WO2021240777A1

WO2021240777A1 - Occupant detection device and occupant detection method

Info

Publication number: WO2021240777A1
Application number: PCT/JP2020/021331
Authority: WO
Inventors: 永菅原
Original assignee: 三菱電機株式会社
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-12-02
Also published as: DE112020007262T8; JPWO2021240777A1; JP7399283B2; DE112020007262T5

Abstract

In an occupant detection device (10), a living body information acquisition unit (11) acquires living body information which is information on the inside of a vehicle and is detected by an electromagnetic wave sensor (21). A living body detection unit (12) searches for a living body existing in the vehicle on the basis of the living body information, and identifies the position and the size of a detected living body. An occupant determination unit (13) determines, on the basis of a positional relationship between the position of the detected living body and the position of each seat of the vehicle and the size of the living body, a seat on which an occupant of the vehicle exists and an attribute of the occupant.

Description

Crew detection device and occupant detection method

The present disclosure relates to an occupant detection device that detects an occupant in a vehicle, and particularly to a technique for determining the attributes of the detected occupant.

For example, in Patent Document 1 below, it is confirmed by using an electromagnetic wave sensor whether or not a seat on which a child seat of a vehicle is installed has a vital sign, and if the seat has a vital sign, a child (infant) in the vehicle. An occupant detection device that determines that there is a occupant has been proposed.

Japanese Unexamined Patent Publication No. 2019-123354

The technique of Patent Document 1 is based on the premise that the occupant is correctly seated in the seat, and it is difficult to correctly detect, for example, the occupant with the backrest tilted down.

The present disclosure has been made to solve the above problems, and an object of the present invention is to provide a occupant detection device capable of accurately determining the seat where the occupant of the vehicle is and the attributes of the occupant.

The occupant detection device according to the present disclosure has a biological information acquisition unit that acquires biological information in the vehicle detected by an electromagnetic wave sensor, and a biological information existing in the vehicle based on the biological information, and the position of the detected biological body is searched for. A biological detection unit that specifies the size and the occupant determination unit that determines the attributes of the seat and occupant of the vehicle based on the positional relationship between the position of the living body and the position of each seat of the vehicle and the size of the living body. To prepare for.

The occupant detection device according to the present disclosure determines the seats with occupants of the vehicle and the attributes of the occupants based on the positional relationship between the position of the living body specified from the biological information and the position of each seat of the vehicle and the size of the living body. Therefore, the attributes of the occupants in the vehicle can be accurately determined.

The purposes, features, aspects, and advantages of the present disclosure will be made clearer by the following detailed description and accompanying drawings.

It is a figure which shows the structure of the occupant detection device which concerns on Embodiment 1. It is a figure which shows the example of the seat arrangement of a vehicle. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a flowchart which shows the operation of the occupant detection device which concerns on Embodiment 1. It is a figure which shows the hardware configuration example of the occupant detection device. It is a figure which shows the hardware configuration example of the occupant detection device. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a figure which shows the example of the distribution of the detection point of the vital sign. It is a flowchart which shows the operation of the occupant detection device which concerns on Embodiment 2. It is a figure which shows the structure of the occupant detection device which concerns on Embodiment 3. It is a flowchart which shows the operation of the occupant detection device which concerns on Embodiment 3. It is a figure which shows the structure of the occupant detection device which concerns on Embodiment 4. It is a flowchart which shows the operation of the occupant detection device which concerns on Embodiment 4. It is a figure which shows the structure of the occupant detection device which concerns on Embodiment 5. It is a flowchart which shows the operation of the occupant detection device which concerns on Embodiment 5. It is a figure which shows the structure of the occupant detection device which concerns on the combination of Embodiments 2-5. It is a flowchart which shows the operation of the occupant detection device which concerns on the combination of Embodiments 2-5. It is a figure which shows the structure of the child leaving warning system which concerns on Embodiment 6. It is a flowchart which shows the operation of the child leaving warning system which concerns on Embodiment 6.

<Embodiment 1>
FIG. 1 is a block diagram showing a configuration of the occupant detection device 10 according to the first embodiment. In the present embodiment, it is assumed that the occupant detection device 10 is mounted on the vehicle. However, the occupant detection device 10 does not have to be permanently installed in the vehicle, and may be realized on a portable device that can be brought into the vehicle, such as a mobile phone, a smartphone, or a PND (Portable Navigation Device). Further, a part or all of the functions of the occupant detection device 10 may be realized on a server installed outside the vehicle and capable of communicating with the occupant detection device 10.

As shown in FIG. 1, the occupant detection device 10 is connected to an electromagnetic wave sensor 21 included in a vehicle equipped with the occupant detection device 10. The electromagnetic wave sensor 21 is a sensor that detects a living body existing in the vehicle, and is composed of, for example, a millimeter wave radar. The electromagnetic wave sensor 21 detects a vital sign, which is a sign indicating the existence of a living body, and outputs information on the position of a detection point of the vital sign as biological information. For the position of the detection point of the vital sign, for example, the distance from the electromagnetic wave sensor 21 to the detection point is calculated based on the frequency spectrum of the reflected wave of the radar, and the electromagnetic wave sensor is based on the phase difference of the reflected wave of the radar received by a plurality of antennas. It can be obtained by calculating the direction of the detection point from 21.

In addition, since the millimeter-wave radar can detect a living body through resin or cloth, the electromagnetic wave sensor 21 is difficult to see, such as a child riding on a rear-facing child seat, a sideways child seat, a child seat with a sunshade, or a person wearing a blanket. Can detect various people. In the present embodiment, the electromagnetic wave sensor 21 is installed on the ceiling of the vehicle, and all the seats of the vehicle are included in the detection range of the electromagnetic wave sensor 21.

As shown in FIG. 1, the occupant detection device 10 includes a biological information acquisition unit 11, a biological detection unit 12, and an occupant determination unit 13.

The biological information acquisition unit 11 acquires the biological information output by the electromagnetic wave sensor 21. The biological detection unit 12 searches for a living body existing in the vehicle based on the biological information acquired by the biological information acquisition unit 11, and specifies the position and size of the detected living body. More specifically, the biological detection unit 12 specifies the position and size of the biological body based on the distribution of the detection points of vital signs included in the biological information.

The size of the living body specified by the living body detection unit 12 may be classified into at least an adult size and a child size, and is defined by, for example, the NHTSA (National Highway Traffic Safety Administration) standard. Standard adult males (AM50), petite adult females (AF05), large adult males (AM95), 10-year-old, 6-year-old and 3-year-old children (10YO, 6YO, 3YO) according to the size of the human body dummy. ) And so on. In the present embodiment, the size of the living body specified by the biological information acquisition unit 11 is classified into two, an adult size and a child size. That is, if the size of the living body is equal to or larger than a predetermined threshold value, it is determined to be an adult size, and if it is less than the threshold value, it is determined to be a child size. Although the definition of "child" differs depending on the country and law, it is preferable that a person of an age (for example, 12 years or younger) who may cause an accident if left in a vehicle is defined as a child.

For example, when the seats of the vehicle are arranged as shown in FIG. 2, an example of the distribution of the detection points of the vital signs detected by the electromagnetic wave sensor 21 is shown in FIGS. 3 and 4. FIG. 3 shows the distribution of vital sign detection points when the vehicle is viewed in a plane, and FIG. 4 shows the distribution of vital sign detection points when the vehicle is viewed from the side. If the detection points of vital signs are distributed as shown in FIGS. 3 and 4, the biological detection unit 12 determines that an adult-sized living body exists at a position on the left side of the center in the front-rear direction of the vehicle.

The occupant determination unit 13 identifies the seat where the occupant of the vehicle is located from the positional relationship between the position of the living body specified by the living body detection unit 12 and the position of each seat of the vehicle, and determines the size of the living body specified by the living body detection unit 12. Based on this, the attributes of the occupant are determined. For example, in the case of FIGS. 3 and 4 above, the biological detection unit 12 determines that the occupant is in the seat on the left side of the second row of the vehicle, and the attribute of the occupant is an adult. In the present embodiment, the attributes of the occupants determined by the occupant determination unit 13 are classified into two categories, an adult and a child, but may be further subdivided as in the above-mentioned human body dummy, for example.

Here, the number of seats specified by the occupant judgment unit 13 for one occupant is not limited to one, and may be multiple. For example, when the detection points of vital signs when the vehicle is viewed in a plan view are distributed as shown in FIG. 5, the position of the living body specified by the living body detection unit 12 straddles the positions of two adjacent seats. Then, the occupant determination unit 13 determines that there is one occupant so as to straddle the two seats. Further, when the occupant tilts the backrest of the seat, the detection points of vital signs may be distributed as shown in FIG. In this case, the position of the living body specified by the living body detection unit 12 straddles the positions of the two seats arranged in front and behind, and the occupant determination unit 13 straddles the two seats. Judge that there is a occupant.

In this way, since the occupant determination unit 13 identifies the seat where the occupant is located from the positional relationship between the living body and each seat specified by the biological detection unit 12, the occupant determination unit 13 correctly detects the occupant existing so as to straddle the plurality of seats. can do. This prevents erroneous detection, for example, in which an occupant seated so as to straddle two seats is detected as two children, and improves the determination accuracy of the occupant's attributes.

FIG. 7 is a flowchart showing the operation of the occupant detection device 10 according to the first embodiment. Hereinafter, the operation of the occupant detection device 10 will be described with reference to FIG. 7.

When the occupant detection device 10 is activated, the biological information acquisition unit 11 acquires the biological information output by the electromagnetic wave sensor 21 (step S101). Then, the biological detection unit 12 searches for a living body (vital sign) existing in the vehicle based on the biological information acquired by the biological information acquisition unit 11 (step S102), and specifies the position and size of the detected living body. (Step S103).

The occupant determination unit 13 executes the following processes of steps S104 to S108 for each detected living body based on the position and size of the living body detected by the living body detection unit 12.

First, the occupant determination unit 13 selects a living body to be processed (hereinafter referred to as "target living body") (step S104), and determines the target living body based on the positional relationship between the position of the target living body and the position of each seat. Identify the seat with the corresponding occupant (step S105).

Further, the occupant determination unit 13 confirms the size of the target living body (step S106). If the size of the target organism is an adult size (YES in step S106), the occupant determination unit 13 determines that the occupant corresponding to the target organism is an adult (step S107). If the size of the target living body is the size of a child (NO in step S106), the occupant determination unit 13 determines that the occupant corresponding to the target living body is a child (step S108).

When the process of steps S104 to S108 is executed for all living organisms, the occupant determination unit 13 outputs the determination result of the position (seat) and attribute (adult or child) of each occupant, and ends the process.

As described above, the occupant detection device 10 according to the first embodiment sets the attributes of the seat and the occupant of the vehicle in the positional relationship between the position of the living body specified from the biological information and the position of each seat of the vehicle. Judgment is based on the size of the living body. Therefore, for example, the positions and attributes of occupants existing so as to straddle a plurality of seats can be accurately determined.

The attributes of the occupants detected by the occupant detection device 10 may include not only humans but also animals. That is, animals may be included in the classification of the size of the living body specified by the living body detection unit 12. Furthermore, the classification of animals may be subdivided into large, medium, small and the like.

8 and 9 are diagrams showing an example of the hardware configuration of the occupant detection device 10, respectively. Each function of the component of the occupant detection device 10 shown in FIG. 1 is realized by, for example, the processing circuit 50 shown in FIG. That is, the occupant detection device 10 acquires the biological information in the vehicle detected by the electromagnetic wave sensor, searches for the living body existing in the vehicle based on the biological information, identifies the position and size of the detected living body, and identifies the position and size of the detected living body. A processing circuit 50 for determining the attributes of the seat and the occupant of the vehicle based on the positional relationship between the position of the living body and the position of each seat of the vehicle and the size of the living body is provided. The processing circuit 50 may be dedicated hardware, or may be a processor (central processing unit (CPU: Central Processing Unit), processing unit, arithmetic unit, microprocessor, microcontroller, etc.) that executes a program stored in the memory. It may be configured by using a DSP (also called a Digital Signal Processor)).

When the processing circuit 50 is dedicated hardware, the processing circuit 50 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable). GateArray), or a combination of these, etc. The functions of the components of the occupant detection device 10 may be realized by individual processing circuits, or these functions may be collectively realized by one processing circuit.

FIG. 9 shows an example of the hardware configuration of the occupant detection device 10 when the processing circuit 50 is configured by using the processor 51 that executes the program. In this case, the functions of the components of the occupant detection device 10 are realized by software (software, firmware, or a combination of software and firmware). The software or the like is described as a program and stored in the memory 52. The processor 51 realizes the functions of each part by reading and executing the program stored in the memory 52. That is, the occupant detection device 10 performs a process of acquiring biometric information in the vehicle detected by the electromagnetic wave sensor when executed by the processor 51, and searches for and detects a living body existing in the vehicle based on the biometric information. The process of identifying the position and size of the living body, and the process of determining the seat with the occupant of the vehicle and the attributes of the occupant based on the positional relationship between the position of the living body and the position of each seat of the vehicle and the size of the living body. , Provide a memory 52 for storing the program that will be executed as a result. In other words, it can be said that this program causes the computer to execute the procedure and method of operation of the components of the occupant detection device 10.

Here, the memory 52 is a non-volatile or non-volatile memory such as a RAM (RandomAccessMemory), a ROM (ReadOnlyMemory), a flash memory, an EPROM (ErasableProgrammableReadOnlyMemory), and an EEPROM (ElectricallyErasableProgrammableReadOnlyMemory). Volatile semiconductor memory, HDD (Hard Disk Drive), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc) and its drive device, etc., or any storage medium used in the future. You may.

The configuration in which the functions of the components of the occupant detection device 10 are realized by either hardware or software has been described above. However, the present invention is not limited to this, and a configuration may be configured in which a part of the components of the occupant detection device 10 is realized by dedicated hardware and another part of the components is realized by software or the like. For example, for some components, the function is realized by the processing circuit 50 as dedicated hardware, and for some other components, the processing circuit 50 as the processor 51 is stored in the memory 52. It is possible to realize the function by reading and executing it.

As described above, the occupant detection device 10 can realize each of the above-mentioned functions by hardware, software, or a combination thereof.

<Embodiment 2>
Children's occupants may not reach the floor when seated. In that case, the distribution of the detection points of the vital signs detected by the electromagnetic wave sensor 21 is as shown in FIG. 10, for example, and the living body that has not reached the floor is detected by the living body detection unit 12. Children's occupants may also lie on their seats. In that case, the distribution of the detection points of vital signs is as shown in FIGS. 11 and 12, for example, and in this case as well, the living body that has not reached the floor is detected by the living body detection unit 12.

On the other hand, adult occupants usually sit with their feet on the floor. Therefore, when the occupant is an adult, the distribution of the detection points of vital signs is as shown in FIGS. 3 and 4, and the living body reaching the floor is detected by the living body detection unit 12.

Therefore, in the occupant detection device 10 according to the second embodiment, the occupant determination unit 13 determines whether or not the living body detected by the living body detection unit 12 has reached the floor of the vehicle, and if not, the living body. Is judged to be a child's occupant. The configuration of the occupant detection device 10 according to the second embodiment is the same as that in FIG.

FIG. 13 is a flowchart showing the operation of the occupant detection device 10 according to the second embodiment. The flow of FIG. 13 is obtained by adding step S111 after step S105 to the flow of FIG. 7. Since the other steps are the same as those in FIG. 7, the description of those steps is omitted here.

In step S111, the occupant determination unit 13 confirms whether or not the target living body has reached the floor. At this time, if the target living body has reached the floor (YES in step S111), the process proceeds to step S106, and the occupant determination unit 13 determines the attributes of the occupant (adult or child) corresponding to the target living body, as in the first embodiment. Is determined based on the size of the target organism. However, if the target living body has not reached the floor (NO in step S111), the process proceeds to step S108, and the occupant determination unit 13 determines that the occupant corresponding to the target living body is a child.

The occupant detection device 10 according to the second embodiment can improve the accuracy of determining the attributes of the occupants by determining the living body that has not reached the floor as a child.

<Embodiment 3>
FIG. 14 is a block diagram showing the configuration of the occupant detection device 10 according to the third embodiment. The configuration of the occupant detection device 10 in FIG. 14 is the configuration in which the child seat detection unit 14 is added to the configuration in FIG. Since the other elements are the same as those in FIG. 1, the description of these elements will be omitted here.

The child seat detection unit 14 detects the seat in which the child seat is installed. The method of detecting the seat in which the child seat is installed may be any method, for example, a method of detecting the image of the child seat from the image in the vehicle taken by the camera, or the output signal of the load sensor provided in each seat. It may be a method of detecting based on the pull-out amount or tension of the seat belt of each seat.

Further, in the present embodiment, the occupant determination unit 13 determines the attribute of the occupant in consideration of the position of the seat where the child seat is installed. Specifically, the occupant determination unit 13 determines that the living body detected in the seat in which the child seat is installed is a child occupant.

FIG. 15 is a flowchart showing the operation of the occupant detection device 10 according to the third embodiment. The flow of FIG. 15 is obtained by adding steps S121 and S122 described below to the flow of FIG. 7. Since the other steps are the same as those in FIG. 7, the description of those steps is omitted here.

In step S121, the child seat detection unit 14 searches for a seat in the vehicle in which the child seat is installed. In the flow of FIG. 15, step S121 is executed after steps S101 to S103, but the order may be reversed.

Step S122 is executed after step S105. In step S122, based on the search result of step S121, the occupant determination unit 13 confirms whether or not the child seat is installed in the seat where the occupant corresponding to the target living body is present. If a child seat is not installed in the seat (NO in step S122), the process proceeds to step S106, and the occupant determination unit 13 determines the attribute of the occupant (adult or child) corresponding to the target living body, as in the first embodiment. Is determined based on the size of the target living body. However, if a child seat is installed in the seat (YES in step S111), the process proceeds to step S108, and the occupant determination unit 13 determines that the occupant corresponding to the target living body is a child.

The occupant detection device 10 according to the third embodiment accurately determines the attribute (child) of the occupant in the seat where the child seat is installed in order to determine the attribute of the occupant in consideration of the position of the seat where the child seat is installed. can do.

<Embodiment 4>
There are individual differences in the physique of a person, and there are large children and small adults. Therefore, it is considered that the age of a person can be judged more accurately by judging from the characteristics of the face and skeleton than by judging from the size of the body. Therefore, in the present embodiment, when the characteristics of the face or skeleton of the occupant are known, the occupant determination unit 13 determines the attributes of the occupant by estimating the age of the occupant from the characteristics.

FIG. 16 is a block diagram showing the configuration of the occupant detection device 10 according to the fourth embodiment. The configuration of the occupant detection device 10 of FIG. 16 is a configuration in which an in-vehicle image acquisition unit 15 and an occupant image detection unit 16 are added to the configuration of FIG. Further, an in-vehicle camera 22 is connected to the occupant detection device 10. Since the other elements are the same as those in FIG. 1, the description of these elements will be omitted here.

The in-vehicle camera 22 is a camera that photographs each seat in the vehicle. The in-vehicle camera 22 may be composed of one camera or may be composed of a plurality of cameras provided for each seat. When the in-vehicle camera 22 is composed of one camera, the in-vehicle camera 22 is installed at a position where all seats can be simultaneously photographed, for example, in the vicinity of an overhead console (OHC) or a rear view mirror. Hereinafter, the image taken by the in-vehicle camera 22 inside the vehicle is referred to as an “in-vehicle image”. In the present embodiment, it is assumed that the in-vehicle camera 22 is composed of one camera installed on the overhead console.

The vehicle interior image acquisition unit 15 of the occupant detection device 10 acquires the vehicle interior image taken by the vehicle interior camera 22. The occupant image detection unit 16 analyzes the in-vehicle image acquired by the in-vehicle image acquisition unit 15 based on the position of the living body detected by the in-vehicle image detection unit 12, and from the in-vehicle image to the living body detected by the in-vehicle detection unit 12. Search for images of the corresponding occupants.

When the image of the occupant corresponding to the living body detected by the biological detection unit 12 is detected, the occupant determination unit 13 extracts the facial or skeletal characteristics of the occupant from the image of the occupant, and the extracted facial or skeletal characteristics. By estimating the age of the occupant based on the above, the attribute (adult or child) of the occupant is determined. When the image of the occupant corresponding to the living body detected by the living body detection unit 12 is not detected, the occupant determination unit 13 sets the attribute of the occupant corresponding to the living body to the size of the living body as in the first embodiment. Judgment based on.

FIG. 17 is a flowchart showing the operation of the occupant detection device 10 according to the fourth embodiment. The flow of FIG. 17 is obtained by adding steps S131 to S134 described below to the flow of FIG. 7. Since the other steps are the same as those in FIG. 7, the description of those steps is omitted here.

In step S131, the vehicle interior image acquisition unit 15 acquires the vehicle interior image taken by the vehicle interior camera 22. In the flow of FIG. 17, step S131 is executed after steps S101 to S103, but the order may be reversed.

Step S132 is executed after step S105. In step S132, the occupant image detection unit 16 searches for the image of the occupant corresponding to the target living body from the in-vehicle image by analyzing the in-vehicle image acquired by the in-vehicle image acquisition unit 15 based on the position of the target living body. ..

Step S133 is executed after step S132. In step S133, the occupant determination unit 13 confirms whether or not the image of the occupant corresponding to the target living body is detected in step S132. If the image of the occupant corresponding to the target living body is detected (YES in step S133), the process proceeds to step S134. In step S134, the occupant determination unit 13 analyzes the image of the occupant corresponding to the target living body and estimates the age from the characteristics of the occupant's face or skeleton to determine the attribute (adult or child) of the occupant. to decide.

If the image of the occupant corresponding to the target living body is not detected (NO in step S133), the process proceeds to step S106, and the occupant determination unit 13 determines the attribute of the occupant corresponding to the target living body (adult) as in the first embodiment. Whether it is a child or a child) is determined based on the size of the target living body.

Since the occupant detection device 10 according to the fourth embodiment determines the occupant's attributes from the characteristics of the occupant's face or skeleton, it is possible to improve the determination accuracy of the occupant's attributes.

<Embodiment 5>
FIG. 18 is a block diagram showing the configuration of the occupant detection device 10 according to the fifth embodiment. The configuration of the occupant detection device 10 of FIG. 18 is a configuration in which a facial expression change detection unit 17 is added to the configuration of FIG. Since the other elements are the same as those in FIG. 16, the description of these elements is omitted here.

The facial expression change detection unit 17 detects the change in the facial expression of the occupant by monitoring the change in the image of the occupant's face detected by the occupant image detection unit 16. More specifically, the facial expression change detection unit 17 can see the eyes (outer corners of both eyes, inner corners of both eyes, upper eyelids, lower eyelids, etc.), nose (base of nose, back of nose, ala of nose, tip of nose, etc.) and mouth from the image of the face of the occupant. Facial parts such as (upper lip, lower lip, etc.) are extracted as feature points, and the presence or absence of changes in facial expressions is determined from the positional relationship of those feature points. However, the method for detecting the change in facial expression is not limited to this, and any method may be used.

Further, in the present embodiment, the occupant determination unit 13 determines the attributes of the occupant in consideration of the detection result of the facial expression change of the occupant by the facial expression change detection unit 17. Specifically, the occupant determination unit 13 determines that the face of the occupant detected by the occupant image detection unit 16 does not change the facial expression for a certain period of time or more, and determines that the face does not belong to the occupant, and determines the attributes of the occupant. , Judgment is based on the size of the living body, not the image.

FIG. 19 is a flowchart showing the operation of the occupant detection device 10 according to the fifth embodiment. The flow of FIG. 19 is obtained by adding step S135 described below to the flow of FIG. Since the other steps are the same as those in FIG. 17, the description of these steps will be omitted here.

Step S135 is executed when it is determined in step S133 that the image of the occupant corresponding to the target living body is detected (when it is determined to be YES in step S133). In step S135, whether or not the occupant determination unit 13 has not changed the facial expression of the occupant's face corresponding to the target living body for a certain period of time or more based on the detection result of the facial expression change of the occupant by the facial expression change detection unit 17. To judge. If the state in which the facial expression does not change continues for a certain period of time or more (YES in step S135), the process proceeds to step S106, and the occupant determination unit 13 determines that the occupant is an adult based on the size of the target living body, as in the first embodiment. Determine if it is a child or a child. If the state in which there is no change in facial expression continues for less than a certain period of time (NO in step S135), the process proceeds to step S134, and the occupant determination unit 13 is the same as in the fourth embodiment of the occupant corresponding to the target living body. By analyzing the image and estimating the age from the facial or skeletal features of the occupant, the attribute (adult or child) of the occupant is determined.

In the occupant detection device 10 according to the fifth embodiment, if there is no change in facial expression on the occupant's face detected by the occupant image detection unit 16 for a certain period of time or more, the attribute of the occupant is based on the size of the living body instead of the image. to decide. This prevents children from being mistakenly identified as adults when they are wearing a mask or wearing a shirt with a person's face printed on them. In addition, for example, in order to hide the fact that the child has been left behind in the vehicle, it is possible to expect the effect of being able to detect the camouflage that makes the child look like an adult by putting on a mask.

The embodiments 2 to 5 described above can be combined with each other. For example, when all of the second to fifth embodiments are combined, the configuration of the occupant detection device 10 is as shown in FIG. The configuration of the occupant detection device 10 of FIG. 20 is the configuration of FIG. 1 with the addition of the child seat detection unit 14, the vehicle interior image acquisition unit 15, the occupant image detection unit 16, and the facial expression change detection unit 17. Further, an in-vehicle camera 22 is connected to the occupant detection device 10.

FIG. 21 shows a flowchart showing the operation of the occupant detection device 10 shown in FIG. 20. The flow of FIG. 21 is obtained by adding the above-mentioned steps S111, S121, S122, and S131 to S135 to the flow of FIG. 7. In other words, in the flow of FIG. 21, step S122 described in the third embodiment is added after step S103 of the flow of FIG. 19, and step S111 described in the second embodiment is added between steps S105 and S132. And step S122 described in the third embodiment are added (step S111 is executed when NO is determined in step S122). According to this modification, the effects of the second to fifth embodiments can be obtained.

<Embodiment 6>
The occupant detection devices 10 of the first to fifth embodiments include, for example, an occupant monitoring system that monitors the physical condition of the occupants in each seat, a child abandonment warning system that prevents children from being left behind in the vehicle, and the like. It is widely applicable to systems that utilize the attributes of. In the sixth embodiment, an example in which the occupant detection device 10 is applied to a child abandonment warning system is shown.

FIG. 22 is a block diagram showing the configuration of the child abandonment warning system 30 according to the sixth embodiment. The child abandonment warning system 30 includes an occupant detection device 10 according to any one of the first to fifth embodiments and an alarm output unit 31 (the child abandonment warning system 30 of FIG. 22 is the first embodiment. The occupant detection device 10 is provided).

The alarm output unit 31 monitors whether or not the occupant in the vehicle is only a child based on the determination result of the attribute of the occupant by the occupant detection device 10, and if the state of only the child continues for a certain period of time or more, the child is left behind. It is judged that there is a risk of being damaged, and an alarm is issued outside the vehicle.

FIG. 23 is a flowchart showing the operation of the child abandonment warning system 30. Hereinafter, the operation of the child abandonment warning system 30 will be described with reference to FIG. 23.

When the child abandonment warning system 30 is activated, the occupant detection device 10 first executes an occupant detection process for determining the presence or absence of occupants in each seat and the attributes of the occupants (adult or child) (step S201). In the occupant detection process, the occupant detection device 10 executes the process shown in FIGS. 7, 15, 17, 19, or 21.

The alarm output unit 31 confirms whether or not there is an occupant in the vehicle based on the result of the occupant detection process (step S202). If there are no occupants in the vehicle (NO in step S202), the alarm output unit 31 determines that all the occupants have disembarked from the vehicle and ends the process.

When there is an occupant in the vehicle (YES in step S202), the alarm output unit 31 confirms whether the occupant in the vehicle is only a child (step S203). If the occupants in the vehicle include an adult (NO in step S203), the process returns to step S201.

When the occupant in the vehicle is only a child (YES in step S203), the alarm output unit 31 confirms whether the occupant in the vehicle has been a child only for a certain period of time or more (step S204). If the occupant in the vehicle is only a child for a certain period of time or longer (NO in step S204), the process returns to step S201.

If the occupant in the vehicle remains only a child for a certain period of time (YES in step S204), the alarm output unit 31 determines that the child may be left behind in the vehicle and goes out of the vehicle. An alarm is issued (step S205).

Although there is no restriction on the timing at which the child abandonment warning system 30 starts the process of FIG. 23, the child abandonment occurs after the vehicle has stopped, so that the process of FIG. 23 is started at the timing when the vehicle stops. good. Alternatively, the child abandonment warning system 30 may detect the getting on and off of the occupant based on the door open / close signal, the output signal of the load sensor of the seat, and the like, and the process of FIG. 23 may be started at the timing when the occupant gets on and off. .. When the process of FIG. 23 is started at the timing when the occupants get on and off, it can be detected that after all the occupants get off the vehicle once, only the child is put on the vehicle again and left behind.

The child abandonment warning system 30 according to the sixth embodiment detects that the child may be left behind and issues an alarm, so that the child can be prevented from being left behind. Further, since the occupant detection process (step S201) for determining the presence / absence of an occupant in the vehicle and the attributes of the occupant is performed by the occupant detection device 10 according to any one of the first to fifth embodiments, the child is left behind. The fear can be detected accurately.

It is possible to freely combine each embodiment, and to appropriately modify or omit each embodiment.

It is understood that the above description is an example in all aspects, and innumerable variations not illustrated can be assumed.

10 occupant detection device, 11 biometric information acquisition unit, 12 biometric detection unit, 13 occupant judgment unit, 14 child seat detection unit, 15 in-vehicle image acquisition unit, 16 occupant image detection unit, 17 facial expression change detection unit, 21 electromagnetic wave sensor, 22 in-vehicle Camera, 30 child car seat warning system, 31 warning output unit, 50 processing circuit, 51 processor, 52 memory.

Claims

A biometric information acquisition unit that acquires biometric information in the vehicle detected by an electromagnetic wave sensor,
A biological detection unit that searches for a living body existing in the vehicle based on the biological information and specifies the position and size of the detected living body.
A occupant determination unit that determines the seat with the occupant of the vehicle and the attributes of the occupant based on the positional relationship between the position of the living body and the position of each seat of the vehicle and the size of the living body.
A occupant detection device equipped with.
The biological detection unit determines the position and size of the biological body based on the distribution of detection points of vital signs included in the biological information.
The occupant detection device according to claim 1.
When the living body is located across a plurality of seats, the occupant determination unit determines that the occupant is present so as to straddle the plurality of seats.
The occupant detection device according to claim 1.
The occupant determination unit determines that the living body that has not reached the floor of the vehicle is a child.
The occupant detection device according to claim 1.
It also has a child seat detector that detects the seat in which the child seat is installed.
The occupant determination unit determines that the living body detected in the seat in which the child seat is installed is a child.
The occupant detection device according to claim 1.
An in-vehicle image acquisition unit that acquires an in-vehicle image that is an image of the inside of the vehicle,
An occupant image detection unit that searches for an image of the occupant from the in-vehicle image,
Further prepare
When the image of the occupant is detected, the occupant determination unit determines the attribute of the occupant by estimating the age of the occupant based on the image of the occupant.
The occupant detection device according to claim 1.
The occupant determination unit estimates the age of the occupant from the facial features of the occupant.
The occupant detection device according to claim 6.
The occupant determination unit estimates the age of the occupant from the characteristics of the skeleton of the occupant.
The occupant detection device according to claim 6.
It is further provided with a facial expression change detection unit that detects changes in the facial expression of the occupant by monitoring changes in the image of the occupant's face.
When the facial expression of the occupant does not change for a certain period of time or more, the occupant determination unit determines the attribute of the occupant based on the size of the living body, not on the image of the occupant.
The occupant detection device according to claim 6.
The biometric information acquisition unit of the occupant detection device acquires the biometric information in the vehicle detected by the electromagnetic wave sensor, and
The biological detection unit of the occupant detection device searches for a living body existing in the vehicle based on the biological information, identifies the position and size of the detected living body, and determines the position and size of the detected living body.
The occupant determination unit of the occupant detection device determines the seat with the occupant of the vehicle and the attributes of the occupant based on the positional relationship between the position of the living body and the position of each seat of the vehicle and the size of the living body. ,
Crew detection method.