Occupant detection device, method, and program

Abstract

To provide a new occupant detection device capable of detecting information about the body of an occupant on a seat in a vehicle interior of a vehicle.SOLUTION: An occupant detection device of an embodiment includes a radio wave sensor, a creation unit, and a calculation unit. The radio wave sensor is positioned above the seat surface of a seat arranged in the vehicle interior of a vehicle, in a vertical direction of the vehicle. The radio wave sensor includes: a transmitting unit that transmits transmission waves in the vehicle interior; and a receiving unit that receives reflected waves generated by reflection of the transmission waves by an occupant on the seat. The creation unit creates three-dimensional map information in the vehicle interior, in which the position of a reflection point of the reflected waves is represented by three-dimensional coordinates, based on the reflected waves. The calculation unit calculates spine information, which is information about the spine of the occupant on the seat, based on the three-dimensional map information.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an occupant detection device, method, and program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is a technique for detecting the posture, physique, etc. of a person based on the reflected wave of the radio wave irradiated onto the person. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-81771 [Patent Document 2] Japanese Patent Publication No. 2021-32879 Summary of the Invention [Problem to be solved by the invention]

[0004] It would be beneficial to have a novel occupant detection device, method, and program that can use this type of technology to detect information about the body of an occupant seated within the passenger compartment of a vehicle.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel occupant detection device, method, and program that can detect information relating to the body of an occupant sitting on a seat in the passenger compartment of a vehicle. [Means for solving the problem]

[0006] The occupant detection device of the embodiment includes a radio wave sensor located above the seat surface of a seat placed in the vehicle cabin in the vertical direction of the vehicle, and having a transmitter that transmits a transmission wave into the cabin and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat; a creation unit that creates three-dimensional map information of the interior of the vehicle cabin based on the reflected wave, which represents the position of the reflection point of the reflected wave in three-dimensional coordinates; and a calculation unit that calculates spine information, which is information about the spine of the occupant sitting on the seat, based on the three-dimensional map information.

[0007] With this configuration, the calculation unit calculates or detects information about the spine as information about the body of the occupant in the seat, so that the posture and physique of the occupant can be grasped based on the information about the spine, and thus occupant protection control can be performed according to the posture and physique of the occupant.

[0008] In the occupant detection device, for example, the spine information includes at least one of a length of the spine and an extension direction of the spine.

[0009] With this configuration, the length of the spine corresponds to the seated height of the occupant, which in turn corresponds to the physique of the occupant. Therefore, when calculating the length of the spine of an occupant in a seat, the physique of the occupant can be determined from the length of the spine. Therefore, for example, as a control related to occupant protection, it is possible to control the deployment of an airbag in the event of a vehicle collision or the tightening of a seat belt in the event of a vehicle collision. Furthermore, since the extension direction of the spine corresponds to the posture of the occupant (e.g., a leaning forward posture, a posture sitting with a tilt to the left or right), when calculating the extension direction of the spine, it is possible to determine the posture of the occupant from the extension direction of the spine. Therefore, for example, as a control related to occupant protection, it is possible to control the shape of the seat (e.g., the inclination angle of the seat surface) to absorb impact during an emergency stop of the vehicle.

[0010] In the occupant detection device, for example, the three-dimensional map information includes intensity information indicating the intensity of the reflected wave corresponding to the reflection point, and the calculation unit calculates the spine information based on the position of the center of gravity of the intensity in a point cloud, which is a group of multiple reflection points, and the position of the upper point in the point cloud that is located highest in the vertical direction.

[0011] According to this configuration, spinal information is calculated using the center of gravity of the intensities in the point cloud, so that the accuracy of the spinal information can be made relatively high.

[0012] In the occupant detection device, for example, the three-dimensional map information includes the position of the seat surface, and the calculation unit calculates the spinal information based on the center position of the seat surface and the position of the upper point that is located highest in the vertical direction among the point cloud, which is a group of multiple reflection points.

[0013] With this configuration, spinal information is calculated based on the center position of the seat and the position of the upper point that is located at the top in the vertical direction in the point cloud, so the amount of calculation required to calculate the spinal information can be relatively small.

[0014] In the occupant detection device, for example, the calculation unit calculates the position of the spine in multiple cross sections perpendicular to the vertical direction, where the positions in the vertical direction differ from each other in a point cloud, which is a group of multiple reflection points, and calculates the spine information based on the positions of the spine in the multiple cross sections.

[0015] According to such a configuration, for example, the calculation unit calculates spine information based on the positions of the spine in a plurality of cross sections of the point cloud, so that the accuracy of the spine information (for example, the extension direction of the spine) can be made relatively high.

[0016] The method of the embodiment is a method executed by an occupant detection device, which is located above the seat surface of a seat placed in the vehicle cabin in the vertical direction of the vehicle and has a radio wave sensor having a transmitter that transmits a transmission wave into the vehicle cabin and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat, and includes a step of creating three-dimensional map information of the interior of the vehicle cabin based on the reflected wave, in which the position of the reflection point of the reflected wave is expressed in three-dimensional coordinates, and a step of calculating spine information, which is information regarding the spine of the occupant sitting on the seat, based on the three-dimensional map information.

[0017] With this configuration, the calculation unit calculates or detects information about the spine as information about the body of the occupant in the seat, so that the posture and physique of the occupant can be grasped based on the information about the spine, and thus occupant protection control can be performed according to the posture and physique of the occupant.

[0018] The program of the embodiment causes a computer of an occupant detection device that is positioned above the seat surface of a seat placed in the vehicle cabin in the vertical direction of the vehicle and has a radio wave sensor that transmits a transmission wave into the cabin and a receiving unit that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat to function as a creation unit that creates three-dimensional map information of the interior of the vehicle cabin based on the reflected wave, which represents the position of the reflection point of the reflected wave in three-dimensional coordinates, and a calculation unit that calculates spine information, which is information about the spine of the occupant sitting on the seat, based on the three-dimensional map information.

[0019] With this configuration, the calculation unit calculates or detects information about the spine as information about the body of the occupant in the seat, so that the posture and physique of the occupant can be grasped based on the information about the spine, and thus occupant protection control can be performed according to the posture and physique of the occupant. [Brief explanation of the drawings]

[0020] [Figure 1]FIG. 1 is a schematic diagram of a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of the radio wave sensor and the control device according to the first embodiment. [Figure 3] FIG. 3 is a schematic diagram of three-dimensional map information according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram of a portion of three-dimensional map information according to the first embodiment. [Figure 5] FIG. 5 is an explanatory diagram for explaining a method for calculating spinal information according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing the processing by the control device of the first embodiment. [Figure 7] FIG. 7 is an explanatory diagram for explaining a method for calculating spinal information according to the second embodiment. [Figure 8] FIG. 8 is an explanatory diagram for explaining a method for calculating spinal information according to the third embodiment. [Figure 9] FIG. 9 is an explanatory diagram for explaining a method for calculating a spinal position in the spinal information calculation method according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following describes in detail the embodiments with reference to the drawings, but the present invention is not limited to these embodiments.

[0022] The following embodiments include similar components. These similar components are given common reference numerals, and redundant explanations will be omitted. The drawings are schematic, and the dimensional relationships and ratios of the components may differ from the actual ones.

[0023] First Embodiment 1 is a schematic diagram of a vehicle C in the first embodiment. A radio wave sensor 2 and a control device 3 constituting an occupant detection device 1 are arranged in a passenger compartment R of the vehicle C. The radio wave sensor 2 is installed on the ceiling of the passenger compartment R. The control device 3 is installed, for example, in a dashboard provided at the front end of the passenger compartment R.

[0024] Furthermore, a plurality of seats S in which occupants M can be seated are installed in the passenger compartment R of the vehicle C. In the case of FIG. 1, a configuration in which the seats S are arranged in two rows (front row and rear row) is shown. However, the seats S are not limited to the above. For example, the seats S may be arranged in one row, or in three or more rows.

[0025] 2 is a block diagram showing the functional configuration of the radio wave sensor 2 and the control device 3 of the embodiment. The radio wave sensor 2 includes a transmitter 21 and a receiver 22.

[0026] The transmitter 21 transmits (radiates) a transmission wave over a wide range within the passenger compartment R of the vehicle C. The transmission wave is, for example, an FMCW (Frequency Modulated Continuous Wave) modulated radio wave (microwave). The receiver 22 receives a reflected wave generated when the transmission wave is reflected by an object within the passenger compartment R. The receiver 22 is equipped with multiple receiving antennas. Here, the transmitted radio wave is reflected when it hits an occupant M who may be present within the passenger compartment R. If the occupant M is moving, the frequency of the reflected wave is shifted in proportion to the occupant M's movement speed (e.g., the speed of movement of the body surface, such as breathing or heartbeat) due to the Doppler effect. Therefore, if the reflected wave received by the receiver 22 is frequency-shifted, it means that a Doppler signal indicating the possibility of the occupant M being present within the passenger compartment R has been received. Therefore, the occupant M can be detected based on the detection result 333 of the object detector 324.

[0027] In the radio wave sensor 2, the transmitter 21 and receiver 22 may be integrated or configured separately. In the case of FIG. 1, one radio wave sensor 2 is installed so as to be able to detect all occupants M that may be present in the vehicle compartment R, but in other embodiments, the vehicle compartment R may be divided into multiple areas and a radio wave sensor 2 may be provided in each area. For example, a radio wave sensor 2 may be provided for each row of seats S.

[0028] The control device 3 is configured by, for example, an MCU (Micro Controller Unit) having an integrated circuit equipped with a hardware processor, a memory, etc. The control device 3 includes an ADC (Analog-to-Digital Converter) 31, a processing unit 32, and a storage unit 33.

[0029] The ADC 31 converts the analog signal acquired from the receiving unit 22 of the radio wave sensor 2 into a digital signal and outputs the digital signal to the processing unit 32 .

[0030] The storage unit 33 is, for example, a storage device such as a RAM (Random Access Memory), a ROM (Read Only Memory), an SSD (Solid State Drive), or an HDD (Hard Disk Drive). The storage unit 33 stores programs executed by the processing unit 32, data required for executing the programs, data generated by executing the programs, etc. The storage unit 33 stores, for example, setting information 331, three-dimensional map information 332, detection results 333, and biometric information 334.

[0031] The setting information 331 stores various setting information such as a frequency range for determining whether or not the signal is a biological signal of the occupant M, and various thresholds (a reflection source threshold for identifying the reflection source, an occupant threshold for detecting the occupant M, etc.).

[0032] The three-dimensional map information 332 is information that indicates the three-dimensional object arrangement state in the vehicle interior R, and is created by the creation unit 322 based on the reflected wave information.

[0033] The detection result 333 is information on the detection result by the object detection unit 324 .

[0034] The biological information 334 is biological information of the occupant M calculated by the calculation unit 326.

[0035] Signal processing using the FMCW method is as follows: First, an FMCW modulated transmission wave is transmitted from the transmitter 21 of the radio wave sensor 2 into the passenger compartment R of the vehicle C. Then, the receiver 22 of the radio wave sensor 2 receives the reflected wave.

[0036] Next, the creation unit 322 creates three-dimensional map information of the interior of the vehicle compartment R based on the reflected waves. This three-dimensional map information includes information on objects (reflection sources) such as metals with high reflectivity in addition to the occupant M. In other words, this three-dimensional map information alone does not allow one to distinguish whether the recognized object is metal or a person.

[0037] Next, the occupant M is detected by object detection unit 324 based on the Doppler shift of the reflected wave and person detection unit 325. Furthermore, the calculation unit 326 calculates biometric information of the occupant M. The biometric information includes information about the body of the occupant M, specifically, information about the spine of the occupant M. The processing of the processing unit 32 will be described in detail below.

[0038] The processing unit 32 is configured by a hardware processor such as a CPU (Central Processing Unit). The processing unit 32 reads a program stored in the storage unit 33 and executes arithmetic processing. The processing unit 32 includes, as functional units, an acquisition unit 321, a creation unit 322, an identification unit 323, an object detection unit 324, an occupant detection unit 325, a calculation unit 326, and a control unit 327. Note that some or all of the units 321 to 327 may be configured by hardware such as a circuit including an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0039] The acquisition unit 321 acquires the reflected wave information from the ADC 31 .

[0040] The creating unit 322 creates three-dimensional map information of the interior of the vehicle compartment R based on the reflected wave information, that is, the reflected waves, and stores the information in the storage unit 33 as three-dimensional map information 332.

[0041] FIG. 3 is a schematic diagram of three-dimensional map information 332 according to the first embodiment. FIG. 4 is a schematic diagram of a portion of the three-dimensional map information 332 according to the first embodiment. As shown in FIGS. 3 and 4, the three-dimensional map information 332 includes information representing the position of a reflection point P of a reflected wave reflected by an occupant M in three-dimensional coordinates. The three-dimensional coordinates have an X-axis, a Y-axis, and a Z-axis. The X-axis, the Y-axis, and the Z-axis are perpendicular to one another. The directions indicated by the X-axis, the Y-axis, and the Z-axis are referred to as the X-direction, the Y-direction, and the Z-direction, respectively. The X-axis (X-direction) is along the width direction of the vehicle C. The Y-axis is along the front-rear direction of the vehicle C, and the Y-direction coincides with the front of the vehicle C in the front-rear direction. The Z-axis is along the up-down direction of the vehicle C, and the Z-direction coincides with the upper side of the vehicle C in the up-down direction. The three-dimensional map information 332 also includes intensity information indicating the intensity of the reflected wave corresponding to the reflection point P. The three-dimensional map information 332 also includes the position of the seat surface Sa of the seat S. 3 and 4 show a schematic representation of the skeleton of an occupant M seated in a certain seat S. This skeleton of the occupant M is shown to show the relationship between the certain seat S and the occupant M, and is not included in the three-dimensional map information 332.

[0042] The identification unit 323 identifies the position of the reflection source in the three-dimensional map information 332 .

[0043] The object detection unit 324 detects the movement of an object in the vehicle interior R based on the Doppler shift of the reflected wave, and stores the detection result in the storage unit 33 as a detection result 333.

[0044] The occupant detection unit 325 detects one or more occupants M based on the setting information 331, the three-dimensional map information 332, and the detection result 333. The occupant detection unit 325 detects the occupant M for each seat S.

[0045] The calculation unit 326 calculates spine information 334a, which is information relating to the spine Ma (see FIG. 4) of the occupant M sitting on the seat S, based on the three-dimensional map information 332. The spine information 334a includes at least one of the length of the spine Ma and the extension direction of the spine Ma (for example, both).

[0046] FIG. 5 is an explanatory diagram illustrating a calculation method of spinal information 334a according to the first embodiment. As shown in FIG. 5, the calculation unit 326 calculates the spinal information 334a based on the center of gravity Pc of the intensity of the reflected waves in a point cloud G, which is a group of multiple reflection points P, and the position of an upper point P1 in the point cloud G that is the highest in the vertical direction of the vehicle C. Specifically, the calculation unit 326 calculates a line L1 connecting the center of gravity Pc and the upper point P1. The calculation unit 326 regards the length of the line L1 as the length of the spine Ma, and regards the direction on the line L1 from the center of gravity Pc to the upper point P1 as the extension direction of the spine Ma. Here, the point cloud G is composed of, for example, the position of the seat surface Sa of the seat S in the vertical direction of the vehicle C and multiple reflection points P located above the seat surface Sa. Note that in FIG. 5, the center of gravity Pc and the reflection point P at the upper point P1 are shown larger than the other reflection points P for ease of understanding.

[0047] The control unit 327 executes calculations other than those executed by the units 321 to 327.

[0048] 6 is a flowchart showing processing by the control device 3 of the embodiment. First, the acquisition unit 321 acquires reflected wave information from the ADC 31 (S1). Next, the creation unit 322 creates three-dimensional map information 332 based on the reflected wave information (S2). Next, the calculation unit 326 calculates the length and extension direction of the spine Ma, which are spine information 334a, based on the three-dimensional map information 332 (S3).

[0049] As described above, in the first embodiment, the occupant detection device 1 includes the radio wave sensor 2, the creation unit 322, and the calculation unit 326. The radio wave sensor 2 is located above the seat surface Sa of the seat S disposed in the vehicle compartment R of the vehicle C in the vertical direction. The radio wave sensor 2 includes a transmitter 21 that transmits a transmission wave into the vehicle compartment R, and a receiver 22 that receives a reflected wave generated when the transmission wave is reflected by the occupant M sitting on the seat S. The creation unit 322 creates three-dimensional map information 332 of the interior of the vehicle compartment R based on the reflected wave, which represents the position of a reflection point P of the reflected wave in three-dimensional coordinates. The calculation unit 326 calculates spine information 334a, which is information about the spine Ma of the occupant M sitting on the seat S, based on the three-dimensional map information 332.

[0050] According to this configuration, the calculation unit 326 calculates, or detects, information about the spine Ma as information about the body of the occupant M sitting on the seat S, so that the posture and physique of the occupant M can be grasped based on the information about the spine Ma. Therefore, control related to occupant protection can be performed according to the posture and physique of the occupant M.

[0051] In the occupant detection device 1, for example, the spine information 334a includes at least one of the length of the spine Ma and the extension direction of the spine Ma.

[0052] According to this configuration, the length of the spine Ma corresponds to the sitting height of the occupant M, which in turn corresponds to the physique of the occupant M. Therefore, when calculating the length of the spine Ma of the occupant M sitting on the seat S, the physique of the occupant M can be determined from the length of the spine Ma. Therefore, for example, as a control related to occupant protection, it is possible to control the deployment of an airbag in the event of a collision of the vehicle C or the tightening of a seat belt in the event of a collision of the vehicle C. As can be seen from the above, the coordinates are an index for determining (recognizing) the physique. Furthermore, since the extension direction of the spine Ma corresponds to the posture of the occupant M (e.g., a leaning forward posture, a posture sitting leaning to the left or right), when calculating the extension direction of the spine Ma, it is possible to determine the posture of the occupant M from the extension direction of the spine Ma. Therefore, for example, as a control related to occupant protection, it is possible to control the shape of the seat S (e.g., the inclination angle of the seat surface Sa) to absorb impact during an emergency stop of the vehicle C.

[0053] The three-dimensional map information 332 also includes intensity information indicating the intensity of the reflected wave corresponding to the reflection point P. The calculation unit 326 calculates spinal information 334a based on the position Pc of the center of gravity of the intensity in a point group G, which is a group of a plurality of reflection points P, and the position of an upper point P1, which is located at the topmost position in the up-down direction among the point group G.

[0054] According to this configuration, the spine information 334a is calculated using the center of gravity Pc of the intensity in the point group G, so that the accuracy of the spine information 334a can be made relatively high.

[0055] <Second embodiment> FIG. 7 is an explanatory diagram for explaining a method for calculating the spinal information 334a in the second embodiment.

[0056] The second embodiment differs from the first embodiment in the method of calculating the spinal information 334a.

[0057] As shown in Fig. 7, the calculation unit 326 calculates spinal information 334a based on the center position Sc of the seat surface Sa and the position of an upper point P1 of the point cloud G that is located at the top and bottom of the vehicle C. Specifically, the calculation unit 326 calculates a line L21 connecting the center position Sc and the position of the upper point P1. The calculation unit 326 regards the length of the line L2 as the length of the spine Ma, and regards the direction on the line L2 from the center position Sc toward the upper point P1 as the extension direction of the spine Ma. Note that in Fig. 7, the point indicating the center position Sc and the reflection point P of the upper point P1 are shown larger than the other reflection points P for ease of understanding.

[0058] According to this configuration, the calculation unit 326 calculates the spinal information 334a based on the center position Sc of the seat surface Sa and the position of the upper point P1 that is located at the top in the vertical direction among the point group G, so that the amount of calculation required to calculate the spinal information 334a can be relatively small.

[0059] <Third embodiment> Fig. 8 is an explanatory diagram for explaining a calculation method of spinal information 334a according to the third embodiment. Fig. 9 is an explanatory diagram for explaining a calculation method of a spinal position in the calculation method of spinal information 334a according to the third embodiment.

[0060] The third embodiment differs from the first embodiment in the method of calculating the spinal information 334a.

[0061] As shown in Fig. 8, the calculation unit 326 extracts, i.e., creates ((b) in Fig. 8) multiple cross sections F from the point cloud G ((a) in Fig. 8). The multiple cross sections F are cross sections perpendicular to the vertical direction of the vehicle C, i.e., the Z axis, and their vertical positions, i.e., Z axis positions (also referred to as Z positions), of the vehicle C are different from one another.

[0062] Next, the calculation unit 326 calculates the position P2 of the spine Ma on the multiple cross sections F ((c) in FIG. 8). In detail, as shown in FIG. 9, the calculation unit 326 selects two reflection points P (for example, reflection points P11 and P12) that are spaced apart by a specified distance on the cross section F. The reflection points P11 and P12 may be points that are not aligned in the X direction or the Y direction, for example. The calculation unit 326 calculates a line L11 that connects the two reflection points P11 and P12, and calculates a perpendicular bisector L12 with respect to the line L11. The perpendicular bisector L12 is a line on the cross section F that is perpendicular to the up-down direction (Z direction) of the vehicle C. Similarly, the calculation unit 326 selects two reflection points P (for example, reflection points P21 and P22) other than the reflection points P11 and P12 that are spaced apart by a specified distance on the cross section F. The reflection points P21 and P22 may not be aligned in the X or Y direction, for example. The calculation unit 326 calculates a line L21 connecting the two reflection points P21 and P22, and calculates a perpendicular bisector L22 relative to the line L21. The perpendicular bisector L22 is a line on the cross section F and is perpendicular to the up-down direction (Z direction) of the vehicle C. The calculation unit 326 calculates an intersection Pm of the two perpendicular bisectors L12 and L22. The calculation unit 326 may regard one intersection Pm as the position P2 of the spine Ma, or may select multiple sets of four reflection points P on the cross section F and regard the average value of the intersection Pm of the multiple sets as the position P2 of the spine Ma. The position of the spine Ma is also referred to as the center of the cross section. Note that in FIG. 9, the reflection points P11, P12, P21, and P22 are shown larger than the other reflection points P for ease of understanding.

[0063] Returning to FIG. 8, next, the calculation unit 326 calculates spine information 334a based on the positions P2 of the spine Ma of the multiple cross sections F. In detail, a line L3 connecting the positions P2 of the spine Ma of the multiple cross sections F is calculated ((d) in FIG. 8). The calculation unit 326 regards the length of the line L3 as the length of the spine Ma, and regards the direction from the position P2 of the lowermost spine Ma to the position P2 of the uppermost spine Ma on the line L3 as the extension direction of the spine Ma. Note that, although three cross sections F are used to calculate the spine information 334a in the example of FIG. 8, the number of cross sections F is not limited to this.

[0064] As described above, in the third embodiment, the calculation unit 326 calculates the position of the spine Ma, which is a position in a plurality of cross sections F orthogonal to the vertical direction of the vehicle C and which differs from one another in the vertical direction of the vehicle C in the point cloud G, which is a group of a plurality of reflection points P. The calculation unit 326 calculates the spine information 334a based on the position P2 of the spine Ma in the plurality of cross sections F.

[0065] With this configuration, for example, the calculation unit 326 calculates the spine information 334a based on the position P2 of the spine Ma of the multiple cross sections F of the point cloud G, so it is possible to relatively increase the accuracy of the spine information 334a (for example, the extension direction of the spine Ma). Furthermore, with the above configuration, it is possible to relatively increase the accuracy of the spine information 334a even when the reflection points P are concentrated on the surface of the occupant M or in the vicinity thereof.

[0066] The program executed by the control device 3 may be provided as a computer program product stored in an installable or executable file format on a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD (Digital Versatile Disk), or flexible disk (FD). Alternatively, the program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Alternatively, the program may be provided or distributed via a network such as the Internet.

[0067] Although the embodiments of the present invention have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims. [Explanation of symbols]

[0068] 1...occupant detection device, 2...radio wave sensor, 3...control device, 21...transmitter, 22...receiver, 322...creator, 326...calculator, 332...three-dimensional map information, 334a...spine information, C...vehicle, F...cross section, G...point cloud, M...occupant, Ma...spine, P...reflection point, P1...upper point, P2...spine position, Pc...center of gravity position, S...seat, Sa...seat surface, Sc...center position.

Claims

1. a radio wave sensor located above a seat surface of a seat arranged in a vehicle cabin in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle cabin, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat; a generating unit that generates three-dimensional map information of the interior of the vehicle cabin, the three-dimensional map information representing positions of reflection points of the reflected waves in three-dimensional coordinates based on the reflected waves; a calculation unit that calculates spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; an object detection unit that detects the occupant by person detection based on a Doppler shift of the reflected wave; Equipped with the calculation unit calculates positions of the spine in a plurality of cross sections orthogonal to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; the calculation unit regards, on the cross section, an intersection between a perpendicular bisector to a line connecting the two reflection points and a perpendicular bisector to a line connecting two other reflection points as the position of the spine on the cross section; Occupant detection device.

2. a radio wave sensor located above a seat surface of a seat arranged in a vehicle cabin in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle cabin, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat; a generating unit that generates three-dimensional map information of the interior of the vehicle cabin, the three-dimensional map information representing positions of reflection points of the reflected waves in three-dimensional coordinates based on the reflected waves; a calculation unit that calculates spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; an object detection unit that detects the occupant by person detection based on a Doppler shift of the reflected wave; Equipped with the calculation unit calculates positions of the spine in a plurality of cross sections orthogonal to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; the calculation unit selects a plurality of sets of four of the reflection points on the cross section, calculates, for each of the plurality of sets, an intersection between a perpendicular bisector to a line connecting two of the reflection points and a perpendicular bisector to a line connecting two other reflection points, and regards the average value of the intersections of the plurality of sets calculated as the position of the spine. Occupant detection device.

3. 1. A method performed in an occupant detection system, comprising: The occupant detection device includes a radio wave sensor located above a seat surface of a seat arranged in a vehicle interior in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle interior, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat, creating three-dimensional map information of the interior of the vehicle cabin based on the reflected waves, the map information representing positions of reflection points of the reflected waves in three-dimensional coordinates; calculating spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; detecting the occupant by human detection based on a Doppler shift of the reflected wave; Including, the calculating step calculates positions of the spine in a plurality of cross sections perpendicular to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; In the calculating step, an intersection between a perpendicular bisector to a line connecting the two reflection points and a perpendicular bisector to a line connecting two other reflection points is regarded as the position of the spine in the cross section. method.

4. 1. A method performed in an occupant detection system, comprising: The occupant detection device includes a radio wave sensor located above a seat surface of a seat arranged in a vehicle interior in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle interior, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat, creating three-dimensional map information of the interior of the vehicle cabin based on the reflected waves, the map information representing positions of reflection points of the reflected waves in three-dimensional coordinates; calculating spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; detecting the occupant by human detection based on a Doppler shift of the reflected wave; Including, the calculating step calculates positions of the spine in a plurality of cross sections perpendicular to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; the calculating step includes selecting a plurality of sets of four reflection points on the cross section, calculating an intersection between a perpendicular bisector to a line connecting two of the reflection points and a perpendicular bisector to a line connecting two other reflection points in each of the plurality of sets, and regarding the average value of the intersections of the plurality of sets calculated as the position of the spine. method.

5. a computer of an occupant detection device including a radio wave sensor located above a seat surface of a seat arranged in a vehicle cabin in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle cabin, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat; a generating unit that generates three-dimensional map information of the interior of the vehicle cabin, the three-dimensional map information representing positions of reflection points of the reflected waves in three-dimensional coordinates based on the reflected waves; a calculation unit that calculates spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; an object detection unit that detects the occupant by person detection based on a Doppler shift of the reflected wave; It functions as the calculation unit calculates positions of the spine in a plurality of cross sections orthogonal to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; the calculation unit regards, on the cross section, an intersection between a perpendicular bisector to a line connecting the two reflection points and a perpendicular bisector to a line connecting two other reflection points as the position of the spine on the cross section; program.

6. a computer of an occupant detection device including a radio wave sensor located above a seat surface of a seat arranged in a vehicle cabin in a vertical direction of the vehicle, the radio wave sensor having a transmitter that transmits a transmission wave into the vehicle cabin, and a receiver that receives a reflected wave generated when the transmission wave is reflected by an occupant sitting on the seat; a generating unit that generates three-dimensional map information of the interior of the vehicle cabin, the three-dimensional map information representing positions of reflection points of the reflected waves in three-dimensional coordinates based on the reflected waves; a calculation unit that calculates spinal information including at least one of a length of a spine of the occupant sitting on the seat and an extension direction of the spine based on the three-dimensional map information; an object detection unit that detects the occupant by person detection based on a Doppler shift of the reflected wave; It functions as the calculation unit calculates positions of the spine in a plurality of cross sections orthogonal to the vertical direction, the positions being different from one another in the vertical direction in a point cloud that is a group of the plurality of reflection points, and calculates the spine information based on the positions of the spine in the plurality of cross sections; the calculation unit selects a plurality of sets of four of the reflection points on the cross section, calculates, for each of the plurality of sets, an intersection between a perpendicular bisector to a line connecting two of the reflection points and a perpendicular bisector to a line connecting two other reflection points, and regards the average value of the intersections of the plurality of sets calculated as the position of the spine. program.

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