JP7399283B2 - Occupant detection device, child left behind warning system, passenger detection method, and child left behind warning method - Google Patents

Description

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

For example, in Patent Document 1 below, an electromagnetic wave sensor is used to confirm whether or not a vital sign is present in a seat in which a child seat is installed in a vehicle, and if there is a vital sign in the seat, it is determined that there is a child (infant) in the vehicle. An occupant detection device has been proposed that determines when a passenger is present.

JP 2019-123354 Publication

The technique disclosed in Patent Document 1 is based on the assumption that the occupant is seated correctly in the seat, and it is difficult to correctly detect, for example, an occupant who has reclined the backrest.

The present disclosure has been made to solve the above-mentioned problems, and it is an object of the present disclosure to provide an occupant detection device that can accurately determine the seat in which an occupant is located in a vehicle and the attributes of the occupant.

The occupant detection device according to the present disclosure includes a biometric information acquisition unit that acquires biometric information inside a vehicle detected by an electromagnetic wave sensor, and a biometric information acquisition unit that searches for a living body present in the vehicle based on the biometric information and locates the detected living body. and a living body detection unit that identifies the size, and an occupant determination unit that determines the seat where the occupant of the vehicle is located and the attributes of the occupant based on the positional relationship between the position of the living body and the position of the seat of the vehicle and the size of the living body. If the living body is located across a plurality of seats, the occupant determination unit determines that there is an occupant straddling the plurality of seats .

The occupant detection device according to the present disclosure determines the seat in which a vehicle occupant is located and the attributes of the occupant based on the positional relationship between the position of the living body identified from biometric 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 determined with high accuracy.

Objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings.

1 is a diagram showing the configuration of an occupant detection device according to Embodiment 1. FIG. FIG. 2 is a diagram showing an example of a seat arrangement of a vehicle. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. 3 is a flowchart showing the operation of the occupant detection device according to the first embodiment. FIG. 2 is a diagram showing an example of a hardware configuration of an occupant detection device. FIG. 2 is a diagram showing an example of a hardware configuration of an occupant detection device. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. FIG. 3 is a diagram showing an example of the distribution of vital sign detection points. 7 is a flowchart showing the operation of the occupant detection device according to the second embodiment. FIG. 7 is a diagram showing the configuration of an occupant detection device according to a third embodiment. 7 is a flowchart showing the operation of the occupant detection device according to the third embodiment. FIG. 7 is a diagram showing the configuration of an occupant detection device according to a fourth embodiment. 13 is a flowchart showing the operation of the occupant detection device according to Embodiment 4. FIG. 7 is a diagram showing the configuration of an occupant detection device according to a fifth embodiment. 12 is a flowchart showing the operation of the occupant detection device according to the fifth embodiment. FIG. 3 is a diagram showing the configuration of an occupant detection device according to a combination of embodiments 2 to 5; 7 is a flowchart showing the operation of the occupant detection device according to a combination of embodiments 2 to 5. FIG. FIG. 7 is a diagram showing the configuration of a child-left-behind warning system according to a sixth embodiment. 12 is a flowchart showing the operation of the child-left-behind warning system according to Embodiment 6.

<Embodiment 1>
FIG. 1 is a block diagram showing the configuration of an occupant detection device 10 according to the first embodiment. In this embodiment, it is assumed that the occupant detection device 10 is mounted on a vehicle. However, the occupant detection device 10 does not need to be permanently installed in the vehicle, and may be implemented on a portable device that can be brought into the vehicle, such as a mobile phone, a smartphone, or a PND (Portable Navigation Device). Furthermore, 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 in which the occupant detection device 10 is mounted. The electromagnetic wave sensor 21 is a sensor that detects a living body present 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 presence of a living body, and outputs information on the position of the detection point of the vital sign as biological information. The position of the vital sign detection point is determined, for example, by calculating the distance from the electromagnetic wave sensor 21 to the detection point based on the frequency spectrum of the radar reflected wave, and by calculating the distance from the electromagnetic wave sensor 21 to the detection point based on the phase difference of the radar reflected waves received by multiple antennas. This can be determined by calculating the direction of the detection point from 21.

In addition, since millimeter wave radar can penetrate resin and cloth to detect living bodies, the electromagnetic wave sensor 21 can detect objects that are difficult to see, such as children in rear-facing child seats, side-facing child seats, child seats with sunshades, or people covered with blankets. It is possible to detect people. In this embodiment, it is assumed that the electromagnetic wave sensor 21 is installed on the ceiling of the vehicle, and that all 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 section 11, a biological detection section 12, and an occupant determination section 13.

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

The size of the living body identified by the living body detection unit 12 may be classified into at least adult size and child size, but, for example, it may be classified into adult size and child size. According to the size of the human body dummies, standard-sized adult males (AM50), petite adult females (AF05), large adult males (AM95), and 10-year-old, 6-year-old, and 3-year-old children (10YO, 6YO, 3YO) ), etc. In this embodiment, it is assumed that the sizes of living bodies identified by the living body information acquisition unit 11 are classified into two sizes: adult sizes and child sizes. That is, if the size of the living body is greater than or equal to a predetermined threshold, it is determined to be adult size, and if it is less than the threshold, it is determined to be 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 old or younger) who could cause an accident if left unattended in a vehicle is defined as a child.

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

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

Here, the number of seats specified by the occupant determination unit 13 for one occupant is not limited to one, and may be plural. For example, when the detection points of vital signs are distributed as shown in FIG. 5 when the vehicle is viewed from above, the position of the living body identified by the living body detection unit 12 may straddle the positions of two adjacent seats. Then, the occupant determination unit 13 determines that there is one occupant straddling the two seats. Further, when the occupant reclines the seat back, the vital sign detection points may be distributed as shown in FIG. 6. In this case, the position of the living body identified by the living body detection unit 12 will straddle the positions of two seats arranged in front and behind each other, and the occupant determination unit 13 will detect the position of the living body so that the living body straddles the two seats. It is determined that there is a crew member.

In this way, the occupant determination unit 13 identifies the seat where the occupant is located based on the positional relationship between the living body identified by the living body detection unit 12 and each seat, so it can correctly detect an occupant who is present across multiple seats. can do. This prevents erroneous detections such as, for example, detecting an occupant sitting astride two seats as two children, and improves the accuracy of determining the attributes of the occupant.

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

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

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

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

Further, the occupant determining unit 13 confirms the size of the target living body (step S106). If the size of the target living body is an adult size (YES in step S106), the occupant determining unit 13 determines that the passenger corresponding to the target living body is an adult (step S107). Further, 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 passenger corresponding to the target living body is a child (step S108).

After executing the processes of steps S104 to S108 for all living organisms, the occupant determining unit 13 outputs the determination results 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 Embodiment 1 detects the seat in which a vehicle occupant is located and the occupant's attributes based on the positional relationship between the position of the living body identified from biometric information and the position of each seat in the vehicle. Judgment is based on the size of the organism. Therefore, for example, the position and attributes of an occupant who is present across a plurality of seats can be determined with high accuracy.

Note that the attributes of the occupant detected by the occupant detection device 10 may include not only humans but also animals. That is, animals may be included in the size classification of living organisms identified by the living body detection unit 12. Furthermore, the classification of animals may be subdivided into large, medium, small, etc.

8 and 9 are diagrams showing examples of the hardware configuration of the occupant detection device 10, respectively. Each function of the constituent elements of the occupant detection device 10 shown in FIG. 1 is realized, for example, by a processing circuit 50 shown in FIG. 8. That is, the occupant detection device 10 acquires biological information inside the vehicle detected by an electromagnetic wave sensor, searches for a living body present in the vehicle based on the biological information, identifies the position and size of the detected living body, The present invention includes a processing circuit 50 for determining the seat where an occupant of a vehicle is located 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. The processing circuit 50 may be dedicated hardware, or may be a processor (Central Processing Unit (CPU), processing device, arithmetic device, microprocessor, microcomputer, etc.) that executes a program stored in memory. It may be configured 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 Circuit). Gate Array), or a combination of these. The functions of each component of the occupant detection device 10 may be realized by separate processing circuits, or these functions may be realized by a single processing circuit.

FIG. 9 shows an example of the hardware configuration of the occupant detection device 10 in a case where the processing circuit 50 is configured using a processor 51 that executes a program. In this case, the functions of the constituent elements of the occupant detection device 10 are realized by software or the like (software, firmware, or a combination of software and firmware). Software etc. are written as programs and stored in the memory 52. The processor 51 implements the functions of each section by reading and executing programs stored in the memory 52. That is, when executed by the processor 51, the occupant detection device 10 performs a process of acquiring biological information inside the vehicle detected by an electromagnetic wave sensor, and a process of searching and detecting a living body present in the vehicle based on the biological information. a process for determining the position and size of the living body, and a process for determining the seat in which the occupant of the vehicle is located 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; , comprises a memory 52 for storing programs to be executed as a result. In other words, this program can be said to cause the computer to execute the procedures and methods for operating the components of the occupant detection device 10.

Here, the memory 52 is a non-volatile or 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 media that will be used in the future. You can.

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

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

<Embodiment 2>
Child occupants may not be able to reach the floor with their feet 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 detection unit 12 detects a living body that does not reach the floor. Additionally, child occupants may lie down on the seats. In that case, the distribution of vital sign detection points will be as shown in FIGS. 11 and 12, for example, and in this case as well, the living body detection unit 12 will detect a living body that has not reached the floor.

In contrast, adult occupants are usually seated with their feet touching the floor. Therefore, when the occupant is an adult, the distribution of vital sign detection points is as shown in FIGS. 3 and 4 shown above, and the living body that reaches 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. is determined to be a child passenger. Note that the configuration of the occupant detection device 10 according to the second embodiment is the same as that in FIG. 1.

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 the flow of FIG. 7 with step S111 added after step S105. Since the other steps are the same as those in FIG. 7, the description of those steps will be omitted here.

In step S111, the occupant determination unit 13 determines whether 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 advances to step S106, and the occupant determination unit 13 determines the attributes of the occupant corresponding to the target living body (adult or child), 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 advances to step S108, and the occupant determination unit 13 determines that the passenger 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 an occupant by determining that a living body that has not reached the floor is 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 such that a child seat detection section 14 is added to the configuration in FIG. Since the other elements are the same as those in FIG. 1, description of those elements will be omitted here.

The child seat detection unit 14 detects a seat in which a child seat is installed. The seat in which the child seat is installed may be detected by any method; for example, it may be a method of detecting an image of the child seat from an image inside the vehicle taken by a camera, or an output signal of a load sensor installed in each seat, A detection method may also be used based on the amount or tension of the seat belt of each seat.

Further, in the present embodiment, the occupant determination unit 13 determines the attributes of the occupant, taking into account 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 where 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 in FIG. 15 is obtained by adding steps S121 and S122, which will be described below, to the flow in FIG. 7. Since the other steps are the same as those in FIG. 7, the description of those steps will be omitted here.

In step S121, the child seat detection unit 14 searches for a seat in the vehicle in which a 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 in step S121, the occupant determination unit 13 confirms whether a child seat is installed in the seat occupied by the occupant corresponding to the target living body. If a child seat is not installed in the seat (NO in step S122), the process proceeds to step S106, where 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 organism. However, if a child seat is installed in the seat (YES in step S111), the process proceeds to step S108, and the occupant determining 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 determines the attributes of the occupant by taking into consideration the position of the seat where the child seat is installed, and therefore accurately determines the attributes of the occupant (child) in the seat where the child seat is installed. can do.

<Embodiment 4>
There are individual differences in the physique of people, including large children and small adults. Therefore, it is thought that a person's age can be determined more accurately from facial and skeletal features than from body size. Therefore, in the present embodiment, when the facial or skeletal features of the occupant are known, the occupant determination unit 13 estimates the age of the occupant from the characteristics, thereby determining the attributes of the occupant.

FIG. 16 is a block diagram showing the configuration of occupant detection device 10 according to the fourth embodiment. The configuration of the occupant detection device 10 in FIG. 16 is such that an in-vehicle image acquisition section 15 and an occupant image detection section 16 are added to the configuration in 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, description of those 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 it can photograph all seats at the same time, such as near an overhead console (OHC) or a rear view mirror. Hereinafter, the image captured by the in-vehicle camera 22 inside the vehicle will be referred to as the "in-vehicle image." In this embodiment, it is assumed that the in-vehicle camera 22 is composed of one camera installed in an overhead console.

The in-vehicle image acquisition unit 15 of the occupant detection device 10 acquires an in-vehicle image captured by the in-vehicle 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 living body detection unit 12, thereby detecting the living body detected by the living body detection unit 12 from the in-vehicle image. Search for the corresponding passenger image.

When an image of the occupant corresponding to the living body detected by the living body detection unit 12 is detected, the occupant determination unit 13 extracts facial or skeletal features of the occupant from the image of the occupant, and extracts facial or skeletal features of the occupant from the image of the occupant. By estimating the age of the occupant based on the age of the occupant, the attribute of the occupant (adult or child) 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 determines the attributes of the occupant corresponding to the living body based on 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 in FIG. 17 is obtained by adding steps S131 to S134, which will be described below, to the flow in FIG. Since the other steps are the same as those in FIG. 7, the description of those steps will be omitted here.

In step S131, the in-vehicle image acquisition unit 15 acquires an in-vehicle image captured by the in-vehicle 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 analyzes the in-vehicle image acquired by the in-vehicle image acquisition unit 15 based on the position of the target living body, thereby searching for an image of the occupant corresponding to the target living body from among the in-vehicle images. .

Step S133 is executed after step S132. In step S133, the occupant determination unit 13 checks whether an image of the occupant corresponding to the target living body has been detected in step S132. If the image of the occupant corresponding to the target living body has been detected (YES in step S133), the process advances to step S134. In step S134, the occupant determination unit 13 analyzes the image of the occupant corresponding to the target biological body and estimates the age from the facial or skeletal features of the occupant, thereby determining the attributes of the occupant (adult or child). to decide.

If the image of the occupant corresponding to the target biological body is not detected (NO in step S133), the process proceeds to step S106, and the occupant determining unit 13 determines the attributes (adult) of the occupant corresponding to the target biological body, as in the first embodiment. or a child) based on the size of the target organism.

The occupant detection device 10 according to the fourth embodiment determines the attributes of the occupant from the features of the occupant's face or bone structure, and thus can improve the accuracy of determining the attributes of the occupant.

<Embodiment 5>
FIG. 18 is a block diagram showing the configuration of occupant detection device 10 according to the fifth embodiment. The configuration of the occupant detection device 10 in FIG. 18 is such that an expression change detection section 17 is added to the configuration in FIG. 16. Since the other elements are the same as those in FIG. 16, explanation of those elements will be omitted here.

The facial expression change detection section 17 detects changes in the facial expression of the occupant by monitoring changes in the image of the occupant's face detected by the occupant image detection section 16. More specifically, the facial expression change detection unit 17 detects the eyes (the outer corners of both eyes, the inner corners of both eyes, the upper eyelids, the lower eyelids, etc.), the nose (the root of the nose, the dorsum of the nose, the wings of the nose, the tip of the nose, etc.), and the mouth from the image of the passenger's face. It extracts facial parts such as the upper lip and lower lip as feature points, and determines whether there is a change in facial expression based on the positional relationship of these feature points. However, the method for detecting changes in facial expressions is not limited to this, and any method may be used.

Further, in the present embodiment, the occupant determining section 13 determines the attributes of the occupant by taking into consideration the detection result of the facial expression change of the occupant by the facial expression change detecting section 17. Specifically, if the facial expression of the occupant's face detected by the occupant image detection section 16 does not change for a certain period of time or more, the occupant determining section 13 determines that the face does not belong to the occupant, and determines the attributes of the occupant. , making decisions based on the size of the living body rather than the image.

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

Step S135 is executed when it is determined in step S133 that an image of the occupant corresponding to the target living body has been detected (when it is determined YES in step S133). In step S135, the occupant determining unit 13 determines, based on the detection result of the occupant's facial expression change by the facial expression change detecting unit 17, whether or not there has been no change in the facial expression of the occupant's face corresponding to the target living body for a certain period of time or more. to judge. If the state in which there is no change in facial expression 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 whether the occupant is an adult based on the size of the target living body, as in the first embodiment. 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 advances to step S134, and the occupant determination unit 13 determines the identity of the occupant corresponding to the target living body, as in the fourth embodiment. The attributes of the occupant (adult or child) are determined by analyzing the image and estimating the age based on the facial or skeletal characteristics of the occupant.

The occupant detection device 10 according to the fifth embodiment determines the attributes of the occupant based on the size of the living body, not the image, if the facial expression of the occupant detected by the occupant image detection unit 16 does not change for a certain period of time or longer. to decide. This prevents children from being misjudged as adults when they are wearing a mask or a shirt with a human face printed on it. It is also expected that the system will be able to see through a disguise made by putting a mask on a child to make them look like an adult, for example, in order to hide the fact that the child has been left behind in a vehicle.

Embodiments 2 to 5 described above can also 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. 20. The configuration of the occupant detection device 10 in FIG. 20 is such that the above-described child seat detection unit 14, in-vehicle image acquisition unit 15, occupant image detection unit 16, and facial expression change detection unit 17 are added to the configuration in FIG. Further, an in-vehicle camera 22 is connected to the occupant detection device 10.

A flowchart showing the operation of the occupant detection device 10 shown in FIG. 20 is shown in FIG. The flow of FIG. 21 is the flow of FIG. 7 with the above steps S111, S121, S122, and S131 to S135 added. In other words, the flow of FIG. 21 adds step S122 described in the third embodiment after step S103 of the flow of FIG. and step S122 described in Embodiment 3 (step S111 is executed when it is determined NO in step S122). According to this modification, the effects of Embodiments 2 to 5 can be obtained.

<Embodiment 6>
The occupant detection device 10 of the first to fifth embodiments may be used, for example, in an occupant monitoring system that monitors the physical condition of an occupant in each seat, or a child-abandoned alarm system that prevents a child from being left behind in a vehicle. It is widely applicable to systems that utilize the attributes of Embodiment 6 shows an example in which the occupant detection device 10 is applied to a child-abandoned alarm system.

FIG. 22 is a block diagram showing the configuration of a child left behind alarm system 30 according to the sixth embodiment. This child leaving alarm system 30 includes the occupant detection device 10 according to any one of the first to fifth embodiments and an alarm output section 31 (the child leaving alarm system 30 in FIG. 22 is the same as the one according to the first embodiment). (This vehicle is equipped with such an occupant detection device 10.)

The alarm output unit 31 monitors whether or not the only occupant in the vehicle is a child based on the determination result of the occupant's attributes by the occupant detection device 10, and detects that the child has been left behind if the only occupant in the vehicle continues for a certain period of time. determines that there is a risk of being attacked, and issues a warning outside the vehicle.

FIG. 23 is a flowchart showing the operation of the child-left-behind warning system 30. The operation of the child-left-behind warning system 30 will be described below with reference to FIG. 23.

When the child leaving alarm system 30 is activated, the occupant detection device 10 first executes an occupant detection process to determine the presence or absence of an occupant in each seat and the attributes of the occupant (adult or child) (step S201). In the occupant detection process, the occupant detection device 10 executes the process shown in FIG. 7, FIG. 15, FIG. 17, FIG. 19, or FIG. 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 occupants have gotten off the vehicle, and ends the process.

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

If the only occupant in the vehicle is a child (YES in step S203), the alarm output unit 31 checks whether the condition in which the only occupant in the vehicle is a child continues for a certain period of time or more (step S204). If the situation in which the only occupant in the vehicle is a child has not continued for a certain period of time or more (NO in step S204), the process returns to step S201.

If the child remains the only occupant in the vehicle for a certain period of time (YES in step S204), the alarm output unit 31 determines that there is a risk that the child may be left behind in the vehicle, and removes the child from the vehicle. A warning is issued (step S205).

Note that there is no restriction on the timing at which the child abandonment warning system 30 starts the process shown in FIG. 23, but since child abandonment occurs after the vehicle has stopped, if the process shown in FIG. 23 is started at the timing when the vehicle has stopped, good. Alternatively, the child-abandoned alarm system 30 may detect the passenger getting on or off based on the door opening/closing signal, the output signal of the seat load sensor, etc., and the process of FIG. 23 may be started at the timing when the passenger gets on or off. . If the process of FIG. 23 is started at the timing when passengers get on and off the vehicle, it can also be detected that after all the passengers have gotten off the vehicle, only the child is put back on the vehicle and left behind.

The child-left-behind warning system 30 according to the sixth embodiment detects that there is a risk that a child may be left behind and issues an alarm, thereby making it possible to prevent children from being left behind. Furthermore, since the occupant detection process (step S201) for determining the presence or 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, children may be left behind. The fear can be detected with high accuracy.

Note that it is possible to freely combine each embodiment, or to modify or omit each embodiment as appropriate.

It is to be understood that the above description in all aspects is illustrative, and that countless variations not exemplified can be envisioned.

10 Occupant detection device, 11 Biological information acquisition unit, 12 Living body detection unit, 13 Occupant determination 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 Left Behind Alarm System, 31 Alarm Output Unit, 50 Processing Circuit, 51 Processor, 52 Memory.

Claims (9)

a biological information acquisition unit that acquires biological information inside the vehicle detected by the electromagnetic wave sensor;
a living body detection unit that searches for a living body existing in the vehicle based on the living body information and specifies the position and size of the detected living body;
an occupant determination unit that determines the seat where the occupant of the vehicle is located and the attributes of the occupant based on the positional relationship between the position of the living body and the position of the seat of the vehicle and the size of the living body;
Equipped with
When the living body is located across a plurality of seats, the occupant determination unit determines that there is an occupant astride the plurality of seats.
Occupant detection device. The living body detection unit determines the position and size of the living body based on a distribution of detection points of vital signs included in the living body information.
The occupant detection device according to claim 1 . It further includes a child seat detection unit that detects a seat in which a child seat is installed.
The occupant determination unit determines that the living body detected in the seat where the child seat is installed is a child.
The occupant detection device according to claim 1 or claim 2 . 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 the occupant from the in-vehicle image;
Furthermore,
When the occupant is detected, the occupant determining unit determines the attribute of the occupant by estimating the age of the occupant based on the in-vehicle image.
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 4 . The occupant determining unit estimates the age of the occupant from the characteristics of the occupant's skeleton.
The occupant detection device according to claim 4 . The occupant detection device according to any one of claims 1 to 6 ;
an alarm output unit that issues an alarm when it is detected that the only occupant in the vehicle is a child based on a determination result of the occupant attribute by the occupant determination unit;
Equipped with
Child left behind alarm system. The biological information acquisition unit of the occupant detection device acquires biological information inside the vehicle detected by the electromagnetic wave sensor,
a living body detection unit of the occupant detection device searches for a living body existing in the vehicle based on the living body information, and specifies the position and size of the detected living body;
The occupant determination unit of the occupant detection device determines the seat where the occupant of the vehicle is located and the attributes of the occupant, based on the positional relationship between the position of the living body and the position of the seat of the vehicle and the size of the living body,
When the living body is located across a plurality of seats, the occupant determination unit determines that there is an occupant astride the plurality of seats.
Occupant detection method. determining the attributes of the occupant of the vehicle by the occupant detection method according to claim 8 ;
When it is detected that the only occupant in the vehicle is a child based on the determination result of the occupant attribute by the occupant determining section, an alarm output section of the child-left-behind warning system issues an alarm.
How to warn if a child is left behind.

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