Inspection system

Abstract

To provide an inspection system that efficiently inspects belongings to be inspected.SOLUTION: An inspection system according to the embodiments includes a first circuit unit, an antenna, a second circuit unit, and a third circuit unit. The first circuit unit estimates whether or not an object to be inspected has a predetermined object. The antenna is capable of receiving radio waves. The second circuit unit determines whether an electronic device is present within a predetermined range based on radio waves received by the antenna. The third circuit unit determines whether or not the object to be inspected has the predetermined object based on the estimation result of the first circuit unit and the determination result of the second circuit unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to an inspection system for inspecting the belongings of an inspection subject.

Background Art

[0002] As an example of such an inspection system, there is a system that uses radar. The inspection system transmits radio waves to the inspection subject and receives the reflected radio waves. The inspection system determines whether the inspection subject is carrying dangerous items such as metal or explosives based on the intensity of the reflected radio waves. The inspection system can also determine whether the inspection subject is carrying dangerous items such as a knife based on the shape of the object shown in the image generated based on the intensity of the reflected radio waves. During the transmission of radio waves, the inspection subject does not need to be stationary and may be walking. Therefore, this inspection system has good inspection efficiency.

[0003] However, in the determination based on the intensity of the reflected radio waves or the shape of the image, electronic devices such as smartphones may be misjudged as dangerous items. To prevent misjudgment, the inspection subject needs to take out the electronic device from the bag or pocket and hand it over to the operator of the inspection system. The inspection subject temporarily stops walking during the inspection. As a result, the inspection efficiency is reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0005] The objective of the present invention is to provide an inspection system that efficiently inspects the personal belongings of those being inspected. [Means for solving the problem]

[0006] The inspection system according to this embodiment comprises a first circuit section, an antenna, a second circuit section, and a third circuit section. The first circuit section is Based on the received signal from the radar antenna It estimates whether the object being inspected possesses a specified object. The antenna is, Second It is capable of receiving radio waves. The second circuit section is the antenna. Received signal Based on this, it is determined whether or not the electronic device is within a predetermined range. The third circuit unit determines whether or not the object to be inspected possesses a predetermined object, based on the estimation result of the first circuit unit and the determination result of the second circuit unit. The radar antenna and antenna unit are located on the same panel. The specified object does not include electronic equipment. [Brief explanation of the drawing]

[0007] [Figure 1] A diagram illustrating an example of an inspection system according to the first embodiment. [Figure 2] A block diagram showing an example of the electrical configuration of the inspection system according to the first embodiment. [Figure 3] A block diagram showing an example of the electrical configuration of a part of the inspection system according to the first embodiment. [Figure 4] A diagram showing an example of a chirp signal transmitted from the primary device of the inspection system according to the first embodiment. [Figure 5] A diagram illustrating an example of the operation of the primary device according to the first embodiment. [Figure 6] A flowchart showing an example of the processing flow of the primary device according to the first embodiment. [Figure 7] A flowchart showing an example of the processing flow of a secondary device in the inspection system according to the first embodiment. [Figure 8] A flowchart showing an example of the judgment process flow of the inspection system according to the first embodiment. [Figure 9] A diagram for explaining an example of an inspection system according to the second embodiment. [Figure 10] A diagram for explaining an example of an antenna panel of an inspection system according to the third embodiment. [Figure 11] A diagram for explaining another example of an antenna panel according to the third embodiment. [Figure 12] A flowchart showing an example of the flow of determination processing of an inspection system according to the third embodiment. [Figure 13] A block diagram showing an example of the electrical configuration of an inspection system according to the fourth embodiment. [Figure 14] A diagram for explaining an example of the process in which an inspection system according to the fourth embodiment receives radio waves from an electronic device. [Figure 15] A diagram for explaining another example of the process in which an inspection system according to the fourth embodiment receives radio waves from an electronic device. [Figure 16] A diagram for explaining an example of an advertisement signal transmitted by an inspection system according to the fourth embodiment to an electronic device. [Figure 17] A block diagram showing an example of the electrical configuration of an inspection system according to the fifth embodiment.

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings. The following description exemplifies devices and methods for embodying the technical idea of the embodiments. The technical idea of the embodiments is not limited to the structure, shape, arrangement, material, etc. of the components described below. Modifications that can be easily conceived by those skilled in the art are naturally included in the scope of the disclosure. To make the description clearer, in the drawings, the size, thickness, planar dimensions, shape, etc. of each element may be changed with respect to the actual implementation mode and represented schematically. In multiple drawings, there may be elements with different relationships and ratios of their dimensions to each other. In multiple drawings, corresponding elements may be assigned the same reference numerals to omit redundant descriptions. Some elements may be given multiple designations, but these designations are merely examples and do not deny the assignment of other designations to these elements. Also, it does not deny the assignment of other designations to elements that do not have multiple designations. In the following description, "connection" may include not only direct connection but also connection via other elements.

[0009] Hereinafter, this embodiment will be described in detail while referring to the drawings.

[0010] (First Embodiment) FIG. 1 is a diagram for explaining an example of an inspection system according to the first embodiment. An example of the inspection system relates to a security system installed in facilities where a large number of people gather, such as stations, bus terminals, airports, shopping malls, concert halls, exhibition venues, etc. The embodiment inspects the belongings of a person walking, but can also inspect the belongings of a stationary person.

[0011] An antenna panel 16 and a camera 20 are arranged on one side wall 14 of the passage 12. The passage 12 includes, for example, a ticket gate at a station, an entrance / exit management gate for a room, etc. The passage 12 may be an area where a large number of people can pass through and stay. An antenna panel 18 is arranged on the other side wall of the passage 12. The longitudinal direction of the passage 12 is referred to as the X direction. The height direction of the passage 12 is referred to as the Y direction. The width direction of the passage 12 is referred to as the Z direction. <0000-0103> Antenna panels 16 and 18 are parallel to each other. The radio wave transmission and reception areas of antenna panels 16 and 18 are referred to as the inspection area. It is not mandatory to provide two antenna panels 16 and 18; only one antenna panel may be provided.

[0013] The camera 20's field of view is the area to be inspected. The inspection system detects when the person being inspected 10 has entered the area to be inspected based on the image captured by the camera 20. Instead of the camera 20, an optical sensor may be used to detect the person being inspected 10. Alternatively, the entry of the person being inspected 10 into the area to be inspected may be detected by transmitting and receiving radio waves using antenna panels 16 and 18.

[0014] The antenna panel 16 includes a substrate, a plurality of first antennas 22, and a plurality of second antennas 24. The number of second antennas 24 may be the same as the number of first antennas 22, or Figure 1 shows an example where the number of second antennas 24 is less than the number of first antennas 22.

[0015] Multiple first antennas 22 are arranged in a two-dimensional array on the substrate of the antenna panel 16 so that they can transmit first radio waves to the area under inspection and receive reflected radio waves from the person under inspection 10 present in the area under inspection. The number of multiple first antennas 22 is determined so that the radio wave transmission and reception range of the multiple first antennas 22 includes the area under inspection.

[0016] If the radio wave transmission and reception range of a single first antenna 22 includes the area under inspection, a single first antenna 22 may be used instead of multiple first antennas 22. If the transmission and reception direction of the first antenna 22 is mechanically or electronically variable in two dimensions, one such first antenna 22 may be used instead of multiple first antennas 22. If the transmission and reception direction of the first antenna 22 is mechanically or electronically variable in one dimension, a single row of such first antennas 22 arranged in a one-dimensional array may be used instead of multiple first antennas 22 arranged in a two-dimensional array.

[0017] The multiple first antennas 22 are spaced equally apart. Any spacing can be chosen for this spacing. One example of a spacing is approximately half the wavelength λ with the highest intensity among the multiple wavelengths of radio waves included in the first radio wave transmitted from the first antenna 22 (approximately half a wavelength). Note that approximately half a wavelength includes an error of up to ±30% of half a wavelength λ / 2.

[0018] Any radio wave can be selected as the first radio wave. An example of the first radio wave is a radio wave with a wavelength of 1 centimeter to 100 micrometers. Radio waves with a wavelength of 1 millimeter to 1 centimeter (frequency of 30 GHz to 300 GHz) are also called millimeter waves. Radio waves with a wavelength of 100 micrometers to 1 millimeter (frequency of 300 GHz to 3 THz) are also called submillimeter waves or terahertz waves.

[0019] When the first radio wave is transmitted to the person being inspected 10, the first radio wave is reflected by objects in the propagation path of the first radio wave. By measuring the reflection intensity of the first radio wave reflected at a certain distance, it is possible to determine whether the object at that distance is a human body or a designated object, and whether the person being inspected 10 is in possession of the designated object. A designated object is a so-called hazardous material that is not permitted to be possessed at the location where the inspection system is installed. Examples of hazardous materials include metal objects such as handguns and knives, powders such as explosives, and liquids such as gasoline. Examples of hazardous materials may also include powders such as narcotics or illegally brought-in items such as gold bars.

[0020] Multiple second antennas 24 are capable of receiving second radio waves. Any radio wave can be selected as the second radio wave. One example of a second radio wave is one with a frequency of 3 GHz to 30 GHz (wavelength of 1 centimeter to 10 centimeters). Radio waves with a frequency of 3 GHz to 30 GHz are also called microwaves. Another example of a frequency for a second radio wave is 920 MHz. Yet another example of a second radio wave is millimeter waves or submillimeter waves.

[0021] The frequency of the second radio wave only needs to be different from the frequency of the first radio wave. Therefore, if a portion of the microwaves is not used as the second radio wave, the portion of the microwaves not used as the second radio wave may be used as the first radio wave.

[0022] The inspection system only needs to be able to distinguish between the second and first radio waves, so the frequency of the second radio wave can be the same as the frequency of the first radio wave. For example, by changing the modulation method, changing the direction of linear polarization, or changing the rotation direction of circular polarization for the second and first radio waves, it is possible to distinguish between the second and first radio waves of the same frequency.

[0023] Multiple second antennas 24 are arranged in a two-dimensional array on the substrate of the antenna panel 16 so as to be able to receive second radio waves transmitted from the area under inspection. The number of multiple second antennas 24 is determined so that the radio wave reception range of the multiple second antennas 24 includes the area under inspection.

[0024] If the radio wave reception range of a single second antenna 24 includes the area under inspection, a single second antenna 24 may be used instead of multiple second antennas 24. If the radio wave reception direction of the second antenna 24 is mechanically or electronically variable in two dimensions, one such second antenna 24 may be used instead of multiple second antennas 24. If the radio wave reception direction of the second antenna 24 is mechanically or electronically variable in one dimension, a single row of such second antennas 24 arranged in a one-dimensional array may be used instead of multiple second antennas 24 arranged in a two-dimensional array.

[0025] By analyzing the received signals of the second radio wave received by multiple second antennas 24, it is possible to determine whether or not an electronic device transmitting the second radio wave is present in the area under inspection.

[0026] Antenna panel 18 is configured similarly to antenna panel 16. Antenna panel 18 includes a substrate, a plurality of first antennas 26, and a plurality of second antennas 28. The first antennas 26 correspond to the first antenna 22 of antenna panel 16. The second antennas 28 correspond to the second antenna 24 of antenna panel 16.

[0027] The first antennas 22 and 26 and the second antennas 24 and 28 do not have to be placed on the same antenna panel substrate, but may be placed on separate substrates.

[0028] Figure 2 is a block diagram showing an example of the electrical configuration of an inspection system according to the first embodiment. The inspection system includes a primary device 62, a secondary device 64, a determination circuit 50, a display unit 58, and an alarm unit 60.

[0029] The secondary device 64 is a passive device that processes the received signal of the second radio wave received by the second antenna 24 or 28. The secondary device 64 does not have the function of transmitting the second radio wave. Electronic equipment present in the inspection area transmits the second radio wave. The secondary device 64 determines whether or not the electronic equipment is within a predetermined range. An example of a predetermined range is the inspection area.

[0030] Examples of electronic devices include devices with communication capabilities. These include personal computers, smartphones, mobile phones, portable game consoles, wristwatches with built-in sensors, clothing with built-in sensors, and shoes with built-in sensors. Wristwatches, clothing, and shoes with built-in sensors contain sensors that measure heart rate, blood pressure, steps, etc., and transmitters that send the measured values ​​to smartphones, etc.

[0031] These electronic devices transmit data for data communication to a base station or access point while connected to the internet. Electronic devices with cellular phone functionality transmit voice signals to the base station during a call. Secondary device 64 receives data or voice signals transmitted from the electronic devices as second radio waves.

[0032] Electronic devices may transmit certain signals when they are not connected to the internet or when they are not making a call.

[0033] For example, when the mobile phone function is turned on, a phone such as a smartphone periodically transmits a channel sounding signal to the base station. The base station needs to evaluate propagation identification for scheduling purposes. The base station uses the channel sounding signal for this evaluation. Secondary equipment 64 receives the channel sounding signal as a second radio wave.

[0034] When the tethering function is turned on, the electronic device functions as an access point. The electronic device (access point) periodically transmits a beacon signal. Secondary device 64 receives the beacon signal as a second radio wave.

[0035] When the BLE (Bluetooth Low Energy) (registered trademark) function is turned on, the electronic device functions as a peripheral. The electronic device (peripheral) periodically transmits a beacon signal to initiate a connection with the central device. The secondary device 64 receives the beacon signal as a second radio wave.

[0036] When the UWB (Ultra Wide Band) function is turned on, the electronic device periodically transmits a device discovery signal to search for other UWB devices. Secondary device 64 receives the device discovery signal as a second radio wave.

[0037] The inspection system determines whether or not an electronic device is present within a predetermined range (inspection area) by receiving data, audio signals, or specific signals as a second radio wave.

[0038] The primary device 62 is an active radar device that transmits a first radio wave to each point of the person being inspected 10, processes the received signals of the reflected radio waves at each point, and determines what the reflective object is. The primary device 62 estimates whether or not the person being inspected 10 is carrying a hazardous material.

[0039] Figure 2 shows the primary device 62 and secondary device 64 connected to the antenna panel 16. The primary device 62 is connected to multiple first antennas 22 and the camera 20. The secondary device 64 is connected to multiple second antennas 24.

[0040] The primary device 62 includes a selector 30, a transmitting circuit 32, a receiving circuit 34, a signal processing circuit 36, an estimation circuit 38, and a controller 40. The selector 30 is connected to first antennas 22-1 through 22-n, where n is an arbitrary positive integer. The transmitting circuit 32 and the receiving circuit 34 are connected to the selector 30. The received signals from each point of the subject 10 output from the receiving circuit 34 are transmitted to the signal processing circuit 36. The signal processing circuit 36 ​​stores the received signals and transmits the processing results, which represent the reflection characteristics of each point of the subject 10, to the estimation circuit 38. The reflection characteristics are the reflection intensity or the Doppler shift amount. The Doppler shift amount is the frequency shift amount that occurs as the subject 10 moves.

[0041] The estimation circuit 38 estimates whether the person being inspected 10 possesses hazardous materials based on the processing results, and transmits the estimation result to the determination circuit 50.

[0042] An example of the estimation circuit 38 is a convolutional neural network. The convolutional neural network includes an input layer, a pooling layer, a fully connected layer, and an output layer. The convolutional neural network learns the results of determining possession of dangerous materials by using a large number of image signals as training data. Image signals indicating the reflection identification of each point of the subject 10 are input to the input layer.

[0043] The estimation circuit 38 estimates that "the person being inspected 10 is possessing a hazardous material" if the image signal contains an object with a shape that can be estimated to be a hazardous material. The estimation circuit 38 estimates that "the person being inspected 10 is not possessing a hazardous material" if the image does not contain an object with a shape that can be estimated to be a hazardous material.

[0044] The output signal from camera 20 is input to controller 40. Based on the image of the inspection area captured by camera 20, controller 40 sends control signals to the transmission circuit 32, the receiving circuit 34, and the signal processing circuit 36, and controls the operating timing of the transmission circuit 32, the receiving circuit 34, and the signal processing circuit 36.

[0045] The secondary device 64 includes a receiving circuit 52, an analysis circuit 54, and a determination circuit 56. The receiving circuit 52 is connected to a plurality of second antennas 24. The received signal output from the receiving circuit 52 is transmitted to the analysis circuit 54. The analysis circuit 54 analyzes the received signal and transmits an analysis result signal representing the characteristics of the second radio wave to the determination circuit 56. Based on the analysis result signal, the determination circuit 56 determines whether or not the electronic device that transmitted the second radio wave is in a predetermined range (inspection target area) and transmits the determination result to the determination circuit 50.

[0046] The controller 40 transmits a control signal to the receiving circuit 52 based on the image of the inspection area captured by the camera 20, and controls the operating timing of the receiving circuit 52.

[0047] The determination circuit 50 determines whether the person being inspected 10 possesses hazardous materials based on the estimation results of the estimation circuit 38 and the determination results of the determination circuit 56. The estimation circuit 38 may also mistakenly identify electronic devices as hazardous materials. Based on the determination results of the determination circuit 56, the determination circuit 50 removes the influence of the estimation results of the estimation circuit 38, which mistakenly identified electronic devices as hazardous materials, and determines whether the person being inspected 10 possesses hazardous materials other than electronic devices.

[0048] The judgment circuit 50 transmits the judgment result to an output device. Examples of output devices are a display unit 58 and an alarm unit 60. The display unit 58 and alarm unit 60 inform the operator of the inspection system whether "the person being inspected 10 is in possession of a hazardous material" or "the person being inspected 10 is not in possession of a hazardous material."

[0049] Primary and secondary devices similar to the primary device 62 and secondary device 64 are also connected to the antenna panel 18. The outputs of the primary and secondary devices connected to the antenna panel 18 are supplied to a judgment circuit similar to the judgment circuit 50. The display unit 58 and alarm unit 60 may be common to the antenna panel 16 and the antenna panel 18, or they may be provided separately.

[0050] The signal processing circuit 36, estimation circuit 38, controller 40, decision circuit 50, analysis circuit 54, and decision circuit 56 may be configured as hardware, or they may be configured as a computer that functions as the signal processing circuit 36, estimation circuit 38, controller 40, decision circuit 50, analysis circuit 54, and decision circuit 56 by running software. The signal processing circuit 36, estimation circuit 38, controller 40, decision circuit 50, analysis circuit 54, and decision circuit 56 may be configured as a cloud system.

[0051] Figure 3 is a block diagram showing an example of the electrical configuration of the transmitting circuit 32, receiving circuit 34, and selector 30 of the primary device 62 of the inspection system according to the first embodiment.

[0052] Selector 30 includes selectors 72 and 74. Selectors 72 and 74 switch connections based on control signals from controller 40.

[0053] The selector 72 is connected to one of the first antennas 22-1 through 22-n. Based on the control signal from the controller 40, the selector 72 switches between the first antennas 22-1 and 22-n to which it is connected.

[0054] Selector 74 is connected to selector 72, the transmitting circuit 32, and the receiving circuit 34. Selector 74 connects either the transmitting circuit 32 or the receiving circuit 34 to selector 74. Selector 72 switches between the transmitting circuit 32 and the receiving circuit 34 to which it is connected based on a control signal from the controller 40.

[0055] The transmitting circuit 32 includes a synthesizer 76 and a transmitting amplifier 78.

[0056] The primary device 62 is equipped with a radar function using a linear frequency-modulated continuous wave (L-FMCW) method, in which the frequency increases linearly over time. The synthesizer 76 generates an L-FMCW signal (hereinafter referred to as the chirp signal).

[0057] The chirp signal output from the synthesizer 76 is transmitted via the transmitting amplifier 78, selector 74, and selector 72 to one of the first antennas 22-1 through 22-n. When the controller 40 detects that the person under inspection 10 has entered between the antenna panels 16 and 18, one of the first antennas 22-1 through 22-n transmits a chirp signal to the person under inspection 10.

[0058] The transmitted chirp wave is reflected by objects present in the propagation path. The chirp signal received by any of the first antennas 22-1 to 22-n is transmitted to the receiving circuit 34 via selectors 74, 74.

[0059] The receiving circuit 34 includes a receiving amplifier 80, a mixer 82, a low-pass filter (LPF) 84, an analog-to-digital converter (ADC) 86, and a fast Fourier transform (FFT) circuit 88.

[0060] The output signal from selector 74 is supplied to receiving amplifier 80. The received signal output from receiving amplifier 80 is input to the first input terminal of mixer 82. The chirp signal generated by synthesizer 76 is input to the second input terminal of mixer 82. Mixer 82 multiplies the received signal and the chirp signal to generate an intermediate frequency (IF) signal.

[0061] The IF signal output by mixer 82 is supplied to FFT circuit 88 via LPF 84 and ADC 86. FFT circuit 88 determines the intensity of the radio waves received by first antenna 22-n from first antenna 22-1.

[0062] The controller 40 also generates a clock signal and supplies it to the transmitting circuit 32 and the receiving circuit 34. The operating timing of the transmitting circuit 32 and the receiving circuit 34 is controlled by the clock signal.

[0063] Figure 3 shows an example where one transmitting circuit 32 and one receiving circuit 34 are provided for multiple first antennas 22, but multiple transmitting circuits 32 and multiple receiving circuits 34 may be provided for multiple first antennas 22. In this case, selectors 72 and 74 are not necessary.

[0064] Figure 4 shows an example of a chirp signal transmitted from the primary device 62 according to the first embodiment. Figure 4(a) shows a chirp signal in which the amplitude A is expressed as a function of time t. Figure 4(b) shows a chirp signal in which the frequency f is expressed as a function of time t. As shown in Figure 4(b), the chirp signal is expressed by the center frequency fc, the modulation bandwidth fb, and the signal time width Tb. The slope of the chirp signal is called the frequency change rate (chirp rate) γ.

[0065] The transmitted signal St(t) of the chirp signal is given by Equation 1.

[0066] St(t) = cos[2π(fc×t+γt)] 2 / 2)] Formula 1 The charplate γ is expressed by Equation 2.

[0067] γ=fb / Tb Equation 2 Reflected radio waves from an object located at a distance R from antenna panel 16 are observed with a delay of Δt = 2R / c from the transmission timing, where c is the speed of light. The received signal Sr(t) is expressed by equation 3, where a is the reflection intensity of the object.

[0068] Sr(t)=a×cos[2πfc(t-Δt)+πγ(t-Δt) 2 ] formula 3 Figure 5 is a diagram illustrating an example of the operation of the primary device 62 according to the first embodiment. Figure 5 shows the object detection principle when multiple objects, for example, three objects, are present. Figure 5(a) shows the relationship between the transmitted signal and time, and the relationship between the received signal and time. As shown in Figure 5(a), the frequency of the transmitted signal changes linearly with time. The received signal is delayed by Δt relative to the transmitted signal. When multiple objects are present, the reflected radio waves from the nearest object, indicated by the dashed line, are received first, and the reflected radio waves from the furthest object, indicated by the dashed line, are received last.

[0069] As shown in Figure 3, the received signal is multiplied with the chirp signal in mixer 82 to obtain the IF signal z(t). The IF signal z(t) is expressed by Equation 4.

[0070] z(t) = a × cos(2πΔtγt) Equation 4 Figure 5(b) shows the relationship between the frequency and time of the IF signal. In an ideal environment free from noise, the frequency is constant for each reflected radio wave. The frequency of the IF signal from the nearest reflected radio wave, indicated by the dashed line, is the lowest, and the frequency of the IF signal from the furthest object, indicated by the dashed line, is the highest.

[0071] The frequency domain reflection intensity can be calculated by performing an FFT on the time-domain IF signal z(t) shown in Equation 4 using the FFT circuit 88. Therefore, the amplitude at each point in the frequency domain, which is the result of the FFT of the IF signal, corresponds to the reflection intensity for each distance from the antenna panel 16. if The relationship between the distance R and the given distance is given by Equation 5.

[0072] f if =Δtγ=2Rγ / c Equation 5 Figure 5(c) shows the relationship between reflection intensity and frequency obtained by performing an FFT on the time-domain IF signal. In this way, by determining the amplitude of the frequency-domain signal of the IF signal, the reflection intensity for each distance from the antenna panel 16 can be determined.

[0073] The radio waves transmitted from the first antenna 22 are reflected by objects as well as by the skin of the person being examined 10. The reflectivity of metal is higher than that of skin. The intensity of the radio waves reflected by metal is higher than that of the radio waves reflected by skin. Radio waves are absorbed by powders such as explosives. The reflectivity of powders is lower than that of skin. The intensity of the radio waves reflected by powders is lower than that of skin. The intensity of the reflected radio waves is determined by the type of material at the point where the radio waves are reflected, such as skin, metal, or powder. Therefore, the signal processing circuit 36 ​​can determine the type of material at the reflection point from the intensity of the reflected radio waves.

[0074] Figure 6 is a flowchart showing an example of the processing flow of the primary device 62 according to the first embodiment. Images captured by the camera 20 are supplied to the controller 40. Based on the images captured by the camera 20, the controller 40 determines whether or not the person to be inspected 10 has entered the inspection area. When the controller 40 detects that the person to be inspected 10 has entered the inspection area, it operates the primary device 62 and starts the processing shown in Figure 6.

[0075] Selector 72 selects one of the first antennas 22 (S12). For example, selector 72 selects first antenna 22-1.

[0076] Selector 74 selects the transmitting circuit 32 (S14). As a result, the transmitting circuit 32 is connected to one first antenna 22 via selectors 72 and 74.

[0077] The chirp signal output from the synthesizer 76 is transmitted to the first antenna 22. The first antenna 22 transmits the chirp wave to the person being examined 10 (S16).

[0078] Selector 74 selects receiving circuit 34 (S18). As a result, one first antenna 22 is connected to receiving circuit 33 via selectors 72 and 74.

[0079] The receiving circuit 34 transmits a received signal representing the reflected radio waves received by the first antenna 22 to the signal processing circuit 36 ​​(S20).

[0080] The controller 40 determines whether all first antennas 22 have transmitted and received data (S22). If there are still first antennas 22 that have not transmitted and received data (S22; No), the controller 40 repeats the process from S12 to S22 for one of the first antennas 22 that have not transmitted and received data.

[0081] If all first antennas 22 transmit and receive signals (S22; Yes), the signal processing circuit 36 ​​processes the received signals and transmits the processing results to the estimation circuit 38 (S24).

[0082] The estimation circuit 38 estimates whether the person being inspected 10 is in possession of hazardous materials based on the processing results transmitted from the signal processing circuit 36 ​​(S26).

[0083] The estimation circuit 38 transmits the estimation result to the determination circuit 50.

[0084] Figure 6 illustrates the operation of receiving a chirp wave transmitted by one antenna 22 with the same antenna 22. However, a chirp wave transmitted by one antenna 22 may be received simultaneously by multiple antennas 22, including the transmitting antenna. Also, although chirp waves were transmitted from all antennas 22-1 to 22-n, the transmitting antenna may be a small number of antennas selected from antennas 22-1 to 22-n.

[0085] Figure 7 is a flowchart showing an example of the processing flow of the secondary device 64 of the inspection system according to the first embodiment.

[0086] The receiving circuit 52 transmits the received signal corresponding to the reflected radio wave received by the second antenna 24 to the analysis circuit 54 (S32).

[0087] If there are multiple second antennas 24 and one receiving circuit 52, the received signals from the multiple second antennas 24 are transmitted to the single receiving circuit 52 via a selector. If there are multiple second antennas 24 and multiple receiving circuits 52, the received signals from the multiple second antennas 24 are transmitted to each of the multiple receiving circuits 52.

[0088] When an electronic device transmits a second radio wave at multiple frequencies, a second antenna 24 capable of receiving broadband radio waves may be provided, and the frequency of the received radio wave may be sequentially switched, so that the second antenna 24 can receive radio waves of different frequencies in a time-division manner. When an electronic device transmits a second radio wave at multiple frequencies, multiple second antennas 24, each receiving radio waves of multiple frequencies, may be provided, and the second antennas 24 may be configured to receive radio waves of different frequencies simultaneously.

[0089] The analysis circuit 54 analyzes the received signal and transmits the analysis result to the determination circuit 56 (S34).

[0090] Examples of analysis include spectrum analysis and sniffer analysis. Examples of spectrum analysis include frequency analysis and time-frequency analysis. Frequency analysis results represent the frequency of the received signal. Time-frequency analysis results represent the bandwidth, signal occupancy, and duty cycle of the received signal.

[0091] Sniffer analysis is the process of analyzing the data structure of a received signal packet to find information that can identify the electronic device that is transmitting the radio waves. Examples of information that can identify an electronic device in the case of BLE communication include the Manufacturer Name and Model Number.

[0092] The determination circuit 56 determines, based on the analysis results, that "the electronic device is within the predetermined range" or "the electronic device is not within the predetermined range" (S36). An example of the predetermined range is the area to be inspected.

[0093] Based on the frequency analysis results, the determination circuit 56 determines that "an electronic device is present within the predetermined range" if it determines that the received signal contains a signal with a frequency that could be transmitted from an electronic device and that the power of that signal is sufficient. Based on the frequency analysis results, the determination circuit 56 determines that "an electronic device is not present within the predetermined range" if it determines that the received signal contains a signal with a frequency that could be transmitted from an electronic device, but that the power of that signal is insufficient. Based on the frequency analysis results, the determination circuit 56 determines that "an electronic device is not present within the predetermined range" if it determines that the received signal does not contain a signal with a frequency that could be transmitted from an electronic device.

[0094] Based on the time-frequency analysis results, the determination circuit 56 determines that "the electronic device is within the predetermined range" if it determines that at least one of the bandwidth, signal occupancy, or duty cycle of the received signal is equal to at least one of the bandwidth, signal occupancy, or duty cycle of a signal that may be transmitted from the electronic device. Based on the time-frequency analysis results, the determination circuit 56 determines that "the electronic device is not within the predetermined range" if it determines that none of the bandwidth, signal occupancy, or duty cycle of the received signal are equal to any of the bandwidth, signal occupancy, or duty cycle of a signal that may be transmitted from the electronic device.

[0095] Based on the sniffer analysis results, the determination circuit 56 determines that "an electronic device is present within the predetermined range" if it determines that the received signal packet contains information that identifies a non-stationary device. Depending on the installation environment of the inspection system, even if the person being inspected 10 is not in the inspection area, the secondary device 64 continuously detects radio waves transmitted from an access point in a WiFi® communication installed by a third party. Such continuously detected electronic devices are stored as stationary devices. If the person being inspected 10 is in the inspection area, the determination circuit 56 determines that "a non-stationary device is present (an electronic device is present within the predetermined range)" if it detects an electronic device other than a stationary device. Based on the sniffer analysis results, the determination circuit 56 determines that "an electronic device is not present within the predetermined range" if it determines that the received signal packet does not contain information that identifies the type of electronic device.

[0096] The judgment circuit 56 transmits the judgment result to the judgment circuit 50.

[0097] Figure 8 is a flowchart showing an example of the judgment process flow of the judgment circuit 50 of the inspection system according to the first embodiment.

[0098] The determination circuit 50 determines whether the estimation result of the estimation circuit 38 is "the person being inspected 10 is in possession of a hazardous material" (S42).

[0099] If the estimation result of the estimation circuit 38 is "the person being inspected 10 does not possess any hazardous materials" (S42; No), the judgment circuit 50 determines that "the person being inspected 10 does not possess any hazardous materials" and displays the judgment result on the display unit 58 or notifies the alarm unit 60 (S44).

[0100] This allows the operator of the testing system to recognize that a secondary test is not required for the person being tested 10.

[0101] If the estimation result of the estimation circuit 38 is "the person being inspected 10 is possessing a hazardous material" (S42; Yes), the judgment circuit 50 determines whether the judgment result of the judgment circuit 56 is "electronic equipment is present within the specified range" (S46).

[0102] If the determination circuit 56 determines that "electronic equipment is within the specified range" (S46; Yes), it is highly likely that the estimation circuit 38 has mistakenly identified the electronic equipment held by the person being inspected 10 as a hazardous material and estimated that "the person being inspected 10 is in possession of a hazardous material." Therefore, the determination circuit 50 determines that "the person being inspected 10 is not in possession of a hazardous material" and displays the determination result on the display unit 58 or notifies the alarm unit 60 (S44).

[0103] If the determination circuit 56 determines that "the electronic device is not within the specified range" (S46; No), the estimation result of the estimation circuit 38 is highly likely to be correct. Therefore, the determination circuit 50 determines that "the person being inspected 10 is possessing a hazardous material," and displays the determination result on the display unit 58 or notifies the system via the alarm unit 60 (S48).

[0104] Although not shown in Figure 8, if the estimation circuit 38 estimates that the person being inspected 10 possesses multiple hazardous materials, and the determination circuit 56 determines that one or more electronic devices are within a predetermined range, and the number of estimated hazardous materials is greater than the number of electronic devices determined, the determination circuit 50 may determine that "the person being inspected 10 possesses hazardous materials" and display the determination result on the display unit 58 or notify the user via the alarm unit 60.

[0105] Although not shown in Figure 8, in facilities where bringing in electronic devices is prohibited, if the estimation result of the estimation circuit 38 is "the person being inspected 10 does not possess any hazardous materials" and the determination result of the determination circuit 56 is "electronic devices are within the designated range", then it may be determined that "the person is concealing prohibited items", and the determination result may be displayed by the display unit 58 or notified by the alarm unit 60.

[0106] This allows the operator of the testing system to recognize that a secondary test is necessary for the subject 10 and to perform the secondary test. Examples of secondary tests include contact testing by the tester or retesting using a more accurate testing system.

[0107] The order of the judgments in S42 and S44 may be the reverse of that shown in Figure 8.

[0108] According to the first embodiment, the person being inspected 10 does not need to stop during the inspection, and their belongings can be inspected efficiently. Even if the primary device 62 estimates that "the person being inspected 10 is carrying a hazardous material," if the secondary device 64 determines that "an electronic device is within a predetermined range," it is thought that the primary device 62's estimation result was a misidentification of the electronic device that the person being inspected 10 is carrying as a hazardous material. In this case, the judgment circuit 50 determines that "the person being inspected 10 is not carrying a hazardous material." Therefore, a secondary inspection is deemed unnecessary, and a decrease in inspection efficiency is prevented.

[0109] (Second Embodiment) The second embodiment is suitable for inspecting hazardous materials present inside shoes. The second embodiment relates to the deformation of the antenna panel. The electrical configuration of the inspection system is the same as that of the first embodiment shown in Figure 2, and is therefore omitted from the illustration.

[0110] Figure 9 is a diagram illustrating an example of an inspection system according to the second embodiment. The antenna panel 92 is positioned on the floor surface of the passageway 12. The inspection target area, which is the shooting range of the camera 20, is the area above the antenna panel 92.

[0111] The antenna panel 92 includes a plurality of first antennas 94 and a plurality of second antennas 96. The plurality of first antennas 94 correspond to the plurality of first antennas 22 and 26 of the first embodiment. The plurality of first antennas 94 are connected to the primary device 62 shown in Figure 2. The plurality of second antennas 96 correspond to the plurality of second antennas 24 and 28 of the first embodiment. The plurality of second antennas 96 are connected to the secondary device 64 shown in Figure 2. While the second antennas 24 and 28 were arranged in a two-dimensional array in the center of the antenna panel 16, the second antennas 96 are arranged in a one-dimensional array in the X-axis direction along the direction of movement of the person being inspected 10.

[0112] The second embodiment provides the following effects in addition to those of the first embodiment. According to the second embodiment, since the antenna panel 92 is positioned close to the feet of the person being inspected 10, it is possible to accurately detect dangerous objects such as knives hidden inside shoes. Furthermore, misjudgments caused by misidentifying sensors in shoes with built-in sensors as dangerous objects are prevented, thus preventing a decrease in inspection efficiency.

[0113] It is also possible to combine the second embodiment with the first embodiment. That is, antenna panels may be placed on the sides (both sides or one side) and floor of the passageway 12. Furthermore, four antenna panels may be placed on both sides of the passageway 12, the floor, and the ceiling so as to surround the person being inspected 10 from four directions: up, down, left, and right.

[0114] (Third embodiment) The third embodiment relates to the deformation of the antenna panel. The electrical configuration of the inspection system is substantially the same as that of the first embodiment shown in Figure 2, so it is omitted from the illustration.

[0115] The estimation circuit 38 estimates whether the person being inspected 10 is carrying a hazardous material, and also estimates the Y-axis position of an object that can be estimated to be a hazardous material based on the signals received by the first antennas 22 and 26. The estimation circuit 38 transmits the estimation result of whether the person being inspected 10 is carrying a hazardous material and the estimation result of the Y-axis position of the hazardous material to the determination circuit 50.

[0116] Figure 10 is a diagram illustrating an example of antenna panels 16 and 18 of an inspection system according to the third embodiment. Multiple second antennas 24 and 28 are arranged in a one-dimensional array along the Y-axis.

[0117] The determination circuit 56 of the secondary device connected to the antenna panels 16 and 18 determines whether or not the electronic device is within a predetermined range, and also determines the position of the electronic device in the Y-axis direction based on the received signals from the second antennas 24 and 28. The determination circuit 56 determines that the position of the second antenna 24 or 28 with the highest level among the received signal levels of multiple second antennas 24 and 28 is the position of the electronic device. The determination circuit 56 transmits the determination result of whether or not the electronic device is within a predetermined range and the determination result of the position of the electronic device in the Y-axis direction to the determination circuit 50.

[0118] Figure 11 is a diagram illustrating another example of the antenna panels 16, 18 of the inspection system according to the third embodiment. Four second antennas 24, 28 are configured as one array antenna 29. Three array antennas 29 are arranged at different positions in the Y-axis direction.

[0119] The determination circuit 56 of the secondary device connected to the antenna panels 16 and 18 determines whether or not the electronic device is within a predetermined range, and also determines the position of the electronic device in the Y-axis direction based on the received signal from the array antenna 29. The determination circuit 56 estimates the direction of arrival based on the received signals from the three array antennas 29 and determines the position of the electronic device in the Y-axis direction. The determination circuit 56 transmits the determination result of whether or not the electronic device is within a predetermined range and the determination result of the position of the electronic device in the Y-axis direction to the determination circuit 50.

[0120] Figure 12 is a flowchart showing an example of the judgment process flow of the judgment circuit 50 of the inspection system according to the third embodiment.

[0121] In S42, similar to the first embodiment, the determination circuit 50 determines whether the estimation result of the estimation circuit 38 is "the person being inspected 10 is possessing hazardous materials". If the estimation result of the estimation circuit 38 is "the person being inspected 10 is not possessing hazardous materials" (S42; No), similar to the first embodiment, the determination circuit 50 determines that "the person being inspected 10 is not possessing hazardous materials" and displays the determination result on the display unit 58 or notifies the person on the alarm unit 60 (S44).

[0122] If the estimation result of the estimation circuit 38 is "the person being inspected 10 is possessing a hazardous material" (S42; Yes), the determination circuit 50 determines whether the determination result of the determination circuit 56 is "electronic equipment is within a predetermined range" (S46), similar to the first embodiment. If the determination result of the determination circuit 56 is "electronic equipment is within a predetermined range" (S46; Yes), the determination circuit 50 determines that "the person being inspected 10 is not possessing a hazardous material" and displays the determination result on the display unit 58 or notifies the alarm unit 60 (S44).

[0123] If the determination result of the determination circuit 56 is "the electronic device is not within the predetermined range" (S46; No), the determination circuit 50 determines whether the Y-axis position of the hazardous material estimated by the estimation circuit 38 matches the Y-axis position of the electronic device determined by the determination circuit 56 (S60).

[0124] If the Y-axis position of the hazardous material estimated by the estimation circuit 38 does not match the Y-axis position of the electronic device determined by the determination circuit 56 (S60; No), the estimation result of the estimation circuit 38 is likely to be correct. Therefore, similar to the second embodiment, the determination circuit 50 determines that "the person being inspected 10 is possessing a hazardous material," and displays the determination result on the display unit 58 or notifies the user on the alarm unit 60 (S48). As a result, the operator of the inspection system recognizes that a secondary inspection of the person being inspected 10 is necessary and carries out the secondary inspection.

[0125] If the Y-axis position of the hazardous material estimated by the estimation circuit 38 matches the Y-axis position of the electronic device determined by the determination circuit 56 (S60; Yes), it is highly likely that the estimation circuit 38 mistakenly identified the electronic device held by the person being inspected 10 as a hazardous material, resulting in the estimation that "the person being inspected 10 is holding a hazardous material." Therefore, the determination circuit 50 determines that "the person being inspected 10 is not holding a hazardous material," and displays the determination result on the display unit 58 or notifies the person via the alarm unit 60 (S44).

[0126] Although not shown in Figure 12, if the estimation circuit 38 estimates that the person being inspected 10 is carrying hazardous materials at multiple locations, and the determination circuit 56 determines that electronic equipment is present at one or more locations within a predetermined range, and the number of estimated hazardous materials is greater than the number of electronic equipment being determined, the determination circuit 50 may determine that "the person being inspected 10 is carrying hazardous materials" and display the determination result on the display unit 58 or notify the user on the alarm unit 60.

[0127] The third embodiment provides the following effects in addition to those of the first embodiment. According to the third embodiment, only when the locations of the electronic device and the hazardous material coincide, the estimation result of the estimation circuit 38 is changed from "the person being inspected 10 is possessing the hazardous material" to "the person being inspected 10 is not possessing the hazardous material" to determine the result. Therefore, the possibility of misidentifying the electronic device as a hazardous material is reduced, and a decrease in inspection efficiency is prevented.

[0128] (Fourth Embodiment) The secondary device 64 in the first to third embodiments is a passive device that receives a second radio wave transmitted from an electronic device. The first to third embodiments assume that the electronic device transmits a specific signal even when it is not connected to the internet or when it is not making a call.

[0129] However, in some cases, electronic devices may not transmit specific signals when they are not connected to the internet or are not making a call. The inspection system of the fourth embodiment includes, in addition to the functions of the inspection systems of the first to third embodiments, a function to cause electronic devices to transmit radio waves.

[0130] Figure 13 is a block diagram illustrating an example of the inspection system of the fourth embodiment. The secondary device 64 of the fourth embodiment includes an antenna 102 and a transmitting circuit 104. The transmitting circuit 104 operates in response to a control signal from the controller 40. The transmitting circuit 104 transmits a transmission request signal to electronic equipment present in the area under inspection via the antenna 102. The other configurations of the inspection system of the fourth embodiment are the same as those of the inspection system of the first embodiment shown in Figure 2.

[0131] An example of a transmission request signal is described below. Figure 14 shows an example of the communication initiation procedure between an access point (AP) and an STA in WiFi communication.

[0132] The access point transmits a beacon signal. The STA, upon receiving the beacon signal, transmits a probe request signal. The access point, upon receiving the probe request signal, transmits a probe response signal. The STA, upon receiving the probe response signal, transmits an authentication request signal. The access point, upon receiving the authentication request signal, transmits an authentication response signal to the STA. The STA, upon receiving the authentication response signal, transmits an association request signal. The access point, upon receiving the association request signal, transmits an association response signal to the STA. After this, data communication begins between the access point and the STA.

[0133] Secondary device 64 functions as a WiFi communication access point, and electronic devices function as STAs. An example of an electronic device is a smartphone. Secondary device 64 (AP) periodically transmits a beacon signal to the area under test. If a smartphone (STA) present in the area under test has its WiFi function turned on, it receives the beacon signal and transmits a probe request signal.

[0134] Since the secondary device 64 does not need to communicate with the smartphone, it does not send a probe response signal even if it receives a probe request signal. Therefore, the authentication request / authentication response and association request / association response in the WiFi communication initiation procedure shown in Figure 14 are not communicated between the secondary device 64 and the smartphone, and no data communication takes place.

[0135] Thus, even when not connected to the internet or not in use, if the WiFi function is turned on, the electronic device will send a probe request signal to the secondary device 64 upon receiving a beacon signal transmitted from the secondary device 64. Therefore, the secondary device 64 can receive the probe request signal transmitted from the electronic device, which is not connected to the internet or not in use, as a second radio wave.

[0136] Figure 15 shows an example of the procedure for initiating communication between a central and a peripheral in BLE communication.

[0137] The central device sends an advertisement signal. Figure 16 shows an example of the modes included in the advertisement signal. The mode is a 2-bit data that indicates whether the peripheral is allowed to send scan requests (scannable) or not (non-scannable). Modes 00b and 01b indicate that the sending of scan requests is not allowed. Mode 10b indicates that the sending of scan requests is allowed. Mode 11b is reserved for future use.

[0138] Upon receiving an advertisement signal, a peripheral, if in mode 10b, sends a scan request signal. Upon receiving the scan request signal, the central sends a scan response signal. Upon receiving the scan response signal, the peripheral sends a connection request signal. Upon receiving the connection request signal, the central sends a connection response signal to the peripheral. Upon receiving the connection response signal, the peripheral sends a key request signal. Upon receiving the key request signal, the central sends a key signal to the peripheral. After this, pairing is performed between the central and the peripheral, and data communication begins.

[0139] Secondary device 64 functions as the central for BLE communication, and the smartphone functions as a peripheral. Secondary device 64 (central) periodically transmits an advertisement signal to the area under test. The mode of the advertisement signal is set to 10b. If a smartphone (peripheral) present in the area under test has its BLE function turned on, upon receiving the advertisement signal, it transmits a scan request signal because the mode is 10b.

[0140] Since the secondary device 64 does not need to communicate with the smartphone, it does not send a scan response signal even if it receives a scan request signal. Therefore, the connection request / connection response and key request / key in the BLE communication initiation procedure shown in Figure 15 are not communicated between the secondary device 64 and the smartphone, and pairing and data communication do not occur.

[0141] Thus, even when not connected to the internet or not in a call, if the BLE function is turned on, the electronic device will send a scan request signal to the secondary device 64 when it receives an advertisement signal transmitted from the secondary device 64. For this reason, the secondary device 64 can receive the scan request signal transmitted from the electronic device, which is not connected to the internet or not in a call, as a second radio wave.

[0142] The fourth embodiment provides the following effects in addition to those of the first embodiment. According to the fourth embodiment, even if an electronic device is not connected to the internet or is not making a call, the electronic device transmits the second radio wave, so it is always possible to determine whether or not the electronic device is within a predetermined range.

[0143] Although a fourth embodiment derived from the first embodiment has been described, the fourth embodiment may also be realized by modifying the second or third embodiment.

[0144] (Fifth embodiment) Figure 17 is a block diagram showing an example of the electrical configuration of the inspection system according to the fifth embodiment. The inspection system of the fifth embodiment includes a database 112 and an automatic learning circuit 114. Other components of the inspection system of the fifth embodiment are the same as those of the inspection system of the fourth embodiment shown in Figure 13.

[0145] The database 112 stores a large number of datasets of processing results from the signal processing circuit 36, estimation results from the estimation circuit 38, and judgment results from the judgment circuit 56. For example, it stores a large number of sets of image signals indicating the reflection identification of each point of the person being inspected 10, estimation results of whether the person being inspected 10 is possessing or not possessing a dangerous object, and judgment results of whether electronic equipment is present or absent within a predetermined range.

[0146] The judgment circuit 50 determines that "the person being inspected 10 does not possess hazardous materials" if the estimation result of the estimation circuit 38 is "the person being inspected 10 possesses hazardous materials" and the judgment result of the judgment circuit 56 is "electronic devices are within a predetermined range." In other words, if the judgment result of the judgment circuit 56 is "electronic devices are within a predetermined range," the judgment circuit 50 determines that the estimation result of the estimation circuit 38, "the person being inspected 10 possesses hazardous materials," is incorrect and effectively changes the estimation result of "the person being inspected 10 possesses hazardous materials" to the judgment result of "the person being inspected 10 does not possess hazardous materials." Thus, the estimation circuit 38 is capable of making incorrect estimations.

[0147] In order to reduce the erroneous estimation of the estimation circuit 38, the automatic learning circuit 114 trains the estimation circuit 38 to change the estimation result from "the person being inspected 10 has a hazardous material" to "the person being inspected 10 does not have a hazardous material" when the judgment result of the judgment circuit 56 is "the electronic device is within a predetermined range".

[0148] If the estimation circuit 38 is composed of a convolutional neural network, the automatic learning circuit 114 includes changing the coupling coefficients between the input layer and the pooling layer of the convolutional neural network, the coupling coefficients between the pooling layer and the fully connected layer, and the coupling coefficients between the fully connected layer and the output layer. When the coupling coefficients are changed, the estimation result for the same image signal changes. The automatic learning circuit 114 changes the coupling coefficients of the convolutional neural network of the estimation circuit 38 so that when the judgment circuit 56 determines that "electronic equipment is within a predetermined range", the estimation result for the image signal input to the estimation circuit 38 becomes "the person being inspected 10 is not carrying any dangerous materials".

[0149] As a result, the estimation circuit 38 estimates that "the person being inspected 10 does not possess any hazardous materials" when "electronic devices are within a predetermined range," thereby improving the estimation accuracy.

[0150] Although a fifth embodiment has been described as a modification of the fourth embodiment, the fifth embodiment may also be realized by modifying the first to third embodiments.

[0151] (modified version) The embodiments described a physical array antenna as the antenna. A virtual array antenna may be used instead of a physical array antenna. An example of a virtual array antenna is a MIMO (Multi Input Multi Output) array antenna.

[0152] The primary device 62 is not limited to radar that uses radio waves. If the hazardous material is a metallic object, a metal detector may be used as the primary device 62. An example of a metal detector is one that detects changes in the magnetic field by displacing a probe and detects metal based on the changes in the magnetic field.

[0153] It should be noted that the present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Moreover, components from different embodiments may be appropriately combined. [Explanation of Symbols]

[0154] 22...Second antenna, 24...Second antenna, 32...Transmitting circuit, 34...Receiving circuit, 36...Signal processing circuit, 38...Estimation circuit, 40...Controller, 52...Receiving circuit, 54...Analysis circuit, 56...Decision circuit

Claims

1. A first circuit unit that estimates whether or not the object to be inspected possesses a predetermined object based on the received signal of a radar antenna, An antenna unit capable of receiving a first radio wave emitted by electronic equipment located within a predetermined range, A second circuit unit determines whether the electronic device is located within the predetermined range based on the received signal from the antenna unit, A third circuit unit determines whether the object to be inspected possesses the predetermined object based on the estimation result of the first circuit unit and the determination result of the second circuit unit, Equipped with, The radar antenna and the antenna unit are arranged on the same panel. An inspection system in which the specified object does not include the electronic equipment.

2. The inspection system according to claim 1, wherein the first circuit unit estimates that the object to be inspected possesses the predetermined object, and the second circuit unit determines that the electronic device is within the predetermined range, and the third circuit unit determines that the object to be inspected does not possess the predetermined object.

3. The first circuit unit is capable of estimating the position of the predetermined object, The second circuit unit is capable of determining the position of the electronic device, The inspection system according to claim 1, wherein the first circuit unit estimates that the object to be inspected possesses the predetermined object, the second circuit unit determines that the electronic device is located within the predetermined range, and if the location of the predetermined object estimated by the first circuit unit matches the location of the electronic device determined by the second circuit unit, the third circuit unit determines that the object to be inspected does not possess the predetermined object.

4. The inspection system according to claim 1, wherein the first circuit unit estimates that the object to be inspected possesses the predetermined object, and the second circuit unit determines that the electronic device is not within the predetermined range, and the third circuit unit determines that the object to be inspected possesses the predetermined object.

5. The first circuit unit is capable of estimating the position of the predetermined object, The second circuit unit is capable of determining the position of the electronic device, The inspection system according to claim 1, wherein the first circuit unit estimates that the object to be inspected possesses the predetermined object, the second circuit unit determines that the electronic device is located within the predetermined range, and if the location of the predetermined object estimated by the first circuit unit does not match the location of the electronic device determined by the second circuit unit, the third circuit unit determines that the object to be inspected possesses the predetermined object.

6. The inspection system according to any one of claims 1 to 5, wherein the second circuit unit analyzes the received signal from the antenna unit by spectrum analysis or sniffer analysis, and determines whether or not the electronic device is within the predetermined range based on the analysis results.

7. The inspection system according to any one of claims 1 to 5, wherein the first radio wave includes a radio wave that transmits data, voice signals, channel sounding, beacons, or device discovery.

8. The electronic device further comprises a fourth circuit unit that transmits a request signal for transmitting the first radio wave, The inspection system according to any one of claims 1 to 5, wherein the request signal includes a beacon signal that causes a probe request signal to be transmitted, or an advertised signal that causes a scan request signal to be transmitted.

9. The radar antenna transmits a second radio wave to the object to be inspected and receives the second radio wave reflected by the object to be inspected. A storage unit that stores multiple datasets, each containing the received signal of the second radio wave, the estimation result of the first circuit unit, and the determination result of the second circuit unit, A fifth circuit unit modifies the estimation result output by the first circuit unit based on the plurality of datasets stored in the memory unit, The inspection system according to any one of claims 1 to 5, further comprising:

10. The inspection system according to any one of claims 1 to 5, wherein the antenna section comprises a plurality of antennas arranged in a two-dimensional array, a plurality of antennas arranged in a one-dimensional array, or a plurality of array antennas arranged in a one-dimensional array, and each of the plurality of array antennas includes a plurality of antennas.

11. The inspection system according to any one of claims 1 to 5, wherein the predetermined object is a metal object or a powder object.

12. The inspection system according to any one of claims 1 to 5, wherein the electronic device is a personal computer, a smartphone, a mobile phone, a portable game console, a wristwatch with a built-in sensor, clothing with a built-in sensor, or shoes with a built-in sensor.

13. The inspection system according to any one of claims 1 to 5, wherein the antenna section includes a plurality of antennas, and the plurality of antennas are positioned differently from each other in the vertical direction.

14. The inspection system according to claim 13, wherein the second circuit unit determines the vertical position of the electronic device based on the level of the received signals from the plurality of antennas.

15. The inspection system according to any one of claims 1 to 5, wherein the first circuit unit irradiates a first radio wave into the predetermined range using the radar antenna, receives a reflected wave of the first radio wave reflected by the object to be inspected located within the predetermined range, and estimates whether or not the object to be inspected possesses a predetermined object based on the intensity of the reflected wave.

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