Identification system, identification method, and program

Abstract

An identification system (2) is provided with a sensor group (6) disposed in an environment in which a sample gas is present, and a signal processing unit (10). The sensor group (6) includes: a first sensor (18) that outputs a first signal corresponding to an adsorption concentration of the sample gas, the first sensor (18) being disposed so as to be exposed to the sample gas; and a second sensor (20) that outputs a second signal corresponding to the adsorption concentration of the sample gas, the second sensor (20) being disposed so as to be shielded from the sample gas. The signal processing unit (10) identifies a physical property of the sample gas on the basis of the first signal output from the first sensor (18) and the second signal output from the second sensor (20).

Description

Identification system, identification method, and program

[0001] The present disclosure relates to an identification system, an identification method, and a program.

[0002] A discrimination system is known that discriminates the odor of a sample gas based on a signal output from a sensor for measuring odor substances when the sensor is exposed to the sample gas (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 10-170422

[0004] However, in the conventional identification systems described above, there is a risk that the signal output from the sensor may fluctuate due to factors such as the ambient temperature around the sensor or deterioration of the sensor over time, which creates the problem of not being able to accurately identify the odor of the sample gas.

[0005] Therefore, the present disclosure provides an identification system, an identification method, and a program that can accurately identify the physical properties of a sample gas.

[0006] An identification system according to one aspect of the present disclosure is an identification system for identifying the physical properties of a sample gas, comprising a group of sensors arranged in an environment in which the sample gas is present, and a signal processing unit, wherein the group of sensors includes a first sensor that outputs a first signal corresponding to the adsorption concentration of the sample gas, the first sensor being arranged to be exposed to the sample gas, and a second sensor that outputs a second signal corresponding to the adsorption concentration of the sample gas, the second sensor being arranged to be shielded from the sample gas, and the signal processing unit identifies the physical properties of the sample gas based on the first signal output from the first sensor and the second signal output from the second sensor.

[0007] Furthermore, an identification method according to one aspect of the present disclosure is an identification method for identifying the physical properties of a sample gas using a group of sensors arranged in an environment where a sample gas is present, the group of sensors including a first sensor that outputs a first signal corresponding to the adsorption concentration of the sample gas, the first sensor arranged to be exposed to the sample gas, and a second sensor that outputs a second signal corresponding to the adsorption concentration of the sample gas, the second sensor arranged to be shielded from the sample gas, the identification method including: (a) acquiring the first signal output from the first sensor and the second signal output from the second sensor; and (b) identifying the physical properties of the sample gas based on the first signal and the second signal acquired in (a).

[0008] These comprehensive or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM (Compact Disc-Read Only Memory), or may be realized by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0009] According to an identification system and the like according to one aspect of the present disclosure, the physical properties of a sample gas can be identified with high accuracy.

[0010] 1 is a diagram showing a configuration of an identification system according to a first embodiment. FIG. 2 is a schematic cross-sectional view of a first sensor and a second sensor according to the first embodiment, taken along line II-II in FIG. 1 . FIG. 3 is a graph showing an example of a first signal output from the first sensor, a second signal output from the second sensor, and a corrected signal generated by a signal processing unit. FIG. 4 is a graph showing an example of a first signal output from the first sensor, a second signal output from the second sensor, and a corrected signal generated by a signal processing unit. FIG. 5 is a block diagram showing a configuration of an identification system according to the first embodiment. FIG. 6 is a flowchart showing an operation flow of the identification system according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing a configuration of an identification system according to a first modification of the first embodiment. FIG. 8 is a schematic cross-sectional view showing a configuration of an identification system according to a second modification of the first embodiment. FIG. 9 is a schematic cross-sectional view showing a configuration of an identification system according to a third modification of the first embodiment. FIG. 10 is a schematic cross-sectional view showing a configuration of an identification system according to a fourth modification of the first embodiment. FIG. 11 is a schematic cross-sectional view showing a configuration of an identification system according to a fifth modification of the first embodiment. FIG. 12 is a block diagram showing a configuration of an identification system according to a second embodiment. FIG. 13 is a flowchart showing an operation flow of the identification system according to the second embodiment.

[0011] (Technology 1) An identification system for identifying physical properties of a sample gas, comprising: a group of sensors arranged in an environment where the sample gas is present; and a signal processing unit, wherein the group of sensors includes: a first sensor that outputs a first signal corresponding to an adsorption concentration of the sample gas, the first sensor being arranged to be exposed to the sample gas; and a second sensor that outputs a second signal corresponding to an adsorption concentration of the sample gas, the second sensor being arranged to be shielded from the sample gas, and the signal processing unit identifies the physical properties of the sample gas based on the first signal output from the first sensor and the second signal output from the second sensor.

[0012] According to Technology 1, the sensor group includes a first sensor arranged to be exposed to the sample gas and a second sensor arranged to be shielded from the sample gas. The signal processing unit identifies the physical properties of the sample gas based on a first signal output from the first sensor and a second signal output from the second sensor. Even if the first signal and the second signal each contain a time-varying component due to, for example, temperature or aging degradation of the sensor group, the first signal and the second signal can be used to generate a signal (hereinafter referred to as a "corrected signal") in which these time-varying components are canceled from the first signal. As a result, the physical properties of the sample gas can be accurately identified based on the corrected signal, which mainly contains a time-varying component due to the physical properties of the sample gas.

[0013] (Technology 2) The identification system according to Technology 1, wherein the sensitivity characteristics of the first sensor and the sensitivity characteristics of the second sensor are identical.

[0014] According to Technique 2, since the sensitivity characteristics of the first sensor and the second sensor are identical, the time-varying components contained in the first signal and the second signal, for example, due to the influence of temperature and the influence of the deterioration of the sensor group over time, generally coincide with each other. As a result, a corrected signal can be generated with high accuracy using the first signal and the second signal, and the physical properties of the sample gas can be identified with even higher accuracy.

[0015] (Technology 3) The identification system according to Technology 1, wherein the sensitivity characteristics of the first sensor and the sensitivity characteristics of the second sensor are different from each other.

[0016] According to Technology 3, since the sensitivity characteristics of the first sensor and the second sensor are different from each other, it is possible to use any combination of existing first and second sensors, thereby reducing the installation cost of the identification system.

[0017] (Technology 4) The identification system according to any one of Technologies 1 to 3, wherein a plurality of the sensor groups are provided, and the plurality of sensor groups include one or more of the first sensors and one or more of the second sensors.

[0018] According to the fourth technique, for example, by varying the type of sample gas to be detected for each sensor group, it is possible to distinguish the physical properties of various sample gases.

[0019] (Technology 5) The identification system according to any one of Technologies 1 to 4, wherein the first sensor and the second sensor are incorporated into the same sensor package.

[0020] According to the fifth technique, the configuration of the identification system can be made compact.

[0021] (Technology 6) The identification system according to any one of Technologies 1 to 4, further comprising a substrate, and the first sensor and the second sensor are arranged adjacent to each other on the same surface of the substrate.

[0022] According to Technique 6, the distance between the first sensor and the second sensor can be made relatively short, so that the temperature distributions in a two-dimensional plane on the substrate are relatively close between the first sensor and the second sensor. As a result, the first sensor and the second sensor show roughly the same temperature change, so that the time-varying components due to the influence of temperature contained in the first signal and the second signal can be made roughly the same.

[0023] (Technology 7) The identification system according to any one of Technologies 1 to 4, further comprising a substrate having a first surface and a second surface opposite to the first surface, the first sensor being disposed on the first surface of the substrate, and the second sensor being disposed on the second surface of the substrate so as to be back-to-back with the first sensor across the substrate.

[0024] According to Technique 7, the distance between the first sensor and the second sensor can be made relatively short, so that the temperature distributions in a two-dimensional plane on the substrate are relatively close between the first sensor and the second sensor. As a result, the first sensor and the second sensor show roughly the same temperature change, so that the time-varying components due to the influence of temperature contained in the first signal and the second signal can be made roughly the same.

[0025] (Technology 8) The identification system according to any one of Technologies 1 to 4, further comprising: a first substrate having a first surface and a second surface opposite to the first surface; and a second substrate having a third surface and a fourth surface opposite to the third surface, the second substrate being disposed so that the third surface faces the first surface of the first substrate; the first sensor being disposed on the first surface of the first substrate; and the second sensor being disposed on the third surface of the second substrate and facing the first sensor.

[0026] According to technique 8, the arrangement interval between the first sensor and the second sensor can be relatively short, so that the temperature distributions in the two-dimensional planes on the first substrate and the second substrate are relatively close between the first sensor and the second sensor. As a result, the first sensor and the second sensor show approximately the same temperature change, so that the time-varying components due to the influence of temperature contained in the first signal and the second signal can be approximately the same.

[0027] (Technology 9) The identification system according to any one of Technologies 1 to 4, wherein the first sensor is disposed so as to cover the second sensor.

[0028] According to Technique 9, the distance between the first sensor and the second sensor can be relatively short, so that the temperature distributions in a two-dimensional plane between the first sensor and the second sensor are relatively close to each other. As a result, the first sensor and the second sensor show roughly the same temperature change, so that the time-varying components due to the influence of temperature contained in the first signal and the second signal can be roughly matched.

[0029] (Technology 10) The identification system according to any one of Techniques 1 to 9, wherein the signal processing unit identifies the physical properties of the sample gas by performing a predetermined calculation using the first signal and the second signal.

[0030] According to the technique 10, a corrected signal can be easily generated by performing a predetermined calculation using the first signal and the second signal.

[0031] (Technology 11) The identification system according to any one of Technologies 1 to 9, further comprising a correction value storage unit that stores the second signal output from the second sensor as a correction value, and the signal processing unit performs a predetermined calculation using (i) the first signal output from the first sensor, and (ii) at least one of the second signal output from the second sensor and the correction value stored in the correction value storage unit, thereby identifying the physical properties of the sample gas.

[0032] According to Technology 11, even if a malfunction occurs in the operation of the second sensor, the signal processing unit can approximately generate a corrected signal by performing a predetermined calculation using the first signal and the correction value.

[0033] (Technology 12) The identification system according to Technology 11, further comprising a switching unit that switches between a first input state in which the first signal output from the first sensor and the second signal output from the second sensor are input to the signal processing unit, and a second input state in which the first signal output from the first sensor and the correction value stored in the correction value storage unit are input to the signal processing unit, wherein the signal processing unit (i) in the first input state identifies the physical properties of the sample gas by performing the predetermined calculation using the first signal and the second signal, and (ii) in the second input state identifies the physical properties of the sample gas by performing the predetermined calculation using the first signal and the correction value.

[0034] According to Technology 12, the input state of the signal processing unit can be switched to either the first input state or the second input state by the switching unit depending on, for example, the operating state of the second sensor, etc. As a result, the reliability of the identification system can be improved.

[0035] (Technology 13) The identification system according to Technology 12, further comprising a power control unit that operates the second sensor in the first input state and stops operation of the second sensor in the second input state.

[0036] According to Technique 13, the power control unit stops the operation of the second sensor in the second input state. Therefore, for example, if a malfunction occurs in the operation of the second sensor, it is possible to prevent unnecessary power from being supplied to the second sensor, thereby achieving power savings.

[0037] (Technique 14) The identification system according to any one of Techniques 10 to 13, wherein the predetermined operation includes at least one of addition, subtraction, multiplication, division, and logarithmic transformation.

[0038] According to technique 14, the corrected signal can be easily generated.

[0039] (Technique 15) The identification system according to any one of Techniques 10 to 13, wherein the predetermined operation includes a lookup table conversion.

[0040] According to technique 15, the corrected signal can be easily generated.

[0041] (Technology 16) The identification system according to any one of Technologies 1 to 15, wherein the signal processing unit identifies an odor of the sample gas as a physical property of the sample gas.

[0042] According to technique 16, the odor of the sample gas can be accurately identified as a physical property of the sample gas.

[0043] (Technology 17) An identification method for identifying physical properties of a sample gas using a group of sensors arranged in an environment in which a sample gas is present, the group of sensors including: a first sensor that outputs a first signal corresponding to an adsorption concentration of the sample gas, the first sensor arranged to be exposed to the sample gas; and a second sensor that outputs a second signal corresponding to an adsorption concentration of the sample gas, the second sensor arranged to be shielded from the sample gas, the identification method including: (a) acquiring the first signal output from the first sensor and the second signal output from the second sensor; and (b) identifying the physical properties of the sample gas based on the first signal and the second signal acquired in (a).

[0044] According to Technology 17, the sensor group includes a first sensor arranged to be exposed to the sample gas and a second sensor arranged to be shielded from the sample gas. The physical properties of the sample gas are identified based on a first signal output from the first sensor and a second signal output from the second sensor. Even if the first signal and the second signal each contain a time-varying component due to, for example, temperature or aging degradation of the sensor group, a corrected signal can be generated from the first signal by using the first signal and the second signal to cancel these time-varying components. As a result, the physical properties of the sample gas can be accurately identified based on the corrected signal that mainly contains a time-varying component due to the physical properties of the sample gas.

[0045] (Technology 18) A program that causes a computer to execute the identification method according to Technology 17.

[0046] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, or a recording medium.

[0047] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0048] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components.

[0049] (Embodiment 1) [1-1. Configuration of Identification System] The configuration of an identification system 2 according to embodiment 1 will be described with reference to Figs. 1 to 4. Fig. 1 is a diagram showing the configuration of the identification system 2 according to embodiment 1. Fig. 2 is a schematic cross-sectional view of a first sensor 18 and a second sensor 20 according to embodiment 1 taken along line II-II in Fig. 1. Figs. 3 and 4 are graphs showing an example of a first signal output from the first sensor 18, a second signal output from the second sensor 20, and a corrected signal generated by the signal processing unit 10.

[0050] 1 and 2, the horizontal direction of the substrate 4 is the X-axis direction, the vertical direction of the substrate 4 is the Y-axis direction, and the thickness direction of the substrate 4 is the Z-axis direction.

[0051] The identification system 2 is an odor identification system for identifying the odor (an example of a physical property) of a sample gas. The sample gas may be, for example, a gas collected from food, exhaled breath collected from a human body, air surrounding a human body, or air collected from a room in a building.

[0052] As shown in FIGS. 1 and 2, the identification system 2 includes a substrate 4, a group of sensors 6, a heater 8, and a signal processing unit 10.

[0053] The substrate 4 is, for example, a printed wiring board, and has a first surface 12 and a second surface 14 opposite to the first surface 12. The substrate 4 is disposed, for example, inside a container (not shown) into which a sample gas is introduced. The substrate 4 is electrically connected to the signal processing unit 10 via a flat cable 16.

[0054] The plurality of sensor groups 6 are mounted on the first surface 12 of the substrate 4 and are disposed inside the container together with the substrate 4. When a sample gas is introduced into the container, each of the plurality of sensor groups 6 mounted on the first surface 12 of the substrate 4 is exposed to the sample gas. That is, the plurality of sensor groups 6 are disposed in an environment in which the sample gas is present. The plurality of sensor groups 6 are disposed, for example, in a matrix on the first surface 12 of the substrate 4. Note that, although the plurality of sensor groups 6 are mounted on the first surface 12 of the substrate 4 in this embodiment, the present invention is not limited thereto, and they may be mounted on the second surface 14 of the substrate 4.

[0055] Each of the multiple sensor groups 6 includes a pair of one first sensor 18 and one second sensor 20. The pair of first sensor 18 and second sensor 20 is arranged adjacent to each other in a predetermined direction (X-axis direction) on the first surface 12 of the substrate 4, i.e., the same surface. As a result, the temperature distributions in a two-dimensional plane (XY plane) on the substrate 4 are relatively close between the pair of first sensor 18 and second sensor 20, so that the pair of first sensor 18 and second sensor 20 exhibit approximately the same temperature changes. Here, the arrangement distance W1 between the first sensor 18 and second sensor 20 of a sensor group 6 is shorter than the arrangement distance W2 between the sensor group 6 and other sensor groups 6.

[0056] The first sensor 18 is an odor sensor that, when exposed to a sample gas, outputs a first signal, which is a detection signal corresponding to the adsorption concentration of odor molecules contained in the sample gas. The first sensor 18 is, for example, configured as an electrical resistance-type odor sensor and has multiple sensing elements (e.g., a total of 16, CH1 to CH16) with different sensing characteristics. Each of the multiple sensing elements has a sensing portion formed of a sensitive film and a pair of electrodes electrically connected to the sensing portion. The electrical resistance value of the sensing portion changes depending on the adsorption concentration of odor molecules in the sample gas to the sensing portion. Each of the multiple sensing elements outputs a first signal corresponding to the electrical resistance value of the sensing portion as a voltage signal or a current signal to the signal processing unit 10 via the pair of electrodes and the flat cable 16.

[0057] The second sensor 20 is an odor sensor that, when exposed to a sample gas, outputs a second signal, which is a detection signal corresponding to the adsorption concentration of odor molecules contained in the sample gas. The second sensor 20 is, for example, configured as an electrical resistance-type odor sensor and has multiple sensing elements (e.g., a total of 16, CH1 to CH16) with different sensing characteristics. Each of the multiple sensing elements has a sensing portion formed of a sensitive film and a pair of electrodes electrically connected to the sensing portion. The electrical resistance value of the sensing portion changes depending on the adsorption concentration of odor molecules in the sample gas to the sensing portion. Each of the multiple sensing elements outputs a second signal corresponding to the electrical resistance value of the sensing portion as a voltage signal or a current signal to the signal processing portion 10 via the pair of electrodes and the flat cable 16.

[0058] The first sensor 18 is disposed so as to be exposed to the sample gas introduced into the container. Specifically, the first sensor 18 (including the plurality of sensing elements) except for the bottom surface that contacts the first surface 12 of the substrate 4 is exposed to the inside of the container.

[0059] On the other hand, the second sensor 20 is arranged so as to be shielded from the sample gas introduced into the container. Specifically, the second sensor 20 (including the plurality of sensing elements) except for the bottom surface that contacts the first surface 12 of the substrate 4 is covered with a cover member 22 and is not exposed to the inside of the container. The cover member 22 is made of a material that has neither heat insulation nor breathability, such as an inorganic material.

[0060] In this embodiment, the sensitivity characteristics of the first sensor 18 and the second sensor 20 are the same. That is, the multiple sensing elements of the first sensor 18 and the multiple sensing elements of the second sensor 20 are formed of the same type of sensing material. As a result, the detection targets of the first sensor 18 and the second sensor 20 are specialized for the same type of sample gas. Note that the type of sample gas to be detected may be different for each sensor group 6. This allows the odors of various sample gases to be distinguished.

[0061] The heater 8 is, for example, an electric heater that generates heat due to electrical resistance to supplied power. The heater 8 is, for example, mounted on the first surface 12 of the substrate 4, and is disposed inside the container together with the substrate 4. When the heater 8 is energized, heat from the heater 8 is transferred to each of the plurality of sensor groups 6, thereby heating each of the plurality of sensor groups 6.

[0062] The energization of the heater 8 is controlled by a heating control unit (not shown). Specifically, as shown in (a) of FIG. 3 and (a) of FIG. 4, the heating control unit energizes the heater 8 during the first period T1 of a period Tm consisting of a first period T1 and a second period T2 following the first period T1. As a result, the heater 8 is maintained in a heated state in which it heats each of the multiple sensor groups 6 throughout the first period T1. Furthermore, the heating control unit stops the energization of the heater 8 during the second period T2 of the period Tm. As a result, the heater 8 is maintained in a non-heated state in which it does not heat each of the multiple sensor groups 6 throughout the second period T2.

[0063] That is, the heating control unit repeatedly switches the heater 8 between a heating state and a non-heating state, with the period Tm as a cycle. As a result, the heater 8 alternates between a heating state in which each of the multiple sensor groups 6 is heated during a first period T1 within the period Tm and a non-heating state in which each of the multiple sensor groups 6 is not heated during a second period T2 within the period Tm. In the heating state, the heater 8 heats each of the multiple sensor groups 6, thereby increasing the temperature of each of the multiple sensor groups 6. In the non-heating state, the heater 8 stops heating each of the multiple sensor groups 6, and each of the multiple sensor groups 6 dissipates heat, thereby decreasing the temperature of each of the multiple sensor groups 6.

[0064] In the non-heated state, odor molecules contained in the sample gas are adsorbed to the first sensor 18 of each of the multiple sensor groups 6. In addition, in the heated state, by heating each of the multiple sensor groups 6 with the heater 8, odor molecules adhering to the first sensor 18 of each of the multiple sensor groups 6 can be desorbed (volatilized) and the first sensor 18 can be cleaned. As described above, since the second sensor 20 is shielded from the sample gas by the cover member 22, odor molecules contained in the sample gas are not adsorbed to the second sensor 20 of each of the multiple sensor groups 6 in the non-heated state.

[0065] Here, consider the following first and second cases. In the first case, (i) the first sensor 18 includes a time-varying component due to the influence of the odor of the sample gas and a time-varying component due to the influence of temperature, and (ii) the second sensor 20 includes a time-varying component due to the influence of temperature. (a) of FIG. 3 is a graph schematically illustrating the time changes of the first signal output from the first sensor 18 and the second signal output from the second sensor 20 over a period Tm in the first case. The horizontal axis of the graph shown in (a) of FIG. 3 represents time, and the vertical axis represents signal strength. The solid line graph represents the time change of the signal strength of the first signal, and the dashed line graph represents the time change of the signal strength of the second signal.

[0066] As shown in (a) of Figure 3, in the first case, the signal intensity of the first signal output from the first sensor 18 changes over time over a period Tm. Specifically, during a first period T1 in which the first sensor 18 is heated by the heater 8, the first sensor 18 is affected by a temperature increase, and the signal intensity of the first signal output from the first sensor 18 increases, as indicated by the dashed circle in (a) of Figure 3. Thereafter, during a second period T2 in which the first sensor 18 is not heated by the heater 8, the first sensor 18 adsorbs odor molecules contained in the sample gas, and the signal intensity of the first signal output from the first sensor 18 increases. Furthermore, during the latter half of the second period T2, the first sensor 18 is affected by a temperature decrease due to heat radiation, and the signal intensity of the first signal output from the first sensor 18 decreases, as indicated by the dashed circle in (a) of Figure 3.

[0067] 3A, the signal intensity of the second signal output from the second sensor 20 changes over time over the period Tm. Specifically, during the first period T1 in which the second sensor 20 is heated by the heater 8, the second sensor 20 is affected by the temperature rise, and the signal intensity of the second signal output from the second sensor 20 increases, as indicated by the dashed circle in FIG. 3A. At this time, the rates of change of the rising curves of the signal intensity of the first signal and the signal intensity of the second signal during the first period T1 are approximately the same. Thereafter, during the second period T2 in which the second sensor 20 is not heated by the heater 8, the second sensor 20 does not adsorb odor molecules contained in the sample gas, and therefore the signal intensity of the second signal output from the second sensor 20 remains approximately constant. Thereafter, the second sensor 20 is affected by a temperature drop due to heat dissipation, and the signal strength of the second signal output from the second sensor 20 decreases, as indicated by the dashed circle in Fig. 3A. At this time, the rates of change of the descending curve of the signal strength of the first signal and the descending curve of the signal strength of the second signal during the second period T2 are approximately the same.

[0068] On the other hand, the second case is a case in which (i) the first sensor 18 includes a time-varying component due to the influence of the odor of the sample gas, a time-varying component due to the influence of temperature, and a time-varying component due to the influence of deterioration over time, and (ii) the second sensor 20 includes a time-varying component due to the influence of temperature and a time-varying component due to the influence of deterioration over time. Figure 4A is a graph schematically showing the time-varying components of the first signal output from the first sensor 18 and the second signal output from the second sensor 20 in the second case during the period Tm. The horizontal axis of the graph shown in Figure 4A represents time, and the vertical axis represents signal strength. The solid line represents the time-varying component of the first signal, and the dashed line represents the time-varying component of the second signal.

[0069] 4A, in the second case, the signal strength of the first signal output from the first sensor 18 varies over time over the period Tm. Specifically, in addition to varying over time as in the first case described above, the signal strength of the first signal output from the first sensor 18 is affected by deterioration over time, and as a result, as indicated by multiple arrows in FIG. 4A, the signal strength of the first signal decreases overall over the period Tm compared to the signal strength of the first signal output from a brand new first sensor 18.

[0070] 4A, the signal strength of the second signal output from the second sensor 20 varies over time over the period Tm. Specifically, in addition to varying over time as in the first case described above, the signal strength of the second signal output from the second sensor 20 is affected by deterioration over time, and as shown by multiple arrows in FIG. 4A, the signal strength of the second signal decreases overall over the period Tm compared to the signal strength of the second signal output from a new second sensor 20.

[0071] Although the present embodiment has been described with reference to a case where the signal strength of each of the first and second signals decreases due to the influence of deterioration over time, the present invention is not limited to this. For example, the signal strength of each of the first and second signals may increase due to the influence of deterioration over time, or offset fluctuations may occur due to the influence of deterioration over time.

[0072] 1 , the signal processing unit 10 is electrically connected to each of the plurality of sensor groups 6 via the flat cable 16 and the substrate 4. For each sensor group 6, the signal processing unit 10 identifies the odor of the sample gas based on the first signal and the second signal output from the paired first sensor 18 and second sensor 20, respectively.

[0073] 1-2. Functional Configuration of Signal Processing Unit The functional configuration of the signal processing unit 10 will be described with reference to Fig. 3 to Fig. 5. Fig. 5 is a block diagram showing the configuration of the identification system 2 according to the first embodiment.

[0074] As shown in FIG. 5, the signal processing unit 10 has, as its functional components, an acquisition unit 24, a calculation unit 26, a discrimination unit 28, and an output unit 30.

[0075] The acquisition unit 24 acquires the first signal and the second signal output from the pair of the first sensor 18 and the second sensor 20, respectively, for each sensor group 6. Then, the acquisition unit 24 outputs the acquired first signal and second signal to the calculation unit 26.

[0076] The calculation unit 26 performs a predetermined calculation using the first signal and the second signal acquired by the acquisition unit 24. Specifically, as the predetermined calculation, the calculation unit 26 generates a corrected signal for each sensor group 6 by subtracting the signal strength of the second signal from the signal strength of the first signal.

[0077] For example, in the first case described above, when the signal intensities of the first and second signals change over time as shown in FIG. 3A, the calculation unit 26 subtracts the signal intensity of the second signal from the signal intensity of the first signal to generate the corrected signal shown in FIG. 3B. The horizontal axis of the graph shown in FIG. 3B represents time, and the vertical axis represents signal intensity. As shown by the dashed circle in FIG. 3B, in this corrected signal, the time-varying component due to temperature contained in the signal intensity of the first signal is canceled out by the time-varying component due to temperature contained in the signal intensity of the second signal. As a result, the corrected signal primarily contains a time-varying component due to the odor of the sample gas. Note that the corrected signal may also contain a time-varying component due to humidity in addition to the time-varying component due to the odor of the sample gas.

[0078] Similarly, for example, in the second case described above, where the signal intensities of the first and second signals change over time as shown in FIG. 4A, the calculation unit 26 subtracts the signal intensity of the second signal from the signal intensity of the first signal to generate the corrected signal shown in FIG. 4B. The horizontal axis of the graph shown in FIG. 4B represents time, and the vertical axis represents signal intensity. As indicated by the dashed circle in FIG. 4B, in this corrected signal, the time-varying component due to temperature contained in the signal intensity of the first signal is canceled by the time-varying component due to temperature contained in the signal intensity of the second signal. Furthermore, in this corrected signal, the time-varying component due to degradation contained in the signal intensity of the first signal is canceled by the time-varying component due to degradation contained in the signal intensity of the second signal. As a result, the corrected signal primarily contains a time-varying component due to the odor of the sample gas. The corrected signal may also contain a time-varying component due to humidity in addition to the time-varying component due to the odor of the sample gas.

[0079] The identification unit 28 identifies the odor of the sample gas based on the corrected signal generated by the calculation unit 26. Specifically, the identification unit 28 calculates the feature amount of the corrected signal and inputs the calculated feature amount into the trained model, thereby identifying which of multiple odor molecules is contained in the sample gas.

[0080] Here, the trained model is constructed by performing machine learning using, as training data, known odor molecules and feature quantities calculated from odor information output from an odor sensor exposed to a sample gas containing the known odor molecules. To construct a logical model in machine learning, for example, a neural network, a random forest, a support vector machine, or a self-organizing map is used.

[0081] The output unit 30 outputs the identification result of the identification unit 28 to the outside of the signal processing unit 10. For example, the output unit 30 outputs the identification result of the identification unit 28 to a display unit (not shown). As a result, the identification result by the identification unit 28 is displayed on the display unit.

[0082] [1-3. Operation of Identification System] The operation of the identification system 2 according to the first embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the flow of the operation of the identification system 2 according to the first embodiment.

[0083] When the sample gas is introduced into the container, as shown in FIG. 6, the first sensor 18 outputs a first signal, and the second sensor 20 outputs a second signal (S101).

[0084] Next, the acquisition unit 24 of the signal processing unit 10 acquires the first signal and the second signal output from the pair of the first sensor 18 and the second sensor 20, respectively, for each sensor group 6 (S102).

[0085] Next, the calculation unit 26 of the signal processing unit 10 performs a predetermined calculation (S103) using the first signal and the second signal acquired by the acquisition unit 24. Specifically, as the predetermined calculation, the calculation unit 26 subtracts the signal strength of the second signal from the signal strength of the first signal to generate a corrected signal for each sensor group 6.

[0086] Next, the identification unit 28 of the signal processing unit 10 identifies the odor of the sample gas based on the corrected signal generated by the calculation unit 26 (S104).

[0087] Next, the output unit 30 of the signal processing unit 10 outputs the discrimination result of the discrimination unit 28 to the outside of the signal processing unit 10 (S105).

[0088] [1-4. Effects] In this embodiment, the sensor group 6 includes a first sensor 18 arranged to be exposed to the sample gas and a second sensor 20 arranged to be shielded from the sample gas. The signal processing unit 10 identifies the odor of the sample gas based on the first signal output from the first sensor 18 and the second signal output from the second sensor 20.

[0089] As a result, even if each of the first signal and the second signal contains a time-varying component due to, for example, the influence of temperature or the influence of degradation over time of the sensor group 6, by using the first signal and the second signal, it is possible to generate a corrected signal from the first signal in which these time-varying components have been cancelled out. As a result, it is possible to accurately identify the physical properties of the sample gas based on the corrected signal that mainly contains a time-varying component due to the influence of the odor of the sample gas.

[0090] [1-5. Various Modifications] [1-5-1. Modification 1] The configuration of an identification system 2A according to Modification 1 of Embodiment 1 will be described with reference to Fig. 7. Fig. 7 is a schematic cross-sectional view showing the configuration of an identification system 2A according to Modification 1 of Embodiment 1.

[0091] In the identification system 2A according to the first modification, the arrangement of the pair of first and second sensors 18 and 20 differs from that of the above-described identification system 2.

[0092] 7, the first sensor 18 is disposed on the first surface 12 of the substrate 4, and the second sensor 20 is disposed on the second surface 14 of the substrate 4. The second sensor 20 is disposed back-to-back with the first sensor 18 across the substrate 4. That is, when viewed from the thickness direction (Z-axis direction) of the substrate 4, the first sensor 18 and the second sensor 20 are disposed so as to overlap each other.

[0093] As a result, the temperature distribution in the two-dimensional plane (XY plane) on the substrate 4 becomes relatively close between the pair of first sensor 18 and second sensor 20, so that the first sensor 18 and the second sensor 20 show roughly the same temperature changes. Therefore, in this modified example, the same effect as in the above-described identification system 2 can be obtained.

[0094] [1-5-2. Modification 2] The configuration of an identification system 2B according to Modification 2 of Embodiment 1 will be described with reference to Fig. 8. Fig. 8 is a schematic cross-sectional view showing the configuration of an identification system 2B according to Modification 2 of Embodiment 1.

[0095] In the identification system 2B according to the second modification, the arrangement of the pair of first and second sensors 18 and 20 is different from that of the above-described identification system 2.

[0096] Specifically, as shown in Fig. 8, the identification system 2B includes two substrates, namely, a first substrate 4a and a second substrate 4b. The first substrate 4a has a first surface 12a and a second surface 14a opposite the first surface 12a. The second substrate 4b has a third surface 12b and a fourth surface 14b opposite the third surface 12b. The first substrate 4a and the second substrate 4b are arranged such that the first surface 12a and the third surface 12b face each other.

[0097] The first sensor 18 is disposed on the first surface 12a of the first substrate 4a. The second sensor 20 is disposed on the third surface 12b of the second substrate 4b so as to face the first sensor 18. That is, when viewed in the thickness direction (Z-axis direction) of the first substrate 4a and the second substrate 4b, the first sensor 18 and the second sensor 20 are disposed so as to overlap each other.

[0098] As a result, the temperature distributions in the two-dimensional plane (XY plane) on the first substrate 4a and the second substrate 4b between the pair of first sensor 18 and second sensor 20 become relatively close, so that the first sensor 18 and the second sensor 20 exhibit roughly the same temperature changes. Therefore, in this modified example, the same effects as those of the above-described identification system 2 can be obtained.

[0099] In this modification, the first sensor 18 and the second sensor 20 are arranged to face each other, but this is not limiting. For example, the first sensor 18 may be arranged on the second surface 14a of the first substrate 4a and the second sensor 20 may be arranged on the third surface 12b of the second substrate 4b, so that the first sensor 18 and the second sensor 20 are arranged in the same direction (the positive side in the Z-axis direction). In this case, too, the first sensor 18 and the second sensor 20 are arranged to overlap each other when viewed in the thickness direction of the first substrate 4a and the second substrate 4b.

[0100] [1-5-3. Modification 3] The configuration of an identification system 2C according to Modification 3 of Embodiment 1 will be described with reference to Fig. 9. Fig. 9 is a schematic cross-sectional view showing the configuration of an identification system 2C according to Modification 3 of Embodiment 1.

[0101] In the identification system 2C according to the third modification, the arrangement of the pair of first and second sensors 18 and 20 is different from that of the above-described identification system 2.

[0102] 9, the first sensor 18 is disposed so as to cover the upper surface (the surface opposite to the substrate 4) of the second sensor 20 via the cover member 22. That is, the first sensor 18 is disposed so as to overlap the second sensor 20 in the thickness direction (Z direction) of the substrate 4.

[0103] As a result, the temperature distribution in the two-dimensional plane (XY plane) on the substrate 4 becomes relatively close between the pair of first sensor 18 and second sensor 20, so that the first sensor 18 and the second sensor 20 show roughly the same temperature changes. Therefore, in this modified example, the same effect as in the above-described identification system 2 can be obtained.

[0104] [1-5-4. Modification 4] The configuration of an identification system 2D according to Modification 4 of Embodiment 1 will be described with reference to Fig. 10. Fig. 10 is a schematic cross-sectional view showing the configuration of an identification system 2D according to Modification 4 of Embodiment 1.

[0105] In the identification system 2D according to the fourth modification, the arrangement of the pair of the first sensor 18D and the second sensor 20 is different from that of the above-described identification system 2.

[0106] 10 , the first sensor 18D is disposed so as to cover the entire second sensor 20 except for the bottom surface thereof via the cover member 22. That is, the first sensor 18D is disposed so as to overlap the second sensor 20 in the thickness direction (Z direction) of the substrate 4. Therefore, the portions of the second sensor 20 except for the bottom surface thereof are doubly covered by the cover member 22 and the first sensor 18D, and the second sensor 20 is shielded from the sample gas by the cover member 22 and the first sensor 18D.

[0107] As a result, the temperature distributions in the two-dimensional plane (XY plane) on the substrate 4 become relatively close between the pair of first sensor 18D and second sensor 20, so that the first sensor 18D and the second sensor 20 exhibit roughly the same temperature changes. Therefore, in this modified example, the same effects as those of the above-described identification system 2 can be obtained.

[0108] [1-5-5. Modification 5] The configuration of an identification system 2E according to Modification 5 of Embodiment 1 will be described with reference to Fig. 11. Fig. 11 is a schematic cross-sectional view showing the configuration of an identification system 2E according to Modification 5 of Embodiment 1.

[0109] In an identification system 2E according to the fifth modification, the arrangement of the pair of first and second sensors 18E and 20 is different from that of the above-described identification system 2.

[0110] 11 , the first sensor 18E is disposed so as to cover the entire second sensor 20 except for the bottom surface thereof without using the cover member 22. That is, the first sensor 18E is disposed so as to overlap the second sensor 20 in the thickness direction (Z direction) of the substrate 4. Therefore, the entire second sensor 20 except for the bottom surface thereof is covered by the first sensor 18E, and the second sensor 20 is shielded from the sample gas by the first sensor 18E.

[0111] As a result, the temperature distribution in the two-dimensional plane (XY plane) on the substrate 4 becomes relatively close between the pair of first sensor 18E and second sensor 20, so that the first sensor 18E and the second sensor 20 exhibit roughly the same temperature changes. Therefore, in this modified example, the same effect as in the above-described identification system 2 can be obtained.

[0112] [1-5-6. Others] In the above, in the first embodiment and its first to fifth modifications, various arrangements of the pair of first sensor 18 (18D, 18E) and second sensor 20 have been described. However, the first sensor 18 (18D, 18E) and the second sensor 20 may be incorporated into the first sensor package and the second sensor package, respectively. In this case, it is preferable to arrange the first sensor package and the second sensor package in the various arrangements described above, but it is more preferable to orient the first sensor package and the second sensor package in the same direction. However, this is not limited thereto, and the orientation of the first sensor package and the second sensor package may be different in order to reduce the cost of mounting on the substrate 20.

[0113] Furthermore, if the position of the first sensor 18 (18D, 18E) relative to the first sensor package is different from the position of the second sensor 20 relative to the second sensor package, the arrangement of the first sensor 18 (18D, 18E) in the first sensor package and the second sensor 20 in the second sensor package may be any of the various arrangements described above, rather than the arrangement of the first sensor package and the second sensor package.

[0114] Furthermore, in the first embodiment and its variants 1 to 5, various arrangements of the pair of first sensor 18 (18D, 18E) and second sensor 20 have been described, but the first sensor 18 (18D, 18E) and second sensor 20 may be incorporated into the same sensor package.

[0115] (Embodiment 2) [2-1. Configuration of Identification System] Next, the configuration of an identification system 2F according to embodiment 2 will be described with reference to Fig. 12. Fig. 12 is a block diagram showing the configuration of an identification system 2F according to embodiment 2. Note that in this embodiment, the same components as those in embodiment 1 above are denoted by the same reference numerals, and their description will be omitted.

[0116] As shown in Figure 12, the identification system 2F of embodiment 2 includes, in addition to the components described in embodiment 1 above, a correction value memory unit 32, a switching unit 34, a reception unit 36, and a power control unit 38.

[0117] The correction value storage unit 32 stores, as a correction value, the second signal output from the second sensor 20. That is, the correction value storage unit 32 accumulates the second signal output from the second sensor 20 as a correction value every time the second sensor 20 outputs the second signal.

[0118] The reception unit 36 ​​is a user interface that receives user operations. When the reception unit 36 ​​receives a user operation, it outputs a reception signal indicating that the user operation has been received to each of the switching unit 34 and the power control unit 38. Note that the reception unit 36 ​​receives the user operation when, for example, a malfunction occurs in the operation of the second sensor 20.

[0119] The switching unit 34 switches the input state of the signal processing unit 10F from one of a first input state and a second input state to the other. The first input state is a state in which the first signal output from the first sensor 18 and the second signal output from the second sensor 20 are input to the signal processing unit 10F. The second input state is a state in which the first signal output from the first sensor 18 and the correction value stored in the correction value storage unit 32 are input to the signal processing unit 10F.

[0120] Normally, the switching unit 34 maintains the input state of the signal processing unit 10F in the first input state. On the other hand, when the receiving unit 36 ​​receives a user operation, the switching unit 34 switches the input state of the signal processing unit 10F from the first input state to the second input state based on a reception signal from the receiving unit 36.

[0121] When the input state of the signal processing unit 10F is maintained in the first input state by the switching unit 34, the acquisition unit 24F of the signal processing unit 10F acquires the first signal and the second signal output from the paired first sensor 18 and second sensor 20, respectively, as in the above-described first embodiment. In this case, the calculation unit 26F of the signal processing unit 10F performs a predetermined calculation using the first signal and the second signal acquired by the acquisition unit 24F, as in the above-described first embodiment. Specifically, as the predetermined calculation, the calculation unit 26F generates a corrected signal by subtracting the signal strength of the second signal from the signal strength of the first signal.

[0122] On the other hand, when the switching unit 34 switches the input state of the signal processing unit 10F from the first input state to the second input state, the acquisition unit 24F acquires the first signal output from the first sensor 18 and the correction value stored in the correction value storage unit 32. In this case, the calculation unit 26F performs a predetermined calculation using the first signal and the correction value acquired by the acquisition unit 24F. Specifically, as the predetermined calculation, the calculation unit 26F generates a corrected signal by subtracting the signal strength of the correction value from the signal strength of the first signal.

[0123] The power control unit 38 controls the power supplied to the second sensor 20. Specifically, when the switching unit 34 maintains the input state of the signal processing unit 10F in the first input state, the power control unit 38 supplies power to the second sensor 20 to operate the second sensor 20. Furthermore, when the switching unit 34 switches the input state of the signal processing unit 10F from the first input state to the second input state, the power control unit 38 turns off (shuts off) the power supplied to the second sensor 20 to stop the operation of the second sensor 20.

[0124] [2-2. Operation of Identification System] The operation of the identification system 2F according to the second embodiment will be described with reference to Fig. 13. Fig. 13 is a flowchart showing the flow of the operation of the identification system 2F according to the second embodiment.

[0125] When the sample gas is introduced into the container, as shown in FIG. 13, the first sensor 18 outputs a first signal, and the second sensor 20 outputs a second signal (S201).

[0126] Next, the correction value storage unit 32 stores the second signal output from the second sensor 20 as a correction value (S202).

[0127] Next, if the accepting unit 36 ​​has not accepted a user operation (NO in S203), the input state of the signal processing unit 10F is maintained in the first input state by the switching unit 34, and the process proceeds to step S204. In this case, the acquiring unit 24F of the signal processing unit 10F acquires the first signal and the second signal output from the paired first sensor 18 and second sensor 20, respectively (S204).

[0128] Next, the calculation unit 26F of the signal processing unit 10F performs a predetermined calculation using the first signal and the second signal acquired by the acquisition unit 24F (S205). Specifically, as the predetermined calculation, the calculation unit 26F subtracts the signal intensity of the second signal from the signal intensity of the first signal to generate a corrected signal.

[0129] Next, the identification unit 28 of the signal processing unit 10F identifies the odor of the sample gas based on the corrected signal generated by the calculation unit 26F (S206).

[0130] Next, the output unit 30 of the signal processing unit 10F outputs the discrimination result of the discrimination unit 28 to the outside of the signal processing unit 10F (S207).

[0131] Returning to step S203, if the accepting unit 36 ​​has accepted the user's operation (YES in S203), the switching unit 34 switches the input state of the signal processing unit 10F from the first input state to the second input state, and the process proceeds to step S208. In this case, the acquiring unit 24F acquires the first signal output from the first sensor 18 and the correction value stored in the correction value storage unit 32 (S209).

[0132] When the input state of the signal processing unit 10F is switched from the first input state to the second input state by the switching unit 34, it is not necessary to always turn off the power supplied to the second sensor 20 in step S208. This makes it possible to reduce the generation of noise caused by switching the power supply to the second sensor 20. Furthermore, since the amount of heat generated by power consumption in the second sensor 20 is approximately equal to the amount of heat generated by power consumption in the first sensor 18 to which power is constantly supplied, it is possible to minimize the difference in temperature change due to power consumption between the first sensor 18 and the second sensor 20.

[0133] Next, the calculation unit 26F performs a predetermined calculation using the first signal and the correction value acquired by the acquisition unit 24F (S210). Specifically, as the predetermined calculation, the calculation unit 26F subtracts the signal strength of the correction value from the signal strength of the first signal to generate a corrected signal. Thereafter, steps S206 and S207 are executed in the same manner as described above.

[0134] [2-3. Effects] In the present embodiment, even if a malfunction occurs in the operation of the second sensor 20, for example, the switching unit 34 switches the input state of the signal processing unit 10F from the first input state to the second input state, and the calculation unit 26F can approximately generate a corrected signal using the first signal output from the first sensor 18 and the correction value stored in the correction value storage unit 32.

[0135] The switching unit 34 may switch the input state of the signal processing unit 10F from the first input state to the second input state not only when a malfunction occurs in the operation of the second sensor 20 but also to operate the second sensor 20 intermittently to reduce power consumption. Furthermore, if the difference between the time when the first signal is output from the first sensor 18 and the time when the correction value is stored in the correction value storage unit 32 is sufficiently large, it is expected that the state of the first sensor 18 and the state of the second sensor 20 will differ significantly. Therefore, in this case, the user may be notified of the odor identification result of the sample gas along with a reliability that is inversely proportional to the magnitude of the time difference.

[0136] (Other Modifications) While the identification system according to one or more aspects has been described above based on the above-described embodiments, the present disclosure is not limited to the above-described embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to the above-described embodiments and configurations constructed by combining components of different embodiments may also be included within the scope of one or more aspects.

[0137] In each of the above embodiments, the identifying unit 28 identifies the odor of the sample gas as a physical property of the sample gas, but this is not limitative and any physical property such as the concentration of the sample gas may be identified.

[0138] Furthermore, in the above-described embodiments, each of the plurality of sensor groups 6 includes one first sensor 18 (18D, 18E) and one second sensor 20, but this is not limited thereto and each of the plurality of sensor groups 6 may include one or more first sensors 18 (18D, 18E) and one or more second sensors 20. Specifically, each of the plurality of sensor groups 6 may include any of (a) one first sensor 18 (18D, 18E) and one second sensor 20, (b) multiple first sensors 18 (18D, 18E) and one second sensor 20, (c) one first sensor 18 (18D, 18E) and multiple second sensors 20, or (d) multiple first sensors 18 (18D, 18E) and multiple second sensors 20.

[0139] In addition, in each of the above embodiments, the calculation unit 26 (26F) performs a predetermined calculation using the first signal and either the second signal or the correction value, but this is not limited thereto, and the calculation may be performed using all of the first signal, the second signal, and the correction value. This increases the number of parameters used when performing the predetermined calculation, making it possible to generate a corrected signal with higher accuracy.

[0140] Furthermore, in each of the above embodiments, the sensitivity characteristics of the first sensor 18 (18D, 18E) and the sensitivity characteristics of the second sensor 20 are the same, but this is not limiting, and the sensitivity characteristics of the first sensor 18 (18D, 18E) and the sensitivity characteristics of the second sensor 20 may be different from each other. This allows, for example, the detection target of the first sensor 18 (18D, 18E) to be specialized for valeric acid, and the detection target of the second sensor 20 to be specialized for alcohol.

[0141] In each of the above embodiments, the calculation unit 26 generates the corrected signal by subtracting the signal strength of the second signal from the signal strength of the first signal as the predetermined calculation, but this is not limiting. The calculation unit 26 may generate the corrected signal by performing at least one of addition, subtraction, multiplication, division, and logarithmic conversion using the signal strength of the first signal and the signal strength of the second signal as the predetermined calculation.

[0142] For example, if each of the multiple sensor groups 6 includes two first sensors 18 (18D, 18E) and one second sensor 20, the calculation unit 26 may perform the predetermined calculation by subtracting the signal strength of the second signal from the average value of the signal strengths of the two first signals output from the two first sensors 18 (18D, 18E), respectively. This can reduce shot noise and the processing load of the calculation.

[0143] Furthermore, for example, when calculating the average value of the signal strengths of a plurality of first signals, the contribution may be weighted according to the arrangement, characteristics, etc. of the sensor group 6. This increases the degree of freedom in the arrangement of the sensor group 6 and in the combination of the first sensor 18 (18D, 18E) and the second sensor 20.

[0144] Furthermore, for example, by performing a logarithmic transformation as the predetermined operation, the bit range can be compressed and the processing load of the operation can be reduced.

[0145] Alternatively, the predetermined calculation may involve a lookup table conversion using the first signal and the second signal as inputs and a corrected signal as output. This allows for accurate correction of the nonlinear responses of the first sensor 18 (18D, 18E) and the second sensor 20. Alternatively, lookup tables may be prepared sparsely and table values ​​may be generated by linearly interpolating between them. This reduces the ROM size of the lookup table. Furthermore, in addition to the first signal and the second signal, information about the first period T1 and the second period T2, the elapsed time since the start of sample gas identification, and other information may be used as input variables for the lookup table. This allows for appropriate correction of signals with different input conditions between the first period T1 and the second period T2. Furthermore, the inputs used when referencing the lookup table are not limited to the first signal and the second signal, but may also be the first signal and a correction value, or the first signal, the second signal, and a correction value. This allows the nonlinear responses of the first sensor 18 (18D, 18E) and the second sensor 20 to be corrected with high precision.

[0146] Alternatively, by disposing a hygrometer inside the container, the calculation unit 26 may generate a corrected signal taking into account the humidity detected by the hygrometer.

[0147] In addition, in each of the above embodiments, the second sensor 20 is covered with the cover member 22, but a heat sink may be attached to the cover member 22. This allows the temperature characteristics of the first sensor 18 (18D, 18E) and the second sensor 20 to be closer to each other.

[0148] Furthermore, in each of the above embodiments, one heater 8 is provided for each of the multiple sensor groups 6, but this is not limited thereto. One heater 8 may be provided for each of a portion of the sensor groups 6, or one heater 8 may be provided for each individual sensor included in the sensor group 6. Alternatively, the heater 8 may be omitted. In this case, for example, a gas other than the sample gas (such as nitrogen gas) is introduced into the container to desorb odor molecules attached to the first sensor 18 of each of the multiple sensor groups 6. Note that factors that cause temperature changes in the first sensor 18 (18D, 18E) and the second sensor 20 include not only heating by the heater 8, but also the operating power of each sensor, the temperature of the gas introduced into the container, etc.

[0149] Furthermore, for example, the signal strengths of the first signal and the second signal when the first sensor 18 (18D, 18E) and the second sensor 20 are first turned on may be stored as initial values, and if the signal strengths of the first signal and / or the second signal during normal use deviate significantly from the initial values, it may be determined that the first sensor 18 (18D, 18E) and / or the second sensor 20 has failed, and the user may be notified of this.

[0150] In each of the above embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a non-transitory recording medium such as a hard disk or semiconductor memory.

[0151] Furthermore, some or all of the functions of the identification system according to each of the above embodiments may be realized by a processor such as a CPU executing a program.

[0152] Some or all of the components constituting each of the above devices may be configured as an IC card or a standalone module that can be attached to each device. The IC card or module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or module may include a super multi-function LSI. The IC card or module achieves its functions when the microprocessor operates according to a computer program. The IC card or module may be tamper-resistant.

[0153] The identification system according to the present disclosure is useful, for example, as an odor identification system for identifying the odor of a sample gas.

[0154] 2, 2A, 2B, 2C, 2D, 2E, 2F Identification system 4 Board 4a First board 4b Second board 6 Sensor group 8 Heater 10, 10F Signal processing unit 12, 12a First surface 12b Third surface 14, 14a Second surface 14b Fourth surface 16 Flat cable 18, 18D, 18E First sensor 20 Second sensor 22 Cover member 24, 24F Acquisition unit 26, 26F Calculation unit 28 Identification unit 30 Output unit 32 Correction value storage unit 34 Switching unit 36 ​​Reception unit 38 Power control unit

Claims

1. An identification system for identifying the physical properties of a sample gas, comprising: a group of sensors arranged in an environment where the sample gas is present; and a signal processing unit, wherein the group of sensors includes: a first sensor that outputs a first signal corresponding to the adsorption concentration of the sample gas, the first sensor being arranged to be exposed to the sample gas; and a second sensor that outputs a second signal corresponding to the adsorption concentration of the sample gas, the second sensor being arranged to be shielded from the sample gas, and the signal processing unit identifies the physical properties of the sample gas based on the first signal output from the first sensor and the second signal output from the second sensor.

2. The identification system according to claim 1, wherein the sensitivity characteristics of the first sensor and the sensitivity characteristics of the second sensor are identical.

3. The identification system according to claim 1, wherein the sensitivity characteristics of the first sensor and the sensitivity characteristics of the second sensor are different from each other.

4. The identification system according to claim 1, wherein a plurality of the sensor groups are provided, and the plurality of sensor groups include one or more of the first sensors and one or more of the second sensors.

5. An identification system according to any one of claims 1 to 4, wherein the first sensor and the second sensor are incorporated into the same sensor package.

6. The identification system according to any one of claims 1 to 4, further comprising a substrate, and the first sensor and the second sensor are arranged adjacent to each other on the same surface of the substrate.

7. The identification system according to any one of claims 1 to 4, further comprising a substrate having a first surface and a second surface opposite to the first surface, the first sensor being disposed on the first surface of the substrate, and the second sensor being disposed on the second surface of the substrate and arranged back-to-back with the first sensor across the substrate.

8. The identification system according to any one of claims 1 to 4, further comprising: a first substrate having a first surface and a second surface opposite to the first surface; and a second substrate having a third surface and a fourth surface opposite to the third surface, and arranged so that the third surface faces the first surface of the first substrate; wherein the first sensor is arranged on the first surface of the first substrate; and the second sensor is arranged on the third surface of the second substrate and is arranged so as to face the first sensor.

9. An identification system according to any one of claims 1 to 4, wherein the first sensor is arranged to cover the second sensor.

10. The identification system according to claim 1, wherein the signal processing unit performs a predetermined calculation using the first signal and the second signal to identify the physical properties of the sample gas.

11. The identification system according to claim 1, further comprising a correction value storage unit that stores the second signal output from the second sensor as a correction value, and the signal processing unit performs a predetermined calculation using (i) the first signal output from the first sensor, and (ii) at least one of the second signal output from the second sensor and the correction value stored in the correction value storage unit, thereby identifying the physical properties of the sample gas.

12. The identification system according to claim 11, further comprising a switching unit that switches between a first input state in which the first signal output from the first sensor and the second signal output from the second sensor are input to the signal processing unit, and a second input state in which the first signal output from the first sensor and the correction value stored in the correction value storage unit are input to the signal processing unit, wherein the signal processing unit (i) in the first input state identifies the physical properties of the sample gas by performing the predetermined calculation using the first signal and the second signal, and (ii) in the second input state identifies the physical properties of the sample gas by performing the predetermined calculation using the first signal and the correction value.

13. The identification system according to claim 12, further comprising a power control unit that activates the second sensor in the first input state and stops the operation of the second sensor in the second input state.

14. The identification system according to any one of claims 10 to 13, wherein the predetermined operation includes at least one of addition, subtraction, multiplication, division, and logarithmic transformation.

15. An identification system according to any one of claims 10 to 13, wherein the predetermined operation includes a look-up table transformation.

16. The identification system according to any one of claims 10 to 13, wherein the signal processing unit identifies the odor of the sample gas as a physical property of the sample gas.

17. A method for identifying the physical properties of a sample gas using a group of sensors arranged in an environment in which the sample gas is present, wherein the group of sensors includes: a first sensor that outputs a first signal corresponding to the adsorption concentration of the sample gas, the first sensor arranged to be exposed to the sample gas; and a second sensor that outputs a second signal corresponding to the adsorption concentration of the sample gas, the second sensor arranged to be shielded from the sample gas, the method comprising: (a) acquiring the first signal output from the first sensor and the second signal output from the second sensor; and (b) identifying the physical properties of the sample gas based on the first signal and the second signal acquired in (a).

18. A program that causes a computer to execute the identification method according to claim 17.

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