifies the amount of calcium carbonate contained in the DUT 2.

The amount of calcium carbonate contained in the object has a high correlation with the deterioration of the concrete. In concrete, the production of calcium carbonate proceeds by causing a chemical reaction between carbon dioxide in the atmosphere and the calcium component in the concrete. As the formation of calcium carbonate progresses, the strength of the structure decreases due to the induction of corrosion of the internal reinforcing bars. As described above, by specifying the amount of calcium carbonate contained in the DUT 2 by the specifying unit 20, it is possible to easily check the deterioration state of the concrete used in the building. Therefore, the measurement using the measuring device 1 is suitable for monitoring the plant and for infrastructure maintenance.

[Method for measuring physical properties of liquid]
FIG. 4 is a diagram for explaining a method of measuring physical properties when the object to be measured is a liquid. In the example shown in FIG. 4, a liquid measurement object 4 is accommodated in the container 3, and a window member 5 that covers the measurement object 4 is provided on the transmission antenna 11 and reception antenna 12 side.

FIG. 5 is a diagram for explaining the influence of the window material 5. The horizontal axis in FIG. 5 indicates the thickness of the window member 5, and the vertical axis indicates the relative reflectance. The relative reflectance is a ratio of the reflectance in a state where the window material 5 is provided to the reflectance when the electromagnetic wave is reflected on the surface of the liquid. The relative reflectance decreases as the thickness of the window material 5 increases. However, when the thickness of the window material 5 is 2 mm or less, the relative reflectance is 0.9 or more.

FIG. 6 is a diagram showing a relationship between the concentration of the sodium chloride aqueous solution and the phase of the reflected wave measured at a predetermined distance as an example of the reference information. As shown in FIG. 6, since the phase of the reflected wave changes depending on the concentration of the sodium chloride aqueous solution, the specifying unit 20 refers to the relationship shown in FIG. The concentration of the sodium chloride aqueous solution can be specified based on the phase of the electromagnetic wave. The specifying unit 20 selects reference information corresponding to the thickness of the window material 5 that covers the object 4 to be irradiated with electromagnetic waves, from a plurality of reference information corresponding to the plurality of window materials 5 having different materials and thicknesses. The concentration of the sodium chloride aqueous solution may be specified by referring to the selected standard information.

FIG. 7 is a diagram showing the relationship between the volume ratio of ethanol in the ethanol aqueous solution and the phase of the reflected wave, measured at a predetermined distance, as an example of the reference information. As shown in FIG. 7, since the phase of the reflected wave changes depending on the volume ratio of ethanol, the specifying unit 20 is reflected by the DUT 4 through the window material 5 by referring to the relationship shown in FIG. 7. The concentration of the ethanol aqueous solution can be specified based on the phase of the electromagnetic wave.

[Measurement method of gas properties]
FIG. 8 is a diagram for explaining a method of measuring physical properties when the object to be measured is a gas. In the example shown in FIG. 8, a gaseous object to be measured 6 is accommodated in the container 3, and a window member 5 that covers the object to be measured 6 is provided on the transmitting antenna 11 and receiving antenna 12 side. When measuring the physical properties of the gaseous object to be measured 6, a metal plate 7 is provided between the object to be measured 6 and the container 3 in order to obtain a sufficiently large reflected wave.

When measuring the physical properties of gas, as the object to be measured, at least one surface is constituted by the metal plate 7 and the surface opposite to the surface constituted by the metal plate 7 is constituted by the window material 5 through which electromagnetic waves pass. The gas accommodated in the container 3 is prepared. And electromagnetic waves are transmitted to gas from the surface on the opposite side to the surface comprised with the metal plate 7, and the specific part 20 measures the phase of a reflected wave.

FIG. 9 is a diagram showing the relationship between the type of gas and the phase of the reflected wave as an example of the reference information. As shown in FIG. 9, since the phase of the reflected wave changes depending on the type of gas, the specifying unit 20 refers to the relationship shown in FIG. 9, so that the metal plate 7 is interposed via the window material 5 and the DUT 6. The type of gas can be specified based on the phase of the electromagnetic wave reflected at.

When measuring the physical properties of the gas, the window material 5 is not used, the measuring device 1 is installed in a room containing the gas, and the measuring device 1 emits an electromagnetic wave to the metal plate installed in the gas. Then, the physical properties of the gas may be measured by specifying the phase of the reflected wave from the metal plate.

[Modification 1]
The reception unit may include a plurality of reception antennas 12 having different positions in the direction in which the transmission antenna 11 transmits electromagnetic waves. The specifying unit 20 may specify the physical property of the object to be measured based on the phase of the reflected wave received by the receiving antenna 12 selected from the plurality of receiving antennas 12. For example, the specifying unit 20 specifies the physical property of the object to be measured based on the phase of the reflected wave received by the receiving antenna 12 corresponding to the distance between the receiving antenna 12 and the object when the reference information is acquired. By doing in this way, even if the measuring apparatus 1 does not have a mechanism for moving the receiving antenna 12, the user can measure physical properties without adjusting the position of the measuring apparatus 1.

[Modification 2]
The receiving unit may have a plurality of transmission paths each having a different length for transmitting the reflected wave received by the receiving antenna 12 to the specifying unit 20. And the specific | specification part 20 may specify the physical property of a to-be-measured object based on the phase of the reflected wave acquired through the transmission path selected from the several transmission path.

[Modification 3]
The measuring apparatus 1 may further include an operation receiving unit (not shown) that receives an operation for specifying the material of the object to be measured. In this case, the acquiring unit 19 acquires a plurality of reference information corresponding to a plurality of materials of the object, and the specifying unit 20 is based on the reference information corresponding to the material indicated by the operation received by the operation receiving unit. You may specify the physical property of a thing.

The oscillator 13 may generate an oscillation signal having a plurality of different frequencies, and the receiving antenna 12 may transmit an electromagnetic wave based on the oscillation signal having a frequency selected based on the material indicated by the operation received by the operation receiving unit. . In this case, the specifying unit 20 specifies the physical property of the object to be measured by referring to the reference information obtained by performing the measurement using the oscillation signal having the selected frequency. By doing in this way, since the measuring apparatus 1 can measure using the electromagnetic wave of the frequency suitable for the material of to-be-measured object, a measurement precision improves.

[Effects of measuring apparatus 1]
As described above, according to the measuring apparatus 1 of this embodiment, reference is made to reference information corresponding to an object corresponding to the material of the object to be measured and corresponding to the distance between the object to be measured and the receiving unit. Thus, the physical property of the object to be measured is specified based on the phase of the reflected wave received by the receiving unit. By doing in this way, the measuring apparatus 1 can measure the physical properties of the measured object even when the shape of the measured object does not change. Since the measuring apparatus 1 can be realized by a configuration in which electromagnetic waves are transmitted and received and the phase of the received electromagnetic waves is measured, the measuring apparatus 1 can be housed in a compact housing and can measure physical properties with high stability at low cost. .

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment, A various deformation | transformation and change are possible within the range of the summary. is there. For example, the specific embodiments of device distribution / integration are not limited to the above-described embodiments, and all or a part of them may be configured to be functionally or physically distributed / integrated in arbitrary units. Can do. In addition, new embodiments generated by any combination of a plurality of embodiments are also included in the embodiments of the present invention. The effect of the new embodiment produced by the combination has the effect of the original embodiment.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Measured object 3 Container 4 Measured object 5 Window material 6 Measured object 7 Metal plate 11 Transmitting antenna 12 Receiving antenna 13 Oscillator 14 Coupler 15 Phase shifter 16 Demultiplexer 17 Mixer 18 Mixer 19 Acquisition part 20 Identification Part

Claims (10)

The distance from the object at a position where a reflected wave, which is an electromagnetic wave generated by reflecting a predetermined electromagnetic wave transmitted toward the object, is reflected by the object, the phase of the reflected wave, and the physical properties of the object are associated with each other. An acquisition unit for acquiring the obtained reference information;
A transmitter for transmitting electromagnetic waves toward the object to be measured;
A receiving unit for receiving the reflected wave from the object to be measured;
The reflected wave received by the receiver by referring to the reference information corresponding to the object corresponding to the material of the object to be measured and corresponding to the distance between the object to be measured and the receiver. A specifying unit for specifying the physical property of the object to be measured based on the phase of
Measuring device. The specifying unit specifies a physical property that affects a dielectric constant of the object to be measured;
The measuring apparatus according to claim 1. The material of the object to be measured is concrete,
The specifying unit specifies an amount of calcium carbonate contained in the object to be measured;
The measuring apparatus according to claim 2. A distance changing unit that changes a distance between the device under test and the receiving unit;
The measuring apparatus as described in any one of Claim 1 to 3. Each of the receiving units has a plurality of antennas having different positions in the direction in which the transmitting unit transmits the electromagnetic waves,
The specifying unit specifies a physical property of the object to be measured based on a phase of a reflected wave received by an antenna selected from the plurality of antennas;
The measuring device according to any one of claims 1 to 4. The receiver is
An antenna for receiving the reflected wave;
A plurality of transmission lines each having a different length for transmitting the reflected wave received by the antenna to the specific unit;
Have
The specifying unit specifies a physical property of the object to be measured based on a phase of the reflected wave acquired through a transmission line selected from the plurality of transmission lines;
The measuring device according to any one of claims 1 to 4. An operation receiving unit that receives an operation of specifying a material of the object to be measured;
The acquisition unit acquires a plurality of the reference information corresponding to a plurality of materials of the object,
The specifying unit specifies a physical property of the object to be measured based on the reference information corresponding to a material indicated by an operation received by the operation receiving unit among the plurality of reference information.
The measuring device according to any one of claims 1 to 6. It further has an oscillating unit that generates a plurality of oscillation signals of different frequencies,
The transmitting unit transmits the electromagnetic wave based on the oscillation signal having a frequency selected based on a material indicated by the operation received by the operation receiving unit.
The measuring apparatus according to claim 7. The distance from the object at a position where a reflected wave, which is an electromagnetic wave generated by reflecting a predetermined electromagnetic wave transmitted toward the object, is reflected by the object, the phase of the reflected wave, and the physical properties of the object are associated with each other. Obtaining obtained reference information;
Transmitting electromagnetic waves from the transmitting antenna toward the object to be measured;
Receiving the reflected wave from the device under test with a receiving antenna;
The reflected wave received by the receiving antenna by referring to the reference information corresponding to the object corresponding to the material of the measured object and corresponding to the distance between the measured object and the receiving antenna. Identifying the physical properties of the object to be measured based on the phase of
Measuring method. As the object to be measured, there is prepared a gas contained in a container having at least one surface made of a metal plate and a surface opposite to the surface made of the metal plate made of a material that transmits electromagnetic waves. Steps,
In the step of transmitting the electromagnetic wave, the electromagnetic wave is transmitted from the opposite surface to the gas.
The measurement method according to claim 9.

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