JP2018013943A - Monitoring tag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring tag capable of appropriately detecting the long-term deterioration of a monitoring object in consideration of an impact of a humid condition of the monitoring object or presence of ionicity impurities.SOLUTION: A monitoring tag 10 for monitoring the state of a monitoring object includes: an IC chip of an RFID tag 20 storing memory information including ID information; an antenna circuit 70 for transmitting the memory information to a reading terminal; and a tamper detection circuit 30. The tamper detection circuit 30 includes: a stimulation response portion 32 for responding to a particular stimulation influencing a characteristic of the monitoring object to change the memory information; and a resistance adjustment unit 33 for adjusting the value of resistance of the tamper detection circuit 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a monitoring tag suitable for applications such as quality control.

  In recent years, various techniques for applying an RF (Radio Frequency) tag (hereinafter referred to as an RFID tag) in which ID (IDentification) information is embedded to applications such as quality control have been developed.

  For example, Patent Document 1 discloses a technique for quality control of a concrete structure using a sensor (pH sensor, temperature sensor, etc.) embedded in the concrete structure and an RFID tag.

However, in the technique of Patent Document 1, a computer chip having a complicated structure, specifically, a sensor chip obtained by calculating and processing sensor information obtained through a sensor embedded in a concrete structure, A tag is required which is equipped with an RFID chip having a memory for storing measured values and which has terminals for connecting the sensor to the computer chip.
For this reason, the technique of Patent Document 1 has a problem in that the tag is enlarged and the arrangement position is limited. In addition, there is a problem that the power required for the calculation processing of the computer chip is not preferable from the viewpoint of power saving.

Therefore, as a monitoring tag for monitoring the state of the monitoring target, an IC chip storing memory information including ID information, an antenna circuit for reading the memory information and transmitting it to the terminal, and detecting the aging of the monitoring target. A monitoring tag including a detection circuit is considered.
Since this monitoring tag is embedded or attached to the monitoring object, the result of the measured quality control, etc., shows that the stimulation response site responds to the stimulation due to aging of the monitoring object, and the detection circuit Although the circuit resistance will change, the circuit resistance may be affected by the wet state of the monitoring object or the presence of ionic impurities, which is problematic in terms of detection accuracy.

JP 2013-257732 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a monitoring tag that can solve the above-described problems of the prior art and can appropriately detect aged deterioration of a monitoring target. There is.

  In order to solve the above problems, the present inventors diligently studied, and as a result, have come up with the invention of a monitoring tag for monitoring the state of a monitoring object shown below.

  The monitoring tag according to the present invention includes an IC chip that stores memory information including ID information, an antenna circuit that reads the memory information and transmits it to a terminal, and a tamper detection circuit. The tamper detection circuit includes a stimulus response part that changes the memory information in response to a specific stimulus that affects the characteristics of the monitoring target, and a resistance adjustment unit that adjusts a resistance value of the tamper detection circuit. Have

  The monitoring tag according to the present invention preferably further includes a sheet-like base material on which the antenna circuit and the IC chip are mounted.

  The antenna circuit is a circuit formed by printing a resin solution containing fine particles of a conductive material on the surface of the substrate, or a circuit formed by pressing and etching a metal foil on the surface of the substrate. It is preferable that

  It is preferable that the resistance adjusting unit includes a resistor or a transistor.

  It is preferable that the resistance adjusting unit uses a photo interrupter.

  It is preferable to have a stimulus responsive part in the light detection part of the photo interrupter.

  It is preferable that the stimulus response site is made of a stimulus responsive metal.

  It is preferable that the monitoring tag according to the present invention further includes a sealing material that seals the tamper detection circuit so that an opening from which the stimulation response site is exposed is formed.

  It is preferable that the monitoring tag according to the present invention further includes a stimulus-responsive resin that covers the stimulus-responsive part.

  According to the present invention, the monitoring target object includes the resistance adjustment unit that can adjust the resistance value of the tamper detection circuit in consideration of the wet state of the monitoring target object or the presence of ionic impurities. It is possible to provide a monitoring tag that can appropriately detect aging deterioration of the aging.

It is a key map of a monitoring tag concerning the present invention. It is a conceptual electric circuit diagram of the monitoring tag of FIG. It is a conceptual diagram of another monitoring tag which concerns on this invention. FIG. 4 is a conceptual electric circuit diagram of the monitoring tag of FIG. 3.

With reference to FIG.1 and FIG.2, the monitoring tag 10 of embodiment which concerns on this invention is demonstrated.
As shown in FIG. 1, the monitoring tag 10 is a monitoring tag that monitors the state of a monitoring target, and includes an RFID tag 20 and a tamper detection circuit 30. Monitoring tag 10 further includes a base material 60, an antenna circuit 70, and a sealing material 80.

  The base material 60 is a substantially rectangular sheet member. A slit portion 61 and an opening 62 are formed around the substrate 60. The base material 60 is divided into an antenna part region 63 and a sensor part region 64 by a slit part 61.

The RFID tag 20 is a radio frequency tag in which solid identification information (Identification) is embedded, and is a passive type RFID tag that does not incorporate a battery. The optimum communication distance of the RFID tag 20 can be selected from several millimeters to several meters depending on the application.
The RFID tag 20 is a device on which an IC chip 22 (see FIG. 2) is mounted, and is a passive type RFID tag that does not incorporate a battery.
As the shape of the RFID tag 20, an optimum shape can be selected from shapes such as a label type, a card type, a coin type, and a stick type according to the application. The optimal communication distance of the RFID tag 20 can be selected from 1 mm to 10 m according to the application.

  The IC chip 22 is a small semiconductor chip of about 0.4 mm to 1 mm square, for example. The IC chip 22 includes a simple microcomputer, EEPROM, RAM, and the like, and has a memory function as a medium for storing a specific ID and the like. Further, the IC chip 22 preferably includes a program for performing an encryption process for preventing data falsification and the like.

It is preferable to use an IC chip 22 that can detect and detect the resistance value of the tamper detection circuit 30. In this embodiment, a wiring connection type IC chip (UCODE G2iL + manufactured by NXP Semiconductors) is used. However, a magnetic field and radio wave resonance type IC chip may be used.
The wiring connection type IC chip 22 includes two tamper circuit pins P1 and P2 (see FIG. 2) and two antenna circuit pins Q1 and Q2 (see FIG. 2) at the four corners of the chip. Both ends of 31 are electrically connected to the two tamper circuit pins P1 and P2, respectively, and both ends of the antenna circuit 70 are electrically connected to the two antenna circuit pins Q1 and Q2, respectively. .

In the case of an IC chip of a magnetic field and radio wave resonance type, the manufacturing method of the RFID tag 20 is not particularly limited. For example, a long base material is prepared by laminating a hard aluminum foil on the surface of an insulating film. An etching resist is formed on the aluminum foil surface by gravure printing, and then etching is performed with a ferric chloride aqueous solution to form a built-in IC antenna (not shown) having a matching circuit with the IC chip 22. it can. Next, after bumps serving as external terminals of the IC chip 22 are aligned with predetermined positions of the built-in IC antenna by a flip chip structure and bonded by applying ultrasonic waves, the IC chip 22 and the built-in IC antenna An antenna tape having a plurality of IC chips 22 mounted thereon can be obtained by filling the gap with a sealing resin and heat-curing it. By cutting the antenna tape and removing the excess part, the same number of RFID tags 20 as the IC chips 22 used can be produced.
Magnetic field and radio wave resonance type IC chips do not have wiring connection portions corresponding to antenna circuit pins. The magnetic field and radio wave resonance type IC chip is electrically connected to the antenna circuit 70 by the resonance of the magnetic field and radio wave.

As shown in FIG. 1, the RFID tag 20 is disposed on the antenna part region 63 of the base material 60.
The antenna circuit 70 is an antenna circuit that reads memory information stored in the IC chip 22 and transmits it to the terminal. The antenna circuit 70 has a meandering shape and is disposed on the antenna portion region 63 of the substrate 60 so that the length of the antenna circuit 70 is increased. The antenna circuit 70 is a circuit formed by printing a resin solution containing fine particles of a conductive material on the surface of the base material 60, or a circuit formed by pressing and etching a metal foil on the surface of the base material. It is preferable that

  The tamper detection circuit 30 includes a circuit unit 31, a stimulus response part 32 incorporated in a part of the circuit unit 31, and a resistance adjustment unit 33 that adjusts the overall resistance of the circuit unit 31. It is a circuit that detects the occurrence of tampering by cleaving or resistance change.

  Normally, a tamper detection circuit is such that when the RFID tag 20 is deliberately peeled off (for the purpose of theft) from an object to which the RFID tag 20 is attached, it is mechanically destroyed. This means a circuit provided, that is, a circuit laid for the purpose of detecting an act (that is, a tampering action) caused by the cleavage or resistance change of the circuit. The detection circuit is such that when a monitoring target to which the RFID tag 20 is attached is exposed to a specific stimulus that affects its characteristics, it is cleaved by a physical or chemical reaction caused by the stimulus. Or a circuit provided such that the resistance is changed (that is, a circuit to which the RFID tag 20 is attached by cleavage of the circuit or change in resistance). REITs buildings shall also include circuitry) laid for the purpose of detecting that it has been exposed to a specific stimulus it became those factors.

  As shown in FIGS. 1 and 2, one of the circuit units 31 is wired to the tamper circuit pin P <b> 1 of the IC chip 22 of the RFID tag 20, and the other passes through the antenna unit region 63 of the base 60 and is a sensor. It extends over the partial area 64 and is connected to the tamper circuit pin P2 of the IC chip 22 by wire again. On the circuit part 31, a stimulus response part 32 and a resistance adjustment part 33 are formed. For this reason, the circuit unit 31 is conductive as a loop circuit r1 that energizes the tamper circuit pin P2 from the tamper circuit pin P1 of the IC chip 22 through the stimulus response part 32 and the resistance adjustment unit 33.

  Each of the stimulus response part 32 and the resistance adjusting unit 33 is electrically expressed as a resistance value of the resistor R1 (hereinafter, both the resistor as an electric circuit and the resistance value thereof are denoted as R1 for convenience. It can be said that this is a resistor circuit having the resistance value of the resistor R2 and other resistors as well. For this reason, the resistance value R of the loop circuit r1 of the circuit unit 31 is equal to the resistance value of the resistor R1 + the resistance value of the resistor R2, since the stimulus response part 32 and the resistance adjusting unit 33 are connected in series.

  In addition, a loop circuit r2 is formed in the RFID tag 20 to energize the tamper circuit pin P2 from the tamper circuit pin P1 without passing through the stimulus response portion 32 and the resistance adjusting unit 33. The loop circuit r2 A resistance circuit having a resistance value R0 is formed above. Therefore, the circuit unit 31 is formed with a circuit in which a resistance circuit having a resistance value R and a resistance circuit having a resistance value R0 are connected in parallel. The overall resistance value RA of the circuit unit 31 is (1 / (1 / R0)) + (1 / (R1 + R2)). A threshold value for distinguishing between high and low resistance values that can be detected by the IC chip 22 is set in advance based on the overall resistance value RA of the circuit unit 31.

  As shown in FIG. 1, the shape of the circuit unit 31 is not particularly limited, so that the circuit unit 31 is flat, curved, rod-shaped, etc. according to the usage environment and purpose of the monitoring tag 10. It can be designed to an optimal shape and size as appropriate.

  When the stimulus response site 32 is exposed to a specific stimulus that affects the characteristics of the monitoring target, the circuit portion 31 is cut by a physical or chemical reaction caused by the stimulus (in other words, the electrical resistance is extremely high). Or exposed in the opening 62 of the substrate 60 so that the electrical resistance of the circuit portion 31 changes.

  The stimulus response site 32 has a function of “responding” when the monitoring object is exposed to a specific stimulus that affects its characteristics, specifically, a physical reaction or chemistry that cleaves the circuit of the circuit unit 31. A portion having a function of changing the memory information to the IC chip 22 by generating a physical reaction or a physical reaction or a chemical reaction that changes the resistance of the circuit, that is, a sensor function for detecting a change in the external environment. means.

  Since the stimulation response part 32 is provided in the circuit part 31, the circuit part 31 can be freely wired in the base material 60, and the stimulation response part 32 can be arrange | positioned in a desired position.

The structure of the stimulation response part 32 is not particularly limited. For example, at least a part of the circuit unit 31 may be covered with the stimulation responsive resin 34. Alternatively, at least a part of the circuit unit 31 can be replaced with a stimulus-responsive metal. All of the circuit unit 31 can be covered with a stimulus-responsive resin, or all of the circuit unit 31 can be formed of a stimulus-responsive metal.
The stimuli-responsive resin and the stimulus-responsive metal can be appropriately selected according to the stimulus to be detected.

  Specifically, examples of the stimuli-responsive resin include a heat-responsive resin material, a pH-responsive resin material, a stress-responsive resin material, a photo-responsive resin material, a resin material that responds to a specific substance, and these A resin material combining a plurality of materials can be exemplified.

Examples of the stimulus-responsive metal include a metal that changes in quality (corrosion or the like) due to a stimulus to be detected and is disconnected or a metal that becomes a nonconductor.
In addition, a stimulus responsive metal can be obtained by changing the thickness or width of a part of the metal forming the loop circuit to improve the stimulus responsiveness.
Specifically, it is preferably at least one selected from the group consisting of zinc, aluminum, cadmium, iron, tin, lead, copper, nickel, silver, titanium and zirconium, zinc, aluminum, iron, copper, More preferably, it is at least one selected from the group consisting of nickel, more preferably at least one selected from the group consisting of aluminum, iron, and copper, and particularly preferably iron.

  The mode in which the stimulus response part 32 changes the memory information of the IC chip 22 in response to a specific stimulus is not particularly limited. For example, when the stimulus response part 32 responds to a specific stimulus, the circuit unit 31 The memory information to the IC chip can be changed by causing a physical reaction or chemical reaction that cleaves the substrate, or a physical reaction or chemical reaction that changes the resistance of the circuit unit 31.

  The resistance adjustment unit 33 includes a transistor or a resistor that adjusts the overall resistance of the circuit unit 31 and is set to a resistance value that takes into account the wet state of the monitoring target or the presence of ionic impurities.

The monitoring tag 10 includes an antenna unit 11 and a sensor unit 12 when viewed from the whole.
The antenna unit 11 is configured by sealing the RFID tag 20 and the antenna circuit 70 on the antenna unit region 63 with a sealing material 80.
The sensor unit 12 is sealed on the sensor unit region 64 with the circuit unit 31 of the tamper detection circuit 30, the resistance adjustment unit 33, and the sealing material 80 so that the stimulus response part 32 is exposed to the opening 62. It is composed.

  Examples of the sealing material 80 include polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, acrylic resin, polycarbonate resin, polytetrafluoroethylene resin, polyurethane resin, epoxy resin, silicone resin, and EVA resin. It is preferable to use one.

The monitoring tag 10 is used as follows.
The method for installing the monitoring tag 10 when a concrete structure is a monitoring object is performed, for example, as follows.
First, the threshold value for discriminating the level of the resistance value that can be detected by the IC chip 22 and the resistance value RA of the entire tamper detection circuit 30 (circuit unit 31) are affected by the resistance value RC of the concrete structure itself and the wet state. Alternatively, the resistance value R2 of the resistance adjusting unit 33 is adjusted in consideration of the influence of the presence of ionic impurities. As a result, even if there is an individual difference in the resistance value RC due to the concrete structure to be installed and an individual difference in the resistance value RC due to the wet state or the presence of ionic impurities, the individual difference is converted into the resistance value of the resistance adjusting unit 33. By adjusting R2, it is possible to set the overall resistance value RA of the circuit unit 31 that is judged that the aging of the concrete structure has progressed to be substantially the same, and the resistance value that can be detected by the IC chip 22 can be increased or decreased. Adjustment of the threshold value for discrimination can be omitted.
Since the resistance value R2 of the resistance adjusting unit 33 can be adjusted more easily than adjusting the threshold value for distinguishing the level of the resistance value that can be detected by the IC chip 22, the adjustment work of the monitoring tag 10 can be performed easily and in a short time. be able to.

Next, the monitoring tag 10 is inserted into an inspection hole previously formed in the wall surface of the concrete structure. The inspection hole may be formed when the monitoring tag 10 is inserted or may be an existing hole formed on the wall surface for other purposes.
The monitoring tag 10 is preferably arranged in contact with the inner wall in the inspection hole in order to detect the state of the concrete building more accurately.

  Every time a period (several months or years, etc.) for judging whether or not the specified aging deterioration has progressed, a general-purpose reader or reader / writer (hereinafter referred to as reader / writer, etc.) approaches without contact from the outside of the concrete structure. To check whether the monitoring tag 10 is operating normally.

  When the monitoring tag 10 is operating normally, the radio wave transmitted from the external antenna built in the reader / writer or the like is transmitted to the built-in IC antenna via the antenna circuit 70, and thereby to the IC chip 22. By inducing power, information is transmitted and received in a non-contact manner between the reader / writer and the IC chip 22. At this time, since the ID information can be acquired, it is possible to easily know which monitoring tag is operating normally.

With reference to FIG. 2, the relationship between the progress of aging of the concrete structure and the electric circuit will be described.
In the state immediately after the monitoring tag 10 is installed in the concrete structure, the stimulus response portion 32 is not affected by the wet state of the concrete structure or the presence of ionic impurities, and thus a resistance circuit having a predetermined resistance value R1. Acts as
Further, the concrete structure itself also acts as a resistance circuit having a resistance value RC that is greater than the resistance value R1 of the stimulus response portion 32. However, in a state immediately after the monitoring tag 10 is installed in the concrete structure, the stimulus response part 32 is covered with the stimulus responsive resin 34 in an insulating state, or the resistance value RC of the concrete structure is the value of the stimulus response part 32. The circuit rc that is very large with respect to the resistance value R1 and forms a parallel coupling with the stimulus response part 32 may be negligible as an electric circuit. For this reason, the resistance value RC of the concrete structure itself hardly affects the overall resistance value RA of the circuit unit 31.

As the aging of the concrete structure progresses, the stimulus response portion 32 of the tamper detection circuit 30 is stimulated to be cleaved or changed in resistance. That is, when the stimulus response part 32 itself is cleaved, it is in an insulated state (resistance value R1 becomes very large), and when the resistance changes, the resistance value R1 increases. Thus, the overall resistance value RA of the circuit unit 31 is affected by the changing resistance value R1.
Furthermore, due to aging of the concrete structure, the concrete structure may be affected by the wet state or the presence of ionic impurities, and the resistance value RC of the concrete structure itself may be reduced. That is, as the concrete structure becomes wet, the resistance value RC of the concrete structure itself gradually decreases. In addition, when the ionic impurities of the concrete structure are electrically connected to the stimulus response portion 32, the resistance value RC of the concrete structure itself becomes substantially as small as the resistance value of the conductor. For this reason, the resistance value RC of the concrete structure itself is a resistance value that cannot be ignored in terms of an electric circuit with respect to the resistance value R1. Then, the overall resistance value RA of the circuit unit 31 is affected by the resistance value RC of the concrete structure itself.
However, the resistance value R2 of the resistance adjustment unit 33 is based on the threshold value that distinguishes the level of the resistance value that can be detected by the IC chip 22 and the resistance value RA of the entire tamper detection circuit 30 (circuit unit 31). Therefore, the IC chip 22 accurately detects the degree of aging of the concrete structure because it is adjusted in consideration of the resistance value RC and the influence of the wet state or the influence of the presence of ionic impurities. be able to.

  As a configuration of the monitoring tag 10, a plurality of stimulus response parts are connected in parallel to form a parallel circuit, and a resistor is arranged in series with each stimulus response part, and corrosion is caused based on a change in the combined resistance value. When adopting a configuration that requires some kind of arithmetic processing, such as specifying a location, it is necessary to provide a computer chip in the RFID tag that performs arithmetic processing on information detected by the sensor unit to obtain a measurement value. Since a terminal for connecting the unit to the computer chip is also required, the RFID tag must be enlarged, and power for arithmetic processing is also required. However, as described above, by providing the stimulation response portion 32 in the circuit portion 31 of the tamper detection circuit 30 connected to the IC chip 22, the above-described computer chip is not required, and the sensor is used as a computer chip. There is no need for a terminal to be connected, and it is possible to construct a system that is power-saving, has a compact and simple structure, and has a high degree of freedom in arrangement.

With reference to FIG.3 and FIG.4, the monitoring tag 10a of another embodiment which concerns on this invention is demonstrated. In addition, about the same structure as the monitoring tag 10, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIG. 3, the monitoring tag 10a is a monitoring tag that monitors the state of the monitoring target, and includes an RFID tag 20 and a tamper detection circuit 30a.
As shown in FIG. 4, the tamper detection circuit 30 a includes a photo interrupter circuit 90 that functions as a resistance adjustment unit, and a stimulus response part 32.

The photointerrupter circuit 90 includes a light emitting diode D that emits light to the stimulus response part 32, a reflection photointerrupter T that reacts to reflected light reflected by the stimulus response part 32, and a light emitting diode D and a reflection type photointerrupter T. A resistor R11 and a coil L are provided so as to operate. Although the photo interrupter circuit 90 has been described as using a reflective photo interrupter, other photo interrupters may be used. The reflective photointerrupter T functions as a photodetection unit of the photointerrupter. Moreover, you may have a stimulus responsive site | part in the photon detection part of a photo interrupter.
In addition, a resistor R10 is provided to detect the state of the photo interrupter circuit 90.

The monitoring tag 10a is used as follows.
Immediately after the monitoring tag 10a is installed in the concrete structure, the stimulus response site 32 is not affected by the pH of the concrete structure and ionic impurities. For this reason, since the reflective photointerrupter T receives a predetermined amount of reflected light reflected by the stimulus response part 32, the reflective photointerrupter T outputs (energizes) the tamper circuit of the tamper detection circuit 30a. The tamper circuit exhibits conduction (or insulation).
However, when the stimulus response site 32 is chemically or physically changed by a specific stimulus, the amount of reflected light is reduced, and the reflection type photointerrupter T is output to the tamper circuit of the tamper detection circuit 30a ( The resistance value in the tamper circuit increases and non-conduction occurs.
By using this method, it is possible to accurately detect the degree of deterioration of the concrete structure over time without being affected by the pH and ionic impurities in the concrete structure.

DESCRIPTION OF SYMBOLS 10, 10a Monitoring tag 11 Antenna part 12 Sensor part 20 RFID tag 22 IC chip 30, 30a Tamper detection circuit 31 Circuit part 32 Stimulus response part 33 Resistance adjustment part 34 Stimulus responsive resin 60 Base material 61 Slit part 62 Opening part 63 Antenna section area 64 Sensor section area 70 Antenna circuit 80 Sealing material 90 Photointerrupter circuit D Light emitting diode T Reflective photointerrupter

Claims (10)

A monitoring tag for monitoring the state of a monitoring object,
An IC chip storing memory information including ID information;
An antenna circuit for reading the memory information and transmitting it to the terminal;
Including a tamper detection circuit,
The tamper detection circuit includes a stimulus response part that changes the memory information in response to a specific stimulus that affects the characteristics of the monitoring target, and a resistance adjustment unit that adjusts a resistance value of the tamper detection circuit. Having a monitoring tag.   Furthermore, the monitoring tag of Claim 1 containing the sheet-like base material carrying the said antenna circuit and the said IC chip.   The antenna circuit is a circuit formed by printing a resin solution containing fine particles of a conductive material on the surface of the substrate, or a circuit formed by pressing and etching a metal foil on the surface of the substrate. The monitoring tag according to claim 2, wherein   The monitoring tag according to any one of claims 1 to 3, wherein the resistance adjusting unit is configured by a resistor.   The monitoring tag according to any one of claims 1 to 3, wherein the resistance adjustment unit includes a transistor.   The monitoring tag according to claim 1, wherein the resistance adjustment unit uses a photo interrupter.   The monitoring tag according to claim 6 which has a stimulus responsive part in a photodetection part of said photo interrupter.   The monitoring tag according to claim 1, wherein the stimulus response site is made of a stimulus responsive metal.   Furthermore, the monitoring tag of any one of Claim 1 to 8 containing the sealing material which seals the said tamper detection circuit so that the opening part which the said stimulus response site | part exposes may be formed.   Furthermore, the monitoring tag of any one of Claim 1 to 9 containing the stimulus responsive resin which coat | covers the said stimulus response site | part.

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