JP7522561B2 - Mobile - Google Patents

Description

The present invention relates to a moving object equipped with an imaging system.

Inspection technology that uses terahertz waves is known. Terahertz waves can be defined as electromagnetic waves with a frequency of 30 GHz or more and 30 THz or less. Patent Document 1 discloses a method for inspecting for prohibited substances such as narcotics enclosed in an envelope. In this method, the substance inside the envelope is identified without opening it by utilizing the characteristic absorption spectrum of prohibited substances such as narcotics in the terahertz band.

JP 2004-286716 A

Recently, the bringing of dangerous objects such as knives into moving vehicles has become a major crime prevention problem, and there is a strong demand for technology to detect such dangerous objects inside moving vehicles, but this technology has not yet been realized.

The present invention aims to provide technology that is advantageous for crime prevention inside a moving body.

One aspect of the present invention relates to a moving body characterized by having an imaging system for acquiring an image formed by terahertz waves, the imaging system including a plurality of illumination sources for irradiating terahertz waves onto an inspection object that uses a passage included in a common area of the moving body, and a plurality of cameras for imaging the inspection object irradiated with the terahertz waves from the plurality of illumination sources, the image being an image of the inspection object , and the number of the plurality of illumination sources being greater than the number of the plurality of cameras .

The present invention provides technology that is advantageous for crime prevention inside a moving body.

FIG. 1 illustrates a vehicle according to an embodiment. FIG. 2 is a diagram showing a schematic diagram of a state in which a vehicle of the first configuration example is stopped in front of a station platform. FIG. 13 is a diagram showing a schematic diagram of a state in which a vehicle of the second configuration example is stopped in front of a station platform. FIG. 13 is a diagram showing a more specific example of the second configuration example. FIG. 2 is a schematic diagram showing an example of an arrangement of a plurality of illumination sources and a plurality of cameras. FIG. 13 is a diagram illustrating a vehicle according to a third configuration example. FIG. 13 is a diagram illustrating a vehicle according to a fourth configuration example. FIG. 13 is a diagram illustrating a vehicle according to a fifth configuration example. FIG. 13 is a diagram illustrating a vehicle according to a sixth configuration example. FIG. 13 is a diagram showing a schematic diagram of a vehicle according to a seventh configuration example. FIG. 13 is a diagram showing a schematic diagram of a vehicle according to an eighth configuration example. FIG. 13 is a diagram showing a schematic diagram of a vehicle according to an eighth configuration example. 1 is a diagram illustrating an example of a vehicle configuration and a station monitoring system configuration; FIG. 1 is a diagram showing an example of the configuration of a ticket gate in which an imaging system included in a camera system according to an embodiment is disposed. FIG. 15 is a diagram showing a modified example of the ticket gate of FIG. 14 . 3A and 3B are diagrams showing an example of the configuration of a partition wall in which an imaging system included in the camera system according to the embodiment is disposed; FIG. 17 is a diagram showing a modified example of the partition wall in FIG. 16 . FIG. 1 is a diagram showing an example of the configuration of an escalator on which an imaging system included in a camera system according to an embodiment is disposed. FIG. 2 is a diagram showing an example of the configuration of a staircase in which an imaging system included in a camera system according to an embodiment is arranged. FIG. 2 is a diagram showing an example of the configuration of a passage in which an imaging system included in a camera system according to an embodiment is arranged. 1 is a diagram showing an example of the configuration of a station where an imaging system included in a camera system according to an embodiment is installed. 1 shows an example of a configuration when a camera system and a railway vehicle according to an embodiment monitor an inspection target. FIG. 1 is a conceptual diagram of a processing system according to a first embodiment. 4 is a flowchart of a process according to the first embodiment. FIG. 11 is a conceptual diagram of a processing system according to a second embodiment. 10 is a flowchart of a process according to a second embodiment. FIG. 13 is a conceptual diagram of a processing system according to a third embodiment. 13 is a flowchart of a process according to a third embodiment. FIG. 13 is a conceptual diagram of a processing system according to a fourth embodiment. FIG. 13 is a conceptual diagram of a processing system according to a fifth embodiment. An example of a processing system layout. An example of a processing system layout. 1 is a diagram showing an example of the operation of a camera system according to an embodiment; 1 is a diagram showing an example of the operation of a camera system according to an embodiment; 1 is a diagram showing an example of the operation of a camera system according to an embodiment; 1 is a diagram showing an example of the operation of a camera system according to an embodiment;

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe multiple features, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicate explanations are omitted.

In the specification, an "embodiment" may refer to an embodiment of an invention described in the claims, or it may refer to an embodiment of an invention not described in the claims.

1(a), (b), and (c) show vehicles 100a, 100b, and 100c according to an embodiment. Vehicles 100a, 100b, and 100c may be rail vehicles, but may also be bus vehicles. In one example, a train may be formed by coupling one vehicle 100a, one or more vehicles 100b, and one vehicle 100c. When vehicles 100a, 100b, and 100c are described without distinguishing one from another, they are referred to as vehicle 100.

The vehicle 100 may include, for example, a side door 110, a through door 111, seats 112, facilities 113, a partition door 114, a passenger cabin passage 115, and a deck 116. Although the side door 110, the through door 111, and the partition door 114 are all doors, in this specification, these doors are given unique names according to convention in order to distinguish them from each other. The side door 110 is a door arranged between the inside and the outside of the vehicle 100. The through door 111 is a door arranged at one or both of the two ends of the vehicle 100. The seats 112 may be used as, for example, unreserved seats or reserved seats. The facilities 113 may include, for example, a washstand, a restroom, or a smoking room. The partition door 114 is a door arranged between a passenger cabin (in other words, a passenger cabin passage 115) in which a plurality of seats 112 are arranged, and the deck 116. The cabin aisle 115 is an aisle provided in the cabin so as to pass beside the space in which the multiple seats 112 are arranged. The cabin aisle 115 can be arranged, for example, between a first seat row consisting of multiple first seats and a second seat row consisting of multiple second seats. The deck 116 is an aisle separated by, for example, a partition door 114, a through door 111, and a side door 110. Note that, although a vehicle is used as an example for the description here, the present technology can be applied to moving bodies (automobiles (passenger cars, buses, trucks, etc.), airplanes, helicopters, ships) that transport people or luggage.

Figure 2 shows a schematic diagram of a vehicle 100 of the first configuration example parked in front of a station platform PF. The platform PF may have a platform door FD. The vehicle 100 may be equipped with an imaging system ICS that acquires an image formed by terahertz waves TW. The imaging system ICS may be positioned to capture an image of an inspection object M that uses a common area of the vehicle 100, which is inside the moving body. A common area is a place or space that can be used by any person (person). The inspection object M is usually a person, but may also be a non-human animal or a robot.

An imaging system ICS' may also be placed on the platform PF. The imaging system ICS may include one or more imaging units 3a, 3b, 3c, 3d, and 3e. The imaging system ICS' may include one or more imaging units 3f. When the imaging units 3a, 3b, 3c, 3d, 3e, and 3f are described without distinguishing one from another, they are referred to as imaging unit 3. Since terahertz waves pass through cloth, leather, synthetic fibers, resin, and the like, a processor (not shown) connected to the imaging system ICS can detect dangerous objects such as firearms, knives, and explosives based on images provided by the imaging system ICS.

The imaging unit 3 may be a passive type imaging unit or an active type imaging unit. The passive type imaging unit 3 does not illuminate the inspection object M with the terahertz wave TW, but acquires an image formed on the imaging surface of the imaging unit by the terahertz wave TW emitted from the surrounding environment or the inspection object M as an electrical image, i.e., captures the image. The active type imaging unit 3 may include an illumination source 1 and a camera 2. In the example of FIG. 2, the imaging system ICS includes a plurality of imaging units 3a, 3b, 3c, 3d, and 3e, each of which is composed of a plurality of illumination sources 1a, 1b, 1c, 1d, and 1e and a plurality of cameras 2a, 2b, 2c, 2d, and 2e. The imaging system ICS' also includes an imaging unit 3f, each of which is composed of an illumination source 1f and a camera 2f. When multiple illumination sources 1a, 1b, etc. are described without distinction from one another, they are referred to as illumination source 1, and when multiple cameras 2a, 2b, etc. are described without distinction from one another, they are referred to as cameras 2.

The multiple cameras 2 may be arranged so that their optical axes face in different directions. The illumination source 1 may emit terahertz waves TW, and the inspection object M may be illuminated by the terahertz waves TW. The camera 2 acquires, as an electrical image, i.e., captures, an image formed on the imaging surface by the terahertz waves TW that are mainly specularly reflected from the inspection object M illuminated by the terahertz waves TW. The imaging system ICS may include a visible light camera that captures an image formed by visible light. Similarly, the imaging system ICS' may include a visible light camera that captures an image formed by visible light.

The vehicle 100 may include a common area. The common area may include, for example, an aisle. The aisle may include, for example, a deck 116 and/or a passenger compartment aisle 115. The deck 116 may include a first aisle 116-1 extending in a first direction (horizontal in FIG. 2) and a second aisle 116-2 extending in a second direction (vertical in FIG. 2) different from the first direction and connected to the first aisle 116-1. The first aisle 116-1 and the second aisle 116-2 may intersect as illustrated in FIG. 2. The first aisle 116-1 and the passenger compartment aisle 115 may be parallel to each other. The second aisle 116-2 and the passenger compartment aisle 115 may be perpendicular to each other.

The inspection subject M on the platform PF may enter the vehicle 100 through the opening of the side door 110, proceed along the second passage 116-2, and change its direction of travel to the direction facing the partition door 114 at the connection point CP between the first passage 116-1 and the second passage 116-2. The inspection subject M may then enter the passenger compartment passage 115 through the opening of the partition door 114. Alternatively, the inspection subject M on the platform PF may enter the vehicle 100 through the opening of the side door 110, proceed along the second passage 116-2, and change its course to the direction of the first passage 116-1 (the side of the equipment 113) at the connection point CP. In other words, the inspection subject M may change its direction of travel at the connection point CP between the first passage 116-1 and the second passage 116-2. The connection point CP can be considered as a branching point or corner where the inspection subject M changes its direction of travel. That is, the connection part CP can be a position where the inspection object moving inside the vehicle (mobile object) changes direction, slows down or stops, or rotates. Alternatively, the connection part CP can be a position where the inspection object moving inside the vehicle (mobile object) is rectified. Rectification here refers to reducing the width of the platform PF on which multiple inspection objects are lined up as they enter the interior of the vehicle 100. Typically, the inspection objects are rectified inside the vehicle 100 so that they are lined up in one or two rows.

Therefore, by positioning the imaging system ICS so as to image the inspection object M at the connection part CP, it is possible to image the inspection object M from various directions as the orientation of the inspection object M changes. Furthermore, by positioning multiple cameras 2 of the imaging system ICS so as to image the inspection object M at the connection part CP, it is possible to further image the inspection object M from various directions and angles. This can improve the probability of the processor connected to the imaging system ICS detecting the position, shape, material, etc. of a hazardous object.

The first passage 116-1 and the second passage 116-2 may intersect at a connection point CP, or the end of the first passage 116-1 may end at the connection point CP, or the end of the second passage 116-2 may end at the connection point CP. Alternatively, the end of the first passage 116-1 and the second passage 116-2 may end at the connection point CP. Furthermore, the cabin passage 115 may be understood as the second passage, and the second passage and the first passage 116-1 may be connected at the connection point CP. Another example of the connection point CP is a connection between a planar passage as the first passage and a staircase as the second passage.

In the example shown in FIG. 2, the imaging system ICS includes imaging units 3a, 3b, and 3c that image the inspection target M at the connection part CP. The imaging unit 3c can be arranged in the passenger cabin so as to image the inspection target M through an opening formed by opening the partition door 114. Usually, the inspection target M instinctively stops in front of the partition door 114, so the imaging unit 3c is advantageous for capturing a large number of images. The imaging unit 3d can be arranged so as to image the inspection target M passing through the passenger cabin passage 115. The imaging units 3c and 3d can be arranged on all or part of the seat 112, shelf, floor, and ceiling. In particular, since terahertz waves can pass through resin and the like, the imaging units 3c and 3d can be easily arranged in various places. Here, the degree of freedom in arranging the imaging units 3c and 3d is higher on the floor and ceiling than on the seat 112, which is fixed in position. Therefore, the imaging units 3c and 3d can be arranged by embedding them in the floor and/or ceiling.

Some airports use body scanners that use millimeter waves, but these are extremely large and take a long time to inspect, so it is not realistic to apply them to ground transportation systems that transport large numbers of people. The example shown in Figure 2 makes it possible to provide a small imaging system and surveillance system.

The imaging unit 3e may be arranged in the passenger compartment so as to image the inspection target M through the opening formed by opening the side door 110. Usually, the inspection target M instinctively stops in front of the side door 110, so the imaging unit 3e is advantageous for capturing a large number of images. One or more illumination sources 1g, 1h may be arranged on the platform PF to assist the imaging by the imaging unit 3e. Also, a reflection surface MR may be arranged on the platform PF to assist the imaging by the imaging unit 3e. The reflection surface MR may include a curved surface. The reflection surface MR may be provided on the vehicle 100. The reflection surface MR may be made of a metal surface. A coating such as paint or a poster made of paper may be provided on the metal surface. Alternatively, the reflection surface MR may be made of a surface of a member such as a resin having a surface roughness of, for example, less than the wavelength of the irradiated electromagnetic wave, preferably less than one tenth of the wavelength, typically on the order of 10 to 100 micrometers.

Figure 3 shows a schematic diagram of a state in which the vehicle 100 of the second configuration example is stopped in front of a station platform PF. Matters not mentioned in the second configuration example may follow the first configuration example. The imaging system ICS may include a plurality of illumination sources 1a, 1b, 1c and a plurality of cameras 2a, 2b, 2b, 2d. The number of the plurality of illumination sources 1a, 1b, 1c and the number of the plurality of cameras 2a, 2b, 2c, 2d may be the same as or different from each other. All or a portion of the plurality of cameras 2a, 2b, 2c, 2d may be arranged at the corners of the walls in the vehicle 100. Although not shown in Figure 3, all or a portion of the plurality of illumination sources 1a, 1b, 1c may be arranged at the corners of the walls in the vehicle 100. All or a portion of the plurality of cameras 2a, 2b, 2c, 2d may be arranged vertically overlapping each other. All or some of the multiple illumination sources 1a, 1b, and 1c may be arranged to overlap in the vertical direction. The imaging system ICS may also be configured to include multiple cameras 1a, 1b, and 1c and multiple illumination sources 2a, 2b, 2b, and 2d.

Figure 4 shows a more specific example of the second configuration example. As illustrated in Figure 4, one or more illumination sources 1 may be arranged vertically stacked at a corner of a wall inside the vehicle 100. The corner may be a corner of the wall facing the connection part CP. Also, one or more cameras 2 may be arranged. The one or more cameras 2 may be arranged at the corner, or may be arranged on the ceiling or floor. The illumination source 1 and the camera 2 may be embedded in a structure such as a wall, ceiling, or floor so that the inspection object M is not visible.

FIG. 5(a) shows a schematic example of an arrangement of multiple illumination sources 1a, 1b and multiple cameras 2a, 2b. As shown in FIG. 5(a), the multiple illumination sources 1a, 1b and multiple cameras 2a, 2b can be arranged on the ceiling C. Here, the multiple illumination sources 1a, 1b and multiple cameras 2a, 2b can be arranged embedded in the ceiling C.

FIG. 5B shows another example of the arrangement of the multiple illumination sources 1 and the multiple cameras 2. As shown in FIG. 5B, the multiple illumination sources 1 may be arranged on the ceiling C, and the multiple cameras 2 may be arranged on the floor F. Here, the multiple illumination sources 1 may be arranged embedded in the ceiling C, and the multiple cameras 2 may be arranged embedded in the floor F. Conversely, the multiple illumination sources 1 may be arranged on the floor F, and the multiple cameras 2 may be arranged on the ceiling C. Here, the multiple illumination sources 1 may be arranged embedded in the floor F, and the multiple cameras 2 may be arranged embedded in the ceiling C. FIG. 6 shows a vehicle 100 of a third example of the configuration. Items not mentioned as the third example of the configuration may follow the first or second example of the configuration. In addition, the third example of the configuration may be implemented in combination with at least one of the first and second examples of the configuration. In the third example of the configuration, the imaging system may include multiple illumination sources 1a to 1d arranged on the multiple seats 112 so as to irradiate the terahertz waves TW to the inspection target M using the passenger compartment aisle 115 as a common area. The imaging system may also include a plurality of cameras 2a, 2b arranged around an entrance (partition door 114) of the cabin so as to image the inspection object M irradiated with the terahertz waves. The cabin aisle 115 may be arranged, for example, between a first seat row S1 consisting of a plurality of first seats 112 and a second seat row S2 consisting of a plurality of second seats 112. The plurality of illumination sources 1a to 1d may be arranged on the seats 112 facing the cabin aisle 115.

The vehicle 100 may be equipped with a sensor 30 that detects the inspection object M. The multiple illumination sources 1a-1d may be controlled based on the output of the sensor 30. For example, the multiple illumination sources 1a-1d may be controlled to emit terahertz TW in response to the inspection object M being detected by the sensor 30. The sensor 30 may also be used in combination with a sensor that detects the approach of the inspection object M and opens the partition door 114.

FIG. 7 shows a schematic diagram of a vehicle 100 of a fourth configuration example. Matters not mentioned in the fourth configuration example may follow the first to third configuration examples. The fourth configuration example may also be implemented in combination with at least one of the first to third configuration examples. In the fourth configuration example, the imaging system may include a plurality of illumination sources 1a, 1b... that irradiate the inspection object M using the passenger compartment aisle 115 as a common area with terahertz waves TW, and a plurality of cameras 2a, 2b... that image the inspection object M irradiated with the terahertz waves TW. In the first seat row S1, illumination source 1a... that is a part of the plurality of illumination sources 1a, 1b... and camera 2a... that is a part of the plurality of cameras 2a, 2b... may be arranged alternately. In the second seat row S2, illumination source 1b... that is a part of the plurality of illumination sources 1a, 1b... and camera 2b... that is a part of the plurality of cameras 2a, 2b... may be arranged alternately. This arrangement is advantageous for capturing images of the left and right sides of the subject M passing through the passenger cabin aisle 115 alternately, and for early detection of whether the subject M is carrying a dangerous object.

FIG. 8 shows a schematic diagram of a vehicle 100 according to a fifth configuration example. Matters not mentioned in the fifth configuration example may follow the first to fourth configuration examples. The fifth configuration example may also be implemented in combination with at least one of the first to fourth configuration examples. In the fifth configuration example, the imaging system may include a plurality of illumination sources 1 that irradiate terahertz waves onto an object to be inspected using the passenger compartment aisle as a common area, and a plurality of cameras (not shown) that image the object to be inspected irradiated with the terahertz waves. The plurality of illumination sources 1 may include at least two illumination sources 1 arranged on the backrest of the seat 112, as illustrated in FIG. 8. Such a configuration is advantageous for irradiating the object to be inspected with terahertz waves from various angles or positions.

9 shows a vehicle 100 of the sixth configuration example. The matters not mentioned in the sixth configuration example may follow the first to fourth configuration examples. The sixth configuration example may also be implemented in combination with at least one of the first to fourth configuration examples. In the sixth configuration example, the imaging system may include a plurality of illumination sources 1 that irradiate terahertz waves to an inspection object using the passenger compartment aisle, and a plurality of cameras 2 to image the inspection object irradiated with the terahertz waves. The plurality of illumination sources 1 may include at least two illumination sources 1 arranged on the backrest of the seat 112, as illustrated in FIG. 9. Such a configuration is advantageous for irradiating the inspection object with terahertz waves from various angles or positions. The plurality of cameras 2 may include at least one camera 2 arranged on the seat 112, for example, on the backrest, as illustrated in FIG. 9.

FIG. 10 shows a schematic diagram of a vehicle 100 according to a seventh configuration example. Matters not mentioned in the seventh configuration example may follow the first to sixth configuration examples. The seventh configuration example may also be implemented in combination with at least one of the first to sixth configuration examples. In the seventh configuration example, the imaging system may include a plurality of illumination sources 1 that irradiate the inspection object M using the passenger compartment aisle with terahertz waves TW, and a plurality of cameras 2 that image the inspection object M irradiated with the terahertz waves TW. The plurality of illumination sources 1 may include at least one illumination source 1 arranged on the seat 112, for example, on the backrest thereof. The plurality of cameras 2 may include at least one camera 2 arranged on the ceiling. The camera 2 arranged on the ceiling is visible from the inspection object M in FIG. 10, but may be embedded in the ceiling.

11 and 12 show a schematic diagram of a vehicle 100 according to an eighth configuration example. Matters not mentioned in the eighth configuration example may follow the first to seventh configuration examples. The eighth configuration example may also be implemented in combination with at least one of the first to seventh configuration examples. In the eighth configuration example, the imaging system ICS has a reflection surface MR1 that reflects the terahertz wave TW, and the reflection surface MR1 may include a curved surface. The reflection surface MR1 may be formed, for example, by a metal surface. A coating such as paint or a poster made of paper or the like may be provided on the metal surface. Alternatively, the reflection surface MR1 may be formed, for example, by a surface of a member such as a resin having a surface roughness equal to or less than the wavelength of the irradiated electromagnetic wave, preferably equal to or less than one-tenth of the wavelength, typically on the order of 10 to 100 micrometers. With this configuration, of the terahertz waves TW irradiated from the multiple illumination sources 1 to the inspection object M, light that is scattered by the inspection object M or light that is not irradiated can be reflected by the reflecting surface MR1 and re-irradiated to the inspection object M, and made to enter the camera 2. This configuration therefore improves the detection performance of the imaging system ICS.

Figure 13 illustrates the configuration of the vehicle 100 and the configuration of the in-station monitoring system 120. Note that, although an example in which a monitoring system is provided in a station is described here, the scope of application of the present technology is not limited to this example. For example, other examples of locations where moving objects depart and arrive include airports, ports (ships), etc. The vehicle 100 may be equipped with a processor 10 and a communication unit 15 in addition to the imaging system ICS described above. The processor 10 processes signals output from the imaging system ICS. The processing may include determining a risk level related to the inspection target M. The processing may include identifying the position of the inspection target M having a predetermined risk level. Alternatively, the processing may include identifying the seat of the inspection target M having a predetermined risk level. The processor 10 can be configured, for example, as a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit), or a general-purpose or dedicated computer with an embedded program, or a combination of all or part of these.

The processor 10 may identify the seat of the inspection target M based on the characteristic information of the inspection target M and the corresponding information that corresponds to the seat information assigned to the passenger having the characteristic corresponding to the characteristic information. The characteristic information may be information extracted by the processor 10 from the image captured by the imaging system ICS. The characteristic information may be, for example, a feature amount identified based on the shape, size, etc. of a partial image extracted from the image captured by the imaging system ICS, information that identifies the type of dangerous object, or information that indicates other characteristics. Alternatively, the characteristic information may be information that indicates the above-mentioned degree of danger. Extraction of a partial image from the image captured by the imaging system ICS may include, for example, extracting a part having a brightness that exceeds a predetermined brightness. AI (artificial intelligence) may be used to extract the characteristic information. More specifically, AI (artificial intelligence) that has undergone deep learning may be incorporated into the processor 10, and the characteristic information may be extracted by the AI. For example, the information indicating the degree of danger in the image captured by the camera 2 appears differently depending on the position and orientation of the camera 2. Therefore, deep learning can be performed based on images captured by multiple cameras 2.

The processor 10 may transmit the results of the above processing to a pre-configured terminal 20 via the communication unit 15. The terminal 20 may be carried by, for example, a conductor aboard the vehicle 100. The terminal 20 may also include a terminal carried by a person other than a passenger aboard the vehicle 100, a terminal installed in a security room located at a station or the like, a terminal installed in an administrative institution such as a police station, etc.

The station monitoring system 120 may include an imaging system 21, a control system 22, and a ticket gate 23. The imaging system 21 may include a camera that acquires an image formed by terahertz waves TW. The imaging system 21 may also include a camera that acquires an image formed by electromagnetic waves of a wavelength other than terahertz waves (e.g., visible light). The imaging system 21 may include a camera that is installed so as to be able to capture an image of an inspection object passing through the ticket gate 23 and acquires an image formed by terahertz waves TW. The ticket gate 23 has a ticket gate function, and may also have a function of reading seat information (information identifying a reserved seat) held by a ticket (including an electronic ticket held in a portable medium such as a mobile terminal) held by an inspection object undergoing ticket gate screening, and notifying the control system 22 of the seat information.

The imaging system 21 may use terahertz waves TW to image the inspection target passing through the ticket gate 23, and transmit the captured image to the supervisory system. The supervisory system 22 may determine the degree of risk of the inspection target based on the image received from the imaging system 21. The supervisory system 22 may also extract characteristic information of the inspection target from the image received from the imaging system 21. The characteristic information may be extracted by an extraction method that is the same as or equivalent to the extraction method of characteristic information by the processor 10 described above. The supervisory system 22 may be configured, for example, by a general-purpose or dedicated computer with a built-in program.

The supervisory system 22 generates correspondence information that associates the characteristic information of the inspection target extracted from the image received from the imaging system 21 with the seat information read by the ticket gate 23. For example, the characteristic information may be information that strongly suggests possession of a firearm, and the seat information may be seat information read by the ticket gate 23 from a ticket held by the inspection target who possesses the firearm. This correspondence information may be transmitted from the supervisory system 22 to the vehicle 100. The characteristic information may include information that identifies the ID of the inspection target (i.e., information that identifies an individual). If the imaging system 21 includes a visible light camera, the visible light image of the inspection target, and further, the ID of the inspection target may be identified from the visible light image by AI or the like. The visible light image of the inspection target having a predetermined risk level is transmitted to the vehicle 100 together with the above-mentioned correspondence information, and may further be transmitted to the terminal 20.

Below, we explain technologies that are advantageous for improving security through camera systems installed in facilities.

With reference to Figs. 14(a) to 22, a camera system 200 according to some embodiments of the present invention will be described. The camera system 200 according to this embodiment is installed in a facility. Examples of facilities include railway stations, departure and arrival terminals such as airports, commercial facilities, and entertainment facilities. The camera system 200 according to this embodiment is installed in a structure of a railway station. Station structures include a station building in which ticket gates, ticket counters, and waiting rooms are located, a platform where railway cars enter the station, and a passageway connecting the station building and the platform. Here, a passageway can be a flat passageway or a place where passengers pass through, such as a staircase, an escalator, or an elevator. Furthermore, a railway car is an example of a moving object. When the facility is an airport, for example, the moving object is an airplane. The camera system 200 according to this embodiment can be a camera system arranged to form part of a station monitoring system.

The camera system 200 includes an imaging system 201 that acquires an image formed by terahertz waves reflected by an object of inspection 250. The imaging system 201 may include one or more illumination units 202 for irradiating terahertz waves, and one or more cameras 203 for acquiring an image formed by the terahertz waves. In the following description, when the multiple illumination units 202 and the multiple cameras 203 are to be distinguished from one another, a subscript is added after the reference numeral, such as illumination unit 202 "a" and camera 203 "a". When it is not necessary to distinguish between the respective illumination units and cameras, they will simply be referred to as "illumination unit 202" and "camera 203". The same applies to the other components.

In this embodiment, the camera 203 that detects terahertz waves is a type called an active camera, and can be used in combination with the illumination unit 202. However, this is not limited to this, and the camera may be a passive type camera. In this case, an image can be acquired by the terahertz waves emitted from the inspection object 250 without illuminating the inspection object 250 with the terahertz waves irradiated from the illumination unit 202.

The imaging system 201 can be arranged to capture an image of an inspection subject 250 using the station. The inspection subject 250 is usually a human being, but can also be a non-human animal or a robot. Since terahertz waves can pass through cloth, leather, etc., a processor (not shown, such as the control system 22) connected to the camera system 200 can detect dangerous objects, such as firearms, knives, and explosives, based on images provided by the imaging system 201 of the camera system 200.

14(a) and 14(b) are a top view and a front view showing an example of the configuration of a ticket gate 211 in which an imaging system 201 included in the camera system 200 of the present invention is arranged. The ticket gate 211 is installed at the ticket gate of a station and divides the inside of the ticket gate from the outside of the ticket gate. Here, the inside of the ticket gate may be an area where a ticket such as an admission ticket or a boarding ticket is required for entry. The ticket gate 211 may be a so-called automatic ticket gate. The imaging system 201 is arranged to acquire an image of the inspection target 250 passing through the passage 240 of the ticket gate 211. For example, the imaging system 201 may acquire an image of the inspection target 250 entering the ticket gate from outside the ticket gate. In the following description, it is assumed that the inspection target 250 passes from outside the ticket gate to inside the ticket gate in the direction of the arrow shown in FIG. 14(a).

14(a) and 14(b), the ticket gate 211 includes the ticket gate 211a and the ticket gate 211b, which are arranged facing each other across the passage. In other words, the width and length of the passage 240 of the ticket gate 211 can be determined by the ticket gate 211a and the ticket gate 211b. The imaging system 201 includes an illumination unit 202 arranged in the ticket gate 211a and a camera 203 arranged in the ticket gate 211b. The terahertz waves emitted from the illumination unit 202 can be specularly reflected by the inspection object 250, such as a person. For this reason, by arranging the illumination unit 202 and the camera 203 at the ticket gate 211a and the ticket gate 211b, which are arranged facing each other across the passage 240, respectively, the terahertz waves emitted from the illumination unit 202 are reflected by the inspection object 250 and are easily detected by the camera 203.

14(b), the illumination unit 202 can illuminate almost the entire range 204 of the passage 240. The spread of the terahertz waves irradiated from the illumination unit 202 can be adjusted by means of a lens or the like. In addition, since the terahertz waves are reflected by metals, the inspection target 250 is illuminated even near the bottom of the ticket gate 211a by the reflection of the terahertz waves on the side of the ticket gate 211b. In addition, in order to effectively utilize the reflection of the terahertz waves on the side of the ticket gate 211 on the passage 240 side, the illumination unit 202 and the camera 203 may be arranged near the end of the ticket gate 211 on the opposite side to the direction of the optical axis of the illumination unit 202 and the camera 203, as shown in FIG. 14(a). In other words, the illumination unit 202 and the camera 203 that photograph the outside of the ticket gate from the ticket gate 211 may be arranged near the end of the ticket gate 211 on the inside of the ticket gate.

The arrangement of the illumination unit 202 and the camera 203 is not limited to the above arrangement. For example, the illumination unit 202 and the camera 203 may be arranged in the ticket gate 211a. For example, the illumination unit 202 and the camera 203 may be arranged near the center of the ticket gate 211, or near the outer end of the ticket gate in FIG. 14(a). For one camera 203, the illumination unit 202 may be composed of multiple illumination devices. For example, the illumination unit 202 may be composed of multiple illumination devices each emitting terahertz waves in a different direction. The illumination unit 202 and the camera 203 may be fixed to the ticket gate 211 in an immovable state, or may be arranged, for example, rotatably, according to the movement of the inspection target 250.

When the imaging system 201 of the camera system 200 is used as a surveillance camera, it may be easier to perform post-processing such as image processing in a processor (not shown) downstream of the imaging system 201 of the camera system 200 by photographing the people who are the subjects of inspection 250 one by one. There is a high possibility that the people who are the subjects of inspection 250 pass through the ticket gate 211 one by one. Therefore, by disposing the imaging system 201 at the ticket gate 211, it is possible to reduce the burden of post-processing such as image processing. In other words, the imaging system 201 can be disposed at a location where the subjects of inspection 250 line up. In addition, it takes about one second for the person who is the subject of inspection 250 to pass through the ticket gate 211. However, the imaging system 201 can acquire images formed by terahertz waves at a frame rate of 50 fps or more. Therefore, it is possible to perform multiple photographing of one subject of inspection 250. In addition, in the multiple photographing, the entire body of the subject of inspection 250 may be photographed, or only a part of the subject of inspection 250 may be photographed.

The imaging system 201 of the camera system 200 may also include a sensor 260 that detects the approach of the inspection target 250. For example, the sensor 260 may be disposed in the ticket gate 211 as shown in FIG. 14(b). The sensor 260 may also be attached to the illumination unit 202 or the camera 203, for example. The illumination unit 202 is controlled based on the output of the sensor 260. For example, the illumination unit 202 may start irradiating terahertz waves in response to the sensor 260 detecting the inspection target 250. This makes it possible to reduce the power consumed by the imaging system 201.

Figure 15 (a) shows an example of an imaging system 201 in which two sets of lighting units 202 and cameras 203 are arranged on a ticket gate 211. As shown in Figure 15 (a), an example is shown in which lighting units 202a and 202b are arranged on ticket gate 211a, and cameras 203a and 203b are arranged on ticket gate 211b. In this case, as shown in Figure 15 (a), lighting unit 202b and camera 203a are arranged to illuminate and photograph the inside of the ticket gate from ticket gate 211, and lighting unit 202b and camera 203b are arranged to illuminate and photograph the outside of the ticket gate from ticket gate 211. By arranging in this way, not only the front side of inspection object 250 but also the back side can be photographed. At this time, as described above, in order to efficiently use the terahertz waves irradiated from the illumination units 202a and 202b, the illumination unit 202a and the camera 203a may be arranged closer to the ticket gate than the illumination unit 202b and the camera 203b. However, the arrangement of the illumination units 202a and 202b and the cameras 203a and 203b is not limited to this, and they can be arranged freely as described above.

As described above, the side of the ticket gate 211 facing the passage 240 may form a reflective surface that reflects terahertz waves. That is, the surface of the ticket gate 211 facing the passage 240 may be made of metal, or may have a rough surface with irregularities of about 1/10 the wavelength of the terahertz waves. For example, as shown in FIG. 15(b), the ticket gate 211 may have a gate-shaped structure including the upper structure 212 so that the terahertz waves are more reflected. In this case, the surface of the upper structure 212 facing the passage 240 may be made of metal, or may have a rough surface with irregularities of about 1/10 the wavelength of the terahertz waves. The terahertz waves are reflected and scattered on the surface of the ticket gate 211, so that the inspection object 250 is illuminated from various angles, and the image quality obtained by the camera 203 may be improved.

In addition, in Figs. 14(a) to 15(b), the illumination unit 202 and the camera 203 are drawn large as separate bodies on top of the ticket gate 211 for the sake of simplicity, but this is not limited to the above. Terahertz waves can pass through materials such as resin. For this reason, a resin window may be provided in part of the ticket gate 211, and the illumination unit 202 and the camera 203 may be disposed inside the ticket gate 211. As the resin, for example, a suitable material such as high density polyethylene or cyclic olefin copolymer may be used. In the following explanation, the illumination unit 202 and the camera 203 are also drawn large in the figures.

Next, an example of applying the imaging system 201 to a partition wall 213 of a station platform 216 will be described with reference to Figs. 16(a) and 16(b). Figs. 16(a) and 16(b) are a top view and a front view showing an example of the configuration of a partition wall 213 in which the imaging system 201 included in the camera system 200 of the present invention is arranged. The imaging system 201 is arranged adjacent to the partition wall 213 that separates the platform 216 from the track side area 217 and includes an openable and closable door section 214. The partition wall 213 is a so-called platform door installed on the platform 216. In this embodiment, the imaging system 201 acquires an image of the inspection object 250 passing through the passage 241 when the door section 214 of the partition wall 213 is open.

The imaging system 201 includes an illumination unit 202a and a camera 203a arranged in the track side area 217. The illumination unit 202a and the camera 203a illuminate and photograph the passage 241 when the door unit 214 is opened from the track side area 217. The imaging system 201 also includes an illumination unit 202b and a camera 203b arranged in the platform 216. The illumination unit 202b and the camera 203b illuminate and photograph the passage 241 when the door unit 214 is opened from the platform 216. By arranging the illumination unit 202a and the camera 203a and the illumination unit 202b and the camera 203b, it is possible to obtain images of the front and back sides of the inspection object 250 getting on from the door 219 of the railcar 218 and the inspection object 250 getting off from the door 219 of the railcar 218. However, this is not limited to this, and the configuration may be such that only one of the lighting unit 202a and camera 203a, and the lighting unit 202b and camera 203b are provided.

As shown in Figs. 16(a) and 16(b), the illumination units 202a and 203b may each include a plurality of illumination devices. As shown in Figs. 16(a) and 16(b), the illumination units 202a and 202b may be arranged at the end of the door pocket 215 in which the door 214 is accommodated when the door 214 is opened, in the direction in which the door 214 opens and closes. Also, as shown in Fig. 16(a), when the door 214 is opened, a part of the door 214 may not be accommodated in the door pocket 215. In this case, the side of the part of the door 214 that is not accommodated may constitute a reflective surface that reflects terahertz waves, similar to the side of the passage 240 side of the ticket gate 211 described above. This may allow for more efficient use of the terahertz waves irradiated from the illumination units 202a and 202b. Also, the body of the railroad car 218 may be used as a reflective surface that reflects terahertz waves. When door portion 214 of partition wall 213 is opened to form passage 241, railroad car 218 may be entering the station. In addition, the body of railroad car 218 may be made of metal. Therefore, the body of railroad car 218 can be used as a reflective surface that reflects terahertz waves.

Also, the cameras 203a and 203b may be attached to a structure such as a pole 220 as shown in FIG. 16(b). Also, as shown in FIG. 16(b), a plurality of imaging devices may be used as the camera 203a or the camera 203b. For example, the cameras 203a and 203b may be arranged at the height of the waist of the inspection object 250 or at a position higher than the inspection object 250 as shown in FIG. 16(b). By arranging the cameras 203a and 203b at a high position, even if the front-to-back distance of the inspection object 250 becomes narrow, it is more likely that images can be acquired one by one than if the cameras 203a and 203b were arranged at a low position. Also, by arranging the cameras 203a and 203b at an angle to the passage 241, it is more likely that images of the front and back of the inspection object 250 can be acquired.

The arrangement of the lighting units 202a, 202b and the cameras 203a, 203b is not limited to the configuration shown in Figs. 16(a) and 16(b). For example, as shown in Figs. 17(a) to 17(c), the lighting units 202a, 202b may be attached to a structure such as a pole 220. In this case, as shown in Figs. 17(a) and 17(b), the lighting unit 202 and the camera 203 may be attached to separate poles 220a, 220b. Also, for example, as shown in Fig. 17(c), the lighting unit 202 and the camera 203 may be attached to the same pole 220.

As described above, when the imaging system 201 is used as a surveillance camera, the burden of post-processing such as image processing can be reduced if the people who are the subjects of inspection 250 can be photographed one by one. Therefore, the imaging system 201 included in the camera system 200 may be applied to a partition wall 213 installed at a station where a bullet train or limited express train stops, where people line up one by one to board. In this case, the width of the door 219 of the railcar 218 used for the bullet train or limited express train is about 700 mm to 1000 mm. Therefore, in the configuration shown in Figures 16 (a) and 17 (a), the maximum distance between the illumination unit 202 and the camera 203 can be narrowed to, for example, 1100 mm or more and 2000 mm or less. This makes it possible to efficiently use the terahertz waves irradiated from the illumination unit 202. In addition, bullet trains and limited express trains often have a fixed train configuration. Therefore, the size of the door portion 214 can be changed according to the size of the door 219 of the railcar 218. For this reason, for example, the distance between the lighting unit 202 adjacent to the door unit 214 corresponding to a narrow door 219 (e.g., 700 mm) and the camera 203 may be, for example, 700 mm or more and 1000 mm or less. In this case, the maximum distance between the lighting unit 202 and the camera 203 may be, for example, 850 mm or more.

The imaging system 201 may also be applied to the partition wall 213 of a railway station, such as a commuter train. In this case, it may be possible to acquire images one by one, except when the train is crowded. Even when multiple inspection targets 250 board or disembark at the same time, the inspection targets 250 often board in two or three rows. Each inspection target 250 can be identified by image processing using a processor or the like provided in the camera system 200. In addition, in a commuter train, the width of the door is about 1300 mm to 2000 mm. For this reason, in the configurations shown in FIGS. 16(a) and 17(a), the maximum distance between the illumination unit 202 and the camera 203 may be, for example, 1500 mm or more and 3000 mm or less. The output of the terahertz waves irradiated from the illumination unit 202 may be changed depending on the distance between the illumination unit 202 and the camera 203. In this case, the illumination unit 202 with a longer distance between the illumination unit 202 and the camera 203 may irradiate terahertz waves with a higher output than an illumination unit with a shorter distance.

In addition, the platform 216 may be located outdoors. For this reason, the imaging system 201 located on the platform 216 or the trackside area 217 is easily affected by the external environment. Terahertz waves are easily absorbed by water, and there is a possibility that sufficient images cannot be obtained in a high humidity environment such as rainfall. Therefore, the imaging system 201 may be equipped with a sensor 261 that detects the external environment, as shown in FIG. 16(b). The illumination unit 202 is controlled based on the output of the sensor 261. For example, when the sensor 260 detects humidity information and the humidity is high, the illumination unit 202 may increase the output for irradiating the terahertz waves. This may improve the image quality of the image acquired by the camera 203.

Also, for example, the lighting unit 202 and the camera 203 may be attached to the body of the railway vehicle 218. In other words, the camera system 200 may include a lighting unit and a camera mounted on the railway vehicle 218. In this case, the camera system 200 may include a communication unit between the imaging system 201 arranged at the station and the imaging system including the lighting unit and the camera included in the railway vehicle 218.

Also, for example, the lighting unit 202 and the camera 203 may start operating when the door unit 214 of the partition wall 213 opens. For example, the imaging system 201 may be linked to the operation of the door unit 214, or may include a sensor that detects that the door unit 214 is open. This makes it possible to reduce power consumption in the imaging system 201.

Next, an example of applying the imaging system 201 to an escalator 221 will be described with reference to Figures 18(a) and 18(b). Figures 18(a) and 18(b) are a side view and a top view showing an example of the configuration of an escalator 221 on which the imaging system 201 included in the camera system 200 of the present invention is arranged.

The imaging system 201 is disposed adjacent to the escalator 221 in order to capture an image of the inspection target 250 passing through the escalator 221. In the configuration shown in FIG. 18(a), the imaging system 201 includes an illumination unit 202 and a camera 203. The illumination unit 202 may include multiple illumination devices, and the camera 203 may include multiple imaging devices. The illumination unit 202 and the camera 203 may be disposed on separate structures such as poles 220 as shown in FIG. 18(a), or may be disposed on the same structure such as poles 220. For example, the illumination unit 202 and the camera 203 may be disposed so as to illuminate and capture images in the direction opposite to the traveling direction of the escalator 221 as shown in FIG. 18(a). This allows an image of the front side of the inspection target 250 to be captured.

Also, for example, as shown in FIG. 18(b), the lighting unit 202 and the camera 203 may be arranged on either side of the escalator 221 in a direction intersecting the traveling direction of the escalator 221. The same effect as the lighting unit 202 arranged in the ticket gate 211a and the camera 203 arranged in the ticket gate 211b described above can be obtained. In this case, the lighting unit 202a and the camera 203a may be arranged to illuminate and capture images in the direction opposite to the traveling direction of the escalator 221, and the lighting unit 202b and the camera 203b may be arranged to illuminate and capture images in the traveling direction of the escalator 221. This allows not only the front side of the inspection object 250 but also the back side to be captured.

As described above, when the imaging system 201 is used as a surveillance camera, it may be more convenient to capture the people who are the subjects of inspection 250 one by one. Since the escalator 221 operates at a constant speed, it is highly likely that images of the subjects of inspection 250 can be captured one by one. As shown in FIG. 18(a), the escalator 221 has steps, and by placing the camera 203 at a high position, it is more likely that images can be captured one by one. In addition, on the escalator 221, the subjects of inspection 250 are usually aligned in one or two rows. For example, in the case of an escalator 221 aligned in two rows, images of the subjects of inspection 250 may be captured using two cameras 203. This increases the possibility of capturing images one by one. As a result, the burden of image processing at a stage downstream of the imaging system 201 of the camera system 200 can be reduced.

As described above, terahertz waves can pass through resin and the like. For this reason, the lighting unit 202 and the camera 203 may be embedded in the floor, wall, or ceiling of the area where the escalator 221 is located. For example, the lighting unit 202 may be installed together with normal lighting on the deck board of the escalator 221.

Next, an example of applying the imaging system 201 to a staircase 222 will be described with reference to Figures 19(a) and 19(b). Figures 19(a) and 19(b) are a top view and a cross-sectional view showing an example of the configuration of a staircase 222 in which the imaging system 201 included in the camera system 200 of the present invention is arranged.

The imaging system 201 is disposed on the stairs 222 to capture an image of the inspection object 250 passing through the stairs 222. In the configuration shown in Figs. 19(a) and 19(b), the imaging system 201 includes an illumination unit 202 and a camera 203. The illumination unit 202 and the camera 203 are embedded in the stairs 222 and disposed so as to illuminate and photograph the inspection object 250 through a window 224 in a riser 223 of the stairs 222. As shown in Figs. 19(a) and 19(b), the illumination unit 202 and the camera 203 can be disposed in the same riser 223 of the stairs 222.

The stairs 222 allow the subject 250 to ascend and descend one step (or two steps) at a time, making it possible to acquire images of the subject 250 from head (or foot) to foot (or head) in sequence.

As described above, various resins that transmit terahertz waves can be used for the window 224 provided in the riser 223 of the staircase 222. By selecting an appropriate resin material depending on the material used for the riser 223 and tread 225 of the staircase 222 where the imaging system 201 is not arranged, it is possible to make the imaging system 201 less noticeable (to hide its presence).

Next, an example of applying the imaging system 201 to a passage 242 will be described with reference to Figures 20(a) and 20(b). Figures 20(a) and 20(b) are side views showing an example of the configuration of a passage 242 in which the imaging system 201 included in the camera system 200 of the present invention is arranged.

The imaging system 201 is disposed in the passage 242 to acquire an image of the inspection object 250 passing through the passage 242. The imaging system 201 includes an illumination unit 202 and a camera 203. At this time, one of the illumination unit 202 and the camera 203 is disposed on the ceiling 227 of the passage 242, and the other of the illumination unit 202 and the camera 203 is embedded in the floor 226 of the passage 242. In the configuration shown in Figs. 20(a) and 20(b), the camera 203 is disposed on the ceiling 227 of the passage 242, and the illumination unit 202 is embedded in the floor 226 of the passage 242, but this is not limited thereto. The illumination unit 202 may be disposed on the ceiling 227 of the passage 242, and the camera 203 may be embedded in the floor 226 of the passage 242.

20(a) and 20(b), the illumination unit 202a and the camera 203a are arranged to illuminate and capture images from one side of the passage 242 to the other side. The illumination unit 202b and the camera 203b are arranged to illuminate and capture images from the other side of the passage 242 to one side. This makes it possible to obtain images of the front and back of the inspection object 250 moving in both of the two passage directions of the passage 242. However, this is not limited to the above, and the passage 242 may have a configuration in which only the illumination unit 202a and the camera 203a are arranged.

Figure 20(b) shows an example in which cameras 203a and 203b are embedded in the ceiling 227 of the passage 242. This makes it possible to make cameras 203a and 203b less noticeable (hide their presence) compared to hanging them from the ceiling 227 as shown in Figure 20(a). Also, the optical axes of the illumination unit 202 and camera 203 are set at a steeper angle to the direction of travel of the inspection subject 250 in the configuration shown in Figure 20(b) than in the configuration shown in Figure 20(a). By making the angle of the optical axis steeper, as shown by the dotted lines in Figures 20(a) and 20(b), it may be more likely that images of the inspection subjects 250 can be obtained one by one.

In the configuration shown in Figures 20(a) and 20(b), one of the illumination unit 202 and the camera 203 is disposed on the floor 226, and the other is disposed on the ceiling 227. As described above, the terahertz waves may be specularly reflected by the inspection object 250. For this reason, it may be easier for the camera 203 to detect the terahertz waves irradiated from the illumination unit 202 if the illumination unit 202 and the camera 203 are disposed so as to face each other.

However, the arrangement of the lighting unit 202 and the camera 203 in the passage 242 is not limited to the configuration shown in FIG. 20(a) and 20(b). For example, the lighting unit 202 and the camera 203 may be arranged on the side wall of the passage 242. In addition, both the lighting unit 202 and the camera 203 may be arranged on the floor 226 or the ceiling 227. In this case, the floor 226 or the ceiling 227 on which the lighting unit 202 and the camera 203 are not arranged may function as a reflective surface that reflects terahertz waves. For example, the entire interior of the passage 242, except for the window part that transmits the terahertz waves of the lighting unit 202 and the camera 203, may function as a reflective surface that reflects terahertz waves. In addition, for example, the lighting unit 202 may include a plurality of lighting devices. In this case, the plurality of lighting devices included in the lighting unit 202 may be arranged in an appropriate number in appropriate places such as the floor 226, the ceiling 227, and the side wall.

When the imaging system 201 is disposed on the stairs 222 or the passage 242 as described above, multiple cameras 203 may be disposed in the width direction of the stairs 222 or the passage 242. This increases the possibility of photographing the subjects of inspection 250 one by one. The imaging system 201 may also be disposed in the narrow parts of the stairs 222 or the passage 242. The narrow parts of the stairs 222 or the passage 242 make it easier for the subjects of inspection 250 to line up.

Figure 21 is a diagram showing an example of the configuration of a station 245 in which an imaging system 201 included in a camera system 200 is arranged. As described above, the imaging system 201 can be arranged in a ticket gate 211, a passage 242, an escalator 221, a staircase 222, a partition wall 213, or the like. In addition, the location of the imaging system 201 including the lighting unit 202 and the camera 203 included in the camera system 200 of this embodiment is not limited to the above-mentioned locations. For example, it may be arranged in other locations where it is considered possible to obtain images of the subjects 250 one by one, such as the entrance to a restroom or a washbasin. In addition, the imaging system 201 including the above-mentioned lighting unit 202 and camera 203 that obtain images using terahertz waves may be arranged in a location where a normal visible light surveillance camera or the like is installed.

In addition, the camera system 200 of this embodiment can monitor the inspection target 250 shown in FIG. 21 in conjunction with the railway vehicle 218. FIG. 22 shows an example of the configuration of a monitoring system in which the camera system 200 monitors the inspection target 250 in conjunction with the railway vehicle 218. The camera system 200 may include a supervisory system 310 and a communication unit 315 in addition to the above-mentioned imaging system 201 arranged at the station. The supervisory system 310 processes the signal output from the imaging system 201. The processing may include determining the risk level of the inspection target 250. The processing may include identifying the position of the inspection target 250 having a predetermined risk level. Alternatively, the processing may include identifying the seat of the inspection target 250 who has boarded the railway vehicle 218 from the ticket passed through the ticket gate 211 when the inspection target 250 having a predetermined risk level passed through the ticket gate 211. The control system 310 can be configured, for example, by a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array), a processor such as an ASIC (Application Specific Integrated Circuit), a general-purpose or dedicated computer with an embedded program, or a combination of all or part of these.

The supervisory system 310 may identify the inspection target 250 based on the characteristic information of the inspection target 250 and the correspondence information that corresponds to the seat information assigned to the passenger having the characteristic corresponding to the characteristic information. The characteristic information may be information extracted by the supervisory system 310 from the image obtained by the imaging system 201. The characteristic information may be, for example, a feature amount identified based on the shape, size, etc. of a partial image extracted from the image obtained by the imaging system 201, information that identifies the type of dangerous object, or information that indicates other characteristics. Alternatively, the characteristic information may be information that indicates the above-mentioned degree of danger. Extraction of a partial image from the image obtained by the imaging system 201 may include, for example, extracting a part having a brightness that exceeds a predetermined brightness. AI (artificial intelligence) may be used to extract the characteristic information. More specifically, AI (artificial intelligence) that has undergone deep learning may be incorporated into the supervisory system 310, and the characteristic information may be extracted by the AI. For example, information indicating the degree of danger in an image captured by the camera 203 appears differently depending on the position and orientation of the camera 203. Therefore, deep learning can be performed based on images captured by multiple cameras 203.

The control system 310 may transmit the results of the above processing to a pre-configured terminal 320 via the communication unit 315. The terminal 320 may be carried, for example, by a conductor aboard the railcar 218. The terminal 320 may also include a terminal carried by a person other than a passenger aboard the railcar 218, a terminal installed in a security room located at a station or the like, a terminal installed in an administrative institution such as a police station, etc.

The imaging system 201 may acquire images of the inspection target 250 passing through the ticket gate 211 and transmit the acquired images to the supervisory system 310. The supervisory system 310 may determine the risk level of the inspection target based on the images received from the imaging system 201. The supervisory system 310 may also extract characteristic information of the inspection target from the images received from the imaging system 201.

The supervisory system 310 generates correspondence information that associates the characteristic information of the inspection target 250 extracted from the image received from the imaging system 201 with the seat information read by the ticket gate 211. For example, the characteristic information is information that strongly suggests possession of a firearm, and the seat information may be seat information read by the ticket gate 211 from a ticket held by the inspection target 250 who possesses the firearm. This correspondence information may be transmitted from the supervisory system 310 to the terminal 320 of the railroad car 218. The characteristic information may include information that identifies the ID of the inspection target 250 (i.e., information that identifies an individual). The imaging system 201 may include a visible light camera, and the visible light image of the inspection target 250, and further the ID of the inspection target 250 may be identified from the visible light image by AI or the like. The visible light image of the inspection target having a predetermined risk level is transmitted to the railroad car 218 together with the above-mentioned correspondence information, and may further be transmitted to the terminal 320. Here, a case has been described in which an image of the inspection target 250 is acquired by the imaging system 201 disposed in the ticket gate 211, but tracking of the inspection target 250 may be started and continued based on images acquired from the imaging systems 201 disposed in the partition wall 213, the escalator 221, the stairs 222, and the passageway 242. Also, tracking of the inspection target 250 may be started from an image acquired by the imaging system 201 disposed in the ticket gate 211, and then tracking of the inspection target 250 may be continued using a surveillance camera using visible light.

A processing system that is advantageous for inspection using terahertz waves will be described below. In the following description, terahertz waves may include electromagnetic waves in a frequency range from 30 GHz to 30 THz. The concept of electromagnetic waves may also include radio waves such as visible light, infrared light, and millimeter waves.
(First embodiment)
An outline of a processing system 401 according to the first embodiment will be described with reference to Fig. 23. The processing system 401 includes a first imaging system including a first illumination source 404 and a first camera 402, a second imaging system including a second camera 405, and a processor including a pre-processing unit 406 and a post-processing unit 407.

The first camera 402 of the first imaging system acquires a first image based on terahertz waves 403 of a first wavelength emitted by a first illumination source 404. The terahertz waves 403 emitted from the first illumination source 404 irradiate the inspection object 410. If the inspection object 410 is a clothed person, the terahertz waves 403 pass through the fibers of the clothing and are reflected by metals or ceramics held by the inspection object 410. In addition, certain substances, such as the explosive RDX (trimethylenetrinitramine), are known to absorb terahertz waves of a specific wavelength, for example, around 0.8 THz, and therefore the reflected waves are reduced. The first image is acquired by the first camera 402 based on these reflected waves.

The second camera 405 of the second imaging system acquires a second image from electromagnetic waves of a different wavelength from the terahertz waves emitted from the first illumination source 404. Visible light, infrared light, and millimeter waves can be used as electromagnetic waves of a different wavelength. When infrared light is used, an illumination source (not shown) different from the first illumination source 404 may be prepared. The second image acquired by the second camera 405 is subjected to image processing in the pre-processing unit 406. The pre-processing unit 406 performs processing to detect the inspection area from the second image.

When the second image is acquired using visible light and the inspection target 410 is a person, the inspection area may be detected by detecting a specific part of the clothing. The inspection area may be identified by creating a model using machine learning and classifying the area of the captured second image using the model. The area may also be identified based on information about the shape of the object stored in the database 409. When the second image is acquired using millimeter waves, a part in the image where the intensity distribution is higher than a predetermined threshold or a part where the intensity difference is large may be detected as the inspection area. When infrared light is used to acquire the second image, a part where infrared light radiation is low due to moisture or a specific part of the clothing from an image detected by night vision may be detected as the inspection area. By using infrared light or millimeter waves, the inspection area can be detected even in dark places or when visibility is poor due to weather. When detecting the inspection area from an image of clothing, an unnatural bulge in the clothing, a person's chest, or a pocket part of the clothing may be detected as the inspection area.

Based on FIG. 24, the inspection of the inspection object 410 by the processor will be described. The pre-processing unit 406 detects the inspection area from the second image acquired by the second camera 405 (S421) by the above-described method (S422, S423). The post-processing unit 407 processes image data for information on the area of the first image corresponding to the inspection area detected from the second image (S425). The first image is an image acquired by the first camera 402 using terahertz waves (S424), and is an image obtained by looking through clothing, etc. If there is a metal or ceramic object under the clothing, an image from the reflected wave can be obtained. Therefore, the shape of the object can be detected by processing the first image. After the inspection area is detected from the second image, the area in the first image corresponding to the inspection area is selected by comparing the first image with the second image. Subsequent image processing of the first image is performed on the area corresponding to the inspection area detected from the second image. By selecting the area corresponding to the inspection area from the first image and performing image processing, unnecessary information can be reduced and processing can be performed. For this reason, the processing load can be reduced and the processing speed can be increased compared to processing the entire image data. Therefore, even if the inspection target 410 is moving, the features can be detected from the first image multiple times during the short distance and short time it moves. The determination unit 408 estimates the object under the clothes based on the multiple detected features (S426). The multiple features may be parts of the object. The determination unit 408 may classify the shape of the object detected from the first image based on the data in the database 409. The classification may be performed by a model created by machine learning. When the inspection target 410 moves or due to the positional relationship between the inspection target and the camera, it is considered that the shape information obtained from the image becomes a part of the object. Even in that case, the accuracy of the estimation can be improved by classifying the features based on the information of the multiple features, accumulating the results multiple times, and making a judgment based on the accumulated classification results (S427). When this processing system is used in a security monitoring system, the danger level of the object detected in the inspection area is judged from the accumulation of classification results for the inspection target 410 (S428). The judgment may be performed based on the accumulated classification results based on a model created by machine learning. When it is determined that the inspection target 410 is holding a dangerous object, the fact that the inspection target 410 is holding a dangerous object can be notified to the outside. For example, when the inspection target 410 passes through a gate where the processing system is installed, a warning may be notified to the outside from the processing system. When the inspection target 410 inserts a ticket and passes through a ticket gate, the ticket and the inspection target 410 may be linked to notify that the inspection target 410 is a target to be monitored. In addition, when the second image is made of visible light, the inspection target 410 can be displayed in an easy-to-understand manner by displaying an image in which the second image and the first image are superimposed on a monitor.
Second Example
This embodiment is an example in which a second illumination source 411 that emits terahertz waves is provided in the second imaging system. This embodiment will be described with reference to FIG. 25. The second illumination source 411 is an illumination source that generates terahertz waves of a second wavelength different from the first illumination source 404. As described in the first embodiment, certain substances are known that absorb terahertz waves of a certain wavelength. Therefore, the first illumination source 404 emits terahertz waves of a first wavelength (for example, about 0.8 THz in the case of RDX, an explosive), which is a wavelength that is easily absorbed by a certain substance, to the inspection object 410. If the inspection object 410 possesses a substance that has a property that easily absorbs terahertz waves of the first wavelength, reflection from the possessed portion is reduced. On the other hand, if a wavelength (for example, about 0.5 THz) that is less absorbed by a certain substance is selected as the terahertz waves of the second wavelength generated by the second illumination source 411, the certain substance will reflect the terahertz waves of the second wavelength. For the same inspection area, the difference in the reflected waves from a particular material can be used to identify the material.

The processing of this embodiment will be described with reference to FIG. 26. The pre-processing unit 406 detects an area with high reflection in the second image acquired by the terahertz wave of the second wavelength as the inspection area (S431, S432). The post-processing unit 407 acquires a first image (S434) based on the terahertz wave of the first wavelength captured by the first camera 402, and starts processing image data for an area of the first image corresponding to the inspection area detected from the second image. For example, the post-processing unit 407 calculates the difference between information on the inspection area in the second image and information on an area corresponding to the inspection area in the first image (S435).

Data for areas where there is similar reflection and absorption in the second image and the first image is nearly cancelled out by calculating the difference between the information from both images. However, data for areas where the reflection and absorption rates differ between the first and second wavelengths is not cancelled out even by calculating the difference between the two. In this way, the difference in the absorption rate of terahertz waves by materials can be used to perform a spectral analysis of the material in the inspection area. This spectral analysis can be used to estimate the type of material. In addition, because scattering and reflection from clothing are cancelled out, unnecessary signals from clothing etc. can be reduced from the obtained image information, improving the signal-to-noise ratio of the image.

If the inspector holds a substance that easily absorbs the first wavelength, the substance detected in the inspection area can be classified based on the difference in absorptance between the first wavelength and the second wavelength (S436). The classification can be performed by the judgment unit 408 based on the database 409, which stores the relationship between the specific substance and the wavelength. The judgment unit 408 may also perform classification using a model created by machine learning. In this manner, it can be estimated that the inspection object 410 holds a substance that absorbs a specific wavelength. It is known that dangerous materials are among the materials that absorb terahertz waves of specific wavelengths. The presence of dangerous materials can be estimated by spectral analysis. The results of multiple spectral analyses can be accumulated to improve the accuracy of detection (S437).

In this way, it is determined that the inspection target 410 may be carrying a dangerous object (S438). This determination may be made based on a machine learning model based on the accumulated classification results. If it is determined that the inspection target 410 is carrying a dangerous object, the fact that the inspection target 410 is carrying a dangerous object is notified to the outside. For example, when the inspection target 410 passes through a gate where a processing system is installed, a warning may be issued, or when the inspection target 410 passes through a ticket gate by inserting a ticket, the ticket may be linked to the inspection target 410, and the person may be notified to the outside as a person to be monitored. The wavelength of the terahertz wave emitted by the second illumination source 411 may be adjusted to the absorption spectrum of the substance to be detected, and a plurality of illumination sources capable of emitting terahertz waves of three or more wavelengths may be combined.
(Third Example)
This embodiment is an example in which the control unit 412 is controlled to control the first illumination source 404 and the first camera 402 of the first imaging system based on detection of a specific area in the second image captured by the second imaging system. This embodiment will be described with reference to Figs. 27 and 28.

The second camera 402 of the second imaging system acquires a second image from electromagnetic waves of a different wavelength from the terahertz waves emitted from the first illumination source 404. The electromagnetic waves of a different wavelength can be visible light, infrared light, or millimeter waves. The second image acquired by the second camera 405 is subjected to image processing in the pre-processing unit 406. The pre-processing unit 406 detects an inspection area from the second image (S452, S453). The detection of the inspection area is performed as described in the first embodiment.

Depending on the position and range of the inspection area detected from the second image and the state of the inspection area, the attitude of the first camera is controlled, the gain of the acquired image is controlled, and the imaging range and angle of view are controlled by zooming, cropping, etc. (S454). The output level and wavelength of the terahertz waves emitted from the first illumination source 404 may be changed depending on the intensity of the reflected signal from the inspection area and the object in the inspection area. By controlling in this manner, the accuracy of the inspection can be improved. The first imaging system controlled by the control unit 412 acquires a first image based on the terahertz waves of the first wavelength (S455).

The post-processing unit 407 processes the inspection area based on the acquired first image (S456). After that, the determining unit 408 determines and classifies the object (S457, S458, S459). When the processing system is a security monitoring system, the degree of danger is determined from the accumulation of the classification results, and when it is determined that the inspection target 410 is holding a dangerous object, the fact that the inspection target 410 is holding a dangerous object is notified to the outside. When the inspection target 410 passes through a gate where the processing system is installed, a warning may be issued, and when the inspection target 410 inserts a ticket and passes through a ticket gate, the ticket and the inspection target 410 may be linked to be monitored.
(Fourth Example)
This embodiment is an example in which an environment monitoring unit 413 is provided to monitor the humidity around the processing unit. This embodiment will be described with reference to Fig. 29. Terahertz waves are easily absorbed by water vapor, but terahertz waves with longer wavelengths are less susceptible to the effects of water vapor. Therefore, the environment monitoring unit 413 is provided to measure the humidity and control the imaging system so that it is less susceptible to the effects of the surrounding environment.

Specifically, when the environment monitoring unit 413 detects that the humidity has increased, the wavelength of the terahertz waves 403 emitted by the first illumination source 402 is switched to a wavelength longer than the wavelength currently being used. Also, the wavelength may be switched to a wavelength that is less susceptible to water vapor depending on the humidity (for example, a region that exists near wavelengths of 1.2 mm or 0.75 mm and has particularly low atmospheric attenuation). Although the resolution of the image captured by the camera decreases as the wavelength of the terahertz waves becomes longer, the effect of water vapor can be reduced and the inspection can be continued.
Fifth Example
This embodiment is an example of imaging using terahertz waves of different wavelengths. A second image is acquired using terahertz waves of a second wavelength longer than that used to capture a first image, and an inspection area is detected from the second image. The inspection area may be determined to be an area where an object of a predetermined shape is present or an area where the spectrum of the reflected wave of a predetermined wavelength has changed, using a model created by machine learning.

This embodiment will be described with reference to FIG. 30. Based on the inspection area detected from the second image, image data of the area of the first image corresponding to the inspection area is processed. The first image captured with terahertz waves of a first wavelength generated from illumination source 404 is image 1, and the second image captured with a second wavelength generated from illumination source 411 is image 2. Image 1 is acquired using terahertz waves with a shorter wavelength than image 2, so it has high resolution and a large amount of information. Therefore, the shape of the object held by inspection object 410 is clear from the image acquired using terahertz waves. However, because terahertz waves with a short wavelength are used, the subject depth is shallow and it is sensitive to changes in the posture of inspection object 410.

In detail, depending on the posture of the test object 410, a partial shape of the object held by the test object 410 is obtained. On the other hand, in the image by the image capture 2, the resolution is lower than that of the image capture 1 because the wavelength of the terahertz wave is long, and the shape of the object is unclear. However, since the terahertz wave with a long wavelength is used, the depth of the subject is deep, and it is insensitive to the change in the posture of the test object 410. In detail, regardless of the posture of the test object 410, the overall shape of the object held by the test object 410 is obtained. By processing the image capture 2 with a low resolution to identify the position of the object held by the test object 410, and processing the data of the image capture 1 based on this detected inspection area, the processing load can be reduced and the processing can be performed at high speed. Therefore, even if the test object 410 is moving, the features of the test object 410 can be detected multiple times during the short distance and short time it moves, and the object under the clothes can be estimated based on the detected features.

In addition, by calculating the difference between images 1 and 2, which were taken with terahertz waves of two different wavelengths, reflections from clothing are cancelled, and noise can be reduced from the obtained image information. In detail, the reflection from the entire clothing is mainly caused by scattering, so there is little difference in intensity, and it is insensitive to changes in the posture of the subject 410 (the acquired image is given random noise overall). Therefore, by calculating the difference image between images 1 and 2, the signal from the clothing is cancelled. Furthermore, by calculating the difference, an image based on the difference in the absorption rate of terahertz waves for the wavelengths of the transmitted material can be obtained. Therefore, the shape of an object containing components other than metal or ceramic can be detected from the difference between the first and second images.

The object in the inspection area is estimated by classifying the shape of the object detected from the image 1 by the determination unit 408. When the inspection target 410 moves, the shape of the object obtained from the image is often partial, so the accuracy of the determination can be improved by accumulating multiple classification results and making a determination based on the accumulated classification results. In the case of a security monitoring system, the degree of danger is determined from the accumulation of classification results, and if it is determined that the inspection target 410 is holding a dangerous object, the inspection target 410 is notified that it is holding a dangerous object. For example, when the inspection target 410 passes through a gate where a processing system is installed, a warning may be issued, or when the inspection target 410 passes through a ticket gate by inserting a ticket, the ticket may be linked to the inspection target 410, and the inspection target 410 may be determined as a target to be monitored.
(Sixth Example)
An application example of the processing system will be described with reference to Fig. 31 and Fig. 32. Fig. 31 shows an example in which a first illumination source 404 of terahertz waves of a first wavelength and a second illumination source 411 of a second wavelength different from the first wavelength are arranged on one side of an entrance/exit 414 of a vehicle or the like. On the other side of the entrance/exit 414, a first camera 402 that performs imaging based on terahertz waves of the first wavelength, a second camera 405-1 that performs imaging based on any of visible light, infrared light, and millimeter waves, and a second camera 405-2 that performs imaging based on terahertz waves of the second wavelength are arranged. By combining these cameras and illumination sources, the processes related to the inspection described in the first to fifth embodiments can also be performed in combination.

The second camera 405-1 tracks the inspection object 410, and the attitude and angle of view of the first camera 402 can be controlled. Spectral analysis can be performed by matching the wavelength of the terahertz waves used by the second camera 405-2, which captures images based on terahertz waves, to the absorption rate of the material. In addition, by using the second cameras 405-1 and 405-2 to detect the inspection area, the processing load on the first image captured by the first camera 402 can be reduced.

Furthermore, by utilizing the difference in the absorption rate of materials with respect to the wavelength of terahertz waves, the shape of an object containing a material other than metal or ceramic can be detected. In this embodiment, the second camera 405 is used for visible light, infrared light, millimeter waves, and terahertz waves of the second wavelength, but the second camera may be only one of visible light, infrared light, millimeter waves, or terahertz. The illumination source and camera can be embedded in the wall, ceiling, or floor so as not to be conspicuous. An illumination source and a camera may be placed on both the left and right sides of the entrance 414. By placing the illumination source and the camera near the entrance 414, the situation where multiple inspection objects 410 overlap is reduced, and the accuracy of the inspection can be improved.

An example in which a processing system is placed near a ticket gate 415 installed at a station ticket gate is described with reference to FIG. 32. A first illumination source 404 of terahertz waves of a first wavelength and an illumination source 411 of a second wavelength different from the first wavelength are placed on one side of the ticket gate 415. A first camera 402 that captures images based on the first wavelength of terahertz, a second camera 405-1 that captures images based on visible light, infrared light, or millimeter waves, and a second camera 405-2 that captures images based on the second wavelength of terahertz are placed on the other side of the ticket gate 415. By placing the processing system near the ticket gate 415, the situation in which multiple inspection targets 410 overlap is reduced, improving the accuracy of the inspection.

The operation of the processing system may be started in response to detection of movement of the inspection target 410 by a sensor provided separately from the processing system, the opening and closing of a vehicle door, insertion of a ticket into a ticket gate 415, etc.

Next, the operation of the camera system 200 will be described with reference to FIG. 33. FIG. 33 is a diagram showing an example of the operation of the camera system 200 according to this embodiment. The configuration of the camera system 200 can be applied to the configuration of the above-mentioned embodiment. In this embodiment, the operation after the camera system 200 acquires an image based on terahertz waves (sometimes called a terahertz image). In FIG. 33, the camera system 200 evaluates the acquired image, and if the desired quality is not achieved, performs an operation of capturing the image again (re-capturing).

First, in S1001, the illumination unit 202 irradiates the inspection object 250 with terahertz waves under desired conditions. Next, in S1002, the camera 203 detects the terahertz waves reflected by the inspection object 250 and acquires information based on the terahertz waves. In S1003, the control unit performs a process of converting the information based on the terahertz waves into an image. Here, the control unit can be, for example, the above-mentioned overall system 310.

Next, the control unit evaluates the image quality of the acquired terahertz image (S1004). Evaluation items can be set appropriately, such as whether an appropriate terahertz image corresponding to the inspection object 250 has been acquired, and whether the image quality is such that an object can be detected from the terahertz image. If the image quality evaluation does not satisfy the desired image quality, the camera system 200 performs the operation of S1005. In S1005, the control unit supplies a control signal to the illumination unit 202 to increase the power of the terahertz waves to be irradiated and to change the wavelength. Then, the illumination unit 202 irradiates the terahertz waves again (S1001). This series of operations makes it possible to properly detect the desired object.

If the control unit determines that the desired image quality has been obtained in the image evaluation, the control unit determines whether an object has been detected and, in some cases, the type of object (S1006). If an object is detected, the control unit outputs an instruction to the monitoring system to display an alert, or to perform an action such as flagging an object or person as a high risk (S1007). If no object is detected, the control unit may flag a confirmed person as a low risk (S1008).

In this series of operations, the lighting unit 202 and the camera 203 can be used in the following combinations. First, if the lighting unit 202 and the camera 203 used in the first shooting are present, the same lighting unit 202 and the same camera 203 may be used for shooting from the second shooting onwards. Also, if the lighting unit 202 and the camera 203 used in the first shooting are present, the same lighting unit 202 as in the first shooting and a different camera 203 from the first shooting may be used for shooting from the second shooting onwards. Furthermore, if the lighting unit 202 and the camera 203 used in the first shooting are present, the second shooting onwards may be performed using a different lighting unit 202 from the first shooting and the same camera as the first shooting. Furthermore, if the lighting unit 202 and the camera 203 used in the first shooting are present, the second shooting onwards may be performed using a different lighting unit 202 from the first shooting and a different camera from the first shooting.

Next, another operation of the camera system 200 will be described using FIG. 34. In this example, the operation of capturing images in synchronization with the opening and closing of the boarding and alighting doors of the railway vehicle, the entrance doors to the passenger compartment, and the platform doors will be described. FIG. 34 is a diagram showing the operation of capturing images in synchronization with the doors. In this embodiment, the control unit may be, for example, the above-mentioned integrated system 310. Descriptions of configurations and operations similar to those of the other embodiments will be omitted. Furthermore, the door may be, for example, the door 219 or the door section 214 of the railway vehicle 218 shown in FIGS. 16-17.

First, in the camera system 200, the illumination unit 202 is in a standby state (S1101). At this time, the camera 203 may also be in a standby state. The control unit detects an open door signal (S1102). When the control unit detects an open door signal, it supplies a control signal to the illumination unit 202 to irradiate the inspection object 250, and supplies a control signal to the camera 203 to photograph the inspection object 250. In response to the control signal from the control unit, the illumination unit 202 starts irradiating terahertz waves (S1103). In response to the start of illumination by the illumination unit 202, the camera 203 starts detecting terahertz waves (S1104). If the control unit does not detect an open door signal, the standby state is maintained (S1101). If the control unit detects an open door signal in S1102, the control unit is always in a state where it can detect a close door signal (S1106). If the control unit detects a door-closed signal in S1106, the control unit supplies a control signal to the illumination unit 202 to stop emitting terahertz waves, and a control signal to the camera 203 to stop detecting terahertz waves (S1107, S1108). Here, when the control unit detects a door-closed signal, at least one of S1107 and S1108 may be performed. If a door-closed signal is not detected, the irradiation and detection of terahertz waves are continued, and the camera system 200 continues capturing images. This series of operations for monitoring the open/closed state of the door allows the camera system 200 to save power, and also enables reliable capturing of images at the required timing.

Next, another operation of the camera system 200 will be described using FIG. 34. In this example, a case where image capturing is performed in synchronization with the operation of the ticket gate 211 will be described. FIG. 34 is a diagram showing the operation of capturing an image in synchronization with the ticket gate 211. In this embodiment, the control unit may be, for example, the above-mentioned integrated system 310. Descriptions of configurations and operations similar to those of other embodiments will be omitted.

First, in the camera system 200, the illumination unit 202 is in a standby state (S1201). At this time, the camera may also be in a standby state. The control unit is in a state in which it is possible to detect a door-opening signal that indicates that the door provided in the ticket gate 211 has opened (S1202). When the control unit detects the door-opening signal, the illumination unit 202 starts emitting terahertz waves (S1203). In addition, in response to the start of illumination by the illumination unit 202, the camera 203 starts detecting terahertz waves (S1204). When the control unit does not detect the door-opening signal, the standby state is maintained (S1201). The detection of the door-opening signal in S1202 can be performed using a signal emitted by a ticket inserted in the ticket gate 211, a signal emitted by contacting a ticket such as an IC card with the ticket gate 211, or a signal that detects the presence or absence of a ticket such as an IC card by using millimeter waves or the like at the ticket gate 211. In this way, by monitoring the open/closed status of the gates of the ticket gate 211, it is possible to save power, and this operation also makes it possible to take reliable photographs.

Next, another operation of the camera system 200 will be described using FIG. 36. In this embodiment, the operation will be described when the sensor 260 described in FIG. 14B is used. FIG. 36 is a flowchart showing the photographing operation at the ticket gate 211. In this embodiment, the control unit can be, for example, the above-mentioned integrated system 310. Descriptions of configurations and operations similar to those of the other embodiments will be omitted.

As described above, the sensor 260 detects the inspection object 250. Here, the sensor 260 may be, for example, a human sensor using infrared rays or a camera using visible light. First, in the camera system 200, the illumination unit 202 is in a standby state (S1301). At this time, the camera may also be in a standby state. Next, the inspection object 250 is detected using the sensor 260 (S1302). A signal from the sensor 260 is sent to the control unit. If the control unit determines that the inspection object 250 has been detected, the control unit supplies a control signal to the illumination unit 202 for irradiating the inspection object 250. In response to the control signal from the control unit, the illumination unit 202 starts irradiating the terahertz wave (S1303). In addition, the control unit supplies a control signal to the camera 203 for photographing the inspection object 250. In response to the control signal from the control unit, the camera 203 starts detecting the terahertz wave (S1304). If the control unit does not determine that the inspection object 250 has been detected, the standby state is maintained (S1301).

This operation allows for power saving and also ensures reliable imaging. In this embodiment, the inspection subject 250 is a person, but it may be an object. This configuration is also applicable to the escalator 221 shown in FIG. 18. In the case of an escalator that has a human presence sensor, the sensor can be shared and used.

The invention is not limited to the above-described embodiment, and various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to disclose the scope of the invention.

ICS: Imaging system, 100: vehicle (moving object), 1: lighting source, 2: camera, 3: imaging unit, 116: deck (corridor, common area), 115: passenger cabin corridor (common area), equipment 113 (common area)

Claims (34)

A moving object comprising an imaging system for acquiring an image formed by terahertz waves,
The imaging system includes a plurality of illumination sources that irradiate terahertz waves onto an inspection object that uses a passage included in a common area of the mobile body, and a plurality of cameras that image the inspection object irradiated with the terahertz waves from the plurality of illumination sources,
The image is an image of the inspection object ,
the number of the illumination sources is greater than the number of the cameras;
A moving object characterized by: The passage includes a deck, and the plurality of cameras include a camera that captures an image of an inspection object using the deck.
2. The moving body according to claim 1 . the aisle includes a cabin aisle passing beside a space in which seats are arranged, and the plurality of cameras includes a camera for capturing an image of an inspection target using the cabin aisle,
3. The moving body according to claim 1 or 2 . The camera for imaging an inspection target using the cabin aisle is disposed on the seat.
4. The moving body according to claim 3 . The plurality of cameras includes a camera disposed on a shelf.
5. The moving body according to claim 1, wherein the movable body is a movable body having a movable member. The passage includes a first passage extending in a first direction and a second passage extending in a second direction different from the first direction and connected to the first passage,
The plurality of cameras includes a camera that captures an image of an inspection object passing through a connection portion between the first passage and the second passage.
6. A moving body according to claim 1, wherein the moving body is a movable body. The passage includes a first passage extending in a first direction and a second passage extending in a second direction different from the first direction and connected to the first passage,
The plurality of cameras include a plurality of cameras for capturing an image of an inspection object passing through a connection portion between the first passage and the second passage, and optical axes of the plurality of cameras are oriented in different directions from each other.
7. A moving body according to claim 1, wherein the moving body is a movable body. The first passage and the second passage intersect at the connection portion.
8. The moving body according to claim 6 or 7 . the passageway includes a staircase;
The plurality of cameras includes a camera that captures an image of an inspection object passing through the staircase.
9. A moving body according to claim 1, wherein the moving body is a movable body. The common area includes a washstand, and the imaging system includes a camera that images an inspection subject using the passageway.
10. The moving body according to claim 1, The common area includes a restroom, and the plurality of cameras include a camera that captures an image of an inspection subject using the restroom.
11. The moving body according to claim 1 , Each of the plurality of illumination sources is embedded in either a ceiling or a floor of the moving body, and each of the plurality of cameras is embedded in either the ceiling or the floor.
2. The moving body according to claim 1 . the common portion includes a first passage extending in a first direction and a second passage extending in a second direction different from the first direction and connected to the first passage,
the plurality of illumination sources irradiate terahertz waves onto an inspection object passing through a connection portion between the first passage and the second passage, and the plurality of cameras capture an image of the inspection object irradiated with the terahertz waves.
2. The moving body according to claim 1 . a wall facing the connection portion has a curved surface that reflects the terahertz wave;
14. The moving body according to claim 13 . The plurality of illumination sources and the plurality of cameras are embedded in a wall facing the connection.
15. The moving body according to claim 13 or 14 . The plurality of illumination sources are arranged on seats so as to irradiate terahertz waves onto an object to be inspected that uses the common area, and the plurality of cameras capture images of the object to be inspected irradiated with the terahertz waves.
2. The moving body according to claim 1 . the plurality of illumination sources includes at least two illumination sources disposed on a backrest of the seat;
17. The moving body according to claim 16 . The plurality of cameras are arranged on a ceiling or a floor of the moving object.
18. A moving body according to claim 16 or 17 . the common area includes an aisle disposed between a first seat row including a plurality of first seats and a second seat row including a plurality of second seats;
The plurality of illumination sources irradiate an inspection object using the passage with terahertz waves, and the plurality of cameras capture images of the inspection object irradiated with the terahertz waves;
a part of the plurality of illumination sources and a part of the plurality of cameras are arranged alternately in the first seat row;
Another part of the plurality of illumination sources and another part of the plurality of cameras are alternately arranged in the second seat row.
2. The moving body according to claim 1 . the plurality of illumination sources are arranged at a plurality of seats so as to irradiate the terahertz waves to the inspection object using the common area , and the plurality of cameras are arranged around the entrance and exit of the passenger compartment so as to capture an image of the inspection object irradiated with the terahertz waves.
3. The moving body according to claim 2. Further comprising a sensor for detecting the test object,
the plurality of illumination sources are controlled based on an output of the sensor.
21. The moving body according to claim 20 . the imaging system has a reflecting surface that reflects the terahertz wave, the reflecting surface including a curved surface;
22. A moving body according to claim 1 . Further comprising a processor for processing a signal output from the imaging system.
the processing includes determining a risk associated with the test subject;
23. A moving body according to any one of claims 1 to 22 . The process includes identifying a location of the test object having a predetermined risk level.
24. The moving body according to claim 23 . The process includes identifying a seat to be inspected that has a predetermined risk level.
24. The moving body according to claim 23 . The processor identifies a seat of the inspection target based on correspondence information that associates characteristic information of the inspection target with seat information assigned to a passenger having a characteristic corresponding to the characteristic information.
26. The moving body according to claim 25 . The feature information is information extracted from an image captured by the imaging system.
27. The moving body according to claim 26 . The processor transmits a result of the processing to a preset terminal.
28. A moving body according to any one of claims 23 to 27 . The imaging system is disposed at a position where an inspection object moving within the moving body is rectified.
2. The moving body according to claim 1 . The imaging system is disposed at a position where an object to be inspected moving within the moving body changes direction.
2. The moving body according to claim 1 . The imaging system is disposed at a position where an object moving within the moving body slows down or stops.
2. The moving body according to claim 1 . The imaging system is disposed at a position where an object to be inspected moving within the movable body rotates.
2. The moving body according to claim 1 . the passage includes a first passage extending in a first direction and a second passage extending in a second direction different from the first direction and connected to the first passage, and a wall facing a connection portion between the first passage and the second passage includes a first corner portion and a second corner portion;
the first corner portion and the second corner portion are arranged such that the inspection object passes between the first corner portion and the second corner portion;
2. The vehicle of claim 1, wherein at least one of the plurality of illumination sources is disposed at the first corner and at least one of the plurality of illumination sources is disposed at the second corner. Two or more of the illumination sources of the plurality of illumination sources are arranged in a vertically overlapping manner at the first corner, and two or more of the illumination sources of the plurality of illumination sources are arranged in a vertically overlapping manner at the second corner,
The cameras are embedded in one of a wall, a ceiling, and a floor.
34. The moving body according to claim 33.

Images