Occupant detection device

Abstract

To identify a seating position of an occupant with high accuracy even if the occupant has a posture protruding from a seat.SOLUTION: An occupant detection device includes: an acquisition unit that acquires point cloud information that shows one or more detection points representing positions of occupants present in a vehicle cabin as a point cloud on a three-dimensional map corresponding to a space within the vehicle cabin based on reflected waves reflected by the occupants in the vehicle cabin reflecting a transmission wave transmitted toward the vehicle cabin of a vehicle; a calculation unit that, on the three-dimensional map, weights each of point clouds that appear in one or more regions of interest that are set for each of a plurality of adjacent seating areas within the vehicle cabin and are assigned different weights, based on the region in which each point cloud appears; and a determination unit that determines that an occupant is present in one seating area when the total value of all weighted point clouds that appear in one of the plurality of seating areas and are in one or more regions of interest set for the one seating area is equal to or greater than a predetermined threshold.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an occupant detection device. [Background technology]

[0002] In vehicle control systems and the like, there are technologies for detecting occupants in a vehicle cabin based on data acquired by radio wave sensors and the like installed in the vehicle cabin. For example, the technology in Patent Document 1 claims that by installing radio wave sensors in appropriate positions in the vehicle cabin, occupants can be accurately detected even in the rear seats, which are used for multiple purposes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-202921 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 may erroneously detect the seating position of an occupant when, for example, the occupant is in a position that protrudes from the seat.

[0005] The present invention has been made in consideration of the above, and aims to provide an occupant detection device that can accurately identify the seating position of an occupant even if the occupant is in a position that extends beyond the seat. [Means for solving the problem]

[0006] The occupant detection device of one embodiment includes an acquisition unit that acquires point cloud information that shows one or more detection points representing the positions of occupants present in the vehicle cabin as a point cloud on a three-dimensional map corresponding to the space within the vehicle cabin based on a transmission wave transmitted toward the vehicle cabin and reflected by an occupant in the cabin; a calculation unit that weights each of the point clouds that appear in one or more regions of interest on the three-dimensional map that are set for each of a plurality of adjacent seating areas within the vehicle cabin and have been assigned different weights, based on the region in which the each point cloud appears; and a determination unit that determines that an occupant is present in one seating area when the total value of all of the weighted point clouds that appear in one of the plurality of seating areas and in the one or more regions of interest set for the one seating area is greater than or equal to a predetermined threshold.

[0007] The occupant detection device of the embodiment can accurately identify the seating position of the occupant even when the occupant is in a position protruding from the seat. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective side view showing an example of the configuration of the interior of a vehicle in which an occupant detection system according to an embodiment is installed. [Figure 2] FIG. 2 is a perspective top view showing an example of the configuration of the interior of a vehicle in which an occupant detection system according to an embodiment is installed. [Figure 3] FIG. 3 is a block diagram illustrating an example of a hardware configuration of the occupant detection system according to the embodiment. [Figure 4] FIG. 4 is a block diagram illustrating an example of a functional configuration of the occupant detection system according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram illustrating an example of an analysis result by the occupant detection system according to the embodiment. [Figure 6] FIG. 6 is a flowchart illustrating an example of a procedure of an occupant detection process performed by the occupant detection device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments described below, as well as the actions, results, and advantages brought about by the configurations, are merely examples. The present invention can be realized using configurations other than those disclosed in the following embodiments, and it is possible to obtain at least one of the various advantages and derivative advantages based on the basic configurations.

[0010] (Configuration example of an occupant detection system) Fig. 1 is a perspective side view showing an example of the configuration inside a passenger compartment R of a vehicle C in which an occupant detection system 1 according to an embodiment is installed. Fig. 2 is a perspective top view showing an example of the configuration inside a rear part of the passenger compartment R of a vehicle C in which an occupant detection system 1 according to an embodiment is installed.

[0011] In the figure, the +X direction is the direction from the center of the left-right direction of vehicle C toward the right, and the -X direction is the direction from the center of the left-right direction of vehicle C toward the left. The left-right direction of vehicle C is the direction as seen from the driver's seat. The +Y direction is the direction from the center of the front-rear direction of vehicle C toward the front, and the -Y direction is the direction from the center of the front-rear direction of vehicle C toward the rear. The +Z direction is the direction downward from the ceiling 5 of vehicle C.

[0012] The vehicle C may be, for example, an automobile powered by an internal combustion engine or a motor, or a hybrid vehicle powered by both of these.

[0013] As shown in Figures 1 and 2, vehicle C of this embodiment is a so-called three-row seat vehicle, and includes, from the front of vehicle C, seat rows SR1, SR2, and SR3. Seat row SR1 includes a driver's seat and a passenger seat. Seat rows SR2 and SR3 each include a plurality of seats adjacent to each other.

[0014] In the example of Figure 2, seat row SR2 includes three seats adjacent to each other, with occupants P seated on either side of the center seat. Seat row SR3 includes two seats adjacent to each other, with occupants P seated on the seat on the right side of vehicle C.

[0015] The occupant detection system 1 has a function of detecting an occupant P present in the vehicle compartment R and the seating position of the occupant P. The detection result of the occupant P by the occupant detection system 1 is used, for example, for a seat belt reminder. The seat belt reminder is a function of notifying the vehicle compartment R of a seat position where the seat belt is not fastened even though the occupant P has been detected. In the embodiment, a case will be described in which an occupant P present mainly in seat row SR2 out of seat rows SR1 to SR3 is detected.

[0016] The occupant detection system 1 includes a sensor device 2 and an occupant detection device 3.

[0017] The sensor device 2 is installed, for example, on the ceiling 5 near the center of the vehicle C in the ±X directions, transmits a transmission wave toward the interior of the vehicle compartment R, and receives a reflected wave generated when the transmission wave is reflected by an object present in the vehicle compartment R. The sensor device 2 of the embodiment is installed behind the seat backs of the seat row SR1 when viewed from the ceiling 5. The occupant detection device 3 is installed, for example, in the dashboard, and is connected to the sensor device 2 via a network such as a CAN (Controller Area Network).

[0018] The installation positions of the sensor device 2 and the occupant detection device 3 are not limited to those described above. Also, the number of sensor devices 2 installed in the vehicle interior R is not limited to the example shown in FIG.

[0019] FIG. 3 is a block diagram showing an example of a hardware configuration of the occupant detection system 1 according to the embodiment.

[0020] As shown in FIG. 3, the sensor device 2 included in the occupant detection system 1 includes a transmitter 21, a receiver 22, a sensor ECU (Electronic Control Unit) 23, and an input / output unit 24.

[0021] The transmitter 21 transmits (irradiates) an electromagnetic wave of a predetermined frequency, such as 60 GHz to 65 GHz, as a transmission wave into the vehicle interior R. The receiver 22 receives a reflected wave generated when the transmission wave is reflected by an object present in the vehicle interior R, and generates an electrical signal indicating the intensity of the reflected wave. The transmitter 21 and the receiver 22 may be configured using, for example, an oscillator circuit, a piezoelectric element, an AD converter, an amplifier, a filter circuit, etc. The transmitter 21 and the receiver 22 may be configured separately from each other, or may be configured integrally.

[0022] The sensor ECU 23 is a microcontroller configured using a CPU (Central Processing unit), memory, etc., and performs processes related to control of the transmitter 21 and receiver 22, generation of data based on the reflected waves received by the receiver 22, etc.

[0023] The input / output unit 24 is an interface device that establishes communication between the occupant detection device 3 and other devices in accordance with a predetermined standard such as CAN.

[0024] As described above, the sensor device 2 has a configuration in which a radio wave sensor including, for example, the transmitter 21 and the receiver 22 is integrated with the sensor ECU 23 that generates data based on transmitted and received waves obtained from the radio wave sensor.

[0025] The occupant detection device 3 included in the occupant detection system 1 is an ECU or the like including a CPU 31, a memory 32, and an input / output unit 33.

[0026] The CPU 31 executes various arithmetic processes in accordance with programs stored in, for example, the memory 32. The memory 32 may be configured using a volatile memory and a non-volatile memory. The memory 32 stores programs that cause the CPU 31 to execute various processes for realizing the functions of the occupant detection device 3, setting data, data acquired from the sensor device 2, data generated by the CPU 31, and the like.

[0027] The input / output unit 33 is an interface device that establishes communication between the sensor device 2 and other devices in accordance with a predetermined standard such as CAN.

[0028] It should be noted that the hardware configuration shown in FIG. 3 is an example, and the hardware configuration of the occupant detection system 1 is not limited to the above.

[0029] FIG. 4 is a block diagram showing an example of a functional configuration of the occupant detection system 1 according to the embodiment.

[0030] As shown in FIG. 4, the sensor device 2 included in the occupant detection system 1 includes a wave transmitting / receiving unit 201 and a generating unit 202 as functional units.

[0031] The wave transmitting / receiving unit 201 transmits a transmission wave such as an electromagnetic wave into the vehicle interior R, receives a reflected wave of the transmission wave reflected by an object present in the vehicle interior R, and generates an electrical signal indicating the intensity of the reflected wave.

[0032] The generation unit 202 generates point cloud information based on the electrical signal generated by the wave transmitting and receiving unit 201. The point cloud information is a point cloud showing one or more detection points representing the position of the occupant P present in the vehicle cabin R on a three-dimensional map corresponding to the space within the vehicle cabin R. The three-dimensional map corresponding to the space within the vehicle cabin R may be, for example, a voxel map. In this case, the detection points representing the occupant P may be voxels within the voxel map.

[0033] Here, the electrical signal generated by the wave transmitting / receiving unit 201 includes not only the occupant P in the vehicle compartment R, but also waves reflected by components of the vehicle C such as the vehicle body and seats, and luggage placed on the seats, etc. Among these, the components and luggage, etc. of the vehicle C maintain a substantially stationary state, or fluctuate in a manner highly correlated with the movement of the vehicle body as the vehicle body sways. Therefore, the components and luggage, etc. of the vehicle C also fluctuate in a manner highly correlated with the sensor device 2 installed, for example, on the ceiling 5 of the vehicle C. On the other hand, the occupant P in the vehicle compartment R is usually seated and making some kind of spontaneous movement.

[0034] Therefore, the point cloud information can be obtained by extracting, from the electrical signals generated by the wave transmitting and receiving unit 201, reflecting objects whose movements are not synchronized with the movement of the vehicle body as detection points representing the occupant P. As an example, the detection points representing the occupant P can be points where the amount of change in the intensity of the reflected waves per unit time caused by movements not synchronized with the movement of the vehicle body is greater than a predetermined threshold. However, the type of points to be set as detection points representing the occupant P can be determined appropriately depending on the function of the sensor device 2 to be used, etc.

[0035] The occupant detection device 3 included in the occupant detection system 1 includes, as functional units, an acquisition unit 301, a calculation unit 302, a determination unit 303, and a storage unit 304. These functional units may be configured, for example, by cooperation between hardware and a program as illustrated in Fig. 3. Furthermore, some or all of these functional units may be configured by dedicated hardware (circuits, etc.) such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0036] The acquisition unit 301 acquires point cloud information generated by the sensor device 2.

[0037] The calculation unit 302 assigns a weight to each of the point clouds included in the point cloud information based on the appearance position of each of the point clouds. In the 3D map in which the point clouds are arranged and correspond to the space within the vehicle cabin R, seating areas where the occupant P should be seated are set corresponding to the multiple seat positions within the vehicle cabin R. Each seating area is further assigned one or more areas to which different weights are assigned. The calculation unit 302 assigns the weights assigned to the areas corresponding to the appearance positions of each of the point clouds.

[0038] The calculation unit 302 also calculates the sum of the weighted point clouds for each of the multiple seating areas set on the three-dimensional map. That is, the sum of the point clouds for a given seating area is the sum of the weighted point clouds for each area set in the seating area.

[0039] The determination unit 303 determines whether or not an occupant P is present in each of the plurality of seating areas. That is, if the total value of the point cloud calculated by the calculation unit 302 for one seating area is equal to or greater than a predetermined threshold, the determination unit 303 determines that an occupant P is present in the seating area, and if the total value of the point cloud is less than the predetermined threshold, the determination unit 303 determines that an occupant P is not present in the seating area.

[0040] The storage unit 304 stores, for example, programs and control parameters that realize various functions of the occupant detection device 3. The storage unit 304 also stores point cloud information acquired by the occupant detection device 3 from the sensor device 2, the total value of the point clouds in each seating area, and determination results such as the presence or absence of an occupant P. The storage unit 304 also stores information such as a three-dimensional map corresponding to the space within the vehicle interior R, the size and arrangement of each seating area in the three-dimensional map, and areas set in each seating area and weights assigned to those areas.

[0041] (Determination method for occupant detection system) Next, a determination method by the occupant detection system 1 according to the embodiment will be described with reference to Fig. 5. Fig. 5 is a schematic diagram showing an example of an analysis result by the occupant detection system 1 according to the embodiment.

[0042] 5 shows the analysis results for seat row SR2 performed by the occupant detection system 1 based on the point cloud information generated by the sensor device 2. The horizontal axis of the graph indicates the position in the left-right direction (±X direction) of the vehicle C, and the vertical axis of the graph indicates the position in the height direction (+Z direction) of the vehicle C.

[0043] As shown in Figure 5, the sensor device 2 generates point cloud information on a three-dimensional map corresponding to the space inside the vehicle compartment R, in which a point cloud PP, which is one or more detection points determined to be reflections from the occupant P, is arranged asynchronously with the movement of the vehicle body.

[0044] On a three-dimensional map corresponding to the space within the vehicle cabin R, seating areas SR2(L), SR2(C), and SR2(R) are set at positions corresponding to the three seats in seat row SR2, respectively.

[0045] Of the three seats in seat row SR2, seating area SR2(L) corresponds to the seats on the left side of vehicle C, seating area SR2(R) corresponds to the seats on the right side of vehicle C, and seating area SR2(C) corresponds to the center seat. In this way, the graph in Fig. 5 shows the seat positions as viewed from sensor device 2, which is installed slightly rearward and above seat row SR2. In other words, on the graph in Fig. 5, seating areas SR2(L), SR2(C), and SR2(R) are shown in this order from the left side of the page.

[0046] Of these seating areas SR2(L), SR2(C), and SR2(R), the seating areas SR2(L) and SR2(R) are examples of the first seating area, and the seating area SR2(C) is an example of the second seating area.

[0047] When viewed from above the vehicle C, that is, from the ceiling 5 where the sensor device 2 is placed, these seating areas SR2(L), SR2(C), and SR2(R) are set to include almost the entire seating surface of each corresponding seat and a portion of the floor surface in front of these seats.

[0048] In a side view of the vehicle C, that is, in the height direction, these seating areas SR2(L), SR2(C), and SR2(R) are set to include a range within a predetermined height position, for example, 1 m downward (in the +Z direction) from the ceiling 5 (0 m). In the example of FIG. 5, a range of 0.8 m in the +Z direction from the ceiling 5 (0 m) is set as the seating areas SR2(L), SR2(C), and SR2(R). In this way, by setting the height positions of the seating areas SR2(L), SR2(C), and SR2(R) higher than the seat surfaces of each seat, it is possible to exclude reflections from the seat surfaces and luggage, etc., and to detect reflections from the occupant P, who is taller than the seat surfaces and luggage, etc.

[0049] These seating areas SR2(L), SR2(C), and SR2(R) are divided into one or more areas W1, W3, W4, and W8 according to their positions in the ±X directions. Different weights are assigned to these areas W1, W3, W4, and W8. In the example of FIG. 5, the weights assigned to the areas W1, W3, W4, and W8 are 1 point, 3 points, 4 points, and 8 points, respectively.

[0050] These regions W1, W3, W4, and W8 are also called regions of interest (ROI). Of these regions W1, W3, W4, and W8, region W1 is an example of a fourth region of interest, region W3 is an example of a third region of interest, region W4 is an example of a second region of interest, and region W8 is an example of a first region of interest. Furthermore, a weighting of 1 point is an example of a fourth weighting, a weighting of 3 points is an example of a third weighting, a weighting of 4 points is an example of a second weighting, and a weighting of 8 points is an example of a first weighting.

[0051] Of these regions W1, W3, W4, and W8, three regions W4, W8, and W3 are set in the seating region SR2(L) in order from the left side of the vehicle C. Of the point clouds PP appearing in the seating region SR2(L), the calculation unit 302 assigns a weight of 4 points to the point clouds PP appearing in region W4, a weight of 8 points to the point clouds PP appearing in region W8, and a weight of 3 points to the point clouds PP appearing in region W3. The calculation unit 302 also counts the total values of the weighted point clouds PP in each of the regions W4, W8, and W3. If the total value of the point clouds PP calculated by the calculation unit 302 is equal to or greater than a predetermined threshold, the determination unit 303 determines that an occupant P is present in the seating region SR2(L).

[0052] That is, if the following formula (1) is satisfied for the seating area SR2(L), the occupant detection system 1 determines that the occupant P is present in the seat corresponding to the seating area SR2(L).

[0053] PP W4 ×4+PP W8 x8+PP W3 ×3≧TH (1) TH: Threshold PP W4 : Number of points in region W4 PP W8 : Number of points in area W8 PP W3 : Number of points in region W3

[0054] Similarly, three areas W4, W8, and W3 are set in the seating area SR2(R) in order from the right side of the vehicle C. The calculation unit 302 also weights the point cloud PP that appears in the seating area SR2(R) based on the areas W4, W8, and W3 in which the point cloud PP appears, and calculates the sum of these weights. If the sum of the point cloud PP calculated by the calculation unit 302 is equal to or greater than a predetermined threshold, the determination unit 303 determines that an occupant P is present in the seating area SR2(R).

[0055] That is, if the above formula (1) is also satisfied for the seating area SR2(R), the occupant detection system 1 determines that the occupant P is present in the seat corresponding to the seating area SR2(R).

[0056] When an occupant P is present in a seat corresponding to these seating areas SR2(L) and SR2(R), the central area of each seating area SR2(L) and SR2(R) is the area where the most point clouds PP are likely to appear. In addition, even if the occupant P in the center seat corresponding to the adjacent seating area SR2(C) loses his / her posture and leans toward either side of the seating area SR2(L) or SR2(R), the point clouds PP of the occupant P in the center seat are unlikely to appear in the central area of the seating areas SR2(L) and SR2(R). Therefore, by setting this central area as the area W8 with the highest weighting, the occupant P in the seat corresponding to the seating areas SR2(L) and SR2(R) can be more easily detected.

[0057] Similarly, the left side edge of the seating area SR2(L) and the right side edge of the seating area SR2(R) are also areas where the point cloud PP is likely to appear when an occupant P is present in the seat corresponding to these seating areas SR2(L) and SR2(R). However, these areas are the farthest areas when viewed from the sensor device 2, which is installed on the ceiling 5 near the center in the ±X directions of the vehicle C, and are also locations where electromagnetic waves are likely to be blocked by the occupant P himself sitting in these seats. For this reason, these areas in the seating areas SR2(L) and SR2(R) are assigned area W4, which is weighted slightly lower than the central area.

[0058] On the other hand, in the region of the seating regions SR2(L) and SR2(R) closer to the seating region SR2(C), a point cloud PP of an occupant P sitting in, for example, the center seat corresponding to the seating region SR2(C) may also appear. Therefore, by setting the region of the seating regions SR2(L) and SR2(R) closer to the seating region SR2(C) as a region W3 with an even lower weight, it is possible to prevent erroneous detection of an occupant P sitting in the center seat with poor posture, for example.

[0059] A single area W1 is set in the center of the seating area SR2(C). None of the areas W1, W3, W4, or W8 is set on either side of the seating area SR2(C) in the ±X direction, i.e., in the area of a predetermined width closer to the seating area SR2(L) or the area of a predetermined width closer to the seating area SR2(R). The calculation unit 302 assigns a weight of 1 point to the point cloud PP that appears in the area W1 among the point clouds PP that appear in the seating area SR2(C), and does not count the point clouds PP that appear in locations on either side of the seating area SR2(C) in the ±X direction where no area is set. In response to this, the determination unit 303 determines whether or not an occupant P is present in the seating area SR2(C) based on the actual number of point clouds PP that appear in the area W1.

[0060] That is, if the following formula (2) is satisfied for the seating area SR2(C), the occupant detection system 1 determines that the occupant P is present in the seat corresponding to the seating area SR2(C).

[0061] PP W1 ×1≧TH (2) TH: Threshold PP W1 : Number of points in region W1

[0062] In the seating area SR2(C), the point clouds PP of occupants P seated in seats corresponding to the adjacent seating areas SR2(L) and SR2(R) on both sides are likely to be detected, and there is a significant adverse effect from erroneously detecting these point clouds PP as the point cloud PP of the occupant P in the seating area SR2(C). For this reason, the seating area SR2(C) is configured such that the area W1, which is assigned the lowest weighting, is provided only in the central area where the point clouds PP of the occupants P on both sides are unlikely to appear, and no areas are set on either side of that area, thereby suppressing erroneous detections due to the occupants P on both sides and enabling precise detection of the occupant P seated in the central seat corresponding to the seating area SR2(C).

[0063] In the example of Figure 5, four regions W1, W3, W4, and W8, each assigned with four types of weighting, are appropriately set as seating regions SR2(L), SR2(C), and SR2(R). However, the number of weighting types, the individual weighting values, and the number of regions can be determined arbitrarily. Furthermore, the types and numbers of regions set for each of the seating regions SR2(L), SR2(C), and SR2(R) are not limited to the above example.

[0064] (Processing example of occupant detection device) Next, an example of the occupant detection process of the occupant detection device 3 according to the embodiment will be described with reference to Fig. 6. Fig. 6 is a flow chart showing an example of the procedure of the occupant detection process by the occupant detection device 3 according to the embodiment. Fig. 6 shows a determination process per one time for the seating areas SR2(L), SR2(C), and SR2(R).

[0065] As shown in FIG. 6, the acquisition unit 301 acquires point cloud information that shows a point cloud of the occupant P on a three-dimensional map of the vehicle interior R, which is detected by the transmitting and receiving unit 201 of the sensor device 2 and generated by the generation unit 202 (step S101).

[0066] The calculation unit 302 counts the points included in one or more regions W1, W3, W4, and W8 set for each of the seating regions SR2(L), SR2(C), and SR2(R) (step S102). The calculation unit 302 also weights each of these points according to the appearance region (step S103). The calculation unit 302 also calculates the sum of the weighted points for any of the seating regions SR2(L), SR2(C), and SR2(R) (step S104).

[0067] The determination unit 303 determines whether the total value of the weighted point group is equal to or greater than a predetermined threshold value (step S105).

[0068] If the sum of the weighted points is equal to or greater than a predetermined threshold (step S105: Yes), the determination unit 303 determines that an occupant P is present in any of the seating areas SR2(L), SR2(C), and SR2(R) to be determined (step S106). If the sum of the weighted points is less than a predetermined threshold (step S105: No), the determination unit 303 determines that an occupant P is not present in any of the seating areas SR2(L), SR2(C), and SR2(R) to be determined (step S107).

[0069] When the determination for any of the seating areas SR2(L), SR2(C), and SR2(R) to be determined is completed, the determination unit 303 checks whether the determination for all of the seating areas SR2(L), SR2(C), and SR2(R) is completed (step S108). If the determination for all of the seating areas SR2(L), SR2(C), and SR2(R) is completed (step S108: Yes), the process ends. If the determination for all of the seating areas SR2(L), SR2(C), and SR2(R) is not completed (step S108: No), the process from step S104 is repeated.

[0070] With the above, one cycle of the occupant detection process of the occupant detection device 3 of the embodiment is completed.

[0071] The occupant detection device 3 starts the process shown in Fig. 6 at a predetermined timing and repeats it until the predetermined timing is reached. For example, when the determination result of the occupant detection device 3 is used for the seat reminder function, the above process is repeated from when the engine of the vehicle C is turned on until it is turned off.

[0072] (Overview) There is a technology that uses radio wave sensors to detect occupants in the vehicle cabin. However, in order to detect occupants in the vehicle cabin with high accuracy and comprehensively, there are restrictions on the installation locations of the radio wave sensors in the vehicle cabin, and it is necessary to install an increased number of radio wave sensors. There is also a possibility that an occupant who is leaning against the seat next to them may be mistakenly detected as sitting in the adjacent seat.

[0073] According to the occupant detection device 3 of the embodiment, the calculation unit 302 weights each of the point clouds PP that appear in one or more regions W1, W3, W4, and W8, which are set for each of a plurality of seating regions SR2(L), SR2(C), and SR2(R) adjacent to each other in the vehicle interior R on the 3D map and to which different weights are assigned, based on the region in which each point cloud PP appears. Furthermore, the determination unit 303 determines that an occupant P is present in one of the seating regions SR2(L), SR2(C), and SR2(R) when the sum of all the weighted point clouds PP that appear in one of the seating regions SR2(L), SR2(C), and SR2(R) in the one or more regions W1, W3, W4, and W8 set for the one seating region is equal to or greater than a predetermined threshold.

[0074] This makes it possible to accurately identify the seating position of the occupant P even if the occupant P is in a position that protrudes from the seat. Furthermore, since the accuracy of determination for each seating position is improved, the degree of freedom in the installation position of the sensor device 2 is increased, and the number of installed sensor devices 2 can be reduced. Therefore, for example, even in the case where one sensor device 2 is installed on the ceiling 5 slightly behind the seat row SR2 as in the above-described embodiment, occupant detection can be performed with high accuracy.

[0075] According to the embodiment of the occupant detection device 3, among the multiple seating areas SR2(L), SR2(C), and SR2(R), the seating area SR2(L) or SR2(R) located at the ends is set with an area W8 located in the center of these seating areas SR2(L) and SR2(R) and assigned a weighting of 8 points, an area W4 located on the end side of these seating areas SR2(L) and SR2(R) and assigned a weighting of 4 points which is smaller than the weighting of area W8, and an area W3 located on the seating area SR2(C) side of these seating areas SR2(L) and SR2(R) and assigned a weighting of 3 points which is smaller than the weighting of area W4.

[0076] This allows the influence of the occupant P sitting in the center seat corresponding to the seating area SR2(C) to be excluded, and the occupant P sitting in the end seats corresponding to these seating areas SR2(L) and SR2(R) to be detected with high accuracy.

[0077] According to the occupant detection device 3 of the embodiment, among the plurality of seating areas SR2(L), SR2(C), and SR2(R), in the seating area SR2(C) sandwiched between the other seating areas SR2(L) and SR2(R) on both sides, an area W1 is set, which is located in the center of the seating area SR2(C) and is assigned a weighting of 1 point, which is smaller than the weighting of the area W3. In addition, the determination unit 303 determines whether or not an occupant P is present in the seating area SR2(C) without taking into account the point cloud PP appearing in the area between the other seating areas SR2(L) and SR2(R) on both sides and the area W1 of the seating area SR2(C).

[0078] This allows the influence of occupant P seated in the end seats corresponding to seating areas SR2(L) and SR2(R) to be excluded, and occupant P seated in the center seat corresponding to seating area SR2(C) to be detected with high accuracy.

[0079] 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]

[0080] 1...occupant detection system, 2...sensor device, 3...occupant detection device, 5...ceiling, 21...transmitter, 22...receiver, 23...sensor ECU, 24...input / output unit, 31...CPU, 32...memory, 33...input / output unit, 201...transmitter / receiver unit, 202...generation unit, 301...acquisition unit, 302...calculation unit, 303...determination unit, 304...storage unit, C...vehicle, P...occupant, PP...point cloud, R...vehicle compartment, SR2(L), SR2(C), SR2(R)...seating area, W1, W3, W4, W8...area, SR1, SR2, SR3...seat row.

Claims

1. an acquisition unit that acquires point cloud information that indicates, as a point cloud, one or more detection points that represent positions of occupants present in the vehicle interior on a three-dimensional map corresponding to a space within the vehicle interior, based on a transmission wave that is transmitted toward the vehicle interior and reflected by the occupants in the vehicle interior; a calculation unit that weights each of the point clouds that appear in one or more regions of interest, which are set for each of a plurality of seating areas adjacent to each other in the vehicle cabin and to which different weights are assigned, on the three-dimensional map based on the region in which the each of the point clouds appears; a determination unit that determines that an occupant is present in one seating area when a total value of all of the weighted point clouds in the one or more regions of interest set for the one seating area that appear in the one seating area among the plurality of seating areas is equal to or greater than a predetermined threshold value, Occupant detection device.

2. The first seating area located at the end of the plurality of seating areas includes: a first region of interest located in a central portion of the first seating area and having a first weighting; a second region of interest distal to the first seating area and assigned a second weighting less than the first weighting; a third region of interest located on a seating area side of the first seating area adjacent to the one seating area, the third region of interest being assigned a third weighting smaller than the second weighting; The occupant detection device according to claim 1 .

3. In a second seating area sandwiched between other seating areas on both sides of the plurality of seating areas, a fourth region of interest is set, the fourth region of interest being located in a central portion of the second seating area and being assigned a fourth weighting that is smaller than the third weighting; The determination unit determining whether or not an occupant is present in the second seating area without taking into account point clouds appearing in areas between the other seating areas on both sides and the fourth region of interest; The occupant detection device according to claim 2 .

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