Biometric detection device, radio wave sensor, biometric detection system, and biometric detection method

Abstract

The present invention comprises: a sensor information acquisition unit (101) that acquires sensor information generated on the basis of reflected waves obtained when radio waves are reflected by an object within a chamber, the radio waves being emitted within the chamber by a radio wave sensor (10) toward an in-chamber region that includes at least a seat present within the chamber; and a sensing unit (104) that senses whether an object is present within the chamber, the sensing being carried out on the basis of sensor information, a first distance to a first target point that is present on an upper surface in a columnar target region having a height in a height direction of the seat serving as a target for sensing whether a living body is present on the basis of the sensor information from the position of the radio wave sensor (10) and that is located at the position closest to the position of the radio wave sensor (10), a second distance to a second target point that is present on the upper surface in the target region from the position of the radio wave sensor (10) and that is located at the position furthest from the position of the radio wave sensor (10) relative to the first target point, and a third distance to a third target point that is furthest from the second target point in the target region.

Description

[Technical Field]

[0001] The present disclosure relates to a living body detection device, a radio wave sensor, a living body detection system, and a living body detection method. [Background Art]

[0002] Conventionally, there is known a technology for detecting a living body present in a room based on information contained in a reflected wave received by a radio wave sensor that is installed in the room, radiates radio waves into the room, and receives the reflected wave of the radiated radio wave reflected by a body surface. For example, Patent Document 1 discloses a technology for detecting a living body present in a vehicle cabin based on information contained in a reflected wave received by a radio wave sensor that is installed in the vehicle cabin, radiates radio waves into the vehicle cabin, and receives the reflected wave of the radiated radio wave reflected by a body surface (see Patent Document 1, for example). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-101415 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] When a radio wave radiated by a radio wave sensor irradiates an indoor structure or the like, the irradiated radio wave is reflected depending on the material of the structure or the like. For example, when a living body is located in a blind spot from the perspective of the radio wave sensor, such as a location blocked by a structure or the like that reflects radiated radio waves in the room, the radio wave radiated from the radio wave sensor may not be directly reflected by the body surface of the living body. Since this point is not taken into consideration in conventional technologies, there has been a problem that there is still a possibility that a living body present in the room cannot be detected.

[0005] This disclosure was made to solve the above-mentioned problems and aims to provide a biological detection device capable of detecting living organisms present in a room. [Means for solving the problem]

[0006] The biological detection device according to this disclosure comprises: a sensor information acquisition unit that acquires sensor information generated based on reflected waves reflected by objects in the room from radio waves emitted by a radio wave sensor toward an indoor area including at least seats present in the room; a detection unit that detects whether or not a living being is present in the room based on the sensor information acquired by the sensor information acquisition unit and a first target point which is a point on the upper surface of a columnar target area having a height in the direction of the height of the seats to be detected based on the sensor information, and is the closest point to the position of the radio wave sensor; a second distance which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor than the first target point; and a third distance which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor, and detects whether or not a living being is present in the room based on the sensor information acquired by the sensor information acquisition unit and a first distance from the position of the radio wave sensor to a first target point which is the closest point to the position of the radio wave sensor; a second distance which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor to a second target point which is the furthest point from the second target point in the target area; and a third distance which is from the second target point to a third target point which is the furthest point from the second target point in the target area. The sensor information includes position information indicating the distance to the object detected by the radio wave sensor. This includes reflected power information indicating the signal strength of the reflected wave, velocity information indicating the speed of the object detected by the radio wave sensor, or position information indicating the distance and angle of the object detected by the radio wave sensor. The detection unit detects an object detected by the radio wave sensor when the distance to the object is greater than or equal to the first distance, and less than or equal to the fourth distance (the sum of the second and third distances). If the reflected power information, velocity information, or position information satisfies the conditions for biodetection to determine whether or not an object is a living organism, then it is detected that a living organism is present in the room. It is characterized by doing so. [Effects of the Invention]

[0007] According to this disclosure, it is possible to detect living organisms present in a room. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram shows the radio wave sensor function equipped with a biodetection device according to Embodiment 1. [Figure 2] This figure shows an example configuration of a biodetection device according to Embodiment 1. [Figure 3]This figure illustrates an example of the installation of a radio wave sensor and the radio waves emitted from the radio wave sensor in Embodiment 1. [Figure 4] This figure shows an example of a target area set by the area setting unit in Embodiment 1. [Figure 5] Figures 5A, 5B, and 5C illustrate an example in Embodiment 1 in which the detection unit detects whether or not a living being is present inside the vehicle based on whether or not the distance to an object detected by a radio wave sensor satisfies a first detection condition. [Figure 6] This is a flowchart illustrating the operation of the biodetection device according to Embodiment 1. [Figure 7] This figure shows an example of a target area set by the area setting unit in the target area setting process, when the area setting unit includes the area below the seat surface as the target area in Embodiment 1. [Figure 8] This figure illustrates an example of how the radiation range of radio waves emitted from the transmitting antenna is controlled by a radio wave sensor in Embodiment 1. [Figure 9] This figure shows an example configuration of a biodetection system comprising a radio wave sensor and a biodetection device in Embodiment 1. [Figure 10] Figures 10A and 10B show an example of the hardware configuration of the biodetection device according to Embodiment 1. [Modes for carrying out the invention]

[0009] To provide a more detailed explanation of this disclosure, the forms for implementing this disclosure will be described below with reference to the attached drawings.

[0010] Embodiment 1. The biodetection device according to Embodiment 1 detects whether or not a living organism is present in a room based on sensor information generated by a radio wave sensor. A radio wave sensor radiates radio waves toward an area including at least a seat present in a room (hereinafter referred to as an "indoor area"), receives reflected waves of the radiated radio waves, detects an object present in the room based on the reflected waves, and generates sensor information. In the first embodiment, it is assumed that the seat is a seat having a backrest.

[0011] In the first embodiment described below, as an example, it is assumed that the room is the cabin of a vehicle. The radio wave sensor is installed in the vehicle cabin, radiates radio waves toward an indoor area including at least a front seat or a rear seat present in the vehicle cabin, receives reflected waves of the radiated radio waves, detects an object present in the vehicle cabin, and generates sensor information. The expression "including a front seat or a rear seat" specifically refers to an area that is above the seat surface of the front seat and in front of the backrest of the front seat including the headrest, or an area that is above the seat surface of the rear seat and in front of the backrest of the rear seat including the headrest. The living body detection device detects whether an occupant is present in the vehicle cabin based on the sensor information generated by the radio wave sensor. In the first embodiment described below, the indoor area in the vehicle cabin is referred to as a "vehicle cabin area". Furthermore, in the first embodiment described below, the term "rear seat" refers to a seat with another seat arranged in front thereof. The term "front seat" refers to a seat with no other seat arranged in front thereof. For example, when the vehicle is a three-row seat vehicle, two rear seats are arranged in the vehicle.

[0012] Note that the living bodies detected by the living body detection device according to the first embodiment include various living bodies such as pets in addition to humans. In the first embodiment described below, as an example, it is assumed that the living body detection device detects a human who is an occupant of the vehicle. Note that vehicle occupants include infants placed in child seats.

[0013] The living body detection device 1 according to the first embodiment is mounted on, for example, the radio wave sensor 10. FIG. 1 is a diagram showing functions of a radio wave sensor 10 equipped with the living body detection device 1 according to Embodiment 1. FIG. 2 is a diagram showing a configuration example of the living body detection device 1 according to Embodiment 1.

[0014] The radio wave sensor 10 is mounted on a vehicle (not shown). In Embodiment 1, the radio wave sensor 10 is assumed to be a millimeter wave radar. The living body detection device 1 detects whether an occupant is present in the vehicle cabin based on sensor information generated by the radio wave sensor 10. The living body detection device 1 is connected to a left-behind detection device 200, and outputs a detection result of whether an occupant is present in the vehicle cabin to the left-behind detection device 200. The left-behind detection device 200 is mounted on a vehicle, for example, and outputs an alarm based on the detection result of whether an occupant is present in the vehicle cabin output from the living body detection device 1. Note that the left-behind detection device 200 may be provided in a location outside the vehicle that is referable by the living body detection device 1, such as a server outside the vehicle (not shown).

[0015] Here, FIG. 3 is a diagram for explaining an installation example of the radio wave sensor 10 and radio waves emitted from the radio wave sensor 10 in Embodiment 1. In FIG. 3, the vehicle is indicated by "100", a front seat is indicated by "S1", and a rear seat is indicated by "S2", and FIG. 3 is a side view of the vehicle. A forward-facing child seat (indicated by "CH" in FIG. 3) is mounted on the rear seat in the vehicle cabin, and an infant (indicated by "H" in FIG. 3) is seated on the child seat. Note that although the vehicle is a left-hand drive vehicle in FIG. 3, this is merely an example, and the vehicle may be a right-hand drive vehicle.

[0016] As shown in FIG. 3, the radio wave sensor 10 is installed, for example, on an overhead console of the vehicle, radiates radio waves toward the vehicle cabin area, and receives reflected waves of the radio waves reflected by an object in the vehicle cabin. As shown in Figure 3, the radio waves emitted from the radio wave sensor 10 installed on the overhead console reach directly into the cabin area in front of the backrests of the front seats, but do not reach the cabin area in front of the backrests of the rear seats because the front seats act as an obstruction. In other words, the radio wave sensor 10 cannot see into the cabin area in front of the backrests of the rear seats. The radio waves emitted from the radio wave sensor 10 reach the cabin area in front of the backrests of the rear seats after being reflected by cabin structures such as the ceiling or the headrests of the seats (hereinafter referred to as "cabin structures"). In other words, the radio waves emitted from the radio wave sensor 10 do not directly reach the occupants (in this case, infants), but are reflected by cabin structures before reaching the occupants. The biodetection device 1 according to Embodiment 1 is capable of detecting occupants inside a vehicle by utilizing the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the vehicle interior structure and illuminated by the occupants, even when the radio waves emitted from the radio wave sensor 10 are not directly directed at the occupants, in other words, even when the radio wave sensor 10 cannot directly see the occupants.

[0017] Although Figure 3 does not show an occupant seated in the front seat, even in the area of ​​the vehicle interior in front of the front seat, the radio waves emitted from the radio wave sensor 10 do not necessarily reach the occupant seated in the front seat directly. For example, if a rear-facing child seat is installed in the front seat and an infant is placed in the child seat, the child seat acts as an obstruction, and the radio waves emitted from the radio wave sensor 10 may not directly reach the infant. However, even in this case, the radio waves from the radio wave sensor 10 will be reflected by the vehicle interior structure, etc., before reaching the infant. The biodetection device 1 according to Embodiment 1 utilizes the phenomenon that even in such cases, radio waves from the radio wave sensor 10 are reflected by the vehicle interior structure, etc., and irradiated to the occupant, thereby enabling the detection of an occupant in the vehicle interior.

[0018] In the following Embodiment 1, the vehicle interior area is defined as the entire space inside the vehicle, and as shown in Figure 3, the radio wave sensor 10 is assumed to be installed on the vehicle's overhead console. However, this is merely an example, and the vehicle interior area may be, for example, the area inside the vehicle that includes the rear seats but not the front seats. Furthermore, the radio wave sensor 10 is not limited to being installed on the vehicle's overhead console. For example, the radio wave sensor 10 may be installed on the ceiling of the vehicle interior or on the dashboard. The radio wave sensor 10 only needs to be installed in a way that it can emit radio waves toward the vehicle interior area.

[0019] Returning to the explanation of Figure 1, we will now describe the function of the radio wave sensor 10. The transmitting antenna Tx is a planar antenna constructed on an electronic circuit board. The transmitting antenna Tx has one or more transmitting antenna elements that radiate radio waves towards the interior of the vehicle.

[0020] The installation positions of each transmitting antenna element differ from those of the vehicle in the direction of vehicle height.

[0021] The receiving antenna Rx is a planar antenna constructed on an electronic circuit board and is mounted on the same plane as the transmitting antenna Tx. However, "same plane" here does not mean that the plane on which the transmitting antenna Tx is mounted and the plane on which the receiving antenna Rx is mounted are strictly identical; it includes planes that are different to a degree that does not cause practical problems. The receiving antenna Rx has one or more receiving antenna elements that receive reflected waves of radio waves radiated from the transmitting antenna Tx.

[0022] The installation positions of each receiving antenna element differ from one another in the vehicle's width direction.

[0023] The radio wave sensor circuit section 13 includes a high-frequency signal generation circuit 14, a radio wave transmission section 15, a radio wave reception section 16, an analog-to-digital conversion circuit (hereinafter referred to as "A / D conversion circuit") 17, a signal processing section 18, and a biological detection device 1. The high-frequency signal generation circuit 14, the radio wave transmission section 15, and the radio wave reception section 16 constitute a radio wave transceiver section 19 that emits radio waves from a transmitting antenna Tx and acquires a received signal based on the reflected wave from a receiving antenna Rx.

[0024] The high-frequency signal generation circuit 14 generates an FM (Frequency Modulation) signal whose frequency changes over time as a sensing signal, and outputs the FM signal to the radio wave transmission unit 15 and the radio wave reception unit 16, respectively. In the radio wave sensor 10 shown in Figure 1, the FM-CW (Frequency Modulation-Continuous Wave) method is used as the modulation method, and the high-frequency signal generation circuit 14 generates an FM signal. However, the modulation method is not limited to the FM-CW method; for example, the FCM (Fast-Chip Modulation) method may also be used. When the FCM method is used as the modulation method, the high-frequency signal generation circuit 14 generates an FCM signal and outputs the FCM signal to the radio wave transmission unit 15 and the radio wave reception unit 16, respectively.

[0025] The radio wave transmitting unit 15 has a transmitting circuit 15-1. The radio wave transmitting unit 15 radiates radio waves from its transmitting antenna element toward the vehicle interior. If there are multiple transmitting antenna elements, the radio wave transmitting unit 15 radiates radio waves toward the vehicle interior from, for example, one of the multiple transmitting antenna elements. That is, the radio wave transmitting unit 15 sequentially switches which transmitting antenna element radiates radio waves from among the multiple transmitting antenna elements. Note that this is just one example, and the radio wave transmitting unit 15 may, for example, radiate radio waves toward the vehicle interior from multiple transmitting antenna elements simultaneously. In this case, the radio wave transmitting unit 15 can distinguish which transmitting antenna element transmitted the signal from using known methods such as coding. When the radio wave transmission unit 15 radiates radio waves from the transmitting antenna element, it outputs an FM signal from the transmitting circuit 15-1 to the transmitting antenna element.

[0026] The transmitting circuit 15-1 amplifies the FM signal output from the high-frequency signal generation circuit 14 and outputs the amplified FM signal to the transmitting antenna element, thereby causing the transmitting antenna element to radiate FM waves, which are radio waves, towards the interior of the vehicle.

[0027] The radio wave receiving unit 16 has a receiving circuit 16-1. When the receiving antenna element receives the FM wave, which is a reflected wave, the receiving circuit 16-1 acquires the received signal of the FM wave from the receiving antenna element. The receiving circuit 16-1 measures the difference (hereinafter referred to as the "frequency difference") between the frequency of the FM signal output from the high-frequency signal generation circuit 14 and the frequency of the received signal f d Extract it. The receiving circuit 16-1 has a frequency difference f d An intermediate frequency signal IF having the specified frequency is generated, and the intermediate frequency signal IF is output to the A / D conversion circuit 17.

[0028] Although Figure 1 shows only one transmitting antenna Tx, one receiving antenna Rx, one transmitting circuit 15-1, and one receiving circuit 16-1, multiple transmitting antennas Tx, Rx, and receiving circuits 15-1 or 16-1 can be configured.

[0029] The A / D conversion circuit 17 converts the intermediate frequency signal IF output from the receiving circuit 16-1 from an analog signal to a digital signal D. The A / D conversion circuit 17 outputs the digital signal D to the signal processing unit 18.

[0030] The signal processing unit 18 is implemented, for example, by a digital signal processing circuit. The signal processing unit 18 acquires the digital signal D related to the FM reception wave received by the receiving circuit 16-1 from the A / D conversion circuit 17. The signal processing unit 18 detects objects present in the vehicle interior area based on the digital signal D. Furthermore, the signal processing unit 18 determines the location of the detected object, in other words, the distance and angle to the object, based on the digital signal D. Furthermore, the signal processing unit 18 determines the relative velocity of the detected object based on the digital signal D. Furthermore, the signal processing unit 18 identifies the signal intensity of the reflected wave that has been reflected by an object based on the digital signal D. The signal processing unit 18 then generates sensor information. The sensor information includes reflected power information indicating the signal strength of the reflected wave, velocity information indicating the velocity of the detected object, or position information indicating the position (distance and angle) of the detected object. The signal processing unit 18 may, based on the acquired digital signal D, suppress reflections from vehicle structures such as seats (front or rear seats), doors, or the ceiling by applying an MTI (Moving Target Indicators) filter, perform frequency analysis on the suppressed digital signal D, and then identify the distance and angle to the object, the relative velocity of the object, and the signal intensity of the reflected wave to generate sensor information. The signal processing unit 18 outputs the generated sensor information to the biological detection device 1.

[0031] Digital signal processing circuits can be implemented using, for example, single circuits, complex circuits, programmed processors, parallel programmed processors, ASICs (Application Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), or combinations thereof. Digital signal processing circuits are not limited to those implemented by dedicated hardware; they may also be implemented by software, firmware, or a combination of software and firmware. Software or firmware is stored as a program in the computer's memory. A computer refers to the hardware that executes programs, and includes components such as a CPU (Central Processing Unit), processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor).

[0032] An example of the configuration of the biodetection device 1 according to Embodiment 1 will be described. The biodetection device 1 includes a sensor information acquisition unit 101, a region setting unit 102, a distance calculation unit 103, a detection unit 104, and an output unit 105, as shown in the configuration example in Figure 2.

[0033] The sensor information acquisition unit 101 acquires sensor information from the signal processing unit 18. The sensor information acquisition unit 101 outputs the acquired sensor information to the region setting unit 102.

[0034] The area setting unit 102 performs an "area setting process" within the vehicle interior, which sets the target area and sets the first target point, the second target point, and the third target point. In Embodiment 1, the target area refers to a columnar area within the vehicle interior that has a height in the direction of the seat (front seat or rear seat) and is the target for which the bio-detection device 1 detects the presence or absence of a living body based on sensor information. The area setting unit 102 sets a target area for each seat in the vehicle interior. The first, second, and third target points will be described later, but first, we will explain how the target area is set by the area setting unit 102.

[0035] Here, Figure 4 shows an example of a target area set by the area setting unit 102 in Embodiment 1. For convenience, Figure 4 shows only the radio wave sensor 10 and one seat. In Figure 4, "S" indicates a seat, and "C" indicates the location of the radio wave sensor 10. In Embodiment 1, the location of the radio wave sensor 10 is represented, for example, by the installation location of the radio wave transmitting unit 15 of the radio wave sensor 10. In Figure 4, the target region is indicated by "R1". The lines L1 to L3 and points P1 to P3 shown in Figure 4 will be discussed later.

[0036] The area setting unit 102 defines a target area as a columnar region having the height of the seat backrest, with the bottom surface being a surface including the seat surface of a square or rectangular seat (hereinafter referred to as the "seat surface"), and the top surface being the seat surface moved to the upper end of the seat backrest. The seat surface is, for example, a virtual square or rectangular surface with the four corners of the seat surface as its four corners. In Embodiment 1, the headrest is included in the backrest. Therefore, the area setting unit 102 defines the target area as a columnar region having a height to the upper end of the headrest, with the upper surface of the seat as the bottom surface and the upper surface of the seat moved to the upper end of the headrest as the top surface. For example, as shown in Figure 4, the area setting unit 102 defines the area that the seat surface passes through when the seat surface is moved parallel to the height of the upper end of the headrest as the target area. The target area is a rectangular prism-shaped area with the seat surface (see "A" in Figure 4) as the bottom surface and the seat surface (see "B" in Figure 4) as the top surface when it is moved parallel to the height of the upper end of the headrest.

[0037] Note that the target area shown in Figure 4 is merely an example, and the area setting unit 102 may set an area having a shape other than the target area shown in Figure 4 as the target area. The area setting unit 102 only needs to set a columnar area within the vehicle interior as the target area, with the bottom surface being a surface in front of the seat backrest and including at least the top surface of the seat, and having a height up to the top end of the seat backrest. For example, the target area may be a cylindrical area or a pentagonal prism area.

[0038] When the region setting unit 102 sets the target region, it sets the following first target point, second target point, and third target point.

[0039] The first target point is a point on the upper surface of the target area and is the point closest to the position of the radio wave sensor 10 (indicated as "P1" in Figure 4). In Embodiment 1, "closest to the position of the radio wave sensor 10" is not limited to being strictly the closest, but includes being close to the position of the radio wave sensor 10 within a margin of error. If there are multiple first target points, the distance calculation unit 103 may select any one of them as the first target point.

[0040] The second target point is a point on the upper surface of the target area and is the point furthest from the position of the radio wave sensor 10 than the first target point (indicated as "P2" in Figure 4). In Embodiment 1, the second target point is the point on the upper surface of the target area that is furthest from the position of the radio wave sensor 10. In Embodiment 1, "furthest from the position of the radio wave sensor 10" is not strictly limited to the furthest point, but includes being farthest from the position of the radio wave sensor 10 within the margin of error. If there are multiple second target points, the distance calculation unit 103 may select any one of them as the second target point.

[0041] The third target point is the point in the target region that is furthest from the second target point (indicated as "P3" in Figure 4). In Embodiment 1, "furthest from the second target point" is not strictly limited to being the furthest point, but includes being farthest from the second target point within the margin of error.

[0042] The area setting unit 102 outputs information regarding the set target area, the first target point, the second target point, and the third target point (hereinafter referred to as "target area information") to the distance calculation unit 103. At this time, the area setting unit 102 also outputs the sensor information acquired from the sensor information acquisition unit 101 to the distance calculation unit 103 along with the target area information. The target area information includes information that allows for the identification of the position and size of the target area in the real space inside the vehicle, and information that includes the coordinates of the first, second, and third target points in the real space inside the vehicle. For example, if the target area is a cylindrical area, the target area information includes the center and radius of the bottom surface of the target area, and the center and radius of the top surface of the target area. For example, the target area information may also include the coordinates of the edges of the bottom surface of the target area, and the coordinates of the edges of the top surface of the target area.

[0043] The actual space inside the vehicle is represented by a three-dimensional coordinate system, for example, with the x-axis parallel to the vehicle's width, the y-axis parallel to the vehicle's height, and the z-axis parallel to the vehicle's length. Since the seat positions, seat sizes, and backrest heights (including headrests) in the actual space inside the vehicle are known in advance, the area setting unit 102 can calculate the coordinates of each element in the actual space inside the vehicle that allow for the identification of the target area.

[0044] The area setting unit 102 may, for example, acquire information regarding the current tilt of the seat backrest and the front-to-back position of the seat from a seat sensor (not shown) provided in the vehicle, and perform the setting of the target area and the calculation of coordinates including the first target point, second target point, and third target point in the actual space inside the vehicle where the target area can be identified. This allows the area setting unit 102 to set a target area that better reflects the current state of the seat and to calculate the coordinates of the first target point, second target point, and third target point.

[0045] Here, as an example, the area setting unit 102 sets the target area as a rectangular prism-shaped area, as shown in Figure 4. The area setting unit 102 also generates information as target area information, including the coordinates of the edges of the bottom surface of the target area, i.e., the coordinates of the four corners of the bottom surface of the target area, and the coordinates of the edges of the top surface of the target area, i.e., the coordinates of the four corners of the top surface of the target area, and outputs this information to the distance calculation unit 103. The area setting unit 102 adds information to the coordinates of the first or second target point among the coordinates of the four corners of the top surface of the target area so as to be able to identify them as the first or second target point. The area setting unit 102 also adds information to the coordinates of the third target point among the coordinates of the four corners of the bottom surface of the target area so as to be able to identify them as the third target point. The area setting unit 102 may, for example, include information indicating the height of the target area in the target area information.

[0046] The distance calculation unit 103 calculates the following first distance, second distance, and third distance from the position of the radio wave sensor 10 and the target area set by the area setting unit 102. The first distance is the distance from the position of the radio wave sensor 10 to the first target point. The first distance is indicated as "L1" in Figure 4. The second distance is the distance from the position of the radio wave sensor 10 to the second target point. The second distance is indicated as "L2" in Figure 4. The third distance is the distance from the second target point to the third target point. In Figure 4, the third distance is indicated as "L3".

[0047] Here, the first target point is point P1 shown in Figure 4, the second target point is point P2 shown in Figure 4, and the third target point is point P3 shown in Figure 4. The distance calculation unit 103 calculates the distance from the position of the radio wave sensor 10 (position "C" in Figure 4) to point P1 as the first distance, the distance from the position of the radio wave sensor 10 to point P2 as the second distance, and the distance from point P2 to point P3 as the third distance. The position of the radio wave sensor 10 is known in advance, and the positions of points P1 to P3 can be determined from the target area information.

[0048] The distance calculation unit 103 outputs the calculated first distance, second distance, and third distance information (hereinafter referred to as "target distance information") to the detection unit 104. At this time, the distance calculation unit 103 also outputs the sensor information output from the area setting unit 102 to the detection unit 104 along with the target distance information.

[0049] The detection unit 104 detects whether or not there are occupants inside the vehicle based on the sensor information acquired by the sensor information acquisition unit 101 and the first distance, second distance, and third distance calculated by the distance calculation unit 103. The distance calculation unit 103 can determine the first distance, second distance, and third distance from the target distance information output from the distance calculation unit 103.

[0050] Here, we will explain an example of a method used by the detection unit 104 to detect whether or not an occupant is present inside the vehicle, based on sensor information and target distance information. The detection unit 104 also detects whether or not there is an occupant in each seat.

[0051] For example, the range of spaces within the vehicle interior that correspond to each seat (driver's seat, passenger seat, left rear seat, middle rear seat, right rear seat, etc.) is predetermined. The detection unit 104 can, for example, determine from the position information included in the sensor information which seat's space the distance to the detected object was detected from. Alternatively, for example, in the radio wave sensor 10, the signal processing unit 18 may identify the seat from which the distance to the object was detected based on the received wave obtained for which transmission wave, and associate the information indicating the identified seat with the position information. The detection unit 104 can determine from the information indicating the seat associated with the position information which seat's space the distance indicated by the position information included in the sensor information was detected from.

[0052] For example, the detection unit 104 detects that an occupant is present inside the vehicle when the distance to the object detected by the radio wave sensor 10 satisfies the following first detection condition. Furthermore, the detection unit 104 can determine the distance to the object detected by the radio wave sensor 10 from the position information included in the sensor information.

[0053] <First detection conditions> "The distance to the object detected by the radio wave sensor 10 is greater than or equal to the first distance, and less than or equal to the sum of the second distance and the third distance (hereinafter referred to as the "fourth distance")."

[0054] The detection unit 104 detects that an occupant is present inside the vehicle when the distance to the object detected by the radio wave sensor 10 satisfies the first detection condition, in other words, when the distance to the object detected by the radio wave sensor 10 is greater than or equal to the first distance and less than or equal to the fourth distance. On the other hand, the detection unit 104 detects that there are no occupants inside the vehicle if the distance to the object detected by the radio wave sensor 10 does not satisfy the first detection condition, in other words, if the distance to the object detected by the radio wave sensor 10 is not greater than or equal to the first distance and less than or equal to the fourth distance, that is, if the distance to the object detected by the radio wave sensor 10 is less than the first distance or greater than the fourth distance.

[0055] Figures 5A, 5B, and 5C illustrate an example in Embodiment 1 in which the detection unit 104 detects whether or not a living being is present inside the vehicle based on whether or not the distance to the object detected by the radio wave sensor 10 satisfies the first detection condition. Figures 5A, 5B, and 5C show the vehicle from the side, and for convenience, only the front seats or rear seats and the occupants seated in the front seats or rear seats are shown in Figures 5A, 5B, and 5C. In Figures 5A, 5B, and 5C, the front seats are indicated by "S1", and in Figure 5C, the rear seats are indicated by "S2". In Figures 5A, 5B, and 5C, the arrows indicate images of radio waves emitted from the radio wave sensor 10. In Figures 5A, 5B, and 5C, the dotted lines indicate the target area.

[0056] Figure 5A shows an example of the interior of a vehicle, where an adult (indicated as "H1" in Figure 5A) is seated in the front seat without changing their posture. Figure 5B shows an example of the interior of a vehicle where an infant (indicated as "H2" in Figure 5B) is seated in a rear-facing child seat in the front seat. In Embodiment 1, "occupants seated" includes cases where an infant is seated in a child seat. Figure 5C shows an example of the interior of a car, with a child (indicated as "H3" in Figure 5C) lying down in the back seat.

[0057] In the example shown in Figure 5A, the occupant is seated in the front seat without changing their posture, and the radio waves from the radio wave sensor 10 are projected onto the area of ​​the vehicle interior in front of the seat backrest. There are no vehicle interior structures or other objects between the occupant and the radio wave sensor 10 that would block the radio waves projected from the radio wave sensor 10. Therefore, the radio waves projected from the radio wave sensor 10 reach the occupant directly. In other words, the radio wave sensor 10 can see directly to the occupant. In this case, the distance to the object detected by the radio wave sensor 10 (i.e., the occupant) is assumed to be between the first distance and the fourth distance within the target area set in the front seat. The detection unit 104 determines whether the distance to the object detected by the radio wave sensor 10 satisfies the first detection condition, and if the distance to the object satisfies the first detection condition, it detects that an occupant is present in the vehicle interior, thereby enabling the detection of an occupant present in the vehicle interior.

[0058] In the example shown in Figure 5B, the occupants are seated in the front seats, similar to the example shown in Figure 5A. However, while the adults in Figure 5A are seated without changing their posture, in the example shown in Figure 5B, the infant is seated in a rear-facing child seat. In this case, the child seat acts as an obstruction, and the radio waves from the radio wave sensor 10 do not reach the occupant directly. In other words, the radio wave sensor 10 cannot directly see the occupant. However, the radio waves from the radio wave sensor 10 are reflected by, for example, the backrest of the front seat and irradiated towards the occupant. The distance from the radio wave sensor 10 to the occupant via the backrest of the front seat is assumed to be between the first distance and the fourth distance within the target area set on the front seat. Because the radio waves from the radio wave sensor 10 do not reach the occupants directly but are reflected by the backrest of the front seats before reaching them, the distance to the detected occupants is longer compared to when the radio waves are directly shone on the occupants. However, the distance to the occupants seated in the seats is the distance detected based on the received waves from the reflected waves that have been reflected by the backrest of the front seats and reached the occupants on the seat surface (more specifically, on the child seat installed on the seat surface), and it is assumed that this distance will not be longer than the fourth distance. The detection unit 104 determines whether the distance to the object (i.e., the occupant) detected by the radio wave sensor 10 satisfies the first detection condition. If the distance to the object satisfies the first detection condition, it detects the presence of an occupant inside the vehicle. This allows the detection of occupants inside the vehicle who are not directly exposed to radio waves from the radio wave sensor 10 due to obstructions.

[0059] In the example shown in Figure 5C, the front seats act as an obstruction, preventing the radio waves from the radio wave sensor 10 from directly reaching the occupants. In other words, the radio wave sensor 10 cannot directly see the occupants. However, the radio waves from the radio wave sensor 10 are reflected by, for example, the backrest of the rear seats and irradiated towards the occupants. In this case, the distance from the radio wave sensor 10 to the occupants via the backrest of the rear seats is assumed to be between the first distance and the fourth distance within the target area set in the rear seats. Because the radio waves from the radio wave sensor 10 do not reach the occupants directly but are reflected by the backrest of the rear seat before reaching them, the distance to the detected occupants is longer compared to when the radio waves are directly shone on them. However, the distance to the occupants seated in the seats is the distance detected based on the received waves from the reflected waves that reach the occupants on the seat surface after being reflected by the backrest of the rear seat, and it is assumed that this distance will not be longer than the fourth distance. The detection unit 104 determines whether the distance to the object (i.e., the occupant) detected by the radio wave sensor 10 satisfies the first detection condition. If the distance to the object satisfies the first detection condition, it detects the presence of an occupant inside the vehicle. This allows the detection of the presence of occupants even if they are not directly exposed to radio waves from the radio wave sensor 10.

[0060] In Embodiment 1, if the distance to the object detected by the radio wave sensor 10 satisfies the above-described first detection condition, the detection unit 104 may further determine, based on the sensor information, whether the detected object is a living organism, and if it determines that the detected object is a living organism, it may detect that there is an occupant inside the vehicle.

[0061] Specifically, the detection unit 104 may detect the presence of an occupant in the vehicle cabin if the distance to the object detected by the radio wave sensor 10 satisfies the above-described first detection condition, and the reflected power information, speed information, or position information included in the sensor information satisfies a preset condition (hereinafter referred to as the "biological detection condition"). In Embodiment 1, the biological detection condition is a condition for detecting whether or not an object is a living organism. For biometric detection, administrators or other relevant personnel may set conditions such as (Condition 1-1) to (Condition 1-3) below. (Condition 1-1) The signal strength is equal to or greater than a predetermined threshold (hereinafter referred to as the "first intensity determination threshold"). (Condition 1-2) The velocity of the object is equal to or greater than a predetermined threshold (hereinafter referred to as the "first velocity determination threshold"). (Conditions 1-3) The size or shape of the detected object is a preset size or shape.

[0062] In (Condition 1-1), the first intensity determination threshold is set in advance to a signal intensity that is assumed to be the signal intensity of a living organism. In (Condition 1-2), an appropriate speed is pre-set as the first speed determination threshold. The living organism is expected to be moving to some extent. In (Conditions 1-3), the predetermined size or shape is set to an appropriate size or shape that can be considered to be the size or shape of a living organism.

[0063] The detection unit 104 determines that the conditions for biometric detection are met and detects that an occupant is present inside the vehicle when the distance to the object detected by the radio wave sensor 10 satisfies the above-described first detection conditions, and the reflected power information, velocity information, or position information included in the sensor information satisfies, for example, any of (condition 1-1) to (condition 1-3).

[0064] For example, the detection unit 104 can determine whether or not the detected object is a living being from the reflected power information included in the sensor information. For example, if the distance to the object detected by the radio wave sensor 10 satisfies the above-mentioned first detection conditions and the signal strength is equal to or greater than the first strength determination threshold, the detection unit 104 will determine that the detected object is a living being, in other words, that there is an occupant inside the vehicle. Furthermore, for example, the detection unit 104 can determine whether or not the detected object is a living being from the velocity information included in the sensor information. The detection unit 104 detects that the detected object is a living being, or in other words, that there is an occupant inside the vehicle, if the distance to the object detected by the radio wave sensor 10 satisfies the above-mentioned first detection conditions and the velocity of the object is equal to or greater than a predetermined first velocity determination threshold. Furthermore, for example, the detection unit 104 can determine whether or not the detected object is a living being based on the location information included in the sensor information. If the distance to the object detected by the radio wave sensor 10 satisfies the above-mentioned first detection condition, the detection unit 104 estimates the size or shape of the detected object, and if the size or shape of the object is a preset size or shape, it detects that the detected object is a living being, in other words, that there is an occupant inside the vehicle.

[0065] The detection unit 104 may, for example, combine (conditions 1-1) to (conditions 1-3) as described above to determine whether the reflected power information, velocity information, or position information included in the sensor information satisfies the conditions for biodetection.

[0066] Furthermore, the detection unit 104 may, for example, use a trained model (hereinafter referred to as the "first machine learning model") that takes sensor information as input and outputs information indicating whether or not the detected object is a living organism to determine whether or not the detected object is a living organism. The detection unit 104 detects that the detected object is a living being, or in other words, that there is an occupant inside the vehicle, when the distance to the object detected by the radio wave sensor 10 satisfies the above-described first detection conditions, and when the sensor information is input to the first machine learning model and information indicating that the object is a living being is obtained.

[0067] There is a possibility that non-living objects may be present in the seats, such as plastic containers filled with water, golf bags, or bags filled with rice. As described above, the detection unit 104 can prevent false detection of non-living objects as occupants by determining whether the detected object is a living organism or not using the conditions for biological detection or the first machine learning model.

[0068] Here, the detection unit 104 determines whether the detected object is a living organism, but this is merely an example. For example, the signal processing unit 18 may determine whether the detected object is a living organism using the method described above, and if it determines that the detected object is a living organism, it may generate sensor information and output it to the biological detection device 1. In this case, the detection unit 104 does not need to consider whether the object based on the sensor information is a non-living organism. In other words, the detection unit 104 can detect whether or not there is an occupant in the vehicle interior, while preventing false detection of a non-living organism as an occupant, by, for example, whether or not the first detection conditions described above are met based on the sensor information.

[0069] The detection unit 104 outputs the detection result (hereinafter referred to as "occupant detection result") of whether or not an occupant is present inside the vehicle to the output unit 105.

[0070] The output unit 105 outputs the occupant detection result output from the detection unit 104 to the abandoned vehicle detection device 200. The detection unit 104 may also have the function of the output unit 105.

[0071] The abandoned vehicle detection device 200 outputs an alarm based on the occupant detection result output from the output unit 105. For example, the abandoned vehicle detection device 200 is connected to a speaker (not shown) mounted on the vehicle, and when the output unit 105 outputs a result indicating that an occupant is present inside the vehicle, it causes the speaker to emit an alarm sound. In this way, the abandoned vehicle detection device 200 notifies people in the vicinity of the vehicle that an abandoned vehicle has been found inside the vehicle. Furthermore, for example, the abandoned vehicle detection device 200 is connected to a portable terminal (not shown) owned by the vehicle owner. When the output unit 105 outputs a result indicating that an occupant is present inside the vehicle, it causes the output device on the portable terminal to output an alarm message or alarm sound. In this way, the abandoned vehicle detection device 200 informs the vehicle owner that an abandoned vehicle has been found inside the vehicle.

[0072] The operation of the biodetection device 1 according to Embodiment 1 will be described below. Figure 6 is a flowchart illustrating the operation of the biodetection device 1 according to Embodiment 1. For example, when the vehicle stops, the biometric detection device 1 performs the operations shown in the flowchart of Figure 6. The biometric detection device 1 performs the operations shown in the flowchart of Figure 6 for each seat in the vehicle interior, and repeats the operations shown in the flowchart of Figure 6 until the detection process for whether or not an occupant is present in all seats is completed, or until it detects that an occupant is present in any of the seats.

[0073] The sensor information acquisition unit 101 acquires sensor information from the signal processing unit 18 (step ST1). The sensor information acquisition unit 101 outputs the acquired sensor information to the region setting unit 102.

[0074] The area setting unit 102 performs target area setting processing (step ST2). Specifically, the area setting unit 102 sets the target area within the vehicle interior and sets the first target point, the second target point, and the third target point. The area setting unit 102 outputs the target area information to the distance calculation unit 103. At this time, the area setting unit 102 outputs the sensor information acquired from the sensor information acquisition unit 101 to the distance calculation unit 103 along with the target area information.

[0075] The distance calculation unit 103 calculates the first distance, second distance, and third distance from the position of the radio wave sensor 10 and the target area set by the area setting unit 102 in step ST2 (step ST3). The distance calculation unit 103 outputs the target distance information to the detection unit 104. At this time, the distance calculation unit 103 also outputs the sensor information output from the area setting unit 102 to the detection unit 104 along with the target distance information.

[0076] The detection unit 104 detects whether or not there are occupants inside the vehicle (step ST4) based on the sensor information acquired by the sensor information acquisition unit 101 in step ST1 and the first distance, second distance, and third distance calculated by the distance calculation unit 103 in step ST3. For example, the detection unit 104 detects that an occupant is present inside the vehicle when the distance to the object detected by the radio wave sensor 10 satisfies the above-mentioned first detection conditions. For example, the detection unit 104 may, if the distance to the object detected by the radio wave sensor 10 satisfies the above-described first detection condition, further determine whether the detected object is a living being based on the sensor information, and if it determines that the detected object is a living being, then detect that there is an occupant inside the vehicle. The detection unit 104 outputs the occupant detection result to the output unit 105.

[0077] The output unit 105 outputs the occupant detection result output from the detection unit 104 to the abandoned vehicle detection device 200 (step ST5).

[0078] Note that while the flowchart in Figure 6 assumes that the processes are carried out in the order of Step ST1 and Step ST2, the order of the processes in Step ST1 and Step ST2 is not limited to this. The processes in step ST1 and step ST2 may be performed in parallel, or the process in step ST1 may be performed after the process in step ST2.

[0079] As described above, the biodetection device 1 according to Embodiment 1 sets a columnar target area having a height in the direction of the seat height, which is the target for detecting the presence or absence of a living being based on sensor information generated based on reflected waves from radio waves radiated by the radio wave sensor 10 toward the interior area of ​​the vehicle, including at least the seats present in the vehicle interior, and reflected by objects in the vehicle interior. The biodetection device 1 also sets a first target point, which is a point on the upper surface of the target area and is the closest point to the radio wave sensor 10; a second target point, which is a point on the upper surface of the target area and is the furthest point from the radio wave sensor 10 than the first target point; and a third target point, which is the furthest point from the second target point in the target area. The biodetection device 1 calculates a first distance from the position of the radio wave sensor 10 to the first target point, a second distance from the position of the radio wave sensor 10 to the second target point, and a third distance from the second target point to the third target point. The biometric detection device 1 then detects whether or not an occupant is present inside the vehicle based on sensor information and the first, second, and third distances. As a result, the biodetection device 1 can detect occupants present in the vehicle interior. More specifically, the biodetection device 1 can detect occupants present in the vehicle interior even if they are in a blind spot from the perspective of the radio wave sensor 10, such as in a location where the emitted radio waves are blocked by vehicle interior structures that reflect the radio waves.

[0080] If the radio wave sensor 10 were installed on the ceiling above the seat cushion of each seat, for example, even if an occupant is in a location shielded by other seats positioned in front of the seat in which they are sitting (see, for example, Figure 5C), the radio waves emitted from the radio wave sensor 10 would likely directly reach the occupant sitting in the seat. However, some vehicle models have a skylight above the seat cushion. In such cases, the number of compatible vehicle models that can detect whether or not an occupant is present in the vehicle based on sensor information generated by the radio wave sensor 10 installed on the ceiling may be limited. Furthermore, from the standpoint of wiring, installing the radio wave sensor 10 on the ceiling is undesirable. Furthermore, even if a radio wave sensor 10 is installed on the ceiling above the seat cushion, if, for example, an object that does not transmit radio waves is covering the occupant on the seat cushion, the occupant will not be directly exposed to radio waves. As described above, the biodetection device 1 according to Embodiment 1 utilizes the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the interior structure of the vehicle and irradiated onto the occupant, thereby enabling the detection of occupants inside the vehicle. As a result, the degree of freedom in the installation position of the radio wave sensor 10, which generates the sensor information used by the biodetection device 1 for occupant detection, is increased. Because the degree of freedom in the installation position of the radio wave sensor 10 is increased, the biodetection device 1 can detect whether or not an occupant is present inside the vehicle without being limited to specific vehicle models.

[0081] In the above embodiment 1, when the biometric detection device 1 detects the presence of an occupant inside the vehicle, it outputs occupant detection information indicating the presence of an occupant inside the vehicle to the abandoned vehicle detection device 200, and the abandoned vehicle detection device 200 outputs an alarm when the biometric detection device 1 detects the presence of an occupant inside the vehicle. However, if the occupant inside the vehicle is, for example, an adult capable of getting out of the vehicle on their own, then that occupant cannot be said to have been left behind. The abandoned occupant detection device 200 does not need to output an alarm if there is an occupant inside the vehicle who is capable of getting out of the vehicle on their own. Therefore, for example, the biometric detection device 1 may determine whether the occupant detected inside the vehicle is a person requiring assistance, and output the determination result to the abandoned person detection device 200. In this way, the abandoned person detection device 200 can output an alarm that is truly deemed necessary and appropriate to the situation inside the vehicle. More specifically, the abandoned person detection device 200 can output an alarm when the occupant inside the vehicle is a person requiring assistance. In Embodiment 1, a person requiring assistance is assumed to be an infant or pet, or any other living being that is unable to leave the vehicle on its own.

[0082] Specifically, in the biometric detection device 1, the detection unit 104 can detect whether or not there is an occupant inside the vehicle, and if an occupant is detected inside the vehicle, it can determine whether or not that occupant is a person requiring assistance.

[0083] The detection unit 104 can determine whether or not a living person is in need of assistance based on the sensor information. For example, the detection unit 104 determines that a living being is in need of assistance if the reflected power information, velocity information, or position information contained in the biological information satisfies a preset condition (hereinafter referred to as the "condition for determining whether a person requires assistance"). In Embodiment 1, the condition for determining whether a person requires assistance is a condition for determining whether an object is in need of assistance. The criteria for determining whether someone requires assistance are set by the administrator or other relevant personnel, such as the following conditions (Condition 2-1) to (Condition 2-3). (Condition 2-1) The signal intensity is equal to or greater than the first intensity determination threshold, and less than or equal to a predetermined threshold (hereinafter referred to as the "second intensity determination threshold"). (Condition 2-2) The velocity of the object is equal to or greater than the first intensity determination threshold, and equal to or less than a predetermined threshold (hereinafter referred to as the "second velocity determination threshold"). (Condition 2-3) The size or shape of the detected object is a preset size or shape.

[0084] In (Condition 2-1), the second intensity determination threshold is pre-set to a signal intensity that is assumed to be, for example, the signal intensity of a reflected wave hitting an infant. For example, an adult has a larger body than a child, and therefore the area hit by the radio waves emitted from the radio wave sensor 10 is larger. The larger the area hit by the emitted radio waves, the stronger the signal intensity of the reflected wave. In (Condition 2-2), an appropriate speed is pre-set for the second speed determination threshold. It is expected that the living organism is moving to some extent. For example, an infant in a child car seat is an example of a person requiring assistance, but it is assumed that the movement of such an infant is more restricted than that of an adult while in the child car seat. In (Condition 2-3), the pre-set size or shape includes, for example, an appropriate size or shape that can be considered to be the size or shape of an infant.

[0085] The detection unit 104 determines that the conditions for determining a person requiring assistance are met if the reflected power information, speed information, or position information included in the sensor information satisfies any of, for example, (condition 2-1) to (condition 2-3), and determines that the occupant present in the vehicle is a person requiring assistance.

[0086] For example, the detection unit 104 determines that the detected occupant is a person requiring assistance if the signal intensity based on the reflected power information contained in the biological information is above a first intensity determination threshold and below a second intensity determination threshold. Furthermore, the detection unit 104 determines, for example, that the detected occupant is a person requiring assistance if the velocity of the object, based on the velocity information included in the sensor information, is above a first velocity determination threshold and below a second velocity determination threshold. Furthermore, the detection unit 104 determines, for example, that the detected occupant is a person requiring assistance if the size or shape of the occupant based on the position information included in the sensor information matches a preset size or shape.

[0087] The detection unit 104 may, for example, combine (conditions 2-1) to (conditions 2-3) as described above to determine whether the reflected power information, velocity information, or position information included in the sensor information satisfies the conditions for determining whether the person requires assistance.

[0088] Furthermore, the detection unit 104 may, for example, use a trained model (hereinafter referred to as the "second machine learning model") that takes sensor information as input and outputs information indicating whether or not the detected object is a person requiring assistance, to determine whether or not the detected occupant is a person requiring assistance. When the detection unit 104 inputs sensor information to the second machine learning model and obtains information indicating that the object is a person requiring assistance, it determines that the detected occupant is a person requiring assistance.

[0089] When the detection unit 104 determines whether or not an occupant is a person requiring assistance, it outputs to the output unit 105 as an occupant detection result information that associates information indicating whether or not an occupant is detected to be present in the vehicle compartment, and, if an occupant is detected, information indicating whether or not the occupant is a person requiring assistance.

[0090] The output unit 105 outputs the occupant detection result output from the detection unit 104 to the abandoned person detection device 200. Based on the occupant detection result output from the output unit 105, the abandoned person detection device 200 outputs an alarm if a person requiring assistance is detected inside the vehicle. This prevents the abandoned person detection device 200 from outputting unnecessary alarms. The biometric detection device 1 can provide the occupant detection result to the abandoned person detection device 200 in a manner that prevents the output of unnecessary alarms. For example, in the biometric detection device 1, the output unit 105 may output the occupant detection result to the abandoned vehicle detection device 200 if the occupants in the vehicle detected by the detection unit 104 are all persons requiring assistance.

[0091] Furthermore, in the above embodiment 1, the target area was defined as the area above the seat surface, but this is merely one example. The target area may include the area below the seat surface. In this case, the area inside the vehicle shall include not only the area above the seat surface of the front or rear seats, but also the area on the floor below the seat surface of the front or rear seats.

[0092] Here, Figure 7 shows an example of a target area set by the area setting unit 102 in the target area setting process, when the area setting unit 102 includes the area below the seat surface as the target area in Embodiment 1. In Figure 7, for convenience, only the radio wave sensor 10 and one seat are shown. In Figure 7, "S" indicates a seat, and "C" indicates the location of the radio wave sensor 10. Also in Figure 7, the target area is indicated by "R2". The lines L1-L2 and L5, and points P1-P2 and P4 shown in Figure 7 will be discussed later.

[0093] The area setting unit 102 includes, for example, the area below the surface including the seat surface within the vehicle interior area, more specifically, the area at the foot of the seat (hereinafter referred to as the "foot area"), as the target area. For example, the area setting unit 102 defines a columnar area as the target area, with the floor surface at the foot of the seat (hereinafter referred to as the "foot surface") as the bottom surface and the seat surface, which has been moved to the upper end of the seat backrest, as the top surface, and having a height from the floor surface to the upper end of the seat backrest. The size of the floor space corresponding to each seat in the vehicle interior is predetermined. In Figure 7, as an example, the floor space corresponding to a seat is the floor surface including the area under and in front of the seat, and has the same width as the seat. Note that "same width as the seat" is not limited to being exactly the same width, but includes being approximately the same. For example, as shown in Figure 7, the area setting unit 102 defines a columnar area as the target area, with the footrest upper surface corresponding to the seat (see "D" in Figure 7) as the bottom surface and the seat upper surface (see "B" in Figure 7) when the seat upper surface is moved parallel to the height of the upper end of the headrest as the top surface.

[0094] Note that the target area shown in Figure 7 is merely an example, and the area setting unit 102 may set an area having a shape other than the target area shown in Figure 7 as the target area.

[0095] When the area setting unit 102 sets the target area, it sets the first target point, the second target point, and the third target point. Here, the third point of reference, that is, the point furthest from the second point of reference in the reference region, is the point indicated as "P4" in Figure 7.

[0096] In this case as well, the area setting unit 102 may, for example, acquire information regarding the current tilt of the seat backrest and the front-to-back position of the seat from a seat sensor provided in the vehicle, and perform the setting of the target area and the calculation of coordinates including the first target point, second target point, and third target point in the actual space inside the vehicle where the target area can be identified.

[0097] The area setting unit 102 outputs the target area information, along with the sensor information, to the distance calculation unit 103. Since the seat height, seat width, seat depth, and the size of the footrest area are known in advance, the area setting unit 102 can determine the coordinates of the four corners of the footrest area corresponding to the seat.

[0098] In this case, the distance calculation unit 103 calculates the distance from the position of the radio wave sensor 10 to the third target point indicated as "P4" in Figure 7 as the third distance. In Figure 7, the third distance is indicated as "L5". In Figure 7, the first distance is indicated by "L1" and the second distance by "L2".

[0099] In the biodetection device 1, by setting the area setting unit 102 to include the area below the surface including the seat cushion, specifically the foot area, in the target area, the biodetection device 1 can detect occupants who are located below the seat cushion, such as a child hiding under the seat cushion.

[0100] Furthermore, in the above embodiment 1, the radio wave transmitting and receiving unit 19 of the radio wave sensor 10 may control the radio wave radiation range. Specifically, the radio wave transmitting / receiving unit 19 controls the radio waves emitted from the radio wave sensor 10, more specifically from the transmitting antenna Tx, to be directed towards the center of the seat backrest in order to minimize the amount of radiation reflected by the interior structure of the vehicle or by other passengers seated on the seat surface before reaching the passengers seated on the seat surface. The radio wave transmitting / receiving unit 19 can control the radio waves emitted from the transmitting antenna Tx using known methods. Known methods for controlling radio waves emitted from the transmitting antenna Tx include DBF (Digital Beam Forming) or Capon. The radio wave transmitting / receiving unit 19 can also use DBF or Capon to control the reception direction of reflected waves received by the receiving antenna Rx, in addition to the transmission side. Note that control of radio waves using DBF or Capon is applicable when at least one of the transmitting antenna Tx or receiving antenna Rx has multiple antenna elements (transmitting antenna elements or receiving antenna elements). For example, if the transmitting antenna Tx and the receiving antenna Rx each have one antenna element (either a transmitting antenna element or a receiving antenna element), the radio wave transmitting / receiving unit 19 can control the radio waves to be directed towards the center of the seat backrest by, for example, using a lens to change the direction of the emitted radio waves, or by mechanically moving the radio wave sensor 10 itself. Figure 8 is a diagram illustrating an example of how the radiation range of radio waves emitted from the transmitting antenna Tx is controlled by the radio wave sensor 10 in Embodiment 1. For convenience, Figure 8 shows only the radio wave sensor 10 and one seat. In Figure 8, "S" indicates a seat. Also in Figure 8, the controlled radio wave emission range is indicated by "E". The radio waves emitted from the transmitting antenna Tx are widely radiated towards the center of the seat back, while radiation is suppressed in areas other than the center of the seat back.

[0101] Furthermore, in the above embodiment 1, the biodetection device 1 is assumed to be mounted on the radio wave sensor 10, but this is merely one example. The biodetection device 1 may be located outside the radio wave sensor 10, and the radio wave sensor 10 and the biodetection device 1 may constitute a biodetection system. Figure 9 shows an example configuration of a biodetection system 1000 in Embodiment 1, which includes a radio wave sensor 10 and a biodetection device 1. Note that Figure 9 omits the specific configuration examples of the radio wave sensor 10 and the specific configuration examples of the biodetection device 1. For example, the biometric detection device 1 may be provided in the abandoned object detection device 200, or it may be provided in a server connected to the radio wave sensor 10 via a network.

[0102] Furthermore, in the above embodiment 1, the biodetection device 1 set the target area, the first target point, the second target point, and the third target point each time, and calculated the first distance, the second distance, and the third distance, but this is just one example. For example, the target area may be fixedly determined in advance within the vehicle interior. Since the installation position of the radio wave sensor 10 is known, if the target area is fixedly determined, the first target point, second target point, third target point, first distance, second distance, and third distance can also be fixedly determined in advance. In the biodetection device 1, the detection unit 104 may store information on the predetermined target area, first target point, second target point, third target point, first distance, second distance, and third distance, and detect whether or not an occupant is present in the vehicle interior based on the stored information on the target area, first target point, second target point, third target point, first distance, second distance, and third distance. In this case, the biodetection device 1 is not required to include a region setting unit 102 and a distance calculation unit 103. Furthermore, regarding the operation of the biodetection device 1 as explained using the flowchart in Figure 6, the biodetection device 1 can omit the processing of steps ST2 to ST3.

[0103] Furthermore, in the above embodiment 1, as an example, the interior of a vehicle was assumed to be the interior of a vehicle, and the biometric detection device 1 detected whether or not an occupant was present in the vehicle based on sensor information generated by the radio wave sensor 10. However, this is only one example. For example, "interior" may refer to a moving object other than a ship or a vehicle such as a train. For example, "occupant" may refer to the occupants of a ship or a train. The biometric detection device 1 can detect whether or not an occupant is present in the interior of various moving objects. Furthermore, the biodetection device 1 can detect whether or not there are living beings in rooms or other areas within a building, not just occupants inside a mobile vehicle. For example, the biodetection device 1 can detect whether or not there is a person inside a room in a nursing home. The biodetection device 1 detects whether or not there is a person inside a room and outputs the detection result to, for example, a monitoring device (not shown). The monitoring device can output an alarm if there is a person left behind in the room. In this case, the biodetection device 1 only needs to operate at a timing instructed by, for example, a manager. The biological detection device 1 can detect living organisms in various indoor environments, even when they are located in blind spots for the radio wave sensor 10 due to the indoor structure, by utilizing the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the indoor structure and irradiated onto the living organism.

[0104] Figures 10A and 10B show an example of the hardware configuration of the biodetection device 1 according to Embodiment 1. In Embodiment 1, the functions of the sensor information acquisition unit 101, the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105 are realized by the processing circuit 1001. In other words, the biological detection device 1 includes a processing circuit 1001 for controlling whether or not a living organism is present in the room. The processing circuit 1001 may be dedicated hardware as shown in Figure 10A, or it may be a processor 1004 that executes a program stored in memory as shown in Figure 10B.

[0105] If the processing circuit 1001 is dedicated hardware, it may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof.

[0106] When the processing circuit is a processor 1004, the functions of the sensor information acquisition unit 101, the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105 are realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in memory 1005. The processor 1004 executes the functions of the sensor information acquisition unit 101, the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105 by reading and executing the program stored in memory 1005. In other words, the biodetection device 1 is equipped with memory 1005 for storing a program that, when executed by the processor 1004, will result in the execution of steps ST1 to ST5 in Figure 6 described above. Furthermore, the program stored in memory 1005 can be said to cause the computer to execute the procedures or methods for processing the sensor information acquisition unit 101, the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105. Here, memory 1005 refers to non-volatile or volatile semiconductor memory such as RAM, ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), magnetic disks, flexible disks, optical disks, compact disks, minidiscs, DVDs (Digital Versatile Discs), etc.

[0107] Furthermore, the functions of the sensor information acquisition unit 101, the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105 may be partially implemented by dedicated hardware and partially implemented by software or firmware. For example, the sensor information acquisition unit 101 can be implemented by a processing circuit 1001 as dedicated hardware, while the area setting unit 102, the distance calculation unit 103, the detection unit 104, and the output unit 105 can be implemented by the processor 1004 reading and executing a program stored in memory 1005. Furthermore, the biometric detection device 1 includes devices such as an abandoned object detection device 200, and an input interface device 1002 and an output interface device 1003 that perform wired or wireless communication.

[0108] As described above, according to Embodiment 1, the biological detection device 1 is configured to include a sensor information acquisition unit 101 that acquires sensor information generated based on reflected waves reflected by objects in the room from radio waves radiated by a radio wave sensor 10 toward an indoor area including at least seats present in the room; and a detection unit 104 that detects whether or not a living being is present in the room based on the sensor information acquired by the sensor information acquisition unit 101, a first distance from the position of the radio wave sensor 10 to a first target point which is a point on the upper surface of a columnar target area having a height in the height direction of the seats to be detected as the target for detection of the presence or absence of a living being based on the sensor information, and is the closest point to the position of the radio wave sensor 10; a second distance from the position of the radio wave sensor 10 to a second target point which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor 10 than the first target point; and a third distance from the second target point to a third target point which is the furthest point from the second target point in the target area. Therefore, the biological detection device 1 can detect living beings present in the room. The biological detection device 1 can detect a living person in a room even if the living person is in a blind spot for the radio wave sensor 10 due to the structure of the room, by utilizing the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the structure of the room and irradiated onto the living person.

[0109] Furthermore, according to Embodiment 1, the biodetection device 1 targets a columnar region having the height of the seat backrest, with the seat top surface, which includes the seat cushion, as the bottom surface and the seat top surface moved to the upper end of the seat backrest as the top surface. Therefore, even if a living being is located in a blind spot for the radio wave sensor 10 due to the structure of the room, the biodetection device 1 can detect the living being in the room by utilizing the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the structure of the room and irradiated onto the living being.

[0110] Furthermore, the biodetection device 1 may have a target area that is a columnar region with a height from the floor to the top of the seat backrest, with the floor surface corresponding to the seat's feet as its bottom surface and the seat surface, which includes the seat cushion when moved to the top of the seat backrest, as its top surface. This allows the biodetection device 1 to detect living beings that are below the seat cushion, such as a child hiding under the seat cushion.

[0111] Furthermore, according to Embodiment 1, in the biodetection device 1, the detection unit 104 detects the presence of a living organism in the room if the distance to the object detected by the radio wave sensor 10 is greater than or equal to the first distance and less than or equal to the fourth distance obtained by adding the second distance and the third distance. Therefore, the biodetection device 1 can detect living organisms present in the room. The biological detection device 1 can detect a living person in a room even if the living person is in a blind spot for the radio wave sensor 10 due to the structure of the room, by utilizing the phenomenon in which radio waves from the radio wave sensor 10 are reflected by the structure of the room and irradiated onto the living person.

[0112] Furthermore, according to Embodiment 1, in the biodetection device 1, the detection unit 104 may detect the presence of a living organism in the room if the distance to the object detected by the radio wave sensor 10 is greater than or equal to a first distance and less than or equal to a fourth distance obtained by adding the second and third distances, and if the reflected power information, velocity information, or position information included in the bioinformation satisfies the conditions for biodetection to determine whether or not the object is a living organism. This prevents the biodetection device 1 from mistakenly detecting non-living objects as living organisms.

[0113] Furthermore, according to Embodiment 1, in the biodetection device 1, if the distance to the object detected by the radio wave sensor 10 is greater than or equal to a first distance and less than or equal to a fourth distance obtained by adding the second distance and the third distance, and the sensor information is input to a first machine learning model that takes sensor information as input and outputs information indicating whether or not the object is a living organism, then the detection unit 104 may detect that a living organism is present in the room. This prevents the biodetection device 1 from falsely detecting non-living objects as living organisms.

[0114] Furthermore, according to Embodiment 1, in the biodetection device 1, the detection unit 104 may determine that a living being is in need of assistance if the reflected power information, velocity information, or position information included in the biological information satisfies the conditions for determining whether an object is in need of assistance. This allows the biodetection device 1 to provide a detection result of whether or not a living being is present in the room in a manner that prevents the output of unnecessary alarms.

[0115] Furthermore, according to Embodiment 1, in the biodetection device 1, the detection unit 104 may input sensor information to a second machine learning model that takes sensor information as input and outputs information indicating whether or not an object is a person requiring assistance, and if it obtains information indicating that an object is a person requiring assistance, it may determine that the living organism is a person requiring assistance. In this way, the biodetection device 1 can provide a detection result of whether or not a living organism is present in the room in a manner that prevents the output of unnecessary alarms.

[0116] Furthermore, according to Embodiment 1, the biological detection device 1 can be configured to include an output unit 105 that outputs a detection result indicating the presence of a living organism in the room when the detection unit 104 detects the presence of a living organism in the room. This allows the biological detection device 1 to provide a detection result indicating the presence of a living organism in the room.

[0117] Furthermore, according to Embodiment 1, the biodetection device 1 can be configured to include an output unit 105 that outputs a detection result indicating the presence of a person requiring assistance in the room when the detection unit 104 determines that the person is a person requiring assistance. This allows the biodetection device 1 to provide a detection result indicating that a person requiring assistance has been detected in the room.

[0118] Furthermore, according to Embodiment 1, the radio wave sensor 10 includes a transmitting antenna Tx that radiates radio waves toward the indoor area, a receiving antenna Rx that receives reflected waves of radio waves radiated from the transmitting antenna Tx, a radio wave transmitting and receiving unit 19 that radiates radio waves from the transmitting antenna Tx and acquires a received signal based on the reflected waves from the receiving antenna Rx, an A / D conversion circuit 17 that converts the received signal acquired by the radio wave transmitting and receiving unit 19 from an analog signal to a digital signal, a signal processing unit 18 that generates sensor information based on the digital signal converted by the A / D conversion circuit 17, a sensor information acquisition unit 101 that acquires sensor information, and the sensor information acquired by the sensor information acquisition unit 101. The system can be configured to include a detection unit 104 that detects whether or not a living being is present in a room based on a first distance from the position of the radio wave sensor 10 to a first target point, which is a point on the upper surface of a columnar target area having a height in the direction of the height of the seat to be targeted for detection of the presence or absence of a living being based on sensor information, and is the closest point to the position of the radio wave sensor 10; a second distance from the position of the radio wave sensor 10 to a second target point, which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor 10 than the first target point; and a third distance from the second target point to a third target point, which is the furthest point from the second target point in the target area. Therefore, the radio wave sensor 10 can detect living beings present in the room. The radio wave sensor 10 can detect living organisms indoors, even if they are located in a blind spot of the sensor due to indoor structures or other factors. This is achieved by utilizing the phenomenon where radio waves from the sensor 10 are reflected by indoor structures and irradiated onto the living organism.

[0119] Furthermore, according to Embodiment 1, in the radio wave sensor 10, the radio wave transmitting and receiving unit 19 can be configured to control the radio wave radiation range. This makes it possible for the radio wave sensor 10 to minimize the amount of radio waves emitted from the transmitting antenna Tx that are reflected by indoor structures or other living beings sitting on the seat surface before being irradiated onto living beings.

[0120] Furthermore, according to Embodiment 1, the biodetection system 1000 includes a radio wave sensor 10 having a transmitting antenna Tx that radiates radio waves toward an indoor area, a receiving antenna Rx that receives reflected waves of radio waves radiated from the transmitting antenna Tx, a radio wave transmitting and receiving unit 19 that radiates radio waves from the transmitting antenna Tx and acquires a received signal based on the reflected waves from the receiving antenna Rx, an A / D conversion circuit 17 that converts the received signal acquired by the radio wave transmitting and receiving unit 19 from an analog signal to a digital signal, and a signal processing unit 18 that generates sensor information based on the digital signal converted by the A / D conversion circuit 17, and a sensor information acquisition unit 101 that acquires sensor information from the radio wave sensor 10. The biodetection device 1 can be configured to include a detection unit 104 that detects whether or not a living being is present in a room based on sensor information, a first distance from the position of the radio wave sensor 10 to a first target point which is a point on the upper surface of a columnar target area having a height in the direction of the height of the seat to be targeted for detection of the presence or absence of a living being based on the sensor information, and is the closest point to the position of the radio wave sensor 10, a second distance from the position of the radio wave sensor 10 to a second target point which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor 10 than the first target point, and a third distance from the second target point to a third target point which is the furthest point from the second target point in the target area. The biodetection system 1000 can detect living beings indoors, even when they are located in a blind spot for the radio wave sensor 10 due to indoor structures or other factors. This is achieved by utilizing the phenomenon where radio waves from the radio wave sensor 10 are reflected by indoor structures or other factors and irradiated onto the living being.

[0121] Furthermore, according to Embodiment 1, in the radio wave sensor 10 of the biodetection system 1000, the radio wave transmitting / receiving unit 19 can be configured to control the radiation range of the radio waves. This makes it possible for the biodetection system 1000 to minimize the amount of radio waves emitted from the transmitting antenna Tx that are reflected by indoor structures or other living beings sitting on the seat surface before being irradiated onto living beings.

[0122] Furthermore, any component of the embodiment can be modified, or any component of the embodiment can be omitted. [Industrial applicability]

[0123] The biodetection device described herein is applicable to biodetection devices that detect living organisms present in a room. [Explanation of Symbols]

[0124] 1 Biometric detection device, 101 Sensor information acquisition unit, 102 Area setting unit, 103 Distance calculation unit, 104 Detection unit, 105 Output unit, 10 Radio wave sensor, Tx Transmitting antenna, Rx Receiving antenna, 13 Radio wave sensor circuit unit, 14 High-frequency signal generation circuit, 15 Radio wave transmission unit, 15-1 Transmission circuit, 16 Radio wave reception unit, 16-1 Receiving circuit, 17 A / D conversion circuit, 18 Signal processing unit, 1000 Biometric detection system, 1001 Processing circuit, 1002 Input interface device, 1003 Output interface device, 1004 Processor, 1005 Memory.

Claims

1. A sensor information acquisition unit acquires sensor information generated based on reflected waves that are reflected by objects in the room from radio wave sensors that emit radio waves towards an indoor area including at least seats present in the room. The system includes a detection unit that detects whether or not a living organism is present in the room based on the sensor information acquired by the sensor information acquisition unit, a first distance from the position of the radio wave sensor to a first target point which is a point on the upper surface of a columnar target area having a height in the direction of the height of the seat that is the target for detecting the presence or absence of a living organism based on the sensor information, and is the closest point to the position of the radio wave sensor, a second distance from the position of the radio wave sensor to a second target point which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor than the first target point, and a third distance from the second target point to a third target point which is the furthest point from the second target point in the target area, The aforementioned sensor information includes: The radio wave sensor includes position information indicating the distance to the object detected, and This includes reflected power information indicating the signal strength of the reflected wave, velocity information indicating the velocity of the object detected by the radio wave sensor, or position information indicating the distance and angle of the object detected by the radio wave sensor. The detection unit, The distance to the object detected by the radio wave sensor is greater than or equal to the first distance, and less than or equal to the fourth distance obtained by adding the second distance and the third distance, If the reflected power information, the velocity information, or the position information satisfies the conditions for detecting whether or not the object is a living organism, then it is detected that a living organism is present in the room. A biological detection device characterized by the following features.

2. A region setting unit sets the target region, the first target point, the second target point, and the third target point based on the sensor information acquired by the sensor information acquisition unit, The system includes a distance calculation unit that calculates the first distance, the second distance, and the third distance. The biological detection device according to claim 1, characterized by its features.

3. The target area is a columnar region having the height of the seat backrest, with the seat top surface, which includes the seat cushion, as its bottom surface, and the seat top surface, which is moved up to the upper end of the seat backrest, as its top surface. A biodetection device according to claim 1 or 2, characterized by the above.

4. The aforementioned target area is a columnar region having a height from the floor surface to the upper end of the seat's backrest, with the floor surface corresponding to the seat's feet as its bottom surface, and the seat surface, which includes the seat cushion when the seat's backrest is moved up to the upper end of the seat's backrest, as its top surface. A biodetection device according to claim 1 or 2, characterized by the above.

5. The detection unit, When the sensor information is input to a first machine learning model that takes the sensor information as input and outputs information indicating whether or not the object is a living organism, and information indicating that the object is a living organism is obtained, it is detected that a living organism is present in the room. The biological detection device according to claim 1, characterized by its features.

6. The detection unit determines, based on the sensor information, whether the living person is a person requiring assistance who is unable to leave the room on their own. The biological detection device according to claim 1, characterized by its features.

7. The sensor information includes reflected power information indicating the signal strength of the reflected wave, velocity information indicating the velocity of the object detected by the radio wave sensor, or position information indicating the distance and angle of the object detected by the radio wave sensor. The detection unit, If the reflected power information, the velocity information, or the position information satisfies the conditions for determining whether the object is a person requiring assistance, the living organism is determined to be a person requiring assistance. The biological detection device according to claim 6.

8. The detection unit, If the sensor information is input to a second machine learning model that takes the sensor information as input and outputs information indicating whether or not the object is the person requiring assistance, and the model obtains information indicating that the object is the person requiring assistance, then the living organism is determined to be the person requiring assistance. The biological detection device according to claim 6.

9. When the detection unit detects that a living organism is present in the room, the output unit outputs a detection result indicating that a living organism is present in the room. A biological detection device according to claim 1, comprising:

10. If the detection unit determines that the living being is the person requiring assistance, the output unit outputs a detection result indicating that the person requiring assistance is present in the room. A biological detection device according to claim 6, comprising:

11. The interior refers to the interior of a vehicle, and the seat refers to the front seat or rear seat within the interior. The biological detection device according to claim 1, characterized by its features.

12. A biological detection device according to claim 1, A transmitting antenna that radiates the radio waves toward the aforementioned indoor area, A receiving antenna that receives the reflected waves of the radio waves radiated from the transmitting antenna, A radio wave transmitting and receiving unit that emits radio waves from the transmitting antenna and acquires a received signal based on the reflected waves from the receiving antenna, An A / D conversion circuit that converts the received signal acquired by the radio wave transmitting and receiving unit from an analog signal to a digital signal, A signal processing unit that generates the sensor information based on the digital signal converted by the A / D conversion circuit. A radio wave sensor equipped with [the following features].

13. The radio wave transmitting and receiving unit controls the radiation range of the radio waves. The radio wave sensor according to claim 12, characterized in that it is a radio wave sensor.

14. A biological detection device according to claim 1, A transmitting antenna that radiates the radio waves toward the aforementioned indoor area, A receiving antenna that receives the reflected waves of the radio waves radiated from the transmitting antenna, A radio wave transmitting and receiving unit that emits radio waves from the transmitting antenna and acquires a received signal based on the reflected waves from the receiving antenna, An A / D conversion circuit that converts the received signal acquired by the radio wave transmitting and receiving unit from an analog signal to a digital signal, The radio wave sensor having a signal processing unit that generates the sensor information based on the digital signal converted by the A / D conversion circuit A biometric detection system equipped with [the following features].

15. The radio wave transmitting and receiving unit controls the radiation range of the radio waves. The biodetection system according to claim 14, characterized by its features.

16. The sensor information acquisition unit acquires sensor information generated based on reflected waves that are reflected by objects in the room from radio waves emitted by a radio wave sensor towards an indoor area including at least seats present in the room, The detection unit includes a step of detecting whether or not a living being is present in the room based on the sensor information acquired by the sensor information acquisition unit, a first distance from the position of the radio wave sensor to a first target point which is a point on the upper surface of a columnar target area having a height in the direction of the height of the seat that is the target for detecting the presence or absence of a living being based on the sensor information, and is the closest point to the position of the radio wave sensor, a second distance from the position of the radio wave sensor to a second target point which is a point on the upper surface of the target area, and is the furthest point from the position of the radio wave sensor than the first target point, and a third distance from the second target point to a third target point which is the furthest point from the second target point in the target area. The aforementioned sensor information includes: The radio wave sensor includes position information indicating the distance to the object detected, and This includes reflected power information indicating the signal strength of the reflected wave, velocity information indicating the velocity of the object detected by the radio wave sensor, or position information indicating the distance and angle of the object detected by the radio wave sensor. The detection unit, The distance to the object detected by the radio wave sensor is greater than or equal to the first distance, and less than or equal to the fourth distance obtained by adding the second distance and the third distance, If the reflected power information, the velocity information, or the position information satisfies the conditions for detecting whether or not the object is a living organism, then it is detected that a living organism is present in the room. A method for detecting biological activity characterized by the following features.

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