In-vehicle monitoring device for a vehicle

Abstract

To enhance certainty of type determination of in-vehicle objects in a vehicle cabin, which is made based on a result of monitoring the cabin using a millimeter radio wave.SOLUTION: A vehicle interior monitoring device 20 is provided, comprising: sensors 31-39 configured to output a millimeter radio wave toward a cabin 3 of a vehicle 1 and detect reflected waves of the millimeter wave reflected by in-vehicle objects, such as passengers or baggage in the cabin 3 of the vehicle 1; and a determination unit 41 configured to determine the types of the in-vehicle objects in the cabin 3 of the vehicle 1 by comparing the detection level of the reflected waves of the millimeter wave with threshold values. The determination unit 41 selects a threshold value to be used to determine whether the in-vehicle objects in the cabin 3 of the vehicle 1 are children or baggage from a first low threshold value and a second low threshold value, and compares the selected threshold value with the detection level of the reflected waves of the millimeter wave to determine whether the in-vehicle objects are children or baggage.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to an in-vehicle monitoring device for a vehicle.

Background Art

[0002] Vehicles such as automobiles are boarded so that passengers including the driver and passengers sit on the seats in the passenger compartment, and travel according to the driving operation, driving support, or autonomous driving of the driver. In addition to internal combustion engines that burn gasoline or ethanol, power sources such as electric motors that use stored electric power and power sources that use hydrogen have been developed as power sources for vehicles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in vehicles such as automobiles, it is desired to be able to detect in-vehicle objects such as passengers and luggage in the passenger compartment and monitor their states. In particular, when the vehicle is traveling in autonomous driving, it may be important to monitor the state of in-vehicle objects in the passenger compartment of the vehicle during autonomous driving.

[0005] In Patent Documents 1 and 2, the state of the passenger is detected by irradiating radio waves such as millimeter waves and detecting the reflected waves. In addition, Patent Document 2 discloses a function for detecting the leaving of an infant.

[0006] However, when using millimeter-wave radio waves in this way and attempting to determine the type of objects inside the vehicle, such as passengers or luggage in the passenger compartment of the vehicle, based on the detection level of the reflected millimeter waves, the detection level of the reflected waves does not necessarily clearly distinguish for each type of object inside the vehicle. Therefore, there is a possibility that the type of object inside the vehicle detected cannot be correctly determined. In particular, the difference between the detection level of the reflected millimeter waves by children including infants and the detection level of the reflected millimeter waves by luggage tends to be basically small. The detection level of the reflected millimeter waves by passengers such as adults is basically higher than the detection level of the reflected millimeter waves by luggage, so it is possible to clearly distinguish. However, the detection level of the reflected millimeter waves by children such as infants may be lower than the detection level of the reflected millimeter waves by luggage. For example, the detection level of the reflected millimeter waves for luggage with a permeable liquid such as a plastic bottle containing liquid may be higher than the detection level of the reflected millimeter waves by children such as infants. In this case, depending on the setting of the threshold value, there is a high possibility of misjudging a plastic bottle containing liquid as a child, or if the threshold value is increased to prevent this, misjudging the child as luggage.

[0007] Thus, in a vehicle, it is required to enhance the certainty regarding the determination of the type of objects inside the vehicle based on the result of detecting the passenger compartment using millimeter-wave radio waves.

Means for Solving the Problem

[0008] The in-vehicle monitoring device for a vehicle according to the present invention includes a sensor that outputs millimeter-wave radio waves toward the passenger compartment of the vehicle and detects the reflected millimeter waves by objects inside the vehicle such as passengers or luggage in the passenger compartment of the vehicle, and a determination unit that determines the type of objects inside the vehicle in the passenger compartment of the vehicle by comparing and judging the detection level of the reflected millimeter waves by the sensor with a threshold value. The determination unit uses, for determining children and luggage as objects inside the vehicle in the passenger compartment of the vehicle, a threshold value As being larger than the range of the detection level of luggage a first low threshold value and , and smaller than the range of the detection level of children a second low threshold value are used. The first lower threshold value is a value larger than the range of the detection level of luggage, including a plastic bottle containing liquid. The second lower threshold value is a value smaller than the range of the detection level of children, including the detection level of an infant sleeping in a child seat installed backward on the seat of the vehicle and the detection level of an infant at the foot of the seat. It is lower than the first lower threshold value. If there is a history of opening and closing of the boarding and alighting doors other than the front side of the vehicle before the vehicle starts running, and the history includes a child, the type determination of the objects inside the vehicle is executed. In the type determination of the objects inside the vehicle, if it is a child priority setting, the second lower threshold value is selected, and if it is not a child priority setting, the first lower threshold value isSelect and compare the selected threshold value with the detection level of the reflected wave of the millimeter wave by the sensor to determine the in-vehicle object between a child and luggage.

[0012] Preferably, it has an alarm unit that issues an alarm to the occupant of the vehicle, and when the occupant gets out of the vehicle from the vehicle, the determination unit determines the passenger compartment to If a child be is determined, an abandonment alarm is issued to the occupant getting out of the vehicle, and when the occupant gets out of the vehicle from the vehicle, the determination unit determines the passenger compartment at If a child be is not determined, it is preferable not to issue an abandonment alarm.

[0013] Preferably, it has a detection unit that detects a plurality of types of operations performed by the occupant when getting out of the vehicle, including opening and closing of the vehicle door, and the alarm unit is based on the type and order of operations of the occupant getting out of the vehicle detected by the detection unit. It is preferable to output alarms in order from a plurality of alarm output devices including a user interface unit provided in the passenger compartment of the vehicle and a user terminal of the occupant who has got out of the vehicle.

Advantages of the Invention

[0014] In the present invention, the sensor outputs millimeter wave radio waves toward the passenger compartment of the vehicle, and detects the reflected wave of the millimeter wave by an in-vehicle object such as an occupant or luggage in the passenger compartment of the vehicle. By using millimeter waves, the detection level of the reflected wave when there is an in-vehicle object such as an occupant in the passenger compartment can be made different from that when there is no in-vehicle object such as an occupant in the passenger compartment. By using millimeter waves, it becomes possible to detect at least the presence or absence of an in-vehicle object based on the detection level of the reflected wave of the millimeter wave. Then, the determination unit determines the type of the in-vehicle object in the passenger compartment of the vehicle by comparing and judging the detection level of the reflected wave of the millimeter wave by the sensor with the threshold value. Thereby, basically, the determination unit can use a plurality of threshold values such as a high threshold value and a low threshold value to determine, for example, an adult and a child or a child and luggage for an in-vehicle object that may be in the passenger compartment of the vehicle. However, the detection level of the reflected wave is not necessarily clearly distinguishable for each type of object inside the vehicle in this way. For example, the difference in the detection level of the reflected wave of millimeter waves by a child and that by a luggage is basically small, and in some cases, their magnitude relationship may be reversed. Therefore, even if the threshold value set in advance is compared with the detection level of the reflected wave of millimeter waves by the sensor, it is difficult to appropriately determine the type of object inside the vehicle. There is a high possibility of misjudging a plastic bottle containing liquid as a child, or raising the threshold value to prevent this, but then misjudging a child as luggage. Therefore, in the present invention, the threshold value used for determining a child and luggage as objects inside the vehicle in the passenger compartment of the vehicle is selected from among a first lower threshold value and a second lower threshold value, and the selected threshold value is used to determine the object inside the vehicle as either a child or luggage. In the present invention, for example, when it can be determined based on the detection history of the opening and closing of the vehicle door or the boarding history that there is a possibility that a child is on board, the threshold value for determining a child and luggage may be selected from among the first lower threshold value and the second lower threshold value as a second lower threshold value lower than the first lower threshold value. Also, when it can be determined that there is no possibility that a child is on board, the first lower threshold value may be selected. Thereby, in the present invention, even if a situation occurs in which the difference between the detection level of the reflected wave by a child and the detection level of the reflected wave by luggage becomes small, it is possible to prevent misjudging a child as luggage. There is a possibility of reducing misjudgment between a child and luggage. As described above, in the present invention, the probability of correctly determining the type of object inside the vehicle based on the result of detecting the passenger compartment using millimeter wave radio waves can be increased.

Brief Description of the Drawings

[0015]

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DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is an explanatory diagram of an automobile 1 to which an occupant replacement determination device according to an embodiment of the present invention is applied. FIG. 1 is a schematic plan view of the automobile 1. FIG. 2 is a schematic longitudinal sectional view of the automobile 1 of FIG. 1. The longitudinal sectional view of FIG. 2 is obtained by cutting the automobile 1 of FIG. 1 at the central position Y0 in the vehicle width direction of the automobile 1. The automobile 1 is an example of a vehicle. The power source of the automobile 1 may be an internal combustion engine that burns gasoline or ethanol, an electric motor that uses stored electric power, a power source that uses hydrogen, or a combination thereof.

[0018] The motor vehicle 1 shown in FIGS. 1 to 2 has a vehicle body 2. The vehicle body 2 has a passenger compartment 3 in which a plurality of passengers can ride. In the passenger compartment 3, a plurality of seats 4 to 6 arranged in the front-rear direction of the motor vehicle 1 are provided. The plurality of seats 4 to 6 of the motor vehicle 1 in FIG. 1 are, in order from the front, a plurality of front-row seats 4 and 5 on which the driver 11 or a passenger 12 can be seated, and a rear-row seat 6 on which a plurality of passengers can be seated side by side in the vehicle width direction of the motor vehicle 1. In this case, the plurality of front-row seats 4 and 5 are the foremost seats, and the rear-row seat 6 is the rearmost seat. A luggage compartment 7 is provided behind the rear-row seat 6.

[0019] The driver 11 opens and closes a right front door (not shown), enters the passenger compartment 3, and sits on the front-row driver's seat 4, and then opens and closes the right front door and exits the passenger compartment 3. The passenger 12 opens and closes, for example, a left front door (not shown), enters the passenger compartment 3, and sits on the front-row passenger seat 5, and then opens and closes the left front door and exits the passenger compartment 3. The child 13 opens and closes, for example, a right rear door or a left rear door (not shown), enters the passenger compartment 3, and sits on the rear-row seat 6, and then opens and closes the right rear door or the left rear door and exits the passenger compartment 3. When assistance is required, such as for an infant, an adult such as the driver 11 or the passenger 12 opens and closes a right rear door or a left rear door, attaches a child seat 14 to the rear-row seat 6, and places the infant on the child seat 14. Note that the child 13 may sit on the front-row passenger seat 5. The passenger 12 may also sit on the rear-row seat 6. An adult or the child 13 who sits directly on the seats 4 to 6 wears a seat belt (not shown). Thereby, the passenger sits on the seats 4 to 6 with the upper body leaned against the backrests of the seats 4 to 6. The seating positions of the passengers sitting on the seats 4 to 6 basically fall within a certain range.

[0020] Then, the motor vehicle 1 travels by the driving operation, driving assistance, or autonomous driving of the driver 11 in a state where passengers including the driver 11 and the passenger 12 are sitting on the seats 4 to 6 in the passenger compartment 3. In such an automobile 1, for example, during driving, it is being considered to monitor the passengers 11 to 13 including the driver 11 in the passenger compartment 3, and to execute processes such as emergency notification and emergency stop control when an emergency occurs to the passengers. Also, in the automobile 1, it is being considered to issue an unattended warning when a child 13 or luggage is left in the passenger compartment 3 after an adult such as the driver 11 gets out of the vehicle.

[0021] FIG. 3 is an explanatory diagram of the control system 20 of the automobile 1 in FIG. 1 that functions as an in-vehicle monitoring device of the automobile 1 in FIG. 1. The in-vehicle monitoring device of the automobile 1 can monitor the passengers and luggage in the passenger compartment 3. The control system 20 in FIG. 3 includes an in-vehicle object determination device 21, a seat control device 22, a door opening / closing sensor 23, a wireless communication device 24, a user interface device (UI device) 25, and an in-vehicle network 26 to which these are connected.

[0022] The in-vehicle network 26 may be a wired communication network compliant with, for example, CAN (Controller Area Network) or LIN (Local Interconnect Network) for the automobile 1. The in-vehicle network 26 may be a communication network such as a LAN, or a combination thereof. A wireless communication network may be included in a part of the in-vehicle network 26.

[0023] The seat control device 22 has, for example, an actuator (not shown), and controls the front-rear position, up-down position, and the angle of the seat back of the plurality of seats 4 to 6 provided in the automobile 1. When, for example, a passenger sitting on each of the seats 4 to 6 is identified, the seat control device 22 may control the front-rear position, up-down position, and the angle of the seat back of the seats 4 to 6 so as to be a predetermined setting for that passenger. The seat control device 22 may further control the height of the holding position of the seat belt on the vehicle body 2 based on the setting for each passenger. At this time, the seat control device 22 may acquire setting data from each part of the automobile 1 through the in-vehicle network 26.

[0024] The door opening / closing sensor 23 detects the opening and closing of a plurality of doors (not shown) provided in the vehicle 1. The door opening / closing sensor 23 may be provided for each door to be opened and closed, for example, for each of the right front door, left front door, right rear door, left rear door, and hatchback door on the rear side of the vehicle body 2 described above. When the door opening / closing sensor 23 detects the opening and closing of the door provided in the vehicle 1, it supplies the detection data to each part of the vehicle 1 through the in-vehicle network 26. Thus, the door opening / closing sensor 23 detects the opening and closing operation of the door of the vehicle 1 when the occupant gets out of the vehicle 1.

[0025] The wireless communication device 24 establishes a wireless communication path with a wireless communication base station (not shown) provided outside the vehicle 1 and transmits and receives data to and from the base station. Examples of the wireless communication base station include a base station for commercial mobile communication and a base station for transmitting and receiving traffic information. The base station is connected to a server device. Further, the wireless communication device 24 may transmit and receive data to and from a user terminal 29 used by an occupant or the like through the base station or directly. The wireless communication device 24 may be capable of communication conforming to standards such as IEEE802.11 and IEEE802.15 in order to directly transmit and receive data to and from the user terminal 29. The control system 20 of the vehicle 1 may include a plurality of wireless communication devices 24 for each communication standard. When the wireless communication device 24 acquires transmission data from each part of the vehicle 1 through the in-vehicle network 26, it transmits the data to the base station or the user terminal 29. When the wireless communication device 24 receives reception data from the base station or the user terminal 29, it supplies the data to each part of the vehicle 1 through the in-vehicle network 26.

[0026] The user interface device 25 is connected to, for example, a liquid crystal device, a touch panel device, various switches, a speaker 27, and a microphone 28 provided in the passenger compartment 3 of the vehicle 1. The liquid crystal device may be provided as a meter panel provided in the front part of the driver 11 for the dashboard provided in the passenger compartment 3, for example. The touch panel device may be provided as a center display provided in the central part in the vehicle width direction of the dashboard provided in the passenger compartment 3, for example. When the user interface device 25 acquires output data from each part of the vehicle 1 through the in-vehicle network 26, it outputs the data from the liquid crystal device as a meter panel, the touch panel device as a center display, and the speaker 27. Thereby, the passenger can know the information of the vehicle 1 through the user interface device 25. Further, when an operation input is made to the touch panel device or a switch, or a predetermined voice input is made in the microphone 28, the user interface device 25 supplies the input data to each part of the vehicle 1 through the in-vehicle network 26.

[0027] The in-vehicle object determination device 21 monitors the passengers and luggage in the passenger compartment 3. The in-vehicle object determination device 21 includes a detection control unit 39, an output control unit 37, an input control unit 38, an input / output unit 44, a timer 43, a memory 42, a CPU 41, and an internal bus 45 to which these are connected. Each part of the in-vehicle object determination device 21 can input and output data through the internal bus 45.

[0028] The output control unit 37 is connected to a first output antenna 31 and a second output antenna 32. The output control unit 37 individually controls the output of the detection radio wave of the millimeter wave frequency from the first output antenna 31 and the output of the detection radio wave of the millimeter wave frequency from the second output antenna 32. The detection radio waves of the two channels of millimeter waves may be output with their output timings shifted from each other or may be output simultaneously. The detection radio waves of the millimeter waves may be continuous in time or may be separated. Different encoded data may be superimposed on the detection radio waves of the millimeter waves by the first output antenna 31 and the second output antenna 32.

[0029] The input control unit 38 is connected to a first input antenna 33, a second input antenna 34, a third input antenna 35, and a fourth input antenna 36. The input control unit 38 receives reflected waves from a load object for each of the millimeter-wave detection radio waves at the first input antenna 33, the second input antenna 34, the third input antenna 35, and the fourth input antenna 36. The input control unit 38 monitors and controls the input of the reflected waves at the first input antenna 33, the input of the reflected waves at the second input antenna 34, the input of the reflected waves at the third input antenna 35, and the input of the reflected waves at the fourth input antenna 36. The millimeter-wave detection radio waves output in two channels can be input in four channels by the four antennas. The input timing of the reflected waves at each input antenna depends on the distance from the output antenna of the output source to the reflected load and the distance from the reflected load to the input antenna. The distance and direction of the reflected load based on these antennas can be basically uniquely specified three-dimensionally when reflected waves from the same reflected load are input to at least three or more input antennas. However, multiple reflected waves from reflected loads in multiple directions may be input to one input antenna simultaneously. For example, by combining two-channel output and four-channel input, it is possible to separate the reflected wave components in each direction from the combined wave with multiple overlapping reflected waves and calculate the distance to the reflected load in each direction. The spatial resolution required to detect a plurality of passengers in the passenger compartment 3 can be ensured by means such as encoded data and timing control superimposed on the detection radio waves.

[0030] The detection control unit 39 controls the output of the detected radio waves of the two-channel millimeter waves by the output control unit 37 and the input of the reflected waves of the four channels by the input control unit 38. The detection control unit 39 may not only control the timing between the output control unit 37 and the input control unit 38, but also set the frequencies of the detected radio waves of the millimeter waves output by the first output antenna 31 and the second output antenna 32 under the control of the output control unit 37. Millimeter waves are being put into practical use not only for those with relatively low frequencies such as about 24 GHz, but also for those with high frequencies such as 60 to 78 GHz. The detection control unit 39 may select one from a plurality of frequencies such as 24 GHz, 60 GHz, and 72 GHz, for example, and set it to the output control unit 37. When the frequency is set, the output control unit 37 executes control to output the detected radio waves of the millimeter waves of the set frequency from the first output antenna 31 and the second output antenna 32. In this way, the output control unit 37, the first output antenna 31, the second output antenna 32, the input control unit 38, the first input antenna 33, the second input antenna 34, the third input antenna 35, the fourth input antenna 36, and the detection control unit 39 can function as a sensor that outputs millimeter-wave radio waves toward the passenger compartment 3 of the vehicle 1 and detects reflected waves from passengers or the like in the passenger compartment 3 of the vehicle 1.

[0031] The input / output unit 44 is connected to the in-vehicle network 26. The input / output unit 44 transmits and receives data to and from each part of the vehicle 1 through the in-vehicle network 26.

[0032] The timer 43 measures time and time. The timer 43 may measure, for example, the periodic timing for outputting detected radio waves and the elapsed time from each output timing of the detected radio waves.

[0033] The memory 42 records the programs executed by the CPU 41, the data used for program execution, and the data generated by program execution. The memory 42 may be composed of a non-volatile memory such as a RAM and a non-volatile memory such as an SSD or an HDD.

[0034] The CPU 41 reads and executes a program from the memory 42. As a result, a control unit that overall controls the operation of the in-vehicle object determination device 21 is realized. The CPU 41 as the control unit may detect and monitor in-vehicle objects such as passengers and luggage present in the passenger compartment 3, for example, based on reflected waves of detection radio waves of millimeter waves. At this time, the CPU 41 as the control unit may select the frequency of the detection radio waves of millimeter waves from a plurality of preset frequencies and instruct the detection control unit 39 to perform the setting. The frequencies of the radio waves that the CPU 41 can instruct the setting for may be a plurality of frequencies including, for example, a first frequency of 60 GHz and a second radio wave of, for example, 24 GHz that is lower than the first frequency. In this case, the detection control unit 39 executes the setting instructed by the CPU 41 and switches the frequency of the detection radio waves of millimeter waves. The CPU 41 as the control unit may also detect in-vehicle objects such as passengers and luggage entering the passenger compartment 3 of the vehicle 1, for example, and monitor the detected in-vehicle objects. At this time, the CPU 41 may determine the type of in-vehicle object in the passenger compartment of the vehicle 1 by comparing and judging the detection level of the reflected waves of millimeter waves by the input control unit 38 with a threshold value. When an adult passenger such as the driver 11 gets out of the vehicle, for example, the CPU 41 as the control unit may determine whether a child 13 or luggage is left in the passenger compartment 3 of the vehicle 1. And when a child 13 or luggage is left in the passenger compartment 3 of the vehicle 1 due to abandonment, the CPU 41 may output an alarm to the alighting passenger from, for example, a liquid crystal device as a meter panel, a touch panel device as a center display, and a speaker 27 through the user interface device 25. The CPU 41 may also output an alarm to the user terminal 29 used by the passenger or the like through the wireless communication device 24.

[0035] As shown in Fig. 1, the in-vehicle object determination device 21 having millimeter-wave sensors 31 to 39 is provided at the central position Y0 in the vehicle width direction of the vehicle 1 at the front edge portion of the ceiling roof of the passenger compartment 3 of the vehicle 1. The in-vehicle object determination device 21 having millimeter-wave sensors 31 to 39 is provided at the position of a so-called overhead console. The in-vehicle object determination device 21 outputs detection radio waves of millimeter waves as a whole toward the passenger compartment 3 with the rear lower direction as the center from its installation position. In this way, the in-vehicle object determination device 21 having millimeter-wave sensors 31 to 39 is provided from the front upper position in front of the seat backs of all the seats 4 to 6 provided in the passenger compartment 3 toward the rear lower direction. Thereby, detection radio waves of millimeter waves can be output toward the front surface of the chests of the passengers sitting on the seats 4 to 6. Note that the central direction in which the in-vehicle object determination device 21 mainly outputs radio waves only needs to be at least rearward. Also, in the in-vehicle object determination device 21 provided at the position of the overhead console, the first output antenna 31 and the second output antenna 32 may be provided at a predetermined interval from each other, for example, along the vehicle width direction or along the front-rear direction. The first input antenna 33, the second input antenna 34, the third input antenna 35, and the fourth input antenna 36 may be arranged, for example, at the four corners of a quadrangle whose four sides are along the vehicle width direction and the front-rear direction.

[0036] Fig. 4 is an explanatory diagram of a first detection state for explaining the detection principle of the millimeter-wave sensors 31 to 39 used in the in-vehicle object determination device 21 of Fig. 3. Fig. 4 shows one seat 4 and the in-vehicle object determination device 21 provided at the front upper position of the seat 4. The in-vehicle object determination device 21 outputs detection radio waves of millimeter waves of a set frequency from an output antenna such as the first output antenna 31 or the second output antenna 32. In FIG. 4, there are no in-vehicle objects such as passengers or luggage on the seat 4. Therefore, the detected radio wave of the millimeter wave output from the in-vehicle object determination device 21 downward and rearward where the seat 4 is located passes through the seat 4. The seat 4 basically has springs strung across a seat frame and is entirely covered with urethane or cloth. The seat 4 with such a structure and material hardly reflects the detected radio wave of the millimeter wave. As a result, the in-vehicle object determination device 21 does not receive the reflected wave from the seat 4.

[0037] FIG. 5 is an explanatory diagram of a second detection state in which a passenger is seated on the seat 4 in FIG. 4. FIG. 5 shows one seat 4, an in-vehicle object determination device 21 provided at a position above and in front of the seat 4, and a passenger seated on the seat 4. In this case, since there is a passenger on the seat 4, the detected radio wave of the millimeter wave output from an output antenna such as the first output antenna 31 or the second output antenna 32 can be reflected on the surface of the passenger. The reflected wave of the millimeter wave by the passenger returns toward the in-vehicle object determination device 21. The reflected wave of the millimeter wave is input to the plurality of input antennas 33 to 36 of the in-vehicle object determination device 21. The in-vehicle object determination device 21 can detect a stronger reflected wave compared to FIG. 4.

[0038] FIG. 6 is an explanatory diagram of a three-dimensional vehicle interior detection map 50 that can be generated based on the detection by the millimeter wave sensors 31 to 39 in the second detection state of FIG. 5. FIG. 6 shows a reflecting surface 51 detected for an occupant sitting on the seat 4 together with the seat 4. The CPU 41 of the in-vehicle object determination device 21 uses a combination of two-channel outputs and four-channel inputs to separate the reflected wave components in each direction from the input wave mixed with a plurality of reflected waves, and can calculate the distance to the reflected luggage in each direction. At this time, the CPU 41 of the in-vehicle object determination device 21 may change the output timing of the detection signals of the millimeter waves from the plurality of output antennas, or change the detection period and timing of the millimeter waves from the plurality of input antennas 33 to 36. As a result, the CPU 41 of the in-vehicle object determination device 21 obtains the distance for each incident direction of the reflected wave based on the installation position of the in-vehicle object determination device 21, and as shown by the solid line in FIG. 6, it is possible to generate a passenger compartment detection map 50 including a three-dimensional reflecting surface 51 along the surface of the occupant.

[0039] When attempting to detect the movement due to breathing on the chest surface of an occupant sitting stably on the seat 4 by the reflected wave of the millimeter wave, the passenger compartment detection map 50 needs to include the movement component of the reflecting surface over time. In this case, the millimeter wave is preferably not a low-frequency one of about 24 GHz, but belongs to a high-frequency range of at least 50 GHz or more, preferably 60 to 78 GHz. By using a high-frequency millimeter wave as the detection radio wave, the passenger compartment detection map 50 can observe the temporal variation component of the chest surface due to breathing. By using a high-frequency millimeter wave detection radio wave, the passenger compartment detection map 50 can obtain a high spatial resolution capable of detecting the movement due to breathing on the chest surface of the occupant present in the passenger compartment 3 of the automobile 1. On the other hand, when attempting to obtain a vehicle interior detection map 50 that widely detects the entire vehicle interior 3 of the vehicle 1 down to every corner, it is advisable to use millimeter waves with a low frequency of 24 GHz or less. Although the detection radio waves of millimeter waves with a low frequency such as 24 GHz cannot detect the movement of the occupant's chest surface or the size and shape of objects inside the vehicle with high precision as in the case of high frequencies, they have the property of easily wrapping around to the back side of luggage and are highly resistant to shielding. When using detection radio waves of millimeter waves with a high frequency of 60 GHz or more, it is not easy to effectively reach the detection radio waves of millimeter waves for, for example, the rear portion of the seat back with a steel plate or the left and right edge portions in the vehicle width direction of the vehicle interior 3. Even if there are objects inside the vehicle in a portion where the detection radio waves of millimeter waves cannot effectively reach, it is difficult to obtain significant reflected waves from such objects inside the vehicle. Note that, like the rear seat 6 in the rear row of FIG. 1, there is a seat back of the rearmost seat on the front side of the luggage compartment 7 that has a steel plate extending across the entire width in the vehicle width direction of the vehicle 1. Therefore, in the present embodiment, the frequency of the millimeter waves used as the detection radio waves is switched and used between at least two frequencies, a high frequency and a low frequency. Here, the case of using 60 GHz and 24 GHz will be described. In the present embodiment, since the frequency of the millimeter waves is switched and used, by simply providing one in-vehicle object determination device 21 for the vehicle interior 3 of the vehicle 1, it becomes possible to detect the entire vehicle interior 3 down to every corner with high resolution. There is no need to provide a plurality of in-vehicle object determination devices 21 corresponding to each of the plurality of seats 4 to 6 in the vehicle interior 3 of the vehicle 1. The number of in-vehicle object determination devices 21 can be reduced to a minimum, suppressing an increase in cost when using millimeter waves for monitoring occupants and the like. Moreover, since the number of in-vehicle object determination devices 21 is reduced, it is less likely that excessive restrictions will occur regarding the arrangement in the vehicle interior 3 for various devices including the in-vehicle object determination device 21.

[0040] FIG. 7 is a flowchart of millimeter wave detection control by the CPU 41 of the in-vehicle object determination device 21 in FIG. 3. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the process in FIG. 7. The CPU 41 may repeatedly execute the process of FIG. 7 at each detection period measured by the timer 43.

[0041] In step ST1, the CPU 41 selects the frequency of the detection radio wave of the millimeter wave for detecting in-vehicle objects such as passengers and luggage existing in the passenger compartment 3 from among a plurality of candidate frequencies such as 60 GHz and 24 GHz. For example, during normal times such as when the vehicle 1 is running, the CPU 41 may select 60 GHz, which is a high frequency, in order to be able to detect the movement due to breathing on the chest surface of the passengers existing in the passenger compartment 3. Also, when the CPU 41 detects the abandonment of in-vehicle objects such as the child 13 and luggage, it may select 24 GHz, which is a low frequency, in order to detect up to every corner of the passenger compartment 3.

[0042] In step ST2, the CPU 41 causes the first output antenna 31 and the second output antenna 32 to output the detection radio wave of the millimeter wave of the selected frequency, and detects the input of the reflected wave of the millimeter wave. The CPU 41 instructs the output control unit 37 to output the detection radio wave of the millimeter wave. The output control unit 37 outputs the detection radio wave of the millimeter wave of the selected frequency from the first output antenna 31 and the second output antenna 32. At this time, the output control unit 37 may scan the passenger compartment 3 by adjusting the interval between the output timing of the detection radio wave of the millimeter wave from the first output antenna 31 and the output timing of the detection radio wave of the millimeter wave from the second output antenna 32. When there are passengers sitting on the seats 4 to 6 in the passenger compartment 3 or there are luggage in the seats 4 to 6 and the luggage compartment 7, the detection radio wave of the millimeter wave is reflected by them. The reflected waves of these in-vehicle objects are input to the first input antenna 33, the second input antenna 34, the third input antenna 35, and the fourth input antenna 36 of the in-vehicle object determination device 21. The input control unit 38 generates information on the input of the reflected wave in the first input antenna 33, information on the input of the reflected wave in the second input antenna 34, information on the input of the reflected wave in the third input antenna 35, and information on the input of the reflected wave in the fourth input antenna 36, and outputs them to the CPU 41.

[0043] In step ST3, the CPU 41 generates a vehicle cabin detection map 50 indicating the position and range in the vehicle cabin 3 of reflective surfaces of in-vehicle objects such as passengers and luggage present in the vehicle cabin 3, based on the detection information of the reflected waves from the input control unit 38. The vehicle cabin detection map 50 may basically be the range of the vehicle cabin 3 indicated by the dashed line in FIG. 1, detected by the reflected waves of millimeter waves. The CPU 41, as a control unit, generates a vehicle cabin detection map 50 that detects the vehicle cabin 3 of the automobile 1, based on the reflected waves reflected in each part of the vehicle cabin 3 of the automobile 1 and detected by the millimeter wave sensors 31 to 39.

[0044] In step ST4, the CPU 41 records the generated vehicle cabin detection map 50 in the memory 42 together with the information of the detection time measured by the timer 43. As a result, a plurality of vehicle cabin detection maps 50 generated at different timings are recorded in the memory 42 in association with the information of each detection time. The plurality of vehicle cabin detection maps 50 include information about the movements of passengers and luggage in the vehicle cabin 3.

[0045] FIG. 8 is a flowchart of the basic in-vehicle object determination control by the CPU 41 of the in-vehicle object determination device 21 in FIG. 3. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the process in FIG. 8, for example, every time it executes the millimeter wave detection control in FIG. 7. The CPU 41 may repeatedly execute the process in FIG. 8 for each detection period measured by the timer 43.

[0046] In step ST11, the CPU 41 determines whether a new vehicle cabin detection map 50 has been generated. The CPU 41 may determine, for example, based on whether a newly generated vehicle cabin detection map 50 is recorded in the memory 42. If a new vehicle cabin detection map 50 has not been generated, the CPU 41 repeats this process. If a new vehicle cabin detection map 50 has been generated, the CPU 41 proceeds to step ST12.

[0047] In step ST12, the CPU 41 estimates the objects inside the vehicle based on the new vehicle compartment detection map 50. The vehicle compartment detection map 50 includes components of the reflection surfaces of passengers and luggage that have reflected the detection radio waves of millimeter waves. The CPU 41 may estimate the objects inside the vehicle based on the difference component between the new vehicle compartment detection map 50 and, for example, the vehicle compartment detection map 50 when there are no passengers or luggage at all. The CPU 41 may estimate the size of the object inside the vehicle from the range where the difference component is included in the vehicle compartment detection map 50. Also, the CPU 41 may estimate the position of the seat 4 to 6 where the object inside the vehicle that caused the difference component exists, etc., based on the position of the range where the difference component is included with reference to the position of the in-vehicle object determination device 21. The CPU 41 may estimate the size and position of each of the multiple objects inside the vehicle existing in the vehicle compartment 3.

[0048] In step ST13, the CPU 41 determines the presence or absence of an object inside the vehicle. If even one object inside the vehicle is estimated in step ST12, the CPU 41 determines that there is an object inside the vehicle and proceeds with the process to step ST14. If no object inside the vehicle is estimated, the CPU 41 determines that there is no object inside the vehicle and ends this control. Thereby, as a determination unit, the CPU 41 can determine the presence or absence and type of passengers, etc., existing in the vehicle compartment 3 of the automobile 1 based on the vehicle compartment detection map 50 of the automobile 1 as a determination based on the detection of the reflected waves by the millimeter wave sensors 31 to 39.

[0049] In step ST14, the CPU 41 determines whether the object inside the vehicle is a person (passenger) or a luggage. In this determination of a person and a luggage, the CPU 41 may use, for example, the detection level in a predetermined direction estimated as the range of the object inside the vehicle in a plurality of vehicle compartment detection maps 50 from the past vehicle compartment detection map 50 to the latest vehicle compartment detection map 50. The bodies of adults sitting on seats 4 to 6 are closer to the sensors 31 to 39 compared to the bodies of children sitting on seats 4 to 6 or the luggage placed on seats 4 to 6. For this reason, the detection level of adults is higher compared to children and luggage. In addition, the bodies of the children sitting on seats 4 to 6 will basically be closer to sensors 31 to 39 than the luggage placed on seats 4 to 6. Therefore, the detection level of the children will be higher than that of the luggage. Therefore, the CPU 41 compares, for example, the acquired detection level with a high threshold that is lower than the detection level of an adult and higher than the detection level of a child. When the acquired detection level is equal to or higher than the high threshold, the CPU 41 may determine that the object inside the vehicle is an adult. In addition, the CPU 41 compares, for example, the acquired detection level with a low threshold that is lower than the detection level of a child and higher than the detection level of luggage. When the acquired detection level is equal to or higher than the low threshold, the CPU 41 may determine that the object inside the vehicle is a child. In addition, when the acquired detection level is smaller than the low threshold, the CPU 41 may determine that the object inside the vehicle is luggage.

[0050] In step ST15, the CPU 41 generates information on the determined object inside the vehicle and records it in the memory 42. In the memory 42, information on the objects inside the vehicle, such as the passengers and luggage in the automobile 1 determined based on at least the latest detection, is recorded for each object inside the vehicle.

[0051] FIG. 9 is an explanatory diagram of the millimeter-wave detection level distribution for the passengers and luggage inside the vehicle. The vertical axis in FIG. 9 represents the millimeter-wave detection level for each object inside the vehicle. On the horizontal axis, three types, namely luggage, children, and adults, are shown as multiple types of objects inside the vehicle. As shown in FIG. 9, each object inside the vehicle, namely the luggage inside the vehicle, the children inside the vehicle, and the adults inside the vehicle, has a distribution range of the millimeter-wave detection level. For example, an adult inside the vehicle reflects millimeter waves at each part of the body as shown in FIG. 6, for example. The millimeter-wave detection level shown in FIG. 9 may be, for example, the maximum value of the reflected waves at each part in FIG. 6. It is considered that even if the average value or median value of the reflected waves at each part of the object inside the vehicle is used, a distribution range of the millimeter-wave detection level having the same tendency as in FIG. 9 can be obtained.

[0052] And an adult inside the vehicle will have a high detection level regardless of which seat 4 - 6 they are sitting on. A child inside the vehicle will have a lower level compared to an adult inside the vehicle regardless of which seat 4 - 6 they are sitting on. And for an infant sleeping in a child seat installed rear - facing on the rear - row seat 6 and for an infant at the feet of the rear - row seat 6, the detection levels tend to be the lowest within the distribution range of children. Luggage inside the vehicle will basically have a low level regardless of which seat 5 - 6 it is placed on. And for luggage such as a plastic bottle containing liquid, which is a permeable liquid, the detection level of the reflected millimeter - wave tends to be the highest within the distribution range of luggage. As a result, the detection level of luggage such as a plastic bottle containing liquid in Fig. 9 may be higher than the detection level of the reflected millimeter - wave by a child such as an infant. When the distribution ranges of the detection levels of multiple types of objects inside the vehicle overlap in this way, just comparing such millimeter - wave detection levels with a threshold value may not be able to accurately determine the type of object inside the vehicle. It is not easy to increase the certainty regarding the determination of the type of object inside the vehicle.

[0053] Therefore, in this embodiment, as multiple threshold values for comparison with the detection level, a high threshold value, a first low threshold value, and a second low threshold value are used. The high threshold value is a value smaller than the range of the detection level of an adult and larger than the range of the detection level of a child. The first low threshold value is a value larger than the range of the detection level of luggage. Therefore, the first low threshold value tends to be larger than the detection level of an infant sleeping in a child seat installed rear - facing on the rear - row seat 6 and the detection level of an infant at the feet of the rear - row seat 6. The second low threshold value is a value smaller than the range of the detection level of a child. Therefore, the second low threshold value tends to be smaller than the detection level of the reflected wave of a plastic bottle containing liquid.

[0054] Figure 10 is a flowchart of the type determination process of in-vehicle objects in the present embodiment by the CPU 41 of the in-vehicle object determination device 21 in FIG. 3. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the type determination process of the in-vehicle objects in FIG. 10.

[0055] In step ST21, the CPU 41 acquires the detection level for the in-vehicle object. In step ST22, the CPU 41 compares the detection level with a high threshold value for determining an adult and others as in-vehicle objects. If the detection level is equal to or higher than the high threshold value, the CPU 41 advances the process to step ST23. If the detection level is smaller than the high threshold value, the CPU 41 advances the process to step ST24. In step ST23, the CPU 41 determines that the in-vehicle object is an adult. Then, the CPU 41 ends the process in FIG. 10.

[0056] In step ST24, the CPU 41 determines whether it is a child priority setting. The child priority setting refers to a setting for preferentially determining a detection level between the first low threshold value and the second low threshold value in FIG. 9 as a child. If it is a child priority setting, the CPU 41 advances the process to step ST25. If it is not a child priority setting, the CPU 41 advances the process to step ST28. Note that the CPU 41 may determine that it is a child priority setting if it can determine that there is a possibility that a child is in the vehicle based on the history of opening and closing of the boarding / alighting doors other than the front side of the automobile 1, and may determine that it is not a child priority setting if it can determine that there is no possibility that a child is in the vehicle.

[0057] In step ST25, the CPU 41 acquires a second low threshold value smaller than the range of the detection level of the child as a threshold value for determining a child and luggage. In step ST26, the CPU 41 compares a second lower threshold value for determining a child and luggage as in-vehicle objects with the detection level. If the detection level is equal to or higher than the second lower threshold value, the CPU 41 advances the process to step ST27. If the detection level is smaller than the second lower threshold value, the CPU 41 advances the process to step ST30. In step ST27, the CPU 41 determines that the in-vehicle object is a child. Then, the CPU 41 ends the process of FIG. 10.

[0058] In step ST28, the CPU 41 acquires a first lower threshold value as a threshold value for determining a child and luggage. Thus, for example, when it can be determined that there is no possibility that a child is riding in the vehicle, the CPU 41 selects the first lower threshold value. Through the processes of step ST25 and step ST28, the CPU 41 can select, from among the first lower threshold value and the second lower threshold value, a threshold value to be used for determining a child and luggage as in-vehicle objects in the passenger compartment 3 of the automobile 1.

[0059] In step ST29, the CPU 41 compares the first lower threshold value for determining a child and luggage as in-vehicle objects with the detection level. If the detection level is equal to or higher than the first lower threshold value, the CPU 41 advances the process to step ST27. If the detection level is smaller than the first lower threshold value, the CPU 41 advances the process to step ST30. In step ST30, the CPU 41 determines that the in-vehicle object is luggage. Then, the CPU 41 ends the process of FIG. 10.

[0060] As described above, in the present embodiment, as a plurality of threshold values used for determination in comparison with the detection level, together with the high threshold value, the first lower threshold value and the second lower threshold value are used. And in the present embodiment, the first lower threshold value and the second lower threshold value are selectively switched and used for determination. Thereby, the CPU 41 can determine an in-vehicle object between a child and luggage based on the detection level of the reflected wave of the millimeter wave. The probability of determining between a child and luggage can be increased. For example, when the second lower threshold is compared with the detection level and the detection level is greater than the second lower threshold, if there is a possibility that the subject is a child including an infant, it is possible to correctly determine that the subject is a child for the detection levels within the possible range. Without missing any infants, it is possible to correctly determine the subject as a child. Also, when the first lower threshold is compared with the detection level and the detection level is less than the first lower threshold, it is possible to correctly determine that the item is a piece of luggage including a plastic bottle containing liquid. Without missing any plastic bottles containing liquid, it is possible to correctly determine the item as luggage. On the other hand, if, for example, determination is made using two thresholds, namely a high threshold and a low threshold, at least one of a child and a piece of luggage will be misjudged.

[0061] FIG. 11 is a flowchart of replacement monitoring control by the CPU 41 of the in-vehicle object determination device 21 shown in FIG. 3. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the replacement monitoring control shown in FIG. 11.

[0062] In step ST41, the CPU 41 determines whether there is a new rear seat occupancy. The CPU 41 may determine whether there is a new occupant getting into the rear row seat 6. The new occupant getting into the rear row seat 6 may be determined by, for example, detecting the opening and closing of the door corresponding to the rear row seat 6. If there is no new occupant getting into the rear row seat 6, the CPU 41 repeats this process. If there is a new occupant getting into the rear row seat 6, the CPU 41 proceeds to step ST42.

[0063] In step ST42, the CPU 41 executes the in-vehicle object type determination shown in FIG. 10. At this time, the CPU 41 may or may not determine the in-vehicle object type according to the child priority setting. The CPU 41 determines the in-vehicle object type as an adult, a child, or luggage. The CPU 41 may execute the in-vehicle object type determination for not only the rear row seat 6 but also all seats including the front row seats 4 and 5. Also, the CPU 41 may execute the in-vehicle object type determination for the luggage compartment 7.

[0064] In step ST43, the CPU 41 updates the riding history based on the determination result of step ST42 and stores it in the memory. When the determination of the types of in-vehicle objects for all seats is performed in step ST42, the CPU 41 may overwrite all of the riding history recorded in the memory 42 based on the determination result of step ST42. As a result, information indicating the latest riding state of the passengers and luggage on at least the rear row seat 6 is recorded in the memory 42. Preferably, information indicating the latest riding state of all passengers and all luggage on all seats 4 to 6 and the luggage compartment 7 is recorded in the memory 42.

[0065] In step ST44, the CPU 41 determines whether the running has ended. The CPU 41 may determine whether the running has ended based on, for example, the presence or absence of an operation of an ignition switch (not shown) for stopping the power source after running. When getting off after running, the driver 11 operates the ignition switch. When the ignition switch has not been operated after running, the CPU 41 does not determine that the running has ended and returns the process to step ST41. The CPU 41 repeats the processes from step ST41 to step ST44 until it determines that the running has ended. The information on the riding history recorded in the memory 42 is updated to correspond to the riding state in the latest running. When the ignition switch is operated after running, the CPU 41 determines that the running has ended and proceeds to step ST45 to start the process for replacement monitoring.

[0066] From step ST45, the CPU 41 specifically executes replacement monitoring control. First, the CPU 41 acquires the latest riding history from the memory 42.

[0067] In step ST46, the CPU 41 determines whether a child is left on the rear seat 6 based on the acquired riding history. If there is a history of opening and closing the boarding and alighting doors other than the front side of the vehicle 1 before the start of travel of the vehicle 1, the CPU 41 may determine that it is a state where there is a possibility that a child is riding. If a child is included in the riding history of the rear seat 6, the CPU 41 proceeds with the process to step ST47 assuming that a child is left on the rear seat 6. If a child is not included in the riding history of the rear seat 6, the CPU 41 ends this control assuming that no child is left on the rear seat 6.

[0068] In step ST47, the CPU 41 outputs a meter warning. The CPU 41 displays a child left-behind warning screen on the liquid crystal device as a meter panel through the user interface device 25. The driver 11 can recognize the possibility of a child being left behind based on the display of the meter panel that changes according to the operation of the ignition switch when the passengers get off the vehicle 1. By thus determining the leaving-behind of a child based on the riding history before getting off and outputting a warning, even if the child is not correctly seated on the rear seat 6 when getting off, for example, if the child is lying down at the foot of the rear seat 6 or sleeping in the child seat 14, the possibility of a child being left behind can be alerted by the warning.

[0069] In step ST48, in addition to the alighting of the passenger from the front side, the CPU 41 determines whether the door of the vehicle 1 is locked. The passenger opens and closes the door to get off. When the passenger leaves the vehicle 1, the door lock is automatically executed. If no passenger is getting off from the front side, or if the passenger who has gotten off has not left the vehicle 1 and the door is not locked, the CPU 41 repeats this determination. When the passenger gets off from the front side and leaves and the door lock is executed, the CPU 41 proceeds with the process to step ST49 based on a plurality of types of operations performed when the passengers get off the vehicle 1.

[0070] In step ST49, the CPU 41 executes the determination of the type of in-vehicle object in FIG. 10 according to the child priority setting. The CPU 41 selects and uses a second lower threshold value lower than the first lower threshold value together with the high threshold value to determine the type of in-vehicle object as an adult, a child, or luggage. The CPU 41 may execute the determination of the type of in-vehicle object for all seats including not only the rear seat 6 but also the front seats 4 and 5. Further, the CPU 41 may execute the determination of the type of in-vehicle object for the luggage compartment 7. In this way, the CPU 41 can select a threshold value for determining a child and luggage from among the first lower threshold value and the second lower threshold value based on the detection history or boarding history of the opening and closing of the doors of the automobile 1. And when it can be determined that it is a state where a child may be boarding, the CPU 41 can select a second lower threshold value lower than the first lower threshold value.

[0071] In step ST50, the CPU 41 determines whether a child is left on the rear seat 6 based on the determination result of step ST49. When a child is detected and determined for the rear seat 6, the CPU 41 proceeds with the process to step ST51 assuming that a child is left on the rear seat 6. When a child is not detected and determined for the rear seat 6, the CPU 41 ends this control assuming that the replacement of the child for the rear seat 6 has already been resolved.

[0072] In step ST51, the CPU 41 outputs a horn warning. The CPU 41 outputs a warning sound for child replacement from the speaker 27 through the user interface device 25. An alighting occupant such as the driver 11 can recognize the possibility of child replacement based on the warning sound output in response to the door lock at the time of alighting. By determining child replacement based on the type determination of the in-vehicle object actually detected after alighting and outputting a warning in this way, even if a child is not properly seated on the rear seat 6 at the time of alighting, for example, if the child is lying down at the foot of the rear seat 6 or sleeping in the child seat 14, the possibility of child replacement can be made known by the warning.

[0073] In step ST52, the CPU 41 determines whether or not a predetermined time has elapsed. The predetermined time may be measured by, for example, the timer 43. The predetermined time may be, for example, an elapsed time of several seconds to several tens of seconds from the processing timings based on step ST44, step ST46, or step ST48. If the predetermined time has not elapsed, the CPU 41 returns the process to step ST49. As a result, for example, after the door is locked, the horn alarm is repeatedly output within a predetermined period. The alighting passenger such as the driver 11 can recognize the possibility of leaving a child behind by the repeatedly output horn alarm. When the predetermined time elapses, the CPU 41 advances the process to step ST53.

[0074] In step ST53, the CPU 41 outputs an alarm to the user terminal 29. The CPU 41 transmits a warning message for leaving a child behind to the user terminal 29 through the wireless communication device 24. The user terminal 29 reproduces the received warning message. The alighting passenger such as the driver 11 who has the user terminal 29 can recognize the possibility of leaving a child behind based on the alarm output of the user terminal 29 that he / she has.

[0075] In step ST54, the CPU 41 determines whether or not the alarm output in step ST53 has been repeated a predetermined number of times. If the alarm output in step ST53 has not been repeated a predetermined number of times, the CPU 41 returns the process to step ST53. As a result, the CPU 41 repeatedly executes the alarm output in step ST53, and can repeatedly output to the alighting passenger such as the driver 11 who has the user terminal 29 the possibility of leaving a child behind. When the alarm output in step ST53 is repeated a predetermined number of times, the CPU 41 ends this control.

[0076] As described above, when the CPU 41 determines that a child has been left in the passenger compartment 3 when a passenger gets out of the vehicle 1 as an alarm unit, it issues an abandonment alarm to the passenger getting out of the vehicle 1, and when it is determined that no child has been left in the passenger compartment 3 when a passenger gets out of the vehicle 1, it does not issue an abandonment alarm. Moreover, the CPU 41 can output alarms in order from a plurality of alarm output devices including the user interface device 25 provided in the passenger compartment 3 of the vehicle 1 and the user terminal 29 of the passenger who has gotten out of the vehicle 1 according to the type and order of operations of the passenger getting out of the vehicle.

[0077] As described above, in the present embodiment, millimeter-wave radio waves are output toward the passenger compartment 3 of the vehicle 1, and reflected waves of the millimeter waves by in-vehicle objects such as passengers or luggage in the passenger compartment 3 of the vehicle 1 are detected. By using millimeter waves, the detection level of the reflected waves when there are in-vehicle objects such as passengers in the passenger compartment 3 can be made different from that when there are no in-vehicle objects such as passengers in the passenger compartment 3. By using millimeter waves, it becomes possible to detect at least the presence or absence of in-vehicle objects based on the detection level of the reflected waves of the millimeter waves. Then, the CPU 41 determines the type of in-vehicle object in the passenger compartment 3 of the vehicle 1 by comparing and judging the detection level of the reflected waves of the millimeter waves by the sensor with a threshold value. Thereby, the CPU 41 can basically determine, for example, an adult and a child or a child and luggage for an in-vehicle object that may be in the passenger compartment 3 of the vehicle 1 by using a plurality of threshold values such as a high threshold value and a low threshold value. However, the detection level of the reflected wave is not always clearly distinguishable for each type of object inside the vehicle in this way. In particular, the difference between the detection level of the reflected wave of millimeter waves by a child and that by a luggage is basically small, and in some cases, their magnitude relationship may be reversed. For example, for a permeable liquid luggage such as a plastic bottle containing liquid, the detection level of the reflected wave of millimeter waves by it may be higher than that by a child. Therefore, even if the pre-fixed threshold is compared with the detection level of the reflected wave of millimeter waves by the sensor, it is difficult to appropriately determine the type of object inside the vehicle. There is a high possibility of misjudging a plastic bottle containing liquid as a child, or raising the threshold to prevent this may result in misjudging a child as a luggage. Therefore, in this embodiment, for the threshold used to determine whether an object inside the vehicle in the passenger compartment 3 of the automobile 1 is a child or a luggage, instead of a fixed single threshold, it is selected from among a first low threshold and a second low threshold. Then, the selected threshold is compared with the detection level of the reflected wave of millimeter waves by the sensor to determine the object inside the vehicle as either a child or a luggage. For example, when it can be determined based on the detection history or boarding history of the opening and closing of the door of the automobile 1 that there is a possibility that a child is on board, for the threshold for determining a child or a luggage, a second low threshold lower than the first low threshold is selected from among the first low threshold and the second low threshold. When it can be determined that there is no possibility that a child is on board, the first low threshold is selected. Thereby, in this embodiment, even if a situation occurs in which the difference between the detection level of the reflected wave by a child and the detection level of the reflected wave by a luggage becomes small or is reversed, it is possible to prevent misjudging a child as a luggage. There is a possibility of reducing the misjudgment between a child and a luggage. As described above, in this embodiment, the certainty of determining the type of object inside the vehicle based on the comparison between the result of detecting the passenger compartment 3 using millimeter wave radio waves and the threshold can be enhanced.

[0078] In this embodiment, when a child is determined based on the determination result when an occupant gets out of the vehicle 1, an abandonment warning is issued to the occupant getting out of the vehicle 1. Thus, in this embodiment, when there is a possibility that a child is left in the vehicle 1 getting out, it is possible to determine in-vehicle objects as children as much as possible and issue an abandonment warning to the occupant getting out of the vehicle 1. Moreover, in this embodiment, even if in-vehicle objects that are not determined as children are left even when in-vehicle objects are determined as children as much as possible in this way, an abandonment warning is not issued to the occupant getting out of the vehicle 1. Thereby, it is possible to prevent an abandonment warning from being excessively issued for luggage, which is an in-vehicle object with an extremely low possibility of being a child, in the same way as for a child.

[0079] The above embodiments are examples of embodiments suitable for the present invention, but the present invention is not limited thereto, and various modifications or changes are possible without departing from the gist of the invention.

Explanation of Reference Numerals

[0080] 1... Vehicle (automobile), 2... Vehicle body, 3... Passenger compartment, 4 - 6... Seats, 7... Cargo compartment, 11... Driver (occupant), 12... Companion (occupant), 13... Child (occupant), 14... Child seat, 20... Control system, 21... In-vehicle object determination device, 22... Seat control device, 23... Door opening / closing sensor, 24... Wireless communication device, 25... User interface device, 26... In-vehicle network, 27... Speaker, 28... Microphone, 29... User terminal, 31... First output antenna (millimeter wave sensor), 32... Second output antenna (millimeter wave sensor), 33... First input antenna (millimeter wave sensor), 34... Second input antenna (millimeter wave sensor), 35... Third input antenna (millimeter wave sensor), 36... Fourth input antenna (millimeter wave sensor), 37... Output control unit (millimeter wave sensor), 38... Input control unit (millimeter wave sensor), 39... Detection control unit (millimeter wave sensor), 41... CPU, 42... Memory, 43... Timer, 44... Input / output unit, 45... Internal bus, 50... Passenger compartment detection map, 51... Reflective surface

Claims

1. A sensor that outputs millimeter-wave radio waves toward the passenger compartment of a vehicle and detects reflected millimeter-wave radio waves caused by in-vehicle objects such as passengers or luggage in the passenger compartment of the vehicle; A determination unit that determines the type of in-vehicle object in the passenger compartment of the vehicle by comparing and determining the detection level of the reflected millimeter-wave radio waves by the sensor with a threshold value; It has, The determination unit, As threshold values for determining a child and luggage as in-vehicle objects in the passenger compartment of the vehicle, a first lower threshold value larger than the range of the detection level of luggage and a second lower threshold value smaller than the range of the detection level of children are used. The first lower threshold value is a value larger than the range of the detection level of luggage, including a plastic bottle containing liquid. The second lower threshold value is a value smaller than the range of the detection level of children, including the detection level of an infant sleeping in a child seat installed backward on the seat of the vehicle and the detection level of an infant at the feet of the seat, and is lower than the first lower threshold value. If there is a history of opening and closing the boarding and alighting door other than the front side of the vehicle before the vehicle starts running and the history includes a child, the type determination of in-vehicle objects is executed. In the determination of the type of in-vehicle object, if it is a child-priority setting, the second lower threshold value is selected, and if it is not a child-priority setting, the first lower threshold value is selected. The selected threshold value is compared with the detection level of the reflected millimeter-wave radio waves by the sensor to determine the in-vehicle object between a child and luggage. An in-vehicle monitoring device for a vehicle.

2. It has an alarm unit that issues an alarm to the passengers of the vehicle. The alarm unit, When it is determined by the determination unit that there is a child in the passenger compartment when a passenger gets off the vehicle, an abandonment alarm is issued to the passenger getting off the vehicle. When it is not determined by the determination unit that there is a child in the passenger compartment when a passenger gets off the vehicle, no abandonment alarm is issued. The in-vehicle monitoring device for a vehicle according to Claim 1.

3. It has a detection unit that detects a plurality of types of operations performed by a passenger when getting off the vehicle, including opening and closing the door of the vehicle. The alarm unit, According to the type and order of operations of the passenger getting off the vehicle detected by the detection unit, alarms are output in order from a plurality of alarm output devices including a user interface unit provided in the passenger compartment of the vehicle and a user terminal of the passenger who has got off the vehicle. The in-vehicle monitoring device for a vehicle according to Claim 2.

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