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 on the basis of the detection level of the reflected waves of the millimeter wave detected by the sensors 31-39. The determination unit 41 makes determination as to whether the in-vehicle objects are children or baggage according to a trend of change in the detection level of the reflection waves of the millimeter wave detected by the sensors 31-39.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 with passengers including drivers and passengers sitting 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 detect in-vehicle objects such as passengers in the passenger compartment and luggage, and to be able to monitor their states. In particular, when the vehicle is traveling in autonomous driving, it may be important to monitor the states of in-vehicle objects in the passenger compartment of the automobile during autonomous driving.

[0005] In Patent Documents 1 and 2, the state of a 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 removal 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 vehicle compartment, based on the detection level of the reflected millimeter-wave signals, 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 detected object inside the vehicle cannot be correctly determined. In particular, the difference between the detection level of the reflected millimeter-wave signals by children including infants and that by luggage tends to be basically small. The detection level of the reflected millimeter-wave signals by passengers such as adults is basically higher than that by luggage, so it is possible to clearly distinguish. However, the detection level of the reflected millimeter-wave signals by children such as infants may be lower than that by luggage. For example, the detection level of the reflected millimeter-wave signals for luggage with a permeable liquid such as a plastic bottle containing liquid may be higher than that 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 increasing the possibility of misjudging a child as luggage if the threshold value is raised to prevent such misjudgment.

[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 vehicle 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 vehicle compartment and detects the reflected millimeter-wave signals from objects inside the vehicle such as passengers or luggage in the vehicle compartment, and a determination unit that determines the type of objects inside the vehicle in the vehicle compartment based on the detection level of the reflected millimeter-wave signals by the sensor. The determination unit When a passenger gets off the vehicle, if the the detection level of the reflected millimeter-wave signals by the sensor at the time of getting off drops by a predetermined amount or more compared to the detection level immediately after boarding, it is determined that the object inside the vehicle is luggage. If the detection level of the reflected wave of the millimeter wave by the sensor at the time of getting off does not drop by a predetermined amount or more compared to the detection level immediately after boarding, it is determination judged that the object inside the vehicle is a child. When it is judged that the object inside the vehicle is a child in the determination at the time of the passenger getting off, the determination of comparing the detection level of the reflected wave of the millimeter wave by the sensor at each time with the detection level immediately after boarding is repeated. In the repeated determination after the determination at the time of the passenger getting off, if the detection level of the reflected wave of the millimeter wave by the sensor at each time drops by a predetermined amount or more compared to the detection level immediately after boarding, it is determined that the object inside the vehicle judged as a child at the time of the passenger getting off is luggage.

[0009] Preferably, the determination unit , before the detected levelIf the variation range It is preferable to determine that it is.

[0010] Preferably, has an alarm unit that issues an alarm. The alarm unit issues an alarm when the determination unit determines that the object inside the vehicle is a child in the determination at the time of the passenger getting off, and does not issue an alarm when the determination unit changes the determination of the object inside the vehicle from a child to luggage in the repeated determination after the determination after the passenger gets off. , it is preferable.

[0011] Preferably, the determination unit It is preferable to determine that it is the time when the passenger gets off when there is getting off of the passenger from the front side of the vehicle and door locking of the vehicle. [Effect of the Invention]

[0013] In the present invention, a sensor outputs millimeter-wave radio waves toward the passenger compartment of a vehicle, and detects reflected millimeter waves from in-vehicle objects such as passengers or luggage in the passenger compartment of the vehicle. By using millimeter waves, the detection level of the reflected waves when there are in-vehicle objects such as passengers in the passenger compartment can be made different from that when there are no in-vehicle objects such as passengers in the passenger compartment. 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 millimeter waves. Then, the determination unit determines the type of in-vehicle object in the passenger compartment of the vehicle based on the detection level of the reflected millimeter waves by the sensor. Thereby, the determination unit can basically determine, for example, an adult and a child, or a child and luggage, about an in-vehicle object that may be in the passenger compartment of the vehicle based on the detection level. However, the detection level of the reflected millimeter waves does not necessarily clearly differ for each type of in-vehicle object. In particular, the difference between the detection level of the reflected millimeter waves by a child and the detection level of the reflected millimeter waves by luggage is basically small, and in some cases, their magnitude relationship may be reversed. For example, in the case of luggage containing a liquid such as a plastic bottle filled with liquid, the detection level of the reflected millimeter waves by a child may be higher. For this reason, even if a threshold value set in advance is compared with the detection level of the reflected millimeter waves by the sensor, it is difficult to appropriately determine the type of in-vehicle object. There is a high possibility that a plastic bottle filled with liquid is determined as a child, or that the threshold value is increased to prevent this, resulting in the child being determined as luggage. Therefore, in the present invention, based on the tendency of the change in the detection level of the reflected wave of the millimeter wave by the sensor rather than a mere threshold value, a child and luggage as objects inside the vehicle are determined. For example, when the detection level of the reflected wave of the millimeter wave by the sensor decreases over time compared to the detection level immediately after boarding, it is determined that the object inside the vehicle is luggage. Also, when the detection level of the reflected wave of the millimeter wave by the sensor maintains the detection level immediately after boarding even after the passage of time, it is determined that the object inside the vehicle is a child. Thereby, in the present invention, even if a situation occurs in which the difference between the detection level of the reflected wave by the child and the detection level of the reflected wave by the luggage becomes small, it is possible to prevent the child from being erroneously determined as luggage. There is a possibility that false determination between a child and luggage can be reduced. As described above, in the present invention, it is possible to enhance the certainty regarding the determination of the type of object inside the vehicle based on the result of detecting the passenger compartment using millimeter wave radio waves.

Brief Description of the Drawings

[0014]

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Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0016] [First Embodiment] FIG. 1 is an explanatory diagram of an automobile 1 to which an occupant replacement determination device according to the first 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 in FIG. 1. The longitudinal sectional view in FIG. 2 is a view obtained by cutting the automobile 1 in 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.

[0017] 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 sit, and a rear-row seat 6 on which a plurality of passengers can sit 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 on the rear side of the rear-row seat 6.

[0018] The driver 11 opens and closes a right front door (not shown), enters the passenger compartment 3, sits on the front-row driver's seat 4, and opens and closes the right front door to exit the passenger compartment 3. The passenger 12 opens and closes, for example, a left front door (not shown), enters the passenger compartment 3, sits on the front-row passenger seat 5, and opens and closes the left front door to exit 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, sits on the rear-row seat 6, and opens and closes the right rear door or the left rear door to exit 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 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 leaning 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.

[0019] And 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 riding so as to sit on the seats 4 to 6 in the passenger compartment 3. In such an automobile 1, for example, it is being considered to monitor passengers 11 to 13 including the driver 11 in the passenger compartment 3 during driving, and to execute processes such as emergency notification and emergency stop control when there is an emergency for the passengers. Also, in the automobile 1, it is being considered to issue an abandonment alarm 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.

[0020] FIG. 3 is an explanatory diagram of the control system 20 of the automobile 1 shown in FIG. 1 that functions as an in-vehicle monitoring device. The control system 20 of the automobile 1 can detect and monitor in-vehicle objects such as passengers and luggage in the passenger compartment 3 as an in-vehicle monitoring device. 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.

[0021] 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 also be a communication network such as a LAN, or a combination of these. A wireless communication network may be included in a part of the in-vehicle network 26.

[0022] The seat control device 22 has, for example, an actuator (not shown) and controls the front-rear position, vertical position, and the angle of the seat back of a plurality of seats 4 to 6 provided in the vehicle 1. When an occupant sitting on each of the seats 4 to 6 is identified, for example, the seat control device 22 may control the front-rear position, vertical position, and the angle of the seat back of the seats 4 to 6 so as to be set in advance for that occupant. 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 occupant. At this time, the seat control device 22 may acquire setting data from each part of the vehicle 1 through the in-vehicle network 26.

[0023] 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 the 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 a door provided in the vehicle 1, it supplies the detection data to each part of the vehicle 1 through the in-vehicle network 26. In this way, the door opening / closing sensor 23 detects the opening and closing operation of the doors of the vehicle 1 when an occupant gets out of the vehicle 1.

[0024] 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 a passenger or the like, either through the base station or directly. The wireless communication device 24 may be capable of communication compliant with 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 received 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.

[0025] 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 on the front side portion 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 portion in the vehicle width direction for 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 on the touch panel device or a switch, or a predetermined voice input is made on 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.

[0026] 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.

[0027] 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-channel millimeter wave may be output with their output timings shifted from each other or may be output simultaneously. The detection radio waves of the millimeter wave may be continuous in time or may be separated. Different encoded data may be superimposed on the detection radio waves of the millimeter wave by the first output antenna 31 and the second output antenna 32.

[0028] 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 the load object for the detected millimeter waves at each of 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 detected millimeter 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 by the input of the reflected waves from the same reflected load 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 the output of two channels and the input of four channels, it is possible to separate the reflected wave components in each direction from the composite wave mixed with multiple reflected waves and calculate the distance to the reflected load for each direction. The spatial resolution required to detect multiple passengers in the passenger compartment 3 can be ensured by means such as encoding data superimposed on the detected radio waves and timing control.

[0029] The detection control unit 39 controls the output of the detection radio waves of the two-channel millimeter waves by the output control unit 37 and the input of the four-channel reflected waves 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 frequency of the detection 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 a relatively low frequency of about 24 GHz, but also for those with a high frequency such as 60 - 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 set frequency is set, the output control unit 37 executes control to output the detection 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 the passengers or the like in the passenger compartment 3 of the vehicle 1.

[0030] 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.

[0031] The timer 43 measures time and time of day. The timer 43 may measure, for example, the periodic timing for outputting detection radio waves and the elapsed time from each output timing of the detection radio waves.

[0032] The memory 42 records the programs executed by the CPU 41, the data used for the execution of the programs, and the data generated by the execution of the programs. 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.

[0033] The CPU 41 reads and executes a program from the memory 42. Thereby, a control unit that overall controls the operation of the in-vehicle object determination device 21 is realized in the in-vehicle object determination device 21. The CPU 41 only needs to have an arithmetic processing function for executing a program, and may be, for example, an ECU, a microcomputer, an ASIC, or the like. The CPU 41 as the control unit may, for example, determine and monitor the presence and type of in-vehicle objects such as passengers and luggage in the passenger compartment 3 based on the detection level of the reflected wave of the detected millimeter wave. At this time, the CPU 41 as the control unit may select the frequency of the detected millimeter wave from among a plurality of preset frequencies and instruct the detection control unit 39 to set the frequency. The frequencies of the radio waves that can be instructed by the CPU 41 to set may be, for example, a plurality of frequencies including 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 detected millimeter wave. The CPU 41 as the control unit may, among other things, detect in-vehicle objects such as passengers and luggage in the passenger compartment 3 of the automobile 1 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 automobile 1 by comparing and judging the detection level of the reflected wave of the millimeter wave by the input control unit 38 with a threshold value. The CPU 41 as the control unit may, for example, determine the presence or absence of a child 13 or luggage left in the passenger compartment 3 of the automobile 1 when an adult passenger such as the driver 11 gets out of the vehicle. And when a child 13 or luggage is left in the passenger compartment 3 of the automobile 1 due to being left behind, 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.

[0034] FIG. 3 is an explanatory diagram of the detection principle by the millimeter wave sensors 31 to 39 used in the in-vehicle object determination device 21 of FIG. 3. As shown in FIG. 1, the in-vehicle object determination device 21 having millimeter-wave sensors 31 to 39 is provided at the center position Y0 in the vehicle width direction of the front edge portion of the ceiling roof of the passenger compartment 3 of the automobile 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 millimeter-wave detection radio waves as a whole toward the passenger compartment 3 from its installation position, centering on the rear lower direction. 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, the millimeter-wave detection radio 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. Further, 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 rectangle whose four sides are along the vehicle width direction and the front-rear direction.

[0035] 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 millimeter-wave detection radio 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 stretched across a seat frame and is covered entirely 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.

[0036] 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.

[0037] FIG. 6 is an explanatory diagram of a three-dimensional vehicle interior detection map 50 that can be generated based on the detection of 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 combines and uses the outputs of two channels and the inputs of four channels 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, a vehicle compartment detection map 50 showing the shape and size of the three-dimensional reflecting surface 51 along the surface of the occupant can be generated.

[0038] 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 vehicle 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 one with a low frequency of about 24 GHz, but one belonging to a high frequency range of at least 50 GHz or more, preferably 60 to 78 GHz. By using a millimeter wave with a high frequency as the detection radio wave, the vehicle compartment detection map 50 can observe the time-varying component of the chest surface due to breathing. By using a detection radio wave of a millimeter wave with a high frequency, the vehicle 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 vehicle 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 in-vehicle objects with high accuracy 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 example, to the rear part of a seat back with a steel plate or to the left and right edge portions in the vehicle width direction of the vehicle interior 3. Even if there is an in-vehicle object in a portion where the detection radio waves of millimeter waves cannot effectively reach, it is difficult to obtain a significant reflected wave from that in-vehicle object. Note that, as in the case of 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 vehicle width in the vehicle width direction of the vehicle 1. Therefore, in the present embodiment, the frequency of the millimeter wave used as the detection radio wave 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, in order to switch and use the frequency of the millimeter wave, 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 on the arrangement in the vehicle interior 3 for various devices including the in-vehicle object determination device 21.

[0039] 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.

[0040] 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. During normal times such as when the vehicle 1 is running, for example, the CPU 41 may select 60 GHz, which is a high frequency, so as to be able to detect the movement due to breathing on the chest surface of the passenger 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 to every corner of the passenger compartment 3.

[0041] 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 is luggage on the seats 4 to 6 and in 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.

[0042] In step ST3, based on the detection information of the reflected wave from the input control unit 38, the CPU 41 generates a vehicle cabin detection map 50 indicating the position and range in the vehicle cabin 3 of the reflecting surfaces of the objects inside the vehicle such as the passengers and luggage present in the vehicle cabin 3. The vehicle cabin detection map 50 may basically be the range of the vehicle cabin 3 indicated by the dashed-dotted line in FIG. 1, which is the range detected by the reflected wave of the millimeter wave. The CPU 41, as a control unit, generates a vehicle cabin detection map 50 that detects the vehicle cabin 3 of the motor vehicle 1 based on the reflected waves reflected from each part of the vehicle cabin 3 of the motor vehicle 1 and detected by the millimeter wave sensors 31 to 39.

[0043] In step ST4, the CPU 41 records the generated vehicle cabin detection map 50 in the memory 42 together with the information on the detection time measured by the timer 43. As a result, in the memory 42, a plurality of vehicle cabin detection maps 50 generated at different timings are recorded in association with the information on each detection time. The plurality of vehicle cabin detection maps 50 include information on the temporal changes in the movement of the passengers and luggage in the vehicle cabin 3.

[0044] FIG. 8 is a flowchart of the basic determination control for the objects inside the vehicle 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.

[0045] 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 the 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.

[0046] 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 reflecting surfaces of the passengers and luggage that reflect the detected millimeter-wave radio waves. The CPU 41 may estimate the objects inside the vehicle based on the difference components between the new vehicle compartment detection map 50 and, for example, the vehicle compartment detection map 50 when there are no passengers or luggage. The CPU 41 may estimate the size of the objects inside the vehicle from the range in which the difference components are included in the vehicle compartment detection map 50. Further, the CPU 41 may estimate the positions of the seats 4 to 6 where the objects inside the vehicle that caused the difference components are present, etc., based on the positions of the ranges in which the difference components are 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 plurality of objects inside the vehicle present in the vehicle compartment 3.

[0047] In step ST13, the CPU 41 determines the presence or absence of objects inside the vehicle. If one or more objects inside the vehicle are estimated in step ST12, the CPU 41 determines that there are objects inside the vehicle and advances the process to step ST14. If no objects inside the vehicle are estimated, the CPU 41 determines that there are no objects inside the vehicle and ends this control. Thereby, as a determination unit, based on the detection of the reflected waves by the millimeter-wave sensors 31 to 39, the CPU 41 can determine the presence or absence and type of passengers, etc. present in the vehicle compartment 3 of the automobile 1 based on the vehicle compartment detection map 50 of the automobile 1.

[0048] 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 levels 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 the seats 4 to 6 are closer to the sensors 31 to 39 than the bodies of children sitting on the seats 4 to 6 or the luggage placed on the seats 4 to 6. For this reason, the detection level of adults is higher than that of 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 value 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 value, 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 value 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 value, 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 value, the CPU 41 may determine that the object inside the vehicle is luggage.

[0049] 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 object 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.

[0050] 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 is the millimeter-wave detection level for each object inside the vehicle. On the horizontal axis, three types are shown as a plurality of types of objects inside the vehicle: luggage, children, and adults. 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, for example, FIG. 6. 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.

[0051] 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 foot 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 children such as infants. When the distribution ranges of the detection levels of multiple types of in - vehicle objects overlap in this way, simply comparing such millimeter - wave detection levels with a threshold may not be able to accurately determine the type of in - vehicle object. It is not easy to increase the certainty regarding the determination of the type of in - vehicle object.

[0052] Thus, since the detection level of the reflected wave does not necessarily clearly separate for each type of in - vehicle object, even if the detection level is compared with multiple thresholds, there is a possibility that the type of detected in - vehicle object cannot be correctly determined. In particular, the difference between the detection level of the reflected millimeter-wave by children including infants and the detection level of the reflected millimeter-wave by luggage tends to be basically small. The detection level of the reflected millimeter-wave by passengers such as adults is basically higher than the detection level of the reflected millimeter-wave by luggage, so it is possible to clearly distinguish. However, the detection level of the reflected millimeter-wave by children such as infants may be lower than the detection level of the reflected millimeter-wave by luggage. For example, the detection level of the reflected millimeter-wave for luggage of a permeable liquid such as a plastic bottle containing liquid may be higher than the detection level of the reflected millimeter-wave by children such as infants. In this case, depending on the setting of the threshold value, there is a high possibility that a plastic bottle containing liquid is determined as a child, or if the threshold value is increased to prevent this, the child is determined as luggage. When determining the type of in-vehicle object based on the result of detecting the vehicle compartment using millimeter-wave radio waves in this way, it is required to increase the certainty.

[0053] FIG. 10 is a flowchart of the process for determining the type of in-vehicle object 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 may repeatedly execute the process of FIG. 10 every time it executes the millimeter-wave detection control of FIG. 7, for example, instead of FIG. 8. The CPU 41 may repeatedly execute the process of FIG. 10 for each detection period measured by the timer 43.

[0054] In step ST21, the CPU 41 acquires the detection level for the in-vehicle object. At this time, the CPU 41 may acquire, for example, the latest detection level for the in-vehicle object.

[0055] In step ST22, the CPU 41 determines whether the acquired detection level is equal to or higher than the high threshold value for determining an adult or other in-vehicle object.

[0056] In step ST23, the CPU 41 determines that the occupant in the vehicle is an adult. Then, the CPU 41 ends the process of FIG. 10.

[0057] In step ST24, the CPU 41 acquires the change over time of the detection level for the occupant in the vehicle. The CPU 41 may acquire, for example, a plurality of detection levels from the past to the latest stored and recorded in the memory for the occupant in the vehicle.

[0058] In step ST25, the CPU 41 selects, from among the plurality of detection levels indicating the change over time acquired in step ST24, the level at the time immediately after the occupant in the vehicle got on. The CPU 41 may obtain the variation range based on the plurality of detection levels at the time immediately after the occupant in the vehicle got on. The detection level of the occupant may vary due to, for example, breathing. This variation component may be included in the variation range.

[0059] In step ST26, the CPU 41 selects, from among the plurality of detection levels indicating the change over time acquired in step ST24, the level of the latest one for the occupant in the vehicle. The CPU 41 may obtain the variation range based on the plurality of latest detection levels for the occupant in the vehicle.

[0060] In step ST27, the CPU 41 calculates the magnitude of the decrease in level for the latest detection level based on the detection level at the time immediately after the occupant in the vehicle got on. When selecting the variation range, the CPU 41 may calculate the magnitude of the decrease in level, for example, for the median value of each variation range.

[0061] In step ST28, the CPU 41 compares the magnitude of the calculated decrease with a predetermined amount. The predetermined amount may be, for example, equal to or greater than the range of variation in the detection level due to the movement of the chest surface that varies according to the breathing of a child. When a child as an object in the vehicle is seated in a stable posture, the detection level in that state falls within a certain range of variation. If it decreases beyond this range, it can be estimated that the object in the vehicle is a load rather than a child. In this way, based on the tendency of the temporal change in the detection level of the reflected millimeter waves by the sensors 31 to 39, the CPU 41 determines, as a determination unit, whether the object in the vehicle is a child or a load.

[0062] In step ST29, the CPU 41 determines that the object in the vehicle is a load. This determination is based on the fact that the detection level varies by an amount that cannot be due to the movement of the chest surface that varies according to the breathing of a child, and it can be said that there is a high degree of certainty. Thereafter, the CPU 41 ends the process of FIG. 10.

[0063] In step ST30, the CPU 41 determines that the object in the vehicle is a child. This determination is based on the fact that the amount of decrease in the detection level over time falls within the range of variation due to the movement of the chest surface that varies according to the breathing of a child, and it can be said that there is a high degree of certainty. Thereafter, the CPU 41 ends the process of FIG. 10.

[0064] FIG. 11 is an explanatory diagram showing an example of the tendency of the temporal change in the detection level of millimeter waves of a child in the vehicle and the temporal change in the detection level of millimeter waves of a load. The horizontal axis in FIG. 11 represents time. The vertical axis represents the detection level of millimeter waves.

[0065] Regarding a child seated on the seat 6 in the vehicle, the temporal change in the detection level of millimeter waves varies so as to increase and decrease according to breathing, as shown by the broken line in FIG. 11. And when the child is seated quietly on the seat 6, as shown in FIG. 11, the temporal change in the detection level of millimeter waves stably falls within a certain level range. Regarding the detection level of millimeter waves over time for a PET bottle containing liquid placed on seat 6 inside the vehicle, as shown by the solid line in Figure 11, the variation is such that it decreases over time. Also, when the liquid level in the PET bottle is fluctuating, as shown by the solid line in Figure 11, it varies. These two detection levels and their variation ranges become approximately the same at time T1 and cannot be determined by the threshold value.

[0066] However, as time passes, the detection level for the PET bottle containing liquid decreases. At time T3 when a long time has passed since time T1, the variation range of the detection level for the PET bottle containing liquid is, generally speaking, entirely below the variation range of the detection level for the child. It is considered possible to determine these two detection levels and their variation ranges at this time T3 using the threshold value. However, at this time T3 when a long time has passed since time T1, for example, it is highly likely that the driver who has gotten off the vehicle has moved far away from vehicle 1. In contrast, at time T2 before time T3, since the liquid level in the PET bottle containing liquid has not stabilized as it did at time T3, the variation range of the detection level for the PET bottle containing liquid is approximately half of the variation range of the detection level for the child and is lower. It is considered difficult to determine these two detection levels and their variation ranges at this time T2 using the threshold value. However, at this time T2 when a little time has passed since time T1, for example, it is highly likely that the driver who has gotten off the vehicle is near vehicle 1.

[0067] Figure 12 is a flowchart of the replacement monitoring control by the CPU 41 of the in-vehicle object determination device 21 in Figure 3. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the replacement monitoring control in Figure 12.

[0068] In step ST41, the CPU 41 determines whether there is a new rear seat passenger. The CPU 41 may determine whether there is a new passenger boarding the rear row seat 6. The boarding of a new passenger on 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 passenger boarding the rear row seat 6, the CPU 41 repeats this process. If there is a new passenger boarding the rear row seat 6, the CPU 41 proceeds to step ST42.

[0069] In step ST42, the CPU 41 executes the determination of the type of in-vehicle object. The CPU 41 may perform the in-vehicle object type determination process of FIG. 10 or the in-vehicle object type determination process of FIG. 8. The CPU 41 determines 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 row seat 6 but also the front row seats 4 and 5. Further, the CPU 41 may execute the determination of the type of in-vehicle object for the luggage compartment 7.

[0070] In step ST43, the CPU 41 updates the boarding history based on the determination result of the type of in-vehicle object in step ST42 and stores it in the memory. If the determination of the type of in-vehicle object is executed only for some of the rear side seats 6 in step ST42, the CPU 41 may add the determination result of step ST42 to the boarding history recorded in the memory 42. Also, if the determination of the type of in-vehicle object is executed for all seats in step ST42, the CPU 41 may overwrite all of the boarding history recorded in the memory 42 based on the determination result of step ST42. Thereby, information indicating the latest boarding state of at least the passengers and luggage in the rear row seat 6 is recorded in the memory 42. Information indicating the latest boarding state of all passengers and luggage for all seats 4 to 6 and the luggage compartment 7 may be recorded in the memory 42.

[0071] In step ST44, the CPU 41 determines whether or not the vehicle has finished traveling and stopped. The CPU 41 may determine whether or not the vehicle has finished traveling and stopped based on, for example, the presence or absence of an operation of an ignition switch (not shown) for stopping the power source after traveling. The driver 11 operates the ignition switch when getting out of the vehicle after traveling. If the ignition switch has not been operated after traveling, the CPU 41 does not determine that the traveling has ended and the vehicle has stopped, and returns the process to step ST41. The CPU 41 repeats the processes from step ST41 to step ST44 until it determines that the traveling has ended and the vehicle has stopped. Thereby, the information on the riding history recorded in the memory 42 can be updated to correspond to the riding state in the latest traveling. When the ignition switch is operated after traveling, the CPU 41 determines that the traveling has ended and the vehicle has stopped, and advances the process to step ST45 to start the leaving monitoring process.

[0072] From step ST45, the CPU 41 starts the leaving monitoring process for children and luggage after the vehicle 1 has stopped. The CPU 41 first acquires the latest riding history from the memory 42.

[0073] In step ST46, the CPU 41 determines whether or not a child has been left on the rear seat 6 based on the acquired riding history. When the riding history records the opening and closing history of the boarding and alighting doors other than the front side of the vehicle 1 before the start of traveling of the vehicle 1 by the door open / close sensor 23, the CPU 41 may determine that there is a possibility that a child is riding. The riding history in the memory 42 may include the detection results of a plurality of types of operations performed when a passenger gets off by a detection unit (not shown) other than the door open / close sensor 23. If a child is included in the riding history for the rear seat 6, the CPU 41 advances the process to step ST47, assuming that a child has been left on the rear seat 6. If a child is not included in the riding history for the rear seat 6, the CPU 41 ends this control, assuming that no child has been left on the rear seat 6.

[0074] 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 in the automobile 1 get off. By determining the leaving-behind of a child based on the boarding history before getting off and outputting a warning in this way, even if the child is not properly seated in the rear seat 6 at the time of getting off, for example, if the child is lying down at the feet of the rear seat 6 or sleeping in the child seat 14, the possibility of the child being left behind can be alerted by the warning. In this case, the liquid crystal device as a meter panel functions as a warning unit that issues a warning to the passengers in the vehicle. The liquid crystal device as a meter panel can issue a leaving-behind warning to a passenger such as the driver 11 getting off the automobile 1 when a child in the passenger compartment is determined when the passenger gets off the automobile 1. The liquid crystal device as a meter panel does not issue a leaving-behind warning when no child in the passenger compartment 3 is determined when the passenger gets off the automobile 1.

[0075] In step ST48, in addition to the getting-off of the passenger from the front side, the CPU 41 determines whether the door of the automobile 1 is locked. The passenger opens and closes the door to get off. When the passenger leaves the automobile 1, the door lock is automatically executed. If no passenger is getting off from the front side, or if the passenger who has got off has not left the automobile 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 advances the process to step ST49 based on a plurality of types of operations performed when the passengers in the automobile 1 get off.

[0076] In step ST49, the CPU 41 executes the determination of the type of objects inside the vehicle in FIG. 10. The CPU 41 determines adults, children, and luggage as the types of objects inside the vehicle based on the detection level. At this time, the CPU 41 determines whether the object inside the vehicle is a child or a luggage based on the change over time of the detection level. Specifically, as a determination unit, the CPU 41 determines that when the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 decreases by a predetermined amount or more over time compared to the variation range of the detection level immediately after boarding, with the variation range of the detection level immediately after boarding as a reference, and stabilizes in a state lower than the variation range of the detection level immediately after boarding, when the vehicle 1 is in a stable stopped state, the object inside the vehicle is determined to be luggage. Also, the CPU 41 determines that when the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 maintains the variation range of the detection level immediately after boarding without decreasing by a predetermined amount or more in the state where the vehicle 1 is in a stable stopped state even after a lapse of time, the object inside the vehicle is determined to be a child. Note that the CPU 41 may execute the determination of the type of object inside the vehicle for all seats including not only the rear seat 6 but also the front seats 4 and 5. Also, the CPU 41 may execute the determination of the type of object inside the vehicle for the luggage compartment 7.

[0077] 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. If a child is detected and determined on the rear seat 6, the CPU 41 advances the process to step ST51 assuming that a child is left on the rear seat 6. If a child is not detected and determined on the rear seat 6, the CPU 41 ends this control assuming that the replacement of the child on the rear seat 6 has already been resolved.

[0078] In step ST51, the CPU 41 outputs a horn alarm. The CPU 41 outputs an alarm sound for child left-behind from the speaker 27 through the user interface device 25. A passenger who has got off, such as the driver 11, can recognize the possibility of a child being left-behind based on the alarm sound output in response to the door lock at the time of getting off. By thus determining child left-behind based on the type determination of in-vehicle objects actually detected after getting off and outputting an alarm, even if a child is not properly seated on the rear seat 6 at the time of getting off, for example, if the child is lying down at the feet on the rear seat 6 or sleeping in the child seat 14, the possibility of child left-behind can be made known to the driver by means of a warning. The speaker 27 can issue a left-behind alarm to a passenger such as the driver 11 getting off from the vehicle 1 when it is determined that a child is left in the passenger compartment when the passenger gets off from the vehicle 1. The speaker 27 does not issue a left-behind alarm when no child is determined in the passenger compartment 3 when the passenger gets off from the vehicle 1.

[0079] 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 those 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 CPU 41 determines that the object inside the vehicle is a child based on the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 as a determination unit, the CPU 41 repeats the determination based on the tendency of the change over time of the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39. Then, in the repeated determination, when the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 decreases by a predetermined amount or more compared to the fluctuation range of the detection level immediately after boarding with respect to the fluctuation range of the detection level immediately after boarding in a state where the automobile 1 is stably stopped over time and stabilizes in a state where it cannot maintain the fluctuation range of the detection level immediately after boarding and decreases below it, the determination of the object inside the vehicle is changed from a child to a luggage. As a result, the CPU 41 can determine that the object inside the vehicle is luggage at time T3 after determining that it is a child at time T2 in FIG. 11, for example. When the predetermined time has elapsed, the CPU 41 advances the process to step ST53.

[0080] In step ST53, the CPU 41 outputs an alarm to the user terminal 29. The CPU 41 transmits a child abandonment alarm message to the user terminal 29 through the wireless communication device 24. The user terminal 29 reproduces the received alarm message. A passenger who has gotten off the vehicle, such as the driver 11 who holds the user terminal 29, can recognize that there is a possibility of child abandonment based on the alarm output of the user terminal 29 that they themselves hold. The wireless communication device 24, as an alarm unit, issues an abandonment alarm to the passengers getting off the vehicle 1 when a child in the passenger compartment 3 is determined when a passenger gets off the vehicle 1. The wireless communication device 24 does not issue an abandonment alarm when a child in the passenger compartment 3 is not determined when a passenger gets off the vehicle 1.

[0081] In step ST54, the CPU 41 determines whether 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. Thereby, the CPU 41 can repeatedly execute the alarm output in step ST53 and repeatedly output to the passengers who have gotten off the vehicle, such as the driver 11 who holds the user terminal 29, that there is a possibility of child abandonment. When the alarm output in step ST53 is repeated a predetermined number of times, the CPU 41 ends this control.

[0082] In this way, the CPU 41, as an alarm unit, issues an abandonment alarm to the passengers getting off the vehicle 1 when a child left in the passenger compartment 3 is determined when a passenger gets off the vehicle 1, and does not issue an abandonment alarm when it is not determined that a child is left in the passenger compartment 3 when a passenger gets off the vehicle 1. 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 off the vehicle 1, according to the type and order of operations of the passengers getting off the vehicle.

[0083] As described above, in the present embodiment, sensors 31 to 39 output millimeter-wave radio waves toward the passenger compartment 3 of the vehicle 1, and detect reflected millimeter-wave radio waves caused by in-vehicle objects such as passengers or luggage in the passenger compartment 3 of the vehicle 1. 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 millimeter-wave radio waves. Then, the CPU 41 determines the type of in-vehicle object in the passenger compartment 3 of the vehicle 1 based on the detection level of the reflected millimeter-wave radio waves by the sensors 31 to 39. However, the detection level of the reflected waves is not necessarily clearly divided for each type of in-vehicle object in this way. In particular, the difference between the detection level of the reflected millimeter-wave radio waves by a child and the detection level of the reflected millimeter-wave radio waves by luggage is basically small, and in some cases, their magnitude relationship may be reversed. For example, in the case of a permeable liquid luggage such as a plastic bottle containing liquid, the detection level of the reflected millimeter-wave radio waves by a child may be higher. Therefore, even if a threshold value set in advance is compared with the detection level of the reflected millimeter-wave radio waves by the sensor, it is difficult to appropriately determine the type of in-vehicle object. There is a high possibility of misjudging a plastic bottle containing liquid as a child, or raising the threshold value to prevent this, which may result in misjudging a child as luggage.

[0084] Therefore, in the present embodiment, rather than simply comparing with a threshold value, children and luggage as objects inside the vehicle are determined based on the tendency of the temporal change in the detection level of the reflected millimeter waves by sensors 31 to 39. For example, when the detection level of the reflected millimeter waves by sensors 31 to 39 decreases by a predetermined amount or more over time compared to the fluctuation range of the detection level immediately after boarding, with reference to the fluctuation range of the detection level immediately after boarding, and stabilizes in a state lower than the fluctuation range of the detection level immediately after boarding, it is determined that the object inside the vehicle is luggage. Also, when the detection level of the reflected millimeter waves by sensors 31 to 39 maintains the fluctuation range of the detection level immediately after boarding without decreasing by a predetermined amount or more in a state where the vehicle 1 is stably stopped, with reference to the fluctuation range of the detection level immediately after boarding, even after a lapse of time, it is determined that the object inside the vehicle is a child. Thereby, in the present embodiment, even if a situation occurs where the difference between the detection level of the reflected waves by a child and the detection level of the reflected waves by luggage becomes small, it is possible to prevent misjudging a child as luggage. There is a possibility of reducing the misjudgment between a child and luggage.

[0085] As described above, in the present embodiment, the certainty regarding the determination of the type of object inside the vehicle based on the result of detecting the passenger compartment 3 using millimeter wave radio waves can be enhanced.

[0086] In the present embodiment, when a child is determined based on the determination result when an occupant gets off the vehicle 1, an abandonment warning is issued to the occupant getting off the vehicle 1. Thereby, in the present embodiment, when there is a possibility that a child is left in the vehicle 1 getting off, it is possible to determine the object inside the vehicle as a child as much as possible and issue an abandonment warning to the occupant getting off the vehicle 1. Moreover, in the present embodiment, when there is an object inside the vehicle that is not determined as a child even though it is determined as a child as much as possible in this way, an abandonment warning is not issued to the occupant getting off the vehicle 1. It is possible to prevent excessive issuance of abandonment warnings for luggage, which is an object inside the vehicle with an extremely low possibility of being a child.

[0087] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the following description, the differences from the above-described embodiment will mainly be explained.

[0088] FIG. 13 is a flowchart of the in-vehicle object type determination process in the second embodiment of the present invention. The CPU 41 of the in-vehicle object determination device 21 repeatedly executes the replacement monitoring control of FIG. 13.

[0089] In step ST61, the CPU 41 determines whether or not the vehicle 1 is stopped.

[0090] In step ST62, the CPU 41 determines whether or not the vehicle body 2 has shaken due to the opening and closing of the door or the like while the vehicle is stopped.

[0091] In step ST63, the CPU 41 acquires information on the change over time of the detection levels of the sensors 31 to 39. The CPU 41 accumulates and records the detection levels of the sensors 31 to 39 in the memory 41. The CPU 41 acquires information on the change over time of the detection levels of the sensors 31 to 39 from the memory 41. The information on the change over time of the detection levels includes information from before the vehicle body 2 shakes to after the vehicle body 2 shakes.

[0092] In step ST64, the CPU 41 selects the fluctuation range of the detection level before the vehicle body 2 shakes from the information on the change over time of the detection levels.

[0093] In step ST65, the CPU 41 selects the fluctuation range of the detection level during which the vehicle body 2 is shaking from the information on the change over time of the detection levels. Here, the period during which the vehicle body 2 is shaking may be, for example, the period during which the vehicle body 2 shakes due to the closing of the door while the vehicle is stopped.

[0094] In step ST66, the CPU 41 calculates the amount of change in the detection level variation range while the vehicle body 2 is swaying, based on the detection level variation range before the vehicle body 2 sways. For example, the CPU 41 may calculate the difference between the maximum or minimum detection level while the vehicle body 2 is swaying and the maximum or minimum detection level before the vehicle body 2 sways, as the amount of change.

[0095] In step ST67, the CPU 41 compares the calculated amount of change with a predetermined amount. Here, the predetermined amount may be, for example, the amount of change that can occur to a child riding in the vehicle when the door is opened or closed while the vehicle is stopped. When the child is quietly seated on the seat 6, the amount of change that can occur to the child is equivalent to the amount of change due to breathing. If the amount of change is equal to or greater than the predetermined amount, the CPU 41 proceeds to step ST68, assuming that it has increased or decreased by an amount equal to or greater than the predetermined amount. If the amount of change is less than the predetermined amount, the CPU 41 proceeds to step ST69, assuming that it has not increased or decreased by an amount equal to or greater than the predetermined amount.

[0096] In step ST68, the CPU 41 determines that the object inside the vehicle is luggage.

[0097] In step ST69, the CPU 41 determines that the object inside the vehicle is a child.

[0098] As described above, in the present embodiment, the CPU 41, as a determination unit, when the vehicle 1 sways due to opening and closing of the door or the like while the vehicle is stopped, if the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 increases or decreases by a predetermined amount or more compared to the detection level variation range before swaying, with the detection level variation range before swaying as a reference, determines that the object inside the vehicle is luggage. Also, when the vehicle 1 sways due to opening and closing of the door or the like while the vehicle is stopped, if the detection level of the reflected wave of the millimeter wave by the sensors 31 to 39 does not increase or decrease by a predetermined amount or more compared to the detection level variation range before swaying, with the detection level variation range before swaying as a reference, determines that the object inside the vehicle is a child.

[0099] The above embodiments are examples of embodiments suitable for the present invention. However, the present invention is not limited thereto, and various modifications or changes can be made without departing from the gist of the invention.

[0100] For example, in the above-described embodiment, in the control system 20 as an occupant replacement determination device of the automobile 1, the CPU 41 of the in-vehicle object determination device 21 executes all processes from the control of the sensors 31 to 39, the determination of the presence and type of in-vehicle objects, to the determination of replacement such as children. In addition to this, for example, other devices 22 to 25 provided in the control system 20 also have an input / output unit connected to the in-vehicle network 26 and a CPU, similar to the in-vehicle object determination device 21. The CPUs of these other devices 22 to 25 may execute part or all of the processes of the above-described CPU 41. A plurality of CPUs may cooperate to execute the processes of the above-described CPU 41 in a distributed manner.

[0101] And in the above-described embodiment, it has the CPU 41 as an alarm unit that issues an alarm to the occupant of the automobile 1. When it is determined by the determination unit that there is a child in the passenger compartment when the occupant gets out of the automobile 1, the alarm unit issues a replacement alarm to the occupant getting out of the automobile 1, and when it is not determined by the determination unit that there is a child in the passenger compartment 3 when the occupant gets out of the automobile 1, no replacement alarm is issued. Also, in the above-described embodiment, it has a detection unit that detects a plurality of types of operations performed when an occupant gets out of the automobile 1, including the opening and closing of the door of the automobile 1. The CPU 41 as the alarm unit outputs alarms in order from a plurality of alarm output devices including the user interface device 25 provided in the passenger compartment 3 of the automobile 1 and the user terminal 29 of the occupant who has gotten out of the automobile 1, according to the type and order of the operations of the occupant getting out of the automobile detected by the detection unit.

Explanation of Signs

[0102] 1…Automobile (vehicle), 2…Vehicle body, 3…Passenger compartment, 4 - 6…Seats, 7…Cargo compartment, 11…Driver (occupant), 12…Passenger, 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…Reflecting 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 from 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 based on the detection level of the reflected millimeter-wave radio waves by the sensor, and has, the determination unit, when a passenger gets off the vehicle, if the detection level of the reflected millimeter-wave radio waves by the sensor at the time of getting off is reduced by a predetermined amount or more compared to the detection level immediately after boarding, it is determined that the in-vehicle object is luggage, and if the detection level of the reflected millimeter-wave radio waves by the sensor at the time of getting off is not reduced by a predetermined amount or more compared to the detection level immediately after boarding, it is determined that the in-vehicle object is a child, when it is determined that the in-vehicle object is a child in the determination at the time of the passenger getting off, the determination of comparing the detection level of the reflected millimeter-wave radio waves by the sensor at each time with the detection level immediately after boarding is repeated, in the repeated determination after the determination at the time of the passenger getting off, if the detection level of the reflected millimeter-wave radio waves by the sensor at each time is reduced by a predetermined amount or more compared to the detection level immediately after boarding, it is determined that the in-vehicle object determined to be a child at the time of the passenger getting off is luggage, An in-vehicle monitoring device for a vehicle.

2. the determination unit, when the fluctuation range of the detection level drops or increases and decreases beyond the fluctuation range due to the movement of the chest surface that fluctuates according to the breathing of the passenger, it is determined that the in-vehicle object is luggage, The in-vehicle monitoring device for a vehicle according to Claim 1.

3. It has an alarm unit that issues an alarm, the alarm unit, in the determination at the time of the passenger getting off, when the determination unit determines that the in-vehicle object is a child, issues an alarm, in the repeated determination after the determination after the passenger gets off, when the determination unit changes the determination of the in-vehicle object from a child to luggage, does not issue an alarm, The in-vehicle monitoring device for a vehicle according to Claim 1 or 2.

4. the determination unit, when there is getting off of the passenger from the front side of the vehicle and door locking of the vehicle, determines that it is the time when the passenger gets off, The in-vehicle monitoring device for a vehicle according to any one of Claims 1 to 3.

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