Machine determination device and machine determination method

Abstract

The machine determination device divides electromagnetic waves into a plurality of regions including a first region and a second region in the frequency domain, and acquires first characteristic information of the electromagnetic waves in the first region and second characteristic information of the electromagnetic waves in the second region from a reference device, and first characteristic information of the electromagnetic waves in the first region and second characteristic information of the electromagnetic waves in the second region from a determination target device different from the reference device; a characteristic information acquisition unit; a similarity calculation unit that calculates a first similarity between a plurality of pieces of first characteristic information from the reference device and a second similarity between a plurality of pieces of second characteristic information from the reference device; a weighting processing unit that performs weighting on the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit; and a determination unit that determines whether the reference device and the determination target device are similar based on a plurality of pieces of first characteristic information and second characteristic information from the reference device, first characteristic information and second characteristic information from the determination target device, and the result of the processing by the weighting processing unit.

Description

Technical Field

[0001] The present disclosure relates to an equipment determination device and an equipment determination method.

Background Art

[0002] Conventionally, an individual determination device has been disclosed that measures conducted noise from a target device and determines authenticity of the target device by comparing the characteristics of the measured conducted noise with the characteristics of conducted noise obtained from a device of the same type as the target device stored in advance (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when measuring a signal related to the characteristics of a target device, such as conducted noise from the target device, variations may occur in the measurement results. When variations occur in the measurement results, there is a problem that it is difficult to improve the determination accuracy when determining whether the target device is similar to another device based on the measured signal.

[0005] The present disclosure solves the above problems, and an object thereof is to provide an equipment determination device and an equipment determination method capable of improving determination accuracy when performing individual determination of equipment as compared with the conventional art.

Means for Solving the Problems

[0006] The device determination apparatus according to the present disclosure divides electromagnetic waves into a plurality of regions including a first region and a second region in the frequency domain. When the characteristics of the electromagnetic waves in the first region are defined as first characteristics and the characteristics of the electromagnetic waves in the second region are defined as second characteristics, a characteristic information acquisition unit that acquires first characteristic information regarding the first characteristics of each of the plurality of electromagnetic waves from a reference device and second characteristic information regarding the second characteristics, and first characteristic information regarding the first characteristics of the electromagnetic waves from a determination target device different from the reference device and second characteristic information regarding the second characteristics; a similarity calculation unit that calculates a first similarity between the plurality of first characteristic information from the reference device and a second similarity between the plurality of second characteristic information from the reference device; A weighting processing unit that weights the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit; Based on the plurality of first characteristic information and second characteristic information from the reference device, the first characteristic information and second characteristic information from the determination target device, the first similarity, and the second similarity, The result of the processing by the weighting processing unit; a determination unit that determines whether the reference device and the determination target device are similar; and The weighting processing unit calculates deviation values for the worst similarity among the first similarities and the worst similarity among the second similarities, and performs weighting based on the deviation values is characterized by this.

Advantages of the Invention

[0007] According to the present disclosure, when a plurality of electromagnetic waves acquired from a device are each divided into a plurality of regions in the frequency domain, the similarity between the plurality of devices is determined based on the similarity of the characteristics for each region among the plurality of electromagnetic waves. Therefore, it becomes possible to determine the similarity between a plurality of devices in consideration of the variation according to the frequency of the electromagnetic waves acquired from the devices, and it is possible to improve the determination accuracy when performing individual determination of devices as compared with the conventional case.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 9

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Embodiment 1. First, with reference to FIG. 1, the configuration of the individual determination system according to Embodiment 1 will be described. FIG. 1 is a block diagram showing the configuration of the individual determination system according to Embodiment 1. The individual determination system according to Embodiment 1 is a system for performing an individual determination as to whether the target device 40 to be determined is a device similar to the original target devices 31 to 3A serving as the determination criteria, based on information indicating the characteristics of the devices acquired from the original target devices 31, 32, 33, ···, 3A. For example, the individual determination system according to Embodiment 1 performs determinations such as authenticity determination of the target device 40, individual identification determination of the target device 40, and determination as to whether the target device 40 and the original target devices 31 to 3A are of the same type.

[0010] The original target devices 31 to 3A and the target device 40 are electronic devices or electrical devices that operate electrically. For example, the original target devices 31 to 3A and the target device 40 have an interface that can measure electromagnetic characteristics from the outside in the operating state. In the first embodiment, the original target device constitutes a reference device, and the target device constitutes a determination target device.

[0011] As shown in FIG. 1, the individual determination system according to the first embodiment includes an electromagnetic characteristic measurement device 10, an individual determination device 20, and an output device 50, and these are electrically connected to each other and configured to be communicable.

[0012] The electromagnetic characteristic measurement device 10 measures electromagnetic waves from the original target devices 31 to 3A and the target device 40, thereby acquiring information regarding the electromagnetic waves from these original target devices 31 to 3A and the target device. For example, the electromagnetic characteristic measurement device 10 measures electromagnetic waves as electromagnetic characteristic signals from the interfaces of the original target devices 31 to 3A and the target device 40 in the operating state, and acquires information regarding the electromagnetic characteristics of the electromagnetic waves. Specifically, the electromagnetic characteristic measurement device 10 measures electromagnetic waves as electromagnetic characteristic signals from the interfaces of the original target devices 31 to 3A and the target device 40 in the operating state, and acquires information regarding the reflection characteristics as the electromagnetic characteristics of the electromagnetic waves. For example, the electromagnetic characteristic measurement device 10 is constituted by a spectrum analyzer or a network analyzer. Note that the electromagnetic characteristic measurement device 10 may be configured to acquire information regarding the impedance characteristics of the original target devices 31 to 3A and the target device 40 in the operating state.

[0013] The individual determination device 20 includes a characteristic information acquisition unit 21, a similarity calculation unit 22, a weighting process unit 23, a determination unit 24, and a storage unit 25. The characteristic information acquisition unit 21 acquires information regarding the electromagnetic characteristics of the original target devices 31 to 3A and the target device 40 based on the signal from the electromagnetic characteristic measurement device 10. The similarity calculation unit 22 calculates the similarity between the electromagnetic characteristics of the original target devices 31 to 3A and the target device 40 based on the information acquired by the characteristic information acquisition unit 21.

[0014] The weighting processing unit 23 divides the electromagnetic characteristics of the original target devices 31 to 3A into a plurality of regions in the frequency domain, and performs weighting for individual determination on the characteristics of each region. For example, when the electromagnetic characteristics of the original target devices 31 to 3A are divided into a plurality of regions including a first region and a second region in the frequency domain, the weighting processing unit 23 determines that the similarity of the characteristics of the first region (first similarity) among the original target devices 31 to 3A is higher than the similarity of the characteristics of the second region (second similarity) among the original target devices 31 to 3A, the first region is weighted higher than the second region. Specifically, the weighting processing unit 23 determines a region where the measurement variation of each region when the individual characteristic data of the original target device is divided into a plurality of regions in the frequency domain is larger than a preset reference value (threshold value), and sets a weighting coefficient. Details of the weighting processing unit 23 will be described later.

[0015] The determination unit 24 performs individual determination by comparing the electromagnetic characteristics of the original target devices 31 to 3A with the electromagnetic characteristics of the target device 40. The storage unit 25 stores programs, parameters, data, and other information used when the individual determination device 20 performs various processes. In other words, the individual determination device 20 is configured such that the characteristic information acquisition unit 21, the similarity calculation unit 22, the weighting processing unit 23, and the determination unit 24 refer to the information stored in the storage unit 25 to perform various processes, and store the results of various processes in the storage unit 25. In the first embodiment, the individual determination device constitutes a device determination device.

[0016] The output device 50 outputs the result of the process performed by the individual determination device 20. For example, the output device 50 is constituted by a liquid crystal display device and visually displays the determination result by the individual determination device 20. Also, for example, the output device 50 is constituted by an LED lamp and switches between lighting and extinguishing according to the determination result by the individual determination device 20. Also, for example, the output device 50 is configured to include a speaker and outputs the determination result by the individual determination device 20 by sound.

[0017] Next, with reference to FIGS. 2 and 3, the hardware configuration of the individual determination device 20 will be described. FIG. 2 is a block diagram showing an example of the hardware configuration of the individual determination device 20 according to Embodiment 1, and FIG. 3 is a block diagram showing an example of a hardware configuration different from that of FIG. 2 of the individual determination device 20 according to Embodiment 1. For example, as shown in FIG. 2, the individual determination device 20 includes a processor 20a, a memory 20b, and an I / O port 20c, and is configured such that the processor 20a reads and executes a program stored in the memory 20b. The memory 20b is constituted by, for example, a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, or a combination thereof. Further, the memory 20b may be a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, or the like. Furthermore, the memory 20b may be an HDD or an SSD.

[0018] Also, for example, as shown in FIG. 3, the individual determination device 20 includes a processing circuit 20d, which is dedicated hardware, and an I / O port 20c. The processing circuit 20d is constituted by, for example, a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, a system LSI (Large-Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each function of the individual determination device 20 is realized by the processor 20a or the processing circuit 20d, which is dedicated hardware, executing a program that is software, firmware, or a combination of software and firmware.

[0019] Next, with reference to FIGS. 4 to 6, the details of the processing performed by the individual determination device 20 according to Embodiment 1 will be described. FIG. 4 is a flowchart showing the process of acquiring the electromagnetic characteristics of the original target device performed by the individual determination device 20 according to Embodiment 1. As shown in FIG. 4, when starting the process of acquiring electromagnetic characteristics, the individual determination device 20 acquires individual characteristic data as information regarding electromagnetic characteristics a plurality of times for each of a plurality of original target devices by the electromagnetic characteristic measurement device 10. Specifically, when starting the process, the individual determination device 20 first starts acquiring the electromagnetic characteristics from A original target devices 31 to 3A (step ST111), and starts acquiring individual characteristic data B times for each original target device (step ST112). In Embodiment 1, A and B are each natural numbers of 2 or more. Also, A and B may be equal to each other or different from each other.

[0020] When performing the process of step ST112, the individual determination device 20 acquires individual characteristic data from a specific original target device among the original target devices 31 to 3A (step ST113). In this process, the individual determination device 20 acquires, for example, information regarding reflection characteristics as individual characteristic data from the original target device. When performing the process of step ST113, the individual determination device 20 stores the acquired individual characteristic data in the storage unit 25 (step ST114).

[0021] When the processes from step ST113 to step ST114 are performed B times for a specific original target device, the acquisition of data from the original target device is completed (step ST115), and the acquisition of data from the next original target device is started. When the processes from step ST112 to step ST115 are performed for all of the A original target devices (step ST116), the individual determination device 20 ends the process of acquiring electromagnetic characteristics.

[0022] FIG. 5 is a flowchart showing the weighting process performed by the individual determination device 20 according to Embodiment 1. The individual determination device 20 divides the individual characteristic data acquired from the original target devices 31 to 3A by the weighting processing unit 23 in the frequency domain, and performs weighting when used for individual determination for the characteristics of each region. Specifically, in a state where the processing shown in FIG. 4 is performed to acquire the individual characteristic data of the original target device, as shown in FIG. 5, when the individual determination device 20 starts the process of weighting the individual characteristic data of A original target devices 31 to 3A (step ST121), it calls the individual characteristic data of the same individual of a specific original target device (step ST122). In other words, when starting the process, the individual determination device 20 refers to the information stored in the storage unit 25 and reads a plurality of individual characteristic data acquired from a specific original target device.

[0023] When the process of step ST122 is performed, the individual determination device 20 divides each of the plurality of individual characteristic data acquired from the original target device into C regions including a first region and a second region in the frequency domain by the weighting processing unit 23 (step ST123). In this process, the weighting processing unit 23 divides each of the plurality of individual characteristic data acquired from the original target device into C regions at regular intervals in the frequency domain. In Embodiment 1, C is a natural number of 2 or more.

[0024] When the process of step ST123 is performed, the individual determination device 20 starts a process of comparing the characteristics of the same regions with each other for two pieces of individual characteristic data of the original target device by the similarity calculation unit 22 and calculating the similarity between the characteristics of the same regions (step ST124-1). In this process, the individual determination device 20 selects any two pieces of individual characteristic data from among the plurality of pieces of individual characteristic data of the original target device, and performs the process of calculating the similarity between the characteristics of the same regions with each other for these two pieces of individual characteristic data for all combinations of the plurality of pieces of individual characteristic data (step ST124-2). For example, in this process, as shown in the following mathematical formula (1), the similarity calculation unit 22 calculates the similarity P(n,i,j) between the characteristics of the same regions with each other for two pieces of individual characteristic data by the mean squared error (MSE) using the error between regions of the same frequency.

[0025] TIFF0007686168000001.tif23166 In the mathematical formula (1), R(n,i,k) represents the k-th point (k = 1 to s) data of the n-th frequency region obtained by dividing the individual characteristic data obtained by the i-th measurement for the original target device. Also, n represents a natural number from 1 to C, i represents a natural number from 2 to B, j represents a natural number from 1 to B - 1. Also, j satisfies i ≠ j and i > j. Also, s is the number of data points in one measurement. Note that the similarity calculation unit 22 may be configured to calculate the similarity between the characteristics of the same regions with each other for two pieces of individual characteristic data by other calculation indexes in statistics such as the mean absolute error (MAE).

[0026] The process of step ST124-2 for all combinations of the plurality of pieces of individual characteristic data acquired from the original target device ( B C 2When performing the operation for (step ST124-3), the individual determination device 20 selects, by the weighting processing unit 23, the similarity Max(Pn) of the combination with the worst (lowest) similarity among the similarities P(n,i,j) related to the combinations of the respective regions (step ST125). When performing the processing of step ST125, the individual determination device 20 sets, by the weighting processing unit 23, a weighting array for giving weights to the respective regions according to the similarity related to the combination of the respective regions, and sets the element of the weighting array of the region with the similarity of Max(Pn) to the smallest value (step ST126).

[0027] In this processing, for example, the weighting processing unit 23 sets a weighting array composed of a plurality of elements set to values of 1 or more, and sets the element of the weighting array of the region with the similarity of Max(Pn) to 1. For example, the weighting processing unit 23 sets, as the weighting array, a weighting array γ corresponding to the k-th data of the n-th frequency region of the u-th original target device, where the number of elements with an initial value of 1 is s u,k and stores it in the storage unit 25. Here, u is a natural number from 1 to A.

[0028] When performing the processing of step ST126, the individual determination device 20 determines, by the weighting processing unit 23, whether the value Max(Pn) selected in the processing of step ST125 is greater than the respectively set weighting threshold α in a state where the weighting threshold α and the weighting coefficient are associated in advance (step ST127-2).

[0029] In the case of YES in the processing of step ST127-2, for the region where the value Max(Pn) selected in step ST125 is greater than the weighting threshold α, the weighting coefficient associated with the exceeded weighting threshold α is stored in the storage unit 25 as the same numerical value for each s / C for the elements of the n-th region corresponding to k from k=(n - 1)*s / C + 1 to k=n*s / C of the weighting array γ u,k (step ST127-3).

[0030] Here, the weighting process is performed using a single weighted threshold α. However, a plurality of weighted thresholds and weighting coefficients may be set according to the degree of measurement variation, that is, the magnitude of the similarity value.

[0031] When the processes of step ST127-2 and step ST127-3 are performed for all C regions (step ST127-4), the individual determination device 20 performs the processes from step ST122 to step ST127-4 for the next original target device. When the processes from step ST122 to step ST127-4 are performed for all A original target devices (step ST128), the individual determination device 20 ends the weighting process.

[0032] Next, with reference to FIG. 6, a process of performing an authenticity determination as an individual determination by measuring the electromagnetic characteristics of the device under test 40, which is the device to be actually determined, and comparing the individual characteristic data of the device under test 40 with the individual characteristic data of the original target device will be described. FIG. 6 is a flowchart showing the process of performing individual determination by the individual determination device according to Embodiment 1. In the process of performing individual identification determination as individual determination, the determination that "the device under test 40 is the same as the original target device being compared" corresponds to the "true" determination in the process of FIG. 6.

[0033] First, the individual determination device 20 measures the reflection characteristics of the device under test 40 by the electromagnetic characteristic measurement device 10 (step ST131), and stores the acquired individual characteristic data in the storage unit 25 (step ST132).

[0034] Next, the individual determination device 20 calls the weighted array γ of the original target device stored in the storage unit 25 in step ST126-4 u,k and the individual characteristic data R(u,k) (step ST141). For example, the individual characteristic data called here may be the individual characteristic data for one time for each individual of the original target device, or may be the averaged data of B pieces of the individual characteristic data of each individual.

[0035] Next, the individual determination device 20 applies the weighting array γ stored in the storage unit 25 to the individual characteristic data of the original target device called in step ST141 and the individual characteristic data of the target device 40. u,k Multiply it by the error between the individual characteristic data R(u,k) of the original target device and the individual characteristic data R´(k) of the target device 40 (step ST142-2), and calculate the discrimination similarity Q(u) (step ST142-3). When using MSE, the discrimination similarity Q(u) is represented by the following formula (2), where the individual characteristic data is R´(k) and the number of measured data is s. TIFF0007686168000002.tif17166

[0036] When the process of step ST142-3 is performed, the individual determination device 20 determines, based on the result of the discrimination similarity Q(u) multiplied by the weighting coefficient in the determination unit 24 and the discrimination threshold β set in advance according to the purpose of individual determination, whether the discrimination similarity Q multiplied by the weighting coefficient is greater than the discrimination threshold β (step ST142-4). If step ST142-4 is false (NO), it is determined to be true (step ST42-5), and the result of step ST142-4 is output by the output device 50 (step ST143).

[0037] If step ST142-4 is positive (Yes), the individual determination device 20 determines that it is false (step ST142-6), and repeats until u, which represents the number of executions of the process from step ST142-1 to step ST142-6, which is the comparison flow between the individual characteristic data of the target device 40 and the individual characteristic data of the original target device, exceeds the number of individuals A of the original target device. Finally, the individual determination device 20 outputs the result of the determination in the process of step ST142-4 by the output device 50 (step ST143).

[0038] As described above, the individual determination system according to Embodiment 1 divides the horizontal axis elements of the two-dimensional waveform into several regions, and performs a weighting process based on the quantified measurement variation degree of each region. Even for data with measurement variations, it is possible to identify the regions with variations and reduce the degree of relevance to the determination. Therefore, compared with the prior art, the determination accuracy when performing individual determination of devices can be improved. Further, the individual determination system according to Embodiment 1 determines whether a plurality of devices are similar to each other based on the similarity of characteristics for each region among the plurality of electromagnetic waves when each of the plurality of electromagnetic waves acquired from the device is divided into a plurality of regions in the frequency domain. As a result of weighting each region, it becomes possible to determine the similarity among the plurality of devices in consideration of the variations according to the frequencies of the electromagnetic waves acquired from the devices. Therefore, compared with the prior art, the determination accuracy when performing individual determination of devices can be improved.

[0039] Note that the individual determination system according to Embodiment 1 is configured to perform individual determination of the target device 40 based on the reflection characteristics as the electromagnetic characteristics in the operating states of the original target devices 31 to 3A and the target device 40, but is not limited thereto. The individual determination system only needs to be configured to perform individual determination of the target device based on the electromagnetic characteristics of the original target device and the target device by the individual determination device. For example, the individual determination device may be configured to perform individual determination of the target device based on the impedance characteristics as the electromagnetic characteristics in the operating states of the original target device and the target device.

[0040] In addition, although the individual determination system according to Embodiment 1 is configured to acquire individual characteristic data a plurality of times from each of the plurality of original target devices 31 to 3A, it is not limited thereto. The individual determination system may be configured to perform weighting in these frequency regions based on the individual characteristic data acquired a plurality of times. For example, the individual determination system may be configured to acquire individual characteristic data once from each of the plurality of original target devices, or may be configured to acquire individual characteristic data a plurality of times from only a single original target device. When the individual determination system is configured to acquire individual characteristic data a plurality of times from only a single original target device, the weighting processing unit may be configured to perform a higher weighting on the first region than on the second region when the similarity of the characteristics of the first region among the plurality of individual characteristic data of the original target device is higher than the similarity of the characteristics of the second region. Further, the individual determination system may be configured to perform weighting for each region by the weighting processing unit so as to determine whether the original target device and the target device are similar based only on a comparison of regions where the variation (similarity) in each region of the individual characteristic data acquired a plurality of times is smaller than a preset threshold value.

[0041] Embodiment 2. Next, with reference to FIG. 7, the individual determination system according to Embodiment 2 will be described. The individual determination system according to Embodiment 2 differs in the processing performed by the individual determination device as compared with the individual determination system according to Embodiment 1, but the other parts are the same. For the same configurations as those in Embodiment 1, the same reference numerals will be given and the description thereof will be omitted.

[0042] FIG. 7 is a flowchart showing the weighting process performed by the individual determination device according to Embodiment 2. The individual determination device 20 according to Embodiment 1 performed weighting for each region using the weighting threshold value α, but the individual determination device according to Embodiment 2 performs the weighting process by using the deviation without setting a threshold value.

[0043] The individual determination device according to Embodiment 2 performs the weighting process shown in FIG. 7 in a state where it has acquired the individual characteristic data of the original target device by performing the process shown in FIG. 4. Note that the weighting process shown in FIG. 7 is the same as the process from step ST121 to step ST125 of the process shown in FIG. 5, where the frequency axis of the individual characteristic data is divided into C regions for each of a plurality of original target devices, the similarity P of each region is calculated for all combinations of the same individual, and the worst numerical value Max(Pn) of the similarity P calculated in each region is taken out.

[0044] The individual determination device according to Embodiment 2 repeats the processes from step ST122 to step ST125 for A, the number of individuals of the original target device.

[0045] Next, the individual determination device according to Embodiment 2 calculates the deviation value for all A×C similarities P(n,i,j) for each region of the original target device with respect to the numerical value Max(Pn) taken out from each region in step ST125 (step ST227).

[0046] Next, the individual determination device according to Embodiment 2 proportionally associates the deviation value and the weighting coefficient so that the maximum value and minimum value of the preset weighting coefficient correspond to the maximum value and minimum value of the deviation value of the value Max(Pn) taken out in step ST125 (step ST228). Note that in the process of step ST228, the minimum value of the deviation value to be corresponded may be a fixed value such as 50 of the average deviation value.

[0047] Next, the individual determination device according to Embodiment 2 prepares a weighting array γ corresponding to the data at the k-th point (k = 1 to s) of the n-th region of the u-th original target device, where the number of elements with an initial value of 1 is s. u,k (Step ST229-2).

[0048] Next, the individual determination device according to Embodiment 2 determines, from the deviation value and the weighting coefficient associated in step ST228, the weighting coefficient corresponding to the deviation value calculated in step ST227 as the weighting array γ. u,kAs the elements of the n-th region corresponding to k from k = (n - 1)*s / C + 1 to k = n*s / C, the same number of s / C values are stored in the storage unit 25 together with the individual characteristic data of the original target device (step ST229-4). Since the processing after step ST229-4 is the same as that in the first embodiment, the description thereof is omitted.

[0049] As described above, the individual determination system according to the second embodiment can determine the weighting coefficient with an objective index regardless of the range of the data of the measurement target by using the deviation value as a method for determining the weight given to each region.

[0050] Embodiment 3. Next, with reference to FIGS. 8 and 9, an individual determination system according to Embodiment 3 will be described. The individual determination system according to Embodiment 3 has different processing performed by the individual determination device as compared with the individual determination system according to Embodiment 1, but the other parts are the same. For the same configurations as those in Embodiment 1, the same reference numerals are given and the description thereof is omitted.

[0051] FIG. 8 is a flowchart showing the weighting process performed by the individual determination device according to Embodiment 3. The individual determination device 20 according to Embodiment 1 is configured to perform weighting on each region in consideration of the measurement variation of the data of the original target device, while the individual determination device according to Embodiment 3 performs weighting on each region in consideration of the measurement variations of the data of both the original target device and the target device 40. For example, the individual determination device according to Embodiment 3 performs a plurality of measurements of the electromagnetic characteristics on the target device 40 that is the device to be actually determined, and compares the individual characteristic data of the target device 40 with the individual characteristic data of the original target device to perform individual determination.

[0052] The individual determination device according to Embodiment 3 starts the process shown in FIG. 8 (step ST331) in a state where it has acquired the individual characteristic data of the original target device by performing the process shown in FIG. 4 and has performed weighting on each region by performing the process shown in FIG. 5. In this process, there are A original target devices, and the individual determination device according to Embodiment 3 has performed D measurements on the same individual.

[0053] In the process of FIG. 8, the individual determination device according to Embodiment 3 measures the reflection characteristics of the device under test 40 using the electromagnetic characteristic measurement device 10 (step ST332), and stores the measurement result in the storage unit 25 (step ST333). The individual determination device according to Embodiment 3 performs the processes from step ST332 to step ST333 B times on the same device under test 40 (step ST334).

[0054] Next, the individual determination device according to Embodiment 3 calls the electromagnetic characteristic data of the device under test 40 stored in the storage unit 25 in step ST233, and divides it into a plurality (C) at regular intervals with the frequency domain preset in the same manner as in step ST123 for weighting (step ST335).

[0055] Next, the individual determination device according to Embodiment 3 calculates the similarity T(n, i, j) of each region for all combinations of the data of the device under test 40 (step ST336). When using MSE, the similarity T(n, i, j) is represented by the following mathematical formula (3), where s is the number of data points in one measurement of the reflection characteristics. TIFF0007686168000003.tif23166 Here, the individual characteristic data R´(n, i, k) of the device under test is the data of the k-th point (k = 1 to s) in the n-th region obtained by dividing the individual characteristic data obtained in the i-th measurement. Therefore, n = 1 to C and i = 1 to D.

[0056] Next, the individual determination device according to Embodiment 3 has a weighting array δ corresponding to the data of the k-th point in the n-th region, where the number of elements is s and the initial value is 1 kPrepare it and select the worst numerical value Max(Tn) of the similarity T(n.i.j) in each region (step ST337). Next, the individual determination device according to Embodiment 3 determines whether it is a value larger than the pre-set weighted threshold α (step ST339-2). For the region with a larger value, a weighting coefficient associated with the weighted threshold α is used as the nth region corresponding to k from k=(n - 1)*s / C + 1 to k=n*s / C in the weighting array δ k For each of the s / C same numerical values as elements of the nth region corresponding to k from k=(n - 1)*s / C + 1 to k=n*s / C in δ, store them in the storage unit 25 together with the data in the storage unit 25 (step ST339-3). In this process, the individual determination device according to Embodiment 3 performs the weighting process using a single weighted threshold α, but a plurality of weighted thresholds corresponding to the degree of measurement variation, that is, the magnitude of the similarity numerical value, may be set.

[0057] FIG. 9 is a flowchart showing the process of performing individual determination by the individual determination device according to Embodiment 3. The individual characteristic data of the target device 40 used below may be the reflection characteristic data for one time or the averaged data of the reflection characteristic data.

[0058] When starting the process shown in FIG. 9 in the state of performing the process shown in FIG. 8, first, the individual determination device according to Embodiment 3 calls the weighting array γ u,k including the weighting coefficient of the u-th individual stored in step ST126-4 and the individual characteristic data R(u,k) (step ST341). The individual characteristic data called here may be the reflection characteristic data for one time for each individual of the original target device or the averaged data of the reflection characteristic data of each individual.

[0059] Next, the individual determination device according to Embodiment 3 calculates the error between the individual characteristic data of the original target device called in step ST341 and the individual characteristic data of the target device 40 stored in the storage unit 25 in step ST339-3, and then calculates the error between the weighting array γ u,k of the original target device called in step ST241 and the weighting array δk Multiply them (step ST342-2) to calculate the discrimination similarity Q(u) (step ST242-3). When using MSE, the discrimination similarity Q(u) is represented by the following formula (4), where R´(k) is the individual characteristic data of the device under test 40 recorded in step ST332, and s is the number of data points in one reflection characteristic measurement. TIFF0007686168000004.tif19166

[0060] Next, based on the result of the discrimination similarity Q(u) multiplied by the weighting coefficient, the individual determination device according to Embodiment 3 outputs the individual determination result (steps ST241-1 to ST241-6) in the determination unit 24 to the output device 50 in the same manner as in Embodiment 1 (step ST342).

[0061] As described above, the individual determination system according to Embodiment 3 can also perform a weighting process considering measurement variations on the device under test 40, so that weighting corresponding to the measurement variations in the device under test 40 can be performed, and thus the accuracy of individual determination is further improved.

[0062] Note that when the individual determination system acquires individual characteristic data from the device under test multiple times, it may be configured to acquire individual characteristic data only once from a single original device under test.

[0063] Note that in the present disclosure, free combinations of each embodiment, modifications of any components of each embodiment, or omissions of any components in each embodiment are possible.

Industrial Applicability

[0064] The individual determination device according to the present disclosure can be used, for example, for individual identification of electronic devices based on the electromagnetic characteristics of the electronic devices.

[0065] Hereinafter, aspects of the present disclosure will be summarized and described as appendices.

[0066] (Appendix 1) When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, and the characteristics of the electromagnetic wave in the first region are defined as first characteristics and the characteristics of the electromagnetic wave in the second region are defined as second characteristics, a characteristic information acquisition unit that acquires first characteristic information regarding the first characteristics of each of a plurality of electromagnetic waves from a reference device and second characteristic information regarding the second characteristics, and first characteristic information regarding the first characteristics of an electromagnetic wave and second characteristic information regarding the second characteristics from a determination target device different from the reference device; a similarity calculation unit that calculates a first similarity between a plurality of pieces of first characteristic information from the reference device and a second similarity between a plurality of pieces of second characteristic information from the reference device; and a determination unit that determines whether the reference device and the determination target device are similar based on the plurality of pieces of first characteristic information and second characteristic information from the reference device, the first characteristic information and second characteristic information from the determination target device, the first similarity, and the second similarity. A device determination apparatus characterized by the above. (Appendix 2) When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, and the characteristics of the electromagnetic wave in the first region are defined as first characteristics and the characteristics of the electromagnetic wave in the second region are defined as second characteristics, a characteristic information acquisition unit that acquires first characteristic information regarding the first characteristics of an electromagnetic wave and second characteristic information regarding the second characteristics from a first reference device, first characteristic information regarding the first characteristics of an electromagnetic wave and second characteristic information regarding the second characteristics from a second reference device different from the first reference device, and first characteristic information regarding the first characteristics of an electromagnetic wave and second characteristic information regarding the second characteristics from a determination target device different from the first reference device and the second reference device; a similarity calculation unit that calculates a first similarity between the first characteristic information from the first reference device and the first characteristic information from the second reference device and a second similarity between the second characteristic information from the first reference device and the second characteristic information from the second reference device; Based on the first characteristic information and the second characteristic information from the first reference device, the first characteristic information and the second characteristic information from the second reference device, the first characteristic information and the second characteristic information from the device to be determined, the first similarity, and the second similarity, a determination unit that determines whether the first reference device and the second reference device are similar to the device to be determined, A device determination apparatus characterized by the above. (Appendix 3) When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, the characteristic of the electromagnetic wave in the first region is defined as the first characteristic, and the characteristic of the electromagnetic wave in the second region is defined as the second characteristic, A characteristic information acquisition unit that acquires the first characteristic information regarding the first characteristic of the electromagnetic wave from the reference device and the second characteristic information regarding the second characteristic, and the first characteristic information regarding the first characteristic of each of the plurality of electromagnetic waves from the device to be determined, which is different from the reference device, and the second characteristic information regarding the second characteristic, A similarity calculation unit that calculates a first similarity between the plurality of first characteristic information from the device to be determined and a second similarity between the plurality of second characteristic information from the device to be determined, Based on the first characteristic information and the second characteristic information from the reference device, the plurality of first characteristic information and the second characteristic information from the device to be determined, the first similarity, and the second similarity, a determination unit that determines whether the reference device and the device to be determined are similar, A device determination apparatus characterized by the above. (Appendix 4) Comprising a weighting processing unit that performs weighting on the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit, The determination unit determines whether the reference device and the device to be determined are similar based on the plurality of first characteristic information and the second characteristic information from the reference device, the first characteristic information and the second characteristic information from the device to be determined, the first similarity, the second similarity, and the result of the processing by the weighting processing unit. The device determination apparatus according to any one of Appendices 1 to 3, characterized by the above. (Appendix 5) When the first similarity is higher than the second similarity, the weighting processing unit performs a higher weighting on the first region than on the second region. The device determination apparatus according to any one of Appendices 1 to 4, characterized in that. (Appendix 6) The reference device is a first reference device, The characteristic information acquisition unit acquires first characteristic information regarding a first characteristic of an electromagnetic wave from a second reference device different from the first reference device and the determination target device, and second characteristic information regarding a second characteristic, The similarity calculation unit calculates a third similarity between the first characteristic information from the first reference device and the first characteristic information from the second reference device, and a fourth similarity between the second characteristic information from the first reference device and the second characteristic information from the second reference device, The determination unit determines whether the first reference device, the second reference device, and the determination target device are similar based on the first characteristic information and the second characteristic information from the first reference device, the first characteristic information and the second characteristic information from the second reference device, the first characteristic information and the second characteristic information from the determination target device, the first similarity, the second similarity, the third similarity, and the fourth similarity. The device determination apparatus according to any one of Appendices 1 to 5, characterized in that. (Appendix 7) A storage unit that stores the first characteristic information and the second characteristic information from the reference device acquired in advance by the characteristic information acquisition unit, and the first similarity and the second similarity calculated in advance by the similarity calculation unit, The determination unit determines whether the reference device and the determination target device are similar based on the first characteristic information and the second characteristic information from the reference device stored in the storage unit and the first similarity and the second similarity, based on the acquisition of the first characteristic information and the second characteristic information from the determination target device by the characteristic information acquisition unit. The device determination apparatus according to any one of Appendices 1 to 6, characterized in that. (Appendix 8) The first characteristic and the second characteristic are reflection characteristics with respect to an input signal from another device. The device determination apparatus according to any one of appendices 1 to 7, characterized in that... (Appendix 9) The first characteristic and the second characteristic are impedance characteristics. The device determination apparatus according to any one of appendices 1 to 8, characterized in that... (Appendix 10) A device determination method performed by a device including a characteristic information acquisition unit, a similarity calculation unit, and a determination unit, comprising: When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, the characteristic of the electromagnetic wave in the first region is defined as the first characteristic, and the characteristic of the electromagnetic wave in the second region is defined as the second characteristic, a step in which the characteristic information acquisition unit acquires first characteristic information regarding the first characteristic of each of a plurality of electromagnetic waves from a reference device and second characteristic information regarding the second characteristic, and first characteristic information regarding the first characteristic of an electromagnetic wave from a determination target device different from the reference device and second characteristic information regarding the second characteristic; a step in which the determination unit causes the similarity calculation unit to calculate a first similarity between a plurality of pieces of first characteristic information from the reference device and a second similarity between a plurality of pieces of second characteristic information from the reference device; a step of determining whether the reference device and the determination target device are similar based on the plurality of pieces of first characteristic information and second characteristic information from the reference device, the first characteristic information and second characteristic information from the determination target device, the first similarity, and the second similarity. A device determination method characterized by the above.

Explanation of Reference Numerals

[0067] 31 to 3A Original target device (reference device), 10 Electromagnetic characteristic measurement device, 20 Individual determination device (device determination apparatus), 21 Characteristic information acquisition unit, 22 Similarity calculation unit, 23 Weighting processing unit, 24 Determination unit, 25 Storage unit, 40 Device under test, 50 Output device, A Number of individuals, P Similarity, Q Discrimination similarity, R Individual characteristic data, R´ Individual characteristic data, T Similarity, α Weighting threshold, β discrimination threshold, γ u Weighting array, δ k Weighting array.

Claims

1. When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, with the characteristic of the electromagnetic wave in the first region being the first characteristic and the characteristic of the electromagnetic wave in the second region being the second characteristic, a characteristic information acquisition unit that acquires first characteristic information regarding the first characteristic of each of a plurality of electromagnetic waves from a reference device and second characteristic information regarding the second characteristic, and first characteristic information regarding the first characteristic of an electromagnetic wave and second characteristic information regarding the second characteristic from a determination target device different from the reference device; a similarity calculation unit that calculates a first similarity between a plurality of pieces of first characteristic information from the reference device and a second similarity between a plurality of pieces of second characteristic information from the reference device; a weighting processing unit that performs weighting on the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit; a determination unit that determines whether the reference device and the determination target device are similar based on the plurality of pieces of first characteristic information and second characteristic information from the reference device, the first characteristic information and second characteristic information from the determination target device, the first similarity and the second similarity, and the result of the processing by the weighting processing unit, wherein the weighting processing unit calculates a deviation value with respect to the worst similarity among the first similarities and the worst similarity among the second similarities, and performs weighting based on the deviation value A device determination apparatus characterized by the above.

2. When the first similarity is higher than the second similarity, the weighting processing unit performs higher weighting on the first region than on the second region The device determination apparatus according to claim 1, characterized by the above.

3. The reference device is a first reference device, and the characteristic information acquisition unit acquires first characteristic information regarding the first characteristic of an electromagnetic wave and second characteristic information regarding the second characteristic from a second reference device different from the first reference device and the determination target device, The similarity calculation unit calculates a third similarity between the first characteristic information from the first reference device and the first characteristic information from the second reference device, and a fourth similarity between the second characteristic information from the first reference device and the second characteristic information from the second reference device. The determination unit determines whether the first reference device and the second reference device are similar to the device to be determined, based on the first characteristic information and the second characteristic information from the first reference device, the first characteristic information and the second characteristic information from the second reference device, the first characteristic information and the second characteristic information from the device to be determined, the first similarity, the second similarity, the third similarity, and the fourth similarity. The device determination apparatus according to claim 1, characterized in that.

4. The apparatus further comprises a storage unit that stores the first characteristic information and the second characteristic information from the reference device acquired in advance by the characteristic information acquisition unit, and the first similarity and the second similarity calculated in advance by the similarity calculation unit. Based on the fact that the characteristic information acquisition unit has acquired the first characteristic information and the second characteristic information from the device to be determined, the determination unit determines whether the reference device is similar to the device to be determined, based on the first characteristic information and the second characteristic information from the reference device stored in the storage unit, and the first similarity and the second similarity. The device determination apparatus according to claim 1, characterized in that.

5. The first characteristic and the second characteristic are reflection characteristics with respect to an input signal from another device. The device determination apparatus according to any one of claims 1 to 4, characterized in that.

6. The first characteristic and the second characteristic are impedance characteristics. The device determination apparatus according to any one of claims 1 to 4, characterized in that.

7. When an electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, the characteristics of the electromagnetic wave in the first region are defined as first characteristics, and the characteristics of the electromagnetic wave in the second region are defined as second characteristics, a characteristic information acquisition unit that acquires first characteristic information regarding the first characteristics of the electromagnetic wave from a first reference device and second characteristic information regarding the second characteristics, first characteristic information regarding the first characteristics of the electromagnetic wave from a second reference device different from the first reference device and second characteristic information regarding the second characteristics, and first characteristic information regarding the first characteristics of the electromagnetic wave from a determination target device different from the first reference device and the second reference device and second characteristic information regarding the second characteristics; a similarity calculation unit that calculates a first similarity between the first characteristic information from the first reference device and the first characteristic information from the second reference device and a second similarity between the second characteristic information from the first reference device and the second characteristic information from the second reference device; a weighting processing unit that performs weighting on the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit; a determination unit that determines whether the first reference device and the second reference device are similar to the determination target device based on the first characteristic information and the second characteristic information from the first reference device, the first characteristic information and the second characteristic information from the second reference device, the first characteristic information and the second characteristic information from the determination target device, the first similarity and the second similarity, and the result of the processing by the weighting processing unit; and the weighting processing unit calculates a deviation value for the worst similarity among the first similarities and the worst similarity among the second similarities, and performs weighting based on the deviation value A device determination apparatus characterized by the above.

8. A device determination method performed by a device including a characteristic information acquisition unit, a similarity calculation unit, a weighting processing unit, and a determination unit, When the electromagnetic wave is divided into a plurality of regions including a first region and a second region in the frequency domain, the characteristics of the electromagnetic wave in the first region are defined as first characteristics, and the characteristics of the electromagnetic wave in the second region are defined as second characteristics. The step of the characteristic information acquisition unit acquiring first characteristic information regarding the first characteristics and second characteristic information regarding the second characteristics of each of a plurality of electromagnetic waves from a reference device, and first characteristic information regarding the first characteristics and second characteristic information regarding the second characteristics of an electromagnetic wave from a determination target device different from the reference device. The step of the similarity calculation unit calculating a first similarity between a plurality of pieces of first characteristic information from the reference device and a second similarity between a plurality of pieces of second characteristic information from the reference device. The step of the weighting processing unit performing weighting on the first region and the second region based on the first similarity and the second similarity calculated by the similarity calculation unit. The step of the determination unit determining whether the reference device and the determination target device are similar based on a plurality of pieces of first characteristic information and second characteristic information from the reference device, first characteristic information and second characteristic information from the determination target device, the first similarity, and the second similarity. The weighting processing unit calculates a deviation value for the worst similarity among the first similarities and the worst similarity among the second similarities, and performs weighting based on the deviation value. A device determination method characterized by the above.

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